U.S. patent application number 12/769281 was filed with the patent office on 2010-11-04 for high solids material moving apparatus.
Invention is credited to Donald W. Bell, Jeffrey D. Hall, David A. Olson, Wayne E. Soost.
Application Number | 20100278666 12/769281 |
Document ID | / |
Family ID | 43030477 |
Filed Date | 2010-11-04 |
United States Patent
Application |
20100278666 |
Kind Code |
A1 |
Olson; David A. ; et
al. |
November 4, 2010 |
HIGH SOLIDS MATERIAL MOVING APPARATUS
Abstract
Described herein is a material moving apparatus having a chamber
that includes a chamber having a cross-sectional shape and a
discharge opening; a pumping ram mounted in the chamber configured
to move material out of the discharge opening of the chamber; and a
discharge pipe connected to the discharge opening of the pump and
having and an inlet and an outlet and a cross-sectional shape
corresponding to the cross-sectional shape of the discharge
opening.
Inventors: |
Olson; David A.; (Albert
Lea, MN) ; Bell; Donald W.; (Austin, MN) ;
Hall; Jeffrey D.; (Albert Lea, MN) ; Soost; Wayne
E.; (Alden, MN) |
Correspondence
Address: |
PAULY, DEVRIES SMITH & DEFFNER, L.L.C.
Plaza VII-Suite 3000, 45 South Seventh Street
MINNEAPOLIS
MN
55402-1630
US
|
Family ID: |
43030477 |
Appl. No.: |
12/769281 |
Filed: |
April 28, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61174248 |
Apr 30, 2009 |
|
|
|
Current U.S.
Class: |
417/437 |
Current CPC
Class: |
F04B 15/023 20130101;
F04B 15/02 20130101 |
Class at
Publication: |
417/437 |
International
Class: |
F04B 19/04 20060101
F04B019/04 |
Claims
1. A material moving apparatus comprising: (a) a chamber having a
cross-sectional shape and a discharge opening; (b) a ram mounted in
the chamber configured to move material out of the discharge
opening of the chamber; and (c) a discharge pipe connected to the
discharge opening of the chamber and having an inlet and an outlet
and a cross-sectional shape corresponding to the chamber
cross-sectional shape.
2. The material moving apparatus of claim 1, wherein the discharge
pipe has a constant size such that the discharge pipe outlet has a
size that is substantially the same as the discharge pipe inlet
size.
3. The material moving apparatus of claim 1, wherein the discharge
pipe is tapered such that the discharge pipe outlet has a size that
is greater than the discharge pipe inlet size.
4. The material moving apparatus of claim 1, wherein the discharge
pipe includes one or more sections.
5. The material moving apparatus of claim 4, wherein the discharge
pipe includes a substantially constant section in which the inlet
size and the outlet size are substantially the same and a tapered
section in which the outlet size is greater than the inlet
size.
6. The material moving apparatus of claim 4, wherein the sections
of discharge pipe have a stepped configuration in which the inlet
size of a distal discharge pipe section is greater than the outlet
size of an adjacent proximal discharge pipe section.
7. The material moving apparatus of claim 4, wherein the sections
of discharge pipe include sections selected from the group
consisting of constant, tapered and stepped sections.
8. The material moving apparatus of claim 6, wherein the discharge
pipe includes alternating constant and tapered sections.
9. The material moving apparatus of claim 1, wherein the chamber
comprises first and second downwardly converging side walls
defining a longitudinal chamber with a discharge opening having a
downwardly converging cross-sectional shape and the discharge pipe
has a corresponding downwardly converging cross-sectional
shape.
10. The material moving apparatus of claim 9, wherein the
downwardly converging sidewalls converge at a point and the chamber
has a triangular cross-sectional shape and the discharge pipe has a
corresponding triangular cross-sectional shape.
11. The material moving apparatus of claim 1, wherein the inlet of
the discharge pipe has a cross-sectional shape that is similar to
the cross-sectional shape of the discharge opening of the
chamber.
12. The material moving apparatus of claim 1, wherein the inlet of
the discharge pipe has a size that is the same as the discharge
opening of the chamber.
13. The material moving apparatus of claim 1, wherein the inlet of
the discharge pipe has a size that is greater than the size of the
discharge opening.
14. The material moving apparatus of claim 1, further comprising a
low friction coating on one or more interior surfaces of the
discharge pipe.
15. The material moving apparatus of claim 1, further comprising
one or more longitudinal ribs along one or more interior surfaces
of the discharge pipe.
16. A material moving apparatus comprising: (a) a chamber having a
triangular cross-sectional shape and discharge opening having a
triangular cross-sectional shape; (b) a ram mounted in the chamber
configured to move material out of the discharge opening of the
chamber; and (c) a discharge pipe connected to the discharge
opening of the chamber and having an inlet and an outlet and a
triangular cross-sectional shape corresponding to the triangular
chamber cross-sectional shape.
17. A method for pumping a high-solids material comprising: (a)
placing the high-solids material in a pumping chamber having a
cross-sectional shape and discharge opening; (b) pumping the
high-solids material out of the discharge opening of the chamber
into a discharge pipe connected to the discharge opening of the
chamber, wherein the discharge pipe has an inlet and an outlet and
a cross-sectional shape corresponding to the cross-sectional shape
of the chamber.
18. The method of claim 17, wherein the high-solids material
comprises at least 10% solids by weight.
19. The method of claim 17, wherein the high-solids material is
compressible.
20. The method of claim 17, wherein the high-solids material is
selected from the group consisting of: bio-solids, including, saw
dust, yard trimmings, compost, wood chips, straw, grass, corn cobs,
and corn stover; garbage or waste material, including, bottles,
cans, clothing, disposables, food packaging, and food scraps; paper
materials, including, newspapers, magazines, cardboard, office
paper, and paper bags; plastic materials, including milk jugs and
other storage containers; and mixtures and combinations thereof.
