PB81-216308
Evaluation of Solvent Loss from Vapor
De&reaser Systems. Phases 2 and 3
Effect of Crosscurr-ant Air Velocity on
Control System Performance
PEDCo-Environmental, Inc.
Cincinnati, OH
Prepared for
Industrial Environmental Research Lab.
Cincinnati, OH
May 81
Kfcl!
U.S. Etepsdisent of Commerce
Natbnal Technical Information Service
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EPA 600/2-81-072
May 1981
EVALUATION OF SOLVENT LOSS FROM
VAPOR DEGREASER SYSTEMS
PHASES 2 AND 3
Effect of Crosscurrent Air Velocity
on Control System Performance
by
PEDCo Environmental, Inc.
Chester Towers
11499 Chester Road
Cincinnati, Ohio 45246
Phase 2
Contract No. 68-02-2535
Task No. 3
Phase 3
Contract No. 68-02-2907
Task No. 1
Project Officer
Charles H. Darvin
U.S. ENVIRONMENTAL PROTECTION AGENCY
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
5555 RIDGE AVENUE
CINCINNATI, OHIO 45268
January 1981
-------
NOTICE
THIS DOCUMENT HAS BEEN REPRODUCED
FROM THE BEST COPY FURNISHED US BY
THE SPONSORING AGENCY. ALTHOUGH IT
IS RECOGNIZED THAT CERTAIN PORTIONS
ARE ILLEGIBLE, IT IS BEING RELEASED
IN THE INTEREST OF MAKING AVAILABLE
AS MUCH INFORMATION AS POSSIBLE.
-------
TECHNICAL RtPORT DATA
fftcasr ffaJ l*sjnn:tttrns on the rci-tnt bftort rump
rPA-600/2-81-072
ORD Report
•i. TITLE ANOSjSTlTLS
Evaluation of Solvent Loss From Vapor Degreaser
Systems
¥m*A2*6W't
5. REPORT DATE
May
6 PERFORMING ORGANIZATION CODE
R. W. Gerstle and E. S. Schindler
8 PERFORMING ORGANIZATION REPORT NO
PH 3230-C (Phase 2)
PN 3481-1 (Phase 3)
0 PERFORMING ORC \MZATION NAME AND AOORESS
PEOCo Environmental, Inc.
11499 Chester Road
Cincinnati, Ohio 45246
10. PHOC.RAM ELEMENT NO.
1AB604
11. CONTRACT-GRANT NO.
(Phase 2) 68-02-2535, Task 3
(Phase 3) 68-02-2907, Task-1
12. SPONSORING AGENCV NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TVPE Of REPORT AND PERIOD COVERED
Final (July 70 - Nov. 80
14. SPONSORING AGENCV CODE
EPA 600/12
15. SUPPLEMENTARY NOTES
IERL Project Officer: Charles H. Darvin
16. ABSTRACT
The U.S. Environmental Protection Agency evaluated available pollution reduction
capabilities of vapor degreasers fitted with add-on control systems as supplied by de-
greaser manufacturers. The principal objectives of this project were to develop and
implement an experimental program for assessing solvent loss from degreasing systems
of various designs, and to report the test conditions, procedures, results, and con-
clusions in a fora usable by air pollution agencies and industry.
Tests were performed from October 1978 to June 1980 to evaluate the effects of
different variables on the rate of solvent loss from degreasers. The variables tested
include the fo'.lowing degreaser control options and operating conditions: freeboard
ratio, load cross-sectional area, refrigerated freeboard duller, hoist speed, lip
exhaust, crosscurrent air velocity, degreaser size, solvent type, and automatic cover.
Various relationships between the test variables are presented in the report.
The factor most likely to ensure long periods of operation with minimum solvent loss,
regardless of *he mix of control options, is installation in an area where cross-
current velocity can be minimized.
KEY WOKtS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air Pollution
Vapor degreasing systems
Solvents, cleaners
Cost effectiveness
KlOENTIFIE«S>OPtN ENDtO TERMS
Control techniques
Oegreasers
Organic compounds
Economic analysis
COSATI I ICIJ
13B
13H
ilK
14A
'•i. ai5:'rilB'JTlON STATEMENT
Unlimited
19. SECURITY CLASS •!nnHrfi
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DISCLAIMER
This report has been reviewed by the Industrial Environ-
mental Research Laboratory, Cincinnati, U.S. Environmental Pro-
tection Agency, and approved for publication. Approval does not
signify that the contents necessarily reflect the views and
policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorse-
ment or recommendation for use.
11
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FOREWORD
When energy and material resources are extracted, processed,
converted, and used, the pollution related impacts on our en-
vironment and even on our health often require that new and
increasingly more efficient pollution control methods be used.
The Industrial Environmental Research Laboratory - Cincinnati
assists in developing and demonstrating new and improved method-
ologies that will meet these needs both efficiently and economi-
cally.
This report presents the results of Phase II and III of an
investigation into the control of air pollutant emissions from
the vapor degreasing process. The study was performed to devel-
op improved methods for operation and control of degreaser to
reduce solvent emissions rates. The results are being used
within the Agency's Office of Research and Development as part
of a larger effort to develop improved technologies for reducing
volitile organic compound discharges to the atmosphere from
metal finishing industries. The findings will also be useful to
other Agency comoonents and industry in dealing with environmen-
tal control problems. The Nonferrous Metals and Minerals Branch
of the Energy Pollution Control Division should be contacted tor
additional information concerning this program.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
111
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CONTENTS
Psaje
Foreword iii
Figures vi
Tables ix
Acknowledgment xi
1. Introduction j.
2. Phase 2 Test Conditions 4
Crosscurrent air velocity 4
Automatic lid 8
Freeboard ratio 15
Refrigerated freeboard chiller 15
Solvent 15
Hoist speed 15
3. Phase 2 Test Results 16
Method analysis 16
Effect of crosscurrent air velocity 18
Effect of freeboard ratio 44
Effect of refrigerated freeboard chiller 44
Effect of automatic ]id 47
Results of tests of hoist speed 48
4. Phase 2 Conclusions and Recommendations 49
Conclusions 49
Recommendations 50
5. Pha.~e 3 Test Conditions 51
Air velocity measurement system 51
laboratory tesLs with 1,1,1-tnchloroethane 55
f.aboratory tests with nethylene chloride 55
Laboratory test without solvent 55
Laboratory tests with sncke 56
Field tests 56
IV
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CONTENTS (continued)
Page
6. Phase 3 Test Results 57
Laboratory tests with 1.1,1-trichioroethane 57
Laboratory tests with rnethylene chloride 73
Laboratory test without solvent 80
Laboratory tests with smoke 82
Field tests 83
7. Phase 3 Conclusions ind Recommendations 84
Conclusions 84
Recommendations 85
.
Appendix A Reduction of Phase 2 Test Data 87
Appendix B Phase 2 Test Conditions and Results 301
Appendix C Reduction of Phase 3 Test Data 311
Appendix D Phase 3 Test Conditions and Results 494
Appendix E Average Draft Velocities Across Degreasers 501
NOTE: If the above appendices are required, copies
r.:ay be obtained by contacting:
Charles Darvin
Industrial Environmental
Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
v
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FIGURES
No. Page
1 Location of Fan and Air Velocity Measuring
Positions in Relation to Degreaser B during
Phase 2 6
2 Sample Output of the Anemometer During Phase 2 7
3 Effect of High Crosscurrent Air Velocity on
Solvent Loss From an Operating Degreaser Using
1,1,1-Trichloroethane 31
4 Effect of Freeboard Ratio on Solvent Loss From an
Operating Degreaser Using 1,1,1-Trichloroethane
at Different Target Air Velocities 32
5 Effect of Refrigerated Freeboard Chiller on Solvent
Loss From an Operating Degreaser Using 1,1,1-
Trichloroethane at 75 Percent Freeboard Ratio 33
6 Effect of Refrigerated Freeboard Chiller on Solvent
Loss From an Operating Degreaser Using 1,1,1-
Trichloroethane at High Crosscurrent Air
Velocities 34
7 Effect of Refrigerated Freeboard Chiller on Solvent
Loss From an Operating Degreaser Using 1,1,1-
Trichloroethane at High Crosscurrent Air
Velocities 35
8 Effect of High Crosscurrent Air Velocity on Solvent
Loss From an Operating Degreaser Using Methylene
Chloride 36
9 Effect of Freeboard Ratio on Solvent Loss From an
Operating Degreaser Using Methylene Chloride 37
10 Effect of Refrigerated Freeboard Chiller on Solvent
Loss From an Operating Degreaser Using Methylene
Chloride at 75 Percent Freeboard Ratio 38
11 Effect of Refrigerated Freeboard Chiller on Solvent
Loss From an Operating Dejreaser Using Methylene
Chloride at 125 Percent Freeboard Ratio 39
vi
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FIGURES (continued)
No.
12 Effect of Refrigerated Freeboard Chiller on Solvent
Loss From an Operating Degreaser Using Methylene
Chloride at High Crosscurrent Air Velocities 40
13 Effect of Powered Lid on Solvent Loss From an
Operating Degreaser Using 1,1,1-Trichloroethane
at High Crosscurrent Air Velocities 41
14 Effect of Automatic Lid on Solvent Loss from an
Operating Degreaser Using 1,1,1-Trichloroethane
at High Crosscurrent Air Velocities 42
15 Effect o-~ Hoist Speed on Solvent Loss From an
Operating Degreaser Using 1,1,1-Trichloroethane 43
16 Fan Stands During Phase 3 53
17 Diagram of Electronic Equipment Used to Measure
Air Velocity at the Degreaser Lip and Integrate
During Phase 3 54
18 Effect of Freeboard Ratio on Solvent Loss from an
Operating Degreaser Using 1,1,1-Trichloroethane
During Phases 1, 2, and 3 63
19 Effect of High Crosscurrent Air Velocity on Loss
from an Operating Degreaser Using 1,1,1-
Trichloroethane During Phase 3 64
20 Effect of Freeboard Ratio on Solvent Loss fron an
Operating Degreaser Usxng 1,1, l-Trichloroet'.iane
at Different Target Air Velocities During Ihase 3 65
21 Effect of Refrigerated Freeboard Chiller on Solvent
Loss fron an Operating Degreaser During 1,1,1-
Trachloroethane at a Target Air Velocity of
0.67 m/s (132 ft/min) During Phase 3 67
22 Effect of Automatic Lid, Freeboard Ratio, and
Refrigerated Freeboaid Chiller on Solvent Loss
from an Operating Degreaser Using 1,1,1-Trichloroe-
thane at a Target Air Velocity of 0.67 m/s
(13? ft/mm) During Phase 3 69
23 Effect of Ambient Temperature on Rate of Solvent
Loss from Degreasers A and B During Test 136 70
24 Results of Test 157 72
vii
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FIGURES (continued)
No.
25 Effect of Freeboard Ratio on Solvent Loss
from an Operating Degreaser Using Methylene
Chloro.de During Phases 1 and 3 74
26 Effect of Freeboard Ratio on Solvent Loss from
an Operating Degreaser Using Methylene Chloride
with Refrigerated Freeboard Chiller During Phase 3 79
27 Effect of Refrigerated Freeboard Chiller on solvent
Loss from an Operating Degreaser Using Methylene
Chloride at a Target Air Velocity of 0.67 m/s
(132 ft/min) During Phase 3 81
Vlll
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TABLES
No. Page
1 Average Velocity Readings Taken Duiing Each Phase
2 Test 9
la Average Velocity Readings Taken During Each Phase
2 Test (English Units) 11
2 Summary of Solvent Loss Data From Phases 1 and 2 for
operating Degreasers Using 1,1,1-Trichloroethane 19
2a Summary of Solvent Loss Data From Phases 1 and 2 for
Operating Degreasers Using 1,1,1-Trichloroethane
(English Units) 20
3 Summary of Solvent Loss Data From Phases 1 and ? for
Operating Degreasers Using 1,1,1-Trichloroethane
With RFC On 21
3a Summary of Solvent Loss Cata From Phases 1 and 2 for
Operating Degreasers Using 1,1,1-Trichlorcethane
With RFC On (English Units) 22
4 Summary of Solvent Loss Data From Phases 1 and 2
for Opera Ling E'egreasers Using Methylene Chloride
With RFC Oft 23
4a Summary of Solvent Loss Data From Phases 1 and 2
for Operating Degreasers Using Methylene Chloride
With RFC Off (English Units) 24
5 Summary cf Solvent Loss Data From Phases 1 and 2 for
Operating Degrea&ers Using Methylene Chloride With
RFC On 25
5a Summary of Solvent Loss Data From Phases 1 and 2
for Operating Degreasers Using Methylene Chloride
With RFC On (English Units) 26
6 Summary of Solvent Loss Data From ^lij^es 1 and 2 for
Operating Degreasers Using 1,1,1-Trichloroethane With
Powered Lid 27
IX
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TABLES (continued)
No. Page
6a Summary of Solvent Loss Data From Phases 1 and 2 for
Operating Degreasers Using 1,1. i.-Tr ichlorethane
With Powered Lid Operating (English Units) 28
7 Summary of Solvent Loss Data From Phases 1 and 2
for Operating Degreasers With Hoist Speed of
0.005 m/s (11 ft/min) 29
7a Summary of Solvent Loss Data From Phases 1 and 2
for Operating Degreasers with Hoist Speed of
0.055 m/s (11 ft/min) (English Units) 30
8 Relationship Between Air Velocity and Solvent Loss
in Phase 2 44
9 Summary of Solvent Loss Data from Phases 1, 2, ..ad
3 for Operating Degreasers Using 1,1.1-Trichloro-
ethane at Calm Air Velocity 58
9a Summary of Solvent Loss Data from Phases 1, 2 and
3 for Operating Degreasers Using 1,1,1-Trichloro-
ethano at Calm Air Velocity 59
10 Summary of Solvent Loss Data from Phase 3 for
Operating Degreasers Using 1,1,1-Trichloroethane
at Calm and High Air Velocities 61
lOa Summary of Solvent Loss Data from Phase 3 for
Operating Degreasers Using 1,1,1-Trichloroethano
at Calm and High Air Velocities 62
12 Summary of Solvent Loss Data from Phase 3 for
Operating Degreasers Using Methylene Chloride
at Calm and High Air Velocities 77
12a Summary of Solvent Loss Data frc-n Phase 3 for
OporaLing Degreasers Using Methylene Chlofide
at Cain and High Air Velocities 78
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ACKNOWLEDGEMENTS
This report was prepared for the Industrial Environmental
Research Laboratory of the U. S. Environmental Protection
Agency at Cincinnati, Ohio. It was conducted under contract
to Centec Consultants Incorporated and PECDO Environmental,
Inc. Mr. Charles H. Darvin was the project officer. Tne
American Society for Testing Materials (ASTM) Committee D-26
on degreasing provided assistance in defining and formulating
the test program. Centec Consultants Inc., and PEDCO Environmen-
tal, Inc., appreciates the direction and extensive review
provided by industry and ASTM. Thanks are also extended to
the companies which provided assistance and degreaser units
for this test program. They include Au'osonics Inc.; Baron-
Blakeslee, Inc.; Branson Cleaning Equipment Company; Detrex
Chemical Industries, Inc.; and many other degreaser system
manufacturers and users.
