Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED METHOD AND APPARATUS FOR THE SEPARATION
OF MATERIALS HAVING DIFFERENT DENSITIES
(1) Field of the Invention
The present invention relates to a method and apparatus for the separation of
materials having different demities in a mixture of the materials to allow for
use or disposal
of the different materials. In particular, the present invention relates to a
method and
apparatus for separating sand, which is used for bedding animals, such as
cows, from manure
in a sand and manure mixture to allow for easy disposal of the manure and
reuse of the sand.
The present invention also relates to a method and apparatus for use in the
mining industry
to separate materials having different densities.
The use of sand as a bedding for animals such as cows has become increasingly
more widespread. It has been found that the use of sand as a bedding material
for cows has
several advantages over the traditionally used chopped straw, sawdust or wood
shavings.
Some of the benefits are improved udder health, increased cow comfort, cleaner
cows,
improved traction and lower cost. One; drawback to the use of sand is the
significant handling
and storage problems associated with the resulting manure and sand mixture.
The sand in the
mixture obstructs the pumps normally used to irrigate the manure suspension
onto the
surrounding ground surface. hurther, when the mixture is filled into pits, the
sand eventually
settles out of the mixture and fills the pit thus, requiring another pit or
excavation of the pit.
Either method of disposal is costly which can
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negate the benefits associated with the use of sand. To
allow for easy disposal or storage of the mixture, the
manure and sand must be separated. In the past, there
was no quick and inexpensive way of separating the
manure from the sand.
(2) Description of the Related Art
The related art has shown an assortment of
liquid and solid separation systems common to waste
water treatment operations as well as the dairy, mining
and petroleum refining industries. The publication
"Handling and Storage Systems For Sand-Laden Dairy
Manure From Free Stall Barns", The Proceedings of the
Third International Dairy Housing Conference, Dairy
Systems for the 21st Century, 1994 ed. Ray Bucklin,
American Society of Agricultural Engineers by some of
the inventors describes the current methods of handling
sand-laden dairy manure and of separating sand from
sand-laden dairy manure. The paper also describes the
characteristics of a settled sand profile and provides
suggestions for long term handling and storage of sand-
laden dairy manure. In addition, the publication,
"Analysis of a Batch Aerated Grit Chamber Used to
Separate Bedding Sand From Dairy Manure" 1995 ASAE
Annual International Meeting Paper No. 95-4705 by the
inventors describes several liquid, solid separation
techniques and their effectiveness in separating sand
from manure in a sand and manure mixture.
Some separation systems such as screening and
dissolved air floatation are ineffective for use in
separating manure and sand. Screening is ineffective
due to the similarities in the particle size
distributions of bedding sand and manure. Dissolved air
floatation is ineffective because the minute bubbles are
unable to float the large, coarse manure particles to
the top of the tank for removal. Some other separation
systems such as sedimentation and the hydrocyclone are
more effective but have disadvantages. Sedimentation is
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an effective sand separation technique. However, the
sand and manure settle out as layers with the manure on
top of the sand. The layer of manure on the sand makes
removal of the sand difficult without also removing the
manure. In addition, dilution ratios in excess of 1:1
(mass parts of water to mass parts of sand laden manure)
are required to separate a significant amount of sand
from the manure. The separation does not increase for
dilution rates greater than 3:1. Hydrocyclones have the
potential to be effective sand separators. However, to
be effective, the solid feed concentration must remain
constant which is difficult to achieve with the manure
and sand mixture.
Applications of aeration such as the Pachuca
tank and continuous flow aerated grit chambers might
also be used to separate sand from manure. However, the
prior art does not disclose any such applications using
these methods for the stated materials. Pachuca tanks
are circular vessels with conical bottoms. Air is
introduced at the apex of the conical bottom. The
purpose of the conical bottom is to redirect settled
solids into the upward flowing fluid so that they may be
resuspended. However, because the manure and the sand
co-exist in coagulated clumps of a large size, the
effectiveness of this technique is reduced. Continuous
flow aerated grit chambers consist of either a circular
or rectangular concrete tank with air diffusers
positioned above the bottom of the tank. The chamber
operates as follows: i) influent waste water
containing water, organic matter and grit enters the
tank; ii) the energy inputted to the water by a
continuous air flow creates hydraulic movement of the
water; iii) grit settles out while organic material is
kept in suspension and carried out of the tank; iv) the
accumulated grit is then removed immediately from the
tank; and v) effluent containing water and suspended
organic matter flows out of the tank. The nature of the
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energy adsorption into the fluid is crucial to effective
grit removal.
The related patent art has also shown various
methods and apparatus for separating different materials
having different sizes or weights using air and water to
provide agitation to separate the materials.
Illustrative are U.S. Patent Nos. 2,933,187 to Old et
al; 4,324,652 to Hack and 4,851,036 to Anthes et al.
Old et al describes an apparatus used for the
floatation separation of particles, specifically
concrete. The apparatus consists of a tank having an
inclined bottom along which is mounted a combination
agitator and conveyor. Water and air are introduced
vertically into the deep end of the tank and the feeding
of the material to be separated is downward into the
tank opposite the air and water. In the separation
process, the lightweight material floats and is
discharged over the wall of the tank at the deep end.
