EPA-670/2-73-031
September 1973
Environmental Protection Technology Series
U-Tube Aeration
I
55
V
UJ
CD
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D.C. 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Development, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studi.es
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series describes
research performed to develop and demonstrate instru-
mentation, equipment and methodology to repair or
prevent environmental degradation from point and non-
point sources of pollution. This work provides the
new or improved technology required for the control
and treatment of pollution sources to meet environ-
mental quality standards.
EPA Review Notice
This report has been reviewed by the Office of Research
and Development, EPA, and approved for publication.
Approval does not signify that the contents necessarily
reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recom-
mendation for use.
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EPA 670/2-73-031
September 1973
U-TUBE AERATION
by
Rex C. Mitchell
Project No. 17050 DVT
Contract No. 68-01-0120
Program Element 1B2043
Project Officer
John N. English
Advanced Waste Treatment Research Laboratory
National Environmental Research Center
Cincinnati, Ohio 45268
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
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ABSTRACT
The results of two experimental and analytical projects to develop and
evaluate the U-tube aeration concept are presented. Experimental data
were obtained to characterize the mass transfer and fluid dynamics be-
havior of U-tube systems over large ranges of design variables and oper-
ating conditions. Tests were made first with a pilot-scale (2-inch-
diameter) U-tube. Subsequently, full-scale (8- to 20-inch-diameter)
prototype systems were successfully designed, constructed (under EPA
grant projects), and operated in sanitary sewer systems in Jefferson
Parish, Louisiana, and Port Arthur, Texas. These field installations
have been effective in reducing previous serious odor and corrosion
problems resulting from sulfides. No maintenance has been required on
aspirated-air systems in approximately 2 years of continuous operation.
Mass transfer and fluid dynamic correlations, plus a design computer pro-
gram, were developed to use in designing U-tube systems. A satisfactory
basis for design now exists, although additional improvements are needed.
It was found that U-tube systems are a practical, flexible, efficient
method for aeration in a number of applications. They are well-suited
to applications in which it is desired to raise the oxygen concentra-
tion of a moving stream, even to saturation.
This report was submitted by the Rocketdyne Division of Rockwell Inter-
national, Canoga Park, California, in fulfillment of Project No. 17050
DVT, Contract 68-01-0120, and incorporates the results from Contract
14-12-434, under the sponsorship of the Environmental Protection Agency.
The technical work was completed in October 1972.
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CONTENTS
Page
Abstract ii
List of Figures iv
List of Tables viii
Sections
I Conclusions 1
II Recommendations 3
III Introduction 5
IV Experimental Studies 7
V Pilot-Scale Experimental Results 23
VI Full-Scale Evaluation Tests 41
VII Data Analysis 59
VIII U-Tube Design 97
IX Acknowledgements 129
X References 131
XI List of Publications 135
XII Glossary 137
XII Appendices 139
111
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FIGURES
No. Page
1 Schematic Diagram of U-Tube Experimental Apparatus 8
2 Center-Plug Aspirator 10
3 Venturi Aspirator Design 11
4 Venturi Aspirator Assembly with Inlet Air Manifold 12
5 Vertical Two-Phase Flow Patterns 16
6 Concentric Return Assembly Used in Silting Experiments 20
7 Dissolved Oxygen Increase Across 28-ft Deep Experimental
U-Tube 25
8 Overall Pressure Drop Due to Air Across 28-ft Deep
Experimental U-Tube 25
9 Comparison of Pressure Drop Across Center-Plug and
Venturi Aspirators 27
10 Photographs of Two-Phase Flow in U-Tube 28
11 Photographs of Two-Phase Flow in U-Tube 29
12 Photographs of Two-Phase Flow in U-Tube 30
13 Air Bubble Slip Velocities Near Top of U-Tube 34
14 Effect of Particle Size on Scour Velocity 36
15 Diagram Illustrating Analysis of Experimental Scour Data 38
16 Basic Configuration for Aspirated-Air U-Tube Designs in
Jefferson Parish Sewer System 43
17 Diagram Illustrating Matching of System and
Pump Characteristics 46
IV
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No. Page
18 U-Tube System at Location 5, Jefferson Parish, Louisiana 47
19 U-Tube System at Location 7, Jefferson Parish, Louisiana 48
20 Field Testing at Location 7, Jefferson Parish, Louisiana 50
21 Pioneer Park Lift Station Discharge Box 53
22 Manhole Downstream of Pioneer Park Lift Station 53
23 Gravity Line Downstream of Pioneer Park Lift Station 54
24 Gravity Line Downstream of Pioneer Park Lift Station 54
25 U-Tube System Tested at Pioneer Park Lift Station,
Port Arthur, Texas 56
26 Two-Phase Pressure Drop Across Pilot-Scale
Venturi Aspirators 62
27 Two-Phase Pressure Drop Across Large Venturi Aspirators 64
28 Experimental Down-Leg Pressure Change for Rocketdyne
Pilot-Scale Data and Port Arthur Data 69
29 Experimental Up-Leg Pressure Change Data and
Hershey Correlation 71
30 Adams' Experimental Up-Leg Pressure Change Data and
Hershey Correlation 73
31 Experimental Mass Transfer Coefficients for
Venturi Aspirator 75
32 Effect of Venturi Throat Diameter on Mass Transfer
Coefficient 77
33 Effect of Venturi Throat Water Velocity on Mass
Transfer Coefficient 77
v
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No. Page
34 Computation Flowsheet for Data Reduction Program 81
35 Experimental Mass Transfer Coefficients for 9-Ft U-Tube 84
36 Experimental Mass Transfer Coefficients for 19-Ft U-Tube 85
37 Experimental Mass Transfer Coefficient for 28-Ft U-Tube 86
38 Experimental Mass Transfer Coefficients for 37-Ft U-Tube 87
39 Experimental Mass Transfer Coefficients for 45-Ft U-Tube 88
40 Experimental Mass Transfer Coefficients for Field
Installations 91
41 Experimental Mass Transfer Coefficient Residual After
Main Effect of Average Air/Water Volume Fraction is Removed 93
42 Experimental Mass Transfer Coefficients for Field
Installations for Average Water Velocity Less Than 1.8 ft/sec 94
43 Experimental Mass.Transfer Coefficients for Field Installations^
for Average Superficial Water Velocity Greater Than 1.8 ft/sec 95
44 Schematic Diagram of Aspirated-Air U-Tube 100
45 Schematic Diagram of Compressed-Air U-Tube 101
46 Computation Flowsheet for Design Program 102
47 Effect of Pipe Size on Performance of Compressed-Air U-Tubes 104
48 Typical Compressed-Air U-Tube Parametric Designs 105
49 Typical Compressed-Air U-Tube Design Trade-Offs 106
VI
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No. Page
50 Effect of Diffuser Depth on Performance of Compressed-
Air U-Tubes 107
51 Effect of Water Flow Rate on Performance of Compressed-
Air U-Tubes 108
52 Typical Aspirated-Air U-Tube Parametric Designs 112
53 Typical Aspirated-Air Design Trade-Offs 113
54 Effect of Pipe Size on Performance of Aspirated-Air
U-Tubes 114
55 Effect of Inlet and Exit Pipe Elevations on Performance
of Aspirated-Air U-Tubes 115
56 Effect of Water Flow Rate oh Performance of Aspirated-
Air U-Tubes 116
57 Schematic Layout of Postaeration Facility 120
58 Schematic Layout of U-Tube Facility 120
59 Effect of Final D.O. Concentration on Performance of
Diffused Air and Mechanical Aeration Systems 121
60 Schematic Diagram of U-Tube Operating Lines 122
61 Cost Comparison (10 mgd) 124
62 Cost Comparison (100 mgd) 124
VII
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TABLES
No. Page
1 Summary of Measurements Made in U-Tube
Aeration Experiments 24
2 Summary of Two-Phase Flow Characteristics in U-Tube
With Venturi Aspirator 31
3 Results of Chemical Analysis for Dissolved Nitrogen 33
4 Constants for Down-Leg Pressure Loss Correlation 67
5 Selected Economic and Physical Design Bases for
Postaeration System Cost Estimates 121
6 Characteristics of Postaeration Systems 123
7 Major Components in Physical Plant Costs 123
8 Cost Comparison for Postaeration of Treated Effluent 125
9 Selected Economic and Physical Design Bases For
Sewer in situ Aeration Systems 127
10 Characteristics of in situ Aeration Systems 127
11 Cost Comparison for in situ Aeration of Sewer Waste Water 128
Vlll
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SECTION I
CONCLUSIONS
1. A U-tube system is a practical, flexible, efficient method for aer-
ation for a number of applications.
2. U-tubes generally are not suitable or competitive in applications
requiring large additions of oxygen (e.g., in activated sludge treat-
ment) . They are better suited to applications in which it is desired
to raise the oxygen concentration of a moving stream, even to satura-
tion (e.g., postaeration of treated effluent, aeration for fish
hatcheries, and in situ aeration of sanitary sewers).
3. There is ample flexibility in the choice of U-tube configurations
plus other design variables to permit efficient specific designs in
a variety of applications and for different requirements.
4. U-tube aeration systems require li.ttle space, can be designed with
no moving parts, require no operating labor and little maintenance,
and can (for suitable application) result in substantial cost savings
over other aeration methods.
5. A satisfactory basis for designing U-tube systems now exists,
although additional improvements are needed.
6. Actual full-scale installations have been successfully designed,
constructed, and operated in sanitary sewer systems in Louisiana and
Texas. Six U-tube systems of two major types in four locations with
pipe diameters from 8 to 20 inches have been effective in reducing
previous serious odor and corrosion problems resulting from sulfides.
No maintenance has been required in approximately 2 years of contin-
uous operation for aspirated-air systems.
7. Deep U-tube systems can be installed without complications, even in
relatively unstable soil and with a high ground water level.
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SECTION II
RECOMMENDATIONS
It is recommended that U-tube aerators be considered for any application
that requires raising the dissolved oxygen level of a flowing water or
wastewater stream. The correlations and design techniques described in
this report can be used for parametric predesign studies in preparation
for economic evaluations of alternative aeration methods; they also can
be used to establish design points and conditions in those cases where
U-tube systems are selected.
Although the design techniques given in this report are recommended as
the best available basis for making design calculations, improvement is
needed in the predictive bases for some elements of a U-tube system.
There is a particular need to improve the aspirator designs and design
correlations which have been used up to this time. Further consideration
also should be given to the use of oxygen in U-tubes. It will be impor-
tant in such cases to provide adequate depth and residence time to ensure
high oxygen utilization efficiencies.
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SECTION III
INTRODUCTION
There are many requirements for aerating water and a variety of techniques
that can be used to accomplish this. The U-tube concept is an interesting
and not widely known aeration method. This type of aeration system is
simple in concept, basically consisting of two elements: (1) a device for
entraining air (or oxygen) into a flowing water stream (e.g., an aspirator
device or a compressor introducing air through a diffuser), followed by
(2) a vertical U-shaped flow path to provide residence time in a zone of
above-atmospheric pressure during which oxygen absorption from the en-
trained air takes place with a very favorable driving force. The U-shaped
flow path can take various forms (e.g., a pair of vertical pipes connected
by a 180-degree return bend at the bottom, or a pair of concentric pipes
with flow downward through one passage and upward through the other).
The label "U-tube" apparently was first used in the literature by Bruijn
and Tuinzaad (Ref. 1) in 1958, although the original aeration experiment
they describe (using an aspirator-air U-tube) was conducted by the Dutch
Research Institute K.I.W.A. Related aeration systems were considered
approximately 40 years ago (Ref. 2). Rocketdyne has been studying and
developing this aeration technique in various forms, first under internal
funding (Ref. 3) and later under EPA sponsorship as described in this
report and Ref. 4 and 5. Speece and other researchers have reported
their work with U-tube aeration systems, primarily using compressed
air injection (Ref. 6 and 7).
A 15-month experimental and analytical effort, initiated in June 1968
under EPA Contract No. 14-12-434, was conducted by Rocketdyne to investi-
gate and begin development of the U-tube aeration concept for various
wastewater applications (Ref. 4). Three major tasks were accomplished:
(1) experimental verification of oxygen transfer efficiencies and explor-
ation of practical aspects of U-tube operation; (2) analytical investi-
gation of two major applications--postaeration of effluent from a sewage
treatment plant and in situ aeration of sanitary sewer flows to prevent
anaerobic conditions; (3) investigation and design of full-scale proto-
type U-tube systems, with particular emphasis on designs for installation
in the Jefferson Parish, Louisiana,sewer system. Assistance was also
given to the EPA in the design of U-tube systems for installation in the
sewer system at Port Arthur, Texas.
These full-scale prototype U-tube systems were installed in Jefferson
Parish and Port Arthur under EPA Grants 11010 ELP and 11010 DYO, respec-
tively. Subsequently, under EPA Contract No. 68-01-0120 (initiated in
June 1971), Rocketdyne provided technical direction for field evaluation
tests of these systems and used the data to improve the design bases
previously developed. This report describes the results of both projects
(EPA Contracts 14-12-434 and 68-01-0120).
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There was an evolutionary process during the two projects, spanning a
period of about 4 years, with respect to the various steps of experimental
testing, data analysis, design, further testing, etc. A flexible pilot-
scale U-tube system was designed originally, based on the limited informa-
tion available in Ref. 1. Data from tests with this pilot-scale system
were used to develop pressure drop and mass transfer correlations and an
initial design computer program. This program was used in selecting
design conditions for the full-scale U-tube systems that were constructed
in Jefferson Parish and Port Arthur. The data from field tests with these
systems were then used, together with the pilot-scale data, to develop
improved correlations which were combined into an improved U-tube design
program. Descriptions of the experimental tests, data analysis, corre-
lations, design techniques, and conclusions are given in this report.
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SECTION IV
EXPERIMENTAL STUDIES
AERATION STUDIES
Basic experiments with deoxygenated tap water were conducted in a pilot
scale (2-inch diameter) U-tube aerator. Four hundred ten (410) test
runs were made over a 4-month period. Data relevant to oxygen transfer
and pressure loss were obtained as functions of U-tube depth, water
velocity, air-to-water ratio, and air aspirator configuration. Five
U-tube depths were investigated, ranging from 9 to 45 feet. Head loss
through the system varied from 1 to 8 feet. Superficial water velocity
(i.e., velocity of water if no air were present) varied from 1.4 to 3-4
ft/sec with a few runs above and below this range. The air-to-water
volume ratio was varied from zero to approximately 0.2. Two air
aspirator designs were investigated. Runs 1 through 94 were made with a
tapered center-plug aspirator configuration. When it became apparent
that permanent pressure losses across this device were excessive, a
second aspirator was constructed; runs 95 through 410 were made with this
venturi aspirator. Performance in terms of pressure loss was markedly
better for the venturi design.
Apparatus
The pilot scale U-tube aerator was located in the Igniter Development
Area (IDA) of Rocketdyne's Santa Susana Field Laboratory. The tube was
suspended from the 50-foot platform of an existing steel tower, with
associated tanks and instrumentation mounted on the platform. A
schematic diagram of the experimental system is shown in Fig. 1.
The U-tube was constructed of 2-inch diameter pipe and hose. The down-
leg contained a ten-foot section of glass pipe located just below the
aspirator exit. The remainder of the U-tube consisted of 8 to 10-foot
sections of 2-inch PVC pipe joined with threaded unions. This seg-
mented construction made it easy to change depth. A section of 2-inch
steel-reinforced rubber hose was installed in the top portion of the
up-leg to make it possible to vary the head loss across the system by
moving the adjustable height bracket. The auxiliary plumbing shown in
Fig. 1 was fabricated primarily of stainless steel tubing. The return
bend initially used was a 2-inch diameter glass section (made by Kimble
Glass Co.) with pipe thread end adaptors. During the program a change-
over was made to a return bend of two 90-degree elbows and a short pipe
nipple. This change was due to difficulty in aligning the legs of the
U-tube at the shorter lengths with the glass return bend.
The deaeration, surge, and U-tube tanks had approximate capacities of
100, 50, and JI gallons, respectively. The deaerator feed pump was a
1/2-hp centrifugal pump rated for approximately 50 gpm at 40 feet of
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AIR
[&
V3
GASEOUS t%}
NITROGEN
DEAERATION TANK
(100 GAL.)
ALUMINUM\
LATHE \
TURNINGS-i\
OVERFLOW LINE
2-INCH PVC
VI
2-INCH LUCITE
STAND-PIPE
BALL VALVE
J^
LIQUID
LEVEL
SITE
GLASS
DRAIN
STA. 12
2-INCH RUBBER HOSE
LEVEL CONTROL
VALVE
MAKE-UP
WATER
AIR FLOW
ORIFICE
METER
U-TUBE
FE.ED TANK (31 GAL.)
ASPIRATOR
(INLET IS STA. 3,
THROAT IS STA. A)
ADJUSTABLE
HEIGHT
BRACKET
2-INCH
GLASS PIPE
EXISTING PLATFORM
50-FEET ELEVATION
\~ U-TUBE
FEED PUMP
L
DEAERATOR FEED PUMP
U-TUBE
2-INCH PVC PIPE
STA. 9
Figure 1. Schematic Diagram of U-Tube Experimental Apparatus
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discharge head. The U-tube feed pump was a 5-hp centrifugal pump rated
for 160 gpm at 70 feet of head. Gate valves were used for water flow
control.
The center-plug aspirator consisted of a hollow, tapered aluminum plug
which was set in a cone attached to the entrance of the U-tube (Fig. 2).
Six sets of radial holes were placed at different diameters in the plug,
and all or part of the holes could be used as desired (normally, one to
three rows of holes were used; the others were closed). The constricted
annular flow area at the U-tube entrance (between the plug and the 2.067-
inch inside diameter of the pipe) caused accelerated water velocity and
reduced pressure, resulting in aspiration of air through the plug holes
into the water stream. A pipe attached to the core of the plug was con-
nected to the air flow orifice meter. By raising and lowering the plug,
variable annular areas (contraction ratios) were attained. Initially,
the plug was used without a flow collimating cone. The cone was added
when it became apparent that for efficient aspiration, the water flow
had to be aligned somewhat parallel to the plug surface.
The second aspirator used was basically a Herschel-type venturi with in-
let and exit full-cone angles of 21 and 7 degrees, respectively. Figure
3 is the venturi construction drawing. The unit was machined from 6061
aluminum. The venturi had a contraction area ratio of 8 based on the full
flow area of 2-inch PVC pipe (2.067-inch I.D.). Entrance pressure loss
was minimized by designing for low entering water velocity (i.e., pro-
viding a large diameter entrance). A threaded section on the diffuser
cone enabled the unit to be screwed into the bottom of the feed tank.
Air was manifolded into 4 ports at the throat (Fig. 4). A pipe attached
to the manifold was connected to the air flow orifice meter. A lucite
orifice meter was constructed and calibrated for measuring air flow.
The differential pressure across the orifice was measured with an inclined
water manometer.
Three Beckman Dissolved Oxygen Analyzers were used for monitoring dis-
solved oxygen—two Model 778 process analyzers and one Model 777 labora-
tory analyzer. Two permanent probes were placed at Stations 1 and 12
(see Fig. 1) for monitoring inlet and outlet dissolved oxygen. The third
probe was used for making intermediate D.O. measurements at Stations 5,
9, or 10 (as shown in Fig. 1). Calibrations were made at the beginning
and at the end of each day's.testing.
Intermediate pressure loss measurements were made at three stations: 5,
8, and 10. Pressures at these stations were measured by use of water
manometers constructed of 1/4-inch tubing, with the top 5 to 7 feet made
of Tygon (clear plastic tubing) so that the liquid level could be ob-
served. Short U-shaped sections of tubing were placed next to the pres-
sure taps to prevent air bubbles from entering the manometer lines (they
were very effective). In some cases, short beds of coarse metal turnings
were also placed in the lines to dampen pressure fluctuations. The dif-
ferential height between the feed tank liquid level and the level in the
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AIR INLET PIPE,
ATTACHED TO ADJUSTABLE
HEIGHT BRACKET
U-TUBE
FEED TANK
FLOW COLL I MAT ING
CONE
ALUMINUM CENTER-PLUG
WITH SIX ROWS OF
EIGHT RADIAL AIR HOLES
U-TUBE ENTRANCE
PIPE
Figure 2. Center-Plug Aspirator
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r 2-375
±.002
^ 2-11 1/2 NPT
DRILL 4 HOLES 1/8 DIA.
BORE 4 HOLES 7/16 DIAMETER X 0.60 DEEP
'1/4-18 NPT.
NOTE:
1 ALL DIMENSIONS ARE ±.01 IN. UNLESS OTHERWISE SPECIFIED
2 THROAT TO BE 0.50 LONG
3 2-INCH PIPE THREADS TO BE 1 1/4 LONG
4 1/4-INCH PIPE THREADS TO BE 3/8 DEEP
Figure 3. Venturi Aspirator Design
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Figure k, Venturi Aspirator Assembly with Inlet
Air Manifold (Scale is in inches)
12
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water columns represented the pressure loss to the various stations. The
lucite standpipe, ball valve, thermometer and dissolved oxygen probe,
shown at the exit of the U-tube in Fig. 1, were attached to the adjustable
height bracket.
A laboratory investigation was conducted to develop techniques for
measuring dissolved oxygen concentration in the water (which also con-
tains entrained air) flowing through the U-tube experimental system.
It was judged that rapid in-line measurements would be more efficient
from experimental operating considerations and would avoid the diffi-
culties with sampling and de-entrainment of the undissolved gases for
a sampling-chemical analysis method. After various laboratory tests
it was found that very satisfactory D.O, measurements could be made in
a two-phase air-water flowing stream with a Beckman polarographic probe
if the probe axis was oriented approximately 30 to 60 degrees downstream
from a position perpendicular to the pipe's centerline axis* With such
an orientation, the problems with impingement and attachment of air
bubbles are eliminated. It was also found, with the probes and instru-
ments used in this study, that a stream velocity as low as 1.0 ft/sec
was sufficient to ensure accurate, stable D.O. readings which were
independent of flow velocity (the manufacturer's literature recommends
a more conservative value of 1.8 ft/sec). The assemblies for installing
the D.O, probes into the experimental U-tube system piping consisted of
a standard Beckman sealed gland assembly which was slightly modified
and welded into a 4-inch long pipe nipple at a 45-degree angle. This
nipple adapted to 2-inch PVC pipe fittings, thus functioning as a
45-degree tee. The D.O, probe was installed in the sealed gland
assembly in such a way that the probe axis was oriented approximately
45-degrees downstream from a position perpendicular to the pipe center
line, and with the probe face extending about 1/2-inch from the pipe
wall into the flowing stream.
Facility Operation
Operation of the system was as follows: Make-up tap water was intro-
duced into the surge tank through the liquid level control valve.
Water was pumped into the deaeration tank where dissolved, gases were
removed under vacuum. The deaerator was evacuated to a vacuum greater
than 25 inches Eg by a Penberthy water jet eductor, which was connected
to the ullage space above the packed bed. Water entered the deaerator
through solid cone spray nozzles and was allowed to trickle over a bed
of aluminum lathe turnings in the tank ullage. The deaerated water
was then pumped, up to the U-tube feed tank where a fraction of the
water overflowed to the surge tank while the bulk of the flow entered
the U-tube, The overflow allowed control of a constant liquid head
above the aspirator; which could, be varied, by changing the length of
the overflow pipe in the feed tank. Water leaving the U-tube entered
a tee attached to the adjustable height bracket (Fig. l). A 2-inch
diameter lucite standpipe screwed into the run of the tee acted as a
vacuum break for the system. The water then returned to the surge tank,
13
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The vertical distance between the water level in the feed tank and the
water level in the lucite standpipe established the head loss (AH)
across the system.
Once the tanks were brought to their operating levels and the U-tube
was full, all water was recycled. Water in the surge and dearation
tanks was held at each desired steady-state level by throttling the
pump discharge valves (VI and V2 in Fig. 1).
Experimental Procedures
A typical test run commenced by setting the approximate desired AH
across the U-tube, System AH was set by varying the level of the
adjustable height bracket at Station 12. The dissolved oxygen probes
were then calibrated in air to 100 percent saturation and placed in
their adaptor gland assemblies,, ¥ith the tapered plug aspirator,, a
contraction ratio was selected and then set by backing the plug a pre-
determined vertical distance away from its seated position (seating
the plug closed the U-tube entrance). No adjustment was necessary with
the venturi aspirator. With the air inlet valve (V3) closed, the pumps
were started. Liquid levels in the deaeration and surge tanks were set,
and the water jet eductor was turned on. The system was allowed to run
until the deaerator reached a steady-state pressure and the inlet and
outlet dissolved oxygen meters gave identical readings.
After attaining steady-state operation with only water flowing, the air
inlet valve was opened. At a given air flowrate, water flowrate meas-
urements were made by diverting the return to the surge tank into a
5-gallon container and measuring the time to fill with a stopwatch.
Four measurements were made for each run to ensure steady-state opera-
tion and a reliable average flowrate. Initially, an orifice flowmeter
was placed in the return line to the surge tank for determination of
water flow. The orifice gave oscillating differential pressure readings,
added to the system AH (causing overflow in the lucite standpipe at
certain AH settings), and hindered the flexibility of the AH setting.
The orifice plate was removed in favor of a bucket and stopwatch meas-
urement technique before the start of experimentation. For Runs 1
through 25) water flowrate was allowed to vary randomly at a given air
setting. After Run 25 the air flow, the plug setting, and/or the
system AH were generally set so that the water flowrate obtained was
15, 20, 25, 30 or 35 gpm plus or minus 1 gpm. After steady-state con-
ditions were obtained, dissolved oxygen measurements, pressure losses,
AH setting, plug aspirator setting, air and water flowrates, and water
temperature were recorded.
The next run was made by either adjusting the air throttle valve,
adjusting the plug setting, and/or resetting the AH across the system
(all while the pumps were running), and then following the same data
acquisition procedures. In this way a series of water flowrate vs
14
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air-to-water ratio measurements was made as a function of system AH or
plug setting for each U-tube length. At each new U-tube length a series
of single-phase (no air) runs was made to characterize the system pres-
sure drop in terms of water flow only.
System Operating Behavior
The performance of the U-tube is directly related to the phenomenon of
vertical, gas-liquid two-phase flow. Such effects as start-up insta-
bility, oscillating flows, regime shifts, up-leg pressure recovery,
and trade-off of air-water flowrate vs pressure loss were important to
the experimentation. Because the explanation of these effects is based
on two-phase flow phenomena, a short, qualitative description of the
field is in order.
Two-phase vertical flow is characterized by a series of regimes or
patterns which are dependent on air-to-water ratio, water flowrate, and
pipe diameter. A visual summary of these regimes is sketched in Fig.
5, taken from a review paper by Anderson and Russell (Ref. 8). Steady-
state U-tube operation is represented by the bubble flow regime, a contin-
uous liquid phase with the gas homogeneously dispersed as bubbles.
Anomalous flow behavior was usually due to approaching slug flow or
the actual onset of slug flow. Froth, annular, and mist flow were not
encountered in this investigation. The slug flow regime is visually
characterized by consecutive passage of alternate slugs of liquid and
bullet-shaped slugs of gas. In contrast to the other regimes, it is
also characterized by varying pressure drops, i.e., pressure fluctua-
tions at a fixed station in the system (Ref. 9).
The dependence of flow regime on air-to-water ratio is visually apparent
from Fig. *}, The dependence on pipe diameter! is more subtle. Although
a precise quantitative equation for predicting the diameter function-
ality of the regimes is not available, a theoretical qualitative des-
cription can be made. For the slug flow regime it is apparent that
the bullet-shaped slug takes on the approximate diameter of the pipe.
Given the injection of 1/4-inch diameter bubbles into 1/2-inch diameter
pipe, a slight degree of bubble coalescence could cause the formation
of a bubble which has the cross-sectional area of the pipe. If this
occurs, slug flow would result. Furthermore, a 1/2-inch diameter slug
of gas is relatively stable hydrodynamically, i.e., the slug would tend
to remain in the system. In the case of 1/2-inch diameter bubbles
injected into a 2-foot diameter pipe, it is apparent that a great deal
of coalescence would have to occur before a 2-foot diameter slug could
form. Also, a 2-foot diameter slug of gas is much less stable hydro-
dynamically and, therefore, would probably break up.
The shear forces at the bubble-liquid interface are proportional to
water flowrate. Higher bubble-liquid interfacial shear would imply
greater interfacial turbulence and lead to bubble breakup. The impli-
cation is that higher water flowrates reduce the tendency toward slug
15
-------
BUBBLE
6 0
SLUG FROTH ANNULAR
INCREASING GAS/LIQUID RATIO
MIST
Figure 5- Vertical Two-Phase Flow Patterns
16
-------
flow at a given air-to-water ratio and pipe diameter. This trend is
qualitatively substantiated by the observations of Griffith and Wallis,
given in Ref. 8.
When starting the experimental U-tube, the AH across the system was set
before the pumps were turned on. The initial down-leg liquid level was
usually in the glass pipe, leaving several feet of air between the
aspirator and the liquid surface. Upon start-up, .this air was flushed
out of the system in the form of long air cones (slug flow). Since no
additional air was allowed into the system, the pressure loss across the
cones was overcome by the system AH, and the U-tube was rapidly flushed
of air. After measurement of the single-phase water flow, air was
allowed to enter the system. To hold the same single-phase water flow-
rate after air introduction, the system AH had to be increased. With
the addition of more air, the AH had to be increased further. This is
reasonable with respect to the bubble flow regime depicted in Fig. 5.
Although pressure loss was incurred in the down-leg, at high air-to-
water ratios and/or low water flow rates, some net pressure recovery
was observed in the up-leg. This is due to the air-lift effect counter-
balancing the frictional losses.
During normal bubble flow operation, very slight (less than 1 percent)
air flow and pressure loss oscillations were observed (with both aspir-
ators). These oscillations did not impede data acquisition and were
probably a result of the system design. At high air-to-water ratio, the
oscillations increased to a noticeable level (perhaps 5 to 10 percent of
the manometer reading). Observations showed the system to be still in
the bubble flow regime, but with a time-dependent bubble density. In
these cases, data acquisition was made by visual time averaging of
pressure losses and air flows. Intermediate and outlet dissolved
oxygen measurements generally showed only small oscillations (perhaps
2 percent of the reading) which were readily averaged. Of course, the
water flow measurement was averaged by the nature of the technique.
Increasing the air-to-water ratio to even higher levels resulted in a
transition to true slug flow. At first, small air caps would form in
the dense bubble zones. With additional air, these caps coalesced into
bullet-shaped cones. Very large oscillations in pressure loss, air
flow, dissolved oxygen, and water flow were apparent at this time.
Net U-tube pressure loss :would eventually overcome the system AH. The
result was upward or reverse flow in the down-leg, due to the air-lift
effect of the cones. Slug flow was easily avoided in actual operation.
At the largest system AH (approximately 8 feet), the maximum air-to-
water ratio at a given water flowrate was usually in the bubble flow
regime. Slug flow was encountered only at extreme conditions and
usually with long U-tubes where the time for slug coalescence was great.
17
-------
AIR BUBBLE CHARACTERIZATION
High-speed motion pictures of the bubbles were taken in the glass
section at the top of the down-leg and at the glass return bend for
the 45-foot U-tube. The 45-foot depth was selected because this was
the only length permitting convenient access to the return bend. For
evaluating mass transfer coefficients, information was needed regarding
bubble size, shape, and slip velocity distributions, plus the change in
these with respect to depth, water flowrate, and air-to-water ratio.
Pictures were taken with two Milliken high-speed cameras at approxi-
mately 400 frames per second. The cameras were set up electrically in
series at the top and bottom of the U-tube enabling simultaneous photog-
raphy at the two stations. Segments of nine runs were photographed for
each aspirator design. Runs were selected with six different water
velocities over a range of air-to-water ratios for the center-plug
aspirator. Three water velocities, but a larger range of air-to-water
ratios were represented in the venturi aspirator system photographs.
Data were taken from enlarged projections of the pictures. The bubbles
measured were close to the center line of the glass pipe to minimize
distortion of the bubble dimensions. Bubble dimensions were determined
for each run at each station from a random sample of bubbles. Bubble
velocities were readily determined from the film speed and the number
of frames required for a bubble to transverse a section of the pipe
between two marks, A summary of the results will be presented in the
Experimental Results section,
NITROGEN TRANSFER
Water samples were taken for two runs (293 and 375) at inlet and outlet
stations to determine the rate of nitrogen transfer relative to that of
oxygen. This information was necessary to properly calculate oxygen
mass transfer coefficients from the measured oxygen concentrations, since
the nitrogen concentrations and mass transfer affect the oxygen transfer.
The way in which these processes were modeled is discussed in Section VII,
in the "Data Reduction Program" subsection. Quantitative analysis for
dissolved gases was performed by a combination of vacuum degassing and
mass spectrometry.
Water samples were taken from the inlet line to the U-tube feed tank
and from the tee at the U-tube exit. Because the analytical technique
could not differentiate between dissolved and entrained gases, con-
siderable care was taken to try to eliminate air bubbles from the
sample. The samplers were thoroughly cleaned, evacuated, and then
pressurized with helium before sampling. Since no entrained gases were
present in the inlet water, the sampling technique was straightforward.
The sampler was attached to the feed tank line (after water purging the
connecting line). The two valves between the line and sampler were
then opened allowing the water to compress the helium to the pump dis-
charge pressure. The upper valve on the sampler was then opened,
allowing the helium to escape and water to flow. When approximately
one liter had been flushed through the sampler, the sample was taken.
18
-------
The outlet water sample required revised equipment and procedure
because of entrained gases, A long de-entrainment column was placed
between the sampler and sample station to remove entrained air from the
water to be sampled. Water flowed by gravity into the middle of the
de-entrainment column until the column was overflowing; water was then
withdrawn for sampling from the bottom of the column. The helium pres-
surized sampler was reduced to atmospheric pressure and then attached
to the sample system after purging of the connecting lines with water
from the column. The sampler was then allowed to fill (by gravity flow)
until approximately one liter had been flushed. The sample was then
taken. While the sampler was filling, the column was still overflowing.
Clear tubing connecting the column to the sampler enabled observation
of any entrained gases entering the sampler. The tall narrow column
negated any appreciable effects of surface aeration.
Subsequently, in the analytical laboratory, dissolved oxygen and
nitrogen were removed from the sample by vacuum Degassing. The total
quantity of gas was determined from the ideal gas law in a system of
known volume. A gas sample was then analyzed on a mass spectrometer
to obtain the quantitative nitrogen-oxygen ratio. The results of these
analyses for the four samples will be presented in the Experimental
Results section.
SILTING STUDIES
Experimental studies of silting/scouring were conducted using a con-
centric pipe return bend. The objective of the effort was to deter-
mine the minimum velocity necessary to begin scouring and transporting
particles out of the bottom of the return bend and up the TJ-tube up-
leg. Four particle size ranges were used: U.S. Sieve No, 30-35
(0.50-0.60 mm) glass beads, U.S. Sieve No. 14-18 (1.00-1,41 mm) ground
glass particles, U.S. Sieve No, 8-10 (2,00-2,38 mm) gravel, and U.S.
Sieve No, 3»5~5 (4,00-5,66 mm) glass beads.
The glass U-bend on the 45-foot U-tube was removed and replaced with
a concentric return configuration, shown in Fig, 6. Water flow came
down the center pipe and went out the side arm. Since the study was
concerned with water-solid interaction, no air was introduced through
the venturi. A series of runs was made without solids to calibrate
the water flow vs head loss characteristics of the system. Then, five
scouring runs were made - two with the 3>5-5 meah beads and one each
with the other particle sizes,
A typical test run commenced by loading the return bend (through the
venturi aspirator) with solids to some level, usually below the down-
leg terminus, A small AH was set across the U-tube and flow was
19
-------
Figure 6. Concentric Return Assembly Used in
Silting Experiments (Scale is in inches)
20
-------
started. The action and depth of scour of the solids was recorded as
the system AH and water flow rate were increased. Water flow rate
measurements were made as a check on the calihration runs, A screen
was placed in the surge tank to catch solids that were flushed out of
the return. The results of these tests are presented in the next
section.
21
-------
SECTION V
PILOT-SCALE EXPERIMENTAL RESULTS
AERATION STUDIES
Four hundred ten (410) test runs were performed to evaluate the aera-
tion characteristics of the pilot-scale U-tube. Not all of the instru-
mentation discussed in the previous section was included from the first
run, e.g., the third dissolved oxygen probe was not available before
Run 139. In general, instrumentation was added as the value of addi-
tional measurements became apparent.
A summary of the tests, including an outline of the system parameters
and measurements which were made, is shown in Table 1. The experimental
data acquired for Runs 1 through 94 (using the center-plug aspirator)
were not of much value because of the poor performance of this aspira-
tor. Therefore, they are not included in this report. Appendix A con-
tains all data for runs using the venturi aspirator. It should be noted
that Appendix A also contains other information which was generated
from the experimental data using the data reduction program which will
be described in the Analytical Studies section. Table 1 and Appendix A
explain which of the values are experimental data and which are calcu-
lated values. The two sets of values are combined in Appendix A for the
convenience of the user.
Figures 7 and 8 illustrate typical trends of the test data. In these
two figures, the applicable oxygen transfer data have been adjusted to
a standard set of conditions (the original data had varying inlet D.O.
and some variations in temperature and ambient pressure) so that they
can be plotted meaningfully. The abscissa on each graph is the amount
of oxygen supplied in mg/1. This quantity is directly related to the
initial air-to-water volume ratio:
Oxygen supplied, mg/1 = 280 (air/water at 14.7 psia, 68°F)
= 263 (air/water at 13.8 psia, 68°F)
It can be seen that the exit D.O. concentration increases, although with
a decreasing rate of increase, as the amount of oxygen supplied is in-
creased. Although not obvious from Fig. 7, the curves will not be as-
ymptotic to the saturation concentration (9.08 mg/1) because of the
ability of U-tube systems to raise the D.O. level above the ambient sat-
uration concentration, if designed for such high exit D.O. levels. As
the water velocity is decreased, the exit D.O. concentration increases
and the overall pressure drop decreases; therefore, the experimental
results clearly illustrate the advantages of low water velocities in
system performance. There are tradeoffs, however, when the system eco-
nomics are considered, since lower velocities require larger capital ex-
penditures. Such tradeoffs need to be considered in each individual
design case.
23
-------
TABLE 1. SUMMARY OF MEASUREMENTS MADE IN U-TUBE AERATION EXPERIMENTS
Run
Numbers
1-25
26-94
95-138
139-16?
168-219
220-252
253-263
264-318
319-325
326-410
Aspirator
Type
center-plug
center-plug
venturi
venturi
venturi
venturi
venturi
venturi
venturi
venturi
U-Tube
Depth *
(ft-in.)
36-9
45-0
45-5
45-5
18-10
8-11
8-11
27-11
27-11
36-6
Water Depth
Above Aspirator
Inlet (in.)
6 ft 12
12
7
7
7
7
7
7
7
7
Dissolved Oxygen Measurements
Aspirator
Exit
X
X
U-bend
Exit
X
X
Platform
X
Pressure Measurements
Aspirator
Exit
X
X
X
X
X
X
X
X
X
U-bend
Sntrance
X
X
X
X
X
X
X
X
X
Platform
X
N3
*Depth is distance from extrance of U-tube (entrance of aspirators) to bottom of return bend;
in some sections of this report, these are rounded to the nearest foot.
The following measurements were made for all runs: water temperature at entrance and exit,
water flow rate, air flow rate, ambient pressure, ambient air temperature, D.O. at entrance
and exit, and overall head loss across the system.
-------
SUPERFICIAL WATER
VELOCITY - 1.9 FT/SE
OXYGEN SUPPLIED. HG/L
Figure 7. Dissolved Oxygen Increase Across 28-ft Deep
Experimental U-Tube (reduced to standard
conditions of 68° F, 1 atm, zero inlet D.O.)
I I i I
\ T
I T
-SUPERFICIAL WATER /2.9 FT/SEC
VELOCITY = 3.
-------
ASPIRATOR EVALUATION
It was noted soon after the beginning of experimentation that permanent
pressure losses across the center-plug aspirator were quite large.
Since these losses were a major fraction of the total energy losses,
design began early on an improved (vehturi) aspirator. It was apparent
soon after installation that the venturi design was markedly superior.
A comparison of pressure drop between the two units was first made using
water. A series of runs was made with the center-plus aspirator at
fixed contraction ratios and variable water flowrate (Runs 73~94).
Similar data were available from several sets of runs with the venturi.
A plot of the permanent pressure loss vs water velocity for the two
aspirators is shown in Fig. 9 for several values of contraction area
ratio, E (defined as cross-sectional area of the 2.067-inch I..D. pipe
divided by minimum flow cross-sectional area in aspirator). It is ap-
parent that the pressure loss for the venturi aspirator (which has a
fixed E of 8.0)*is approximately equal to the pressure loss for the
center-plug aspirator with the contraction ratio set at 2.9. It was
possible to obtain a given amount of aspiration with the venturi aspira-
tor at a much lower permanent head loss than with the center-plug aspir-
ator. Another advantage of the venturi aspirator concept is that the
minimum dimension of the flow passage remains higher than for a center-
plug aspirator, thus reducing the chance of plugging.
AIR BUBBLE CHARACTERIZATION
High-speed motion pictures were taken of the two-phase fluid flow
during nine runs with each type of aspirator in a U-tube 45-ft deep.
These pictures were used in determining various air bubble characteri-
stics, A random sample of approximately 25 bubbles in each of several
frames was used for determining bubble shapes, sizes, and slip veloci-
ties for each run. Measurements were made from projected enlargments
of the motion pictures.
Figures 10, 11, and 12 show enlargements of six frames, selected at
random, from the motion pictures for Runs 131? 136, and 137* In each
figure, the top photograph shows a section in the U-tube located
approximately 7 ft below the aspirator outlet (the flow direction is
from top to bottom), and the bottom photograph shows the glass return
bend (with flow from right to left). It can be seen that the air
bubbles are approximately oblate spheroids, with larger bubbles
generally having greater eccentricity than small bubbles. There is
some observable flattening of the bubble leading surfaces as compared
with the trailing surfaces; however, this is not a large effect except
for the largest bubbles.
Table 2 summarizes the results for runs with the venturi aspirator.
The pictures taken during runs with the center-plug aspirator, as well
26
-------
s
t
BC.
o
in
in
O
Q-
§
O
CO
LU
a.
