FINAL REPORT OF
Pilot Scale Investigation
OF A
VENTURI-TYPE CONTACTOR FOR
REMOVAL OF S02 BY THE
LIMESTONE WET-SCRUBBING PROCESS
PREPARED BY
Cottrell Environmental Systems, Inc.
A DIVISION OF RESEARCH-COTTRELL, INC.
UNDER CONTRACT TO UNDER PROJECT
AIR POLLUTION CONTROL OFFICE CES-116
ENVIRONMENTAL PROTECTION AGENCY
UNDER CONTRACT NUMBER R.J.GLEASON
EHSD-71-24 OCTOBER, 1971
-------
Final Report
PILOT SCALE INVESTIGATION OF A VENTURI-
TYPE CONTACTOR FOR REMOVAL OF S02 BY
THE LIMESTONE WET-SCRUBBING PROCESS
Submitted By
COTTRELL ENVIRONMENTAL SYSTEMS, INC.
Division of Research-Cottrell
Bound Brook, New Jersey
For The
AIR POLLUTION CONTROL OFFICE
OF THE ENVIRONMENTAL PROTECTION AGENCY
Division of Control Systems
Under Contract EHS-D-7l-24
October, 1971
Prepared By:
R. . G eason
Program Manager
,,' /' 1
,:LvA='I12,,;d ;1,/~,)~"
Leonard Wochin er
Program Engineer
e~
C. T. Sui
Systems Analyst
-------
SUMMARY
Control of sulfur dioxide emission from a coal-fired
power generating boiler using a cocurrent venturi-type
scrubber in series with a wetted film packed tower has been
studied in a one-thousand cfm pilot system.
Sulfur dioxide absorption characteristics were studied
in detail with three types of alkali materials, calcium oxide,
sodium carbonate and calcium carbonate. Sulfated lime/fly ash
and dolomitic lime were also tested and their absorption
properties were compared to the calcium oxide results.
The primary objectives of this work were the development
of design data for predicting sulfur dioxide absorption in
1) a venturi scrubber with limestone-injection wet scrubbing
and 2) a combination of a venturi scrubber and packed tower
with direct lime/limestone wet scrubbing. A simplified method
for expressing the S02 absorption was developed with standard
linear correlation techniques. Process parameters relevant to
the type of absorption device were studied so that the S02
absorption efficiency could be estimated for similar operating
systems.
Sulfur dioxide absorption efficiency for the cocurrent
scrubber can be predicted by the following equation:
Y = 30.7 + 4.57(R) + 0.952(~p) + 0.647(L/G)
+ l5.16(I) - 2.751(I)2 - 0.598(SL),
when calcium oxide is used as absorbate. The scrubbing vari-
ables showing significant effect on the absorption (stoichio-
metry (R), throat pressure drop (~p), liquid-to-gas ratio (L/G) ,
'"
-------
ionic strength (I), and slurry concentration (SL» are con-
ditions pertinent to most venturi-type scrubbers.
For sodium carbonate absorption, a less complicated
correlation was developed, i.e.
Y = 25.36 + 3.l05(6p) - 0.0550(6p)2 + .02ll(V)
Variables attributing liquid-phase resistance did not affect
the S02 absorption efficiency (Y). Only throat pressure drop
(6p) and total gas flow (V) demonstrated significant sensitivity
on efficiency.
The S02 absorption efficiency of the venturi was measured
at 55% for maximum removal conditions using calcined limestone.
Sodium carbonate allowed 80% removal at comparable conditions.
Venturi absorption with a mixture of sulfated lime and
fly ash was also characterized as input to the imminent TVA/
'Shawnee scrubber demonstration project. Significantly lower
absorption efficiencies were measured with sulfated lime/fly
ash than with commercially calcined limestone.
Dolomitic lime (CaO.MgO) demonstrated excellent absorption
efficiency in the single test made. The difference in absorption
efficiency between calcium oxide, dolomitic lime, and sulfated -
lime/fly ash at comparable operating conditions are:
.
% Absorption
Calcium
Oxide
% Absorption
Dolomitic
Lime
% Absorption
Sulfated
Lime
32
64
16
-------
The wetted film packed tower was studied with limestone
(calcium carbonate) and correlations were developed for the S02
absorption (Y) only for the particular packing utilized.
However, critical operating variables were identified. For
example, sulfur dioxide removal was sensitive to inlet S02 con-
centration (ppm), limestone slurry concentration (% CaC03),
and total slurry concentration (SL) , as can be seen from the
following:
Y = 165.05 - 0.0463 (ppm)
+ 30.48 (% CaC03) - 9.l26(SL)
This correlation could predict the absorption efficiency
to an accuracy of t 1.9% for a limestone ground to 75%-200 mesh.
A similar correlation was found for material containing 61%-200
mesh.
Long term scaling studies with CaC03 were not possible,
but an 80-hour sustained operation was completed successfully
with very favorable results. It is concluded that scaling can
be controlled by direct limestone addition to the scrubbing
circuit and that liquid-to-gas ratio and slurry concentration
are primary variables.
It is recommended that additional on-site test work be
conducted in the existing pilot unit employing limestone,
sulfated lime/fly ash, and dolomitic limestone in order to
determine the absorption efficiency and operational reliability
with these materials.
-------
ACKNOWLEDGEMENTS
The work upon which this publication is based was per-
formed pursuant to Contract EHS-D-71-24 with the Environmental
Protection Agency. The guidance of the Air Pollution Control
Office and its Contract Technical Officer, R. Borgwardt,
contributed significantly to the success of this work.
Experiments were carried out at the Tidd
Ohio Power, a subsidiary of American Electric
cooperation of AEP and the Tidd Power Station
a key part in executing this study.
Power Station of
Power.
The
personnel played
Part of the work reported here was conceived and performed
by the Tennessee Valley Authority personnel. The progress
resulting from the limestone tests is due, in part, to TVA
participation.
The authors are indebted to other members of Cottrell
Environmental Systems, A. B. Walker, J. D. McKenna, Dr. N. W.
Frisch, R. F. Brown, A. P. Konopka, and D. W. Coy; their
constructive and informative comments while the test work was
in progress and during the preparation of this manuscript
have contributed a great deal to this report.
-------
TABLE OF CONTENTS
I.
II.
INTRODUCTION. . . . . . . . . . . . . . . . . . . .
THEORY BACKGROUND. . . . . . . . . . . . . . . . .
A. ABSORPTION RATE IN THE VENTURI. . . . . . . . .
B. ABSORPTION RATE IN THE TOWER. . . . . . . . . .
C. PROCESS CHEMISTRY. . . . . . . . . . . . . . .
PROCESS EQUIPMENT. . . . . . . . . . . . . . . . .
A. PILOT PLANT LAYOUT. . . . . . . . . . . .. . .
B . ANAL YT I CAL . . . . . . . . . . . . . . . . . . .
III.
IV.
1. Chemical Reagents. . . . . . . . . . . . . .
RESULTS AND DISCUSSION. . . . . . . . . . . . . . .
A. SODIUM CARBONATE. . . . . . . . . . . . . . . .
1. FDS Results - Na2C03. . . . . . . . . . . . .
2. Packed Tower Results - Na2Co3 . . . . . . . .
B. FDS RESULTS - CALCIUM OXIDE. . . . . . . . . .
1. Open-Loop: Dry Injection and Wet Slurry -
Task III and IV . . . . . . . . . . . . . . .
2. Closed-Loop: Dry Injection/Wet Slurry
Combination. . . . . . . ... . . . . . . . . .
3. Variations in CaO Stoichiometry - Task VIa. .
4. Process Variables Affecting the Venturi
Scrubber Performance - Tasks VIb to VIf . . .
5. FDS Results - Task VI . . . . . . . . . . . .
6. Power Requirements For Tests VIa Through
VId . . . . . . . . . . . . . . . . . . . . .
7. Effect of Mode Change - Task VII. . . . . .
8. Lime Feed via Slurry Without Dry Injection -
Task VIIa . . . . . . . . . . . . . . . . . .
9. Slurry Feed To The Venturi and Tower -
Task Vllb . . . . . . . . . . . . . . .
. . .
10. Clarified Solution to Tower and FDS - Task
VI Ie . . . . . . . . . . . . . . . . . . . .
11. Tower Absorption
. . .
. . . . . . . .
. . .
Page
1
5
5
8
12
15
15
20
22
23
23
25
26
30
30
34
38
38
42
46
46
47
50
51
53
-------
TABLE OF CONTENTS (continued)
V.
VI.
VII.
C.
OTHER ALKALI MATERIALS - TASK VIII. . . . . . .
1. Dolomitic Lime - Task VIIIc . . . . . . . . .
2. Sulfated Lime/Fly Ash via Dry Injection -
Task VIIId . . . . . . . . . . . . . . . . .
3. Sulfated Lime/Fly Ash with Wet Slurry -
Task VIIIe . . . . . . . . . . . . . . . . .
D . LIMESTONE. . . . . . . . . . . . . . . . . . .
1. Limestone Efficiency Tests - Open-Loop. . .
2. Limestone Scaling Experiments - Closed-Loop
a. Sea 1 ing . . . . . . . . . . . . . . . . .
b. Absorption. . . . . . . . . . . . . . . .
CONCLUSIONS. . . . . . . . . . . . . . . . . . . .
RECOMMENDATIONS. . . . . . . . . . . . . . . . . .
REFERENCES. . . . . . . . . . . . . . . . . . . . .
APPENDIX A - OPERATING CONDITIONS AND RESULTS FOR
THE SODIUM CARBONATE AND CALCIUM OXIDE
TESTS. . . . . . . . . . . . . . . .
APPENDIX B - OPERATING CONDITIONS AND RESULTS FOR
THE LIMESTONE TESTS. . . . . . . . . .
,f
Page
58
60
60
63
66
66
68
70
75
84
87
88
89
115
-------
FIGURE
FIGURE
111-1
111-2
111-3
111-4
FIGURE
FIGURE
FIGURE IV-l
FIGURE IV-2
FIGURE IV-3
FIGURE IV-4
FIGURE IV-5
FIGURE IV-6
FIGURE IV-7
FIGURE IV-8
FIGURE IV-9
LIST OF ILLUSTRATIONS
Page
. . . 16
. . . 17
. . . 19
. . . 21
- PILOT PLANT LAYOUT. . . . . . . . .
- PILOT PLANT SCHEMATIC DIAGRAM. . .
- DIMENSIONS FOR FLOODED DISC SCRUBBER
- SCHEMATIC DIAGRAM FOR S02 ANALYTICAL
SYSTEM. . . . . . . . . . . . . . .
- TWO STAGE SODIUM CARBONATE SCRUBBER -
TASK II A&B . . . . . . . . . . . . . . .
TOWER ABSORPTION TESTS FOR SODIUM CAR-
BONATE - TASK IIC . . . . . . . . . . . .
- MASS-TRANSFER COEFFICIENTS FOR SODIUM
CARBONATE THROAT VELOCITY BETWEEN 50 AND
250 FEET PER SECOND. . . . . . . . . . .
- MASS-TRANSFER COEFFICIENT AS A FUNCTION
OF GAS MASS VELOCITY. . . . . . . . .
- DRY INJECTION WITHOUT RECIRCULATION -
TASK III . . . . . . . . . . . . . . . . .
- ABSORPTION EFFICIENCY FOR TASKS III & IV
- CALCIUM OXIDE SLURRY TO FDS - TASK IV
- TWO STAGE CALCIUM OXIDE SCRUBBER WET
SLURRY - TASK V . . . . . . . . . .
- CALCIUM OXIDE DRY INJECTION TO FDS -
. . .
TASK VIA. . . . . . . . . . .
. . .
. . .
FIGURE IV-I0 - LIME DRY INJECTION TO FDS WITH CLARIFIER
RECYCLE - TASKS VIB, C, D & F . . . . . .
FIGURE IV-II - CALCIUM OXIDE DRY INJECTION TO FDS WITH
VARIABLE SLURRY CONCENTRATION - TASK VIE.
FIGURE IV-12 - ABSORPTION EFFICIENCY FOR CALCIUM OXIDE
AND SODIUM CARBONATE AS A FUNCTION OF
THE PRESSURE DROP ACROSS THE FDS . . . . .
FIGURE IV-13 - WET SLURRY TO FDS WITH CLARIFIER RECYCLE -
TASK VIlA. . . . . . . . . . . . . . . .
24
24
28
32
33
35
36
37
39
40
40
45
48
-------
LIST OF ILLUSTRATIONS (continued)
FIGURE IV-14
FIGURE IV-IS
FIGURE IV-16
FIGURE IV-17
FIGURE IV-18
FIGURE IV-19
FIGURE IV-20
FIGURE IV-21
FIGURE IV-22
- COMPARISON OF S02 ABSORPTION VS.
PRESSURE DROP. . . . . . . . . . . . . .
- TWO STAGE VARIABLE SLURRY - TASK VIIB
- WET SLURRY WITH CLARIFIER OVERFLOW TO
FDS - TASK VIIC . . . . . . . . . . . . .
- DRY INJECTION OF DOLOMITIC LIME TO
FDS - TASK VIII C & D . . . . . . . . . .
- COMPARISON OF S02 ABSORPTION EFFICIENCY
VS. cao/s02 BETWEEN DRY LIME (TASK III)
DOLOMITIC LIME (VIIIC) AND SULFATED
LIME/FLY ASH MIXTURE (VIIID) ......
- LIME/FLY ASH SLURRY TO FDS - TASK VIIIE
- COMPARISON OF S02 ABSORPTION EFFICIENCY
VS. PRESSURE DROP BETWEEN CALCIUM OXIDE
(TASK VI & VII) AND SULFATED LIME/FLY
ASH (TASK VI I IE) ............
- OPERATING MODES USED FOR LIMESTONE
EFFICIENCY TESTS. . . . . . . . . . . .
- FLOW DIAGRAM FOR OPEN-LOOP SCALING
TESTS. . . . . . . . . . . . . . . . . .
FIGURE IV-23 - TWO-STAGE CALCIUM CARBONATE SCRUBBER
FIGURE IV-24 - TASK C-6 EFFICIENCY PROFILE, SLURRY CON-
CENTRATION AND STOICHIOMETRY DURING THE
RUN ..................
FIGURE IV-25 - PROCESS CONDITIONS FOR TASK C6 . . . . .
Page
49
50
53
61
62
64
65
67
71
71
74
83
-------
TABLE IV-l
TABLE IV-2
TABLE IV-3
TABLE IV-4
TABLE IV-5
TABLE IV-6
TABLE IV-7
TABLE IV-8
TABLE IV-9
LIST OF TABLES
- STATISTICAL PARAMETERS FOR THE SODIUM
CARBONATE CORRELATION FOR FDS . . . . . . .
- STATISTICAL PARAMETERS FOR SODIUM CAR-
BONATE MASS-TRANSFER CORRELATION. . . . .
- MASS-TRANSFER COEFFICIENTS FOR SODIUM
CARBONATE IN WETTED FILM PACKED TOWER
- TEST RESULTS USED IN FDS CALCIUM OXIDE
CORRELATION. . . . . . . . . . . . . . .
- STATISTICAL PARAMETERS FOR THE CALCIUM
OXIDE CORRELATION. . . . . . . . . . . .
- STATISTICAL PARAMETERS FOR THE CALCIUM
OXIDE CORRELATION. . . . . . . . . . . .
- SELECTED RUN DATA FOR THE PACKED TOWER
- THE COMPARISON BETWEEN THE SOLUBILITY
DATA FROM RADIAN CORP. AND DATA FROM THE
EFFICIENCY MEASUREMENT. . . . . . . . . .
- SUMMARY DATA SHEET FOR THE TVA TEST
PROGRAM. . . . . . . . . . . . . . . . .
TABLE IV-IO - PACKING WEIGHTS BEFORE AND AFTER EACH
TABLE IV-II
TABLE IV-I2
TASK. . . . . . . . . . . . .
. . . . . .
- LIMESTONE CONCENTRATION IN THE HOLD TANK
DURING TASK C6 . . . . . . . . . . . . . .
- STATISTICAL PARAMETERS FOR EFFICIENCY
CORRELATION (FIRST 40 HRS RUN) EQUATION
IV - 9 . . . . . . . . . . . . . . . . . . .
TABLE IV-13 - STATISTICAL PARAMETERS FOR EFFICIENCY
CORRELATION (LAST 26 HRS RUN) EQUATION
IV -10 . . . . . . . . . . . . . . . . . .
TABLE IV-I4 - STATISTICAL PARAMETERS FOR STEADY STATE
WT.% LIMESTONE CORRELATION. . . . . . . .
Page
27
29
31
41
43
52
55
59
69
72
76
78
80
81
-------
I.
INTRODUCTION
The ever-growing problem of sulfur dioxide atmospheric
emission has been intensively studied in recent years by a
host of researchers. Among the several processes that have
been proposed, lime or limestone wet scrubbing holds the
most promise for first generation S02 control systems.
Simplicity in design, widespread abundance of limestone, and
avoidance of by-product marketing complexities have all con-
tributed to process acceptance economically and technically.
While future generations of more economic S02 control systems
might evolve, based upon a by-product recovery, legislative
pressures demanding near-term flue gas desulfurization will
require industries to make use of the best available, perhaps
expedient, techniques.
Early in 1972, three prototype pilot plants will go on
stream at TVA's Shawnee Stearn Plant, Paducah, Kentucky,
evaluating the Limestone Injection Wet-Scrubbing Process for
sulfur dioxide and fly ash abatement. The pilot plant systems
are being designed so that the key process variables affecting
performance, process chemistry, scaleup, and economics will
be defined. Each pilot plant will be equivalent to a 10-12 MW
power generating statiQn having a flue gas flow capacity of
30,000 cfm. The expected sulfur dioxide removal is 90% for a
4 percent sulfur fuel. Among the three parallel scrubbing
trains, a venturi-type scrubber will be installed in series
with an absorber. To facilitate the forthcoming prototype
design and its operation, Cottrell Environmental Systems (CES)
has carried out (under APCO Contract No. EHS-D-7l-24) an
experimental test program for sulfur dioxide removal in an
existing two-stage pilot scrubber having a capacity of 1,000
cfm. The specific objectives of this study were:
-1-
-------
1. Characterization of the maximum absorption
capacity of a venturi scrubber,
2. Determination of the absorption capabilities
of a venturi scrubber with calcium oxide in-
jected into the boiler flue gas before the
venturi (simulation of the Limestone In-
jection Wet-Scrubbing Process),
3. Comparison of the scrubbing characteristics of
sulfated lime/fly ash material prepared at the
Shawnee Steam Plant with commercially calcined
limestone, and
4. Evaluation of other alkali material such as
dolomitic lime, and limestone.
Other tasks were added to the program to study uncalcined
limestone capabilities using the venturi in series with a
packed tower contactor.
Initially, the venturi scrubber and the packed tower
absorption performance were determined with sodium carbonate
solutions. Results of the highly efficient sodium carbonate
absorption were subsequently used as a guide in selecting
the operating conditions for the calcium oxide tests.
The primary effort of the soda ash and calcium oxide
experimentation and data analyses had been directed toward
the understanding of the key variables affecting the S02
absorption within the venturi scrubber. However, where possible,
the mass-transfer characteristics for the packed tower were
also defined. Statistical analyses of the significant process
-2-
-------
variables have resulted in the development of simplified
expressions for predicting S02 absorption. It is anticipated
that these correlations for both the packed tower and the
venturi scrubber can be used in estimating the absorption
efficiencies for the Shawnee scrubber pilot program. At the
same time the results of this work could guide the pilot plant
design.
For limestone (calcium carbonate) wet scrubbing, the
packed tower absorption capability and operating characteristics
were the underlying objectives of the experimental program,
while the venturi scrubber was considered secondary. Several
limestone materials, comprising a range of chemical and
physical properties, demonstrated high absorption efficiencies
under properly controlled conditions. Tower scaling (encrus-
tation buildup of reaction products on the packing) was
studied carefully under various operating conditions. The
limestone efficiency and scaling results were so encouraging
that the original test program with calcium oxide and sodium
carbonate was delayed and a new limestone test series was
undertaken.
The second calcium carbonate test program explored
further the scaling and absorption properties within the
packed tower and the flooded disc scrubber. TVA and Radian
Corporation have analyzed, on a limited basis, the slurry
composition of the major process streams, and the results of
their analysis have been invaluable in understanding important
variables affecting the absorption as well as scaling.I,2
Considerable effort has been applied in studying the slurry
chemical composition and its relationship with absorption
efficiency. Results of this limestone study have contributed
-3-
-------
significantly to the understanding of the hydrated lime and
limestone absorption program. The limestone data as analyzed
in this report will be useful in planning the Shawnee test
work.
The process conditions for the limestone tests were
based upon TVA bench scale experimental studies performed by
the Chemical Development Division, Muscle Shoals, Alabama, and
the Howden-ICI actual plant experience of the Fulham Power
Station, London.3 The results obtained with the limestone
tests, while limited, are of great commercial significance in
light of the Howden-ICI experience.
-4-
-------
II.
THEORY BACKGROUND
A.
ABSORPTION RATE IN THE VENTURI
Using
Chilton and
venturi can
the concept of "transfer
colburn,4 the absorption
be expressed as:
units" introduced by
efficiency for the
N = -In (l-Y)
oG
(II-I)
where
N = number of overall gas
oG
transfer units,
= absorption efficiency,
phase
Y
fraction.
When applying this expression, the product of the inter-
facial area per unit volume and the mass-transfer coefficients
Sxu~be cqnstant over the entire absorber. Also, an irre-
versible chemical reaction must be involved.
Although the interfacial area per unit volume for a
Flooded Disc Scrubber (or Venturi) decreases down stream of
the throat, Johnstone, et alS showed that a major portion of
the mass-transfer takes place within a short distance from the
interfacial generating point because of high droplet turbulence
created as the liquid layers are atomfzed. If all of the
mass-transfer takes place within a short distance down stream
from the throat, where the interfacial area is relatively
constant, then equation (II-I) is valid.
For the Venturi Scrubber, Galeano6 found it convenient
to express the number of transfer units in terms of gas flow
and overall mass-transfer coefficients as in the following:
-5-
-------
where K
F
Q
a
h
M
c
G
N h M (II-2)
= Ka c
oG c;-
or N = KF (II-3)
OG Q
= overall mass transfer coefficient in terms of
velocity, ft/hr.,
= interfacial area, sq. ft.,
= gas flow rate, cu.ft./hr.,
= absorbent surface per unit of volume absorber,
sq.ft./cu.ft.,
= height of absorber actively involved in the
absorption, ft.,
= molar density of gas, lb-mole / cu. ft. ,
= gas flow rate, lb-moles/(hr.) (sq. ft.).
Nukiyama and Tanasawa 7 studied the mean drop diameter
produced by a gas-atomizing nozzle and developed an empirical
relationship for the droplet diameter as a function of the gas
velocity, liquid-to-gas ratio, surface tension, solution
density, and liquid viscosity:
where
D = 585 (~\~ + 597 (~\ .45 (L/G)1.5
p ~ p) ap)
(11-4)
p, a, and
viscosity
~ are the density, surface tension, and
of the liquid, respectively.
droplet diameter, microns,
D = mean
p
Vt = gas throat velocity, ft/sec.,
L/G =
liquid-to-gas ratio, gal/lOOO cu.ft. .
-6-
-------
Assuming the properties of air and water for the present
study, this equation simplifies to:
Dp = 16050/Vt + 1.41 (L/G)1.5
(II-5)
When the absorbent surface area per unit volume, a,
is expressed in terms of D , the resulting equation is7:
p
L/G x(30.5)3 x 1012
D 2
x P = 244 L/G
(30.5)2 x 103 Dp
(II-6)
a =
7.49 x 1000 x D 3
-..E.....
6
Combining equation (II-2), (II-6), and (II-5), the expression
for the number of transfer units can be shown in terms of gas
velocity, liquid-to-gas ratio, and active height of the
absorber.
N G -
o -
244 Kh L/G
3600 (16050 + 1.41 L/Gl.5Vt)
(II-7 )
The ratio (Me/G) was replaced by 1/(3600 Vt).
The active height for the venturi scrubber was studied
by Johnstone, et a15 and it was determined that the absorption
rate is a maximum a short distance down stream from the liquid
inlet where the relative velocity between the gas and liquid
is the greatest. For a gas film controlled mass-transfer
system, the absorption rate decreased to the same level as
predicted for the quiescent drops within one foot after liquid
injection. However, liquid film controlled absorption reached
equilibrium within 2 to 3 inches after injection.
-7-
-------
To compute the mass-transfer coefficients for Na2Co3
and CaO, the active height of the Flooded Disc Scrubber was
set at I foot for each case throughout this report.
B.
