&EPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 2771 1
EPA-600-7-79-021
January 1979
Solids Transport Between
Adjacent CAFB
Fluidized Beds
Interagency
Energy/Environment
R&D Program Report
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development. U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the
effort funded under the 17-agency Federal Energy/Environment Research and
Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the rapid development of domestic
energy supplies in an environmentally-compatible manner by providing the nec-
essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants and their health and ecological
effects; assessments of. and development of, control technologies for energy
systems; and integrated assessments of a wide range of energy-related environ-
mental issues.
EPA REVIEW NOTICE
This report has been reviewed by the participating Federal Agencies, and approved
for publication. Approval does not signify that the contents necessarily reflect
the views and policies of the Government, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/7-79-021
January 1979
Solids Transport Between
Adjacent CAFB Fluidized Beds
by
D.M. Bachovchin, P.R. Mulik, RA Newby.
and D.L Keairns
Westinghouse Research and Development Center
Pittsburgh, Pennsylvania 15235
Contract No. 68-02-2142
Program Element No. EHE623A
EPA Project Officer: Samuel L. Rakes
Industrial Environmental Research Laboratory
Office of Energy. Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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PREFACE
The Westinghouse Research and Development Center is carrying
out a program under contract to the United States Environmental Protection
Agency (EPA) to provide experimental and engineering support for the
development of the Chemically Active Fluid-Bed (CAFB) process. The process
was originally conceived at the Esso Petroleum Company, Ltd., Abingdon,
UK (ERCA), as a fluidized-bed gasification process to convert heavy
fuel oils to a clean, medium heating-value fuel gas for firing in a
conventional boiler. Westinghouse, under contract to EPA, completed
an initial evaluation of the process in 1971. Conceptual designs and
cost estimates were prepared for new and retrofit utility boiler
applications using heavy fuel oil. Westinghouse continued the process
evaluation from 1971 to 1973 and formulated an atmospheric pollution
control demonstration plant program for retrofit of a utility boiler
utilizing a high-sulfur, high-metals content fuel oil (for example,
2
vacuum bottoms). The CAFB process represented an attractive option for
use of these low-grade fuels, for which pollution control using hydro-
desulfurization or stack-gas cleaning was not economical. Application
of a pressurized CAFB concept with combined-cycle power plants was also
2
assessed. Experimental support work was initiated during 1971 to 1973
to investigate two areas of concern - sorbent selection and spent sorbent
processing - to achieve an acceptable material for disposal or utilization.
The preliminary design and cost estimate for a 50 MWe demonstration plant
at the New England System Manchester Street Station in Providence, RI were
completed in 1975. Commercial plant costs were projected and development
requirements identified. Experimental support on the sulfur removal
system continued in order to provide a basis for the detailed plant design.
A number of design and operation parameters from the preliminary design
study that required further development were identified. Demonstration
on a commercial scale of the pulsed-flow solids transport system between
iii
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the gasifier and regenerator was identified as one of the areas requiring
development. This report presents the results of the program initiated
at that time to develop a design basis and operating procedures for the
pulsed-flow solids transport system. A solids transport test facility
was built and operated to provide an understanding of the pulsed-flow
system for plant design and operation. The design and performance
projections are applied to the CAFB process designed by Foster Wheeler
Energy Corporation (FW) under contract to EPA for retrofit on a 20 MWe
gas-fired boiler at a Central Power and Light (CPL) plant in San Benito,
Texas.
Additional support work carried out under the present contract
(68"02-2142), which will be reported, includes:
• Sorbent selection '
• Processing spent sorbent to minimize
environmental impact^
• Environmental impact from disposal of processed
and unprocessed spent sorbent*
* Engineering evaluation of the CAFB process.
iv
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ABSTRACT
A pulsed, dense-phase pneumatic transport system for controlled
circulation between adjacent fluidized beds was experimentally investigated
and a model developed to predict performance. The program provides tech-
nical support for the EPA program to demonstrate the Chemically Active
Fluid Bed (CAFB), a process being developed to produce a clean, low
heating-value fuel gas from fossil fuels.
A cold model test facility capable of transporting up to about
6.3 kg/s (50,000 Ib/hr) was built and operated to allow examination of
the effects of key parameters. The data generated were utilized in the
development of a mathematical model of the system which allows projec-
tion of the effects of key variables. Solids flow is controlled by
pulsed air input, whose on-time (<0.3 to 0.4 s) and off-time (1.5 to
2.0s) should be controlled for best, performance. The system pressure
balance should also be carefully controlled. The expected demonstration
plant bed-material density may result in higher air requirements than
had been predicted in the plant design. The use of wider legs and more
nozzles or greater transport-gas capacity may alleviate this difficulty.
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TABLE OF CONTENTS
Page
SUMMARY 1
1. INTRODUCTION 4
2. CONCLUSIONS 7
3. RECOMMENDATIONS 9
3.1 CAFB Plant Operation 9
3.2 Further Study 10
4. BACKGROUND AND PLANT REQUIREMENTS 11
5. TEST FACILITY 14
5.1 Design Basis 14
5.2 Specifications 19
5.2.1 Fluidized-Bed Vessels 20
5.2.2 Transfer Legs 20
5.2.3 Centrifugal Blower 20
5.2.4 Cyclone Collectors 21
5.2.5 Dust Collector 21
5.2.6 Pulsation Control System 21
5.2.7 Instrumentation and Control Package 22
5.2.8 Additional Specifications 23
5.3 Construction and Costs 23
6. TEST PROGRAM 24
6.1 Summary 24
6.2 Test Material 24
6.3 Procedures 27
6.3.1 Experimental Technique 27
6.3.2 Solids Flow Rate Determination 28
6.4 First Test Series - Inserted Pipe Sparger 30
6.4.1 Introduction 30
6.4.2 Results and Discussion 30
6.5 Second Test Series - Recessed Nozzle Sparger 38
6.5.1 Introduction 38
6.5.2 Results and Discussion 38
vii
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TABLE OF CONTENTS (Cont)
7. SOLIDS TRANSPORT MODEL 60
7.1 Model Development 6o
7.1.1 Time Sequence 60
7.1.2 Steady State Assumptions 62
7.1.3 Mass Balances 63
7.1.4 Momentum Balance 65
7.1.5 Horizontal Pressure Drop 66
7.1.6 Dilute Phase Flow Area 67
7.1.7 Fluidizing Time 69
7.1.8 Vertical Section Voidage 70
7.1.9 Dilute Phase Voidage 71
7.1.10 Model Summary and Procedure 72
7.2 Model Performance 75
8. DEMONSTRATION PLANT PERFORMANCE PROJECTIONS 79
8.1 Total Transport Gas Flow Rate 79
8.2 Pulse Gas On- and Off-Times 79
8.3 Process Related Parameters 82
8.4 Particulate Properties 85
8.5 Leg Geometry Variation 87
9. ASSESSMENT 91
10. REFERENCES 94
APPENDICES
A. SOLIDS TRANSPORT TEST FACILITY SPECIFICATION DETAILS 96
A.I. Drawings and Photographs 96
A. 2. Instruments and Auxiliary Equipment 111
B. SUPPLEMENTAL TEST DATA 119
C. MODEL DEVELOPMENT DETAIL 134
C.I. Jet Area 134
C.2. Fluidizing Time 137
C.3. Defluidizing Behavior and Vertical Section 140
Voidage Estimation
D. MODEL PROGRAM LISTING 142
E. MODEL PREDICTIONS 149
viii
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LIST OF FIGURES
1. CAFB Material Circulation System 12
2. Test Facility Schematic 15
3. Test Facility Fluid-Bed Vessels 16
4. Test Facility Transport Leg 18
5. Inserted Pipe Sparger 31
6. Recessed Nozzle Sparger 39
7. Effect of Pulse Air Rate 52
8. Effect of Pulse Air Rate 52
9. Effect of Pulse Air Rate 53
10. Effect of Pulse Air Rate 53
11. Effect of Off-Time 54
12. Effect of Off-Time 54
13. Effect of Pulse Air Rate at Constant On-Off Times 55
14. Effect of Off-Time at Lower Fluidizing Velocities 55
15. Effect of Off-Time at Lower Fluidizing Velocities 56
16. Effect of Off-Time at Lower Fluidizing Velocities 56
17. Observed Transport Flow Profile 59
18. Nomenclature for Transport Model 61
19. Solids Transport Model Flow Profile 64
20. Jet Expansion Model 68
21. Transport Leg Model Flow Sheet 73
22. CAFB Demonstration Plant Transport Leg Design 77
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LIST OF TABLES
1. Particle Size Distribution at Beginning of Final Test Series 26
2. Particle Size Distribution at Conclusions of Final Test Series 26
3. Transport Data - First Test Series 33
4. Transport Data - Second Test Series 41
5. Transport Leg Model - Variables 74
6. Comparison of FWEC Final Design Data and Model Predictions 78
7. Effect of Total Gas Flow Rate 80
8. Effect of On- and Off-Times at Constant Total Gas Flow Rate 81
9. Effect of On- and Off-Times at Constant Gas Flow Rate during Pulse 83
10. Effect of Temperature 83
11. Effect of Receiving Vessel Absolute Pressure 85
12. Effect of Pressure Gradient across Transfer Leg 85
13. Effect of Average Particle Size 86
14. Effect of Particle Density 86
15. Effect of Horizontal Slot Height 88
16. Effect of Vertical Height at Constant AP/L 88
17. Effect of Horizontal Length 90
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NOMENCLATURE
Note: The model computer program listing features different nomenclature,
which is detailed in the listing. Different unit multiples
(e.g., ym) are noted in text.
Symbol Definition Dimensions
2
A Projected area of rising slug or bubble m
(Appendix C.2)
2
A_ Fluid-bed cross-sectional area m
2
A Relative entrainment interface area m
C Drag coefficient of fluid bed on rising -
gas slug (Appendix C.2)
d Nozzle diameter m
o
d Average particle, dimension m
d . Particle dimension of i sieve fraction m
Pi
D Four times mean hydraulic radius m
2
g Gravitational acceleration m/s
2
g Conversion constant 1 kg m/(N s )
G. Overall average pulse gas input rate kg/s
A
Gc Solids flow rate kg/s
O
h Final height of plane jet (Fig. C-l) m
H, Horizontal slot height m
k = vs3/v3
L_ Length of horizontal leg section m
L_ Length of vertical leg section m
S
xi
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NOMENCLATURE (Cont)
Symbol Definition Dimensions
Vertical component of Lg u»
M Gas molecular weight ~
N Number of nozzles per leg
2
P Pressure N/m
2
P. Pressure at leg bend N/m
2
P_ Transport gas pressure issuing from nozzles N/m
2
P. Pressure at leg discharge N/m
2
P. Pressure at top of leg N/m
AP = PI - P4 N/m2
AP° E P3 - P4 N/m2
2
APT Level recorder pressure drop N/m
L
r Radius of noninterfering circular jets m
2
S- Cross-sectional area of leg m
2
S2 Inside area of N nozzles m
2
S. Area of dilute phase horizontal flow m
t Time s
Fluid! zing time in response to imposed AP s
QFF
t Pulse off -time 8
t-.,. Pulse on-time 8
t_ Time required for repacking s
t_ Response time for defluidization s
tc Time during which solids may flow: minimum s
& f
of t.., t™
T Gas temperature R
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NOMENCLATURE (Cont)
Symbol Definition Dimensions
T.R. Transport ratio = mass of solids moved per
mass of transport gas required
Uf Fluidizing velocity (superficial) m/s
U _ Minimum fluidizing velocity (superficial) m/s
U Interstitial gas velocity relative to solids m/s
U Superficial horizontal solids velocity m/s
8 (eq. 13)
v Rise velocity of slug m/s
v- Downward velocity of gas in leg vertical m/s
section
v« Pulse gas nozzle exit velocity m/s
v- Velocity of gas exiting leg in dilute phase m/s
VR = Vsl - Vl m/S
VRH Interstitial gas velocity in stagnant: solid m/s
area of horizontal leg section
v , Downward solids velocity in leg vertical m/s
section
v - Velocity of solids in dilute phase at leg m/s
discharge
W Leg width
m
Wu Horizontal air rate during pulse kg/s
H
W Transport air rate during pulse kg/s
x1 Distance from nozzle plane to plane of mutual m
jet interference
x. Distance from nozzle plane to plane of hori- m
zontal ceiling lip
x. Weight fraction of ifc sieve size
xiii
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NOMENCLATURE (Cont)
Symbol Definition Dimensions
x Center-to-center nozzle separation m
n
y Distance from virtual origin of plane jet to m
nozzle plane (Fig. C-l)
y Distance from virtual origin of circular m
jet to nozzle plane (Fig. C-2)
z Upward height of rise of bubble (Fig. C-2) m
Az Packed-bed slab thickness (Fig. C-2) m
a Angle of leg downcomer from vertical Deg.
g Plane jet half-angle Deg.
e. Vertical section voidage
e~ Dilute phase discharge voidage
£ Packed bed voidage
9 Circular jet half-angle Deg.
M Gas viscosity kg/m/s
3
p. Gas density at transfer leg bend kg/m
o
P2 Gas density issuing from nozzles kg/m
P
3
Gas density at transfer leg discharge kg/m
PB Bulk density kg/m3
PDS Superficial bulk density of horizontal kg/m3
section material
Ppg Fluid-bed density kg/m3
Pg Gas density kg/m3
p Particle density kg/m3
xiv
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ACKNOWLEDGEMENT
The authors acknowledge the contributions and support of
Mr. S. L. Rakes who served as the EPA project officer. Mr. P. P. Turner
and Mr. R. P. Hangebrauck, Industrial Environmental Research Laboratory,
EPA, are acknowledged for their continuing contributions and support of
the program.
The following Westinghouse personnel made significant contribu-
tions to the design, construction and operation of the facility:
M. J. Balogh, T. R. Dristas, W. J. Havener, W. K. Hess, R. B. Mitchell,
R. D. Novak, and E. J. Vidt. R. G. Ballinger, W. D. Ciprella, and
E. P. Tully of the Peter F. Loftus Corporation performed the detailed
mechanical design and equipment specification for the facility.
xv
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SUMMARY
The chemically Active Fluid Bed (CAFB) process is being developed
as a retrofit to existing boilers to allow the efficient use of high-
sulfur liquid or solid fuels in an environmentally acceptable manner.
This atmospheric-pressure fluidized-bed gasification process utilizes
limestone feed to the gasifier to achieve desulfurization. During the
gasification process, fuel sulfur is absorbed by lime, which is the
major bed material constituent. The spent lime can be regenerated in a
separate vessel and the regenerated material returned to the gasifier.
Regeneration of the spent sulfur sorbent offers the opportunity to
minimize the quantity of limestone required to meet the sulfur emission
standards.
The regeneration of the bed material requires the controllable,
efficient, and nonmechanical transfer of high-temperature particulate
between vessels featuring different chemical environments. During the
early development work on the CAFB process by the Esso Research Centre
Q
at Abingdon, UK (ERCA), a pulsed transfer technique evolved for the
simultaneous transfer of material to and from the regenerator.
Westinghouse has designed, built, and operated a large cold model
test unit to examine the transport process, as part of a broad CAFB
engineering support program sponsored by the U. S. Environmental Protec-
tion Agency (EPA). The purpose of this program is to gain an under-
standing of the transport technique, its limitations, and the associated
physical phenomena. With such an understanding projections of performance
under different sets of conditions could be made, with more confident
scale-up and optimization possible. The test facility was also designed
to be able to support the CAFB demonstration plant program at the Central
Power and Light Company (CPL). A 20 MWe gas-fixed boiler at the CPL La Palma
9
Power Station in San Benito, Texas is being retrofitted with the CAFB process.
-------
Transport system optimization must deal with the following desir-
able features: high solids capacity, minimum air requirement, controlla-
bility, a seal against reactor gas exchange, and freedom from plugging
or other malfunction.
Pulsed transport air is added to the junction of the horizontal
and vertical sections of each transport leg. In the first method of air
introduction tested, air was supplied internally to the leg via a pipe
sparger. Then a method was tested whereby air was supplied through noz-
zles in the back wall of the transfer slot elbow. This method was
clearly superior in terms of both solids capacity and efficiency.
Variables tested included pulse on-time, off-time, and flow rate;
and fluidizing velocity. A mathematical model of the system was developed
on the basis of a momentum balance. The model allows the projection of
demonstration plant transport system performance at various conditions.
Each pulse of nozzle gas was found to cause the vertical seal
between vessels to be destroyed. This takes a short time (0.4s), during
which effective solids flow can take place. Gas added after this time
is wasted, passing upward. Exchange of reactor gas may also occur after
this point. Between pulses sufficient time (>1.5 s) must be allowed
for the repacking of vertical leg solids. At given pulse on- and off-
times, higher gas input will produce more solids flow at reduced effi-
ciency. The pressure gradient across a leg will determine whether a
leg will fluidize and how long it will take. The gradient should there-
fore be minimized. The model predicts that higher solids densities
allow better transport performance.
On the basis of this model we project that, as currently designed,
the desired particulate flow can be achieved in the demonstration plant,
but the efficiency (i.e., the solids-to-gas ratio) will be lower than those
optimally obtained in the FW and Westinghouse experimental programs. The
air requirement may be reduced by using wider legs and more nozzles.
Every effort to control pulse on- and off- times near the optimum conditions
-------
identified in this study should be made. Further study, concentrating
on particle density, particle size, nozzle configuration, leg dimensions,
and simulation of operational problems is recommended.
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1.0 INTRODUCTION
The controlled transport of high-temperature solids is required for
the successful commercialization of many advanced fossil fuel processing
systems. An application that illustrates this need is the circulation
of sulfur sorbents in high-temperature sulfur removal systems that
2 3 10
regenerate the sorbent for reutilization in the desulfurizer. ' '
Westinghouse, under contract to EPA, is providing experimental and
engineering support for the development of such a process, the Chemically
Active Fluid Bed (CAFB). The work performed is in support of the EPA
program to demonstrate this technology. The CAFB process was originally
conceived by ERCA to gasify high-sulfur residual oil to produce a clean,
low heating-value fuel gas. The current demonstration program includes
the use of lignite as a fuel.
In the CAFB process, fuel, is gasified in a fluid bed composed of
lime, which will chemically capture fuel sulfur. Regeneration of the
lime will require simultaneous transfer of solids to and from the gasi-
fier vessel and the adjacent regenerator vessel. A method has been
developed whereby this transfer is caused and controlled by the pulsed
introduction of transport gas.
A preliminary design and cost estimate for a 50 MWe demonstration
plant for the CAFB process carried out by Westinghouse reviewed alterna-
3
tive solids transport systems. The need for a compact transport system
with the potential for reduced gas transport requirements resulted in the
selection of a pulsed, dense-phase transport system that ERCA was using
Q
on a 1 MWe equivalent CAFB pilot facility. Westinghouse recommended that
simulation tests be carried out on the demonstration scale to develop
design and operating data, the purpose of this program was to gain an
understanding of the transport technique, its limitations, and the
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associated physical phenomena. With such an understanding projections of
performance under different sets of conditions could be made, with more
confident scale-up and optimization possible. The test facility was also
conceived to be able to test proposed solutions for demonstration plant
troubles that might arise.
The design of the solids transport test facility was initiated in
1975 on the basis of the available information from the ERCA pilot plant
facility and discussions with ERCA personnel, as a direct scale to the
50 MWe plant design. The 50 MWe demonstration plant program, however,
was not continued, primarily because of the decision to minimize the use
of oil in boilers capable of firing coal in the Northeast following the
oil embargo. The EPA program to demonstrate the CAFB process was con-
tinued in 1975 with a contract to Foster Wheeler Energy Corporation (FW)
to retrofit a CAFB process on a 20 MWe gas-fired boiler at Central Power
and Light's (CPL) plant in San Benito, Texas. The CPL plant is designed
to utilize residual oil as fuel. CPL, however, is interested in using
lignite coal as a fuel, and the test program includes the use of lignite.
The pulsed-flow solids transport system remains an area of concern.
Westinghouse, as part of a CAFB engineering support: program sponsored
by EPA, continued with the support program to build the solids transport
test facility for development of information useful for the plant design
and operation.
The program objectives were directed toward developing a sufficient
understanding of the solids transport system to provide a basis for pro-
jection, improvement, and correction of the performance of the CAFB
demonstration plant now scheduled for operation in 1979. Transport system
optimization must deal with the following desirable features: high solids
capacity, minimum air requirement, controllability, a seal against reactor
gas exchange, and freedom from plugging or other malfunction.
The transport test facility has been built to provide data for this
investigation. Pulsed transport air is added to the junction of the
horizontal and vertical sections of each transport leg. In the first
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method of air introduction tested, air was supplied internally to the
leg via a pipe sparger. Then a method was tested whereby air was sup-
plied through nozzles in the back wall of the transfer slot elbow.
Variables tested included pulse on-time, off-time, and flow rate;
and fluidizing velocity. A mathematical model of the system was developed
on the basis of a momentum balance. The model allows the projection of
demonstration plant transport system performance at various conditions.
Design and performance projections reported are related to the CPL plant
design. Previous solids transport data collected by FW on a cold model
are also compared with the model projections.
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2.0 CONCLUSIONS
• The inserted pipe sparger tests were not satisfactory with
regard to solids flow capacity and transfer efficiency. Pre-
sumed reasons were obstruction of the solids flow stream and
limited transport gas interface for solids entrainment.
• The recessed nozzle system similar to that being used in the
CAFB demonstration plant yielded solids flows of 80 to
2
110 kg/s-m . This compares with projected needs of 110 to
2
150 kg/s-m with the current demonstration plant design.
Transfer ratios (mass of solids to mass of air) in excess of
100 were frequently obtained.
• Each pulse of transport gas imposes a pressure drop upon the
vertical section of a transport leg that is in excess of that
needed to fluidize the leg. The nonequilibrium state existing
during the short time required to fluidize the leg is a ver-
tical seal only during which transfer of solids may occur.
This time is about 0.3 to 0.4 s. Longer on-tlmes only waste
transport gas.
• If a pulse is long enough to complete fluidization, a minimum
time is required to complete defluidization and repacking of
solids prior to the next pulse. This time is about 1.5 s.
Proportionately less time is needed at shorter on-tlines.
Excessive off-time may result in overpacking and resistance
to new pulse jets.
• Unless both beds are highly expanded, adequate solids flow in
each direction simultaneously is not possible under continuous
(i.e., not pulsed) aeration control.
-------
A model has been developed that allows the projection of trans-
port system performance under different conditions and sets of
variables. The model is essentially a momentum balance with
appropriate assumptions. The following points are model pre-
dicted trends:
- Other conditions being constant, a higher gas input rate will
yield increased solids flow and reduced transport efficiency.
- Temperature, pressure level, and particle size have only
moderate effects upon performance.
- The pressure gradient across a leg is important in that it
determines whether a leg will fluidize or not during a pulse.
Within either of these regimes the imposed pressure gradient
does not seem to have a major effect.
- Both solids flow rate and transport ratio (mass of solids to
gas) are sensitive to particle density. Heavier particles
are more rapidly moved than lighter ones.
- The model predicts that increasing any of several leg dimen-
sions (vertical height, horizontal length, horizontal depth)
will iaitMEove capacity and. efficiency.
It is projected that, if the solids density is as low as
expected, transport gas requirements will be high relative to
those optimally obtained in the FW and Westinghouse test programs
(transport mass ratios of about 40). Necessary flow should still
be achievable.
On-times in excess of the leg fluidizing times may result in
significant transfer of reactor gases from one vessel to
another, particularly from the higher pressure bed.
The stagnant solids region at the base of the horizontal sec-
tion is the most likely place for caking of solids to occur.
The solids transport legs seem to have a preference for the
larger bed particles. This may result in the build-up of
unreactive fines in either bed.
8
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3.0 RECOmENDATIONS
3.1 CAFB PLANT OPERATION
• Every effort should be made to keep the pulse on-time slightly
lower than the leg fluidizing time ('vQ ,3s), yielding substan-
tially improved efficiency and preventing massive flows of
reactor gas between the two vessels. This procedure may be
practical using two solenoid valves in series, with offset
phases.
• For maximum efficiency and capacity the off-time should be 1.5
to 2.0 s, depending on the on-time used.
• Piping volume between the pulsation control and delivery sys-
tems should be minimized to reduce capacitance effects and
allow the actual and desired pulse wave forms to be alike.
• Within other process constraints the pressure gradients across
the transfer legs should be minimized by manipulation of bed
operating pressures, bed levels, and fluidizing velocities.
Furthermore, if the pulse duration is longer than the fluidiz-
ing time, the beds should be operated at as nearly the same
pressures as possible because gas will be exchanged between
the two vessels when seals are blown.
• Bed compositions should be periodically monitored to ascertain
whether or not untransportable fines are building up in either
system. If so, recycle of cyclone fines to opposite beds (if
possible within system pressure balance and other constraints)
may remedy this problem.
• Wider legs of similar design, with proportionately more noz-
zles, and with less gas input per nozzle, should produce
higher capacity and require much less transport gas.
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3.2 FURTHER STUDY
• The effect of particle density should be experimentally
confirmed. In conjunction, particle size effects should be
investigated.
• The effects of nozzle diameter, penetration, and spacing should
be explored to complete model applicability and provide oper-
ating flexibility.
• Further systematic investigations of leg dimension (height,
horizontal length, width, horizontal depth, angle of tilt) may
confirm better designs.
10
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4.0 BACKGROUND AND PLANT REQUIREMENTS
The material circulation concept for the CAFB process is illus-
trated schematically in Figure 1. The gasifier and regenerator are
to be located in a single rectangular vessel, partitioned to prevent
intermixing of the two atmospheres. The partition is pierced by trans-
fer slots to carry controlled amounts of material in each direction.
Each slot has a vertical section in which solids move downward as a
packed bed to provide at least a partial seal against gas backflow.
A horizontal section is needed to allow packing, and, hence, to prohibit
"freewheeling" of solids between pulses. Pulsed gas (boiler stack gas)
is to blow material from the horizontal section in the proper direction,
the transferred material to be replaced with solids from the vertical
packed-bed supply line. In each fluid bed a partial obstruction will
regulate the circulation of material and provide some control of solids
residence time.
Placing the two beds in close contact at the same level has the
significant advantages of allowing compact, economical construction, and
conserving process heat at the interface and in the transfer duct sys-
tem. The main disadvantage is that the short vertical legs between
relatively dense fluidized vessels cannot provide a complete or stable
partial seal in both directions simultaneously. The pulsed transport
mode of operation should allow this weakness to be circumvented at some
cost in efficiency in comparison to similar designs with continuous
control aeration.
The potential problems of blown seals and uncontrollable or unpre-
dictable solids flow rates have required a testing program to identify
11
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Owg. 6WAAIJ
Gasifier
FluMlzIng
Gas
ft
Pulse
Gas
FluMizing
Gas
Figure la. System Schematic - Side View CAFB
Material Circulation
Gasifier
Owg. 6WAA1S
Regenerator
(f
Partition
Figure Ib. System Schematic - Top View CAFB
Material Circulation
12
-------
and understand the key parameters and their effects. This knowledge
will be useful in optimizing the transfer system performance in the
demonstration plant. The specific performance requirements include:
• The capacity to achieve the necessary solids circulation rates
(2.5 to 3.8 kg/s) in each direction
• A minimum pulse gas flow requirement (maximum transport
efficiency)
• The minimum necessary pulse gas delivery pressure
• A predictable and controllable relationship between gas
input rate and solids flow
• The prevention of a significant flux of regenerator gas into
the gasifier via the transfer ducts, and the converse
• Freedom from plugging caused by agglomeration, geometric
obstacles, and other malfunctions
• The assurance that the full spectrum of material present
(particle size, density, etc.) will be periodically trans-
ferred to the other bed, in order to prevent the build-up
of inactive material in either bed.