The heavier particles are moved along the tank upwardly
toward the remote end where it is discharged. A
removable, vertically oriented screen extends across the
tank, intermediate the ends of the tank and prevents the
lightweight material from moving with the heavy material
toward the shallow end of the tank.
Hack describes a method and apparatus for
scrubbing crude oil (bitumen) from tar-sands. The
apparatus includes a pair of counter-rotating screw
conveyors which tumble the tar-sand so as to rub the
grains together and scrub the oil from the sand
particles while at the same time moving the
progressively cleaner sand toward the discharge end. An
air-aspirating venturi underneath the sand lying in the
bottom of the cell allows for simultaneously flushing
and aerating the sand being tumbled to push the oil
particles through the sand and carrying them to the
surf ace .
Anthes et al describes a process and apparatus
~ 1
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for separating relatively floatable particulate material
from a mixture also having relatively non-floatable,
particulate material. The apparatus includes a column
with at least one baffle to promote turbulence within
the column. Air is introduced into the column below the
point of introduction of the mixture to be separated.
Water is also added to the column. The rates of
introduction of the mixture, air and water and the
number and configuration of the baffles must be such as
to create a substantial amount of turbulence in the
column to keep the relatively floatable particulate
matter at the upper portion of the column.
Also of interest is U.S. Patent No. 4,617,113
to Christophersen et al which shows a floatation
separating system. Only of minimal interest are U.S.
Patent Nos. 2,168,942 to McClave; 4,297,208 to Christian
and 5,368,731 to Pesotini.
There remains a need for an apparatus which
easily and quickly separates the materials having
different densities in a mixture of the materials to
allow for use or disposal of the different materials.
OBJECTS
It is therefore an object of the present
invention to provide an apparatus and method for
separating materials having different densities in a
mixture of the materials to allow for use or disposal of
the different materials. Further, it is an object of
the present invention to provide an apparatus for
separating materials having different densities which
uses air and water to disperse the mixture to separate
the mixture into the different materials. Still
further, it is an object of the present invention to
provide an apparatus for separating materials having
different densities in a mixture of the materials where
the material having the greater density settles out of
the aqueous suspension for removal and the material
having the lesser density is suspended in the aqueous
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suspension for removal. Further still, it is an object
of the present invention to provide an apparatus for
separating sand from manure in a manure and sand mixture
which is quick and inexpensive and which provides
reusable sand and an easily handlable manure suspension.
Further, it is an object of the present invention to
provide a method for separating manure and sand in a
manure and sand mixture which is quick and inexpensive
and which provides reusable sand and an easily handlable
l0 manure suspension. Still further, it is an object of
the present invention to provide an apparatus which uses
air and water to agitate an aqueous suspension
containing the manure and sand mixture in order to
separate sand from manure. Further still, it is an
object of the present invention to provide an apparatus
which uses rotating paddles to help disperse the
mixture. These and other objects will become
increasingly apparent by reference to the following
drawings and the description.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of the
separation apparatus 10 with the mixture loader 102, the
hopper 104, and the upper and lower collection bins 112
and 114.
Figure 2 is a top view of the apparatus 10
without the drive motor 44 showing the conveying and
dispersing screw means 40 with the screw conveying
portion 46 and the dispersing portion 50.
Figure 3 is a cross-sectional view along the
line 3-3 of Figure 2 showing the arcuate insert 16
adjacent the second side 12D of the trough 12 and the
spray bar 56.
Figure 4 is a cross-sectional view along the
line 4-4 of Figure 2 showing the overflow weir 20 and
the lower discharge spout 24.
Figure 5 is a cross-sectional view with parts
in elevation along the line 5-5 of Figure 2 showing the
CA 02214270 1999-11-26
spray bar 56 and the upper discharge spout 14.
Figure 6 is a cross-sectional view along the line 6-6 of Figure 1 showing the
screw conveyor 106 in the feed opening 108.
Figure 7 is a cross-sectional view along the line 7-'~ of Figure 1 showing the
water and air supply hoses 38 and 36, the fluid distribution manifold 26 and
the fluid orifices
28 in the bottom 12E of the trough l:Z.
Figure 8 is a cross-secaional view along the line 8-8 of Figure 1 showing
partition 60, the separate chamber 62 and the aeration tube 64.
Figure 9 is a cross-sectional view along the line 9-9 of Figure 1 showing the
partition 60, the separate chamber 62 and the aeration tube 64.
DETAILED DESCRIPTIOrJ OF TFIE PREFERRED EMBODIMENT
The present invention relates to an apparatus for separating a first material
from
a second, less dense, material in a mixture of the materials, which comprises:
(a) a container
means having a top and a bottom; (b) dispersing means mounted on the container
means
between the top and the bottom of the: container means to disperse and
separate the mixture
in the container means; (c) fluid supply means positioned below the dispersing
means adjacent
the bottom of the container for introducing a fluid into the container means
below the
dispersing means to assist in separating the mixture, wherein the fluid is a
mixture of air and
water; (d) feed means for feeding the mixture above the fluid supply means in
the container
means; (e) first removal means provided in the container means for removing
the first
material from the container means; and (f) second removal means on the
container means for
removing the fluid with the second less dense material from the container
means.
