Note: Descriptions are shown in the official language in which they were submitted.
33';'
This application is a divis1on of Canadian patent
application Serlal No. 2~1,933 filed December 1/, 1~375.
BACKGROUND OF THE INVENTION
:
Many efforts have been made to develop improved ways
of handling cattle excrement and waste wa-ter from the cleaning
of cattle and preparing them for milking. While such material
has some value as fertilizer, modern farming methods rely much
more heavily upon chemical fertilizers to provide carefully ~ -
balanced soil nutriments; and the animal wastes are spread on
the fields principally as a means of distributing them where
they can leach into the soil and be of some additional benefit.
Agricultural authorities have recognized for some time
that ruminant animal feces contain substantial amounts of
undigested fibrous material which is preponderantly short pieces
that consist of bundles of capillary tubes. The undigested
fibrous material has little value for soil building purposes,
and in recent years several efforts have been made to separate
it from the remaining waste material and recover it in a useable
form. Convers~ly, except for the liquid in and around the
~0 capillary tubes of the fibrous material, practically all of the
valuable soil improving chemicals in the animal waste are not in
the undigested fibrous material. The fi~rous material is coarse
enough that it makes the natural animal waste very difficult to
handle with anything but mechanical spreaders; whereas, if the
fibrous material can be separated from the liquids and finer
solids, the latter can be handled by an ordinary slurry pump
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which distributes it like liquid fertili~er.
SUMMAR~ OF THE INVENTION
The principal object o~ the invention is to provide a
method, or process and apparatus for rapidly and inexpensively
separating the feces of ruminant animals into a mass of cleansed
fibxous material which may be used for such purposes as animal
bedding, and a filtrate of liquid and fine suspended solids
which may be used as a liquid fertili~er.
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- A ~urther object of the invention is to provlde
apparatus for performing the above defined method or process
which is sufficiently compact, reliable and inexpensive that it
may be purchased and operated by dairy farmers having moderate
sized dairy herds.
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~ In its broader aspe~ts, the invention to which the
claims of this divisio~al application are directed comprehends
an apparatus for separating from ruminant animal feces the
undigested fibrous material that is preponderantly short pieces
which consist o bundles of capillary tubes. The apparatus
includes a supply tank to receive a slurry that contains
ruminant animal feces and added liquids including urine with
means in the supply tank for agitating the slurry to make it
substantially homogeneous. A first stage separator separates
the slurry into a filtrate consisting preponderantly of liquid ~;
and fine solids, and a filter mass consisting preponderantly of
the`short pieces of fibrous material. The first stage separator
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includes a first s-tage hopper, a foraminous separator drum which
is rota.table on a horizontal axis at the bottom of the hopper, a
squeeze roller surmounting the separator drum slightly
downstream of the vertical diameter of the drum, and means
urginy the squeeze roller against the separator drum with heavy
pressure to compress the capillary tubes and express the
majority of the liquid therefrom. A filtrate discharge is
provided for the separator drum with the filtrate discharge
including a conduit for conducting the filtrate to a storage .:
means for use as liquid fertilizer. Diverter means are provided
for varying the flow to the conduit of the filtrate discharge
hetween substantially zero and substantially lO0~ with the
balance of the filtrate returning to the supply tank. A filter .~
mass scraper blade bears on the separator drum downstream from : ~ :
the sclueeze roller. Means are providecl for pumping the slurry :
from the tank into the hopper and means rotate the separator
drum to force the filter mass forwardly beneath the roller and
onto the scraper. :
The complete system as disclosed includes a storage
pit which recelves feces, urine, wash water and prep water which
forms a slurry; A pit which is 15 feet by l~ feet by lO feet
deep will provide storage of the average daily input from a lO0
cow herd for five days at.an average input of 33 gallons per cow
per day.
Prior to processing through the separation apparatus,
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the slurry is agita-ted for a period o:E about 1~ minutes -to
assure that it is homogenous. The homogenous slurry is then
started through the separating apparatus which includes a first
stage tandem separator, an auger to receive the solid Eil-ter
mass from the first stage separa-tor and mix it with water to
form a suspensi.on, and a tandem second stage separator which
receives the suspension from the auger and completes the
processing of the fibrous material.