In the present study we constructed a large cold test facility to
generate data with which to gain a more thorough understanding of the
pulse-transport system. The resulting mathematical model should allow
projections of the effects of major system variables and more satis-
factory extrapolation to hot conditions. With this facility we also
hoped to determine whether the above listed qualitative expectations
are realistic, to note possible operational problem areas, and to sug-
gest methods to avoid or solve such problems.
13
-------
5.0 TEST FACILITY
5.1 DESIGN BASIS
The solids transport test facility has been designed to simulate
the pulsed, dense-phase pneumatic transport method that has been utilized
in the ERCA pilot plant and has been selected for use in the CPL demon-
stration plant. The scale of the facility was selected to be representa-
tive of the demonstration plant and future commercial CAFB plants. The
facility was also designed with sufficient flexibility to permit a wide
range of operating conditions and transport leg designs, since only
small-scale data were available. A schematic of the test facility is
presented in Figure 2.
The major design basis considerations specified prior to detailed
design are summarized below.
Scale of model - 10-25 MWe
Solids circulation rate expected - 4 kg/s (maximum)
Vessel design (see Figure 3)
Two identical semicylindrical vessels
Operating pressure - 120 kPa
Design pressure - 140 kPa
Operating temperature - ambient
Materials of construction - sheet metal with clear sections
(Plexlglas, Lucite, glass, etc.) as shown in drawing
Locations of clear observation sections - one 1.2 m strip on wall
of each vessel as shown, one section on each lid, one section
above each entrance and exit of two transport legs
Dimensions -3m tall, 0.7 m radius, 1.5 m bed depth (max.), 1.2 m
freeboard (min.), transfer leg exit 8 cm above distributor
plate (indention in vessel wall)
Skid mounted to permit transfer leg interchange (maximum separation
of 1.2 m)
14
-------
Dug. 1699B3<4
H*
Ul
Air
Disposal
*-0Back-Pressure Control Valve
Blower
LR ) Level Recorder
Pulse
Valve 4
Systems
Exhaust
Distributor
Fluidizing Air
Annubar Flow Measurement
Balancing Valve
ulsation Control Vessel
Figure 2. Test Facility Flow Diagram
-------
Dwg. 1699635
Top View
Plexiglas View Ports
Baffle
k0.38m
Pulsed Flow
Inlet Manifolds
Cyclone
Stand Leg
Side View 3-°
1
1.2
m
1.!
V
m \
.m j >
0.6m
1
View
Port
>m *
0.9m
i*
O.^m t
-0.7 m -H* *l
0.46m|
©
\
\
,
1
1
i
s
r
Transfer-*
Legs
i
i
©
•^•^^5
^
r
!f
-«-
^ff
II
II
ii
II
1
V
^^^^^_
^TT^
>
^-Lid
=^035 Outlet
fx.
^- Cyclone
Stand Leg
"~~~^~- Baffle
"^^— Bed
/-Drain
i* ,
P Distributor
P-^Gas Inlet
^-Plenum
Figure 3. Test Facility Fluid-Bed Vessels
16
-------
Internals - vertical baffle plate (2.1 m tall) to separate inlet from
outlet (should be removable)
Distributor plate is orifice type with 325 mesh screen cover-
ing holes. Hole diameter, number, and spacing to be deter-
mined based on 3 kPa AP at bed operating velocity of 1.2 m/s.
Inlets and Outlets - air to plenum, air exit through wall, cyclone
standleg through wall, bed loading port and bed drain through wall;
sizes to be determined.
Lid bolted or hinged
Transport legs (see Figure 4)
Two identical transport legs (single design shown)
Design pressure - 140 kPa
Materials of construction - totally clear plastic material or con-
structed with clear sections for observation
Dimensions - duct height 12.7 cm, duct width 0.456 m, leg height
0.853 m, horizontal leg length 0.37 m (see drawing)
Transport legs are flanged at both ends to permit easy changing
of legs.
Transport gas rate (average maximum) - 0.047 m^/s at M.30 kPa
(based on 80 kg solids transferred per 1 m3 transport gas)
Transport gas pulse duration (s) - 0.5, 1, 2, 3, 4, 5, continuous
Pulse % on time - 10O, 75, 5O, 40, 30, 20, 10
Instantaneous transport gas rate - 0.12 m /s (maximum)
Aeration gas locations as shown in drawing
o
Aeration gas rate (maximum) - 0.025 m /s at standard conditions
Aeration pipes - diameter, hole size, number of holes to be deter-
mined on the basis of permissible pressure drop
Transport gas pulse-pipe design - pipe diameter (2.5 to 5 cm), hole
size, number to be determined on the basis of permissible pressure
drop (^ kPa) . Pipe should be permitted to rotate to change hole
orientation. Alternate locations for pipe provided.
Bed material - crushed brick or other material having proper bulk
density. Particle size about 600 to 3000 ym range. Bed pressure
drop of about 0.1 kPa/cm bed depth. Minimum fluidization velocity
of 0.3 to 0.6 m/s.
17
-------
Dwg. 1699B36
Supplying Vessel
0.79m
Vibration Isolator
Side View Port
Top View Ports
Receiving
Vessel
Note: Width =0.457m
Figure 4. Test Facility Transport Leg
18
-------
Air requirements - about 2 standard m3/s at 130 kPa delivery pres-
sure. Supplied by new blower(s).
Loading and draining system - standard feeder and pneumatic trans-
port system (packaged system) capable of filling or draining beds.
Fill both beds through single vessel. Drain both vessels separately.
Cyclone(s) - maximum pressure drop of 3.7 kPa. Collect large mate-
rial (>400 vim) and recycle to beds. Single cyclone for both beds
or two cyclones in parallel.
Filter - collect fines passing through cyclone(s). Sufficient
efficiency to meet environmental restrictions. Maximum pressure
drop of 3.7 kPa.
Pulsing valves - capable of meeting pulse frequency and duration
requirements at specified flow rates by simple adjustments.
Back-pressure valve - capable of providing a pressure differential
between the two vessels of 0.25 to 1.25 kPa
Operation - pulse-gas rates will be continuously recorded to pro-
vide record of instantaneous and average transport gas usage.
Solids transport rates will be determined by recording the bed
level change (pressure drop change) of one of the beds as a function
of time when one transport leg is shut off. This method will be
supplemented by direct observation of the flow in the transport
legs or tracer experiments.
5.2 SPECIFICATIONS
A complete set of drawings of the system and its components is in
Appendix A-l. These are numbered F940-1 to F940-11. As shown in Fig-
ure F940-1, the facility consists of two identical fluidized-bed vessels
and the following major support systems:
1. Transfer legs (TL-1 and TL-2)
2. 186 kW centrifugal blower (CB-1)
3. Cyclone collectors (CC-1 and CC-2)
4. Baghouse dust collector (DC-1)
5. Pulsation control system, including pulsation control vessels
(PCV-1 and PCV-2)
6. Instrument and control package.
19
-------
5.2.1 Fluidized Bed Vessels
The two identical semicylindrical vessels are illustrated in Fig-
ure 3 and Drawing F940-2 in the Appendix. These 0.7 m radius by 3 m
2
tall vessels have cross-sectional flow areas of 0.63 m below the trans-
o
fer leg hoppers and 0.74 m above. View ports were included as
described under Section 5.1 above. Design parameters were:
Operating pressure - 140 kPa
Design pressure - 160 kPa
Operating and design temperature - 340 K.
One of the units was mounted on a track system to permit the use of
different leg designs requiring other vessel separation (maximum separa-
tion of 1.8 m).
The distributor plates each contained 252 0.95 cm holes drilled at
4.76 cm triangular pitch (F940-2). Weeping of solids through the dis-
tributor holes was prevented by overlaying a 325 mesh stainless steel
screen.
5.2.2 Transfer Legs
The transfer legs (Figure 4 and Drawing F940-3) of 0.058 m flow
area featured standlegs of 0.85 m vertical height slanted at 15° from
the vertical. View ports (Drawing F940-3) were installed to allow
observation of solids flow characteristics. There were two pressure
taps in both the vertical and horizontal sections of each leg for fur-
ther examination of the flow behavior. Provision was made to aerate
the vertical leg section continuously (maximum rate 0.00566 m /s) if
desired or necessary. Design and operating temperatures and pressures
were the same as for the fluidized-bed vessels.
5.2.3 Centrifugal Blower
Fluidizing and pulse air were supplied by a five-stage centrifugal
blower (CB-1), which was Model 1255 supplied by the Lamson Division
of Diebold, Inc. This unit is rated to supply 2.83 standard m^/s at a
20
-------
delivery pressure of 140 kPa. Blower capacity is regulated by a manual
butterfly valve mounted on the intake. The blower will generate 157 kPa
o
at approximately 1.18 m /s, and the pressure curve is relatively flat
from that point to no delivery.
5.2.4 Cyclone Collectors
Two identical cyclones (CC-1 and CC-2) were used to control emis-
sions and prevent excessive loss of bed material. Each of these units
(Model VM810/150, Size 77, supplied by the Ducon Company, Inc.) hfes a
capacity of 1.42 mr/s of air at 325 K and is rated for positive pressure
operation up to a gauge pressure of 7.5 kPa. Adjustable pressure
switches, set at 7.5 kPa, are employed to protect the unit. The maximum
dust loading on each unit is 1.15 mg/nr of particles ranging from 1 to
1500 ym in size. The cyclones are capable of removing 99 percent of
all particles larger than 40 pm at a maximum pressure drop of 1.5 kPa
at the above dust loading. Collected dust is removed by rotary valves
and can be either recycled to the fluid bed or collected for disposal.
5.2.5 Dust Collector
7
This unit (DC-1) has a capacity of 2.83 m /s of air at 320 K, is
rated for positive pressure operation up to 5 kPa gauge pressure, and
is protected by a rupture disc. The collector (Model 645-10-20, Micropul
o
Division, U. S. Filter Corp.) has a maximum dust loading of 0.46 mg/m
of particles 1 to 40 pm in size and is capable of removing 99 percent
of the material 1 urn or larger at a maximum pressure loss of 1.5 kPa.
5.2.6 Pulsation Control System
Identical systems draw air from the blower discharge for pulsing
each transfer leg. Each system consists of an orifice-type flow mea-
suring device, a pulsation control vessel, a balancing valve, a solenoid
valve, and the actual injection configuration. The average maximum
transport gas rate is 0.05 m3/s, with an instantaneous maximum rate of
0.12 m3/s. The solenoid valves and their control system allow variable
pulse frequency (1.5 to 90 pulses/min) with the capability to vary the
on-time from 0 to 100 percent of the pulse cycle length.
21
-------
Pulsation control vessels (PCV-1 and PCV-2) are 1.8 m3 units
located between the flow measuring elements and the control valves.
These units dampen pulsations at the flow meters sufficiently to pro-
duce accurate measurements of average transport gas flow over the range
investigated. Design parameters are:
Operating pressure - 140 kPa
Design pressure - 160 kPa
Operating temperature - 340 K
Design temperature - 345 K.
5.2.7 Instrumentation and Control Package
Relative locations of all instrument measurement points are found
in Drawing F940-1 in Appendix Al. Accurate positions can then be
located from the appropriate detailed drawings. A list of instrument
and auxiliary equipment specifications is contained in Appendix A2. In
the following brief discussion of the instrumentation package, parentheti-
cal codes refer to designations used in these Appendices.
Process temperatures (TI-1 through TI-4) are measured at blower
inlet and discharge and between each vessel and the corresponding
cyclone. Pressures (PI-1 through PI-4) are measured at blower discharge,
cyclone inlets, and at the baghouse inlet.
Fluidization velocities can be independently controlled with 30-cm
butterfly valves (V-l). A back-pressure control valve (PC-3) permits
maintenance of equal bed pressure levels at different fluidizing velocities
or the converse. Flow rates are metered with Annubar (Ellison Instrument
Co.) velocity head sensors (FE-1, 4).
Transport gas flow is metered with flange top orifice plates (FRT-2,
3), and the square root of the differential pressure signal is recorded.
The signals are computer integrated for average flow rate. The solenoid
valves (VFC-2, 3), controllers (FC-2, 3), and hand-operated 10-cm
balancing valve (V-l) provide control of the transport gas curve.
22
-------
Pressure differentials are monitored across the distributor
plates and across the fluidized beds. In addition, the level of
either bed can be recorded (LR-1) by manipulation of valves between the
level recorder and the bed vessels. The rate of bed level decrease
(or increase) is used to determine the bed material transfer rate.
Finally, pressures at various points in the transport legs can be
monitored or recorded (PT-1, 2, PR-1, 2).
5.2.8 Additional Specifications
Diagrams describing system layout, the control panel, electrical
plan, instrumentation schematics, and structural details are included
as Drawings F940-4 through F940-11 in Appendix Al.
5.3 CONSTRUCTION AND COSTS
Detailed engineering design and construction supervision were per-
formed by Peter F. Loftus Corporation. Site construction was done by
Garfield, Inc. The facility was constructed at the Westinghouse Waltz
Mill Site. Facility costs included:
Engineering and design (Loftus) - $24,000
Site construction (Garfield) - 79,000
Capital equipment - 64,000
Alumina (bed material) - 2,350 .
23
-------
6.0 TEST PROGRAM
6.1 SUMMARY
An activated alumina catalyst was used as the bed material in our
simulation of the CAFB transfer system. Solids flow rates were measured
during one-directional tests at points of equal bed height. Independent
variables included pulse duration, time between pulses, airflow during
pulse, and fluidizing velocity.
The test program was divided into two segments during which two
different pulse gas introduction systems were examined. The first
sparger (first test series) was a multiorifice pipe distributor inserted
directly into the transport leg bend. The second test series used a
sparger that was a series of nozzles inserted just through the back wall
of the standleg. Extensive data with each system demonstrated the
superiority of the second system, in terms of both achievable solids
flow and transfer efficiency. The data were used to test a mathematical
model (Section 7) that was being developed simultaneously. Optimization
of the pulse curve was possible using feedback understanding from the
model.
6.2 TEST MATERIAL
Activated alumina was selected as the test material on the basis of
its bulk density (specific gravity M., as expected for CAFB material),
particle size distribution, and availability in bulk. The first alumina
used was Alcoa type F-l with nominal size distribution of 8 to 10 mesh
(1680 to 2380 vim).
The high porosity of this material (top pore size 3 to 10 urn)
suggested that it would be prone to attrition. A series of tests were
performed to determine attrition losses during long-term exposure of the
24
-------
material to a fluidized-bed environment. In addition, experiments
were performed to determine other pertinent data - minimum
fluidization velocity, particle size distribution, and bulk density.
Experimental conditions for the attrition test were as follows:
• Test unit - 7.0-cm diameter Plexiglas tube (0.91 m high)
• Distributor - high-velocity orifice type
• Operating velocity - 1.2 m/s (slugging)
• Test duration - 96 hr.
Attrition losses, without recycle, were approximately 10 percent
by weight of the initial charge. These data indicate that the greatest
attrition loss occurred for particles ranging in size from 2000 to
2800 urn. Elutriation due to slugging may have been responsible for loss
of some of the larger particles, but no analysis of the elutriated
material was conducted. Due to the shift in particle size distribution,
the minimum fluidization velocity was reduced from 0.76 m/s initially
to 0.67 m/s in 96 hr. Extrapolation of the test results to a 1.5 m bed
depth with operation at 1.2 m/s indicates that the elutriation rate
would be approximately 1 percent: in 96 hr, with no recycle of fines.
This material was used for the tests on the first sparger configura-
tion (Section 6.4 below). Low fluidizing velocities, just in excess of
the minimum as determined in the above tests, were used to prevent exces-
sive entrainment. Entrained fines were not recycled.
At the break during which the transfer leg pulse system was modified,
bed material was withdrawn and analyzed for size distribution (Table 1).
Despite the low fluidizing velocity, a significant reduction in average
size was evident. The size distribution, and the low amount of makeup
solids needed during the first series of runs, indicate that, as in the
attrition tests above, attrition consists primarily of the breakdown of
the very largest particles into moderate sized ones. At the same time,
the loose bulk specific gravity was found to be 0.982, and the packed
25
-------
TABLE 1
PARTICLE SIZE DISTRIBUTION AT BEGINNING OF
FINAL TEST SERIES
U. S. Mesh Avera«e SiZ6' dpi (Mm) Wt
+8
-8 +12
-12 +16
-16 +20
-20 +30
-30 +40
-40
2605
2030
1435
1016
718
508
350
0.1
41.0
35.8
11.2
6.0
2.8
3.0
99.9
Linear mean size (Zx.d .) = 1530 ym
i pi
Surface mean size (l/(Zx./d .)) = 1274 pm
i pi
TABLE 2
PARTICLE SIZE DISTRIBUTION AT CONCLUSION
OF FINAL TEST SERIES
U. S. Mesh
+8
-8 +12
-12 +16
-16 +20
-20 +30
-30 +40
-40
Average Size, d . (ym)
pi
2605
2030
1435
1016
718
508
350
Wt %, x.
2.1
12.9
26.0
21.2
14.2
8.0
15.0
99.9
Linear Mean Size = 1104 um
Surface Mean Size = 794 urn
26
-------
specific gravity was 1.133. Effective aerodynamic particle densities
could not be measured because the very large pores allowed absorption of
even high surface tension immersing fluids (Mercury). Alcoa quoted the
true specific gravity (immersion in helium) as 3.3.
The test series with the second sparger design was primarily con-
ducted at higher fluidizing velocities (VL.O m/s). Greatly increased
attrition and elutriation were very apparent, requiring that we recycle
fines continuously. Solids makeup requirements, to replace baghouse
fines only in this case, were nonetheless larger when compared to cyclone
replacement losses at the lower velocity. When our initial stockpile
of alumina was depleted, replacement material was purchased from
Reynolds Metals Company because of a large cost difference and the poor
performance of the Alcoa material. The Reynolds alumina (RA-1), which
was to fare no better, was nominally sized at 8 to 14 mesh (1190 to
2380 urn).
The particle size distribution of the bed material, at the conclusion
of the test sequences, is shown in Table 2. The susceptibility of these
materials to attrition is obvious by comparison with data in Table 1.
The loose bulk specific gravity of the final material was 1.14 and the
packed bulk specific gravity was 1.23. Calculations were performed with
particle sizes and bulk densities estimated by interpolation between
these sets of results.
6.3 PROCEDURES
The experimental technique was largely dictated by the method of
solids flow determination. First, the overall technique will be out-
lined, then the solids flow measurement procedure will be discussed.
6.3.1 Experimental Technique
Prior to a day's series of runs, the bed levels would be noted and
adjusted, if desired. Fluidization velocities were then set using the
blower intake butterfly valve. Usually, the balancing valves in the
transport air lines were set at preselected openings to determine the
27
-------
approximate levels of airflow desired. The actual average and pulse
instantaneous airflow, however, would vary considerably with the pulse
on- and off-times selected for the particular run. For the inserted
pipe sparger the cyclone discharge valves were set to divert solids into
a collecting drum. For the final nozzle configuration runs the valves
were set to recycle fines to the source bed.
After starting fluidizing airflow, all but one solenoid valve were
isolated via the hand shut-off valves (see Figure 940-1 in Appendix A-l).
The desired pulse rate and percent off-time were then set for the test
solenoid valve. The shut-off valves for airflow to the transport system
for the other leg were then opened, and this leg was pulsed to develop
a bed height difference, the deeper bed to be used as the feeding bed
in the run. Again, all transport air shut-off valves were closed, except
those in the line prepared for the test.
At this point temperatures, pressures, pressure differentials, and
fluidizing air rates were recorded and the transport leg pressure trans-
mitter selector switches set to the desired position for recording.
Solids flow was then initiated by starting transport air at the preselected
pulse rate. While material was being transferred, the transport airflow
would be recorded for future integration. Within a few minutes solids
flow would stop because of the depletion of material in the feeding bed
above the leg hopper. Transport air was then stopped manually and both
final bed heights recorded. Pulse rates could now be reset in prepara-
tion for the next run. In the second test series a repeat run in the
opposite direction was made, both pulse systems having been preset.
6.3.2 Solids Flow Rate Determination
The pulsing, turbulent nature of solids movement in the transport
legs would make direct measurement of solids flow in the leg difficult.
Several techniques were evaluated as methods to determine rates of solids
circulation between the vessels: solid tracer particles based on color,
magnetic properties, electric conductivity, etc.; heat transport rate
measurement between the vessels; an external, mechanical solids circulation
loop as used by FW in their cold model studies; continuous monitoring
28
-------
techniques based on X ray, Y radiation, microwave, sonic energy,
inductance, capacitance probes, light source probes, heat transfer probes,
momentum or strain probes. All of these techniques are complex, expensive,
and subject to great uncertainty. We decided, therefore, to try measuring
the solids flow rate by bed level changes, as recorded by a pneumatic
differential pressure transmitter. This decision required that runs be
one-way and not steady state with respect to bed levels and, hence, to
level-dependent parameters such as the system pressure balance. The
level recorder was carefully selected to reduce any response time effect
to insignificance. The method proved completely satisfactory except for
failure to allow longer, steady-state runs. The rate could be calculated
as
c. -
Two potential problems with this method were the random fluctuations
in pressure drop characteristic of fluid beds and the possibility that
the transport rate might be dependent on bed height and, hence, upon
time. It was evident that the. transport rate was bed -level dependent
mostly at great bed-level differences - that is, the start and finish of
each test sequence. The lower-than-characteristic rate at the beginning
of the run was attributed to the high degree of packing and consequent
resistance to motion of the leg solids when first pulsed. The low rate
at the end of the run was due to the inability to fill the solids hoppers
as the mean bed level fell below. It was decided to measure the trans-
port rate at the point of equal bed heights. This could be done by
noting the two final bed levels and averaging.
For the first test series solids transfer rates were sufficiently
low that the bed-level change rate could be accurately approximated by
the incremental difference over a 30 s time interval around the equal
bed point, during which the rate was fairly constant. The time scale
of random fluctuations (about 0.5 to 2 s) was small enough compared to
this interval that fluctuations did not cause significant error. The
main source of error was in accurately reading the pressure differentials
at the two ends of the intervals.
29
-------
The second test series featured solids transfer rates high enough
that runs lasted only 20 to 30 s. Using a long time increment as before
was undesirable because the rate would not be nearly constant over the
wide variation in bed depth involved. A short interval was not acceptable
because the bed fluctuations would obscure the real rate. A technique
was developed, therefore, to solve this dilemma. The level recorder
curve was fitted to a quadratic equation of AP versus time, whose
Li
slope (d(AP )/dt) at the required bed-level point could be mathematically
L
computed. This approach proved to be successful.
6.4 FIRST TEST SERIES - INSERTED PIPE SPARGER
•
6.A.I Introduction
The first sparger tested was a steel pipe (6.03 cm od, 5.25 cm id)
inserted through a flange at the elbow of each transfer slot. The pipe
was drilled with 32 0.95-cm diameter holes in a single line from end to
end of the transfer width. The holes were located 1.27 cm apart, center-
to-center, and were oriented horizontally or angled downward at 45°,
depending on the specific test. The holes and pipe were designed for
uniform gas distribution. The sparger is illustrated in Figure 5 and
detailed in Appendix A-l, drawing F940-3.
The objectives of the initial test program were (chronologically
arranged):
• To develop the experimental techniques for maximum benefit. In
particular, the suitability of the solids flow measurement method
had to be confirmed and its details resolved
• To conduct an initial survey of the effects of major parameters
to guide program development for system optimization
• To evaluate the initial design for potential success
• To optimize the performance of the initial design, if it proved
acceptable.
6.4.2 Results and Discussion
The results of tests with this system are listed in Table 3. Flow
rates obtained were unacceptably low (<1 kg/s in all but one run),
30
-------
Gas
5.25 cm ID
Dwg. 6W»A1U
V
6.03cm, OD
12.7cm
a. Side View
Solids
\ \ \ \
b. Front View
Figure 5. Inserted Pipe Sparger
32 Holes
0.95cm Diameter
1.27 cm Center-to-
Center
31
-------
TABLE 3
TRANSPORT DATA - FIRST TEST SERIES
to
Run
No.
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
28
29
30
31
32
33
34
Leg
No.
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
1
2
2
1
2
1
1
On-Time,
s
3.25
3.25
10.60
10.20
5.20
6.80
2.30
2.40
6.40
5.10
3.70
4.10
2.30
2.40
1.80
1.90
4.60
4.30
2.40
2.10
2.40
1.20
1.20
0.80
0.80
0.60
0.50
2.00
Off-Time,
s
3.2
3.2
2.7
2.6
1.3
1.7
0.6
0.6
4.3
3.4
2.4
2.8
0.6
0.6
1.2
1.2
6.9
6.4
3.7
3.1
3.7
1.9
1.8
1.3
1.3
0.8
0.8
7.8
Pulse Rate,
kg/s
0.0387
0.0379
0.0614
0.0604
0.0666
0.0623
0.0691
0.0713
0.0479
0.0567
0.0539
0.0520
0.0691
0.0701
0.0667
0.0620
0.0374
0.0388
0.0398
0.0376
0.0469
0.0530
0.0465
0.0548
0.0558
0.0644
0.0656
0.0260
Solids Rate,
kg/s
0.10
0.08
0.10
0.18
0.26
0.29
0.00
0.00
0.21
0.26
0.37
0.31
0.00
0.00
0.39
0.37
0.21
0.21
0.21
0.31
0.31
0.42
0.37
0.37
0.39
0.00
0.00
0.18
Transfer
Ratio
2.6
2.1
1.6
3.0
3.9
4.7
0.0
0.0
4.4
4.6
6.9
6.0
0.0
0.0
5.8
6.0
5.6
5.4
5.3
8.2
6.6
7.9
8.0
6.8
7.0
0.0
0.0
6.9
Fluid! zing
Velocity,
m/s
0.70
0.70
0.70
0.70
0.70
0.70
0.70
0.70
0.70
0.70
0.70
0.70
0.69
0.69
0.69
0.69
0.69
0.69
0.69
0.69
0.69
0.69
0.69
0.69
0.69
0.69
0.69
0.69
-------
TABLE 3 (Continued)
Run
No.
35
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Leg
No.
