Note: Descriptions are shown in the official language in which they were submitted.
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SOLID FEED GUIDE APPARATUS FOR A SOLID FEED
PUMP
BACKGROUND OF THE INVENTION
[00011 The subject matter disclosed herein relates to a pump for a solid, such
as
particulate matter.
[00021 A typical pump designed for solids, such as particulate matter, has a
single
continuous channel. For example, the pump may be a rotary pump that drives the
solids along a circular path. Thus, the rotary pump has stationary and
rotating
components that interface with one another. Unfortunately, the flow of solids
at the
inlet and outlet of the pump may cause high stresses and friction between the
stationary and rotating components of the pump, thereby causing high heat
generation
in the pump.
BRIEF DESCRIPTION OF THE INVENTION
[00031 These and other features, aspects, and advantages of the present
invention
will become better understood when the following detailed description is read
with
reference to the accompanying drawings in which like characters represent like
parts
throughout the drawings, wherein:
[00041 In a first embodiment, a system includes a solid fuel pump. The solid
fuel
pump includes a housing, a rotor disposed in the housing; a curved passage
disposed
between the rotor and the housing, an inlet port coupled to the curved
passage, an
outlet port coupled to the curved passage, a solid fuel guide extending across
the
curved passage, and a first roller at an interface between the solid fuel
guide and the
rotor.
[00051 In a second embodiment, a system includes a solid feed pump. The solid
feed pump includes a housing, a rotor disposed in the housing, a curved
passage
disposed between the rotor and the housing, an inlet port coupled to the
curved
passage, an outlet port coupled to the curved passage, a solid feed guide
extending
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across the curved passage, and multiple discrete contacts distributed along an
interface between the solid feed guide and the rotor.
[0006] In a third embodiment, a system includes a solid feed pump. The solid
feed
pump includes a housing, a rotor disposed in the housing, a curved passage
disposed
between the rotor and the housing, an inlet port coupled to the curved
passage, an
outlet port coupled to the curved passage, a solid feed guide extending across
the
curved passage, and a discrete static contact at an interface between the
solid feed
guide and the rotor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features, aspects, and advantages of the present
invention
will become better understood when the following detailed description is read
with
reference to the accompanying drawings in which like characters represent like
parts
throughout the drawings, wherein:
[00081 FIG. 1 is a schematic block diagram of an embodiment of an integrated
gasification combined cycle (IGCC) power plant utilizing a solid feed pump;
[0009] FIG. 2 is a cross-sectional side view of an embodiment of a solid feed
pump;
[0010] FIG. 3 is a cross-sectional side view of an embodiment of a solid feed
guide;
[0011] FIG. 4 is a cross-sectional side view of another embodiment of a solid
feed
guide;
[0012] FIG. 5 is a cross-sectional side view of an embodiment of a bearing, as
shown in FIG. 3, disposed in a recess of the solid feed guide;
[0013] FIG. 6 is a face view of an embodiment of a solid feed guide, taken
along
line 6-6 of FIG. 3;
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[00141 FIG. 7 is a face view of an embodiment of a solid feed guide, taken
along
line 6-6 of FIG. 3;
[0015] FIG. 8 is a perspective view of an embodiment of a solid feed guide;
[0016] FIG. 9 is a side view of a solid feed guide with a movable discrete
contact
located behind the solid feed guide; and
[00171 FIG. 10 is a cross-sectional side view of a solid feed guide with a
plurality
of adjustable movable discrete contacts.
DETAILED DESCRIPTION OF THE INVENTION
[00181 One or more specific embodiments of the present invention will be
described below. In an effort to provide a concise description of these
embodiments,
all features of an actual implementation may not be described in the
specification. It
should be appreciated that in the development of any such actual
implementation, as
in any engineering or design project, numerous implementation-specific
decisions
must be made to achieve the developers' specific goals, such as compliance
with
system-related and business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that such a
development effort might be complex and time consuming, but would nevertheless
be
a routine undertaking of design, fabrication, and manufacture for those of
ordinary
skill having the benefit of this disclosure.