Description
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/174,248, filed Apr. 30, 2009, the content of
which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] Material moving pumps are known for moving liquids, solids
or liquid entrained discrete solid material, or other product, for
example manure, straw, crushed animal bones, sawdust, or feathers.
Typically material moving pumps include a ram that reciprocates in
a chamber undergoing a working stroke or power stroke during which
material is moved through the chamber, and a return stroke whereby
the ram returns to its starting position and more material is
introduced into the chamber ahead of it. Such pumps are
satisfactory for the pumping many materials.
SUMMARY OF THE INVENTION
[0003] Described herein is a material moving apparatus that
includes a chamber having a cross-sectional shape and a discharge
opening; a ram mounted in the chamber configured to move material
out of the discharge opening of the chamber; and a discharge pipe
having an inlet and an outlet, wherein the discharge pipe is
connected to the discharge opening and has a cross-sectional shape
that corresponds to the discharge opening cross-sectional shape. In
one embodiment, the discharge pipe outlet has a size that is
substantially similar to the discharge pipe inlet. In another
embodiment, the discharge pipe outlet has a size that is greater
than the size of the discharge pipe inlet. In one embodiment, the
discharge pipe has a substantially constant size such that the
discharge pipe outlet has a size that is substantially the same as
the discharge pipe inlet. In another embodiment, the discharge pipe
is tapered such that the discharge pipe outlet has a size that is
greater than the discharge pipe inlet. In another embodiment, the
discharge pipe has more than one section. In one embodiment, the
discharge pipe sections have a stepped configuration. In another
embodiment, the discharge pipe sections have
alternating/interspersed tapered and constant sections. In one
embodiment, the chamber has a downwardly converging cross-sectional
shape and the discharge pipe has a corresponding downwardly
converging cross-sectional shape. In one embodiment, the downwardly
converging sidewalls of the chamber converge at a point and the
chamber has a triangular cross-sectional shape and the discharge
pipe has a corresponding triangular cross-sectional shape.
[0004] This summary is an overview of some of the teachings of the
present application and is not intended to be an exclusive or
exhaustive treatment of the present subject matter. Further details
are found in the detailed description and appended claims. Other
aspects will be apparent to persons skilled in the art upon reading
and understanding the following detailed description and viewing
the drawings that form a part thereof, each of which is not to be
taken in a limiting sense. The scope of the present invention is
defined by the appended claims and their legal equivalents.
IN THE DRAWINGS
[0005] FIG. 1 is a schematic top plan view of a material moving
apparatus described herein;
[0006] FIG. 2 is a schematic side elevational view of the material
moving apparatus of FIG. 1;
[0007] FIG. 3 is a schematic cross sectional view of the material
moving apparatus of FIG. 2 taken along line 3-3;
[0008] FIG. 4 is a schematic top plan view of a material moving
apparatus with a discharge pipe described herein;
[0009] FIG. 5 is a schematic side elevational view of the material
moving apparatus of FIG. 4;
[0010] FIG. 6 is a schematic cross-sectional view of the material
moving apparatus of FIG. 4 taken along line 6-6;
[0011] FIG. 7 is a schematic top plan view of a material moving
apparatus with a discharge pipe described herein;
[0012] FIG. 8 is a schematic side elevational view of the material
moving apparatus of FIG. 7;
[0013] FIG. 9 is a schematic top plan view of a material moving
apparatus with a discharge pipe described herein;
[0014] FIG. 10 is a schematic side elevational view of the material
moving apparatus of FIG. 9;
[0015] FIG. 11 is a cross-sectional illustration showing the
dimensions of the discharge pipe in FIG. 9 taken along line
11-11;
[0016] FIG. 12 is a cross-sectional illustration showing the
dimensions of the discharge pipe in FIG. 9 taken along line
12-12;
[0017] FIG. 13 is a cross-sectional illustration showing the
dimensions of the discharge pipe in FIG. 9 taken along line
13-13;
[0018] FIG. 14 is a cross-sectional illustration showing the
dimensions of the discharge pipe in FIG. 9 taken along line
14-14;
[0019] FIG. 15 is an illustration of the pressure in a triangular
discharge pipe;
[0020] FIG. 16 is an illustration of the pressure in a circular
discharge pipe;
[0021] FIG. 17 is an illustration of an altitude of a right
triangle;
[0022] FIG. 18 is a schematic top plan view of a material moving
apparatus with a discharge pipe described herein;
[0023] FIG. 19 is a schematic side elevational view of the material
moving apparatus of FIG. 18; and
[0024] FIG. 20 is a cross-sectional illustration of a discharge
pipe with ribs.
[0025] While the invention is susceptible to various modifications
and alternative forms, specifics thereof have been shown by way of
example and drawings, and will be described in detail. It should be
understood, however, that the invention is not limited to the
particular embodiments described. On the contrary, the intention is
to second modifications, equivalents, and alternatives falling
within the spirit and scope of the invention.
DETAILED DESCRIPTION
[0026] Although industrial pumping equipment is known and is widely
used, conventionally available pumps typically cannot pump a
material having more than 10% solids by weight. Described herein is
a system and apparatus for pumping high solids materials. As used
herein, the term "high-solids material" includes dry and low
moisture materials including materials having more than about 10%,
20%, 25%, 30%, 40%, 50%, 60%, 70%, 75%, 80% or 90% solids by
weight.
[0027] In one embodiment, the material is compressible. As used
herein, the term "compressible" refers to the tendency of a
material to change its volume and density when subjected to
pressure, for example, the volume of a compressible material can be
reduced in response to applied pressure. In some materials, the
compressible material retains its compressed shape, even after the
pressure is removed or decreased. In some embodiments, the
compressible material slowly expands after the pressure is removed
or decreased.
[0028] Examples of solid materials include bio-solids, which
include, but are not limited to, saw dust, yard trimmings, compost,
wood chips, straw, grass, corn cobs, and corn stover. Other
materials include garbage or waste material, including, but not
limited to, bottles, cans, clothing, disposables, food packaging,
and food scraps. Still other materials include paper materials,
including, but not limited to, newspapers, magazines, cardboard,
office paper, and paper bags. Other solid material can include
plastics, including, but not limited to plastic bags, milk jugs and
other storage containers. The high-solids material can also include
mixtures and combinations of the materials listed herein or other
similar materials.