2
1
2
1
2
1
2
1
2
2
1
2
1
2
1
2
2
1
2
1
2
1
2
1
2
1
2
1
2
1
On- Time,
8
2.20
1.20
1.20
0.60
0.60
0.40
0.40
0.20
0.20
7.80
9.60
4.90
5.00
4.90
2.30
2.20
5.90
6.20
4.00
3.50
1.60
1.90
4.00
4.40
2.40
2.40
1.20
3.30
3.20
3.30
Off-Time,
8
8.7
4.5
4.6
2.4
2.3
1.7
1.5
1.0
0.9
2.0
2.4
1.2
1.3
1.2
0.6
0.5
3.9
4.1
2.7
2.4
1.1
1.3
6.0
6.7
3.7
3.7
4.6
2.2
2.1
2.2
Pulse Rate,
ke/s
0,0227
0,0261
0.0262
0.0320
0.0335
0.0382
0.0411
0,0427
0.0616
0,0753
0,0868
0.0820
0.0930
0.0794
0.1050
0.1138
0.0643
0.0786
Q.0571
0.0766
0.0796
0.0901
0.0445
0.0584
0.0444
0.0591
0.0409
0.0826
- 0.0767
0.0816
Solids Rate,
kg/s
0.18
0.21
0.13
0.23
0.31
0.42
0.37
0.52
0.42
0.16
0.23
0.23
0.57
0.34
0.00
0.00
0.10
0.34
0.26
0.73
0.57
0.99
0.39
0.39
0.31
0.57
0.31
0.73
0.42
0.42
Transfer
Ratio
7.9
8.0
5.0
7.2
9.3
11.0
9.0
12.2
6.8
2.1
2.6
2.8
6.1
4.3
0.0
0.0
1.6
4.3
4.6
9.5
7.2
11.0
8.8
6.7
7.0
9.6
7.6
8.8
5.5
5.1
Fluidizing
Velocity,
m/s
0.69
0.70
0.70
0.70
0.70
0.70
0.70
0.70
0.70
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.67
0.68
0.68
0.68
0.68
-------
TABLE 3 (Continued)
Run
No.
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83*
84
85
86
87
88
89
90
91
Leg
Mo.
2
2
1
2
1
2
1
2
1
2
1
1
2
1
1
1
2
2
1
2
1
2
1
1
2
1
On-Time,
8
3.20
3.20
3.30
3.20
3.30
0.50
0.60
0.10
0.10
0.10
0.10
0.00**
0.00**
0.70
0.70
4.50
4.10
4.70
4.40
4.70
4.40
0.50
0.60
0.60
0.60
0.60
Off-Time,
8
2.1
2.1
2.2
2.1
2.2
2.2
2.4
1.1
1.1
1.1
1.1
0.0
0.0
2.8
2.8
6.8
6.2
7.1
6.5
7.1
6.5
1.8
2.5
11.4
11.4
5.5
Pulse Rate,
kg/ s
0.0781
0.0781
0.0816
0.0781
0.0816
0.0579
0.0788
0.0528
0.0484
0.0451
0.0439
0.0496
0.0166
0.0078
0.0268
0.0219
0.0160
0.0184
0.0250
0.0189
0.0247
0.0141
0.0226
0.0103
0.0087
0.0136
Solids Rate,
kg/s
0.52
0.37
0.57
0.47
0.52
0.84
0.99
0.94
0.84
0.94
0.78
0.00
0.00
0.10
0.57
0.13
0.21
0.21
0.31
0.21
0.42
0.37
0.52
0.47
0.29
0.34
Transfer
Ratio
6.7
4.7
7.0
6.0
6.4
14.5
12.6
17.8
17.4
20.8
17.8
0.0
0.0
12.8
21.3
5.9
13.1
11.4
12.4
11.1
17.0
26.2
23.0
45.6
33.3
25.0
Fluidizing
Velocity,
m/s
0.68
0.68
0.68
0.68
0.68
0.68
0.68
0.68
0.68
0.68
0.68
0.62
0.62
0.62
0.74
0.74
0.74
0.72
0.72
0.72
0.72
0.72
0.72
0.64
0.64
0.64
*Runs 83-99: jets directed 45° downward.
**Continuous aeration.
-------
TABLE 3 (Continued)
Run
No.
92
93
94
95
96
97
98
99
Leg
No.
2
1
2
1
2
1
2
1
On-Time,
3
0.60
0.40
0.40
1.50
1.90
0.10
0.10
0.00**
Off-Time,
s
5.3
3.7
3.4
1.0
1.3
0.9
1.1
0.0
Pulse Rate,
kg/s
0.0104
0.0127
0.0127
0.0417
0.0317
0.0215
0.0193
0.0421
Solids Rate,
kg/s
0.31
0.47
0.23
0.05
0.31
0.78
0.52
0.00
Transfer
Ratio
29.8
37.0
18.1
1.2
• 9.8
36.3
26.9
0.0
Fluidizing
Velocity,
m/s
0.64
0.64
0.64
0.60
0.60
0.60
0.60
0.60
**Continuous aeration.
u>
In
-------
especially in light of the larger flow area used relative to the CAFB
design. Efficiencies, measured as mass ratio of solids transferred to
gas required, were correspondingly poor, although much of this is the
result of suboptimum combinations of on- and off-times. These results
were attributable to the obstruction of the solids flow by the sparger
pipe. The design was concluded to be unpromising. Optimization with
regard to pulse variables, therefore, was not pursued.
This test series was useful, however, in providing clues to under-
standing the system and its limitations. At the beginning of the
sequence there was little basis for choosing on- and off-times. By
trial and error, covering combinations of on-times from 0. 1 to 10.6 s
and off-times from 0.5 to 11.4 s, we came to realize several important
points:
• The transfer leg fluidizes with each pulse, and large quantities
of transport gas are lost upward.
• Solids transport apparently occurred early in each run before
fluidization had culminated. Short on-times were therefore
desirable.
• No transfer could be achieved with continuous aeration (runs 77,
78, 99), presumably because no time is allowed for defluidizing.
• No transport could be achieved for off-times less than a critical
value of around 1.0 s (runs 12, 13, 18, 19, 32, 33, 50, 51), sug-
gesting that a minimum time is required for defluidization.
• Exceptions to the above point are those runs that have very short
on-times, 0.1 or 0.2 s, and off-times just less than 1.0 s
(runs 43, 44, 97). Less defluidizing time is required if the
process of blowing the seal leg has not been completed.
• Angling the sparger holes downward by 45° yielded significant
improvement in transport efficiency (runs 83-99), presumably
because it prevented the jet from bypassing the horizontal solids.
The additional resistance encountered by the air jets resulted
in lower overall transport gas rates and, hence, no improvement
in net solids flow.
36
-------
These observations were very useful In planning and analyzing the
runs on the subsequent pulse configuration. Other corollary observa-
tions were made during this sequence.
• Small differences in leg cross-section, caused by using differ-
ent sight-glass thicknesses on the two legs, caused noticeable
differences in performance before being corrected.
• The level recorder tracings clearly indicated the on-off nature
of solids flow. In other words, solids flow does not act to
even out over a pulse cycle.
• The transport rate was somewhat dependent on bed level differ-
ence, particularly near the beginning and end of each run. The
hopper feeding difficulties at low bed-levels and the great
initial inertia of the leg solids, both discussed previously,
are certainly important. Hindsight now indicates that some
dependence of the system performance on system pressure
balance changes with bed depth can be expected.
• Solids flow occurs in a fast moving dilute phase above a region
of apparently stagnant solids. This void is filled between
vessels largely from the receiving vessel side. A brief back-
flow of solids seems to occur following the blowing of the
vertical seal.
• Vertical upflow of transport gas commences soon after the start
of a pulse and is composed of large bubbles or slugs apparently
adjacent to the upper slanted face of the vertical section.
• "Freewheeling," the flow of solids with no pulse air input,
was only seen to occur with great bed depth differences, in
which case solids would move so as to partially alleviate the
difference. It is probably caused by a very low-pressure
gradient across the transfer leg with bed pressure fluctuations
causing the gradient to become negative periodically.
37
-------
6.5 SECOND TEST SERIES - RECESSED NOZZLE SPARGER
6.5.1 Introduction
The fact that FW had finished design of the transfer slot, and the
poor performance of the inserted pipe sparger, made it desirable for
us to convert to a system similar to the FW design for further study.
With the installation of the new test system our objectives were:
• To confirm that the new design would permit the required flow
• To optimize the pulse variables for maximum efficiency and sta-
ble operation
• To begin to understand the transport process from a more funda-
mental vantage point, to allow more confidence in extrapolating
to different conditions, particularly those expected in the
CAFB plant.
The new nozzle configuration is illustrated in Figure 6. Nine
1.91-cm id nozzles, protected against backflow of solids by 325 mesh
screens, are inserted into the back of each transfer leg, near the base
of the leg. These nozzles are oriented horizontally and are arranged
linearly, spaced 5.08 cm center to center. Additional sets of nozzle
inserts (Figure 6d) are available for future testing of additional nozzle
diameters and insertion lengths, if desired. This design should allow
maximum "bite" of the gas jets into the horizontal solids with minimum
obstruction of the downward solids flow path. Nozzle diameter, spacing,
and distance from nozzle to the transfer slot overhang are the same as
for the CAFB design; the number of nozzles, however, is greater because
of the greater width of the transfer leg.
6.5.2 Results and Discussion
A total of 272 formal tests were made with the new transport air
injection system. The results and main variables are listed in Table 4.
Further details may be found in Appendix B. An extensive matrix of
pulse durations of from 0.05 to 4.0 s and off-times of from 0.5 to 3.1 s
was tested, chosen because of the results of the previous test series.
38
-------
Dug. 6444*17
CO
vo
2.5 cm Copper Male
Tube Adapter
2.5 cm Copper Tube •
(size to fit) Solder In Place
2.5cm Copper Sweat Union
2.5 cm SCH 40 Carbon
Steel Half Couplings
Welded Into Manifold
Pipe Manifold
ID 10.23 cm
Stockham Angle
Globe Valve
2.5cm
Copper Tube^
Male Adapter
2. Jem
Air Manifold
Steel Pipe
10.23 cm ID
Manifold End Cap
5.08 cm Center-to-Center
Transfer leg
Nozzle Tube
(Welded Into Transfer Leg)
Rubber Tubing 3.2 cm ID
Length to Fit
Figure 6a. Sparger Manifold - Side View
Figure 6. Recessed Nozzle Sparger
Figure 6b. Sparger Nozzle Configuration and
Manifold - Top View
-------
Dwg. 6W+A19
1.9cm
2.54cm
1
Figure 6c. Nozzle Insertion - Side View
Nozzle Tube
Thru Wall (steel)
— Interchangeable Nozzle Insert
(size range, 0.635 to 2.54 cm ID)
Nozzle Insert Cap (steel)
7.9x 7.9mm
Notch for Screen
3. 18 cm 2. 54 cm GaskeHcm
K\\\\ 'ft 15$
/A\\\\\ \ \ \^
- 325 Mesh Screen
(Epoxy into nozzle insert)
0.238cm
0.318 cm
0.64cm
Figure 6d. Nozzle Construction
40
-------
TABLE 4
TESTS RESULTS - SECOND TEST SERIES
Run
No.
1
2
3
4
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
28
29
30
31
32
33
34
Leg
No.
1
2
1
2
2
1
2
1
2
1
2
1
2
1
1
2
1
2
1
2
1
1
2
2
1
1
2
2
On-Time,
8
0.10
0.10
0.50
0.50
0.25
0.25
1.00
1.00
0.75
0.75
0.10
0.10
0.05
0.05
0.50
0.50
0.20
0.20
2.00
2.00
1.00
2.00
2.00
0.50
0.50
0.20
0.20
1.20
Off -Time,
8
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.4
Pulse Rate,
kg/s
0.0341
0.0430
0.0445
0.0528
0.0504
0.0334
0.0617
0.0480
0.0578
0.0472
0.0422
0.0286
0.0373
0.0236
0.0478
0.0468
0.0386
0.0393
0.0600
0.0552
0.0547
0.0601
0.0523
0.0433
0.0454
0.0374
0.0383
0.0451
Solids Rate,
kg/s
1.56
2.60
3.46
2.41
1.58
2.40
2.17
2.57
2.03
2.62
2.75
2.41
2.76
1.83
2.82
1.45
2.55
1.58
3.04
1.92
2.40
1.85
2.04
3.14
2.82
3.47
2.52
2.18
Transfer
Ratio
45
60
77
45
31
71
35
53
35
55
65
84
74
77
59
31
65
40
50
34
43
30
39
72
62
92
65
48
Fluid iz ing
Velocity,
m/s
1.10
1.10
1.01
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.07
1.07
1.07
1.07
1.01
1.04
1.04
1.04
1.04
1.07
1.07
1.01
1.01
1.01
1.01
1.04
1.04
1.04
-------
TABLE 4 (Continued)
Run
No.
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
Leg
No.
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
On-Time,
8
1.20
0.10
0.10
3.00
2.80
1.00
1.00
1.50
1.50
2.50
2.50
4.00
4.00
1.00
1.00
2.00
2.00
0.50
0.50
3.00
3.00
0.20
0.20
1.50
1.50
0.10
0.10
2.50
2.50
0.75
Off-Time,
s
2.4
2.0
2.0
2.0
1.8
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
Pulse Rate,
kg/s
0.0487
0.0299
0.0319
0.0596
0.0618 .
0.0549
0.0456
0.0484
Q.0601
0.0660
0.0499
0.0560
0.0662
0.0750
0.0654
0.0643
0.0736
0.0700
0.0666
0.0648
0.0737
0.0525
0.0572
0.0652
0.0751
0.0324-
0.0348
0.0636
0.0747
0.0728
Solids Rate,
kg/s
2.59
2.81
2.38
1.82
1.15
2.14
2.76
3.19
1.98
2.16
2.28
1.51
1.13
0.06
1.27
2.06
0.21
0.14
1.13
1.88
0.88
2.88
3.11
1.79
0.32
2.75
3.06
1.84
0.33
0.00
Transfer
Ratio
53
93
74
30
18
39
60
65
32
32
45
27
17
0
19
31
2
1
17
28
11
54
54
27
4
84
87
28
4
0
Fluidizing
Velocity,
m/s
1.04
1.04
1.04
1.04
1.04
0.98
0.98
1.01
1.01
1.01
1.01
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
0.98
1.01
1.04
1.04
1.04
-------
TABLE 4 (Continued)
Run
No.
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
Leg
No.
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
1
2
2
1
1
2
2
1
1
On-Time,
s
0.75
4.00
4.00
0.50
0.50
1.00
1.00
0.20
0.20
1.50
1.50
0.20
0.20
2.00
2.00
0.10
0.10
3.10
3.10
0.40
0.40
0.20
0.20
0.80
0.80
2.00
2.00
0.40
0.40
1.00
Off -Time,
8
1.0
1.0
1.0
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
3.0
3.0
3.0
3.0
3.0
3.0
2.9
2.9
3.0
Pulse Rate,
kg/s
0.0576
0.0643
0.0741
0.0548
0.0494
0.0528
0.0616
0.0404
0.0427
0.0561
0.0650
0.0384
0.0379
0.0530
0.0648
0.0325
0.0318
0.0567
0.0652
0.0473
0.0479
0.0347
0.0323
0.0387
0.0461
0.0525
0.0476
0.0319
0.0380
0.0479
Solids Rate,
kg/s
2.32
1.27
0.45
2.90
2.74
3.13
2.14
2.72
2.98
2.23
2.27
4.09
3.06
2.14
2.36
3.40
3.13
1.50
1.77
2.99
3.25
3.73
2.64
2.53
3.28
2.18
1.98
2.43
2.62
3.43
Transfer
Ratio
40
19
6
52
55
59
34
67
69
39
34
106
80
40
36
104
98
26
27
63
67
107
81
65
71
41
41
76
69
71
Fluid iz ing
Velocity,
m/s
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
0.91
0.94
0.94
0.98
0.98
0.98
0.98
0.98
0.98
0.98
0.98
1.01
1.04
1.04
1.04
1.04
1.04
1.04
1.04
-------
TABLE 4 (Continued)
Run
No.
Leg
No.
On-Time,
s
Off-Time,
s
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
2
2
1
1
2
2
1
1
2
2
1
1
1
2
1
1
2
1
2
2
1
1
2
2
1
1
2
2
1
1
1.00
0.60
0.60
1.50
1.50
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.10
0.10
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
3.0
2.9
2.9
3.1
3.1
0.5
0.5
1.6
1.6
1.0
1.0
1.8
1.8
1.4
1.4
1.2
1.2
0.5
0.5
0.5
0.5
1.6
1.6
1.2
1.2
1.0
1.0
0.8
0.8
1.4
Pulse Rate,
kg/s
0.0413
0.0358
Q.0429
0.0497
Q.0405
0.0699
Q.0803
Q.0523
Q.0500
Q.0709
Q.0733
0.0485
0.0461
0.0544
0.0554
0.0582
0.0626
0.0747
0.0736
0.0726
0.0826
0.0411
0.0432
0.0465
0.0464
0.0528
0.0593
0.0711
0.0717
0.0425
Solids Rate,
kg/s
2,
3,
3.
2,
,94
,18
.87
,24
2.11
0.34
0.00
5.45
3.83
0.77
0.52
4.88
4.16
3.
4.
1.
2.
38
04
84
79
0.57
0.92
0.00
0.00
4.85
4.34
4.10
5.
5,
3.
1,
.88
,13
.90
.29
0.53
4.91
Transfer
Ratio
71
88
90
45
52
4
0
104
76
10
7
100
90
62
72
31
44
7
12
0
0
118
100
88
126
97
65
18
7
115
FluidIzIng
Velocity,
m/s
1.04
1.04
1.04
1.04
04
04
04
04
04
04
04
04
04
04
04
04
04
0.98
0.98
04
04
04
04
04
04
04
04
1.04
1.04
1.04
-------
TABLE 4 (Continued)
*»
Ul
Run
No.
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
Leg
No.
2
2
1
1
2
2
1
1
2
2
1
1
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
On-Time,
s
0.20
0.20
0.20
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
1.00
1.00
1.00
0.40
0.40
0.20
0.20
0.60
0.60
1.00
1.00
0.40
0.40
0.40
0.40
0.20
0.20
0.20
0.20
Off-Time,
s
1.4
1.8
1.8
0.9
0.9
0.8
0.8
0.7
0.7
0.6
0.6
1.0
1.0
1.8
1.8
1.8
1.5
1.5
2.7
2.7
3.0
3.0
1.6
1.6
1.4
1.4
1.4
1.4
1.0
1.0
Pulse Rate,
kg/s
0.0434
0.0406
0.0409
0.0432
0.0480
0.0595
0.0516
0.0533
0.0717
0.0724
0.0610
0.0854
0.0729
0.0669
0.0914
0.0797
0.0829
0.0788
0.0816
0.0676
0.0746
0.0931
0.1013
0.0849
0.0888
0.1092
0.0899
0.0811
0.1070
0.0977
Solids Rate,
kg/s
4.09
3.77
4.58
4.33
3.37
3.47
2.69
2.75
1.89
0.57
0.91
1.50
1.22
3.46
5.66
6.56
6.75
5.54
3.87
4.80
2.38
2.23
3.17
5.06
3.35
4.65
5.52
7.65
4.10
3.66
Transfer
Ratio
94
92
111
100
70
58
52
51
26
7
14
17
16
51
61
82
81
70
47
71
31
23
31
59
37
42
61
94
38
37
Fluidizing
Velocity,
m/s
1.04
1.04
1.04
0.98
1.01
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.01
1.01
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.07
1.07
1.07
1.07
1.07
1.07
1.07
-------
TABLE 4 (Continued)
Run
No.
155
156
157
158
159
160
161
162
163
164
165
167
168
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
Leg
No.
1
2
2
1
1
2
2
1
1
2
2
1
2
1
2
1
2
1
1
2
1
2
1
2
1
2
1
2
1
2
On-Time,
8
0.20
0.20
0.10
0.10
0.10
0.10
1.00
1.00
1.00
1.00
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
Off-Time,
s
0.8
0.8
1.0
1.0
0.8
0.8
2.0
2.0
1.6
1.6
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
Pulse Rate,
kg/s
0.1187
0.1301
0.0950
0.0768
0.0949
0.1185
0.0928
0.1017
0.1245
0.1065
0.0907
0.0893
0.0949
0.0855
0.0557
0.0586
0.0430
0.0405
0.0407
0.0445
0.0487
0.0568
0.0666
0.0591
0.0362
0.0361
0.0431
0.0382
'*• 0.0279
0.0198
Solids Rate,
kg/ s
3.03
1.46
4.35
3.91
0.00
0.00
2.71
1.20
4.16
1.82
5.32
4.53
3.09
4.65
5.37
4.30
3.51
3.93
3.75
2.61
3.92
4.87
4.58
3.90
3.98
3.53
3.33
3.23
1.92
1.08
Transfer
Ratio
25
11
45
50
0
0
29
11
33
17
58
50
32
54
96
73
81
97
92
58
80
85
68
65
110
97
77
84
68
54
Fluidizing
Velocity,
m/s
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
1.07
0.98
0.98
0.98
0.98
0.98
0.98
0.98
0.98
1.01
1.01
1.01
1.04
-------
TABLE 4 (Continued)
Run
No.
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
Leg
No.
1
2
1
2
1
2
1
2
1
2
1
2
1
2
2
1
1
2
2
1
1
2
1
2
1
2
2
1
1
2
On-Time,
s
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
Off-Time,
s
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.8
1.8
1.8
1.8
1.6
1.6
1.4
1.4
1.2
1.2
2.0
2.0
2.0
2.0
2.0
2.0
1.8
1.8
1.6
1.6
Pulse Rate,
kg/s
0.0145
0.0200
Q.0308
Q.0273
Q.0359
Q.0370
Q.0504
Q.0467
Q.0614
Q.0638
Q.0346
Q.0332
Q.0291
0.0273
0.0273
0.0308
0.0308
0.0284
0.0346
0.0370
0.0310
0.0275
0.0410
0.0361
0.0370
0.0308
0.0325
0.0333
0.0385
0.0336
Solids Rate,
kg/s
2.37
1.12
3.76
2.90
5.41
2.99
5.80
5.07
5.09
5.11
4.59
3.53
2.55
3.49
2.40
2.64
2.71
2.53
2.88
1.84
2.74
1.89
3.87
2.90
3.06
3.37
3.63
3.20
3.57
2.66
Transfer
Ratio
163
56
121
106
150
80
115
108
82
80
132
106
87
127
87
85
87
89
83
49
88
68
94
80
82
109
111
96
92
79
Fluidizing
Velocity,
m/s
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
1.04
0.37
0.37
0.79
0.79
0.55
0.55
0.55
0.55
0.55
0.55
-------
TABLE 4 (Continued)
Run
No.
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
Leg
No.
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
2
1
1
2
On-Time,
8
0.40
0.40
0.40
0.40
0.40
0.40
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
0.40
0.40
0.40
0.40
0.40
0.40
Off-time.
s
1.4
1.4
1.2
1.2
1.0
1.0
1.0
1.0
0.8
0.8
0.6
0.6
1.4
1.4
1.8
1.8
2.0
2.0
1.8
1.8
1.6
1.6
1.4
1.4
2.0
2.0
2.0
2.0
1.8
1.8
Pulse Rate,
kg/s
Q.0375
Q.0403
0.0403
0.0378
Q.0316
0.0493
0.0357
Q.0357
Q.0469
Q.0447
0,0582
0,0514
0.0287
0.0305
0.0263
0.0260
0.0349
0.0450
0.0464
0.0361
0.0377
0.0477
0.0501
Q.0367
0.0261
0.0279
0.0361
0.0391
0.0386
, » 0.0360
Solids Rate,
kg/s
1.90
2.37
3.14
2.38
1.32
3.00
3.57
3.08
1.45
2.70
0.39
1.02
2.70
3.47
3.01
2.57
2.28
2.52
2.62
2.81
2.76
2.60
2.06
1.68
1.22
1.88
2.71
3.44
3.20
4.39
Transfer
Ratio
50
58
77
63
41
60
99
86
30
60
6
19
94
113
114
98
65
56
56
77
73
54
41
45
46
67
75
88
82
121
Fluid iz ing
Velocity,
ml B
f •
0 55
v . j j
n 55
V. JJ
0 55
V m JJ
0 55
vf . J J
0 55
V • JJ
0 55
\J • JJ
0 55
V • J J
0 55
w • J J
0 55
V • *JJ
0 55
V • JJ
0 55
v • JJ
0 55
V • J J
0 55
vf . JJ
0 55
W • J ^
0 55
v • *J j
0 55
v • JJ
0 55
v • JJ
0 55
v/ • j j
0 55
v • J J
0 55
v • JJ
0.55
** • ~J ^
0 55
v • j j
0 55
v • *J ^
0 55
v • J J
0 VI
V . J/
0 VI
V . J 1
0 37
v/ • j /
0 37
V» • J /
0 ^7
V/ • J /
0.37
-------
TABLE 4 (Continued)
Run
No.
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
Leg
No.
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
On-Time,
s
0.40
0.40
0.40
0.40
0.40
0.40
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
Off-Time,
s
1.4
1.4
1.2
1.2
1.0
1.0
2.0
2.0
1.6
1.6
1.2
1.2
1.4
1.4
1.8
1.8
1.0
1.0
1.4
1.4
1.0
1.0
0.8
0.8
0.6
0.6
Pulse Rate,
kg/s
0.0425
0.0425
Q.0473
0.0507
0.0523
Q.0507
0.0490
0.0418
0,0462
Q.0540
0.0628
0.0528
0.0506
0.0594
0.0528
0.0456
0.0590
0.0666
0.0329
0.0345
0.0418
0.0424
0.0418
0.0472
0.0660
0.0616
Solids Rate,
kg/s
3.25
3.27
2.85
2.66
1.89
2.69
2.71
3.18
3.51
2.80
0.47
2.66
2.62
3.00
2.86
4.06
2.53
0.54
3.59
3.98
3.57
3.48
3.23
3.20
0.00
0.00
Transfer
Ratio
76
76
60
52
36
52
55
75
75
51
7
50
51
50
54
89
42
8
109
115
85
82
77
67
0
0
Fluid iz ing
Velocity,
m/s
0.37
0.37
0.37
0.37
0.37
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
0.40
-------
Overall pulse air rates of from 0.015 to 0.13 kg/s were used. The
fluidizing velocity was about 1.0 m/s for most runs. This value was
selected as a compromise between the desires for maximum bed expansion
and for limited attrition and entrainment. Fluidizing velocities as
low as 0.37 m/s were tested later.
The results were clearly superior to those of the previous sequence.
With proper selection of the pulse pattern, solids transfer rates in
excess of 4.0 kg/s were often obtained. Several runs had rates greater
than 5.0 kg/s. These values compare with the CAFB expected rate require-
ment of 3.0 to 4.0 kg/s. A more accurate comparison can be made on a
flow per unit area basis. Expressed in this manner our rates were
optimally 80 to 110 kg/s/m2. With the existing CAFB design, required
rates will be 110 to 150 kg/s/m2. Transfer efficiencies (mass of
solids/mass of gas) varied considerably, but values in excess of 100
were frequently obtained.
Important information regarding optimum on- and off-times was
obtained. Pulse gas entering after about 0.4 s from the start of an
individual pulse is wasted, pass-ing vertically upward through a fluidized
stand-leg. For on-times in excess of this value, at least 1.2 s is
needed for complete defluidization of the vertical leg prior to the next
pulse. For shorter on-times proportionately less defluidizing time is
needed. In any case, off-times slightly longer than the minimum defluidiz-
ing time will result in a loss of efficiency due to incomplete packing.
The optimum configuration, therefore, would have an on-time of less than
0.4 s and an off-time of about 1.6 to 2.0 s. A shorter on-time or a
longer on-time would result in a lower fraction of transfer time. This
would result in either a lower transfer rate or decreased transfer
efficiency, depending on whether the overall flow rate was increased.