Mr. Richard W. Gerstle served as PEDCO Project Director
tor Phase 2 and Mr. Rooert D. Wilson, for Phase 3. Mr. Edmund
S. Schindlcr was Projecc Manager.
XI
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SECTION 1
INTRODUCTION
The U.S. Environmental Protection Agency (EPA) initiated a
research program to evaluate the solvent loss reduction capabil-
ities of various degreaser modifications, controls, and oper-
ating practices on open-top vapor degreasers. PEDCo Environ-
mental, Inc., was contracted to carry out the research program.
The American Society for Testing and Materials (ASTM) was asked
to assist EPA in defining and formulating the test program and
reviewing its progress. A special ASTM subcommittee of Commit-
tee D-26 on degreasers was established for this purpose.
The program began with the writing of a detailed test plan,
which was submitted to EPA for technical review.* The plan
provided details of tests, test location, types of solvents,
variables and control modifications to be tested, parameters to
be measured, and test procedures. The test plan was implemented
after approval by EPA. The results of these tests, which are
referred to as Phase 1, were presented in the report "Evaluation
of Solvent Loss From Vapor Degreaser Systems."!
Phase 1 quantified the ability of a control device to
reduce solvent loss from a job-shop-size degreaser at the ideal
operating conditions suggested by the manufacturer and EPA. It
also tested the effect of nonideal operating conditions on
solvent loss, but did not evaluate the effectiveness of control
devices operating at nonideal conditions. The test data showed,
nowever, that a slight draft across the lip of the degreaser
increased solvent loss dramatically. On the basis of this
PEDCo Environmental, Inc. Degreasir Systems Evaluation Test
Plan. Prepared under EPA Contract No. 68-02-2535, Task No. 3.
Cincinnati, Ohio, March 1978.
PEDCo Environmental, Inc. Prepared under EPA Contract No.
68-02-2535, Task No. 3. Cincinnati, Ohio, October 1979.
-------
increase, the EPA decided that control devices should be eval-
uated for the ability to control solvent loss at two cross-
current air velocities: 0.67 m/s (132 ft/min) and 1.12 m/s (220
ft/min).
Phase 2 comprised the supplemental tests that were per-
formed to supply this evaluation. Tests were also conducted to
supplement the Phase 1 data about variations in hoist speed.
The present report describes only the test conditions that
differ from those of Phase 1. Because the background data,
including test site, solvent, and degreaser descriptions, were
the same as in Phase 1, the reader is referred to the first
report for these data.
Section 2 of the present report describes Phase 2 test
conditions, and Section 3 discusses Phase 2 test results.
Section 4 presents Phase 2 conclusions and recommendations,
which are based on relevant tests in Phase 1 as well as tests in
Phase 2.
Some Phase 2 results were unusual. Although the refrig-
erated freeboard chiller (RFC) substantially reduced solvent
loss when methylene chloride (MC) was used, it substantially
increased solvent loss when 1,1,1-trichloroethane (TE) was used.
Further, Phase 2 results indicated that changing the freeboard
ratio (FR) reduced solvent loss only slightly, regardless of
solvent. Phase 3 was conducted to verify these results and
examine the interaction of air velocity, RFC, and FR.
Section 5 of this report describes the Phase 3 test condi-
tions that differ from those of Phase 1, and Section 6 presents
the results of Phase 3 tests. Section 7 provides Phase 3 con-
clusions and recommendations based on tests in Phase 3 and on
relevant tests in Phases 1 and 2.
Actual test data are given in five appendixes. Appendix A
presents the Phase 2 raw test data, including the successive
degreaser weights as measured throughout each test and a statis-
tical breakdown of the data. Appendix B summarizes data from
-------
individual Phase 2 tests according to the modifications and
operating conditions used. Appendix C contains the Phase 3 raw
test data, and Appendix D summarizes data from Individual Phase
3 tests.
Although Phase 1 and 2 showed a direct relationship between
solvent loss from a vapoi degreaser and draft velocity across
it, no definitive data were available on average draft veloci-
ties. Thus, the Nonferrous Metals and Minerals Branch of the
Energy Pollution Control Division, with assistance from PEDCo
Environmental, undertook a study to obtain such data. /Appendix
E discusses this study.
The equipment and instrumentation in these tests were
calibrated in English units of measure. Although the data are
given in this report in the International System of Units (SI)
as well as in English units, the original measurements of sol-
vent loss (and all calculations derived from them) v/ere in
English units. The reader is cautioned that data expressed in
SI equivalents can differ slightly from the original data.
-------
SECTION 2
PHASE 2 TEST CONDITIONS
The Phase 2 tests were designed to evaluate the effect on
solvent loss cf high crosscurrent air velocities across the lip
of the degreaser. The tests measured the ability of selected
control devices (i.e., modifications and operating conditions)
to reduce solvent loss under these conditions. The system
modifications and operating conditions that were teoted in
combination with the increased air velocity are as follows:
Automatic lid
Freeboard ratio
Refrigerated freeboard chiller
Solvent
A few tests were also conducted to measure the effect of
different hoist speeds on solvent loss. These tests, which were
unrelated to the evaluation of crosscurrent air velocities, were
included to supplement specific test data from Phasi.: 1.
The modifications and operating conditions are cescribed in
the following subsections. Only those that are significantly
different from the Phase 1 tests are discussed in detail.
CROSSCURRENT AIR VELOCITY
Most of the tests in Phase 1 were run under conditions of
calm air at the lip of the degreaser. "Calm air", was defined as
an average velocity of 0.1 m/s (20 ft/min). For the Phase 2
tests, higher air velocities were created by installing two
fans—one for each of the two deyreasers—within the testroom.
-------
Figure 1 shows the locations of the fans and air velocity mea-
suring positions in relation to Degreaser B; the locations are
the same for Degreaser A.
Each fan was 51 cm (20 in.) in diameter and had three motor
Feti.ings: high, or 1700 m3/s (2900 cfm); medium, or 1500 m3/?
(2550 cfm}; a.id low, or about 1200 m3/s (2000 cfm). It was
mounted about j.22 cm (48 in. ) from the degreaser, the bottom of
the fan bfing level with the degrtuser lip. Air velocity mea-
surements were made with a Kurz Model 444 hot-wire anemometer,
NBS traceable calibi. :ioii.
Two target air velocities were used in the tests: 0.67 m/s
(132 ft/min) and 1.12 m/s (220 ft/min). Before each test, air
velocity measurements were taken at six equally spaced points on
a line running 10 cm (4 in. ) above the upwind lip of the de-
greaser. Velocities were changed by adjusting the fan speed or
obstructing portions of the front or back of the fan with tape.
During the test, air velocity measurements were taken at 23
positions on each degreaser. Because only one anemometer was
available, each measurement was taken separately. First, an air
velocity profile lyng within 5 percent of the target velocity
was achieved at the 10-cm level. The probe was then mounted for
15 minutes in the probe stand for each of positions 1 through 6
at the 10-cm level. The sequence of positions was randomly
selected. Air velocity at each of the other 17 positions was
measured for 1 minute during each 6-hour test segment. The
output of the velocity probe was recorded throughout the test.
The probe is very sensitive to turbulence, as shown in
Figure 2. The velocity response curve was fitted to a poly-
nomial equation as follows:
V = 0.268 X2 + 1.648 1C < V < 600 ft/min
where V = velocity (ft/mm)
X = percent of chart
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163 cm
(64 in.)
8
9
10 11
6
5
a
3
2
1
T
n
86 cm 17
(34 In.) *-i-
A
FAN
TOP VIEW DEGCEASCR B
•AIR VELOCITY MEASURING POSITION
. j'o,", 1 Jg
• •
VAPOR
PHASE
LIQUID SOLVENT
• -i- (12 in.) \(
T T T
46 cm
3 (18 in.)
. FAN
C
.... WJ ...
VAPOR
PHASE
LIQUID SOLVENT
TrtONT VIEW JEGREASER B
SIDC VIEW DECREASES B
Figure 1. Location of fan and air velocity measuring positions in relation to Degreaser B
during Phase 2.
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£ 1-5 (300)
n
*•»
* 1.0 (200)
>-
t—
»—«
o
* 0.50 (100)
S 0.25 (50)
00
O
0.05 (10)
-70--
-.10
CHART SPEED,
0.508 cm/min (0.2 in./min)
Figure 2. Sample output of the anemometer during Phase 2.
7
-------
During actual testinq the anemometer chart was read visu-
ally, and the readings were not integrated over the time period.
The portion of the chart presented in Figure 2 shows air
velocity fluctuations from 0 to 1.08 m/s (0 to 212 ft/min);
0.406 m/s (80 ft/min) was the visual average of the portion of
the chart presented in Figure 2.
Table 1 lists the average velocity readings for each test
at positions 1 through 6 [at 10 cm (4 in.}, 30.5 cm (12 in.),
and 46 cm (13 in.) above the degreaser lip] and at positions 7
through 11 [at 10 cm (4 in.) above the degreaser lip].
AUTOMATIC LID
A biparting lid designed for Degreaser A closed automati-
cally whenever the load was removed from the degreaser. Lid
controls were integrated into che timer controls for the hoist
system. The lid remained totally closed for 98 out of 391
seconds, or 25 percent of the time required for each load cycle.
This figure excludes closing and opening times of 20 seconds
each.
The lid was installed so that the top closed at a level
that would be considered 55 percent FR. Baffles were added to
increase the FP to 75 percent. The lid could not be installed
directly on top of ; 75 percent FR collar modification because
the motor housings were located on the ends of the lid and would
obstruct airflow. This would be inconsistent with the intent to
test the lid on a degreaser with a 75 percent FR. The motor
housing extended up to a level that would be considered 92
percent FR. Although the housing would not act as a 92 percent
FR, its exact effect couH not be quantified and was thus not
correlated with other tests in the series. The motor housings
were removed, and the lid was installed directly on the 50
percent FR degreaser; the baffles were added to increase FR to
75 percent.
8
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TABLE 1. AVERAGE VELOCITY READINGS TAKEN DURING EACH PHASE 2 TEST
Test
No.
101
102
103
104
105
106
107
108
109
110
111
112
113
Dogreastr
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
Target
velocity,
m/s
0.67
0.67
1.12
1.12
0.67
0.6?
1.12
1.12
0.67
0.67
1.12
1.12
0.67
0 67
1.12
1.12
Calm
Calm
0.67
Calm
1.12
1.12
0.67
Calm
1.12
Average velocity of positions 1 through 6, m/s
J>t 10 cm
above lip
0.60
0.69
0.99
1.14
0.36
0.77
0.69
0.91
0.69
0.68
1.03
0.92
0.70
0.57
1.C3
1.12
Calm
Calm
0.45
Calm
1.17
0.51
Calm
1.28
At 30 en
above lip
0.39
0.41
0.67
0.66
0.34
0.94
0.51
0.96
0.33
0.49
0.67
1 46
0.20
1.19
0.66
0.34
0.22
0.58
0.20
0.55
At 46 cm
above lip
0.20
0.23
0.27
0.30
0 09
0.61
0.28
0 4S
0.23
0.30
NA
1.06
0.07
0.94
0.4/
0.10
0.11
0.36
0.07
O.IS
Average velocity at 10 an above, lip, m/s
Average for positions
7 through 9
0.09
0.11
0.11
0.32
0.10
0.27
0.33
0.16
0.27
0.05
0.21
At posi-
tion 10
0.20
0.15
0.10
0 36
0.19
0.29
0.41
0.19
0.10
0.41
O.C8
0.20
At posi-
tion 11
0.03
0.05
0 05
0.08
0.29
0.11
0 26
0.37
0.05
0.41
0.20
0.56
(continued)
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TABLE 1 (continued).
Test
No.
114
115
116
117
118
119
120
121
122
123
124
125
126
Oegreaser
A
B
A
B
A
B
A
B
A
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
Target
velocity,
m/s
0.67
0.67
1 12
1.12
1.12
1.12
0.67
0.67
0.67
0.67
1.12
1.12
0.67
0.67
1.12
1.12
Cairn
Cain
Average velocity of positions 1 through 6, m/s
At 10 cm
above lip
0.70
0.78
1.05
1.04
1.09
1.21
0.52
0.57
0.39
0.89
0.90
1.15
0.60
0.50
1.06
0 91
0.09
0.06
At 30 cm
above IID
0.46
0.60
0.30
0.62
1.07
0.96
0.94
0.47
0.55
0.76
0.84
0.72
0.92
0.68
1.22
1.06
0.08
0.08
At 46 cm
above Up
0.19
0.33
0.09
0.23
0.43
0.17
0.58
0.39
0.40
0.34
0.40
0.29
0.59
0.41
1.00
0.54
0.10
0.10
Average velocity at 13 cm above, lip. n/s
Average for positions
7 through 9
0.04
0.10
0.29
0.20
0.19
0.57
0.05
0.05
0.19
0.21
0.30
0.20
0.98
0.05
0.12
0.18
At posi-
tion 10
0.10
0.20
0.27
0 IB
0.41
0.51
0.05
0.08
0.11
0.29
0.25
0 33
0.36
0.03
0.47
0.56
At posi-
tion 11
0.13
0.15
0.29
0.79
0.66
0.79
0.51
0.05
0.09
0.29
0.15
0 56
0.08
0.03
0.30
0.36
(continued)
-------
TABLE 1 (continued)
Test
1.0.
127
128
129
130
131
132
133
134
135
Degrcaser
A
B
A
B
A
B
A
B
B
A
6
A
a
A
B
A
B
TjrrjL't
velocity.
n/s
Call
Cain
Cain
Cain
0.67
0.67
Cain
Cain
Cain
Average vclocil) of position-. 1 through 6. n/s
At 10 en At 30 cm
above lip | above lip
0. \f
0.09
0 09
0.06
0.74
0.54
0.13
O.OS
0.13
0.12
0.09
0.10
0.18
0.97
0.06
At 46 en
above Up
0.14
0 10
1.67
0 10
0.03
0.47
0.06
Averane velocity at '0 cm .^ivc, lip. m/s
Average 'or positions
7 through 9
0.10
0.09
0.10
0.09
0 03
0.22
O.OS
0.06
At posi-
tion 10
0 04
0.08
0.07
0.18
0.18
0.25
0.05
0.10
At posi-
tion 11
0 06
0 03
0.04
0.10
0.46
O.OS
O.OS
O.OS
-------
TABLE la. AVERAGE VELOCITY READINGS TAKEN DURING EACH PHASE 2 TEST
(English Units)
10
Test
No
101
102
103
IG4
105
106
107
108
109
HO
111
II?
113
Dcgrtasrr
;
D
A
II
*
B
A
a
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
Target
velocity.
ft/nln
112
13?
220
??0
112
13?
220
?20
13?
13?
220
220
132
132
220
220
Cain
CaLn
132
Cain
220
?:0
13?
