EPA-600/2-77-103
June 1977
Environmental Protection Technology Series
A METHOD OF MANURE DISPOSAL FOR
A BEEF PACKING OPERATION
First Interim Technical Report
Environmental Research laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati. Ohio 45288
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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 ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-77-103
June 1977
A MEI'HOD OF MANURE DISPOSAL
FOR A BEEF PACKING OPERATIOO
First Interim Teclmical Report
by
Roy Ricci
Procedyne Corporation
New Brunswick, ID 08903
;project 12060 OOF
Project Officer
Jack L. WitherCM
Industrial Pollution Control Division
Industrial EnvirOl1IreI1t Research Laboratory
Corvallis, Oregon 97330
INDUSTRIAL ENVIOONMENI'AL RESFAlOI LABORATORY
OFFICE OF RESE'AICH AND DEVEI.DPMENI'
U. S. 'ENVIOONMENl'AL ProrECI'ION AGENCY
CIOCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental
Research Laboratory-Cincinnati, U.S. Environmental Protection Agency,
and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the U.S.
Environmental Protection Agency, nor does mention of trade names
or commercial products constitute endorsement or recommendation for
use.
ii
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FOREW)RD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our envirorment and even on our
health often require that new and increasingly IIDre efficient pollution con-
trol methods be used. The Industrial Envirormental Research Laboratory -
Cincinnati (IERL-CI) assists in developing and denunstrating new and lirproved
methodologies that will meet these needs both efficiently and econanically.
"A Method of Manure Disposal For a Beef Packing Operation" contains
bench and pilot scale studies, process calculations, and process design to
dewater and incinerate paunch manure fran a beef slaughtering operation.
For additional infonnation, please contact the Focx:1 and Wood Products Branch
of the Industrial Envirormental Research Laboratory, Ci (IERL-Ci).
David G. Stephan
Director
Industrial Envirormental Research Laboratory
Cincinnati
i ; ;
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ABSTRACT
This report contains the preliminary studies, process development,
process calculations, and process design for a system to successfully
handle the paunch manure in a beef slaughtering operation.
These studies resulted in a system in which the paunch manure is
collected from the slaughtering operation and is fed to a screening
device which separates the coarse solids. The screenings are dewatered
to a solids content of 37 percent. This dewatered material is then
sent to a fluid bed incinerator via a screw conveyor. The liquid stream
from the screening is fed to a settler and is combined with the liquid
stream from the dewaterer prior to sand filtering. The filter cake is
fed to the incinerator using a screw conveyor. The filtrate is recycled
back to the settler.
Work was completed as of February 1971.
iv
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Foreword
Abstract
Tables.
Figures
CONTENTS
Page No.
. . . . . . . . . . . . . . . . . . . . . . iii
. . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
. . . . . . . . . . . . . . . . . . . . . . . . . Vl
. . . . . . . . . . . . . . . . . .'. . . . . . . . . .vii
1.
2.
Introduction. . . . . . . . . . . . . . . . . . . . . . 1
Preliminary Studies. . . . . . . . . . . . . . . 4
Paunch Manure Characteristics . . . . 4
Present Disposal System. . . . . . . . . . . . . 5
Paunch Manure Filtration Studies . . . . . . 10
Process Development. . . . . . . . . . . . . . . . . . 16
Dewatering. . . . . . . . . . . . . . . . . . . . 16
Filtration. . . . . . . . . . . . . . . . . . . . 20
Sedimentation. . . . . . . . . . . . . . . 21
Incineration. . . . . . . . . . . . . . . . . . . 28
Process Calculations. . . . . . . . . . . . . . . . . . 37
Paunch Table. . . . . . . . . . . . . . . . . . . 37
Paunch Bin. . . . . . . . . . . . . . . . . 39
Primary Dewaterer . . . . . . . . . . . . . . . . 40
Dewaterer . . . . . . . . . . . . . . . . . . . . 41
Settler and Filter. . . . . . . . . . . . . 42
Incinerator. . . . . . . . . . . . . . . . . . . 43
Material and Heat Balance . . . . . . . . . 43
Fuel and Air. . . . . . . . . . . . . . . . . . . 47
Cyclone. . . . . . . . . . . . . . . 50
Scrubber. . . . . . . . . . . . . . . . . . . . . 50
Economics of an Air Preheater . . . . . . . . . . 52
Economics of a Waste Heat Boiler . . . . . . 55
Summary of the Process Design. . . . . . . . . . . . . 58
Description of the Process. . . . . . . . . . . . 58
Equipment List. . . . . . . . . . . . . . . . . . 59
Conclusion. . . . . . . . . . . . . . . . . . . . 62
3.
4.
5.
6.
References. . . . . .
. . . .
. . 63
. . . . .
. . . . . . .
v
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Nurrber
I.
II.
III.
IV.
v.
VI.
LIST OF TABLES
Paunch Solids Concentration
.... ... ... ..............
Paunch Waste Stream Characteristics
................
Filtration Test Results
. ... ......... ... ...... .....
Conditions and Results of Filtration
ExJ?eri1rer1ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Paunch Manure Incineration Experi1rer1ts
............
Feed to Incineration ExJ?eri1rer1ts
..................
vi
Page
5
10
14
23
32
32
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LIST OF FIGURES
Figure No. Title Page No.
1 Paunch Manure Disposal Process 2
2 Paunch Processing Area - Illinois Packing 6
Corrpany
3 Present Paunch Manure Handling Operation 7
4 Paunch Processing Area - Illinois Packing 8
Company
5 M3.terial Balance for Paunch Wash Operation 9
6 Filtration Through Sand and Manure in 11
Layers
7 Filtration Through Sand and Manure Mixture 12
8 Regenerating Filter 22
9 Graph of % Solids to Settler vs. % of Layer 24
Split
10 Graph of & Solids to Settler vs. % Solid 25
Split into Layers
11 Graph of % Solids to Settler vs. % Layer 26
Split
12 Graph of % Solids to Settler vs. % So1ids 27
inLayer
13 Conceptual Drawing-Procedyne Fluid Bed 29
Reactor
14 Process Schematic for pilot Plant Incinerator 31
15 Preheater Terrperature Profiles 15
16 Process Flavsheet (Procedyne Corp. IMg. 60
D-05l49)
17 M3.terial Balance (procedyne Corp. IMg. 61
D-05l4l)
vii
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SECI'ION I
INTRODUCI'ION
The objective of this project is to develop, design, install and
dem::>nstrate a fluidized bed incineration system for the efficient dis-
posal of paunch manure waste generated in beef packing operations.
The process, shown schematically in Figure 1, is being engineered and
fabricated by Procedyne Corporation for installation at the Illinois
Packing Co., Chicago, Ill.
Paunch Mmure is partially digested feed material rerroved fran
the stomach of cattle during preParation for market. It is the only
major portion of the animal with no practical ccmrercial value. Dis-
posal is costly -- approximately $12/ton when hauled fran the pre-
mises for dumping. In addition, a significant portion of the solid
waste is disposed as sewage and adds a substantial burden to munici-
pal sewage disposal facifities.
The USDA statistical report on comrercial slaughter for the
United States indicates that a total of 35,026,400 head were slaugh-
tered in 1968. When related to the paunch manure disposal problem of
approximately 50 lbs/stock (including sack waters), it is seen that
1,751,320,000 lbs. of waste that must sarehow be disposed at minimal
cost and with maximum consideration to the reduction of the pollution
problems resulting from present disposal practice. The same statisti-
cal data indicates that the 1968 slaughter for the state of Illinois
was 1,407,000 head; thus 70,350,000 pounds of paunch manure.
Paunch manure is untreatable in conventional sewage treatIrent
plants (1) for the following reasons:
1.
2.
It has a very high biochemical oxygen demand.
Its high solids content tends to mat into wasses
which clog bar screens.
It settles out in conventional tanks and in time
hardens to the consistency of low density rock.
It clogs hopper bottans, pits and Pump suctions.
It sets up like concrete in pipe lines, requiring
augering for rerroval.
The cellulose material will not decanpose in digesters
and fo:rms straw blankets which clog and eventually
fill digesters.
The entrapped rroisture in the cellular material can not
be dewatered by vacuum filters.
The material has an objectionable odor which rapidly
decanposes into an intolerable stench.
Because of its cellular type rroisture it cannot be dried
in a flash dryer nor can it be burned in suspension.
3.
4.
5.
6.
7.
8.
9.
For these major reasons and many minor ones, no canmunity treats paunch
1
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PAl:JI.'\CH WASH
WASTE STREAM
PRIMARY
SCREEN
N
COARSE SOLIDS
'IO SEWER
FINE
SOLIDS
PRIMARY
DEWATERING
CLARIFIER
SAND
FILTER
Figure 1.
Paunch Manure disposal process.
GAS
CLEANrnG
STACK
FLUID
BED
INCINERATOR
AIR
FUEL
-------
m:mure in sewage treabrent plants but disposes of it separately, usual-
ly by land fill.
The research and develor:rnent activities described in this report
have culminated in a final process design which is currently being en-
gineered for construction. A surrmary of the process design is present-
ed in the last section of this report, Section V.
3
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SECI'ION II
PRELIMINARY STUDIES
PAUNCH MANURE CHARACI'ERISTICS
The quantity and physical-chemical COIIq?Osition of paunch manure
are dependent upon the caTIpOsition of the animal feed and the environ-
ment in which the animals are held during the processing period. Due
to this fact, it is difficult to relate existing literature data to the
present problem. Furtherrrore, data obtained in the past do not accurate-
ly reflect present conditions because of changing feed practices (2).
Physical and chemical data as required for the present process develop-
ment were obtained as presented in this section.
The quantity of paunch manure was established in terms of pounds
of wet paunch waste per animal. A m:nnber of measurements on fresh
paunch sacks shows that the average weight of the paunch contents is
approximately 55 lbs /anima.l. That number compares to the typical
value of 50 lbs/anima.l reported in the literature.
Simultaneous research conducted by the Federal Water Quality Of-
fice Fobert S. Kerr Research Center produced physical and chemical data
on dried paunch material. BOD analysis on the material established the
ultimate first stage BOD of the soluble material to be 84,000 mg/l of
paunch content and that of the nonsoluble fraction to be 24,000 mg/l of
paunch content. These data suggest that approximately 80% of the total
BOD in a paunch wash stream will be in the form of dissolved paunch
solids. Corrposi tion of the dried paunch material was reported as
follows:
Lehydrated paunch
Average % of 10 samples
fuisture
Protein
Ash
Fat
Calcium
PO
~ae Fiber
Carbohydrates
15.3
10.3
6.7
4.4
0.5
1.4
21.2
42.0**
** Calculated by subtracting the total percentage of TIDisture, pro-
tein, ash, fat, and crude fiber fran 100%. For purposes of material
balance calculations. the combustible fraction of the paunch material
was assurred to be cellulose with the TIDlecular formula (C6H 05).