ABSORPTION RATE IN THE TOWER
Tower design is
transfer units which,
definite integral.
simplified by using the concept of
for dilute solutions, are based on the
N =jY 1
oG
Y2
dy
y - y*
(II-8 )
where
y
= concentration of solute in the bulk gas,
mole fraction,
concentration of solute in the gas in
equilibrium with the bulk liquid, mole
fraction.
y* =
The integral in equation (II-8) expresses the difficulty
of a scrubbing solution to absorb solute from the gas. If
Henry's law is applicable, equation (II-8) can be expressed
as:
N = In
oG
[(l-l/A) (Yl-mx2)/( Y2-mx2») + l/AJ
(l-l/A)
(11-9 )
where
A = absorption facto~ = L, dimensionless
mG
G = gas flow rate, lb-mole/(hr) (sq. ft.),
L = liquid flow rate, lb-mole/(hr) (sq. ft.),
m = slope of the equilibrium curve,
x = concentration in the bulk liquid, mole
fraction.
-8-
-------
If it can be assumed that the liquid is well mixed
vertically, the chemical reaction is irreversible, and the
product of the transfer coefficient per unit area and the
interfacial area per unit of liquid volume is constant along
the vertical path of integration, then equation (11-9) can
be expressed as follows:
NoG = -In (l-Y)
(11-10)
Chilton and Colburn3 have developed a relationship for
the number of transfer units for a packed tower
-
NOG = K a P Z
G
(II-II)
where
K
= overall mass transfer coefficient,
Ib-mole/(hr) (sq. ft.) (atm),
= surface area per unit volume of packing,
sq.ft./cu.ft.,
p = total pressure of the system, atm.,
Z = height of tower, ft.,
G = gas flow rate, lb-mole/(hr) (sq. ft.) ,
NoG = number of t~ansfer units as defined by
equation (11-10).
a
In, terms of locally applicable coefficients, the rate
of mass-transfer is given by
FS02 = kg (YS02g - YS02i) = k£ (XS02i-XS02£)
(11-12)
where
FSO
2
= mass-transfer flux, lb-mole/(hr) (sq. ft.),
-9-
-------
k~
k
g
Yso
2
XSO
2
i
g
~
= liquid phase mass-transfer coeffieients,
lb-mole/(hr) (sq. ft.) (mole fraction),
= gas phase mass-transfer coefficient,
lb-mole/(hr) (sq. ft.) (mole fraction),
= concentration of S02 in the gas, mole
fraction,
= concentration of S02 in the liquid,
mole fraction,
= refers to the interface,
= refers to the bulk gas stream,
= refers to the bulk liquid stream.
Since YS02i and XS02i are extremely difficult to measure,
overall mass-transfer coefficients are employed to eliminate the
dependence on the interfacial compositions.
FA = KOG (yso - Yso *) = KOL (Xso * - XS02n)
2g 2 2 ~
= overall gas phase mass-transfer coefficients,
lb-mole/(hr) (sq. ft.) (mole fraction),
= overall liquid phase mass-transfer coefficient,
lb-mole/(hr) (sq. ft.) (mole fraction),
Ys02* = concentration of S02 in the gas in equilibrium
with the bulk concentration in the liquid
where
KOG
KOL
(11-13)
mole fraction,
Xs02* = concentration of S02 in the liquid in
equilibrium with the bulk concentration in the
gas, mole fraction.
-10-
-------
For irreversible chemical reaction in the packed tower,
*
YS02 = o.
Therefore
F = K Y
A oG S02g
(11-14)
As can be seen from equation (11-14), the rate of mass-transfer
is proportional to the mole fraction of S02 in the gas stream.
In terms of the two-resistance theory with a solute
exhibiting a partial pressure in accordance with Henry's law
1 -~+~
KOG - kg kR,
(11-15)
where
m = slope of the equilibrium curve.
The rapid, irreversible reaction which occurs in a tower also
gives rise to an equilibrium curve with a slope of nearly
zero for the S02 concentration under consideration. Equation
(11-15) reduces to
KOG
=
k
g
(11-16)
thus placing all the resistance to mass-transfer in the gas
phase.
Although the major resistance derived in equation
(11-16) is in the gas phase, the lack of an equilibrium con-
dition does not necessarily eliminate the possibility of a
liquid phase resistance. Other factors must be considered,
namely, the diffusivity of the solute in the liquid-phase, the
concentration of the unreacted reagent, the rate of diffusion of
the reagent, the rate of dissolution for heterogenous slurries,
etc.
-11-
-------
Using
be better to
following:
the two-resistance theory as a basis, it would
express the overall transfer coefficient by the
1
KOG
=
1
k
g
+
1
kR,
(11-17)
Here the type of liquid phase resistance is not defined, in
~ of vapor/liquid equilibrium, and in fact can incorporate
all liquid phase resistances.
C.
PROCESS CHEMISTRY
The removal of S02 from gas streams by absorption is
well known. Water itself is a relatively poor solvent for
502; consequently, its use would entail vast quantities of
water to reduces02 levels appreciably. Further, the S02 is
readily released by environmental influences (temperature,
pH, etc.).
The use of alkaline solutions to fix S02 is frequently
practiced. Thus, S02 reacts as follows with soluble hydroxide.
--~
S02 (g) ~--- S02 (aq)
-~ +
S02(aq) + H20 ~- H + HS03
HS03
+ OH
--~
S03- + H20
Thus, the absorption proceeds via a S03
rich liquor.
-12-
-------
The partial pressure of S02 in this alkaline system
is essentially proportional to the square of the hydrogen
ion concentration. In s03- solutions, this concentration is
quite small and the corresponding S02 pressure is negligible.
In fact, at ordinary temperatures, a level of S02/Na ~ 0.9
can be achieved before S02 back pressure becomes significant.
The use of lime for absorption of S02 from sulfuric acid
tail gas, in the absence of C02 proceeds:
Ca(OH)2 + S02 + H20 ---~ Cas03.2H20 J
In the presence
8
pearson,et aI proposed
for combustion gas.
of C02' the situation is more complex.
possible lime and limestone reactions
CaO + H20 -----~
Ca(OH)2
Ca(OH)2 + C02 -----~
cac03 + H20
CaC03 + C02 + H20 -----7
Ca(HC03)2
Ca(HC03)2 + s02 + H20 -----7
Cas03. 2H20 J, + 2c02
cas03.2H20 + 1/202 -----~
CaS04. 2H20 J,
While it is possible to define the equilibrium situation
based on a knowledge of the components present and the final
equilibrium conditions (temperature, etc.), the kinetic com-
petition of various important reactions is not well defined.
-13-
-------
Both carbon dioxide and sulfur dioxide are weak acids,
the former being weaker. The presence of carbon dioxide
alters appreciably the kinetics of S02 absorption. It is
expected that absorption will proceed through a calcium
carbonate step as a result of the approximate 50+ ratio of
C02/S02 in the gas.
In the slurry at pH ~ 5-6, sufficient levels of dissolved
carbonate salts exist to react with the HS03-' Calcium sulfite
precipitation results.
Oxidation of sulfite species is also important, resulting
ultimately in calcium sulfate, a sparingly soluble species.
Conversion of S03= to S04= influences the equilibrium partial
pressure of S02 over the liquor.
-14-
-------
III.
PROCESS EQUIPMENT
A.
PILOT PLANT LAYOUT
The two-stage absorption
was designed for a test program
flexibility and versatility.
operation used in this work
that would allow maximum
A layout of the pilot plant system is illustrated in
Figure III-I. The complex piping network shown was necessary
to accommodate the 13 operating modes planned. Slurry flow
rates to the scrubber and other process units were measured by
venturi-type flow meters. In-line pH probes (Leeds-Northrup)
were installed at the discharge of each scrubber. Immersion-
type pH elements were placed in the clarifier and the hold tank.
All temperature measurements were made with iron-
constantan thermocouples except the wet bulb temperature on
the inlet.
The absorption section of the pilot plant contained the
Flooded Disc Scrubber (FDS) in series with a packed tower, as
illustrated in Figure 111-2. The flue gas, containing both
particulates and sulfur dioxide, passed first through the FDS
where the entering gas quickly cooled to its dew point (l20°F) .
Scrubbing solution or slurry entering the absorber tangentially
above the throat flowed cocurrently through the FDS and into
a cyclonic demister. The fly-ash-stripped gas then passed
vertically through a conical hat gas/liquid splitter before
entering the packed tower.
-15-
-------
V-VENTURI SCRUBBER
D - DEMISTER
-A - ABSORBER
C -CLARIFIER
II
,I
II
" ~ -,
I~--~:
~-1,. - ---'
GIV
I
.....
0'1
I
H-HOLDING TANK
M-MIXING TANK
B-BULK FEEDER
GOO
o
FAN
vav
VP
AP
GIV-GAS INLET VENTURI
GOV-GAS OUTLET VENTURI
GOO~AS OUTLET ORIFICE
VV -VENTURI VENTURI
A V -ABSORBER VENTURI
e V -CLARIFIER VENTURI
V BV-VENTURI BY.PASS VENTURI
ABV-ABSORBER 8Y'~S VENTURI
V P -VENTURI PUMP
AP -ABSORBER PUMP
C P ~LARIFIER PUMP
HP ~OLDIN6 TANK PUMP
MP -MIXING TANK PUMP
~ -HAND VA1.V E
FIG.mi PILOT PLANT LAYOUT
MP
-------
INLET
+
FDS
MECHANICAL
JACK
TOWER
DEMI STER
FIG. m- 2 PILOT PLANT SCHEMATIC DIAGRAM
-17-
802
S02
-------
The FDS scrubber is a cocurrent absorber with a
variable throat orifice. Pressure drop across the scrubber
is varied by adjusting the disc position within a venturi
throat, Figure 111-3.
The packed tower is a countercurrent absorption device
containing a packing with low pressure drop characteristics
and high specific surface (68 sq.ft./cu.ft.). The packing
section was fabricated from rigid corrugated sheets of asbestos
coated with neoprene. It was five feet in height and sixteen
inches in diameter. Pressure drop across the packing at gas
velocities between 8 and 10 feet per second under well irri-
gated conditions is approximately one inch of water.
It will
port that many
of conditions.
become evident throughout the body of this re-
modes of operation were tested over a wide range
Tank sizes and clarifier volume listed below
were sized and selected on the basis of studying the process
variables.
Process Units
Size
Material Of
Construction
FDS Scrubber
6" to 8" diameter
See Figure 111-3
16" diameter x 5'
3l6SS
3l6SS
Packed Tower
Tower Slurry
Tank
Mixing Tank
FDS Slurry
Tank
1500 gallons agitated
1500 gallons agitated
CS
CS
55 gallons
CS
Cyclonic
Demister
Clarifier
Blower
4' diameter x 4'
1200 gallons
1000 cfm at l1p
inches H20
SS
CS
= 40
CS
ulO-
-------
"IIIHT
.1
YARIAILE
GAS FLOW
LIQUID - J
INLET
. {COftfNlT
I I
I ;
II
II
:\~ {LIQUID 'LOWS
~'\ AU)N8 WALL
8"
/LiQUID oe.N8AGES
I'ROII WALL
8„4~
FI8.~1 D__IONS '011 'LOODED DISC SCRUB."
-,
3.
-19-
-------
B.
ANALYTICAL
Sulfur dioxide concentration in the gas phase was
determined by an Enviro-Metrics 502 analyzer Model 5-645 and
by titrimetric techniques. Gas samples were drawn from the
scrubbers, filtered and pumped through the instrument as shown
schematically in Figure III-4. Each analyzer was calibrated
daily by use of standard gas obtained from compressed gas
cylinders. Throughout any test period, the instruments were
continually checked for proper calibration.
Samples were drawn from the flue gas by a Gast pump rated
at 3 cfm. The sample gas passed through a fiber glass filter
before entering the pump. Most of the particulates were re-
moved in the filter. A high gas flow of I to 1.5 cfm passed
through the coarse rotameter and into the venting lines. A
small sample bypass stream from the inlet to the coarse
rotameter passed through the instrument. A maximum rate of
25,000 cc per hour flowed through the analyzers.
Instrument sampling and calibration were timed and con-
trolled so that the same volume of gas passed through the in-
strumentation. The analyzer meter reading, indicating the 502
level, was recorded and then the 502 concentration was cal-
culated for each test.
Instrument response was checked by introducing cali-
bration gases at two levels of 502 concentration. A linear
response was measured for instrument readings between 30 and
90% on the meter scale. Wet analysis of the 502 concentration
confirmed the results of the instrumentation throughout the test
program. Sulfur dioxide concentration ranged from 950 to
-20-
-------
3-W1lf fiLTER
1rWAY
:5 NO
G~T PUMP ANALYZER
I 'OS VENT
. I OUT
IV STANDARD SASES
~
I N2
2 S02ANALYZER
802 -H
SOt-L
NO -H COARSE FINE
METER METER
NO -L
TOWER
OUT
VENT
COARSE
METER
FINE
METER
I
S~ ANALYZER
FIG.m-4 SCHEMATIC DrA~RAM FOR 502 A~ALYTICAL SYSTEM
-------
2350 ppm.
measured
Fly ash concentrations of the inlet gas were not
during this program; however, previous studies
the particulate at 2.4 to 3.5 grains/SCFD.
measured
Nitric oxide analysis was attempted early in the
experimental program. The gas sample was passed through the
same sampling equipment that was used for the S02 analysis and
into the NO instrument. A three-way valve was used to divert
the gas sample from the S02 analyzer to the NO instrument. A
fixed bed of Mallcosorb removed the S02 from the gas stream
before it entered the NO unit.
Results of the nitric oxide analysis were erratic from
the beginning. The outlet gas concentration on the packed
tower was sometimes higher than that measured at the inlet to
the FDS. To avoid undue time losses in the test program, the
NO analyses, which were a secondary part of the planned tasks,
were abandoned.
1. Chemical Reagents
Calcium oxide used in all experimental work calling
for calcined limestone was donated to the project by Basic
Chemicals, Cleveland, Ohio, Table A-I of Appendix A.
Dolimitic lime used in comparison to the calcium oxide
was 99% MgO.CaO with approximately 50% - 200 mesh. J. E.
Ba~er Company, York, Pennsylvania, donated this material to the
project.
Limestone and lime reagent used for the test program
studying the packed tower characteristics was provided by TVA.
A list of the chemical compositions of these materials are
shown in Table B-1, Appendix B.
-22-
-------
IV.
RESULTS AND DISCUSSION
The experimental test plan for the sodium carbonate and
the calcined limestone required thirteen operating modes; each
studying a specific variable or condition. A description for
each of the planned tasks is given in Table A-2 of Appendix A.
Throughout the following section, reference will be made to
these tasks as the results are discussed.
A.
SODIUM CARBONATE
Absorption efficiency experiments with sodium carbonate
were made to determine the maximum mass-transfer properties
of the FDS scrubber and the packed tower. Gas flow through
the absorbers was adjusted between 300 to 900 ACFM* while the
liquid-to-gas ratios were varied over the range of 5 to 14
gallons per 1000 cf for the FDS, and 7 to 34 gallons per 1000
cf for the tower. Operating modes for this test series are
illustrated in Figures IV-l and IV-2.
Sodium carbonate and water were mixed continuously in an
agitated tank from which a carbonate solution was withdrawn
and pumped to the disc scrubber and/or the tower. Stoichiometry
to each absorber was controlled by adjusting the carbonate
feed rate and the liquid flow rate.
Sodium carbonate stoichiometry for the inlet S02 varied
between 90 and 250%.
* Flow rate basE~ on outlet conditions at the dewpoint
temperature.
-23-
-------
WATER
PACKED
TOWER
DEMISTER r
r
WATER
SLURRY
TANK
GAS IN
GAS OUT
FIG. IV-I TWO STAGE SODIUM CARBONATE SCRUBBER-TASK IIA8B
GAS IN
WATER
MIXING
TANK
GAS OUT
PACKED
TOWER
DEMIST ER
T
y
SLURRY
TANK
FI G.IV-2 TOWER ABSORPTION TESTS FOR SODIUM CARBONATE-TASK lie
-24-
-------
1. FDS Results - Na2C03
Absorption efficiency characteristics for the FDS were
measured for five levels of gas flow, five levels of disc
pressure drop, four levels of liquid-to-gas ratio, and the
above range of stoichiometries.
S02 absorption efficiencies increased rapidly from 30
to 73% as the pressure drop across the scrubber increased from
1 to 13 inches of water. At high pressure differentials, 13
to 25 inches of water, the S02 absorbed increased more slowly
and reached 80 to 83%. Stoichiometry did not significantly
affect the efficiency. However, slightly greater absorption
occurred at increased gas flow rates. A linear regression
analysis for 46 selected run conditions resulted in the
following expression:
Y = 25.36 + 3.105 (6p) - 0.0550 (6p)2 +
.02l1(V)
(IV-I)
Y = S02 absorption efficiency, %,
where 6p = pressure drop across the FDS, inches of H20'
V = volt~e of gas flow, CFM at II0oF. and approxi-
mately 390 inches of H20.
The positive coefficient for the gas flow does not
follow any expected absorption mechanism. Increasing gas
velocity at the entry of the scrubber may have caused significant
shearing action on the liquid as it disengaged from the wall,
hence some interfacial surface area generation and mass-
transfer could have occurred before the throat. Similarly
increased gas velocity downstream from the throat can contribute
-25-
-------
to mass-transfer. The statistical results of the carbonate
regression analysis and the limitations for equation (IV-l)
are listed in Table IV-l. The experimental data used in the
regression analysis are listed in Table A-3, Appendix A.
With the absorption efficiency depending almost
exclusively on the pressure drop and showing independence of
stoichiometry and liquid-to-gas ratio, a gas film controlled
mass-transfer appears to exist. Using equation (II-7), the
overall mass-transfer coefficients for each data set were
calculated.
These results are illustrated in Figure IV-3.
A regression analysis on the overall mass-transfer co-
efficients yielded the following expression:
KG = 4.16 + 0.53 (Vt) - 1.73 (L/G)
( IV - 2 )
where
L/G = liquid-to-gas ratio, gal. per 1,000 cf.,
Vt = throat velocity, ft./sec.,
KG
= overall mass-transfer coefficient, lb-mole/
(hr) (sq. ft.) (a tm) .
Statistical limitations for equation (IV-2) are given
in Table IV-2.
2. Packed Tower Results - Na2C03
An average of 98% S02 absorption efficiency was obtained
when the tower operated at a gas velocity of 7.7 to 13 feet
per second and liquid flows of 6 to 34 gallons per 1000 cf.
Sodium carbonate passed through the tower and drained into
the pond as shown in Figure IV-2.
-26-
-------
TABLE IV-l
STATISTICAL PARAMETERS FOR
THE SODIUM CARBONATE CORRELATION FOR FDS*
Number of Data Points
= 46, See Table A-3
Correlation Coefficient
= 0.8890
Standard Error for the Estimate = 7.26%
Significance of Regression (F)
= 52.8
Pressure Drop Range (6p)
= 1 to 25 inches of H20
= 50 to 254 ft./sec.
Gas Velocity Range (throat)
Gas Volume Range (V)
Stoichiometric Range
= 300 to 920 CFM at 110°F.
and 380 inches of H20.
= o. 9 to 2. 5
Sulfur Dioxide Inlet Range
= 1000 to 2350 ppm.
*
Y = 25.36 + 3.105 (6p)-0.0550 (6p)2 + .0211(V)
-27-
-------
FIGURE I V- 3
MASS TRANSFER COEFFICIENTS FOR SODIUM CARBONATE
.
THROAT VELOCITY BETWEEN 50AND 250 FEET PER SECOND
300
D LtG 6 TO 7.5
0 L/G 7.6 TO 8.5
6 L/G 8.6 TO 10.6
0 L/G 10.6 TO 14.1
250
....
z 0
ILl'
-2 8 8
0
iL~ 0
I LLN-200
tI.) 11.1"" &
00 0 LI.
I 0 . &.
a::
, 0:: X 0
ILl, G
LLcn <:> G
~ ~ 150
0
c(o
a::~ Q
.....
m
C/)..J
C/)
c( 100
2 0 0
G <:>
Q
0
50
50 75 100 125 150 175 200 225 250
THROAT VELOCIT'. 'T. / SEC.
-------
TABLE IV-2
STATISTICAL PARAMETERS FOR SODIUM CARBONATE
MASS-TRANSFER CORRELATION
Number of Data Points
= 46, See Table A-3
Correlation Coefficient
= 0.864
Standard Error for Y-Data
= 29.3
Standard Error for Estimate
= 15.1
= 63.6
Significance of Regression (F)
Mass-Transfer Coefficient Range (KG)= 22.2 to 136.0 Ib-rnoles/
( sq . ft. ) (hr) (a trn) .
Throat Velocity Range (Vt)
Liquid-to-Gas Ratio Range (L/G)
= 51 to 254 ft/sec.
= 6.7 to 14.1
Sulfur Dioxide Inlet Concentration
Range
= 1,000 to 2,350 pprn.
-29-
-------
Overall mass-transfer coefficients for the tower were
computed from equation (11-11) and ranged from 0.6 to 1.7
(lb-moles)/(hr.) (sq. ft.) (atm) , see Table IV-3. A regression
analysis of the overall mass-transfer mechanism in terms of
gas flow and liquid rate was made using the following equation:
K = C G a, L b
oG
(IV-3)
The statistical analysis indicated a strong dependence
of the overall mass-transfer coefficient on the gas rate and a
negligible effect of liquid rate, as indicated by the following
equation:
K = 6.69(10)-5 G 1.17 L 0.026
oG
(IV-4)
where
KOG = lb-mole /(hr) (sq. ft.) (atm) ,
G
L
= gas mass velocity, lb/(hr) (sq. ft.) ,
= liquid mass velocity, lb/(hr) (sq. ft.).
The mass-transfer coefficients for sodium carbonate are
compared in Figure IV-4 with sodium hydroxide experiments per-
formed with the same type of packing in the laboratory. The
slightly lower absorption efficiency of the sodium carbonate
indicates some liquid film resistance.
B.
FDS RESULTS - CALCIUM OXIDE
1. Open-Loop:
III and IV
Dry Injection and Wet Slurry - Task
oxide
could
Several operational modes were selected for the calcium
program so that the variables influencing performance
be isolated and their effects measured.
-30-
-------
TABLE IV-3
MASS-TRANSFER COEFFICIENTS FOR SODIUM
CARBONATE IN WETTED FILM PACKED TOWER
PP F ec Ga s F r. sq. t. atm.
.
860 16 7.8 10 0.731
680 8 7.8 11.9 0.816
700 4 7.8 15.8 0.949
820 15 7.8 22.4 0.733
730 30 7.8 6 0.586
830 35 7.8 6 0.583
800 18 7.7 30 0.71
960 26 7.8 30 0.66
930 35 7.8 34 0.60
780 28 7.8 34 0.609
910 20 12.6 6 1.137
878 7 12.6 6 1.419
1000 20 12.6 7.5 1.151
852 6 12.6 18.7 1.465
852 10 12.6 18.8 1. 327
780 20 12.6 ' 7.4 1.089
750 17 12.6 9.8 1.125
900 20 12.6 12.2 .1.133
804 11 13 11.9 1. 311
1000 30 12.6 12.2 1.043
960 4 12.6 12.2 1.668
1000 38 12.6 18.8 0.999
1040 32 12.6 18.8 1.032
860 16 12.8 18.5 1.2
700 11 12.6 .21 1.232
( tiS
Liquid & Gas
Ratio
1 11000C )
Mass
Transfer Coefficient
(lb-moles)
(h ) ( f) (
Inlet
S02 Cone.
, M)
Outlet
S02 Cone.
,PPM)
Gas Velocity
)
-31-
-------
FIG.IV-4
MASS TRANSFER COEFFICIENT AS A FUNCTION OF GAS MASS VELOCITY
-
g
:.
."
]J
:a
"'
z
~
II: 2
.
(D
<
'"
I r- 3
w g
IV
I =I
-<
r- 4
CD
CI)
CD 5
1:
""
::z: 6
:u
en 1
D
.
.,. 8
:-t
0"-- O.2N , - L .A , "
EI NA2C °3 ( ~ -
......... ........
I~ ~ ......
~ .....
~ ....
'" .... ~
P LO.~ U ~rf. ~ "'.... "'",
'-- .. '" to
L "
"
"
.. .. . . .
9
~-
8°
2
3 4 561898
. SS TRANSFER COEFFIC : . ~ LB-MOLESI HRtFT~ATM.
2
3
4
-------
Initially, an open-loop dry injection operation was
employed with the venturi scrubber as shown in Figure IV-5.
The process conditions were fixed at a liquid-to-gas ratio of
10 gallons per 1,000 cf, and a pressure drop across the venturi
of 10 inches W.G. Stoichiometry varied between 0.8 to 2.1
moles of CaO/mole of S02.
GAS IN
GAS OUT
WATER
PACKED
TOWER
'CAO
DEMISTER
T
F~8. ~v...s DRY INJECTION WITHOUT RECIRCULATION '1MK III
-33-
-------
input.
removal
Absorption efficiency improved with increasing lime
At stoichiometric lime conditions, approximately 30%
was achieved in the venturi while at twice the
equivalent calcium oxide, absorption reached 45% efficiency.