Further, the pr~aent invention relates to an apparatus for separating a first
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material from a second, less dense, material in a mixture of the materials,
which comprises:
(a) an inclined container means having. a bottom and sides between spaced
apart ends with one
of the ends being lower than. the other end wherein the lower end can contain
an aqueous
suspension and wherein the second less dense material overflows from the end
which is lower;
(b) screw means for dispersing the mixture and conveying the first material
mounted between
the ends of the container means in closely spaced relation to one of the sides
and the bottom
wherein the screw means comprises a ahaft with conveying members and
dispersing members
along the shaft between the ands of the container means, the shaft of the
screw means is
rotatable to rotate the conveying members to convey the first material out of
the other end of
the container means which is higher and to rotate the dispersing members to
disperse the
mixture; (c) fluid supply means for introducing a fluid into the container
means intermediate
the ends wherein the fluid includes air and water; (d) drive means for
rotating the shaft of the
screw means; (e) spray means mounted along a segment of the container means
above a water
level in the container means for washing the first material conveyed by the
screw means; and
(f) feed means for feeding the; mixture; above the fluid supply means in the
container.
Still further, the present invention relates to a method for separating a
first
material from a second, less dense, material in a mixture having the first and
second
materials, which comprises: (a) providing an apparatus including a container
means having
a top and a bottom; dispersing means mounted on the container means between
the top and
the bottom of the container means to disperse and separate the mixture in the
container means;
fluid supply means positioned lbelow the dispersing means adjacent the bottom
of the container
for introducing a fluid into the container means for suspending the second
less dense material
and for dispersing the mixture;, wherein the fluid is a mixture of air and
water; feed means
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for feeding the mixture above the fluid supply means in the container means;
first removal
means provided in the container means for removing the first material from the
container
means; and second removal :means on the container means for removing the fluid
with the
second less dense material from the container means; (b) depositing the
mixture into the feed
S means of the apparatus which feeds the mixture into the container means
containing an
aqueous suspension and into t:he dispersing means; (c) activating the
dispersing means and the
fluid supply means to agitate the aqueous suspension to disperse the mixture
in the aqueous
suspension and to separate tle first material from the second material in the
mixture; (d)
removing the first material from the container means through the first removal
means; and
(e) removing the second material from the container means through the second
removal
means.
Finally, the present invention relates to a method for separating a first
material
from a second, less dense, material in a mixture having the first and second
materials, which
comprises: (a) providing an inclined container means having a bottom and sides
between
spaced apart ends with one of the ends. being lower than the other end wherein
the lower end
can contain an aqueous suspension and wherein the second less dense material
overflows from
the end which is lower; screw means for dispersing the mixture and conveying
the first
material mounted between the: ends of the container means in closely spaced
relation to one
of the sides and the bottom wherein the screw means comprises a shaft with
conveying
members and dispersing members along the shaft between the ends of the
container means,
the shaft of the screw means is rotatable to rotate the conveying members to
convey the first
material out of the other end of the container means which is higher and to
rotate the
dispersing members to disper;;e the mixture; fluid supply means for
introducing a fluid into
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the container means intermediate the ends for suspending the second less dense
material and
for dispersing the mixture wherein thE: fluid includes air and water; drive
means for rotating
the shaft of the screw means; spray means mounted along a segment of the
container means
above a water level in the container means for washing the first material
conveyed by the
screw means; and feed means for feeding the mixture above the fluid supply
means in the
container means with the fluid supply means, screw means and spray means
activated; (b)
introducing the first material and the second less dense material into the
feed means which
feeds the mixture into the container means containing an aqueous suspension;
(c) activating
the dispersing means and the 1.-'luid supply means to agitate the aqueous
suspension to disperse
the mixture in the aqueous :suspension and to separate the first material from
the second
material in the mixture; (d) removing the first material through the screw
means by conveying
the first material out of the other end of the container means which is
higher; and (e)
removing the second material and the fluid by flowing the second less dense
material and the
fluid over the one end of the container means which is lower.
As shown in Figures 1 to 9, the second, less dense material 154 and the fluid
from the fluid supply means or fluid distribution manifold 158 form an aqueous
suspension.
A weir 20 is located adjacent the top of the container means or trough 12 to
allow for
removing the suspended second material 154 and the fluid from the container
means or
trough. The container means or trough 12 slopes upward from the first or lower
end 12B to
the second upper end 12A at ;i slope o~f between about 1 ° and 45
° . The container means or
trough 12 adjacent the second or upper end 12A has opposed sides 12C and 12D,
wherein one
of the sides 12D has an arcuate shape. and the other side 12C forms a right
angle with the
bottom 12E of the container means or trough 12. A spray means or spray bar 56
is provided
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along the top of the container means or trough 12 adjacent the side 12D having
the arcuate
shape for washing the first material 152 as it is moved upward by a screw
means 40 toward
the second or upper end 12A of the container means or trough 12. The screw
means 40 has
first and second portions 46 and SO which share a unitary shaft 42. The first
portion or
dispersing portion 50 of the screw means 40 has paddles 52 which act as a
dispersing means
to disperse the mixture 150 and as a conveying means to move the first
material 152 toward
the second or upper end 12A of the container means or trough 12. The second
portion or
screw conveying portion 46 of the screw means 40 has screw members or flights
48 which
act to convey the second material 154 toward the second or upper end 12A of
the container
means or trough 12. The mixture 150 is slowly fed into the trough 12 from a
hopper 104 by
a screw feed or conveyor 106.