In the present disclosure, the term "filter mass" is :~
10 used to define the solid material which is carried through the ~
two separation stages and constitutes the fibrous end product ~ -
that is suitable for use as bedding. The term "filtrate" is
used to define the mixture of liquids and finer solids, there
being a first filtrate which is separated from the filter mass
; in the first stage, and a second filtrate which is separated
from the filter mass in the second stage. The first stage ~;.
separator has a filtrate discharge with a diverter so that the
flow of filtrate may be directed either to a liquid retention ~
pond or returned to the pit to be remixed with the slurry. The -;: :
latter course is followed only if the total volume of liquids in
the slurry is insufficient for proper processing. Ultimately, -
the first filtrate goes to the storage pond for use as liquid
fertilizer. The second filtrate consists principally of water
with very small quantities of liquicls which are desirable for
; use as fertilizer and with some small quantities of suspended
solids, so it is always returned to the slurry storage pit.
The tandem separator units of the first stage separator
and the tandem separator devices of the second stage separator
all consist of a driven foraminous drum, a squeeze roller or
pressure roller, and a scraper which removes the filter mass
from the drum surface. The rollers are forced against -the drum
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surfaces uncler he.avy spring pressure, and the rotation of the
foraminous drums forces the filter mass through the n:ip between
the drum and the roller, and onto the scraper. ~s will ~c
described in detail, the drum structures and roller structures
differ in the various units, as do the spring pressures applied
to the rollers. The objective of the apparatus is to heavily
compress -the short pieces of fibrous material so as to express
as much liquid as possible from the capillary tubes which form
the body of each piece of the fibrous material. "Dirty" liquid
10 is expressed from the capillary tubes in the first stage separa- -
tion, and the tubes take up clean water when the filter mass is
formed into a suspension before going through the second stage
separation. The second stage separa-tion compresses the fibrous
particles much more heavily than does the first stage separa-tion,
thus expressing the clean water and residual "dirty" liquid from
the capillary tubes in a sort of flushing action. As a result,
the filter mass delivered hy the second stage separator is
thoroughly cleansed, odorless, and substantially free of harmful
bacteria. Material produced experimentally has been tested for
klebsiellae and salmonellae bacteria, and the counts have been
negative. There have been positive counts on other types of
bacteria; but in reasonably extensive experimental use of the
product for bedding, no animal illness has been attributed to the
bedding.
The economics of the method and the apparatus are
extremely favorable. Based on experimental data accumulated to
date, the cleansed fibrous material from 100 cows will produce
approximately 36,500 cubic feet of bedding a ycar a~ a cos~ of
about 79 cents per 100 cubic feet. ~
The filtrate sent to -the retention pond has an estimated ~;
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nutrient value o~ approximately $21.35 per day per 100 cows,
based upon the following figures:
1. Nitrogen. 36 pounds per day equals $9.80; based
upon the fact that a 28% nitrogen fertilizer costs $150.00 a
ton.
2. Phosphorus. 46 pounds per day, or $9.70 per day;
based upon the fact that a 46% phosphorus fertilizer costs
$93.00 a ton.
3. Potassium. 26 pounds per day, or $1.85 per day;
based upon the fact that a ton of 60~ potassium fertilizer cos-ts
$85.00.
The filtrate delivered to a retention pond is sufficiently
dilute that it may be pu~ped by an irrigation system or handled
by vacuum tank vehicles. The suspended solids in the filtrate
rise to the surface and form a crust so that the retention pond ;
is substantially odor free also.
The typical "output" for a representative herd is as
follows: ~
1. Volume of raw waste 1000-1200 gallons per day per ; ~-
100 cows.
2. Minimum diluent water-800 gallons per day per 100
cows.
3. Typical processing time-l to 1 1/2 hours per day
per 100 cows.
4. Cubic feet of recovered fibre-100 cubic feet per day
per 100 cows.
5. Filtrate to pond-1300-1500 gallons per day per 100 '~
cows when using 800 gallons per day per 100 cows of diluent water.
6. Electric power requirement-31 kilowat-t hours. At
2.5 cents per kilowatt hour the operating cost for the above output
is 79 cents.