[0029] Conventional "pumpable" materials are generally liquids that
have no fixed shape, but rather an ability to take on the shape of
the container in which they are placed. The response of a typical
"pumpable" liquid to an applied pressure or pressure gradient is to
flow. Therefore, the "pumpable" liquid will tend to flow out of a
pumping chamber and into a discharge pipe when subjected to
pressure.
[0030] In contrast, when pressure or a shear stress is applied to a
high-solids material, conventionally considered "unpumpable," the
volume and density of the material may change, but the material may
not flow or, depending upon the solids content, may flow very
little. In one embodiment, the high solids material is elastic,
such that the material deforms under pressure but returns to its
original shape when the stress is removed. In another embodiment,
the high solids material is plastic, such that the material deforms
under pressure, but does not return to its original shape when the
stress is removed.
[0031] When some materials having more than 10% solids by weight
are pumped using conventional pumping equipment, the material
compresses due to friction between the material and the interior
surface of the equipment. As more material is pumped from a pumping
chamber into a discharge pipe, the material is further compacted
and compressed and the frictional forces are further increased. To
date the only method to pump high solids material is to increase
the pumping pressure to overcome the frictional forces between the
material and the surfaces of the equipment. However, even with
increased pressure, the pumping distance is very limited due to the
high frictional forces. The discharge pipe becomes plugged with
material, which needs to be cleaned out or replaced. This results
in a costly and time consuming process, resulting in many
high-solids materials being considered un-pumpable.
[0032] Many commercial pumps have a pumping chamber with downwardly
converging sidewalls, often a triangular shaped chamber. Thus, for
the sake of simplicity, the disclosure herein emphasizes a pump
with a triangular shaped chamber. However, other suitable shaped
chambers are possible and one of skill in the art could readily
apply the teachings herein thereto. For many high-solids materials,
the pressure exerted by the ram when the material is moved through
the chamber causes the material to take on the shape of the
chamber. Once the pressure is removed from the block of compressed
material, for example, when the block is removed from the chamber,
the pressure within the block is relieved by the expansion of the
block. For some materials, the block of compressed material tends
to stay in the shape of the chamber even after expanding. For
example, a compressed material may stay in the shape of a
triangular block, even after removal from a triangular shaped
pumping chamber. When non-circular blocks of material are pumped
into a conventional pipe having a circular cross-section, the
blocks of material can rotate and flip, resulting in a stack or
jumble of blocks in the circular pipe. As more blocks are added to
the pipe, the pipe becomes plugged or blocked.
[0033] Described herein is a pump in which high solids materials,
previously considered to be unpumpable, can be pumped efficiently,
over substantial distances, at relatively low pressure. In general,
the pump described herein has a discharge pipe with a
cross-sectional shape that corresponds to the cross-sectional shape
of the chamber. The correspondingly shaped discharge pipe can be
the same or a larger size than the chamber. In some instances, a
larger size discharge pipe may be desirable, since it allows for
slow and controlled expansion of the block of material. In general,
the discharge pipe should be large enough to allow for expansion of
the material, but not so large that the blocks of material are able
to rotate or flip within the discharge pipe. In essence, the
discharge pipe operates as a constraining device, limiting the
expansion and rotational movement of the compressed blocks of
material. The appropriate size differential between the chamber and
the discharge pipe can vary depending upon the physical properties
of the high solids material. In one embodiment, the discharge pipe
is at least about 1% larger than the chamber, at least about 5%
larger than the chamber, at least about 10% larger than the
chamber, or at least about 25% larger than the chamber, or up to
about 50% larger than the chamber. In another embodiment, the
discharge pipe is tapered to allow the material to expand slowly
without rotating or stacking within the discharge pipe.
[0034] By using a discharge pipe having a shape that corresponds to
the shape of the pumping chamber and/or discharge opening of the
pumping chamber, high solids materials can be pumped a much farther
distance than previously possible. While not wishing to be bound by
theory, it is believed that high solids materials are pumpable when
the natural tendencies of the material to compress and remain in a
compressed shape are considered and a mechanism is provided to
allow for a slow decompression and controlled expansion of the
compressed material.
[0035] Material Moving Apparatus
[0036] FIGS. 1-5 show a material moving apparatus indicated
generally at 10. Although the disclosure herein focuses on the use
of a pump, the invention described herein is applicable to many
different types of material moving equipment in which compressed
high solid material is transferred from one location to another.
For example, in one embodiment, the material moving apparatus can
be a compactor, such as trash compactor, to which a discharge pipe
is connected.
[0037] In general, a material moving apparatus 10 includes a
chamber 32 into which high solids material is introduced. The high
solids material is then transferred from the chamber 32 into a
discharge pipe 60. In one embodiment, the chamber 32 is a pumping
chamber in which a plunger or ram 50 assembly is mounted for
reciprocation along a longitudinal axis X-X. The chamber 32 can be
any suitable size. The cross-sectional shape of the chamber 32
(i.e., perpendicular to the longitudinal axis X-X) can be any
suitable shape, including circular, square, triangular,
trapezoidal, rectangular, oval, and the like. In one embodiment,
the cross-sectional shape of the chamber 32 is non-circular (i.e.,
is not a circle). In another embodiment, the chamber 32 has
parallel side-walls, for example, a square or rectangular
cross-sectional shape. In yet another embodiment, the chamber 32
has non-parallel side walls. In yet another embodiment, the chamber
32 has downwardly converging non-parallel side walls, where the
sidewalls meet at a bottom surface or a point of the chamber 32. In
the embodiment shown in FIG. 3, the non-parallel sidewalls 37, 38
are substantially planar and oriented in an upwardly open
V-configuration that terminates in an apex at the base 36 of the
apparatus 10. However, other converging configurations are known
and can be used, including, for example, a downwardly converging
chamber having curved sidewalls or a curved base is possible, for
example, a chamber having a parabolic or inverted bell
cross-sectional shape, or a pump having substantially planar
non-parallel tapering sidewalls that terminate at a substantially
planar base, thereby approximating a trapezoid in cross-section. In
one embodiment (not shown), the sidewalls and base angles of the
trapezoid are substantially the same and form an isosceles
trapezoid. If desired, the material moving apparatus 10 can be
mounted on support legs 11.