Calm
""
Average veloc
At 4~ In.
atovc lip
119
135
195
?24
£9.6
151
135
ISO
136
134
203
181
138
-.13
202
?21
CalT
Cain
US
Calm
230
100
Cain
*"
ty of (Millions 1 in
At 12 in. ~ "
above lip
76.9
M) B
131.7
130
£6
186
110
IDS
65 8
95 8
132
287
40
134
i:«
66
4j.5
MS
38. 5
108
rough 6. ft/Bin
""At "18 In"
abo/e Up
38 61
4S.22
S3. 33
60.0
18
121
:s
89
4S
SB. 3
NA
201)
14
1B6
93
19
22
71
13
29
Average velocity at 4
Average for positions
7 through 9
18.33
21 67
20. B3
63 33
70.0
52.22
65
32
S2.S
10
42.22
n. above I)
At posi-
tion 10
40
30
20
70
36.67
S6.67
BO
38 33
20
BO
IS
SO
p. ft/Bin
A~t posi-
tion II
S
10
10
IS
S6.67
21.67
M.67
72
10
80
40
110
(continued)
-------
TABLR la (continued)
Ul
lei!
ho
114
US
116
11;
IIH
119
120
1?)
u:
173
124
12:
126
Drqiuser
A
b
A
B
A
B
A
Target
veludly.
ft/mln
132
A»eidic veloi
At 4 in
atove Up
ity of pull lions 1 th
At .' In.
itmve lip
1
!
1
iU j 90 B
8 132 ' 154 i 117.5
1
t ??3 ?C6 1 M ?
B 270 204 > ,<2 9
B
i
ryuytt 6. ft/Bin
At IB Li.
..'
45.4
220 , 214 I 210 j 85
220 219 ! 1B6 32. 5
* 11? 10? IB4.!,
B 13? i 112 91.7
A
B
132
132
76.4
Uf
107.5
<49
A 220 178 66
B
A
B
A
B
220
227
M?. IS
132 ! 130 ! 102
115
77 5
79.2
66 1
79
58
117
132 { 98 6 , 134.6 > U)
;<» 209
22C . 1BO
A Cain
B
;
Cain
IH 33
II 67
:4i
19'
?0i! 106
16
16
20.33
20
Aver«g> velocity at 4
Average fot po'.'lloni
7 tnrough 9
7.3)
20
S6.67
W 0
36 67
111.67
9 67
10
36 67
41.67
60
60
IS
9
22.83
IS
In above 1
At (
-------
TABLE la (continued}
Test
No
171
128
129
130
131
13?
133
134
135
^«
A
B
A
B
A
B
A
B
A
8
A
B
A
b
A
B
A
B
lirgel
vfloctty.
ft An 1.1
. . in
Calm
Calm
132
13?
Calm
Calm
Calm
Cain
Average velocity of positions 1 through 6. ft/nln
At 4 In
aooit li.i
22 67
17 81
17 5
12.17
145
107
26
9.5
It 12 In
above Up
25 81
21.5
18
'9
35 8
191 6
11
At It In.
abbvc Up
is'ij
I) 67
19
6.S
93 3
11.31
Average velocity at 4 In. above lip, ft/nln
Average for positions
7 through 9
19.33
16.67
20
18
5.67
41.33
10
11
At posi-
tion 10
8
16
14
15
35
50
B
13
At posi-
tion 11
12
S
B
20
90
10
10
1C
-------
FREEBOARD RATIO
Freeboard ratio is the fraction (or percentage) that re-
sults when degreaser wall height (above the vapor line) is
divided by the width of the degreaser top opening. In Phase 2,
FR was tested at 75 and 125 percent only.
REFRIGERATED FREEBOARD CHILLER
Two RFC designs were tested in Phase 2: RFC I, with a
refrigerant temperature 2-ange of 1° to 2"C (34° to 36°F), and
RFC II, with a range of -29° to -40°C (-20° to -40°F). The
third RFC design that was tested in Phase 1—RFC II at a range
of -23° to -32°C (-9° to -26°F)~was not tested in this phase.
SOLVENT
As in Phase 1, the two solvents tested in Phase 2 were TE
and MC.
HOIST SPEED
In Phase 1, the hoist speeds tested were 0.04 m/s (8 ft/
min) and 0.08 m/s (16 ft/min). In Phase 2, the hoist speed
tested was 0.055 m/s (11 ft/mm), which is the maximum speed
suggested by manufacturers.
Pullies were used to increase the speed to 0.162 m/s
(32 ft/min), then to reduce it by one-third to 0.055 m/s.
15
-------
SECTION 3
PHASE 2 TEST RESULTS
METHOD OF ANALYSIS
The test program was conducted under a factorial design,
wherein each variable is at a different and distinct level. In
this case, air velocity was tested at the three levels: calm;
0.67 m/s (132 ft/min); and 1.12 m/s (220 ft/min) . The calm air
velocity tests were selected from Phase 1. The RFC was operated
at two levels (off and on), FR was at two levels (75 and 120
percent), and two solvents were chosen (TE and MC). Replication
of each test on a second degreaser was not considered a variable
in the factorial design.
Analysis of variance with tests of significance is the
typical method of evaluating the results. This analysis tells
us, based on mean values and standard deviation, whether the
difference in mean values between tv/o levels of a variable is
caused by something other than chance. Further, it tells us the
probability of error in accepting a difference as significant
when it is in fact caused by chance. The analysis of variance
also indicates th-* interaction of the variables. For example,
as a variable changes from one level to the next it changes the
other variables in one of two ways: by the magnitude or by the
direction of the change.
An initial screening of the data showed some factors that
limit the value of an analysis of variance. A factorial design
using analysis of variance requires a random testing sequence
for the purpose of limiting the effect of variables beyond our
control. A good example of variables beyond our control can be
16
-------
seen in tests that are separated by a long tima span. In this
case, a bias is introduced because the tests at the end of the
period may be operated by different personnel than the tests at
the beginning. A random test sequence limits the effect on the
data base of these uncontrollable variables.
Several overriding constraints, however, caused us to
select a test sequence that was not totally random. Solvent
changes required at least 3 to 4 days: the degreasers had to be
drained, dried, boiled out with water and sodium carbonate or
bicarbonate, drained and dried again, and filled with new sol-
vent. Because of the large effort involved in changing the
solvent on a random basis, it was decided to operate the tests
in two sets, each with a different solvent. This test method
limits the comparison of the two solvents in terms of absolute
values of solvent loss, but does not limit the comparison of the
effects of the other variables on each solvent.
Another constraint was the use of calm air tests from Phase
1, which was separated by many months from Phase 2. This bias
rfas acceptably reduced by rerunning three Phase 1 tests at the
beginning of Phase 2.
A third constraint was the discovery, shortly after Phase 2
testing started, that RFC II was defective. Consequently, tests
using the RFC' s were postponed until the unit was repaired, and
the teiit'ng of ether variables continued. The possibility of a
time bias was recognized, but testing had to stop for 1 month
while the chiller was repaired. An additional test without the
RFC's was added near the end of the tests to flag any bias prob-
lems resulting from this change in schedule.
Another requirement of a factorial design is the setting of
variables at levels that are consistent from one test to the
next. The measured airflow over the degreaser at 10 cm did not
meet this requirement. Before each test, the windspeed at the
downwind lip of the degreaser was set within + 5 percent of the
17
-------
two velocities (either 0.67 m/s or 1.12 m/s). This tolerance
would normally be sufficient to meet the requirement of a fac-
torial design. During the test, however, continuous measure-
ments of velocity taken at the 10-cm level showed evorage velo-
cities that were sometimes quite different from the average
obtained at the beginning of the test. The differences were
great enough to prevent this requirement of the factorial design
froir. being met.
Tables 2 through 7 and Figures 3 through 15 present the
test results. Appropriate comparisons with Phase 1 data have
b> .n included.
EFFECT OF CROSSCURRENT AIR VELOCITY
Pests on operating degreasers using TE and MC showed a
direct relationship between air velocity at the lip and solvent
loss rate. As the velocity increased the solvent loss in-
crea- ed, and the rate of increase in solvent loss increased with
increasing air velocity. Three different air velocities were
used in tests of an operating degreaser with RFC off, load area
of 50 percent, hoist speed of 0.04 m/s (8 ft/min), FR of 75
percent, and using TE. When compared with the base case,*
solvent loss decreased by a range of 7 to 25 percent at calm
air; increased by 2 to 13 percent at 0.67 m/s (132 ft/min): and
increased by 65 to 144 percent at 1.12 m/s (220 ft/min) (Figure
3). At 125 percent FR (and all other conditions the same), a
similar effect was observed in relation to the base case (Figure
3). Changes in solvent loss ranged from a decrease of 4 percent
to an increase of 31 percent at calm air, an increase of 64 to
* Base case: Degreaser with 50 percent FR and operating under
conditions of calm air (0.1 m/s, 20 ft/min).
18
-------
TABLE 2. SUMI1ARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2 FOR
OPERATING DEGREASERS USING 1.1,1-TRICHLOROETHANE
vo
d
ex
Ol
IA
41
1
3
101
102
109
105
106
o
ft
b
c
101
102
d
e
106
i
0
Ii
J
.'
.'
.'
/
/
Ol
c
I
c
•1
£
/
.'
.'
.'
/
/
l_
•»
i«
g&.
. i
i£
.'
/
/
.'
/
/
1 U
!=
JC
• w
Ol
L. U
•X A
?H
io-
a* •*-
41 «-»
£2
50
75
75
75
125
125
125
Ai
;•
•25^
0.1
0.1
0.6'
1.12
0.1
0.67
1.12
Ocgreaser A
u
O >, Jl
13— o.
0.59
1 17
0.705
1.03
• irr
1.04
0.97
1.181
2.551
1.363
1.846
1.9C.4
Decrease (Increase)
free base case
kg/h
0.07
(0.141)
(1-511)
(0.323)
(0.806)
(0.924)
I
7.0
(13.2)
(144)
(30.6)
(77.0)
(88.3)
Degreaser B
L
••- *•
a «
O X«l
££fc
3 U
«r1 O •
*?::=
0.69
1.14
0.776
0.92
kg/h
1.00
0.75
I.Oi:
1.651
0.95!
1.641
I.2C.5
Decrease (Increase)
froo base case
kr,/h
0.25
(0.015)
(O.«l)
0 045
(0.640)
(0.265)
%
24.5
(1.73)
(65.4)
4.27
(64.4)
(22.8)
a Hoist speed of 0.04 m/s and a load area of 50 percent unless otherwise Indicated.
Time-weighted average of weight loss of Tests 1, 6. 7. 8 and 89. from Phase 1.
c Time-weighted average of Tests 22. 43, C4. 87 and 90. weioht loss only from Phase 1.
Tine-weighted average of Tests IDS. 127 and 129; wetqht loss and air velocity at lip only.
Time-weighted average of Tests 105 and 130; weight loss and air velocity at lip only.
-------
TABLE 2a. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2
OPERATING DEGREASERS USING 1,1,1-TRICHLOROETHANE
(English Units)
FOR
Test conditions
o
z
o.
o
Ol
o»
1
3
101
10J
109
105
106
z
fc*
u
J,
C
101
102
d
e
106
c
o.
o
-*
.'
/
.'
.'
.'
.'
Ol
c
•—
o
c
of
0
./
,'
/
/
/
.'
%,s
k c
S u
1?
t. o
0. u
,'
,'
.'
/
,'
.'
1 L.
u u
«*- o
ac JQ
|o
i- a
u. k
50
75
75
75
125
125
01 Q
w
a a
a, w «.
01 •- E
i- u <
« o •-*
l- — »-
20
?0
132
220
20
132
220
Solvent loss data
Degreaser A
L.
•o >*•*-
1. •- <*.
S5 ai •-
s: > —
119
195
139
203
Ib/h
2.30
M4
1.604
i 623
1.004
1 072
1-330
Decrease (Increase)
from base case
Ib/h
0.16
(0.304)
(3.323)
(0 705)
(1./72)
(2.030)
t
7.0
(13.2)
(144)
(30.7)
(77 0)
(88.3)
Degreaser B
k
n a r-
•o x*-.
£"£
a u
x > •—
135
224
153
181
Ib/h
2.20
1.66
2 238
3.639
2.106
3 618
2.780
Decrease (Increase)
from base case
It/h
0 54
(0.038)
(1 439)
0.094
(1.418)
(0.589)
1
24.5
(1.73)
(65.4)
4.27
(64.5)
(26.8)
a Hoist speed of 8 ft/mm and t load area of 50 percert unless otherwi'c indicated.
" limo-weiijliieJ average of weight loss of Tests 1. 6. 7. 8. and 89, from Phase 1.
c Tune-weighted average of Tests 22, 43, 84, 87, and 10, weight loss only from Phase 1.
d Tune-weighled average of Tests 109, 127. ard 129, weight loss and air velocity at lip only.
e Time-weichted average of Tests 105 and 130, weight loss anrl air velocity at lip only.
-------
TABLE 3. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2 FOR
OPLRATING DEGREASERS USING 1,1,1-TRICHLOROETHANE WITH RFC ON
Test conditions*
d
3C
OL
S
01
ft-
1
3
16
17
103
104
18'
107
108
°
Ml
«l
ft-
b
c
d
e
103
104
30
107
108
c
Ql
O
•o
/
/
/
/
/
/
/
/
g-
^
o
*4
O*
>
5
./
/
/
/
/
/
/
/
u
rt
gs
•eg
O. U
/
/
/
/
/
/
/
/
1 k
8-
£
• U
11
/
/
/
/
/
/
kM
.
3 U
0.35
0.63
0.70
1.02
kg/h
1.04
0.97
0.99
0.96
1.B38
2.964
0.68
1.736
4.172
Decrease (Increase)
fron base case
kg/h
0.07
0.05
0.08
(0.798)
(1.924)
0.36
(0.696)
(3.132)
S
7.0
5.2
8.3
(76.7)
(184)
34.8
(66.4)
(300)
Degreaser B
k
a to
V >* wi
3 U
I/I o •
to r- a
0.766
0 876
0 57
1.12
kg/h
1.00
0.75
0.92
0.82
2.277
2.598
0.13
2.061
1.635
Decrease (Increase)
fron: base case
Ig/h
0.25
0.08
0.18
(1.277)
(1.598)
0.47
(1.061)
(0.68S)
S
24.5
7.7
18.2
(128)
(160)
47.3
(107)
(68.9)
Hoist speed of 0.04 m/s and a load area of 50 percent unless otherwise Indicated.
b Time-weighted average (TWA) of weight lost of Tests 1.6. 7, 8, and 89 from Phase 1.
c TWA of Tests 22. 43. 84. 87. and 90. weight loss only, from Phase 1.
d TWA of weight loss of Tests 11, 14. 19, 25. 34. and 88 for Jtgreaser A; 19. 25. and 34 for Degreaser B. from Phase 1.
e TWA of weight loss of Tests 18 and 86 for Degreaser A; Test 18 for Uegreaser B. from Phase 1.
Test djta from Phase 1.
-------
TABLE 3a. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2 FOR
OPERATING DEGREASEPS USING 1.1,1-TRICHLOROETHANE WITH RFC ON
(Engl.sh Units)
Test conditions*
.
c-.