T~IE _ AWINGS
Fig. 1 is a diagrammatic showing of a system embodying
the invention;
Fig. 2 is a plan view of the apparatus, with par-ts
broken away, showing the first and second stage tandem structures
and the conveyor for moving the filter mass from one to the other;
Fig. 3 is a side elevational view taken substantially
as indicated along the line 3-3 of Fig. 2, omitting the second
stage apparatus for clarity of illustration;
Fig. 4 is a side elevational view taken substantially
as indicated along the line 4-4 of Fig. 2, omitting the first
stage apparatus for clarity of illustration;
Fig. 5 is a sectional view taken substantially as
indicated along the line 5-5 of Fig. 2;
Fig. 6 is a sectional view taken substantially as ;
indicated along the line 6-6 of Fig. 2;
Fig. 7 is a ~ragmentary sectional view on an enlarged
scale taken substantially as indicated along the llne 7-7 of
Fig. 5; and
Fig. 8 is a fragmentary sectional view taken substantially
as indicated along the line 8-8 of Fig. 5.
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DETAILED DESCRIPTION OF THE INVENTION
General Description of the System
.
Referring first to Fig. 1, the system of the present
invention includes a slurry storage pit, slurry agitating and
slurry delivery means, indicated generally at S; a first stage
separator, indicated generally at I, which includes a first
separator unit IA and a second separator unit IB; a second stage
separator, indicated generally at II, which includes a first
separator device IIA and a second separator device IIB; and a
conveyor-suspension developer, indicated generally at III, which ~ -
receives the filter mass from the first stage separator I, mixes
it with water to form a suspension, and delivers it to the
second stage separator II.
Filtrate from separator unit IB and from separator ~
devices IIA and IIB is returned to the pit. Filtrate from the ~ :
unit IA is selectively delivered to a pond or returned to the
pit.
The cleansed filter mass from the second stage
separator II may conveniently be received by a conventional
apron type conveyor, indicated generally at C, which delivers
the cleansed filter mass to a storage pile which is in any .
convenient sheltered location.
Fig. 2 shows that the actual layout of the system is
~uite different from the diagrammatic showing of Fig. 1, which
is to be understood as providing a basic component
identification and flow sheet. In practice, the elements I, II
and III are directly above the slurry pit S, and most o the
conduits shown in Fig. 1 do not exist. Filtrate from the first
stage separator which is to return to the pit flows out the
bottom of the separator into the pit. Filtrate from the second
stage separator II flows through a short conduit into the bottom
of the first stage separator I.
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The Slurry Storage Pit,
Agita-tor and Slurry ~elivery
_.
Referring further to E`ig. 1, a slurry storage pit,
indicated generally at 10, consists of a rec-tangular storage
tank which is below the level of the barn and milk house floors
in a location where it may be easily filled with animal e~crelllent,
and wash water and prep wa-ter from the milk house. In most areas
of the country, additional water may be added to the slurry in
the storage pit 10 in order that -the slurry may have a proper
viscosity for handling in the sys-tem. In a location where water
is in short supply, the slurry may be thinned by returning to
the storage pit 10 some or all of the filtrate from the first
stage separator I as well as from the second stage separator II,
with the first filtrate being sent to the storage pond only after
some recycling. Thin slurry is about 5% solids; thick about 10%.
The slurry storage pit 10 is provided with a cover 11
that has openings for conduits which are part of a slurry agitating
and delivery system, indicated generally at 12, and for conduits
which are part of the filtrate handling system IV. There are, ~ !
of course, also suitable removable access closures for servicing
components which are inside the storage pit.
The slurry agitating and delivery system 12 includes a
slurry pump 13 which is located in the bottom of the pit 10 and is
connected by a vertical drive shaft in a pipe 14 with an electric
motor 15. The present system may utilize, for e.~ample, a ten
horsepower single phase motor 15 driving a 600 gpm pump at 800 rpm. ~;~
The pump 13 delivers slurry through a delivery conduit 16
to a tee 17 from which a first branch 18 returns to the pit 10 and
a second branch 19 connects with the first stage separator I.
The return conduit 18 is connected to a rotary joint 20
which is journalled in the pit cover 11, and fi.~edly secured to
the rotary joint 20 is a conduit 21 which terminates in a
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generally horizon-tally disposed ayitatiny nozzle 22. The jo.int
20 is surro~nded by a gear 23 so t~lat lt m~y lo .~ c~ nl .,
an electric mo-tor 24 through a worm 25. The supply of slurry
in the pit 10 may be rendered substantially homoyeneous by
operating the pump 13 in conjunction with the motor 2~ for
rotating the agitating nozzle 22 with the flow of slurry through
the tee 17 being entirely into the return conduit 18.