Other specific embodiments of the method and apparatus are now briefly
described. The apparatus of the first embodiment includes a tank with an upper
grate, a
lower grate, an air supply tube and a water supply tube. The apparatus of the
second
embodiment includes a tank having a screened grate, an air supply tube and a
water supply
tube. The apparatus of the third embodiment includes a tank having an upper
portion and a
conical lower portion with a grate between the two portions. In operation, all
three
embodiments essentially operate similarly. The chamber of the tank is filled
with water. The
mixture is then dumped into the chamber to form the aqueous suspension with
the water. In
all three embodiments, the flow of air and water if present, agitates the
mixture in the
suspension which causes the mixture to break down and the sand to separate
from the manure.
The sand settles on the floor of the tank while the manure remains suspended
in the
suspension.
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Figure 1 shows the preferred separation system 100 which uses the separating
apparatus 10 of the present invention. The mixture 150 is separated into first
and second
materials 1S2 and 154 with tlhe second material 154 being less dense than the
first material
152. In addition, a third material 156 is preferably also contained in the
mixture 150 and
separated from the first and second material 152 and 154. However, in a
preferred
embodiment, the separation of the third material 156 is by the density and
size of the third
material 156. In a preferred embodiment, the first material 152 is sand, the
second less dense
material 154 is animal manure and the third material 156 is preferably coarse
undigested feed
It is understood that the system can be used to separate a variety of
different mixtures having
materials of different
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densities. For instance, in the aggregate industry, the
system could be used to separate sand and clay.
The separation system 100 includes a material
loader 102, a hopper 104, the separation apparatus 10
and an upper and lower collection bin 112 and 114. The
system 100 is used to separate materials 152 and 154
having different densities which are mixed together in
a mixture 150. The material loader 102 is preferably a
standard front end loader such as those well known in
the art (Figure 1). However, any means of loading the
mixture 150 into the hopper 104 can be used. The feed
bin or hopper 104 is preferably similar to those well
known in the art. The hopper 104 preferably has a wide
open top and narrows toward the bottom. A screw
conveyor 106 is located in the bottom of the hopper 104
for moving the mixture 150 from the hopper 104 and out
the feed opening 108. A drive motor 110 is provided to
rotate the screw conveyor 106. The hopper 104 is
positioned so that the feed opening 108 is directly over
the fluid orifices 28 in the bottom 12E of the trough 12
(to be described in detail hereinafter). The shape of
the hopper 104 and the size of the screw conveyor 106
and the~feed opening 108 allows only a limited amount of
the mixture 150 to be fed into the separation apparatus
10 at one time. The metering of the mixture 150 into
the separation apparatus 10 allows the mixture 150 to be
separated easier and more efficiently.
The separation apparatus 10 includes a trough
12, a fluid distribution manifold 26 and a conveying and
dispersing screw means 40 (Figure 2). The trough 12 has
an upper end 12A and a lower end 12B with opposed first
and second sides 12C and 12D and a bottom 12E extending
therebetween forming an upper portion 12F and a lower
portion 12G. In the upper portion 12F of the trough 12,
the sides 12C and 12D of the trough 12 are perpendicular
to the bottom 12E of the trough 12 with the top of the
trough 12 open (Figure 3). In the upper portion 12F,
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the tops of the sides 12C and 12D opposite the bottom
12E have flanges 12H which extend outward away from the
inside 12I of the trough 12. In the lower portion 12G
of the trough 12, the sides 12C and 12D adjacent the
bottom 12E of the trough 12 are perpendicular to the
bottom 12E. The sides 12C and 12D extend upward a short
distance perpendicular to the bottom 12E. The sides 12C
and 12D then angle outward away from the other side as
the sides 12C and 12D extend upward. The top of the
trough 12 at the lower portion 12G is wider than the
bottom 12E of the trough 12 (Figures 7 to 9). The sides
12C and 12D of the lower portion 12G of the trough 12
extend upward at about an 18° angle from the vertical
perpendicular to the bottom 12E of the trough 12. The
slope of the sides 12C and 12D of the lower portion 12G
of the trough 12 is such as to control the turbulence
and water velocity in the pool area at the lower end 12G
of the trough 12. The shape of the lower portion 12G of
the trough 12 allows the first material 152 to be
retained in the trough 12 without allowing the second
material 154 and the first fractions of the first
material 152 to settle out of the aqueous suspension
158. The angled sides 12C and 12D of the lower portion
12G of the trough 12 allow for faster and more efficient
separation of the mixture 150. The lower portion 12G of
the trough 12 adjacent the lower end 12B forms a pool
area. The trough 12 is inclined upward such that the
lower end 12B of the trough 12 is lower than the upper
end 12A of the trough 12. The trough 12 is preferably
mounted on legs 15. The legs 15 can be provided with
wheels (not shown) to allow the trough 12 to be
portable. The trough 12 preferably angles upward at a
slope of between 1° and 45° with about 18° being
preferred. A shallow groove 12J is provided in the
bottom 12E of the trough 12 adjacent the first side 12C
of the trough 12. The groove 12J extends the entire
length of the upper portion 12F of the trough 12. A
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wash water outlet 18 would be provided in the bottom 12E
of the trough 12 at the upper end 12A adjacent the first
side 12C of the trough 12. In a preferred embodiment,
the wash water outlet 18 is provided directly in line
with the groove 12J and is aimed such as to discharge a
f low of water down the trough 12 in the groove 12J as
needed. An upper discharge spout 14 is located in the
bottom 12E of the trough 12 adjacent the upper end 12A
of the trough 12. In a preferred embodiment, the trough
12 has a length of 99 inches (21 cm) between the ends
12A and 12B with the upper portion 12F having a length
of 48 inches (10 cm). In the upper portion 12F, the
sides 12C and 12D of the trough 12 have a height of 10.0
inches (25.4 cm) and the bottom 12E has a width of 12.0
inches (30.5 cm). In the lower portion 12G, the bottom
12E has the same width as in the upper portion 12F of
the trough 12. However, the sides 12C and 12D of the
trough 12 at the lower end 12B have a height of about
21.0 inches (53.3 cm) such that the trough 12 is deepest
at the lower end 12B of the trough 12. The sides 12C
and 12D and bottom 12E of the trough 12 are preferably
constructed as a unitary piece. The trough 12 is
preferably constructed of steel, however, any similar
durable material can be used.