These results are summarized in Figure IV-G.
S02 absorption efficiency for wet slurry feed exhibited
higher removal than the dry injection. Using the operating
mode shown in Figure IV-7, with a liquid-to-gas ratio (FDS)
of 10 gallons per 1,000 cf and pressure drop across the FDS
of 10 in. W.G., 40 to 50% 502 absorption was achieved, i.e.
between 10 to 15% more 502 was removed by the wet slurry than
by the dry injection, again see Figure IV-G.
Absorption measurements made with water containing no
alkali ranged between 2 and 4% at the same operating con-
ditions as illustrated in Figure IV-G. Hence, the efficiency
difference between dry injection and wet slurry can be con-
tributed to the method for lime addition, i.e. water absorption
for the dry injection could contribute only a small fraction
to the total removal.
Detailed operating data for these experiments are pre-
sented in Appendix A, Tables A-4 and A-5.
2. Closed-Loop:
Dry Injection/Wet Slurry Combination
Due to practical, as well as economical, considerations,
most commercial wet scrubbing processes will be based on a
closed-loop system. For the first operating mode using complete
solution recirculation, a lime slurry was pumped to the venturi
while a clarified solution was passed through the tower, as
shown in Figure IV-8.
-34-
-------
r J(IO
6alO
!S alO
4al0
~
:I
~
2 alO
I alO
--5
.
- -
.
C ~LCIUM OXIDE SLURRY fiE ,.
TMK 1. '\
I -
II .. 2 iii
~~
r. '1M me IDE Of ~y
ItWECTION-TASK m
,
.
-
-
-
-
. ..
-
- .-"
6p ON FDS AT 10 INCHES -~ -
Lie AT 10 8ALLONS PER 1 )00 Cf
ID I~
STOICHIOMETRIC RATIO (CM>/SOt)
FIG.IV-e ABSORPTION EFFICIENCY FOR TASKS III Ii IV
2.0
-]11-
-------
GAS IN
CAO
W~ER
MIXING
TANK
GAS OUT
PACKED
TOWER
DE MISTER
RRY
TANK
FIG.IV-7 CALCIUM OXIDE SLURRY TO FDS - TASK IV
-36-
r
-------
GAS IN
MS OUT
DEMISTER
PACKED
TOWER
CAO
~
WATER
IXING
TANK
SLURRY
TANK
FIG.IV-8 TWO STAGE CALCIUM OXIDE SCRUBBER WET SLURRY-TASK V
To establish constant operating conditions, the process
mode and flows were fixed for several operating days (approxi-
mately 8 hours per operating day). Scale buildup within the
venturi was severe; the throat disc position (controlling the
annular velocity) had to be periodically adjusted to compensate
for pressure drop increase. Finally, after 25 hours of
operation, the venturi scrubber had to be dismantled and cleaned
before the run could be continued.
Results of this test are shown in Table A-G.
Pressure
drop across the venturi during this test varied from 7 to 22
inches W.G.
-37-
-------
Once a stable operation had developed, absorption efficiency
ranged from 42 to 58% in the FDS as the pressure drop across
the disc increased with a constant L/G of 18 gallons per 1,000
cf. A clarified solution was passed through the tower through-
out the run. This had two effects on the tower performance:
1) absorption was limited by restricting the alkali input, and
2) the process was stabilized by eliminating scaling. For a
liquid-to-gas ratio of 15 gallons per 1,000 cf, absorption
efficiencies of 37 to 63% were measured near the end of the test.
3. Variations in CaO Stoichiometry - Task VIa
Following the above lime slurry run, a CaO dry injection
mode was used with the same clarifier solution recirculation
to the tower, see Figure IV-9. Venturi scrubber absorption
efficiency, 40% removal, was measured at L/G of 18 gallons
per 1,000 cf and at a FDS pressure drop of 7.7 inches W.G.
Results of these tests are given in Table A-7.
An unusually high tower efficiency was measured during
the latter part of these tests; for inlet concentration between
660 to 900 ppm, complete removal of the S02 was indicated.
Subsequent tests could not reproduce the high efficiency with
the same tower feed. If lime slurry passed over from the
clarifier, then the high absorption efficiency could be
expected.
4. Process Variables Affecting the Venturi Scrubber
Performance - Tasks Vlb to Vlf
The major portion of the test program used a dry in-
jection scheme as shown in Figure IV-IO. Again, a clarified
-38-
-------
GAS IN
GA S OUT
PACKED
, TOWER
DEMISTER
WATER
SLURRY
TANK
I
I
I,
FIG.IV-9 CALCIUM OXIDE DRY INJECTION TO FDS - TASK VIA
solution circulated through the tower while a slurry from the
clarifier underflow passed through the FDS. Among the variables
studied were stoichiometry, differential pressure, liquid-to-gas
ratios, and ionic strengths. The ionic strength was adjusted
by the addition of sodium chloride. Concentration of the slurry
that passed through the venturi was controlled by the mode
illustrated in F'igure IV-II. FDS inlet concentration was con-
trolled by proportionating the clarifier underflow and overflow.
Results of the tests selected from the main body of data and con-
sidered at constant conditions are summarized in Table IV-4.
-39-
-------
GAS IN
GAS OUT
PACKED
TOWER
CAO
DEMISTER
. WATER
FIG.IV-IO LIME DRY INJECTrON T() FDS WITH CLARIFIER RECYCLE- '~SKS VI BaC.DaF
GAS IN
GAS OUT
PACKED
TOWER
DEMISTER
WATER
SLURRY
TANK
FIG. IV-II CALCIUM OXID.E DRY INJECTION TO F D S
WITH VARIABLE SLURRY CONCENTRATION TASK VI E
-40-
-------
- ---------
I ~ABLE IV-'
TEST RESULTS USED IN FDS CALCIUM OXIDE CORRELATION
mass-transfer
SOi collection CaO/S02 Pressure Liquid and Gas Slurry coefficient
Test fficiency Ratio Drop Ratio . Ionic COncentration lb.-mol..
.1!2..:. Elli ~ (') (Mole'JMo1e) (I.W.C.) (gal /MCP) Strenqth (') (hr) (sq.ft) (atm)
1 2/24 12:15 48.9 1.20 6.0 18.0 0.1 17.5* 27.5
2 II 13:15 40.4' 1.24 6.0 18.0 0.1 17.5* 21.2
3 II 15:00 34.5 0.97 6.1 10.0 0.1 17.5 * 23.3
4 II .16:00 33.3 .85 5.9 10.0 0.1 17.5 * 22.2
5 II 18:00 46.9 1.05 6.8 23.0 0.1 17.5 * 24.9
6 II 18:30 54.1 1.11 6.8 23.0 0.1 17.5 * 30.6
7 2/25 10:15 42.6 1.10 5.8 18.0 0.1 17.5 * 22.6
8 II 11: 25 43.1 1.02 5.8 18.0 0.1 17.5 * 22.9
9 II 12:45 45.5 1.22 5.8 18.0 0.1 17.5 * 24.7
10 II 14: 05 45.9 1.04 5.6 18.0 0.1 17 5 * 24.8
11 II 15:35 45.1 . 1.12 5.6 18.0 0.1 . * 24.2
17.5 *
12 II 16:45 41.8 0.97 6.0 lit. 0 0.1 17.5* 22.2
13 4/16 12:30 57.6 1.17 6.8 10.0 1.0 17.5 * 27.9
14 II 13:30 53.8 1.06 7.2 10.0 1.0 17.5 * 43.4
15 II 15:15 54.8 1.09 8.2 10.0 2.0 17.5 * 45.5
°16 II 16:15 56.1 1.03 8.6 10.0 2.0 17.5 * 47.5
17 II 19: 00 54.3 .9 6.0 10.0 4.0 17.5 * 43
18 II 22:00 53.8 1.04 6.0 10.0 4.0 17.5 * 42.4
19 3/31 12:00 35.7 1.25 6.5 10.0 .1 17.5 * 24.5
20 4/5 15:45 37.5 1.06 12.0 10.3 0.1 17.5*. 28.1
21 4/4 11: 30 57.7 1.16 18.2 10.0 0.1 17.5 * 56.2
I 22 II 19:30 54.3 1.09 19.8 20.0 0.1 43.2
.e:o. 17.5 *
..... 23 4/15 11:45 52.4 0.97 12.7 20.0 0.1 17.5 * 35.8
J 24. 4/1 . 10:00 41.7 1.0 6.3 10.0 0.1 17.5 * 29.8
25 4/4 10:30 55.2 1.08 18.4 10.0 0.1 17.5 * 52.6
26 II 15:45 56.5 1.03 18.7 20.1 0.1 17.5 * 45
27 4/15 10:15 49.1 1.02 12.5 20.1 0.1 17.5 * 32.4
28 4/1 17:00 41.2 1.01 12.0 10.0 0.1 17.5 * 32.2
29 2/24 17:30 46.8 1.1 6.4 23.0 0.1 17.5 24.4
30 5/5 15:00 48.6 1.17 6.4 10.0 0.1 3.8 36.8
31 II 16:00 46.7 1.42 7.4 10.0 0.1 3.6 35.5
32 5/6 10:45 50.0 1.03 6.5 10.0 0.1 1.1 38.4
33 II 12:20 48.7 1.11 7.8 10.0 0.1 1.4 38
34 II 13: 20 51.1 1.23 7.8 10.0 0.1 1.8 40.7
35 II 15:00 47.8 0.92 7.3 10.0 0.1 5.8 36.6
36 II 10:00 47.4 0.83 1.5 10.0 0.1 6.0 36.3
37 II 17:00 48.2 1.07 7.8 10.0 0.1 6.7 37.4
26.6
38 5/13 17:30 38.5 1.0 5.8 10.0 .1 16.0 26.5
3!J . 16:30 38.2 0.98 6.1 10.0 .1 19.0
40 . 15130 41.3 0.98 6.1 10.0 .1 19.5 29.3
* These slurry concentrations were estimated from the results of Tests 38 through 40.
-------
The underlying purpose of these experiments was the
characterization of the flooded disc performance over a wide
range of operating conditions. Tower performance, a
secondary consideration, was determined for only two slurry
conditions and two liquid-to-gas ratios.
5. FDS Results - Task VI
To describe the FDS performance in terms of the key
process variables, a regression analysis of 37 sets of selected
data was carried out with a computerized multiple linear re-
gression program. Many process models were screened for each
of the parameters considered significant. The empirically-
derived linear correlation accepted as the best representation
of the data for scrubbing with CaD slurry while collecting
dry CaO is:
Y = 29.51 + 5.128 (R) + 0.983 (t!p)
+ 0.701 L/G + 15.72 (I) -2.845(1)2
- 0.645 (SL).
( IV - 5 )
where
y
R
= S02 absorption efficiency of FDS, %,
= stoichiometric ratio, moles of CaO/mole of
S02 in inlet,
t!p = pressure drop across throat, inches
L/G = liquid-to-gas ratio, gals./mcf.,
I = ionic strength of NaCl, molarity
SL = slurry concentration, % by weight.
of H20'
Statistical limitations for this expression are given in
Table IV-5.
-42-
-------
TABLE IV-5
STATISTICAL PARAMETERS FOR
THE CALCIUM OXIDE CORRELATION
Number of Data Sets
=
37, See Table IV-4
Correlation Coefficient
=
0.862
3.66%
Standard Error for the Estimate =
Significance of Regression (F)
=
14.4
Stoichiometric Range, R
=
0.83 - 1.42
Pressure Drop, ~p
=
5.8 - 19.8 inches of water
Liquid-to-Gas Ratio, L/G
=
10 - 23 ga1s.jMCf
0.1 - 4
Ionic Strength, I
=
Slurry Concentration, SL
=
1.1 - 17.5%
-43-
-------
Raw data for the tests used in the correlation are given
in Tables A-8 through A-13.
Absorption efficiencies for the lime and sodium carbonate
correlations, equations (IV-I) and (IV-5), are compared in
Figure IV-12. For low pressure drop, the sodium carbonate and
lime showed approximately the same absorption, hence probably
the same mass-transfer mechanism. At higher pressure differentials,
the lime slurry had a significantly higher absorption resistance.
During all of the lime tests, including some experiments
not mentioned thus far, scale buildup in the venturi throat and
the scrubber walls caused geometric changes in the absorber.
The deposited solids in the throat, as well as the walls, was
usually uniform. Normally, a coating of about 1/8 to 1/4 inch
occurred very rapidly within the first few hours. The disc
had to be adjusted to compensate for the pressure increase
resulting from the narrowing down of the throat annulus. Pre-
dicting the gas velocity in the throat from the disc position
was impossible. A semi-empirical formula describing the venturi
pressure drop in a flooded disc scrubber has the general form:*
2
6p = A Vt (L/G + B)
( IV - 6 )
where
A and B = constants,
Vt
L/G
6P
= throat velocity, ft/sec.,
= liquid-to-gas ratio, gal/mcf.,
= pressure drop across FDS, inches
H20.
The pressure drop and velocity data for the sodium
carbonate tests were used in determining constants A and B.
* Robinson, M., "Gas Absorption Mechanisms and Devices,
Special Reference to Flooded-Disc Scrubbers", Project
PRJ67-9, June 1, 1967.
with
Report
-44-
-------
FIGURE IV-12
ABSORPTION E6'FICIENCY FOR CALCIUM OXIDE AND
SODIUM CARBONATE AS A FUNCTION OF THE PRESSURE DROP
ACROSS THE FDS
90
80
","
""
"
;'
70
#-
..
>-
u
Z
&aJ
U 60
-
LA.
LA.
&aJ
Z
o
-
t- 50
Q.
0:
o
(t)
CD
ct
/
/
/
/
/
/
/
I
I
/
I
40
/
----
SODIUM C RBONATE
CORRE ATION
30
CALCIUM OXIDE
CORREl TION
o
o
5 10 15 20
PRESSURE DROP FOR FDS.INC !S H20
25
-45-
-------
The resulting equation is:
-6 2
6p = 3.39 x 10 Vt (L/G + 105)
(IV-7)
Mass-transfer coefficients for the lime absorption were
computed from this pressure correlation and equation (II-7).
The calculated coefficients for each run are shown in Table
IV-4.
6. Power Requirements For Tests VIa Through VId
The estimated horsepower requirements for the lime tests
described in sections IV B-2, 3, 4, and 5 are shown in Table
A-13. The major portion of the power needed for the S02
absorption is in the gas phase; approximately 70 to 85% of the
horsepower is consumed by the fan at venturi pressure drop of
6 to 12 inches of H20, respectively. For a venturi pressure drop
of 6 inches, between 3.2 5d 3.8 horsepower are needed per mega-
watt output on the generator, while at 12 inches 6p on the
venturi, 5.3 horsepower per megawatt is used.
7 .
Effect of Mode Change - Task VII
Three mode changes were made in the process which
deviated from the flow patterns used in the developing of
equation (IV-5):
1. Lime Feed via Slurry without dry injection
2. Slurry Feed to Tower and FDS
3. Clarified Solution to Tower and FDS.
-46-
-------
with these mode changes, the absorption effects for either
slurry liquors and/or clarified solution could be isolated.
Operating conditions and absorption efficiency measurements for
each of the tests are discussed below in section B-8, 9, and 10.
Detailed data on each test run are given in Tables A-14 through A-16. .
8. Lime Feed via Slurry Without Dry Injection -
Task VIla
In this mode, a 1.0% lime slurry was passed from the
mixing tank to the hold tank where it was mixed with the venturi
discharge. A slurry blowdown from the clarifier was circulated
through the venturi while the clarified overflow was sent through
the tower. Tower discharge bypassed the hold tank and entered
directly into the clarifier, see Figure IV-13.
FDS absorption efficiency for this test was higher than
achieved for the same operating conditions predicted with
equation (IV-5). Between 48 to 53% of the inlet S02 was removed
with a pressure differential across the disc of 6.5 to 8.5
inches W.G. and a L/G of 10 gallons per 1,000 cf. Slurry tem-
perature to the disc for this run measured 100 to 102°F or about
20 to 40°F lower than normal. This lower temperature may have
influenced the absorption by increasing lime solubility and re-
ducing the S02 vapor pressure.
Results of the test are compared to equation (IV-5) in
Figure IV-14. Approximately 10 to 15% more absorption took place
for this test than predicted by the correlations. Detailed
operating conditions for the test are presented in Table A-14.
-47-
-------
GAS IN
CAO
WATER
MIXING
TANK
GAS OUT
PACKED
TOWER
OEMISTER
SLURRY
TANf(
FIG.IV-13 WET SLURRY TO FDS WITH CLARIFIER RECYCLE-TASK VilA
-48-
-------
1001
I
.
\D
I
# 80
>
u.
z
...
-
51! 60
II.
...
1&1
B
..
t: 40
IE
. 0
(I)
~
.. 20
o
(I)
FIGURE IV-14
COMPARISON OF S02 ABSORPTION VS.PRESSURE DROP
BETWEEN LIME SLURRY (VII A) AND DRY LIME ( V~)
I I I I
I
I
~':E SLURRY ABSC RPTION (TASK VII A) -
.--
-------
9. Slurry Feed to the Venturi and Tower - Task Vllb
For .this test, slurry containing calcium oxide, reaction
products, and fly ash circulated through both the tower and
the FDS, as illustrated in Figure IV-IS. The solids concentra-
tion to the venturi was held at 15 to 19% while the tower
slurry varied from 3.4 to 4.4%. Process conditions remained
constant throughout the run at L/G = 10 gallons per 1,000 cf
for the FDS and 20 gallons per 1,000 cf for the tower.
GAS IN
GAS OUT
PACKED
TOWER
DEMISTER
I
CAO
M1X1..
TANK
URRY
TANK
FIG.IV-is TWO STAGE VARIABLE SLURRY-TASK VU B
-50-
-------
Results of these tests are given in Table A-IS. The
efficiency for the FDS (approximately 39%) was about 10% less
than determine!d with the lower slurry concentration predicted
by equation (1V-5). This data was added to the results used
in equation (1V-5) and a slightly improved regression was
derived, i.e.
Y = 30.7 + 4.57 (R) + 0.952 (lip)
+ 0.647 (L/G) + 15.16 (I) - 2.751 (1)2
(IV-8)
- 0.598 (SL)
where
= S02 absorption efficiency of FDS, %,
= stoichiometric ratio, moles of CaO/mole
of S02 in inlet,
lip = pressure drop across disc, inches of H20,
L/G = liquid-to-gas ratio, gals/mcf.,
I = ionic strength of NaCl, molarity
SL = slurry concentration, % by weight.
y
R
Statistical parameters for this correlation are given in
Table IV-6.
10. Clarified Solution to Tower and FDS - Task Vllc
The objec:tive of this test was the determination of the
FDS absorption efficiency without solid suspension. A
clarified solution was pumped to both the FDS am; the tower in
the mode given in Figure IV-16. S02 removal, as expected,
dropped off considerably. Between 13 to 15% of the S02 was
absorbed in the FDS for inlet gas concentration at 1,560 to
1,650 ppm. pH of the lime solution varied between 11.1 to 5.2
-51-
-------
TABLE IV-6
STATISTICAL PARAMETERS FOR
THE CALCIUM OXIDE CORRELATION
Number of Data Points
Correlation Coefficient
Standard Error of the Estimate =
Significance of Regression (F) =
Stoichiometric Range, R
Pressure Drop Range, 6p
Liquid-to-Gas Ratio Range, L/G =
Ionic Strength Range, I
Slurry Concentration Range, SL =
=
40, See Table IV-4
=
0.873
3.57%
=
17.6
0.83 - 1.42
=
5.6 - 19.8 inches of water
=
10 - 23 gals/MCF
0.1 - 4
1.1 - 19.5%
-52-
-------
as it passed through the FDS; hence, a major portion of the
alkali was consumed. The dissolved lime contributes only a
small fraction of the required absorbate. Results of this test
are summarized in Table A-16.
8A8 IN
IAS OUT
PACKED
TOWER
DEM I STER
"'XING
TANk
WATER
FI8.1Y-8 WET 'LURRY wrrH CLARIFIER OVERFLOW. TOFDS-TASK Vllc
. .
11. Tower Absorption
Operating parameters for the tower were deliberately
fixed at one level for most of the test program to minimize
-53-
-------
FDS process variations. Yet, efficiency for the tower ranged
from 24 to 96%. Uncontrollable process conditions such as
inlet s02 concentration, gas dew point temperature, and inlet
liquid alkalinity, varied considerably. An attempt to correlate
the tower absorption efficiency data with the variations that
did occur did not yield any meaningful mathematical expression.
A weak absorption efficiency relationship with inlet gas con-
centration, liquid phase temperature, and solution pH was
evident.
For the majority of tests, a clarified solution passed
through the tower. Solution pH entering the absorber at pH 10
to 11.2 changed considerably as it absorbed the S02. Exit pH
varied between 2.0 and 9.4. Estimated stoichiometry for the
input s02 and Ca(OH)2 indicated a limiting alkalinity when a
saturated clarified solution was fed; however, for most tests,
minor solution turbidity was observed at the clarifier over-
flow. The alkaline nature of the solids creating the turbidity
could affect the stoichiometry significantly. Absorption
efficiency measurements for a major portion of the calcium
oxide tests are presented in Table IV-7.
Solution ionic strength was varied by the addition of
sodium chloride for three levels. The object of these tests
was the simulation of steady-state conditions where chloride
ion and sodium ion would build up in a closed-loop process.
The three levels of concentration selected, 1.0, 2.0, and 4.0
molality, indicated a maximum absorption at I = 2. At an ionic
strength of 1, the absorption ranged from 46 to 65% while at
I = 2, the absorption was between 91 and 94%. Increasing the
sodium chloride concentration to I = 4 adversely affected the
absorption; and between 79 and 91% removal was observed. A
-54-
-------
TABLE IV-7
SELBC'l'ED RUB DATA FOR THE PAC1CED TONER
S02 . Slurry JI~:!e-Transfer
102 Colleetion Inlet; Liquid. Slurry Temp. of pH of pH Gas Teap. Gas Temp. Coefficient
'reat Bffic:ienc:y Loadinq Ga. Ratio COnc:entratlon Clarifier Ionic Tover of Tower 1:0 Tower Prom Tower 1 b-mol 8
~ ~ Time (') (ppa) (gals/cfla) C') C-P.) Strenqd1 2:!!!!. Underflow (-P.) C-P.) (hi.) Cllq.ft:.) (am):
1 2/24 12:15 72.6 690. 15. 0.1 138. 0.1 10.7 5.2 150. 140. 0.32
2 2/24 13:15 45.3 840. 15. 0.1 145. 0.1 10.4 5.2 152. 148. 0.15
3 2/24 15:00 37.0 1080. 15. 0.1 148. 0.1 10.4 5.0 152. 150. 0.11
4 2/24 16:00 33.2 1200. 15. 0.1 140. 0.1 10.6 5.1 152. 148. 0.10
5 2/24 17:00 35.3 990. 15. 0.1 120. 0.1 10.6 5.7 140. 135. 0.11
6 2/24 18:00 23.5 1020. 15. 0.1 135. 0.1 10.6 5.8 150. 148. 0.07
7 2/24 18:30 32.3 945. 15. 0.1 136. 0.1 10.6 5.7 150. 140. 0.10
8 3/30 14:00 89.8 960. 15. 0.1 95. 0.1 11.8 4.2 115. 100. 0.58
9 3/30 16:30 55.6 810. 15. 0.1 105. 0.1 11.2 4.8 118. 108. 0.20
10 3/H 10:00 51.4 1110. 15. 0.1 102. 0.1 11.1 4.7 118. 102. 0.18
I 11 3/Jl 12:00 52.8 1080. 15. 0.1 108. 0.1 11.1 4.8 120. 110. 0.19
U1 12 4/1 10:00 49.1 1120. 15. 0.1 100. 0.1 11.1 4.0 118~ 108. 0.17
U1 13 4/1 12:00 48.7 1170. 15. 0.1 110. 0.1 11.0 4.1 122. 115. 0.17
I 14 4/1 14:00 44.4 1080. 15. 0.1 116. 0.1 11.2 4.1 122. 118. 0.15
15 4/1 17:00 36.7 1200. 15. 0.1 109. 0.1 11.3 5 120. 105. 0.12
16 4/5 15:45 51.7 1200. 15. 0.1 104. 0.1 11.4 4.5 112. 105. 0.17
11, 4/7 11:30 55.6 810. '15. 0.1 110. 0.1 9.9 3.6 115. 105. 0.2
18 4/7 13:30 64.8 415. 15. 0.1 112. 0.1 11.3 3.9 118. . 108. 0.25
19 4/7 16100 n.o 363. 15. 0.1 112. 0.1 11.2 4.5 118. 110. 0.28
20 4/7 20100 57.8 450. 15. 0.1 108. 0.1 11.2 . 3.8 115. 100. 0.18
U 4/14 10130 90.3 180. 15. 0.1 111. 0.1 11.0 4.0 115. 107. 0.57
22 4/14 11130 94.0 705. 15. 0.1 111. 0.1 11.0 4.5 117. 109. ' 0.69
23 4/14' 12140 95.6 720. 15. 0.1 112. 0.1 11.0 4.7 118. 112. 0.77
24 4/14 15:U 88.0 600. 15. 0.1 103. 0.1 10.9 4.2 112. 108. 0.52
25 4/14 18:00 51.6 620. 15. 0.1 108. 0.1 10.5 4.6 120. 110. 0.18
26 4/14 19:00 52.4 630. 15. 0.1 108. 0.1 10.5 4.5 118. 112. 0.18
27 4/14 22:20 30.6 735. 15. 0.1 108. 0.1 10.4 4.0 118. 112. 0.09
. ... IIiDor 8O~Qtion turbidity was evident tbroUCJbcNt the t.eat proqraa.