[001.9] When introducing elements of various embodiments of the present
invention, the articles "ca,v" "an," "de," and "said" are intended to mean
that there are
one or more of the elements. The terms "comprising," "including," and "having"
are
intended to be inclusive and mean that there may be additional elements other
than the
listed elements.
[0020] Embodiments of the present disclosure include a solid feed pump with a
solid feed guide at an inlet and/or outlet, wherein the solid feed guide
includes unique
features to increase support, reduce friction, reduce stresses, and reduce
heat
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generation at an interface between the solid feed guide and a rotor. As
discussed in
detail below, the unique features may include one or more static or movable
contacts
at the interface between the solid feed guide and the rotor. For example, the
contacts
may include curved protrusions, such as semi-spherical, cylindrical, or convex
protrusions, at discrete points between the solid feed guide and the rotor. By
further
example, the contacts may include rollers, such as cylindrical or spherical
rollers. In
certain embodiments, the contacts are disposed directly between the solid feed
guide
and the rotor, whereas other embodiments position the contacts at an offset
from the
interface. In each of the disclosed embodiments, the contacts reduce friction,
wear,
heat generation, and stresses at the interface.
[0021] FIG. 1 is a diagram of an embodiment of an integrated gasification
combined cycle (IGCC) system 100 utilizing one or more solid feed pumps 10
with
unique features at a rotating interface as mentioned above. The solid feed
pump 10
may be a posimetric pump. The term "posimetric" may be defined as capable of
metering (e.g., measuring an amount of) and positively displacing (e.g.,
trapping and
forcing displacement of) a substance being delivered by the pump 10. The pump
10 is
able to meter and positively displace a defined volume of a substance, such as
a solid
fuel feedstock. The pump path may have a circular shape or curved shape.
Although
the solid feed pump 10 is discussed with reference to the I0CC system 100 in
FIG. 1,
the disclosed embodiments of the solid feed pump 10 may be used in any
suitable
application (e.g., production of chemicals, fertilizers, substitute natural
gas,
transportation fuels, or hydrogen). In other words, the following discussion
of the
IGCC system 100 is not intended to limit the disclosed embodiments to I0CC.
[0022] The IGCC system 100 produces and bums a synthetic gas, i.e., syngas, to
generate electricity. Elements of the IGCC system 100 may include a fuel
source 102,
such as a solid feed, that may be utilized as a source of energy for the IGCC.
The fuel
source 102 may include coal, petroleum coke, biomass, wood-based materials,
agricultural wastes, tars, asphalt, or other carbon containing items. The
solid fuel of
the fuel source 102 may be passed to a feedstock preparation unit 104. The
feedstock
preparation unit 104 may, for example, resize or reshape the fuel source 102
by
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chopping, milling, shredding, pulverizing, briquetting, or palletizing the
fuel source
102 to generate a dry feedstock (e.g., particulate matter).
[0023] In the illustrated embodiment, the solid feed pump 10 delivers the
feedstock from the feedstock preparation unit 104 to a gasifier 106. The solid
feed
pump 10 may be configured to meter and pressurize the fuel source 102 received
from
the feedstock preparation unit 104. The gasifier 106 may convert the feedstock
into a
syngas, e.g., a combination of carbon monoxide and hydrogen. This conversion
may
be accomplished by subjecting the feedstock to a controlled amount of steam
and
oxygen at elevated pressures, e.g., from approximately 20 bar to 85 bar, and
temperatures, e.g., approximately 700 degrees Celsius to 1600 degrees Celsius,
depending on the type of gasifier 106 utilized.
[0024] The gasification process may include the feedstock undergoing a
pyrolysis
process, whereby the feedstock is heated. Temperatures inside the gasifier 106
may
vary during the pyrolysis process, depending on the fuel source 102 utilized
to
generate the feedstock. The heating of the feedstock during the pyrolysis
process may
generate a solid, (e.g., char), and residue gases, (e.g., carbon monoxide,
hydrogen, and
nitrogen). The char remaining from the feedstock from the pyrolysis process
may
only weigh up to approximately 30% of the weight of the original feedstock.