5 -
3 -
2 -
1 -
CENTER-PLUG
VENTURI
CONTRACTION AREA
RATIOS AS SHOWN
1 2 3 k
SUPERFICIAL WATER VELOCITY IN PIPE, FT/SEC
Figure 9. Comparison of Pressure Drop Across Center-Plug
and Venturi Aspirators
27
-------
Figure 10. Photographs of Two-Phase Flow in U-Tube (Run 131,
superficial water velocity = 2.9 ft/sec, initial
air/water volume ratio = 0.014 at 1 atm, 68° F)
28
-------
Figure 11. Photographs of Two-Phase Flow in U-Tube (Run 136,
superficial water velocity = 2.4 ft/sec, initial
air/water volume ratio = 0.063 at 1 atm, 68° F)
29
-------
Figure 12. Photographs of Two-Phase Flow in U-Tube (Run 137,
superficial water velocity =2.0 ft/sec, initial
air/water volume ratio = 0.088 at 1 atm, 68° F)
-------
TABLE 2. SUMMARY OF TWO-PHASE FLOW CHARACTERISTICS
IN U-TUBE WITH VENTURI ASPIRATOR
Run
Number
131
132
133
13^
135
136
137
138
Superficial
ifater Velocity
(ft/sec)
2.9
2.4
2.0
1.9
2.8
2.4
2.0
2.8
Initial
Air/Water Volume
Ratio at 1 atm,
68° F
0.014
0.046
0.066
0.022
0.039
0.067
0.094
0.045
Mean values for eight runs
Location
in U-tube
top
bottom
top
bottom
top
bottom
top
b ott om
top
bottom
top
b ott om
top
bottom
top
bottom
top
bottom
Bubble
Mean Major
Diameter
(inch)
0.18
0.18
0.17
0.17
0.19
0.20
0.21
0.20
0.20
0.19
0.23
0.20
0.19
0.19
0.19
0.19
0.19
0.19
Bubble
"lean Minor/
fean Major
Diameter
0.53
0.55
0.61
0.52
0.53
0.53
0.47
0.47
0.46
0.45
0.46
0.49
0.59
0.48
0.54
0.47
0.52
0.50
X,
Total Area/
Jubble Volume
(inch'1)
39-8
39.2
40.2
41.3
40.2
36.0
29.7
42.9
40.4
45.6
26.3
.37.6
37.8
42.3
39.8
41.7
36.9
40.8
Mean Slip
Velocity
(ft/sec)
0.08
0.19
0.24
0.20
0.23
0.01
0.23
0.20
0.17
-------
as Run 130 with the venturi aspirator, were of poorer quality than the
later eight runs represented in Table 2; therefore, the information
from these eight runs was used as the primary basis for characterizing
the two-phase flow. The superficial water velocity is, as previously
defined, the velocity with which the water would flow at the measured
flow rate if the air were not present. In all cases, this velocity was
calculated from the measured water flow rate and the known pipe diam-
eter. The initial air-to-water volume ratio expresses the amount of air
introduced in the aspirator before any gas is dissolved. The "top" lo-
cation in the U-tube was a section located approximately 7 ft below the
aspirator outlet in the ten-foot length of glass pipe. The "bottom"
location was about six inches above the bottom of the glass return bend
section. The mean diameter values given in Table 2 are arithmetic mean
values of the approximately 50 to 75 randomly chosen bubbles for each
case (i.e., approximately 25 bubbles chosen from each of 2 or 3 frames).
The ratio of mean minor diameter to mean major diameter is given because
it has greater statistical validity than the mean of the individual
ratios for each bubble. The total air-water interfacial area per unit
volume of air, X, is the variable actually used in later analytical
studies to characterize the effects of bubble size and shape on the mass
transfer. It was calculated by summing the values of interfacial area
divided by bubble volume for each individual bubble in a run (treating
the bubbles as oblate spheriods with the measured major and minor diam-
eters) and dividing by the total number of bubbles measured for that
run. This variable thus combines the effects of bubble size and shape
distribution, and is not a function of the absolute bubble population or
air-to-water ratio. It can be seen from the results in Table 2 that
there is no apparent effect of water velocity or air-to-water ratio on
the bubble shapes or sizes. Even more surprising, however, is the ab-
sence of a difference in bubble size between the top and the bottom of
the U-tube, a distance of 36 ft. If most of the bubbles remained as
discrete entities throughout their passage through the down-leg, there
would be a detectable change in mean bubble size between the top and
bottom. Apparently, there is enough net bubble coalescence to compen-
sate for the increase in pressure (plus some small amount of gas disso-
lution). The balance of these two effects may not be neutral in other
physical situations; however, the pilot-scale U-tube with venturi
aspirator and 45-ft length seems to be characterized by approximately
constant air bubble size throughout at least the down-leg.
Slip velocity is defined as the difference between the actual (not
superficial) water velocity (uw) and the bubble velocity (ua), i.e.,
us = uw - ua. It is an important parameter in the evaluation'of'mass
transfer coefficients through the U-tube. With this definition the slip
velocity is positive in the down-leg and negative in the up-leg. The
slip velocity values are inherently less accurate than the other experi-
mental data because the possible error in determining both water velocity
and bubble velocity is large with respect to their difference (slip
velocity). It was not possible to obtain meaningful slip velocities at
the return bend because of the flow curvature there.
32
-------
Figure 13 shows the experimental slip velocities at the top of the down-
leg for the venturi and center-plug aspirators. The data for the center-
plug aspirator show more scatter than the venturi aspirator data, which
is reasonable since the latter were taken from pictures with greater
magnification, hence, improved definition. In spite of the scatter,
the data suggest a mean slip velocity of about 0.2 ft/sec, especially
in the case of the venturi aspirator. The slip velocity appears to be
independent of water velocity or air-to-water ratio over the ranges of
variables included in these two-phase flow tests.
NITROGEN TRANSFER
Procedures and apparatus for the analysis of dissolved gases have been
discussed in the Experimental Studies section. The results for the
four samples (i.e., entrance and exit samples for Runs 293 and 375) are
shown in Table 3«
TABLE 5. RESULTS OF CHEMICAL ANALYSIS FOR
DISSOLVED NITROGEN
Run Number
Superficial water velocity (ft/sec)
Air/water at 1 atm, 68°F
D.O. concentration (mg/l):
entrance
exit
D.N. concentration (mg/l):
entrance
exit
D.N. change/D.O. change
293
1.9
5.8
2.2
7.4
3.8
16.8
2.5
375
1.4
7.0
1.1
5.6
2.6
12.9
2.3
It can be seen that the D.O. concentrations in Table 3 disagree some-
what with the meter readings for entrance and exit D.O., stations 1 and
12 (Appendix A). This discrepancy is thought to be due primarily to
errors in the sampling and analytical procedures. However, this is not
of particular importance since the significant results are the ratios of
D.N. change to D.O. change. These ratios were used in estimating nitro-
gen mass transfer coefficients from the experimental oxygen mass transfer
coefficients, using the data reduction programs as discussed in
Section VII.
33
-------
o
o
LU
OQ
CO
03
I
o
o
1.0
0.8
0.6
0.4
0.2
-0.2
-Q.k
- DATA WITH VENTURI
ASPIRATOR
-1-90 6^2. 4 °2
.0 Q2.0
. °2.9 02.*
NUMBERS BESIDE DATA POINTS
ARE SUPERFICIAL WATER
VELOCITIES IN FT/SEC
1 1 I
1 i
D-
DATA WITH CENTER-
PLUG ASPIRATOR
1 *i
r^*io Q o
LJ D
4.3 D''9
D
3.7
t i i
0.02 0.04 0.06 0.08 0.10 0 0.02 0.04 0.06 0.08
AIR-TO-WATER VOLUME RATIO
Figure 13. Air Bubble Slip Velocities Near Top of U-Tube
SILTING STUDIES
The objective of the siIting-scouring studies was to develop a basis for
designing U-tubes so that they would be free from plugging problems due
to silting.
The first part of this section briefly describes some relevant physical
factors and previous experimental studies in the area of silting and
scouring in pipe flow. The remainder of the section contains the ex-
perimental data and information on scouring generated during this
investigation.
The behavior of a moving slurry containing solid particles of greater
density than the liquid can be described at various velocities as
follows:
1. At very low velocities, the particles will settle out under free or
hindered settling.
2. Above a certain "minimum velocity" there will be no particles
settling out of the slurry; however, a vertical concentration
gradient will exist.
3. When the velocity exceeds the "standard velocity", there will be
adequate mixing to eliminate any appreciable vertical concentra-
tion gradient.
34
-------
In a sewage stream, the organic materials and most of the other poten-
tially cohesive materials will be less dense or, at most, of comparable
density to water. Therefore, these will be less likely to cause set-
tling problems than the more dense materials such as sand, rocks,
bottles, tin cans, etc. — materials which are essentially noncohesive.
With noncohesive materials, the movement of solid particles depends
only upon the physical properties of the individual particles such as
size, shape, and density, and upon their relative position with respect
to other particles. Natural sediments are irregular in shape, and,
therefore, the definition of size as a single length or diameter must
be made arbitrarily. One of the common definitions is the sieve diameter,
the size of sieve opening through which the given particle vill just
pass. In any particular sediment, the sizes of the individual particles
may vary over a wide range. However, since larger particles will (with
other factors being constant) settle out of a slurry more readily than
smaller particles, the design approach taken in the subsequent discus-
sions is to prevent sedimentation of particles of a specific maximum
sieve size. Then, any smaller particles will not settle out, but it
will be necessary to prevent particles larger than the design size from
entering the U-tube.
A single solid particle in a stationary fluid will be acted upon by
forces due to buoyancy, gravity, and fluid friction (usually lumped into
the "drag" force). A particle released from rest will accelerate until
these forces just balance; the resulting velocity is the "terminal
velocity". If the upward fluid velocity in a vertical pipe containing
a solid particle is equal to the terminal velocity of the particle,
then the particle will have no net vertical movement. If the upward
fluid velocity exceeds the terminal velocity, the particle will be
transported upward. Curve No. 1 in Fig. 14 shows the terminal velocity
of quartz or sand spheres (specific gravity = 2.64) as a function of
particle size. Irregular particles will have lower terminal velocities
than spheres, of the order of 60 percent of .the spherical particle
terminal velocity (Ref. 10), represented by curve 2 in Fig. 14.
Ensuring that no restrictive sediment bed will develop on the bottom of
the U-tube may require higher velocities than those needed to exceed
the settling velocities of the particles. This flow situation is much
less tractable, analytically. Several generalizations which have been
reported in the literature, all based at least partly on experimental
data, are described in the following paragraphs, and results are
included in Fig. 14.
Spells (Ref. 11) developed a correlation based upon consideration of
the Froude number (to represent gravitational forces) and the Reynolds
number (to account for viscous forces) plus experimental data (for
particles approximately 50 to 200 microns):
35
-------
CJ
UJ
in
o
O
10
8
6
-I I I I I I
III I I I III
I \ I I I I III
1
0.8
0.6
0.4
0.2
0.1
0.08
0.06
0.04
0.02
0.01
I I Illlll-
LEGEND
TERMINAL SETTLING VELOCITY OF QUARTZ SPHERES
TERMINAL SETTLING VELOCITY OF IRREGULAR SAND PARTICLES
MINIMUM VELOCITY FOR 2-INCH DIAMETER PIPE—SPELLS
(REF. 11 )
MINIMUM VELOCITY FOR 2-INCH DIAMETER PIPE—CAIRNS
IMPROVEMENT OF SPELLS'S CORRELATION (REF.-12)
SAFE VELOCITY TO PREVENT SEDIMENTATION—CRAVEN
(REF. 13)
EXPERIMENTAL SCOUR VELOCITIES (THIS INVESTIGATION)
0.004
0.01 0.02
(100^)
0.04 0.1 0.2 0.4 1
PARTICLE SIZE, CENTIMETERS
10
Figure 14. Effect of Particle Size on Scour Velocity
-------
where Dp = particle diameter, D = pipe diameter, Pp = particle density
Pm = mean density of the slurry, and BI is an empirical constant which
is reported as 0.0251 for the "minimum velocity" and 0.0741 for the
"standard velocity". This correlation has given only rough agreement
with other published data. Cairns (Ref. 12) considered Spells' equation
and used additional data to give his recommended improved form of the
equation:
vO.3
where C is the solids concentration in volume percent, and the particle
size, Dp, is in feet. The results of parametric calculations with each
of the above equations are presented in Fig. 14 (curves 3 and 4,
respectively).
Curve number 5> shown in Fig. 14, is given by Craven (Ref. 13) and is
the one for which the experimental data used to generate it most
closely approximate the conditions expected in a typical U-tube appli-
cation to a sewer line. Therefore, it might be expected to be the
most reliable design tool of all the correlations shown in the figure.
Craven found that no permanent deposit of sediment would occur in full-
flowing pipes if:
where Q is the volumetric flowrate through the pipe. The expression on
the left side of the equation is dimensionless.
Relatively few applicable studies were found in the limited literature
search which was conducted. No work was found which investigated silt-
ing or scouring in vertical or curved pipes, which are the cases of
interest in a U-tube. Therefore, brief experimental studies were con-
ducted as a part of this project. The experimental procedures for the
silting studies were discussed in the Experimental Studies section.
One difficulty in evaluating and applying the scouring data was the un-
certainty in defining and evaluating values for scour velocity (i.e.,
that minimum velocity necessary to cause settled particles to dislodge
from the solid bed and be transported into the up-leg of the U-tube).
Figure 15 illustrates the concentric return bend assembly used in the
experiments (a photograph of the assembly was previously given in
Fig. 6). It was realized that a non-uniform velocity profile existed
in a direction perpendicular to the solid bed surface. Since it was not
possible to determine the actual surface velocity (which would be a most
reasonable definition for scour velocity), the scour velocity was de-
fined as the average water velocity through the area formed by an imagi-
nary cylinder extending from the down-leg bottom to the solids bed
37
-------
(4-INCH ID)
CYLINDRICAL CONTROL SURFACE
-FOR DEFINING SCOUR VELOCITY
Figure 15.
B = DEPTH 0^ SCOUR
uc = SCOUR VELOCITY
_ Ojw
Qw = WATER FLOWRATE
Diagram Illustrating Analysis of
Experimental Scour Data
surface (see Fig. 15). The scour velocities were evaluated at constant
water flowrate by determining the distance B at which solids ceased to
be removed from the solid bed at the bottom of the return bend. With
the depth of scour and U-tube AH as data, average scour velocities were
determined for each particle size.
A series of scour depth and U-tube head loss measurements were taken for
each test run. Head loss measurements enabled evaluation of water vel-
ocity from a series of calibration runs. The scour velocity was deter-
mined at each depth of scour, and an average was taken for the run.
38
-------
Velocities showing large deviations from the average (usually at the
start of a run) were discarded. The results are as follows:
Particle
Size Range
(mm)
Number of
Determinations
Range of
Scour Velocity
(ft/sec)
Average
Scour Velocity
(ft/sec)
4.00 - 5.66
2.00 - 2.38
1.00 - 1.41
0.50 - 0.60
6
10
5
5
0.39 - 0.42
0.29 - 0.32
0.23 - 0.25
0.20 - 0.21
0.40
0.31
0.24
0.20
These data are represented by curve 6 in Fig. 14. This particular
curve in Fig. 14, it should be remembered, is a representation of scour
velocities of a particular concentric return bend at the bottom of a
U-tube for particles in the range 0.50 to 5.66 millimeters. Caution
should be used in extrapolating the results beyond this particle size
range or to different systems. However, the results do give some basis
for determining velocities necessary to keep a U-tube return bend free
of solids with diameters less than 1/4-in.
It can be seen that there are considerable differences between the data
obtained herein and predictions from various other investigations for
velocities required to scour or prevent silting (Fig. 14, curves 1
through 5~). The fact that the required velocities from this investiga-
tion are lower than the others plotted in Fig. 14 is due at least partly
to the definition of scour velocity used in this case. The actual veloc-
ity at the bed surface was undoubtedly higher than the average velocity
(based on a constant velocity profile across the flow cross-section at
the minimum point) which was used to calculate the values given in the
above table and in Fig. 14.
Of the relationships illustrated in Fig. 14, it is judged that design
velocities selected from approximately the range recommended by curve 5
should be used to prevent sedimentation in the bottom of a U-tube.
Thus, it should be possible to prevent sedimentation of sand and rock
particles up to the size of fine gravel by designing a U-tube for mini-
mum water velocities of approximately 1.5 to 3 ft/sec. The experimental
results of this investigation suggest that these may be rather conserva-
tive. This is a very practical requirement for a U-tube application;
therefore, preventing sedimentation in a U-tube system is not expected
to be a serious design problem.
39
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SECTION VI
FULL-SCALE EVALUATION TESTS
Several full-scale U-tube systems were installed in sanitary sewer lines
in Jefferson Parish, Louisiana, and Port Arthur, Texas, under EPA Grants
11010 ELP and 11010 DYO, respectively. These grant projects have been
reported in Ref. 14 and 15. Design and optimization studies were con-
ducted during this project in support of these EPA grant projects. Sub-
sequently, field evaluation tests were made at each location. The follow-
ing sections describe the application sites, design approach, final U-tube
system designs, and evaluation tests that were conducted.
JEFFERSON PARISH
Application Sites
Jefferson Parish is adjacent to the west side of Orleans Parish in which
the city of New Orleans lies. The portion of Jefferson Parish in which
the aeration systems were installed is bounded by Lake Pontchartrain on
the north and the Mississippi River on the south. More specifically,
the sewer lines under study collect waste water from part of the area
north of Air Line Highway and flow northward to the Helois Treatment
Plant. This area is quite level and much of it is below the elevation
of Lake Pontchartrain and the Mississippi River at this point. The dif-
ficulties of sewer construction caused by the high gfound water level and
low rigidity of the soil have necessitated the use of minimum slopes on
gravity sewer lines plus numerous pumping stations. The net waste water
velocities are small compared with those in many areas, and there have
been septicity problems in the sewers. It is, of course, important to
prevent septic (anaerobic) conditions from developing in a sewer line
because of the resultant odor, corrosion, and subsequent treatment plant
problems which this can cause. The Jefferson Parish Department of Sani-
tation has been active in improving its sewer systems to eliminate many
of the potential trouble spots, primarily by installing additional lift
stations and more force mains to decrease the average sewage residence
times. This project had the objective of investigating aeration as a
method for septicity control.
The "Old Metairie" section of Jefferson Parish, Louisiana, was selected
for U-tube aeration installations because of its need for additional
sulfide control in force mains. Two sites (designated locations 5 and T)
in the Old Metairie area which exhibited unusually high corrosive attack
and gas odor were selected for installation of venturi aspirated U-tube
aeration devices.
Design Approach
The primary objective of each aeration facility was to efficiently dis-
solve as much oxygen in the waste water stream as possible within the
particular constraints of each chosen site.
/ 41
-------
A very important consideration which imposed constraints on the designs
was that they should not offer any opportunity for plugging. Most of the
specifications for lift pumps in this area require passage of a "3-inch-
diameter sphere" (in a few cases, 4-inch diameter is specified). Conse-
quently, in the U-tube designs no cross section with a dimension less
than 4 inches was permitted. This imposed a constraint on the minimum
flowrate for which an aspirated-air U-tube could be applied. With pres-
sure drops typical of those for the Jefferson Parish designs, the flow-
rate must be greater than about 300 gpm to keep the required aspirator
throat diameter at least 4 inches.
Another possible source of plugging could be the return bend at the bottom
of the U-tube. A concentric configuration would have several construction
advantages; however, it could produce two possibilities of plugging in
this application: the annular space between the inner and outer pipes
would be less than 4 inches for these applications, and the abrupt edge
at the bottom of the inner pipe could possibly result in some hang-up of
material. Consequently, all designs used a literal U-bend between sepa-
rate down and up pipes, as shown in Fig. 16. It was,necessary to ensure
that all solid material would be carried up the up-leg and transported
from the U-tube system. Although an up-leg velocity of approximately
2 ft/sec would be sufficient to transport sand and prevent silting (as
discussed in a previous section), this might not be high enough to trans-
port larger items which could still be passed by the pumps. The Parish
design rules for lift pump vertical risers require the velocity to be at
least 4 ft/sec. This lower limit on up-leg velocity was also used in
these designs.
One major constraint was shared by all of the aspirated-air systems; the
throat pressure must be less than the ambient pressure to aspirate air
into the flowing water stream. This is not particularly difficult in a
gravity-flow system where the pressure at the entrance to the aspirator
is merely due to the height of liquid above it. In a force-main appli-
cation, however, the design is more difficult because the aspirated
entrance pressure can be considerably greater than the ambient pressure.
If the pressure drop downstream of the aspirator is substantial, the
aspirator contraction ratio must be much larger (throat smaller) than
for a corresponding gravity flow application. This, in turn, leads to
a higher ratio of permanent pressure drop-to-throat pressure decrease,
R, since R increases with increasing venturi contraction area ratio.
The "permanent pressure drop" across the venturi (the difference between
the'measured pressures upstream and downstream of the venturi) is gener-
ally much less than the equivalent on-phase throat pressure decrease
(the difference between the measured upstream pressure and the static
pressure at the venturi throat if no air were introduced there). Conse-
quently, R is generally less than 1. High values of R correspond to
high-energy losses in the aspirator.
Another set of design considerations centered around the existing system
and pump characteristics. Many of the existing lift pumps were operating
below their design lifts, and most could also be uprated with larger
42
-------
EXISTING L
MANHOLE /
EXISTING FORCE MAIN
SITE PLAN
VENTURI ASPIRATOR
= a^
CONCRETE PIT FOR
INSTRUMENTATION
GRADE
FROM =32
FORCE
MAIN
PVC PIPE (DIAMETER = Dfi)
PVC PIPE (DIAMETER = Dg)
PRE-CAST CONCRETE
PIPE (I.D. = DC)
L.R. RETURN BEND IS PREFERABLE IF
CASING DIAMETER CAN BE INCREASED
HORIZONTAL PIPE SPOOLS SHOULD BE
AS SHORT AS POSSIBLE, EXCEPT SPOOL
UPSTREAM OF ASPIRATORS SHOULD BE
AT LEAST 3D] LONG
SECTION A-A (SHOWN SCHEMATICALLY)
Figure 16. Basic Configuration for Aspirated-Air U-Tube
Designs in Jefferson Parish Sewer System
43
-------
impellers without changing motors. There was, however, considerable vari-
ation in the characteristics at the sites, and this was considered in the
designs.
A number of configurations for these aerators were considered in the pro-
cess of choosing the final configuration sketched in Fig. 16. A large
number of parametric computations were made for different configurations
and design conditions using the design computer program previously devel-
oped from the pilot-scale U-tube data described.
Typical U-tube parametric design trends are illustrated and discussed
in Section VIII, U-Tube Design. The primary conclusions developed during
the Jefferson Parish design work are summarized in the following paragraphs,
It was soon found that it is very important to keep the elevation of the
aspirator as high as possible and the elevation of the exit line to the
manhole as low as possible. Both of these conditions help minimize the
required aspirator contraction area ratio, with attendant improvement in
system pressure drop characteristics. Having the aspirator as high as
possible also is of value in reducing or, in some cases, preventing the
upstream force main from partially draining during pump off-cycles.
Excessive drainage would have undesirable effects on start-up of the
aspirator system each time the pump was operating.
Other parametric calculations led to the conclusions that the velocities
in all parts of the aspirated-air U-tube system should be as low as possi-
ble within the design constraints. This meant, in this particular appli-
cation, that the up-leg velocities should be greater than 4 ft/sec but
as near to 4 ft/sec as actual pipe sizes would permit. This conclusion
also meant that the down-leg velocities should be approximately 1.5 to
2.0 ft/sec to keep them as small as possible while still maintaining
proper air bubble entrainment. It was concluded that the added expense
of pipe reducers to permit a larger down-leg pipe size was definitely
justified by the increase in oxygen transfer which results from the longer
residence time.
For the particular conditions of location 5 and 7, it was predicted that
some air could be aspirated even without a reduced diameter throat sec-
tion (i.e., in the elevated pipe without a venturi). As the desired
amount of oxygen to be supplied (or exit D.O. concentration is increased,
it becomes necessary to constrict the throat cross section to a greater
extent. This results in an increase in exit D.O. concentration, but also
produces an excessive overall head loss. The rapid increase in head loss
for small throat cross-sectional areas is a result of the "magnification
effect" previously discussed, which is characteristic of, and an inevit-
able consequence of, a force main application. The cost in head loss for
incremental increases in exit D.O. concentration becomes relatively
greater as the exit D.O. levels approach saturation. It was found that
the decrease in exit D.O. concentration with increasing water flowrate
(producing a reduced residence time for air bubbles in the U-tube") is
44
-------
somewhat less rapid than the increase in head loss. However, this trend
again illustrated the importance of keeping the water velocities as low
as possible within the design constraints.
An alpha value of 0.8 (ratio of oxygen mass transfer coefficient in waste
water of interest to coefficient for "tap water") was used in all the cal-
culations for Jefferson Parish aeration systems. This is the value cus-
tomarily used by the EPA National Environmental Research Center at Cincin-
nati, and very similar to the value of 0.82 given in Ref. 16 for fresh
raw domestic sewage. If the sewage had no remaining dissolved oxygen and
a high initial oxygen demand, the measured oxygen transfer would be less
than predicted with the 0.8 alpha factor. The actual amount of oxygen
uptake, in such a case, may be even greater than the change in D.O. pre-
dicted with an alpha of 0.8; however, the final D.O. level would be
smaller than the predicted value because of the high initial oxygen
demand. The lower alpha values reported in the literature for various
samples of raw sewage may include this effect.
After generating parametric design data, as summarized in the previous
paragraphs, the pump characteristics (for the pump upstream of each sta-
tion) were matched with the flow characteristics of the force main plus
the U-tube system to be added. Figure 17 illustrates this procedure.
Point A, representing the original operating point before any changes
to the sewer system, is located at the intersection of the pump charac-
teristic curve and the original total system head curve. Point B is the
new operating point after installation of a U-tube system (there could
be many U-tube characteristic curves drawn and, consequently, many differ-
ent point B's, but an efficient U-tube design was chosen in each case).
If the new flowrate, Qg, was lower than desired, then pump modifications
were considered. In most cases, the existing pump and motor could accept
a larger impeller without other changes. The pump characteristic curve
with a larger impeller is represented by the "up-rated pump character-
istic curve" in Fig. 17, and point C is the resulting operating point
after installation of a U-tube system.
Designs
The final design characteristics for the two aspirated-air U-tube systems
at locations 5 and 7 were established, and specified all the important
design parameters which influence the system operation. Careful consid-
eration was also given to aspirator design and instrumentation for the
purposes of obtaining good information about the operating character-
istics. Such instrumentation would not be required in a strictly opera-
tional aeration system, but was most important for these initial devel-
opment systems. These design characteristics and details of instrumenta-
tion and aspirators were used by deLaureal Engineers, Inc. (the consult-
ing engineering firm assisting Jefferson Parish with the grant project)
to prepare detailed construction drawings.
45
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ORIGINAL PUMP
CHARACTERISTIC
CURVE
UP-RATED PUMP
CHARACTERISTIC CURVE
TOTAL SYSTEM AH
INCLUDING U-TUBE
ORIGINAL TOTAL
SYSTEM AH
VERTICAL LIFT
ON PUMP
DISCHARGE
Figure 17.
WATER FLOW RATE
Diagram Illustrating Matching of System
and Pump Characteristics
Location 5 is situated at the end of 3000 feet of 12- inch force main
through which the nominal flowrate is 1500 gpm while location 7 is at
the end of 2050 feet of 10-inch force main through which nominal flow-
rates of 600 gpm are encountered. The final designs are presented in
Fig. 18 and 19, respectively.
The U-tubes were fabricated from fiberglass-reinforced PVC pipe and
secured in 4- foot- diameter steel casings with concrete. Details of the
U-tube construction and installation can be found in Ref. 14. Venturis
selected for this application were essentially standard Dall flow tubes
(a type of short-length, contoured venturi flowmeter manufactured by
BIF Industries) modified by drilling additional holes in the throat
walls for use in air aspiration. Down- leg and up- leg line diameters
were selected to provide average superficial water velocities of approx-
imately 1.5 and 4 ft/sec, respectively, at each location. All pipe
46
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20-IN. MITERED
90* ELBOW
TOP OF EXIT MANHOLE EL. 1(3.17
EL. 32.67'
EFFLUENT
DISCHARGES
INTO MANHOLE
12-IN. PIPE
,(12.00 IN. ID)
12.0
]k X 12 CONCENTRIC
REDUCER —i
PRESSURE TAP
EL. 31.17
12-IN. PIPE
(12.00-IN. ID)
llt-IN. PIPE —'
(13.25-IN. ID)
PRESSURE TAP
EL. 1.50
ALL DIMENSIONS AND ELEVATIONS IN FEET,
MEASURED TO CENTERLINES, AND FLANGE FACES
(AS APPROPRIATE)
FLOW
FROM
EXISTING
SEWER
VENTURI ASPIRATOR
6.1(0-IN. THROAT DIA
3.52 AREA RATIO
20-IN. PIPE
(19.00-IN. ID)
PRESSURE TAP
EL. 3.17
20 X 1A ECCENTRIC REDUCER
U-BEND EL. 0.00
Figure 18. U-Tube System at Location 5, Jefferson Parish, Louisiana
47
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12-IN. MITERED
90" ELBOW
TOP OF EXIT MANHOLE EL.
EFFLUENT
DISCHARGES
INTO MANHOLE
PRESSURE TAP
EL. 145.33
•8-IN. PIPE
(7.98-IN. ID)
PRESSURE TAP
8 X 10-IN.
CONCENTRIC
REDUCER-
-IN. PIPE
(7.98-IN. ID)
FLOW IN
FROM
EXISTING
SEWER
VENTURI ASPIRATOR
4.00-IN. THROAT DIA
6.25 AREA RATIO
12-IN. PIPE
(12.00-IN. ID)
PRESSURE TAP
EL. 1.5
ALL DIMENSIONS AND
ELEVATIONS IN FEET,
MEASURED TO CENTERLINES
AND FLANGE FACES (AS
APPROPRIATE)
12 X 8 ECCENTRIC REDUCER
EL. 0.00
Figure 19. U-Tube System at Location 7, Jefferson Parish, Louisiana
48
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diameters (venturi throat, down-leg, and up-leg) were selected based on
the average flowrate encountered at each location and optimized using the
first-generation design computer program. The U-tube discharge point was
positioned as low as possible in the manhole. This not only reduced the
total head loss across the system but also reduced the amount of f^S
stripping in the exit manhole.
The method of aeration can be understood by following the flow of waste
water through the U-tube. As the sewage leaves the force main and enters
the throat area of the venturi, the velocity increases, thereby decreas-
ing the pressure at the throat to below atmospheric pressure at the throat
to below atmospheric pressure. This creates a pressure differential fav-
orable to aspiration of air into the stream. The turbulent flow down-
stream of the venturi promotes mixing of the sewage and aspirated air.
The down-leg acts as reactor in the sense that it provides retention time
and the increased pressure as a function of depth, both of which enhance
oxygen transfer from the entrained air bubbles to the sewage. The stream
proceeds up the up-leg, aided by an air lift effect, and discharges into
the manhole with an increased dissolved oxygen level. This prevents sep-
tic conditions from developing for a considerable distance downstream.
Test Procedure and Results
Experimental test procedures for evaluating these U-tube installations
which involve force mains required that personnel be assigned to the pump
station as well as the U-tube installation. Personnel at the pump station
(constantly in contact with U-tube personnel via two-way radio communica-
tions) were responsible for manual operation of the /pump cycles, record-
ing both the pump discharge pressures, and the wet well levels. Concur-
rently, personnel at the U-tube installation were required to perform
the necessary functions, e.g., setting air flowrates, measuring and record-
ing pressures for selected points in the U-tube installation, and also
sampling the stream and analyzing for dissolved oxygen (D.O.). Instru-
mentation of the U-tube installation consisted of a water manometer
(seven tubes manifolded together), differential pressure gages, air com-
pressor (for supercharging), air flowmeter, plus chemicals and apparatus
for on-site determination of D.O. Figure 20 shows the typical test setup
at location 7.
The typical test run consisted of the following sequence of events: (1)
the water flowrate was set (this was accomplished by having' either one
or two pumps on line); (2) the desired air flowrate was set; (3) after
the water and air flows were stabilized, pump discharge pressure, wet
well levels, and air flowrate were measured and recorded; (4) pressures
at stations 3, 5. 6, 7, 9, and 10 in the U-tube were measured and re-
corded; (5) the stream was sampled at stations 3 (upstream of the aspi-
rator) and 12 (at the U-tube discharge point); and (6) the samples were
analyzed for D.O. on site.
49
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On
O
Figure 20. Field Testing at Location 7, Jefferson Parish, Louisiana
-------
Variation of the water flowrates was limited because the only method of
control was by using one lift pump for low flow or both lift pumps simul-
taneously for high flow. This had to be controlled manually at the pump
station because, in normal operation, the pump cycles are automatic and
alternate from one pump to the other unless there is an unusually high
wet well level, in which case both pumps automatically come on line.
Water flowrates were determined by reference to the discharge pressure
read on 0- to 60-psi gages mounted on each pump discharge line. The dis-
charge pressures were correlated to flowrates by making a series of runs
without air aspiration and measuring the pressure drop across the venturi
(which had been calibrated by the manufacturer). From these data, a plot
was constructed that correlated pump discharge pressures to water flow-
rates whether or not air was being aspirated.
Air flowrate measurements were obtained by use of an integrating-type
volumetric gas meter attached to the venturi aspiration jacket with a
2-inch line, and, in some tests by use of a rotameter. Regulation of
selected air flowrates was accomplished by means of a throttling valve
located upstream of the flowmeter. For air flowrates above maximum aspi-
ration rates, a high-capacity, low-pressure compressor was utilized.
Variation of supercharging flowrates was accomplished by running the com-
pressor at full capacity and setting the by-pass valve (vent to atmos-
phere) to attain the desired flowrate. This procedure worked success-
fully at location. 5. However, at location 7, supercharging raised the
pump head to its cutoff point and thus precluded measurements in this
regime.
Pressure measurements were obtained at various points along the U-tube
using the manometer board. It can be seen (Fig. 20) that the seven tubes
(attached to stations 3, 4, 5, 6, 7, 9, and 10) are connected to a mani-
fold with isolation valves. During head measurements, a pressure (either
positive or negative) was set on the manifold such that the water column
would be on scale when the isolation valve was opened. After equilibrium
was reached, both the pressure on the manifold as read on a differential
pressure gage and the height of the water column were measured and re-
corded. This procedure was repeated for each station along the U-tube.
At location 5, a rather comprehensive set of hydraulic and oxygen trans-
fer data was obtained. The variations in water and air flowrates pro-
vided 17 different A/W ratios, ranging from 0.02 to 0.79. In addition,
a number of runs were conducted without air aspiration for flowrate cali-
brations and head loss measurements. However, at location 7, pump capac-
ity was substantially lower and only three different A/W ratios (ranging
from 0.04 to 0.20) could be obtained by aspiration. And, as previously
mentioned, runs with supercharging were not possible. A summary of all
data obtained from these locations is contained in Appendix B.
51
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PORT ARTHUR
Application Sites
Port Arthur, Texas, located in southeastern Texas on the shore of Sabine
Lake, is typical of many cities along the Gulf Coast in terms of the dif-
ficulty of preventing anaerobic conditions from developing in sewer lines.
The city is essentially at sea level, the terrain is very flat, and the
temperatures are relatively warm. Under EPA Grant 11010 DYO, the City
of Port Arthur installed a number of aeration and oxygenation systems at
selected points in its sewer system. Their purpose is twofold: to reduce
the degree and extent of anaerobic conditions in sections of the sewer
system, and to provide information about the practical operating charac-
teristics and relative advantages of various devices for introducing oxy-
gen into the waste water (one employing a pair of U-tubes, two pressurized
aeration tanks, and two force mains) and three cryogenic oxygen injection
installations (one using a U-tube, one force main with a diffuser, and
one force main without a diffuser). The U-tube aerators are located at
Pioneer Park lift station and Lake Charles lift station. The Pioneer
Park lift station, which contains a compressed-air U-tube in line with
each of the two parallel pumps used in alternate cycles, was selected as
the field test site under this program. This U-tube station had been
instrumented previously for testing under EPA Grant 11010 DYO. Consider-
able sulfide attack had become apparent in the 30-inch concrete gravity
line downstream of this station, and it was necessary to replace it in
September 1971, after the unusually short life of 20 years. . Examples of
the severe corrosion can be seen in Fig. 21 through 24.
Designs
The basic design approach was similar to that used for the Jefferson Parish
installations, although the designs were prepared primarily by the Environ-
mental Protection Agency, the City of Port Arthur, and the city's consult-
ants, making use of parametric design information provided by Rocketdyne.
The physical characteristics inherent in these sites dictated the desir-
ability of using compressed-air U-tubes rather than aspirated-air U-tubes.
With this basic premise, parametric design calculations were made with
the design program developed previously from the pilot-scale data, con-
sidering the physical constraints of the particular application sites.
At the Pioneer Park lift station location (which is the case to which the
following details apply), the lift pumps are located in a large, dry well
adjacent to the wet well from which the pumps take their suction flow.
There was ample space in the dry well to install the additional piping
needed for a U-tube. Therefore, it was relatively simple to make this
installation by splicing between the pump discharge line and the exit
line which goes to a manhole from which the 30-inch gravity main flows.
This lift station has a nominal flow capacity of 1400 gpm. The station
52
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Figure 21. Pioneer Park Lift Station Discharge
Box (Showing the 8-inch discharge
line, and severe damage to concrete
walls of the box; exposed large
aggregate and reinforcing bars were
originally covered with approximately
4 inches of concrete)
Figure 22. Manhole Downstream of Pioneer
Park Lift Station (Manhole
collapsed as a result of severe
H2S attack; mortar has been
stripped from brick work)
-------
in
Figure 23. Gravity Line Downstream of
Pioneer Park Lift Station (Complete
deterioration of the gravity line;
top portion shows rings of concrete
that had joined sections of concrete
gravity line. In some sections, the
line has been completely eaten away
by H2S attack, leaving only dirt, as
shown in this photograph)
Figure 24. Gravity Line Downstream of
Pioneer Park Lift Station (A
section of gravity line, seen in
preceding photograph, as viewed
from above ground. The concrete
joint ring remains; however, the
top section of gravity line failed
completely)
-------
was ideally suited for a compressed-air injection system because of the
on-site availability of electrical power to run the compressor and required
solenoid valves.
The final U-tube installation and associated piping at the pump discharge
is presented in Fig. 25. Only one of the two parallel systems is shown
for clarity. It can be seen that the pump discharge stream travels up
through an 8-inch line, through the electromagnetic flowmeter, and across
to the top of the U-tube down-leg. At this point, the stream is expanded
to an 18-inch down-leg, with an air-injection collar located at the top.
Here, compressed air was forced into the stream through 32, 1/8-inch-
diameter holes uniformly spaced around the circumference of the line.
The stream proceeds downward at a reduced velocity and continually in-
creasing pressure. These factors are important for efficient oxygen trans-
fer from the entrained air bubbles. The stream then passes through an 18-
by 12-inch reducer, travels around the U-bend, up the 12-inch up-leg at
increased velocity (and aided by the lift provided by entrained air), and
finally is discharged through an 8-inch line into the discharge manhole
supplying a gravity main. Since this was to be an experimental aeration
station, the U-tube was fitted with taps which allowed for pressure meas-
urements and/or sampling of the stream, as shown in Fig. 25.
Test Procedure and Results
For efficient experimental evaluation of this installation, personnel were
stationed on the lower level (pump and flow control), intermediate level
(air injection control and monitoring), and upper level (supplemental con-
trols, instrumentation readout, chemical analysis). The following sequence
of events took place during each experimental run: (1) the water flowrate
was adjusted to the desired level using a gate valve downstream of the
pump; (2) the air injection flowrate was set, then measured with an in-
line rotometer; (3) the water flowrate was measured with a Brooks Model
7108 electromagnetic flowmeter; (4) the pump discharge pressure was meas-
ured using a pressure gage; (5) the head loss measurements were conducted
at stations 1, 4, 6, 7, 9, and 10 (Fig. 25) using a water manometer; and
(6) water samples were drawn from stations 1 and 10 and analyzed on site
for IDOD (initial oxygen demand) and D.O. using the Modified Winkler test.
Periodically, water samples were analyzed for sulfide concentration.
Using this procedure, a matrix of tests was conducted in which water flow-
rates were varied from 400 to 1400 gpm, while the air flowrates were varied
from 0 to 14 cfm. From these tests, oxygen transfer and pressure drop data
were obtained for 18 different air-to-water ratios (y) ranging from 0.01
to 0.19. The complete data are given in Appendix B.
In each test, water samples were drawn from upstream of the air injector
(station 1) and at the top of the up-leg (station 10). A 15-minute IDOD
test was performed on the influent and effluent samples (the influent D.O.
level was always zero); the IDOD and D.O. tests were performed on effluent.
55
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EL. 102.75
FLOWMETER
INSTALLED DURING
TESTING ONLY
• ALL LENGTH DIMENSIONS AND ELEVATIONS
IN FEET
• ALL NOMINAL PIPE SIZES
IN'INCHES
Figure 25. U-Tube System Tested at Pioneer Park Lift Station,
Port Arthur, Texas
56
-------
These values were then used to calculate the oxygen transfer which actually
occurred in the U-tube by the relation:
total oxygen transfer = IDOD (in) - IDOD (out) + D.O. (out)
To further evaluate the desirability of U-tube aeration of sewage, deter-
minations of total sulfides were made for influent and effluent samples
collected from five different runs. The results (presented in Appendix B)
show substantial decreases in sulfide concentration from 25 to 87 percent.
The hydraulic characteristics of this U-tube installation also were in-
vestigated by measurement of the pressure at the selected points. Pres-
sure measurements were obtained using an open end water manometer which
was manifolded to each of the test points. Data were obtained for each
of the six U-tube test stations in each of 29 runs. This provided detailed
characterization of head loss through the system.
57
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SECTION VII
DATA ANALYSIS
The basic elements of a U-tube aeration system are: (1) a unit for intro-
ducing air (or oxygen) into a flowing water stream, followed by (2) two
connected vertical conduits through which the air-water mixture flows down
and back up, thus giving a substantial residence time in a region of above-
ambient pressure. The device for introducing air could be -one of several
types of aspirators (in which air is induced by a local high-velocity, low-
pressure region in the flowing water stream), 'or the device could be some
type of diffuser through which compressed air is injected.
In addition to the type of device for introducing air, there are numerous
variations in configuration, relative sizes of system components, and oper-
ating conditions that may be considered for each type. This variety of
possibilities, and the complexity of the physical processes occurring with-
in a U-tube system,^makes it not satisfactory to present the experimental
results in terms of graphs or equations giving overall oxygen transfer for
various combinations of U-tube geometry, size, and operating .variables.
Similarly, the widely used "figure-of-merit"--weight of oxygen transferred
per unit of power expended (e.g., Ib oxygen/hp-hr)--can be very misleading
if used to compare different types of aeration systems, since amortized
capital costs and other expenses also can be very significant.
The primary goal of the data analysis performed was to develop a general
design basis for predicting mass transfer and pressure loss characteris-
tics for various U-tube systems under wide ranges of operating conditions.
Since this report summarizes the results of two projects, performed in se-
quence, there was an evolutionary process with respect to the various steps
of experimental testing, data analysis, design, etc. Data from the pilot-
scale U-tube tests were used to calculate mass transfer coefficients and
to develop an initial design program. This computer program was used to
establish design conditions for the full-scale U-tube systems constructed.
The data from tests with these full-scale systems were then used, together
with the pilot-scale data, to improve the pressure drop and mass transfer
correlations. The new correlations were incorporated into an improved
data reduction program to calculate mass transfer coefficients. Then, the
mass transfer coefficients were calculated as a function of pertinent pa-
rameters which would be known in a prospective design situation. Finally,
the best available components drawn from this series of developments were
combined into an improved U-tube design computer program, which is described
in Section VIII of this report. The remainder of this section describes the
data analysis and correlations which were developed for use in design.
PRESSURE LOSS CORRELATIONS
Discussed below are the relationships developed to predict pressure loss
characteristics in venturi aspirators and in the two vertical sections
59
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(down-leg and up-legj of a U-tube system. Use was made of available theory
and data from the literature, where possible, in addition to the experimen-
tal results of this project.
Venturi Aspirator Pressure Loss
Equations were developed to predict the pressure loss across a venturi as-
pirator. These were based on the one- and two-phase data generated during
this project, plus applicable data and information found in the literature.
Characterization of the pressure loss across a venturi with single-phase
liquid flow is straightforward and the loss can be correlated easily as a
function of the water velocity and the throat-to-inlet-diameter ratio for
a given type of venturi contour. However, when air is injected into a
flowing water stream at the throat of a venturi, the interactions of the
air and water create a complicated flow pattern that is intractable to
analysis except on an overall basis.
A complete theoretical treatment of the pressure losses in a venturi as-
pirator would have to consider all sources of energy losses, including:
1. Boundary layer (friction) losses
2. Gas-liquid interfacial friction losses
3. Losses due to momentum exchange in the mixing region
4. Losses due to compressing the gas from the inlet throat pressure
to the exit pressure
The gas-liquid interfacial friction loss cannot be evaluated theoretically.