It has been found -that about 15 minutes of agitation of the slurry
is desirable before any portion of it is delivered through the
conduit 19 to the firs-t stage separa-tor I.
The First _tage Separa-tor I
Referring now particularly to Figs. 2, 3 and 5, the
first stage separator I includes a casing, indicated generally
at 26, part of which provides a hopper, indicated generally at 27,
and the rest of which forms a housing, indicated generally at 28,
for the separator units IA and IB. The casing 26 is best seen
in Fig. 5 to include a hopper frame formed of angle members that
include laterally spaced rear upright angle members 29, front
angle members 30, top angle members 31, and a lower transverse
structural member 32. A hopper back panel 33 is secured to the
rear angles 29, a hopper front panel 34 is secured to the front
angles 30, side panels 35 are mounted on the rear and front angles
29 and 30, and a lower plate 36 is carried upon the structural
members 32. Surmounting the hopper is a sealed top wall 37 which
is secured by bolts so that it is removable for access to the
interior of the hopper. The back panel 33 of the hopper has an
opening through which the conduit 19 communicates with the
interior of the hopper. A cross rod 38 which is pivotally
supported in the rear angles 29 carries a deflector pla-te 39
30 which may be moved from the position i.llustrated in Fig. 5 to a .
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position nearer the delivery condui-t 19. Its p~lrpose is to
prevent slurry from being pumped directly acJainst the drum and
roller of the first separator unit IA.
As seen in Figs. 3 and 5, the hopper side plates 35
have forwardly extending portions 35a which provide the sides .
of the housing 28 for the separator units IA and IB; and spaced
laterally outwardly from the side plates 35-35a are external
lateral frame plates 40 which provide supports for the components
of the two separator units.
10The first separator unit IA consists generally of a
foraminous separating drum assembly, indicated generally at 41;
a squeeze roller assembly, indicated generally at 42; and a
scraper 43 which is mounted upon an inclined slide plate 44 upon
which a filter mass which is separated from the slurry in the
first separator unit slides by gravity into the second separator
unit.
Referring now particularly to Figs. 5 and 7, the
foraminous separator drum assembly 41 includes a transverse shaft
4-5 which is journalled in bearings 46 in the external lateral .~
20 frame plates 40; and fixedly carried upon the shaft 45 is a tube ; ;:
47 which cooperates with fixed annular members 48 to receive .
drum end members, indicated generally at 49, which include
central discs 50, three radial arms Sl, and annular circumfer~ ~-
ential drum skin supports 52. Between the drum end members 59
are several intermediate drum skin supports 53 which are like the
drum end members 49 but of lighter construction. A drum skin
54 is of foraminous sheet metal having an evenly distributed -
pattern of .125 inch diameter holes 55 that are on staggered
centers .1875 inch apart so that the foraminous skin 54 is 40
open area. Bonded to the inner surfaces of the side plate portions
31 1 ;.,~ :
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35a surrounding the drum end members 49 are annular seals 56
which are in sealing contact with the circumferential surfaces
of the skin supports 52 and the e~treme end portions of ~he
skin 54 as seen in Fig. 7. In practice, the drum is 24" long
and 18" in diameter.
Referring now particularly to Figs. 2, 3, 5 and 7,
-the squeeze roll assembly 42 includes a pair of arms 57 which
are mounted upon the external lateral Erame plates 40 on pivots
58. Bearings 59 in the pivoted arms 57 rotatably support a
squeeze roller, indicated generally at 60~ which consists of
a shaft 61 journalled in the bearings 59, an enlarged central
portion 62, and a polyurethane sleeve 63 which is bonded to the
portion 62. The shaft 61 extends through slots in the plates
35-35a which are arcs of circles about the pivots 58. In practice,
the squeeze roller 60 is five inches in diameter, ~ith the enlar~ed
shaft portion 62 providing a three inch core surrounded by a one
inch polyurethane sleeve which has a durometer of 45 (Shore A)
and which is provided with eight grooves 64 that are .0625 inch
deep, .25 inch wide, and have a 9-l/2 lead so that they make
l/4 turn of the roll in its 23-1/2 inch length. Grooves 64
enhance feeding of the filter mass between squeeze roller 60
and drum skin 54. The spiral configuration minimizes loading
of the grooves with fibers and distributes any deflection of ~ ;~
the roller due to fibers packed in the groove throughout the ~
roller revolution. ,
The squeeze roll assembly 42 also includes means,
indicated generally at 65, for forcing the squeeze roller 60
against the drum skin 54 with a heavy pressure. As seen in
Fig. 3, each of the means 65 includes a rod 66 which is pivoted
at 67 on the lateral frame plate 40 and which extends through
- a hole in an inverted channel member that provides a saddle 68
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at the free end of the arm 57. A compression spring 69 surrounds .