-------
TABLE. IV-7, cont'd
SBL8C'1'BD RUIf DATA FOR 'l'BB PACKED '1'01IER
S02 Slurry Mass-Transfer
SOj Co11ecUon rn1et Liquid. Slurry Temp. of pH of pH Gas Temp. Gas Temp. Coefficient
Test fficiency Loadinq Gas Ratio eoncentratJ.on Clarifier ronic Tower of Tower to Tower Prom Tower Ib-mols I
..!!!!.:. 2!!! !!!!!! C,) Cppm) Cqals/cf.) C,) cop.) Strenqth ~ Underflow cop.) (op.) Chi.) csq.ft.) (a~
28 4/15 10115 30.8 780. 15. .0.1 114. 0.1 10.8 4.2 .115. 113. 0.09
29 4/15 11145 29.6 750. 15. 0.1 109. 0.1 11.1 4.2 115. Ill. 0.09
30 4/U 12145 41.6 945. 15. . 0.1 109. 0.1 11.1 4.2 115. Ill. 0.13
31 4/15 15100 52.4 870. 15. 0.1 107. 0.1 11.3 4.4 115. Ill. 0.19
32 4/15 16:30 54.9 825. 15. 0.1 107. 0.1 11.3 4.5 115.' 110. 0.21
33 4/15 17:30 57.2 780. 15. ,0.1 107. 0.1 11.3 4.4 118. 110. 0.21
34 4/15 20130 52.3 810. 15. 0.1 110. 0.1 11.0 4.8 118. 112. 0.18
35 4/15 22:00 51.1 810. 15. 0.1 108. 0.1 11.0 4.8 ' 118. 112. ; 0.18
I 36 2/25, 10115 53.1 1110. 15. 0.1 118. 0.1 10.0 5.8 138. 125. 0.19
V1 37 2/25 11120 40.6 1110. 15. 0.1 132. 0.1 10.8 6.2 144. 134. 0.13
m 38 2/25' 12:45 57.7 900. 15. 0.1 140. 0.1 11.3 5.9 142. 142. 0.21
I U 2/25 14105 57.7 900. 15. 0.1 138. 0.1 11.3 6.0 138. 137. 0.21.
40 2/25 15135 64.0 840. 15. 0.1 130. 0.1 11.4 5.9 138. 135. 0.25
41 2/25 16 :45 54.2 960. 15. 0.1 115. 0.1 11.3 5.8 132. 128. 0.19
42 5/5 9:30 60.9 1065. 15. 0.1 96. 0.1 11.0 3.6 122. 106. : 0.24
43 5/5 10:30 79.0 1050. 15. 0.1 106. 0.1 11.0 3.8 116. 105. 0.39
44 5/5 11115 73.9 1020. 15. 0.1 102. 0.1 11.0 3.8 116. 108. 0.34
45 5/5 13130 63.6 1320. 15. 0.1 104. 0.1 11.1 2.4 118. 112. 0.25
46 5/5 15100 73.7 1110. 15. 0.1 110. 0.1 11.2 2.3 120. 115. 0.34
47 5/5 16100 86.5 960. 15. 0.1 112. 0.1 11.3 2.2 120. 1'16. 0.50
48 5/6 10145 82.6 1010. 15. 0.1 102. 0.1 11.4 2.0 118. 110. '0.44
49 ,5/6 12120 76.0 1015. 15. 0.1 102. 0.1 11.0 2.0 118. 110. 0.36
50 5/6 13120 76.0 870. 15. 0.1 104. 0.1 1.2 2.2 118. 110. 0.36
51 5/6 15100 86.0 930. 15. 0.1 106. 0.1 11.3 2.4 120. 112. 0.49
52 5/6 16100 83.3 900. 15. 0.1 106. 0.1 11.3 2.2 118. 112. 0.45
53 5/6 17100 85.1 870. 15. 0.1 108. 0.1 11.2 2.2 118. 114. 0.48
-------
TABLE IV-7 cont'eS
SELBCTBD RUIf DATA POR TIm PACItBD '1'OWBR
502 Slurry Mass-Transfer
80j Collection Inlet Liquid' Slurry Temp. of pH of pH Gas Temp. Gas 'reap. Coefficient
Teat fficiency Loadinq Gas Ratio Concentration Clarifier Ionic . Tover of Tover to Tower Prom Tower 1b-mo18
~ 2!!!. !!!!!!. (,) . (ppm) (gals/cfm) (,) (.P.) Strength ~ Underflow (.p .) (Op.) (hi.) (sq. ft.) (atm)
54 4/16 11:30 46.1 600. 15. 0.1 110. 1.0 11.2 4.4 115. 113. 0.16
55 4/16 12:30 63.7 750. 15. 0.1 109. 1.0 11.2 5.8 115. 110. 0.26
56 4/16 13:30 65.3 900. 15. 0.1 106. 1.0 11.2 5.8 115. 115. 0.27
I 57 4/16 15:15 94.3 840. 15. 0.1 106. 2.0 11.2 7.0. 114. 110. 0.72
U1 58 4/16 16:15 91.5 870. 15. 0.1 108. 2.0 11.2 6.6 114. 110. 0.63
-..,J
I 59 4/16 19:00 91.0 900. 15. 0.1 108. 4.0 10.8 9.4 118. 118. 0.59
60 4/16 20:00 79.0 570. 15. 0.1 108. 4.0 10.9 6.5 118. 118. 0.39
61 4/16 22:00 79.1 630. 15. 0.1 110. (.0 11.0 6.2 118. 118. 0.39
62 5/1J 14: 00 79.1 1420. 20. 4.4 98. 0.1 11.10 3.8 112. 100. 0.4
63 5/1 15130 84.5 1125. 20. 3.4 102. 0.1 11.1 2.5 113. 103. 0.48
64 5/13 16:30 77.1 1260. 20. ].5 102. 0.1 11.1 2.4 115. 106. 0.38
65 5/13 17130 85.9 1110. 20. 3.4 104. 0.1 11.1 2.2 115. 108. 0.5
-------
summary of the tower conditions for the ionic strength experi-
ment is shown in Table IV-7, Tests 54 through 61.
For Tests, 55 and 56, ionic strength = 1, the amount of
S02 being absorbed per unit time was compared to the hydroxide
solubility predicted with an equilibrium modelP The consumed
hydroxide calculated from the absorbed S02 and solution flow
was very close to the theoretical saturation solubility of the
liquid. With ionic strength equal to 1.055, the theoretical
[OH)- concentration is 1.133 x 10-2 g-moles/liter which is
almost exactly the predicted hydroxide consumption of
1.24 x 10-2 or 1.44 x 10-2 g-moles/liter for tests 55 and 56
respectively. These results are summarized in Table IV-8.
To determine the S02 absorption during slurry feed to
the tower, several tests were performed with slurry inputs
ranging from 3.4 to 4.4% solids. Absorption measured between
77 and 86% with inlet 802 concentrations ranging from 1110 to
1420 ppm. Results of these experiments are listed in Tests
62 to 65 of Table IV-7. No outstanding absorption improvement
could be seen with the high slurry feed (3.4 to 4.4%) compared
to the efficiency measurements with clarified solution.
Tower mass-transfer coefficients ranged from 0.1 to 0.77
lb-moles/(hr) (sq. ft.) (atm) for the tests shown, in Table IV-7.
High ionic strength solutions and slurry feed gave mass-
transfer coefficients between 0.4 and 0.7.
c.
OTHER ALKALI MATERIALS - TASK VIII
Thus far the absorption measurements have simulated the
Dry Injection-Wet Scrubbing Process with a soft burned
calcium oxide. In the next section, other limestone materials
-58-
-------
TABLE- IV-8
The Comparison Between the Solubi1itr Data from
Radian Corporation (1) and Data from the Eff1ciency Measurement
S02 Removed Tower s02 Tower Feed Tower Feed Ionic Conc. of [OH] in
Efticiency in Tower Inlet loading Temp. Tower Feed
(%) (PPM) (0 F) PH Value Strength gr.-mo1s/1iter
Radian's Data 131 11.214 1.055 1.133')(10-2
Measured Data
I
U1 1.24X10-2 (4)
\0 (2) 63.7 750 109 11.2 1.
I
(3) 65.3 900 106 11.2 1. 1.44X10-2 (4)
(1)
Radian Corporation: A Theoretical Description of the Limestone Injection-Wet Scrubbing Process,
Volume 11, B-2, (1970).
Table 4- Test #55
(2 )
(3)
Table 4- Test #56
(4 )
Hydroxide consumed in the Tower by the absorbed S02
-------
[-
were processed for comparison. A high grade dolomitic lime,
containing approximately 99% MgO.CaO and a partially sulfated
lime/fly ash material having 25.3% CaO were processed with mode
conditions similar to the calcium oxide tests.
Specific operating conditions for these tests (section IV
CI, 2, and 3) are summarized in Tables A-17 through A-19.
1. Dolomitic Lime - Task VIIIc
Task VIIIc, absorption efficiency measurements with
dolomitic lime (CaO.MgO), were performed with the operational
scheme illustrated in Figure IV-17. Venturi scrubber absorption
efficiencies for this "once through" process ranged from 56 to
69% removal with a FDS 6p between 7.0 and 8.2" of W.G. The
dolomitic lime gave an efficiency 27 to 37% higher than measured
with the calcined limestone. With calcium oxide, the absorption
efficiency for a similar operation (Task III) was 30% for a
stoichiometric ratio of 1.0 and a lip = 10" W.G. These results
are compared in Figure IV-18. Stoichiometric ratio for the
dolomitic lime was computed with the CaD plus the MgD.
2. Sulfated Lime/Fly Ash via Dry Injection - Task VIIId
Partially sulfated lime/fly ash material from the Shawnee
Power Station, Paducah, Kentucky was processed in the pilot
system using again the operating mode illustrated in Figure
IV-17. The lime/fly ash material tested contained 25.3% free
CaO. Under these conditions, fly ash loading was appreciably
higher than usual. Although absorption efficiency was low,
there is no evidence that fly ash concentration was directly
responsible. Absorption e~ficiencies of 11.6 to 18.4% were measured
-60-
-------
GAS IN
GAS OUT
pACKED
TOWER
DEMISTER
SLURRY
TANK
FIG. IV-IT DRY INJECTION OF DOLOMITIC LIME TO FDa-TASK VIIIC8D
for an L/G = 10 gallons per 1,000 cf and a pressure drop ranging
from 5.7 to 10.8 inches of water. Stoichiometric ratio, as
given in Table A-18, was controlled at 0.93 to 1.02.
Results of this test are graphically compared in Figure
IV-18 to calcium oxide and dolomitic lime. As the graph indi-
cates, the sulfated lime performed poorly in comparison to
both calcium oxide and dolomitic lime under similar operating
conditions. With dry injection, calcium oxide removed 30% of
the inlet S02 while the sulfated lime/fly ash absorbed approxi-
mately 17%.
-61-
-------
100
60
50
fI.
,
>-
~ 40
LLI
-
o
-
iL
IJ..
LLI
Z
~ 30
Q.
a:
o
CJ)
CD
~
N
o
CJ)
20
FIGURE'IY-18
~OMPARISONOFS02 ABSORPTION EFFICIENCY VS CAO/S02
BETWEEN DRY LIME (TASK III) DOLOMITIC LIME (VIII C) AND
SULFATED LIMEIFLY ASH MIXTURE (YIU D) -
e-c
90
I
80
70
-
o
-
-
-
-
.
~~
~~
V~
V
-------
Pressure drop across the disc .increased from 6.8 to 10.8
inches W.G. in 4 hours of operation while the throat setting
remained in the opened position. This increase in 6p would
indicate a significant buildup of solids within the throat area.
Absorption in the packed tower with a clarified solution
input was between 37 and 50% removal for L/G = 20 gallons per
1,000 cf. The efficiency for the tower did change during the
process run and its final value was 37.5%. This low efficiency
is predictable from the pH values (6.8 to 8.6) for the tower
slurry tank inlet in Table A-IS. Calcium oxide for the same
process conditions, Task VIb, demonstrated similar low absorption
with a clear liquid feed, i.e. 25 to 35% removal as given in
Table A-S.
3. Sulfated Lime/Fly Ash With Wet Slurry - Task VIIIe
The operating mode for this task is shown in Figure
IV-19. A 4% slurry of lime/fly ash was passed from the mix
tank to the slurry tank feeding both the venturi and the tower.
The clarifier was bypassed to allow a slurry input to the tower.
FDS sulfur dioxide absorption was lower than the lime
for a comparable mode. These results are compared in Figure
IV-20. Here, the 502 removal efficiency for the 4% slurry
measured approximately 20 to 31% for the FDS while the calcium
oxide, at the same process conditions, allowed 47% removal.
Residence times in the slurry tank were approximately the same
for the calcium oxide and sulfated lime/fly ash, i.e. 40 to 60
minutes.
Tower efficiency for the 4% sulfated lime/fly ash slurry
was outstandingly good; 93 to 97% 502 removal was established
-63-
-------
GAS IN
GAS OUT
PACKED
TOWER
DEMISTER
MIXING
TANK
4°k
SLURRY
SLURRY
TANK
FIG.IV-19 LIME/FLY ASH SLURRY TO FDS -TASK VIII E
at a L/G ratio of 20 gallons per 1,000 cf. Calcium oxide at
similar conditions, 3.4 to 4.4% solids, gave lower absorption,
i.e. between 77 ~ 87% removal. The sulfated lime/fly ash was
well mixed in the slurry tank before entering the tower while
the calcium oxide test used clarifier blowdown. . The sulfated
lime presumably dissolved to a greater extent in the agitated
vessel than the calcium oxide did in the large stagnant clarifier.
Detailed operating conditions for the sulfated lime tests
are given in Table A-19.
-64-
-------
100
I
0\
L11
I
~
~ 80
z
III
-
U
-
IL
:; 60
z
.0
-
~
a.
~ 40
(/)
a:a
c
'"
g 20
00
FIG. IV-20
COMPARISON OF SO-2. ABSORPTION EFFICIENCY VS.
PRESSURE DROP BE TWEE14 CAL.CIUM OXIDE (TASK VI a VII)
AND SULFATED LIME/FLY ASH (TASK VIII E)
CALCIUM
OXI DE
Q)
G>
@ S LFATED LIM I FLY ASH
MIXTU E
4% SLURRY INPUT
FI AL MEASUR MENT
5
10 15 20
PRESSURE DROP, I. W. G.
25
30
-------
D.
LIMESTONE
The limestone programs were carried out in two separate
test series in cooperation with the Tennessee Valley Authority.
In the first program, several types of limestone and one
hydrated lime were processed in an open-loop system; absorption
efficiencies were compared for each alkali type. Following
these tests, a second investigation was performed studying the
scale accumulation within the tower absorber using a limestone
selected from the first test run.
1. Limestone Efficiency Tests - Open-Loop
Eight absorption tests were executed with four carbonate
compounds, one hydrated lime, two liquid-to-gas ratios, and two
operating modes. The four calcium carbonate materials were
provided by TVA; a list of these materials and their chemical
analyses are given in Table B-1, Appendix B.
Block diagrams illustrating the two operating modes are
shown in Figure IV-2l. For the major portion of these experi-
ments, reaction slurry was fed to both the FDS and the packed
tower. Alkali slurry flowed countercurrently to the gas as it
passed from the tower slurry tank to the venturi slurry tank.
A two percent by weight CaC03 or Ca(OH)2 slurry was pumped from
the mixing tank to the tower slurry tank at the stoichiometric
rate. An equal slurry flow passed from the tower tank to the
venturi slurry tank where it then overflowed to the discharge.*
Hydrated lime, the most efficient alkali of the group,
removed 99% of the S02' Limestone and chalk gave an efficiency
of 96% while cement dust, the least effective material, scrubbed
*
Calcium flow rates into and out of the tower slurry tank
were equal when balanced conditions prevailed.
-66-
-------
WATER
GAS IN
SLURRY
RECYCLE
ENTURI
SLURRY
TANK
T
GAS OUT
PACkED
TOWER
DEMISTER
TOWER
SLURRY
TANK
COUNTER-CURRENT SLURRY FLOW
GAS IN
Tr
GAS OUT
PACKED
TOWER
DE MISTER
TOWER
SLURRY
TANK
WATER FEED TO F D S
SLURRY
RECYCLE
CA COI
+
WATER
NIXING
TANK
SLURRY FEED
SLURRY
RECYCLE
'CA CO!
+
WATER
MIXING
TANK
I
FIG.IV-21 OPERATING MODES USED FOR LIMES1'ONE EFFICIENCY TESTS
-------
76% of the inlet S02. Only a small fraction of the absorbed
S02 was removed in the FDS; between 9 ~ 21% was sorbed with
the residual alkali from the tower. The planned operating con-
ditions for each test are listed in Table B-2, Appendix B.
Detailed operating results for these experiments are given in
Table IV-9; each efficiency measurement listed is an average of
four readings over a three hour period.
The coarse grind limestone, 75% - 200 mesh, allowed an
absorption efficiency of 88.4% while a finely ground material,
89% - 325 mesh, achieved 96% removal.
Liquid-to-gas ratio in the tower had considerable in-
fluence on S02 reduction. At L/G of 40 gallons per 1,000 cf
(Task A6 - coarse grind limestone) the efficiency across the
tower was 81.6%; however, at L/G of 20 for the same operating
mode, the S02 removal dropped to 58.2%. Such sensitivity to the
liquid flow implies a significant liquid-phase absorption
resistance.
2. Limestone Scaling Experiments - Closed Loop
To determine the operating conditions for minimum scaling
using limestone alkali, four continuous 40 hour tests were made.
Operating parameters, such as liquid-to-gas ratio, tower slurry
tank residence time, and tower slurry tank temperature were
varied. The scale deposition for each test was measured by
weighing the packing before and after each run; in most cases
new packing was installed for the subsequent test. Following
these preliminary experiments, an eighty-hour continuous opera-
tion was carried out and the scale accumulation measured. A
description of the program plan is given in Table B-3.
-68-
-------
------ - -~ -~- - ~- --~-- ---~ --~ --- -~~
-
TABLE ::V-9
SUMMARY D~.'rA SHEET FOR 'rHE '1'VA TEST PROGMK 1
Limestone Limestone 2
Selma Cement Lime
.:aterial Used Chalk Dust - Pine Coarse Coarse' Coarse Coarse Hydrate Fine Coarse
Task No. A2 A3 .M.- AS A6 A7 A8 A9 A4' AS'
---: -
Gas Flow, CFH 3 900 900 600 600 800 900 800 . 600 900 sea
Tower Liquid Rate, GPH 35 36 24 24 32 18 32 24 36 23.7
FDS Liquid Rate, CPM 9.4 9 6 6 8 9 8 6 9 5.3
Cas Velocity, Tower, Ft/Sec. 10.7 10.7 9.3 9.3 9.5 10.7 9.6 9.3 10.1 6.0
Gas Velocity, FDS, Ft/Sec. 99 105 132 132 121 98 87 132 98 105
~ower Pressure Drop, inches H20 3.9 6.5 1.1 0.9 1.2 1.3 1.3 1.9 15.8 0.32
FDS Pressure Drop, inches H20 12.7 6.4 7.3 7.3 7.1 7.9 9.4 7.2 6.5 6.9
CaO/S02 Ratio 1.11 1.06 1.16 1.00 1.0a 1.10 1.62 1.04 1.01 1.54
S02 Concentrations, PPM
FDS in 1550 1135 1650 1980 1467 1637 1485 1544 1270 1475
FDS out 1405 1025 1288 1795 1155 1415 1402 1212 1300 1427
Tower out 48 268 62 209 212 592 199 16 193 100
I Fraction of S02 Remo~ed, ,
0\ FDS 9.4 9.7 21.9 9.4 21.2 4 13 .6 4 5.6 21.5 3.3
\D Tower 96.6 73.5 95.1 88.4 81.6 58.2 85.8 98.7 85.1 93.0
I
Overall 96.9 76.4 96.1 89.5 85.5 63.8 86.6 98.9 85.1 93.2.
Gas Temperature, ep
FDS in 371 377 361 361 348 391 369 357 360 355
FDS out 122 122 118 116 92 102 101 118 121 109
Tower out 114 116 110 109 91 99 98 111 113 98
Liquid Temperature, ep
FDS in 119 121 118 116 40 40 41 121 121 .106
FOS out 126 124 125 124 75 97 95 123 125 116
Tower in 112 114 110 110 89 95 96 112 115 100
Tower out 122 122 117 116 124 106 101 118 120 106
L/G ratio, FDS, Gal. ~r 1000 cf 10.4 10 10 10 10 10 10 10 10 10.(;
tlG ratio, Tower, Gal. per 1000 cf 39 40 40 40 40 20 . 40 40 40 n..5
1. Operating conditions for each task shown are an average of four readings measured over a
three hour period.
-
2. Tasks A4' and AS' were not considered at stead:istate condition or at the specified operating
level.
3. Gas flow at tower outlet teznperature and approkl~tely 380 inches of H20
4. Water 'was fed to t11e FDS for this te5t.
-------
The operating modes for this test series are shown in
Figures IV-22 and IV-23. Originally, a closed-loop scheme, as
illustrated in Figure IV-23, was proposed for all tests. Al-
though operational problems encountered during the program re-
quired plan modifications, the continuous eighty hour run was
performed with the closed-loop process. One experimen~ (Task CS)
as described belo~was executed in a open-loop system for part
of the run.
a. Scaling
The detailed operating conditions for each test are
summarized in Table B-4. The preliminary experiments were 40
hour runs performed as a guide in determining the scale buildup
at various opetating conditions. Although the process para-
meters for these tasks were not constant during any run, a
general trend in the scale accumulation could be seen. With
high tower L/G, a lower solids buildup was measured than with
low L/G, see Table IV-IO, Tasks C2 and C3. Residence time for
the slurry in the tower hold tank showed no effect as the hold
time was varied from 5 to 10 minutes.
The profile of solids buildup on the packing looking from
the top to the bottom section did show a pattern of scaling;
very little scale deposited in the top section and a consistent
quantity precipitated on the bottom three or four elements.
This profile of solids buildup suggested an absorption-
supersaturation taking place within the tower with an induced
encrustation after one or two feet.
From the profile of solids deposited on the packing and
the reduced deposition at high L/G, one could conclude that
incoming solution from the slurry tank was at low supersaturation
but once supersaturation did develop within the tower, the rate
----
of encrustation was consistent.
-70-
-------
i
1-
GAS IN
r
MIXING
TANK
GAS OUT
PACKED
TOWER
DEMISTER
TOWER
SLURRY
TANK
FIG. IV -2 2 FLOW DIAGRAM FOR OPEN...LOOP SCALING TESTS
GAS IN
VEN1-URI
SLURRY
TANK
GAS OUT
DEMISTER
CAC03
--., .__.
TOWER
SLURRY
TANK
FIG. 1'1-23 TWO STAGE CALCIUM CARBONATE SCRUBBER
~ l.~
-------
TABLE IV-IO
PACKING WBIGB'fS BEFORE AND AP'1'BR BACH '1'A8K
'raek C-2 'raek C-3 'raek C-4 'raek C-5 !faet c-'
(CO IIOURS) * (80 IIOURS)
Weight Weight Weight Before Weight Weight Weight
PackiD9 Before Gain Before Gain Before Gain Gain Before Gain Before Gain Pactinq
No. lbs. lbs. lbe. lbe. lbe. lbe. lbe. lbe. 1be. lbs. lbe. lbs. Pod tion
. .* i
1 8 7 4 2 8 4 22 2 9 .5 9 3 1
2 6. 14 5 9 4 13 21 5 8 1.5 8 3 2
I
.... 8 7 3 ~
to.) 3 8 13 6 10 6 15 17 8 8 1.5 1
I
4 6 16 6 10 8 14 12 8 7 3.5 7 6 4
5 6 14 6 12 6 20 8 8 7 3.5 7 C 5
'fotal I 64 43 66 31 10.5 23
* Packing was weighed slightly vet.