[0038] In one embodiment, the side walls 37, 38 define a chamber 32
that has a proximal end 44 defined by a rear wall 31 of the chamber
32 and a distal end 35 defined by a discharge opening 40 of the
apparatus 10. The sidewalls 37, 38 define an inlet opening 33 at
the top of the chamber 32. In one embodiment, the inlet opening is
located at the widest horizontal dimension of the chamber 32 to
facilitate receipt of high solids material from the collection
hopper 20. In general, it is desirable to have a large inlet
opening 33 for the chamber 32 to provide a wide feed point for the
solids material. Downwardly converging sidewalls 37, 38 help funnel
the solids material to the base 36 of the chamber 32. In the
embodiment shown in FIG. 2, the inlet opening 33 of the chamber 32
is located at the proximal end 44 of the chamber 32. If desired, a
top or cover 39 can enclose the distal end 34 of the chamber 32.
The cover 39 can be removable for purposes of accessing the chamber
32 for cleaning or other maintenance.
[0039] The invention described herein can be used in connection
with any sized material moving apparatus, from small scale pumps
having a pumping chamber size of no more than about 3 inches, no
more than about 6 inches or no more than about 9 inches, to
industrial sized pumps having sizes greater than about 11 inches,
greater than about 16 inches, greater than about 20 inches, greater
than about 24 inches, greater than about 30 inches or even greater
than about 36 inches. In one embodiment, shown in FIG. 3, the cross
sectional shape of the chamber 32 is a right triangle, wherein the
right angle is located at the base 36 of the chamber 32. When
referring to the "size" of a right triangle herein, the length of
the hypotenuse is being discussed. Thus, when used in connection
with the chamber 32, the term "size" refers to the length of the
chamber cover 39 (e.g., the distance between the tops of the two
sidewalls 37, 38). For chambers having other cross-sectional
shapes, the term "size" can refer to the greatest distance between
the sidewalls of the chamber, for example, the "size" of a
semi-circular (or half circle) chamber would be the diameter of the
circle.
[0040] Use of a discharge pipe 60 having a shape that corresponds
to the shape of the chamber 32 results in a significant reduction
in frictional forces between the high solids material and the
interior surfaces of the discharge pipe 60. The reduced friction
allows the material to be pumped at a relatively low pressure, as
compared to conventional pumping equipment in which a discharge
pipe having a circular cross-section is used. In general, the
pumping pressure can vary depending upon the physical properties of
the high solids material, the size of the pump and the pumping
distance. Additionally, the pumping pressure can be affected based
on whether the material is pumped into a pressurized container,
into a container at atmospheric pressure, or into a vacuum.
However, in some embodiments described herein, the pumping pressure
can be reduced to less than about 1/2 of the pressure used in
conventional pipes, to less than about 1/3 of the pressure used in
conventional pipes, or to less than about 1/4 of the pressure used
in conventional pipes. In fact, the reduction in pressure is
possible while pumping the material a greater distance as compared
to conventional discharge pipes.
[0041] The apparatus 10 can also include a hopper 20 for
introduction of material into the chamber 32. The hopper 20
includes a hopper opening 21 defined by one or more hopper 20
sidewalls 22, 23, 24, 25 and is configured for contiguous
relationship to and to be coextensive with the inlet opening 33 of
the chamber 32 such that the high solids material is transferable
from the inside of hopper 20 to the chamber 32.
[0042] In the embodiment shown in FIG. 2, the hopper 20 is
configured to abut the inlet opening 33 of the chamber 32 at the
proximal end 44 thereof. In the embodiment shown in FIG. 2, the
rear wall 22 of the hopper 20 is substantially in vertical
alignment with the rear wall 31 of the chamber 32.
[0043] The hopper 14 can be divided into two stages with an upper
collection portion 26 and a lower passageway 27. In one embodiment,
the upper collection portion 26 can include downwardly converging
side walls extending from hopper opening 21 to the lower passageway
27. The lower passageway 27 can include side walls connected to and
integrally extended from the lower edges of the respective
sidewalls of the collection portion 26. In one embodiment, the
sidewalls of the lower passageway 27 form a vertically extended
passageway in which the horizontal dimensions of the passageway
remain relatively constant through the vertical length thereof.
[0044] The apparatus 10 also includes a plunger or ram 50 assembly
mounted for reciprocation in chamber 32. In general, the ram 50 is
configured to substantially conform to the interior shape and
dimensions of the chamber 32, allowing suitable clearance. In the
embodiment shown in FIG. 1, the ram 50 is generally V-shaped, with
downwardly converging side walls 52, 53 terminating in an apex 54.
The ram 50 can include a forwardly directed face 51 to help
efficiently move material through the chamber 32. In the embodiment
shown in FIG. 1, the face 51 of the ram 50 is generally triangular
in shape to confirm to the triangular shape of the chamber 32. The
ram side walls 52, 53 are generally disposed in adjacent, close
parallel relationship to the side walls 37, 38 of chamber 32. The
ram top surface generally follows or is parallel to the inner
surface of the cover 39 when working in the distal end 35 of
chamber 32. In one embodiment, the ram side walls 52, 53 are in
contact with the interior surface of the chamber.
[0045] Any suitable motor for reciprocation of ram 50 in chamber 32
can be used, including, mechanical, hydraulic, pneumatic,
electrostatic and electrical motors. In one embodiment, the motor
includes a double-acting hydraulic reciprocating motor that
includes an elongate, hydraulic cylinder 55.
