U.S. patent application number 13/458886 was filed with the patent office on 2012-11-08 for material moving apparatus.
Invention is credited to Donald W. Bell, Jessica Conway, David A. Olson, Wayne E. Soost.
Application Number | 20120282127 13/458886 |
Document ID | / |
Family ID | 47090355 |
Filed Date | 2012-11-08 |
United States Patent
Application |
20120282127 |
Kind Code |
A1 |
Olson; David A. ; et
al. |
November 8, 2012 |
MATERIAL MOVING APPARATUS
Abstract
Described herein is a material moving apparatus that includes a
chamber into which a compressible material is introduced. The
chamber includes an input opening for receiving the material, a
discharge opening and a sealing mechanism to prevent flow of air or
other gasses between the input opening and the discharge opening.
In one embodiment, the material moving apparatus can be used to
introduce compressible biomass into a gasification reactor.
Inventors: |
Olson; David A.; (Albert
Lea, MN) ; Conway; Jessica; (Chatfield, MN) ;
Bell; Donald W.; (Austin, MN) ; Soost; Wayne E.;
(Alden, MN) |
Family ID: |
47090355 |
Appl. No.: |
13/458886 |
Filed: |
April 27, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61482748 |
May 5, 2011 |
|
|
|
Current U.S.
Class: |
417/489 |
Current CPC
Class: |
F04B 15/023 20130101;
F04B 7/04 20130101 |
Class at
Publication: |
417/489 |
International
Class: |
F04B 7/04 20060101
F04B007/04 |
Claims
1. A material moving apparatus comprising: (a) a chamber having an
input opening located proximate an upstream end for receiving a
compressible material and a discharge opening defined in a
downstream end of the chamber; (b) a ram mounted in the chamber
configured to compress the material and urge the compressed
material out of the discharge opening of the chamber; and (c) a
valve located downstream of the discharge opening configured to
control movement of the compressed material out of the discharge
opening of the chamber.
2. The material moving apparatus of claim 1, wherein the ram has a
retracted position and a terminal position such that the terminal
position of the ram is located upstream of the downstream surface
of the chamber thereby forming a sealing chamber in a downstream
portion of the chamber for accumulation of compressed material.
3. The material moving apparatus of claim 1, wherein the chamber
comprises a pumping chamber and a sealing chamber.
4. The material moving apparatus of claim 3, wherein the pumping
chamber defines a first enclosure having a first cross-sectional
dimension and the sealing chamber defines a second enclosure with a
second cross-sectional dimension, wherein the cross-sectional
dimension of the second enclosure defined by the sealing chamber is
greater than the cross-sectional dimension of the pumping
chamber
5. The material moving apparatus of claim 3, wherein the pumping
chamber defines a first enclosure having a first cross sectional
shape and the sealing chamber defines a second enclosure having a
second cross-sectional shape, wherein the cross-sectional shape of
the sealing chamber is different than the cross-sectional shape of
the pumping chamber.
6. The material moving apparatus of claim 1, wherein the valve
comprises a check valve.
7. The material moving apparatus of claim 6, wherein the check
valve has an open position and a closed position and the valve is
configured to remain in the closed position until the compressed
material is at a specified pressure whereupon the valve moves to
the open position.
8. The material moving apparatus of claim 7, wherein the check
valve opens at a pressure of at least 5 psi.
9. The material moving apparatus of claim 7, wherein the check
valve opens at a pressure between about 10 psi and about 1000
psi.
10. The material moving apparatus of claim 6, wherein the check
valve comprises a flap valve.
11. The material moving apparatus of claim 1, further comprising a
discharge pipe operably connecting the material moving apparatus to
a gasification reactor.
12. The material moving apparatus of claim 1, wherein the
compressible material comprises biomass.
13. The material moving apparatus of claim 1, wherein the
compressible 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.
14. A method for moving a compressible material, the method
comprising: (a) placing a compressible material in a chamber having
an input opening for receiving the compressible material and a
discharge opening; (b) compressing the material to form a
compressed material; (c) controlling the compression of the
material using a valve located downstream of the discharge opening;
and (d) pumping the compressed material out of the discharge
opening of the chamber.
15. The method of claim 14, further comprising: pumping the
compressed material out of the discharge opening of the chamber
into a discharge pipe, wherein the discharge pipe operably connects
the material moving apparatus to a gasification reactor.