Longer on-times or shorter off-times result in unacceptable loss of gas
upwards. Simultaneous shorter on-times and off-times provide efficient
and rapid transfer but would be mechanically difficult. Projected
optimum on- and off-times for the demonstration plant are presented in
Section 8.0.
50
-------
The data can best be examined by expressing the transfer efficiency
as
Mass Solids Transfer Mass Gas Transfer
Solids Flow Time Pulse On-Time
This is the ratio of instantaneous solid-to-gas flow rates and is
termed the modified transfer ratio to distinguish it from the apparent
(real) transfer ratio, which is
Mass Solids Transfer Mass Gas Transfer
Unit Real Time Unit Real Time
Note that the solids flow time may be significantly less than the
on-time, its maximum value being the fluidizing time of the vertical
section. Estimating the maximum solids flow time, t , by 0.35 s, the
M
data are summarized in Figures 7 through 16, each of which illustrates
a specific sequence of runs. Because of the number of interrelated
variables, some of which could not be independently controlled, these
graphs should not be interpreted as correlations. They are useful,
however, in identifying the key principles in the transport process.
Figures 7 through 10 show how increasing instantaneous gas flow
rate affected the transfer efficiency in series of exploratory runs at
off-times of 1.0, 1.5, 2.0, and 3.0 s, respectively. Note that on-time
is not constant on any of these graphs, but is related to the gas flow
rate. The striking feature is that efficiency increases sharply with
decreasing gas input rate at the low values of airflow. The two pre-
sumed interrelated reasons for this are that 1) high solids mass flow
is required to compensate for decreased velocity in the momentum balance,
and 2) horizontal transport occurs in a denser phase (i.e., the jets are
more persistent). Although the ratios are large here, the low flows
result in solids transfer rates not being correspondingly large. Also,
the low velocity runs generally correspond to long pulse on-times, so
true efficiencies suffer, as actual solids flow time is less than gas
input time. This is why the true transfer ratios (Table 4) showed less
variation in value.
51
-------
C.rvt 6969M-*
i
300
250
200
ISO
ion
so
O
o
°oo
Based on Runs 48 -67
ton varies dependency with Wp
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Wp =Gas Flow Rate During Pulse, kg/s
0.8
Figure 7. Effect of Pulse Air Rate on Modified Transfer Data
•JM
300
250
200
150
100
so
DO
o
Based on Runs 68-85
»oH = l-5*
ton varies dependent!? with Wp
o «S=»M
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Wp =Cas Ftow Rite During Pulse, kg/s
Figure 8. Effect of Pulse Air Rate on Modified Transfer Ratio
52
-------
Curve 696950-A
Ul
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1 1 1 1 1 1 1
0.1 0.2 0.3 0.4 0.5 0.6 0.7
Wp =Gas Flow Rate During Pulse, kg/s
0.8
0.1 0.2 0.3 0.4 0.5 0.6
Wp =Gas Flow Rate During Pulse
0.7 0.8
Figure 9. Effect of Pulse Air Rate on Modified Figure 10.
Transfer Ratio
Effect of Pulse Air Rate on
Modified Transfer Ratio
-------
Curvi 6969S5-*
Curvi 696952-A
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Oton=0.2 Wp -0.3 -0.4 kg/s From Runsll4 - 127
•ton=0.2 Wp~ 0.55 -0.7 kg/s From Runsl41, 142, 151 -1J6
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£
i i i i i
0 0.5 1.0 1.5 2.0 2.5 3.
Off-Time, s
1.5 2.0 2.5 3.0
Off-Time, s
Figure 11. Effect of Off-Time on Modified
Transfer Ratio
Figure 12. Effect of Off-Time on Modified
Transfer Ratio
-------
Curve 696957-A
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ton=1.0s RUNS
OUf=0.55m/s Wp -0.09 -0.13 kg/s 233-340
•Uf=0.40m/s Wp- 0.12 -0.147 kg/s 253-264
AUf = 1.0m/s Wp~ 0.13 -0.155 kg/s Misc.
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WD =Gas Flow Rate During Pulse, kg/s Off-Time, s
Figure 13. Effect of Pulse Air Rate
on Modified Transfer
Ratio
Figure 14. Effect of Off-Time at Lower
Fluidizing Velocities
-------
Curv. 696956-A
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OUf=0.55m/s Wp =0.15 -0.22 kg/s Runs 211 -222
•Uf=0.37m/s Wp =0.18 -0.234 kg/s Runs 243 -252
AUf=1.0m/S Wp =0.15 -0.23 MISC.
•
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Off-Time, s
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OUf=0.55m/s Wp =0.21 -0.26 kg/s Runs 225 -232
• Uf=0.40m/s Wp =0.21 -0.28 kg/s Runs 265 -272
•
e o
O o
o
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•
•
0
o
-
0
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) 0.5" 1.0 1.5 2.0 2.5 3.
Off-Time, s
Figure 15. Effect of Off-Time at Lower
Fluidizing Velocities ^
Figure 16. Effect of Off-Time at Lower
Fluidizing Velocities
-------
In Figure 7 the curve Is displaced substantially lower than those
in Figures 8, 9, and 10. This is because with the 1.0 s off-time com-
plete defluidization does not occur, and great efficiency loss occurs
as gas blows upward. The exceptions are the cases where fluidization
is not completed (A in Figure 7). Here the modified transfer ratio is
similar to those of the other off-times. The curves for 1.5 s and
2.0 s off-times are similar, indicating that defluidization is substan-
tially complete. The 3.0 s curve has slightly higher efficiencies at
corresponding gas inputs. This suggests that we are now seeing effects
of increased packing tightness.
Figures 11 and 12 show how important it is to allow sufficient
defluidizing time between pulses. The scatter in these diagrams is
attributed to variation in the gas flow rate, upon which, we have seen,
efficiency strongly depends. It was not feasible to control the gas
flow rate rigorously during a pulse, independently of other variables
(notably, in this case the off-time). The data, however, were grouped
and plotted in reasonably narrow ranges of air input rate. The longer
off-times needed for longer pulses are also evident by comparison of
these figures, although partially compensated by the air rate variation.
One would suspect that the curves would level out at high off-time
when no significantly better packing between pulses could be achieved.
Figure 13 illustrates the effect of gas flow rate at constant on-
and off-times. This is contrasted with Figure 9, wherein a relationship
between on-time and flow rate rather than the on-time value is specified.
If the two isolated points in Figure 13 at lower gas flow rate are indeed
significant (which is questionable), the drop in efficiency is probably
related to the difficulty the weak jets encounter in breaking through the
packed solids. This did not occur in Figure 9, presumably because the
long pulse durations at low gas flow rates did not accurately represent
the amount of time during which the bulk of the pulse flow occurred. In
other words, the assumption of a square wave pulse curve is faulty at
high pulse lengths.
57
-------
Several sets of runs were made at fluidizing velocities lower than
the 1.0 to 1.1 m/s in the bulk of the tests. These runs were possible
because the reduction of particle size during the high velocity runs
lowered the minimum fluidizing velocity (U f) to 0.3 m/s (calculated
value) from the initial value of 0.67 m/s (experimental, 0.55 m/s cal-
culated). If sufficient material is used to keep the solids hopper
full, the effect of fluidizing velocity should be to determine bed
expansion. This would determine the pressure balance across a leg,
which would, in turn, determine whether or not the leg solids fluidize,
how long it takes to fluidize the solids, and gas loss during a pulse.
The low-fluidizing velocity runs are summarized in Figures 14 to 16.
No substantial effect can be noticed from these figures. This is under-
standable since we were still substantially above the minimum fluidizing
velocity, which had changed. Furthermore, the bed pressure drop per
unit length in the bed never changed much over the entire run sequence
and was also at about the bulk density of the material. This indicates
that no significant bed expansion occurred, even during the later higher
velocity runs relative to P ,. We were never able to expand the bed suf-
ficiently to affect the fluidizing- characteristics of the leg material,
and certainly not enough to prevent fluidizing there. That our data
show no dependence of the transport performance on the fluidizing
velocity does suggest that the bed expansion effect is the only one.
Other findings during this phase of the study include the following:
• Fines entering the transfer leg appear to be blown out more
effectively than larger material when the leg fluidizes. Visu-
ally, the leg material appeared to contain only very small amounts
of fines compared to bed material near windows, and under stagnant
conditions. If fines are generated and recycled in the CAFB sys-
tem, a quantity of nontransferable material may accumulate. A
potential solution would be to recycle fines via dip legs to
opposite beds.
58
-------
The basic flow profile, visually noted, is illustrated in Fig-
ure 17. Transport gas is divided into a fast-moving horizontal
dilute phase and upward moving slugs or bubbles near the upper
vertical face, moving more slowly. Some recirculation seemed
to occur near the base of the vertical section. After a short
time all gas would apparently rise upward and blow the leg
completely. A relatively stagnant area exists below the dilute
phase. This may cause possible agglomeration problems if hot.
Data was collected on pressure profiles in the direction of
flow in the transport legs. Appendix B contains more details.
Although actual pressure fluctuated significantly (±5 kPa) with
pulsing at any point within a leg, the horizontal pressure drop
was about 2 to 2.5 kPa, and the average total pressure drop
across a leg 7 to 7.5 kPa, independent of run conditions.
Dwg. 6W+A18
Fast-moving
Dilute Phase
Stagnant Solids
Figure 17. Observed Transport Flow Profile
59
-------
7.0 SOLIDS TRANSPORT MODEL
7.1 DEVELOPMENT
7.1.1 Time Sequence
Using the data generated with the second pulse air introduction
system, a mathematical model of the solids transport system was developed.
This model is basically a momentum balance corrected for some of the
major unsteady aspects of the flow behavior. We will first describe the
sequence of events that we believe occurs within the leg during a single
pulse cycle. Then, following a brief accounting of the unsteady aspects
and their presumed importance, the model will be developed in detail.
The nomenclature used is as in Figure 18. With no transport gas
input the overall pressure drop, (P--P,), which is determined by the bed
pressure balance, is easily sealed by the packed solids in the horizontal
and vertical sections. Gas flows between vessels at a low rate estimated-
from the Ergun equation for packed-bed pressure drop (expressed in terms
of relative interstitial gas-solids velocity):
(1)
where £ is the voidage in the leg; U the relative velocity; and p, d
p r p
and p the gas viscosity, average particle size, and gas density, respec-
O
tively. Assuming the fluid-bed vessels to be operating at approximately
equal fluidizing velocities, the imposed pressure drop will be:
P3 - PA = PFB * V«c '
where p__ is the fluid-bed density.
CD
60
-------
0-9.
Figure 18. Nomenclature for Transport Model
With the introduction of pulse air, solids flow begins, and the
pressure P. Jumps to a level larger than P.. The pressure drop now
imposed upon the vertical leg section will now be
P1-P4
- P3>
FB
(3)
If the imposed pressure gradient is greater than the density of the
vertical leg solids, in other words,
P, - P, (1 - e )e
8
(4)
then the state is unstable and the leg will fluidize to relieve the
excess pressure, liberating pulse gas in the upward direction and causing
loss (or reversal) of solids flow. In practice, the fluidization of the
downcomer is inevitable unless p__ is rather low.
CD
61
-------
The fact that a short time interval is needed for the t'luidization
to occur is what makes the pulse system work, and makes it indeed neces-
sary. Estimation of the fluidizing time will be discussed later. The
important point is that, once fluidization is complete, further pulse
gas is wasted. The transport gas input must be halted for a sufficient
time to allow defluidization.
7.1.2 Steady State Assumptions
Solids flow was modeled assuming a steady state flow pattern during
the effective portion of each pulse - in other words, before fluidiza-
tion has occurred. In this first detailed examination of the fluid
mechanics of this system it has been necessary to neglect several
unsteady aspects of the momentum exchange process. These include the
following:
• A finite time is required for jet formation and decay. This
"hollowing-out" of the horizontal portion of the leg would
require unsteady terms in the gas and solids mass balances and
in the momentum balance. The much greater model complexity
entailed did not: seem appropriate at this time, so we retained
the steady state assumption. Jet formation did appear rapid *$*•
in the experiments, and it seems that solids pushed out when
the void is formed are replaced from the same (horizontal)
direction.
• Depending on the specific piping arrangement, the velocity of
gas issuing from the pulse nozzles may not be constant during
a pulse. In this study an average flow during the pulse was
derived and used in the analysis. The results suggest that
the order of proportionality between solids and gas flow is
not a strong function of gas velocity except at low values.
These instances, corresponding to very long on-times and low
flow rates, are inefficient and, hence, not of practical
interest.
62
-------
• The system pressure balances may change somewhat with time if
unequal transfer of material in the two directions occurs (see
6.3.2 above). This will effect both the fluidizing time and
the gas bypass rate. The steady state assumption depends on
roughly constant bed levels. We circumvented this potential
problem by taking data at the point of equal bed depth in each
run.
• It was initially assumed that the vertical solids voidage was
constant at the packed bed value during the entire effective
pulse time. This was found to be a poor assumption for short
off-times, when defluidization and/or repacking are not com-
plete. The assumption of packed bed voidage had to be relaxed
for these cases which are very poor operating points, although
the constancy assumption remains. Relaxation of this assumption
would require more knowledge of the unsteady behavior of
fluidized systems than is now available and would greatly com-
plicate the model solution.
7.1.3 Mass Balances
On the basis of experimental observations, the flow configuration
of Figure 19 was used for the steady state portion of the model. The
control volume is represented by the dotted boundary. Gas enters the
system at the nozzle, generating a jet which entrains and carries solids
to the receiving vessel in dilute phase transport above a region of
stagnant solids. The mass balance for the pulse gas is then
vS + Ve8 - veSP + ve(S - 8 . (5)
In the above equation the terms represent:
(A) Gas in at nozzle,
(5) Gas in from above with solids (for the present application
v1 will usually be negative)
63
-------
Dwg.
Solids
Entrain
Gas in
Dilute-Phase Flow Region £3
Stagnant Solids
Nozzles
Control Volume Boundary
'S3
3
Solids Gas
out out
V
! RH
Gas out
Figure 19. Solids Transport Model Flow Profile
-------
(y Gas out in dilute phase
(5) Gas out through the stagnant solids.
For solids the mass balance is
VslSlpp(1 - el> = vs3S3pp(1 - E3} '
where the left-hand term represents the solids entering from above, and
the right-hand term is the efflux of solids in the lean phase.
Defining
k 5vs3/V3
and
VR = Vsl - Vl '
equation 6 may be written:
(v + v ^ f 1 — c^Q = Irw (^ — e \ C
*• 1 VR;U £l;bl ^3^ £3;S3
Note that v, and v , are positive downward, while v_ is positive
1 si K
upward. All velocities are actual (i~e. not superficial).
7.1.4 Momentum Balance
A momentum-force balance for the horizontal direction was developed.
Note that because of the angle of the vertical section, solids enter the
control volume with a finite, though small, horizontal momentum. The
overall balance is
-P1(S1 - S2)gc = 4>2S2 - v^e^ - k2v^pp(l - e3)S3
© ' ® © ©
-P3Slgc + P2S2gc ' Vl
-------
where the various terms are:
(A) Force of gas on projected area to rear of leg
(iT) Gas momentum in at nozzle
(c) Gas momentum out in dilute phase to receiving vessel
(to) Solids momentum out in dilute phase to receiving vessel
^h Pressure of outlet stream (assumed constant over the entire
cross-section)
(f) Pressure of gas in at nozzle. (Note that the control surface
crossed by the gas in the vertical section has no vertical
component.)
(G) Gas momentum out via vertical section. If the net flow of gas
in the vertical section, is, downward, the sign of this term is
reversed.
(S) Solids momentum in from above.
In this balance the viscous fluid-wall effect and the momentum of
the gas leaking through the stagnant solids have been neglected.
7.1.5 Horizontal Pressure Drop
The vertical and horizontal, relative velocities can be estimated
from the Ergun equation (equation 1) using pressure gradients of
(Pj^ - P4^/Ls and (pi ~ P3^LH» respectively. The jet pressure, PZ, is
assumed equal to P.. P~ and P. (Figure 18) must be estimated from sys-
tem pressure balances.
The pressure drop (P. - P_) in the horizontal dilute phase was
12
modeled by the correlation of Wen and Simons:
41.82 U_u p__
0.25 • (U)
t P
where
3
(P, - P3)/L.. is the pressure gradient (N/m )
d is the particle size (m)
D is four times the mean hydraulic radius (m)
66
-------
PDS is the average dispersed solids density in the
horizontal section (kg/m )
Ug is the superficial solids velocity in the entire
horizontal area. (m/s)
The parameter p is defined as
Uo
(
2(1 - e )S + (1 - e)(S. - S.)
- - - — - -, (12)
where the average dilute phase density is approximated as twice the final
density due to acceleration. The superficial velocity UQ is then
J
kv-S (1 - e )p
U_ = 3 * 3 P (13)
S 2 S1PDS
7.1.6 Dilute Phase Flow Area
Referring to Figure 19, the areas S, and S_ will be known in any
application, but S_ must be estimated. For this model we estimate this
dilute phase flow area by assuming that the similarity of jet expansion
is valid for the heterogeneous system. The final flow area will,
therefore, be a function of" leg geometry only.
The jet model is illustrated in Figure 20. The individual gas jet
at each nozzle expands as a circular jet until interference from neigh-
boring jets is encountered. Beyond this point expansion is as a plane
jet. No further jet expansion is assumed to occur once the jet passes
beneath the lip of the horizontal section. From this point dilute phase
horizontal transport occurs to the exit of the transfer leg. In practice,
the dilute phase exists at the top of the horizontal section because of
buoyancy. The actual mechanics must be very complex. The vertical
position of the dilute phase has no influence in the model.
The distance from the nozzle outlet to the transition from circular
jets to a plane jet is
x - d
n _ o
xi = *
67
-------
Owg. 6W»A11
No Further Expansion
Lip of Horizontal Roof
Plane Jet
Circular Jets
Nozzles
n
Figure 20a. Top View of Jet Expansion Model
.Virtual Origin.
Plane Jet
Virtual Origin. Circular Jet
Figure 20b. Side View of Jet Expansion Model
68
-------
where
x is the distance between nozzle centers
n
d is the nozzle diameter and
o
0 is the circular jet half-angle.
If
x- >^ x, , the final area S. is given
by
I N(2 ^ tan 0 + dQ)2, (15)
where
x. is the distance from the nozzle to horizontal ceiling
and
N is the number of nozzles.
If
Xl < V
S3 = W[xn + (do - xn)(l5M> + 2 xh tan 8], (16)
where
W is the channel width
and
B is the plane jet half -angle.
In the model $ was taken as 7.64° and G as 6.35°. Development of
these equations and half angle estimates are in Appendix Cl. Equation 15
applied to our data. It was assumed that the dilute phase flow region
was a rectangular channel of this area. Confirmation of this approach
at other geometries is needed before extrapolation to variant cases.
7.1.7 Fluidizing Time
No unrestrained bed of solids can seal a pressure gradient in excess
of the bed density. The process of fluidizing the vertical leg requires
a short amount of time (<0.4 s) , during which a virtual seal exists,
allowing solids flow in the proper direction.
69
-------
The time required to fluidize a leg when a pressure drop in excess
of the bulk density of the material in the leg is imposed is approximated
by
(17)
The derivation of equation 17 is given in Appendix C2.
For
—-vp (1 - e.) g/g
v
and
Equaticp 17 reduces to
If
then
Ls > V
which yields improved flow. In the model solids flow was assumed to stop
completely during a pulse at t^ given by equation 17 with AP = (P. - P,)
as defined in Figure 18.
7.1.8 Vertical Section Voidage
The vertical void fraction, e., was assumed to be constant during
any given pulse. The valve of e. can, however, be significantly greater
than the normal packed density if sufficient defluidizing time is not
allowed. Experimentally, we observed that at least 1.5 s defluidizing
time is required for complete repacking (i.e. insensitivity of transfer
efficiency to off-time) when the pulse on-time exceeded t... Propor-
tionately less time is needed for shorter on-times because only partial
70
-------
expansion of the vertical leg section solids occurs. The voidage e.
will thus be a function of the pulse on-off times. Its importance
is in determining the optimum on-time, t.. (requiring an iterative
procedure), and the amount of pulse gas that escapes vertically upward
during each pulse. As the off-time is reduced, e.. will approach unity,
and bypassing of pulse gas will be complete.
In the model, semiempirical relationships were used to reflect this
behavior. The rationale behind these is discussed in Appendix C3.
For > i «M
'OFF'0-54,
0.87
and for tQN < t^
t_ - 0.54 t..
el • l - » - V< 0.87 >'
In either case e.. cannot be less than e or greater than unity.
7.1.9 Dilate Phase Voidage
It was necessary to estimate the voidage in the dilute phase at
plane three in Figure 19 (or to estimate the degree of particle accelera-
tion). Depending on the degree of acceleration achieved, the voidage
will be somewhere between e. and ^0.95. The degree of acceleration will
depend on particle properties, system geometry, the nozzle gas character-
istics, and the transport gas waveform.
On the basis of our data, an empirical relationship was derived to
estimate the dilute phase voidage, e_. The ratio of dispersed density
to initial settled density was presumed to be dependent upon the particle
Reynolds number at the nozzle and the on-, off-, and fluidizing times.
The dependence on periodicity is presumably needed to account for the
development and degeneration of the jet and dilute phase during the
pulse cycle.
71
-------
For _
\-1.44
0.0376-- ---*! (2D
1 - e I «•«-""! t
^ ' l 'OFF
\ i \
For tON < t^
\-0.543 / , \-0.045
..
t n,
One can see from these equations that the final void fraction is not
strongly dependent on the nozzle velocity. This is compatible with the
jet similarity formulation. The voidage varies strongly with the shape
of the pulse curve around a median of about 0.85 because of end effects.
The void fraction e. will also probably depend upon the relative
entrainment area available which would be
(23)
where x. is the distance from nozzle to horizontal overhang, and W is.
the leg width. These were not varied in our experiments and so no
effect of this group is included in equations 21 or 22. The extension
of the model to conditions of significantly different x, is not recom-
mended at this stage.
7.1.10 Model Summary and Procedure
Solution of the model for the overall average solids flow rate at
any set of conditions requires the simultaneous solutions of the above
equations. Table 5 lists the independent and dependent variables
covered by the model. A flow sheet for the solution of these equations
is given in Figure 21. A listing of a computer program to solve these
equations will be found in Appendix D.
72
-------
No
Dwg. 1699837
Input Variables
Set LIM =0
Calculate
*3
,
Eq. 15 or 16
Guess
Calculate
TM-el
Eqs. 17. 19, 20
| Calculate VR, VRH| Eq. 1
Calculate v
J Eq. 24
Calculatee3 | £qs. 21 or 22
Calculate k | Eqs. 5.9. and 10
~TT
| Calculate V3. vi | Eqs. 5, 9
| Calculate vsi. v$3 I Efls. 7. 8
Calculate P2. New | Eqs. 12, 13. 11
Figure 21. Transfer Leg Model Flow Sheet
73
-------
TABLE 5
TRANSFER LEG MODEL - VARIABLES
A. INDEPENDENT (INPUT) VARIABLES
Transfer Leg Geometry
is
Si
"o
xh
x
W
N
n
Participate Properties
Pulse Gas Properties
T
M
u
System Properties
GA
'on
Angle of vertical section
Length of vertical section
Length of horizontal section
Cross-sectional area of leg
Nozzle outlet area (total)
4 times the mean hydraulic radius of leg cross section
Nozzle diameter
Distance from nozzle to overhang
Distance between nozzle centers
Leg width
Number of nozzles
Loose bulk density
Particle (aerodynamic ) density
Average particle size (projected surface area mean)
Temperature
Molecular weight
Viscosity
Pressure at leg discharge
Total pressure drop cross leg
Overall pulse gas average mass flow
Pulse duration
Time between pulses
B. DEPENDENT VARIABLES
V2
V3
VR
VRH
P,=P2
£1
S
Wp
WH
T.R.
Dilute phase flow area
Downward interstitial gas velocity
Pulse gas nozzle velocity
Interstitial velocity of gas in dilute phase at exit
Upward interstitial gas velocity relative to solids
Horizontal interstitial gas velocity in stagnant solids
Downward moving bed solids velocity
Dilute phase exit solids velocity
Pressure at bend of transfer slot
Moving bed voldage in vertical section
Dilute phase exit voldage
Fluid!zing time
Overall solids flow rate
Transport air rate during pulse
Horizontal air rate during pulse
Transport ratio (mass)
74
-------
Referring to Figure 19, the area S_ is first calculated from either
equation 15 or 16. An initial guess for P_ (=P. ) must then be made to
begin the iterative procedure. A reasonable first guess would be
3 kPa in excess of P^.
The fluidizing time and vertical section voidage are then determined
from the simultaneous solution of equations 17 and either 19 or 20,
depending on the pulse duration. The relative gas velocities upward
and horizontally through the stagnant solids below the transfer region
are calculated from the Ergun equation (equation 1) using voidages e..
and e , and pressure gradients (P1 - P/)/L and (P.. - P_)/L , respectively.
p i *T s J. j ri
The jet velocity is
_ x ,0/,
v9 = — =- ( - - - ), (24)
2 P2S2 *<»
where G. is the overall average mass flow rate of air. At this point
the voidage e_ can be determined from the appropriate equation (21 or 22).
If v1 and v_ are eliminated from the momentum balance (equation 10)
by using the mass balances (equations 5 and 9) , a direct solution for the
ratio, k, of solids to gas velocity at the transfer leg outlet can be
obtained. Then all velocities, v- , v_, v _, and v__, can be obtained
-L J oJ. S/
from equations 5, 9, 7, and 8. A new value of P- is now calcu-
lated by successively applying' equations 12, 13, and 11. The
procedure is repeated until the calculated value of P~ agrees with the
guessed value. The overall solids flow rate is
G = v S (1 - e )p (- - 1- - ) (25)
S S3 3 J P 'ON + tOFF
where t is the minimum of t... and t...
S ON N
7.2 MODEL PERFORMANCE
Tabulated predictions compared to experimental values obtained with
the final configuration are presented in Appendix E, together with pre-
dicted values of other parameters. The average error was 0.67 kg/s, which
75
-------
is about the reproducibility of the experimental data at the highest
flow rates obtained. The worst performance occurs for very short off-time
runs, which feature incomplete defluidization between pulses and are
unstable and not optimum. In general, if the model predicts e. > e , the
off-time is too short for safe operation.
A significant source of error in the modeling work is the assumption
of a square-wave pulse curve, as discussed previously. The solids flow
measurement was also limited to an accuracy of ±20 percent. The activated
alumina material used in the study proved to be attrition-prone and was
difficult to characterize as to particle density and, hence, voidage.
In light of these limitations and the large number of assumptions required
in the model development, performance is good.
To test the model, we applied it to the conditions of the tests
conducted by FW on the three-tube sparger transfer slot selected for
the demonstration plant design. The geometry of the transfer leg is
shown in Figure 22. The bulk specific gravity of the material was
given as 1.43. In addition, the following conditions were assumed or
gleaned from the FW report:
• The effective void fraction was 0.45.
• The leg discharge pressure (P ) was 112 kPa (absolute).