[0046] In use, high solids material is placed into the chamber 32.
The ram 50 advances in the chamber 32 (working stroke or power
stroke) to push the high solids material towards the discharge
opening 40. When the ram 50 reaches a first location within the
chamber 32, the movement of the ram 50 is reversed in toward the
rear of the chamber 32 (reverse stroke). When the ram 50 reaches a
second location, direction is again reversed to advance the ram 50
in the chamber 32 for reciprocal movement to the first location. If
desired, the apparatus 10 can also include one or more pressure
sensors capable of sensing a jam or blockage in the discharge pipe
60 or the presence of a bulky non-compressible material that may
not be suitable for pumping.
[0047] Discharge Pipe
[0048] At the distal end 35 of the chamber 32, the sidewalls 37, 38
and cover 39 define a discharge opening 40. The discharge opening
40 includes a flange 41 or other device configured for connecting a
proximal end 70 of a discharge pipe 60 to the apparatus 10.
Correspondingly, the discharge pipe 60 includes a mating device or
flange (not shown) configured for attachment to the discharge
opening 40 of the apparatus 10.
[0049] According to one embodiment, the discharge pipe 60 has a
cross-sectional shape having a geometry that corresponds to the
cross-sectional shape of the discharge opening 40. As used herein,
the term "shape" refers to the two-dimensional outline of an
object. As used herein, the term "corresponding" refers to two
shapes that have a comparable number, orientation and proportion of
straight line elements, curved line elements and angles. For
example, for a triangular shape a corresponding geometry is a
triangle. For a trapezoidal shape, a corresponding geometry is a
trapezoid. For a square, a corresponding geometry is a square. For
a circular shape, a corresponding geometry is a circle. Although in
the examples provided, the corresponding shape has an identical
number of straight line elements, curved line elements and angles,
some deviation in the number and type of elements is possible while
still accomplishing the desired function of the discharge pipe
(e.g., controlling or constraining rotational movement and/or
expansion of the compressed material). For example, a discharge
pipe having a non-equilateral pentagonal shape, with a
substantially triangular "base" portion and a somewhat rectangular
"expansion area" can correspond to a discharge opening 40 having a
triangular shape. Alternately, a V-shaped discharge pipe (i.e.,
without a cover), can correspond to a triangular shaped discharge
opening 40. Additionally, the relative lengths of the sides and the
size of the angles need not be identical (i.e., some deviation is
acceptable).
[0050] In another embodiment, the discharge pipe 60 has as
cross-sectional shape that is similar to the cross-sectional shape
of the discharge opening 40. As used herein, two shapes are said to
be "similar" if each internal angle is equal to an internal angle
of the other and all sides of one shape are in equal number and
proportion to sides of the other shape. Notably, two shapes can be
similar in shape, but not in size. If the discharge pipe 60 has
substantially the same size and shape as the discharge opening 50,
the two shapes are said to be "congruent."
[0051] In the embodiment shown in FIG. 3, a discharge opening 40
from chamber 32 is triangular in cross sectional shape and is
surrounded by a flange 41 for connection to a discharge pipe 60. In
the embodiment shown in FIG. 6, the discharge pipe 60 has a
corresponding triangular cross-sectional shape, e.g., an apex 66
located at the base of the discharge pipe 60, two legs or sidewalls
67, 68 extending from the apex 66 and a cover 69 opposite the apex
66. In an alternate embodiment, the discharge pipe 60 does not have
a cover.
[0052] The term "triangle" refers to a polygon with three corners
and three sides. Many types of triangles exist and are suitable for
use in connection with the chamber 32 or discharge pipe 60
described herein. In an equilateral triangle, all sides are the
same length and all angles are equal (60.degree.). In an isosceles
triangle, at least two sides are equal in length with two equal
angles: the angles opposite the two equal sides. In a scalene
triangle, all sides and internal angles are different from one
another. A right triangle has one of its internal angles equal to
90.degree. (a right angle). The side opposite to the right angle is
the hypotenuse. The other two sides are the legs of the triangle.
Any of these types of triangles can be used for the chamber 32
and/or discharge pipe 60.
[0053] In one embodiment, the apex or base 36 of the pump forms a
right angle and the cross-sectional shape of the chamber 32 is an
isosceles triangle, in which the two sidewalls 37, 38 form the legs
of the triangle and are equal in length. In this embodiment, the
chamber cover 39 forms the hypotenuse of the right triangle. A
discharge pipe with a corresponding cross-sectional shape may then
have an apex 66 and sidewalls 67, 68 that form a triangle. In one
embodiment, the cross-sectional shapes of the two triangles are
similar (i.e, the discharge pipe 60 forms an isosceles right
triangle). In another embodiment, the shapes of the two triangles
are congruent (i.e., the same size). In another embodiment, the
cross-sectional shape of the discharge pipe 60 corresponds to, but
is larger than the cross-sectional shape of the chamber 33. In one
embodiment, the discharge pipe is at least about 1% greater in size
than the discharge opening 40, or at least about 2% greater in size
than the discharge opening 40, at least about 5% greater in size
than the discharge opening 40, but generally less than about 50%
greater in size than the discharge opening 40, or less than about
25% greater in size than the discharge opening 40, or less than
about 10% greater in size than the discharge opening 40.
[0054] In the embodiment shown in FIGS. 7-10, the angle of the apex
or base 66 of the discharge pipe 60 is approximately a right angle
(90.degree.) and the cross-sectional shape of the discharge pipe 60
is an isosceles triangle, in which the two sidewalls 67, 68 form
the legs of the triangle and are equal in length. The cover 69 of
the discharge pipe 60 forms the hypotenuse of the right triangle.
However, it is not necessary that the cross-sectional shape of the
chamber 32 and/or the discharge pipe 60 be a right triangle. The
cross sectional shape can be an oblique triangle (i.e., a triangles
that does not have a 90.degree. internal angle), an acute triangle
(i.e., a triangle in which all the internal angles smaller than
90.degree.), or an obtuse triangle (i.e., a triangle that has one
angle larger than 90.degree.).