16. The method of claim 15, further comprising: compressing the
material under a pressure sufficient to form a compressed material
that is air-impermeable.
17. The method of claim 16, wherein the material is compressed
under a pressure of at least about 5 psi.
18. The method of claim 14, further comprising: transporting the
compressed biomass to a downstream receptacle.
19. The method of claim 18, wherein the downstream receptacle
comprises a discharge pipe, a gasification reactor, or a
combination thereof.
20. The method of claim 19, wherein the gasification reactor is
operated under a vacuum of between about 0.5 psi to about 5 psi.
Description
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/482,748, filed May 5, 2011, the contents of
which are herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] Gasification is an endothermic process that converts carbon
based materials, such as coal, petroleum, biofuel, or biomass into
a combustible gas by the partial or incomplete combustion of the
raw material at high temperatures (i.e., between about 1000.degree.
C. to 5000.degree. C.) with a controlled amount of oxygen and/or
steam. The process takes place in a device called a gasifier or a
gasification reactor, which can range in size, shape, and design.
Instead of the biomass burning quickly, the material in the
gasifier has limited oxygen such that the combustion occurs in
multiple separate stages. The lack of oxygen and slow burn rate
encourage the fuel to release combustible gases that include carbon
monoxide (CO), hydrogen (H.sub.2), methane (CH.sub.4) and trace
amounts of higher hydrocarbons, for example, ethane
(C.sub.2H.sub.4) and ethane (C.sub.2H.sub.6). This combustible
mixture can also be called producer gas, which can be used to run
internal combustion engines (both compression and spark ignition),
as substitute for furnace oil and to produce methanol--which is
useful both as fuel for heat engines as well as chemical feedstock
for industries. However, in order for the gasification process to
be effective, only a limited amount of oxygen can be introduced
into the reactor.
[0003] Although gasification of fossil fuels is currently widely
used on an industrial scale to generate electricity, it is
desirable to use other organic materials, such as wood, biomass, or
even plastic waste on an industrial scale for energy production.
However, despite the interest in commercialization of biomass
gasification, the known processes are, for the most part, not
economically viable.
SUMMARY OF THE INVENTION
[0004] Described herein is a material moving apparatus. The
apparatus includes a chamber having an input opening for receiving
a compressible raw material and a discharge opening. A ram is
mounted within the chamber and configured to compress the raw
material and urge the compressed material towards the discharge
opening of the chamber. A valve is located downstream of the
discharge opening and is configured to control the pressure under
which the material is compressed by controlling movement of the
compressed material out of the discharge opening of the chamber. In
one embodiment, the material is compressed to form a compressed
material that is impermeable to air and/or other gasses. For
example, the material can be compressed under a working pressure of
at least about 5 psi and up to about 1000 psi.
[0005] In one embodiment, the material moving apparatus includes a
downstream receptacle, for example, a discharge pipe operably
connecting the material moving apparatus to a gasification reactor.
In one embodiment, the gasification reactor operates under a vacuum
of at least about 0.5 psi and up to about 5.0 psi. Advantageously,
the compressed material is substantially air-impermeable, thereby
preventing movement of air and/or other gasses from the pumping
chamber into the downstream recepticle.
[0006] In one embodiment, the compressible material comprises
biomass that can be gasified in a gasification reactor. Examples of
biomass include, for example, 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.
[0007] In one embodiment, a single chamber functions as both a
pumping chamber and a sealing chamber. In another embodiment, the
material moving apparatus includes a sealing chamber that is
distinct from the pumping chamber. For example, it may be desirable
to have a separate sealing chamber that defines an enclosure with a
different shape and/or size is than the enclosure defined by the
pumping chamber to prevent back-flow of the compressed material
into the pumping chamber and/or input receptacle of the material
moving apparatus. In one embodiment, the pumping chamber defines a
first enclosure having a first cross-sectional dimension and the
sealing chamber defines a second enclosure with a second
cross-sectional dimension, wherein the cross-sectional dimension of
the second enclosure defined by the sealing chamber is greater than
the cross-sectional dimension of the pumping chamber. In another
embodiment, the pumping chamber defines a first enclosure having a
first cross sectional shape and the sealing chamber defines a
second enclosure having a second cross-sectional shape, wherein the
cross-sectional shape of the sealing chamber is different than the
cross-sectional shape of the pumping chamber.