This loss would be a function of bubble size and shape distribution, velo-
cities of liquid and air bubbles, and the physical properties of both air
and water. The bubble size would be affected by the geometry and size of
the injection manifold plus the flowrates of air and water. An estimate
could be made of the loss due to momentum exchange; however, it would be
necessary to make gross assumptions concerning the shape of the interface
between the water and the air-water mixture downstream of the air inlet.
The pressure loss due to the compression of the gas can be estimated from
the ideal gas law assuming isothermal compression. This loss can be sig-
nificant when the pressure ratio of the aspirator is high due to a large
contraction area ratio; however, it would normally be less than 5 to 10
percent of the total pressure drop across an aspirator. Part of the com-
pression loss is recovered later in the system as the pressure decreases.
The initial efforts in developing an equation to predict venturi aspira-
tor pressure loss involved an approximate theoretical analysis. Compari-
son of these initial theoretical predictions with the pilot-scale data
showed considerable discrepancies in some regions. Since it was beyond
60
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the scope of the project to develop the theoretical analysis further, it
was decided to modify it and develop a semi-empirical correlation. Two
correlations were developed: one for the pilot-scale data (which repre-
sents a conventional conical entrance and diffuser venturi contour), and
one for the full-scale data (which are for a shortened, more complex cur-
vature type of venturi contour) . Combining the data for the two differ-
ent types of aspirators would have led to unsatisfactory behavior of the
correlation.
One unexpected, and disappointing, observation was apparent from the field
data for the full-scale aspirators. These venturies were originally se-
lected because their weight, length, and cost were much lower than for con-
ventional conical venturies in the large sizes involved (12- and 8-inch
pipe), and also the manufacturer's information specified that the one-
phase pressure losses were even lower than those for a conventional ven-
turi (about 10 percent of the entrance to throat pressure difference for
the contraction ratios used in Jefferson Parish) . However, the observed
pressure losses with water alone flowing averaged about 39 and 26 percent
of the entrance-to-throat differential for the venturies at Jefferson
Parisb locations 5 and 7, respectively. These are much higher than both
the manufacturer's specifications and the observed losses in the pilot-
scale conventional venturi (for which the corresponding average loss was
about 17 percent). The reasons for the high single-phase losses of the
aspirators used in Jefferson Parish are not known.
Pilot-Scale Aspirator. The aspirator pressure loss data obtained for the
pilot-scale aspirator (2.07-inch pipe ID, area ratio of 8) are shown in
Fig. 26. The single-phase pressure drops varied between 16 and 20 per-
cent of the total throat velocity head, with an average of 17.6 percent.
This agrees well with the predicted single-phase head loss for typical
Herschel venturies (10 to 20 percent of the pressure difference between
the inlet and throat) and indicates normal conditions during the runs.
The experimental data were analyzed using a least squares computer pro-
gram, and a semi-empirical correlation was developed:
Ap = 0.00191 (y)0'901 (uth)3'122 + 0.00246(uth)2 (1)
The pressure drop, Ap, is expressed in feet of water, u^h is the super-
ficial water throat velocity, in ft/sec, and y is the air-water volume
ratio at 68°F and 13.8 psia. The correlation predicts that the pressure
drop is approximately linear with respect to y. This is also apparent
from the trends of the experimental pressure loss data in Fig. 26. Also
shown in Fig. 26 are parametric curves generated from the correlation
equation at throat velocities of 11.9, 15.3, 19.1, 23.0, and 27.6 ft/sec.
A search of the literature uncovered only two other sets of data on ven-
turi aspirators. Jackson's data (Ref. 17 and 18) are for two venturi
61
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O u
oe
o
o
oe
o
Q.
O
oe
o
a:
ae
a.
ROCKETDYNE EXP. DATA:
V UTH = 11.9 FT/SEC
O UTH = 15.3 FT/SEC
A UTU = 19-1 FT/SEC
I n
D UTU = 23.0 FT/SEC
I n
'TH
27.6 FT/SEC
(LARGE VENTURI)
JACKSON EXP- DATA
- 23.0
'BAUER DATA^(SMALL VENTURI)
/UTH- 2I';
0.0k 0.08 0.12 0.16
INITIAL AIR/WATER VOLUME RATIO
AT 68°F, 13.8 PSIA
0.20
Figure 26. Two-Phase Pressure Drop Across Pilot-Scale
Venturi Aspirators
62
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sizes and with air and water. Bauer's data (Ref. 19) are for carbon diox-
ide and water, but should still be comparable, assuming that no large
amount of carbon dioxide was dissolved within the actual venturi (since
the venturi was rather small, this is probably not a bad assumption).
These additional data also are plotted in Fig. 26. The data could not be
plotted directly since neither the throat velocity nor the air-to-water
ratio were held constant. The data were first plotted as a function of
throat velocity, since the gas-to-water ratios were nearly constant. A
slight arbitrary adjustment of the resulting curves to account for the
small changes in y gave curves from which pressure loss could be read as
a function of throat velocity for constant y. Values were read from this
intermediate curve and plotted in Fig. 26 for comparison with the experi-
mental data obtained during this project.
The Bauer data show good agreement with the curves generated from Eq. 1
for both throat velocities tested (21.4 and 32.0 ft/sec). The Jackson
data show excellent agreement at uth = 15.3 ft/sec, but the other six
Jackson data points show pressure drops considerably lower than those
computed from Eq. 1 at-the higher throat velocities. The reason for these
differences is not known, but may be due to differences in geometry and
details of the air injection ports.
Full-Scale Venturi Aspirator, bnly the data for the venturi aspirator at
Jefferson Parish location 5 (12.00-inch pipe ID, 3.52 area ratio) were
used in developing the correlation since there were only a small number
of valid data points for the aspirator at location 7. The single-phase
pressure drops for the location 5 aspirator were all high relative to the
manufacturer's specifications, indicating either errors in measurement
or some unusual condition in the flow system that would account for the
low head recovery. As discussed previously, a different form than Eq. 1
was found to be best for these data. The dependence on y was assumed to
be linear and the final equation contains a quadratic function of u^ as
the y coefficient:
Ap - (48.7538-7.8410uth+0.3634uth2)yK).007432uth2 (2)
With no air flow (y = 0), the high value of the uth coefficient indicates
the poor single-phase pressure recovery, as was shown by preliminary com-
putations from the individual data points with no air flow.
The experimental data are shown approximately in Fig. 27, together with
the pressure losses computed from Eq. 2 at three throat velocities. The
experimental velocities were not all exactly equal to the three major
values shown on the graph. The points labelled 15.3 ft/sec actually had
throat velocities in the range" 15.3 to 15.7 ft/sec. The points labelled
19.3 ft/sec had velocities ranging from 18.2 to 20.1 ft/sec. The actual
velocity for each data point was used in developing the correlation.
63
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Recommendation for Design. The predictions of Eq. 2 are unnecessarily
pessimistic; it seems reasonable to expect that future development and
testing of large-scale aspirators can result in much better pressure
loss performance. Consequently, an equation was developed to represent
the pilot-scale data combined with those of Ref. 17 and 18:
AP = 0.004 (y0)°'6(u.
'th
2.6
0.0026(u h)'
(3)
where the pressure drop across the aspirator, Ap, is given in feet of
water; y0 is the air-water volume ratio at the aspirator entrance, ex-
pressed at 68°F and 1 atm; and u^ is the single-phase or superficial
water velocity at the throat, in ft/sec. Until more data are available
from large venturi aspirators, it is recommended that Eq. 3 be used to
predict pressure drops.
DATA FOR JEFFERSON
PARISH LOCATION 5
fj UT() - 8.0 FT/SEC
0.10
o.zo
0.30
INITIAL AIR/WATER VOLUME RATIO
AT 77° F. I ATM
0.40
Figure 27. Two-Phase Pressure Drop Across Large
Venturi Aspirators
64
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Down-Leg Pressure Loss
A literature search located only limited references pertinent to the phe-
nomenon of vertical downward two-phase flow. Unfortunately, all of the
correlations which were presented pertained to slug flow or higher air-
to-water ratio flow regimes. Extrapolation of empirical results across
two-phase flow regime boundaries is meaningless. Therefore, it was neces-
sary to develop a correlation for down-leg pressure drop with bubble flow
from the U-tube data. Both the large-scale field data and the pilot-scale
data were used.
Development of Correlation. For convenience in design usage, it was de-
cided to correlate the data in terms of the mean head loss per foot,
evaluated as follows. The starting point was the energy equation as it
applies to the down-leg portion of a U-tube:
i_ dz + dG + & = 0
where u is the velocity of the mixture in ft/sec, z is the height in the
pipe in feet, g is the mechanical energy loss converted into heat in
Ibf-ft/lbm, p is the absolute pressure in lbf/ft2, and p is the mixture
density in lbm/ft3. For this section of the pipe, the velocity can be
considered constant. This, plus identifying the mechanical energy loss
term with head loss (h^ through the relation dG = dhL/p, gives:
To integrate Eq. 4, the behavior of hL with respect to z must be known.
The simple assumption that the head loss per foot is constant is consis-
tent with the original purpose of defining a mean head loss per foot and,
as will be seen later in this section, is upheld by the experimental data.
With the postulate that dhj/dz is a constant, i.e., -m (m is positive),
Eq. 4 can be written as:
dp - mdz •*• -£-pdz = 0 (5)
' fL
5C
Introducing the air-to-water volume ratio, y, and noting that the density
of water, pw, is much larger than the density of air, pa, results in the
relationship:
pw
P = TT,
l+y 1+y 1-t-y
65
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Substituting Eq. 6 into 5 and converting the units of pressure to feet of
water by dividing through by gpw/gc, leads to the following equation:
dp - mdz + T—dz + 0 (7)
where p now has units of feet of water and m has units of feet of water
per foot.
Under the assumption that y is inversely proportional to pressure (i.e.,
yp is constant, which neglects for this purpose the effect of gas absorp-
tion on down-leg pressure), Eq. 7 can be integrated along the down-leg of
the U-tube to yield:
y p (l-m)p - my p
»2 - ?! - FT l" (1-nOPi - n,y|p'- * »--> LI C8)
where the subscripts 1 and 2 refer to the top and bottom of the down-leg,
respectively.
Measurements were made of p^, ?2, and z in the field as well as in the
pilot scale testing program. The product yipi is known from the relation
71P1 = XoPo wnere YO anc* Po are tne initial injected air-to-water volume
ratio and initial pressure, respectively. From this information, values
of m can be determined from Eq. 8.
In one-phase flow, the parameter m is usually correlated in terms of the
Fanning equation and friction factor. In that case, m would be a function
of the velocity; u, the pipe diameter, D, and the fluid viscosity and den-
sity (through a Reynolds number effect). In the two-phase flow case, then,
it might be expected that m would still be a function of these parameters
as well as the air-to-water volume ratio.
Values of m were determined from the Rocketdyne pilot-scale data as well
as the field data. The field data obtained from Jefferson Parish were not
useful in this correlation. In many cases, slug flow was present, leading
to enormous pressure drops. In several other cases, the data erroneously
indicated that there was more pressure gain in the down-leg than could be
accounted for by just the difference in elevation (i.e., m<0). It was de-
cided to rely on the data obtained from the Port Arthur testing, together
with the pilot-scale data, for use in developing the down-leg pressure loss
correlation. The Port Arthur data were quite usable, except for runs 837
through 849 in which it was apparent that slug flow was dominating the loss
mechanisms.
Table 4 summarizes the average values of m and 90-percent confidence in-
tervals for m which were developed for the various sets of experimental
data, assuming that the experimental data errors were all normally
distributed.
66
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TABLE 4. CONSTANTS FOR DOWN-LEG PRESSURE LOSS CORRELATION
Origin of Data
Rocketdyne Pilot-Scale U-Tube
Rocketdyne Pilot-Scale U-Tube
Rocketdyne Pilot-Scale U-Tube
Rocketdyne Pi lot- Scale U-Tube
Rocketdyne Pi lot- Scale U-Tube
Rocketdyne Pilot-Scale U-Tube
(all of above)
Port Arthur
All of Above
Distance Between
Pressure Taps z -,
feet
6.7
16.6
25.7
34.3
43.2
All Five Lengths
7.0
--
Head Loss per Foot (m)
With 90-Percent
Confidence Interval,
ft water/ ft
0.024 ±0.002
0.020 ±0.002
0.025 ±0.002
0.028 ±0.004
0.019 ±0.002
0.023 ±0.001
0.023 ±0.005
0.023 ±0.001
Equation 8 could also be applied to a small increment of length (|z|) in
the down-leg, to calculate the pressure at the bottom of the increment
(Pi+l) from tne pressure at the top of the length increment (p^). How-
ever, Eq. 8 is not very convenient for this purpose since it defines P2
only implicitly. When the values of m were being determined from measured
values of y^, p^, p2, and |z|, Eq. 8 was solved exactly using Mueller's
iteration scheme to find the root of this nonlinear equation. To avoid
this unnecessary complexity when applying Eq. 8 to a small increment of
length (for pi+1 close to pi), Eq. 8 can be linearized by expanding the
logarithmic terms in the series form:
In (1+6)
6-62/2 +63/3
For small 6, Jin (l+6)=:6. If this is done, an explicit relation can be
found for Pi+i, which is suitable for a small step in length (e.g., 0.1
ft):
(9)
Equation 9 can then be used to predict Pi+i from p^ and yi and for small
|z| (i.e., small step sizes). This was done in the data reduction and
design programs, using a value of m = 0.023.
67
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Discussion of Down-Leg Pressure Loss Data and Correlation. Part of the
experimental data are shown in Fig. 28, together with the corresponding
predicted curves predicted from Eq. 8, using the values of m which best
fit each set of data (m = 0.025 for the pilot-scale data with this
length, and m = 0.023 for the Port Arthur data, as given in Table 4).
There are a number of interesting observations which can be made from
this graph, as well as from examination of trends in the other data not
included in Fig. 28.
The data for the two U-tube systems with pipe diameters differing by al-
most an order of magnitude are essentially equivalent in terms of down-
leg pressure change. The small differences between the two sets of data,
and the two regression curves plotted in Fig.' 28, are almost entirely due
to a general difference in the absolute pressure range between the two
cases. The absolute pressures at the top of the down-leg were typically
about 48 ft water for the data at Port Arthur and about 32 ft water for
the pilot-scale data. When this effect is taken into account, it can then
be seen from Fig. 28 that, for y greater than ~0.025, there appears to be
little or no other discernible difference between the Rocketdyne pilot-
scale data and the .Port Arthur data. . This-indicates that changing the
diameter of the pipe has little effect, although this result runs con-
trary to what is experienced in one-phase flow. For y less than 0.025,
there are larger differences between the losses for the two sets of data
(Fig. 28), which is reasonable since the one-phase (i.e., y=0) losses are
known to be a strong function of pipe diameter.
Another conclusion which can be drawn from the data (see Fig. 28) is that
there"appears to be essentially no dependence on water velocity. This is
true even though the data cover about a threefold range of velocity.
Extensive analysis of all the data indicated not only the total pressure
change per foot was independent of the pipe diameter and the fluid velo-
city (for y > 0.025), but for y > 0.025 the actual head loss per foot, m,
was also independent of the air-to-water volume ratio, y. This result is
consistent with the earlier assumption that the head loss per foot is con-
stant, which was made to integrate Eq. 7.
For the purpose of this correlation, only those values of m for y > 0.025
were considered. This was large enough so that the two-phase losses were
the controlling factor. Furthermore, to avoid slug flow regimes, almost
all the m values analyzed had an associated y value of less than 0.15.
This is why the regression curves presented in Fig. 28 are limited to
this range on y. It should be noted that any possible lack of fit these
curves have for their respective data is, in large part, due to the fact
that all the pilot-scale and Port Arthur data were used to obtain the
correlation. For clarity, only part of these data are shown in Fig. 28.
68
-------
1.00
Ul
ce
EO.N. 8 FOR
PORT ARTHUR
CONDITIONS
EQN. 8 FOR
ROCKETDYNE
CONDITIONS
0 0.04 0.08 0.12 0.16 0.20
INITIAL AIR/WATER VOLUME RATIO AT 1 ATM
Figure 28. Experimental Down-Leg Pressure Change for
Rocketdyne Pilot-Scale Data and Port
Arthur Data
69
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Up-Leg Pressure Loss
Up-leg pressure gradient measurements were made only for the 37-foot pilot-
scale U-tube. The average pressure differential per foot, F, is presented
in Fig. 29 as a function of air-to-water ratio at standard conditions. It
should be noted that F also includes the static pressure change, for reasons
which will be apparent below.
The data scatter is great enough that direct correlation of the data did
not appear fruitful in predicting the up-leg pressure gradient. Therefore,
the Hershey correlation for the prediction of pressure gradients in air-
lift pumps was used (Ref. 20). It was judged that the correlation would
be applicable to the up-leg of the U-tube, since similar two-phase flow
conditions were involved. The correlation is (see the Glossary for defi-
nitions of symbols):
p + 2 f* u 2 p /g D
at--- pV^
, w m m
1 + y + T—
gc dp
dum
dp
f* =
Po =
4Poua
TT D2 p2
0.048 (Re)
Du p
m w
-0.13
-25 -05 °-83
y = 3.5 (QsD Z'V U'5) (11)
Qa = Qs - Y Qw (12)
The term dp/dL is the pressure loss or recovery per foot at local condi-
tions, including the static head. Under U-tube flow conditions, the de-
nominator can be simplified to 1 + y since the derivative term is small.
The solution for dp/dL requires solving Eq. 10 through 12 simultaneously.
Predictions of up-leg pressure change were made using the Hershey corre-
lation to evaluate F at various depths in the column, and then integrat-
ing F to yield the total pressure differential across the up-leg. The
two curves shown in Fig. 29 were generated by dividing these integrated
results for total pressure change by the up-leg length. It is apparent
that the 2 and 3 ft/sec water velocity curves bracket the bulk of the
data. Many of the points below the band of the two curves appear to be
erroneous; some are for water velocities below 2 ft/sec.
70
-------
1.04
SUPERFICIAL
WATER VELOCITY
FT/SEC
V
HERSHEY CORRELATION
3 FT/SEC WATER VELOCITY
- HERSHEY CORRELATION
2 FT/SEC WATER VELOCITY
I I I
'0 Q.Ok 0.08 0.12
INITIAL AIR/WATER VOLUME RATIO AT I ATM, 68°F
0.16
Figure 29. Experimental Up-Leg Pressure Change
Data and Hershey Correlation
71
-------
As a further check on the utility of the Hershey correlations, a compari-
son was made of the predictions with Adams' data for 4-inch diameter pipe
(Ref. 21). Adams reports only the two-phase pressure loss effects. The
single-phase loss for 4-inch steel pipe at 3.7 fps was estimated to be
0.012 ft water/ft and was added to his two-phase recovery data. This cor-
rection enabled a common basis of comparison between the data and the Her-
shey correlation. The integrated form of the equation was used to develop
the curves shown in Fig. 30. Adams reports linear pressure recovery with
respect to the air-to-water ratio. The Hershey Equation predicts devia-
tion from linearity. For the 30- and 40-foot lengths, the curves agree
up to about y = 0.10. For the 10- and 20-foot lengths, the two sets of
curves begin to diverge at lower values of y.
In summary, the Hershey correlation predictions agree quite well with, but
are slightly more conservative (i.e., predicted head loss is slightly
higher) than, the experimental data for up-leg head loss obtained during
this project. On the other hand, the Hershey correlation predictions be-
gin to be less conservative than Adams' experimental data for air-to-water
ratios above approximately 0.1. It was concluded that the Hershey corre-
lation could and should be used for subsequent estimates of up-leg head
loss.
ASPIRATOR MASS TRANSFER
Mass transfer coefficients were evaluated for the pilot-scale venturi as-
pirator from the experimental data obtained during this project. Corres-
ponding data for the large aspirators in the field tests were not obtained
because of the difficulty of obtaining water samples immediately downstream
of the aspirators. Coefficients were defined by the basic transport
equation:
§ = KLa CCs - C> C13)
Where C is the local concentration of dissolved oxygen, t is time, "a" is
the air-to-water interfacial area per unit volume of two-phase fluid, Cs
is the local saturation value for dissolved oxygen concentration, and KL
is the liquid-phase mass transfer coefficient. Integration of the above
equation, assuming constant Cs, gives
where the subscripts 4 and 5 refer to the venturi throat and diffuser
exit, respectively. The liquid residence time in the diffuser was taken
as V/Q, where V is the diffuser volume and Q is the fluid volumetric
72
-------
l.OZr
1.00
EXPERIMENTAL DATA (REF. 21)
FOR DEPTH SHOWN
40 FEET
30 FEET
20 FEET
10 FEET
'0.94
LLJ
O.
UJ
O
'0.92
CO
to
UJ
DC
0.
<0.90
O
0.88
HERSHEY CORRELATION .
PREDICTIONS FOR DEPTH
SHOWN
10 FEET
20 FEET
30 FEET
40 FEET
0.04 0.08 0.12 0.16
AIR/WATER RATIO AT 1 ATM, 68°F
0.20
0.24
Figure 20. Adams' Experimental Up-Leg Pressure Change
Data and Hershey Correlation
-------
flow rate. C^ and C^ were measured venturi inlet and exit D.O. levels
(Runs 139-219). With a specific assumption about how to evaluate a "mean"
value of Cs (at some "mean" diffuser pressure), the overall mass transfer
coefficient, I^a, was evaluated from the expression
No attempt was made to evaluate KL alone since the effective mean value
of "a" was not determinable. It was also not possible to separate the
effects of oxygen transfer during bubble formation from transfer in the
remainder of the aspirator diffuser.
Jackson concluded that the majority of the mass transfer occurred in his
venturi aspirators after considerable pressure drop had been recovered
(Ref . 17) . Accordingly, Cs was evaluated at a pressure corresponding to
3/4 of the distance from the throat to the diffuser exit. It was shown
that evaluating Cs half-way down the diffuser or at the diffuser exit
shifted the calculated coefficients by less than ±6 percent. The dis-
solved oxygen saturation data of Montgomery (Ref. 22) were used, together
with Henry's law to evaluate Cs at various temperatures and pressures.
K^a was also corrected to 20° C by the expression:
(16,
where T is the experimental water temperature in degrees Centigrade.
The calculated coefficients are shown in Fig. 31 as a function of super-
ficial water velocity, uw, and air-to-water ratio, y. It is apparent
that below y = 0.04 the scatter is severe, whereas above y = 0.04 the
trend of B^a as a function of flow rate becomes readily discernible. The
severe scatter below 0.04 is due to high percentage errors in both the
air flow rate and the dissolved oxygen measurements at low air-to-water
ratios. The resulting dependence of KLa upon yl (initial air-to-water
ratio expressed at 1 atm and 68°F) and uw (superficial water velocity
in pipe) or on yl and Q (water flow rate) can be represented within about
±3 percent by the equations:
2 K'-t
(KLa)2Q = 3.84 yl (p"
(KLa)2Q = 3090 y°0 u^'85 (17)
where KLa is in hr , Q is in gpm, and u is in ft/sec.
74
-------
CO
VO
o
o
CM
SUPERFICIAL
WATER VELOCITY,
FT/SEC
O 1.9
A
D 2,9
"0 0.02 0.04 0.06 0.08 0.
INITIAL AIR/WATER VOLUME RATIO AT 1 ATM, 68°F
Figure 31. Experimental Mass Transfer Coefficients
for Venturi Aspirator
75
-------
Although Eq. 17 for venturi mass transfer coefficients was adequate for
data reduction, a more general description was required for application
to a design program. Specifically, an equation was desired which in-
cluded the effects of throat velocity and throat diameter. The general-
ized equation was developed on an empirical basis, as described in the
following paragraphs.
The work of Jackson and Collins (Ref. 17) was the only source of applica-
ble experimental data which was found. This study compared the oxygen
transfer and energy loss characteristics of two sizes of venturi aspira-
tors. A comparison of the two units, with the range of variables inves-
tigated for each, is given below:
Venturi
\
Large
Small
Entrance Throat
Diameter Diameter
(inch) (inch)
3.75
0.75
1.25
0.25
Throat
Velocities
(ft/sec)
23, 31, 36, 45
21, 30, 37, 45
Air-to-Water
Volume Ratios
0.163-0.184
0.141-0.188
Conveniently, the contraction ratios for Jackson's units and aspirator
used in the 2-inch U-tube in this project were essentially the same, 9
and 8 respectively. Unfortunately, Jackson's aspirators were horizontally
mounted. The assumption that mass transfer is independent of orientation
had to be made. Jackson's minimum throat velocities were comparable to
the experimental throat velocity at 30 gpm (23.1 fps) for this investiga-
tion. Jackson operated only at approximately y = 0.18 with his lowest
throat velocities. At 30 gpm the maximum air-to-water ratio attained was
0.057 for this investigation. Extrapolations had to be made to find a
common basis of comparison with respect to air-to-water ratio.
A linear extrapolation of the 30 gpm curve (Fig. 31) to y = 0.18 gave KL&
equal to 11,400 hr~l. This value is plotted with Jackson's mass transfer
coefficients as a function of throat diameter in Fig. 32. Evaluation of
the slope shows that, at y = 0.18, I^a is approximately proportional to
throat diameter raised to the -1.35 power. A plot of I^a versus throat
velocity (with y approximately equal to 0.18) is shown in Fig. 33. The
slopes for Jackson's two horizontal aspirators are 1.40 and 1.30; the
slope for the vertical venturi tested in this project is 2.72. It should
be noted that Jackson's lowest throat velocity is roughly equal to the
largest for this investigation. The discrepancy in the slopes (i.e., a
different throat velocity functionality) is probably due to the different
orientation of the aspirators or the difference in throat velocity range.
Since Jackson's data are for horizontal aspirators (the most likely orien-
tation for large-scale facilities), these data were used as a basis for
determining the throat velocity dependence. Therefore, KLa was concluded
to be proportional to the 1.35 (mean of 1.30 and 1.40) power of throat
76
-------
200
100
80
60
kO
o 20
x
(D.
10
8
6
23 FT/SEC
I
0.1 0.2 0.4 0.6 1 2
THROAT DIAMETER, INCHES
Figure 32. Effect of Venturi Throat Diameter
on Mass Transfer Coefficient
200
100
80
60
2 20
x
10
10
0.25-INCH-
DIAMETER
THROAT
0.73-INCH-
DIAMETER
THROAT
1.25-INCH-
DIAMETER
THROAT
y = 0.18
I I I L
20
kO 60
100
SUPERFICIAL WATER VELOCITY
AT VENTURI THROAT, FT/SEC
Figure 33. Effect of Venturi Throat Water
Velocity on Mass Transfer
Coefficient
-------
velocity. Based on the linear air-to-water dependence shown in Fig. 31,
the general form for the venturi mass transfer coefficient is:
where I^a is the mass transfer coefficient at 68°F in hr , 114 is the
throat velocity in ft/sec, D^ is the throat diameter in inches, and y°
is the initial air-to-water volume fraction at 1 atm and 68°F.
Equations 15 and 18 can be combined, with some rearrangement, to give
= 1 -exp
• 0_ . o 0.35 C2.025 '
-29.4 yl u, E V
. ^.
(19)
*
in which the venturi entrance velocity, U3, is in ft/sec; the venturi dif-
fuser volume, V, is in ft^; and the venturi entrance pipe diameter, Dg,
is expressed in inches. For the more specific case of a venturi with a
conical diffuser (of half-angle b), Eq. 19 becomes:
C . c = 1 "exP
s L3
V0.35
-0.00222 y° / "3 \ ^2.025,
(u,Y
4)
(20)'
Equation 20 predicts that the amount of oxygen transfer in a venturi as-
pirator will increase as y°, uj, or E increase, and will decrease as b or
Dj increase. The values of b and E have a strong effect on the oxygen
transfer (primarily as they affect residence time in the diffuser). The
air-to-water fraction also has a strong effect on the transfer, as should
be expected. Neither the entrance velocity nor the entrance pipe diameter
is predicted to have a very pronounced effect on the oxygen transfer.
Representative parametric values for oxygen transfer in a venturi aspira-
tor (with b = 7.5 degrees), as predicted by Eq. 20, are given on the top
of the following page.
Potential users of Eq. 20 should keep in mind that it was developed from
a limited set of data (the experimental data obtained during this project
plus all applicable data which could be found in the literature). These
data were for three venturi aspirators, with entrance pipe nominal diameters
^Alternate convention used for expressing exponents, i.e., exp(a) = ec
78
-------
yo
0.05
0.05
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.15
0.15
0.20
0.20
0.25
0.25
U3
(ft/sec)
2
4
2
2
2
4
4
4
4
4
4
4
4
6
6
6
8
8
2
4
2
4
2
4
D3
(inch)
2
12
2
12
24
2
12
12
12
12
12
12
24
2
12
24
2
24
2
12
2
12
2
12
E
4
4
4
4
4
4
2
4
6
8
10
12
4
4
4
4
4
4
4
4
4
4
4
4
C5 - C3
cs - c3
0.0122
0.0083
0.0242
0.0130
0.0102
0.0307
0.0030
0.0165
0.040
0.071
0.111
0.158
0.0130
0.0353
0.0190
0.0150
0.0390
0.0165
0.0360
0.0247
0.048
0.033
0.059
0.041
of 3/4, 2, and 4 inches. The diffusers were conical in each case, with
full-cone angles of about 7 degrees. The nozzle contraction area ratios
were 8 and 9. Equation 20 was developed to permit design predictions,
since no other design basis was available, and it should give reasonable
estimates of venturi aspirator oxygen transfer for aspirators which are
geometrically similar to the three for which experimental data exist.
Equation 20 should also give reasonable predictions for substantially
larger aspirators than these three, since the effect of diameter appears
to be modest, as long as the aspirators have similar configurations.
However, for large scale applications the length and cost of a conical
diffuser with a small divergence angle would become excessive, and other
diffuser designs would probably be used: perhaps a cone with larger di-
vergence angle, or with a contoured divergence section (e.g., the aspira-
tors designed for the Jefferson Parish applications, as described in the
next major section). Alternately, in large scale applications, the as-
pirator might be a "trough," i.e., have venturi contours in only one
plane, with a rectangular flow cross section at any station. It would
be fortuitous if Eq. 20 gave accurate predictions for such geometrically
79
-------
different types of venturi aspirators, or for a wide range of contraction
area ratios differing from the 8 to 9 range represented by the experimental
data. Additional data are needed to permit development of a more general
relationship for predicting venturi oxygen transfer.
DATA REDUCTION PROGRAM
Mass transfer coefficients were calculated from the various sets of data
generated during these projects, in order to reduce the oxygen transfer
data to a common basis which could be used for design. It was necessary
to develop a computer program to perform these calculations. The original
version of the program was used to calculate coefficients for the pilot-
scale data. Subsequently, the program was modified and used to calculate
coefficients for the full-scale data obtained in Jefferson Parish and Port
Arthur. The computation scheme, assumptions, and relationships which were
used in the program are described in this section.
The major components of the computation scheme built into the computer
•program are shown in the flowsheet of Fig. 34. It can be seen that the
program estimates an initial value for the mass transfer coefficient, KL,
performs finite-difference calculations throughout the experimental U-tube
system, compares the calculated exit D.O. concentration with the experi-
mental concentration, and repeats the iteration until satisfactory agree-
ment is reached.
Solubility data for oxygen in water in 1-atmosphere air pressure (0.21-
atmosphere oxygen partial pressure) were taken from Ref. 22, and curve-
fitted over the temperature range 50° to 85°F with the equation
C = 187.6 T"°'714 - 0.16 (21)
with Cs in mg/1 and T in degrees F. The solubility data for nitrogen in
water at 1-atmosphere nitrogen pressure were taken from Ref. 23, and curve-
fitted over the temperature range 50° to 85°F with the equation
C' = 242.0 T~°'6 + 0.07 (22)
with the same units as for Eq. 21 (superscript prime refers to nitrogen,
while symbols without a superscript refer to oxygen). These data were
adjusted to other pressures as required using Henry's Law.
In experimental runs for which D.O. concentration was measured at the as-
pirator exit, these values were used by the program. Where these values
80
-------
READ INPUT AND CALCULATE
BACKGROUND PARAMETERS
CALCULATE OXYGEN TRANSFER AND
PRESSURE DROP THROUGH ASPIRATORS
ESTIMATE INITIAL VALUE OF KL
I
SET STEP-SIZE AND MAKE FINITE-DIFFERENCE
CALCULATIONS THROUGH DOWN-LEG OF U-TUBE
PERFORM CALCULATIONS THROUGH RETURN BEND
SET STEP-SIZE AND MAKE FINITE-DIFFERENCE
CALCULATIONS THROUGH UP-LEG OF U-TUBE
MAKE CALCULATIONS THROUGH EXIT HOSE
IS CALCULATED CEX|T
SUFFICIENTLY CLOSE
TO EXPERIMENTAL C
YES
GO THROUGH ITERATION
ROUTINE TO ESTIMATE
BETTER VALUE OF KL
EXIT ?
CALCULATE TRUE EXIT CONDITIONS
AND OTHER OUTPUT PARAMETERS
PRINT OUTPUT FOR THIS CASE
1
_/^LAST CASE FOR\
\THIS RUN? J
NO
Figure 34. Computation Flowsheet for Data Reduction Program
81
-------
Pt.n ^n an Atw.n
"
pt,n+l Pa,n+l
X
were not obtained experimentally, they were estimated using Eq. 19. Nitro-
gen transfer in the aspirator was calculated with a relationship analogous
to Eq. 19, with the assumption that KLa for nitrogen is 0.9 times the value
for oxygen, based on Ref. 24 and 25.
The calculations for a single distance step in the U-tube employed the fol-
lowing equations (i.e., given values at the end of step n, these equations
were used to calculate values at the end of step n+1). All symbols are
defined in the Glossary.
um,n = V1 + yn)
Ata,n = h/(um,n ' V
Atw,n = h/um,n
Pt,n+l = pt,n - h Fn
C — r -i- Y i cr - n At-
i ~ *-_ + I*T a_ i v.' ^J_ "*-.. „
n+1 n L n s n w,n
n — r i * if'a (r' - r' ~\ At
I, _ — \j ~ J\T cllu *-*J i-ll^
n+1 n L n1- s 'n w,n
n . = n - K.a (C - Q At /M
n+1 n L nv s 'n a,n
n' = n1 - KT'a (C1 - C') At /M'
n+1 n L nv s -'n a,n
Vl(pt,n+l ' Pv3
These equations apply for iteration steps in the down-leg, return bend,
up-leg, or exit section—with appropriate values for F, us, and X in each
section. The change in pressure per unit length in the down-leg (F^) was
82
-------
based on empirical relationships derived from the experimental data
(Eq. 9 was used in the final version of the program). The value of F in
the return bend was estimated from conventional fluid dynamics relation-
ships, considering the two-phase velocity. The Hershey correlation was
used to estimate values of F at each step in the up-leg, as discussed in
the previous section on Pressure Loss Correlations. The values of us
and X, obtained from the motion pictures of two-phase flow in the exper-
imental apparatus (as described in the Pilot-Scale Experimental Results
section), were uSjd = 0.2 ft/sec, us u = -0.2 ft/sec, and Xd = Xu = 470
The entering D.N. (dissolved nitrogen) concentration was assumed to be
saturated with respect to normal air at the ambient pressure. The values
of KL were estimated at 0.9 times KL in accounting for nitrogen transfer
in the system.
MASS TRANSFER COEFFICIENTS
The mass transfer coefficients calculated from the experimental data with
the data reduction computer program are presented in Appendices A and B
for the pilot-scale and full-scale data, respectively. Results from the
analysis of the pilot-scale data were used in design of the full-scale
field installations. This first analysis was presented in Ref. 4 and is
summarized here. Values of the mass transfer coefficient for the pilot-
scale data are presented in Fig. 35 through 39, plotted as a function of
initial air-to-water volume ratio. At the time of this analysis, three
specific conclusions were drawn from these results: (1) KL is essentially
independent of water velocity over the range 1.4 to 3,4 ft/sec (with re-
spect to the results of that investigation); (2) KL decreases slightly
with increasing air-to-water ratio, except that the negative slope be-
comes quite large for air-to-water ratios less than about 0.04; (3) KL
decreases slightly with increasing U-tube depth. Limitations of experi-
mental accuracy at small air-to-water ratios (yo less than about 0.03)
raised some question about the validity of the results for very small
values of yo. At low ratios, the air orifice manometer differential was
very small, leading to possibly large air flow rate errors. Also, for
low y , the change in D.O. across the U-tube was small, leading to com-
paratively larger errors in the difference.
These pilot-scale mass transfer coefficient data were curve-fitted to
form a generalized predictive equation for use in design. After consider-
ing the limitations on experimental accuracy and the fact that field in-
stallations normally would be designed for y0 levels in the range of 0.05
to 0.2, it was decided at that time to curve-fit only the data for yo
above 0.04. A single-parameter, least-squares analysis was first per-
formed on each set of data for a single U-tube depth, considering six
83
-------
20
10
9
8
7
6
UJ
I/)
O
00
vO
<
o
= 2
o
o
o
-< 0.9
H- 0.8
£ 0.7
z 0.6
0.5
0.3
D
SUPERFICIAL WATER
VELOCITY, FT/SEC
V I-**
O 1.9
A 2.4
D 2.9
O 3.4
KL = 0.00048 (y0)
-0.425
= 0.00042(yr°-55 EXP(-0.018 L)
0.0 0.04 0.08 0.12 0.16 0.20
INITIAL AIR/WATER RATIO AT 13.8 PSIA AND 68°F
Figure 35. Experimental Mass Transfer Coefficients for 9-Ft
U-Tube (2-inch pipe)
84
-------
vO
<
m->
O
X
O
O
oc
LU
10
9
8
7
6
D
A
I
0.9
0.8
0.7
0.6
0.5
0.4
0.3
SUPERFICIAL WAT£R
VELOCITY, FT/SEC
V
O
A
D
O
1.4
1.9
2.4
2.9
3.4
= 0.00042(y0)~0'390
I
I
I
I
I
0.04 0.08 0.12 0.16
INITIAL AIR/WATER RATIO AT 13.8 PSIA AND 68°F
0.20
Figure 36. Experimental Mass Transfer Coefficients for
19-Ft U-Tube (2-inch pipe)
85
-------
o
LLJ
to
O
oo
vO
<
»"»
o
X
10
9
8
7
6
5
o
o
UJ
u_
to
z
<
<
0.9
0.8
0.7
0.6
0.5
0.3
D
L O
SUPERFICIAL WATER
VELOCITY, FT/SEC
V 1.4
O 1.9
A 2.4
D 2.9
O 3.4
O
-0.55 EXP(-0.018 L)
O
A H
0.00047(y0)"°'269
j_
0 0.04 0.08 0.12 0.16 0.20
INITIAL AIR/WATER RATIO AT 13.8 PSIA AND 68°F
Figure 37. Experimental Mass Transfer Coefficient for
28-Ft U-Tube (2-inch pipe)
86
-------
o
UJ
in
°00
vO
<
XI
o
X
o
o
cc
LU
U.
1
]
0.8
0.6
0.4
0.3
i r
A
O
1 T
SUPERFICIAL WATER
VELOCITY, FT/SEC
V
O
A
8
1.4
1.9
2.4
2.9
3.4
0.00037(y0)"0'2t52
.KL=0.00042(y0)-°-55EXP(-°-0l8L)
I I
I
0.04 0.08 0.12 0.16
INITIAL AIR/WATER RATIO AT 13.8 PSIA AND 68°F
0.20
Figure 38. Experimental Mass Transfer Coefficients for
37-Ft U-Tube (2-inch pipe)
87
-------
o
LU
in
O
CO
<
•o
o
X
1-
LU
O
LU
O
z
<
in
in
30
20
10
8
1
0.8
0.6
0.1*
0.3
V
A
SUPERFICIAL WATER
VELOCITY, FT/SEC
V 1.4.
O 1.9
A2.4
D2.9
O3.4
0.00036(y0)r0-3U
O
= 0.00042(y0)-°-55
J L
0 0.04 0.08 0.12 0.16
INITIAL AIR/WATER RATIO AT 13.8 PSIA AND 68°F
0.20
Figure 39. Experimental Mass Transfer Coefficients
for 45-Ft U-Tube (2-inch pipe)
88
-------
different forms of a single-parameter equation. The best single-equation
form for all five sets of pilot-scale data was
KL * Al ^
where A^ and B^ are constants. The best-fit equation in each case is
plotted and written on the appropriate graph (Fig. 35 through 39).
The five individual equations of this form were then modified to yield a
general expression for KL as a function of yo and U-tube depth. The
average value of AJ for the five depths (0.00042) was assumed constant.
A new exponent (B2) was defined so that the value of KL at yo = 0.10 was
the same for each depth as the value of KL predicted with the least
squares equation derived for that specific depth, i.e.,
B2
K. = 0.00042 (0.10)
Lt
The resulting values for B_ as a function of depth are as follows:
Depth, feet ^2_
9 -0.487
19 -0.391
28 -0.316
37 -0.398
45 -0.250
It is apparent that B2 becomes more positive with depth except for the
37-ft U-tube. A semilogarithmic representation of B2 versus depth gave
an excellent linear relationship except for the 37-foot depth. The con-
clusion was that B2 could be represented as B2 = A2exp(A3L), where L is
depth in feet. The constants A2 and A3 were evaluated as -0.55 and
-0.018, respectively, giving the final form of the equation (for yo
greater than 0.04) as
KL - 0.00042 (yo)-' -. (24)
where KL is the mass transfer coefficient at 68 °F, in ft/sec, yo is the
air-to-water ratio at 13.8 psia and 68° F, and L is the U-tube depth in
feet. This equation is also plotted in Fig. 35 through 39. It can be
seen that for all depths except 37 feet, Eq. 24 predicts results almost
identical to those from the individual equations for each depth. The
agreement with the least-squares equation at other depths strongly sug-
gests that the 37-foot data have some bias.
89
-------
Analysis of the data from the full-scale installations proceeded along
slightly different lines. Whereas the pilot-scale data were correlated
in terms of initial air-to-water volume ratio and U-tube depth, it was
decided subsequently that it would be preferable not to have the U-tube
depth as one of the primary independent variables. Rather- it was de-
cided to correlate the mass transfer coefficients from the full-scale
data as a function of an "average" air-to-water volume ratio (y) in the
U-tube rather than an initial one at specified standard conditions (yo) .
It was then expected that most of the dependence on length would be re-
moved. The data obtained at both Port Arthur and Jefferson Parish, Sta-
tions 5 and 7 (tabulated in Appendix B) , are presented in Fig. 40. Here,
y is defined as a residence time weighted average y:
where u is the local superficial water velocity, dl is a differential
path length in the U-tube, and y is the local air-to-water- volume ratio.
In practice, an approximate form of Eq. 25, which could be evaluated for
an as-yet-unsolved design case, was used to calculate values of y.
It can be seen that there is much more scatter in the field data than for
the pilot-scale results. This is not unexpected in view of the many un-
controllable variations in a sewer line, and the fact that these data
were taken in two different states and over a period of several days at
each field site. It is also interesting to note that there are no sig-
nificant differences between the data from Jefferson Parish and those
from Port Arthur.
To determine a correlation representing the data presented in Fig. 40,
several other independent variables were defined. These are p, the resi-
dence time weighted average pressure; u, the residence time weighted
average superficial water velocity; and Co, a variable equal to the D.O.
concentration minus the immediate oxygen demand of the incoming stream.
It is recognized that there are probably many more significant indepen-
dent variables than the ones just listed; however, these were judged to
be the most important ones for use in developing a correlation to be
used for design purposes.
Many models involving various combinations of these independent variables
were tested using a multiple stepwise linear regression program. It was
determined that the most significant variable other than y was the average
velocity, u. The other two variables, p, and Co, as well as various com-
binations of these, did not explain the variability of the data in Fig. 40
as well as u.
Upon examination, the dependence of KL upon velocity appears to contra-
dict one of the conclusions that was drawn from the pilot-scale data.