the rod 66 and is adjus-tably pres-tressed by means of a nut 70
which screws onto a threaded end portion of the rod 66. In
practice, the springs 6~ may have a rate of 240 pounds pcr inch
of deflection, and are preloaded to 125 pounds. The contact
of the roller 60 with the drum skin 54 is 15 downstream Erom
the vertical diameter of the drum.
The first separator unit is completed by a lower
flexible seal 71 which is mounted upon the lower plate 35 and
bears upon the foraminous skin 54 of the drum assembly 41, and
a rather stiffly flexible upper seal 72 which is mounted upon :
the front hopper wall 34 and bears upon the squeeze roller 60. ~ :
The seal 72 is suf~iciently stiff that it also acts as a
squeegee which scrapes adhered solid material from the squeeze .~
roller so that as such material builds up it may fall o~f the ; .
roller and onto the slide 44. -:
It has been found that although the present apparatus
functions entirely satisfactorily with a hopper that is not .
sealed, the sealed hopper as here disclosed substantially in~
creases the rate in which the slurry may be processed through .
the first separator unit IA. As long as the drum is rotating,
the gas pressure in the top of the hopper 27 forces liquid ~:
through the drum; but when drum rotation is stopped, the solids ~
in the slurry promptly seal the holes 55 in the foraminous drum .
skin and also maintain the seal at the annular seals 56. If
the pressure in the hopper exceeds the head pressure in return
conduit 18 all of the slurry discharged by pump 13 is recircu- ~:
lated through nozzle 22. `
The second separator unit IB consists generally of a
second foraminous separator drum assembly, indicated generally ~ .
-at 73; a squeeze roller assembly, indicated generally at 74;
and a scraper 75.. which is mounted upon a transverse bracket ; :
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plate 76 that is at ~he front of the llo~lsing 28 where thc ~ilter
mass which is separated from the slurry in the second separa-tor
unit slides directly into the conveyor-suspension generator III.
Referrin~ now particularly to Figs. 5 and 7, the sec-
ond foraminous separatox drum assembly 73 is in all structural
respects like the assembly ~1. Generally, it includes a trans-
verse sha~t 77 which is journalled in bearings 78 in the external
lateral frame plates 40; and fixedly carried upon the shaft 77
are drum end members and drum skin supports 79. A drum skin 80 ;~
is of foraminous sheet metal having rows of .25 inch diameter
holes 81 that are .5 inch apart in the rows with an angular
separation of 6 between rows. The foraminous skin 80 is 20%
open area. Bonded to the inner surfaces of the side plate por-
tions 35a surrounding the ends of drum 73 are annular seals
which are like the seals 56 in structure and function. In
practice, the second drum is 24 inches long and 10 inches in
diameter. ~
Referring now particularly to Figs. 2, 3, 5 and 7, the -
squeeze roll assembly 74 includes a pair of arms 82 which are -~
mounted upon the external lateral frame plates ~0 Oll pivots 83.
Bearings 84 in the pivoted arms 82 rotatably support a squeeze
roller, indicated generally at 85, which includes a central core
86 and a polyurethane sleeve 87 which is bonded to -the core 86.
In practice the squeeze roller 85 is five inches in diameter,
with the core 86 three inches and the polyurethane sleeve 87
being one inch and having a durometer of 55 (Shore A). The ~-
sleeve is provided with eight grooves 88 that are .0625 inch
deep, .25 inch wide, and have a 9-1/2 lead do that -they make
1/4 turn of the roll in its 23-1/2 inch length.