[0055] In one embodiment, shown in FIGS. 4 and 5, the cross
sectional shape of the discharge pipe 60 has a substantially
constant size moving from the proximal end 70 of the discharge pipe
60 towards the distal end 75 of the discharge pipe. When referring
to the "size" of a right triangle, the length of the hypotenuse is
being discussed. The term "size" of the discharge pipe 60 thus
refers to the hypotenuse of a right triangle, or the length of
discharge pipe cover 69 (e.g., the distance between the two
sidewalls 67, 68). As used herein, the term "substantially
constant" means that the size is the same within an accepted margin
of error. In this embodiment, referred to herein as a "constant"
discharge pipe, the length of the two sidewalls 67, 68 and the
cover 69 remain substantially constant along the length of the
discharge pipe 60. The constant discharge pipe 60 can be visualized
as shown in FIGS. 4 and 5, in which the length of C (the hypotenuse
at the outlet 62 of the discharge pipe) is substantially the same
as the length of B (the hypotenuse at the inlet 61 of the discharge
pipe) and the length of F (the altitude at the outlet 62 of the
discharge pipe 60) is substantially the same as the length of E
(the altitude at the inlet 61 of the discharge pipe 60).
[0056] When referring to the "size" of a triangle that is not a
right triangle, any suitable linear referent can be used, for
example, the altitude A of the triangle can be used. The "altitude"
refers to a straight line extending through the apex 36 of the
triangle (located at the base 36 of the chamber 32) and
perpendicular to (i.e. forming a right angle with) the chamber
cover 39 (see, FIG. 17). The term "altitude," when used in
connection with a discharge pipe 60 that is not a right triangle
refers to a straight line extending through the apex 66 of the
discharge pipe 60 and perpendicular to the cover 69 of the
discharge pipe 60. As used herein, the term "substantially
constant" means that the size is the same within an accepted margin
of error. In this embodiment, the length of the two sidewalls 67,
68 and the cover 69 remain substantially constant along the length
of the discharge pipe 60, as does the altitude of the triangle. For
non-triangular shapes, the "size" can refer any other linear
measurement of the shape, such as the length of a side or a
diameter of the shape.
[0057] In another embodiment, shown in FIGS. 7 and 8, the discharge
pipe 60 is tapered such that the size of the cross-sectional shape
increases from the proximal end 70 of the discharge pipe 60 moving
towards the distal end 75 of the discharge pipe. Put another way,
an inlet 61 of the discharge pipe 60 may have a smaller size than
an outlet 62 of the pipe. A tapered discharge pipe 60 is believed
to allow the blocks of compressed material to relax and gradually
expand as the material moves from the proximal end 70 to the distal
end 75 of the discharge pipe 60. In one embodiment, the taper
results in a proportional or uniform scaling of the cross-sectional
shape of the discharge pipe 60 wherein corresponding angles of the
two shapes are equal and the corresponding sides are in proportion.
However, in other embodiments, the taper need not result in a
proportional or uniform increase in size. The taper can be
visualized as shown in FIGS. 7 and 8, in which the length of B (the
hypotenuse at the outlet 62 of the discharge pipe) is greater than
the length of A (the hypotenuse at the inlet 61 of the discharge
pipe) and the length of E (the altitude at the outlet 62 of the
discharge pipe 60) is greater than the length of D (the altitude at
the inlet 61 of the discharge pipe 60).
[0058] As shown in FIG. 15, the compressed block of high solids
material 12 tends to rest along the base of the discharge pipe 60.
As the size of the discharge pipe increases, an "expansion area" 65
is provided near the cover 69 of the discharge pipe 60. While not
wishing to be bound by theory, it is believed that providing an
expansion area 65 in to which the compressed block of material 12
is able to expand, allows the pressure within the block of material
to be relieved, along with the pressure exerted on the sidewalls
67, 68. Hence, the friction between the solid material and the
interior surfaces 63, 64 of the sidewalls 67, 68 is reduced. In
contrast, in a circular discharge pipe (shown in FIG. 16), the
compressed material 12' exerts a pressure P in all directions,
resulting in increased friction along the length of the discharge
pipe 60.
[0059] In general, to reduce costs and the size of the discharge
pipe 60, it may be desirable to have a discharge pipe 60 with the
least amount of taper necessary to maintain the friction forces
between the compressed material 100 and the sidewalls 67, 68 of the
discharge pipe 60 less than the force exerted by the apparatus 10.
In one embodiment, the taper results in an increase in size of at
least about 1% per linear foot of pipe, or at least about 2% per
linear foot, or at least about 3.5% per linear foot and up to about
10% per linear foot, or up to about 5% per linear foot, or up to
about 4% per linear foot. In one embodiment, the taper results in
an increase in size of between about 2% and about 3.5% per linear
foot.
[0060] For example, for a 3 inch pump (i.e., a right triangle
chamber 32 with a cover 39 having a length of 3 inches between the
two sidewalls 37, 38), it may be desirable to have a 3 inch
discharge pipe 60 (i.e., a right triangle discharge pipe 60 with a
cover 69 having length of 3 inches between the two sidewalls 67,
68) at the inlet 61 of the discharge pipe 60 that tapers over a
distance of 5 linear feet to a size of 3.5 inches at the outlet 62
of the discharge pipe. As the size of the apparatus 10 increases, a
proportional increase in the taper may be desirable. For example,
for a 6 inch pump, it may be desirable to have a 6 inch discharge
pipe 60 at the inlet 61 of the discharge pipe 60 that tapers over a
distance of 5 linear feet to a size of 7 inches at the outlet 62 of
the discharge pipe. In another example, for a 30 inch pump, it may
be desirable to have a 30 inch discharge pipe 60 at the inlet 61 of
the discharge pipe 60 that tapers over a distance of 5 linear feet
to a size of 35 inches at the outlet 62 of the discharge pipe.