[0008] A variety of valves can be used in connection with the
material moving apparatus described herein. In one embodiment, the
valve comprises a check valve, such as a flap valve.
[0009] A method for moving a compressible material is also
described.
[0010] 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
[0011] FIG. 1 is a schematic top plan view of a material moving
apparatus described herein;
[0012] FIG. 2 is a schematic side elevational view of the material
moving apparatus of FIG. 1;
[0013] FIG. 3 is a schematic cross sectional view of the material
moving apparatus of FIG. 2 taken along line 3-3;
[0014] FIG. 4 is a schematic top plan view of a material moving
apparatus with a discharge pipe described herein;
[0015] FIG. 5 is a schematic side elevational view of the material
moving apparatus of FIG. 4;
[0016] FIG. 6 is a schematic showing a material moving apparatus
operably connected to a downstream recepticle;
[0017] FIG. 7 is a schematic top plan view of a material moving
apparatus with a check valve located downstream of the pumping
chamber.
[0018] FIG. 8 is a schematic side elevational view of the material
moving apparatus of FIG. 7;
[0019] FIG. 9 is a cross-sectional view of the material moving
apparatus of FIG. 7 taken along line 9-9; and
[0020] FIGS. 10A and B are side-elevation views of the sealing
chamber of the material moving apparatus showing a phantom valve in
an open position and closed position.
[0021] 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
[0022] The invention described herein provides a material moving
apparatus suitable for transporting material from an ambient or
high pressure environment to a low pressure or vacuum environment,
without the transfer of unwanted air or gasses between the two
environments. In particular, the invention provides a material
moving apparatus that includes a chamber into which a compressible
raw material is introduced. The chamber includes an input opening
for receiving the material, a discharge opening and a sealing
mechanism to prevent flow of air or other gasses between the input
opening and the discharge opening. The invention provides a
solution to a long-felt need in the gasification industry, namely,
how to introduce biomass into a gasification reactor while
preventing air and/or other unwanted gasses from entering the
reactor.
Compressible Material
[0023] The material moving apparatus and method described herein
can be used to transport a compressible material. 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.
[0024] In one embodiment, the material is compressed by application
of a working pressure of at least about 5 psi and up to about 1000
psi, or of at least about 10 psi and up to about 200 psi, or
between about 10 psi and about 50 psi.
[0025] In one embodiment, the compressible material includes a high
solids material. 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. High solids materials are described in more
detail in U.S. Patent Publication Number 2010/0278666, entitled
"HIGH SOLIDS MATERIAL MOVING APPARATUS", the disclosure of which is
incorporated by reference in its entirety.
[0026] In a more particular embodiment, the compressible material
includes biomass. As used herein, the term "biomass" refers to any
carbon based material, and can include, but is 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 biomass
can also include mixtures and combinations of the materials listed
herein or other similar materials.
[0027] The properties of each type of biomass can vary and thereby
affect performance of the biomass as an energy source for a
gasification plant. Some properties of the biomass that can affect
performance include moisture content, ash content and ash
composition, elemental composition, heating value, bulk density and
morphology, volatile matter content and the presence of other fuel
related contaminants such as N, S, Cl, alkalies, and heavy
metals.
Material Moving Apparatus
[0028] FIGS. 1-5 show a material moving apparatus indicated
generally at 10. In general, a material moving apparatus 10
includes a chamber 32 into which a compressible material is
introduced. 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 ram 50 is configured to compress
the material disposed within the chamber 32 and urge the compressed
material out a discharge opening 40 of the chamber 32.
[0029] 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.
[0030] In one embodiment, the side walls 37, 38 define a chamber 32
that has a proximal (or upstream) end 44 defined by a rear wall 31
of the chamber 32 and a distal (or downstream) end 35 which defines
a discharge opening 40. 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 raw material from a 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
raw material. Downwardly converging sidewalls 37, 38 help funnel
the 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 (or upstream) end 44 of the chamber 32. If desired,
a top or cover 39 can enclose the distal (or downstream) end 34 of
the chamber 32. The cover 39 can be removable for purposes of
accessing the chamber 32 for cleaning or other maintenance. If
desired the downstream end 34 of the chamber 32 can be tapered such
that the portion proximate the discharge opening 40 has a
cross-sectional area that is greater than a cross-sectional area of
the chamber 32 located upstream. The increase in cross-sectional
area can be as little as a fraction of a percent, for example as
little as about 0.01% and up to about 10% over a distance of
between about 10 inches to about 60 inches, 0.03% and up to about
10% over a distance of between about 10 inches to about 60 inches
or as little as about 0.05% and up to to about 5% over a distance
between about 10 inches to about 60 inches.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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.