• The imposed pressure differential (P_ - P.) was *x»2.4 kPa.
• The operating temperature was 310 K.
• The fluidizing velocities were sufficiently high that
fluidization of the downcomer solids did not occur. Solids
therefore would be transferred during the entire on-time.
• The average particle size was 750 ym
• The flared inlet to the leg was assumed only to affect
the ability of the bed to keep the leg full of solids.
Table 6 compares FU's test results with the predictions of the
model for a single leg. The experimental results and model predictions
support one another well. The surmised relative freedom of the FW tests
76
-------
from downcomer fluidization or voidage variation, allow these data points
to fall into the range of conditions that is most easily and accurately
modeled. These stable operating points result from the high fluidizing
velocities and, hence, high bed expansion characteristic of that study.
Note that our experimental system and that of FW have equivalent values
of x. . Application of the model to variations in this parameter has
not been tested and is not recommended.
52.1cm
8.9cm
DM9. 6WM16
30.5cm
3.08 cm ID Tube
Figure 22. CAFB Demonstration Plant Transport Leg Design
11
77
-------
TABLE 6
COMPARISON OF FWEC FINAL DESIGN DATA* AND MODEL PREDICTIONS
FW Average Actual Predicted
Run On-Time, Off-Time, airflow rate, solids rate, solids rate,
No. s s kg/s kg/s kg/s
LS-1 0.5 7.5 0.0120 1.34 1.26
-2 0.7 9.2 0.0110 1.21 1.33
-3 0.5 12.0 0.0086 0.86 0.98
-4 0.5 2.6 0.0300 2.38 2.17
-4R 0.5 2.6 0.0277 2.47 2.15
-5 0.5 4.0 Q.0221 2.03 1.78
-5R 0.5 4.0 Q.0207 1.99 1.76
-6 0.5 7.0 Q.0149 1.64 1.34
I
* See Reference 11.
-------
8.0 DEMONSTRATION PLANT PERFORMANCE PROJECTIONS
The use of the model was extrapolated to conditions expected or
possible in the CAFB demonstration plant. In the experimental portion
of this work it was often not possible or feasible to change only one
variable at a time. The model allows us to explore the effects of each
variable individually. Tables 7 through 17 present the results of this
investigation. The base conditions used are as follows, with any changes
listed in the appropriate tabler
Leg geometry - as per Figure 22 (per leg)
Particle size - 1500 ym
Packed bed voidage - 0.45
Particle density - 1800 ikg/m
Gas - air at 500 K
Pressure at leg discharge - 128 kPa abs
Imposed AP* on leg (P_ - P^> - 4 fcPa.
8.1 Total Transport Gas Flow Rate
Table 7 shows that increasing the transport gas rate while holding
all other parameters constant will result in increased solids transfer
but lower efficiency (T.R.). If the demonstration plant requires 3.2 kg/s
solids flow in each direction, then two legs, each with a transport gas
flow rate of about 0.04 kg/s, will be needed at this set of conditions.
The efficiency is rather low; the reasons for this will be seen later.
8.2 Pulse Gas On- and Off-Times
Table 8 shows the effect of the transport gas waveform at constant
total pulse gas input. Points 13 through 19 in this table predict that
solids flow and transport efficiency both will be maximized at
about 0.2 s on-time with the time between pulses at 1.5 s. As the
79
-------
TABLE 7
EFFECT OF TOTAL GAS FLOW RATE
Point tQN, tQFF, t^, GA, W?, WR, EI e3 (P2-P3), T.R., Gg,
- _s a _s_ kg/s kg/8 kg/s ^ ^_ kPa kg/kg kg/a
1
2
3
4
5
6
7
8
9
10
11
12
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
0.29
0.29
0.29
0.29
0.29
0.28
0.28
0.28
0.28
0.27
0.26
0.24
0.007
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.050
0.070
0.100
0.200
0.04
O.Q6
0,09
0,12
0,15
0,18
0,21
0,24
0,30
0,42
0.60
1.20
0.0324
0.0504
0.0804
0.1105
0.1406
0.1707
0.2008
0.2309
0.2911
0.4118
0.5929
1.1977
0./-5
0.45
0.45
0.45
0.45
0.45
0.45
0.45
0.45
0.45
0.45
0.45
0.84
0.84
0.84
0.84
0.84
0.84
0.84
0.84
0.84
0.84
0.83
0.82
3.6
3.6
3.6
3.6
3.7
3.8
3.8
3.9
4.1
4.4
5.0
6.5
193
135
91
70
58
50
45
41
36
30
27
23
1.35
1.35
1.37
1.40
1.45
1.51
1.57
1.64
1.79
2.13
2.66
4.50
-------
00
TABLE 8
EFFECT OF ON- AND OFF-TIMES AT CONSTANT TOTAL GAS FLOW RATE
>itit
._
13
14
15
16
17
18
19
20
21
22
23
24
fcON'
s
0.1
0.2
0.3
Ot
.4
0.5
1.0
1.5
0.3
0.3
0.3
0.3
0.3
'OFF'
s
1.5
1.5
1.5
1.5
1.5
1.5:
us
1.0
1.5
2.0
2.5
3.0
V
s
0.25
0.27
0.28
0.29
0.29
0.29
0.29
0.24
0.28
0.27
0.25
0.24
_GA>
kg/8
0.03
0.03
0.03
0.03
0.03
0.031
0.03
0.03
0.03
0.03
0.03
0.03
-i'_
kg/a
0.480
0.255
0.180
0.142
0.120
0.075
0.060
0.130
0.180
0.230
0.280
0.330
WR,
kg/s
0.4734
0.2464
0.1707
0.1331
0.1105
0.0654
0.0504
0.0967
0.1707
0.2214
0.2723
0.3232
El
-
0.45
0.45
0.45
0.45
0.45
0.45
0.45
0.70
0.45
0.45
0.45
0.45
E3
_
0.67
0.76
0.84
0.84
0.84
0.84
0.84
0.84
0.84
0.74
0.61
0.46
-------
on-time is increased the amount of time available for solids flow increases
up to a point (tj , but the dilute phase voidage increases. These effects
cause opposite changes in solids flow rate. Points 20 to 24 show that
both flow rate and efficiency increase regularly with off-time. This is
because more time is allowed for repacking between pulses, allowing e_
to become lower. Note that for t „ =0.3 and t__ =1.0 the vertical
voidage is predicted to be 0.70 with a resulting high e, and the loss of
approximately half the transport gas upward (compare horizontal and
total gas input rates during pulse, W_ and W_) . This point should be
avoided.
Table 9 lists the expected flows at the same on- and off -times as
Table 8, but at constant transport gas flow rate during the pulse. This
is perhaps a better way to look at this effect because nozzle velocity is
constant. The trends are similar to the previous case with efficiencies
varying more and solids flow rates less, as might be expected from
Table 7.
8.3 Process Related Parameters
Certain, variables "t^fTiiMwftig leg operation will. be. determined by
the overall process specifications and pressure balance. Table 10 shows
the predicted operation at various temperatures. An overall temperature
is used in the model for gas at any point. Solids temperature does not
enter into the calculation. Operation will apparently not depend strongly
on the precise temperature so consideration of temperature profiles and
heat transfer effects will not be necessary. Because no gas is entrained
from either vessel during a pulse (i.e. W > W , some pulse gas going
upward and some horizontally) the very hot reactor gases will not signifi-
cantly mix with transport gas in the legs except at the entrance and exit.
Gas temperatures in the leg should therefore all be in the 400 to 600 K
range, assuming an input gas temperature of about 400 K. The main effect
of temperature, according to the models, is in determining gas loss
upward during the early part of the pulse, using the Ergun equation.
82
-------
TABLE 9
EFFECT OF ON- AND OFF-TIMES AT CONSTANT GAS FLOW RATE DURING PULSE
oo
u>
>int
_
44
45
46
47
48
49
50
51
52
53
54
55
'ON'
s
0.1
0.2
0.3
0.4
0.5
1.0
1.5
0.3
0.3
0.3
0.3
0.3
tOFF'
s
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.0
1.5
2.0
2.5
3.0
Si'
s
0.26~
0.27
0.28
0.28
0.28
0.28
0.28
0.24
0.2J3
0.27
0.25
0.24
GA'
kg/s
0.0156
0.0294
0.0417
0.0526
0.0625
0.1000
0.1250
0.0577
0.0417
0.0326
0.0268
0.0227
V
kg/e
0.25
0.2?
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
WH,
kg/s
0.2420
0.2414
0.2409
0.2409
0.2409
0.2409
0.2409
0.2175
0.2409
0.2415
0.2422
0.2428
V
-
0.45
0.45
0.45
0.45
0.45
0.45
0.45
0.70
0.45
0.45
0.45
0.45
£3>
-
0.66
0.76
0.84
0.84
0.84
0.84
0.84
0.94
0.84
0.74
0.61
0.45
(P2-P3) ,
kPa
5.5
4.6
3.9
3.9
3.9
3.9
3.9
2.0
3.9
4.8
5.9
7.0
T.R.,
kg/kg
69
54
40
30
24
12
8
18
40
51
62
73
Gs«
kg/s
1.08
1.60
1.67
1.57
1.50
1.20
1.00
1.03
1.67
1.67
1.67
1.66
TABLE 10
EFFECT OF TEMPERATURE
Point
-
38
39
40
41
42
43
'ON,
s
0.3
0.3
0.3
0.3
0.3
0.3
'OFF,
s
1.5
1.5
1.5
1.5
1.5
1.5
V
s
0.29
0.28
0.28
0.28
0.28
0.28
GA>
kg/s
0.03
0.03
0.03
0.03
0.03
0.03
V
kg/s
«^M£i^M
0.18
0.18
0.18
0.18
0.18
0.18
WH,
kjj/s
*"**"™^~
0.1689
0,1712
0.1721
0.1740
0.1754
0.1774
el
-
0.45
0.45
0.45
0.45
0.45
0.45
e3
-
0.84
0.84
0.84
0.84
0.84
0.83
(P2-P3),
kPa
3.7
3.8
3.8
3.9
4.0
4.2
T.R.,
kg/kg
49
50
52
54
57
62
GS«
kg/ s
1.46
1.51
1.55
1.63
1.70
1.87
T,
K
400
500
600
800
1000
1500
-------
The pressure at the discharge end of the leg will have little if any
effect °n operation, provided the overall imposed pressure drop is
constant. This is demonstrated in Table 11 where P_ varies from 102 to
180 kPa absolute, and (P_ - P.) is maintained at 4 kPa as in the other
tables. The reason for the slight dependence lies again in the Ergun
equation pressure dependence.
If the two fluid beds are operated at different pressures, bed
levels, and/or fluidizing velocities, the pressure drop across each
leg may be different, necessitating operation of the pulse system at
different conditions to maintain equal and opposite transfer rates. The
effect of the imposed pressure difference is illustrated in Table 12,
where P« - P, is varied from 0 to 20 kPa. At no pressure difference
P_ - P, = P_ - P. and no tendency to fluidize occurs. At P~ - P, = 2 kPa
fluidization is now possible but takes more time than the pulse (at this
on-time). A sharp drop in both flow rate and efficiency occurs with a
further increase in AP°. Thus the imposed pressure drop simply
determines in which of two regimes the system will operate, fluidizing
on nonfluidizing. Within either category operation is nearly independent
of the pressure, drop. The designer should expect that AP* will be, in
practice, sufficiently large that the leg will fluidize with enough on-time,
8.4 PARTICULATE PROPERTIES
As particle size increases, upward gas loss will increase, according
to the Ergun equation. In addition, the horizontal pressure loss will
12
increase (according to the Wen and Simons correlation used in the model
0.25
(P0 - P0)'tt d * ). A look at the momentum balance shows the factors
L J P
have opposite effects on solids flow rate. Table 13 shows that the
transfer rate and efficiency do go through minima as particle size
increases. The effect is small, however, as might be expected.
On the other hand, particle density is seen to be of paramount
importance. Comparison of points 63 and 66 in Table 14 clearly indicates
this. These predictions show why the tests performed at FW were so
84
-------
TABLE 11
EFFECT OF RECEIVING VESSEL ABSOLUTE PRESSURE
ruj.ni
-
25
26
27
28
29
30
'ON'
s
0.3
0.3
0.3
0.3
0.3
0.3
OFF,
s
1.5
1.5
1.5
1.5
1.5
1.5
tM'
kg/s
0.28
0.28
0.28
0.29
0.29
0.29
GA>
kg/s
0.03
0.03
0.03
0.03
0.03
0.03
wp,
kg/8
0.18
0.18
0.18
0.18
0.18
0.18
V
kg/s
0.1717
0.1715
0.1710
0.1702
0.1695
04689
el
-
0.45
0.45
0.45
0.45
0.45
0.45
£3
-
0.84
0.84
0.84
0.84
0.84
0.84
(P2P3),
kPa
3.8
3.8
3.8
3.7
3.7
3.7
T.R.,
kg/kg
52
51
51
50
49
48
GS'
kg/s
1.56
1.54
1.52
1.49
1.47
1.45
P3>
kPa, abs
102
108
120
140
160
180
00
in
TABLE 12
EFFECT OF PRESSURE GRADIENT ACROSS TRANSFER LEG
APC
dnt
—
31
32
33
34
35
36
37
tON'
s
0.3
0.3
0.3
0.3
0.3
0.3
0.3
tOFF>
s
1.5
1.5
1.5
1.5
1.5
1.5
1.5
V
s
****
0.32
0.28
0.25
0.22
0.21
0.16
GA>
kg/s
0.03
0.03
0.03
0.03
0.03
0.03
0.03
wp,
kg/s
0.18
0.18
0.18
0.18
0.18
0.18
0.18
V
kg/s
0.1759
0.1733
0.1710
0.1691
0.1674
0.1660
0.1559
el
-
0.45
0.45
0.45
0.45
0.45
0.45
0.45
e3
-
0.81
0.81
0.84
0.81
0.78
0.75
0.63
(P2-P3),
kPa
4.1
4.1
3.8
4.1
4.4
4.5
5.6
T.R.,
kg/kg
61
61
51
50
50
50
50
Gs>
kg/s
1.82
1.83
1.52
1.51
1.51
1.49
1.49
(P3~V
kPa
0
2
4
6
8
10
20
-------
TABLE 13
EFFECT OF AVERAGE PARTICLE SIZE
•int
-
56
57
58
59
60
61
W
s
0.30
0.30
0.30
0.30
0.30
0.30
'OFF'
s
1.5
1.5
1.5
1.5
1.5
1.5
V
8
0.30
0.30
0.29
0.28
0.28
0.27
V
kg/s
0.03
0.03
0.03
0.03
0.03
0.03
V
kg/s
0.18
0.18
0.18
0.18
0.18
0.18
V
kg/s
0.1813
0,1782
0,1755
0,1707
0,1666
0,1631
el
-
0.45
0.45
0.45
0.45
0.45
0.45
E3
-
0.80
0.85
0.85
0.84
0.84
0.84
(P2-P3),
kPa
2.9
3.0
3.3
3.8
4.1
4.5
T.R.,
kg/kg
54
47
48
50
52
53
GS*
kg/s
1.62
1.42
1.45
1.51
1.55
1.58
V
pm
500
750
1000
1500
2000
2500
TABLE 14
EFFECT OF PARTICLE DENSITY
lint
-
62
63
64
65
66
tQN.
s
0.3
0.3
0.3
0.3
0.3
tOFF*
s
1.5
1.5
1.5
1.5
1.5
V
s
0.27
0.28
0.30
0.30
0.32
GA'
kg/s
0.03
0.03
0.03
0.03
0.03
wp,
kg/ s
0.18
0.18
0.18
0.18
0.18
WH,
kg/a
0,1716
0.1707
0,1702
0.1691
0.1680
el
-
0.45
0.45
0.45
0.45
0.45
e3
-
0.83
0.84
0.85
0.81
0.81
(P2-P3),
kPa
3.2
3.8
4.0
5.5
6.5
T.R.,
kg/kg
43
50
55
80
94
GS«
kg/ s
1.28
1.51
1.64
2.40
2.82
PP
kg/m
1500
1800
2000
2500
3000
-------
much more efficient than can be expected in the demonstration plant.
FW's particle density was (bulk specific gravity 1.43, e = 0.45) at
2
least 2900 kg/m , whereas, if the plant material has a bulk specific
gravity of 1.0, the particle density will be 1800 kg/m3. The effect of
particle density is difficult to separate from the intricate momentum
balance. Higher particle density results in a higher horizontal pressure
drop (equations 11 to 13) and, hence, higher PI and P.. One would
also expect the particles to be less completely accelerated so kv. is
lower. A look at the momentum balance (equation 10) shows that
Gs = kv3Pp(l-e3)S3aP1,P2,pp,(^-), (26)
all of which factors are increased. This particle density dependence
might also be suspected if entrainment is expected to be on a volume-for-
volume basis as is common with homogeneous jets.
8.5 LEG GEOMETRY VARIATION
In Table 15 the horizontal channel height is varied from its normal
0.089 m, with all other leg dimensions remaining constant. This
variation essentially allows variation in the stagnant solids inventory
in the horizontal line. Solid flows are given both on an absolute and
per unit area basis for comparison. Thinner slots are both less
efficient (T.R. column) and of lower capacity. As expected, they are
much more efficient on a per unit area basis simply because proportionately
less area is devoted to stagnant solids. Thus, transport gas is saved
by going to the deeper channel, but the probability for agglomerate
formation in the stagnant region might increase. The model predicts
solids flow to be proportional to channel width, if the number of nozzles
is increased accordingly.
At some point it might be desired to operate the transport leg
between deeper fluid beds. The vertical height could thus be greater,
but the imposed pressure drop would be correspondingly larger, AP/L,
remaining about the same. Table 16 shows the effect of vertical height
at constant pressure gradient. A deeper packed vertical bed will require
87
-------
TABLE 15
EFFECT OF HORIZONTAL SLOT HEIGHT
tint
_
67
68
69
70
71
'or
3
0.3
0.3
0.3
0.3
0.3
tOFF*
s
1.50
1.50
1.50
1.50
1.50
**•
s
0.29
0.29
0.28
0.28
0.27
GA>
kg/s
0.03
0.03
0.03
0.03
0.03
wp,
kg/a
0.18
0.18
0.18
0.18
0.18
V
kg/s
0.1626
0.1657
0.1688
0.1704
0.1719
el
-
0.45
0.45
0.45
0.45
0.45
E3
-
0.85
0.85
0.84
0.84
0.83
(P2-P3) »
kPa
3.3
3.6
4.0
4.3
4.6
T.R.,
kg/kg
60
58
54
52
50
Gs/si«2
kg/s/m
78
89
105
116
130
Y
m
0.1530
0.1274
0.1020
0.0892
0.0764
V
kg/s
1.81
1.73
1.63
1.57
1.51
00
00
TABLE 16
EFFECT OF VERTICAL HEIGHT AT CONSTANT AP/L
Point
-
72
73
74
75
76
77
W
s
0.3
0.3
0.3
0.3
0.3
0.3
'OFF'
s
1.5
1.5
1.5
1.5
1.5
1.5
tM'
s
0.35
0.32
0.29
0.28
0.25
0.20
GA«
kg/s
0.03
0.03
0.03
0.03
0.03
0.03
WP->
kg/s
0.18
0.18
0.18
0.18
0.18
0.18
V
kg/s
0.1720
0.1715
0.1705
0.1704
0.1699
0,1688
el
-
0.45
0.45
0.45
0.45
0.45
0.45
£3
-
0.81
0.81
0.85
0.84
0.81
0.73
(»2-F3>.
kPa
4.5
4.5
4.2
4.3
4.5
5.2
T.R.,
kg/kg
63
63
53
52
52
52
Gs«
kg/s
^^Ibvw-
1.88
1.88
1.58
1.57
1.55
1.55
V
m
0.800
0.700
0.600
0.564
0.500
0.400
-------
more time to fluidize (equation 17) and, in this case, the transition
from fluidizing to nonfluidizing flow occurs, with a corresponding
increase in solids flows and efficiency. Whether this transition occurs
will, of course, depend on the pressure drop and on-time.
Horizontal length is important because it effects the pressure at
the transport slot elbow. The dependence is shown in Table 17. The
increased pressure effect is evidently more important than the decreased
solids flow time, at least for this selection of variables.
Use of the model for other values of the distance between the
nozzles and the horizontal ceiling is not recommended until equations 21
and 22 can be corrected for this variable, as discussed at the end of
Section 7.1.9. This distance could be altered by nozzle insertion or
reduction of vertical slot width. Reduction of this distance will
probably yield sharply lower solids flow rates because of the reduction
in entrainment area. Confirmation of the effect of other nozzle diameters
and spacings would also be useful.
The model suggests that an increase in the angle of tilt of the
downcomer from the vertical wiUL yield slightly improved performance
at low angles. Part of the improvement will be due to the additional
solids horizontal momentum existing upon entering the jet entrainment
area. The main effect, however, is in allowing the use of a longer
downcomer at equivalent vertical spacing of leg hopper and discharge.
Referring back to Figure 18, L increases as L remains constant. The
5 v
effect should be negligible at small angles.
It was noted above that gas bubbles tend to rise along the upper
face of a sloped downcomer. Intuitively it may be felt that a completely
vertical section will offer more resistance to flow, the bulk solids
presumably being more resistant than the solids/wall boundary. An
intuitive case can also be made for the opposite view. The sloped wall
may exert a downward reaction force component on the solids and/or gas
bubble. This issue has not been resolved in this study, the model not
accounting for such a mechanism, and is left for future study. The
widened hopper for ensuring a full downcomer in the CAFB design appears
to be a good idea and is recommended.
89
-------
TABLE 17
EFFECT OF HORIZONTAL LENGTH
lint
—
78
79
80
81
82
83
W
s
0.3
0.3
0.3
0.3
0.3
0.3
tOFF'
8
1.5
1.5
1.5
1.5
1.5
1.5
V
s
****
0.34
0.30
0.28
0.26
0.22
Ga>
kg/s
0.03
0.03
0.03
0.03
0.03
0.03
wp,
kg/s
0.18
0.18
0.18
0.18
0.18
0.18
V
JCg/8
^•^™«^^^»
0.1732
0,1727
0,1710
0,1704
0.1697
0,1684
el
-
0.45
0.45
0.45
0.45
0.45
0.45
E3
-
0.81
0.81
0.85
0.84
0.82
0.78
(P2-P3) ,
kPa
0.7
1.5
3.2
4.3
5.5
8.6
T.R.,
kg/kg
36
43
48
52
57
66
GS«
kg/s
^•••i-^^
1.08
1.29
1.43
1.57
1.70
1.98
V
m
0.100
0.200
0.400
0.503
0.600
0.800
-------
9.0 ASSESSMENT
A model has been developed that enables projection of the solids
flow rates which will result from a given combination of control variables
Because the model is largely theoretical, extrapolation to other con-
ditions should be reasonably reliable. The main uncertain effect is that
of nozzle insertion (or distance of nozzle from horizontal slot lip).
Other candidates for additional confirming research effort would include
nozzle diameter and spacing, overall leg dimensions, and particle density,
the latter effort needed to confirm the great significance of this
variable as suggested by the model.
In the preceding section a discussion of the effects of changes in
key parameters was given, based upon use of the transport model. With
the current leg design it will be difficult to achieve the required solids
flow rate and transport efficiency if the material density is as low as
expected. An optimum pulse length of just less than the fluidizing time
(M).3 s) is very desirable. In the event this is not possible, this limit
should be exceeded by as little as possible. An off-time of 1.5 to 2.0 s
shoulb be used depending on the on-time. Each leg will then in all likeli-
hood require 0.04 to 0.05 kg/s transport gas. Gas storage capacity between
pulse control elements, and the legs should be minimized so the pulse wave
form will be as desired. Delivery pressure is important only in that good
gas distribution between the nozzles will be needed. The beds should be
operated so as to keep their operating pressures as nearly equal as
possible. Within process constraints, fluidizing velocities large
enough to cause considerable bed expansion will allow longer on-times
and easier, more efficient operation of the transport system. Higher
density material will transport more easily and efficiently. There may
be a trade-off between material activity and regenerability based upon
its density. Certainly further study of the particle density effect
is warranted.
91
-------
Great transport efficiency improvement can probably be made by using
more leg width (wider legs or more legs) and a proportionate increase in
number of injection nozzles. Table 7 illustrates this point. Using three
times the leg width and a gas flow (point 2 in the table) of 0.01 kg/s per
three nozzles would require 0.03 kg/s of gas to move 4.08 kg/s of solids
at a transfer ratio of 136. To achieve this flow with the current design
would require at least 0.10 kg/s total air to move 3.66 kg/s at an
efficiency of 37. Smaller increases in capacity and efficiency should
result from increased leg depth or length in any direction (Tables 15-17).
The vessels will exchange gas at a low rate in response to the
pressure drop imposed across each leg full of packed bed solids between
pulses. During the pulses, transport gas will partition and flow upward
in addition to horizontally, so that little if any reactor gas should be
entrained with the transported solids. If, however, the pulses are
long enough to fluidize the transport leg vertical solids, there may be a
significant backsurge of gas, especially while pulse air remains on. This
will be particularly true for gas going from the high-pressure bed to
the other. Every effort should be made to reduce the pulse on-time to
below the fluidizing time to maintain the transient virtual seal. The
use of two solenoid valves in series, with phases staggered by a fraction
of a second, to control pulses may be a means to accomplish this.
Agglomeration and/or plugging will most likely occur in the region
of stagnant solids at the bottom of the horizontal leg. Use of a
narrower section would reduce this potential problem at a cost in trans-
port efficiency. If the dilute phase flow area could be increased, by
using more or wider nozzles as suggested by the jet expansion model, or
by the use of a long, narrow sparger slot so as to form a plane jet, the
dimensions of this stagnant region could be reduced. Continued experi-
mental studies of such alternative geometries is, therefore, encouraged.
It is possible that the nature of this transport mode could exclude
materials of small particle size from exchange between vessels. This
would result in the buildup of an inactive bed component with time in
either bed. Careful monitoring of this possibility, such as by
92
-------
periodically analyzing samples of cyclone fines, should be performed,
A possible solution would be to recycle fines to opposite beds, if
possible within overall system'constraints and pressure balances.
93
-------
10. REFERENCES
1. Archer, D. H., D. L. Keairns, J. R. Hamm, R. A. Newby, W.-C. Tang,
L. M. Handman, and L. Elikan, Evaluation of the Fluidlzed Bed
Combustion Process, Vols. I, II, and III. Report to EPA, Westinghouse
Research and Development Center, Pittsburgh, PA, November 1971, GAP
Contract 70-9, NTIS PB 211-494, 212-916, and 213-152.
2. Keairns, D. L., D. H. Archer, R. A. Newby, E. P. O'Neill, E. J. Vidt,
Evaluation of the Fluidized-Bed Combustion Process, Vol. IV,
Fluidized-Bed Oil Gasification/Desulfurization. Report to EPA,
Westinghouse Research and Development Center, Pittsburgh, PA,
December 1973, EPA-650/2-73-048d, NTIS PB 233-101.
3. Keairns, D. L., R. A. Newby, E. J. Vidt, E. P. O'Neill, C. H. Peterson,
C. C. Sun, C. D. Busaglia, and D. H. Archer, Fluidized Bed Combustion
Process Evaluation - Residual Oil Gasification/Desulfurization
Demonstration at Atomospheric Pressure. Report to EPA, Westinghouse
Research and Development Center, Pittsburgh, PA, March 1975,
EPA-650/2-75-027 a&b, NTIS PB 241-834 and PB 241-835.