In order to establish data for heat balance calculations, c120rimetric
measurements on dried paunch material were made with Parr Oxygen Bcmb
Calorimeter. Data on two samples produced heat of combustion, H,
values of 3890 and 4120 Cal/gm for an average value of approximately
4000 cal/gm or 7200 Btu/lb.
4
-------
The data presented above adequately establish the chemical and
thenrodynamic properties of the paunch material required for process
design purposes. Physical and chemical characteristics pertinent to
the paunch disposal operation and unit operations in the disposal sy-
stem under design are presented in sections which follow.
PRESENI' DISPOSAL SYSTEM
In the present paunch handling system the unbroken paunch sacks
are conveyed to a table where they are carefully washed and anyex-
cess fat is manually trinmed before emptying as shown in Figure 2.
'Ihe empty paunch sacks are then throughly washed and sent on for pack-
aging. All three streams, the paunch sack preliminary wash, the palIDch
manure slurry, and the paunch final wash are caTIbined and fed through a
trough to one of two palIDch manure drain bins as shown in Figure 3.
The'solids content of that manure slurry has been estimated to be 5%
solids by weight.
. The palIDch manure is settled periodical 1 y in each of the drain bins
during the day shift by alternating the feed between the two bins. 'Ihe
bins are unloaded ea::h evening into a disposal truck which carts the ma-
terial to a fann outside of the City of Chicago to be discharged at a
rate of approximately 50-60 gpTl into a plant sanitary sewer line which
runs from the plant to a Chicago municiPal sewer line and then to the
Chicago Sanitary District Treatment Plant.
Several field studies were made of the operation of the palIDch
table under actual operating conditions. Flawrates of water were
rreasured and these are shown in Figure 4. Original estimates of paunch
manure weights were checked and it was fOlIDd that the contents of 14
sacks weighed an average of 55 lbs. each. Taking the stated maximum
capacity at the palIDch table of 95 sacksjhour, the material balance at
the table can be surmarized in the follCMing block diagram Figure 5.
The concentration of solids in paunch manure was determined at
random intervals throughout the preconstruction study period. Exam-
ples of results of these laboratory tests are presented in Table 1.
TABLE I. PAUNCH SOLIDS CONCENTRATION
Sample Number Date
1
Paunch & Fluid 1/30/70
2
PalIDch 6/15/70
3
PalIDch 10/13/70
4
PalIDch 10/22/70
5
% Total Solids
14
17.0
18.5
18.4
-------
Constant Water Flow
Water Line
(not in 1.1Se)
o
~ ,
~
o
o
r-i
tLt
E J
:1
+J
='
.J ti ~~
Paunch
Viscera
"Water Flow Can Be Reversed
. Paunch is Cut Open
~ Water from Drain Bins
Figure 2.
Paunch processing area, Illinois Packing Co.
-------
Preliminary
Paunch Wash
'-J
Bin Unload-
ing l)(:x)rs
Paunch
~\ T
Figure 3.
Screens
1'1
J
to Sanitary Sewer
Water + dissolved solids + suspended solids
Present Paunch Manure Handling Operation.
-------
1215 GPH
12.79 ga1./cow
Constant Water Flow
Paunch is
Laid Here
a:ld Scraped
Clean
co
possible
Separate
Drain Line
"",I
.~ I
el
~~ ~I
~~I
.Q
.~ I
(IJ
01
p...
I
1274 GPH
12.10 ga1./cow
Constant Water Flow
Water Lines
(not in use)
1156 GPH: 12.17 gal/cow
Water for Table }
~~
Paunch
Paunch Wash
p.aunch is
EffiP7d
ff
To Trough and Drain Bins
Figure 4.
Sluice
Q)
:>
o
.Q
~
"'"
o
o
.....c
~
e
o
"'"
~
Q)
+J
=='
.c::
u
~
Viscera
. Wa ter Flow can be Revisl~d
Paunch is Cut Open
~ Water from Drain Bins
Paunch processing area, Illinois Packing Co.
-------
Table water 1156 GPH
Paunch Wash 1264 GPH
Sack Rinse 1212 GPH
\D
Figure 5.
Table Area
To Paunch Tank
5230 #/hr. in 3632 gals./hr. H20
Paunch
55 Jbs./sack X 95 sacks/hr.
= 5230 Jbs./hr.
Material Balance For Paunch Wash Operation.
-------
The first result represents a sample of manure and sack fluids, the
others a sample of free drained paunch manure. San'ples of the waste
paunch stream running to the sewer were taken rronthly by Illinois
Packing persormel during the four rronth period - April to July 1970~
and these samples were sent to Pollution Control laboratories Inc.
Chicago, Ill. Resul ts obtained are s~ in Table II.
TABLE IL PAUNCH WASTE STREAMS CHARACrERISTICS
Date (1970)
Parameter April 1 May 2 June 3 July 4
BOD (nq/l) 8,353 5,693 2,990 10,500
COD (nq/l) 16,334 7,108 11,178 12,534
00 (nq/l) 0.1 0.1 0.1 0.1
Total Solid
(nq/l) 18,064 8,274 4,244 2,361
pH 7.40 7.25 6.20 6.55
Nitragen,
Kjedha1 (rng/l) 238 463 259 291
Except for supplying data regarding ranges of efficient con-
centrations, the above information was of little value in further de-
fining plant design parameters. Because of the fluctuating stream
concentration found, no further sampling was deemed useful at the tine.
A scheduled, periodic sampling program will be initiated six to eight
weeks prior to the disposal plant start-up in order to establish base
line rreasurements for system evaluation PUrPOses.
PAUNCH MANURE FTI..TRATION STUDIES
The first experirrents with the filtration of paunch manure and
water mixtures were made to develop compressibility data for paunch
manure on sand beds using classical techniques (3). 'Ihese involve a
detennination of filtration rate, filtration volume, and pressure
drop, and then calculating specific cake resistance at several levels
of pressure. 'Ihe log of cake resistance is plotted against log of P. i
the slope of the curve is designated as the compressibility S of the
cake. For paunch manure, which produced a mat-like cake because of the
presence of many straw like particles, the compressibility S, was
found to be 0.9 (vs. 1. 0 max.) .
A second group of experirrents involved batch filtration in a
3 1/2 " Plexiglass column with varying static heads of water above the
beds. Results are shown graphically in Figures 6 and 7 for two condi-
tions of sand and manure in layers and sand and manure mixed. Filtra-
tion rates were better for mixed material but quite low for both cases.
Several different fluidizing materials are used by Procedyne in its
fluid bed systems. For incineration of waste materials, sand is the
econanical choice. Two specific sands were used in the project and these
are designated as Sand M:; and Sand P.
10
-------
30
0.1525
25 0.134
.
! 20
~ 0.1072
~
R
~ .
15 0.081 ~
.
~
~ }
i
10 three layers; ~
0.054
1<1: ~
5 0.02017
o I r ,--
1 2 3 4
WATER HEAD , m.
FIGURE 6. FTI..TRATION THroUGH SAND f\ND .MANURE m lAYERS.
11
-------
120 0.65
.
! .
+J
4-1
.
96 0.52 tJ1
i i
~ i
~ 72
0.391 ~
2" layer
~
~
~ 48 - 0.26.
168
144
1" layer
0.91
0.78
24
__L
4
3" layer
0.13
o
o
--_J_----_J_--_--L
123
WATER HEAD, IN .
FIGURE 7.
FILTRATION THROUGH SAND .AND MANURE MIXTURE.
l?
-------
Approximate screen size distribution of these sands is
as follows:
+ 30 m.
-30 + 50 m.
-50 + 80 m.
- 80 m.
Sand MG
( %)
1
35
30
34
Sand P
(% )
25
60
10
5
The coarse sand P is somewhat purer and is more stable
as a recycle sand when quenched in the filter circuit. It
was the sand used for the subsequent filtration experiments.
In order to further investigate the filtration properties of
paunch manure-sand mixes, a third program of a group of 15
fixed bed experiments were performed. These experiments were
performed in 3" and 8" cylindrical chambers made of both steel
and plexiglass depending on the need for either pressure or
visibility in each experiment.
As noted previously, various samples of paunch manure were
used throughout the entire experimental program and these varied
in concentration from 14-18%. Materials used in Experiments
1 and 2 were from a 14% lot. Materials used for the other 13
experiments were from a 17.1% lot. Sand to manure ratios were
held at 4:1, a value which permits a reasonably economical
operation of the sand recycle system. The material itself was
first filtered on a Buchner funnel using filter paper (repeat-
ing a procedure developed during the first group of experiments)
in order to establish a basis for comparison of results when us-
ing sand as a filter medium. Results of those tests are shown
in Table III.
The following conclusions were drawn from the above series
of experiments:--
( a)
(b)
The basic filtration quality though lab filter paper
on a total solids basis (TS), was 5360 mg/liter and
total organic carbon (TOC) was 3000 ppm. This establishes
that there will be present in the feed stock to the pro-
cess, a fraction containing certain minimum dissolved or
colloidal volatile solids. These cannot be removed by
normal filtration techniques. The concentration of these
dissolved and colloidal solids will vary depending on
several factors e.g. diet of the cow, length of time in
slaughtering process, age of paunch manure before process-
ing etc.
Although several different kinds of
using sand as a filter media it was
solids did not increase much beyond
for any of these experiments.
experiments were made
noted that total
7000 to 8000 mg/liter
13
-------
TABLE III.
FILTRATION TEST RESULTS
Expt. No.
Other Comments
A-I
B-1
B-5
B-6
I-'
,j::>.
B-7
B-8
B-12
B-13
Technique
Filtration through
Laboratory Buchner
Same as A-I except sand
on an 80 mesh screen is
the filter bed-3" 0
column, 3" deep bed.
Simulation of deep bed
multilayer concept-3"0;
containing three, 4"
deep sand manure layers.
Filtrate removed by
free draining
Same as B-5 except
5 psig pressure use
on filter
Same as B-5 except each
4" layer of manure sand
was well mixed before
adding to filter.
Pressure was increased
to 10 psig.
Same as B-1 except
the 80 mesh screen is
replaced by a sample
of porous stainless
steel belt.
Same as B-5 except
one manure-sand
layer followed by
one sand layer; no
pressure
Same as B-12 except
10 psig pressure
Filtrate Results
TS (Total So1.~=5360 mg/liter
TOC(tot. Organic Carbon) =
3000 ppm
TS(lst. 15 sec.) = 1300
TS(after 15 sec.) =7330
'1!)C "" " =5900
TS - 6910
TOC - 5540
TS - 8870
TOC - 6900
TS - 7350
TOC - 6060
TS - 7310
TOC - 5530
TS - 7230
TS - 7650
Eaton-Dikeman
Filter Paper grade
512
Avg. filtration rate
0.91 gpm/sqf Rapid
blinding after 1st
15 sec. used to wet
bed 84% moisture in
cake.
Avg. filtration rate-
.115 gpm/sq.ft.
Avg. filtration rate-
.837 gpm/sq.ft.
Filtration rate average
1. 5 gpm/sq. ft.