However, further study indicates that the velocity effects 'noted in the
90
-------
20
-3-
o
10
Ul
o
CC
LU
c/>
i/>
O
D o °
o oo
. D
O
0 oa o
a o
Q> o
D° oc% D
o o
D°
D D
D
DATA ORIGIN
O JEFFERSON
PARISH
PORT ARTHUR
D
J 1 1 1 1 1 1 L-
• I 1 1-
0.04 0.08 0.12 0.16 0.20 0.24 0.28
AVERAGE AIR/WATER VOLUME RATIO
Figure 40. Experimental Mass Transfer Coefficients for Field
Installations
91
-------
two sets of data are not inconsistent. First, it is reasonable to expect
that if there were a velocity dependence it would be related to the effect
of velocity on the turbulence of the inflow stream. Figure 41 shows the
experimental transfer coefficient after an estimate of the effect of y has
been removed, as a function of the average velocity. This was constructed
by fitting the data in Fig. 40 with the model
Sin K. = b y + b1 (26)
L 0 1
where bo and bj were determined using a least-squares criterion. The ordi-
nate of Fig. 41 is just (An KL - bo y). It can be seen that these residuals
tend to increase as a function of u up to about u = 2.2 ft/sec. After that,
they remain relatively constant. This indicates that for u > 2.2 ft/sec,
the flow is sufficiently turbulent so that no further increase in mass
transfer coefficient occurs.
This threshold phenomenon is probably why there appeared to be little velo-
city effect in the data from the pilot-scale U-tube. The vast majority of
those data had velocities greater than 2.4 ft/sec. Taking the threshold
velocity as approximately 2.2 ft/sec appeared to be the best choice for
correlating the data from the full-scale installations. It was found that
the general form, KL = bo exp(b^y), was the simplest and yet most efficient
model for fitting the data in Fig. 40. Letting bo and b^ be functions of
u up to u = 2.2 ft/sec led to the following correlation
KL = 6.16xlO"4 exp [0.0963 u + (-10.2908+4.3516u)y] (26a)
for u < 2.2 ft/sec
K. = 7.62xlO"4 exp [-0.7173y] (26b)
L
for u > 2.2 ft/sec
Equation 26a reduces to Eq. 26b for u = 2.2 ft/sec. Plots of this regres-
sion and the data are given in Fig. 42 and 43. These data and regression
curves were separated into two graphs for clarity.
Comparing the field data for large-scale U-tube systems in aerating un-
treated sewage with the earlier data from the pilot scale U-tube system
aerating tap water, it was found that KL values for the field data were
almost always lower than the corresponding values derived from the tests
with tap water, as expected. There was a somewhat larger dependence of
Kl on Yo for tne pilot-scale data. Comparing the two sets of data at
conditions in the range of most practical interest, i.e., approximately
30- to 40- foot U-tube depths and yo in the range of 0.05 to 0.2, gave
92
-------
1.0
•;•
0.8
0.6
0.4
0.2
=>
10
-0.2
-0.4
-0.6
A
A
A
A
A
A
A &
i /\ ' 1 L.
-*s
A
TT> L
A A
A
-0.8
-l.CL
1.0 2.0 3.0
AVERAGE SUPERFICIAL WATER VELOCITY- FT/SEC
Figure 41. Experimental Mass Transfer Coefficient Residual
After Main Effect of Average Air/Water Volume
Fraction is Removed
93
-------
20
o
UJ
in
-a-
o
-10
z
LU
5
UJ
o
o
to
I 3
OC
D
O D
O
SUPERFICIAL WATER
VELOCITY, FT/SEC
O 0.8
D 1.1
0 1.5
O
0.05 0.10 0.15 0.20 0.25
AVERAGE AIR/WATER VOLUME RATIO
0.30
Figure 42. Experimental Mass Transfer Coefficients for Field
Installations for Average Water Velocity Less Than
1.8 ft/sec
94
-------
20
UJ
to
MO
o
x
o
o
u_
CO
<
o:
SUPERFICIAL WATER
VELOCITY, FT/SEC
A 2.0
V 2.5
O 3.0
0.05 0.10 0.15 0.20
AVERAGE AIR/WATER VOLUME RATIO
0.25
0.30
Figure 43. Experimental Mass Transfer Coefficients for Field
Installations for Average Superficial Water Velo-
city Greater Than 1.8 ft/sec
-------
values of alpha (the conventional ratio of mass transfer in waste water
to that in deaerated tap water at standard conditions) from about 0.7 to
0.9. An alpha value of 0.80 was selected to represent the field data, in
order to reduce the regression Eq. 26 to standard conditions (i.e., to
predict values of K at 20° C for an alpha value of 1.0):
Lt
KL = 7.70xlO"4 exp [0.0963 u + (-10.2908+4.3516 u)y] (27a)
for u < 2.2 ft/sec
KL = 9.52xlO"4 exp [-0.7173 y] (27b)
for u > 2.2 ft/sec
96
-------
SECTION VIII
U-TUBE DESIGN
The basic goal in any U-tube design effort is to provide a system which
will effectively absorb as much oxygen as possible within the specfic
requirements and constraints of the application. In some cases, the
goal will be roughly to dissolve as much oxygen as possible, within
some constraint on head loss or costs. In other cases, the goal will
be more nearly to dissolve some required amount of oxygen with minimum
head loss. There are endless variations and particular constraints
which may be encountered. The purpose of this section is to summarize
design bases and techniques which, together with good engineering judg-
ment, can be used to design a U-tube aeration system. Examples are
given in the final subsection of preliminary design and economic com-
parisons between U-tube systems and some other aeration systems.
DESIGN VARIABLES AND GENERAL CONSIDERATIONS
A U-tube aeration system consists of two basic elements: (1) a device
for introducing or entraining air into a flowing water stream, followed
by (2) a vertical U-shaped flow path to provide residence time in a
zone of above-atmospheric pressure during which oxygen absorption from
the entrained air takes place under favorable driving force conditions.
(For simplicity, reference will be made only to use of air, although
the phrase "air or oxygen" could be substituted in almost all cases.)
The air entrainment component ordinarily will be either some type of
aspirator or some type of diffuser to introduce compressed air. The
U-shaped flow path can take various forms, e.g., a pair of vertical
pipes connected by a 180-degree return bend at the bottom, a pair of
concentric pipes with flow downward through one passage and upward
through the other, or a rectangular "trough" with a vertical partition
to force water flow down one side of the partition, under the parti-
tion, and up the other side.
There are tradeoffs to consider in choosing the type of air entrainment
element. A diffuser with compressed-air source will be more flexible
(both in design conditions and in operation), will permit use of higher
air-to-water ratios, and will generally have lower head losses than a
corresponding aspirated-air system. On the other hand, use of an
aspirator as the air entrainment element has the advantages of requiring
no moving parts, essentially zero maintenance, and can make use of nat-
ural head in situations in which the elevation profile of the flowing
stream provides this.
Major considerations in the conceptual design of the vertical U-shaped
flow path include two competing requirements: (1) oxygen transfer is
generally enhanced by having low velocities, hence long residence times,
but (2) it is necessary to keep the velocities high enough (particularly
in the upward path) to prevent sedimentation and plugging in the system.
97
-------
It is also important to keep the velocity in the downward path high
enough to avoid the slug flow regime. If the application is aeration
of waste water in a sewer; particular care must be taken to avoid any
chances for plugging. In such applications, it probably is best to
use a pair of vertical pipes connected by a 180-degree return bend at
the bottom, to provide a smooth flow path throughout the system. It
is also important in this type of application to size the upward pipe
to maintain velocities high enough to prevent settling of solids--
generally in the range of 3 to 5 ft/sec minimum. If the application
is aeration of a natural water stream or treated effluent, it should
be possible in most cases to use either a pair of concentric pipes
(for low to moderate capacities) or a rectangular trough with center
partition (for large capacities). Either of the latter configurations
is less expensive than the type of configuration recommended for a
sewer application.
Other variables which can be controlled, although not always indepen-
dently, include: pipe sizes (or, more generally, flow cross-sectional
areas) in various portions of the system, velocities (which are deter-
mined by the flow areas), air-to-water ratio, U-tube depth, and some
other aspects of the system geometry. There are generally many com-
binations of design configurations and parameters which will produce
a given amount of oxygen transfer. It is the task of the designer to
determine those conditions which best meet his requirements, including
consideration of initial and operating costs.
U-TUBE DESIGN PROGRAM
A computer program was developed to perform parametric design computa-
tions for U-tube aeration systems. It is almost necessary to use a
computer program in making accurate design calculations for such sys-
tems because of the need to make finite-difference calculations with
reasonably small step-sizes. Although parametric design curves or
regression equations representing them could easily be presented for
particular cases, this would not be of much general use since the spe-
cific requirements for different applications can cause substantial
changes in the parametric performance characteristics. The design
problem becomes particularly difficult in cases where the exit pressure
is specified but the entrance pressure is unknown; it then becomes
necessary to iterate the series of finite-difference calculations in
order to converge on a solution which also matches the specified exit
pressure. Because of the complexity of the computations, the design
bases and system design criteria which were developed during these
projects were incorporated into a computer program.
Actually, two versions of the design program were developed as the two
projects evolved. The initial design program, which was developed
from the pilot-scale data, was used in design of the full-scale U-tube
systems for Jefferson Parish and Port Arthur; this already has been
98
-------
discussed in the section on Full-Scale Evaluation Tests. Subsequently,
the program was improved, making use of the full-scale field data, into
the form described in this section.
Configurations and Problem Type Options
Three major configurations or problem types can be analyzed with the
program: (1) aspirated-air U-tubes installed in a force main (i.e.,
full-flowing pipe under pump head), as illustrated by the schematic
sketch in Fig. 44; (2) compressed-air U-tubes installed in a force
main, as illustrated by the sketch of Fig. 45; and (3) eductors, which
are standard, commercially available units (sometimes called air-lift
pumps), in which compressed air is injected at the bottom of a vertical
tube through which a liquid is flowing upward. Therefore, eductors
are essentially compressed-air U-tubes with the diffuser located at
the bottom of the up-leg (station 9 in Fig. 45). It would be straight-
forward to modify the program to analyze other variations in U-tube
configurations. The symbols shown for various dimensions in Fig. 44
and 45 are those used by the program, some of which appear in the output.
Program Outline and Description
The major calculation steps of the design computer program are shown in
the flow-sheet of Fig. 46. It can be seen that the program repeats
most of the calculations interatively until the convergence criterion
for the particular case is satisfied. The usual procedure was to
iterate the entrance pressure (p..) until the calculated exit pressure
(p1?) matched the specified exit pressure within a given tolerance, for
specified values of entrance and exit pipe elevations plus other var-
iables . The convergence techniques had to be somewhat more complex
than those used for the data reduction program.
The usual input variables are (for the aspirated-air U-tube option):
• Geometric information about the venturi aspirator
• Radii of curvature of bends and elbows
• Slip velocities and values of X to characterize bubbles
• Throat pressure (or venturi contraction area ratio)
• Ambient pressure
• Water temperature
• Alpha
• Inlet D.O. concentration
• Water flowrate
• Initial air-to-water ratio
99
-------
o
o
GRADE
Figure 44. Schematic Diagram of Aspirated-Air U-Tube
-------
GRADE
!5
EXISTING
MANHOLE
20
DIFFUSER
RING
-1
10
XX
25
i!3
•g
•^FROM
FORCE
MAIN
10
12
'11
Figure 45. Schematic Diagram of Compressed-Air U-Tube
-------
READ INPUT AND CALCULATE
BACKGROUND PARAMETERS
COMPRESSED-AIR
U-1UBE
EDUCTOR
READ OTHER INPUT, MAKE
PRELIMINARY CALCULATIONS.
SET UP SIZES AND
INITIAL CONDITIONS
JASPIRATED-AIR U-TUBE
READ OTHER INPUT, MAKE
PRELIMINARY CALCULATIONS,
SET UP STEP-SIZES AND
INITIAL CONDITIONS
CALCULATE OXYGEN TRANSFER
AND PRESSURE DROP THROUGH
INJECTION REGION
READ OTHER INPUT, HAKE
PRELIMINARY CALCULATIONS,
SETUP STEP-SIZES AND
INITIAL CONDITIONS
CALCULATE OXYGEN TRANSFER
AND PRESSURE DROP
THROUGH ASPIRATOR
PERFORM FINITE-DIFFERENCE
CALCULATIONS THROUGH DOWN-
LEG OF U-TUBE
CALCULATE OXYGEN TRANSFER
AND PRESSURE DROP THROUGH
INJECTION REGION
MAKE CALCULATIONS
FOR RETURN BEND
D
PERFORM FINITE-DIFFERENCE
CALCULATIONS THROUGH UP-
LEG AND EXIT PIPE OF
SYSTEM
CALCULATE OUTPUT PARAMETERS
AND WRITE OUTPUT FOR THIS
CASE
Figure 46. Computation Flowsheet for Design Program
102
-------
• Pipe diameters (D , D , D )
• System dimensions (a10, an> a^, &1&, aig)
A complete listing of the program, detailed instructions for preparing
input data, and a sample data deck are given in Appendix C. Examples
of the program output are given in Appendix D. Typical examples of
parametric design trends are given later in this section.
Important Relationships and Assumptions
Most of the equations and relationships developed for the data reduc-
tion program were used as part of the design program. Equation set
23 is used for the basic numerical integration. Pressure losses are
calculated using basic fluid dynamics principles plus Eq. 3 (for the
aspirator), 9 (for the down-leg), and 10 through 12 (for the up-leg).
Equation 19 was used to estimate mass transfer in the aspirator. Ox-
ygen mass transfer coefficients were evaluated from Eq. 27; nitrogen
mass transfer coefficients were assumed to be 0.9 times the value for
oxygen at the same conditions. Equations 21 and 22 were used to re-
present the equilibrium gas solubility data.
U-TUBE PARAMETRIC DESIGN TRENDS
In designing a U-tube system, it is important to consider parametric
trade-offs between various design variables to determine those condi-
tions that best meet the requirements and constraints of a particular
application. There are generally a large number of combinations of
design parameters that will produce a given amount of oxygen transfer.
The following two subsections illustrate and discuss typical effects
of the major design variables on performance of compressed-air and
aspirated-air U-tubes.
Design Trends for Compressed Air U-tubes
Figures 47 through 51 summarize results from a large number of cal-
culations made with the U-tube design program. Each curve in these
figures represents a series of calculation cases. The examples in
this and the next subsection all have the following fixed conditions,
unless otherwise specified: water flow rate, Qw, is 5 mgd (3472 gpm);
incoming water has zero dissolved oxygen (D.O.), no sulfides or rapid
chemical oxygen demand, and an alpha value of 0.9; water and air tem-
peratures are 68°F; and the ambient pressure is 1 atmosphere.
Figure 47 shows the effects of pipe diameter, as represented by the
superficial water velocity. The superficial water velocity is defined
as the mean velocity with which the specified water flowrate (in this
case 3472 gpm) would flow if no air were present. As the water velocity
is increased (pipe diameter is decreased) the exit D.O. concentration
decreases and the pressure drop increases. Therefore, the operating
cost is minimized by making the pipe diameter as large as practical;
103
-------
12
11
10
9
8
7
6
o
•z.
o
o
Q
Q - 3^72 GPM
40 FT CASTING
INITIAL AIR TO WATER
VOLUME RATIO AT 68°F
AND 1 ATMOSPHERE
-PIPE ID = 23.25" 17.13" 15.25" 13.25" 12.061
1
012345 6 789 10
SUPERFICIAL WATER VELOCITY, FT/SEC
Figure 47. Effect of Pipe Size on Performance of
Compressed-Air U-Tubes
LU
LU
o
104
-------
= 3^72 GPM
PIPE SIZES: 23.75 INCHES ID IN AND DOWN,
29.0 INCHES ID UP
z
o
O
O
o
o
—I 1
CASING DEPTH, FEET = 100
20
60 80 100
OXYGEN SUPPLIED, MG/L
120
Figure 48. Typical Compressed-Air U-Tube Parametric Designs
105
-------
CASING DEPTH, FEET
23.25 INCHES
ID IN AND
DOWN
29.0 INCHES
ID IIP
23^5678
OVERALL A H, FEET WATER
Figure 49. Typical Compressed-Air U-Tube Design Trade-Offs
106
-------
10
9
8
LJ
•z.
O
WATER ONLY (Y - 0)
o
0.1
--2
-3
3
2
QC
Ul
1 §
- LU
0 LLl
U-
-1
CC
LJ
Y = INITIAL AIR TO WATER VOLUME RATIO
AT 68*F AND 1 ATMOSPHERE
Q = 3^72 GPM
PIPE SIZES: 23.25 INCHES ID IN AND DOWN,
23.25 INCHES ID UP
kO FEET CASING
_L
_L
J
10 20 30
DIFFUSER DEPTH, FEET
Figure 50. Effect of Diffuser Depth on Performance of
Compressed-Air U-Tubes
107
-------
o
<
o
o
o
a
X
LU
10
9
8
7
6
5
3
2
1
0
2000
Y - 0.1
o
WATER ONLY (YQ - 0)
PIPE SIZE: 23.25 INCHES ID
THROUGHOUT SYSTEM
40 FEET CASING DEPTH
Y = INITIAL AIR TO WATER VOLUME
° RATIO AT 68°F AND 1 ATMOSPHERE
3000 4000
WATER FLOW RATE, GPM
k
3
2
CC.
LU
o §
5000
Figure SI. Effect of Water Flow Rate on Performance
of Compressed-Air U-Tubes
108
-------
however, this will also increase the capital cost. In each design
study, there should be made trade-offs between operating and capital
cost, taking into account the constraints and priorities of the partic-
ular case. The lowest practical superficial water velocity in the down-
leg is of the order of 2 ft/sec, and each case should be checked to
avoid slug flow and other difficulties in the down-leg. The up-leg
velocity may have to be at least 3 to 5 ft/sec if there is appreciable
silt.
Figure 48 displays predicted performance trends for what are probably
the largest pipe sizes that could even be considered for this case:
23.25-inch I.D. (24-inch schedule 20 pipe) for the down-leg, and
29.00-inch I.D. (30-inch schedule 20 pipe) for the up-leg. The super-
ficial water velocities are 2.62 and 1.69 ft/sec, respectively. This
series of curves displays the effects of two important independent
variables: amount of oxygen in air supplied, and U-tube depth, ex-
pressed as the depth of a casing containing the U-tube (which is 0.5
foot shorter than the casing) on the two primary dependent variables
or performance parameters: exit dissolved oxygen concentration (all
inlet oxygen concentrations are zero for standardization) and total
pressure drop across the U-tube system. The two quantities used in
this report to express the relative amounts of air and water are di-
rectly related by the expression:
Oxygen supplied, mg/1 = 280 (air-to-water volume ratio at 68°F,
1 atmosphere)
It can be seen in Fig. 48 that both the D.O. concentration and pressure
drop increase with increasing air rate (shown as mg/1 of oxygen sup-
plied) and with increasing U-tube depth. Each performance variable
increases at a rate less than linear (i.e., has a negative second deriv-
ative), and the exit D.O. concentration particularly levels off as high
amounts of oxygen are supplied. This region of diminishing returns
should be expected; when very large amounts of oxygen are present, the
oxygen utilization is less efficient. For reference, it might be noted
that the saturation concentration of dissolved oxygen at 68°F and in
contact with normal air at 1 atmosphere pressure is 9.08 mg/1. There-
fore, it is seen that the effluent water can be supersaturated for a
considerable range of higher air rates and deeper U-tubes.
To more clearly visualize the trade-offs between exit D.O. concentra-
tion and pressure loss, the parametric results of Fig. 48 were cross-
plotted in Fig. 49, in which the amount of oxygen supplied is an impli-
cit parameter. It can be observed that the required pressure loss for
an incremental increase in exit D.O. concentration becomes relatively
greater as the exit D.O. level increases. It is also interesting to
examine the crossing-over of the curves for various U-tube depths. One
conclusion which can be drawn is that a deeper U-tube does not necessar-
ily result in improved performance. For example, at a fixed overall
pressure drop of 3 ft water, the exit D.O. concentrations for 40, 60,
109
-------
80, and 100 feet casings are 9.5, 9.6, and 6.2 mg/1, respectively. How-
ever, it should be further noted that the amount of air which must be
added is much less for the deeper U-tubes; the values (see Fig. 48) cor-
responding to these four points are about 79, 39, 21, and 12 mg/1 for 40,
60, 80, and 100 feet casings. Another observation which can be made from
both Fig. 48 and 49 is that there are almost asymptotic upper limits on the
exit D.O. concentration that can be obtained from a U-tube of a particular
depth; e.g., if an exit D.O. concentration of 7 mg/1 is desired for a de-
sign point, it is essentially impossible to reach this with a 20-foot
U-tube, probably inefficient to accomplish it with a 30-foot U-tube, and
begins to be more efficient for U-tubes of 40 feet or more in depth.
All of the parametric curves discussed so far were for cases with the
air diffuser ring mounted at the top of the down-leg (i.e., &25> shown
in Fig. 45, is zero). Figure 50 shows the effect of lowering the eleva-
tion of the diffuser ring (i.e., increasing the diffuser depth, a2$) on
the two major performance variables, for several values of yo. As the
diffuser ring elevation is lowered, the pressure drop across the U-tube
is decreased, eventually becoming negative (i.e., there is a net pres-
sure increase across the U-tube due to the air-lift effect). This ef-
fect is not gained without cost, however. The exit D.O. concentration
decreases (because the air is in contact with the water during only a
portion of the U-tube) and also the required air pressure increases,
since it must be injected at a region of higher water pressure. A
value of a25 equal to about 34 feet corresponds to having the diffuser
ring at the bottom of the down-leg (since about 6 feet of the 40-foot
casing depth is taken up by two L.R. elbows. (In practice, S.R. or
special elbows would probably be used for pipe this large,) In this
extreme case, the compressed-air U-tube is essentially an eductor, and
the pressure increase (air lift) is nearly 4 feet of water for y0 = 0.3.
From various parametric studies, it appears that it will generally be
preferable to design for the diffuser ring at the top of the down-leg;
however, the design flexibility offered by allowing this location to
vary may be of value in some cases, e.g., those in which no net pres-
sure drop across the system can be allowed.
Figure 51 illustrates the effect of changing the water flow rate on'a
fixed U-tube design. The major point of these curves is to illustrate
the flexibility of a compressed air U-tube. For example, if the de-
sign point were Qw = 3000 gpm and yo = 0.3, the exit D.O. concentra-
tion and pressure drop would be about 9.9 mg/1 and 2.8 feet of water.
If the water flow rate were increased to 4500 gpm and if the air flow
rate were also increased to maintain a yo of 0.3, the concentration
and pressure drop would be about 8.4 mg/1 and 2.4 ft water. If the
air flow rate were maintained at the original level, thus giving a
y0 of 0.2 at Qw = 4500 gpm, the concentration and pressure drop would
be about 7.3 mg/1 and 2,0 feet of water.
110
-------
Design Trends for Aspirated-Air U-Tubes
This subsection illustrates and discusses typical effects of the major design
variables on performance of aspirated-air U-tubes. Figures 52 through 56 sum-
marize results from a large number of calculations made with the U-tube design
program. Each curve in these figures was constructed from the results of a
series of calculation cases. The following conditions were held fixed (the
same conditions were used in the compressed-air examples given in previous
subsection), unless otherwise specified: water flow rate, Qw, is 5 mgd (3472
gpm); incoming water has zero D.O., no sulfides or rapid chemical oxygen de-
mand, and an alpha value of 0.9; ais = 2; aig = 8 ft (drop in elevation be-
tween inlet and outlet pipes); water and air temperatures are 68°F; and the
ambient pressure is 1 atmosphere.
Figure 52 displays the effects of U-tube depth' and amount of oxygen supplied
on the two primary performance variables (exit D.O. concentration and overall
pressure drop) and on the required aspirator contraction area ratio, E (de-
fined as the entrance pipe cross-sectional area divided by the throat cross-
sectional area). Curves for each of these three variables are shown as a
function of the amount of oxygen supplied (i.e., the amount of oxygen in the
air which is aspirated into the flowing water stream), and for six casing
depths (which are about 0.5 foot greater than the U-tube depth). For lower
amounts of oxygen supplied, it would be possible in this case to aspirate with-
out a venturi (i.e., E=l). This is a result of the value of a^g, which produces
a siphon effect. As the desired amount of oxygen to be supplied (or exit D.O.
concentration) is increased, it becomes necessary to constrict the throat cross-
sectional area (i.e., include a venturi). This results in an increase in exit
D.O. concentration, but also produces a substantial increase in pressure loss.
This is caused by a major constraint that is characteristic of any aspirated
air U-tube: the aspirator must cause enough local acceleration of the fluid
to reduce the pressure at the aspirator throat to less than the ambient air
pressure, to aspirate air into the flowing water stream. This is not particu-
larly difficult in a gravity-flow system where the pressure at the entrance to
the aspirator is merely due to the height of liquid above it. In a force-
main application, however, the design is more difficult because the aspirated
entrance pressure can be considerably greater than the ambient pressure. If
the pressure downstream of the aspirator (ps - pi2 using the station numbers
shown in Fig. 44) is substantial, the aspirator contraction ratio must be much
larger (i.e., throat smaller) than for a corresponding gravity flow applica-
tion. This in turn, leads to a higher value of R (pressure drop across the
aspirator divided by equivalent one-phase pressure drop from aspirator entrance
to throat), since R increases with increasing venturi contraction area ratio.
This "magnification effect" does cause a rapid increase in pressure loss across
a U-tube in a force main for small throat cross-sectional areas (high values of
E), This is a very important design consideration, and it imposes more restric-
tive constraints (and generally results in a higher overall head loss) on a
design for an aspirated-air U-tube in a force main than for as aspirated-air
U-tube in a gravity flow line, or for a compressed-air U-tube in either type
of application. It is generally uneconomical to select a design point which
falls very far into the high slope portion of the AH curve (e.g., 70 mg/1
oxygen supplied for a 40-ft casing, as shown in Fig. 52).
Ill
-------
CASING DEPTH,
FEET
Q = 31*72 GPM
PIPE SIZES: 23.25 INCHES ID IN AND
DOWN, 29.0 INCHES ID UP
• 8.0 FEET
CASING DEPTH,
FEET
CASING DEPTH,
FEET
20 1(0 60 80
OXYGEN SUPPLIED, MG/L
Figure 52. Typical Aspirated-Air U-Tube Parametric Designs
112
-------
20 TO 60 FEET CASINGS
CASING DEPTH, FEET
PIPE SIZES: 23.25 INCHES ID IN AND
DOWN, 29.0 INCHES ID UP
a]g = 8.0 FEET
-7 -6 -5 -k -3 -2 -1 0 1 2 3 A 5
OVERALL 4H (NOT INCLUDING a,g), FEET WATER
Figure 53. Typical Aspirated-Air Design Trade-Offs
113
-------
10
9
^ Q
C3 0
X
i 7
H
I 6
UJ
O
z
o
(_)
t 3
X
UJ
2
1
0.10
PIPE
ID = 23.25"
]g
= 3^*72 GPM
FT CASING
=8.0 FEET
17.13" 15.25" 13.25" ~
6
k
2
0
-2
Q
=3
LU CTl
-8
0123 45678 9 10
INLET SUPERFICIAL WATER VELOCITY, FT/SEC
Figure 54. Effect of Pipe Size on Performance of
Aspirated-Air U-Tubes
114
-------
i—i—r
i—i—r
10
9
PIPE SIZE: 23.25 INCHES ID
THROUGHOUT
40-FT CASING
O
O
0
DROP
10
8
6
4
2
0
-2
-4
-6
-8
-10
-------
10
9
8
<_>
z
o
o
•
a
x
ui
Y -= 0.25
o
0.2
0.1
PIPE SIZE: 23.25 INCHES ID
THROUGHOUT
40 FT CASING
a} = 8.0 FEET
2000
3000
WATER FLOWRATE, GPM
2 2
to
C3
0 E
o
-2 tj
-6
-8 £
cc
LLl
Figure 56. Effect of Water Flow Rate on Performance of
Aspirated-Air U-Tubes
116
-------
Figure 53 is analogous to Fig. 49 for compressed-air U-tubes, and represents
a cross-plot of the data in Fig. 52, in which the amount of oxygen supplied
is an implicit parameter. Many of the parametric trends are similar; how-
ever, several substantial differences can be noted. There is a more pro-
nounced effect of U-tube depth on the trade-off curves for aspirated air than
for compressed-air U-tubes. The cross-overs in the curves for various depths
are less pronounced and occurs at lower values of air-to-water ratio than for
compressed-air U-tubes. Consequently, the efficiency of aspirated-air U-
tubes is almost always better as the depth increases, for practical ranges
of air-to-water ratio. Such improvements in operating performance must be
balanced against the increased capital cost of deeper U-tubes, however.
The effects of pipe diameter, as represented by the superficial water veloc-
ity, are shown in Fig. 54. It is interesting to note that the total pressure
drop curves for higher values of yo pass through pronounced minimums as the
velocity is changed. This behavior is somewhat different from that predicted
for compressed-air U-tubes (Fig- 47). The primary reason for the minimum in
the aspirated-air cases is that the higher velocities make it possible to
aspirate with a smaller value of E, thereby effecting a substantial decrease
in system pressure drop. This saving initially overcomes the increase in
pressure drop across the aspirator, as the velocity is increased, although
the latter eventually becomes the more dominant factor, hence causing the AH
curves to turn upward again. The large difference in AH between y0 = 0.22
and 0.25 is caused by the rapid increase in E in this region. For example,
with 23.25-inch ID pipe, E = 1.89 at yo = 0.22 and E = 9.65 at yo = 0.25.
Aspirated-air U-tubes do not have as much design flexibility as is avail-
able for compressed-air U-tubes. One of the major differences is that
it is not practical (or of any advantage) to install the air injection
location for aspirated-air U-tubes at different elevations in the down-leg,
as was illustrated for compressed-air U-tubes in Fig. 50. However, in
some cases, it is possible to arrange to have the elevation of the exit
pipe (station 11 to 12 in Fig. 44) lower than the elevation of the aspira-
tor (i.e., to have ais + aig greater than zero). Because of the "magnifi-
cation effect" in aspirator characteristics, discussed earlier in this
subsection, modest differences between these two elevations can have a
very substantial effect on the performance of an aspirated-air U-tube, as
illustrated in Fig. 55. The exit D.O. concentration is affected very
little by increasing a^g; however, the pressure drop across the system is
reduced substantially. If a^g is made large enough, it is possible to
reduce AH to zero or below. It should not be concluded that this im-
provement is obtained without cost—there must be a difference in eleva-
tion; however, if this is available or can be provided easily, then this
is a very important direction for optimization in a particular aspirated-
air U-tube design.
Figure 56 illustrates the effect of changing the water flow rate on
parametric U-tube designs in which all geometry variables are fixed
except for the aspirator contraction ratio, which is changed as
117
-------
necessary. It can be seen that there is considerable flexibility in
design without the need to change pipe size.
ECONOMIC COMPARISONS
Results of preliminary economic comparisons between U-tube systems and
current conventional aeration methods are described. Comparisons are
made for two major applications: Postaeration of treated waste water
effluent, and in situ aeration of sanitary sewers. The predesign cost
estimates were made, in most cases, without the benefit of firm pricing
based upon detailed designs and, consequently, do not establish the
absolute costs of the processes. However, these estimates given an
approximate value of costs to be expected, in addition to the primary
purpose of comparing the cost of U-tube aeration with costs for various
other aeration systems.
Postaeration of Treated Effluent^
Two commonly used systems, diffused air and mechanical aeration, were
selected for economic comparisons with U-tube aeration. A prime con-
sideration for diffused aeration is the type of diffuser to be used.
Choice of an air diffuser on the basis of oxygen transfer efficiency
(oxygen dissolved/oxygen supplied) alone would lead to use of small
bubble diffusers such as porous tubes (Ref. 26 and 27). However because
of the higher pressure and maintenance requirements for small bubble
diffusers, spargers were selected as the diffuser type for this compar-
ison. Plug flow (i.e., no mixing in the direction of flow) was assumed
for the aeration tanks, since this would result in higher driving
forces for mass transfer and, consequently; lower costs than for other
conventional flow assumptions.
Mechanical or entrainment-type aerators employ some type of circular,
rotating element, such as a plate with vertical blades or inclined
vanes extending from the periphery of the plate. The element typically
rotates in a horizontal plane a short distance below the water surface,
and air is entrained by the moving blades of the turbine. Although
other types of mechanical aerators have been described, this basic type
of design was selected for this study.
U-tube aeration systems might have several configurations, as previously
discussed. However, for comparable in-tube velocities, air-to-water
ratios, and depth, all configurations should perform essentially the
same with respect to oxygen transfer. Two types of U-tube configura-
tions were chosen for these comparisons: (1) concentric circular pipes
with flow downward through the inside pipe and upward through the an-
nulus, and (2) a wide rectangular trench with a vertical flat partition
extending across the width to divide the trench into two passages—with
the water flowing downward through one passage, under the bottom edge
of the partition, and upward through the other passage so formed.
118
-------
The aeration systems were considered as an extension of an existing
plant and secondary effluent discharge channel. Typical system layouts
are illustrated by Fig. 57 and 58, although the specific details were
varied to result in low-cost systems for the various flowrates and
amounts of dissolved oxygen to be added. The principal design and
cost bases, which were assumed or established from the preliminary de-
sign studies, are given in Table 5.
Performance data for diffused air and mechanical aeration systems at
standard conditions (i.e., for tap water at 20°C., 1 atmosphere, con-
taining no dissolved oxygen, and with a = 1.0) were adjusted to the
conditions given in Table 5 with the relationship
(28)
In (Dl/D2)
where N is the aerator performance rating (e.g., in Ib oxygen/hp/hr),
superscript prime refers to standard conditions, and subscripts 1 and
2 refer to initial and final conditions, respectively. This expression
was used to calculate the efficiencies of a turbine-type aerator and a
sparger at several levels of final D.O. content. Performance ratings
at standard conditions (14.7 psia, 68°F, a = 1) from Ref. 28, 29, and
30 are shown in Fig. 59 along with the efficiency curves for the two
aeration methods. Mechanical aerators typically have higher-power
performance ratings (N) than diffused air systems; however, they also
have higher capital, operating, and maintenance costs.
After selecting up-leg and down-leg velocities plus casing diameters,
the U-tube depth was optimized. Optimization consisted of deriving
operating lines (based on the computer printouts) of the form shown in
Fig. 60 for various casing depths ranging from 20 to 70 feet. For
selected exit D.O. levels, each casing depth gave an associated U-tube
plus the power required to pump the flow at a given AH was evaluated
for each casing depth at a given exit 0.0. An optimum casing depth
(corresponding to optimum cost) was selected at several exit D.O.
levels. Values of some of the important system characteristics are
given in Table 6 for three values of final dissolved oxygen concentration.
The major constituents of the physical plant costs are listed in Table 7.
Major equipment costs such as mechanical aerators, pumps, and motors
were based on manufacturers' quotes. Estimates of concrete construction,
air and water piping, excavation, and other similar costs were obtained
from standard sources of cost data (Ref. 31 and 32). Factors such as
maintenance, operating labor, power, plant overhead, and administrative
costs were also considered in the total estimates.
119
-------
N)
O
SECONDAI
*Y EFFLUE
NT TANKS
SECONDARY EFFLUENT DISCHARGE CHANNEL
AIR-
SPARGERS
OR
MECHANI-
CAL
AERATOR
LOCATION
o
Figure 57.
Schematic Layout of
Postaeration Facility
SECONDARY^
EFFLUENT ~t
A
t_
•tl-
u
D
SURGE
BASIN
>
J
J
J
A
AERATED
EFFLUENT
TRENCH-TYPE U-
PLAN VIEW
SECTION A-A
-VENTURI ASPIRATOR
T
AH
Figure 53. Schematic Layout of
U-Tube Facility
-------
TABLE 5. SELECTED ECONOMIC AND PHYSICAL
DESIGN BASES FOR POSTAERATION SYSTEM
COST ESTIMATES
1. Aeration plant flowrates of 10 mgd and 100 mgd
2. Aeration installation is immediately downstream of the
treatment plant, and laboratory facilities, proximate utili-
ties, and buildings are available.
3. Water temperature is 75°F.
4. Ambient pressure is 14.5 Ib/sq in. abs.
5. D.O. saturation level is 8.33 mg/liter.
6. Incoming waste water (secondary treatment plant effluent)
has 1.0 mg/liter D.O.
7 a - Oxygen transfer rate in effluent _ 0 90
Oxygen transfer rate in tap water
8. Capital costs amortized at 4.5% over 25 years
9. Electrical power cost = $0.01/kw-hr
10. Cost of land = $5000/acre
11. Total direct plant costs (including contractor, engineer-
ing, and legal fees) =1.35 times physical plant cost
o
30-
—14.5 PSIA, 75°F, a = 0.9
01^.7 PSIA, 68°F, a = l.o
(STANDARD CONDITIONS)
MECHANICAL AERATOR
DIFFUSED AIR
12345678
FINAL DISSOLVED OXYGEN
CONCENTRATION, MG/L
Figure 59. Effect of Final D.O. Concentration on Performance of
Diffused Air and Mechanical Aeration Systems
121
-------
o
<
o
o
C3
X
o
o
LU
>
o
to
INCREASING U-TUBE
DEPTH
U-TUBE PRESSURE DROP
Figure 60. Schematic Diagram of U-Tube
Operating Lines
In this study, aeration costs are presented as cost per weight of
dissolved oxygen. This basis was selected because it can be readily
applied to all three aeration systems. Mechanical and diffused aera-
tion systems are not readily comparable (Ref. 27) except for indivi-
dual cases on a realistic set of selected conditions which permit a
determination of the total cost per unit of oxygen transferred. Effi-
ciencies of diffused air systems are customarily defined in terms of
oxygen transfer efficiency, whereas efficiencies of mechanical aerators
are stated in terms of the oxygen transferred to the liquid per unit
of power input. The cost per unit weight of oxygen dissolved parameter
provides a meaningful, common basis for comparing different types of
aeration systems.
Cost comparisons for all three systems are shown as functions of final
dissolved oxygen concentration in Fig. 61 and 62 for 10 mgd and 100
mgd flow, respectively. Table 8 presents more detail for several cases,
Two sets of values are given for U-tube aeration cost at each capacity.
One (AH available) assumes that the required head loss is available and
that no pumping equipment or pumping costs are incurred. The other
curve (AH pumped) includes the power, pumps, and all equipment needed
to supply the reauired head loss. If .it is desired to convert these
122
-------
TABLE 6. CHARACTERISTICS OF POSTAERATION SYSTEMS
10 mgd
Dissolved oxygen input rate, Ib/day
Air input rate for diffused air
aeration, scfm
Tank size for diffused air aeration,
feet depth x width x length
Tank size for mechanical aeration,
feet depth x width x length
Number of U-tubes
Depth of U-tubes
Type of U-tube configuration
100 mgd
Dissolved oxygen input rate, Ib/day
Air input rate for diffused air
aeration, scfra
Tank size for diffused air aeration,
feet depth x width x length
Tank size for mechanical aeration,
feet depth x width x length
Number of U-tubes
Depth of U-tubes
Type of U-tube configuration
Final Dissolved Oxygen Concentration,
% Saturation
30
125
130
8x10x31
7x10x20
2
20
1250
580
15x24x50
/
7x30x35
2
20
60
330
350
8x10x38
7x20x30
2
45
90
540
570
8x10x45
7x25x30
2
60
Concentric pipes
3300
1560
15x24x58
7x30x50
2
45
5400
2540
15x24x66
7x50x90
2
60
Trench-type with rectangular flow
cross section
TABLE 7. MAJOR COMPONENTS IN PHYSICAL PLANT COSTS
Land
Excavation
Utilities
Aeration tank or surge tank
Channels, flow gates, and wiers to connect to existing effluent channels
Aeration device
Pumps and motors (where applicable)
Air compressor and piping (diffused air only)
Installation
123
-------
16
LU
I '2
X
o
CO
£
o
o
10
8
6
5 4
_U-TUBE
AERATION
(AH PUMPED)
I I
MECHANICAL
AERATION-
_U-TUBE AERATION
(AH AVAILABLE)
1
I
20
60 80
100
FINAL DISSOLVED OXYGEN CONCENTRATION,
PERCENT OF SATURATION
o
to
o
z
LU
o
X
o
to
o
o
UJ
DIFFUSED
AIR
MECHANICAL
AERATION
U-TUBE AERATION
(AH PUMPED)
hU-TUBE AERATION
(AH AVAILABLE)
I I
I
20
1*0
60 80
100
FINAL DISSOLVED OXYGEN CONCENTRATION,
PERCENT OF SATURATION
Figure 61. Cost Comparison (10 mgd)
Figure 62. Cost Comparison (100 mgd)
-------
TABLE 8. COST COMPARISON FOR POSTAERATION OF TREATED EFFLUENT
N>
in
Total Exit D.O. c
-------
cost figures to annual costs, this can be accomplished easily by multi-
plying them by the pounds of oxygen transferred per year, using the
pounds per day figures given in Table 6.
It is apparent that the U-tube is a highly attractive aerator for both
small and large capacities when the necessary driving force (AH) is
available. Even if the AH must be supplied by pumping, the U-tube is
the most economical system at 10 mgd, and for high values of exit dis-
solved oxygen concentration at 100 mgd.
It is interesting to note that the estimated costs for mechanical
aeration are higher than for diffused-air aeration, even though the
power performance ratings for diffused air systems are considerably
lower. Higher estimated costs for operating and maintaining mechanical
aerators are primarily responsible for this. As actual cost data on
operating and maintenance expenses for a specific application become
available, these cost components can be established with greater
certainty.
In Situ Aeration of Sanitary Sewers
Four concepts for in-line aeration of sanitary sewers were selected
for economic comparison: (1) an aspirated-air U-tube at the end of a
force main, (2) and aspirated-air U-tube in a gravity flow line, (3) a
compressed-air U-tube in a force main, and (4) an eductor station.
Three of the four types of systems were tested in the Jefferson Parish
and Port Arthur projects, mentioned previously.
Table 9 summarizes the principal design and cost bases which were aasu-
med for all systems. Important characteristics of the individual sys-
tems are given in Table 10. The design techniques and procedures were
generally similar to those used for the postaeration comparisons. The
second case (aspirated-air U-tube in gravity line) required nonstandard
use of the U-tube design program, i.e., running multiple cases of type
1 to match the calculated upstream pressure with the ambient pressure.
Cost elements for each of the systems were amortized capital, maintenance,
power, and operating labor plus materials. Construction costs were based
on actual bid prices received by Jefferson Parish (Ref. 33). A flowrate
of 3 mgd was assumed as a basis, and construction bids for smaller sys-
tems were adjusted to this capacity, where necessary, using a plant
scale factor approach. The construction bid prices were assumed to in-
clude contractor's fee, contractor's overhead, and contingency. Fixed
capital costs were taken as 110% of the construction bid prices (10%
engineering fee).
It should be noted that the construction bid prices are for experimental
one-of-a-kind units which include several features which would not be
necessary for strictly operational systems. For these reasons (plus the
126
-------
TABLE 9. SELECTED ECONOMIC AND PHYSICAL DESIGN
BASES FOR SEWER IN SITU AERATION SYSTEMS
1. Flowrate of 3 mgd (2085 gal/min) 5,
2. Water temperature is 28°C
(82.4°F)
Ambient pressure is 14.7 Ib/sq
in. abs.
D.O. saturation level is 7.84
mg/liter
6.
7.
Incoming waste water has 0.2
mg/liter D.O.
a ^ 0.8
General cost bases are iden-
tical to those given in
Table 5.
TABLE 10. CHARACTERISTICS OF IN SITU
AERATION SYSTEMS
System Characteristics
Eductor station Construction cost basis is $13,000 for 1,500
gal./min. unit.
Casing is 20 ft. deep.
Air compressor supplies 40 vol. % air at 59
ft. head.
Exit D.O. is 3.3 mg./liter
Compressed air Construction cost bases for 300 gal./min.