The squeeze roll assembly 74 also includes means, in-
dicated generally at 89, for forclng the squeeze roller 85 against
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the drum skin 80 with a heavy pressure. ~s seen in Fig. 3, each
of the means 89 includes a rod 90 which is pivoted at 91 on the
lateral frame plate 40 and which extends through a hole in an
inverted channel member that provides a saddle 92 at the free
end of the arm 82. A compression spring 93 surrounds the rod
90 and is adjustably prestressed by means of a nut 9~ which
screws onto a threaded end portion of the rod 90. In practice,
the springs 93 may have a rate of 500 pounds per inch of deflec-
tion, and are preloaded to 250 pounds. The contact of the roller
85 with the drum skin 80 is 30 downstream from the vertical
diameter of the drum.
Referring now particularly to Figs. 5 and 8, at the
bottom of the first stage separator I is a filtrate receiver
structure, indicated generally at 96. The structure 96 includes
an inclined rear pan 97 which has an integral upright rear wall
98 aligned with the rear hopper wall 33; and -the rear pan 97 and
its rear wall 98 are welded along their side edges to the external
lateral frame plates 40. Substantially at the forward edge of
the inclined pan 97 is a perpendicular intermediate pan 99 whicl
is seen in Fig. 8 to extend only half way across the pan 97, and
as seen in Fig. 5 the intermediate pan 99 is surmounted by a
vertical partition lO0 that extends entirely across the machine -
between the lateral frame plates 40. Spaced forwardly of the
intermediate pan 99 and the upright partition 100 is a front pan -~
that includes an inclined lower portion lOl which directs fil-
trate through an opening in the pit cover ll and a vertical upper
portion 102 that, in effect, forms the front of the housing 28.
The filtrate receiver structure 96 is provided at one
side with an opening having a collar 104 to which a conduit 106
is connected. As seen in Fig. 1, the conduit lOÇ goes to a
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stor~ge pon~ from which -the filtrate may be removed -for use as
fertilizer. The collar 104 is seen in Fiy. 8 to be substantially
at the intersection of the rear inclined pan 97 and the perpen-
dicular intermediate pan 99; and a diverter 108 is pivoted at
109 so that it may be moved by means of an external handle 110
(Fig. S) bet~een a f.irst limit yosition 108a and a second liMit
position 108b which are indicated ln broken lines in Fig. 8.
When the diverter is in the position 108a, one hundred percent
of the filtrate from the firs-t separator uni-t IA, disregarding
leakage under the diverter 108, goes through the collar 104 and
the conduit 106 to the pond. With the diverter in the position
108b, one hundred percent of the filtrate from th~ first unit ..
IA, disregarding leakage, is diverted past the intermediate pan
99 and flows off the front of the rear pan 97 into the slurry
pit 10. Since the filtrate that drai.ns through the skin 5~ of
the first perforated separator drum assembly 41 drains across
the entire width between the side plates or panels 35-35a, by
ad~usting the diverter 108 between its A position and its B posi-
tion an operator can exercise a rough control over the percentage
of filtrate that goes to the pond and the percentage that returns
to the pit. Thus, disregarding leakage, from zero to 100~ may
go to the pond and the balance to the pit.
A frame (not shown) stands on the pit cover 11 and
-supports the first stage separator I above the oyenin~ thro~lgl
which the filtrate returns to the pit.
The Conveyor-Suspension Developer III
As best seen in Figs. 2 and 5, the conveyor-suspension
developer III extends across the front of the firs-t stage sepa-
rator I and across the rear of the second stage separator II, ~:
and it is seen in Fig. 5 to be upwardly inclined from the first
stage separator to the second stage separator. In practice, the ~
angle of inclination is 20 from the horizontal. ~ :
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As seen in Fig. 3, the conveyor-suspension developer
includes a flanged U-shaped trough III which i5 secured to the
upright fron-t wall 102 of the filtrate receiver means 96. As
best seen in Figs. 2 and 6, the trough III extends above the ;
rear end portion of the second stage separator II where it has ~ ;
a discharge opening 112 above the rear of the first separator
device IIA. The trough III has an infeed end panel 113 and an
outfeed end panel 114; and bearings 115 and 116 in the r~spec-
tive end panels rotatably support a helical conveyor, indicated
generally at 117, which consists of a shaft 118 and flight 119. ;~
The shaft projects through the bearing 116 in the outfeed end ~ -
panel 114 and is drivingly connected to an electric gear motor
120 which is supported upon the end panel 114 by a bracket 121.