Rate-.363
gpm/sq.ft.
Rate-l.74 gpm/sq.ft.
% moisture in cake-8l%
-------
(c)
(d)
( e)
Batch filtration rates are improved to some extent with
pressure (or vacuum) from under 0.2 gpm/sq ft filter
area to approx. 1.75 gpm/sq ft at pressures of 10 psig.
Cake rroisttire content could not be decreased to belCM 81% (or 19%
solids) on a sand free basis during this series of experinEnts.
This value is on the lCM side for autogenic incineration when
compared with an acceptable level of 25-30%.
The most general conclusion reached was that the fil-
tration rates for paunch manure were disappointing;
the dewatering characteristics were likewise. These
results confirmed the work done on compressibility
during the earlier testing program.
At this point in the process development program it be-
came necessary to change the process which had a single de-
watering stream to one which wa~ have two:-
( 1)
(2 )
A major dewatering stream-which would process the
fibrous and larger particles of paunch manure to
higher than 35% moisture levels.
A minor dewatering stream consisting of the finer
paunch manure particles which would be processed
through the moving bed sand filter.
15
-------
SECTION III
PROCESS DEVELOPMENT
DEWATERING
Preliminary work in the laboratory was directed towards
the investigation to determine the extent of dewatering that
could be attained by the following treatments:
1)
2)
Simple dewatering
Pressure dewatering
The preliminary filtration studies indicated that only
the unbound water could be removed. These tests were carried
out using a simple screen and in later cases vacuum filtra-
tion. The maximum attainable solids content was 18.5% Pres-
sure dewatering tests were conducted using hand operated rolls,
of the type used for rolling metal in metal fabrication shops.
Three tests were run:
1-
2-
3-
Paunch Manure containing 18% solids was put on a
screen and rolled. The solids concentration of the
rolled paunch manure was increased to 23%. The solids
concentration of the liquid extracted was 4%.
Paunch Manure (18% solids) was again put on a screen,
but this time was rolled and recycled continuously
through the rollers until no further liquid could be
extracted. The solids content of the material from
this test was 27%.
The third experiment was conducted to test the effect
of sand as a dewatering aid. 1/2 part of sand was
added to 1 part paunch manure and processed through
the rollers. The solids concentration of the sand-
manure mixture was 54%. Correcting for the sand, the
solids concentration of the paunch manure was 23%.
These tests (1&2) indicate that the solids content of
the paunch manure can be raised to approach the autogenic
point and thus economic operation.
Primary Dewatering
In the development of the flow sheet for this process
the need for simple (primary) dewatering became apparent.
This step was required to:
(a)
Remove free draining liquid to reduce the load on
main dewatering equipment.
Provide a constant feed stream to the main dewatering
(b)
16
-------
equipment i.e. to eliminate any effect of large water
inputs upstream of the dewatering system.
Preliminary investigations into equipment for this
service indicated that it could be broken down into two
broad categories a) simple screens and b) vibrating screens.
The use of either of these two approaches for this duty is
classical in the chemical and mineral processing industries.
Simple screens are not normally used in dilute slurry pro-
cessing service. Their use is normally restricted to the
handling of dry or near-dry solids. However, recent ~e-
velopments in this equi~ment have been made by compan1es
active in the meat pack1ng, domestic sewage, and pulp and
paper industries. These screens, set at predetermined vary-
ing angles, using patented screen configurations, have the
ability to dewater solids content slurries and discharge the
dewatered solids without cloqging the screens. Screens of this
type are the Nauer Bros. Inc. "Hydrosieve" and the Dorr-Oliver
"DSM Screen".
The second category of screen available is the vibrating
type. There are many of this type available, the vibration
to the screen being induced electro-magnetically, by unbalanced
fly-wheels or eccentric shafts. In this type of machine, the
vibration induced to the screen ensures discharge of the solids
deposited on it.
In an effort to provide a plant whose operation would be
economic as well as simple, and based on the experience of
screen manufacturers in dewatering paunch manure, the angle
screen described above was given primary consideration. The
Hatfield Packing Co., Hatfield, Pa. and Wilson Packing Co.,
Cedar Rapids, Iowa were visited to observe this equipment in
operation. Those operations supported manufacturers claims
that paunch manure could be dewatered to 18% solids on this
equipment.
Mechanical Dewatering
As described elsewhere
paunch manure are a mixture
These materials are fibrous
tain, when dewatered of all
80% water.
in this report, the solids in
of hay, straw, grain, and corn.
and cellular in nature and con-
surface moisture, approximately
The laboratory investigation conducted on this material
has shown that mechanical dewatering would be necessary in
order to reduce the quantity of water in this material.
The investigation of the types of equipment available
to dewater this material uncovered the following:
1-
The substantial work done previously in the dewatering
of this material was discouraging in that only one de-
vice could be found to dewater this material to the extent
17
-------
2-
3-
4-
5-
required.
No information was available as to the quality of the
liquid stream exiting from this dewatering device. The
solids concentration in this stream was not available
from previous tests.
The advancements made in dewatering equipment spurred by
recent interest in ecology would require investigation
for applicability to paunch manure dewatering.
Developmental work would be required to provide a ma-
chine suitable for paunch manure dewatering.
Due to the inexperience of some ~~t manufacturers
on paunch manure, actual operating tests would be re-
quired to judge the suitability of the various machines
offered.
Equipment Investigated
The following types of dewatering equipment were investi-
gated:
1-
2-
3-
4-
Screw Presses
Disc Presses
Rollers
Miscellaneous
Screw Presses
conventional Design. This press is essentially a screw con-
veyor with the cross-sectional area decreasing with the length
of the conveyor. This reduction is accomplished by either
changing pitch of the screw or shaft diameter. The exit is
usually restricted so that the material to be discharged is
further subjected to compression, usually by means of a
pressurized cone.
Manufacturers of this type of equipment were contacted
and invited to quote. Those quotations that were received
indicated that this type of equipment is generally more ex-
pensive than the other types of equipment available.
It has been reported (1) that
after compression, tend to swell.
press tends to overload the drive,
stall.
paunch manure particles,
This action in a screw
causing the machine to
A field test was conducted on a screw press and the
machine failed before any dewatered paunch manure was dis-
charged. Failure was due to an overloaded motor.
18
-------
Most screw presses are of the conventional design de-
scribed above. The quotations received showed them to be
expensive, no doubt due to the heavy duty drives and motors
required to accomplish dewatering of this material.
Improved Screw Presses An improved design of screw presses
has recently been made available. It improves on the basic
design of a conventional screw press in that it incorporates
an expansion zone to compensate for swelling after compres-
sion. This reduces the drive and Plotor requirement.
A device of this type was tested on paunch manure (18% solids)
The test proceeded smoothly with the paunch manure dewatered
to 38 weight percent solids. The liquid underflow stream
contained 3.5% solids.
Disc Presses
During the search for suitable equipment for the dewater-
ing of paunch manure, it was found that extensive testing had
been done with this type of equipment. This press consists
of a pair of inclined screened discs that rotate very slow-
ly. The paunch manure is fed in the top and is squeezed as
it passes through the ~educing area caused by the incline of
the discs.
The manufacturer reported that paunch manure could be de-
watered to 40% solids. Subsequent investigation in an effort
to arrange for field testing showed that 1) presses were not
being used for paunch manure dewatering at the present time
2) presses were not available on which to test the material
3) data for the solids content of the liquid stream were not
available.
Rollers
The application of rollers for dewatering operations is
old. It is the classical method for the removal of syrup from
sugar cane. Despite this, most roller manufacturers are not
inclined to quote on, or are disinterested in the application
of roller machinery to dewatering applications. Although five
manufacturers of roller equipment were contacted, only one
was interested in this application. A developmental program
was initiated and executed for four months. After a dis-
couraging start, machine development has progressed to the
point where the solids stream from the rollers is 37%. This
has been confirmed in two tests. The liquid discharge from
this equipment contains 6% solids, the highest concentration
of solids in the liquid stream of any of the machines tested.
19
-------
Further development no doubt could decrease this concentra-
tion of solids.
Miscellaneous
Investigation into the various types of dewatering equip-
ment available uncovered several miscellaneous machines avail-
able for dewatering service.
Roller Type Hydraulic Press This machine consisted of two
rolls separated by a floating ring. It had been used primarily
in the wood and pulp industry. Its main disadvantage was the
high hydraulic pressures required for its operation. This
machine has been out of production for some time.
Multiple Roller Presses These units are a fairly new develop-
ment finding application in the sanitary field. It consists of
a porous belt that travels through several stages of compres-
sion and shear rolls. The material to be dewatered is placed
on the belt and travels through the rolls. Sufficient infor-
mation was not available nor units available for field test-
ing with paunch manure.
Summary
The actual operating tests run in the field on paunch
manure showed that this material could be dewatered to a solids
content approaching 40%. This was accomplished on both the
three roll mill and the newer design of screw presses.
Manufacturers of other equipment, namely the disc press
and conventional design of screw press, state their equipment
is also capable of attaining this solids composition.
In addition to the solids concentr~ionof the solids
stream exiting from the dewatering equipment, it is important
that the solids in the liquid stream be held to a minimum.
This is a necessary requirement for the process design of
the disposal plant.
Thus, in the selection of dewatering equipment, the con-
servation of solids is a prime requirement. Those solids
discharged in the liquid stream must be removed in additional
processing steps, and it is these streams which dictate the
quality of water leaving the process.
FILTRATION
It was found that liquid streams from the mechanical
20
-------
dewatering devices could contain up to 4-5% solids in the
form of fines, colloidal materials and solubles. A fourth
group of filtration experiments were then conducted using
feed streams having concentrations ranging from 0.7% to
4.85% solids. During the course of these experiments, it
was noted that the fines could be concentrated to some ex-
tent by settling. Work on settling is described in a later
section of this report.
In addition to the use of classical techniques (Buchner
funnel & filter leaf) the Procedyne bench scale regenerat-
ing filter was also used. This filter and its auxiliaries
are described schematically in Figure 8. Typical results
from that program are shown in Table IV. From this last
series of exper~ments it was concluded that filtration
rates up to 0.5 gpm/sq.ft. could be obtained. In all of the
batch or semi-continuous experiments during Part I and Part II
rapid blinding of the filtration area took place with the
formation of a thin manure cake. This of course resulted in
a rapid increase in pressure drop and decrease in filter rate.
Only a continuous removal of sand and the manure layers
prevents blinding. This removal is accomplished while de-
watering takes place in a moving bed filter. Filtrate
qualities varied from 0.35 to 0.48% solids compared with
.31% solids in soluble or colloidal form and represents material
which cannot be removed without additional treatment of the
water tertiary treatment devices.
SEDIMENTATION
As in the case with all commonly used dewatering devices
in which the solid stream is concentrated; the liquid stream
contains water soluble and colloidal solids and a quantity
of small particles in the form of fines. The production of
fines in the two streams from the two dewatering devices
has been described above.