§
Ol
HI
1
•3
16
17
103
104
18f
107
108
O
lA
b
c
d
e
103
104
30
107
:os
1
o
•o
/
J
/
J
J
J
j
J
J
Ol
c
I
•*
c
V
a
/
/
.'
/
/
/
/
/
Primary
condenser
J
/
/
/
/
/
/
/
1 U
vr—
L. .—
ll
te a
J
J
/
/
/
/
Freeboard
ratio. 1
50
75
50
75
75
75
125
125
125
ii
iZ
IP
-------
TABLE 4. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2 FOR
OPERATING DEGREASERS USING METHYLENE CHLORIDE WITH RFC OFF
to
Ul
Test conditions8
i
OL
01
frl
VI
o
t-
34 1)
35b
117
118
36"
120
119
3
-•— E
0.1
0.1
0.67
1.12
0.1
0.67
1.12
Solvent loss data
Degreaser A
k
ID ID
•o >» in
3~0 E
I/I O •
ID— OL
z >^-
0.70
1.05
0.52
1.09
kg/h
0.78
0.61
3.001
5.767
0.59
1.889
3.634
Decrease (Increase)
from base case
kg/h
0.17
(2.22)
(4.98)
0.19
(1. 11)
(2.854)
X
21.6
(287)
(644)
24.6
(144)
(369)
Oegreaser B
~- «j>
a ID
«£•"
3 U
VI 0 •
Q *~ n
z >-
0.78
1.04
0.57
1.21
kg/h
1.05
0.87
1.444
2.377
0.78
1.234
4.077
Decrease (Increase)
from be:e case
kg/h
0.18
(0.39)
'.2.26)
0.27
(0.18)
(3 027)
X
17.2
(37.2)
(126)
26.3
(17.2)
(288)
b Hoist ipecd of 0.04 n/s and a lo«d area of 50 percent unless otherwise Indicated.
Test results fron Phase 1.
-------
TAbL£ 4a. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2
OPERATING DEGREASERS USING METHYLENE CHLORIDE WITH RFC OFF
(English Units)
FOR
to
.fo
Test conditions"
o
z
a
3
Ol
ai
34"
3"5b
n/
118
36b
120
119
d
*>
Wl
•1
37
74
117
118
41
120
119
i
/
/
/
/
/
/
?
i
**
s
>
3
J
j
/
J
/
/
*i
•a ai
^1
a. v
J
J
/
/
/
/
«l-^
• U
•ss
eta
?M
lo
ti
U. k
50
75
75
75
125
125
115
i •
•i a.
u
a «
li§
20
20
132
220
20
132
220
Solvent lost data
Degreaser A
!•
— «-» C
V X--*
QJ *J «H
3 O
•o ^~ o
138
206
102
214
Ib/h
1.71
1.34
6.616
2.715
1.29
4.164
8.012
Decrease (Increase)
frora base case
Ib/h
0.37
(4.906)
(11.005)
0.42
(2.454)
(6.302)
1
21.6
(287)
(644)
24.6
(144)
(369)
Degreaser B
— *• e
154
204
112
239
Ib/h
2.32
1.92
3.183
5.241
1.71
2.720
8.990
Decrease (Increase)
from base case
Ib/h
0.40
(0.863)
(2.921)
0.61
(0.40)
(6.670)
*
I/. 2
(37.2)
(126)
26.3
(17.2)
(208)
* Hoist speed of 8 ft/mln and a load area of 50 percent unless otherwise Indicated.
Test results from Phase 1.
-------
TABLE 5. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2 FOR
OPERATING DEGREASERS USING METHYLENE CHLORIDE WITH RFC ON
to
Ul
lesi conoi lions
o
a.
o
k
w
£
34b
35h
4jb
44b
121
122
36b
45b
123
124
o
z
37
74
38
75
121
122
41
42
123
124
C
oj
0
_J
/
/
/
J
/
/
/
/
/
ai
c
*o
&
/
/
/
/
/
/
J
/
/
k.
gtl
^•s
k O
a. w
/
/
/
/
/
.'
/
J
/
1 k
<•- *^
• u
Of O
QC A
/
/
/
/
/
/
v
j> r>
i £
50
75
50
75
75
75
125
125
125
125
1 »
t-
10 i«
a! »*
L'-C
, ^ L
0.1
0.1
0.1
0.1
0.67
1.12
0.1
0.1
0.67
1.12
»aiveni toss aaia
Oegreaser A
f 4J
V *t l/l
O «J ^.
30 C
vt o *
0.387
0.97
0.66
1.06
kg/h
0.78
0.61
0.88
0.73
1.515
2.582
0.59
0.59
1.607
2.649
Decrease (Increase)
from base case
kg/h
0.17
(0.10)
0.05
(0.74)
(1.80)
0.19
0.19
(0.83)
(1.87)
J
21.6
(13.5)
6.4
(95.3)
(233)
24.5
24.6
(107)
(241)
Degreaser B
- S
T3 X V!
S.2 i
0.894
1.157
0.50
C.919
kg/h
1.05
0.87
C 89
0.59
1.575
1.849
0.78
0.41
0.806
1.217
Decrease (Increase)
from base case
kg/h
0.18
0.16
0.4*
(0.525)
(0.799)
C.27
0.64
0.244
(0.167)
S
17.2
15.5
44.0
(49.7)
(75.7)
26.3
61.2
23.4
(15.6)
a Hoist speed of 0.04 m/s and a load area of 50 percent unless otherwise Indicated.
Test results from "hase 1.
-------
TABLE 5a. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2 FOR
OPERATING DEGREASERS USING NETMYLENE CHLORIDE WITH RFC ON
(English Units)
Test conditions'
a.
s
er.
•j
ai
34b
3Sb
43b
47b
121
122
36b
45b
123
124
i
£
1—
37
74
38
75
121
122
41
42
123
124
c
a*
ex
o
J
,
/
/
/
/
/
/
J
J
J
O)
c
8
c
•y
J
/
/
/
/
/
/
/
/
i.
•S ?
£ 8
/
/
/
/
/
.'
/
/
/
1 L.
JC
*»- IQ
01 O
/
/
/
/
/
/
Tl
!-*«
Io
S =
U. i.
50
75
50
75
75
75
125
125
125
125
1 •
•i ex
u
•*• 4J
fJJ 6
*O O «J
20
20
20
20
132
220
20
20
132
?20
Solvent loss data
Degreaser A
— «J C
«O IO f
Ol •* fc»
1. — «•-
X >^
76.4
178
130
209
Ib/h
1.71
1.14
1.94
1.60
3.339
5.692
1.29
1.29
3.543
5.839
Decrease (Increase)
fron base case
Ib/h
0.37
(0.23)
0.11
(1.629)
(3.982)
0.42
3.42
(1 833)
(4.129)
S
21.6
(13.5)
6.4
(95.3)
(233)
24.6
24.6
(107)
(241)
Degreaser B
k
" *J C
« «•=
i/l O *
22:=
176
227
98.6
180
Ib/h
2.32
1.92
1.96
1.30
3.4'2
4.,, 7
1 71
0.90
1.777
2.682
Decrease (Increase)
from base case
Ib/h
0.40
0.36
1.02
(1.152)
(1.757)
0.61
1.42
0.543
(0.362)
S
17.2
15.5
44.0
(49.7)
(75.7)
26.3
61.2
i23.4.
(16.6)
8 Hoist speed of 8 ft/mln and a load area of 50 percent unless otherwise Indicated.
Test results fron Phase I.
-------
TA*IE 6. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AMD 2 FOR
OP:RATING DEGREASERS USING I,I,I-TRICHLOROETHANE WITH POWERED LID OPERATING
Test conditions*
o
z
(X
Ol
**
Wl
Ol
t-
1
3
112<1
113d
nod
IIId
S
•4
VI
•1
t-
b
c
n;
n:
nc
in
c
Ol
OL
O
•O
_J
/
'
•'
/
y
Solvent boiling
/
/
•'
/
/
Primary
condenser
/
/
/
/
/
«l 0
—
kg/h
Decrease (Increase)
frosa base case
kg/h
S
Moist speed of 0.0*4 n/s ant a load area of 50 percent unless otherwise Indicated.
Tlme-w»1ghted average of weight loss of Tests 1, 6, 7. 8 and 89. from Phase 1.
Time-weighted average of Tests 22. 43. 84. 87 «..H 90, weight loss only. frrr. *!:a«? 1.
Autonv.tlc powered lid totally clo-H r.'i/T»l seconds of cycle.
-------
TABLE 6a. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2 FOR
OPERATING UEG--:/\SERS USING 1,1,1-TRICHLOROETHANE WITH POWERED LID OPERATING
(English Units)
to
CO
Test conditions*
o
O.
k
at
a
t-
1
•3
112d
113d
110d
o
z
*>
•1
b
c
112
113
110
111
3
/
/
/
/
/
?
o
c
3
/
/
/
/
/
k
•1
gw
~?
iS
/
/
/
/
/
• k
«!•—
S- —
ai o
ae a
/
li
v **
U. k
50
75
75
75
75
75
So.
n a
S5|
iS^£
20
20
132
220
13:
220
Solvent loss data
Oegresser A
•^ *• c
»"1
•o x->.
Of *J *•
k ^- *••
a u
mo •
«• - o>
I >^-
100
252
88
230
Ib/h
2.W
2.1«
3.589
8.821
3.935
7.5»4
Decrease (Itj-rease)
fron base case
Ib/h
0.16
(1.289)
(6.521)
(1.635)
(5.224)
1
7 «
(56.0)
(284)
(71.1)
(227)
Degreaser B
— ' «j j:
u ^ *»-
3 U
MO •
V Ol^-
Ib/h
De:rease (Jnrrrase)
from base «.ase
Hoist speed of 8 ft/rain and a load area of 50 percent unless otherwise indicated.
b Time-weighted average of weight loss of Tests 1. 6. 7. 8, and 89. from Phase 1.
c Time-weighted average of Tests 'V, 43. 84. 87, and 90. weight loss only, from Phase 1.
** Automatic powered lid totally closed 98/391 seconds of cycle.
-------
TABLE 7. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2 FOR
OPERATING DEGREASERS WITH HOIST SPEED OF 0.055 m/s (11 ft/min)
vO
Test conditions0
o
z
Q.
•J
VI
01
t-
1
3
125
11"
109
126
S.
+•
b
c
110
33
109
112
1
0
•J
/
/
/
/
/
?
I
Ol
in
/
/
/
/
/
frl
II
k O
a. u
/
/
/
/
/
i i.
Cl —
k •—
e
ae xi
?H
la'
S7
k a
ik k
50
75
75
75
125
125
a> a.
01 *>
k U VI
>-p- E
0.
0.
0.
0.
0.
Solvent loss data
Degreaser A
"O
u
Ol
0.
VI
--- VI
1 E
0.04
kg/h
1.363
Decrease (Increase)
from base case
kg/h
(0.323)
S
(30.7)
Degreaser B
•o
Ol
Ol
a.
IA
X E
0.04
0.04
0.055
0.08
0.04
0.055
kg/h
1.00
0.75
0.909
0.84
0.955
0.733
Decrease (Increase)
from base case
kg/h
0.25
O.C91
0.16
0.045
0.2C7
r.
24.5
8.95
15.9
4.27
26.5
Load a<-ea of 50 percent unless otherwise Indicated.
b Ttor-weighted average of weight loss of Tests 1. 6. 7. 8. and 89. from Phase 1.
c Tirne-we'gV.ed average of Tests 22. 43. 84. 87. and 90. weight loss only, from Phase 1.
Test results from Phase 1.
-------
TABLE 7a. aUKMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 2 FOR
OPERATING DEGRE^SERS WITH HOIST SPEED OF 0.055 m/s (11 ft/min)
(English Units)
OJ
o
Test conditions*
£"
ex
01
••
M
t-
1
'3
1:5
II*
109
120
S
**
«ft
>-
b
c
11C
33
109
112
1
o
•o
-J
/
/
/
/
/
/
Ol
c
"»•
I
*J
1
£
/
/
/
/
/
/
tS
II
tt. U
/
/
/
/
/
/
1 t.
«J —
fc. »~
^ w
c
• o
t«
%- «
ae a
?~
Is
v *•
Ik U
bO
75
75
75
1ZS
1Z5
I*
iZ
« a
t;5c
?o^
20
20
20
20
20
20
Solvent loss data
Degreaser A
•o
K
V*
C
** f
£Z
£Z
8
Ib/h
3.004
Decrease (Increase)
froa base case
Ib/h
0.705
I
30.7
Degreaser B
1
a.
•A
SI
z «-
8
8
11
16
8
11
Ib/h
2.20
1.66
2.003
1.85
2.106
1.617
Decrease (Increase)
from base case
Ib/h
0.54
0.197
0.3S
0.094
0.583
S
24.5
8.95
15.9
4.27
26.5
Load area of 50 percent unless otherwise indicated.
b Time-weighted average of weight loss of Tests 1, 6. 7. 8, and 89. from Phase 1.
c Time-weighted average of Tests 22, 43, 84, 87, and 90. weight loss only, from Phase 1.
Test results from Phase 1.
-------
SHADED POINTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
£ 75% FR
O 125% FR
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAD AREA
RFC OFF
TOO
LJ
- (100)
§
00
£
(200)
(300)
(400)
I
I
I
0.2
(40)
0.4
(80)
0.6
(120)
0.8
(160)
1.0
(200)
1.2
AVERAGE MEASURED CROSSCURRENT AIR VELOCTY, m/s (ft/min)
Figure 3. Effect of high crosscurrent air velocity on solvent
loss from an operating degreaser using 1,1.l-trichloroe^hane.
31
-------
SHADED POINTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
O TARGET AIR VELOCTIY, 0.1 m/s (20 ft/min); RFC OFF
O TARGET AIR VELOCITY, 0.67 m/s (132 ft/min); RFC OFF
A TARGET AIR VELOCITY, 0.57 m/s (132 ft/min)
D TARGET AIR VELOCITY, 1.12 m/s (220 ft/min)
? TARGET AIR VELOCITY, 1.12 m/s (220 ft/min)
RFC OFF
RFC OFF
RFC ON
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAD AREA
(400)
75 100
FREEBOARD RATIO, %
125
Figure 4. Effect of freeboard ratio on solvent loss
from an operating degreaser using 1,1,1-trichloroethane
at different target air velocities.
32
-------
SHADED POINTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
O BOTH RFC'S OFF
D RFC 1 ON; REFRIGERANT TEMPERATURE, >0°C (32°F)
A RFC 11 ON; REFRIGERANT TEMPERATURE, -29° TO -40°C (-20° TO -40°F)
HOIST SPEED, 0.04 m/s (8 ft/min)
SOS LOAD AREA
100
(100)
o
5 (200)
1/1
1/1
O
o
I/I
(300)
(400)
(500)
_L
I
0.2 0.4 0.6 0.8 1.0 1.2
(40) (80) (120) (160) (200) (240)
AVERAGE MEASURED CROSSCURRENT AIR VELOCITY, m/s (ft/min)
Figure 5. Effect of refrigerated freeboard chiller on
solvent loss from an operating degreaser using
1,1,1-trichloroethane at 75 percent freeboard ratio.