[0061] In another embodiment, shown in FIGS. 18 and 19, the
discharge pipe 60 includes more than one sections that are
"stepped" from the proximal end 70 to the distal end 75 of the
discharge pipe, in which the size of the inlet 61 of a distal pipe
section is greater than the size of the outlet 62 of an adjacent
proximal pipe section. As used herein, the terms "distal pipe
section" and "proximal pipe section" are relative to one another
such that a specific section of pipe can be distal to a first
section of pipe, but proximal to a second section of pipe. The term
"distal pipe section" refers to a section of discharge pipe that is
located closer to the distal end of the discharge pipe than another
pipe section. The term "proximal pipe section" refers to a section
of discharge pipe that is located closer to the proximal end of the
discharge pipe than another pipe section. The desired increase in
size from a proximal discharge pipe 60 to an adjacent distal
discharge pipe 60 can vary depending upon the physical properties
of the solids material being pumped. In general, to reduce costs
and the size of the discharge pipe 60, it may be desirable to have
a discharge pipe 60 with the least increase in size necessary to
maintain the friction forces between the compressed material 100
and the sidewalls 67, 68 of the discharge pipe 60 less than the
force exerted by the apparatus 10. In one embodiment, the step
results in an distal pipe section having a size that is at least
about 1%, or at least about 2%, or at least about 3.5% and up to
about 10%, or up to about 20%, or up to about 30%, 40% or 50%
greater than an adjacent proximal pipe section. For example, a
discharge pipe 60 can be 3 inches at the outlet 62 of a proximal
pipe section and 4 inches at the inlet 61 of the adjacent distal
pipe section.
[0062] In yet another embodiment, shown in FIGS. 9 and 10, the
discharge pipe 60 includes alternating or intermittent constant C
and tapered T sections of discharge pipe 60. The constant C and
tapered T sections can have any suitable length. In one embodiment,
the maximum length of the constant C section of the discharge pipe
60 is determined by the distance that the solid material can travel
within the discharge pipe 60 until the expansion area 65 is filled
with material 12. In one embodiment, the constant C section of the
discharge pipe 60 is converted to a tapered T section of a
discharge pipe 60 is a distance less than the distance that the
solid material 12 can travel within the discharge pipe 60 until the
expansion area 65 is filled with material 12. The length of tapered
discharge pipe 60 can vary depending upon the size of the discharge
pipe 60 and the properties of the material 12. In one embodiment,
the length of the tapered discharge pipe 60 is sufficient to
re-introduce an expansion area 65 above the material 12 within the
discharge pipe 60. In one embodiment, the tapered T and/or constant
C section of the discharge pipe 60 have a length of at least 1
linear foot, or at least about 3 linear feet, or at least about 5
linear feet and less than about 10 linear feet or less than about 7
linear feet.
[0063] In one embodiment, the discharge pipe 60 can include a low
friction coating on the interior surfaces 63, 64 of the sidewalls
67, 68 to reduce friction between the sidewalls 67, 68 and the high
solids material. Low friction surface coatings generally have a
coefficient of friction of less than about 0.30, or less than about
0.20, less than about 0.10, or less than about 0.05, or between
about 0.05 to 0.20, depending on the load, sliding speed, and
particular coating used. Low friction surface coatings are known
and include, but are not limited to materials such as glass or
polymeric coatings such as Polytetrafluoroethylene (PTFE, trade
name Teflon.RTM.); molybdenum disulfide (MoS.sub.2); tungsten
disulfide (WS.sub.2); and graphite.
[0064] In another embodiment (shown in FIG. 20), the discharge pipe
60 can include one or more longitudinal ribs 71 extending along one
or more interior surfaces 63, 64, of the sidewalls 67, 68 or cover
69 to reduce the surface area of the discharge pipe 60 in contact
with the compressed block of material 12. In FIG. 20, the
longitudinal ribs are shown as indentations 71 along the interior
sidewall that create an open space 72 between the block of
compressed material 12 and the interior surface of the discharge
pipe 60. In other embodiments, the ribs can include ridges or
projections extending from one or more interior surfaces of the
discharge pipe 60.
In Use
[0065] In use, a loosely packed high solids material is transferred
to collection hopper 20 through the opening 21 thereof. If desired,
the high solids material can be shredded prior to placement in
hopper. The size of the shredded material can vary, for example,
depending upon the size of the pump or properties of the material.
In one embodiment, the material is shredded into pieces having a
maximum dimension that is less than about 1/2 the size of the
chamber 32, less than about 1/3 the size of the chamber 32, less
than about 1/4 the size of the chamber, or less than about 1/8 the
size of the chamber. For example for a 3 inch chamber, the material
can be shredded in to pieces having a maximum dimension of 1 inch,
for example, a maximum dimension of 1 inch.times.0.2 inches, or a
maximum dimension of 0.5 inches.times.0.2 inches. For example for a
30 inch chamber, the material can be shredded in to pieces having a
maximum dimension of 10 inches, for example, a maximum dimension of
10 inches.times.2 inches or a maximum dimension of 5 inches.times.2
inches.
[0066] With the ram 50 in the rearward or refracted position, the
high solids material is fed into the inlet opening 33 of the hopper
20 and into the chamber 32. Ram 50 reciprocates in chamber 32 as
previously described. As the ram 50 advances in the chamber 32 it
moves the high solids material collected therein forward toward the
discharge pipe 60. Upon retraction of the ram 50, additional high
solids material can be transferred into the chamber 32.
[0067] When the high solids material is advanced by the ram 50 in
the chamber 32, it may be compacted into a shape defined by the
interior surface of the chamber 32. In one embodiment, the interior
surface is a triangle defined by the sidewalls 37, 39 and cover 39
of the chamber 32. In this embodiment, when the high solids
material is compressed by the ram 50, the material forms a
triangular block. When the interior surface of the chamber defines
some other shape, such as a trapezoid or square, the material will
become compressed into a correspondingly shaped block of
material.