The fines from the primary dewatering device were prin-
cipally small strawlike particles and tended to settle ra-
pidly. That stream was also fairly dilute. The fines from
the secondary device were somewhat ITOre concentrated and tended
to settle more poorly.
Two specific sets of
out with the two types of
of these are described in
9 thru 12.
settling experiments were carried
particles produced. The results
the graphs presented in figures
As shown in the flowsheet developed for the process, the
21
-------
12"
f
9"
k
I
r-l6"1
c
Air
B
18"
"
A.
Sand and nanure receiver
B.
Sight glass
c.
Pressure gauge
1°4
I
D.
Pipe containing 1 3/4" dicureter screw feeder
E.
Filter chamber
F.
Two 6" X 14" screens on both sides
G.
Feed Hopper
H.
Screw drive system
I.
Filtrate receiver
Figure 8.
Regenerating filter.
22
H
-------
TABLE IV. mNDITIQ'1S AND RESULTS OF EXPERIMENTS
EXP:r. NO. EXPERIMENr DESCRIPrION FILTRATION FILTRATE SAND QUALITY CAKE QUALITY
RATE QUALITY %HO %SOL. %SAND %SOL. %H20
GPM/SQ. ET. 2.
1 Vacuum filtration with 0.215 0.41% 23
sand, 0.7% solution
( initial) Buchner Lab.
filter paper
2 Vacuum filtration 0.51 0.48% 21. 7 -
t.'1rough Buchner funnel
without any sand through
lab filter paper, feed
concentration 0.7%, 11"
Hq vacuum
3 Vacuum filtration 0.595 0.464 17.3 -
through 170 mesh screen,
11" Hg., 0.7% initial
solution, Buchner Funnel.
t\J 4 Hot vacuum filtration 1.35 0.342 26.3% 1. 67% 14.65 -
w t..'1rough 13° mesh screen, initial in the
tElTp. 165 P, 27" Hg., No sand
sand, initialconc. 0.7% resev.
5 Procedyne truncated filter, 0.5 37 15
P=10 psi sanple is collected
on the screen, 0.7% sol.
(initial)
6 Filtration through trun- 0.44 0.494% 38.7 9.3 -
cated filter, continuous solid
feed of O. 7% sol. and sand
Sand rate 450 gms./5 min.
Mixed Sand 86.73 1.84 11.4
Sand fran scr~ 87.6 0.31 12.1
7 Truncated Procedyne 0.5 0.9% 24% 3.7%
Filter, vaccum 14" w.g.
feed, 6400 ~s of 6.8% sol.,
3,200 gms sand, 0.5 psi back
pressure.
-------
80
70
60
50
40
~
~
~ 30
dP
Conditions: 0 I
20 1) temperature 165 F
2) expected feed str
from dewaterer.
8 - Top Layer
10 0 - Bottom Layer
o
0.4
Figure 9.
1.2
2.0
2.8
3.6
4.2
% SOLIDS TO SErI'LER
Graph of % solids to settler versus % laver SDlit.
24
-------
801
70
60
50
-
~
~ 40
U)
-
~
~ 30
~
H
~
0\0 20
10
o
0.4
Figure 10.
.
cnIDITIONS:
o
1) temperature 165 F
2) ~ stream from prirrary
dewaterer.
o - Top Layer
8 - Bottom Layer
1.2
2.0
4.2
2.8
3.6
% SOLIDS 'IO SEITLER
Graph of % solids to settler versus % solid split
into layers.
25
-------
I
~
8
80
~
70
60
50
40
~
~
U)
~ 30
0\0
20 0
10
~ - 'Ibp Layer
o - Bottom Layer
o
0.4
Figure 11.
0.8 1.2 1.6 2.0 2.4
% SOLIDS 'ill SEITLER
Graph of % solids to settler versus % layer split.
26
-------
80
70
60
50
~
~ 40
Cf.I
~
dP 30
2J
10
Figure 12.
CONDITIONS:
1) Room temperature
2) Expected stream from
Bauer Hydro sieve
A - Bottom Layer
o - Top Layer
0.4
1.2
1.6
2.4
2.0
0.8
% SOLIDS 'IO SEITLER
Graph of % solids to settler versus % solids
in layers.
27
-------
concentrated, more difficult to settle fines are taken
through the filter directly and the easily settlable
materials from the primary dewatering device are settled
first before feeding to the filter. Filtrate from the
filter is recycled through the settler before sewering to
take advantage of the settler's capacity and residence time.
INCINERATION
A recently developed technique for disposing of sludge
from municipal waste treatment plants involves the use
of fluidized bed reactors. In this device, sludge con-
taining 25-30% organic solids is fed into a fluidized
bed of inert material at approximately 1400oF. The
reactor is capable of completely oxidizing (incinerating)
all of the organic material. This operating technique is
based on the principle long used for processing in
the chemical industry, that when solids are suspended in an
upward moving stream of gases, the mixture posseses
the characteristics of a liquid. The properties of this flu-
idized bed, in terms of mixing, result in good heat
transfer which can be utilized effectively to inci~erate
manure. Incineration of paunch manure in a fluid bed
reactor has not been attempted commerically- Incineration
studies were performed on a 6" bench scale fluid bed
reactor in order to establish the incineration character-
istics of paunch manure.
Description of Laboratory Apparatus
The experimental unit used for these studies consists of
a 6" diameter reactor made up of four sections. Each
section is made up of type 330 Stainless Steel. The
bottom section A (Refer Fig. 13) of the unit is called
the plenum chamber where the plenum burner is mounted. There
are provisions for a relief valve and for excess air in the
plenum. The plenum chamber is lined with 3" of castable re-
fractory. A metal distributor is placed above the plenum
chamber. This plate is similar to a bubble cap distributor
plate.
The section B ab01ethis distributor plate is called the
feed section into which the feed is conveyed by screw. A ra-
diant section C of 8" height is placed over this 4" feed
section. The radiant section consists of an 8" reactor sec-
tion, surrounding which is an annular 2" space around this
6" by 811 cylinder. Gas is fired through this annular space
tangentially by means of a North American Burner. Castable
refractory of 1" thickness is used around the 2" annular
section to protect the metal jacket surrounding the radiant
28
-------
Sand OVer Flow
Section (D)
Free Board Section
(E)
Radiant Barrier
Exhaust-Tangential
Exit
N
2Ai.r
Refractory Material
Reaction Zone
Armular Conbustion
Zone of Radiant Burn-
er
Radiant Burner
Fired Tangentially
into Armular (C)
Section
Propane
Air
I I ( I .(
\ \ \ I \
....
\ -" /1
" .. "no /~I Feed Screw
_:~~J~ D~triliution P~te
-">
- - - Plenum (A)
-.-
Feed Zone (B)
Propane Burner
FlrnRE 13.
Conceptual Drawing - Procedyne Fluid Bed Reactor
29
-------
section. This metal jacket holds the inside 1" thick re-
fractory. The next higher reactor section is a 4" refractory
lined section which is accessible for refractory evaluation
purposes.
The sand overflow section sits on top of this, and is
also a 4" section. The free board and expanded section (E)
completes the fluidized bed reactor. A detailed schematic
diagram is shown in Fig. 14.
General Test Procedure
The bed is initially heated to l4000F by means of both the
plenum burner and the radiant burner. When the steady state
temperature is attained, propane gas to the plenum and
radiant burner and the air requirements are adjusted ac-
cording to the heat requirement of the material being burn-
ed. Combustion air for paunch manure combustion was sup-
plied at 4% excess oxygen in the exit gases.
When the flow rates of air and gas are adjusted, sand
in the feed screw hopper is blown initially with air and
the screw is started. Sand, which is initially present in
the hopper, is fed to the incinerator slowly and then the
actual feed is started. The speed of the screw is adjusted
to give precalculated feed rates. Gas samples, temperature
and pressure measurements at various points are taken when
the feed rate and off-gas rate were uniform. Several types
of experiments were run during the early part of the work
on paunch manure. From a feedstock point of view these
could be divided into three general catagories:
(1)
Paunch manure at 18% dry solids plus sand in ratios
of 1 part manure to 4 parts sand.
(2 )
Paunch manure in the 28-31% dry solids range as
produced from squeezing in Procedyne's bench scale
rollers.
( 3)
Paunch manure-sand mixtures from early bench scale
filtration studies.
Results from this experimental program were used in the in-
cineration scaleup calculations described elsewhere in this
report.
Data from each one of the three experimental catagories
are shown in the Table V.
On the basis of the low levels of CO present in the off-
gas, it was concluded that the residence time in the reactor
30
-------
COMBUSTIOO
PRODucr5
WATER IN
EXHAUST GAS
SCRUBBER
A-2
N.C.
@ j--
I I
~
I
- - ..,
I
I
I
- I
I
L-
@
PROPANE
WATER
oor
C-l
r--
I
I
AIR
I 0-g-II
A - 1
CYCWNE
o
@
----,
I
I
I
I
$
,
,
1
1
~ FEED BIN
1 SCREW
Q~I srARrUP B~
LV
I-'
REACTION
ZONE
(BID )
M-l
FEED
CARBCN SAND
PRODOCT
~2
- --
DISTRIBUI'ION
PLATE
@
N2 e
I
L_--
PLENUM
---@
- -- - --
----
- -- - -
Process sChematic for pilot plant incinerator.
Figure 14.
-------
TABLE V.
PAUNCH MANURE ThCINERATION EXPERIMENl'S
Expt. Number
Peed Stock
1
patmeh Manure
31% Solids .
Peed Rate 16.5 lbs/hr
Plenum Tenp. 15000p
Bed Temp. 1300-14100p
P1uid Bed Height 12"
Main Air P1CM 3.5 Scfm
Heat input 23,200 Btu/hr
Calc. Heat Loss 15,000 II
% CO in exit .02%
2 3
patmch Manure Pi1ter Mix #5
18% Solids + 3.36% solids
Sand 12.0% H~O
84.64% and
11. 0 lbs/hr 11.5 lbs/hr
14300p 15000p
1465-1510 1590-1260
12" 12"
3.0 3.0
27,200 Btu/hr 18,200
tr.
tr.
. -- ---- ----------~--
was too short. It was decided to increase the height of the bed and
another 4 II high X 6" dianeter section was added to the laboratory fluid
bed reactor.
The experi1rental program was then continued. Peedstocks for the
program were chosen to simulate feeds fran the dewatering system being
developed in the other preconstruction studies connected with the pro-
ject. As before, one set of results fran each of the three types of
feedstock exper.irrents are described in Table VI.
TABLE VI.
FEED TO INCINERATIOO EXPER!MENrS
1 2 3
Paunch Manure % Sol. 4.46 % Sol. 13.15
37% % ~ 22.66 % H20 31. 40
Solids % d 72. 70 % sand 55.45
6. 75 lbs/hr 12.6 lbs/hr 12.4 llis,lhr
3.9 Scfm 3.75 Scfm 2 . 89 Scfm
1540-1480 1500 14000p
1332 1300 14000p
32
Expt. Nurrber
Peed
Rate
Air for Canbustion
Plenum Tenp.