U Weiqht gain wae calculated by subtraoting 0.5 lb.. of mol.tare fRla
each .ect!cm. Pi.. new 8ect!on. of pacti~ 8hDw84 2.., 1M. of 9a1a
when vetted with vater.
-------
Based on 1:he aforementioned reasoninq, the operatinq con-
ditions selected for the long term demonstration test combined
a low level tOWE!r hold tank volume with a maximum practical
tower liquid-to-gas ratio, i.e. a ten minute residence time on
the hold tank and a L/G of 45 gallons per 1,000 cf.
Some time after the actual test program, a chemical
analyses of the solutions entering and leaving the tower showed
that the dissolved CaS04.2H20 was approximately the same for
the tower inlet and outlet.l On the other hand, calcium sulfite
in the solution leaving the tower was supersaturated to approxi-
mately six times its solubility; yet the liquid entering the
tower (leaving the hold tank) was not supersaturated at all.
Hence, the assumption of low supersaturation for the solutions
leaving the hold tank was correct and the decision for high
liquid-to-gas flow would tend to reduce scaling.
Stoichiometry at the start of the run was near 100% for
the first 40 hours and 120% for the last 40 hours. Two lime-
stone grinds were used during the run--for the first 40 hours
a limestone having 75% - 200 mesh was employed, while during
the second 40 hours, the same material with 61% - 200 mesh was
used. A chemical and particle analyses for these materials
are given in Table B-5. Solids concentration in the slurry was
held between 4.4 and 8.9%.
The absorption efficiency varied from a low of 55% to a
high of 98%. Near the end of the run, the absorption was
highest. A profile plot of stoichiometry, slurry concentration
and tower efficiency is shown in Figure IV-24. An explanation
for the variation in efficiency is discussed in the following
absorption section.
-73-
-------
I
"
~
I
~OO
..
U)
a:
'"
ID ~
ID
~ 75 ....12
(.) %
(I) £!
% LLI
~ ~
o Z8
m 0
a: L:
o :c
iL. ~
>- ~
~2 (.)4
!!! z
(.) 0
ii: (.)
iL. >
1&1 G::
~ 0 0::0
-J :)
C ...J
a: en
...
~
FIG. IV-24
TASK C-6 EFFICIENCY PROFILE, SLURRY CONCENTRATION
AND STOICHIOMETRY DURING THE RUN
SEE TABLE 8-4
JI', ~?~
--A "t. >---- - - - ) :J.---\~)..... .-t:) j
I'""';P""----- - ,.., ,., '- -)
~. . ~
~ T 0 EFFICIENCY
'-~
~ J~ A
... ""- ..... ~ /'- ../ / ......... ........... ....... ...... /--
~~ "'~/ "I~
rlwG
o
6 SLURRY CONC.
j~ }i"\
. (
G-i.
fi .
.~./ .1" to' GGB:J-
'C]
.
G- - -
o S~OICHIIOMETIRY
10
30 40 50
HOURS IN OPERATION
70
20
60
2.4 ~
~
2.2 a:
N
o
2.0 en
~
c1
1.8
>-
a:
1.6 :;;
2
o
1.4 %
()
-
o
1.2 t-
(I)
1.0
0.8
80
-------
During t.he continuous scaling run, an equipment breakdown
interrupted the test about half way through the run. The
packing was removed from the tower and each section was examined
and weighed. Most of the encrustation deposited during the
40 hours was on the packing periphery. The encrustation had a
mud-like consistency and not the hard scale observed during the
calcium oxide tests. Scale was not evident on the well-irrigated
surfaces. For the second 40 hours the same packing was used;
encrustation that did develop was again predominantly at the
periphery. The measured weight gain after 40 and 80 hours is
given in Table IV-IO.
After the first 40 hours, 10.5 pounds of solids had built
up, and during the next 40 hours, an additional 12.5 pounds were
deposited, weight gain determined on dry basis. No pressure
increase could be measured throughout the 80 hour test. The
amount of solids clinging to the packing was a small fraction
of the packing~void volume; pressure measurement on the tower
was approximately 1.0 inches of H20 at the start and finish of
the test, as given in Table B-4.
b. Absorption
The absorption efficiency for the preliminary scaling
runs varied considerably. Limestone stoichiometry, slurry con-
centration and the inlet gas composition were changing through-
out the test series. To explain the efficiency variation,
the operating conditions fo~ the 80 hour run were examined
carefully. Slurry chemical analysis performed by TVA and
Radian Corporation were combined with the absorption efficiency,
inlet S02 concentration and slurry concentration measured in
the field.l A list of the TVA analysis for test C-2 to C-6 is
given in Table B-6.
-75-
-------
By digital computer simulation of the absorption process,
the calcium carbonate concentration was determined for the
absorbate over the entire 80 hour run. With a known chemical
analysis as a starting point, the caco3 slurry concentration
was calculated and for each point in time an efficiency measure-
ment was made. The predicted carbonate slurry concentration
fit well with the chemical analyses. The computer simulation
could not take into consideration process changes such as
spills, leaks or uncontrolled water addition. A comparison of
the computed and analyzed carbonate concentration is given in
Table IV-II.
TABLE IV-II
LIMESTONE CONCENTRATION IN THE HOLD
TANK DURING TASK C6
Calcium Carbonate Concentration, %
Date Time Computer Predicted TVA Radian
1/25 2230 1.89 (start) 1. 89
1/26 1300 1.19 0.54
1/26 1500 1.19 1.13
1/26 2100 1.46 0.94
1/29 1400 0.36 (Start) 0.36
1/29 2100 1.44 2.16
1/30 1230 1.32 1. 65
1/30 0103 1.78 1. 60
-76-
-------
Using the computer-estimated value of limestone concen-
tration, the analyzed sulfur dioxide absorption efficiency in
the tower, and the measured tower hold tank slurry concentration,
a correlation was developed which predicts the absorption
efficiency for each of the limestone materials employed.
For the first 40 hours, where limestone ground to 75% -
200 mesh was used, an outstandingly good correlation was
realized. The absorption efficiency, predicted to within +1.9%,
showed sensitivity to inlet S02 concentration and limestone
concentration as seen below:
y = 165.05 - 0.0463 (pprn)
+ 30.48 (% CaC03) - 9.l26(SL)
( IV - 9)
where
y = S02 absorption efficiency, %,
ppm = tower inlet S02 concentration in ppm,
% CaC03= concentration of limestone slurry in the
hold tank, %,
concentration of all solid in hold tank, %.
SL
=
Statistical parameters and the variable range for this correla-
tion are listed in Table IV-12.
For the second half of the run, a similar linear correla-
tion having a precision of t 3% efficiency was developed for
limestone with 61% - 200 mesh. Here the last 26 hours of
operation were studied so that a mixture of the two limestone
types could be avoided, i.e. 14 hours of the run time were
deleted because of the limestone mixture. The predicted effi-
ciency showed less sensitivity to inlet S02 concentration and
greater sensitivity to the limestone concentration.
-77-
-------
TABLE IV-12
STATISTICAL PARAMETERS FOR
EFFICIENCY CORRELATION
(First 40 Hours Run*)
Equation IV-9
Number of Data Points = 30
Correlation Coefficient = 0.987
Standard Error For Estimate = 1.9
Significance of Regression (F) = 349
% Efficiency Range, y = 53% to 97%
Sulfur Dioxide Inlet Range = 1160 to 1900 ppm
% CaC03 Range = 1.131% to 1.89%
% Total Solids Range, SL = 5.4% to 9%
* Limestone Used - Tiftona Limestone 50.5% CaO, 75% - 200
Mesh.
-78-
-------
Y = 56. 273 - O. 017 a (ppm) + 50. 313
(% caC03) - 4.15 (SL)
(IV-lO)
See Table IV-13 for statistical limitations.
To make use of these efficiency correlations, the lime-
stone slurry concentrations must be known. Three factors in-
fluence the residual limestone concentration in the tower slurry
liquor: 1) the actual absorption efficiency for the process,
2) the stoichiometric feed ratio of cac03/s02 and 3) the
overall slurry concentration. For a system with 6% total
slurry, the limestone concentration can be predicted by:
% caC03 = 1.23 - 0.033 (% eff.) + 2.236 R
(IV-II)
where
R = stoichiometric feed ratio, mols of cac03/mole s02'
Table IV-14 presents the conditions for equation (IV-II).
Using this expression and equation (IV-9) or (IV-lO), the
absorption efficiency can be predicted for either limestone
material for a liquid-to-gas ratio of 45 gallons per 1,000 cf.,
and a total slurry of 6% by weight.
Clearly, if the absorption efficiency is dependent upon
the lime~ne slurry concentration and the inlet gas s02 concen-
tration, then one or both of these conditions must be controlled
for a desired S02 removal. Reviewing once again the aO-hour
demonstration run, the computer-predicted carbonate slurry
concentration was compared to the material balance expression,
equation (IV-II).
-79-
-------
TABLE IV-13
STATISTICAL PARAMETERS FOR
EFFICIENCY CORRELATION
(Last 26 Hours Run*)
Equation IV-IO
Number of Data Points = 26
Correlation Coefficient = 0.95
Standard Error For Estimate = 3.08
Significance of Regression (F) = 69
% Efficiency Range, Y = 75.5% to 97.9%
Sulfur Dioxide Inlet Range = 960 to 1380 ppm
% CaC03 Range = 1.317% to 1.847%
% Total Solids Range, SL = 5.5% to 8%
.*
Limestone Used - Tiftona Limestone 50.8% CaO,
61% - 200 Mesh.
-80-
-------
,TABLE IV-14
'STATISTICAL PARAMETERS FOR
STEADY STATE WT.% LIMESTONE CORRELATION
Number of Data Points = 16
Correlation Coefficient = 0.995
Standard Error For Estimate = 0.054
Significance of Regression (F) = 741.8
% Cac03 Range = 0.1616% to 2.07%
% Efficiency Range, Y = 53% to 92%
Range For Stoichiometric Ratio = 1. 0 to 1. 3
-81-
-------
At several points during the test, the limestone steady-
state composition at R = 1.20 and the predicted limestone con-
centration were coincident, as illustrated in Figure IV-25.
For these points of intersection, all conditions for equation
(IV-II) and (IV-9) or (IV-lO) could be satisfied by a limestone
stoichiometry of 120%.
The computed values for calcium carbonate stoichiometric
ratio for R = 1.0 was included in Figure IV-25 to illustrate
the change in calcium carbonate concentration. Equations (IV-9)
through (IV-II) should be most useful in planning the Shawnee
test program for direct limestone addition to the scrubbing
circuit.
-82-
-------
I
co
W
I
&
1&.1
~
~IO
z
-I
>-
~80
1&.1
(.)70
I&.
;:; 80
at 50
FIG.IV- 25 PROCESS CONDITIONS FOR TAgK C6
~
N !
/
/1 "\ ,, ;/ If""
!/' \\ J) \1 (f' I r\/
2 /- / ........
A. 7 '\ / \- \ / 'I ~ 1"'- I
A.
-
& 1 @/ ' I '-=' ~ \ I
1&1
. 1\ \ , / :
o '" V \ I ~ / ''' " ! I'
~ J
o I
~ , V ~J ~ / (J \ .J
~ i \
1&1 V \
~ i
!2000 I "
~ ~ V \ J
~ 1800
I C! ~'"
0 1.
.,100 ~
I&. \:T ,
0 G:1
zl400 -
\ l/ r" ......-1. :'" r ~
0 ~ "'" ..,
S 1200 ( "
6" '\ ~ &.. ~
& ...........
CI ~ 1000 " / l;
1&.1
0 ~ 800 ""
I '\1 'f
0 .. .1.
U 800 .J ,.. ....... ...
y ~ J 1t"'" ~J
400
~~ ~
- 200
i~
0
o
10
20
30 40 50
HOURS IN OPERATION
80
70
80
2.0
1.8
I. 8 it
~
1.4 ~
If)
1.2 8
c
1.0 u
z
0.8 2
~
c
0.8 &
to-
z
0.4 1&1
(.)
z
0.2 8
0.0
1 WT., CACOa C~:r~I~D
I WT % CACOI STEADY STATE
Rei.!
a WT y. CAcoa STEADY STATE
R=LO
o % EFFICIENCY IN TOWER t Y
o CONCENTRATION OF so! AT
INLET TO TOWER, PPM
-------
v.
CONCLUSIONS
1. Sulfur dioxide absorption with sodium car-
bonate in a FDS contactor can be varied by
controlling the pressure drop across the
venturi throat. Other operating parameters,
i.e. liquid-to-gas ratio, stoichiometric
ratio or S02 concentration did not signifi-
cantly affect performance for the range of
conditions tested.
2. Calcium oxide absorption of S02 is less
efficient than Na2co3 for similar operating
conditions. variations in liquid-to-gas
ratio, stoichiometry, throat pressure drop,
slurry concentration and ionic strength all
affected the S02 absorption efficiency.
sensitivity of these variables indicates a
significant liquid phase mass-transfer re-
sistence.
3. With lime reagent, the scale formation is
rapid and severe. High slurry concentration
(15 to 20% by weight) through the venturi
scrubber did not eliminate the severe encrus-
tation of the FDS internals.
4. Addition of sodium chloride to a slurry of
calcium hydroxide improves the sulfur dioxide
absorption. The increase in ionic strength
with the NaCl simulates, to some extent, the
steady-state conditions for a.closed-lpop
system.
-84-
-------
5. Sulfated lime/fly ash material from the
Shawnee Power Station showed significantly
lower absorption efficiency than the calcium
oxide at comparable operating conditions.
6. Dolomitic lime (CaO.MgO) demonstrated out-
standingly good absorption efficiency for the
single test made.
7. A limestone slurry, circulating through a
high specific-surface packed tower can absorb
greater than 90% of the flue gas S02. Lime-
stone utilization in the experimental tower
was 78% at 1000 ppm S02 and 60% at 1500 ppm
S02. Absorption efficiency is adversely
affected by increasing S02 concentration and
by high slurry concentration. S02 absorption
can be improved by increasing the calcium car-
PonatE~ slurry concentration in the absorbing
liquor.
8. A finely ground limestone (90% - 325 mesh)
increases the S02 absorption by 8 to 10% over
a material with (75% - 200 mesh). Absorption
increases with higher liquor-to-gas ratio in
the tower.
9. Scale formation in a limestone/s02 scrubbing
system can be controlled by maintaining a
reaction product slurry in the absorbing
liquor and by circulating a high liquid flow
-85-
-------
rate through the tower. stagnant
irrigated areas should be avoided
absorber design.
non-
in the
10. The demonstrated ability of the limestone
system to remove S02 to low levels and the
short term significant reduction in scaling
behavior experienced in the present lime-
stone tests indicate the commercial applica-
bility of the system.
-86-
-------
VI.
RECOMMENI)ATIONS
1. Results of the limestone studies indicate
a strong influence of 502 concentration and
slurry composition on efficiency. Further
work in this area is needed to define these
effect:s over a broader range of conditions.
2. Composition of the alkaline solution has a
striking effect on the 502 absorption as was
demonstrated in the experiments varying the
ionic strength and slurry concentrations.
Future studies with lime or limestone should
includ.e, as part of the program, thorough
analyses of the liquor phase.
3. Dolomitic lime demonstrated outstandingly high
absorption efficiency. This material should
be tested in depth in future limestone studies.
4. Scaling 9f the pilot unit with lime slurries
was severe throughout this program. Future
studies with lime injection should be con-
sidered with controlled pH.
5. The high 502 removal efficiency obtained with
limestone plus the promising reduction in
scaling obtained call for a major program
devoted to exploration and exploitation of
these results.
-87-
-------
VII.
REFERENCES
1. Barkley, J., (TVA) , Schwitzgebel, K., (Radian), et. al.,
"Chemical and X-ray Analysis of Samples Taken During The
Runs: C5(11: p.m. 1/21/71) and C6(3:00 p.m. 1/6/71) at
the Tidd Plant in Brilliant, Ohio," Technical Note
200-006-12, February 26, 1971.
2. Letter from Potts, J. M. of TVA to Gleason, R. J. of CES,
January 19, 1971.
3. Lessing, R., "The Development of a Process of Flue Gas
washing Without Effluent", Journal of the Society of
Chemical Industry, November, 1939, p~ 373-388.
4. Chilton, T. H. and Colburn, A. P., "Mass-Transfer Co-
efficients," Industrial Eng. Chem., ~, p. 1183 (1934).
5. Johnstone, H. F., Field, R. B. and Tassler, M.
Absorption and Aerosol Collection in a Venturi
Ind. Eng. Chern., 46, p. 1601 (1954).
C., "Ga s
A tomi zer" ,
6. Galeano, S. F., "Removal and Recovery of Sulfur Dioxide In
The Pulp Mill Industry", Doctoral Dissertation, University
of Florida, 1966.
7. Nukiyama, S. and Tanasawa, Y., Trans. Soc. Mech. Engrs.
(Japan), ~, No. 18, 68 (1939).
8. Pearsop, J. L. Nonhepe1, G. and Ulander, P. H., N.J.,
J. Inst. Fuel VIII 39, 'pp. 119-156 (February, 1935).
9. Lowell, P. S., et. aL, "A Theoretical Description of the
Limestone Injection-Wet Scrubbing Process", Radian Cor-
poration, APCO, Contract No. CPA-22-69-l38, Vol. II, June
9, 1970.
-88-
-------
A P PEN D I X
A
OPERATING CONDITIONS AND RESULTS
For
THE SODIUM CARBONATE AND CALCIUM OXIDE TESTS
-89-
-------
TABLE A-I
CHEMICAL AND PHYSICAL ANALYSIS OF CALCINED LIMESTONE
Particle Size 100%-200 Mesh
Loss on Ignition 3.15% Loss Free Basis
CaO 94.40 97.47
MgO 0.76 0.78
A1203 0.45 0.46
Fe203 0.11 0.11
Si 02 0.96 0.90
C02 0.8
-90-
-------
TABLE A-2
PILOT TEST PLAN
TASK I - Pilot Plant Modification and Calibration
IA - Engineering and Purchasing of additional components,
tank, mix tank, piping, agitators, pumps, etc.
i.e.,
hold
IB - Install hold tank
IC - Install mix tank
ID - Piping modifications and additions to allow for all modes.
IE - Install agitators
IF - Install and calibrate venturi flowrneters for both gas and liquid
flow measurements.
IG - Install and calibrate analytical equipment including S02 analyzer,
NO analyzer, temperature recorder, pH meter, etc.
x
TASK II - Utilization of Sodium Carbonate Slurry For Determination of
optimum Operating Conditions and Maximum Efficiency of
Scrubber
A - Operating as shown in Figure IV-I, 5 levels of 6p, at 5 levels
of gas flow will be tested. (25 tests)
B - Operating as shown in Figure IV-I, tests will be conducted at
four levels of liquid-to-gas ratio, at ~ levels of gas flow.
llftests) .
C - Operating as shown in Figure IV-2, fresh water will be fed to the
venturi and carbonate slurry to the packed tower at 3 levels of
L/G, at 3 levels of 6p and 2 levels of gas flow. (18 tests)
~ASK III - Evaluation of the Contribution of Calcined Limestone to
502 Removal During Capture in the Venturi
III (a) -
Introduce dry calcined limestone to the gas stream at four
stoichiometric levels using standard predetermined operating
conditions and measure S02 removal. Mode of operation is
shown in Figure IV-5. (4 tests).
-91-
-------
TABLE A-2 cont'd
TASK IV - Measurement of the S02 Removal When a Lime Slurry is
Introduced to the Veneuri
IV(a) - As is shown in Figure IV-7, a lime slurry is fed to the venturi
on a once through basis at four concentrations. Measure pH
at venturi sump and hold tank. (4 tests)
TASK V - Measurement of S02 Removal Efficiency When Venturi and
Packed Bed are operated in Series
V (a) -
As shown in Figure IV-S, lime is fed to hold tank; the venturi
and packed tower are operated in series and solids are
accumulated in the clarifier~ For the standard operating
conditions and when steady-state has been achieved, S02' pH
and temperature measurements will be made at all points
shown in Figure 111-1. (1 test)
TASK VI - The Effect of Major Process Variables will Be Studied for
The Integrated venturi-Packed Bed System Where the
Additive is Calcined Limestone
VI(a) - Inject d:y additive into gas stream as per Figure IV-9. Vary
lime sto1chiometry at 4 levels. All other parameters held
constant at standard levels. (4 tests)
VI (b) - With mode as per Figure IV-lO vary L/G ratio. Hold liquid
hold time constant by varying level in hold tank. (3 tests).
VI (c) - Vary bp of venturi at 2 L/G ratios, all other parameters at
constant standard levels. Mode as per Figure IV-IO. (6
tests)
VI (d) - Vary hold time at constant L/G and constant bp.
per Figure IV-IO. (3 tests)
Mode as
VI (e) -
Vary slurry concentration (3 levels) to venturi by dilution
of liquid to venturi with clarifier overflow as per Figure
IV-ll. All parameters held constant except slurry concen-
tration. (3 tests).
VI (f) - Vary ionic strength (3 levels) of scrubbing liquor by salt
addition. Operate as per mode in Figure IV-IO. (3 tests).
VI (g) - Determine power requirements for operating conditions
described in VlI-a through VlI-f from the data obtained.
-92-
-------
TABLE A-2 cont'd
TASK VII - Investigate the Effect of Mode Change
VII (a) -
Add the dry lime to the hold tank and feed the packed bed
recycle directly to the clarifier as per Figure IV-13.
Holding all parameters constant, measure S02 removal.
(1 test)
VII (b) - Split clarifier overflow and underflow between packed bed
and venturi as per Figure IV-B. Measure S02 removal. (1
test)
VII (c) - Deliver clarifier overflow to venturi as shown in Figure IV-l6.
(1 test)
TASK VIII - Investigate the Effect of Changing the Nature of the
Additive
Inject calcined dolometic limestone into the gas stream
as shown in Figure IV-17. Operate at standard constant
conditions and determine S02 removal efficiencies. (1
test)
VIII(d) - Conduct one run with partially sulfated lime/fly ash
mixture feeding the dry additive in the inlet stream as
per Figure IV-17. (1 test)
VIII(C) -
VIII(e) - Conduct one run with partially sulfated lime/fly ash
mixture feeding the lime/fly ash to the hold tank (with
at least one hour hold time) as per Figure IV-19. (1 test)
'~'ASK IX - Data Reduction and Analysis
IX(a) - Data analysis
IX(b) - Tabulation and graphical representations
IX(c) - Work session with NAPCA
~ASK X - Final Report Preparation and Presentation
X(a) - Prepare draft of final report
-93-
-------
TABLE A-2 cont'd
X(b) - Prepare graphics
X(c) - Work session with NAPCA
Xed) - Final draft presentation
X(e) - Reproduction and binding - 200 copies
X(f) - Presentation
PROGRAM MANAGEMENT:
Monthly Reporting
Contract Administration
-94-
-------
-- ..~--~-c'"' .. ~~ ......~---............~-. ---,;--- .-.---------- .
TABLE A-3
TEST RESULTS USED IN FOS SODIUM CARBONATE CORRELATION
Inlet S02 Outlet 502 6P Gas Stoichiometric Liquid ""S Flow Thr03t
Test Concentration Concentration In. Flow Ra tio Rate Inlet Disc Velocity
~ ~ Time ppm ppm ~ ~ ~ Na2C03/S02 -91!!!!..- SCFM Position Ft./Sec.