An arcuate insert 16 is mounted in the inside
12I of the trough 12 between the second side 12D and the
bottom 12E of the trough 12. In a preferred embodiment,
the arcuate insert 16 extends the entire length of the
upper portion 12A of the trough 12. Preferably, the
arcuate angle of the arcuate insert 16 is dependent on
the radius of the flights 48 on the conveying portion 46
of the conveying and dispersing screw means 40 (to be
described in detail hereinafter). The arcuate insert 16
creates an arcuate shape along the second side 12D of
the trough 12 adjacent the bottom 12E of the trough 12.
In a preferred embodiment, the arcuate insert 16 is
mounted in the trough 12 however, the trough 12 could
,.
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also be constructed with the second side 12D having an
arcuate lower side portion.
An overflow weir 20 is located at the lower
end 12B of the trough 12. An overflow channel 22 is
located behind the overflow weir 20 on the side opposite
the trough 12. The overflow channel 22 guides the
second material 154 and fluid into a lower discharge
spout 24. The lower collection bin 114 is positioned
below the lower discharge spout 24 to collect .the
removed fluid and second and third materials 154 and
156. Additional overflow weirs 20 are also provided
along the sides 12C and 12D of the trough 12 adjacent
the lower end 12B of the trough 12 to increase the
removal area for the fluid and second and third
materials 154 and 156. The overflow channel 22 is
extended accordingly around the sides 12C and 12D of the
trough 12 such that the overflow channel 22 extends
behind all of the overflow weirs 20. The height of the
overflow weir 20 is preferably adjustable to allow
variations in the water level. In a preferred
embodiment, the top of the overflow weir 20 is
positioned 2.5 inches (6.4 cm) down from the height of
the lower end 12B of the trough 12. The trough 12 as
described above with the overflow weir 20, the upper and
lower discharge spouts 14 and 24, the wash water outlet
18, the groove 12J and the arcuate insert 16 is
preferably similar to the fine material screw
classifiers manufactured by McLanahan Corporation of
Hollidaysburg, Pennsylvania.
A fluid distribution manifold 26 is located
below the bottom 12E of the trough 12 in the lower
portion 12G of the trough 12. Fluid orifices 28 are
located in the bottom 12E of the trough 12 over the
fluid distribution manifold 26 and allow the fluid
distribution manifold 26 to be in fluid communication
with the inside 12I of the trough 12 (Figure 7) . The
orifices 28 must be located below the water line in the
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lower portion 12G of the trough 12. In a preferred
embodiment, the orifices 28 are located 28.0 inches
(71.0 cm) from the lower end 12B of the trough 12 and
1.25 inches (3.18 cm) from each side 12C and 12D of the
trough 12. In a preferred embodiment, there is a single
fluid distribution manifold 26 and orifices 28.
However, it is understood that any number of fluid
distribution manifolds 26 or orifices 28 can be used
when necessary. The placement of the fluid distribution
manifold or manifolds 26 and the orifices 28 can be
varied. However, the feed opening 108 of the hopper 104
should be varied accordingly such that the mixture 150
is always.fed directly over the orifices 28. The fluid
distribution manifold 26 has a pair of fluid inlets 30
on each side each having an air inlet 32 and a water
inlet 34 (Figure 7). The air inlets 32 are connected by
air hoses 36 to an air supply (not shown). The air
supply i.s preferably a compressor; however, any type air
supply may be used. The air supply provides 1 to 20 CFM
of air to the manifold 26 with a pressure of 1 to 100
PSI. Preferably, the pressure is not necessary to
overcome the static head of the water in the container
plus the frictional losses in the inlet. The air inlets
32 are preferably connected to an air valve (not shown)
and an air meter (not shown) to allow the user to adjust
the amount of air flowing into the fluid distribution
manifold 26 and the trough 12. The water inlets 34 are
preferably connected to a water supply by water hoses
38. In a preferred embodiment, the water supply is of
any type such as a direct hook up to the water supply
for a building (not shown) housing the apparatus 10 or
to a pond (not shown). In a preferred embodiment, the
water supply provides 1 to 10 gallon/minute/ton per hour
of feed to the water inlets 34. The water inlets 34 are
preferably connected to a water valve (not shown) and a
water meter (not shown) which allows the user to vary
the amount of water entering the fluid distribution
CA 02214270 1997-08-27
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manifold 26 and the trough 12.