U-tube in units are: $11,300 for 20 ft. deep, $11,800
force main for 30 ft. deep, and $12,800 for 50 ft. deep.
Design points ore:
Depth, ft. 20 30 50
Air volume % at 1 atm. 4.5 12 24
Exit D.O., mg./liter 2.0 4.0 7.0
Extra head on pump, ft. 2.2 4.5 10
Aspirated air Construction cost bases for 1,800 gal./min.
U-tube in units are: $20,300 for 30 ft. deep and
force main $22,700 for 50 ft. deep.
Design points have dynamic AH of 4.0 ft.,
' static AH of 7.0 ft., and exit D.O. concen-
trations of 4.2 mg./liter for 30 ft. deep and
5.4 mg./liter for 50 ft. deep.
Aspirated air Construction cost bases for 1,800 gal./min.
U-tube in units are identical to those for aspirated-
gravity main air U-tubes in force mains.
Design points are:
Depth, ft. 30 30 50 50
Total AH, ft. ,4 11 4 11
Exit D.O., mg./liter 2.6 4.6 2.7 5.6
127
-------
fact that the bids were received during an extremely busy construction
period following a major hurricane), the costs are probably much higher
than those which should be expected for a straight operational system.
In addition there can be large differences in cost due to subsurface
soil characteristics and availability of specialized construction
equipment; therefore, extreme care should be taken in extrapolation of
construction costs to other locations or applications. Although the
estimates do not establish generalized absolute costs of the processes,
they do give a comparison of relative costs of four types of systems.
A summary of cost estimates for all systems at selected values of exit
D.O. is given in Table 11. The differential head column refers to the
net increase (or decrease) in system head due to pressure loss (or
recovery) through the aerator. Costs are given for two conditions:
assuming that the differential head is free or assuming that the addi-
tional power costs required to pump the differential head must be paid.
The total costs generally range from about 4 to 10 cents per pounds of
oxygen added. A general trend for all U-tubes is lower cost at higher
differential head, over the range of values investigated.
TABLE 11. COST COMPARISON FOR IN SITU AERATION OF SEWER WASTE WATER
Cost, cents/lb. D.O.
System
Eductor
station
Compressed
air U-tube in
force main
Aspirated
air U-tube in
force main
Aspirated
air U-tube in
gravity main
Casing
depth,
ft.
20
20
30
50
30
50
30
30
50
50
Exit
D.O.,
mg. /liter
2.2
2.0
4.0
7.0
4.2
5.4
2.6
4.6
2.7
5.6
Differential
head. AH, ft.
3.0
2.2
4.5
10.0
M.O
11.0
4.0
11.0
4.0
11.0
Amortized
capital
3.8
11.0
5.4
3.3
4.3
3.8
7.3
3.9
7.9
3.6
Maintenance
and operat-
ing labor
1.9
5.0
2.5
1.5
0.9
0.7
1.4
0.8
1.5
0.7
Power
3.9
0.9
0.9
1.2
1.8
1.4
1.1
1.7
1.0
1.4
Total
10.3
16.1
8.0
5.0
5.2
4.5
8.7
4.7
9.4
4.3
Total
including
AH cost
or credit
9.6
16.9
8.8
6.0
7.0
5.9
9.8
6.4
10.4
5.7
It can be seen that the total costs are comparable for three of the
systems with similar values of depth and differential head: a com-
pressed air U-tube in a force main, or aspirated-air U-tubes in a force
or gravity main. Of these three, an aspirated-air U-tube in a gravity
line would present considerably more difficult design and operational
problems because of the variations in flowrate and the need to provide
differential head within the gravity line. Either of the other two
systems would be easier to design and more flexible in operation.
128
-------
SECTION IX
ACKNOWLEDGEMENTS
The support of these projects by the Environmental Protection Agency and
the interest and involvement exhibited by the Project Officers, Charles
L. Swanson, Gerald Stern, and John N. English, are acknowledged with
sincere thanks.
This project was conducted in the Advanced Programs Department at
Rocketdyne, with Dr. B. L. Tuffly, Program Manager, responsible for
overall administration, and Dr. Rex C. Mitchell, Project Engineer, re-
sponsible for the technical content and conduct of the program. Mr. A.
D. Lev performed the pilot-scale tests and a significant part of the
data analysis following these tests. Ms. K. J. Youel and Messrs. B.
Minnich, J. D. Perret, F. D. Raniere, and R. Rushworth also contrib-
uted to the project under Contract No. 14-12-434. Mr. J. Quaglino
directed the field evaluation tests during Contract 68-01-0120. Messrs.
K. W. Fertig and W. H. Moberly performed most of the subsequent data
correlation analyses; Dr. W. Unterberg also contributed to this effort.
Messrs. Fertig, Lev, Moberly, and Quaglino wrote portions of this re-
port. Messrs. J. Barrett, J. Duncan, and J. Rainer served as editors
for various portions of this report.
The field testing could not have been accomplished without the coopera-
tion and assistance of many individuals from de Laureal Engineers, Inc.,
the Jefferson Parish Sanitation District, and the City of Port Arthur.
Especially helpful were Mr. Robert A. Copper, de Laureal Engineers'
Project Director for the EPA grant project in Jefferson Parish; Messrs.
A. J. Englande and Dr. P. Boudreaux, who assisted in the field testing
at Jefferson Parish; and Messrs. R. Joe Sewell and Tony Humphrey, who
helped in the field testing at Port Arthur. Their efforts are sincerely
appreciated.
This report has been assigned Rocketdyne control number R-9101.
129
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SECTION X
REFERENCES
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U-Tubes and the Aeration Process," J. of the Amer. Water Works
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Paddles and by an Aspirator," Bulletin 268, Engineering Experiment
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3. RR 67-17, Water Pollution Research IR§D Task 60626-22010, Annual
Report for Period 1 October 1966 to 30 September 1967, Rocketdyne
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4. Mitchell, R. C., and A. D. Lev: The U-Tube for Water Aeration,
Report R-8043, Rocketdyne Division, Rockwell International, Canoga
Park, California, EPA Contract No. 14-12-434, March 1970.
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Aeration with Other Methods for Aerating Wastewater," Water-1970,
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the ASCE, 95_, No. SA3, 563-574 (1969).
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715-724 (June 1970).
8. Anderson, R. J., and T. W. F. Russell: "Designing for Two-Phase
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131
-------
13. Craven, J. P.: "The Transportation of Sand in Pipes: Full-pipe
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de Laureal Engineers, Inc., EPA Grant 11010 ELP, Contract WPRD 121-
01-68, to be issued 1973.
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System for a. Sewage Lift Station," presented at the ASCE Texas
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17. Jackson, M. L., and W. D. Collins: "Scale-Up of a Venturi Aerator,"
I. § E. C. Process Design and Development, 3_, 386-393 (1964).
18. Jackson, M. L.: "Aeration in Bernoulli Types of Devices," AIChE
Journal, 1£, 836-842 (Nov. 1964).
19. Bauer, W. G., A. G. Frederickson, and H. M. Tsuchiya: "Mass Trans-
fer Characteristics of a Venturi Liquid-Gas Contractor," I § E. C.
Process Design and Development, 2_, 178-187 (1963).
20. Hershey, R. L.: The Flow of Gas-Liquid Mixtures in Pipes, unpub-
lished D. Sc. Thesis, Massachusetts Institute of Technology (1935).
21. Adams, J. L.: Oxygen Transfer Characteristics of Diffused Air
U-Tube Systems, unpublished M. S. Thesis, New Mexico State Univer-
sity, Los Cruces, New Mexico (June, 1967).
22. Montgomery, H. A. C., N. S. Thorn, and A. Cockburn: J. Appl. Chem.,
1£, 280 (1964).
23. Handbook of Chemistry and Physics, 37th ed, Chemical Rubber Pub-
lishing, Co., Cleveland, 1606 (1955).
24. Dobbins, W. E., "Mechanism of Gas Absorption by Turbulent Liquids,"
Proc. of the First Int. Conf. on Water Pollution Research, London,
Eng., 61-96 (Sept. 1962).
25. Tsivoglou, E. C., R. L. O'Connell, C. M. Walter, P. J. Godsil, and
G. S. Logsdon: "Tracer Measurements of Atmospheric Reaeration--
I. Laboratory Studies," J. Water Poll. Control Fed., 37, 1343-1362
(Oct. 1965). ~~—
132
-------
26. Morgan, F. and J. K. Bewtra: "Air Diffuser Efficiencies," Journal
WPCF. 32_, 1047-59 (1960).
27. Cleasby, J. L., and E. R. Baumann: "Oxygenation Efficiency of a
Bladed Rotor" Journal WPCF, 4-0, 422 (1968).
28. Rating of Air Diffusion Apparatus, Chicago Pump, Food Machinery and
Chemical Corporation, Technical Information Bulletin A-l (March,
1961).
29. Bewtra, J. K., and W. R. Nicholas: "Oxygenation From Diffused Air
in Aeration Tanks," Journal WPCF, 36_, 1195-1224 (1964).
30. Turborator Aerator Performance Data, Engineering Data Sheet Appli-
cation Data, Section 7882.4, Chicago Pump Division of Food Machin-
ery and Chemical Corporation (July 1968).
31. Aries, R. S., and R. D. Newton: Chemical Engineering Cost Estima-
tion, McGraw-Hill Book Co., New York, 7 (1955).
32. Smith, R.: Preliminary Design and Simulation of Conventional
Waste-Water Renovation Systems Using the Digital Computer,' U. S.
Dept. of the Interior, Federal Water Pollution Control Adminis-
tration (March, 1968).
33. Swanson, C. L., FWPCA: Letter to R. C. Mitchell, Rocketdyne
(29 December 1969).
34. Standard Methods for the Examination of Water and Wastewater, 12th
ed., American Public Health Association, New York, (1965).
133
-------
SECTION XI
LIST OF PUBLICATIONS
Mitchell, R. C., and A. D. Lev: The U-Tube for Water Aeration, Report
R-8043, Rocketdyne Division, Rockwell International, Canoga Park,
California, EPA Contract No. 14-12-434, March 1970.
Mitchell, R. C., and A. D. Lev: "Economic Comparison of U-Tube Aeration
with Other Methods for Aerating Wastewater," Water--1970, Chemical Engi-
neering Symposium Series, Vol. 67, No. 107, 1970.
135
-------
SECTION XII
GLOSSARY
a = air-water interfacial area per unit total volume of water-air
mixture
A = area
b = half-angle of venturi conical diffuser
C = concentration of dissolved gas
Cg = saturation concentration of dissolved gas
D = diameter; dissolved oxygen concentration deficit (C -C)
S- ,
E = aspirator contraction area ratio (cross-sectional area of
pipe divided by minimum flow cross-sectional area in aspir-
ator)
f* = friction factor for gas lifts (see equation set 10)
F = Change in pressure per unit length (includes both static
head and friction losses)
h = step-size, distance along tube for one calculation step
AH = differential head
K = overall mass transfer coefficient including interfacial
area (K = K_a)
K. = overall mass transfer coefficient (dimensions are length/
^ time)
L = U-tube depth, measured from top of down-leg to bottom of
return bend
M = molecular weight
n = number of moles
n. = number of moles of "inert" vapors (i.e., air components
1 which are not oxygen or nitrogen)
N = performance rating of aerators (ib oxygen transferred/hp-
hr)
p = absolute pressure
p = ambient absolute pressure
p = vapor pressure of water at prevailing temperature
Q = volumetric flow rate
Q = air flow relative to water flow
8
r = plant production rate
B, = ratio of venturi permanent pressure drop to pressure de-
crease between entrance and the throat: (p_ - pf.)/(p, - p, )
137
-------
Re = Reynolds Number
t = t ime
At = average time for air bubble to move the distance h
a
At = average time for water to move the distance h
T = temperature
u = velocity
u = slip velocity = water velocity minus air bubble velocity
s
u = superficial water velocity (i.e., velocity with which the
water in an air-water mixture would flow, at the specified
volumetric water flow rate, if the air were not present)
V = volume
X = air-water interfacial area per unit volume of air
y = ratio of air volume to liquid volume
y = y before mass transfer begins
tt = ratio of mass transfer coefficient for waste water of
interest to mass transfer coefficient of "tap water"
|Jl = viscosity
p = density
Subscripts
a = air
d = down-leg of U-tube
m = two-phase mixture of water and air
p = solid particle
s = saturated conditions (e.g., C ); slip between water and air
(for u and 0 )
x s ^s7
t = total
T = evaluated at temperature T
u = up-leg of U-tube
w = water
20 = evaluated at a temperature of 20°C (68°F)
Superscripts
o = evaluated at standard conditions (l atm, 68 F unless other-
wise specified)
1 = nitrogen, rather than oxygen transfer
= mean value
138
-------
SECTION XII
APPENDICES
Page
A. Pilot-Scale U-Tube Experimental Data 141
B. Full-Scale U-Tube Experimental Data 153
C. U-Tube Design Program 159
D. Sample Output From U-Tube Design Program 177
139
-------
APPENDIX A
PILOT-SCALE U-TUBE EXPERIMENTAL DATA
This appendix contains experimental data, plus other quantities calcu-
lated with the original data reduction computer program, for the pilot-
scale U-tube experimental tests made with a venturi aspirator. Runs 1
through 94 were made with a center-plug aspirator which produced very
poor performance. Since this aspirator design was rejected, these data
are not given. The information is arranged into three tables, each of
which presents results in order of increasing run number. An outline
of the contents of the tables and identification of which values are
experimental ones are given in the following paragraphs.
Table A-l contains experimental data for those tests made without air
flow (water flow only). The true exit head values include a correction
for the curvature and extra length of the outlet hose.
Table A-2 contains measured values of U-tube depth (distance from the
entrance of the down-leg to the bottom of the return bend), water flow
rate, air-to-water volume percentage (A/W on the print-outs) expressed at
13.8 psia and 68°F (typical conditions at the experimental site),
ambient pressure, and water temperature. The amount of oxygen supplied,
expressed as mg/1, is equal to 2.63 times the air-to-water volume percentage
expressed at 13.8 psia and 68°F. The remaining four columns in Table
A-2 contain calculated values of superficial water velocity (the
velocity of water in the pipe at the measured volumetric flow rate if
no air were present), true overall pressure drop through the system
(DELTA H), and values of the mass transfer coefficient KL, at the water
temperature and at 68°F (20°c).
Table A-3 summarizes values of dissolved oxygen concentration, dissolved
nitrogen concentration, and head loss relative to the inlet tank water
level—with values of each quantity for several stations in the U-tube
system. The entrance and exit D.O. concentrations ENTR and EXIT(EXP),
are experimental values in all cases. The D.O. concentrations at the
exit of the venturi aspirator are experimental values for runs 139-16?
and 180-219} inclusive. The D.O. values at the exit of the return bend
for runs 225-252 are experimental data. The entries for D.O. concen-
trations at the platform (i.e., the junction between the straight
section of up-leg and the flexible exit hose) are experimental values
for runs 273-318. The EXIT (CALC) column gives values of D.O. calculated
at the exit of the flexible hose; these were printed primarily as a
check (by comparing with the EXIT (EXP) column) that the program had
successfully converged. The TRUE EXIT columns for D.O., D.N., and head
loss give the calculated values at the exit of a U-tube which has a
straight pipe up-leg rather than partly straight pipe plus a flexible
141
-------
outlet hose as did the experimental system. The TRUE EXIT HEAD values
are identical to the DELTA H values of Table A-2. These true exit
values should be used in applying the experimental results to other
applications. The values of D,N» are all estimated ones, based on the
assumptions discussed in the Data Reduction Program section. The head
loss columns for the venturi exit and U-bend entrance contain experi-
mental data exclusively. The column for head loss at U-bend exit con-
tains entirely calculated values. The values for head loss at the plat-
form are experimental data for runs 332-410.
The quantity, weight of oxygen transferred per unit of power expended
(N) , is a widely used figure-of-merit. However, it can lead to very
misleading conclusions if used to compare different types of aeration
systems, since power cost is only one component of the total aeration
cost. Values of N at standard conditions (tap water at 1 atm, 20° C,
and zero inlet D.O.) were calculated for experimental data contained in
this appendix and were found to range from less than 1 to nearly 7 lb
oxygen/hp-hr. Ranges of N values for each of the five U-tube depths
are given below.
Range of N Values (at standard
U-Tube Depth conditions) from Experimental
(ft) Data (lb oxygen/bp-hr)
45 1.4 to 5.1
37 1.0 to 6.7
28 0.7 to 6.0
19 1.1 to 4.0
9 0.5 to 1.8
It should be remembered that the ranges of water velocities and air-to-
water ratios were not identical for the five U-tube depths; therefore,
some differences between the ranges of N for different depths could
result from this. In general, the experimental N values seem to
increase with increasing U-tube depth, decreasing water velocity and
increasing air-to-water ratio. If an aspirated-air U-tube were
installed where the required head is available naturally, the value of
N would literally be infinite.
142
-------
TABLE A-l. EXPERIMENTAL DATA FOR U-TUBE TESTS WITH
VENTURI ASPIRATOR, NO AIR FLOW
Run
Number
95
96
97
98
99
100
101
102
103
104
105
168
169
170
171
172
173
174
175
176
177
178
179
220
221
222
223
224
264
265
266
267
268
269
270
271
272
326
327
328
329
330
331
403
404
405
406
407
408
409
410
U-tube
Depth
(ft)
45.4
45.4
45.4
45.4
45.4
45.4
45.4
45.4
45.4
45.4
45.4
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
8.9
8.9
8.9
8.9
8.9
27.9
27.9
27.9
27.9
27.9
27.9
27.9
27.9
27.9
36.5
36.5
36.5
36.5
36.5
36.5
36.5
36.5
36.5
36.5
36.5
36.5
36.5
36.5
Supf. Water
Velocity
(ft/sec)
2.1
1.0
1.9
2.5
2.6
3.0
3.0
3.4
3.5
3.8
2.9
1.8
2.0
2.2
2.4
2.5
2.7
2.8
3.0
3.2
3.4
3.5
3.6
2.7
2.3
1.9
1.4
3.0
1.6
2.0
1.8
2.1
2.3
2.4
2.5
2.8
3.0
1.6
1.9
2.2
2.4
2.7
3.0
1.6
2.0
2.2
2.4
2.7
2.9
3.1
3.4
Water
Flowrate
(cpm)
22.1
10.3
19.9
25.8
27.6
30.9
31.9
35.0
37.0
39.3
30.1
18.9
20.6
22.2
25.2
26.5
28.1
29.4
3L2
33.1
35.2
36.2
37.2
28.0
24.2
20.1
14.9
31.4
16.7
20.4
18.8
21.9
23.7
25.3
25.8
28.8
31.8
16.7
20.0
23.0
25.6
27.8
31.2
16.9
20.4
23.3
25.5
28.4
30.3
32.4
35.2
Head Relative to Inlet (ft)
Venturi
Exit
0.7
0.2
0.7
1.0
1.3
1.4
1.7
1.8
2.0
2.2
1.4
0.6
0.7
0.9
1.0
1.2
1.3
1.4
1.6
1.7
1.8
1.9
2.0
1.3
0.9
0.7
0.4
1.5
0.5
0.8
0.7
0.9
1.0
1.1
1.2
1.4
1.7
0.5
0.7
0.9
1.0
1.3
1.5
0.5
0.7
0.9
1.0
1.3
1.5
1.7
1.9
Bend
Entrance
1.2
0.3
1.0
1.7
1.9
2.3
2.6
2.9
3.2
3.4
2.4
0.7
0.9
1.0
1.3
1.4
1.7
1.8
1.9
2.1
2.2
2.4
2.5
1.4
1.0
0.7
0.4
1.6
0.7
1.0
0.9
1.2
1.3
1.4
1.6
1.9
2.3
0.7
1.0
1.4
1.6
2.0
2.3
0.7
1.0
1.3
1.6
2.0
2.2
2.5
2.7
True
Exit
1.8
0.9
1.3
2.2
2.6
3.1
3.5
4.0
4.4
4.8
3.1
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.3
2.5
2.7
2.9
1.6
1.2
0.8
0.4
2.1
0.9
1.3
1.1
1.5
1.7
1.9
2.0
2.3
2.8
0.8
1.3
1.8
2.2
2.4
3.0
0.8
1.3
1.7
2.2
2.7
3.1
3.6
4.0
143
-------
TABLE A-2. U-TUBE EXPERIMENTAL DATA WITH CALCULATED
MASS TRANSFER COEFFICIENTS
PUN
NO.
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
16?
164
165
DEPTH
(FT)
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.42
45.4,?
45.47
45.4?
45.42
S.W.VEL
(FT/SEC)
1.93
2.32
1.91
2.40
1.90
1.90
2.90
2.40
2.90
2.80
1.83
2.40
2.90
2.90
2.41
1.91
2.45
2.41
2.92
2.90
2.32
1.87
1.40
2.86
2.37
2.90
2.41
1.95
1.90
2. 83
2.40
2.00
2.83
2.40
2.40
2.40
2.35
2.34
2.94
2.80
2. 84
2.90
1.90
1.94
1.86
1.92
1.92
1.66
1.S2
1.85
1.87
2.33
2.43
2.33
2.36
2.37
2. e<3
2.90
2.90
QW
(GPM)
20.2
24.3
20.0
25.1
19. 9
19.9
30.3
25.1
30.3
29.3
19. 1
25. 1
30.3
30.3
25.2
20. 0
25.6
25.2
30.5
30.3
24.3
19.6
14.6
29.9
24.8
30.3
25.2
20.4
19.9
29.6
25.1
20.9
29.6
25.1
25.1
25.1
24.6
24.5
30. 8
29.3
29^7
30.3
19.9
20.3
19.5
20. 1
20..1
19.5
20.1
19.4
19.6
24.4
25.4
24.4
24.7
24.9
30. 1
30. 3
30.3
A/W
« V/0)
2.10
3.25
4.10
5.50
7.67
8.90
4.36
7.10
2.10
4.82
10.34
6.33
3.27
4.65
3.25
5.35
0.82
2.36
2.90
4.26
7.06
9.57
1.25
i.to
0.84
1.44
4.51
6.60
2.10
3.90
6.70
9.40
4.50
0.90
2.70
5.22
6.49
7.20
3.80
5.20
2.60
3.40
10.10
6.90
3.85
1.70
1.40
2.14
3.60
7.70
9.18
6.20
3.90
2.80
1.30
7.00
3.78
3.80
2.40
P. AMB
(FTH20)
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.8
31.8
31.8
31.8
31.8
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
32.0
32.0
32.0
32.0
31.9
31.9
31.9
31.9
31.9
32.0
32.0
32.0
32.0
32.0
32.0
32.0
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
TW
-------
RUN
-ptrr;—
180
181
182
133
trs
186
18'
IPS
189
190
"VT
192
193
194
195
196
T°T
198
log
7.00
201
203
-Z0"4
205
706
207
208
209
210
211
212
213
215
216
21"7
218
219
225
226
227
27.8
229
230
231
232
233
234
735
236
23-*
738
239
240
241
242
243
244
245
246
247
248
249
250
251
257
753
DEPTH
~ TFT)
18.33
18.83
18.83
13.83
tS.8-?
18.83
18.83
13.83
18.83
18.33
18. -87
18.83
18.83
13.33
13.83
18. P -
"IS. 53
13.83
18.3?
18.33
18.33
18.«3
I^T^
18.83
18.83
18.83
18.83
18. "3
18.33
18.33
13.13
18.83
18.8
18.3
13.3
18. 3
18.8
8.92
3.07
3.9?
3.92
3.02
8.0?
3. "2
8.0?
3.02
3.02
3.92
8.9?
8.0?
8.97
3.o?
8.Q2
3.92
3.92
8.P?
3.92
3.0 2
3.0?
3.9?
?.° 2
3.0?
8.92
3.02
3.0?.
9.07
S.4.VEI
2.34
1.87
1.94
2.31
2. ?3
2.44
1.88
2.45
1.91
2.90
7. ?5
2.33
1.91
2.37
2, "9
7. R9
2. 3T
2.34
2.91
2.43
2. 83
2. 37
1 ."''O
1.91
1.94
1. 9?
1.93
2.35
2.41
2.3-3
2.33
2.37
2.00
2.P7
2. 10
2. 33
2.91
2. 35
1.37
1.37
7.44
2.41
1.93
1.94
2.32
2.39
1.R6
2. =6
2.33
2. ."4
2.93
2.36
2. fr 3
2.97
2.37
1. °0
->.. 93
2. 17
1.90
.r..o4
2.36
1. 37
2. S4
2.41
1. 96
2. ' 3
TABLE A- 2.
OK A/W
T,P»11
24. 5
19.6
20.3
24.2
7-9. 6
25.5
19.7
25.6
20.0
30.3
79. 8
24.9
19.9
24.3
30.2
30.2
24.1
24.5
30.4
2K.4
29.3
74. 8
10.0
20.0
20.3
20.1
10.9
24.6
25.2
25. 0
24.9
24.8
30.3
30.0
30.3
30.1
30.4
24.6
19.6
19^6
25.5
25.2
20.2
20.3
24.3
25.0
19.5
29.9
29.6
29.7
30. 6
?O. 9
3C. 1
30. 5
24.8
19.9
30.6
24.8
10.9
30.3
24.7
19.6
29.7
25.1
20.5
24.4
-------
RUN DEPTH
Tltr.— — TFT1
254 3.92
255 3.92
256 3.Q2
257 3. "2
253 8.92
259 8.07
260 3. 'V
261 8.02
262 fi.o?
763 -
273
274
275
276
277
278
279
280
2H1
282
283
284
285
286
287
_2P3
289
290
291
292
293
295
296
297
298
209
-30.0 .
301
302
303
304
305
^06
307
303
309
310
311
312
313
314
315
316
317
318
320
321
?22
3?3
325
--3.9T '
27.02
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.52
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27.92
27. 52
27.92
27.92
27.92
27.92
27.92
....2.7... 9? .
27.52
27.92
27.92
27.92
27.92
27.92
27.92
27.52
27.92
27.92
27.5.2
27.92
27.. 52_
TABLE A- 2,
S.W.VcL QW A/4
"IPT/SETTl (GPMI (V/D1
l.T* ?0. 2 3i03
2.41 25.4 5.50
?..«4 29.7 2.29
1.F7 19.6 6.88
2.43 25.4 3.47
2.34 29.7 t.88
1.54 20.3 10.94
2.35 24.6 10.04
2.P3 30.-1 6.05
1.P3 19.7
1.88
2. 35
2. £3
2. 36
1.94
1 . c. 1
2.36
2.86
2.4C
1.86
2.4C
2.81
1.91
1. 65
2.39
2. E7
2.5C
2.4C
1.S2
1. E5
1.68
1.8H
2.33
2. t3
2.41
1.54
1.46
1.5C
2.3C
3.^2
2. 35
2.32
1.57
2.92
2. K4
2.41
1.51
3.41
2.35
1.51
2.88
2.53
2.4C
1.54
3.37
1.46
1.43
1.44
1.42
...... 3_._4..C —
19.. .7
24.6
29.6
24.7
20.3
20. 0
24. 7
30. 1
25. 1
19.7
75. 1
29.4
20. C _.
19.8
25. 0
30.0
30.3
25.1
?0. 1
19.4
19.7
19.7
24.4
29.6.
25.2
20.3
15.3
19. 9
29. 3
34.7
24.6
24.3
20. 1
3C.5
29.7
25.2
ZSjJSl
35.7
24.6
2.Q..O....
30. 1
30.6
25. 1
20.3
35.2
15.3
15. 0
15.1
14. 9
3_5_t6_
12.96
4. 08
2.15
1.72
2.78
7.10
10.31
6.23
3.21
1.37
3.97
5.57
2.57
3.55. .
14.^2
7.12
4.11
5.37
9.15
14.11
16.59
5.79
1.81
0.8"
.0.67...
2.58
4.61
6.0?
8.^9
2.53
3.79
6.12
7.19
1 > . 44
3.53
4.73
7.82
16.78
1.40
9.40
.1 5_,.7 9_
5.85
6.51
10.87
17.83
3.57
2.35
3.64
5.68
7.77
- . AnJQ3.-_.
(Continued)
P.AMB TH
( FTH2 m TFT '
32.0 68.
32.0 69.
32.0 •'O.
32.0 70.
32.0 •'O.
32.0 70.
32.0 71.
32.0 "U.
32.0 71.
32.0
32. .0 .
32.0
37.0
32.0
32.0
32.0
32.0
37.0
31.9
31.9
31.9
31.9
31.9..
31.9
31.9
31.9
31.9
31.9
3_U9
31.9
31.3
37.0
32.0
32,0 ..
32.0
32.1
37.0
32.0
32.0
32 0
32.0
32.0
37.0
_ 31.9
31.9
31.9
"> 1 . 9
31.9
31.9
3JL._9_ .
31.9
31.9
31.9
31.9
31.9
31.7
31.7
31.7
31.7
._- 3U7
70.
64.
64.
6?.
63.
64.
64.
64.
64.
64.
64.
65.
65.
66.. .
67.
67.
67.
67.
68 .
63,.
68.
5fl.
55.
57.
...57...-
58.
58.
59.
59.
60.
60,_
60.
61 .
67.
65..
65.
65.
66.
67.
67.
... 67^
67-
68.
63.
63.
68.
53.
53.
54.
54.
__.5.5.t ...
DELTA H KL(TW) KL(20 C»
3.96 0.217E-02 0.217E-02"
5.52 0.130E-0?. 0.12SE-02
5.60 0.245E-02 0.239E-02
".16 0.153E-02 0.149E-02
6.54 0.131E-02 0.127E-02
6.75 0.190E-02 0.185F-02
4.94 0.146E-02 0.14CJF-02
6.84 0.155E-02 0.149F-02
-'.89 0.163E-02 0.156E-02
4.58
2.30
2.74
3.74
3.54
7.80
3.22
3 .95.
4.44
2.94
2.27
3.61
4.24
3 .10
3.51
4.60
5.35
6.24
5.66
3.77
4.35
2.45
2 .09
2.48
.3,32
3.01
2.50
1.95
3.10
4.09
3,80
3.56
4.20
3 36
. 5.01
5.29
4.97
3.95
5 .98
5.19
3.71
6. IS
6 .86
6.01
4.42
7.36
1 .63
1.87
1 .89
2.0Q
__..7_.A3
0,
. ..0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.116F-02 0.113E-TI2
.115E.-02
. 140E-02
. 150E-02
.250F-02
.809E-03
.756F-03
. 10.1 E- 02..
.134F-02
.299F-02
-114F-02
.9306-03
.128F-02
...787ET.03 _._
.709F-03
.934E-03
.106E-02
.103F-07
.939E-03
. Oj.742.Er03
0
0
0
0
0
0
0
0
0
0
o
0
0
n
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.905F-03
.704F-U3
.219E-02
.326F-Q2
.460.E-02
. 146F-02
. 117E-02
.904F-Q3
.870E-03
. 166F-02
I ^4F— O1
. 102P-02
. 106E-02
.R57F-03
. 141F-02
. 118E-02
. 103F-02
.719F-03
.401E-02
.983E-03
.755F-03
.129E-02
.107E-02
.865E-03
.656E-03
. 144E-02
.128F-02
.824F-03
.633F-03
.505E-03
O
0
0
0
')
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
f\
0
0
f)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
Q.«.71_Q?-Q3 ___0
.IZUEr.OZ.
. 147F.-0?
. 160F-02
.268E-02
.852E-03
.797F-03
. 106£r02
.141E-02
.3156-02
.120F.-02
.968E-03
.133E-02
.80.8F-_03_..
.718F-03
.946E-03
.107F-02
.104F-02
.939F-03
.742F-OJL
.905F-03
.803E-03
.260F-02
.377E-02
.532F-02
.167E-02
.133F-02
»107F-07
.980E-03
.184F-02
* AQC. A7
.113F-02
.116F-0?
.97RF-03
.146E-02
.122F-02
.107F-02
.739F-03
.4Q7E-02
.996F-03
.765F-03
.130F-02
.1076-02
.865E-03
.6S6F-03
.144F-02
.156P-02
.100E-02
.767F-03
,«,08F-03
146
-------
TABLE A-2. (Concluded)
RUN
MO .
232
233
235
336
337
339
339
240
3.4.1 .
342
344
345
346
247
34 B
349
350
356
357
358
_3^9
.360
361
362
363
364
3b7
368
?69
370
371
372
373
374
375
377
378
379
280
381
332
383
384
385
386
3H8
389
390
391
392
393
394
395
396
397
398
400
401
402
CEPTH
IFT)
36.50
36.50
'6. .50
26.50
36.50
26.50
36.50
36.50
_.36_._5.0_
36.50
36.50
36.50
36.50
36.^.5.0
26.50
36.50
36.50
36.50
36.50"
26.50
''6.50
36.50
36.50
36.50 _
36.50
34.50
36,50
26.50
36.50
36.50
26.50
26.50
26.50
26.50
_36_._5_0_
36.50
26.50
36.50
36.50
36.50
36.50
36.50
36 ..50
36.50
36.50
36.50
36.50
26.50
26.50
36.50
36.50
26.50
26.50
36.50
26.50
36.50
._26_..5£_
36.50
26.50
S.W.VCL
(FT/SEC )
L..9.S
1.44
2.8C
2.41
l.fj
1.46
1.67
1.45
2.41
2. 67
I. 89
2.41
2.83
2.E5
2.41
U.t>._ . .
.. 1.46.. ...
1.41
1.38
1.4?
1.45
1.42
LSI
1.92
1.9C
f-51
L.v
l.SC
1.83
l.SC
1.S4
.. 1.66
1. 66
1.S3
1.43
2.4.1
2.J5
2.29
2.41
2.39
2.39
2.35
2. 38
2.38
2.29
2.E7
2. 81
2.e'e
2.65
2.83
2.fll
2. 85
2.P8
2.92
3.22
3.22
Q a 1
3.32
3.37
ow
(G°M)
~15JY~
2_9.«_3_
25.2
19.7
15.3
19. 6
15.2
25.2
30. 0
. .L9, 8_.
25.2
29.6
79. 8
25.2
20.0
,_.X9..6 ...
14.7~
14.4
15.6
15.2
14.9
20. 0
20.1
19.9
20.0
_ 1.9 ._9_
19.9
20.2
19.7
19.9
20.3
. 19.5
19.5
20.2
15. 0
25.2
24.6
25. 0
25.2
25.0
25.0
24.6
24.9
24.9
25.0
30.0
29.4
30. 1
29.8
29.6
29.4
29. 8
30.1
30.5
34.7
33.8
34.6
34.7
35.2
A/W
P.AXH
(V/CM (FTH2C)
__2.7.L ...JJ.2.0 .
3.61 32.0
2.78
5.78
5.83
9.11
10.39
5.66
3.22
1.0.. 7.7
6.36
3.94
4.41
6.36
14.20
>~. oV
4.98
11.17
11.97
8.40
1.49
2.65
3.86
5. 70
8t~53~
10.29
12.59
11.73
12.99
11.90
13.12
13.50
7.00
1.96
3.18
5.07
5.94
b.'iZ
6.69
7.55
fl.iZ.9.
9.03
10.02
0.78
1.65
2.37
3.22
3.88
4.25
4.66
5.26
5.65
3.45
2.92
1.70
3.00
3.91
32.0
32.0
32.0
32.0
32.0
32.0
32.0
31.9
31.9
31.9
31.9
31.9
3J. ,9_. _.
31.9 ..
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
.3JL.V_._
31.9
31.9
31.9
31.9
31.9
31.9
31.9
31.9
33.0
33.0
33.0
33.0
33.0
33.0
33.0
33.0
33.0
33.0
33.0
31.8
31.8
31.8
31.8
31.8
31.8
31.8
31.3
31.8
31.8
31.8
31.7
31.7
31.7
TW
(F)
...66.^
67.
69.
69.
70.
71.
72.
72.
71.
74,
74.
75.
75.
76.
76.
76.,
.. 70_.
71.
71.
71 .
72.
72.
73.
73.
73.
73.
.-7_3,_
73.
74.
75.
75.
76.
77.
77.
bB\
70.
_JUL._
70.
70.
71.
71.
71.
71 .
72.
72.
73.
73.
74j_
74.
74.
75.
75.
75.
75.
75.
75.
54.
54.
55.
3ELTA H
(FEFT)
2 ..55
2.15
4.04
3.53
2.89
3~*32 """
2.82
4.71
4,23
5.44
5.87
fr .17
5.79
4.41
r_"__2_..8A
2 .80
2.63
7 .77
3.03
3.24
2.88
3.12
3.24
^-47
KL ( TW I
(FT/SFCI
0.324E-02.
0.201F-02
0.226E-02
0. 48RF-02
0.210E-02
0. 127E-02
0. 158E-02
0.194F-02
0.103E.-02
0.121E-02
0.131F-02
0. 11 7P-07
0. 150E-02
0.930F-03
_0...853£.T-a3_
0.438E-03
0.277E-02
O.974F-f>1
0.910E-03
O.UOE-02
0.6 IOE-02
0.210E-02
0. 154E-02
O. \7DF-n7
*L ( 20 C )
( FT/SEC)
0.33.2E-0-2
0.290E-02
0.198E-02
0.220E-02
0.469F-02
0.202E-02
Q.120E-0?
0.1"50C-02
0.186F-02
Oj.95.5F.- 03 ..
0.112E-02
0.120E-02
0.102F-02
0.135E-02
0.837F-03
_.0_..1_46E-02
0.421E-03
0.266E-02
O.937E-Q3
0.863E-03
0.104E-02
0.197E-02
0.144E-02
0.1 12F-02
-3-.S3 .SLOW Er 0_2. __0 ,JLQ.3_F._^02_
3.99 O.lllE-02 0.103E-02
4.18 0.104E-02 0.964E-03
4.33 0.983F-03 0.896E-03
3.92
4.21
4.34
3.78
4.32
1.82
3.40
3~.72
4.09
4.44
4.75
4.98
5.23
5.62
6.08
4.17
4.30
4.86
5.18
5.49
5.70
6 .06
5.44
5.P5
7.50
6.63
5.70
6.51
7.52
0.941E-03
0. 101E-02
0.117E-02
0.971F-03
0.951E-03
0.522F-02
0. 154E-02
0. 145E-02
0.139E-02
0.137E-02
0.134E-02
0. 133E-O2
0.129E-02
0.119F-02
0.535E-02
0.249E-02
0. 172E-02
0.142E-02
0.132F-02
0.129F-02
0.132E-02
0.131E-02
0.127E-02
0. 159E-02
0. 168E-02
0.149F-02
0. 11BE-02
0.121E-02
0.858E-03
0.908E-03
^3_._104ILL0.2_
0.863E-03
0.834E-03
TJ.510E-03
0.508E-02
0 t2JU5Fr.Q2__
0.150E-02
0.141E-02
0.134E-02
0.132F-02
0.129E-02
0.128E-02
0.122F-02
0.113E-02
0.501E-02
0.23AE-02
0.159E-02
0.131E-02
0.122E-02
0.118E-02
0.120E-02
0.120E-02
0.115E-02
0.145E-02
0.153E-02
0.180E-02
0.142E-02
0.1A4E-02
147
-------
TABLE A-3. U-TUBE EXPERIMENTAL DATA WITH CALCULATED GAS
CONCENTRATIONS AND HEAD LOSSES AT OTHER STATIONS
D.O. CCNCENTR4TIONS (MG/LI 0. N. CONC.(MG/LI
RUN FNTP VENTURI BENO PLATF EXIT EXIT TRUE ENTR BEND TRUE
NO. EXIT FXIT ~ fCALCI (EXP» EXIT " EXIT EXIT
HSAO REL&TIVE TD INLET (FEET)
VENTURI BEND 9E*IO PLATF FXIT T°UF
EXIT ENTR EXIT
(FX
-------
TABLE A-3. (Continued)
RUN ENTR
NO.
ISO 1.94
181 l.BO
183 2.13
185 2.27
186 2.41
187 2.41
188 ?..?0
189 2.3J
190 2.13
191 2.27
192 2.78
193 T..36
194 2.25
195 2.11
196 2.11
197 J.19
1°8 1.81
199 1.67
200 2.08
201 J.06
203 2.17
204 1.92
205 1.99
206 1.R3
207 I.P3
208 1.74
209 l.Pl
210 1.83
211 1.64
212 1.73
213 1.55
215 1.47
216 1.45
217 1,55
--J 1.45
219 1.45
225 I,o2
226 1.94
227 1.61
228 1.62
229 1.7Q
230 1.70
231 1.77
232 1.60
233 1.51
234 1.70
235 1.67
236 1.57
237 1.55
238 1.51
23° 1.45
240 1.43
241 l.?5
242 1.68
243 1.66
244 1.41
245 1.40
246 !.40
247 l.?9
248 1.39
249 1.39
250 1.37
251 1.37
252 1.37
253 1.45
254 1.45
255 1.56
256 1.42
257 1.59
258 1.42
259 1.34
260 1.41
261 1.41
fBZ T.24
263 1.50
— n.'
VFNTl(l>
FXTT
2. '19
7.17
7.59
7.47
2.79
2.79
7.76
2.87
7.17
7. 6'.
7.16
2.R6
7.T
2.51
7.65
2.70
7.50
2.34
2.7?
2.69
7.27
'.09
7.33
2.27
2.38
7.35
2.39
'.44
2.4Q
7.11
1.6?
1.66
1.79
2.07
7.01
7.11
7.13
1.87
2.21
2.12
2.36
2.2°
7.45
2.14
T.75
2.09
2.11
2.16
7. 7.0
2.22
1.11
1.59
1.70
1.75
2.00
lioo
2.16
7.76
1.66
1.66
2.00
1.72
2.02
2.21
1.95
2.13
2.28
2°31
1. CIMCF'ITUATInN1; CIS/I)
I REN1")
EXIT
7.V
3.51
1.40
1.2=
3. 9K
4.70
4. 01
4. fl<1
'.2'
'.60
4.51
4. '1
4.52
3.71
3.13
4.6'1
4. ?H
3. '4
'.2?
3.11
3. ?.4
3. 35
3.68
3.0?
4.74
4.10
3.64
1.17.
4.04
3.2!
2.6".
2.43
2.67
3.0?
3.09
3.16
'.31
2. flfj
2.51
2.3a
3.31
3.46
3. 20
3. 34
4. 2°
t.04
2. 45
2.67
2.C2
2. 61
2. 72
2. 80
2. 36
7.71
I."
2. 7?
2. Or)
2.16
2. ""6
2.50
3.04
3.60
-2.10
2.44
2.68
2.14
3.17
3.07
2.51
3. 53
3. 36
7.62
3.63
OLATF
'.!?
4.')1
1.54
4.34
5.27
4.42
•i.51
'.51
1. 03
5.03
5.55
5.05
4.01
t-,22
•i.16
4. 84.
3.60
4.71
4.2.)
1.47
1.71
4.11
4.44
4.87
4 .90
'.09
4.28
4 .« 7
1.57
'.89
'.66
'.96
1.35
3.44
1.52
'.31
7.95
2.31
i.99
1.31
1.46
?.20
? .34
1.04
> .45
2.6'
7.52
2.72
1» 80
?.36
>• 71
'..93
' o j
7.16
7.76
1.7*
7.50
3.04
2\\3
2.44
2.68
7.14
1.12
3.02
3.51
'.51
1.36
2.62
?.63
PMT
(C»Lr.i
1.5')
4.1,1
4.21
3.92
4.91
6.03
5.01
t.Jl
!.92
4. -4
5.74
5.31
5.76
4.6'
4.91
5.51
5.61
4.25
5.41
4.71
1.75
4.50
4.70
5.21
5.65
•i.76
4.75
4.91
5.35
•4.14
3.10
3.D2
3.42
3.88
4.01
4.11
2.98
3.96
4.04
3.40
4.01
4.77
4.44
4.V)
6.04
2.2)
3.27
3.53
3.15
3.49
1.54
3.70
3.01
1.74
2.41
3.80
4.21
2. •'7
3.13
4.81
1.47
4. .77
5.40
2.73
1.42
3.55
Z.76
4.51
4.18
3.51
5.21
4.80
3.56
5.27
EXIT
(EXPI
1.50
4.69
4.73
3.92
4.9!