1 9/23 17:30 1640 920 3.0 395 12.9 3.5 5 406 1 51
2 9/23 18:00 1870 980 4.6 ]95 7.8 3.0 5 508 2 III
3 9/23 18 : ]0 1970 830 2.9 395 7.8 2.88 5 508 3 162
4 9/24 16 : 00 1240 375 8.0 719 7.8 4.32 9 916 0 127
5 9/24 16: 30 1260 260 11.0 719 7.5 4.33 9 916 1 160
6 9/24 17:10 1170 374 8.0 719 7.6 2.36 9 920 0 126
7 9/24 17:20 1170 296 11.2 719 7.8 2.36 9 920 1 iS9
8 9/29 17:00 1150 798 4.3 569 9.6 2.07 8 720 0 96
9 9/29 17:45 1970 865 5.7 569 10.0 1.84 9 707 1 123
10 9/29 18:00 2030 750 9.3 569 9.7 2.03 9 701 2 163
'11 9/30 16:30 1370 890 1.90 246 9.7 4.70 4 300 3 97
12 9/30 16:55 154'0 655 5.3 246 9.7 Ll!; 4 300 3 ~7
13 10/01 8:50 1690 940 1.85 ~~5 8.1. 4.34 5 482 0 66
14 10/01 9:40 1640 940 2.35 395 8.0 4.47 5 482 1 84
is 10/01 9:50 1620 940 4.15 438 7.2 4.08 5 482 2 124
Iii 10/01 10:10 1640 940 11. 85 ]95 8.0 4.43 5 482 3 163
17 10/01 1h15 1550 845 10.75 395 8.0 4.15 5 482 3 163
18 10/01 11: 30 1450 940 0.25 395 8.0 4.43 5 482 2 III
I 19 10/01 11: 40 1500 940 2.15 395 8.0 4.29 5 482 1 84
\0 20 10/01 11:50 1400 940 1.65 ]95 8.0 4.59 5 482 0 66
1.11 21 10/05 17:25 2220 890 4.53 622 9.5 3.97 9 681 0 106
I 22 10/05 18:25 2350 470 16.23 557 10.5 4.27 9 681 2.5 190
23 10/05 18: 37 2160 515 16.23 557 10.6 4.65 9 681 2.5 190
24 10/06 10:45 1870 704 5.80 728 6.7 3.84 8 816 0 128
25 10/06 11:14 1920 680 8.0 728 6.7 3.74 8 816 1 161
26 10/06 11:35 2060 610 14.6 645 7.6 3.94 8 816 2 190
27 10/06 11:45 2060 470 10.0 645 7.6 4.27 8 816 1.5 163
28 10/06 12:00 2010 610 10.0 645 7.6 4.38 8 816 1.5 163
29 10/08 15:50 1000 645 1.65 443 6.8 4.24 5 505 0 77
30 10/08 16:05 1020 625 2.30 399 7.7 4.54 5 504 1 88
31 10/08 16: 35 1000 400 14.45 399 7.7 4.61 5 504 3 171
32 10/08 16:55 1000 175 28.75 399 7.8 4.59 5 501 3.75 254
3] 10/08 18:06 1000 350 12.25 719 7.5 4.49 9 908 0 128
34 10/08 17:55 lOuv 324 12.25 719 7.., 4.57" 9 90a 0.5 143
35 10/08 171]0 1000 275 15.:;'5 8"2 6.8 4.10 9 908 1.5 206
36 10/08 17:20 1000 250 20.05 719 7.6 4.47 9 904 2 215
37 10/06 10110 1830 470 14.15 449 13.7 3.78 10 492 3 192
38 10/06 15130 18]0 515 14.15 (CQ 13.7 3.78 10 .!lZ 3 192
39 10/07 14115 1920 515 14.40 524 7.1 5.23 6 589 2.80 205
40 10/07 15105 1870 515 14 .40 524 7.1 5.37 6 589 2.80 205
41 10/07 15:05 1750 515 14.40 521 9.4 5.77 8 585 2.80 203
42 10/07 15:25 1700 470 14.40 521 9.4 6.02 8 585 2.80 203
43 10/07 16:30 1110 238 14.40 524 11.8 5.35 10 573 2.70 197
44 10/07 16:40 1080 2"34 14.40 524 11.8 5.50 10 573 2.70 197
45 10/07 16:50 1110 234 14.40 524 14.1 5.35 12 573 2.5 182
46 10/07 17:00 1080 210 14.40 524 14.1 5.50 12 573 2.5 182
\
"' 1. Velocities based on inlet gAS conditions
!
.. '
-------
TABLE A-4
.
OPERATING CONDIT:IONS FOR TASK !:II
Date 10/21 10/21 10/21 10/21 10/21 10/21 10/21 10/21 10/21 10/21 10/21
Time 13:55 13:55 14:47 15:15 15:45 11:05 11: 30 11:45 10:00 10:25 10:40
Gas Flow, cfm 1021 1021 1021 1021 1021 1027 1024 1024 1037 10U 1024
FDS L/G ratio, qa1/mcf 6.8 6.8 7.0 6.9 6.9 7.0 6.5 6.8 6.6 6.5
Tower L/G, ratio, ga1/mcf 14.2 14.2 ;1.4 . 2 14.2 14.2 7.1 7.1 7.1 7.1 7.1
Gas Velocity FDS, ft/sec 181 152 152 181 181 184 184 184 186 184 184
Tower pressure drop, inches H20 0.7 0.7 0.7 0.7 0.7 0.6 0.7 0.7 0.7 0.7 0.7
FDS pressure drop, inches H20 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.8. 10.0 10.0 10.0
CaO/S02 ratio 2.25 2.52 1.86 1.99 2.13 1.53 1.-47 1.53 0.97 2.75 0.98
5°2 concentration, ppm 640 605 640 622 675 875 807 775 972 960
FDS in
FDS out 337 337 404 320 404 505 505 470 672 640
Tower out 202 202 202 236 0 278 135 218 219 118
Fraction of 502 removed, ,
FDS 47.3 44.3 36.9 ~8.6 40.2 42.::1 37.4 39.4 3C.9 33.3
Tower 40.1 40.1 50.0 26.3 100.0 45.0 73.3 53.6 67.4 81.t:
Overall 68.5 66.6 68.4 62.0 100.0 68.2 83.3 71.8 77.4 87.7
I Gas Temperatures, of.
\D FDS in 338 338 338 338 338 340 338 338 348 342 338
0'1 FDS out 105 105 105 105 105 105 105 105 IDS 108 105
I Tower out 72 72 70 70 70 99 88 88 88 88 88
Liquid Temperatures, of.
FDS in 62 62 64 62 62 62 62 62 62 62 62
FDS out 98 98 98 98 98 98 98 98 98 98 98
Tower in
Tower out 95 92 92 92 92 100 100 100 100 100 100
pH Measurements
Tower outlet
FDS outlet 11.4 11.4 11.0 10.8 10.8 10.7 11.3 11.3 6.5 7.6 8.2
Hold Tank
Clarifier tank
Disc Position 1.30 1.30 1.30 1.90 1.90 1.94 1.94 1.94 1.94 1.94 1.94
Pressure at outlet, in. Hg gau$le -1.7 -1.7 -1.8 -1.8 -1.8 -1.8 -1.8 -1.8 -1.8 -1.8 -1.8
* L/G on FDS based on inlet qas conditions.
- .
-------
TABLE A-4 cont'd
*
OPERATING CONDITIONS FOR TASK III
Date 10/22 10/22 10/22 10/22
Time 15:20 15:50 15:50 16:15
Gas Flow, efm 1030 1030 1030 1030
FOS L/G ratio, gal/mcf 6.7 6.7 6.7 6.7
Tower L/G, ratio, ga1/mef 14.2 14.2 14.2 14.2
Gas Velocity FOS, ft/see 182 182 182 182
Tower pressure drop, inches H20 0.8 0.8 0.8 0.80
FOS pressure drop, inches H20 10.0 10.0 10.0 10.0
CaO/SO ratio 0.80 0.80 1.15 1.04
S02 eo~centration, ppm
FOS in 1275 1275 1260 1345
FOS out 925 925 872 975
Tower out 455 404 353 370
Fraction of S02 removed, ,
PDS 27.5 27.5 30.8 27.5
I Tower 50.8 56.3 59.5 62.1
\D OVerall 64.3 68.3 72.0 72.5
-..J Gas Temperatures, of.
I FOS in 350 350 350 360
FOS out 108 102 102 112
Tower out 72 72 72 88
Liquid Temperatures, .op.
FOS in 62 62 62 70
FOS out 100 95 95 108
Tower in
Tower out 95 95 92 102
pH Measurements
Tower outlet
FOS outlet 8.1 7.8 8.8 5.5
Hold tank 12.0
Clarifier tank
Disc Position 1.90 1.90 1.90 1.75
Pressure at outlet, in. Bg gauge -1.8 -1.8 -1.8 -l.q
-------
..
'!'ABLE A-5 -
"
OPERATING CONDITIONS FOR TASK IV
Date 10/27 10/27 10/27 10/27 10/27 10/27 10/27 10/27 10/27 10/27
Time 11 : 55 12:05 10:55 11: 20 11 :45 9:35 10:00 15:30 15:50 14 :20
Gas Flow, cfm 1049 1049 1049 1049 1049 1047 1047 1049 1049 1047
FDS L/G ratio, ga1/mcf 6.6 6.6 6.9 6.8 6.0 6.0 6.4 6.6 6.7
Tower L/G, ga1/mcf 7.1 7.1 21.3 21.3 21.3 21.3 21.3 21.3 21.3
Gas Velocity FDS, ft/sec. 177 177 177 177 177 177 177 177 177 177
Tower pressure drop, inches H20 0.8 0.8 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
FDS pressure drop, inches H20 9.7 9.7 10.0 10.0 10.0 10.0 10.0 9.9 3.8 10.0
CaO/SO ratio 0.78 0.78 0.75 0.96 1.39 1.33 1.15
S02 co~centration, ppm
FD5 in 1580 1580 1640 1600 1600 1600 1640 1680 1760 1600
FDS out 940 940 1000 980 960 940 882 882 882 962
-Tower out 600 600 no 520 450 300 225 330 330 375
Fraction of 5°2 removed, ,
I FD5 40.5 40.5 39.0 38.8 -40.0 41.3 46.2 47.5 49.9 39.9
\0 Tower 36.2 36.2 26.0 46.9 52.1 68.1 74.5 62.6 62.6 61.0
co Overall 62.0 62.0 54.9 67.5 71.3 81.2 86.3 80.4 81.2 76.6-
I Gas Temperature, of.
FDS in 360 360 360 360 360 358 358 360 360 358
FDS out 112 112 110 110 108 105 110 105 105 108
Tower out 88 92 68 68 68 68 58 65 65 68
Liquid Temperature, of.
FDS in 70 70 70 70 70 72 72 65 68 68
FDS out 108 106 108 108 108 104 108 102 102 105
Tower in
Tower out 102 105 92 92 92 88 92 88 88 92
pH measurements
Tower outlet
FDS outlet 5.5 5.6 5.4 5.5 5.5 5.7 5.7 7.4 7.2 5.7
Hold Tank 12.0 12.0 12.0 12.0 12.0 12.0 12.0 12.0 12.0 12.0
Clarifier Tank
Disc Position 1. 75 1.75 1. 75 1.75 1. 75 1.75 1.75 1.75 1.75 1.75
Pressure at outlet, in. Hg gauge -1.8 -1.8 -2.0 -2.0 -.l.O -2.0 -2.0 -1.9 -1.9 -2.0
*
L/G on FDS based on inlet gAs conditions.
-------
TABLE A-6
OPERATING CONDITIONS FOR T~~K V
Date 2/4 2/4 2/9 2/9 2/10 2/11 2/11 2/15 2/15
Time 1500 1620 1300 1700 1445 1100 1430 2000 2130
Gas Flow, cfm 700 700 700 700 700 700 700 700 700
FDS L/G ratio, gal/mef 18 18 18 .18 18 18 18 18 18
Tower L/G, ratio, gal/mcf 15 15 15 15 15 15 15 15 15
Gas Velocity FDS, ft/sec * 118 118 78 80 93 77 77 77 77
Tower pressure drop, inches H20 0.4 0.4 0.4 0.4 0.4 0.4 0.3 0.4 0.4
FDS pressure drop, inches H20 6.0 6.0 6.0 6.0 6.5 11.4 22.0 7.0 9.1
Cao/s02 ratio 0 0 0.58 0.71 0.69 1.23 1.11 0.93 1.43
'S02 conce~tration, ppm
FDS ~n 1320 1310 1360 1080 1460 1820 1660 2000 2000
FDS out 1120 1125 124 620 830 860 700 1070 1035
Tower out 770 775 560 290 605 440 440 450 380
Fraction of s02 removed, ,
FDS 15 14.1 42.7 43.2 42.3 58 46.4 53.0
Tower 31.3 31.2 53.3 27.2 48.8 37 58.0 63.4
I OVerall 41.5 40.9 58.9 73.2 58.5 75.8 73.5 77.5 82.7.
\0
\0 Gas temperatures, OF
I FDS in 348 346 348 352 365 370 362
FDS out 119 110 120 120 128 129 122 130 131
Tower out 90 92 112 115 115 118 118 115 121
Liquid temperatures, of
FDS in 105 98 . 118 110 121 124 112 115 118
FDS out 118 110 122 122 128 129 122 1'30 131
Tower in 108 98 118 114 123 125 118 118 118
Tower out 111 106 120 120 126 128 122 129 130
-' Clarifier 60 70 112 113 113 110 112 101 112
pH measurements <2
Tower outlet <2 2.6 5.1 4.2 4.5 5.7 6.0 5.9
PDS outlet °2.4 2.0 5.6 5.1 5.4 6.4 8.8 7.6 10.1
Hold tank tanki 4.4 4.0 11.8 11.4 11.4 11.1 11.1 10.9 10.9
Clarifier 4.4 3.0 5.8 5.6 5.6 6.1 10.1 11.2 10.7
Disc Position 1.5 1.5 0.1 0.2 0.8 0 0 0 0
* .Gas velocity through the tower for all tests in this series was
8.6 ft/sec.
-------
TABLE A-7
OPERATING CONDITIONS FOR TASK VI-a
Date 2/16 2/16 2/17 2/17 2/17 2/17 2/18 2/18
Time 1020 1115 1130 1430 1745 1830 1400 1730
Gas Flow, cfm 700 700 700 700 700 700 700 700
FDS L/G ratio, 9a1/mcf 18 18 18 18 18 18 18 18
Tower L/G ratio, qa1/mcf 15 15 15, 15 15 15 15 15
Gas Velocity FDS, ft/sec 77 77 77 99 77 77 77 77
Tower pressure drop, inches H20 0.3 0.3 0.4 0.4 0.7 0.7 0.8 0.8
FDS pressure drop, inches H20 6.0 6.0 5.0 6.2 6.0 6.0 7.7 7.7
CaO/SO ratio 0.89 0.96 1.62 1.14 1.12 1.09 0.96 0.985
S02 co~centration, ppm
FDS in ' 2280 2160 1515 1635 1680 1680 1485 1500
FDS out 2010 1320 780 875 840 660 885 900
Tower out: 1600 1040 20 0 0 0 0 0
I Fraction of S02 removed, ,
I-' FDS 12.7 39.0 51.5 46.5 50.0 60.7 40.5 40.0
o Tower 20.4 21.2 97.3 100 100 100 100 100
o Overall 29.8 51.9 99 100 '''n 100 100 100
I Gas temperatures, OF
FDS in
FDS out 135 132 135 135 142 140 135 128
Tower out 118 118 125 129 138 138 126 124
Liquid temperatures, of
FDS in 118 118 120 123 144 142 135 126
FDS out 138 136 136 135 144 142 138 132
Tower in 122 122 125 128 146 146 136. 128
Tower out * 72 72 81 78 80 80 136 132
Clarifier 112 112 115 125 136 136 116 118
pH Measurements
Tower outlet 5.8 .4.8 5.8 7.3 8.0 8.0 5.1 5.0
FDS outlet 12.0 12.0 10.5 10.7 11.0 11.0 11.8 10.5
Hold tank 3.7 3.7 4.2 6.3 5.8 7.0 4.4 4.2
Clarifier tank 6.0 6.2 11.6 11.6 11.6 11.6 11.1 10.7
Disc Position 0 0 0 1.0 0 0 0 0
* Tower out thermocouple was not workinq for low value readin9s.
-------
TABLE A-a
OPERATING CONDITIONS FOR TASK VI-b
Date 2/24 2/24 2/24 2/24 2/24 2/24 2/24 2/24 2/24
Time 1100 1215 1315 1400 1500 1600 1730 1800 1830
Gas Flow, cfm 700 700 700 700 700 700 700 700 700
FDS L/G ratio, ga1/mcf 18 18 18 10 10 10 23 23 23
Tower L/G ratio, ga1/mcf 15 15 15 15 15 15 15 15 15
Gas Velocity FDS, ft/sec 81 81 77 96 99 99 77 77 71
Tower pressure drop, inches H20 0.6 0.6 0.6 0.5 0.6 0.6 0.6 0.6 0.6
FDS pressure drop, inches H20 6.0 6.0 6.0 5.8 6.1 5.9 6.4 6.8 6.8
CaO/SO ratio 1.05 1.11 1.21 0.93 0.81 1.06 1.01 1.07
S02 co~centration, ppm
FDS in 1350 1350 1410 1650 1800 1860 1920 2060
I FDS out 720 690 840 1080 1200 990 1020 945
..... Tower out. 100 188 460 680 800 640 780 640
o
..... Fraction of S02 removed, ,
I FDS 46.5 49.0 40.5 34.5 32.5 46.8 41.0 54.3
Tower 86.2 72.6 45.3 37.0 33.2 35.3 23.5 32.3
Overall 92.6 . 86.0 68.3 59.0 55.5 65.6 59.4 69.0
Gas temperatures, of
FDS in 320 320 320 335 335 355 360 360 360
FDS out 140 150 152 155 152 152 140 150 150
Tower out 122 140 148 150 150 148 135 148 140
Liquid temperatures, of
FDS in 122 142 149 150 150 142 12~ 142 142
FDS out 138 150 152 156 155 152 138 150 150
Tower in 142 154 159 160 148 142 138 150 152
Tower out 138 150 150 153 150 150 138 144 146
Clarifier 122 138 145 152 148 140 120 135 136
pH Measurements
Tower outlet 5.2 5.2 5.2 5.1 5.0 5.1 5.7 5.8 5.1
FDS outlet 9.8 9.6 9.3 9.5 9.4 9.4 9.8 9.8 9.8
Hold tank 10.8 10.2 10.2 10.2 10.8 9.8 9.6 10.0
Clarifier tank 11.2 10.7 10.4 10.3 10.4 10.4 10.6 10.6 10.6
Disc position 0.25 0.25 0 0.9 1.0 1.0 0 0 0
Hold tank volume 470 460 460 280 250 250 650 690 590
-------
TABLE A-9
OPERATING CONDITIONS POR TASK VIC
* * * *
Date 3/30 3/30 3/31 3/31 4/1 4/1 4/1 4/1 4/5 4/7 4/7 4/7 4/7
Time 1400 1630 1000 1200 1000 1200 1400 1700 1545 1130 1330 1600 2000
Gas Flow, elm 700 700 700 700 700 700 700 700 680 700 700 700 700
FDS L/G ratio, qa1/mef 10 10 10 10 10 10 10 10 10.3 10 10 10 10
Tower L/G, ratio, qa1/mef 15 15 15 15 15 15 15 15 15.4 15 15 15 15
Gas Velocity FDS, ft/see 162 138 151 130 142 124 143 181 197 277 231 194 195
Tower pressure drop, inehes H20 0.5 0.6 0.6 0.7 0.6 0.7 0.7 0.8 0.7 0.6 0.7 0.8 0.8
FDS pressure drop, inches H20 6.5 6.4 6.0 6.5 6.3 6.2 6.1 12.0 12.0 12.6 12.7 11.7 13.0
CaO/SO ratio 1.04 0.97 1.04 1.21 0.96 1.02 1.00 0.97 1.02 1.01 1.04 1.24 0.96
S02 co~centration, ppm
FDS in 1935 1860 2160 1680 1920 2040 1890 2040 1920 2220 1765 1485 1530
FDS out 960 810 1110 1080 1120 1170 1080 1200 1200 810 415 363 450
Tower out 98 360 540 510 570 600 600 760 58 360 146. 116 190
Fraction of S02 removed, ,
FDS 50.4 56.5 48.6 35.7 41.7 42.6 42.9 41.2 37.5 63.5 76.5 75.6 70.6
Tower 89.8 55.6 51.4 52.8 49.1 48.7 44.4 36.7 95.2 55.6 64.8 68.0 57.8
I OVerall 94.9 80.6 75.0 69.6 70.3 70.6 68.3 62.74 97.0 83.8 91.7 92.2 87.6
.....
0 Gas Temperatures, .P. .
IV FDS in 335 330 342 342 355 355 358 355 345 336 338 335 338
I FDS out 115 118 118 120 118 122 122 120 112 115 118 118 115
Tower out 100 .108 102 110 108' 115 118 115 105 105 1~8 110 106
Liquid temperatures, .P.
FDS in 98 108 104 110 104 11S 118 108 108 110 114 113 110
FDS out 115 118 118 120 118 122 122 118 118 118 118 118 118
Tower in 100 114 118 118 104 120 124 105 118 120 118 123 110
Tower .'ut 115 116 116 120 112 118 122 118 114 115 118 118 114
pH measurements 4.1 C.5
ToweL outlet 4.2 4.8 4.7 4.8 . 4.0 4.1 5.0 4.5 3.6 3.9 3.8
FDS outlet 11.0 10.9 11.3 U.1 11.2 11.2 11.1 11.2 11.8. 11.7 11.7 11.8 11.8
Hold tank 11.8 11.5 11.3 11.5 11.1 11.3 11.0 11.6 10.8 9.7 11.1 11.4 11.4
Clarifier tank 11.8 11.2 11.1 11.1 11.1 11.0 11.2 11.3 11.4 9.9 11.3 11.2 11.2
Disc Position 1.5 '1.0 1.25 0.75 1.0 0.5 1.0 1.75 2.0 2.8 2.4 2.0 2.0
Pressure at outlet, in. Hq qauqe -1.4 -1.6 -1.6 -2.2 -2.6 -3.0 ,:,,2.6 -2.4. -2.4
* Efficiency measurements made durinq these tests were
considered in error because of air in1eakaqe at the
FDS discharqe.
-------
TABLE A-9 cont'd
OPRRA'l'ING .~I'1'IONS FOR 'l'ASK VIe
Date 4/13 4/13 4/14 4/14 4/14 4/14 4/14 4/14 4/14 4/15 4/15 4/15 4/15 4/15 4/15
Time 1045 2235 1030 1130 1240 1545 1800 1900 21.20 1015 1145 1245 1500 1630 1730
Gas Plow, cfm 700 700 700 700 700 700 700 700 700 700 700 700 700 700 7<'0
FDS L/G ratio, ga1/mef 10 10 10 10 10 20 20 20 10 20 20 20 20 20 20
Tower L/G, ratio, gal/mef 15 15 15 15 IS 15 IS IS 15 15 15 15 15 15 15
Gas Veln~ity FeS, ft/sec ISO 172 173 192 190 192 194 149 148 151 150 103 110 111
Tower ~ressure drop, inches H20 0.9 1.7 1.4 1.6 1.9 1.8 1.9 1.7 . 1.9 1.4 1.4 1.4 1... 1." 1.5
res pressure drop, inches H20 17.5 18. 18.1J 18.2 12.5 18.7 19.3 19.8 12 12.5 12.7 13.1 8." 9." 10.1
CaO/S02 ratio 1.02 1.08 1.04 1.10 1.16 1.00 1.05 1.03 1.07 0.99 0.93 0.78 0.92 0.94 1.03
502 concentration, ppm
FDS in 1740 1740 1740 1665 1620 1380 1380 1380 1390 1530 1575 2070 2055 2025 1990
ros out 540 780 705 720 600 620 630 735 7An 750 945 870 825 780
Tower out 350 0 76 42 32 72** 300" 300" 510" 540 528 552 414 372 3J4
'Fraction of 5°2 removed, ,
rDS 69.0 55.2 57.7 55.5 56.5 55.1 54.3 46.7 49.0 52." 54.3 57.7 59.3 58.7
TO'o;er 100 90.3 94.0 95.6 88.0 51.6 52.4 30.61 30.8 29.6 41.6 52.4 54.9 57.2
I 0... e !"I\ 11 79.9 100 95.6 97.5 98.0 94.8 78.3 78.3 63.0 64.7 66.5 73.3 79.9 81.6 82.3
...... C1as Te:n:,eri\ tures, eF.
0 f'uS in 335 320 315 310 323 315 325 332 330 298 315 308 310 310 318
W
I FOS out 112 112 115 117 118 112 120 118 118 115 115 115 115 115 118
Tower out 103 106 107 109 112 105 110 112 112 113 III 111 110 110 110
Liquid te~peTatures, .P.
ros in 103 111 113 115 107 112 112 115 115 111 110 110 110
ros out 117 114 121 120 121 115 118 118 118 119 118 117 115 118 116
Tower in 115 112 116 118 118 109 112 112 112 115 110 112 110 110 112
Tower out 115 112 115 115 117 112 116 114 116 116 115 114 115 115 114
pH lIIeasurem",nts
Tower outlet 2.6 4.0 4.5 4.7 4.2 4.6 4.5 4.0 4.2 4.2 4.2 4." 4.5 4.4
ros outlet 11.8 11.0 12 12 12.0 11.0 10.8 10.8 10.2 11.1 11.1 10.9 11.2 10.5 10.5
Hold tank 10.8 10.2 11.2 11.2 11.1 11.1. 11.2 11.2 11.2 11.0 11.1 11.0 11.1 11.0 10.8
Clarifi~r tank 11.1 11.0 11.0 11.0 11.0 10.7 10.5 10.5 10.4 10.8 11.1 11.1 11.3 11.3 11.3
Disc Position 1.25* 4.0 1.75 1.75 2.0 2.0 2.0 2.0 1.:'.5 1.37 1.37 1.37 0 .25 .25
Pressure at outlet, 1n. Kg gauge -2.7 -2.6 -2.8 -2.8 -2.45 -2.7 -2.7 -2.7 -2.2 -2.1 -2.1 -2.1 -1.9 -2.0 -2.1
~ Some scale WAS deposited on the FDS at this time, subsequent reading is a cleaned disc.