Bed Tenp.
-------
TABLE VI. (cant I d)
17,300 But/hr
17,390 Btu/hr
15,900 But/hr
Heat Supplied
18,200
"
"
Radiation Losses
"
14,000
12,000
CO in exit gas
.04%
0.05%
0.0%
The general conclusions reached were that feeding of the various feeds
was very satisfactory, no rmjor rrechanical problems were encountered and
that paunch IPanure could be bUI1led satisfactorily, although 16" bed heights
at this scale would be considered an absolute minimum.
Incinerator Design Considerations
The steps used in the basic design of the incinerator are as follCMS:
(a)
(b)
(c)
Calculate rnini.rmm1 fluidization velocity for the sand to be used.
Detenni.ne an operating velocity (based in part on experirrental
results.
Perform a IPaSS balance on the system. Inputs are; paunch IPanure +
m::>isture, sand, fuel, and air. Outputs are prcxiucts of canbustion,
excess air and ash.
Perform a heat balance on the sytem. Heat inputs are heat of can-
bustion fran paunch IPanure and heat of canbustion fran fuel. Out-
puts are heat loss by radiation and in exhause gases.
Gas flCMs in the fluidized system are the sum of fluidizing and
oxidizing gas required plus prcxiucts of canbustion.
The dianeter of the reactor is detennined fran (b) and (e).
The height of the fluidized bed is determined errq;:>iricall y fran
experiIrental results.
(d)
(e)
(f)
(g)
Fluid bed incinerators contain a distributer plate through which fluidiz-
ing gas passes and which holds up the fluid bed rmterial.
In designing the plate and its holes, calculations are based on the
fOl1CMing considerations:
(a)
(b)
(c)
Hole spacing must permit uniform distribution of the fluidizing gas.
Bubble coalescence should not take place right at the plate, other-
wise channeling and spouting takes place.
Slugginq of the bed should be avoided. This places a restiction
on naxirourn bubble size.
Pressure drop across the bed cannot exceed 10% of the total pres-
sure drop.
Limits are placed on the ratio of orifice dianeter to particle
dianeter.
(d)
(e)
One then proceeds with the follCMing generalized approach:
(a)
List fluidization velocity, reactor dianeter, height and inert
33
-------
(b)
(c)
material size.
Assume a nurrber of holes n and calculate bubble flCM per hole,
hole spacing LI' bubble volurre and bubble dia:rreter.
Calculate maximum bubble dianeter d and new bubble dia:rreter
dl resulting fran the coalescence ~een two adjacent bubbles.
dl < LI estimated bubble volume is acceptable. If
~
not, a new dianeter ?2 is calculated and a distance L2 between
adjacent bubble trackS is taken as equal to 2 X LI. That dia:rre-
ter d2 is then corrpared with L2 and the procedure repeated l.llltil
d is Iess than L/2.
That bubble dia:rreter d is the estimated maximum dia:rreter which
must agree with d in section (c).
For the particul~urnber of holes n and the spacing, calculate
pressure drop across the plate considering each opening as an
orifice. This is canpared with an empirically deternri.ned ac-
ceptable number.
Each hole in the plate in an orifice and the dia:rreter of each ori-
fice d can be determined, nurrber of holes n and mass flCM.
The ra€fo of the orifice dia:rreter to particle dia:rreter is ccm-
pared and must fall into an acceptable range with pressure drop
and weepage of particles through the plate controlling paraneters.
This generally implies that several calculations are made for
various n' s (number of holes) l.llltil a satisfactory value of d
. f d or
1S oun.
Thickness and detailed construction of the plate will depend
on weight of bed and terrperature considerations.
(d)
(e)
(f)
(g)
(h)
(i)
(j)
The free board in fluidized bed systems pennits disengaging of the
solids from the fluidizing gas stream. The gas, in the form of
bubbles, erupts on the surface of the fluidized bed. These erupting
gas bubbles can and do intermittently splash solids into the free
board region above the surface of the bed. This intenni ttent burst-
ing action of bubbles causes velocity fluctuations and these fluct-
uations SIIDOth to an average velocity at a certain height. If the
gas exit is situated i1rm=diately above the top of the bed, a con-
siderable aIrount of solids will be entrained by gas. With higher
gas exit, the aIrount of entrairnrent is smaller, and finally a level
is reached above which entrairnrent beccxres approximately constant
and this height is called transport disengaging height (T D H) .
It has been found that the entrainrrent fran a bed of closely
sized solids is not significant l.llltil a superficial velocity U
considerably in excess of terminal velocity, Ut is reached. uHder
these conditions, free board acts like a pneumatic conveying tube.
Thus, according to Zenz and Weil, when the aIrol.lllt of solids conveyed
becorres constant, this is te:rned as the saturation carrying capa-
city of the gas stream under pneumatic transport conditions initial-
ly present.
Several investigations (4,5,6) have shown that elutriation rates
increase sharply with rising superficial gas velocity, decrease with
34
-------
increasing dianeter of fines, and decrease with increasing free board
up to a limiting value of the free board beyond which no further efl""I.
trainrrent occurs, Ha.vever, TOO is not as sensitive to gas velocity;
it increases by about 70% for a doubling in gas velocity. Hence, it is
advisable to design the free board of a fluidized bed very near to
T D H. In spite of the importance of T D H in fluid bed design, there
is very little info:rnation available on T D H except for the work of
Zenz and Weil on FCX: Catalyst.
Virtually all the reported work on entrainment fran fluidized
beds has been carried out with either of two sinplifications: Singly,
closely sized fractions or a mixture of two such fractions in small
laboratory tmits. It was felt that these results may not establish a
correct criterion for elutriation since the column diameter, particle
diameter, particle density, density of gas, viscosity of gas are
affecting entraimnent eitherway, depending on the specific conditions.
Hence, for engineering design of free board for Procedyne' s
fluidized bed reactor, T D H is calculated fran the basic concept
of bubble theory and checked by using the correlation developed by Zenz
and Weil and as reported in a recent publication. (7)
As already pointed out the bursting action of the bubbles on the
surface of a fluidized bed projects agglarerates of particles into
the space above the bed. These particles (depending on size) will be
carried by the gas into the free board. Practically all the gas that
is in excess of minirm.xn fluidizing conditions passes through the bed
in the fonn of bubbles. These bubbles graN in size as they pass
through the bed with a velocity that is higher than superficial velo-
city of gas. While the bubbles travel through the bed, they collide
with other bubbles and trap sane solids in the bubble and wake. These
solids that are in the wake are also carried along with the bubble.
When these bubbles reach the surface of the fluidized bed they burst,
thus thra.ving the solids in the bubble in the free board. At this
stage, sane of the solids will be having a velocity equal to bubble
velocity. When this phenClIEI10n occurs, sane particles will be carried
CMay in the free board by gas depending on the tenninal velocity of
gases. Sane of them will fall back into the bed. The folla.ving
generalized approach was therefore used in calculating T D H.
(a) Sm3.ll bubbles fonn at the distributor, coalesce, gra.v and speed
up as they rise through the bed.
(b) The velocity of rise of a crCMd of bubbles is related to the velo-
city of rise of a single bubble in a bed. The absolute rise of bubbles
in bubbling bed is calculated by Davidson's (8) rrodel.
(c) Bubbles are assumed to be spherical and their diameters are cal-
culated by Davidson's (8) rrodel.
(d) When a bubble bursts, the particles in the wake and bubble are
thrown up. The particles whose Ut< %' are carried in the free
board.
(e) The frequency of bubbles at the surface of bed is calculated fran
35
-------
(4)
(Uo - Umf)
~
n = 1.5
(f)
(g)
'!he voidage of the wake in the bubble is equal to the voidage
@ Umf.
RatIo of volurre of wake to bubble is taken to be 0.2, for irregu-
lation sand from the data of Rowe and Partridge (9).
'!he basic equation for entrai.nnent is the sane as that used by
Lewis et al (10).
The entrairurent rate is maximum 1% of the total sand in the bed
per day.
(h)
(i)
36
-------
SECTION IV
PROCESS CALCULATIONS
Basis for Design:
(1)
95 cattle X
hour
55# paunch manure
cattle
=
5225# paunch manure
hour
Now, paunch manure as removed from the sack is 14% (wt) dry
solids, this is equivalent to:
5225# paunch manure X 14
hour 100
=
731# Dry solids
hour
PAUNCH TABLE OPERATION
The paunch manure, after removal from the sack is free
drained, draining to 17% dry solids, the water drained con-
taining dissolved and very fine solids.
731 = 4310# paunch manure
.17 hour
(after draining)
5225#/hour - 4310#/hour = 915#/hour. Total material
drained away.
Solids in drainage is 3000 ppm
9l5#/hour X .003 = 3#/hour solids in drainings.
Based on the calculations above, stream OA is composed of the
following.
Paunch Manure Total Dry solids Water %Solids
(As Rec' d) 5225 731 4494 14
Paunch Manure (drained) 4310 728 3582 17
Paunch Manure Drainings 915 3 912 0.3
Water is added for the following:
STREAM
FUNCTION
OC
OD
OE
Table Rinse
Sack Wash
Sack Rinse
37
-------
At present, at Illinois Packing Co., these three streams are
continuous, each approximately 20 gpm, or total of 60 gpm.
Significant improvements in the disposal plant efficiency will
be realized by installing foot pedal valves OC and OD. This
will result in significant water savings, estimated at 2/3 of
the present water usage. The new water rate is assumed to be
20 gpm. This figure is designated stream OB. Stream OE, the
sack rinse, will be sewered directly.
Present System
FF
6
~OC
OE,,-
.. OB
Present Water Flow - 60 gpm (20 gpm each flow)
Pedal Controlled System
~
OB~
r+
OE -
6
\
38
-------
Under this system; OB will flow at rate of 20 gpm.
20 gallons X 60 minutes X 8.33#
minutes hour gallon
=
10,000 #
hr
It is assumed that this water will extract fine particles of
paunch manure in range of 3000 ppm.
10,000# X 0.003 = 30# fine solids
hour
Stream 1, exiting from the paunch table is composed of streams
OA and OB and is as follows:
OA
OB
Total Stream 1
Free Water
Bound Water
Dry solids
912
3582
731*
10,000
10,912
3,582
731*
15,225
*of this 731# of Dry solids, 33# is estimated to be dissolved
or very fine solids.
PAUNCH BIN
This stream (1), is fed to the paunch bin which functions
as both surge bin and feed tank to the remainder of the pro-
cess. The plant design is based on a 16-hour per day opera-
tion, or an hourly rate of 365.5# of paunch manure on a dry
basis.
Feed to process:
(Stream 2A)
Free Water 5456.0
Bound Water 1791. 0
Dry solids 365.5
7612.5
39
-------
PRIMARY DEWATERING
2A Primary 3A
Dewatering
Solids 365
Water 7247
3B
1.