6.03
5.03
6.31
3.9J
4.44
5.74
6.33
5.76
'..64
4.81
5.91
5.60
4.75
5.41
4. 78
'.75
4.29
4.79
5.21
5.65
5.76
4.75
4. C8
5.35
4.14
3.19
3.02
3.42
3.88
'i. 01
4.10
2. OS
3.96
4. C4
1.40
4. OB
4.77
4.88
4.46
4.60
6.04
7.20
'.22
3.51
3.15
3.49
3.54
'.70
3.03
1.74
2.41
'.89
4.21
2.77
3.81
4.89
3.47
4.27
5.40
2.73
3.42
3.55
2.76
A. 51
4.19
1.51
5.21
4.80
3.56
5.27
TRUF
fXIT
3.37
4.49
4.06
3.77
4.69
5.78
4.78
6.0?
3.73
4.20
5.45
6.06
5.44
4.36
4.50
5.51
5.25
3.93
5.07
4.46
3.67
4.11
4.56
4.94
5.35
5.43
4.46
4.66
4.98
3.92
3.11
2.87
3.20
3.61
3.70
3. 77
2.66
3.55
3.57
2.98
3.48
4.13
4.19
3.76
1.78
5. IB
2. C7
2.80
1.01
2.73
2.94
7.94
3.01
2.72
3.30
2.16
3.34
3.70
2.41
3.22
4.18
2.90
3.50
4.61
2.43
3.00
3.05
2.41
3.90
3.45
2.91
4.41
3.18
2.87
4.52
I). N.
EMTR
l.BB
3.78
4.28
4.76
4.54
4.82
4.8?
4.60
4.60
4.26
4.44
4.56
4.72
4.50
4.22
4.22
4.38
3.62
3.34
4.16
4.17
4.34
3.84
3.98
3.66
3.66
3.48
3.62
3.66
3.28
3.46
3.10
2.94
2.90
3.10
2.90
2.90
3.24
3.88
3.36
3.24
3.40
3.40
3.54
3.20
3.06
3.40
3.34
3.14
3.10
3.06
2.90
2.86
2.70
3.36
3.12
2.82
2.80
2.30
2.78
2.78
2.78
2.7-.
2.74
2.74
2.90
2.90
3.12
2.84
3.18
2.84
2.68
2.82
2.82
2.48
3.00
CONC. (Mr,/ LI
BEN!)
FXIT
6.29
8.92
10.41
7.93
6.51
9.27
11.65
o. 54
12.38
6.52
7.94
10.62
12.31
10.59
8.17
1.61
10.90
10.54
".43
10.41
o.l8
5.7!)
7.94
10.55
11.08
12.13
12.44
10.07
10.10
10.74
8.19
4.67
4.79
6.02
7.47
7.99
S'.IO
4.06
6.37
6.37
5.16
6.86
7.73
8.75
7.73
8.31
10.61
3.85
5.10
5.95
6.02
6.43
6.56
6.63
4.17
6.,)5
1.30
5.76
6.94
4.61
6.82
9.01
5.15
7.17
9.06
4.65
5.48
6.63
4.52
7.77
7.49
5.80
8.71
7.94
6.08
9.45
TP.'IF.
EXIT
8. 01
11.71,
13.30
10.01
8.06
11.71
14.31
12.12
14.13
fl.ll
10.12
13.30
14. 7^
13.27
10.51
11.06
11.57
13.2D
11.08
13.07
11.77
6.90
10.44
13.55
14. O'
14.0Q
15.03
12.00
13.04
13.65
10.80
5.87
6.1.1
8. OB
10. D3
10.75
10.88
6.82
8. 00
0.2"
7.1 =
a ,94
11.11
12.41
11.24
11.95
13.07
4.42
7.07
8.56
1.6''
9.40
0.58
0.03
6.53
8.77
4.34
1.56
10.47
6.43
10.14
11.80
8.53
10.81
12.75
6.53
8.17
0.72
6.22
11.42
11.03
1.55
12.55
11.56
9.07
13.21
HEAR RELATIVE Tn INLET (FFETI
VENTURI
' EX IT
1.40
1.15
1.35
l.RO
2.20
l.BO
1.60
1.15
1.80
2.65
2.80
2.50
l.fil)
2. 85
1. 10
3.60
2.90
3.00
4.25
3.35
4. ,)0
1.40
1.20
1.40
1.70
1.90
2.20
2.60
3.00
3.20
1.75
1.50
2.20
2.15
l.tO
4.00
4. ?5
1.70
1.10
1.20
l.c j
2.7Q
1.65
l.°0
2.80
3. HO
2.20
1.90
2.50
3.10
1.75
4. 10
4.75
5.15
1.65
1.25
2.20
1.80
1.35
3.00
7.. 90
1.70
1.70
3.65
2.. 10
1.55
1.20
2.70
2.75
1.50
3.65
3.75
2.20
3.80
4.90
1.75
BEND
ENTR
2.00
1.95
2.35
2.40
2.80
2.80
2.80
3.20
3.30
3.50
3.65
3.65
3.20
4.15
4.2')
4.60
4.20
4.50
5.35
4.70
5.15
2.00
1.95
2.35
2.75
3.30
3.75
3.75
4.15
4.65
2.7J
2.01
2.85
3.65
4.35
5.00
5.25
1.90
1.45
1.55
2.25
3.15
2.15
2.65
3.40
4.60
3.50
2.15
2.80
3.50
4.20
4.65
5.25
5.75
1.90
1.60
2.50
2.20
1.85
3.30
3.40
2.35
4.10
4.25
2.90
1.90
1.60
3.15
3.00
2.00
4.25
4.25
2.90
4.60
5.40'
2.65
REND
f XIT
2.11
2.02
2.42
2.51
2.97
2.93
2.87
3.33
3.38
3.68
' 3.83
3.78
3.27
4.27
4.39
4.79
4.32
4.62
5.54
4.83
5.33
2.11
2.02
2.42
2.83
3.38
3.83
3.87
4.28
4.78
2.82
2.11
3.03
3.83
4.54
5.19
5.44
2.01
1.52
1.62
2.37
3.28
2.23
2.73
3.52
4.74
3.59
2.32
2.99
3.68
4.40
4.84
5.45
5.96
2.02
1.67
2.68
2.32
1.92
3.49
3.53
2.42
4.29
4.39
2.99
2.01
1.67
3.28
3.18
2.07
4.39
4.43
2.99
4.73
-5.60~
2.73
PLATF
2.22
1.91)
2.33
2.57
3.15
2.93
2.70
3.30
3.12
3.86
3.93
3.65
3.02
4.13
4.46
4.83
4.15
4.43
5.55
4.68
5.30
2.25
2.02
2.31
2.66
3.13
3.52
3.75
4.16
4.58
2.82
2.25
3.23
3.97
4.61
5.21
5.46
4.34
3.85
3.95
4.70
5.61
4.56
5.06
5.85
7.07
5.92
4.65
5.31
6.01
6.73
7.17
7.78
8.2°
4.35
4.10
5.01
4.65
4.25
5.87.
5.86
4.75
6.62
6.77
5.32
4.34"
4.00
5.61
5.51
4.40
6.72
«.76
5.32
7.06
"7. 93"
5.06
EXIT
(EXPI
2.50
2.50
2.70
3.00
3.50
3.30
3.20
3.60
4.00
1.80
4.7.0
4.50
3.65
4.80
5.00
5.25
5.25
5.50
6.20
5.80
6.20
2.50
2.25
2.75
3.25
3.. 80
3.90
4.50
5.00
5.50
3.50
2.50
3.50
4.25
5.25
5.80
6.10
2.50
2.50
3.00
3.00
4.00
4.00
5.00
5.00
6.00
6.00
3.00
3.75
4.50
5.00
5.75
6.50
7.25
2.50
2.50
3.30
3.50
3.50
4.25
4.50
4.50
5.25
5.50
5.50
" 2.50
2.50
4.00
3.75
4.00
5.50
5.00
5.50
7.00
6. f}~
7.00
TRUE
EXIT
2.32
1.88
2.15
2.61
3. 32
2.88
2.42
3.22
2.73
4.01
3.99
3.45
2.64
3.93
4.50
4. 83
3;91
4.19
5.52
4.49
5.23
2.40
1.99
2.11
2.39
2.75
3.10
3.57
3.99
4.33
2.78
2.40
3.44
4.08
4.65
5.20
5.44
4.40
3.79
3.86
4.75
5.52
4.35
4.74
5.65
6.83
5.22
4.-S5
5.39
6.02
6.73
7.13
7.73
8.2T
4.41
3.93
5.18
4.61
4.07
5.^)1
5.71
4.45
6.60
6.53
4.84
3.96
5.52
5.60
4.16
6.54
6.75
4.94
6.84
T. 89
4.58
149
-------
TABLE A-3. (Continued)
BUM FNTP
NT.
273 1.38
274 1.88
275 1.81
276 1.01
277 1.96.
278 1.96
270 1.88
280 1.70
281 7.4P
282 2.40
283 7.38
284 7.79
285 2.44
786 2.40
287 2.24
28B l.c 8
280 i.yp
290 2. IP
291 2.44
292 2.52
293 2.85
295 2.39
296 2. 13
297 2.72
298 2.39
29" 2.58
300 2.64
301 7.64
302 2.43
303 2.05
304 2.43
305 2.49
306 2.61
307 2.02
308 2.11
300 7.20
310 2.35
311 2.24
312 2.15
313 2.32
314 1 .89
315 1.96
316 1.96"
317 2.22
318 1.96
320 2. "3
321 2.33
322 3.09
323 2.89
325 2.95
VFNTur- I
FXIT
2.14
7.08
2.0.1
2.07
2.4f
2.50
2.43
2.19
2.52
2.72
7.85
2.58
2.92
3.26
2.82
2.45
2.63
2.01
3.21
3.44
3.17
Z.50
2.21
2.30
2.62
2.96
7.86
3.11
2.71
2.63
2.O3
3.35
3.30
2.44
2.64
2.35
3.27
2.45
2.C9
3.19
2.55
2.69
2.fl«
3.72
2.48
3. "2
2.96
3". 28
3.15
3.45
8F.N1? PIATF [KIT
FX IT
4.C5
3. 1C
~L • '6
4. 1C
1.55"
5.26
A . ? 2
3. S2
3.'.£
' • 4 8
4.15
3.45
'., 19
6. 1?
4 . 6C
3 • b 3
3. "91
5.0C
6.C7
7.31
* • 6 6-
4.14
2. 13
3.T5
3. "8
4. SB
5.66_
5.7P
3.85-
Z.76
'. ft
5.?4
£ • c C
3 .06.
' . 99
4 . c 7
£ .45
3.46
5.20
6.36
4.24
4. 17
5. C7
6.16
3.52
4.79
4.67
5.41
5. 48
4.11
ICALC)
4.8] 5.27
.1.54 3.84
3.10 3.34
4.79 5.15
5.46 5.58
6.34 6.86
5. 14 5. £3
i . » 5 4.20
« .C6 4.27
c . 1 c' 5 . 61
6.C4 5.46
J . 3 1 '< . 1 4
6.13 £.61
7.74 7.65
5.40 5.65
4.C4
3.72 3.76.
3.21 3.62
5.00 3. '.2
b.71 3.92
6.66 3.92
5.40 3.76
4.02 3.58
4.19 <.. BO
5.46 4.98
5.27 4.76
4.00 4.51
6.42 4.38
7.47 4.98
5.62 4.4P
4.19 3.06
'•.66 3.96
6.09 4.36
7.39 4.38
8.55 5.04
5.91 5.70
4.87 4.78
3.53 4.26
3.34 4.44
4.63 4.78
6. 1 1 5.16
7.01 5.78
7.15 5.28
4.52 4.86
2.87 4.K
5.95 4.8b
6.47 4.9P
7.95 5.72
4.33 4.04
4.71 4.22
6.09 4.4C'
7.83 4.70
3.92 4.4E
6.37 4.3C'
7.75 4.64
5.15 3.78
5.00 3.92
6.20 3.92
7.43 4.44
4.12 3.92
5.66 5.86
5.91 5^.66
6.62 6. IP
6.80 5.7t>
4.54 5.90
C1.. M- . 1 Tj/ L I M
HF\in TP!JC V=NTUP
FXIT EX. IT
10.46 13.41
7.32 9.45
6.30 8.02
P. ?<> 10.65
12.9" 15.7,3
14.67 16.74
11.40 14.35
8.00 10.47
7.05 8.55
11.10 13.80
11 .36 14.0'(
e.06 10.12
l''.0» 10.21
If. 71 16.75
11 .90 14.57
f ."6 11.40
0.08 17.59
17.70 14.98
If'. 41 16.51
15.93 16.52
13.67 16.34
H.55 10.75
6.99 7.17
5.60 6.44
3.98 11.26
12.2? 15.17
14.06 17.39
15.04 17.37
8.45 10.61
8.91 11.41
17.3? 15.22
17. 9P 15.70
16.02 I7. 51
P. 56 11. .17
Q.70 12.45
12.45 15.03
13.92 16.80
6.33 7.57
13.02 15.31
15.73 16.70
10.15 12. °8
10.47 13. OS
1'3.11 15.20
15.52 16.35
8.12 10.36
11.27 !3."0
13.25 16.02
15.70 19. D3
17.18 18.88
10.37 12.70
EX IT
1.15
1.50
2.20
1.B5
1.65
1.80
2.40
2.85
1.35
1.75
2.15
2.50
1.7C
I.b5
3.15
3j_6_5
3.r-0
2. CO
2.70
1.30
0.05
1.20
1.70
1.65
1.30
0.75
1.80
2. 40
2.25
2.00
2.65
1.75
3.25
3.50
3.25
.3. CO
3.75
3.35
1.85
4.10
4. HO
3.95
2.25
5.00
0.65
0.70
0.7C
n.ST
5.15
~t\' > r* r.L w i i v r '
T 8FNO BEMO
F.NTR
2.45
2.35
3.00
EX IT
2.52
7.46
3.17
3.25 3.36
3.35
4.20
4.15
3.90
2.40
7.40
3.70-
3.65
3.85
5.00
4.90
4.95
6.00
6.20
5.20
6.30
2.85
1.90
1.90
2.40
2.65
2.70
2.55
3.85
3.50
3.00
3.75
4.55
4.60
4.50
5.00
5.35
5.70
4.65
5.80
5.35
6.00
6.75
6.75
6.25
6.60
1.70
2.15
2.45
2.85
6.70
3.42
4.28
4.27
4.03
2.52
2.47
3.82
3.82
3.92
5.08
5.02
5.13
6.19
6.33
5.28
6.38
2.97
1.96
2.01
?.57
2.77
2.77
2.58
3.0?
3.67
3.25
3.87
4.67
4.68
4.60
5. IP
5.48
5 .78
5.11
5.92
5.43
6.19
6.95
6.83
6.34
6.86
1.73
2.18
2.48
2.88
6.06
PL1TF EXIT
2.42
2.67
3.59
3.51
3.08
3.66
4.10
4.36
2.9!
2.38
3.73
4.14
3.45
4.13
4.78
5.32
6.26
5.90
4.35
5.08
2.67
2.07
2.32
3.08
2.95
2.64
2.24
3. '.5
3.99
3.67
3.71
4.40
3.99
4.95
5.30
5.17
4.64
5.78
5.46
4.37
*».21
6. 92
6.29
5.11
7.79
1.60
7.02
2.16
7.39
7.36
(FX»I
3.00
3.00
4.00
4.00
4.00
5.00
5.00
5.00
3.00
3.00
4.50
4.50
4.50
6.10
6.00
6.00
7.50
7.50
7.50
9.25
3.50
2.50
2.50
3.50
3.50
3.50
3.50
4.50
4.50
4.50
4.50
5.50
5.50
5.50
6.50
6.50
6.50
6.25
7.50
7.50
7.25
9.75
a. so
8.50
7.70
2.50
?.oo
3.50
4.00
7.90
TPIJC
FXIT
2.30
2.74
3. 74
3.54
2.80
3.22
3.95
4.44
2.94
2. it
3.61
4.24
3.10
3.51
4.60
5j_35
6.24
5.66
3.77
4.35
2.45
2.09
2. *«
3.32
3.01
2.50
1.95
3.10
4. 11
3.90
3.56
4.20
3.36
5.01
5.29
4.97
3.95
5.98
5.19
3.71
6.14
6.86
6.01
*.*2
7.34
1.63
1.87
1.89
2.00
7.43
150
-------
TABLE A-3. (Concluded)
RUN F*|T°
Nil.
332 1.66
331 1.73
334 1.54
315 1.'4
336 1.44
337 1.42
33" 1.65
33*) 1.10
340 1.10
141 1.80
34? I.(5
344 1.1.8
}45 l.<>0
346 1.77
347 1.77
34H 1.34
341 1.^7
150 1.47
351 1.56
355 1.59_
356 1.5°
357 1.57
358 1.57
35" 1.57
360 1.55
361 1.47
162 1.22
361 1.18
364 1.30
365 l.ft
366 1.38
367 1.36
368 1.44
361 1.67
370 1.50
371 1.5P
372 1.47
371 1.40
174 I . 18.
375 1.53
376 1.11
377 1.38
378 1.38
371 1.55
380 1.73
381 1.71
382 1.71
383 1.71
3fl4 1.7"
385 1.78
3P6 1.78
387 1.45
388 1.45
389 1.45
310 1.43
HI 1.41
312 1.43
113 1.34
314 1.34
395 K34
316 1.14
3"7 1.73
318 t.50
400 l.Bl"
401 1.71
402 1.71
I).'I. CUI"CFI,TFAlIt)NS (HG/L) n. N. CCNC.IMG/LI
iEI'TW I HPir PLATF F»|T FXIT |-R (jf fuTf prun T«UE
FXIT FX|"T
ICALC) (EXPI EXIT
FXIT EXIT
---- H;AO BELSTIVE TH [MLF
VENTURl RENO BEND PLATF
F.tTP FXIT
EXIT
Ta gc
1.94
1.811
1.58
1.55
1. 12
1.30
1.81
2.44
7.21
2.12
2.06
2.14
2.11
1.71
1.66
2.44
2.51
2.41
1.74
1.80
1.65
1.76
2.03
1.P1
1.31
1.57
1.57
1.71
1.66
2.12
2.44
2.24
2.41
2.20
Z.21
1.82
1.11
1.40'
1.50
1 .70
2.06
2.14
2.1"
2.54
7.58
2.tt
1.41
.56
.66
.74
.84
.11
.12
.00
2. '15
2.23
I .14
2.16
2.25
2.18
6.*41
i. 17
3. 16
3.7P
6.H2
7. 11
6)41
4.13
3.1B
?.44
(.71
5.5Q
5.51
4.C7
7.3 2
7.24
7.26
3. 71
3.^6
4,?7
4. »0
5.76
6.12
6.74
6.26
6. 17
t.t.2
4.42
4.40~~
2. '6
4.24
4.?2
4. SI
E.J7
'.. 68
t.r 7
6,14..
2.57
2.13
3.C1
3.21
3.50
•".55
3.74
3. -7
4.04
3.59
3.23
3.C5
3.47
2.50
5.81 «. S5
7.07 6.12
2.30 2.13
.3.13 _3..06_
4.57 4.62
7.68 1.61
t.74 7.75
".26 6.77
9.11 6.65
6. M '..55
4.70 4.16
7.77 7.95
5,»0 6..C9
4.15 4.44
,_4.2.2 _4.52__
6.^5 >.29
8.13 5. 1C
f..?; 7.0')
•:.T> '..41
1.C7 7. Id
5.C7 5.45
7.>;5 7.57
6.61 5.50
8.00 6.02
4.03 3.SS
4.73 4.94
5.24 5.51
^.••4 e.24
6.54 f..1(
7.01 7.21
_.J..49 7.62_
•i.09
1. J5
3. 04
3.07
7.99
5.96
b.96
3.84
4. 75
5.35
6.21
6.65
6.83
7.17
7.43
1.53
7. 61
2.50
2. 10
3.62
3.81
4.22
4.54
4.65
4.89
5.20
5.26
4.49
4.10
3.69
4.98
6.15
8.10
8.38
6.39
6. 39
7.13
5.30
7.64
3.61
8.01
3.16
4. 86
5.40
.6.11
7^20
7.55
8.00
7.70
8.04
8. 11
7.98
5.93
5.63
2.98
4.73
5.24
6.07
6.6)
7.04
7.31
7.42
7. 50
1.98
2.87
3.53
3. 71
4.07
~4. 4~7~
4.71
5.07
5.09
4.31
1.94
3.57
4.76
3.32
3.46
3.08
2.86
2.38
2.84
3.30
3.80
3.60
3.60
3.3C
3.36
3.20
2.54
2.54
2.66
3.1'
3.14
3.12
3.18
3.18
3.14
3.U
3.1T
2.94
J,44
2.76
2.60
2.76
2.76
2.76
_Zj9.8
3.34
3. Of
3.16
2.94
2.80
3.06
3.06
2.62
2.76
2.76
3.10
_3.*.4.6_
3.42
3.42
3.56
3.5o
3.5/1
2.90
2.90
2.10
2.86
2.86
2. 66
2.68
2.63
2.63
2.68
3.46
_L-JO_
3.7U
3. ..58.
3.58
8.68 11.49
11.36 14.54
3.81 4.44
4.3° 5.40
7.53 11.08
11.72 14.97
13.59 16.55
14.21 16.68
15.13 17.41
10.71 13.70
7.11 10.35
14.13 16.12
10. C4 13.63
7.12 10.54
8.50 11.22
10.41 13.26
14.44 16.04
14.11 16.21
17.34 14.6,1
10.61 13.69
12.53 15.50
14.16 16.25.
12. «1 15.79
16.01 17.10
14.10 16.87
5.06 7.56
7.75 10.13
1.26 1>.73
11.1° 14. Ib
12.35 15.11
13.07 15.64
11.69 15.91
14.51 16.18
14.13 16.06
14.25 16.00
14.05 15.85
14.26 16.01
14.53 17.06
15.71 17.81
4.37 5.51
6.31 P.. 46
8.04 10.63
10.24 13.38
11.15 14.24
11.57 14.58
12.16 15.08
12.57 15.38
12.80 15.46
13.13 15.63
1.42 3.77
4.24 5.15
5.57 7.22
6.42 8.47
7.43 9.63
P. 11 10.70
8.30 10.98
8.63 11.35
1.11 11.93
9.35 12.16
7.72 9.93
6.93 1.06
6.66 8.44
9.15 11.99
1.10
0.70
1.35
1.15
1.75
1.35
O.bO
1.75
O.
-------
APPENDIX B
FULL-SCALE U-TUBE EXPERIMENTAL DATA
This appendix contains experimental data, plus mass transfer coeffi-
cients calculated from the data, for full-scale U-tube installations at
Jefferson Parish, Louisiana, and Port Arthur, Texas. The data are pre-
sented in three tables, the contents of which are described in the fol-
lowing paragraphs.
Table B-l contains the experimental data obtained at the two U-tube sites
in Jefferson Parish, Louisiana. Series 500 run numbers were assigned to
data for location 5, and series 700 run numbers correspond to data for
location 7. Qw is the water flowrate; y is the air-to-water volume frac-
tion at 1 atm and 77°F. Initial oxygen demand for the influent (lOOD^)
and dissolved oxygen for the effluent (D.0.e) were determined by the
Winkler method. The influent dissolved oxygen levels and effluent IDOD
levels had been spot checked and found to be consistently zero. Total
oxygen transfer was then determined by adding IDOD^ and D.O.e-
Static heads (H) at the various stations are given in inches of water,
referenced to the elevation of the venturi centerline. These values
may be converted to absolute pressures by the relationship:
P = H + z + pQ
where z is the distance between the venturi centerline and the station
pressure tap (see Fig. 18 and 19 for dimensions) and p0 is the ambient
pressure. For example, for run 500, the value given for H^ = 48 means
that the static head at station 3 is 48 inches of water above the as-
pirator centerline and the absolute pressure at station 3 (if p0 = 1 atm)
is 4.0 + 0 + 34.0 = 38.0 feet of water; the value of tij - -98 means that
the static head at station 7 is 98 inches of water below the aspirator
centerline and the absolute pressure is -8.2 + 39.0 + 34.0 = 64.8 feet of
water. It should be noted that head measurements at station 9 for loca-
tion 5 were not obtained, because this test port became plugged during
the U-tube installation and could not be cleared. The mass transfer
coefficients (KL) were calculated from the other data using the data re-
duction program as described in Section VII of this report. It can be
noted that some tests were made to obtain pressure drop information
alone, without making oxygen measurements.
Tables B-2 and B-3 contain the field test data obtained at the Pioneer
Park lift station, Port Arthur, Texas. Dissolved oxygen determinations
at this location were conducted using the 15-minute modified Winkler
method (azide). The total oxygen transfer in the U-tube was calculated
as: D.O.Q + IDOD. - IDOD-.
6 1 c
153
-------
TABLE B-l. JEFFERSON PARISH U-TUBE EXPERIMENTAL DATA
Run
No.
500
501
502
503
504
SOS
506
507
503
509
510
511
512
513
514
515
516
517
518
519
s:o
521
522
523
524
525
526
527
528
529
530
531
532
533
534
0 com
>
-------
TABLE B-l. (Concluded)
Run
No.
535
556
537
538
539
540
S41
542
543
544
545
546
547
543
549
700
701
702
703
704
705
706
707
708
709
710
711
712
713
Qu. 8P»
1830
1940
1940
1940
1980
1900
1920
2030
1950
2000
2020
1940
2000
2020
2160
620
535
520
580
610
190
190
795
890
770
795
830
840
890
y
at 1 atm,
77 F
(volume
fraction)
0.114
0.077
0.066
0.042
0.040
0.039
0.062
0.059
0.061
0.021
0.020
0.020
0
0
0
0
0
0
0
0
0.209
0.209
0.042
0.038
0.083
0.075
0.072
0
0
IDODj, mg/i
0.9
1.2
0.6
0.5
-
-
0.5
-
-
-0.7
-
-
-
-
-
-
-
-
-
0.0
-
1.2
-
1.2
-
-
-
D.0.e, mg/H
5.5
3.5
4.1
1.9
-
-
3.0
-
-
1.8
-
-
-
-
-
-
-
-
-
-
6.0
-
3.4
-
5.1
-
-
-
Oxygen
Transfer,
mg/t
6.4
4.7
4.7
2.4
-
-
3.5
-
-
1.1
-
-
-
-
-
.
-
-
-
-
6.0
-
4.6
-
6.3
-
-
-
Head Relative to Venturi Centerline, inches of water
Station 3
84
-8
5
-19
-27
-
-10
-11
-
-45
-43
-
-61
-
-63
-51
-71
-68
-69
-69
S3
61
17
12
100
100
-
-41
-40
Station 5
22
-74
-58
-79
-78
-81
-76
-75
-75
-87
-83
-82
-87
-85
-85
-82
-82
-80
-80
-80
-13
-13
-53
-52
-3
-1
-10
-60
-62
Station 6
-15
-81
-75
-82
-82
-85
-81
-81
-81
-83
-83
-82
-82
-90
-90
-69
-69
-67
-74
-74
-23
-23
-54
-S3
-22
-21
-20
-59
-63
Station 7
-110
-105
-90
-90
-87
-90
-90
-91
-94
-88
-88
-88
-87
-85
-83
-94
-94
-90
-92
-93
-96
-95
-89
-87
-89
-92
-91
-92
-90
Station 9
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-64
-69
-76
-80
-79
-99
-101
-73
-75
-87
-88
-92
-62
-66
Station 10
-117
-90
-85
-93
-94
-96
-94
-96
-96
-96
-94
-95
-95
-94
-92
-63
-63
-87
-91
-90
-108
-109
-93
-90
-95
-96
-101
-81
-80
KL x 103
at 20 C,
ft/sec
0.816
0.737
0.957
0.596
-
-
0.647
-
-
0.572
-
-
-
-
-
-
-
-
-
-
-
-
1.14
-
0.795
-
-
-
-------
TABLE B-2. PORT ARTHUR U-TUBE EXPERIMENTAL DATA
on
Run
• No.
807
819
820
821
822
823
824
s:s
826
827
828
829
850
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
V
gpm
1400
1379
1386
1379
1365
1344
1386
1379
1379
1379
1344
1120
1127
1113
1120
833
833
833
833
833
574
581
567
567
581
315
378
399
406
399
588
574
y at 1 atm,
77 F
(volume fraction)
0
0.043
0.011
0.022
0.033
0.04S
0.011
0.022
0.033
0.054
0.078
0.094
0.066
0.040
0.013
0.018
0.054
0.090
0.090
0.126
0.182
0.129
0.132
0.132
0,026
0.048
0.277
0.187
0.111
0.038
0.051
0.130
IDODj,
mg/J,
--
—
7.70
7.70
7.70
6.50
6. SO
7.40
7.10
9.03
9.03
8.73
9.33
10.02
9.33
9.33
9.03
--
6.91
6.91
6.30
--
5.70
2.20
2.90
2.60
6.30
8.13
6.92
5.70
7.22
6.30
IDODe,
ug/Z,
—
.-,
--
--
--
--
6.20
5.90
5.00
4.78
5.70
6.30
6.78
7.52
7.52
7.57
8.60
--
1.42
1.42
0
-
1.75
0
l.S
0
0.12
4.18
3.94
4.33
5.88
3.85
D.O. ,
rag/H
--
--
0
0
0
0
0
0
0
0
0
0
0.80
0.60
0
0
0
-
1.2
0.9
3.2
--
1.80
2.20
2.30
1.70
0
4.20
3.70
3.80
2.90
3.60
Oxygen
Transfer,
mg/l
.-
--
--
--
--
—
0.30
1.50
2.10
4.25
3.33
2.43
3.35
3.10
1.81
1.76
0.43
--
6.69
6.39
9.5
--
5.75
4.40
3.7
4.30
6.18
8.15
6.68
5.17
4.24
6.05
Head Relative to Pump Centerline, feet of water
Station
1
24.0
24.5
23.8
24.1
24.2
24.3
--
--
--
25.0
27.8
29.6
26.1
21.9
20.6
19.4
22.0
27.7
29.8
31.0
34.8
31.6
33.1
32.2
29.8
--
36.6
33.4
31.7
31.3
25.8
31.4
Station
4
23.3
23.8
23.5
23.6
23.7
23.8
23.5
23.6
23.7
24.3
24.8
27.5
24.3
21.8
21.2
20.1
21.7
27.3
28.9
30.3
33.3
26.3
31.2
28.2
28.4
27.8
25.3
23.3
28.5
26.2
21.6
25.5
Station
6
23.4
23.5
23.4
23.4
23.4
23.3
--
--
--
23.5
23.4
22.2
22.4
22.2
22.1
21.1
21.3
21.3
21.4
22.9
26.0
24.2
23.5
23.8
21.2
--
25.3
23.2
23.7
22.3
22.0
21.4
Station
7
23.4
23.2
23.3
23.2
23.1
22.9
--
--
—
23.1
22.9
21.8
21.9
21.8
22.0
21.0
20.8
20.7
20.6
20.4
19.6
19.6
20.1
20.2
20.4
19.9
19.8
19.0
19.5
19.4
19.8
19.6
Station
9
23.0
22.6
22.9
22.8
22.6
22.4
--
—
--
22.6
22.3
21.2
21.5
21.4
21.9
20.8
20.4
20.3
20.1
19.9
18.7
19.4
19.7
19.6
19.5
19.8
18.2
19.1
19.5
19.3
19.8
19.6
Station
10
23.0
22.9
22.6
22.7
22.6
22.3
23.6
22.7
22.6
22.7
22.3
21.3
21.4
21.2
21.2
20.2
20.3
20.2
20.3
20.1
19.7
20.3
19.8
20.1
20.3
19.8
19.9
19.7
20.0
20.1
20.4
20.4
KL x 103
at 20 C,
ft/sec
—
--
--
--
--
--
0.324
0.896
0.870
1.06*
0.531
0.263
0.513
0.741
1.44
0.714
0.517
--
0.809
0.538
0.523
--
0.498
0.321
—
0.530
0.132
0.237
0.323
0.936
0.547
0.352
-------
The meaning of the static head columns is identical to that explained
above for Table B-l. Figure 25 gives the physical dimensions of the
U-tube system and locations of the stations.
Table B-3 contains total sulfide data obtained from five runs at the
Port Arthur installation. Standard chemical methods (Ref. 34) were
utilized for these on-site determinations.
TABLE B-3. PORT ARTHUR TOTAL SULFIDE CONCENTRATION DATA
Run
No.
827
831
834
837
840
Qw>
gpm
1379
1113
833
833
567
y
at 1 atm,
77°F
(volume fraction)
0.054
0.040
0.054
0.013
0.132
Total
Sul fides
Influent
(mg/£)
2.0
1.6
1.5
0.8
0.6
Total
Sul fides
Effluent
(mg/£)
0.4
0.2
0.5
0.6
0.4
Percent
Reduction
80
87
66
25
33
157
-------
APPENDIX C
U-TUBE DESIGN PROGRAM
This appendix contains a listing of the U-tube design program developed
during this project, complete instructions for preparing input data cards,
and sample input data. Engineering and computational details about the
program are given in Section VIM, U-tube Design; samples of the program
output are given in Appendix D.
As previously discussed in the U-tube Design section, the program in its
current form can make analyses for three major configurations or problem
types: (l) aspirated-air U-tubes installed in the end of a force main
(i.e., full-flowing pipe under pump head); (2) compressed-air U-tubes
installed in a force main; and (3) eductors, which are essentially com-
pressed-air U-tubes with the diffuser located at the bottom of the up-leg.
These are indicated by the value of KTYPE (l, 2, or 3 for the three cases,
respectively), which is one of the input variables.
Three types of input data cards are used to supply the required informa-
tion to the program. The first two types (called General Information
and Problem Type cards) are identical in format for all three problem ,
types. The third type of input data card (called a Case card) is different
for each of the problem type options. Multiple cases may be run. Blank
cards are used to terminate the reading of one card type and step back
to the previous card type in the input sequence. The input data cards
described below, in the order in which they must appear in the data deck.
General Information Card (actually 2 cards - FORMAT 12F6.1/3F6.k, 12)
Variables marked with a superscript 2 can be left blank for KTYPE = 2;
Variables marked with a superscript 3 can be left blank for KTYPE = 3.
2 3
ANGC Full-cone angle of aspirator contraction section, degrees
2 3
ANGE Full-cone angle of aspirator diffuser sect ion,degrees
ELR Center 1ine-to-face distance for pipe elbows divided by nominal
pipe diameter (normally 1.5 for long-radius or 1.0 for standard
radi us elbows)
159
-------
ELK
F21
2,3
F22
2,3
USDOWN
USUP
XI DOWN
XIUP
PEXTRA
ALPHA
DPTOL
2,3
HTEST
STPSZ
Normal loss coefficient for pipe elbows, expressed as one-phase
loss in velocity heads (normally 0.46 for long-radius or 0.75
for standard-radius elbows)
Length of straight pipe spool downstream of aspirator (see
Fig. 44) divided by pipe diameter
Length of straight pipe spool upstream of aspirator (see Fig.
44) divided by pipe diameter
Slip velocity in downward flow, ft/sec (normally use results
from this project, 0.2 ft/sec)
Slip velocity in upward flow (opposite sign convention to
USDOWN so that it is also positive), ft/sec (normally use
results from this project, 0.2 ft/sec)
Air-water interfacial area per unit volume of air in down-leg,
I/ft (normally use results from this project, 470./ft)
Air-water interfacial area per unit volume of air in up-leg,
I/ft (normally use results from this project, 470 ./ft)
Difference between ambient pressure and aspirator throat pressure,
calculated on one-phase basis, ft water (normally use about
3-4 ft water)
Ratio of mass transfer coefficient for waste water of interest
to mass transfer coefficient of "tap water" (normally use about
0.9 for treated effluent, 0.8 for not seriously septic sewage)
Tolerance within which the exit pressure must match the soecified
value before the iteration procedure will terminate (for most
purposes, a value of about 0.01 ft water is a good value to
use)
Tolerance within which the numerical root-solving procedure
in subroutine HERSHY must converge (a value of about 0.001
is recommended)
Stepsize for the finite-difference calculations along the U-
tube path, ft (for most cases, the results for the numerical
integration are effectively constant for STPSZ below 0.5 ft
down to such small values that roundoff errors begin to become
important; a value of about 0.1 ft is recommended for routine
calculati ons)
160
-------
KTOP Maximum number of iterations permitted in converging to required
criterion (most cases have converged, with DPTOL approximately
0.01 ft water, in 2 to 8 iterations; therefore, a value of about
20 for KTOP is recommended)
Problem Type Card (FORMAT 311, 2X, F5.1, 6F10.2)
KTYPE Gate number which indicates the problem type: 1 for aspirated-
air U-tube, 2 for compressed-air U-tube, 3 for an eductor
IPR Gate number which permits printing intermediate output at the
end of each iteration if IPR = 1; otherwise leave blank
JPR Gate number which permits printing intermediate output at the
end of each numerical integration step in each of the iterations
if JPR = 1; otherwise leave blank
AID Distance from grade down to incoming pipe center!ine (see
Fig. kk for diagram), ft
A16 Distance of horizontal exit spool (see Fig. kk), ft
D2 Inside diameter of incoming pipe, inch
D9 Inside diameter of up-leg pipe, inch
PAMB Ambient pressure, ft water (1 atmosphere = 3^.0 ft water at
77 F)
T Water temperature, F
Cl Inlet D.O. concentration minus immediate oxygen demand, mg/liter
Case Card, if KTYPE = 1 (FORMAT 6F10.2, II, F9.1)
A18 Distance from incoming pipe centerline up to aspirator
centerline, ft
A19 Distance from incoming pipe centerline down to outlet pipe
centerline, ft
YO Initial air-to-water volume fraction at 68 F, 1 atmosphere
All Depth of casing bottom below grade, ft
D6 Inside diameter of down-leg pipe, inch
161
-------
QW Water flow rate, gal./min
KE Gate number set to 0 is E is to be calculated by program, and
set to 1 if E is to be read as input data
E (When KE=1) Specified venturi aspirator contraction area ratio,
i.e., cross-sectional area of incoming pipe divided by area of
aspi rator throat
Case Card, if KTYPE = 2 (FORMAT 6F10.2)
D6 Inside diameter of down-leg pipe, inch
A19 Distance from incoming pipe centerline down to outlet pipe
centerli ne, ft
YO Initial air-to-water volume fraction at 68 F, 1 atmosphere
All Depth of casing bottom below grade, ft
A25 Distance from bottom of entrance elbow to bottom of diffuser
ring (see Fig. 45 for diagram), ft
QW Water flow rate, gal./min
Case Card, if KTYPE = 3 (FORMAT 4F10.2, II, F9.2)
A19 Distance from incoming pipe centerline down to outlet pipe
centerli ne, ft
YO Initial air-to-water volume fraction at 68, 1 atmosphere
All Depth of casing bottom below grade, ft
QW Water flow rate, gal./min
KP Gate number set to 0 if P9 is to be calculated by program, and
set to 1 if P9 is to be read as input data
P9 Pressure at bottom of eductor (Station 9 in Fig. k$), ft water
absolute
162
-------
As many Case cards as desired can be placed in series. If one blank card
is placed after a Case card, the program will next expect a Program Type
card, followed by Case cards. If two blank cards are placed after a Case
card, the program will next expect a General Information Card, followed by a
Problem Type card and Case cards. There should not be a blank card immed-
iately following a General Information Card or a Problem Type card.
Table C-l presents a listing of a sample data deck. Included are examples
of each of the KTYPE options and branching-back options, by use of blank
cards.
Following Table C-l is a listing of the U-tube design program.
163
-------
TABLE C-l. SAMPLE INPUT DATA DECK FOR U-TUBE DESIGN PROGRAM
5'0.
.01
1 0
0.
o.
0.
0.
2 0
23.25
23.25
23.25
23.25
23.25
60.
-Ql
11 4
3.0
3.0
31 3
15. 1.0
.001 .2
0.
3.
0.
3.
0.
0.
0.
0.
0.
0.
22. 1.0
.OOJ .JL
.0 12.
6.5
6.5
.5 0.
,JL5
.7* 1.
10
. 23.25
.10
.10
.10
.20
23 .2.5 _ _
.05
.10
.20
.25
.75 G.
10
12.
.05
.1
12.
2. .2
23.25
40.5
50.5
5_CU5_
50.5
,29.0
20.0
20.0
20.0
20.0
0. .2
13.25
44.25
44.25
13.25
.2
34,
23.25
23-. 25
23_.25
23.25
34.
0.
0.
0.
0.
0.
.2
34.
19.
19.
34.
470. 470.
... - .68.....
3470.
3470.
3470.
68.
3472.
3472.
... . 3472. . ..
3472.
3472.
470. 470.
75.
1900.
1900.
82.4
3.
. ..0.
1
1.
1
0.
3.
-.8
1 3.
L 3.
.2
.BO OOCOCC10
00000020
Q 0 0.0 0.0.3D ...... .
7.72 00000040
7.72 00000050
7.72_ . £LQ C-OHGM)
7.72 .00000070
OOOOOOSC
00000090
00000100
00000110
0000012.0
00000130
C 0000 140
QDOOQ150
00000160
.9 00000170
00000 ISO
000001^0
52 00000200
52 OQ.OOQ2LO
00000220
00000230
OOOOQ240
-------
c
C DESIGN PROGRAM FDR IN-LINE AERATOR SYSTEMS
C KTYPF.M FOR ASPIRATFU-AIR U-TUBF
C KTY°E*2 FOR COMPRESSED-AIR U-TUBE
C KTYPE=3 FOR EDUCTOR
C
C THIS IS MAIN PROGRAM. ALSO NEEDED ARE SUBROUTINES COEFF,
C FNTR, HERSHY, INTRO, OUT, AND STtP ... '
C PLUS FUNCTIONS AL, DPD, AND HL
C
COMMON MT3,<.KL,ALPH4,AV,13,«9tJ10,«ll ,A15,A16,A1B, »19,A24, A25,
1 AEL?,AEL9,«NCC,ANCF, C.CN.CS ,CSN,CSR,CSNR ,C1 ,C5,C6,C7,L8, C9.C10
2 Cl?,CNl,CN5,CN6,CN7,CNO,CN9,CN10,CNli,CSl,CS5,CS6,CS7,CS8,CS9,
3 CS10,CS12,CSNl,CSNf ,CSNt,CSN7,CSNK,CSN9,CSN10,CSN12, DP,DP1,IIP2
4 DPOUn2,lH.,r9, l,FLK,rLR,F21,F22,H,HD,HH,HH5,HLD,HTtST,l-'U,
5 IPR,H,JP",KF,KL,KLN,KP,KTOP,KTYPF, NSD,NSH,NSH5,NSU, PAKE,
6 PEXTRA,PT3l,P13,P15,P19, PG.P1 ,P2,P3,P4,C5,P6,P7,P8,P9,P10,P12 ,
7 GH,R,ST»S2,T,TC, W2 ,UP6,UM9 ,USDOWN,USUP,UW2,UW6,UH9, VD1F,
B XIPOWN,XIII'>,XKL7,XKL6,XKL9,XN2,XNN2, YO,Y1,Y2,YJ, ,Y6,Y7,YB,Y9,
9 Yir,V12, »31,AELfr,D12,KOUNT
1 tIFRST
CPMMON/PASS.X/] PASS, 1EPP
DIUFNSION IRLNKI1A2)
EQUIVALENCE 1 IBLNK ( 1) , AIT3)
C
REAL KL.KLN
DO 10 1=1,142
10 IBLNK(I)="
ICO P.FAC (E,91'0)»NGC,AMGt,rLR,[LK,F21 , F22,USDOWN,USUP , X1DOMN.X IUP ,
1PEXTRA,ALPH»,UPTOL,HTFST,STPS2,KTCP
950 FOOM,9f>6)A19,YO,All,CW,KP,P9
956 FORM«TI4F10.2,I1,F9.2)
1F(«11-5.I1C1, 101,11B
C
C PRELIMINARY CALCULATIONS AND 1-PHASE ZONE
C
118 D6=Dfc/12.
1ERR=C
CALL 1NTRC
170 GO 10(122, 124, 176), KTYPE
122 A21=-F21*D7
IF(A21-STPS2*4.)1221,1221,1222
1221 HH5=A21
NSH5=1
GO TO 124
1??2 N5HS=IFlX(A?l/STPSZ/4.t.5)
HH5=A7I/N?H5
124 NSD=IFIX(«9/STPSZ«.?I
HD = A9
IF(NfD.&T.O) HD = I9/N1D
126 NSU=IFIX(A15/STPSZ+.5)
HU=AI5/NSU
IFO16-. 11138, 136, 126
17P IF(A16-STPS7*4. 1130, 130,132
130 HH=A16
NSH=1
GO TO 13C
132 NSH=IFIX(M6/STPS2/4.*.5)
HH=A16/NSH
C
138 Krum*o
ITM=C
XP3=C.