** Water flow to the packed tower to remove the scale build-up.
-------
TABLE A-9 cont'd
OPBRA'nRG CONDITIONS POR TASK VIC
Date 4/15 4/15
Time 2030 2200
Gas Plow, cfm 700 700
FOS L/G ratio, gal/met 20 20
Tower L/G, ratio, gal/met 15 15
Gas Velocity FOS, ft/sec 112 112
Tower pressure drop, inches H20 1.8 1.8
F08 pressure drop, inches H20 7.6 8.0
CaO/SO ratio 1.02 1.02
S02 co~centration, ppm
FOS io 1800 1800
F08 out 810 810
I Tower put 386. 396
I-' Fraction of 8°2 removed,'
0 FOS 55.0 55.0
olio
I Tower 52.3 51.1
OVerall 78.6 78.0
Gas Temperatures, oPe
FDS in 325 325 .
PDS out 118 118
Tower out 112 112
Liquid temperatures, oPe
PDS in 110 110
FOS out 118 118
Tower in 112 112
Tower out 114 114
pH measurel\'ents
Tower outlet 4.8 4.8
FOS outlet 11.6 11.7
Hold tank 11.0 11.0
Clarifier tank 11.0 11.0
018C Position .25 .25
Pr...ure at outlet, in. B9 gauge -1.9 -1.9
-------
TABLE A-10
OPERATING CONDITIONS FOR TA~l( n-cl
Date 2/25 2/25 2/25 2/25 2/25 2/25 2/25 2/25
Time 0900 1015 1120 1140 1245 1405 1535 1645
Gas Flow, cfm 700 700 700 700 700 700 700 700
FDS L/G ratio, qal/mef 18 18 ... 16 18 18 19 18
.L..
Tower L/G ratio, qa1/mcf 15 15 15 15 15 15 15 15
Gas Velocity FDS, ft/sec 77 77 77 77 77 77 77
Tower pressure drop, inches H20 0.5 0.5 0.6 0.5 0.6 0.6 0.6
FDS pressure drop, inches H20 6.0 5.8 5.8 5.8 5.6 5.6 6.0
CaO/SO ratio 1.00 1.06 0.98 0.99 1.18 1.0 1.08 0.93
S02 co~centration, ppm
FDS in 1920 1935 1950 1650 1665. 1530 1650
FDS out 1110 1110 900 900 840 960
Tower out 520 660 380 380 300 UO
Fraction of 502 removed, ,
FDS 42.5 43.0 45.5 45.9 45.'1 41.7
Tower 53.1 40.6 57.7 57.7 64. 54.2
OVerall 73.1 66.2 77.0. 77.2 80.4 73.3
I Gas temperatures, OF
~. FDS in 320 320 320 320 315 320 320
o
U1 FDS out 138 138 144 142 138 138 132
I Tower out 125 125 134 142 137 135 128
Liquid temperatures, of
FDS in 122 122 134 142 138 135 122
FDS out 138 138 140 146 140 138 130
Tower in 138 138 148 150 145 110 125-
Tower out 135 135 140 142 138 135 130
Clarifier 118 118 132 140 138 130 115.
pH Measurements
Tower outlet 5.8 6.2 5.9 6.0 5.9 5.8
FDS outlet 10.0 9.0 9.8 9.8 11.4 11.3
Hold tank 11.0 11.0 11.2 11.4 11.4 11.2
Clarifier tank 10.0 10.8 11.3 11.3 11.4 11.3
Disc position 0 0 0 0 0 0 0 0
Hold tank volume 6(,0 600 600 400 400 400 250 280
* pH on the FDS outlet fluctuated with the variations in flow from
the demister. Chart readinq was an estimate of pH durinq hiqh
flow conditions.
-------
TABLE A-II
OPERATINl; CONDITIONS POR 'rASK vre
Date 5/5 * 5/5 * 5/5 * 5/5 * 5/5 5/5 5/6 5/6 5/6 5/6 5/6 5/6
Time 0930 1030 1115 1330 1500 1600 1045 1220 1320 1500 1600 1100
Gas Flow, cfm 700 700 700 700 700 700 700 700 700 700 700 100
FDS L/G ratio, ga1/mcf 10 10 10 10 10 10 10 10 10 10 10 10
Tower L/G ratio, gal/mcf 15 15 15 15. 15 15 15 15 15 15 15 15
Gas Velocity FDS, ft/sec. 175 176 112 112 113 113 104 127 127 104 104 104
Tower pressure drop, inches H20 0.4 0.4 0.4 0.6 0.65 0.7 0.6 0.6 0.6 0.6 0.6 0.6
FDS pressure drop, inches H20 6.8 7.3 7.4 7.0 6.4 7.4 6.5 7.8 7.8 7.3 7.5 1.8
CaO/SO ratio 1.12 1.01 1.01 068/108 1.17 1.42 1.03 loll 1.23 0.92 0.83 1.07
502 cogcentration, ppm
FDS in 1755 1620 1620 2200 2160 1800 2020 1980 1780 1780 1710 1680
FDS out 1065 1050 1020 1320 1110 960 1010 1015 870 930 900 870
Tower out 416 221 266 480 292 130 176 244 209 130 150 130
Fraction of S02 removed, ,
FDS 39.3 35.2 37.0 40.0 48.6 46.7 50.0 48.7 51.1 47.8 47.4 48.2
Tower. 60.9 79.0 73.9 63.6 73.7 86.5 82.6 76.0 76.0 86.0 83.3 85.1
I Overall 76.3 86.4 83.6 78.2 86.5 92.8 91.3 87.7 88.3 92.7 91.2 92.3
....
0 Gas Temperature, of.
0\ FDS in 328 330 328 330 335 335 322 322 322 320 320 322
I FDS out 112 116 116 118 120 120 118 118 118 120 118 118
Tower out 106 108 108 112 115 116 110 110 110 112 112 114
Liquid Temperature, of.
FDS in 100 106 105 108 110 110 104 104 102 108 108 108
FDS out 102 110 105 106 105 106 98 105 96 98 94 96
Tower in 96 106 102 104 110 112 102 102 104 106 106 108
Tower out 110 118 115 118 120 120 118 118 118 120 118 118
pH measurements
Tower outlet 3.6 3.8 3.8 2.4 2.3 2.0 2.0 2.4 2.2
FDS outlet 11.6 11.4 11.4 11.8 11.2 11.8 11.4 11.5 11.5 11.3 11.4
Hold tank 11.8 11.5 11.5 11.4 11.!i' 10.3 11.6 11.3 11.3 11.3 11.2
Clarifier tank 11.0 11.0 11.0 11.1 11.2 11.4 11.0 11.2 11.3 11.3 11.2
Disc Position 1.75 1.15 0.25 0.25 0.25 0.25 0 0.75 0.75 0 0 ('
Pressure at outlet, in. Hg gauge -1.6 -1.6 -1.6 -2.1 -2.0 -2.0 -1.6 -1.6 -1.6 -1.6 -1.6 -1.6
Slurry Concentration to FDS, 6.7 6.4 6.6 3.4 3.8 3.6 1.1 1.4 1.8 5.8 6.0 6.7
weight'
. These tests were not considered at 8steady statew. 6\ slurry
tests were repeated at the end of this test series, 5/6/71.
-------
~
TABLE A-12
OPERA'l'IHG CCNDI'nONS POR 'I'M!!: VI:,.
Date 4/16 4/16 4/16 .4/16 4/16 4/16 4/16 4/16
Time 1130 1230 1330 1515 1615 1900 2000 2200
Gas Plow, cfm 700 700 700 700 700 700 700 700
FDS L/G ratio, qa1lmcf 10 10 10 10 10 10 10 10
Tower L/G, ratio, qa1/mef 15 15 15 15 15 15 15 15
Gas Velocity PDS, ft/sec 119 118 118 104 104 104 104 104
Tower pressure drop, inches H20 1.6 2.2 2.1 2.9 3.0 3.2 3.0 2.9
FDS pressure drop, inches H20 6.7 6.8 7.2 8.2 8.6 6.0 6.0 6.0
CaO/SO ratio 1.23 1.13 1.02 1.05 0.99 1.00 1.60 0.87
S02 co~centration, ppm
FDS in 1650 1770 1950 1860 1980 1950 1231'1 1380
I FDS out 600 750 900 840 870 900 570 631'1
~ Tower out 324 273 312 48 72 84 120 132
o Fractj.on of. S02 removed, ,
-..J FDS 63.6 57.6 53.8 54.8 56.0 53.8 53.7 54.3
I Tower 46.0 63.6 65.3 94.3 91.7 90.7 78.9 79.0
OVerall 80.4 84.6 84.0 97.4 96.4 95.7 90.2 90.4
Gas temperatures, of.
FDS in 325 315. 315 318 318 322 320 320
FDS out 115 115 115 114 116 119 118 119 -
Tower out 113 110 115 110 110 118 118 118
Liquid temperatures, of.
FDS in 110 110 110 112 112 112 112 112
FDS out 120 120 122 125 124 130 130 130
Tower in 110 110 110 112 112 114 114 114
Tower out 115 115 115 115 116 118 118 118
pH measure."r.ents
Tower outlet 4.4 5.7 5.7 7.0 6.7 5.4 6.5 6.2
FDS outlet 10.7 11.4 11.2 11.5 11.4 11.2 11.4 11.4
Hold tank 11.2 11.4 11.3 11.5 11.4 11.8 11.7 11.6
Clarifier tank 11.2 11.2 11.2 11.2 11.2 10.8 10.9 11.0
Disc Position 0.5 0.5 0.5 0 0 0 0 0
Pressure at outlet, in. Hq qauqe . -1.8 -1.8 -1.8 -1.9 -1.9 -2.0 -2.0 -2.0
NaCl Ionic Strength, I 1 1 1 2 2 4 4 4
-------
TABLE A-13
POWER REQUIREMEN'l'S FOR TASKS VIa, b, c, AND d
Gas Ap Ap Liquid Rates Horsepower (Slurrv) Horsepower (qas )
Rate FOS Tower FOS Tower Clarifier FOS. Tower Clarifier FOS Tower' Total Horsepower/ '
Task No. cfm '!!2Q." H 0" 5I?!! ~ qpm Pump Pump Pump (100' Efficiency) Horsepower Megawatt
-2-
I I
.....
I 0 VIa 700 7 .8 12.6 10'.5 12.6 0.086 0.092 0.085 0.769 0.087 1.119 3.6
I en
I
VIb 700 6 .6 12.6 10.5 23.1 0.085 0.092 0.165 0.659 0.0659 1.067 3.4
VIb 700 6 .6 7 10.5 17.5 0.042 0.092 0.124 0.659 0.0659 0.983 3.2
VIb 700 6 .6 16.1 10.5 26.6 0.118 0.092 0.192 0.659 0.0659 1.197 3.8
VIc 700 12 .8 7.0 10.5 17.5 0.042 0.092 0.124 1.31 0.0800 1.648 5.3
VId 700 6 .6 12.6 10.5 23.1 0.085 0.092 0.124 0.659 0.0659 1-.026 3.3
-------
TABLE A-14
OPERATING CONDITIONS FOR TASK VIla
Date 5/10 5/11 5/11 5/11 .
Time 1745 1015 1140 ..1500
Gas Flow, efm 700 700 700 700
FDS L/G ratio, qal/mef 10 10 10 10
Tower LIG, ratio, qa1/mef 15 15 15 15
Gas Velocity FDS, ft/sec 105 105 105 112
Tower pressure drop, inches H20 0.6 0.6 0.6 0.6
FDS pressure drop, inches H20 6.8 6.5 8.5 7.1
CaO/SO ratio 0.81 1.0 1.1 1.0
S02 co~centration, ppm
FDS 'in 1845 1860 1610 1500
FDS out 1290 900 750 780
Tower out 471 468 480 325
Fraction of 502 removed, ,
I FDS 30.1 51.6. 53.4 48.0
.... Tower 63.5 48.0 36.0 58.3
o
\0 OVerall 74.5 74.8 70.2 78.3
I Gas Temperatures, eF.
FDS in 330 330 325 330
FDS out 118 118 117 118
Tower out 110 108 110 112
Liquid temperatures, eF.
FDS in 108 100 102' 100
FDS out 95 100 100 108
Tower in 105 100 102 102
Tower out 118 115 117 108
pH measurements ~.9
Tower outlet 3.4 4.6 4.6
FDS outlet 5.8 11.6 11.8 11.2
Hold tank 11.0 11.6 11.6 11.5
Clarifier tank 11.1 10.7 6.7 11.0
Disc Position 0 0 0 0.25
Pressure at outlet, in. Hq qauqe -1.4 -1.5 -1.6 -1.6
slurry ConeentratioD to PDS, 22.4
. ~ V8iC)ht
-------
TABLE A-IS
. OPERATING CONDITIONS FOR TASK VIIb
Date 5/13 5/13 5/13 5/13
Time 1400 1530 1630 1730
Gas Flow, cfm 700 700 700 700
FDS L/G ratio, qa1/mcf 10 10 10 10
Tower L/G ratio, qa1/mcf . 20 20 20 20
Gas Velocity FDS, ft/sec. 104 105 105 105
Tower pressure drop, inches H20 0.8 0.9 1.0 1.1
FDS pressure drop, inches H20 7.1 5.8 6.1 6.1
CaO/SO ratio 0.99 1.0 0.98 0.97
S02 co~centration, ppm
FDS in 1860 1830 2040 1890
FDS out 1420 1125 1260 1110
Tower out 297 174 288 156
Fraction of S02 removed, ,
FDS 23.7 38.5 38.2 41.3
Tower 79.1 84.5 77.1 85.9
OVerall 84.0 90.5 85.9 91.7
Gas Temperature, of.
I FDS in 322 323 325 323
~ FDS out 112 113 115 115
~ Tower out 100 103 106 108
o Liquid Temperature, of.
I
FDS in 98 101 103 103
FDS out 92 97 102 102
Tower in 98 102 103 104
Tower out 110 112 115 115
pH measurements
Tower outlet 3.8 2.5 2.2
FDS outlet 5.7 5.8 5.8 5.9
Hold tank 10.6 10.6 10.6 10.4
Clarifier tank 11.1 11.1 11.2 11.2
Disc Position 0 0 0 0
Pfessure at outlet, in. Hg qa~e -1.6 -1.6 -1.6 -1.6
S urry Concentration to F S, ., 15.0 16.0 19.0 19.5
Slurry Concentration to Tower, n.' 4.4 3.4 3.5 3.4
-------
TABLE A-16
OPERA'rXNG CONDITIONS POR '!'ASK VXIC
Date 5/12 5/12 5/12
Time 1300 1420 1540
Gas Flow, cfm 700 700 700
FDS L/G ratio, qa1/mef 10 10 10
Tower L/G, ratio, gal/mcf 15 15 15
Gas Velocity FDS, ft/sec 105 105 105
Tower pressure drop, inches H20 0.7 0.7 0.7
FDS pressure drop, inches H20 7.6 6.8 7.5
CaO/SO ratio 0.99 0.985 0.96
802 coacentration, ppm
FDS in 1560 1610 1650
FDS out 1320 1380 i440
Tower out 845 910 1105
Fraction of S02 removed, ,
FDS 15.4 14.3 12.7
I Tower 36.0 34.1 23.3
I-' OVerall 45.8 43.5 33.0
I-' Gas Temperatures, oPe
I-'
I FDS in 330 330 328
FDS out 120 120 120
Tower out 113 114 116
Liquid Temperatures, .P.
FDS in 110 110 110
FDS out 100 102 100
Tower in 109 110 110
Tower out 120 120 120
pH measuremel'.CS
Tower outlet 2.1 2.1 2.1
FDS outlet 5.2 5.2 5.2
Hold tank 10.8 10.8 10.6
Clarifier tank 11.1 10.8 10.6
Disc Position 0 0 0
Pres8ure at outlet, in. Be; quae;e -1.6 -1.6 -1.6
-------
TABLE A-I?
OPERATING CONDITIONS POR TASK VIIIC
Date 6/9 6/9 6/9
Time 1730 1830 1915
Gas Plow, cfm 700 700 700
FDS L/G ratio, gal/mcf -10 10 10
Tower L/G ratio, gal/mcf 20 20 20
Gas Velocity PDS, ft/sec. 193 162 162
Tower pressure drop, inches H20 0.7 0.7 0.7
FDS pressure drop, inches H20 8.2 7.0 7.2
CaO/SO ratio 1.12 1.05 1.08
S02 co~centration, ppm
FDS in 1620 1680 1500
FDS out 510 540 660
Tower out 220 12Q 100
Praction of S02 removed, ,
FDS 69.0 67.8 56.0
Tower 56.7 77.4 83.0
I Overall 86.4 93.0 93.8
..... Gas Temperature, .P.
.....
IV FDS in 310 305 305
I PDS out 112 110 110
Tower out 106 108 105
Liquid Temperature, .P.
FDS in 88 88 88
FDS out 100 102 100
Tower in 102 102 102
Tower out 106 104 106
pH Measurements
Tower outlet 7.2 7.0 6.6
FDS outlet 9.4 7.4 6.8
Hold tank 8.8 8.5 7.8
Clarifier tank
Disc Position 2.0 1.5 1.5
Pressure at outlet, inches Hg. gauge -1.6 -1.6 -1.6
-------
TABLE A-18
OPERATING CONDITIONS POR TASK VIIId
Date 5/18 5/18 5/18
Time 1000 1100 1500
Gas Flow, efm 700 700 700
FDS L/G ratio, qa1/mef 10 10 10
Tower L/G ratio, qal/mcf' 20 20 20
Gas Velocity FDS, ft/see 105 105 105
Tower pressure drop, inches H20 0.8 0.8 0.7
PDS pressure drop, inches H20 5.7 6.8 10.8
CaO/SO ratio 1.02 0.93
S02 co~centration, ppm
FDS in 1470 1290 1410
FDS out 1200 1140 1200
Tower out 600 570 . 750
praetion of S02 removed, ,
FDS 18.4 11.6 14.9
Tower 50.0 50.0 37.5
Overall 59.2 55.8 46.8
I Gas Temperature, of.
.... FDS in 328 328 330
.... FDS out 103 104 108
UJ Tower out 103 104 104
I Liquid Temperature, 0p.
FDS in 65 65 62
FDS out 100 100 120
Tower in 95 96 98
Tower out 103 104 104
pH measurements
Tower outlet 2.5 2.5 2.4
FDS outlet 10.4 10.4 6.0
Hold tank 8.6 8.6 6.8
Clarifier tank 10.4 10.4 7.0
Disc Position 0 0 0
Pressure at outlet, in. Hq qauqe -1.5 -1.5 -1.4
-------
TABLE A-19
OPERATING CONDITIONS FOR TAS1( vrrIe
Date 5/19 5/19 5/19
Time 1700 1815 1900
Gas Flow, cfm 700 700 700
FDS L/G ratio, qa1/mcf 10 10 10
Tower L/G ratio, qal/mcf 20 20 20
Gas Velocity FDS, ft/sec. 139 139 139
Tower pressure drop, inches H20 1.0 1.0 1.0
FDS pressure drop, inches H20 7.0 7.0 7.0
CaO/SO ratio 1.0 0.97 0.96
S02 co~centration, ppm
FDS in 1690 1920 2040
FDS out 1110 1330 1620
Tower out 60 96 42
Fraction of S02 removed, ,
FDS 34.3 -30.7 20.6.
'l'ower 94.6 92.8 97.4
Overall 96.4 95.0 97.9
I Gas Temperature, of.
.... FDS in 335 335 335
.... FDS out 120 120 120
,a:..
I Tower out 118 118 118
Liquid Temperature, of.
FDS in 118 118 118
FDS out 110 110 110
Tower in 114 114 116
Tower out 118 118 118
pH measureInents
Tower outlet 5.7 5.6 5.2
FDS outlet 5.5 5.4 5.2
Hold tank 11.0 11.0 10.8
Clarifier tank
Disc position 1.0 1.0 1.0
Pressure at outlet, in. Hq qauqe -1.6 -1.6 -1.6
Slurry Concentration to FDS 4 4 4
weiqht ,
-------
A P PEN D I X
B
OPERATING CONDITIONS AND RESULTS
For
THE LIMESTONE TESTS
-115-
-------
TABLE B-1
Limestone Materials Received From TVA
Particle Amount Chemical Analysis, %
~ Size Received, lb CaO MgO K20 Na20 Ign Los.
Tiftona
Limestone 75%-200M 4700 50.5 1.5 0.4 0.3 41.5
Cement
Kiln Dust 90%-200M 1000 41.5 2.4 3.1 0.19 22.8
Selma
Chalk 89%-200M 1000 43.1 0.59 0.49 0.18 35.1
Hydrated
Lime 99%-325M 1000 70.2
Tiftona
Limestone 89%-325M 350 50.5 1.5 0.4 0.3 41.5
-116-
-------
A 1.
I'
i i
[ ,
[ I
A 2.
A 3.
I'
[
: !
, '
I
, !
[ I
, I
A 4.
A 5.
I
I'
I
! I
I:
I
I'
, ,
i:
II
I'
A 6.
A 7.
TABLE
B-2
Limestone Test Program
Alter existing pilot plant hardware arrangement to accommodate
the mode sho,m in Figure IV-2l.
lime feeder, piping, etc.
This involves relocating pumps,
Measure effi(~iency of 502 removal when scrubbing with a 2% chalk
slurry.
Mode of operation as per Figure IV-2l.
L/G to Venturi to be 10 gal/l,OOO cf, and to packed tower to be
40 gal/l,OOO cf.
Pressure drop in venturi to be 7".
Measure the efficiency of 502 removal when scrubbing with a
2% cement dust slurry.
Mode of operation and operating
parameters as per Task A2.
Measure the efficiency of 502 removal when scrubbing with a 2%
slurry of "local" limestone having a mesh size of 90% minus
325.
Mode of operation and operating parameters as per Task A2.
Measure the efficiency of 502 removal when scrubbing with a
2% slurry of "local" limestone having a particle size of 70%
minus 200 mesh.
Mode of operation and operating parameters as
per Task A2.
Measure the 502 removal efficiency when employing the slurry
and operating parameters as in Task AS.
The mode will be
altered such that the slurry goes only to the packed tower and
fresh water will be delivered to the venturi.
Measure the 502 removal efficiency when employing the mode
and slurry as in Task A6.
The liquor rate to the packed tower
-117-
-------
A 8.
A 9.
. A 10.
All.
TABLE
B-2
c.ont'd
will be reduced to 20 gal. per 1,000 cf.
All other operating
parameters as per Task A6.
Measure the 802 removal efficiency when employing the mode and
operating parameters as in Task AS but increasing the
stoichiometric feed rate to 150% of the stoichiometric re-
quirement.
Measure the 502 removal efficiency when scrubbing with a 2%
slurry of lime (CaO). The mode and operating parameters as per
Task. A2.
Return pilot plant hardware to the arrangement existing prior
to this test program.
Open critical elements for inspection and
clean as necessary.
Final Report Preparation and Presentation:
Minimal data analysis will be employed.
Tabulation and graphical
data representations wil~ b~incorporated into a single compre-
hensive report.
-118-
-------
Task
C 1
C 2
C 3
TABLE. B-3
. PROPOSED TEST PLAN
Alter pilot plant equipment so that the recirculation
system shown in Figure IV-23 is established. "Items of
work needed for the hardware change are: . (a)
change
piping tD include clarifier in the circuit, (b)
install
limeston.e feeder on hold tank, (c)
fabricate and install
helical coil for t.he hold tank, and (d)
set. up
sampling equipment. for particulate analysis.
... A continuous "around the clock" plugging study for a
minimum of 40 hours will be performed.
L/G to the
venturi will be 10 ga1/1,000 cf and the packed tower
will be 30 gal/l,OOO cf.
Gas flow rate to be such that
a velocity of 9.5 ft. per sec. will be maintained.
Pressure drop on the FDS to be controlled at 7 inches
of water..
A 5% w/w slurry is plan~ed for the packed
tower scrubbing liquor." Hold volume for the packed
tower recirculation tank will allow 30 minutes residence
t.ime for slurry.
Following this continuous test, remove
the packing from the tower and compare the weight of
each section of packing to its original.
Flooded disc
section will also be inspected for scaling.
Repeat Task C2 with the L/G for the packed tower at
50 gal/l,OOO cf.
PacKing will be removed and weighed
after 40 hours of continuous operation.
-119-
-------
Task
C 4
C S
C 6
C 7
C 8
TABLE
B-3
cant'd
Repeat Task C3 with aO slurry residence time of 10
minutes in the hold tank.
Repeat Task C2 with a slurry residence time of 10
minutes in the hold tank.