-------
SHADED POINTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
O BOTH RFC'S OFF
C RFC 1 ON; REFRIGERANT TEMPERATURE, >0°C (32°F)
A RFC II ON; REFRIGERANT TEMPERATURE, -29° TO -40°C (-20° TO -40°F)
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAD AREA
TOO
(100) -
§
5 (200)
in
<§ (300)
(400) -
0 0.2 0.4 0.6 0.8 1.0 1.2
(40) (80) (120) (160) (200) (240)
AVERAGE MEASURED CROSSCURRENT AIR VELOCITY, m/s (ft/min)
Figure 6. Effect of refrigerated freeboard chiller on solvent loss
from an operating degreaser using 1,1,1-trichloroethane at
125 percent freeboard ratio.
34
-------
SHADED POINTS: PHASE 1 DATA
UNSHADED POINTS: PHASE 1 DATA
O RFC I; REFRIGERANT TEMPERATURE, >0°C (32°F); 75% FR
D RFC I; REFRIGERANT TEMPERATURE, >0°C (32°F); 125% FR
V RFC II; REFRIGERANT TEMPERATURE, -29° TO -40°C (-20° TO -40°F); 75% FR
A RFC II; REFRIGERANT TEMPERATURE, -29° TO -40°C (-20° TO -40°F); 125% FR
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAD AREA
TOO
fee
~ (100) -
o
-------
SHADED POINTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
O 752 FR
A 125X FR
HOIST SPEED, 0.04 m/s (8 ft/min)
502 LOAD AREA
200
(1000)
0.2 0.4 0.6 0.8 1.0 1.2
(40) (80) (120) (160) (200) (240)
AVERAGE MEASURED CROSSCURRENT AIR VELOCITY, m/s (ft/min)
Figure 8. Effect of high crosscurrent air velocity on solvent loss
from an operating degreaser using methylene chloride.
36
-------
SHADED POIHTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
O CALM AIR VELOCITY. 0.1 s;/S (20 ft/min); RFC ON
D TARGET AIR VELOCITY, 0,67 ro/s (132 ft/min); RFC OFF
6 TARGET AIR VELOCITY. 0.67 m/s {132 ft/min); RFC ON
<7 TARGET AIR VELOCITY, 1.12 m/s {220 ft/min); RFC OFF
OTARGET AIR VELOCITV, 1.12 m/s (220 ft/min); RFC ON
HOIST SPEED. 0.04 m/s (8 ft/min)
505 LOAD AREA
75 100
FREEBOARD RATIO, I
125
Figure 9. Effect of freeboard ratio on solvent loss from an
operating degreaser using methylene chloride.
37
-------
SHADED POINTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
A RFC OFF
ORFC I Ofi; REFRIGERANT TEMPERATURE, >0°C (32°F)
DRFC II ON; REFRIGERANT TEMPERATURE, -29e TO -40°C (-20° to -40°F)
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAD AREA
(1000)
0.2 0.4
(40) (80)
AVERAGE MEASURED CROSSCURRENT AIR VELOCITY, m/s (ft/min)
0.6
(120)
0.8
(160)
1.0
(200)
1.2
(240)
Figure 10. Effect of refrigerated freeboard chiller on solvent loss
from an operating degreaser using methylene chloride at
75 percent freeboard ratio.
38
-------
SHADED POINTS: PHASE 2 DATA
UNSHADED OPOINTS: PHASE 1 DATA
A RFC OFF
ORFC I ON; REFRIGERANT TEMFFIWURE, >0°C (3:°F)
DRFC II ON; REFRIGERANT TEMPERATURE, -29° 10 • »0°r. (-20° TO -40°F)
HOIST SPEED, 0.04 m/s (f*./niin)
50% LOAD AREA
200
(200)
(400)
(600)
(800)
(1000)
I
i
) 0.2 0.4 0.6 0.8 1.0 1.2
(40) (80) (120) (160) (200) (240)
AVERAGE MEASURED CROSSCURRENT AIR VELOCITY, m/s (ft/m1n)
Figure 11. Effect of refrigerated freeboard chiller on solvent loss
from an operating degreaser using methylene chloride at
125 percent freeboard ratio.
39
-------
SHADED POINTS: PHASE 2 DAIA
UNSHADED POINTS: PHASE 1 DATA
O RFC I REFRIGERANT TEMPERATURE. O^C (32°f); 75° FR
D RFC II REFRIGERANT TEMPERATURE. 0"C (32°F); 1255 FR
V RFC II REFRIGERANT TEMPERATURE. -?9° TO -40°C
(-20° TO -40°?); 75* FR
A RFC II REFRIGERANT TEMPERATURE. -29" TO -40'C
(-20 TO -40"F); 725" FR
100
(100)
w
| (200)
§ (300)
o
Ul
cc.
3 (400)
h-
X
UJ
5
«" (500)
(60C)
(700)
_L
_L
OFF ON
REFRIGERATED FREEBOARD CHILLER
Figure 12. Effect of refrigerated freeboard chiller on
solvent loss from an operating degreaser using methylene chloride
at high crosscurrent air velocities.
40
-------
SHADED POINTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
D NO AUTOMATIC LID, RFC I OFF
O AUTOMATIC LID, RFC I OFF
S7 NO AUTOMATIC LID, RFC L ON
A AUTOMATIC LID, RFC I ON
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAD AREA
75% FR
THE AUTOMATIC LID IS TOTALLY CLOSES FOR
98 SECONDS DURING EACH 391-SECOND CYCLE
Ul
I/}
-------
D
A
SHADED POINTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
TARGET AIR VELOCITY, 0.67 m/s (132 ft/min); RFC I OFF
TARGET AIR VELOCITY, 0.67 m/s (132 ft/min); RFC I ON
TARGET AIR VELOCITY, 1.12 m/s (220 ft/min); RFC I OFF
TARGET AIR VELOCITY, 1.12 m/s (220 ft/min); RFC I ON
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAO AREA
75% FR
THE POWERED LID IS CLOSED FOR 98 SECONDS
DURING EACH 391-SECOND CYCLE
100
^ (100)
o
o
to
I/O
o
(200)
(300)
NO POWERED LID
POWERED LID
Figure 14. Effect of automatic lid on solvent loss from an
operating degreaser using 1,1,1-trichloroethane at
high crosscurrent air velocities.
42
-------
SHADED POINTS: PHASE 2 DATA
UNSHADED POINTS: PHASE 1 DATA
O HOIST SPEED, 0.04 m/s (8 ft/min)
A HOIST SPEED, 0.055 m/s (11 ft/min)
D HOIST SPEED, 0.08 m/s (16 ft/min)
BOX LOAD AREA
60
50
75 100
FREEBOARD RATIO, %
Figure 15. Effect of hoist speed on solvent loss from an
operating degreaser using 1,1,1-trichloroethane.
-------
77 percent at 0.67 m/s (132 ft/min), and an increase of 27 to 88
percent at 1.12 m/s (220 ft/min). A similar trend was indicated
when the RFC was turned on (Figure 5 and 6).
When MC was used as the solvent, the trend was the same as
when TE was used (Figure 8). Compared with the base case, sol-
vent loss at 75 percent FR decreased by 17 to 22 percent at calm
air; increased by 37 to 287 percent at 0.67 m/s (132 ft/min);
and increased by 126 to 644 percent at 1.12 m/s (220 ft/min). A
similar effect was observed at 125 percent FR. Solvent loss de-
creased by 25 to 26 percent at calm air; increased by 17 to 144
percent at 0.67 m/s (132 ft/min); and increased by 288 to 319
percent at 1.12 m/s (220 ft/min). A similar trend was indicated
when the RFC was turned on (Figures 10 and 11).
When all the data are averaged together (i.e., air velocity
sets grouped with an equal number of each level of the other
variables), a simple relationship can be developed between air
velocity and solvent loss, as shown in Table 8.
TABLE 8 RELATIONSHIP BETWEEN AIR VELOCITY AND
SOLVENT LOSS IN PHASE 2
Velocity
Low:
Medium:
High:
0.1 m/s (20 ft/min)
0.67 m/s (132 ft/min)
1.12 m/s (220 tt/min)
Mean solvent
loss, kg/h (Ib/h)
0.76 (1.68)
1.66 (3. 67)
2.69 (5.92)
Increase (decrease)
from base case, %
(25)
63
163
When an operating degreaser using TE had an automatic lid
installed at 75 percent FR and all other conditions remained the
same, results still showed an increase in solvent loss as air
velocity increased (Figure 13).
EFFECT OF FREEBOARD RATIO
Figures 4 and 9 present the data on the relationship of FR
primarily, but also air velocity and RFC, to solvent loss. The
figures present the results of tests on an operating degreaser
using TE and MC respectively at primarily two different free-
board heights.
-------
An operating degreaser with 125 percent FR, RFC off, load
area of 50 percent, hoist speed of 0.04 m/s (8 ft/min), and
using TE showed a slight decrease in solvent loss when compared
with the same degreaser at 75 percent FR. At calm air and 75
percent FR, solvent loss ranged from 7 to 25 percent below the
base case; at cao.ni air and 125 percent FR, solvent loss in-
creased to a range of 4 percent below to 31 percent above the
base case. At 0.67 m/s (132 ft/min) and 75 percent FR, solvent
loss ranged from 2 to 13 percent above the base case; at 0.67
m/s and 125 percent FR, solvent loss increased to a range of 64
to 77 percent above the base case. At 1.12 m/s (220 ft/min) and
75 percent FF, solvent loss ranged from 65 to 144 percent above
the base case; at 1.12 m/s and 125 percent FR, solvent loss
decreased to a range of 27 to 88 percent above the base case.
In summary, at calm air solvent loss increased as FR increased
from 75 to 125 percent; at 0.67 m/s solvent loss increased as
the FR increased from 75 to 125 percent; while at 1.12 m/s
solvent loss decreased substantially as FR increased from 75 to
125 percent.
When the RFC was turned on (and all other conditions re-
mained the same), the effect of changing the FR from 75 to 125
percent was similar; however, at 0.67 m/s (132 ft/min) solvent
loss increased when the FR was changed from 75 to 125 percent,
and at 1.12 m/s (220 ft/min) it increased for one degreaser and
decreased for the other. There was a slight tendency for the
solvent loss rate to decrease as the FR increased from 75 to 125
percent at three different air velocities and TE solvent.
Similarly, when MC was used the solvent loss also tended to
decrease as the FR was increased from 75 to 125 peicent (all
other conditions remaining the same) (Figure 9). When the RFC
was off, .".t calm air and 75 percent FR, solvent loss ranged from
17 to 22 percent below the base case; at calm air and 125 FR,
solvent loss decreased to a range of 25 to 26 percent below the
45
-------
base case. At 0.67 m/s (132 ft/min) and 75 percent FR, solvent
loss ranged from 37 to 287 percent above the base case; at 0 67
m/s and 125 percent FR, solvent loss decreased to a range of 17
tc 144 percent above the base case. At 1.12 m/s (220 ft/min),
solvent loss on one degreaser increased from 126 to 288 percent
above the base case as FR was increased from 75 to 125 percent;
solvent loss from the other riegreaser decreased from 644 to 369
percent above the base case as FR was increased from 75 to 125
percent. When the RFC was turned on and all other conditions
were the same, the effect on the trend in solvent loss of chang-
ing FR from 75 to 125 percent remained essentially the same.
EFFECT OF REFRIGERATED FREEBOARD CHILLER
Figures 7 and 12 present the data in a form that accentu-
ates the effect of the RFC. The data show that when TE was used
as the solvent the RFC definitely increased solvent loss (Figure
7); when MC was used as the solvent, the RFC definitely de-
creased solvent loss (Figure 12). This interaction is very
unusual and was totally unexpected. The data were examined
thoroughly to determine the cause of this phenomenon, and two
possible explanations can be forwarded: either the RFC actually
increased solvent loss when TE was used or the time lag between
the tests with and without the RFC was sufficient to introduce a
bias into the results. If the tests had been run in random
sequence, the bias could have been minimized.
Test 130 was run for the purpose of confirming either of
the above explanations. This test was a repeat of Test 105, but
was run directly after Test 107 without changing the fan posi-
tion. SoJvent loss increased dramatically from Test 107, RFC
on, to Test 105, RFC off, indicating that the RFC reduced the
rate of solvent loss. Because Test 130 did not confirm the
theory that the RFC increased solvent loss with solvent TE,
comparisons of tests using TE and with RFC off or on cannot be
46
-------
made. When MC is used as the solvent, it can be concluded tnat
the RFC does reduce solvent loss. We suggest, because of ques-
tions about the effect of the RFC with one solvent, that the
effect of the RFC be verified en botn solvents.
EFFECT CF AUTOMATIC LID
Figures 13 and 14 present the results of tests comparing
(against the base case) solvent loss from an operating degreaser
with and vithout automatic lid, and also comparing the inter-
actior of the lid with an RFC. Unfortunately, the results
appear to be influenced by the same time bias that influenced
the RFC results. The tests with and without the automatic lid
and the RFC off were separated by a coupDe of months. These
tests showed that an automatic lid increased solvent loss sub-
stantially, which was contrary to the expected results. It is
very likely that some variable beyond our control changed be-
tween the test with and that without the automatic lid, and
consequently no conclusions can be drawn from this series of
tests.
The tests conducted with RFC on were sufficiently close in
time to keep this bias at a minimum. As sh<~wn in Figure 14,
when an automatic lid was used on an operating oegreasc-r with
RFC on and an air velocity of 0.67 m/s (132 £t/min), a slight
decrease in solvent loss occurred when compared with a similar
degreaser with no automatic lid. When the automatic lid was
used and the air velocity was 1.12 m/s (220 ft/min), a slight
increase in solvent loss occurred when compared with a similar
degreaser with no automatic lid. The conclusion is that the
automatic lid adds no additional control capability if an RFC is
already operating on the degreaser.
47
-------
RESULTS OF TESTS OF HOIST SPEED
In Phase 2, additional tests were included to increase in-
formation about the effect of hoist speed on solvent loss.
Three tests were contemplated, but because of equipment problems
only two of the tests could be run. The new data are plotted in
Figure 15 alongside the data from Phase 1 (see Figure 14 in the
earlier report); only the new data, however, are given in Table
7 (except for the base case). Also shown in Table 7 and Figure
15 are new data from test group 109 at 125 percent FR and
0.04-m/s (8-ft/min) hoist speed. These data replace those for
test group 31, Phase 1, which were questionable because the
cooling water to the load was not turned on during the test.
The results confirm those reported in Phase 1: As hoist
speed is increased, solvent loss also increases. Except for the
data at 75 percent FR and hoist speed of 0.08 m/s (16 ft/min)
and at 125 percent and 0.04 m/s (8 ft/min), solvent loss was
higher (when compared with the base case) ar 0.055 m/s (11
ft/min) ^han at 0.04 m/s, and higher at 0.08 m/s than at 0.055
m/s.