The expected yields in streams 3A and 3B are as
a. 3A = .8 of total solids in 2A = 292#/hr.
b. 3B = .2 of total solids in 2A = 73#/hr.
c. Solids in stream 3A = 18%
follows:
2.
Water in Stream 3A:
292.4 = l625#/hr. - total weight stream 3A
.18
1625 - 292 = l333#/hr. water in stream 3A
3.
Water in Stream 3B:
Total Water - water in 3A = water in 3B
7247 - 1333
= 5914 # /hr . ( 8 )
4.
Determination of Bound Water - Stream 3B only:
Total Water - free water = bound water
5914 - 5456.0 = 458#/hr.
5.
Solids Concentration in 3B:
73
73 + 5914
X 100 = 1.22%
6.
Thus, balance about the primary dewaterer:
2A
Dewaterer
Solids = 292#
Water = 1333#
% Solids = 18%
Primary
Solids 365#
Water 7247#
% ::iolids 4.8%
3A
Solids 73#
Water 5914#
% Solids 1.2%
40
-------
Stream 3A, the solids rich stream, goes forward to the
dewaterer, stream 3B, relatively weak in solids, goes to
the settler for thickening.
DEWATERER
Stream 3A is fed directly to the dewaterer, yielding 2 streams:
4A, high in solids content and 4B, a se~arate liquid rich stream.
Dewaterer
4A
-
...
-
-
3A
Solids 292#
Water 1333#
% Solids 18%
,
4B
1.
The expected compostions of 4A and 4B are as follows:
a. 4A has a composition of 40% dry solids
b. 4B has a composition of 5% dry solids
c. 82.5% of entering solids in stream 3A will be re-
covered in stream 4A
Let stream 4A = X and 4B = Y
Total weight of stream 3A = 1625#/hr.
Therefore X + Y = 1625#/hr.
and
Simultaneous solution of these equations yields the
following:
Stream 4A + 4B = 3A
Water 364 969 1333
Solids 241 51 292
Total 605#/hr. 1020#/hr. 1625#/hr.
Thus, balance about the dewaterer:
41
-------
3A
4A
Liquids = 1333
Solids = 292
% Solids = 1%
Solids = 241
Liquid = 364
% Solids = 40%
Dewaterer
.
4B
Solids = 51
Liquid = 969
% Solids = 5%
SE~TLER AND FILTER
Stream 4A is fed directly to the incinerator, Stream 4B
is sent directly to the sand filter where combining with
Stream 6A (from the settler), it is filtered, the solids
Stream 7A going to the incinerator, and the filtrate 7B go-
ing back to the settler for further treatment. This is shown
schematically below.
- -
Primary 3A 4A
~ ....
Dewaterer Dewaterer ~
3B 4B Incinerator
Settler 6A"",- Filter 7A
"""-
- ~
I I
2A
--.-
I
I
6B
.
r
1- ---
7B
~-
- - -
It can be shown that those streams indicated by the dashed
lines (6A, 6B, 7A, 7B) are dependent on the settler and fil-
ter performance. Stream 7B is recycled, affecting both
stream 6A and stream 6B which in turn affects stream 7A and
7B, and so forth. By a series of consecutive, iterative cal-
culations, these streams are determined to be:
42
-------
Stream 6A 6B 7A 7B
Dry Solids 69 37 87 33
Water 1625 6453 430 2164
% Solids 4.1% 0.58% 0.17% 1. 57%
Stream 4B, the required sand for filtration is also arrived
at by these calculations. This value is 1352# sand/hour.
INCINERATOR
The feed to the incinerator has been determined to be:
Stream 4A 7A Total
Dry solids 241. 87 328
( # /hr)
Water (# /hr) 364 430 794
Sand (#/hr) 1352 1352
This is 90% of the total dry solids entering the process,
being fed to the incinerator as 29.4% solids (sand free
basis). The following process design criteria have been
determined:
a.
% ash in dry solids - 8%
Heat of combustion of paunch manure -
Excess Air (dry basis) 4%
Paunch manure taken to be cellulose.
7200 Btu/lb.
b.
c.
d.
MATERIAL AND HEAT BALANCE CALCULATIONS:
1.
Feed to Incinerator
a.
Pounds of combustibles present:
329.4 (.92) = 303#/hr
b.
Pounds-moles of combustibles present (as cellulose) :
(M.W. Cellulose = l62#/hr-mole)
303
162
=
1. 87#-moles
hour
c.
Combustion equation:
C6H1005
+
602 - - - - 6C02
+
5 H20)
43
-------
c.l.
Stoichiometric quantity of Oxygen required for com-
plete combustion:
(1.87)
(6 )
=
11.22# - moles/hr.
c.2.
Amount of Nitrogen, (a)-above provided by air.
11.22#-moles 02
hr.
x 3.76# moles N2
# mole 02
=
42.2# moles N2
hr.
d.
Water present in the feed.
793.6# H20
hr.
x
1# mole H20
18# H20
=
44.1# moles H2Q.
hr.
2 .
From combustion of paunch manure
a.
C02 from combustion of paunch, from combustion equa-
tion:
1.87 X 6 = 11.22# moles C02
hr.
b.
H20 from combustion of paunch, from combustion equa-
tlon:
1.87 X 5 = 9.35# moles H20
hr.
c.
Nitrogen present (1-c.2) above
42.2# moles N2
hr.
d.
Water present in feed (I-d) above
44.1# moles H20
hr.
3.
Heat from combustion of manure
303#/hr X 7200 BTU/# = 2,181,600 Btu/hr.
Heat Output (All Discharged at 1400oF)
4.
a.
Heat required to heat water in feed:
to 14000F
793.6 X 1700
=
1,345,000 Btu/hr.
b.
Heat required by C02
NCPAT = Q
44
-------
11.22 X 1328 X 11.48 Btu = 170,800 Btu
hr.
c.
Heat required by N2 present
(42.2) (7.35) (1328) = 412,000 Btu/hr
d.
Heat required by H20 formed.
( 9 . 35 ) ( 18 ) ( 1 7 0 0 ) = 2 8 6 , 0 0 0 B t u/hr
e.
Heat required by excess 02 present:
Let X represent # moles of excess 02
X (71 75) ( 1328) = 10, 280 X B t u/hr
f.
Heat required by excess N2 present:
excess N2 = 3.76 X
3 . 76 ( X) ( 7 . 35 ) ( 132 8 ) = 36, 700 X B t u/hr
5.
Heat losses from System
a.
Incinerator - 9.5' O.D. X 23.75' high
b.
Area of shell - II D H
c.
(3.14) (9.5) (23.75)
Area of Heads = II D2
4
= 710 ft2
( 90)
= 142 ft2
(2 )
d.
3.14
---r
Total exposed area of incinerator = 852 ft2
e.
Total heat losses:
852 ft2 X 440 Btu
ft2
=
375,000 Btu/hr
6.
Heat Loss from Recirculating Sand:
1362 X .25 X 1328 = 450,000
Btu
hr
45
-------
7.
Summation of Heat Losses
Water in Feed
C02 formed
H20 formed
N? present
EXcess 02
Excess N
Surface fteat Losses
Recirculating Sand
1,345,000
170,000
286,000
412,000
10,280X
36,700X
375,000
450,000
Total Heat Losses (Btu/hr)
3,038,800 + 46,980X
8.
Total heat requirement
Heat losses - Heat supplied by combustion of paunch =
heat required.
3,038,800 + 46,980X - 2,184,600 = 857,200 + 46,980 (Btu/hr)
X=18.2
46
-------
CAIDJALTIONS OF FUEL AND AIR REQUIREMENI'S
The calculations are based on a fuel oil carnpostion of 87% Carbon, 12%
Hydrogen and 1% Sulfur, and exit gases from the incinerator at 1500oF. The
basic equations used are ccmron to the combustion literature (11) and calcu-
lations are developed as follows.
1. Heat available;
.87 #Carbon
1# combustible
= 66 BTU
Scf air
2. Air required (Sef)
= Btu/hr required
66
3. Air required (lb. -rroles)
= BTU/hr. required
23.694
5. N2 in this air (lb-rroles)
= BTU/hr required
113,000
= BTU/hr required
30,000
4. 02 in this air (lb-rroles)
Air required for conbustion:
6. Air required (Scf)
#Fuel
= % C(1.514) +%H(4.54) + %S(.568)
7.
002 forrred (Scf)
#Fuel
= 188 Scf or .525 lb-rroles
#Fuel #Fuel
= .315 (%C) = 27.4 Scf
#Fuel
8. H20 forrred (Sef)
#Fuel
or .076 lb-rroles CO2
# Fuel
= 1.89 (%H) = 22.68 Scf
#Fuel
or .063 lb-rrole H20
#Fuel
From equation (3) and (6) above:
9.
.525 lb-rrole Air
#Fuel
x
N #Fuel = BTU/hr required
23,694
or: N=Fuel required
= BTU required
12,500
47
-------
Rewriting equations (7) and (8) above:
10.
lb-no1es CO2 formed = .076 (BTU required)
(12,500)
= 5.2 + .284X
11.
lb-no1es H20 formed = .063 (BTU required)
12,500
= 4.32 + .236X
Surrm3.tion of Products
A
B
C
D
CO2
11.22
H20
9.35
44.1
(4.32 + .236X)
(5. 2 + . 284X)
Where:
A = Products of conbustion of paunch m:mure.
B = Water in paunch m:mure.
C = Products of canbustion of additional fuel.
D = Excess Air
Thus :
002 = 16.42 + .284X
H20 = 57.77 + .236X
N2 = 70.70 + 5.32X
02 = X
Calculation of excess oxygen on a dry basis:
Total no1es of dry gas
= 87.12 + 6.60X
4 = X
100 87.12+6.604X
X = 4.76 lb-no1e
hr
Composition of Flue Gases (lb.-no1es/hr.)
CO2
H20
N2
°2
17.77
58.89
95.90
4.75
177.31
lb. -no1es/hr .
48
N2
42.2
(28.5 + 1.56X)
3.76X
°2
X
-------
Addi lional heat required:
BTU (required) = 857,200 + 46,980X
hr
= 1,080,000 BTU
hr.
Fuel oil required:
N = BTU/hr required = 86.5 # /hr .
12,500
Air requirement
(lb.-moles/hr.) :
For manure canbustion
For fuel conbustion
For excess air requirerrent
53.4
45.5
22.7
121.6
lb. -moles/hr .
or:
121. 6 lb. -moles
hr.
X 359
60
= 727 SCFM
Effect of sulfur content of fuel;
sulfur content is assurred at 1%.
86.5 (.01)
32
=
.027 lb.-moles sulfur
S + 02
02 requirement
S02 in stack =
~
802
for sulfur = .027 lb~-moles
0.027 lb.-moles/hr.