From Task C2 through CS, the minimum scaling mode will
be determined and a continuous test will be performed
for at least 96 hours.
Packing will be removed and
weighed after the 96 hours of operation.
pilot hardware will be returned to the arrangement needed
° 0
for the original contract work.
Recondition pumps if
packing and impellers are damaged during the high slurry
test program.
A summary report will be prepared which will state the
results of this work with minimal data analysis.
-120-
-------
\
TABLE B- 4
OPERA'!: rh~ CCml:I":'!ONS 1"0R TASK C-2
Date 1/13 1/14 1/14 1/14 1/14 1/14 1/14 1/14 1/14 1/15 1/15
Time 2130 0100 0300 0600 1000 1200 1420 2030 2300 0100 0330
Limestone Used* B B B B B B B B B B B
Gas Flow, cfm 700 700 700 700 700 700 700 700 700 700 700
FOS L/G ratio, gal/mcf 10 10 10 10 10 10 10 10 10 10 10
Tower L/G ratio, gal/mcf 30 30 30 30 30 30 30 30 30 30 30
Gas velocity FDS, ft/sec. *** 110 115 130 137 108 110 115 116 98 88
Gas velocity Tower, ft/sec. 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35
Tower pressure drop, inches H20 1.2 2.2 2.2 3.6 4.3 6.0 7.0 8 6.8 6.0 13.2
FDS pressure drop, inches H20 6.9 7.0 7.0 7.0 7.0 6.8 8.0 7.0 6.9 7.0 7.0
CaO/S02 ratio (inlet analysis) 1 0.6 1 1 0.9 1 1. 7** 1.0 1.1 1.1
S02 Concentration, ppm 1032 1063 1030 1030
FDS in **** 1350 1580 1500 1550 1930 1500 1325
FOS out 1525 1600 1550 1230 1560 1500 1225 1250 875 950
Tower out 695 1020 880 850 1050 660 336 520 570 320 460
Praction of S02 removed, ,
FDS 15.1 8.8
I Tower 54.5 36.3 43.3 30.9 57.7 77.6 57.6 54.4 63.5 51.6
.... OVerall 4!'.6 69.9 55.4
t\,) Gas temperatures, 0p
....
I FOS in 329 342 350 350 349 345 340 335 338 335
FOS out 118 122 122 120 122 122 120 122 120 110
Tower out 111 110 112 112 115 116 118 110 10.2
Liquid temPeratures, Op
FDS in 110 122 122 122 110 105 116 115 112 110
FDS out 115 122 120 120 122 121 120 120 120 115
Tower in 115 122 120 115 119 118 118 120 115 108
Tower out 115 120 118 120 122 120 118 118 118 110
PH measurements
TO\oler outlet 4.8 4.6 4.8 4.6 4.8 5.2 5.6 5.2 4.9 4.2
FOS outlet 6.3 6.2 6.4 6.5 6.4 5.3 6.6 6.6 6.5 6.4
Hold tank 5.3 5.0 5.2 5.2 5.9 5.5 5.2 5.5 5.6 5.4
Clarifier tank 4.7 4.6 4.6 4.6 4.8 4.7 4.7 4.7 4.7 4.6
*Limestone received from !VA for the "around-the-clock" tests desi.gnated as AJOld Tiftona from TVA shown as Type 8.
**Stoichiometry was 1.0 at 2015
...FDS gas velocity based on outlet gas volume.
**** Some difficulties in SOig analyses were experienced during this test
High efficiencies and native absorption on PDS should not be con-
sidered valid.
-------
TABLE B-4 cont'd
OPERATING CONDITIONS FOR TASK C-3
Date 1/11 1/12 1/12 1/11 1/13
Time 1600 0930 1730 2230 0100
Limestone Used* A A A A A
Gas Flow, cfm 700 700 700 700 700
FDS L/G ratio, gal/mef 10 10.0 10.3 11
Tower L/G ratio, gal/mef 50 45.5 61.0 40
Gas velocity FDS, ft/sec.*** 76 76 76 76 76
Gas velocity tower, ft/sec. 8.35 8.35 8.35 8.35 8.35
Tower pressure drop, inches H20 1.0 1.0 1.0 1.2 1.7
FDS pressure drop, inches HfO 5 4.9 4.4 4.4
CaO/S02 ratio (inlet ana1ys s) 1 1 1 1 1
S02 concentration, ppm
FDS in **** 1350 1825 1920 2000
FD5 out 500 1785 733
Tower out 150 625 429 500
Fraction of 502 removed, ,
FDS 63.0 2.2 61.9
Tower 60.0 65.0 41.5
OVerall 88.9 65.8 77.7 75.0
Gas temperatures, Op
I FDS in 330 ~4' 364 342 .
.... FDS out 125 122 122 122
t\) Tower out 127 118 121 118
t\) Liquid temperatures, 0p
I FDS in 130 122 122 122
FDS out 122 122 122 122
Tower in 12 118 121 120
Tower.out 125 121 122 122
pH measurements
Tower outlet 6.0 5.2 5.6 5.3
FDS outlet 4.0 4.4 4.1 3.8
Hold tank 6.3 5.6 5.7 5.4
Clarifier tank 5.2 5.1 5.0
Hold tank volume 600 600 760 700 700
*Limestone received from TVA for the waround-the-clocka tests designated
***FDS gas velocity based on outlet gas volume.
**** Some difficulties in 502 analyses were experienced during this ~est.
High efficiencies and negative absorption on PDS should not be con-
sidered valid.
as A Old Tiftona from TVA shown as Type B.
-------
,
!
TABLE B-4 cent'd
OPERATINt; rONDITIONS FOR TASK C-4
Date 1/18 1/18 1/18 1/18 1/18 1/19 1/19 1/19 1/19 1/19 1/19
Time 1330 1700 1900 2130 2330 0130 0530 1030 °1440 1500 2230
Limestone Used B B B B B B B B B B B
Gas Flow, cfm 700 700 700 700 700 700 700 700 700 700 700
FDS L/G ratio, gal/mcf 10 10 10 10 10 10 10 10 10 10 10
Tower r./G ratio, gal/mcf 40 40 40 40 40 40 40 40 40 40 40
Gas velocity FDS, ft/sec. *** 138 138 138 138 138 138 138 138 138 D8 138
Gas velocity Tower, ft/sec. 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35
Tower pressure drop, inches H20 0.8 0.5 0.7 0.7 0.7 0.7 0.8 1.4 1.2 0.9
FDS pressure drop, inches H20 7.8 6.4 7.0 7.0 7.0 7.0 7.8 7.9 7.2 7.0
CaO/S02 ratio 1.6 1.0 .9 1.0 0.9 1.2 0.9 0.9 1.4
502 Concentration, ppm
FDS in **** 1150 1750 1700 1325 1230 950 1250 1350 1475
FDS out 1390 1900 1900 1500 1250 1025 1500 1350 1400
Tower out 400 150 1125 320 350 488 700 680 800
J Fraction of 5°2 removed, '
~ FDS 5.1
I\) Tower 71.3 92.2 40.8 78.7 72.0 52.4 49.7 42.9
w Overall 45.8
J Gas temperatures, of
FDS in 335 335 330 330 330 330 335 330 333 338
FDS out 110 90 105 105 105 105 115 110 112 112
Tower out 105 80 100 100 100 102 105 105 105 105
Liquid temperatures, 0p
FDS in U2 100 105 105 105 105 112 110 112 108
FDS out 125 120 US 110 110 112 120 118 120 120
Tower in 108 83 100 100 100 100 105 105 105 105
Tower out 111 100 110 110 110 112
pH measurements
Tower outlet 4.9 5.7 5.5 5.2 5.3 4.2 4.7 4.9 4.9 4.8
FDS outlet 6.6 6.9 7.0 5.4 7.2 7.4 6.7 6.3 6.7 6.5
Ho1p tank 5.6 6.3 5.7 5.7 5.9 5.8 5.7 5.5 5.5 5.5
Clarifier tank 7.1 7.1 7.1 7.1 7.2
***FDS gas velocity based on outlet gas voluwe.
**** Some difficulties in SO analyses were experienced during this test.
High efficiencies and nigative absorption on FDS should not be con-
sidered valid.
-------
TABLE B-4 cont'd
OPEMTING CONDITIONS POR TASK C-4
I
.....
t\)
A
I
Date
Time
Limestone Used
Gas Flow, cfm
FDS L/G ratio, gal/mcf
Tower L/G ratio, gal/mcf
Gas velocity FDS, ft/sec.***
Gas velocity Tower, ft/sec.
Tower pressure drop, inches H20
PDS pressure drop, inches H20
CaO/SO ratio
502 co6centration, ppm
FDS in ****
FDS out
Tower out
Fraction of 502 removed, ,
FDS
Tower
Overall
Gas temperatures, op
FDS in
FDS out
Tower out
Liquid temperatures, °P
FDS in
FDS out
Tower in
Tower out
pH measurements
Tower.outlet
FDS outlet
HOld tank
Clarifier tank
4.7
7.1
5.3
1/19
2230
B
700
10
40
138
8.35
1.6
7.0
1650
1625
1040
1.6
36.0
37.0
325
110
103
105
120.
105
1/20
0330
B
700
10
40
138
8.35
1.6
7.0
1.0
850
702
400
17.4
42.4
52.9
332
105
104
102
112
102
102
4.6
6.4
5.4
1/20
0330
.d
700
10
40
138
8.35
1.6
7.0
500
425
100
15.0
76.5
80.0
325
100
98
102
112.
102
***PDS gas velocity based on outlet gas volume.
**** Some difficulties in 502 analyses were experienced during this
High efficiencies and negative absorption on FDS should not be
sidered valid.
.
test.
con-
-------
TABLE B-4 cont'd
OPD1:"T~ COND.l.!!OJ!!.. ~OR TASK C-5
Date 1/20 1/20 1/20 1/20 1/20 1/20 1/20. 1/21 1/21 1/21 1/21 1/21
Time 1130 1230 1400 1700 1900 2100 2300 0100 0300 050e 0730 ens
Limestone Used B B B B B B B B B B B B
Gas Flow, cfm 700 700 700 700 700 700 700 700 700 700 700 700
FDS L/G ratio, qal/mcf 10 10 10 10 10 10 10 10 10 10 10 10
Tower L/G ratio, qal/mcf 40 40 40 40 40 40 40 40 40 40 40 40
Gas velocity FDS, ft/sec.... 141 141 141 141 141 141 141 141 115 115 138 108
Gas velocity Tower, ft/sec. 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35
Tower pressure drop, inches H20 0.8 1.0 1.0 0.8 1.1 1.1 1.1 1.1 1.9 1.9 3.1 5.4
. FDS pressure drop, inches H20 6.6 6.4 7.2 6.6 7.2 6.7 7.0 7.0 7.0 7.0 7.0 5.8
CaO/SO ratio 1.1 1.1 2.1 1.4 1.1 2.0 1.7 1.45 1.45
S02 co~centration, ppn
FDS in .*** 1250 1075 1050 950 850 750 850 775 600 500 600 750
FDS out 800 600 425 350 300 250 300 378 250 234 300 275
I Tower out 17 200 235 100 185 155 285 330 160 125 150 120
I-'
IV Fraction of S02 removed, ,
U1 FDS 36.0 44.2 59.5 63.1 &..7 6b.6 64.7 ;1.3 58.3 53.2 50.0 63.3
I Tower 97.8 66.7 44.7 71.4 38.3 38.0 5.00 12.7 36.0 53.4 50.0 54.6
Overall 98.6 81.4 77.6 89.4 78.3 79.3 66.5 57.4 73.4 75.0 75.0 84.0
Gas temperatures, 0p
FDS in 335 330 330 330 333 .332 328 330 332 332 335
FDS out 85 108 110 105 115 115 117 118 112 110 115
Tower out 70 102 105 102 112 112 113 112 112 105 110
Liquid temperatures, .p
FDS in 100 105 105 105 108 III 112 110 108 102 85
FDS out 110 115 115 115 118 118 118 118 118 126
Tower in 75 102 105 100 112 112 115 115 112 106 110
Tower out 80 105 110 105 115 115 118 118 118
pH measurements
Tower outlet 5.6 5.0 5.2. 4.8 5.1 4.5 5.3 4.6 5.0 4.8 4.8
FDS outlet 5.0 6.0 4.9. 5.2 4.9 4.9 4.8 4.8 4.8 4.7 4.3
Hold tank 6.3 7.1 6.2 6.4 6.6 6.4 6.4 6.2 6.4 6:0 5.7
Clarifier tank 6.4 5.9 5.7 5.6 5.5 5.5 4.3
***FDS qas velocity based on outlet qas volume.
*.** Some difficulties in SO~ analyses were experienced durinq this test.
Hiqh efficiencies and n qative absorption on FDS should not be con-
side red valid.
-------
TABLE B-4 cont'd
OPE:-':'TIM; CONDITIONS POR TASK C-5
Date 1/21 1/21 1/21 1/21 1/21 1/21 1/21
Time 1100 1300 1500 1700 1900 2100 2300
Limestone Used B B B B B B B
Gas Flow, cfm 700 700 700 700 700 700 700
FDS L/G ratio, ga1/mef 10 10 10 10 10 10 10
Tower L/G ratio, gal/mcf 40 40 40 40 40 40 40
Gas velocity FDS, ft/sec.*** 111, 132 115 .115 115 115 115
Gas velocity Tower, ft/sec. 8.35 8.35 8.35 8.35 8.35 8.35 8.35
Tower pressure orop, inches H20 5.0 5.0 3.2 3.3 3.6 3.9 4.3
FDS pressure drop, inches H20 5.8 6.0 5.2 4.6 4.2 4.6 4.0
<:&0/S02 ratio 1.21 1.3 0.8 1.0 0.9 0.9 0.9
S02 Concentration, ppm
FDS in **** 825 890 1125 1300 1500 1600 1650
FDS out 225 225 1050 1250 1375 1550 1525
Tower out 210 240 330 370 355 425 360
I Fraction'of S02 removed, , 72.8' 74.8 1.7 5.; 8.4 3.1 7.6
FDS
.... Tower 6.7 68.6 70.4 74.2 72.6 76.4
t\)
0'1 Overall 74.6 73.1 70.7 71.6 76.4 73.5 78.2
I Ga3 temperatures, of
FDS in 335 340 335 335 335 335 333
FDS out 120 115 120 118 119 121 120
Tower out 115 70 120 119 119 120 120
Liquid temperatures, of
FDS in 110 105 118 114 115 118 118
FDS out - 115 120 118 118 120 119
Tower in 120 115 120 119 119 121 121
Tower out
pH measurements
Tower outlet 4.9 4.8 3.0 3.8 5.9 5.8 5.3
FDS outlet 4.5 3.7 3.7 4.1 4.6 4.9 5.1
Hold tank 5.7 5.. 5.7 5.8 6.2 6.0 5.9
C1~rif ier tank 5.2 5.1 5.0 4.8 4.2 4.2 4.2
*** FDS gas velocity based on outlet gas volume.
**** Some difficulties in SO~ analyses were experienced during this test.
High efficiencies and n gative absorption on FDS should not be con-
sidered valid.
-------
TABLE B-4 cant'd
OPERATING CONDITIONS FOR TASK C-6
Date 1/25 1/25 1/25 1/26 1/26 1/26 1/26 1/26 1/26 1/26 1/27
Time 1630 2130 2400 0200 0400 1115 1230 1500 1715 2230 0300
Limestone Used B B B B B B B B B B B
Gas Flow, efm 700 700 700 700 700 700 700 700 700 700 700
FDS L/G ratio, gal/mcf 10 10 10 10 10 10 10 10 10 10 10
Tower L/G ratio, gal/mcf 45 45 4S 45 45 45 45 45 4S 45 45
Gasove10city FD5, ft/see.*** 127 141 141 141 141 141 135 135 135 141 141
Gas velocity Tower, ft/~ec. 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35 8.35
Tower pressure drop, inches H20 1.0 1.0 1.1' O.q 1.0 1 0 1.C 1.0 0.9 0.9 0.9
FD5 pressure drop, inches 820 6.4 7.0 6.5 6.8 7.3 6.0 6.2 5.8 6.2 7.0 7.0
CaO/SO ratio 0.9 1.0 0.9 1.0 1.0 1.0 1.2 1.2 0.9 1.1 0.9
5°2 co~centration, ppm
FD5 in 1700 1700 1920 1930 1890 1680 1360 1260 1380 1400 1565
I FDS out 1580. 1635 1900 1760 1735 1560 1220 1160 1320 1440
.... Tower out 540 620 880 560 460 320 100 34 240 280
II.,) Fraction of S02 removed, ,
'-01 FD5 7.1 3.9 1.0 8.8 8.2 7.2 10.3 8.0 5.8 8.0
I
Tower 65.9 62.1 53.7 68.2 73.5 79.5 91.8 97.1 81.9 80.6
Overall 68.3 63.5 54.2 71.0 75.7 81.0 92.7 97.4 82.9 82.2
Gas temperatures, of
FDS in 335 328 335 330 330 330 33S 333 335
FDS out 105 120 120 118 120 118 118 118 118 118 115
Tower> out 108 120 120 118 120 118 118 118 115 115 116
Liquid temperatures, of
FDS in 40 114 112 115 118 112 112 112 110 114 114
FDS out 85 118 120 118 ,120 120 120 120 118 118 118
Tower in 108 118 121 118 '120 118 118 118 115 115 114
Tower out 108 118 121 120 122 118 120 120 118 118 118
pH measurements
Tower outlet 5.4 5.4 4.9 5.2 5.4 5.5 5.9 6.6 4.3 5.7 4.8
FDS outlet. 4.6 4.4 5.2 5.0 4.8 5.4 6.8 6.8 6.6 4.8 4.8
Hold tank 5.3 5.5 5.3 5.7 5.4 6.2 6.4 6.1 6.0 6.4 6.3
Clarifier tank 3.2 3.4 3.4 4.7 4.6 4.3 4.5 40.9 4.9 4.6 4.5
***FD5 gas velocity based on outlet gas volume.
-------
TABLE 8-4 cont'd
OPERATING CONDITIONS FOR TASK C-6
Date 1/29 1/29 1/29 1/30 1/30 1/30 1/30 1/30 1/30 1/30 1/30 1/30 1/31
Time 1405 1620 2100 0200 0600 1230 1330 1415 1505 1830 2100 2330 0100
Limestone Used A A A A A A A A A A A A A
Gas Flow, cfm 700 700 700 700 700 700 700 700 700 700 700 700 700
FDS L/G ratio, gal/mcf 10 10 10 10 10 10 10 10 10 10 10 10 10
To~er L/G ratio, ga1/mcf 45 45 45 45 45 45 45 45 45 45 45 45 45
Gas v31Qcity FDS, ft/sec.*** 127 127 127 141 141 IH 141 141 141 141 141 141 141
Gas velocity Tower, ft/sec. 8.35 8.35 8.35 0.35 8.3~ 8.35 8.35 0.35 8.35 8.35 8.35 8.35 8.35
Tower pressure drop, inches H20 0.8 0.8 0.8 0.7 0.6 0.6 0.6 1.1 1.1 0.9 0.9
FDS pressure ,trop, inches H20 6.4 7.0 7.0 7..0 7.0 6.4 6.0 7.2 7.6 6.4 7.0
CaO/SO, ratio 1.2 1.2 1.2 1.2 1.1 1.3 1.2 1.2 1.2 1.2 1.2 1.2 1.2
S02 Cogcentration, ppm
FDS in 1440 1440 1360 1280 1480 1450 1420 1240 1260 1160 1000 1000 1080
I FDS out 1320 1340 1280 1140 1380 1340 1300 1120 1100 960 979 1000
I-'
't\J Tower out 360 220 210 280 280 400 320 120 140 84 20 20 72
00 Fraction of S02 removed, ,
I FDS, 8.4 8.0 5.9 11.0 6.8 7.6 8.5 11.2 5.2 4.0 4.0 2.9
Tower 72.8 83.5 83.6 75.5 79.8 70.2 75.4 87.5 92.4 97.9 97.9 92.8
Overall 75.0 84.8 84.6 78.2 81.1 72.5 77.5 90.4 88.9 92.8 98.0 98.0 93.3
Gas temperature, of
'FDS in 342 340 342 335 330 325 330 330 320 325 330
FDS out 122 112 122 120 120 120 120 116 120 118 118
Tower out 122 110 120 118 118 120 118 112 118 112 112
Liquid temperatures, of
FDS in 119 100 118 118 116 118 115 115 114 115 116
FDS out 126 118 125 122 122 122 122 122 120 121 120
Tower in 122 112 121 no 118 120 118 113 120 112 114
Tower out 125 115 123 120 120 122 122 118 120 118 120
pH measurements 4.4
Tower outlet 5.8 3.5 5.8 5.6 5.4 5.4 5.5 5.1 5.3 4.8
FDS outlet 5.4 4.2 5.4 5.4 4.7 5.S 6.0 4.4 4.4 4.0 4.9
Hold tank 7.6 5.4 6.4 6.2 6.2 5.8 6.2 6.4 6.3 6.2 6.0
Clarifier tank 3.6 5.0 5.0 5.2 4.9 5.2 5.2 5.1 4.9 5.0 5.0
***FDS 9a8 velocity based on outlet 9a8 volume.
-------
TABLE B-5
Limestone Materials Supplied By
TVA For The Scaling Test Series.
Shipment
Shipment
Designation
A
B
Particle Size
61%-200 Mesh
75% - 200 Mesh
Amount Received, 1bs.
2000
4700
Chemical Analysis
CaO %
MgO %
K20 %
Na20 %
Ign. Loss
50.8
50.5
1.5
0.4
0.3
41.5
41.5
*
Limestone supplied by TVA called "Tiftona Limestone".
Shipment "1\." was a special supply of CaC03 for the
scaling test series; Material "B" was received from TVA
for the first test series.
-129-
-------
TABLE B-6
Analytical Results Oft So114s from 'fIDI) puot-Ylaftt Limestone SlI11'TY ScrubblM Teeta--.Tanuary 13-'1. 1911
a Chem1cal anal7ah, CaO 80114. COIlpO.UWQ
:ask '0., Llae.toD. .1urr,r Salllt'le Stack I{O.. SOa relllOVed, ot 8011d8. " utili- calculated !Tom che~1c~: analY.!.
4a~e, end coocectraUoli ~ Piltrate Flow rate Aoa1781s, ~ ot Input S Acid AUOo. caSO.' CSSCIs' Acid
~~~'! IJno:! sourceb Point so114 a 'D1t tts/mift.' l'l'!II 1302 J cull!U1ati VI') ~ ~ .!Qz. ~ ~ --L CaCO.., 2H:>0 1/2?:>0 ~ ~
C-2 ~, 'l'L-} Hold tank }.O }.1 'rOO l}50c 112.6 11.0 1.9 9.1 4.2 45.2 42 49 8 4 11j'
1/:,/n P1' outlet }.5 2.0 49 41.4 9.6 2.0 7.6 6.1 40.6 44 41 8 6 So9
:.m!\:'. FOO outlet 51.5 1.6 49 4}.1 2.0 0.4 1.6 9.4 8.0 11 9 2 9 91
C-2 21>, orr..-} Hold tank 1.2 2.} 700 106} - '1.8 17.' '.5 1,.8 5.6 80.1 14 74 14 6 le8
1il~/71 I'l' outlet 1.4 2.2 46 ".} 14.2 1.4 12.8 7.9 70.5 20 69 6 8 10}
::~.15 !1r. FI>S outlet '.1 2.0 46 10.1 5.0, o.} 4.7 54.} 82.2 } 25 1 516 e,
C-2 21>, orr..-} Uold tank 5.' '.2 'rOO 1030 20.6 8.2, 0.2 8.0 '1.5 69.9 11 4, 1 }8 9'
1/15/11 PI' outlet 7.' 2.7 47 15.8 7.7' <1.2 7.5 44.1 85.4 4 40 1 44 S:;
c~~:> ~. FOO outlet 8.6 2.1 55 14.} 6.7 o.} 6.4 47.7 81.8 5 }Ii 1 48 88
C-' 51>, TL-4 lIu11.! tlmlt 4.7 7.0 700 1825 - '.2.0 11.1 6.6 4.5 6.4 "(,.2 40 211 27 6 91
1/12/n PI' outlet 4.4 4., 64 '7.0 12.9 6.2 4.1 12.6 61.1 26 25 ), 1} 97
:900 !u'. FDS outlet 5.6 2.2 66 20.0 9.6 6.2 ,.4 ,8.2 84.0 6 18 25 }8 87
C-5 5S, 'fir.4 Hold tank 1.1 7.2 700 600 ,6.4 9.8 0.12 9.68 5.9 It2 '}4 ~ 1 6 ~,
I 1/21/n PI' outlet 2.4 6.6 25 '5.8 ,., 0.24 ,.06 11.5 1.2 54 1 12
------- |