Figure 9 shows the new data at 125 percent FR and hoist
speed of 0.04 m/s (8 ft/min). The data show an increase in
solvent loss as the FR is increased beyond 100 percent. This
anomaly cannot be explained. Because the test was repeated
twice on both degreasers with essentially the same results, the
difference cannot be attributed to chance.
48
-------
SECTION 4
PHASE 2 CONCLUSIONS AND RECOMMENDATIONS
CONCLUSIONS
High Crosscurrent Air Velocity
When crosscurrent air velocity across the lip of the de-
greaser is increased above calm air velocities, solvent Joss
from an operating degreaser increases above the base case (50
percent FR, 0.04 m/s or 8 ft/min hoist speed, and 50 percent
load area) for either solvent. Further, as the average air
velocity across the lip of the degreaser increases to higher
levels, the proportional increase in solvent loss is greater.
Freeboard Ratio at High Crosscurrent Air Velocity
When crosscurrent air velocities are increased, there is
only a slight decrease in solvent loss as the FR is increased
from 75 to 125 percent with either solvent tested. This conclu-
sion is in agreement with Phase I testing, which indicated de-
creasing savings as FR was increased beyond 100 percent.
Freeboard Ratio at Calm Air Velocity
Under calm air conditions, solvent loss appears to increase
as FR is increased from 100 to 125 percent when TE is used as
the solvent and when the RFC is off. When MC is used, however,
solvent loss decreases when the FR is increased to 125 percent.
This conclusion contradicts Phase I results, and should be veri-
fied.
Refrigerated Freeboard Chiller at High Crosscvirrent Air Velocity
With MC solvent, the degreasers using different RFC designs
showed substantial reductions in solvent loss at both high
49
-------
crosscurrent air velocities when the RFC was operated. With TE
solvent, the degreasers using different RFC designs generally
showed substantial increases in solvent loss at high air veloci-
ties when the RFC was operated. Because of this unexpected
result, an additional test was conducted; it did not verify the
initial results. Replication of this series of tests will help
in identifying the factors involved in this unusual set of
results.
Automatic Lid at High Crosscurrent Air Velocity
The automatic lid was tested only with TE, and conclusions
can only be drawn about its effect on this solvent. The lid
siiows a slight decrease in solvent loss when the RFC is used and
an increase in solvent loss when the RFC is not used, when com-
pared with a degreaser operating under the same conditions but
without the lid. This conclusion is contradictory and should
also be verified through additional tests.
Hoist Speed at Calm Air Velocity
An intermediate hoist speed of 0.055 m/s (11 ft/min) was
tested for comparisoi with previously tested speeds of 0.04 m/s
(8 ft/min) and 0.08 rn/s (16 ft/min). As was expected, the re-
sults showed that the 0.055-m/s speed results in greater solvent
loss than the 0.04-m/s speed and less solvent loss than the
0.08-m/s speed.
RECOMMENDATIONS
Based on the above conclusions, we recommend that addi-
tional testing be conducted to verify the effect on solvent loss
of the refrigerated freeboard chiller and the automatic lid, and
to verify the increase in solvent loss when the freeboard ratio
is increased from 100 to 125 percent with solvent TE and cnlm
air conditions. Further, we recommend additional testing of
high crosscurrent air velocity at freeboard ratios of 50 and 100
percent to assess the ability of increased FR as a control tech-
nique under this condition.
50
-------
SECTION 5
PHASE 3 TEST CONDITIONS
The Phase 3 tests were designed to study the relationship
between air velocity and solvent loss control obtainable by usf;
of FR, RFC, and automatic lid. The aim was to use factorial
analysis for distinguishing significant trends from nonsignifi-
cant ones. Combining data from Phases 1, 2, and 3 made such
factorial analysis possible.
The first three Phase 3 tests showed that the baseline rate
of solvent loss from operating Degreasers A and B with TE had
changed. Although replacement of the primary condenser coil in
Degreaser A brought the operation back into design specifica-
tions, it did not restore the previous baseline rate. Because
of the baseline shift, raw data from Phases 1 and 2 cannot be
combined with raw data from Phase 3 in a rigorous statistical
analysis.
The first task in Phase 3 was to solve earlier problems in
air velocity measurement. Then four types of laboratory tests
were run: with TE, MC, no solvent, and smoke. As discussed in
Appendix E, a survey of seven industrial plants was also con-
ducted.
AIR VELOCITY MEASUREMENT SYSTEM
An improved air velocity system was developed for Phase 3
to overcome problems in the previous system design. These
problems included:
0 Inability to achieve the same air velocity from test
to test
0 Inability to maintain constant air velocity during a
test
51
-------
0 Accelerated insti.rr.nent degradation caused by excessive
handling
0 Turbulence
Figure 16 shows t.1 e design of the fan stands during the
Phase 3 tests, and Figure 17 is a block diagram of I .he elec-
tronic equipment used to measure and integrate the data gener-
ated by the air velocity probes. The fan stand design allowed
the relationship between the air velocity probes, fan, and
degreaser lip to be reproduced consistently and the fan and
probe to be raised or lowered easily, as required by changes in
the degreaser freeboard.
A constant-voltage transformer was used to control the
voltage supplied to the fans and thus minimize the fluctuations
in fan blade velocity. Cyclino of electric motors and heaters
and changes in utility system voltage tend to cause such fluctu-
ations. A separate variable transformer was included for each
fan, so that slight differences in fan motor design could be
overcome by adjusting the voltage. Thus, air flow character-
istics could be made very similar for each degreaser.
The electronic signal from the air velocity probe was fed
into a signal multiplier and then into an integrator, and the
integrator output was totaled by electromechanical counters.
Because budget considerations precluded simultaneous integration
of all six signals, only two signals (cne from each degreaser)
were integrated at the same time. Data from two probes were
recorded during each load cycle, which lasted 6.5 minutes.
Thus, a complete set of data from all six probes was recorded
every 19.5 minutes. All available data on ajr velocity were
recorded each hour, and the accuracy of the air velocity probes
was checked before each test.
52
-------
FRONT VIEW OF FAN FOR DECREASES B
SIDE VIEW OF FANS FOR DEGREASER A AND 8
Figure 16. Fan stands during Phase 3.
53
-------
S
ANEMOMETERS
PROBE ELECTION
i-l Vdcl
PORTABLE _
ANEMOMETER
0-5 Vdc
—o •* ,
SO-" T
JUUl
INTEGRATOR
BUFFER/SHOOTHING/BUEFERT"
STRIP CHART 2
SQUARING
INTEGRATOR
EXTRA GAIN
BUFFER/SHOOTHIHG/BUFFERT"
STRIP CHART 2
JUUl
Figure 17. Di igram of electronic equipment used to measure
air velocity at the degreaser lip and integrate data during Phase 3.
-------
LABORATORY TESTS WITH 1,I,1-TRICHLOROETHANX
Phase 3 laboratory tests began with Tests 136, 137, and
138, which were run to determine whether baseline performance
with TE had shifted. After the detection of such a shift, Tests
151, 152, and 153 were performed to obtain additional data on
the new baseline rate of solvent loss. Test 156 was run at the
same conditions as Test 152 to document the effect of a new
primary condenser in Degreat-er A on solvent loss rate. As part
of the shakedown of equipment associated with fans and air
velocity measurement, Tests 154 and 155 were conducted. Other
Phase 3 tests with TE included one (Test 138) at 125 percent FR
and calm airflow with the RCF off to verify unusual data from
Phases 1 and 2 (i.e., results indicating that under some con-
ditions degreaser operation at 125 percent FR can cause more
solvent loss than operation at 100, 75, and possibly even 50
percent FR) and one (Test 136) to determine the effect of two
different ambient temperatures on solvent loss. In addition,
Tests 139 through 145 were run to measure the solvent loss
control obtainable by use of FR, RFC, and automatic lid at high
air velocity (0.67 m/s or 132 ft/min).
LABORATORY TESTS WITH METHYLENE CHLORIDE
Laboratory tests with MC included two (Tests 146 and 158)
to verify the repeatability of laboratory results and four
(Tests 147 through 150) to determine the solvent loss control
obtainable by use of FR and RFC at high air velocity (0.67 m/s
or 132 ft/mm).
LABORATORY TEST WITHOUT SOLVENT
Test 159 was run without solvent in either degreaser, but
with primary cooling water on, RFC off, and heat off. Previous
tests had shown unusual weight gains (C.5 to 1 kg or 1 to 2 Ib)
that lasted 1 or 2 hours, although they disappeared by the end
of each test. Changes in cooling water pressure were believed
to cause these gains.
55
-------
LABORATORY TESTS WITH SMOKE
Tests were performed with smoke to gain information about
the airflow characteristics of each degreaser. This information
was used for modification of the airflow system to correct any
serious imbalances between the two degreasers. Smoke tests were
also used to investigate degreaser operation at the conditions
that produced unusual Phase 2 results with TE (i.e., 125 percent
FR and calm airflow).
FIELD TESTS
Airflow was measured over degreasers at seven industrial
plants to gain information about field conditions versus labora-
tory conditions and give the EPA an appropriate basis for regu-
lations.
56
-------
SECTION 6
PHASE 3 TEST RESULTS
LABORATORY TESTS WITH 1,1,1-TRICHLOROETHANE
Baseline Performance
At the beginning of Phase 3, three tests with TE from
Phases 1 and 2 were selected for repitition to determine whether
baseline degreaser performance had changed. These were the 50,
100, and 125 percent FR tests with RFC off at a calm airflow,
hoist speed of 0.04 m/s (8 ft/min), and load area of 50 percent.
The test at 50 percent FR indicated that solvent loss from the
operation of Degreaser A had increased significantly. Although
solvent loss from Degreaser B had also increased, the increase
was not sufficient to cause concern to the manufacturer of that
unit. An additional test at 75 percent FR was run to obtain
data about new baseline performance at all four FR's previously
tested. Table 9 summarizes baseline solvent loss data from
Phases 1, 2, and 3, and Figure 18 depicts the results of Phase 3
baseline performance tests and comparable earlier tests.
When called in to examine Degreaser A, the manufacturer
noticed that the primary condenser was not performing up to
specifications and required replacement. After replacement,
another test was run at 75 percent FR to observe the effect of
the new condenser. The vapor line dropped 20.3 cm (8 in.) to
the Jesign position, but solvent loss changed only slightly, as
shown in Figure 18.
The most important result of the baseline performance tests
was that FR acted in a similar fashion on both degreasers in
Phases 1, 2, and 3. Additional freeboard effectively controlled
57
-------
TABLE 9. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1. 2, AND 7 TOR OPERATING
DEGREASERS USING 1.1,1-TRICHLOROETHANE AT CALf AIR VELOCITY
Test conditions*
S
OL
S
w
Of
t-
1
3
4d
109e
151
152
137
138
156f
o
w
£
b
c
23
109
51
52
37
138
156
S
O
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,1
/
/
/
/
/
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Ot
c
J>
**
4*
O
v>
,
/
/
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/
/
/
/
'
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/
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i i.
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£2
h. M
0
01 ~-
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50
75
100
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50
75
100
125
75
i •
01 Q.
> *•
i w
• "
0."
•2^1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
Col vent loss data
Degreaser A
"n^^^^™~™
•o a
T3 >, V*
3 U
i^ O "
»> OJ —
E > —
0.1
0.1
0.1
0.1
0.1
0.1
0. i
0.1
0.1
kg/h
1.04
0.97
0.55
1.36
1.58
1.25
1.30
1.17
1.23
Decrease (Increase)
from base case
kg/ii
0.073
0.19
(0.32)
(0.21)
(0.19)
(0.26)
(0.13)
(0.19)
S
6.96
47.0
(30.6)
(51.3)
(20.0)
(24.6)
(12.2)
(17.96)
Degreaser B
^
i o
3 U
in O •
ai ai —
s: > —
0.1
0.1
O.T
0.1
0.1
0.1
0.1
0.1
0.1
kg/h
l.CO
0.75
0.47
0.96
1.16
0.96
0.76
1.00
0.07
Decrease (Increase)
from base case
kg/h
0.25
0.53
0.043
(0.16)
O.C37
0.24
(0.0059)
0.13
S
24.5
53.2
4.27
(16.3)
3.68
24.0
(0.59)
12.9
Moist speed of 0.1 m/s and load ar»a of 50 percent unless otherwise Indicated.
Time-weighted average of weight loss during Tests 1.6, 7. 8, and 89. from Phase 1.
Time-weighted average of weight loss during Tests 22. 43. 84. 87. and 90. from Phase 1.
Phase 1 test.
Phase 2 test.
Rppeat cf Test 152 after replacement of primary condenser coll on Degreaser A.
-------
TABLE 9a. SUMM*,oy QF SOLVENT LOSS DATA FROM PHASES 1. 2. AND 3 FOR OPERATING
DECREASE*: USING 1.1,1-TPICHLOROF.THANE AT CALM AIR VELOCITY
vo
Test conditions*
0
z
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M
1
3
4d
109e
151
152
137
138
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b
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2]
109
151
152
137
13£
15f
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/
/
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i8
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JC.
d,"
«- a
01 o
oc x>
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50
75
100
125
50
75
100
125
75
01 a.
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f^J E
"•2£
20
20
20
20
20
20
20
20
20
Solvent loss data
Oegreaser A
— we
•o 2>^
2 -if
°>~
?0
20
20
20
20
20
20
20
20
Ib/h
2.10
2.14
1.72
3.004
3.4RO
2.760
2 C66
2.581
2.713
Decrease (Increase)
from base case
Ib/h
0.16
1.08
(0.704)
(1.18)
(0.46)
(0.566)
(0.281)
(0.413)
S
6.96
47.0
(30.6)
(51.3)
(20.0)
(24.6)
(12.2)
(17.96)
Oegreaser B
L.
- «J C
•a « •—
•O >t^,
S -if
„.,_
20
20
20
20
20
20
20
20
20
Ib/h
2.20
1.66
1.03
2.1C1
2.559
2.119
1.672
2.213
1.917
Decrease (Increase)
from base case
Ib/h
0.54
1.17
0.094
(0.359)
O.Obl
0.528
(0.013)
0.283
I
24.5
53.2
4.27
(16.3)
3.68
24.0
(0.59)
12.9
Hoist speed of 8 ft/mln and load area of 50 percent unless otherwise Indicate
Time-weighted average of weight loss during Tests 1, 6, 7, d, and 89, from Phase 1.
" lime-rfeighted average of weight loss during Tests 22, 43, 34, and 90, from Phase 1.
d Phase I tost.
c Phase 2 test.
Repeat of Test 152 after replacement of prirary condenser coli on Degreaser A.
-------
solvent loss from new and used degreasers; although the baseline
rate of solvent loss shifted, the relative effect of increasing
FR did not change.