Cariposi tion of stack gases:
CO2
H20
N2
°2
S02
17.77
58.89
95.90
4.75
0.027
177.337 lb.-moles/hr. (1064 SCFM)
Solids content of incinerator exit gases. This stream is based on the fol-
lowing 1) solids discharge is canposed of ash and sand, 2) all ash is car-
ried over, and 3) sand carry over is equal to 1% of bed capacity per 24 hrs.
of operation.
Ash content
Sand content
Loading to cyclone
26 f/hr
10 #/hr
233 grains
Sef.
49
-------
CYC:I.mE
Gases to cyclone (lb. -rcoles/hr . )
CO2
°2
N2
H20
S02
17.77
4.75
95.90
58.89
0.03
177.34 lb.-moles/hr.
The solids to the cyclone as shown above are 26 lb. /hr of ash and 10 lb. /hr .
of sand. Based on a solids collection efficiency of 90% of all particles
above the 5 micron size and a particle size analysis as follows:
Sand - All above 5 micron size
Ash - 32% 0-5 microns
36% > 5-10 microns
23% > 10-20 microns
8% > 20-40 microns
1% > 40-80 microns
On this basis it is assumed that 100% of the sand and 60% of the ash entering
the cyclone will be collected.
Collected in cyclone:
Sand
Ash (26) (.6)
10#
15#
Solids loading to scrubber:
Ash - 11# or 72 grains/scf.
SCRUBBER
The stream fed to the scrubber is as follows:
Gases (lb. -rcoles/hr . )
C02
°2
N2
H20
17.77
4.75
95.90
58.89
50
-------
5°2
0.03
177.34 lb.-moles/hr.
Solids
Ash 6l#/hr (72 grains/scf.) This stream entering the scrubber will be at
1400 F 6 The gases exiting fran the scrubber will be saturated and leaving
at 185 F. The water evaporated in the scrubber is 1585 #/hr.
Canposition of gases leaving scrubber (lb.-moles/hr.):
C02
°2
N2
H20
502
17.77
4.75
95.90
146.90
0.03
265.35
lb. -moles/hr .
Solids fran Scrubber
Scrubber is to be sized on 1/2 the ITBXimum allcwable particulate emission
(City of Chiacgo Envirorurental Control Ordinance, Chapter l7) of 0.2
grains/scf. at 50% excess air. The allCMable emission mrler this code is
4.1 #/hr. the design criteria is 2.0 #/hr. or 0.1 grains/scf.
51
-------
ECONOMICS OF AN AIR PREHEATER INSTALLATION
6he temperature which the air is heated to will be
1200 F. This provides a maximum amount of heat transferred
to the air, while not pinching in the warm end temperatur3
difference in the heat exchanger to too Iowa value (200 F).
Let X = lb. moles/hr of excess 02
then 53.4 + 100X is the Ib moleslhr of
21
air,
following the
calculation
include air
heat losses
are:
procedure already established. This does not
for combustion of supplementary fuel. The total
with no air preheating, as previously computed
857,200 + 46,980 X Btu/hr
Heat added to the system by preheating the air with flue
gases is:
(53.4 + 100X) (7.3)
21
Therefore the heat losses are reduced to:
(1200-72) = 439,000 + 39,200X
Btu/hr
418,200 + 7,780X
For supplementary fuel with flue gases leaving at l400oF.
66 Btu of heat are available for every scf of air used in
supplying supplementary heat.
Using the same equation numbers as in the master calcu-
lation:
3.
Air required (lb moles)
hr
= Btu/hr required
23,694
4.
02 in this air
= Btu/hr required
113,000
5.
N2 in this air
= Btu/hr required
30,000
6.
Air required for combustion of 1 lb. of fuel oil is
0.525 lb. moles as computed previously
7.
C02 formed
= 0.076 Ib moles/lb fuel
8.
H20 formed = 0.063 Ib moles/lb fuel
From (3) and (6)
N = no. of Ibs. of fuel oil/hr = Btu/hr required
12,500
52
-------
Rewriting equation (7) and (8) above =
9.
1b IIDles CO2 formed = 0.076
hr
(Btu . eel
(hr reqw.r
12,500
= 2.543 + 0.0473X
10.
1b IIDles
hr
H20 formed = 0.063
(Btu . eel
(~ reqw.r
12,500
= 2.11 + 0.0392X
Surrmation of Products
CO H20 N2 02
2
A. 11.22 9.35 42.2
B. 44.1
c. (2.543+0. 0473X) (2.il +0. 0392X) (13.94+0. 259X)
D. 3.76X X
Where:
A. = Products of carbustion of paunch nanure
B. = Water in paunch manure
c. = Products of corrbustion of additional fuel
D. = Excess Air
CO2 = 13.76 + 0.0473X
H20 = 55.6 + 0.0392X
N2 = 56.1 + 4.02X
° =
2
X
Calculation of excess 02 on a dry basis = 4%
4
100
X
=
X
69.86 + 5.067X
3.50 1b IIDles 02/hr
=
Corrposi tion of flue gases
CO
~3
02
2
13.96 1b IIDles/hr
55.74
70.2
3.50
143.40
53
-------
Additional heat required = 418,200 + 7,780 = 445,400 Btu
hr
Fuel oil required
= 445,400 = 35.7 lb/hr.
12,500
Air requirerrent (lb l1Dle/hr)
Por IPaIlure conbustion
Por fuel conbustion
Por excess air
53.4
18.7
16.7
88.8 or 531 SCFM
Fuel Oil Required
lb/hr
Air Required
SCEM
No preheater
Preheater
86.5
35.7
727
531
Arumal savings in fuel (4000 hrs/yr oPeration)
50.8 ]b X gal X $0.10 X 4000 hr = $2730
hr 7.44 lb gal yr
Annual savings in bla.ver electricity (based on centrifugal bla.ver Performance)
14.4 BHP X (727-531) SCFM = 4.7 BHP
600 SCFM
4.7 BHP X kw
1. 34 HP
Xl
0.85
X 4000 hr
yr
X $0.02 = $ $331
kwh
Capital expense of additional bla.ver capacity - $300.
Btu/hr transferred in preheater
Air goes fram 1300p to 12000p
531 SCFM X 60 Min X 7.3 BTU
- 0
359 hr lb l1Dle P
X (1200-130)
0p = 694,000 BTU
hr
Heat released by cooling products to 500~ (CCl1lputed for determination of
Heat capacity of this stream.
CO2 13.96 [( 1400;-77) 11.45 - (500-77) 9.9] = 153,100 BTU/hr
H20 55.74 [(1400-77) 8.92 - (500-77) 8.2] = 465,000
N2 70.2 [(1400-77) 7.35 - (500-77) 7.1] = 472 ,500
02 3.50 [(1400-77) 7.75 - (500-77) 7.2] = 25,300
Total Heat Released 1,115,900 BTU/hr
54
-------
Using the attached graph, a stream with this heat capacity would only be
o
cooled to 900 F.
Based on a previous quotation for a heat exchanger in similar service,
the purchase price of this heat exchanger is estimated at $16,400 plus $3600
for installation. A cyclone would have to be added to protect the preheater
from erosion. Because the incinerator itself could be smaller due to lesser
air requireITeIlts, the savings in incinerator cost is estimated at $3000; hav-
ever the plenum chamber and distributor would have to be designs for high
temperature. The extra cost incurred for this would be about $6000. Net in-
crease in incinerator cost is then $3000.
Net change in operating cost after preheater addition =
Fuel $2730/yr
Electricity 331
3061/yr savings
Net change in investment after preheater addition =
Cyclone (refractory lined) $ 5,000
Preheater 20,000
Blaver - 300
Incinerator 3,000
$27,700 increase
Return on investment before taxes =
3061
$27,700 X 100 = 11%
This is the minimum ROT rrost companies would consider. The fact that the
corrosion and erosion problems have been severe with knCMl operating 'lll1its
would dissuade all companies from this investment for this particular plant.
OCONOMICS OF A WASTE HEAT BOILER INSTALLATION
Heat ava~lable when flue gases, as shCMl, in the master calculation, are
cooled to 500 F.
lb rroles
hr
195,000 BTU/hr
491,000
645,000
34,000
1,365,000 BTU/hr
C02
H20
N2
°2
17.77
58.89
95.90
4.75
This would be equivalent to
1,365,000 = 11.6
118,000
gal/hr fuel for steam generation
or
11.6 gal X $ 0.10
hr gal
X 4000 hr as a credit
yr
55
-------
1,200,000
800,000
~
0
~ 400,000
..
I
U)
~
~
0
o
400
Figure 15.
800 1200
TEMPERATURE, of
1600
Preheater Tenperature Profiles.
56
-------
A conventional industrial waste heat boiler could be purchased for about
$10,000. The erosion problem resulting fran the carryover fran fluid bed
incinerators would require installation of a hot, refractory-lined cyclone
at about $5000.
Special corrosion problems knONIl to exist fran trace ccmponents with off
gas fran incinerators may raise this to $25,000. Piping and installation, ty-
ing into the existing steam system, and instrurrentation could bring this to
$35,000.
Operation of a boiler in accordance with local codes usually requires an
operator or part of an operator if the boiler is located in the pcMerhouse.
A9surre the effective labor rate for boiler attendance is $0.50/hr - This is a
very optimistic rate and depends on the waste heat boiler being part of an
installation of several standard boilers.
The estimated return on invest:rrent before taxes would then be (4000 hr/yr
operation) :
$4640/~ - $2000/yr X 100 = 7.5% which is unattractive.
35,000
57
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SECl'ION V
SUMMARY OF THE PR!XESS DESIGN
DESCRIPI'ION OF THE PROCESS
The process equiprrent flowsheet for the processing of paunch
rranure is shCMll in Figure 16 (procedyne Corporation Drawing D-05149) .
Paunch rranure and fluid fran the paunch sack (OA), plus water fran
the table and fran sack washing operations (OB), currently runs by gra-
vity to an existing paunch storage bin. A new screw conveyor (2700)
will be installed in the bin to feed paunch to the slurry transfer
purrp (1100).
Stream 2A, fran the transfer purrp (1100), is fed to the primary
dewaterer (1200), a screening device which seperates the coarse solids
in the paunch rranure stream (stream 3A) from the free water and fines
(stream 3B). That stream is fed into a dewaterer (1300) which dis-
charges material with solids content raised to approximately 37%
(stream 4A). Stream 4A is fed into the fluid bed incinerator (0100) via
screw conveyor system (1400). Stream 4A contains approximately 2/3 of
the solids to be incinerated.
Returning to the screening device (1200), the liquid stream 3B is
fed into a settler (1500) where it is settled before becoming part of
a feed stream to sand filter (1700). That feed stream (6A) is canbined
with the liquid stream (4B) from the dewaterer and transferred via pump
1600 to filter 1700. Solids content of stream 6A + 4B is estimated to
be approximately 4.5% and contains approximately 1/3 of the solids to be
incinerated by the fluid bed incinerator 0100. Filter 1700 is also fed
with clean recycled sand overflowing fran incinerator 0100 (stream 5B) .
Product stream 7A from the filter, containing approximately 15% solids
(on a sand free basis) is fed to incinerator 0100 using screw conveyor
system 1800. Makeup sand (stream 5A) is also added via conveyor 1800.