A conveying and dispersing screw means 40 is
located between the ends 12A and 12B of the trough 12.
The conveying and dispersing means 40 includes a screw
conveying portion 46 and a dispersing portion 50 which
share a common shaft 42. The shaft 42 is rotatably
connected at the upper and lower ends 12A and 12B of the
trough 12. A drive motor 44 is connected to the shaft
42 at the upper end 12A of the trough 12 to rotate the
conveying and dispersing means 40. The drive motor 44
is preferably a 2 to 25 hp motor. In a preferred
embodiment, the screw 42 has a total peripheral diameter
including the flights 48 of 10 to 44 inches ( cm) and
rotates at a speed of 5 to 30 rpm.
The conveying portion 46 of the screw means 40
extends the entire length of the upper portion 12F of
the trough 12 and into the lower portion 12G of the
trough 12. The conveying portion 46 extends from the
upper end 12A of the trough 12 to-slightly above the
fluid distribution manifold 26. The conveying portion
46 has screw members or flights 48 which are mounted on
the shaft 42 and extend the entire length of the
conveying portion 46. The flights 48 are of such a size
and the conveying portion 46 is positioned such that the
flights 48 are closely adjacent the bottom 12E of the
trough 12 and the arcuate insert 16 (Figure 3). The
flights~48 are spaced apart from the bottom 12E of the
trough 12 and the arcuate insert 16 a distance of
between 1 times and up to 4 times the diameter of the
largest particle of the first material 152 to be removed
by the screw conveying portion 46 of the trough 12 and
the arcuate insert 16 so that two particles can not get
caught between the flights 48 and the trough 12 or
arcuate insert 16. This helps to prevent the conveying
and dispersing screw means 40 from jamming. The
diameter of the largest particle of the first material
152 is preferably about 0.5 inches (1.3 cm) and the
CA 02214270 1997-08-27
.. ,,
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flights 48 are spaced a distance of 0.5 to 2.00 inches
( cm) from the bottom 12E of the trough 12 and the
arcuate insert 16. Preferably, the flights 48 do not
extend above the sides 12C and 12D of the trough 12.
Preferably, the flights 48 extend outward from the
center line of the shaft 42 5 inches to 22 inches in
radius and are preferably spaced 5.0 inches (12.7 cm)
apart center to center such that the pitch ( f 1 fight to
flight the diameter) is between 0.25 and 0.50 inches
(0.64 and 1.3 cm) the peripheral of the shaft 42 with
the flights 48.
In a preferred embodiment, the dispersing
portion 50 of the screw means 40 extends from the lower
end 12B of the trough 12 to slightly above the orifices
28 of the fluid distribution manifold 26 toward the
upper end 12A of the trough 12. The dispersing portion
50 includes paddles 52 mounted on the shaft 42. The
paddles 52 extend outward a distance of from center line
5 inches to 22 inches (12.7 cm to cm). The paddles
52 are preferably spaced 5.0 inches (12.7 cm) apart
center to center along the shaft 42 and are spaced 90°
apart in a spiral around the shaft 42. In some cases,
they are closer or further apart. A flight 54 similar
to the screw flights 48 of the conveying portion 46 is
positioned on the end of the shaft 42 adjacent the lower
end 12B of the trough 12 (Figure 4). The flight 54 acts
to prevent the aqueous suspension 158 contained in the
lower portion 12G of the trough 12 from building up and
packing around the bearing (not shown) around the shaft
42. The flight 54 moves the first material 152 away
from the bearing similar to the flights 48 of the screw
conveying portion 46.
A spray bar 56 is mounted on the flange 12H on
the second side 12D of the upper portion 12F of the
trough 12. The spray bar 56 is positioned parallel to
and above the conveying portion 46 of the conveying and
dispersing screw means 40. The orifices 58 of the spray
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bar 56 are located on the inner side of the spry bar 56
and are angled downward such that the spray bar 56
sprays water on the flights 48 of the conveying portion
46 adjacent the arcuate insert 16 (Figure 5). The
orifices 58 are positioned at approximately a 45° angle
with the second side 12D of the trough 12 so as to move
the removed third material 156 toward the first side 12C
of the trough 12. In a preferred embodiment, the spray
bar 56 is connected to the same water supply as the
water inlets 34 of the fluid distribution manifold 26.
The spray bar 56 preferably has a length such as to
extend 75% of the length of the conveying portion 46 of
the dispersing and conveying means which extends above
the water level in the lower end 12B of the trough 12.
In a preferred embodiment, the spray bar 56 has a length
of about 24 inches ( 61. 0 cm) and an inner diameter of
0.0625 inches (0.1588 cm). The orifices 58 have a
diameter of 0.0625 inches (0.1588 cm) and are spaced 10
inches (2.54 cm) apart at the lower end 12B and about
2.0 inches (5.08 cm) at the upper end 12A near the upper
end 12A of the trough 12. The greater spacing of the
orifices 58 at the upper end of the spray bar 56 allows
for better dewatering of the first material 152 as the
material 152 moves toward the upper discharge spout 14.