Effect of High Crosscurrent Air Velocity
Phase 3 tests at high crosscurrent air velocity (0.67 m/s
or 132 ft/min) increased solvent loss above the rate -at calm
airflow by roughly the same amounts as Phase 2 tests at 0.67-m/s
i
air velocity. A 32 to 42 percent increase above the baseline
rate for Phase 3 was found at 50 percent FR; a 17 to 21 percent
increase, at 75 percent FR; and an 18 to 35 percent increase, at
100 percent FR. Table 10 summarizes Phase 3 data on solvent
loss from operating degreasers using TE at calm and high air
velocities, and Figure 19 depicts the effect of high air veloc-
ity on solvent loss during Phase 3.
Effect of Freeboard Ratio
Figure 20 shows the effect of 50, 75, and 100 percent FR on
solvent loss at different target air velocities during Phase 3;
baseline conditions in this phase were 50 percent FR and calm
airflow. As indicated by Figure 20, solvent loss at 50 percent
FR and 0.67-m/s (132-ft/min) air velocity was 32 to 42 percent.
At 75 percent FR and 0.67-m/s air velocity, the additional
freeboard almost totally controlled the average increase caused
by the higher air velocity; solvent loss was only 0 to 3 per-
cent, which amounted to a control effect of 32 to 39 percent.
At 100 percent FR and 0.67-m/s air velocity, solvent load ranged
from a 4 percent decrease to a 36 percent increase; the control
effect was thus 3 to 36 percent.
Effect of Refrigerated Freeboard Chiller
As in Phase 2, two types of refrigerated freeboard chiller
were used: RFC I, which operated at a refrigerant temperature
greater than 0°C (32°F), and RFC II, which operated at a refrig-
erant temperature of -29° to -40°C (-20° to -40°F). Figure 21
shows the results of Phase 3 TE tests with these RFC's.
60
-------
TABLE 10. SUMMARY OF SOLENT LOSS DATA FROM PHASE 3 FOR OPERATING
DEGREASERS USING 1,1,1-TRICHLOROETHAHE AT CALM AND HIGH AIR VELOCITIES
Test conditions*
o
z
1
Ol
VI
1—
152
152
137
138
142
145
141
144
140
139
143
S
«J
I/I
4»
t-
151
152
137
138
142
145
141
144
140
139
143
C
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/
./
/
/
/
/
/
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/
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6
£
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s
/
/
/
./
/
/
/
/
/
/
/
Primary
condenser
/
J
/
/
/
/
/
/
/
/
/
1 k
k •—
»- —
£
Ol
ce *>
J
/
/
Freeboard
ratio. S
50
75
100
125
50
75
100
50
15
100
7b
1 •
4> A
> —
f *>
—
0.1
0.1
0.1
0.1
0.65
0.70
0.68
0.74
0.71
0.65
0.68
kg/h
1.500
1.253
1.298
1.172
2.239
1.628
2.152
1.517
1.267
1.241
0.781
Decrease (Increase)
from base case
kg/h
0.327
0.279
0.408
(0.659)
(0.049)
(0.572)
0.0627
0.313
0 337
0.799
S
20.7
17.64
25.8
(41.70)
(3.07)
(362)
3.97
19.8
21.4
50.6
Degreaser B
Measured air
velocity at
lip, m/s
0.1
0.1
0.1
0.1
0.70
0.69
0.67
0.76
0.65
0.65
O.fto
kg/h
1.162
0.962
0.759
1.005
1.539
1.158
1.109
1.844
1.091
0.952
Decrease (Increase)
from base case
kg/h
0.200
0.403
0.157
(0.377)
O.OC4
0.053
(0 682)
0.071
0.210
S
17.2
34.7
13.5
(32.5)
0.35
4.57
(58.7)
6.14
18.1
8 Hoist speed of 0.1 m/sec and load area of VI percent unless otherwise Indlcatsd.
Automatic lid.
-------
Cfl
t-0
TABLE lOa. SUMMARY OF SOLVENT LOSS DATA FROM "HASE 3 FOR OPERATING
OEbREASERS USING 1,1,1-TRICHLOROETHANE AT CALM AND HIGH AIR VELOCITIES
Test conditions*
S
ex
1
O»
VI
,2
151
152
137
138
14?
145
141
144
140
139
143R
o
VI
Ol
1—
151
152
137
US
\*l
145
141
144
140
139
i.
0
j
/
/
j
j
j
j
j
j
j
j
143 b
en
c
1
«v*
i"
Of
S
J
J
/
/
/
J
/
J
J
/
'
t
>,%
go*
~?
k. O
o. u
,
J
J
J
J
J
J
J
J
J
J
1 U
01 O>
u^
ci"
•?TJ
u u
0- 10
Of O
cto
J
/
/
•o
r.
2 0
Of ••-
01 W
k 10
U. k
50
75
100
125
50
75
100
50
75
100
75
i»-x.
3 "o
.•*.
a "o **"
"'.? IX
Ol OJ —
E > —
20
20
20
20
138
136
132
147
127
129
Ik/h
iD/n
2.559
2.119
1.672
2.213
3.390
2.550
2.442
4.061
2.402
2.096
Decrease (Increase)
from base case
Ib/h
0.44
0 887
0.346
(O.R31)
(0.009)
0.117
(1.502)
0.157
0.463
S
17.2
34.7
13.5
(32.5)
(0.35)
4.57
(58.7)
6.14
18.1
a Hoist speed of 8 ft/mm and load area of 50 perrcnt unless otherwise Indicated.
Automatic lid.
-------
SHADED POINTS: PHASE 3 DATA
UNSHADED POINTS: PHASE 1 AND 2 DATA
OTEST AFTER REPAIR OF DEGREA5F.R A
CALM AIR VELOCITY, 0.1 m/s (20 ft/min)
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAD AREA
50
75 100
FREEBOARD RATIO, %
125
Figure 18. Effect of freeboard ratio on solvent loss from an
an operating degreaser using 1,1,1-trichloroethane during
Phases 1, 2, and 3.
63
-------
O 50% FR
O 75? FR
O 100% FR
HOIST SPEED. 0.04 m/s (8ft/min)
50% LOAD AREA
RFC OFF
(60)
O.'i
(ZO)
TAPPET AIR VELOCITY, m/s (ft/mm)
Figure 19. Effect of high crosscurrent air velocity
on loss from an operating degreaser using
1,1,1-trichloroethane during Phase 3.
64
-------
O TARGET AIR VELOCITY, 0.1 m/s (20 ft/min)
D TARGET AIR VELOCITY, 0.67 m/s (132 ft/m1n)
HOIST SPEED, 0.04 rn/s (8 ft/min)
50% LOAD AREA
RFC OFF
50
75 100
FREEBOARD RATIO,
125
Figure 20. Effect of freeboard ratio on solvent loss
from an operating degreaser using 1,1,1-trichloroethane at
different target air velocities during Phase 3.
65
-------
As indicated by Figure 21, use of RFC I on a degreaser
operating at 50 percent FR and 0.67-m/s (132-ft/min) air veloc-
ity can totally control the increased solvent loss caused by the
higher air velocity. In fact, RFC I decreased solvent loss to 4
percent less than the Phase 3 baseline value; i.e., it produced
a 46 percent control effect. When used on a degreaser operating
at 75 percent FR and 0.67-m/s air velocity, RFC I decreased
solvent loss to 20 percent less than the Phase 3 baseline value;
this was a 23 percent incremental control effect not attribut-
able to FR. Use of RFC I on a degreaser operating at 100 per-
cent FR and 0.67-m/s air velocity decreased solvent loss to 21
percent less than the Phase 3 baseline value; this equaled a 57
percent incremental control effect not attributable to FR.
Although RFC II increased solvent loss at 50 percent FR, it
reduced solvent Ions at the higher FR's. Figure 21 shows that
use of RFC II on a degreaser operating at 50 percent FR and 0.67
m/s (132 ft/min) air velocity increased solvent loss to 59
percent above the Phase 3 baseline value; this was 27 percent
more solvent loss than occurred at the high draft velocity
without RFC II. When used in a degreaser operating at 75 per-
cent FR and draft air velocity of 0.67 m/s, RFC II decreased
solvent loss to 6 percent less than the baseline value; this
constituted a 6 percent incremental control effect not attribut-
able to FR. Use of RFC II on a degreaser operating at 100
percent FR and draft air velocity of 0.67 m/s decreased solvent
loss rate to 18 percent lesb than the baseline value; thus, the
incremental control effect not attributable to FR was 13 per-
cent.
Effect of Automatic Lid
The automatic lid tested in Phase 2 was tested again in
Phase 3, but was operated differently. In Phase 2 the lid wns
closed only when the load was not being cleaned or moved up or
66
-------
SHADED POINTS: RFC II ON; REFRIGERANT TEMPERATURE,
-29 TO -40°C (-20 TO -40°F)
UNSHADED POINTS: RFC I ON; REFRIGERANT TEMPERATURE,
>0°C (32°F)
O 50% FR
D 75% FR
A 100% FR
TARGET AIR VELOCITY, 0.67 m/s (132 ft/min)
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAD AREA
OFF ON
REFRIGERATED FREEBOARD CHILLER
Figure 21. Effect of refrigerated freeboard chiller on solvent
loss from an operating degreaser during 1,1,1-trichloroethane at a
target air velocity of 0.67 m/s (132 ft/min) during Phase 3.
67
-------
down (about 25 percent of the time). In Phase 3 the lid was
also closed when the load was being cleaned, but not when it was
being moved up or down (70 percent of the time). The 1 id was
tested at 75 percent FR and a draft air velocity of 0.67 m/s
(132 ft/min). Figure 22 shows that the lid decreased solvent
loss to 50 percent less than the baseline value; this was a 53
percent incremental control effect not attributable to FR. The
effects of FR and RFC are also presented on Figure 22 to allow
comparison of the different means of control.
Effect of Ambient Temperature
Figure 23 presents the results of Phase 3 tests to deter-
mine the eflect of ambient temperature on the rate of solvent
loss from Degreasers A and B. The ambient temperature was
measured separately near each degreaser at the end of every hour
of testing. Hours of rapid temperature change were excluded
from the data base. The linear regression fit of the data shows
that an ambient temperature increase of 0.7° to 4.3°C (4.9° to
7.7°F) reduced solvent loss by 0.45 kg/h (1.0 Ib/h). The use of
a linear regression fit, however, should not be construed to
suggest that the relationship between ambient temperature and
solvent loss rate is linear; we expect that experimentation over
a larger temperature scale would show a nonlinear relationship.
The buoyancy of gas inside the freeboard area con-pared with
the buoyancy of ambient air outside the degreaser is probably
the controlling factor. As the buoyancy of air inside the tank
increases, air moving out of the degreaser increases in velocity
and takes with it solvent vapors.
Phase 3 data should probably not t.- used to correct or
adjust previous data to room temperature, especially data from
tests run with different control systems or operational pro-
cedures. The best course would be to reject '^sts run at an
ambient temperature other than 21°C (70°F).
68
-------
O RFC OFF
D RFC : ON; REFRIGERANT TEMPERATURE, >0°C (32°F)
O RFC II ON; REFRIGERANT TEMPERATURE,-29°C TO -40°F (-20° TO -40°F)
A AUTOMATIC LID
TARGET AIR VELOCITY, 0.67 m/s (132 ft/min)
HOIST SPEED, 0.04 m/s (8 ft/min)
50? LOAD AREA
50
75 100
FREEBOARD RATIO, %
125
Fiy-ire 22. Effect of automatic lid, freeboard ratio, and
rsf-igerated freeboard chiller on solvent loss from an
o^rating degreaser using 1,1,1-trichloroethane at a
target air velocity of 0.67 m/s (132 ft/min) during Phase 3.
69
-------
-J
o
Z.I
(6.0!
2.3
(5.0)
S '••
- (4.0)
V 1.4
3 (3.0)
0.9
(-'-SI
0.45
(1.0)
DEGREASER A
r = -0.68268
y * -4.9099x + 83.36
I
10 15.0 21.2 26.7
(50) fFO) (70) (80)
AMBIENT T'MPERATURE. °C (°F)
2.7,
(6.0)
2.3
(5.0
'.8
I-
1(3.0)
I/)
*/»
o
^ 0.9
cJ(2.0)
0.45
(1.0)
ULGREASER B
r = -0.905
> • -7.69Zx * 84.615
I
10 15.6 21.1 26.7
(50) (60) (70) (80)
AKBIENT TEMPERATURE. °C (°F)
Figure 23. Effect of ambient temperature on rate of solvent
loss from Degreasers A and B during Test 136.
-------
Other Tests
Tests 154 and 155 were run sequentially at the same fan
speed setting (about 1.32 m/s or 260 ft/min). They showed that
either RFC can reduce solvent loss at high crosscurrent air
velocities and that other variables affect the measured air
velocity. The use of an RFC reduced measured air velocity from
about 1.32 m/s (260 ft/min) to 1.11 m/s (220 ft/min). Early in
the testing program, it was recognized that turning on the
degreaser altered the measured air velocity by 10 to 20 percent,
and the test procedure was subsequently changed to accommodate
this phenomenon by adjusting the fan speed after the degreaser
had warmed up. Passing the load basket through the lip area
reduced the average velocity in one test to 0.42 m/s (84 ft/min)
from 0.67 m/s (132 ft/min) at the initial fan speed setting.
The ambient temperature control system malfunctioned near the
end of one test and allowed the temperature to increase about
27°C (80°F); a significant increase was noticed in the recorded
air velocity.
Figure 24 presents the results of Test 157, which concerned
only Degreaser B. I'our randomly selected air velocities were
tested with the RFC on (after a 3-hour stabilization period);
then the same air velocities were tested in random order with
the RFC off (after a 1-hour stabilization period). Each point
on the f:gure represents the solvent loss rate during 1 hour of
testing. As Figure 24 indicates, the RFC controlled solvent
loss at crosscurrent velocities up to 1.02 m/s (200 ft/min), but
not at higher velocities. Figure 24 also shows that above 1.02
m/s (200 ft/min) the solvent loss rate increased rapidly, pos-
sibly with the square of the velocity. Because the data were
taken every hour, they cannot be accepted with the same confi-
dence as data taken over longer intervals, although the corre-
lation with data from extended tests is better than would be
expected.
71
-------
9.1
(20)
6.8
(15)
2.3
(5)
O RFC II ON
O RFC II OFF
50i FR
EACH DATA POINT SHOWS LOSS RATE FOR 1 HOUR
I
I
I
0.25 0.51 0.76 1.02 1.27 1.52 1.78
(50) (100) (150) (200) (250) (300) (350)
AVERAGE MEASURED CROSSCURRENT AIR VELOCITY, m/s (ft/min)
Figure 24. Results of Tost 157.
72
-------
LABORATORY TESTS WITH METHYLENE CHLORIDE
Baseline Performance
Phase 1 tests of an operating degreaser using methylene
chloride at calm airflow and 75 and 125 percent FR were repeated
during Phase 3 to determine whether baseline performance had
changed. Table 11 summarizes bareline solvent loss data from
Phases 1 and 3, and Figure 25 presents the results of comparable
Phase 1 and 3 baseline tests. The data indicate no significant
shift in performance between the two phases.