4. Rakes, S. L., A Synoptic Review of the EPA Chemically Active
Fluid Bed Program, EPA, Research Triangle Park, NC, November 1977.
5. Sulfur Oxide Control System for the Chemically Active Fluid-Bed
Process, Westinghouse report to EPA. To be issued.
6. O'Neill, E. P., D. L. Keairns, and M. A. Alvin, Sorbent Selection
for the CAFB Residual Oil Gasification Demonstration Plant. Report to
EPA, Westinghouse Research and Development Center, Pittsburgh, PA,
March 1977, EPA-600/7-77-029, NTIS PB 266-827.
7. Engineering Evaluation of the Chemically Active Fluid Bed Process,
Westinghouse report to EPA. To be issued.
94
-------
8. Craig, J. W. T., G. L. Johnes, G. Moss, J. H. Taylor, Study of
Chemically Active Fluid Bed Gasifier for Reduction of Sulfur Oxide
Emissions. Report to EPA, Esso Research Centre, Abingdon, UK,
APCO Contract CPA 70-46, February 1971.
9. Chemically Active Fluid Bed (CAFB) Process Preliminary Process Design
Manual, Foster Wheeler Energy Corp., prepared for EPA, Contract
No. 68-02-2106.
10. Newby, R. A., S. Katta, and D. L. Keairns, Calcium-Based Sorbent
Regeneration for Fluidized-Bed Combustion: Engineering Evaluation.
Report to EPA, Westinghouse Research Laboratories, Pittsburgh, PA,
March 1978, EPA-600/7-78-039.
11. Bazan, J. A., Chemically Active Fluid Bed (CAFB) Process Solids-
Transport Studies. Report to EPA, Foster Wheeler Energy Corporation,
Livingston, NJ, EPA-600/7-77-114, October 1977.
12. Wen, C. Y., and H. P. Simons, Flow Characteristics in Horizontal
Fluidized Solids Transport, A.I.Ch.E. Jour.. 5 (2): 263-267;
June 1959.
95
-------
APPENDIX A.I
SOLIDS TRANSPORT TEST FACILITY PHOTOGRAPHS AND ENGINEERING DRAWINGS
NOTES
1. Photographs Include:
Overall view
Blower/baghouse
Control panel
2. The drawings were prepared before the Institu-
tion of the current requirement for use of
Standard International Units. Significant
dimensions are given in the proper units in
the body of the test.
96
-------
97
RM-78261
-------
98
RM-78262
-------
99
RM-78263
-------
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-------
APPENDIX A.2
SOLIDS TRANSPORT TEST FACILITY
INSTRUMENT AND AUXILIARY EQUIPMENT SPECIFICATIONS
A.2.1 INSTRUMENTATION
System
Air Pulse Controllers
Air Pulse Valves
Bimetallic
Thermometers
Item
No.
FC-2, 3
VFC-2, 3
TI-1, 2,
3, 4
Description
(2) - Leeds & Northrup 10676,
Series 80 duration adjusting-
type controllers. Impulse
rate adjustable from 0.5 to
30 pulses/min. Manual
station included.
Maximum load current:
5 A RMS, 120 V
Accessories;
(2) - Leeds & Northrup No. 023868
capacitors to change impulse
rate to 1.5 to 90/min.
(2) - Leeds & Northrup No. 143-82604
SPOT switches to select one
of two solenoid coils
(2) - ASCO No. 8215A93, solenoid
operated valves (plus 2
standby valves), size -
6.4 cm
(4) - Ashcroft Model 50 E160E,
(060) bimetallic thermom-
eters with 13 cm diameter
dials
Accessories:
(4) - Ashcroft Model T38S75T
(060) thermometer wells,
304 SS
111
-------
System
Flow Indicators
Flow Sensors and
Recorders
Description
FE-1, 4 (2) - Ellison Instrument Type 75,
316 SS, schedule 40
Annubar sensors
FI-1, 4 (2) - Ellison Instrument Model
77B-12, Eagle Eye flow
meters
FE-5, 6 (2) - Ellison Instrument Type 71,
316 SS Schedule 40 pipe
nipple Annubar flow sensors
FI-5, 6 (2) - Ellison Instrument Model
77B-1 Eagle Eye flow meters
FRT-2, 3 (2) - ITT Barton Model 752
electronic differential
pressure transmitters com-
plete with Model 297 single
channel power supply,
integrally mounted.
Range: 7.5 kPa gauge,
adjustable 20 to 100% of
calibrated span.
Bellows material: SS,
complete with molecular
bonded strain gauge trans-
ducer assembly. Solid
state electronics weather-
proof unit.
Output Signal: 4 to 20 mA dc.
Power Requirement: 115 V,ac
60 Hz
(2) - Telmar Model 509000 square
root extractor transmitters.
Input: 4-20 mA dc into
100 Ohms
Output: 1-5 V dc
Accuracy: ± 0.1% to full
scale
Power Requirement: 115 V,ac,
60 Hz
112
-------
System No. Description
Flow Sensors and FRT-2, 3 Accessories:
Recorders (Cont) (2) - Paddle-type orifice plates
for 10 cm-schedule 40 pipe.
To develop 3.74 kPa
differential at flow of
0.118 m3/s. (Tagged FE-2
and 3)
Orifice diameter - 5.71 cm
(2) - Paddle-type orifice plates
for 10 cm-schedule 40 pipe.
To develop 3.74 kPa W. C.
differential at flow of
0.59 m3/s. (Tagged FE-2
and 3)
Orifice diameter - 4.13 cm
(2) - Pairs-orifice flanges, weld-
neck type, for 10 cm-
schedule 40 pipe.
Flange top locations.
FR-2 (1) - Leeds & Northrup No. 602-61-
61-000-000-3089-3089-6-58-
656-291XL extended perform-
ance two-pen recorder.
Both ranges: AZAR, contin-
uously adjustable-100 mV to
100 V.
Span stop response time:
1/3 s
Chart speed: selectable in
20 steps from 0.0071 to
0.423 mm/s.
Power requirement: 115 V,
ac, 60 Hz.
(1) - Leeds & Northrup No. 923-2030-
1 Numatron digital indicator.
Range: ± 3900 mV
Accessories:
(2) - Action AP-1020-S frequency
to dc converters.
113
-------
System
Flow Sensors and
Recorders (Cont)
Item
No.
Level Recorder
LR-1
Description
(2) - Leeds & Northrup No. 036211
relays to supply pulse
signals to frequency/dc
converters.
(2) - Leeds & Northrup No.
P.R.-195-M-0.1-A-0.5 195 Ohm
dropping resistors to
condition signal to
Numatron indicator.
(2) - Leeds & Northrup Std. 3232-7
(032047) toggle switches to
select one of two signals to
Numatron indicator.
(1) - ITT Barton Model 202A
differential pressure
circular chart recorder,
single pen-case material:
die-cast aluminum.
Chart size: 30.5 cm circular.
Range: 0-5 kPa
Sensing element: Barton
Model 199 forged steel with
6900 kPa rating.
Chart drive: 240 s
Movement power: 120 V,ac
60 Hz.
Manometers
Accessories;
(1) - Model 254-3A, 3-valve
manifold.
PDI-1, 3 (2) - Meriam Model 30 EB25 FF
102 cm well-type manometers.
Wetted parts: SS
Range: 0-10 kPa
. Indicating fluid: 295 red
fluid unity (S. G. 2.95)
PDI-2, 4 (2) - Meriam Model 30 EB25 FF
90 cm well-type manometers
Wetted SS
Range: 0-26 kPa
Indicating fluid: 295 red
fluid (S. G. 2.95)
114
-------
System No. Description
Pneumatic Transmitters PT-1, 2 (2) - ITT Barton Model 273A
indicating pneumatic
pressure transmitters
Input: 0-45 kPa
Dial Size: 15 cm
Output: 21 to 103 kPa,
gauge
Accessories;
(2) - Fairchild Hiller Model
65332 pressure regulators
with drip-well filter and
6.4 cm output gauge.
(2) - Honeywell Model No.
SP470A1018 four-position
manual selector switches.
Pressure Controller PC-3 (1) - Fisher Controls No. 4162R-
7810, 30.5 cm medium
pattern butterfly valve,
860 kPa nominal, ASA
connections, iron body and
disc, 17-4PH shaft and
pins, with Fisher 656
size 40 power actuator.
(1) - Fisher Controls No. 416ZR
Wizard Pilot, yoke mounting.
Accessories;
(1) - Fisher Controls 67 FR-221
air set.
Pressure Gauges PI-1 (1) - Ashcroft Model 1009 general
service pressure gauges
Range: 0-103 kPa
PI-2, 3 (2) - Ashcroft Model 1188P low-
pressure gauges.
Range: 0-10 kPa
PI-4 (1) - Ashcroft Model 1188P
low-pressure gauge
Range: 0-5 kPa
115
-------
System
Pressure Gauges
(Cont)
Pressure Recorders
PR-1, 2
Purge Air Supply
Regulator
VPR-3
Purge Rotameters
FI-7
Description
Accessories;
(4) - Ashcroft Model 1/4-112E SS
pressure snubbers.
(2) - ITT Barton Model 242A
pressure recorder receivers
Case material: die cast
Aluminum with black epoxy.
Input signal: 21 to 103
kPa, gauge.
Chart range: 0-100 linear,
Circular, 30.5 cm diameter
Single pen.
Chart drive: 24 hr/
revolution and 30 min/
revolution
Power requirement: 120 V.ac,
60 Hz.
(1) - ITT Hammel Dahl Conoflow
Model No. FH-60XT-KG1
Airpak filter regulator with
integral 5 cm diameter output
pressure gauge.
(19) - Fischer & Porter Type 10A3135N-
53R2110 purge rotameters with
differential pressure
regulators and integral inlet
needle valves.
116
-------
A.2.2 AUXILIARY EQUIPMENT
Item
Control Room
Item
No.
CR-1
Balacning Valve
V-l
Balancing Valve
V-2
Shutoff Valve
V-3
Blast Gage Valve
V-4
Rupture Disc
Description
Noise Control Products Corp.
prefabricated and assembled room
with inside dimensions of 2.1 m
wide by 3.0 m long by 2 m clear
ceiling height. Room provides
housing for control panel, purge
rotameter manifold assembly, and
operating personnel.
Mosser Industries, Inc. (Model AW)
manually operated butterfly valve,
1030 kPa line pressure, 172 kPa
differential pressure, ductile
iron body and blade, TFE-asbestos
packing, TFE/glass bearings, SS
shaft, and clearance-type seat.
Mosser Industries, Inc. (Model AT)
manually operated butterfly valve,
1030 kPa line pressure, 140 kPa
differential pressure, cast-iron
body, steel blade, steel shaft,
and Buna-"N" 0-ring seals.
Center Line Inc., (Series A) -
manually operated butterfly valve
designed for bubble-tight shutoff
at 1030 kPa and 356 K. Valve has
a cast-iron body, bronze disc,
Buna-"N" 0-ring and sleeve, SS
stem and disc pin.
Mosser Industries, Inc. (Model GT)
Threaded gate valve rated for
140 kPa differential pressure and
capable of an uninterrupted flow
of solids through the line in the
full open position.
Pike Metal Products Corp.
(assembly G) - SS bolted-type
and flanged with the capacity to
discharge 2.93 m2/s air at 340 K
with a bursting pressure of
59 kPa, gauge.
117
-------
Item
Item No. Description
Pressure Switches PS-1, 2, Delaval Turbine, Inc., Barksdale
and 3 Controls Division (Model D1H) -
diaphram operated, differential
pressure-type to withstand a
maximum temperature of 350 K and
69 kPa, gauge, 10 psig maximum
pressure on either side of the
diaphram. PS-1 and PS-2 will
shut down blower (CB-1) when the
line pressure reaches 7.45 kPa,
gauge. Pressure switch PS-3
will shut down blower (CB-1)
when the line pressure reaches
5.0 kPa, gauge.
118
-------
APPENDIX B
SUPPLEMENTAL DATA
NOTES: 1. These data pertain to the second series of tests
(with the rear-wall nozzle sparger).
2. The bed height given is the average settled height
of the two beds.
3. Bed pressure drops for runs 1-23 are from a point
7.6 cm above the distributor to the freeboard. Bed
pressure drops for subsequent runs were taken from
a point level with the leg discharge into that bed
to a point level with the leg top leading from that
leg (total length 79 cm).
4. Distributor pressure drops include the lower 7.6 cm
of fluid bed.
5. Two leg pressures could be recorded at a time. Switch
positions in Table B2 are illustrated in Figure Bl.
119
-------
Legl
Dwg. 6W*A22
Leg 2
4-Way Switch No. 1
4-Way Switch No. 2
Figure Bl. Leg Pressure Recorder Switch Locations
120
-------
TABLE Bl
RUN
SUPPLEMENTAL DATA
BfCD FLUIDtZING VELOCITIES
HEIGHT BED ONE TWO
TEMPERATURES
BL04EK BEOS
1
2
3
4
6
7
8
9
10
1 1
12
13
14
IB
16
17
18
1?
2U
21
22
23
29
30
31
32
33
34
35
36
37
38
39
MO
41
42
43
44
45
<46
47
48
49
BO
SI
B2
B3
54
BB
56
B7
58
1
M
.81
.81
.89
• 88
.87
.86
.85
.84
.84
.83
.82
.82
.81
.80
1.26
.25
.25
.24
.23
.22
.21
. 13
. 12
. 12
• 11
. 1 1
. 10
. 10
.09
.09
.08
.08
.07
.1)7
.06
.06
.06
.06
• 06
. 06
.06
.06
.06
.06
.06
.OB
.OB
.05
.OB
.05
.05
.OB
M/5
. 10
• 08
.01
• 03
.04
• OH
• 04
• OH
.04
.04
• OB
.05
.05
.05
.02
.06
.07
.07
.08
• OH
.08
.07
.98
.U3.
.03
• 99
.01
.03
.03
.98
.98
.98
.98
.98
.99
1.00
1 .UU
1.01
.02
.02
.02
.03
.03
.04
.04
.Ob
.04
• OS
.03
.U3
.03
1 .03
1
M/S
. 13
.08
• 02
• 03
• 04
• U4
• 04
• 04
.04
• 04
• 05
• 05
• lib
• Ob
.07
* 10
• I 1
. 12
• 12
* 12
• 13
• 12
• 07
• U7
.07
.07
• OB
.03
• 03
.08
.08
.08
• 08
• U2
• 03
.04
.05
.115
.U6
.07
.07
.07
• U8
.08
.09
.U9
.09
• UH
. 1)8
.07
1 .07
1 .07
IN
K
269.
269.
274.
277.
278.
279.
28Q.
281.
281 .
281.
280.
28Q.
279.
279.
262.
262.
263.
263.
263.
262.
262.
262.
272.
272.
272.
271.
271.
271.
271.
271.
271.
271.
271 .
269.
269.
269.
269.
270.
270.
270.
270.
271.
271 .
271 .
271 .
272.
272.
272.
272.
276.
276.
276.
OUT
K
322.
329.
336.
338.
339.
339.
339.
340.
341 .
341.
340.
340.
339.
339.
322.
322.
322.
322.
322.
323.
323.
330.
331.
332.
332.
331.
331.
331.
331.
331.
331 .
331 .
331.
324.
326.
329.
329.
330.
330.
330.
330.
330.
331 .
331 .
331 .
332.
332.
332.
332.
J33.
333.
333.
K
309.
314.
316.
319.
322.
323.
324.
326.
327.
327.
328.
328.
328.
328.
297.
306.
310.
311.
312.
313.
314.
317.
318.
318.
319.
319.
319.
319.
319.
319.
319.
319.
319.
299.
303*
307.
309.
312.
314.
316.
316.
317.
319.
321.
322.
324.
323.
322.
320*
319.
319.
319.
121
-------
TABLE Bl (Cont)
RUN
BFD FLUlOtZIMG
HEIGHT RED ONE
M/S
59
6U
61
62
63
6M
65
66
67
68
69
70
71
72
73
7M
75
76
77
78
79
8U
81
82
63
8M
85
86
87
88
89
90
91
92
93
9M
95
96
97
98
99
1UU
101
102
1U3
10H
lOb
106
107
1GB
10V
nn
1 11
1 12
1 U
1 1M
1 15
.05
.05
.OM
.04
.OH
• 03
.03
.02
.02
.02
.01
.01
.01
.00
.00
.00
.99
.09
.08
.07
.06
.05
• Of
.03
.02
• 01
.00
.08
.08
.08
.08
.07
.07
.07
.07
.07
.07
.07
.07
.07
.07
• 06
.06
.06
.06
.06
.06
.06
.06
.06
.06
.06
.US
.05
.05
• OH
• OM
1
1
03
99
1 .01
.02
.02
• 03
.03
.03
.OM
• OM
.OM
.OM
.03
.03
• 03
.03
.03
.92
*96
.96
.97
.97
.97
.98
.98
.98
.97
UOO
1.00
1.00
1.00
.99
.99
.99
.01)
.00
.00
.00
.01
.01
• 01
• 01
• 01
.01
• Ul
• 01
• 01
• 01
.01
.01
.01
• 9M
• 96
.97
.98
VELOCITIES
TWO
M/S
.07
.03
• 05
• 1)7
• 07
• 07
.07
• 08
.Ofl
• 08
• OR
• 08
• 08
• 08
• 08
• 08
.08
.93
• 9M
• 96
• 96
• 97
• 98
• 98
• 98
.98
• 9ft
• 02
.03
• UM
• OM
• U5
• Of
• OM
• UM
• OM
• OM
.05
• 05
• 05
• 05
• 06
• t>6
• 06
• 06
• 06
• 06
• 06
.06
• 06
• 1)6
.1 1
• 03
• OM
• D6
• U7
TEMPERATURES
HLOWEK BEOS
IN
K
276.
272.
273.
27M.
27M.
27M.
27M.
27M.
27M.
27M.
27M.
27M.
27M.
277.
277.
277.
277.
281.
281.
281 .
261.
282.
282.
282.
282.
282.
282.
286.
286.
287.
287.
268.
288.
289.
289.
290.
290.
290.
290.
291.
292.
292.
293.
293.
293.
293.
293.
293.
293.
2V3.
293.
293.
293.
2bS.
288.
286.
288.
OUT
K
333.
331 .
333.
33M.
33M.
33M.
33M.
33M.
33M.
33M.
336.
336.
337.
337.
337.
337.
337.
336.
338.
341.
3M1.
3M2.
3M2.
3M2.
3M2.
3M2.
3M2.
3M3.
3MM.
3MM.
3MM.
3M3.
3M2.
3M1.
3MM.
3M7.
3M7-
3M8.
3Mb.
3M9.
3M9.
3M9.
3M9.
3M9.
3M9.
35U.
351.
351.
351 .
351 .
351.
351 .
351.
3M2.
3MM.
3M5.
3M6.
K
319.
305.
311.
317.
317.
318.
319.
321.
321 .
322.
322.
322.
322*
322.
322.
322.
322.
302.
309.
315.
317.
319.
320.
321.
322.
322.
322.
31M.
318.
321.
322.
322.
320.
318.
320.
322.
323.
32M.
325.
326.
327.
327.
328.
328.
329.
329.
330.
330.
330.
330.
330.
330.
330.
302*
308.
312.
317.
122
-------
TABLE Bl (Cont)
RUN
HEI
116
1 17
1 10
1 19
120
121
122 1
123 1
12*4 I
125 1
126 1
127
128
12V
130
131
132
133
134
135
136
137
136
139
1<40
141
142
113
144
145
146
147
146
149
ISO 1
Ibl 1
1B2
1S3
1S4
Ib5
1B6
157
1S8
159
1*0
161
162
163
164
I6f,
167
166
17C
171
17?
173
BFD
GHT
M
.04
.03
.03
.02
.02
.02
.01
.01
.00
.00
.00
.99
.99
.9V
.99
.99
.99
.99
.99
.99
.99
.99
.99
.00
.00
.0(1
• 00
.00
.00
.00
.00
.00
.00
.on
.00
.00
.99
.99
.99
.99
.99
.9V
.9V
.99
.99
.99
.99
.99
.99
.99
.98
.98
. va
.98
.96
.98
FLUIDIZING VELOCITIES
RED ONE TWO
TEMPERATURES
BLOWER BEOS
M/S
.99
.00
. UCJ
.0(1
.00
. ou
.01
.01
.01
.01
.01
.01
.9E>
.96
.97
.98
.99
.99
.00
.00
.00
.00
.00
.00
.01
.02
.03
.04
.04
.04
.05
.05
.05
.05
.05
.05
.05
.05
.05
.05
.05
.06
• 06
.06
.06
• U6
.06
.06
.06
.06
.06
.116
.116
.06
• U6
1 .06
M/S
1 .08
1 .09
1 .1)9
.09
.09
. 10
. 10
. 10
• 10
. 10
• 1C
• in
.fJ3
.05
.06
.07
• (18
.08
.09
.C!9
.09
• U9
• 09
• OS
.06
.06
.07
• 08
.09
.09
.09
.09
.09
.09
.09
• US
.05
.05
.05
• 05
. ns
.06
.116
.06
.116
.06
. OA
.06
.06
• 116
• l<6
• U6
• HA
.1)6
1 .UA
1 .06
IN
K
288.
289.
289.
269.
290.
290.
290.
290.
291.
291.
29J .
291 .
263.
263.
263.
283.
284.
284.
283.
263.
263.
263.
283.
288.
288.
288.
289.
289.
289.
289.
289.
269.
269.
289.
289.
290.
290.
290.
290.
291 .
291 .
292.
292.
292.
292.
29*.
292.
292.
2V7.
292.
291 .
291 .
291.
291 .
291 .
291 .
OUT
K
347.
347.
347.
347.
347.
348.
348.
348.
348.
348.
348.
348.
329.
333.
336.
339.
342.
342.
342.
342.
342.
342.
342.
346.
346.
346.
346.
347.
347.
347.
347.
347.
347.
348.
346.
348.
348.
348.
348.
348.
346.
348.
346.
349.
34V.
34V.
349.
34V.
349.
349.
349.
349.
349.
349.
34V.
349.
K
321.
322.
323.
324.
325.
326.
326.
327.
327.
327.
327.
327.
299.
304.
309.
314.
318.
319.
321 •
322.
322.
322.
322.
311.
314.
317.
320.
323.
323.
324.
325.
326.
326.
327.
327.
327.
327.
328.
328.
328.
326*
329.
329.
329.
329.
329.
329.
329.
329.
329.
330.
330.
330*
330.
33U.
330.
123
-------
TABLE Bl (Cont)
RUN HFO FLUIDTZING VELOCITIES
HFI6HT RED ONE T*0
M
M/S
M/S
IN
K
TEMPERATURES
BEDS
OUT
K
174
I7b
176
177
178
179
IBtl
181
182
183
184
IBS
186
187
188
189
190
191
192
193
19S
195
196
197
198
199
20U
201
202
203
204
205
206
207
208
209
210
21 1
212
213
21 4
215
216
217
21B
21V
220
221
222
.98
.98
.98
.97
.97
.97
.97
.97
.97
.97
.96
.96
.90
.96
.96
.96
.95
.95
.95
.95
.95
• 94
.94
.94
.94
,9H
.94
.93
.93
.93
.93
.93
.93
1 .02
1.01
1.01
1.01
1 .01
.01
.01
.01
.01
.n i
.01
.01
i.uo
i *ou
i .00
1.06
• 95
.95
.96
.96
.96
.97
.97
.98
.98
.98
.99
.99
• 00
.00
.00
.01
.01
• 01
.01
.01
.01
• 01
.01
.01
.02
.02
.02
.02
.02
.02
.02
1.02
.32
.32
.75
.76
• bO
.51
.51
.51
.51
.51
.51
.51
.bl
• bl
.51
.52
.06
.99
.99
• 00
• 00
• ni
• 01
.02
.0?
.02
.03
• 03
• 04
• 05
• 05
• 05
• 05
• 05
• 05
• 05
• 06
• 06
• 06
• 06
• 06
• 06
• 06
• 06
• 06
• 06
• 06
• 06
.06
.36
• 36
• 83
• 04
• b9
.59
.59
.59
• 60
.60
.60
.60
• 60
• 60
• 60
291 .
276.
276.
2/6.
276.
276.
276*
276.
276.
276.
276.
277.
277.
277.
277.
277.
277.
278.
278.
27 8.
278.
278.
278.
27B.
278.
278.
278.
278.
278.
278.
278.
278.
278.
278.
278.
279.
279.
280.
280.
281 .
2B1 .
281.
281 .
282.
2B2.
282.
28 t.
284.
286.
349.
316.
320.
322.
324.
327.
329.
331.
333.
336.
336.
336.
336.
335.
33b.
335.
334.
334.
334.
334.
334.
334.
333.
333.
333.
333.
333.
333.
333.
333.
333.
333.
333.
336.
338.
341.
341 .
341.
342.
342.
342.
343.
343.
343.
343.
344.
344.
344.
344.
330*
293.
296*
298*
301 .
303*
305.
307.
309.
312.
313.
315*
317*
318.
319.
319.
320.
320*
32U.
320.
321.
321.
321.
321.
322.
322.
322.
322.
322.
322.
322.
322.
322.
303.
306.
308.
311.
314.
315.
316.
317.
318.
319.
321.
321 .
322*
322.
323*
323.
124
-------
TABLE Bl (Cont)
RUN
223
224
225
226
227
228
229
230
231
232
233
234
23S
23*
237
23R
23V
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
26b
266
267
2e8
269
2/U
2/1
2/2
BED
HEIGHT
1 .00
• 00
.00
• ou
.00
.on
.ou
.99
.99
.99
.99
.99
.V9
.99
.99
.99
.99
.99
1 .02
1 .02
.02
.02
.02
.02
.01
.01
.01
1 .01
I .01
1.01
.01
01
01
01
i .01
01
01
01
1.01
.01
.01
1.01
01
0 1
01
01
01
fit
I) I
i .ni
FLUIDTZING
BED ONE
M/S
.52
.52
.52
.52
.52
.52
• 52
.52
.52
.52
.52
.52
.52
.52
.52
.52
.52
.52
.32
.33
.33
.33
.33
.33
.33
.34
• 34
.34
.34
.34
.34
• 34
.34
.34
.34
.34
.34
.34
.34
.34
.34
.34
.34
.34
.34
.34
.34
.34
.34
.34
VELOrITIES
TWO
M/S
• 6Q
• ttll
.60
• 60
• 60
.60
• 60
• 60
.60
.60
« bO
• 60
• 60
• 60
• 60
.60
• 60
• 60
• 40
• 41
• 41
• 41
• 42
• 42
• 4?
• 42
• 42
• 42
• 42
• 42
• 42
• 42
• 42
• 42
.42
• 42
.42
• 42
• 42
• 42
• 42
• 42
• 42
• 42
.42
.42
• 42
.42
.42
.42
TEMPERATURES
qLOWER
INI
K
288.
287.
286.
284.
284.
284.
284.
284.
284.
284.
28<4.
284.
284.
284.
28<4.
284.
28«4.
264.
2&4.
285.
285.
286.