Filtrate from the filter (stream 7B) is recycled back to settler 1500
and combines with other streams fran the dewatering part of the process
before entering the sewer system as overflow from the settler 1500
(stream 6B) .
Fluidizing air (stream 5C), which also supplies oxygen for canbustion,
is fed to incinerator 0100 from blower 2400. COI1'bined feed streams 4A
and 7A are expected to contain 25-30% solids on a sand free basis, as
well as the recycling sand used for filtration.
The system is expected to be self incinerating at approximately 30%
solids content. Burner system 1000 is used to burn a small arrount of
oil (5D) to maintain the incinerator terrperature at approximately 15000F
during periods of high lIDisture feed. A burner-fuel system is also
58
-------
required to start up the s~stem, bringing the tanperature of the in-
cinerator to at least 1300 F before starting a feed stream.
Stream 5A contains the prcx1ucts of canbustion, CO2 and water, and
excess air required by the process, as well as a trace of fluidizing
sand carried away from the incinerator by the canbustion gases. That
stream flows through a cyclone separator (1900) which rerroves a high
proportion of the solids from the - canbustion gases, dropping them into
portable ash bin (2000) via stream 8B.
Exit gases leave the cyclone (1900) as stream 8A and are fed to a
water scrubber (2300) for cooling and final rerroval of Particulates
before entering the atrrosphere via stack 9A. Scrubber (2300) is Part
of a system which includes tank (2100) to which IPakeup water is added
via stream 9B. Circulating pump 2200 circulates scrubbing water over
sc~ (2300). OverflCM water from tank (2300) enters the sewer via
stream 9C. Solids, which accumulate by. settling in tank (2100), are
rerroved pericx1ically as a wet ash.
MAJOR EQUIPMENT LIST & W\TERIAL BALANCE
The major equiprent list for the process is as follCMs:
ITEM
DESCRIPl'ION
0100
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
Procedyne Fluid Bed Incinerator
Burner
Slurry Transfer Pump
PrirPary DaY'aterer
Dewaterer
Paunch Conveyor
Settling Tank (Procedyne)
Filter Feed Pump
Procedyne Sand Filter
Sand Conveyor
Cyclone
Ash Bin (portable)
Scrubber Feed Tank
Scrubber Feed Pump
Scrubber
BlCMer
Panel Board (Procedyne)
Settler Feed Pump
Paunch Bin Conveyor
Figure 17 (Procedyne Drawing D-05l4l) gives the results of all calcu-
lations made on process flCMs. Streams described above and illustrated
in Figure 16 are all defined in tenns of flCM rate. Data used for the
calculations are described in Section II and calculations presented in
Section IV.
59
-------
~
ZA.
.
I i
. ,
~--~"J . . .~O
t ' .
,.
i~
Existing 110:)
Paunch
Bin
(j)
o
Figure 16.
Process f10wsheet
~c
___._e______--
7S
010:)
~A
SA. B
I
~
z'go
w
Fuel oil
8A
SA
2300
r---1
T S&
9C~ ater
]( 2200
EQUIPMENT LIST
0100
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
INCINERATOR
BURNER
SLURRY TRANSFER PUMP
PRIMARY DEWATERER
DEWATERER
PAUNCH CONVEYOR
SETTLING TANK
FILTER FEED PUMP
SAND FILTER
SAND CONVEYOR
CYCLONE
ASH BIN (PORTABLE)
SCRUBBER FEED TANK
SCRUBBER FEED PUMP
SCRUBBER
BLOWER
PANEL BOARD
SETTLER FEED PUMP
PAUNCH BIN CONVEYOR
-------
tIA
"tf6'ff
5A
t:rr:LDIV&
I
'"
""Ll~"
rANK
tA
c/.atrt/h
,JA,
#I
I>LW"'''£.IICII
IIKI/'ICII no.«
'8
58
.$CII1UJlI£/f
44
~
66.
&.1
1'/1 TO'
TA
5~
iernE'''
5b
'"
TB
0'\
......
STJ!F">.H UNITS OA 08 1 2A 3A 38' 4A 48 5A 8 5C 0-55 6A 68 7A 8 BA 88 9A 98 9C ~OTES
1 Patmch Manure 8.D.5. '/hr 731(2 731 365 292 73 241 51 - - - 69 37 87 87 33 - - 1. Fnt'l Oil i, aS$um~-d to bt' '2 FuC'1 011-
- - 1 \ max. sulfur per Chicago Environ-
2 Water (Bound) I/hr 3582 - 3582 1791 1333 458 364 - - - - - - - - - - - mental Control Ordinance (~apter 17)
3 Water (Free) '/hr 912 0,000 1O~12 5456 - 456 - - - - - - - - - - - City of Chicago.
4 Water (Total) '/nr 4494 ,000 14,194 7247 1333 914 364 969 - - 1625 6953 430 2164 - - 3150 2165 2. Based on 8Bd.... feeel rate of 95 cattlel hr.
5 Sand '/hr - - - - - - 10 352 - 10 1352 - - 10 - - -
6 Ash Ilhr - - - - - - - - 26 - - - - - - 11 15 4 - 7 3. Based on allowable particulat8 -155100-
? Total Streaa I/hr 5225 ,000 15)2 7612 1625 987 605 1020 36 352 - 10 1694 6490 1869 2197 11 25 4 3750 2172 Envit'OTm.ental Control 0rdi.uDc..e - (c.apt... 17)
City of Chlcaao.
8 Fuel 011 I/nr - - - - - R - - - - - -
gal/hr - - - - - - - - - 1] - - - - - - - - -
9 Air '1DDIe/hr - - - - - - - - - 1216 - - - - - -
- - - -
SCFM - - - - - - - - 727 - - - - - - - - - -
10 Flue Gasu 1Il101 e/hr - - - - - - - - 77.34 - .. - - - - - - - - 263.35 - -
11 C02 'role/hr - - - - - - - - 17.77 - - - - - - - - - 17.71 - -
202 'mole/hr - - - - - - - - 4,15 - - - - - - - - - 4. 7S - -
13 N2 'mole/hr - - - - - - - - 95.90 - - - - - - - - - 93.90 - -
4Mz" hlOle/hr - - - - - - - - 58.89 - - - - - - - - - - 146.90 - -
5502 'lIOle/hr - - - - - - - - 0.03 - - - - - - - - - 0.03 - -
6 ota! SCFM - - - - - - - - 1040 - - - - - - - - - - 1590 -
Figure 17.
Material balance
-------
SECI'ION VI
CONCLUSIONS
The results of the pre1iIninary studies have led to a process
design TIDre carp1ex than that originally proposed. The principal
departure from the proposed process being the breakdONI'l of the dewater-
ing operation into two distinct steps. This split in the dewatering
operation was necessitated by the radically differing proPerties of the
coarse and fine fractions of the paunch material.
The project is presently in the engineering design phase for which
the material presented herein forms the design basis. Results of the
design phase will be presented in a subsequent interim technical report.
62
-------
10.
11.
SECl'ION VII
REFERENCES
1.
Hermingson, Durham & Richardson, "Re}X>rt on the Processing and
Disposition of Patmch Manure", prepared for the City of cmaha,
Nebraska, (1964). .
2.
Taiganides, E.P., and Hazen, T.E., "Properties of Fann Animal
Excreta, ""Transactions of the ASAE, Vol. 9, No. 1. pp 374-376
(1966) .
3.
Perry, Chilton & Fitzpatrick, "Perry's Chemical Engineers'
Handbook", 4th Edition, M::Graw-Hill, New York (1963).
4.
Jolly, L., and Stantan, J.E., Journel of Applied Chemistry
(London), 2. 562 (1952).
5.
Leva, M., "Elutriation of Fines from Fluidized SystemS', Chemical
Engineering Progess, 47, 39, (1951). -
6.
Wen, C. Y. and Hashinger, R. F ., American Institute of Chemical
Engineering Journal, 6, 220, (1960).
7.
Zenz, F.A. and Weil, N.A., "A Theoretical-Elrpirical Approach to
the Mechanism of Particle Entrainrrent fran Fluidized Beds." AIaiE
Journal, 4, 472, (1958).
8.
Davidson, J.F., and Harison, D., "Fluidized Particles," CaIrbridge
University Press, New York, (1963).
Rcwe P.N. and Par-..ridge, B.A., "X-Ray Study of Bubbles in Fluid
Beds", Transactions of the Institute of Chemical Engineers, 43,
T157, (1965).
9.
Lewis, W.K., Gilliland, E.R., and Lang, P.M., "Entrainrrent fran
Fluidized Solids," Chemical Engineering Progress Synposiurn Series,
Vol. 58, 65, (1962).
North American Manufacturing Co., "North American Canbustion Hand-
book" First Edition, North American Mfg. Co., Cleveland, Ohio
(1965) .
63
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO. 12. 3. RECIPIENT'S ACCESSION-NO.
EPA-600!2-77-103
4. TITLE'AND SUBTITLE 5. REPORT DATE
June 1977 issuing date
A METHOD OF MANURE DISPOSAL FOR A BEEF PACKING 6. PERFORMING ORGANIZATION CODE
OPERATION - First Interim Technical Report
7. AUTHOR(S) 8. PERFORMING ORGANIZATION REPORT NO.
Roy Ricci
9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT NO.
Procedyne Corporation lBB037
221 Somerset Street 11. CONTRACT/GRANT NO.
New Brunswick, NJ 08903 12060 EOF
12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED
Industrial Environmental Research Lab. - Ci n., OH Interim
Office of Research and Development 14. SPONSORING AGENCY CODE
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268 EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The report contains the preliminary studies, process development, process
calculations, and process design for a system to successfully handle the paunch
manure in a beef slaughtering operation.
These studies resulted in a system in which the paunch manure is collected
from the slaughtering operation and is fed to a screening device which separates
the coarse solids. The screenings are dewatered to a solids content of 37 percent.
This dewatered material is then sent to a fluid bed incinerator via a screw
conveyor. The liquid stream from the screening is fed to a settler and is
combined with the liquid stream from the dewaterer prior to sand filtering.
The filter cake is fed to the incinerator using a screw conveyor. The filtrate
is recycled back to the settler.
17. KEY WORDS AND DOCUMENT ANAL YSIS
a. DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group
Industrial Wastes, Industrial Waste Meat Packing Industry,
Treatment, Incinerators, Dewatering) Paunch Manure Disposal, 13B
Filtration, Meat Fluid Bed Incineration
18. DISTRIBUTION STATEMENT 19. SECURITY CLASS (This Report) 21. NO. OF PAGES
Unlimited IINrl A<:;<:;TFIFO 72
20. SECU RITY CLASS (This page) 22. PRICE
UNCLASS I FI ED
EPA Form 2220-1 (9-73)
64
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Office of Research and Development
Technical Information Staff
Cincinnati, Ohio 45268
OFFICIAL BUSINESS
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33
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