Effect of High Crosscurrent Air Velocity
Phase 3 tests of operating degreasers using methylene
chloride at high crosscurrent air velocity (0.67 m/s or 132
ft/rain) increased solvent loss above the rate at calm airflow by
slightly less than comparable Phase 2 tests. A 60 to 64 percent
increase in solvent loss above the baseline rate was found at 75
percent FR, and a 17 to 26 percent increase was estimated at 100
percent FR. Solvent loss at 100 percent FR and calm airflow was
not tested. The estimated increase at 100 percent FR resulted
from straight-line interpolation between data at 75 and 125
percent FR. Table 12 summarizes Phase 3 data on solvent loss
from operating degreasers using MC at calm and high air veloci-
ties.
Effect of Freeboard Ratio
Figure 26 shows the effect of 75 and 100 percent FR on
solvent loss. At 75 percent FR and 0.67-m/s (132-ft/min) air
velocity, solvent loss was 60 to 64 percent more than the base-
line value. At 100 percent FR and 0.67-m/s air velocity, how-
ever, solvent loss was 10 to 28 percent more than the baseline
value. This indicates that the change from 75 to 100 percent FR
caused a net reduction in solvent loss rate of 36 to 50 percent.
Effect of Refrigerated Freeboard Chiller
The refrigerated freeboard chillers tested were of two
designs: RFC I, which operated at a refrigerant temperature
73
-------
O PHASE 1 DATA
D PHASE 3 DATA
CALM AIR, 0.01 m/s (20 ft/min)
HOIST SPEED. 0.04 m/s (8 ft/min)
50* LOAD AREA
RFC OFF
60
<_>
O
1/1
ir>
O
40
X 20
O
CO
(20)
(40)
(60)
50 75 100
FREEBOARD RATIO, %
125
Figure 25. Effect of freeboard ratio on solvent loss
from an operating degreaser using methylene chloride
during Phases 1 and 3.
74
-------
TABLE 11. SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 3 FOR OPERATING
DEGREASERS USING HETHYLENE CHLORIDE AT CALM AIR VELOCITY
Test conditions*
d
ae
a.
s
o>
*J
M
£
34b
35b
36b
158C
146C
o
*•
(A
£
37
74
41
158
146
g.
o
•o
_l
/
y
/
/
/
o>
c
^~
s
**
£
/
/
/
/
/
L.
fi
ll
£8
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/
/
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1 L.
S"
1. i—
<•- ••-
ft
«*- «
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«
Jio
o« -^
»*•
k 9
U. k
50
75
125
75
125
i
ii
t.
•*- *«
-------
TABLE Ha.
SUMMARY OF SOLVENT LOSS DATA FROM PHASES 1 AND 3 FOR OPERATING DEGREASERS
USinn METHYLENE CHLORIDE AT CALM AIR VELOCITY
Test conditions*
S"
a
01
VI
•s
34b
35b
36b
158C
146"-
VI
f
37
74
41
158
K6
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1- •*•
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51
^.
tf""
3 U
«2tt
20
20
20
20
20
Ib/h
2.32
1.92
1.71
1.976
1.371
Decrease (Increase)
from base case
Ib/h
0.40
0.61
0.344
0.9*9
S
17.2
26.3
14.8
40.9
a Hoist speed of 8 ft/rim and load area or 50 percent unless otherwise specified.
b Phase 1 test.
c Phase 3 test
-------
TABLE 12. SUMMARY OF SOLVENT LOSS DATA FROM PHASE 3 FOR OPERATING OEGREASERS
USING METHYLENE CHLORIDE AT CALM AIID HIGH AIR VELOCITIES
-j
-J
Test conditions*
S
a.
01
w>
1?
158
146
150
147
148
149
VI
£
15E
14E
ISC
147
14(
14<
e
a.
o
J
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/
/
/
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'
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c
•1
£
,
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u
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SOI
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ai •«
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75
125
75
75
100
100
i •
a a.
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3 W
lA O •
•n r~ Q.
o> e ^
£ > •—
0.1
0.1
0.75
0.66
0.65
0.71
kg/h
0.644
0.779
1.058
1.145
0.711
0.732
Decrease (Increase)
from base case
kg/h
(0.135)
(0.415)
(0.502)
(0.067)
(0.089)
X
(21.0)
(64.4)
(77.9)
(10.4)
(13.8)
Degreaser B
•- «J
•O •—
0.1
0.1
0.74
0.64
0.71
0.56
kg/h
0.897
0.622
1.440
1.F20
1.145
U.769
Decrease (Increase)
from base case
kg/h
0.275
(0.543)
(0.623)
(0.248)
0.126
S
30.6
(60.5)
(69.5)
(27.6)
14.1
Hoist speed of C.I m/s and load area of 50 percent unless otherwise Indicated.
-------
TABLE lla.
oo
SUMMARY OF SOLVENT LOSS DATA FROM PHASE 3 FOR OPERATING OEGREASERS USING
METHYLENE CHLORIDE AT CALM AND HIGH AIR VELOCITIES
Test conditions'
3
IX
M
V
h-
158
146
150
147
148
149
0
VI
t-
158
146
150
147
148
149
S
/
/
/
/
/
'
f
0
c
"o
/
/
/
/
V
'
U
f?
T o
Q. U
J
J
J
i
j
'
1 k.
0) U
t. ^>
.«
•S3
a a
J
J
t- ««
U. i.
75
125
75
75
100
100
• •
f «»
a> **.E
u *u ^.
"0 0 *>
20
20
132
132
132
132
Solvent loss data
Degreaser A
— ** c
10 ra >p-
Ci "
S U
£— ex
fs;^
20
20
140
130
127
139
1.418
1.716
2.331
2.523
1.565
1.613
Decrease (Increase)
from base case
Ib/h
(0.298)
(0.913)
(1.105)
(0.147)
(0.195)
I
(21.0)
(64.4)
(77.9)
(10.4)
(13.8)
Degreaser B
• ••» C
^J fc?*^
!-»-<«-
3 U
irt 0 -
*o— ex
a; a; -
20
20
146
126
140
110
lh/h
1.976
1.371
3.172
3.349
2.522
1.698
Decrease (Increase)
from base case
Ib/h
0.605
(1.196)
(1.373)
(O.S46)
0.278
S
30.6
(60.5)
(69.5)
(27.6)
14.1
Hoist speed of 8 ft/min and load area of 50 percent unless otherwise Indicated.
-------
O CALM AIR VELOCITY, 0.1 m/s (20 Ft/min); RFC OFF
Q TARGET AIR VELOCITY, 0.67 m/s (132 ft/min); RFC OFF
A TARGET AIR VELOCITY, 0.67 m/s (132 ft/min); RFC I ON;
REFRIGERANT TEMPERATURE, >0°C (32°F)
O TARGET AIR VELOCITY, 0.67 m/s (132 ft/min); RFC II ON;
REFRIGERANT TEMPERATURE, -29 TO -40°C (-20 TO -40°F)
HOIST SPEED, 0.04 m/s (8 ft/min)
S0% LOAD AREA
50
75 100
FREEBOARD RATIO, %
12f.
Figure 26. Effect of freeboard ratio or solvent loss from
an operating degreaser using methylene chloride with
refrigerated freeboard chiller during Phase 3.
79
-------
greater than 0°C (32°F), and RFC II, which operated at a refrig-
erant temperature of -29° to 40°C (-20° to -40°F). Figure 27
depicts the results of Phase 3 MC tests with these RFC's.
As Figure 27 shows, use of RFC I on a degreaser operating
at a targot air velocity of 0.67 m/s (132 ft/tnin) increased
solvent loss by L4 percent at 75 percent FR and by 4 percent at
100 FR. Use of RFC II increased solvent loss by 9 percent at 75
percent FR, but reduced solvent loss at 100 percent FR to 14
percent less than the baseline value; this was 42 percent incre-
mental control effect at 100 percent FR.
LABORATORY TEST WITHOUT SOLVENT
Test 159 was designed to be run without solvent in either
degreaser. The aim was to determine whether the variable flow
rate of cooling water through the degreaser significantly affect-
ed data variability, especially whether it caused the unusual
weight gains that sometimes appeared at one reading but disap-
peared by the end of the test. Before Test 159 was run, the
cause of the weight gain was discovered, and corrections were
made to the system. The unusual weight gains were attributed to
flexible plumbing connections to the load. Weight was attached
to the flexible hose to keep it in proper position for drainage
of excess water from the load. Occasionally the weight or hose
landed on the degreaser during the weighing portion of the
cycle. This generally occurred at • r-s same time as problems
with the load entry or exit guides and disruption of the loading
cycle. When the loading cycle was re---.arted, the problem with
the hose was inadvertently corrected and thus was not detected
at first.
A comparison of the test results using student's "t" sta-
tistical tests suggests that the weight loss indicated by the
regression line is caused by chance at the 95 peicent confidence
level. A comparison of Syx, Sx, Sa, and Sc values (as defined
in Appendix A) from Test 159 with values fmn other tests indi-
cates that the variability of the data is similar. Similarity
80
-------
UNSHADED POINTS: RFC I "N; REFRIGERANT TEMPERATURE, >0°C (32°F)
SHADED POINTS: RFC II ON; REFRIGERANT TEMPERATURE, -29 TO -40°C
(-20 TO -40°F)
TARGET AIR VELOCITY, 0.67 m/s (132 ft/min)
O 75% FR
D 100% FR
HOIST SPEED, 0.04 m/s (8 ft/min)
50% LOAD AREA
401 1 1
20
UJ
ce
o
(20)
co
co
O
°(40)
(60)
(80)
PHASE 3 BASELINE
OFF ON
REFRIGERATED FREEBOARD CHILLER
Figure 27. Effect of refrigerated freeboard chiller on solver.t loss
from an operating degreaser using methylene chloride at a target
air velocity of 0.67 ni/s (132 ft/min) during Phase 3.
81
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in variability shows that the tests were run in the same manner,
but that most of the variability resulted from some factor other
than solvent loss.
LABORATORY TESTS WITH SMOKE
The smoke tests were intended to be visual indicators of
velocity and turbulence in the degreaser tank. Although many
attempts were made to get a clear photographic record of air
velocity in the freeboard area while the degreaser contained
boiling solvent, none was successful. The turbulence caused by
the fan rapidly dispersed the smoke trace. There was some
mixing of smoke down into the freeboard area, but it could not
be quantified and had no apparent direction. A simulated de-
greaser and fan combination was set up in a nearby laboratory
area. This equipment r; ho wed that the draft blowing over the
leading lip aspirated air from just below the lip into the draft
passing across the top. This air moving up the inside front
wall set up a circu1 ar flow in the box as shown in Figure 28.
DRAFT
ASPIRATED AIR
J
SIMULATED DEGREASER
Figure 28. Turbulence created by a draft passing
*f across the top of a simulated degreaser.
If similar flow exists in a degreaser, the solvent loss rate
will be increased by higher air velccities.
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FIELD TESTS
A field survey was conducted to determine air velocities
near open-top vapor degreasers in industrial use. The aim was
to put cne laboratory results in proper perspecti'.e. As dis-
cussed in Appendix E, seven plants were studied in the Cin-
cinnati area. They included two aircraft firms, three machinery
manufacturers, one electrical equipment company, and one heavy
equipment repair shop. The degreassrs ranged from 0.55 m2 (6
ft2) to 3.9 m2 (42 ft2). The overall average air velocity found
at the plants was 0.445 m/s (87.6 ft/mm). Twenty-four 5-minute
velocity readings were taker, at each degreaser. Sixteen samp-
ling places were on the long face of each degreaser, and eight
places were on the short face. The readings were recorded on
strip charts, and a 5-minute average was estimated. The range
of 5-minute averages was from 0.35 to 0.568 m/s (69.4 to 112
ft/min) for all seven plants. The highest instantaneous peak
velocity recorded was 3.04 m/s (600 ft/mm); the lowest was 0
m/s. The overall average reflects the sum of the average velo-
city for each face divided by 14 (the number of faces measured).
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SECTION 7
PHASE 3 CONCLUSIONS AND RECOMMENDATIONS
CONCLUSIONS
The use of sophisticated monitoring and control equipment
in Phase 3 yielded data of sufficiently high quality to answer
the questions raised in Phase 2. The conclusions presented
below aie based on data from Phases 1 and 2, as well as from
Phase 3.
High Crosscurrent Air Velocity
When crosscurrent air velocity across the lip of the de-
greaser was increased to 0.67 m/s (132 ft/nun), solvent loss
increased to 40 percent more than the baseline value for both
solvents. As the air velocity at the lip was increased further,
solvent loss increased at a proportionately higher rate. Au
discussed in/Appendix E, crosscurrent air was found to be lower
in velocity and much less turbulent at industrial plants in the
Cincinnati area than in Phase 3 laboratory tests. Phase 1
tests, however, were run with crosscurrent air lower in velocity
and less turbulent than that at the plants visited. Therefore,
the range of laboratory conditions tested overlaps typical
inductrial conditions.
Freeboard Ratio at High Crosscurrent Air Vclocitjes
As FR was increased from 50 to 125 percent at high cross-
current air velocities, solvent loss decreased. Increasing FR
from 50 to 75 percent reduced solvent loss by 40 percent with
TE, and increasing FR from 75 to 100 percent reduced solvent
loss by 20 percent with TE and 40 percent with MC. The two 40
percent reductions are significant.
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Although increasing FR from 75 to 100 percent with TE
reduced solvent loss, the reduction (20 percent) was only half
that caused by increasing FR from 50 to 75 percent. Further,
Phase 2 tests indicate that increasing FR from 75 to 125 percent
reduces solvent loss very little. Thus, solvent loss reduction
seems to decrease as FK is increased above 100 percent FR.
Refrigerated Freeboard Chiller at High Crosscurrent Air Velocity
Phase 3 tests with TE show that RFC I increased the control
effect by 46. 23, and 21 percent at 50, 7b, and ICO percent FR,
respectively, and that RFC II increased the control effect by
27, 6, and 13 percent at the same FR's. These were increased
above those attributable only to FR. Phase 3 tests with MC
showed that no increase in control effect occurred with RFC I 75
or 100 percent FR or with RFC II at 75 percent FR; at 100 per-
cent FR, however, RFC II increased the control effect by 42
percent. Again, this was an increase above that attributable to
FR alone. Based on these tests and Phas'i 2 tests with MC, an
increase in control effect of roughly 20 percent can be expected
from an RFC of either design at the FR's and high air velocities
tested.
/.litomatic Lid at High Crosscurrent Air Velocities
As in Phase 2, the automatic lid was tested only with TE,
and conclusions can only be drawn about its effect on this
solvent. Phase 3 testing showed that the use of this device
reduced solvent loss by 53 percent.
RECOMMENDATIONS
The best solvent loss reduction technique is to lower air
velocity at the lip of the degreaser. The position of the
degreaser and the work flow to and from the degreaser, however,
can severely limit the extent to which lowering of air velocity
is possible. Other solvent loss reduction techniques include
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increasing FR and using an RFC and automatic lid. We recommend
that these other techniques be considered equally effective
means of reducing solvent loss for the degreaser sizes and air
velocities found at industrial plants, and that they be accepted
as only slightly less effective than lowering the airflow rate
at the lip of the degreaser.
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