286.
286.
286.
286.
287.
287.
287.
287.
287.
287.
28/.
287.
287.
287.
287.
2dV.
767.
207.
287.
287.
287.
287.
287-
287-
207.
287.
287.
287.
OUT
K
344.
344.
345.
345.
346.
346.
34o.
346.
346.
346.
346.
346.
346.
346.
346.
346.
346.
346.
342.
344.
346.
347.
340.
348.
348.
348.
349.
349.
349.
349.
349.
349.
349.
349.
349.
349.
349.
34V.
349.
349.
349.
349.
34V.
349.
34V.
34V.
34V.
349.
34V.
349.
BEOS
K
323.
323.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
306*
309.
31 1 .
314.
317.
318.
319.
321.
322.
322.
322.
323.
323.
323.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
324.
125
-------
TABLE B2
SUPPLEMENTAL DATA
ALL UNITS KILOPASCALS rXCCPT SWITCH POSITIONS
to
RUN
1
2
3
*
6
7
8
9
10
11
12
13
IM
IB
16
17
18
19
20
21
22
23
29
30
31
32
33
3M
35
36
37
38
39
GAUGE PRESSURES
BLOWER
PRESSURE DROPS
LEG PRESSURES.GAUGE
M9.
M9.
M2.
M2.
M3.
M2.
M2.
HI.
11*
Ml.
M2.
M2.
M2.
M2.
MM.
MM.
MM.
MM.
MM.
MM.
MM.
Ml.
Ml.
Ml.
Ml.
Ml.
Ml.
Ml.
Ml.
Ml.
Ml.
BED
ONE
1.7
3.2
2.0
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.7
1.9
1.9
1.9
1.9
2.0
2.0
2.0
2.0
2.0
2.0
1.9
2.0
2.0
1.9
1.9
1.9
1.9
2.0
2.0
2.0
2.0
BED
TWO
1.6
3.1
.7
.7
.7
.7
.6
.7
.7
.7
.7
.7
.7
.7
.7
.7
.0
.0
.0
.0
.0
.0
.7
.9
.9
2.0
2.0
2.0
2.0
1.9
1.9
1.9
1.9
BED
ONE
7.8
6.M
9.0
7.2
6.6
8.8
6.6
9.2
6.9
9.0
6.M
8.7
5.8
8.7
13.6
10. M
13.9
10.7
13.9
10.7
1M.2
10. M
7.8
7.7
7.5
7.7
7.9
7.7
7.7
•
BED OIST D1ST SWITCH 1 SWITCH 2
TWO ONE TWQ POS P POS P
7.8 M.3 3.7
8.5
7.2
8.7
9.2
7.1
9.2
6.6
9.M
6.9
9.2
7.2
9.5
7.1
11.6
13.9
10.1
13.6
11.0
13.9
10. M
13.6
7.9
8.2
8.1
7.8
8.1
8*2
7.8
M.6
M.3
M.2
M.O
M.O
M.O
3.8
M.M
M.O
M.M
M.3
M.3
M.2
3.8
M.2
3.8
M.3
M.O
M.O
3.9
M.2
M.O
M.I
3.9
3.7
M.O
3.5
3.7
3.5
2.9
2*9
2.9
3*3
3*1
3.3
3.3
3.2
2.9
3.2
2.9
2.9
3.3
2.7
2.9
3.1
3.3
2.8
3.5
2.9
3.3
3.M
3.3
3.5
3.3
2.9
3.7
1
3
M
3
1
1
1
3
1
1
3
1
3
3
3
3
1
1
3
3
1
1
3
3
1
6.7
6.3
8.1
8.5
5.M
5.M
5.8
8.5
6.3
6.3
13.0
7.6
13. M
6.7
9.M
8.5
8.5
8.5
9.0
8.5
8.5
8.5
9.0
9.M
9.0
2
3
M
2
M
2
2
2
M
2
2
M
2
M
M
M
M
2
2
M
M
2
2
M
M
2
9.0
9.9
M.9
9.9
8.5
8.5
6.7
8.5
8.5
8.5
8.5
12.1
12.1
12.5
9.9
11.2
11.2
11.2
10.8
10.3
11.2
10. 8
10.8
1!:!
10.8
-------
TABLE B2 (Cont)
to
RUN GAUGE PRESSURES
BLOWER
HO HI.
HI HI.
H2 M :
H3 4|.
HH Ml.
H5 «U.
H6 HI.
H7 Ml.
H8 HI.
H9 M|.
50 HI.
SI HU
52 HI.
53 Ml.
5H Ml.
55 Ml.'
56 Ml,
12 *»•
58 Ml.
!2 « •
60 M2.
61 H2.
62 H2.
*3 H2.
6H MS.
*5 ***•
66 M2.
67 M2.
68 M2.
69 M2.
70 M2.
71 H2.
72 H2.
PRESSURE DROPS
LEG PRESSURES-GAUGE
BEO I
ONE
.
.
.
.
•
.
.
.
•
.
•
.
.9
.9
.9
.9
.9
.9
.9
.9
.7
.7
.7
.7
.7
.7
.7
.7 |
z.o ;
2.0 4
2.0 2
2.0 2
2.0 2
JED
rwo
.7
.9
.7
.7
.
.
.
.
,
,
•
•
.
,
.
.
•
.
.
.
.
.
.
.
•
•
•
.
1.0
NO
!.0
!.0
!.0
BEO
ONE
7,9
8.1
7.9
6,1
8, 1
7^^
,9
7,9
8, 1
7,7
8,2
7,5
7.6
7.8
7.9
7.9
6*1
BED DIST
TWO ONE
8.1
8.4
8.1
7.9
8. 1
8. 1
7.9
8.1
7.8
7.7
8.2
7.9
7.9
6.1
8. 1
6.1
3.8
H.8
H.O
H.O
3,7
H.O
H.O
3.8
H, 1
3.7
H.O
H.2
H.O
H.O
H.O
3.7
DIST
TWO
3.3
3.5
3.H
3*7
3.0
3.5
3.3
3.3
2.9
3.3
2.9
3.2
3.3
3,3
3,3
2,9
SWITCH 1
COS P
1
3
1
1
3
3
1
1
3
3
1
1
3
3
1
3
3
1
1
3
3
1
1
3
3
1
1
3
3
1
1
8.5
9.0
8.5
9.0
9.0
8.5
9.0
9.H
8.5
9.0
8.5
9.0
9.0
9.0
9.0
9.0
8.5
6.5
9.H
9.0
8.5
8.5
8.5
9.0
8.5
6.5
9.0
6.5
8.5
8.5
9.0
9.0
8.1
SWITCH 2
POS P
2
H
H
2
2
H
H
2
2
H
H
2
2
H
H
2
2
H
H
2
2
H
H
2
2
H
H
2
2
H
H
2
2
11.2
10.6
11*2
11,2
11,2
1 1,2
10,8
11.2
10.8
11.2
11.2
1 1 .2
10.8
11,2
11,2
11.2
11,2
1 1 .2
1 1.2
10.8
10,6
10,6
10,8
10,8
10.8
10*6
11.2
10.8
1 1.2
10.8
10.6
11.2
11.2
-------
TABLE B2 (Cent)
RUN
GAUGE PRESSURES
BLOWER
BED
ONE
BED
TWO
PRESSURE DROPS
LEG PRESSURES-GAUGE
BED
ONE
BED
TWO
OIST
ONE
OIST
TWO
SWITCH 1
POS P
SWITCH
POS
P
N>
00
73
7M
75
76
77
76
79
80
81
82
83
8M
85
86
87
88
89
90
91
92
93
9M
95
96
97
98
99
100
101
102
103
104
IDS
M2. ;
M2. 2
M2. 2
to.
40.
MO.
to.
HI.
Ml.
Ml.
Ml.
Ml.
Ml.
M8. J
M8. 4
M8. 't
MS. ;
M8. \
M8. ;
MB. :
M8. 2
M8. 2
M8. ;
MS. ;
MB. 2
M8* 2
MB. ;
M8. 2
M8. 2
M8. 2
M8. 2
M8. 2
M8. 2
».0 2.0
1.0 2.0
J.O 2.0
• .5
. .5
.5
. .5
• M
• M
. .M
. .M
. .M
.M
1.0 2.0
NO 2.0
(.0 2.1
!.0 2.1
!.0 2.0
!.Q 2.0
!.Q 2.0
!.l 2.0
1.2 2.0
1.2 2.0
1.1 2*0
J.O 2.0
l.Q 2.0
'.0 2!o
(.1 2.0
2.2 2lo
1.2 2.0
2.2 2.0
!.2 2.0
t.2 2.0
8.8
7.8
8.1
7.5
7.8
8.1
6.9
7.S
7,5
7.7
8.7
• •1
8.1
8.M
8.1
8.1
8.1
8.1
3.8
M.O
M.O
M.M
M.8
M.M
M.M
M.M
M.M
3.3
2.9
2.9
3.7
3.3
3.3
3.3
3.7
3.3
3
3
1
2
M
M
i
M
M
2
2
M
2
M
M
2
2
M
M
2
2
M
M
2
2
M
M
2
2
M
M
2
8.5
8.1
9.0
10.3
10.8
10.8
13:?
10.8
10.8
10.8
10.8
10.8
11.2
10. a
10.8
11.2
11.6
11.2
10.8
11.2
10.8
11.2
11.2
11.2
11.2
10.8
11.6
12.1
11.2
11.6
11.6
12.1
M
M
3
3
1
3
3
1
1
3
1
3
3
1
1
3
3
1
1
3
3
1
1
3
1
1
3
3
1
10.8
10.8
9.
10*
1:
9,
lOt
9.'
9,
10.
f
• •
.M
.9
• 9
.M
.0
• M
t?
.1
.4
.1
l§:3
9.9
10.6
11.2
10. fl
I0.fi
11.2
-------
TABLE B2 (Cont)
"UN
106
107
108
109
110
111
112
113
114
It!
1 17
121
122
123
124
125
126
127
128
129
1)0
131
132
133
134
135
136
137
138
S.USE PRESSURJS
II:
M:
5!:
18.
H8.
«*8.
MS.
H8.
M8«
18.
28.
2§f
48.
2.2
2.2
2.2
2.2
2.2
2.2
1:8
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
i 8
20
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
PRESSURE DROPS
UES PRESSURES-S»USE
SJ,TCHp2
3.7
2
1
1
2
2
4
1
7-8
3.7
7.5
3.7
12.1
1**
1
77:22
7*2
3
3
I
10.8
I
10.8
-------
TABLE B2 (Cont)
RUN GAUGE PRESSURES
BLO*ER
PRESSURE DROPS
LEG PRESSURES-GAUGE
139 17.
110 17.
Ill 17.
112 17.
113 17.
Ill 17.
IIS 17.
116 17.
117 17.
118 17.
119 17.
ISO 17.
1S1 17.
152 17.
1S3 17.
151 17.
155 17.
156 17.
157 17.
156 17.
159 17.
160 17.
161 17.
162 17.
163 17.
161 17.
165 17.
167 17.
16B 17.
170 17.
171 17.
172 17.
173 17.
BED
ONE
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
BED
TWO
2.0
2.0
2.0
2*0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2*0
2.0
2.0
2,0
2;o
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2,0
2.0
2.0
2.0
2,0
2.0
2,0
2.0
BED BED OIST DIST SWITCH
ONE TNO ONE TWO POS
7.8 8*1 1*1 3.3 2
1
1
2
7.2 8.7 1.1 3.7 2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
1
1
P
6.1
8.1
7.6
8.5
7.6
7.6
7.1
7.6
7.6
8.1
8.1
8.1
8.1
8.1
7.6
8.i
8.5
8.1
6.1
9.0
8.5
8.5
7.2
7.6
7.6
7.6
7.6
7.2
7.2
SWI
POS
3
1
1
3
3
1
1
3
3
1
3
1
3
3
1
1
3
1
3
3
1
3
TCM 2
P
10.3
10.8
.1
.0
.0
• 0
.0
.9
.5
9.0
9.0
10,8
9,
9.
9,
9,
9.
9.
9.
9.0
9.0
9.1
9,1
8,5
8.1
-------
TABLE B2 (Cont)
RUN GAUGE PRESSURES PRESSURE DROPS LEG PRESSURES-GAUGE
BLOWER BED BED BED BED DIST OIST SWITCH 1 SNITCH 2
ONE TWO ONE TWO ONE TWO POS P POS P
7.5 7,8 M.M 3.7
17M
175
176
177
17B
179
180
181
182
183
IBM
18S
186
187
188
189
190
191
192
193
19M
195
196
197
198
199
200
201
202
203
20
-------
TABLE B2 (Cont)
RUN
GAUGE PRESSURES
PRESSURE DROPS
BLOWER
BED
ONE
LEG PRESSURES-GAUGE
BED
TWO
BED
ONE
BED
TOO
OIST
ONE
OIST
TWO
SNITCH
COS
SNITCH
POS
CO
N>
207
208
209
210
211
212
211
214
215
216
217
218
219
220
221
222
223
224
22S
226
227
228
229
230
231
232
233
234
23S
236
237
238
239
27
27
34
34
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
.2
• 2
.7
.7
• S
.5
.6
.6
.6
.7
• 7
.7
.7
.7
.7
.7
.7
.7
.7
.7
.7
.7
.7
.7
.7
.7
.7
.7
.7
t7
.7
.7
.7 ]
.2
.2
.7
.7
.2
.3
.3
.4
.4
• 4
.4
.5
.5
.5
• 5
.5
.5
• B
.5
.5
.6
.5
.5
.5
• S
.S
.5
.5
.S
1.5
.5
.5
L.&
8.1 8.1 2.7 2.2
8.1 7.8 3.3 2.9
7.8 8*1 2*9 2.6
8.1 8.4 3.3 2.3
2
2
2
2
2
2
2
2
2
2
2
2
2
11.2
a.s
11.2
9.4
11.2
9.4
8.S
11.6
11.6
8.6
9.4
11.6
9.4
11.6
-------
TABLE B2 (Cont)
RUN
2HO
2«U
GAUGE PRESSURES
PRESSURE DROPS
LEG PRESSURES-GAUGE
2H3
2H«i
CO
2M6
2H7
2H8
2<49
250
251
252
253
25*4
255
256
257
258
259
260
2*1
262
263
26<4
265
266
267
268
269
270
271
272
WER B
Q
31.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28.
28*
28.
28.
28.
28.
28.
EO B
NE T
.7
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
.5
1.5
1.5
EO
WO
.5
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
. 2
• 2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
1.2
1.2
BED
ONE
7.9
BED
TWO
8.M
DIST
ONE
2*7
DIST
TWO
2.2
SWITCH
POS
1
P
SNITCH
POS
2
P
-------
APPENDIX C
MODEL DEVELOPMENT DETAILS
C.I JET AREA
Cl
It is well known that homogeneous jets have similar geometries.
Application of jet expansion assumptions to predict the dilute phase
flow area in this model was achieved by assuming that gas jets into
solids also possess similarity. In addition, it was assumed that the
relation of a plane jet to a circular jet in a fluidized system was
similar to the relation in a homogeneous system.
Figure C-l illustrates the nomenclature and geometry involved.
Circular jets issue from nozzles with a half-angle 9 at the virtual
origin. When the jets interfere a plane jet is formed, whose half-angle
is slightly larger due to the lesser degree of freedom. It is assumed
that the jet radius is equal to half the nozzle center-to-center spacing
at the transition point. From trigonometry we know that (refer to
Figure C-l):
rrr^r = tan 9 (c-l)
and
d
y = tan 0 . (C-2)
From these
x - d
(c'3) and
134
-------
Owg. 6WtA10
Ul
Circular Jet
Plane
of
Nozzle
Plane Jet Dilute Phase Flow
(Constant Area)
Center Line
n
Figure C- 1. Geometry and Nomenclature of Jet Expansion
-------
If x.. £ x,, then a transition to a plane jet occurs and
h
2(xh
and
= tan B (C-4)
X
-?-—r = tan 0 . (C-5)
Combining Equations C-3, 4, 5 yields
h = x + (d - x ) (|~|) + 2x^
n on tan o n
and thus
S3 - h - W = W[xn + (do - xn) () -h 2Xh tan 0] . (C-7)
and
(16)
If x- > x,, then jets are spaced widely enough not to interfere and
the radius of a jet at x, is
r = (xh + y2) tan 0 . (C-8)
But
y2 = dQ/(2 tan 9) , (C-9)
d
r = ^ tan 0 + ~ . (C-10)
Therefore ,
S_ = Nnr2 = 7- N(2 x. tan 0 + d )2 . (C-ll) and (15)
J 4 n o
These estimates of the dilute phase flow require predicting the jet
C2
half-angles, 0 and 6- Merry found that for a circular horizontal gas
Cl
jet into a fluidized bed, 0 was 6.35°. We used this value. Rajaratnam
presents a detailed discussion of both circular and plane turbulent
136
-------
homogeneous jets. Following his discussion it can be shown that the
angle formed between the circular jet centerline and the line consisting
of the locus of those points where velocity is half the centerline
velocity is about 5.4°. For a plane jet this angle is 6.5°. Similarity
requires that the ratio of plane jet to circular jet half-angles
(6.5°/5.4° = 1.20) be the same for all homogeneous jets when the half-
angles are defined consistently. We have assumed this ratio also applies
to consistently define half-angles in the heterogeneous case. Therefore
6 was taken as 1.2 x 6.35 = 7.64°.
C.2 FLUIDIZING TIME ESTIMATION
The fluidizing time denotes the time required for significant gas
bypassing to be achieved once a large pressure gradient is imposed upon
a bed of solids. Figure C-2 illustrates the phenomenon. A pressure
gradient in excess of bed density has been applied to a bed. Fluidized
solids exist above the bed boundary (z > L ). The local pressure gradient
(AP/L ) in the bed is assumed to be neither a function of height nor time
d
(the bed is pushed up by the bubble). Voidage is constant at e^
The net force on a thin layer of solids ahead of the bubble is
(—) A (Az). The mass of the layer is p A(Az) (1 - e^. The acceleration
ofSthis slab is then
d z c rr-121
i?'Vp«--i> '
Boundary conditions are that at t = 0
z=0 (C-13)
and £ - 0
-------
Dwg. 6UM+A2I
_ I - ,_ __„ _ _ ^_^
Packed Bed
(Interparticle Locking
Forces Not Yet
Overcome)
00
z=o
Gas Bubble or Slug
Figure C-2. Fluidizing Dynamics
-------
Solving
AP g
'* - (C-15)
2Lspp(l - EI) L '
the leg will be fluidized (the bubble will have risen, clearing a path
for gas bypassing), at time t, where z = L .
M S
.
2L 2p (1 - e )
(C-16) and (17)
After t = tM all available gas passes upward, clearing the rest of the
leg rapidly, until such time as the pressure gradient is reduced to a
stable level consistent with the bed density.
An alternative expression can be derived from a force balance on
a rising gas slug in a fluid bed. We assume that the bed is initially
fluid and that C_ is the drag coefficient of the fluid bed on the slug
front. If the slug is approximated by a rising blunt-nosed cylinder
starting at z = 0, with z the position of its top,
is the force balance. Assuming CD is constant, with the same boundary
conditions as before, at z = Lg, t = t^;
provided also that p (1 - e.^) » p .
Standard drag coefficient correlations (Perry03) for a disc oriented
perpendicularly to flow suggest that for a Reynolds number in excess of
about 100, C is of the order unity. Thus equation C-18 reduces to
(C-19)
139
-------
which is equation C-16 with
(AP/L<,) = pn (1 - e,) g/g . (C-20)
S p 1 c
C3. DEFLUIDIZING BEHAVIOR AND VERTICAL SECTION VOIDAGE ESTIMATION
Equations 19 and 20 (Section 7.1.8) were derived empirically
to reflect experimental trends. The density of material in the vertical
section will not return to its packed value unless sufficient time is
allowed between pulses. To approximate behavior at short off-times we
assumed that the density was proportional to the relative time allowed.
, ~ Elv a , time allowed for packing . ^ (C-21)
1 - E time required for complete packing
The data suggest that about the first half-second of off-time does not
permit substantial packing. Evidently this is due to the need to allow
pulse gas to escape against the direction of solids flow. The little
packing that does occur in this time is more than reversed by the next
pulse, so each subsequent pulse sees a higher vertical voidage, and a
seal is not possible.
The best value of this response time for our data was ^0.54 s.
Therefore, only off-time in excess of this value permits a voidage less
than one, and equation C-21 is modified to:
(1 " £i} _ ^FF " °-54 _ 'OFF - 0.54. . .
(1 - e ) 1.41-0.54 " ( 0.87 ' (L L.L}
p and
(19)
^OFF " **.
P
In this equation 1.4 is the experimental minimum time required for.
complete repacking at long on-times.
140
-------
At shorter on-tlmes (tQN < y less time is required for repacking.
Sutton and Richmond SUgge8t that bed heights fall exponentially with time,
approaching the packed density asymptotically. Packing occurs most
rapidly early during deaeration. We have approximated this behavior by
t = 0.87/5*
P V tM
f°r ^N < Si' yieldin8 Equation 20 in Section 7-1.8.
REFERENCES
CL. Rajaratnam, N., Turbulent Jets, New York: Elsevier Scientific
Publishing Company; 1976, Chapters 1 and 2.
C2. Merry, J. M. D., Penetration of a Horizontal Gas Jet into a
Fluidized Bed, Trans. Instn. Chem. Engrs. 49: 189-195; 1971.
C3. Perry, J H., ed., Chemical Engineer's Handbook. 4th Edition,
New York: McGraw-Hill Book Go.; 1963, Chapter 5, p. 60.
C4. Sutton, H. M., and R. A. Richmond, Improving the storage Conditions
of Fine Powders by Aeration, Trans. Instn. Chem. Engrg., 51:
97-104; 1973.
141
-------
APPENDIX D
SOLIDS TRANSPORT MODEL PROGRAM LISTING
142
-------
1*
2*
3*
1*
5*
6*
7*
P»
9*
1C*
11*
12*
13*
11*
15*
16*
17*
ie*
19*
2C*
21*
22*
23*
21*
25*
26*
§7*
8*
29*
30*
31*
32*
33*
31*
35*
36*
37*
38*
39*
10*
11*
MOMENTUM BALANCE MODEL FOR CAFB SOLIDS TRANSFER
REAL KtKl.K2.K3.K1.K5.K6.L.MU.NOZ.M
INTEGER KUN
REMEMBER TO USE PROPER I/O DEVICE CODES
INPUT-5
IOUT=6
SYSTEM
INPUT VARIABLES
GENER«L OAT*? PARTICLt PROPERTIESt LEG GEOMETRY
C
C
C
C
C
C
C****
C****
c****
C****
C****
C****
c****
C****
C****
C****
C****
C****
C****
C****
C****
C****
10
20
22
MATERIAL
N=NUM8ER OF DATA POINTS FOR THIS GEOMETRY AND
EprpACKED BED VOIDAGE* NORMAL LOOSE
DPrAVEKAGE PARTICE SIZE. MICROMETERS
RHOP=PARTICLE DENSITYt KILOGRAMS PER CUBIC METER
Sl^CROSS-SECTIONAL FLOW AREA OF LEG. SQUARE METERS
S2=CROSS-SECTIONAL FLOW AREA OF NOZZLES ITOTAL). SQUARE METERS
L=VERTICAL LENGTH. METERS
HL=HORIZONTAL LENGTH. METERS
AL=ANGLE OF DOUNCOMER FROM VERTICAL. RADIANS
DT=HEAN HYDRAULIC DIAMETER OF LEG, METERS
ON=NOZZLE DIAMETER. CENT METERS
XHrQISTANCE FROM NOZZLE TO OVERHANG* CENTIMETERS
XM=NOZZLE SEPARATION fCENTER-TO-CENTER). CENTIMETERS
NOZ=NUMBER OF NOZZLES
XU=LEG WIDTH, METERS
M=MOLECULAR WEIGHT OF TRANSPORT GAS
READ (INPUT,10) N.EP.DP.RHOP
FORMAT (I5.3F1C.3)
READ (1NPUT*20) SI»S2 , L,HL.AL.DT.ON.XH.XN.NOZ
FORMAT I2FR.6.BF8.1)
READ XW
FORMAT «F10.3)
READ (INPUT.22) M
FORMAT fFlJ.5>
DP=.000001*OP
DN=.C1*DM
XH=.01*XH
XNr.Cl*XN
WRITE
-------
*2* 23 FORMAT UHI,///» RUN TON TOFF TM GA UP WN*»
13* !• El E3 PO SKAT GSPV/I
44* c
45* c CALCULATION OF DILUTE PHASE FLOW AKEA 53. SQUARE METERS
14* C
17* Xl-(XN-ON)/.223
18* H = .223*XH*OIM
19* S3=NOZ*.7fl5*H**2
50* IF (XI .GE. XH! 60 TO 25
51* HrXN+
-------
83*
84*
85*
86*
87*
88*
89*
9C*
-91*
92*
93*
C
C
C
95*
96*
97*
98*
99*
100*
101*
102*
103*
104*
105*
106*
107*
108*
109*
110*
111*
112*
113*
11%*
115*
116*
117*
118*
119*
120*
121*
122*
123*
12**
125*
ITERATE ON PRESSURE AT NOZZLE
00 501 JP=1»1CO
12 P3=P3*
PP=ABS E1=CS
IF
IF (TON -6T. THI GO TO 150
ElrES-IES-EP)/TP*ITOM*TOFF-TNH-.5*)*SORTfTH/TON>
IF (El .ST. ESI E1=ES
IF (El .LT. EP> E1=EP
TN2=SORT(RHOP*(1.-E1)*L««>2/OALP*2.I
IF (ABSITH-TH2) .LT. .01) 60 TO 150
TH=TH2
60 TO 145
CONTINUE
IF (IDALP/L) .6E. (RHOP*( 1 .-EP ) *9.8 » > 60 TO 151
E1=EP
TH=10COOO.
CONTINUE
6AS DENSITIES
RH01=Pl/T*H/8. 314/1000.
RH02=RH01*P2/P1
RH03=RH01*P3/P1
*=1.75*I1.-E1>/E1*RH01/DP
B=150.*«1.-E1I/E1/DP)**2*NU
C=-DALP/L
UPWARD RELATIVE VELOCITY
IF (C .6T. 0.) VR=-(SORT(B**2*4.***C>-B)/2./A
IF (C .LE. 0.) VR=
-------
126*
127*
128*
129*
130*
131*
132*
133*
13**
135*
136*
137*
138*
139*
1*0*
1*1*
1*2*
1*3*
1***
1*5*
1*6*
1*7*
1*8*
1*9*
150*
151*
152*
153*
15**
155*
156*
157*
158*
159*
160*
161*
162*
163*
16**
165*
166*
167*
168*
169*
C
C
C
C
C
C
C
C
NOZZLE VELOCITY
V2=GA/RH02/S2* 60 TO 170
DILUTE PHASE VOIOA6E CORRELATION
E3-1 •-< !•-£! )«(RH02*V2*DP/MU)**(-.OH22H)»(TS/ < TON+TOFF-TNN ) )••
11-1. Itim*. 03759
IF (TNN «GE. TM) GO TO 170
)»/2./A.
IF 1C .ST. 0.) VRH=-(5QRT/2./4.
SOLUTION OF NOHENTUN BALANCE
VEC-1.