[0036] 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.
[0037] In use, raw 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 (terminal position) 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 (retracted position), 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
pressure within the chamber 32.
[0038] In one embodiment, the material moving apparatus 10 includes
a singular chamber that functions as both a pumping chamber 32 and
a sealing chamber 132. For example, the terminal position of the
ram 50 can be located upstream from the discharge opening 40 of the
chamber, such that a "defacto" sealing chamber is formed. The term
"sealing chamber" refers to a chamber in which raw material is
compressed to form a substantially air-impermeable plug which
functions to "seal" the downstream portion of the system (which can
include a gasification reactor) off from the input opening 33 of
the material moving apparatus 10 and prevent air or other gasses
from the input opening 33 of the hopper 20 and/or pumping chamber
32 from traveling downstream of the compressed material.
Essentially, the distal end 35 of the chamber 32 located downstream
from the terminal position of the ram 50 can accumulate compressed
material and thereby function as a sealing chamber. If desired, the
distal end 35 of the chamber 32 can be tapered, such that the
portion of the distal end 35 downstream from the terminal position
of the ram 50 has a cross-sectional dimension that is greater than
the cross-sectional dimension of the chamber 32 proximate the
terminal position of the ram 50.
[0039] In another embodiment, such as is shown in FIGS. 7-9, the
material moving apparatus 10 includes a sealing chamber 132 that is
distinct from the pumping chamber 32. The sealing chamber 132
includes sidewalls 137, 138 that define a chamber 132 having a
proximal (or upstream) end 144 and a distal (or downstream) end 135
which defines a discharge opening 140. As with the pumping chamber
32, the sealing chamber 132 can be any suitable size and have any
suitable cross-sectional shape (i.e., perpendicular to the
longitudinal axis X-X), including circular, square, triangular,
trapezoidal, rectangular, oval, and the like.
[0040] It may be desirable to have a separate sealing chamber 132
that defines an enclosure with a different shape and/or size is
than the enclosure defined by the pumping chamber 32 to prevent
back-flow of the compressed material into the pumping chamber 32,
inlet opening 33 and/or input hopper 20 of the material moving
apparatus 10. For example, if the dimensions of the compacted
material disposed within the sealing chamber 132 are greater than
the dimensions of the material disposed within the pumping chamber
32, the compacted material will be less likely to backflow into the
pumping chamber 32. Backflow of the material may be undesirable
because it can result in deterioration of the seal formed by the
compacted material that prevents the introduction of air and/or
other gasses into the downstream receptacle, resulting in the
introduction of unwanted gasses downstream. To reduce the
likelihood of backflow, the sidewalls 37, 38 and/or cover 39 of the
pumping chamber 32 can define a first enclosure having a first
cross-sectional dimension and the sidewalls 137, 138 and/or cover
139 of the sealing chamber 132 can define a second enclosure with a
second cross-sectional dimension, wherein a cross-sectional
dimension of the second enclosure defined by the sidewalls 137, 138
and/or cover 139 of the sealing chamber 137 is greater than a
cross-sectional dimension of the enclosure defined by the sidewalls
37, 38 and/or cover 39 of the pumping chamber 32. As used herein,
the term "cross-sectional dimension" refers to a maximum
corresponding distance between the sidewalls 137, 138 (or 37, 38)
and/or between a sidewall 137, 138 (or 37, 38) and a cover 139 (or
39), when the cross-sectional shape of the two chambers is similar
or identical. Similarly, if the cross-sectional shape of sealing
chamber 132 is different than the cross-sectional shape of the
pumping chamber 32, the likelihood that the compacted material will
backflow into the pumping chamber is reduced. For example, the
sidewalls 37, 38 and/or cover 39 of the pumping chamber 32 can
define a first enclosure having a first cross sectional shape and
the sidewalls 137, 138 and/or cover 139 of the sealing chamber 132
can define a second enclosure having a second cross-sectional
shape, wherein the cross-sectional shape of the sealing chamber 132
is different than the cross-sectional shape of the pumping chamber
32. For example, the pumping chamber 32 may have a triangular
cross-sectional shape, and the sealing chamber 132 may have a
circular or rectangular cross sectional shape, the basic shape
being consistent in each component. In yet another embodiment, the
sealing chamber 132 is tapered such that the cross-sectional
dimension proximate the upstream end 144 of the chamber 132 is
smaller than the cross-sectional dimension proximate the downstream
(or terminal) end 135 of the sealing chamber 137. The change in
cross-sectional area can be as little as a fraction of a percent
and ranges from 0.01% and up to about 10% over a distance of
between about 10 inches to about 60 inches, 0.03% and up to about
10% over a distance of between about 10 inches to about 60 inches
or as little as about 0.05% and up to to about 5% over a distance
between about 10 inches to about 60 inches.