The conveyor 117 is 6 inches in diameter and 8 feet lon~, and
is driven at a speed of 115 rpm. The flight 119 clears the ;
bottom of the trough 111 by about 1/4 inch.
At the infeed end portion of the trough 111 is an inlet
122 for fresh water which is mixed with the filter mass from the
second separator unit IB to form a suspension of the fibrous
material. The heavily compressed and squeezed capillaries of the
fibrous material have had most of the "dirty" liquid and naturally
occurring mucous squeezed out of them in the first stage separa-
tor, and they promptly absorb fresh water which is subsequently
expressed in the second stage separator II, so the capillaries
of the fibrous material undergo a sort of flushing action. Where
water is scarce, the step of forming a suspension may be elimi-
nated; although the resulting solid end product is not quite as
clean as that produced by the preferred method.
Admission of water to the trough 111 -through the inlet
122 is controlled by a manual valve (not shown); and is also
controlled by a pressure switch 123 in the form of an inverted
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cup which has a fit~ing by means of which i-t is mounted on -the
side of the tro~l~h adjacent the lower end of thc au~er. Wlle
the liquid level rises into the cup it suspends the flow of
water through -the inlet 22.
As seen in Fig. 5, paddle switches 4~a and llla are
suspended, respec~ively, above the slide 44 and the infeed area
of the trough 111. Each such paddle switch serves exclusively a
safety function to shut off the pump 13 and/or the first stage
separator in the event of malfunction or over supply to the
second separator unit IB or oE the helical conveyor 117. ::
The Second Stage Separator
Referring now particularly to Figs. 2, 4 and 6, the
second stage separator II is seen to be quite similar in general
construction to the first stage separator I; but it is
considerably smaller. The second stage separator has a casing,
indicated generally at 125, which includes a hopper portion,
indicated generally at 126, and a housing portion, indicated
generally at 127. Side panels 128 are joined by a back panel
129 that has a small forwardly extending bottom flange 130; and
20 - surmounting the bac~ panel 129 and side panels 128 is a hopper
closure 131 which has a central opening to receive material from
the conveyor outfeed 112.
Spaced outwardly from the side panels 128 are lateral
frame plates 132 which carry the bearings for the foraminous
cylinders and pressure rollers of the separator devices IIA and ::
IIB of the second stage separator. Except for the fact that the
cylinders ahd the pressure rollers are shorter than are the .
separator drum assembly 73 and squeeze roller 85 of the
separator unit IB~ and the pressure rollers have sleeves of
higher durometer, the components o:E the separator devices IIA
and IIB are substantially identical with those of the separator
unit IB. ~ ~
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The First separator device IIA consists generally of
a first foraminous separator cylinder assembly, indica-ted gen-
erally at 133; a pressure roller assembly, indicated generally
at 134; and a scraper plate 135 which is supported upon a slide
136 tha-t feeds a partially clearlsed filter mass into the second
separator device IIB.
The first foraminous separator cylinder assembly 133
is in all structural respects like the assembly 73. Generally,
it includes a transverse shaft 137 which is journalled in bear-
ings 138 in the lateral frame plates 132; and fixedly carried
upon the shaft 137 are cylinder end members and cylinder skin
supports 139. A cylinder skin 140 is of foraminous sheet metal
having rows of .25 inch diameter holes 141 that are .5 inch
apart in the rows with an angular separation of 6 between rows.
The foraminous skin 140 is 20% open area. Bonded to the inner
surfaces of the side panels 128 surrounding the ends of cylinder
133 are annular seals which are like the seals 56 in structure ~;
and function. In practice, the first cylinder is 15" long and
10" in diameter.
Referring now particularly to Figs. 2, 4 and 6, the
pressure roll assembly 134 includes a pair of arms 142 which
are mounted upon the la-teral frame plates 132 on pivots 143.
Bearings 144 in the pivoted arms 142 rotatably support a pres-
sure roller, indicated generally at 145, which includes a central
core 146 and a polyurethane sleeve 147 which is bonded -to the
core. In practice the pressure roller 145 is five inches in
diameter, with the core 146 three inches and the polyurethane
sleeve 147 being one inch and having a durometer of 70 (Shore
The sleeve is provided with eight grooves 148 that are .0625
inch deep, .25 inch wide, and have a 15 lead so that they make
1/4 turn of the pressure roll in its 23-1/2 inch length.