OGSP=0.
200 CONTINUE
6ROUPED KNOUNS IN BALANCES
K1=P3*S1-P1*S1«P1*S2-P2*S2-V2**2*S2*RHQ2«VEC*VR**2*S1*E1*RH01*
ISIN(AL)
K2=(S3*a.-E3>/«l.-ElM**2/Sl*SIN(AL)*fRHOP*(l.-Ell-VEC*RH01*Ell-
U1.-E3)*RHOP*S3
K3=S3*E3*RH03
K*=V2*S2*RH02-VR*El*RH01*Sl-VRH*EP*tSl-S3>*RH01
K*t=El*RH01*S3**S3*E1*RH01*SIN(AL>
A=K1*K5**2-K2*K***2-M*K5*K6
B=K 3*K **K 6-2 .*K 1 *K3*K 5
CrKl*K3**2*K3*K***2
QrB**2-*.*A*C
IF (Q .LT. O.I K=~B/2./A
IF 10 .LT. 0.) 60 TO 50C
ZKP=(-B+SQRT/2./A
K=ZKP
IF (ABSIZKP-.5) .6T. ABSIZKN-.5» K=ZKN
DILUTE PHASE 6AS AND SOLIDS VELOCITIES
500 V3=K*/(S3*E3*RH03-K*E1*RH01*S3*<1.-E3>/(1.-E1»
VS3=K*V3
-------
170*
171*
172*
173*
174*
175*
176*
177*
178*
179*
180*
181*
182*
183*
184*
185*
186*
187*
188*
189*
190*
191*
192*
193*
194*
Hi:
197*
198*
199*
200*
201*
202*
18?:
205*
206*
207*
208*
209*
210*
211*
212*
213*
C
C
C
C
C
C
C
C
E
C
IF IVS3 .LT. 9.1 VS3=0.
560 CONTINUE
DOWNWARD VELOCITY OF 6AS
V1=K*V3*«1.-E3)*S3/«1.-E1)/S1-VR
IF (VEC .LT. O.I 60 TO 502
CHECK ASSUMPTION THAT GAS NET FLOW IS UPWARD
IF NOTt CORRECT
IF (VI .LT. 0.) 60 TO 502
VEC=-1.
60 TO 200
502 CONTINUE
TOTAL AND HORIZONTAL 6AS MASS FLOW RATEtDURIN6 PULSE
WP=6A*CTON+TOFF)/TNN
WHrWP-(VR-VS3*S3*ll.-E3>/*El*RH01*Sl
DOWNWARD SOLIDS VELOCITY
VS1=VS3*I1.-E3>*S3/S1/U«-E1 )
PRESSURE FROH WEN AND SIMONS CORRELATION* PASCALS
= <2.*(1.~E3>*S3+(1.~E1)***.25*P3
IF
-------
*•
00
21%*
215*
216*
217*
218*
219*
220*
221*
222*
223*
229*
225*
226*
227*
22S*
229*
230*
231*
232*
233*
23%*
235*
236*
237*
238*
239*
2*0*
2*1*
2*2*
2*5*
247*
2*8*
250*
251*
252*
253*
25**
255*
C
C
C
50* CONTINUE
*50 CONTINUE
PREDICTED SOLIDS FLOW RITE
6SP=VS3*S3*I1.-E3>*RHOP*TS/ITON*TOFF)
IF UIH .EQ. 21 60 TO 506
CHECK TO SEE SOLIDS VELOCITY LESS THAN NOZZLE VELOCITY
505 IF (VS3 .LT. V2I 60 TO 506
LIH=1
E3=E3-.01
IF
1000 CONTINUE
2000 CONTINUE
CALL EXIT
END
-------
APPENDIX E
COMPARISON OF EXPERIMENTAL SOLIDS
TRANSFER RATES AND MODEL PREDICTIONS - 1978 TESTS
I 149
-------
Run
No.
On
Time,
s
COMPARISON OF EXPERIMENTAL AND PREDICTED SOLIDS FLOW RATES
Fluid-
Off izing AP
Time, Time, (Pi-P3> ej
1
2
3
»•
6
7
8
9
10
1 1
12
13
1H
15
16
17
IB
i9
20
21
22
2ti
29
30
31
32
33
3H
3S
36
37
38
39
Hfl
HI
H2
H3
HM
H5
. 10
. 10
.50
.50
.25
.25
1.00
1 .00
.75
• 7b
.10
.10
.05
.05
.50
.50
.20
.20
2.00
2.00
1.00
2.00
2.00
.50
.50
.20
.20
1.20
1.20
.10
.10
3.00
2.80
1 .00
1.00
1 .50
1.50
2.50
2.50
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2. HQ
2. HO
2.00
2.00
2.00
1 .85
2.00
2.00
2.00
2.00
2.00
2.00
.32
.32
• 3H
.3H
.33
.33
• 3H
• 3H
.3H
.3H
.32
.32
.31
.31
• 3H
• 3H
.33
.33
• 3H
.3H
• 3H
• 3H
• 3H
• 3H
• 3H
.33
.33
.3H
• 3H
.32
.32
.3H
.3H
• 3H
• 3H
.3H
• 3H
• 3H
.3H
kPa
3.29
3.HH
2.Q7
2.17
2.SH
2.H6
2.07
2.07
2.07
2.07
3.HH
3.23
H.f5
H.Q2
2.07
2.07
2.65
2.65
2.07
2.07
2.07
2.07
2.07
2.07
2.07
2.65
2.65
2.39
2.39
3.25
3.28
2.07
2*07
2.07
2.07
2.07
2.07
2.07
2.07
.HSO
.HH9
.HH9
.HH9
• HH8
• HH8
.HH7
.HH7
.HH7
• HH6
.HH6
• HH6
• HH5
• HH5
• HH5
• HH5
.HHH
.HHH
.HHH
• HH3
• HH3
• HH1
• HH1
• HHO
• HHO
• HHO
.H39
.139
• H39
• H38
• H38
• H38
.H37
• H37
.H37
• H36
.H36
• H36
.H35
E3
• 61 1
• 615
.815
• 815
.757
• 753
.813
.811
• B1H
• 812
.611
• 60H
• HH7
• HH5
.815
• 815
• 72H
• 72H
• 809
.808
• 812
• 809
.808
.813
• 81H
.720
• 721
• 7H6
• 7H7
• 600
• 600
.807
.828
• 811
• 809
• 808
• 809
.808
• 806
Measured
Solids
Flow.
kg/s
1.56
2.6Q
3.H5
2. HI
1.57
2.39
2.17
2.57
2.03
2.62
2.75
2. HI
2.76
1.83
2.02
1.H5
2.55
1.57
3. OH
1.92
2.39
1.85
2. OH
3.1H
2.82
3.H6
2.52
2.18
2.58
2.61
2.38
1.81
1.15
2.1H
2.76
3.19
1.98
2.15
2.28
Predicted
Solids
Flow,
kg/s
2.29
2.5H
3.00
3.11
3.H2
3.16
2. Ha
2.H6
2.73
2.70
2.55
2.19
2.05
1.62
3.02
3.02
2.97
2.99
1.84
1 . 8H
2.H7
1.85
1.85
3.02
3.03
2.98
2.99
2.52
2.52
2.22
2.27
1.H8
1.51
2.H9
2.H8
2.12
2.13
1.65
1.65
-------
COMPARISON OF EXPERIMENTAL AND PREDICTED SOLIDS FLOW RATES
Run
No.
On
Time,
8
Off
Time,
8
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
6H
65
66
67
68
69
70
71
72
73
7*4
75
76
77
78
79
80
81
B2
83
8H
B5
86
87
88
89
90
4.00 2
4.00 J
1.00
1 tOO
2.UO
2.00
.50
.bU
3.00
3.00
.20
.20
1 .50
1.50
.10
. 10
2.50
2.50
.75
.75
H.OO
4.00
.50
.50
1.00
1.00
.20
.20
1 .50
1 .50
.20
.20
2.00
2.00
.10
.10
3. 10
3. 10
.HO
.HO
.20
.20
. BU
.80
2.00
!.00
!.OQ
.00
.00
.00
.00
.00
.00
.00
.00
• 00
.00
.00
.00
.00
.00
.00
.00
• 00
.00
.00
.00
.5Q
.50
.50
• so
.50
.50
.50
.50
.50
.50
.50
.50
.50
.50
.50
.50
.50
.50
3.00
3.00
3.0.0
3.00
3.00
Fluid-
izing
Tine,
s
.3H
.35
.27
.28
.32
.31
.27
.27
.33
.32
.28
.28
• 31
.29
.33
.33
.33
.31
.27
.28
.33
.32
.35
.35
.35
.35
.34
,3H
.35
.35
.3H
• 3H
.35
.35
.33
.33
.35
.35
.35
.35
.33
.33
.34
• 3H
.34
AP
(Pl-P3)
kPa
2.07
2.07
.92
1 .03
1 .20
.23
.98
.98
1 .36
.18
.47
.48
.22
02
1
2.51
2.53
.34
.24
.97
.96
1 .38
1.30
1.84
1.83
1.81
t.82
2,46
2.47
1.81
1.81
2.45
2.45
1 .81
1.81
2.98
2.98
1.81
1.81
1.84
1.84
3.00
2.98
2.79
2.79
2.79
.435
.435
.696
.656
.556
.596
.696
.695
.525
.565
.6H1
• 6H1
.595
.6HH
.H55
.455
• 53H
• 58H
• 69H
.673
• 513
.553
.428
.428
.427
.427
.427
.426
.426
.426
.425
.425
.425
.424
.424
.424
.423
.423
.423
.423
.422
.422
.422
.421
.421
• 80S
• 806
.946
.944
.938
.939
.947
.947
• 935
• 938
• 875
• 876
.939
.943
• 726
.727
.936
.939
• 946
• 945
• 935
.937
.878
.877
• 875
.753
.753
• 874
.875
.752
• 751
• 873
.874
.644
.644
.873
.873
.878
.878
.644
• 643
• 640
.642
.635
Measured
Solids
Flow,
kg/a
1.51
1.13
.06
1.27
2.05
.21
.14
1 .13
1.88
.88
2.B7
3.11
1.79
.31
2.75
3.06
1 .84
.33
.00
2.32
1.27
.45
2.90
2.73
3.12
2.T4
2.72
2.97
2.23
2.27
4.08
3.06
2. 14
2.36
3.40
3.12
1.50
1.76
2.99
3.25
3.73
2.63
2.53
3.28
2.18
Predicted
Solids
Flow~
kg/ s
1.24
1.24
J.U7
1.20
1.00
.95
1.53
1.52
.83
.73
2.77
2.84
1.15
.98
2.81
2.85
.93
.84
1 .27
1.29
.68
.62
2.96
2.93
2.3Q
2.31
3.40
3.4H
1.91
1.92
3.37
3.37
1 ,6H
1.64
2.bH
2.52
1.25
1.25
3.14
3.15
2.ba
2.54
3.U9
3.11
2.34
-------
COMPARISON OF EXPERIMENTAL AND PREDICTED SOLIDS FLOW RATES
In
ro
Run
No.
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
1 10
1 1 1
1 12
1 13
1 14
1 IS
1 16
1 17
1 18
1 19
120
121
122
123
124
125
126
127
128
129
130
131
132
135
On
Time,
8
2*00
.40
.40
1 .00
1.00
.60
.60
1 .SO
l.SO
.40
.40
.40
• 40
.40
.40
.40
.40
.40
.40
.40
.40
.10
. 10
.20
.20
.20
.20
.20
.20
.20
.20
.20
.20
.20
.20
.20
.20
.10
• 10
• 0
. 0
. 0
. 0
. 0
. 0
Off
Time,
s
3.00
2*90
2.90
3.00
3.00
2.90
2.90
3.10
3. 10
.50
.50
.60
.60
.00
.00
.80
.80
.40
.40
.20
.20
.50
.50
.50
.50
.60
.60
.20
.20
.00
.00
.80
.80
.40
.40
.80
.80
.90
.90
.80
.80
.70
• 70
.60
.60
Fluid-
izing
Time
S
.34
.34
.34
.34
.34
.34
.34
.34
.34
.05
.05
.35
.35
.27
.27
.35
.35
.35
.35
.32
.32
.11
.1 1
.18
.05
.34
.34
.34
.34
.29
.28
.21
.21
.34
.34
.34
.34
.30
.30
.25
.25
.19
.19
.1 1
.11
AP
(Pl-P3>
kPa
2.79
2.74
2.76
2.79
2*78
2.72
2.73
2.85
2.86
.09
.09
1.91
1.91
.99
.99
2.07
2.07
1.77
1.77
1.36
1.37
.35
.35
.46
.00
2.51
2.52
2.31
2.31
1.49
1.51
.77
.77
2.43
2.43
2.60
2.60
1.92
1.95
1.36
1.33
.79
• 84
.33
.37
el
.421
.420
.420
.420
.419
.419
.419
.418
.418
.990
.990
.417
.417
.687
.687
.416
.415
.422
.421
.553
.553
.950
.950
.870
.990
.412
.412
.421
.421
.625
.625
.812
.812
.410
.410
.409
.409
.575
.575
.714
.713
.842
.842
.947
.947
E3
.633
.663
.665
.640
.638
.660
.662
.617
.613
• 993
• 993
• 865
.865
• 946
.946
• 838
• 838
• 890
• 890
• 920
• 921
.983
.983
.985
.993
.737
• 738
.777
.777
• 869
• 870
.942
.942
.753
.754
.719
.719
.799
.800
.874
.873
.935
• 936
.980
.980
Measured
Solids
Flow,
kg/ s
r.98
2.43
2.62
3.43
2.94
3.18
3.87
2.24
2. 10
.34
.00
5.44
3.83
.77
.52
4.88
4.16
3.38
4.03
1.84
2.78
.57
.92
.00
• 00
4.85
4.33
4.09
5.87
5.13
3*89
1.29
.53
4,90
4.08
3.77
4.57
4.32
3.36
3.46
2.68
2.75
1.89
.57
.91
Predicted
Solids
Flow,
kg/ a
2.34
3.5U
3.57
2.95
2.94
3.26
3.3Q
2(64
2.64
.01
.01
3.25
3.24
1.74
1.76
3.34
3.32
3.14
3.15
2.41
2.44
.89
.88
J9S
.03
3.38
3.4l
3.78
3.78
2,86
2.96
1.95
1.96
3.58
3.59
3.24
3.25
2.5Q
2.59
2.18
2.05
1.42
1 .69
.90
.81
-------
COMPARISON OF EXPERIMENTAL AND PREDICTED SOLIDS FLOW RATES
Run
No.
On
Time,
s
Off
Time,
s
136
137
138
139
1MO
m
1M2
1«»3
1MM
IMS
1M6
1M7
118
1M9
150
151
1S2
153
15«4
155
156
157
1S8
15,9
160
161
162
163
16H
165
167
168
170
171
172
173
I7H
176
176
177
178
179
IfaO
1 .00
1.00
1.00
• MO
.MO
.20
.20
.60
.60
1 .00
1.00
.MO
• MO
.MU
• MO
.20
.20
.20
.20
.20
.20
.10
. 10
. 10
. 10
\ .00
1 .00
1 .00
1 .00
.MO
.MO
• MO
.MO
.MO
.MO
.MO
.MO
.MO
• MO
• MO
.MU
.MU
.MU
.00
.00
.80
.80
.80
• SO
.BO
.70
.70
.00
.00
.60
• 6Q
• MO
.MO
.Mu
.MO
.00
.00
.80
.80
.00
.00
.80
.80
2.00
2.0U
1 .60
1 .60
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.0Q
2.00
2.00
mid-
Lzing
:ime
S
.28
.28
.35
.35
.35
• 3M
• 3M
• 3M
• 3M
• 3M
.3M
.35
.35
.36
.36
.3M
• 3M
.28
.29
.21
.21
.33
.33
.25
.2M
.36
.36
.36
.36
.35
.35
.35
.35
.36
.36
.36
.36
.36
.36
.36
• 36
.36
.36
AP
(Pl-P3)
kPa
.96
• 96
2.07
2.17
2.07
2.71
2.68
2.69
2.6M
2.79
2*83
2.07
2.07
1 .8M
1 .90
2.69
2.63
1 .68
1 .6M
.87
.89
3.02
2*88
1.5M
1.65
2.07
2.07
1.93
1.90
2.32
2.31
2.3M
2.30
2.17
2.18
2.07
2.07
2.07
2.07
2.07
2.07
2.20
2. 17
el
.681
.681
.MOB
.M05
• M05
• MOM
.MOM
.MOM
• M03
• M03
• M03
• M02
• M02
• M09
.M08
• M01
.M01
.618
.617
.809
.809
• M2M
.M21
.710
.716
.398
.398
.397
.397
.397
.396
.396
.395
.395
.394
.39M
.39M
.393
.393
.393
.392
.392
.392
£3
• 9MB
• 9M5
• 83B
• 8MO
• 8M1
• 750
.7M9
• 701
• 699
• 6M3
• 6M5
.866
.865
.891
• 891
.758
.756
.871
• 870
• 9M2
• 9M3
• 722
.718
.875
.879
.810
.810
• 86M
• 86M
• 81 1
• 81 1
.81 1
.811
.809
.809
.809
.808
.808
.809
.810
• 81 1
.810
.810
Measured
Solids
Flow,
kg/s
1.50
1*22
3. Mb
5.66
6.55
6.7M
5.53
3.87
M.8Q
2.38
2.23
3.1 6
5.05
3.35
M.65
5.b2
7.65
M.09
3.65
3.02
1 *M6
M.35
3.91
.00
• UO
2.71
1 .20
M.16
1 .81
b.32
M.52
3.09
M.65
5.37
M.30
3.5Q
3.93
3.7M
2.61
3.92
M.B6
M.57
3.89
Predicted
Solids
Flow,
kg/s
1.1M
1.12
2.58
3.87
3.67
M.30
M.21
3. 60
3.M6
3«U7
3.16
3.69
3.7Q
3.52
3.78
M.SH
M.3H
3.81
3. 6*4
2.63
2.79
M.38
3.9Q
2.9
-------
COMPARISON OF EXPERIMENTAL AND PREDICTED SOLIDS FLOW RATES
tn
Run
No.
181
182
183
18<4
165
186
187
188
189
190
191
192
193
19M
19*
19ft
1 97
198
199
200
201
202
203
20H
205
206
207
208
209
210
21 1
212
213
21H
215
216
217
218
219
220
221
222
223
22*4
On Off
Time, Time,
8 3
•HO 2.00
•MO 2.00
•HO 2*00
•HO 2.00
•HO 2.00
.HO 2.00
•20 1.20
.2U
.20
• 20
.20
• 20
.20
.20
.20
.20
• HO
• HO
.HO
• HO
.HO
• HO
• HO
• HO
• HO
• HO
.20
. 2U
.20
.20
.20
.20
.20
.20
.20
• 80
.80
.80
.80
.60
.60
.HO
• HO
• 20
• 20
.HO 2*00
•HO 2.00
•HO 2.00
•HO 2.00
•HO 2.00
•HO 2*00
•HO .80
•HO .80
•HO .60
.HO .60
•HO .HO
•HO .HO
•HO .20
.HO .20
•HO .00
•HO .00
.20 .00
•20 .00
Fluid-
izing
Time,
s
.36
.36
.36
.36
.36
.36
• 3H
• 3b
• 3H
.35
.3H
• 3H
• 3H
• 3H
• 3H
• 3H
.36
• 36
.36
.36
.36
.36
.36
.37
.33
.33
.36
.36
.36
.36
.36
.36
.36
.36
.37
.37
.37
.37
.33
.33
.28
.28
.30
.30
AP
(PI-PS)
kPa
2.07
2.07
2.07
2.07
2.07
2.07
2.28
2.28
2.29
2.29
2.30
2.31
2.35
2.33
2.39
2. HO
2.07
2.07
2.06
2.06
• 8H
• 85
.71
• 70
.31
• 31
2.07
2.07
2.07
2.07
2.07
2.07
2.06
2.06
.85
• BH
.71
.71
.31
.31
.9H
.95
• H6
• H6
El
—
.391
.391
.391
.390
• 39U
.390
.392
.391
.391
.391
.390
.390
.390
.390
.390
.390
• 386
.386
.386
.385
.385
.385
.391
.391
• 530
.530
.383
.383
.382
.382
.382
.381
.381
.381
.380
.380
.387
.386
.527
.526
.667
• 667
.597
.596
£3
.807
.807
• 808
• 807
• 805
.802
.752
• 755
.760
.759
.761
.762
.765
• 76H
.767
.767
.833
.832
• 832
• 831
• 859
.860
.885
.865
.917
.917
.805
• 80H
• 807
• 806
.806
• 80H
.832
.832
• 861
• 860
• 886
.886
.917
.917
• 9H3
• 9HH
.856
.855
Measured
Solids
Flow,
kg/s
3.98
3.53
3.33
3.23
1.92
1 .08
2.37
1.12
3.75
2.90
5. HI
2.99
5.80
5.07
5.09
5. 10
H.59
3.53
2.55
3.H9
2.39
2.63
2.71
2.53
2.87
1.8H
2.73
1.89
3.87
2.90
3.06
3.36
3.63
3.20
3.57
2.66
1.90
2.37
3.1H
2.38
1.32
3.00
3.57
3.07
Predicted
Solids
Flow,
kg/s
3.32
3?32
3.37
3.3H
3.29
3.27
3.66
3.66
3.72
3.70
3.77
3.78
3.9H
3.89
H.ll
H.15
3.3&
3.35
3.32
3.32
3.18
3.20
3.08
3.08
2.3H
2.35
3.32
3.31
3. 36
3.36
3.36
3.33
3.35
3.36
3.25
3.22
3.12
3.1H
2.38
2.37
1.61
1 .68
2.77
2.77
-------
COMPARISON OF EXPERIMENTAL AND PREDICTED SOLIDS FLOW RATES
Run
No.
in
On
Time,
s
225
226
227
228
229
230
231
232
233
23H
235
236
237
238
239
2HO
2H1
2H2
2H3
2H«4
2H5
2<46
2H7
2<4B
2H9
250
251
252
253
25M
255
256
257
256
259
260
.20 .80
.20 .80
.20 .60
.20 .60
.20 l.HO
.20 I.HQ
.20 1 .80
.20 1.8Q
•00 2.00
•00 2.00
.00 1.8Q
•00 1 .80
.00 1.60
•00 1.60
1.00 l.HO
1.00 l.HO
.HU 2.00
•HO 2.00
.HO 2.00
•HO 2.00
• HO
.HO
.HO
• MO
.HU
• HO
.HO
.HO
1 .00
1.00
1 .00
1 .00
1 .00
1 .00
1 .00
1 .00
.80
• uo
• HO
• HQ
.20
.20
.00
.00
.00
.00
.60
• 60
.20
.20
.HO
.HO
)ff
[line,
8
.80
• 8Q
.60
.60
l.HO
I. HQ
1 .80
1.80
2.00
2.00
1 .80
1.8Q
1.60
1 .60
1 .HO
1 .HO
2.00
2.00
2.00
2.00
.80
• UO
• HO
.HO
.20
.20
.00
.00
.00
.00
.60
.60
.20
.20
.HO
.HO
Fluid-
izing
Time,
8
.22
.22
.17
.19
.36
.36
.35
• 3B
.36
.36
.37
.37
.37
.37
.37
.37
.36
.36
• 36
.36
.36
.37
.37
.37
.33
.33
.28
.28
.36
.36
.37
.37
.33
.33
.37
.37
AP
(Pl-P3)
kPa
.77
.77
.3b
.38
2.37
2.37
2.52
2.52
2.07
2.07
.95
.95
.83
.83
.69
.69
2.07
2.07
2.07
2.07
2.06
.96
.70
.70
.31
.31
.95
• 9<<
2.07
2.07
1 .82
.82
.30
.29
• 6B
.68
el
.799
.799
.888
.858
.376
.376
.375
.375
.375
.37H
.37H
.37H
.373
.373
.380
.379
.372
.372
.371
.371
.371
.370
.377
.377
.519
.519
.662
.661
.368
.368
.368
.367
.517
.517
.373
.373
.937
.936
.982
.980
.732
.733
.695
.69H
.798
.801
• 830
• 828
.856
.857
• 88H
.882
.802
• 802
• BOH
• 805
• 832
.832
.886
.886
.917
.918
.9HH
.800
.799
.857
.858
.916
• 916
.883
.88*4
Measured
Solids
Flow,
kg/s
1.H5
2.70
.39
1 .02
2.70
3.H6
3.01
2.57
2.28
2.52
2.62
2.81
2.76
2.60
2.U5
1 .68
1.22
1 .88
2*71
3.HH
3.20
H.38
3.25
3.26
2.85
2.66
1 .89
2.68
2./I
3.18
3.50
2.8U
.H7
2.66
2.62
3.00
Predicted
Solids
Flow,
kg/s
1.76
1.73
.79
.89
3.51
3.52
3.12
3.12
2.66
2.66
2.57
2.57
2.H6
2.M7
2.33
2.32
3.35
3.35
3.HO
3.H2
3.H2
3.3H
3.17
3.17
2.H3
2.H5
1.70
1.70
2.69
2.68
2.M8
2.H9
1.73
1.72
2.3
-------
COMPARISON OF EXPERIMENTAL AND PREDICTED SOLIDS FLOW RATES
Run
No.
261
262
263
26
-------
TECHNICAL REPORT DATA
(Please read Inunctions on the reverse before completing)
1. REPORT NO.
EPA-600/7-79-021
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Solids Transport Between Adjacent CAFB
Fluidized Beds
5. REPORT DATE
January 1979
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
D. M. Bachovchin, P.R. Mulik, R.A.Newby, and
D. L.Keairns
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Westinghouse Research and Development Center
Pittsburgh, Pennsylvania 15235
10. PROGRAM ELEMENT NO.
EHE623A
11. CONTRACT/GRANT NO.
68-02-2142
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 7/75 - 8/78
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES jERL-RTP project officer is Samuel L. Rakes, MD-61, 919/541-
2825.
is. ABSTRACT Tne repOrj gives results of an experimental investigation of a pulsed,
dense-phase pneumatic transport system for controlled circulation between adjacent
fluidized beds. A model was developed to predict performance. The program pro-
vides technical support for EPA's program to demonstrate the Chemically Active
Fluid Bed (CAFB) Process, being developed to produce a clean, low heating value
fuel gas from fossil fuels. A cold model test facility, capable of transporting up to
about 6.3 kg/s, was built and operated to demonstrate effects of key parameters.
Generated data were utilized in the development of a mathematical model of the sys-
tem which allows projection of the effects of key variables. Solids flow is controlled
by pulsed air input, whose on-time «0.3 to 0.4 s) and off-time (1. 5 to 2.0 s)
should be controlled for best performance. The system pressure balance should also
be carefully controlled. Expected demonstration plant bed-material density may
result in higher air requirements than was predicted in the plant design. Wider legs
and more nozzles or greater transport-gas capacity may alleviate this difficulty.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Pollution
Fluidized Bed Processors
Solids Flow
Gasification
Fossil Fuels
Mathematical Models
Pollution Control
Stationary Sources
Chemically Active Fluid
Beds
13B
131,07A
20D
13H
21D
12A
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report)
Unclassified
1.NO. OF PAGES
173
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (t-73)
57
------- |