Preferably, the majority of the third material 156 and
other organic solids have been washed from the first
material 152 before the first material 152 reaches the
upper end 12A of the spray bar 56. The spray bar 56
preferably has a water output of 4 gallon/minute
preferably 1 to 10 gallon/ton per hour of manure..
A partition 60 is located in the lower portion
12G of the trough 12 adjacent the first side 12C
(Figures 7 to 9). The partition 60 extends the entire
length of the lower portion 12G of the trough 12. The
bottom of the partition 60, except for at the front part
60A of the partition 60, is mounted on the side 12C of
the trough 12 just below the point at which the side 12C
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.. .. . .
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begins to angle outward so that the partition 60 forms
a wall in the trough 12 perpendicular to the bottom 12E
of the trough 12. The partition 60 with the angled
first side 12C of the trough 12 forms a V-shaped chamber
62. The front part 60A of the partition 60 adjacent the
upper portion 12F of the trough 12 is bent inward toward
the conveying and dispersing screw means 40 such that
there is a space between the bottom of the partition 60
and the first side 12C of the trough 12. The partition
60 preferably is of a height as to be flush with the top
of the sides 12C and 12D of the trough 12. The fluid
supply means 64 is positioned along the bottom of the
chamber 62. The fluid supply means 64 preferably
extends from the lower end 12B of the trough l2.to the
point where the partition 60 begins to bend inward away
from the second side 12D of the trough 12 such that the
entire tube 64 is located below the water level in the
chamber 62. The secondary fluid distribution manifold
64 provides both air and water into the chamber 62.
IN OSE
To use the separation system 100, the system
100 is first configured such that the feed opening 108
of the hopper 104 is directly above the fluid orifices
28, the upper collection bin 112 is beneath the upper
discharge spout 14 and the lower collection bin 114 is
beneath the lower discharge spout 24. Next, the water
and air inlets 34 and 32 of the fluid distribution
manifold 26 are connected to the water and air supplies
respectively. The spray bar 56 and the wash water
outlet 18 are also connected to the water supply and the
aeration tube 64 is connected to an air supply.
Preferably, only one water supply and one air supply is
needed. The fluid distribution manifold 26, the spray
bar 56, and the aeration tube 64 are preferably all
activated prior to inserting the mixture 150 into the
trough 12. However, it is possible to activate the
spray bar 56 and the aeration tube 64 after the
.,
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apparatus 10 has begun operating. The wash water outlet
18 is activated as needed when the upper portion 12F of
the trough 12 appears clogged with the third material
156. The mixture 150 is then dumped into the hopper 104
using the mixture loader 102. The drive motor 44 is
activated to begin rotation of the conveying and
dispersing screw means 40. Next, the screw conveyor 106
in the hopper 104 is activated and the mixture 150 is
fed into the trough 12. In a preferred embodiment, the
mixture 150 is not fed into the trough 12 until the
water level in the lower portion 12G of the trough 12 is
level with the overflow weir 20 at the lower end 12B of
the trough 12 (Figure 4). As the mixture 150 moves
along the screw conveyor 106, the mixture 150 is spread
out so that the mixture 150 is carefully metered into
the trough 12. As the mixture 150 leaves the feed
opening 108, the mixture 150 drops into the trough 12
above the fluid distribution orifices 28 and the paddles
52 of the dispersing portion 50 of the conveying and
dispersing screw means 40. The rotating paddles 52
contact the mixture 150 and act to disperse the mixture
150. The contact of the rotating paddles 52 with the
water in the lower portion 12G of the trough 12 also
acts to further disperse the mixture 150 which has
entered the water in the pool area in the lower portion
12G of the trough 12. In addition, the air and water
introduced through the fluid distribution orifices 28
also helps to disperse the mixture 150. As the mixture
150 becomes dispersed, the mixture 150 and the water in
the pool area form an aqueous suspension 158, the upward
momentum imparted by the air and water introduced
through the fluid distribution orifices 28 into the
aqueous suspension 158 causes the second material 154 to
become suspended in the aqueous suspension 158. The use
of air along with the water to disperse the mixture 150
and create the current f low in the aqueous suspension
158 decreases the total amount of water needed n the
CA 02214270 1997-08-27
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separation process. As a result of using less water the
second material 154 is less diluted and has less volume
when it flows out of the lower discharge spout 24 which
means that less area is needed for storage of the
separated second material 154. Using less water also
reduces the cost of operating the system 100. As the
separation process continues, the level of the aqueous
suspension 158 in the lower portion 12G of the trough 12
rises so that the aqueous suspension 158 including the
second material 154 and the water flows over the
overflow weir 20 at the lower end 12B of the trough 12.