Valve
[0041] The material moving apparatus 10 includes a valve 150
located downstream of the discharge opening 140 of the sealing
chamber 132. For the sake of brevity, the valve 150 will be
described in connection with a material moving apparatus 10 that
includes a separate sealing chamber 132. However, it is noted that
the discussion can apply equally to a material moving apparatus 10
that includes a singular chamber 32 that functions both as a
pumping chamber and a sealing chamber.
[0042] The valve 150 is located downstream of the sealing chamber
132. In one embodiment, the valve 150 is located at the terminal
end 135 of the sealing chamber 132. The valve 150 is configured to
prevent the material from exiting the sealing chamber 132 until the
material is compacted sufficiently to render the compacted material
substantially air-impermeable. Significantly, the compacted
material that is accumulated in the sealing chamber 132 provides a
seal or plug that impedes the passage of air (including, for
example, oxygen) from the pumping chamber 32 to a downstream
recepticle (for example, a discharge pipe 60 and/or gasification
reactor 200).
[0043] Any suitable valve 150 can be used in connection with the
material moving apparatus 10 described herein. As shown in FIGS.
10A and B, the valve 150 includes a valve plate 155 that has an
upstream surface 151 and a downstream surface 152 and an open
position (P.sub.o) and a closed or restrictive position (P.sub.c).
When the valve 150 is in a closed position (P.sub.c), the upstream
surface 151 of the plate 155 is configured to provide an opposing
surface positioned substantially perpendicular to the force exerted
by the ram 50 (i.e., along the axis X-X) to compress the raw
material. As the ram 50 pushes the raw material against the
upstream surface 151 of the valve 150, the pressure exerted on the
raw material, and hence the upstream surface 151 of the valve 150,
increases. The pressure at which the valve 150 is configured to
open can vary, but generally, the valve 150 is configured to open
at a pressure of least about 5 psi and can withstand pressures of
up to about 500 psi. In general, pressures between about 10 psi and
200 psi, or between about 10 psi and 50 psi are sufficient to
compact the raw material to a density that renders the material
substantially air-impermeable. As used herein, the term
"substantially air impermeable" refers to a material through which
air flow remains substantially undetected (i.e., using a sensor
located downstream of the sealing chamber) when subjected to a
vacuum pressure of at least 0.5 psi and up to about 5.0 psi. When
the excess working pressure on the valve is relieved or when a
pressure of below about 5 psi, or between about 1 psi and about 10
psi is detected, the valve returns to a restrictive position
(P.sub.c).
[0044] A variety of valves 150 can be used in connection with the
material moving apparatus 10 described herein. In one embodiment,
the valve 150 comprises a check valve that is configured to allow
the compressed material to flow in only one direction (i.e.,
downstream) and prevent the material from flowing upstream. In
another embodiment, the valve 150 is operably connected to a pump
175 which helps provide a counterbalancing force against the
working force exerted by the ram 50 on the upstream surface 151 of
the valve 150. Examples of suitable pumps include, but are not
limited to, mechanical, hydraulic, pneumatic, electrostatic and
electrical pumps.
[0045] A swing check valve is a check valve which has a plate that
swings on a hinge or trunnion between an open and a closed
position. One example of a swing check valves is a flapper
valve.