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The pressure roll assembly 13~ also includes means,
indicated generally at 149 (Fig. 4), for forcing the pressure
roller 145 against -the cylinder skin 140 wi-th a heavy pressure.
Each of the means 149 includes a rod 150 which is pivoted at
151 on the lateral frame plate 132 and which extends through a
hole in an inverted channel member that provides a saddle 152
at the free end of the arm 142. ~ com~rcssion sprill~ 153 s~lr-
rounds the rod 150 and is adjustably prestressed by means of a
nut 154 which screws onto a threaded end portion of -the rod 150.
In practice, the springs 153 may have a rate of 2700 pounds per
inch of deflection, and are preloaded to 1300 pounds. The con-
tact of the pressure roller 145 with the cylinder skin 140 is
30 downstream from a vertical diameter of the cylinder.
The second separator device IIB is identical to the
device IIA, and thus is described only generally as including
a foraminous cylinder assembly, indicated generally at 155; a
pressure roller assembly, indicated generally at 156, which in-
cludes a pressure roller 157; and a scraper 158 which is integral
with a slide plate 159 that delivers cleansed fibrous material
to the conveyor C ~Fig. 1). It differs only in that the contact
of the pressure roller 157 with the cylinder assembly 155 is 15 ~
downstream from the vertical diameter of the cylinder, instead ~ ;-
of 30 as is the case with the pressure roller '45.
-On the forwardly projecting flange 130 at the bottom
of the hopper back panel 129 is a flexible sealing s-trip 160
which bears against the skin 140 of the separator cylinder assem-
bly 133.
A second filtrate receiver structure, indicated gener-
ally at 161, includes a rear pan 162 which connects to the hopper
rear wall 129; a downwardly and forwardly inclined bottom pan
163, and a forward pan 164 which connects to the underside of
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-the slide 159. soth sides oE the pans are welded to the lateral
frame plates 132; and the lower, forward end portion of the
bottom pan 163 is laterally inclined as seen at 165 to direct
the second filtrate into an outlet opening which has a collar
166. A conduit 167 connects the collar 166 to a collar 105
(Fig. 8) that surrounds an opening in the adjacent lateral frame
plate 40 of the first stage separator I, so the second fil-trate
drains directly into the pit from beneath the first stage separa-
tor.
As seen in Fig. 6, the hopper 125 of the second stage
separator II is provided with a paddle switch 125a which operates
to stop the conveyor drive motor 120 and the first stage separa-
tor if there is an excessive quantity of suspension in the hopper
126.
Flushing System
There are several areas of the apparatus in which the
filtrate may be so viscous or so small in quantity that it tends
to clog and foul the apparatus; and to avoid this ~ water fl~lsh-
ing system is provided. Figs. 2 and 3 show pipes 168 which
supply water to nozzles at opposite sides of the housing 28 to
flush the interior of the foraminous separator drum for the
separator unit IB.
Figs. 2 and 4 show pipes 169 and 170 which deliver
water to nozzles for flushing the interiors of the foraminous
cylinders in the second stage separator devices IIA and IIB,
respecti~ely. A pipe 171 supplies a set of nozzles which flush
the outer faces of the two cylinders. At the rear, upper end of
the bottom pan 163 of the second stage separator is a pipe 172
which supplies water to a nozzle for flushing that pan.
The apparatus is provided with automatic controls which
stop the motor 15 for the slurry pump every 30 minutes to permit
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the slurry ayitatin~ and delivery condui-ts -to back flush by
gravity, thus clea:ring the inlet to the pump 13 of any material
tending to clog it. At the same time, solenoid valves for the
flush nozzle plumbing 168-172 are opened to Elush the par-ts as
~ust described. This requi.res about 30 second~,and there is
no need to stop the processing of material while it goes on
since the pressurized 'nopper 27 con-tinues to supply slurry to
the first separator unit IA even though the pump 13 is shut
down.
The foregoing detailed description is given for clear- ..
ness of understanding only and no unnecessary limitations should
be understood therefrom as modifications will be obvious to
those skilled in the art.
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