The second material 154 flows into the overflow channel
22 and out through the lower discharge spout 24 into the
lower collection bin 114. At the same time, the first
material 152 which has a greater density settles out of
the aqueous suspension 158 onto the bottom 12E of the
trough 12 due to gravity. The first material 152 which
has settled on the bottom 12E of the trough 12 is moved
upward by both the paddles 52 of the dispersing portion
50 or the screw flights 48 of the conveying portion 46
of the conveying and dispersing screw means 40 depending
upon the location of the first material 152 in the
trough 12. The paddles 52 of the dispersing portion 50
move the settled first material 152 toward the flights
48 of the conveying portion 46 of the conveying and
dispersing screw means 40. As the first material 152 is
moved upward out of the aqueous suspension 158 and into
the upper portion 12F of the trough 12, the close
proximity of the flights 48 of the screw conveying
portion 46 with the bottom 12E of the trough 12 and the
arcuate insert 16 prevents the first material 152 from
sliding back into the aqueous suspension 158. As the
first material 152 is moved upward by the screw
conveying portion 46 of the conveying and dispersing
screw means 40, the water from the spray bar 56 acts to
wash the first material 152 to remove additional amounts
of the second material 154 as well as other material
CA 02214270 1997-08-27
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such as the third material 156. The wash water outlet
18 at the upper end 12A of the trough 12 introduces a
flow of water along the first side 12C of the trough 12
preferably in the groove 12J in the bottom 12E of the
trough 12 which moves the removed second material 154
and other materials 156 down the trough 12 and into the
aqueous suspension 158. The groove 12J in the upper
portion 12F of the trough 12 allows the removed second
other materials 154 to flow down the trough 12
undisturbed by the flights 48 of the screw conveying
portion 46.. The flow of water from the wash water
outlet 18 and the spray bar 56 also creates a current
flow which causes the aqueous suspension 158 and the
suspended second material 154 to flow over the overflow
weir 20 at the lower end 12B of the trough 12. In
addition, the flow of water down the trough 12 past the
flight 48 creates a syphoning effect which acts to
remove additional water from the first material 152 as
the first material 152 is conveyed up the trough 12.
The inclined angle of the trough 12 also aids in
allowing the water in the first material 152 to drain
back into the lower portion 12G of the trough 12. The
separated, washed and relatively dewatered first
material 152 is conveyed up the trough 12 through the
upper discharge spout 14 and into the upper collection
bin 112.
In a preferred embodiment, the mixture 150
also contains a third material 156 made up of large
sized, coarse components. The third material 156
settles out of the aqueous suspension 158 with the first
material 152 and is moved upward out of the aqueous
suspension 158 by the flights 48 of the screw conveying
portion 40. As the third material 156 is moved upward,
the third material 156 is washed from the first material
152 by water from the spray bar 56. The third material
156 is washed into the groove 12J in the bottom 12E of
the trough 12 and is then washed down the trough 12 by
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water from the wash water outlet 18. As the large sized
coarse components of the third material 156 are washed
downward, the third material 156 is diverted by the
partition 60 into the separate side chamber 62 in the
lower portion 12G of the trough 12. The partition 60
prevents the coarse third material 156 from continuously
recirculating around the trough 12. The upward flow of
air from the aeration tube 64 in the chamber 62 causes
the third material 156 collected in the chamber 62 to
become suspended in the water in the chamber 62. As the
separation process continues and the level of the
aqueous suspension 158 in the lower portion 12G of the
trough 12 including the chamber 62 rises, the suspended
third material 156 flows over the overflow weir 20 at
the lower end 12B of the trough 12 and into the overflow
channel 22. The third material 156 is recombined with
the first material 152 in the overflow channel 22 and
flows out of the lower discharge spout 24 and into the
lower collection bin 114. The partition 60 also changes
the geometry of the lower portion 12G of the trough 12
which creates a faster flow rate of the first material
152, third material 156 and water over the overflow weir
- 20.
In a preferred embodiment, the mixture 150
contains sand as the first material 152. The second
material 154 is mostly comprised of organic solids such
as animal manure however, the second material 154 can
also contain silt or clay or other material less dense
than sand. The third material 156 is preferably coarse
organic matter such as undigested feed or corn. The
first material 152 which is removed preferably contains
only less than 2.0% organic matter (dry basis). Field
studies have indicated that sand bedding containing less
than 2.0% organic matter (dry basis) is suitable for
rebedding. The second material 154, third material 156
and water which is discharged through the lower
discharge spout 24 contains less than 2.0% sand. The
CA 02214270 1997-08-27
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sand fraction remaining is extremely fine and can be
pumped with little difficulty or resultant wear to
processing equipment. The second material 154, third
material 156 and water which is collected in the lower
collection bin 114 may be used to fertilize and irrigate
using conventional well known methods and apparatuses
for spreading fertilizer. The system preferably
operates as a continuous process and separates 2,000
lbs. of mixture per hour. This would handle about 12 to
15 cows per hour. Eight hours equals a 100 cow herd.
The average number of cows per herd is less than 100.
Large farms may have over 2,000 cows. The amount of
mixture 150 able to be handled by the apparatus will
depend on the size of the container pool volume and the
screw diameter. Overall, the system removes about 95%
of the sand from the mixture 150. It is understood that
the apparatus 10 and system 100 can be made in a variety
of different sizes depending upon the amount of mixture
100 needed to be separated in a given amount of time.
It is intended that the foregoing description
be only illustrative of the present invention and that
the present invention be limited only by the hereinafter
appended claims.