[0046] As used herein, the term "flapper valve" refers to a valve
150 in which a valve plate 155 rotates around a hinge 160 to open
and shut. In one embodiment, the flapper valve includes a
spring-loaded plate 155 (or flapper) that allows materials to pass
through in the downstream direction, but will not allow material to
flow upstream. In one embodiment, the force at which the valve
opens is dependent upon the torsion force of the spring. In another
embodiment, the opening and closing of the valve is controlled by a
pump 175, for example a mechanical pump or a hydraulic pump, in
which case the material moving apparatus may include a pressure
sensor within the sealing chamber 137 to determine when the valve
should be opened or closed.
[0047] Other examples of check valves include lift-check valves and
stop check valves and compression valves.
Gasification Reactor
[0048] In one embodiment, shown schematically in FIG. 6, the
material moving apparatus 10 is operably connected to a downstream
receptacle, for example, a discharge pipe 60 and/or a gasification
reactor 200. In the embodiment shown, the material moving apparatus
10 includes a discharge pipe 60 downstream of the sealing chamber
132. In general, there are four types of gasification reactors
available for commercial use: counter-current fixed bed, co-current
fixed bed, fluidized bed and entrained flow. In some reaction
processes, the gasification reactor is operated under a vacuum of
at least about 0.5 psi and up to about 5 psi. The compressed
material 350 formed within the sealing chamber 137 of the material
moving apparatus 10 still functions as a seal to prevent entry of
gas (including oxygen) into the downstream receptacle from the
material moving apparatus 10. It is believed that throughput and
efficiency of the gasification reaction can be increased, and waste
material decreased, if the gasification process can be operated
under a vacuum.
[0049] To further improve efficiency, it may be desired to reduce
the average size of the raw material prior to placement within the
input hopper 20 of the material moving apparatus 10, for example,
using a shredder. The size of the shredded material can vary, for
example, depending upon the size of the pump or the type of
gasification reactor. In one embodiment, the material is shredded
into pieces having a dimension that is less than about 10 inches,
5, inches, 2 inches or 1 inch. However, larger size pieces can
still be used, as long as they can enter the pumping chamber and be
compressed.
Discharge Pipe
[0050] As with the valve discussion above, the discharge pipe
discussion herein will be written in connection with the distal end
135 of the sealing chamber 132. However, it is to be understood
that the discussion would apply equally to a material moving
apparatus 10 having a discharge pipe 60 extending directly from the
distal end 35 of the pumping chamber 32. In one embodiment, the
material moving apparatus 10 includes a discharge pipe 60 that
extends downstream from the distal end 135 of the sealing chamber
132. The discharge pipe 60 includes a flange or other device
configured to mate with a respective flange or device on the distal
end 135 of the sealing chamber 132 such that the enclosure defined
by the sidewalls 137, 138 and cover 139 of the sealing chamber 132
is in fluid communication with the lumen of the discharge pipe 60.
Various configurations for the discharge pipe are possible and
include, for example, configurations described in U.S. Patent
Application Publication No. 2010/0278666, entitled "HIGH SOLIDS
MATERIAL MOVING APPARATUS", the disclosure of which is incorporated
by reference herein in its entirety.
In Use
[0051] FIG. 6 provides a schematic of a material moving apparatus
10 in use. In use, loosely packed raw material 300 is transferred
to collection hopper 20 of the pumping chamber 32. As the ram 50
advances from a rearward or refracted position, the ram 50 urges
the raw material 300 into the sealing chamber 132. Upon retraction
of the ram 50, additional raw material 300 can be transferred into
the pumping chamber 32. As the raw material 300 is advanced by the
ram 50 to the sealing chamber 132, the material is compacted by the
working pressure exerted by the ram 50 as it pushes the material
against the upstream surface 151 of the closed valve plate 155.
[0052] Once the material is compacted 350, the valve 150 moves to
an open position and the compacted material 350 is released from
the discharge opening 140 of the sealing chamber 32, for example,
into a downstream receptacle, such as a discharge pipe 60 and/or a
reaction chamber of a gasification reactor 200. The compacted
material 350 forms a plug that impedes the flow of gas, for example
air, more specifically oxygen, from the pumping chamber 32 into the
downstream receptacle.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
* * * * *