[0068] When the material is released from the discharge opening 40
of the chamber 32, the high solids material does not immediately
return to its original loosely packed state. Instead, some
materials remain substantially in the shape of the compressed
block. When non-circular blocks of material are released into a
conventional circular discharge pipe, for example, the exterior
surfaces of the blocks of material do not align with the interior
surface of the circular discharge pipe. As such, the blocks can
rotate (side-to-side) or tip (forwards and backward). The
disorderly aggregation of blocks can result in the formation of a
jam that can form a blockage in the discharge pipe. As additional
blocks of material are introduced into the discharge pipe from the
chamber, the blockage increases in size. Eventually, the pressure
exerted by the barrier on the interior surface of the discharge
pipe results in frictional forces that exceed the pumping pressure
of the apparatus 10 and the solids material can no longer be
advanced along the length of the discharge pipe. To remove the
barrier, the equipment must be shut down to remove jam, costing
valuable time and money.
[0069] In contrast, when blocks of material are released from the
chamber 32 into a correspondingly shaped discharge pipe 60, the
exterior surfaces of the block align with the interior surfaces of
the discharge pipe 60, reducing the likelihood that the blocks will
rotate or tip and cause a blockage in the discharge pipe.
[0070] In one embodiment, the discharge pipe 60 is tapered such
that an inlet 61 of the pipe 60 has a smaller dimension than an
outlet 62 of the pipe. When the blocks of high solids material are
fed into a tapered discharge pipe, the blocks of material gradually
expand as they advance from the proximal end 70 towards the distal
end 75 of the discharge pipe 60. At distal end 75 of the discharge
pipe 60, the material returns to a loosely packed state (i.e., the
material is no longer a block).
[0071] At distal end 75 of the discharge pipe 60, the high solids
material is subject to very little pressure (as compared to the
proximal end 70 of the discharge pipe 60). Due to the
compressibility of the high solids material, the exit of the
material from the discharge pipe 60 outlet 62 can be stopped using
minimal force. If a blockage occurs in the discharge pipe 60 when
the outlet 76 is obstructed, the blockage will generally occur near
the proximal end 70 of the discharge pipe 60. Furthermore, once the
obstruction is removed from the distal end 75 of the discharge pipe
60, the blockage near the proximate end 70 will tend to dissipate
on its own.
Working Example
[0072] Office paper was shredded into rectangles having an
approximate dimension of 1 inch.times.0.2 inches to form a
high-solids material. The loosely packed shredded paper was
introduced into the chamber of a 3 inch chamber (i.e., a
right-triangle shaped chamber in which the right angle formed the
base of the chamber and which had a 3 inch hypotenuse). The 3 inch
pump was connected to a 3 inch (diameter) round discharge pipe.
[0073] The total distance that the material was able to be pumped
was only about 24 inches from the outlet of the chamber before a
jam occurred, when pumped at a pressure of 350 PSI.
[0074] A tapered right-triangle 48 inch long discharge pipe was
then attached to the pump. The right angle of the discharge pipe
was oriented at the base or apex 66 of the discharge pipe and the
top or hypotenuse of the triangle was measured 31/8 inches at the
inlet 61 and 31/2 inches at the outlet 62 (see FIGS. 11 and 12).
The inlet 61 of the tapered discharge pipe 60 was slightly larger
than the discharge opening 40 of the chamber 32 to allow for a
first decompression of material.
[0075] A 5 foot a section of constant discharge pipe having a size
of 31/2 inches at the inlet 61 and 31/2 inches at the outlet 62
(see FIGS. 13 and 14) was attached to the outlet 61 of the tapered
pipe. Thus the total length of the discharge pipe was 9 feet (see
FIGS. 9 and 10).
[0076] Using this configuration, the material was able to be pumped
at a pressure of 350 PSI along the entire 9 linear foot distance
with out any blockage or plugging. The pressure in the chamber was
then reduced to 125 PSI. The material was still able to be pumped
along the entire 9 linear foot distance without any blockage or
plugging. Thus, by using a triangular shaped discharge pipe, the
chamber pressure could be decreased by approx. 1/3 and the pumping
distance could still be increased by more than 4 times (as compared
to a circular discharge pipe).
[0077] Two additional sections were then added to the discharge
pipe. The third section was 5 feet long and 31/2 inches at the
inlet and 4 inches at the outlet. The forth section was 5 feet long
and 4 inches at the inlet and 5 inches at the outlet, providing a
discharge pipe having a length of 19 feet. When pumped at a
pressure of 125 PSI, the material was able to be pumped the entire
19 feet without blockage. Thus, the material was pumped
approximately 10 times the original distance of 2 feet at a 1/3 the
original pressure.
[0078] It should be noted that, as used in this specification and
the appended claims, the singular forms "a," "an," and "the"
include plural referents unless the content clearly dictates
otherwise. It should also be noted that the term "or" is generally
employed in its sense including "and/or" unless the content clearly
dictates otherwise.
[0079] It should also be noted that, as used in this specification
and the appended claims, the phrase "configured" describes a
system, apparatus, or other structure that is constructed or
configured to perform a particular task or adopt a particular
configuration. The phrase "configured" can be used interchangeably
with other similar phrases such as "arranged", "arranged and
configured", "constructed and arranged", "constructed",
"manufactured and arranged", and the like.
[0080] All publications and patent applications in this
specification are indicative of the level of ordinary skill in the
art to which this invention pertains. All publications and patent
applications are herein incorporated by reference to the same
extent as if each individual publication or patent application was
specifically and individually indicated by reference.
[0081] This application is intended to cover adaptations or
variations of the present subject matter. It is to be understood
that the above description is intended to be illustrative, and not
restrictive. It should be readily apparent that any one or more of
the design features described herein may be used in any combination
with any particular configuration. With use of a molding process,
such design features can be incorporated without substantial
additional manufacturing costs. That the number of combinations are
too numerous to describe, and the present invention is not limited
by or to any particular illustrative combination described herein.
The scope of the present subject matter should be determined with
reference to the appended claims, along with the full scope of
equivalents to which such claims are entitled.
* * * * *