OOOOC100
00000200
000" 300
OOOOC400
00000500
OOOOC/600
00000700
00000800
JOOOC900
00001000
*0000 1 IC'O
00001200
,00001300
00001400
.ooorisoo
U0001600
00001700
ooooieoo
00001900
OOOC2000
OOGC2100
OOOC2200
00002300
00002400
00002500
0000i600
0000270C
OOC12800
00002900
00003000
00003100
00003200
00003300
00003400
00003100
OOCC3600
00003700
00003600
00003900
00004000
00004100
C000<.200
000043CO
C0004400
00004500
00004600
00004700
C0004BOO
C0004900
00005000
00005100
00005200
CCOOi300
00005400
OOOOE5PO
OCC05600
00005700
00005800
OOCC1.9GO
OOC06000
COOOtlOO
00006200
OOC06300
000064CO
00006500
OC006600
00006700
COC06600
00006900
OC0070CO
OOC07100
OC007200
POCG730C
00007400
00007500
00007600
&OOC7700
00007600
00007900
OOC08000
00008100
00008200
COOCB300
000084CO
165
-------
142
1*0
177
9CC]
178
IPO
200
202
XDP=C.
XR=0.
CALCULATIONS FROM STATICN 3 TO 6
KOUNT=KCUNT41
CALL COEFF
CALL FNTR
IF(IFRR.GT.O) GO T C' 25G
POWN-LEC CALCULATIONS
IF(KTYPE-D150,15C, 220
H=H[,
DC IPO J=1,NSD
CALL STEPdl
IF(C+2r.)177,177,17t
WRITE(6,9001)C,P1,P2,Y1 ,Y2
FOR^ATC C IS OUTSIDE (-20,501 IN DOWN-LFG1/'
1= '.5F12.6)
GO TC(1C4,107,112),KTYPE
IF(C-50.1180,177,177
CONTINUE
C7=C
CN7=CN
CS7=CS
CSN7=CSN
Y7=Y2
REPIICER AND RETURN BEND
U«6=UW6*(1.+Y7)
IF(lFIX(A31«.6))2C4,204,202
HLD=(PP-P7)/2.
TALL STEP(3)
CALL STEPI3)
CSN6=CSN
Y8=Y?
GO TC 206
ce=C7
CN8=CN7
CSNB=CSN7
Y8=Y7
206 HLD=2.*FLK* (UW9» ( 1. +Y? ) ) **2/6A.3*B
P9=P8-HLn
CS=CS*PM/P8
CSN=CSN*PM/PE
CALL STEPI4)
C9=C
CN9=CN
CS9=CS
CSN9=CSN
Y9=Y2
C
C DP-LEG CALCULATIONS
C
220 H=HU
DC 300 J=1,NSU
CALL STEP(2)
1F(C«20.)240,?40,29E
2«0 WRITEI6.924CIC,P1,P2,YI,Y2
9240 FORMAT! • C IS OUTEIDE (-20,50) IN UP-LEGV
I',JF12.5)
GO TI?(104,1C7,112) ,«TYPE
298 IFIC-50.1300,240,240
300 CONTINUE
P1C=P2
CK-C
CN10=CN
CS10=CS
CSN1C=CSN
Y10=Y2
00058500
00008fcOO
OOOOB700
OOO.J88CO
00008900
00009000
00009100
00009200
00009300
COC0940C
00009500
0000960C
00009700
00009800
00009900
0001000C
0001010C
00010200
00010300
C,P1,P2,Y1,Y2 000104CO
00010500
00010600
00010700
00010800
00010900
00011000
00011100
OOC11200
00011300
00011400
00011500
00011600
00011700
00011800
C0011900
00012000
00012100
00012200
00012300
OOG12400
CC012500
00012600
000127CO
OC01280C
OOC12900
C0013000
00013100
00013200
00013300
C0013400
00013500
00013600
00013700
00013800
00013900
00014000
00014100
00014200
C001430C
00014400
00014500
00014600
00014700
00014800
00014900
00015000
00015100
00015200
G0015300
00015400
00015500
00015600
00015700
00015800
00015900
00016000
00016100
00016200
00016300
00016400
00016500
00016600
00016700
00016800
C,Pl,P2tYl,Y2 -
166
-------
FXIT FLBCIW ANt' HORIZONTAL SPOOL CALCULATIONS
IF(M6-.1)3?2, 322,310
310 UM9=UK9»(1.+Y2)
HLC - «FL9/tl.+Y2l«ELK*UM9*UM9/64.348
P11=P10-HLD
PM=(Pll+P10l/2.
CS-CS*PM/P10
CSN=CSN*PM/P10
CALL STEPI5I
DO 320 J=1,NSH
320 CALL STEP(6)
322 P12=P2
C1?=C
CS12=CS
CSN1?=CSN
TFST CONVFRGENCF ANC1 CALCULATE NtH ENTRANCE PRESSURE
PP=P!2-PAMB
rP*=ABS(DP)
GO 10(3*5,335, 325), KTYPE
32? IF(KP)620,3?6,620
326 IFIDPA-20. 1328, 328,327
327 OPA=20.
328 P'=»9-SICN(nP»1DP)
Pl=Pt>*P19
NAMfcLIST/"C9/Pl1P9,Pin,P12,Cl,C9,C10,C12,CNl,CN9,CNIO,CN12,CS12,
A CSN12,Y12,P19,L'P
I FCKOUNT-K TOP 1330,330,600
330 IFIDPA-DPTOL)t20,33I,331
331 1F(1PR)1<,0,1<.0,332
332 WRITF(6,RC9)
GC TO 140
335 1F(PPA-20.)337,337,336
336 DP»=20.
337 P5=P5-SIGN(DPA,DP)
P1=P5*P15
NAMFL1ST/"(CE/P5,P6,P7,P8,P9,P10,P12,C1,C5
A CN5,CNft,CN7,CN8,CN9,CN10,CNl?,CS12,CSNl2
lF(KnilNT-KTOP)338,338,600
33P IF(OP«-OPTOL)6?0,339,339
339 IF(IPlU140,l0
340 WPITE<6,RC5)
R=.01
GO TO 140
CALCULATF IMPROVED ESTIMATE FOR P3 TO
FOR KTYPC=1 (TO STATEMENT 600)
345 P1=P3»P13
NAMELIST/°CM/P1,P3,P4,P5,P6,P7,PB,P9,P10,
A,C1Z,CN1,CN5,CN7,CN10,CN12,CS12,CSN12,Y12
IF(E-1.00011351,351,352
351 R=P.
GO TO 353
352 R=(P3-P5)/(P3-P4)
353 IF(KOUNT-KTnP)354,354,600
354 IF(DPA-DPTCL)620,355,355
355 IF(IPR)357,357,356
356 WPITE(6,RCM)
357 IF(1TM-1)358,450,500
358 ITM*1
359 XP3=P?
XDP=DP
XR=R
XDPA=DPA
360 IF(KE)36fl,368,362
362 IF(P-.8)370,370,364
364 IFIR-1.2)365,365,366
365 R=.8
GO Tfl 370
366 TP=.7*DP
GO TC 371
368 IFIR-.99) 370,370,400
370 TP=DP/(1.-R)
371 TPA=ABS(TP)
IF(TPA-2.)3fO,380,372
00016900
00017000
00017100
00017200
00017300
00017400
00017500
00017600
00017700
00017800
00017900
00018000
00018100
00018200
00018300
00018400
00018500
00018600
00018700
oooiaeoo
00018900
00019000
00019100
00019200
00019300
00019400
00019500
00019600
00019700
00019800
00019900
00020000
00020100
00020200
00020300
00020400
00020500
00020600
00020700
00020800
00020900
00021000
00021100
00021200
,C6,C7.C8.C9,CIO,C12.CN1,00021300
,Y12,P15,P1,DP 00021400
00021500
00021600
00021700
00021800
00021960
00022000
00022100
MATCH P(CXIT) 00022200
00022300
00022400
00022500
P12,C1,C5,C6,C7,C8IC9,C1CU0022600
,P13,DP,E,R,XP3,XDP,XR 00022700
00022800
00022900
00023000
00023100
00023200
00023300
00023400
00023500
00023600
00023700
00023800
00023900
00024000
00024100
00024200
00024300
00024400
00024500
00024600
00024700
00024800
00024900
00025000
00025100
00025200
167
-------
372
374
37t
3PO
IF(TPA-20.)374,374,i76
TP=TP»(1.-TPA/40.)
r,0 TC 3RP
TP=1C.*TP/TP«
p3=rP3-TP
GC TC 140
4CC
4C01
FOR^ATI'l P CPEATF"? THAN 0.99, LAST RESULTS FOLLOW1)
GC TC 62n
45C ITM=?
500
510
52C
54C
-. 3)511, 530, E3C
IF(r>PA-XPPA )359,359,52C
DP-Xr>P
CC TC 360
1F(PP»-XO"»)54C,540,559
XP=P3+D'>/(DO-yDP|*(X'>3-P3)
fC TO 56C
560
570
572
IF(XP-.9*XPT) 572, SVC, 590
XP= .C,*XP3
PD TC 500
IFIXP-1.2*XD3) 59r',590,562
X«=:1.2»XP?
P3=XP
IF(°.GT.P.9f'.AND.KCUNT.GT.12) GO TO 400
GC TP 140
60P
6001
C
620
frAO
6401
fr60
FfRMATCl KTOP EXCEECtD, LAST BESULTS FOLLOW)
CALL OUT
IF( 1FH)66C,6«.C,640
WRITf (f,,640))
FORM»T(1H1)
GO T0(ir4,)r7,li2 I.KTYPF
FND
FUNCTION *L (OItl,DIA2)
AL !S LENGTH Of STANDARD REDUCFR FOR TWO DIAMETERS IN FEET
1C2
105
106
)07
ice
109
110
111
112
113
114
115
118
AL=C.
GO TL 11?,
D=»MAX1(CIA1,D1A2)
M6P=IFIX( 12.*P».9)-7
AL=.4f,P
GP TP IIP
GO T?(10P,118,)09,109,110,110,111,111,112,112,113),N6D
AL=.?
GC TC IIS
AL=.If3
co TC lie
*L=.667
r,c TC lie
AL=1.0P3
GO TC HE
»L=1.17
GC TC IIP
AL=1 ,?5
r-c TC 11"
IFIN6D-12))'-7,115,115
t L=1.67
"ETIIRN
ENP
»»**»** »»*<.*»»»*«*.»»*****»***»*.**«****»,**»»** ***«*»*»*«*»*»«»»
StJETUTIMF COEFF
OOC253CO
00025400
00025500
00025600
00025700
C0025600
00025900
00026COO
OCC26100
00026200
00026300
00026400
00026SOO
C00266CO
00026700
00026600
00026900
0002700C
00027100
00027200
00027300
00027400
00027500
C0027600
00027700
OC027800
00027900
0002POOO
00026100
CC028200
C0028300
C0028400
00028500
00028600
00028700
CCC2880C
0002890C
00029000
00029100
0002V200
D0029300
0002940C
OOOZ9500
OC029600
00029700
C002980C
C0029900
00020000
C0030100
OOC2C20C
•0003O300
00030400
C003D500
00030600
OOC3C700
000308CC
00030900
C0031000
OP031100
00031200
00031300
00031400
00031500
00031600
OC031700
O0031800
00031900
00032000
OOC32100
00032200
00032300
00032400
OOC32500
00032600
OOC3270C
OOC32ECO
00032900
00033000
C0033100
00033200
00033300
0003340C
'00033500
00033600
168
-------
c
•
c
c
c
c
c
c
c
c
c
c
c
c
c
c
COMMON »IT3,AKL,AIPf'»,«V,A3,A°,A10,All,A15,A16,A18,A19,A24,A25,
! Ar.L2,AFL9,»NtC, ANCE , C ,CN,CS,CSN,CSP .CSNR.C1 ,C5,C6,C7,C3,C9,C10
2 Cl?,fNl,CW,CN6,CN7,CN6,CN9,CN10,CN12,CSl,CS5,CS6,CS7,CSb,CS9,
? CS]0,CSl?,CSNl,CSM5,CSNt,CSN7,CSN3,CSN9,CSN10,CSNi2, DP.DP1.DP2
4 PrDL,n?,D6,D<=, E,6LK,FLR,F21,F22,H,HD,HH,HH5,HLD,HTEST,HU,
'. lPp.Il.JP',KF,KL,KLN,KV,KTOf>,KTYPE, NSD,NSH,NSH5,NSU, PAMB,
6 PFXTRA,PTC!L,P13,Plt.,P19, PO,P1,P2,P3,P4,P5,P6,P7,P8,P9,P10,P12,
7 CM,R,STPSZ,T ,TC, U«t2,UMt,IIK9,IISDOWN,USUP,UW2,UW6,UH9, VDIF ,
8 XIL>nWN,XIiJP,XKLr,XKL&,XKL9,XN2,XNN2, YO,vi,Y2,Y5,V6,V7,YB ,Y9,
9 Y1(1,Y12, *31,AEL6,D12,KCII,MT
1 ,IFRST
RFAL KL.KLN
IFIIFSST.MF.15) GC TO 10
IFRST=n
Pl?= P»MB
10 GC Tn (100,;00,300) ,KTYPE
100 A*0=A11-*10««10+1.5
PIw=P3
POUT = P12
GC TO 250
200 A50=A 11— A10— A2F + 1 .5
PIN=Pf
PCI'T = P12
250 «51=A15+A16*3.
WT=JS 5'C*D6*D6* A51*L'9*D<*
HTt!=D6»P6»A5C/WT
KTU=D9*P9* AM/WT
PBOT=PIN»'50/( l.«34.*Yn/(PIN-fA50/2. ) 1
UAV=UWt»WTn-»UW9*WTU
YAV=17.*YC*{( l./PIN + l./PBCT)»WTD*(l./PBOT-H./POUT)»WTU)
GO TO 50T
300 U»V=UW«
YAV=17.»Y?*(1 ./P9*1./P12)
SOO U=AMIM(UAV,2.2)
KL=7. 704 t-4»EXP(.0963»U+( -10. 2908*4. 35 16»U)*YAVI
KLN=.9*KL
OETURN
FND
FUNCTION fPD(X,Y)
PPO IS ?-PH»SE DPRESS IPOS.) FOR DOWNWARD VERTICAL FLOW
X IS STFP DISTANCE, Y IS A/W AT START OF STEP
DPD = X*U./I J.«Y)-.Cr27)
RETURN
FND
00033700
00033800
,00033900
00034000
,00034100
00034200
00034300
00034400
00034500
00034600
00034700
00034800
00034900
00035000
00035100
00035200
00035300
00035400
00035500
OC035600
00035700
C0035BOO
00035900
00036000
00036100
00036200
00036300
00036400
00036500
00036600
00036700
00036800
00036900
00037000
00037100
00037200
00037300
00037400
00037500
00037600
00037700
00037800
00037900
*0003BOOO
00036100
C0038200
00038300
00036400
00038500
00038600
00038700
00036800
00038900
00039000
SUBROUTINE ENTR 00039200
THIS MAKES CALCULATIONS FOR THE ZONE BETWEEN ASPIRATOR OR
DIFFUSE" INLET AND START OF DOWN-LEC (STATION 3 TO 6)
COMMON AIT3,AKL,ALPHA,AV,A3,«9,A10.A11,A15,A16,A18,A19,A24,A25,
1 A.EL2,AEL9,ANGC,ANC.E, C,CN,CS,CSN,CSR ,CSNR ,C1,C5,C6,C7,C8,C9,C1C
2 Cl?,CNl,CN5,CN6,CN7ltN8,CN9,CN10,CN12,CSl,CS5,CS6,CS7,CS8,CS9,
3 CS1C,CS12,CS1J1,CSM5,CSN6,CSN7,CSNB,CSN9,CSN10,CSN12, tP,DPl,OP2
4 DPDL,D2tDb,D9, E.ELK .ELR.F21 ,F22,H,HD,MH,HH5,HLD,HTEST,HU,
5 IPR,Il,JPR>KE,KL,KLN,KPtKTOP,KTYPE, NSO,NSH,NSH5,NSU, PAMB,
6 PFXTRA,PTOL,P13,P15,P19, PO,Pl,P2,P3,P4,P5,P6tP7,PE,P9,P10,P12,
7 OW,R,STPS7,T,TC, I'H2,IJK6,UM9,USDOHN,I)SUP,UW2,UM6,UW9, VOIK,
8 XIDOWN,XIUP,XKL2,XKL6,XKL9,XN2,XNN2, YO,Y1,Y2,V5,Y6,Y7, YB,Y<*.
9 Y10.Y12, «31,A6L6,D12,KOUNT
1 .IFRST
COMMCM/P AfsSX/IPASP T I ERR
CMl=CSNR*.7P*PAMB/34.
IPASS=0
GO TO(1PO,200,300),KTYPF
100 Y3=YO*34./P3
IF(KE)120,104,120
104 IF(P3-PAKE+PEXTRA)10B,108,110
108 E=l.
C*>-C 1
CN5=CN1
P4=P3
P5-P3
60 TC 138
00039300
00039400
00039500
00039600
,00039700
00039600
,00039900
CC040000
00040100
00040200
00040300
00040400
00040500
00040600
00040700
00040800
00040900
00041000
C0041100
00041200
00041300
00041400
00041500
00041600
00041700
00041800
00041900
C0042000
169
-------
110 E=SQRT< 1+64.34P/UW2/UW?*(P3-PAMB + PEXTRAM 00042100
P4=P«MB-PFXTR» 000422CO
CO TD 130 G0042iOO
120 P4=P3-(E»F.-l)*irW2*IIH2/t4.348 0.0042400
IF(P4n22,130,l30 00042500
122 P4=.C1 00042600
130 UTH= E*UW2 000*2700
PFLP = .004*YG**.A*inH**2.6+.0026*t)TH*UTH 00042 BOO
P5=P3-DELP 00042900
IFIP5-20.U31,132,132 00043000
131 iF(iPAss.r.T.o) cr TO isc 00043100
P3 = P3 * ?C. P5 00043200
IPASS = IPASS + 1 00043300
WRITF(6,1311)P5 00043400
1311 FORMAT!' •/• P5 = '^7.2,' , SET ECUAL TO 20 •) OOC43500
CO TO 100 00043600
150 IERR=1 OC0437CO
WR!TF(6,151) P5,DfLP,E,UTH,YO 000436UC
151 FORMATCl'/'.X, 'Pi> TCP LOW **» CASt NOT RUN'/5X,'P5 = 'iFT.?!1 DELP00043900
1 = '^7.2,' E '.F7.2,1 UTH ',fl.2,* YO = ",F7.2 ) 000440CC
GO TO 199 C0044100
132 PM=.75*P5+.25*P4 00044200
YM=YC*34./PM 000443CO
CS=CSR*PM/34. 0004440C
CSN=CSN"»PM*.7607/34. 00044500
C UNITS ARF: VDIFIFT?), 02(FT),AKL(SbC-1I, YO(FRACTIOM), 00044600
C UW?*5-(C5-Cl+CNI-CNl)/RHD)*UW2*(1.4YO)/(UW2*(] .+YO )-USC.CWN00046000
1) 00046100
CS=CSR*P5/34. 00046200
CSN=CSNR*.78*P5/34.
CS5=CS
CSN5=CSN
Y5=Y?
C=C5
CN=CN5
XN2=P.7r*YO-(C5-CI 1/32.
XNN2-32.45*YO-(CNf-CNl )/2e.014
AV=Y2/(1.+Y2)*XIDOWN
I F ( HH5- . 01)1381, 13E I, 13P2
1381 H=.C1
GC TO 139
1382 H=HH?
139 DO 140 J=I,NSH5
140 CALL STEPC7)
UH?=UW?*(1.+Y2)
HLD=FLK*UM2*UM2/64.348-ArL2/tl.«Y2)
CS=Ci*PM/P2
CSN=CSN*PM/P2
CALL STEP18)
= UW?*(1.-»Y2)
141
142 P6=P2-.C4*UM2*UM2/64.348+[)P[)(«3,Y2l
H=A3/2.
HLD=(P6-P?)/2.
CALL STEPO)
CALL STEP(9)
144 C6=C
CN6=CN
CS6=CS
CSN6=:CSN
Y6=Y2
Pfr=P2
199 RETURN
2CO CS=CER*Pf./34.
CS5=CS
CSN=CSNR*.7B*PS/34.
CSNT-CSN
00046300
00046400
00046500
00046600
00046700
00046600
000469CC
00047000
00047100
00047200
COC47300
C0047400
00047500
00047600
00047700
00047800
00047900
00046000
00048100
00046200
00048300
00046400
0004850C
00048600
00048700
00048800
00048'900
0004900C
00049100
000492CC
00049300
00049400
00049500
000496CO
0004970C
00049800
00049900
OOG50000
000501CO
CC050200
C0050300
00050400
170
-------
C=Cf>
CNf. = CNl«(C5-Cl )*ICSN-CN1 I/ICS-C1)
CN-CN5
P2=PE
C = 1292.S*P2/34.0*4<>2./YO)/(UN2*I1.*YO)-USDOWN0005]200
») 00051300
Y5=Y2 OOC51400
XN2=l.7C*YO-ICr— Cll/2?.
XNM?r3?.4?*YO-(CNi.-CNl 1/26. 014
AV=V2/I1.+Y?I*XIDCWN
GO TC 1*1
C
300 P2=PC
Y2=YC*34./P9
Y2=Y2»ll.»Y2l»UW9/(W9*tl.+Y2)«USUP»
Y9=Y2
»V-Y2/I1.+Y?)*XIUP
XN2=8.7*Yr
XNN2=32.4S*YO
C-C1
C9=C1
C5=C1
CN-CN1
CN9=CN1
CS=CSR*P9/34.
CS"=CS
CSN=CSNR».7t* 09/34.
CSN9-CSN
GO TC 199
ENC
C
C
00051500
00051600
OOC51700
00051800
00051900
00052000
00052100
00052200
00052300
00052400
00052500
00052600
00052700
C0052800
00052900
OOOS3000
00053100
U005320C
00053300
00053400
00053500
00053600
00053700
00053800
00053900
C , 00054000
SUBROUTINE HFRSHY 00054200
C THIS SUPROtJTINr CALCUHTES -DP/DL FOR AIR-WATER UPWARD
C VERTICAL FLOW
C
COMMON AIT3,AKL,ALPHA,AVtA3|A9tA10,All,A15lA16,A18,A19lt24>«25>
1 AH2,AEL9,ANGCiANGf , C ,CN,CS,CSN,CSR ,CSNR,C1 ,C5fC6,C7 ,C8,C9,C10
2 C12,CNl,CN5,CN6,CN7iCN8fCN9,CN10lCN12iCSl,CS5iCS6iCS7iCS8|CS«,
3 CS10,CS12,CSNlCSN7tCSN8,CSN9tCSN10iCSN12t UP,DP1>UP2
4 CPDL,C2,D< ,C9, E ,ELK,ELR ,F21 t F22tHiHU, HH.HHSt HLD.HTEST.HUi
5 IPP.Il.JPR.KE.KL.KLN.KP.KTOP.KTYPE, NSD, NSH.NSH5 iNSU, PAMBi
6 PEXTRA,r'Tn.,P13tP15,P19i PO.P1 ,P2tP3,P4,P5,PfciP7,P8 tP».P10f PI 2 ,
7 OW,R,c.TPSZ,7,TCt UM2,UM6,UM9,USDOWN,USUPtUW2,UW6tUW9,V01F,
8 X1DOWN,XIUP|XKL2,XKL6,XKL9,XN2,XNN2, YOfYliY2 tY5,Y6,Y7,Y8,Y9,
9 Y10,Y12t »31,AEL6,D12,KOUNT
1 ,IFRST
Bl=3.5/D9**2.r73/32.174**.415
Y=Yl
XP=C.91*Y
100 TOP=El*IOW*|Y-XP)/446»8)**.83-XP
RPT^C. B3*P1*( OK/448. 8)**. 83/1 Y-XP)**. 17+1.
XP1=XP«TDP/EOT
TESl=AhSIXPl-XP)
XP=XP1
IF(TrST-HTESTI110,110,100
110 UM=U^9
F=.0»8/(D9*UH9*62.25*1'.90.)*«.13
DPDL=(1.42.»F*UM9*UM9/32.174/D9)/tl.«XP)
RETUBN
TNP
C
C
C
00054300
00054400
00054500
00054600
,00054700
00054BOO
,00054900
00055000
0005S100
30055200
00055300
00055400
00055500
00055600
00055700
00055800
00055900
OOC56COO
00056100
OU05620C
OC056300
000564GO
00056500
00056600
00056700
00056800
00056900
000570CO
00057100
00057200
00057300
C »»*»**»»»»*« *»»*«*»*»**»*****»*»»** **t »**»*»»*»«»* «****« t****+**«0005740C
FUNCTION HL(X,DtUI
C Ht IS 1-PHAsr HE»L' LOSS FOR RE APPROX 100,000 TO 1C,OOC,OCQ
C X AND 0 IN FT, U IN FT/SEC
C
IF(X-. 1)100,110, 110
IPO X=.l
110 RE=62.25*1'«90.*U*C
120 IFIRF-.7E6I13C, 200,200
130 HL=. 00448/16. 087*X/D*U*U/( RE/3.5C5I**. 1513
140 GO TC 210
200 HL=.00356/16.087»X/D*U*U/(Rt/2.Ffcl**.1144
25C RETURN
END
C
00057500
00057600
00057700
00057600
00057900
00058000
00058100
00058200
0005E300
00058400
00058500
00058600
000587CO
00056800
171
-------
00058900
00059000
*»*»*****« ***************************************************** ***COO 59 100
SUPRtJUTINF INTRO 00059200
THIS MAKES CALCULATIONS FOR INITIAL GEOMETRY PHIS 1-PHASE 20NtG0059300
00059400
COMMON A1T3,«KL,ALPHA,AV,A3,A9,A10,A11,A15,A16,A18,A19,A24,A25, 000595CO
1 AFL2,*EL9,ANGC,ANGE, C ,CN, CS.CSN, CSR ,CSNR ,C1 ,C5,C6,C7 ,C8,C9, CIO, 00059600
2 C12,CN1,CN5,CN6,CN7,CNS,CN9,CN10,CN12,CS1,CS5ICS6,CS7,CS8,CS9, C0059700
3 CSir,CS12,CSNl,CSN5,CSN6,CSN7,CSN8,CSN9,CSN10,CSN12, DP, DPI ,DP2 ,00059800
4 DPDL,r2,D6,C9, F, ELK , E LR ,F21 ,F22,H ,HD,HH,HH5,HLD,HTEST,HU, 00059900
5 1PP,I1,JPR,KF,KL,KLN,KP,KTOP,KTYPE, NSD ,NSH,NSH5,NSU, PAMB, 00060000
6 PEXTRA,PTOL,P13,P15,P19, PO.P1 , P2 , P3 ,P4,P5 ,P6,P7,PB,P9,P10,P12, 00060100
7 OW,R,STPS2,T,TC, UM2 ,UM6,UM9,USDOWN,USUP,UW2,UH6,UW9, VDIF, 00060200
8 XlrOWN,XIUP,XKL2, XKL6,XKL9,XN2,XNN2, YO, Yl , Y2, Y5, Y6, Y7, Y6 , Y9, 00060300
9 Y10.Y12, »31,AEL6,Dl2,KnllNT
1 ,1FRST
UW=CK*4./3. 1416/448. 8
l)W2 = t'W/D2/P2
UW°=UW/D?/r9
AEL?=ELR*IF!X(12.*0?+.8)/12.
ArL6=rLR*IFIX(12.*D6+.9)/12.
AFL9=FLR*IFIX (12.*D9+.t)/12.
IF(A16-.l)8n,eC,9C
80 M5 = «ll-AlC-A19-AFL9-D9/2.-.E
GO TC 95
90 A15 = All-A10-A19-2.*AEL9-(5<>/2.-.5
95 IFtKTYPF-21100,100,300
ICO UW6=UW/Ofr/D6
A3=Al(n2,P6)
A3I = «L(D6,D<>)
IF(KTYPE-l)50n,12(1,200
120 IFU18-. 05)130,140, 140
130 «24=0.
P13=0.
GO TO 150
140 A24=A1E*?.12*[)2
»1T3=A?4/.707+F22*D2
P13 = AlS+HL(An3,D2,t.'K2)*.4+UW2*UW2/64.348
200
2 1C
300
310
320
500
510
5CC1
5?0
00060400
00060500
00060600
00060700
00060800
00060900
00061000
00061100
00061200
00061300
00061400
00061500
00061600
00061700
00061800
00061900
00062000
00062100
00062200
00062300
10062400
00062500
00062600
OOC62700
OOO62800
00062900
00063000
OOO63100
00063200
00063300
00063400
00063500
00063600
C0063700
00063800
00063900
00064000
00064100
COC64200
00064300
00064400
00064500
00064 6CO
00064700
000648CO
00064900
00065000
00065100
00065200
00065300
00065400
*** ********** *********************************** *********«********00065 5 00
SUBROUTINE OUT 00065600
00065700
COMMON AIT3,AKL,ALPHA,AV,A3,A9,MO,AllfA15,A16,A18,A19,A24,A::5, 00065800
1 AEL2,AEL9,ANCC,ANGE, C ,CN,CS ,CSN,CS* ,CSNR ,C1 ,L5,Cfc ,C7 ,CB ,C9 ,C 10,00065900
2 C12,CNl,CN5,CN6,CN7,CN8,CN9,CN10,CN12,CSl,CS5,CS6,CS7,CS8,CS9f 00066000
3 CS10,CS12,CSN1,CSN5,CSN6,CSN71CSN8,CSN9,CSN10,CSN12, DP, DP 1 ,DP2 ,00066100
4 DPDL,D2,D6,D9, F , ELK ,ELR ,F21 ,F22,H ,HD ,HH,HH5,HLD,HTEST,HU, 00066200
5 IPP.I1, JPR,KE,KL,KLN,KP,KTOPfKTYPE , NSD,NSH,NSH5 ,NSUt PAMB, 00066300
6 PEXTRA.PTCL ,P13 ,P 15 , P19, PO , PI , P2, P3, P4.P5 , P6, P7 , P8 ,P9,P10, P12 , 00066400
7 OW.R.STPSZ.T.TC, UM2 ,UM6,UM9,USDOWN,USUP,UM2,UM6 ,UW9, VDIF, ' 00066500
f> XIDOHN.XIUP ,XKL2,XKL6,XKL9,XN2,XNN2, YO,Y1 , Y2, Y5 , Y6.Y7, Y8 , Y9, 00066600
9 Yir,Y12, A31,AEL6,D12,KCUNT 00066700
1 .IFRST 00066800
REAL KL.KLN 00066900
A21=F21*02 00067000
A22=F22*R2 00067100
D2P=12.*D2 00067200
A9=A11-.5-D9/2.-AFL9-A31-A3-AEL2-A10+A18
GO TO 500
A9=All-.E-P9/2.-AEL9-A31-A3-A25-AFL2-A10
IF(A9-8.)210,220,?20
Pt=D2
A3=0.
P15=ELK*UW?*LIW2/64.34B+HL(A25,D2,UW2)-A25-AEL2
P5=PAMB+5.-P15
GO TO 500
IF(KP)3?0,310,320
A9=All-A10-AEL2-AFL9-D9/2.-.5
P19-FLK/64.34e»(UW2*l)W2«2.*UW9*UW9) +HL ( A9.D2 ,UW2)-A9-AEL2
P9=PAM6*5.-P19
GO TO 500
A9=0.
IF(JPR)510,520,510
WRITE16,5001)UW2,L»W9,D2,D6,D9,A3,A9f A 15, A16
FCRMATI•! LM2,UH9,D2106,D9,A3,A9,A15,A16t/9E12.5)
RETURN
END
172
-------
P6P=12.*D6
D9P=12.«D9
YOP*1CO.*Y3
Y5P-1CO.*Y5
Y6P=1CO.«Y6
Y7P=1CO.*Y7
Y8P-100.»Yf>
Y9P=1CC . *YO
IF(KTYPE-2)5C,lfcC,l6C
ico
110
P=°«1CO.
lFfF-.r.iuor,ioo,iir
GC TC 12C
F23=.3
A20=«24«A?2?,UH2l-HIW2*UW2/6'..348»
1 P6,I'W )*uw;*ilw<»/<'-.3<.t» ( .C4*3.*E
IFU1*-. 05)152,300,300
PPl = rPl-|lWO
r.o TC 300
»1B=0.
»21=0.
IFIK7YPE-?) 17C,17?,1BC!
DPI = UW2*UH2/t2.3'.°*(FLK«.C4) t
1*
00067300
00067400
00067500
0006760C
C0067700
00067800
00067900
00066000
00066100
00068200
00066300
C0068400
00068500
00068600
0006B70C
00066800
OOC689CO
OC06900C
l./TAN(ANGE/2.)l»Fi3»D200069100
COC69200
00069300
00069400
00069500
COC69600
OC069700
OC069EOO
00069900
00070COO
00070100
000702CO
00070300
C0070400
OOC7C5CO
00070600
0007C700
0007C8CO
00070900
00071000
00071100
C0071200
OOP713CO
HL(A?5,02,UH2) « HL I f9, C6.IIW6 I
A16
I.17*(F»E-1.1».4*ELK*.C4)+HL(A9,
LK)«HLIS2,[)9,UW9) -A19
KL(S2,C9,UW9I
172 DPI - PP1
174 DPI = OP1
GC TP ?CC
ICC P6P=P?»
PF=.ri
C5=C1
C6=C1
C7=C1
CP=C1
CNC=CM
CN6 = r.»ll
CN7=CM
CNF=C»I1
CSf^.Ol
CS6=.C1
C.S7=.C1
CSS=.Ol
CVJf-.Cl
CSVfc^.Cl
C£N7=.C1
Y6P=.11
Y7P=.C1
YPP=.C1
PO=Pt;+P19
- UW9*UWt»A2.3«8»ELK
- A19
l°f. A2r=.1'l
PC=.'J1
P3=.rj
A9=.ri
DP1='1?«APL9«HL(S2,C9,UW9)+IPW9«UW9/64.348*ELK
GC TC 300
200 A?n^«FL2*3.*AEL9+A16
tPl=UW2«OH2/64.34f»(fLK.*.'--e)tHl.(»9,D2,l/W2)»UW9*UW9/6*.348«(3.*ELK)000755PO
1 «HL (52,re',UW9)-Al
-------
IF(el6-.Cc)21", 210,300 C0075700
t4.34e*FLK r.oo75scc
.
c 00075900
30? CPNTINUF 00076000
X2=KL*1.E4 00076100
X«- = KL*1.r«. CC076200
X9*KL*1.F4 00076300
pp?=PC-pl? OC076490
r ' ' COQ765CO
WIITEC., JCC1) 0^076600
K01 FTPMATIIHI ,///) 00076700
WPITMA.KPDKTVPE ,A11,YCP,A25,WC,D2P, OW.D6P, E,D9P 00076800
If02 FORMMITU, 'KTYPb', T44.il, T6l,'All (CP. TO CASING BUT. ) • ,Ti2, F/>. 200076900
I/ T14,'1N1T. A/WAT 6FF.1ATM ( 0/0) • , T43.F5 .2 , T61,'A25 ISTR. I/RCG0077000
2P TC DJFFUSER ) ',T92,F6.2/ T14, 'OXYGEN SUPPLIED (M&/L)', T42.F5 . 1 ,00077100
3 Tfl.TXIST. PIPE I.D. (INCH) '.T92.F7.3/ T14, 'WATER FLOWRATt UPM )00077200
4',T3c,F7.C, Ttl.'DOV.'N PIPE I .0. ( INCH 1 • ,T92 , F7 . 3/ T 14, • VENTURI CPN00077300
ITRACTI^M <>»TI'.J',T<-3,F5.2, T6l,'HP PIPE I. D. (INCH)', T92.F7.3/1 GG0774GO
C 00077500
WPTTEU<,l"03)°Ave,T,A9,UW2,A JO.UW9.A 15,P4,A16,R,A18,ELK 00077600
1003 FC?MAT(T1^, 'A>«ei:N'T PRESS. (FT H2C> ) • ,T43,FA.l , Tftl , 'TEMPERATURE (F00077700
1) ',T92tF5.1/ T14,««9 (CCWN-LKG LENGTH, FT ) • ,TITE(6,1004) 00079600
1004 FORMATIT6, 'STATION' ,12?, '1 ', T33 , '3 ' ,T43, ' 5' , T53, ' 6' ,T63, ' 7' , T7300079700
1, '8' ,TS3,'9', T93, ' 1 T ,T102 ,' 1 2'//T6, ' LOCATION • ,T2C, ' ENTRANCE ', T00079800
230, 'AS". IN', T40, '2-PHASE', T50, 'LEG TOP', T6O, 'LEG BOT. • , 00079900
3T70,'BFND IN1, Tflfl.'BEND PUT', T9C,'LEG TCP', T1C1 , ' EXIT1/) OOOBOOOO
C OC08C100
WRITF(6,lCOD)Cl,Cl,C5,Ct,C7,C8,C9,C10,C12, CN1.CN1 ,CN5 ,CN6 ,CN7, 00080200
1CN8,CN9,CN10,CN12, PO ,P3 ,P5 ,P6, P7, PB,P9,P10, P12 C0080300
100r FCRM»T(!>X,'D.C.{KG/L)',4X,9(F5.2,5X)//5X, ' D.N. ( MG/L ) ' ,4X, 9 ( F5 .2 ,00080400
15X)//5X, 'P (^T H2CI)',3X, c>( fb. 2 ,4X ) /) 00080500
C 00080600
WRITF(6,l'?Ofc)CSf ,CS6,CS7,CSE,CS9,CS10,CS12,CSN5,CSNt,CiN7,CSN8, 000f0700
1CSN9.CSN1C.CSN12, Y5P ,Y6P ,Y7P .VPP.Y9P , Y10P, Y12P, ALPHA, 00080800
2X2,Xfc,X6,X9,X9,X9,X9 00080900
IfOb FTRMJTI5X, 'SAT. L.C.', 25X, 7 ( F5 .2 ,5X )// 00081000
»5X, 'S»T. D.N.', 24X,7(F6.2,4X)// 00081100
55X, 'A/W (0/0)', ?5X,7(F5.2,5X)// OOOE1200
C^X, 'KL*E4, INCL. ALPH«= • ,F4.2 , • (FPS)', 4X ,7( F6. 2,4X I ) COO81300
RETURN 00081400
END OOC81500
C COC81600
C 00081700
C 00081800
C #****##* *******+#****#*********# ******************* #********+++ **^00081900
SUBOOUTINF STEP(LEG) 00082000
C 00082100
C THIS SL'PROUTINE MAKES CALCULATIONS FOR ONE LENGTH INCREMENT 00082200
C LEG=1 FCR DOWN-LEG (STATICN 6-7) 00082300
C LEG=2 FOR L'P-LEG (ST.S-10) 00082400
C LEG=3 FO" EOTTO* REDUCER (ST. 7-8) 00082500
C LrG=4 FOR RETURN BEND (ST. 6-9) C0082600
C LEG=5 FOR EXIT EL6DW (ST. 10-11) 00082700
C LFG=6 FOR HPRIZONTAL FX1T PIPE (ST. 11-12) 00062800
C LFG=7 FDR HORIZONTAL ENTRANCE PIPE (FROM ST. 5) 00082900
C LFC=8 FCR ENTRANCE ELBOW 00083000
C LEG=« FC" ENTRANCE REDUCER (TO ST. 6) 00063100
c 00063200
COMMON AIT3,AKL,ALPHA,AV,A3,A9,A1P,A11,A15,A16,A18,A19,A24,A25, 00083300
1 AEL2,
-------
'
8 XIDOWN,XIUPIXKL2IXKL6>XKL9,XN2IXNN2, YO ,Y1 ,Y2,Y5,Y6, Y7, Y8.Y9,
9 Y10.Y12, A31.AEL6.012.KOUNT
1 ,IFRST
REAL KL.KLN
XN1*XN2
XNN1'XNN2
Y1-Y2
UM2*UW2*(1.*Y1)
UM6cUM6*(l.*Yl)
UM9«UW9*(1.*Y1>
GO TO ( 1 20 i 140 i 160 t 170, 180. 190, 200, 21 0,220). LEG
120 OTA«H/(UM6-USOOWN)
P2«Pl*DPD(HtYl)
GO TO 230
140 OT»«H/(UH9+USUP)
DTW«H/UM9
CALL HERSHY
P2=P1-OPDL»H
GO TO 230
160 UWR-(UM6»UM9l/2.
DTA*H/(UMR-USDOWN)
DTW'H/UMR
P2«P1*HLD
GO TO 230
170 DTW«1.570e*AEt9/UM2
OT»«OTM
P2-P1-HLO
GO TO 230
180 DTW«.7854*AEL9/UM9
DTA=DTW
P2«P1-+(LD
GO TO 230
190 DTW«H/UM9
OTA'DTW .
P2=Pl-«L(Htn9,UM9)
GO TO 230
200 DTMCH/UH2
OT»«DIW
P2=P1-HL(H,D2,UM21
210 DTH=.7854»AFL2AI«2
DTA-DTU
P2=P1-HLD
GO TO 230
220 UNR*(UM2*UM6>/2.
DTM=HAIHR
DTA'H/(UHR-USDOHN)
P2«P1*HLD
230 OC*KL»AV»ICS-CI»DTH
DCN-KLN»AV*(CSN- CN )*DTW
CN=CN»OCN
XN2=XN1-DC/32.»OTA/OTW
XNN2 =XNN l-OCN/28 . 01 4»DTA/DTH
XNTiXN2»XNN2»0.4235»YO
PO «XN2/XNT*(P2-.7B)
PN =XNN2/XNT*(P2-0.78)
CS«CSR*PO/7.122
CSNiCSNR*PN/34.
RHO«1292.8»P2/34.0»492./(T+459.7I
Y2 * P1/P2»Y1-«DC«DCN)/RHO
GO 70(240,250,240, 260, 270, 250, 240,240. 2401, LEG
240 AV*Y2/I1.+Y2)*XIDOWN
GO TO 300
250 AV*Y2/I1.*Y2)»XIUP
GO TP 300
260 UMO'UW2*(1.«YO)
Y2«Y2*(UMO-USDOHN)/UMO»UM9/(UM9*USUP)
GO TO 250
270 Y2=Y2»(UM9+IISUP)/OM9
GO TO 250
300 ILEG'LEG
NAMELIST /PRJ/C,CN,CS,CSN,P1,P2,Y2,»V,KL,KLN,H,ILEG
^IF(JPRI302,302,301
301 MRITEI6.PRJ)
302 CONTINUE
RETURN
END
00084100
00084200
00084300
00084400
00084500
00084600
00084700
00084800
00084900
00085000
00085100
00085200
00085300
00085400
00085500
00085600
00085700
00085800
00085900
00086000
00086100
00086200
00086300
00086400
00086500
00086600
00086700
00086800
00086900
00087000
00087100
00087200
00087300
00087400
00087500
00087600
00087700
00087800
00087900
00088000
00088100
OOOKR200
000883CO
00088400
00088500
00088600
OOOE8700
00088800
00088900
00089000
00089100
00089200
00089300
00089400
00089500
00089600
00089700
00089800
000899GO
00090000
00090100
00090200
00090300
00090400
00090500
00090600
00090700
00090800
0009O900
00091000
00091100
00091200
00091300
00091400
00091500
00091600
00091700
00091800
00091900
00092000
175
-------
APPENDIX D
SAMPLE OUTPUT FROM U-TUBE DESIGN PROGRAM
Several typical print-outs from the U-tube design program are reproduced
in this Appendix. The program was described in Section VIII and Appen-
dix C. Most of the quantities appearing in the print-outs have been
previously defined and/or are listed in the Glossary; however, the
following notes may be helpful.
There are a number of physical dimensions given in the print-outs.
These are defined in the U-tube schematic diagrams of Fig. 44 and 45;
however, some translation is necessary because of the limitations of
computer printers: the variable ag (shown in Fig. 44) is printed as A9.
The quantities "1-PHASE DP" and "2-PHASE DP" are the net pressure dif-
ferences between the entrance (station 1) and exit (station 12) with
water flow only and with air-water flow, respectively. The variable
"V. PERM. DP THROAT DP" is the ratio of venturi permanent pressure drop
to pressure change from entrance to throat, multiplied by 100 (this is
100 times the variable R, previously defined). The values of XI are
values of air-water interfacial area per unit air volume (variable X as
previously defined). The nine-column table in the bottom portion of the
print-out contains values for each of the printed variables at each of
the nine stations listed at the top of the table (the station numbers
are those given in Fig. 44 and 45). The pressures given in the lower
table of each print-out are static pressures. The air-to-water volume
ratios are local values, expressed at the local temperature and pressure.
177
-------
KTYPE
1N1T. A/K AT lEFdATK (C/o
OXYGEN SUPPLIlL (MC/L)
HATER FLCWHATi UPM)
VbNTUKI CCNTkJCTlCN RATIC
AMfclENT PRESS. (Fl P2o)
A9 (UCWN-LEl LtNGTH, FT)
A10 (GRAl.t. TC L-XISt. C-L)
A15 (UP-LEb LINGTH)
A16 (tXIT HORIZONTAL")
A18 (RISI- TC 'SP1KATCX C-L
A19 U*tlP TL IUTLET C-LI
A20 (LVEPALL I'LRIZCNIAL)
A21 (SPOOL M 'SH. EXIT)
A22 (SPOOL .41 ASk. ENTR.)
1-PnASE f.P (Fl h2G)
?-Pl-lASt UP (FT H20)
LOCATION ENTRANT. ASP. IN
D.O.(MG/L) C.C C.O
D.N.(MC/Ll 15'.C7 15. C7
P (FT H2D 27.60 ILL'.
SAT. C'.C.
SAT. L.N.
A/W CC/fc)
KL*E4, INCL. ALPHA=G.9C (FPS)
1
14. C
i47i.
1.00
iO.CC
C.C
it .67
0.0
) C.O
t.Ov.
1.94
-/.fc2
-6.10
"' 5 6
.1-PHAJb Ltfc TCP
O.C C.29
15. U7 14.97
27.60 iO.55
7.41 7.7b
12.32 ii.27
6.59 5.96
9.C6 V.OE
All (GR. TO CASINO LCT.)
A25 (STK. LRCP TO D1FFUSERI
DLki\ PIPE I. L.I INCH)
UP PIPL I.LJ.IINCHI
TEMPI RAlUkb (F)
SUPERFICIAL UW IN (FT/SbC)
SC'PbRFlClAL iW UP (FT/SfcC)
SU^F. TnRLAT PRESS. (FT H^O )
V. PERM. CP/lhRUA"; LP (0/u)
ELtiCK LOSS COEFFICIENT
ELbCW CL-10-i ACl/UIA.
SLIP VtLCClTY DOWN (FT/b£C)
SLIP VELOCITY UP (FT/StC)
XI DOWN (1/HT)
XI UP (I/FT)
7 b v
LLG b^T. tENb 1!< fcENU oUl
T -A'SP T E'XTT)
A22 (SPOOL AT ASP. ENTR.)
1-PHASE LP (Fl H2C)
2-PHASE LP (FT h20)
i ;
•H EfjTRANCL ASP. IN 2
/L) 0.0 0.0
20) 28. t6 28.66 2
C.
N. 1
'0 1
INCL. ALPKA=G.VO (FPS)
1
10.00
3472.
l.CC
34.0
30. CO
~ G.C
26.67
C.C
C.C
t.co
18.33
"I". 94
1.V4
-7.62
-5.34
5
-PHASE
0.0
5.C7
6.66
7.64
2.7C
b.72
All (GR. TO CASING BOT.)
A25 (STK. DRLP TO 01FFUSLR)
bXISl. PIPE I. D. (INCH)
DOWN PIPE I. D. (INCH)
UP PIPL I.L>. (INCH)
TCMPLRA1URE IF)
SUPERFICIAL UW IN (FT/SEC)
SUPERFICIAL UW UP (FT/StC)
SUPF. THROAT PRESS. (FT H2C 1
V. PERM. UP/ThRCAT LP (0/0)
ELbOK LOSS COEFFICIENT
ELbCW CL-TO-FACL/L.1A.
SLIP VELOCITY OOk'S (FT/SEC)
SLIP VELOCITY UP (FT/SEC)
XI UOWN (1/F1)
XI UP (I/FT)
6 7 fc 9
LTG 1CP LcC BUI. BLNLi IN btND Ot'T
U.50 i.4i 3.5t 4.0fc
14.93 16. U 16.26 16.70
7.99 13. b2 14.12 13.93
13.57 26.14 26.67 26.93
11.65 6.C5 5.68 4.89
b.72 8.72 b.72 8.72
40.00
0.0
23.250
23.251.
<.9.000
66.0
2.62
1.69
C.O
C.46
1.5
0.2
_ 47C.
10 12
LEG TOP EXIT
5.91 5.91
17.72 17.72
34.00 34. CJ
7.45 7.45
15.34 15.3*
8.36 8.36
6.72 8.72
178
-------
KTYPfc 1
IN1T. A/V. AT 7 14.91
P (FT h2C) 29.42 2S.42 29.42 31.86
SAT. D.O. 7. 84 6.17
SAT. D.N. 13.04 13. i*
A/H (0/0) iB.i>6 17.09
KL*E4, 1NCL. ALPhA=0.90 (FPS) B.38 8.38
KTYPE 1
1NIT. A/K AT .jPF.lATM (C/0) 20.00
OXYGEN SUPPLIit (Mt/L) 56.1,
HATfcR FLCWRATL (bPM) 347i.
VENTUR1 CCNTRACTiCN RATIU 1.94
AMBIENT PREiS.IFT Hi.0) 34.0
A9 (DOWN-LEO LLNLTH, FT) 30. iO
A1C (tRAL'E ID EXIST. C-L) 0.0
A15 (liP-LEG LCNGTH) 2fc.67
A16 (LXIT HCP120NTAL) 0.0
A18 «ISF TO ASPIKATCR C-L) 6.0
A19 (WOP TL CUTLET C-L) 0.00
A2o (OVERALL hOkiiCNTAD 19. 56
A21 (SPOOL AT ASP. EXIT) 1.94
A22 (SPOCL AT ASP. ENTR.) 1.94
1-PHASE OP (FI H20) -7.77
2-PHASE \» (FT h2C) -3.70
STATION 1 3 5 6
LCCATICN ENTRANCt ASP. IN 2-PHASE LEG TOP
D.D.(M6/L) 0.0 C.O 0.01 0.76
D.N.(HG/L) 15. t7 IS. 07 15.06 14.92
P (FT K20) 30.30 50.30 20.12 32.46
SAT. D.O. 8.03 b.34
SAT. O.N. 13. 3!" 14.09
A/W (0/01 24. 1C 22.31
All (GR. TC CASING BOT.)
Ai5 (STR. DROP TO DIFFUSER)
EX1SI. PIPfc 1.0. (INCH)
DOWN PIPE l.Lu(INCH)
UP PIPE I. D. (INCH)
TtMPERiTURt IF)
SUPERFICIAL UW IN (FT/SEC)
SUPERFICIAL UW UP (FT/StC)
SUPF. THROAT PRESS. (FT H20)
V. PERM. DP/THRC1AI BP (0/ttl
ELbOM LOSS COEFFICIENT
ELBOh tL-TO-FACE/DIA.
SLIP VbLUClTY DOWN (FT/SEC)
SLIP VELOC11Y UP (FT/SfcC)
XI DOWN (1/F1)
XI UP (I/FT)
769
LEG 1)01. BEND IN BENU OUT
•>.35 4.57 5.20
16.46 16.66 17.24
57.90 59.39 5V. 34
13.97 14.28 14.12
25.67 -i6.:>7 26.61
9.15 6.9U 7.45
8.38 fc.jll 8.38
All (GR. TO CASING BOT.)
A25 (STR. DRUP TO U1FFUSERI
LXIST. PIPE I. U. (INCH)
DOWN PIPE I. L.. (INCH)
UP PIPE I. D. (INCH)
TEMPERATURE (F)
SUPERFICIAL UW IN (FT/SEC)
SUPERFICIAL UW UP (FT/SEC)
SUPF. THRCAT PRESS. (FT H20)
V. PERM. DP/THROAT UP 10/0)
ELLOW LOSS COEFFICIENT
ELBOW CL-TO-rACE/DIA.
SLIP VELOCITY DOWN (FT/SECI
SLIP VELOCITY UP (FT/SECI
-XI UOWN (I/FT)
Vl UP (1/t-T)
789
LEG bCT. BEND IN BEND OUT
5.02 5.28 5.99
16.74 16. V7 17.63
57.55 59.00 58.95
14. 'J6 14.37 14.24
25.64 26.31 26.34
12.29 11.96 10.08
40. OO
0.0
2^.250
23.250
29.000
68.0
2.62
1.69
29.42
0.0
0.46
1.5
0.2
0.2
470.
470.
10
LEG TOP
7.21
18.27
33.99
7.72
15.22
12.76
it. 38
40.00
0.0
23.250
23.250
29.000
68.0
2.62
1.69
30. CO
58.2
0.46
1.5
0.2
0.2
470.
470.
10
LEG TOP
8.03
16.57
34.00
7.91
15.14
17.23
12
EXIT
7.21
18.27
33.99
7.7Z
15.22
12.76
8.38
12
EXIT
8.03
16.57
34.00
7.91
15.1*
17.23
KL*E4i INCL. ALPHA=0.9» IFPS)
8.06
B.06
179
-------
KTYPfc
INIT. A/I. Al ..IFtlATM (.?/•-)
OXYGEN SOPPLIH. (MG/L)
«ATtR FLLWKAT. (r.Py) 3
VENTtjf- 1 tUNiHAclltjN RATIL;
AfbltNT P°[i,S.(FT H2G)
A9 (CUWN-Lfcv. LiNolHi FT)
AlO (GrtALF TT fXlST. C-L)
A15 IUP-Lt(.. 1 L'HOTH)
A16 (bXIT hi h lit. MAD
Alfl (SISI TC' '.SPJRATC.^ 0-L )
A1S (OKCP TL ^UlLLf C-L)
A20 (C;VFR»LL F.tRIiCNlALI
A?l (SPClL AT ASt . EXIT)
A22 (SPCCL AT ASP. (NTk.)
1-PHASt IP (Ft HLC)
2-PH4SE E.P (FT K<-C)
STATITN i 1
LICAT1CN ENTRtNLL /'SF. IN ;-
L..G.(Mi,/L) O.i. C...
D.N.IMl/L) 15.0V :^.tV 14
P (FT H2U) 37.77 3J.77 .'0
SAT. C'.Cj. &
SAT. EJ.N. 13
A/W (0/0) 29
KL*E4f 1NCL. ,"LPilA = C.'-. (FPS) 7
KTYPt
INif. A/W AT tFFilATM (0/C)
JXYCtN SUCPLKL IMo/L)
WATtR FLIWAH C.PM) i
VtNTU'I CDN1"/H.T1LN R^IIC
AM&ItNT PKH,S.(F". H^C)
49 (DCVN-Lbl LlNGTtl, 1- T )
AlO (WALE 1C. tXIST. C-L)
A15 (UP-Ll.o Li.\oTh)
Alo UXI 1 HLRIZL'ITAL)
Alb (ulit IT AiPlKATCR C-L)
A19 IL.-RCP TL LUTLLl C-L)
A20 (;,VLKALL rCFl^LNTALI
»21 (SPbtL fT »SP. 1X11)
A22 (SPOLL AT AST. LNTR.)
1-PHAS6 tP (H n.T'l
2-PH«St IP IH 1-^0)
STATI(?N; 1 i
1
25. Co
7u .0
472.
L.ib
24. L
3 j.l ,/
„.,.
26.07
0.0
i. .0
L.LO
2 1 . 1 •*
1.V4
1.44
-6.5^
;.7f
5 t
PHASE LIG TCP
.42 1.1.1
.9V l«t.U6
.73 3t.97
.0^ 14. ii
.4. 27. ,7
.9C 7.90
1
21 .00
56.0
472 .
9.2i
34.0
5o.oO
P.C
4t.o7
0.0
0.0
fc ^
I. 1 .24
1.94
1.94
-;..i7
5.00
5 6
LCCATILM INTRANLi A^P. IN 2-PhASL LIL TCP
O.O.IhG/L) O.i. u.f.
D.N.(Ml,/L) I' .07 1S.'J7 It
P (FT hJU) 3 9. JO . 9.0i- 31
SAT. f .H. E
SAT. l-.N. 13
A/H (C/i.) 23
KL*L4, 1NCL. -.LFhA=(..'i thpS) u
.40 l.li
.00 1,.92
.44 ^3.to
.jb f.04
.93 14.71
.to 21. 4C
.13 t, . 1 3
All (OR. TC, CASINO bC'T.)
A2t. (STP. DRCP TO UlhhUSLR)
t/lST." PIPt l.U.(iNChl
PGriN PIPE I.D.I INCH)
UP pjf't. l.U.(iNCH)
TtMPERATURt (F)
SUI-LhUClAL LH IN (hT/SECI
SU'PERFICIAL UK UP (l-T/SECf
SUPF. THRLAT PKtSS.(H H20)
V. PUP.M. L.P/TIIRUAT UP (0/01
LLLUfc LUSS CuLFFICItNT
ELLCW OL-IL-FACE/L-IA.
SLIP VLLLOlTY DLiWN (FT/SLC)
SLIP VELOCITY UP (H/SEC)
XI ULWN (1/FI)
XI UP ll/FT)
7 t 9
1Kb tL'T. LLNl, IN bL'NO CUT
5.75 o.,2 6.79
16.95 17.^1 17.94
57.il 5b.tl Ml. 56
ti.44 tbi\ 9 2o. 11
15.44 la.s..5 12.76
V.Vi, 7.VO 7.9o
All IGR. TC CASING bLT.)
A.-5 (Slk. LlkOP TO UIFFUSER)
i XiST . PiPt 1.U.I1NCH)
UOKN PIP: I .1.1. ( INCH)
UP PIPE l.u.(lNLH)
Tl.;>PtRATURE IF)
SIIPFRFlCiAL UW IN (FT/StC)
SCPtRFlCiAL UW UP IhT/SbC)
SUPF. THKDAT fRESS.(FT H20)
V. PERM. W/THRLAT UP (0/01
tLtDV, LCSS COEFFICIENT
ELbUW CL-)C-t-ACt/UlA.
SLIP VELOCITY LC«N ( hT/SEC )
SLIP VcL-CITY UP (FT/StC)
XI LUWN » 1/n )
Xi OP (1/hT)
7 i. 9
LCL bu'T. utNU IN t'ENo OUT
7.7^. V.95 o.60
19.64 19.94 ^0.79
7o.ba 7B.17 7a.l2
It.lb 16. 4t lb.33
34.54 35.24 35.27
v.i.l O.E2 7. 41.
O.lj tl.U fc.ij
40.00
0.0
2O.25C
ti.250
29.CUO
66.0
2.62
1.69"
jO.OO
90. i
0.46
1.5
u.2
" 0.2
••70.
47o.
10
LEO TCP
8.69
i'fa.75
33. V9
8 .04
lt.C-8
zl.75
7.90
6O.OO
0.0
2_>.2SO
^3.250
29.000
6o.O
2.62
1.69
JO. CO
U4.0
0.46
1.5
0.2
0.2
470.
470.
10
LEG TOP
10.24
21.93
34.00
7.69
15.23
it>.78
8.13
12
EXIT
6.69
18.75
33.99
8.C4
15.08
21.75
7.90
12
LX1T
10.34
21.93
34.00
7.69
15.23
16.76
b.li
180
-------
"TYI-L 2
1NIT. A/w AT <.th,l«TM (0/0) Zt.OO
rXT-FN SUPPLIEO Iff./L) 56.0
xATfo FLCWKiTF (CF-N) 3472.
VCNTUM CC'MTfJCTICN KATIC l.CC
eMr-IKVT POtS^.IFT HwO) 34.0
"0 IDTHN-LT LtV.TH, t-TI 1C. 00
•MC1 (r,"«C'F TO rXliT. C-L) C.O
'i? d'p-Ltb LENGTH) 14.67
«16 C"X!T HCHIICNTAL) 0.0
• It (-lit TC J?P1''ATCR C-L) 0.0
A19 (C^.OP TC C'.'TLFT C-L) C.O
12Z (CVF'-'ALL HC">r;C'NTAL) 13.EB
»21 ('PCTL AT fSf. FX1T) O.C
«22 (fPOTL aT tS". CNTR.) 0.0
1-P"«SE IV (FT H2C-I 0.11
?-?HiSi I" (FT hZO) 0.9C
5TATICN 1 j 5
LCOT1CN FNTRSNU ASP. IN i-PHASE
r.O.(»C-/L) O.C O.C 0.20
r.N.C'G/L) It. 17 15.1.7 15. 1U
P (FT V'2n) 3'.r-C. 3<..cf 37.95
SAT. r.C. 10.12
SAT. n.\. 16.62
A/K (C/C) 19.11
KL*^4. INCL. •LPt'A=C'.tc (FPS) 7.67
KTYPL 2
INIT. A/V AT tBF.lATM (0/0) 40. OC
"XYGtN SUPPLIft (ft/L) 112.0
KATFR FLTKRATr (GPM 3472.
VFNTU"! CCMTPACT10N RATIO 1.00
AMBifrrr PRESS. (FT H20) 34.0
«•» (DCWN-LEG LFNGTHt FT) 10.00
>10 IGRAl'E TC EXIST. C-L) C.O
Alf U'P-LfC LFNGTH) 14.67
A16 (EXIT KOHZLNTAL) 0.0
tlR ("IS! TO ASPII'TtR C-L) C.t
A19 (rROP T'; OUTLET C-L) o.O
A20' (CVFRALL HORIZTNTAL) li.ee
A21 (SPCCL «T ASP. FXIT) 0.0
A22 (SPOCL AT ASP. ENTR.) C.O
1-PHASE LP (FT H2CI 0.11
2-PHASE &•> (FT H2C) 1.31
STATION 135
LOCATION ENTRANCE ASP. IN 2-PHASE
D.O.(CC/L) r.c 0.0 C.29
D.N.ItT./L) 15.07 15.07 15.12
P (FT H?0) 35.31 3.5.31 38.36
?AT. 0.0. 10.22
SAt. r.H. 17.00
A/W (C/0) 37.47
KL*E4, INCL. ALPHA=0."0 (FPS) 6.54
6
LEG TOP
0.20
16.10
37.95
10.12
16.62
19.11
7.67
t
LEG TOP
0.29
15.12
38.36
10.22
17.00
37.47
c.54
All (G». TO CASING BOT.)
A^b (STR. DRCP TO D1FFUSER)
FX1ST. PIPE I. D. (INCH)
DOWN PIPE I. D. (INCH)
UP PIPE I. D. (INCH)
Tl fP£«ATL'RE IF)
SUPERFICIAL UK IN (FT/SEC)
SUPERFICIAL LM UP (FT/SEC)
SUPF. THROAT PRESS. (FT H20)
v. PERM. DP/THROAT DP (O/o)
ELBOH LESS COEFFICIENT
ELBCW CL-TO-FACt/C-lA.
SLIP VELOCITY DOWN (I-T/SEC)
SLIP VELOCITY UP (FT/SEC)
XI DOWN (I/FT)
XI UP ll/FT)
76V
LEG BCT. EEND IN BEND OUT
1.92 2.24 3.14
15. 5E 15.73 16.15
46.25 47.66 47.60
11.76 12.09 11.94
20.31 20.96 20.99
15.55 15.06 12.74
7.67 7.B7 7.87
All (OR. 10 CASING GOT.)
A25 (STR. DRCP TO DIFFUSE*)
EXIST. PIPE I.D.(INCH)
DOWN PIPE I.D.I INCH)
UP PIPE I. D. (INCH)
TEMPERATURE IF-)
SUPERFICIAL UK IN (FT/SEC)
SUPERFICIAL UK UP (FT/SEC)
SDPF. THRCAT PRESS. (FT H20)
V. PERK. DP/THROAT DP 10/C)
ELBOW LOSS COEFFICIENT
ELBOW CL-TO-FACE/U1A.
SLIP VELOCITY DOWN (FT/SEC)
SLIP VELOCITY. UP (FT/SEC)
XI DOWN (I/FT)
XI UP (I/FT)
769
LEG BOT. BEND, IN BEND OUT
2.40 2.60 3.90
15.70 15. B7 16.37
45.57 46.HO 46.73
11.73 12.02 11.92
19.95 20.51 20.52
31.37 30.51 26.40
6.54 6.54 6.54
20.00
0.10
23.250
23.250
29.000
6E.O
2.62
1.69
C.01
0.0
0.46
1.5
0.2
0.2
470.
470.
10
LEG TOP
5.19
16.59
34.00
8.24
14.99
17.62
7.87
20. OC
C.10
23.250
23.250
29.000
68.0
2.62
1.69
0,01
C.O
0.46
1.5
0.2
C.2
470.
470.
10
LEG TOP
6.23
16.74
34.00
8.48
14.89
36.06
6.54
12
FX1T
5.19
16.59
34.00
8.24
14.99
17.62
7.87
12
tXJT
6.23
16.74
34.00
8.48
14.89
36.06
6.54
181
-------
KTYPf
INI7. A/W Al frCF.lATM (0/0)
CXYGFN SUPPLIED (MC/L)
2
1C. 00
26.0
WATf* FLOKRATE (CPM1 3472.
VFNTU'.I CONTRACTION RATIO
AMfllENT PP.ESJ.IFT H20)
A9 IDOKN-LEG LCNCTH, FT)
A10 (GRALF TO EXIST. C-L)
»15 (LIP-Lr& LINC-TM)
• 16 (tXIT HCKIZCVTA!.)
A1P ("ISf TO ASPIRATOR L-L )
A19 (CiRCP TU OUTLET C-L)
A2G (OVERALL HORIZONTAL)
*21 (SPOOL AT ASP. LXIT)
• 22 (SPtiCL AT ASP. ENTR.)
1-PHASE DP O T H2C. )
2-PHASt DP (FT H.'O)
STATKN 1 3
1.00
34.0
31.1. 00
0.0
34.67
0.0
U.C
0.0
ia.ee
0.0
0.0
0.14
1.68
5 6
IOC AT I ON FKTRANCE ASP. IN i-PHASI- LFG TOP
O.O.IHC/L) 0.0 0.0 C
D.M.IMG/l) U .07 15.07 15
F (FT H20) 25.68 -.l.tl 36
SAT. U.O. 10
S*T. P.N. n
t/W (O/Ot 9
KL*F<., INCL. ALPKA=0.90 (FPS) 8
.06 0.06
.01 15.03
.73 3fc.73
.32 10.3?
.lc. 17.16
.43 9.43
.62 P. 62
All (GR. ID CASING BOT.)
A25 (SIR. t/RCP TO DIFFUSER)
EXIST. PIPE I. D. (INCH)
DOWN P*PE I.D.(INCH)
UP PIPE l.L.(INCH)
TEMPERATURE (F)
SUPERFICIAL UW IN (FT/SEC)
SUPERFICIAL UH UP (FT/SEC)
SL'PF. THROAT PRESS. (FT H20)
V. PtRM. UP/THROAT OP (0/0)
EL&OW LOSS COEFFICIENT
ELEOW CL-TO-FACE/01A.
SLIP VELOCITY DOWN (FT/SEC)
SLIP VELOCITY UP (FT/SbC)
XI DOWN (I/FT)
XI UP I I/FT 1
7 k 9
LEG BOT. BEND IN BEND OUT
3.23 3.42 3.95
16.83 17. Cl 17.50
66.08 67.62 67. SB
16.89 16.16 15.96
29.60 30.34 30.41
5.31 5.18 4.30
8.62 6.62 B.tZ
40.00
0.10
23.250
23.250
29.000
68.0
2.62
1.69
0.01
0.0
0.46
1.5
0.2
0.2
470.
470.
10
LEG TOP
6.35
18.86
34.00
7.42
15.35
8.23
&. 62
12
EXIT
6.35
16.86
34.00
7.42
15.35
8.23
8.62
STATION
LOCATION
D.C.(MG/L)
D.N.tMCVLI
P (FT H20)
SAT. D.P.
SAT. D.N.
A/W (0/C)
KTYPT
1NIT. A/W •! 66F.1ATM (C/0)
OXYGEN SUPPLIED (MC/L)
z
20.00
56. G
WATER FLOWRATt (LPM) 3472.
VENTU"U CONTRACTION RATIO
AMBIENT PRESS. (FT H20)
•9 (DOWN-LEG LFNGTH, FT)
A1C (GRADE TO EXIST. C-L)
•15 (DP-LEG LENGTH)
A16 (FX1T HOPI70NT*L)
Alt (RISl TP ASPIRATOR C-L)
Al° (DKCC TO OUTLFT C-L)
A20 (OVERALL HORIZONTAL)
421 (SPOOL Al ASP. EXIT)
A2? (SPOOL AT ASP. ENTR.)
1-PHASF UP (FT H20)
2-PHASE L'P (FT H?0)
1 3
1.00
34.0
30.00
C.O
31.67
O.C
0.0
0.0
13.88
0.0
0.0
0.14
2.46
5 6
1 ENTRANCF ASP. IN 2-PHASE LLG TOP
•L) 0.0 0.0 0
•LI 15.07 15.07 15
!0) 36.46 36.48 39
'. 10
1. 17
') 18
:NCL. ALPHA=O.VC (FPS) 7
.09 0.09
.09 15.09
.53 39.53
.54 10.54
.52 17.52
.36 18.36
.90 7.9C
AII (GR. 10 CASING BOT.)
A25 1STR. DROP TO DIFFUSER)
EXIST. PIPE l.D.(INCH)
DOWN PIPE I. U. (INCH)
UP PIPE I. D. (INCH)
TEMPERATURE (F)
SUPERFICIAL UW IN (FT/SEC)
SUPERFICIAL UW UP (FT/SEC)
SUPF. THROAT PRESS. (FT H20)
V. PERM. DP/THROAT DP (0/0)
ELBOW LOSS COEFFICIENT
ELBOW CL-TO-FACE/OIA.
SLIP VELOCITY DOWN (FT/StC)
SLIP VELOCITY UP (FT/SEC)
XI DOWN (I/FT)
XI UP (I/FT)
769
LEG BOT. BEND IN BEND OUT
4.89 5.17 5.95
17.75 18. Cl 18.74
65.16 66.63 66.58
16.05 16.35 16.19
29.03 29.71 29.76
10. PI 10.55 8.88
7.90 7.90 7.90
40.00
0.10
23.250
23.250
29.000
68.0
2.62
1.69
0.01
0.0
0.46
1.5
0.2
0.2
470.
470.
10
LEG TOP
8.60
19.86
34.00
7.89
15.15
17.06
7. 90
12
EXIT
6.60
19.86
34.00
7.69
15.15
17.06
7.90
182
-------
KTYPI'. 2
INIT. A/W AT 66F.1ATM (0/0) 30.00
"OXYGEN SUPPLIED P (FT H2C) 3.13
STATrF* 135
LOCATION ENTRANCE ASP. IN 2-PHASE
D.O. (MG/L) 0.0 0.0 0.11
b.N.lMG/ir 15.07 15.07 15. OS
P IFT H20) 37.13 37.13 40.lt
SAT. D.O. 10.71
SAT. D.N. 17.81
A/W 10/0) 26.95
KL*E4, INCL. ALPHA=0.90 IFPS) 7.ii
KTYPF 2
INIT. A/W AT 6BF.1ATM 10/0) 40. CO
OXYGEN SUPPLIED (MG/L) 112.0
WATFR FLOWRATF (GPM) 3472.
VENTURI CONTRACTION RATIO 1.1)0
AMBIENT PRESS. (FT H2CI 34.0
AV (DOWN-LEG LFNCTH, FT) 30.00
A10 (GRADE TO EXIST. C-LI 0.0
A15 (UP-LEG LENGTH) 34.67
A 16 (EXIT HORIZONTAL) 0.0
A18 (RISE TO ASPIRATOR' C-L) 0.0
All (DROP TO OUTLET C-L) C.O
A20 (OVERALL HORIZONTAL) 13.88
A21 (SPOOL AT ASP. EXIT) G.O
A22 (SPOOL AT ASP. ENTR.) O.C
1-PHASE DP (FT H20I 0.14
2-PHASE OP IFT H20) 3.67
STATION 135
LOCATION ENTRANCE ASP. IN 2-PHASE
D.O. IMG/LI 0.0 O.C 0.14
D.N. (MG/L) 15.07 15.07 15.10
P IFT H20) 37.68 37.68 40.73
SA_T. D.O. 10.66
__
SAT; D.N. ie.05
A/W (0/0) 35.30
KL*E4, INCL. ALPHA«0.90 IFPS) 6.63
6
LEG TOP
0.11
15.09
4C.19
10.71
17.81
26.95
7.23
6
LtG TOP
0.14
15.10
40.73
10.86
18.05
35.30
6.63
All IGR. TO CASING COT.)
A25 ISTR. DRUP TO DIFFUSCRI
EXIST. PIPE I. D. (INCH)
DCWN PIPE I. U. (INCH)
UP PIPfc I. D. (INCH)
TtMPERATURE IF)
SUPLRF1CIAL UW IN IFT/SLC)
SUPERFICIAL UW UP (FT/SEC)
SUPF. THROAT PRESS. IFT H20)
V. PERM. DP/THROAT DP la/0)
ELBOW LOSS COEFFICIENT
ELBOW CL-TO-FACf/DIA.
SLIP VELOCITY DCWN (FT/StC)
SLIP VELOCITY. UP IFT/SEC)
XI DOWN (I/FT)
XI UP ll/FT)
769
LtG BOT. BEND IN BEND OUT
5.75 6.C8 6.99
18.23 18.52 19. i7
64.31 65.71 65.65
16.06 16.38 16.26
211.54 29.18 29.21
16.45 16.08 13.68
7.23 7.23 7.23
All IGR. TO CASING BCT.)
Ai5 ISTR. DROP TO DIFFUSE*)
EXIST. PIPE 1.0. (INCH)
OCWN PIPt I. U.I INCH)
UP PIPE 1.0. (INCH)
TEMPERATURE (F)
SUPERFICIAL UW IN (FT/SEC)
SUPERFICIAL UW UP (FT/StC)
SUPF. THROAT PRESS'. (FT H20)
V. PERM. L'P/THRCAT DP 10/C)
ELbOW LCSS COEFFICIENT
ELtOW CL-10-FACE/DIA.
SLIP VELOCITY DOWN (FT/SEC)
SLIP VELOCITY UP (FT/SIC)
XI DOWN (I/FT)
XI UP (I/FT)
7 b 9 '
LLG BOT. BEND IN BEND CUT
6.18 6.53 7.50
18.44 IE. 75 19.64
63.51 64. b4 64. 7E
16.04 16.34 16.24
/
28.10 28.71 26.73
22.22 21.74 IS.tC
6.63 0.63 6.63
40. CO
0.10
23.250
23.250
2V. 000
68.0
2.62
1.69
0.01
0.0
0.46
1.5
0.2
0.2
470.
47C.
10
LEG TOP
9.51
20.08
34.00
8.14
15.04
26.14
7.23
40.00
0.10
23.250
23.250
29.000
68.0
2.62
1.69
0.01
0.0
0.46
1.5
0.2
0.2
47C.
470.
10
LEG TOP
9.91
20.07
34.00
8.29
14.97
35.34
6.63
12
EXIT
9.51
20.08
34.00
8.14
15.04
26.14
7.23
12
EXIT
9.91
20.07
34.00
8.29
14.97
35.34
6.63
183
-------
STATION
LOCATION
D.O.(MG/l)
D.N.IMC/L)
P (FT H20)
SAT. D.O.
SAT. D.N.
A/W (C/0)
KTYPE
1N1T. A/W AT 6tF,lATM (0/0)
rXYGFN SUPPLIED (KG/L)
z
5C.OO
140. C
WATER FLOWRATF (GPM 2472.
VENTURI CONTRACTION RATIO
AMRICNT PRESS. (FT H20)
A9 (COWN-LFG LENGTH, FT)
A10 (CRATF TO FXIST. C-L)
A15 (UP-LEG LENGTH)
«lt (EXIT HOP.IZCNTAL)
A18 I'lSl TC ASP1RATDR C-L 1
Al° (DROP TO CUTLET C-L)
420 (OVERALL HORIZONTAL)
«21 (SPUOL AT ASP. EXIT)
A22 (SPOOL AT ASP. ENTR.)
1 -PHASE PP (FT H20)
?-PH»SC OP (FT H20)
1 1 3
1.00
34.0
30.00
0.0
34.67
0.0
G.C
0.0
I3.ee
c.o
o.c
0.14
4.13
5 t
>N FNTRANU ASP. IN 2-PHASE LEG TOP
,/L) 0.0 0.0 0
/L) 15.07 15.07 15
'201 38.13 38.13 41
0. 10
,N. 18
•0) 43
INCL. ALPHAO.90 (FPS) t
.16 C.16
.11 15.11
.16 41. ie
.9t> 10.96
.25 18.25
.48 43. 4P
.07 6.07
All (GR. TO CASING BOT.)
A2L, (STR. URUP TO 01FFUSEK)
FXIST. PIPE l.D.IINCH)
DOWN PIPE I. \j. (INCH)
UP PIPE I. D. (INCH)
TEMPERATURE (F)
SUPERFICIAL UW IN (FT/SEC)
SUPERFICIAL UW UP (FT/SEC)
SUPF. THROAT PRESS. (FT H2C)
V. PERM. LP/IHROAT DP (0/0)
ELBOW LOSS COEFFICIENT
ELBOW CL-1C-FACE/DIA.
SLIP VtLOClTV DOWN (FT/SEC)
SLIP VELOCITY UP (FT/SEC)
XI DCWN (I/FT)
XI UP (I/FT)
769
LEG BOT. bl.NC. IN BEND OUT
6.33 6.70 7.70
It. 49 IB. 60 19.69
62.76 64. C2 63.95
15.97 16.27 16.16
27.71 26.29 28. 29
28.10 ?7.51 23.65
6.07 6.07 6. 1-7
4C.CO
0.10
23.250
23.250
29.000
68.0
2.62
1.69
C.01
O.C
0.46
1.5
0.2
0.2
470.
470.
10 12
LEG TOP EXIT
10.06 10.06
19.96 19.96
34.00 34.00
6.40 6.40'
14.93 14.93
44.62 44.62
6.07 6.07
KTYPfc 2
INIT. A/W AT 68F.1ATM ( C/0 ) 2C
OXYGEN SUPPLIbf (MG/L) 5o
WATFK FLOWRATE (C,PM) 3472
VENTURI CONTRACTION RATIO 1
AMBIFNT PRESS. (FT H20) 34
A9 (DCWN-LEC LENCTH, FT) 50
A10
A15
A16
A18
A19
«2C
A21
A22
(&RAPE TO tXIST. C-LI
(UP-LFG LFNGTH)
(FXIT HORIZONTAL)
(RISE TC ASPIRATOR C-L)
(DROP TC OUTLET C-L)
(OVERALL HORIZONTAL)
(SPOOL AT ASP. EXIT)
(SPOCL AT ASP. ENTR.)
1-PHASC DP (FT H20)
2-PHASE DP (FT H20)
STATION
LOCATION
D.O.-IMG/L)
D.N.
(MG/L)
P (FT H20)
SAT.
SAT.
A/W
D.O.
D.N.
(0/0)
KL*E4, ISCL
1 3
0
54
0
0
0
13
0
0
0
3
5
.00
.0
.00
.0
.00
.0
.67
.0
.0
.0
.68
.0
.0
.16
.76
ENTRANCF ASP. IN 2-PHASfc
0.0 O.C' 0.
15.07 15.07 Ib.
37.78 37.73 40.
10.
18.
17.
. »LPHA=0.90 (FPS) 7.
06
06
63
68
0V
7E
96
All (GR. TO CASING BOT.)
A25 (SIR. DROP TO C1FFUSER)
EXIST. PIPE I. D. (INCH)
DOWN PIPE 1.U.I1NCHI
UP PIPE I. D. (INCH)
TEMPERATURE (F)
SUPERFICIAL UW IN (FT/SEC)
SUPERFICIAL UW UP
SUPF.
THROAT PRESS
V. PIRM. DP/THROAT
ELEOW
ELBC'W
SLIP
SLIP
(FT/SEC)
.(FT
DP
H20)
(0/0)
LOSS COEFFICIENT
CL-TO-FACE/D1A.
VELOCITY DOWN
< FT/SEC)
VELOCITY UP (FT/SEC)
XI DOWN (1/F1)
6
LEG TOP
0.06
15.06
40.83
1C. 88
It). 09
17.78
7.96
XI UP
7
(I/FT)
6
LEG BOT. BEND IN
7.60
20.79
84.39
20.15
37.99
8.16
7.96
7.85
21.10
C5.SO
20.45
36.70
7.99
7.96
9
BEND OUT
a.
21.
85.
20.
38.
6.
7.
55
9t
85
28
75
71
96
60.00
0.10
23.250
23.250
29.000
68.0
2.62
1.69
0.01
0.0
0.46
1.5
0.2
0.2
470.
470.
10
LEG TOP
10.72
23.10
34.00
7.68
15.24
16.65
7.96
12
EXIT
10.72
23.10
34.00
7.68
15.24
16.65
7.96
184
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KTYPE 2
INIT. A/W AT 6BF.1ATM 10/0) 20.CO
L'XYGfN SUPPLIED IMG/L) 5t.O
VATER FLOWRATE IGPM) 3472.
VENTURI CONTRACTION RATIO 1.00
All
-------
KTVPE 3
1NIT. A/W AT 68F.1ATM (0/0) 15.00
OXYGEN SUPPLIED (MG/L) 42.0
WATER FLOWRATE (GPM) 1800.
VENTURI CONTRACTION RATIO 1.00
AMBIENT PRESS.(FT H20) 34.0
A9 (DOWN-LEG LENGTH, FTI 23.28
AID (GRADE TO EXIST. C-L) 3.50
A15 (UP-LEG LENGTH) It.ZU
A16 (EXIT HORIZONTAL) 0.0
A18 (RISE TO ASPIRATOR C-L) 0.0
A19 (DROP TO OUTLET C-L) ' 8.00
A20 (OVERALL HORIZONTAL) 4.50
A21 (SPOOL AT ASP. EXIT) 0.0
A22 (SPOOL AT ASP. ENTR.) 0.0
1-PHASE DP (FT H20) 7.12
2-PHASE DP (FT H20) -8.36
All (GR. TO CASING EOT.) 30.00
A25 (STR. DROP TO DIFFUSER) 0.0
fcXIST. PIPE I.D.(INCH) 26.400
DOWN PIPF I.U.(INCH) 26.400
UP PIPL I.D.(INCH) 13.250
TEMPERATURE (F) 82.4
SUPERFICIAL UW IN (FT/SEC) b.ll
SUPERFICIAL UW UP (FT/SEC) 4.19
SUPF. THROAT PRESS.(FT HIO) o.oi
V. PERM. DP/THROAT DP (0/0) 0.0
tLBOW LOSS COEFFICIENT 0.75
ELBOW CL-TO-FACE/DIA. 1.0
SLIP VELOCITY DOWN (FT/SEC) 0.2
SLIP VELOCITY UP (FT/SEC) 0.2
XI UOWN (I/FT) 470.
XI UP (1/l-T) 470.
STATION
LOCATION
D.O.IMG/L)
O.N.IMG/L)
P (FT H20)
SAT. 0.0.
SAT. D.N~.
A/H (0/0)
KL*E4, INCL. ALPHA=0.80 (FPS)
1 3
ENTRANCE ASP. IN
0.20 0.20
13.43 13.43
25.63 25.63
5
2-PHASE
0.20
13.43
0.01
0.01
0.01
0.01
8.76
6
LEG TOP
0.20
13.43
0.01
0.01
0.01
0.01
8.76
7 a
LEG BCT. BEND IN
0.20 0.20
13.43 13.43
9 10
BEND OUT LEG TOP
0.01
0.01
0.01
0.01
8.76
0.01
0.01
0.01
0.01
8.76
0.20
13.43
49.03
11.37
19.37
9.97
8.76
1.47
13.75
34.01
7.53
13.21
14.24
8.76
12
EXIT
1.47
13.75
34.01
7.53
13.21
14.24
8.76
186
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
1. Report No.
3. Accession No,
w
4. Title
U-TUBE AERATION
7. Author(s)
Mitchell, R. C.
Rocketdyne Division of
Rockwell International
Canoga Park, California
5. Report Data June 1073
6.
8. PerfenriMg Organization
Report No R-9101
10. Project No.
17050 DVT
12. Sponsoring Organization
IS. Supplementary Notes
Environmental Protection Agency
Environmental Protection Agency Report
Number EPA 670/2-73-031, September 1973.
11. Contract/Giant No.
EPA 68-01-0120
13. i*jj>pe of Report and
Fencxl
16. Abstract
The results of two experimental and analytical projects to develop and evaluate the
U-tube aeration concept are presented. Experimental data were obtained to character-
ize the mass transfer and fluid dynamics behavior of U-tube systems over large ranges
of design variables and operating conditions. Tests were made first with a pilot-
scale (2-inch diameter) U-tube. Subsequently, full-scale (8- to 20-inch diameter)
prototype systems were successfully designed, constructed (under EPA grant projects!
and operated in sanitary sewer systems in Jefferson Parish, Louisiana, and Port
Arthur, Texas. These field installations have been effective in reducing previous
serious odor and corrosion problems resulting from sulfides. No maintenance has
been required for aspirated-air systems in approximately 2 years of continuous
operation.
Mass transfer and fluid dynamics correlations, plus a design computer program,were
developed for use in designing U-tube systems. A satisfactory basis for design
now exists, although additional improvements are needed.
It was found that U-tube systems are a practical, flexible, efficient method for
aeration for a number of applications. They are well-suited to applications in
which it is desired to raise the oxygen concentration of a moving stream, even to
saturation. (Mitchell-Rocketdyne) ;
17a, Descriptors
'Aeration, *Sulfide Control, *0dor Control, *Corrosion Control, *Aerobic
Conditions, *Water Pollution Control, Sewers, Effluent Streams, Natural Streams,,
Oxygenation
17b. Identifiers
*U-Tube Aerator, *Design,
17c. COWRR Field & Group
•Performance
18. Availability
19. Security Class.
(Report)
30, Seatrttyjidass.
(Page)
21. No. of
Pages
22. Price
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
US. DEPARTMENT OF THE INTERIOR
WASHINGTON. D.C. M240
Abstractor Rex C. Mitchell
I institution Rocketdyne Division, Rockwell International
WRSIC 102 (REV. JUNE 1971)
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