[0025] A partial oxidation process may then occur in the gasifier 106. The
combustion may include introducing oxygen to the char and residue gases. The
char
and residue gases may react with the oxygen to form carbon dioxide and carbon
monoxide, which provides heat for the gasification reactions. The temperatures
during the partial oxidation process may range from approximately 700 degrees
Celsius to 1600 degrees Celsius. Steam may be introduced into the gasifier 106
during gasification. The char may react with the carbon dioxide and steam to
produce
carbon monoxide and hydrogen at temperatures ranging from approximately 800
degrees Celsius to 1100 degrees Celsius. In essence, the gasifier utilizes
steam and
oxygen to allow some of the feedstock to be "burned" to produce carbon
monoxide
and release energy, which drives a second reaction that converts further
feedstock to
hydrogen and additional carbon dioxide.
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[00261 In this way, a resultant gas is manufactured by the gasifier 106. This
resultant gas may include approximately 85% of carbon monoxide and hydrogen in
equal proportions, as well as CH4, HCl, HF, COS, NH3, HCN, and H2S (based on
the
sulfur content of the feedstock). This resultant gas may be termed untreated,
raw, or
sour syngas, since it contains, for example, H2S. The gasifier 106 may also
generate
waste, such as slag 108, which may be a wet ash material. This slag 108 may be
removed from the gasifier 106 and disposed of, for example, as road base or as
another building material. Prior to cleaning the raw syngas, a syngas cooler
107 may
be utilized to cool the hot syngas. The cooling of the syngas may generate
high
pressure steam which may be utilized to produce electrical power as described
below.
After cooling the raw syngas, a gas cleaning unit 110 may be utilized to clean
the raw
syngas. The gas cleaning unit 110 may scrub the raw syngas to remove the HCl,
HF,
COS, HCN, and H2S from the raw syngas, which may include separation of sulfur
111 in a sulfur processor 112 by, for example, an acid gas removal process in
the
sulfur processor 112. Furthermore, the gas cleaning unit 110 may separate
salts 113
from the raw syngas via a water treatment unit 114 that may utilize water
purification
techniques to generate usable salts 113 from the raw syngas. Subsequently, the
gas
from the gas cleaning unit 110 may include treated, sweetened, and/or purified
syngas, (e.g., the sulfur 111 has been removed from the syngas), with trace
amounts
of other chemicals, e.g., NH3 (ammonia) and CH4 (methane).
100271 A gas processor 116 may be utilized to remove residual gas components
117 from the treated syngas such as, ammonia and methane, as well as methanol
or
any residual chemicals. However, removal of residual gas components 117 from
the
treated syngas is optional, since the treated syngas may be utilized as a fuel
even
when containing the residual gas components 117, e.g., tail gas. At this
point, the
treated syngas may include approximately 3% CO, approximately 55% 142, and
approximately 40% CO2 and is substantially stripped of H2S. This treated
syngas may
be transmitted to a combustor 120, e.g., a combustion chamber, of a gas
turbine
engine 118 as combustible fuel. Alternatively, the CO2 may be removed from the
treated syngas prior to transmission to the gas turbine engine.
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100281 The IGCC system 1.00 may further include an air separation unit (ASU)
122. The ASU 122 may operate to separate air into component gases by, for
example,
distillation techniques. The ASU 122 may separate oxygen from the air supplied
to it
from a supplemental air compressor 123, and the ASU 122 may transfer the
separated
oxygen to the gasifier 106. Additionally the ASU 122 may transmit separated
nitrogen to a diluent nitrogen (DGAN) compressor 124.
100291 The DGAN compressor 124 may compress the nitrogen received from the
ASU 122 at least to pressure levels equal to those in the combustor 120, so as
not to
interfere with the proper combustion of the syngas. Thus, once the DGAN
compressor 124 has adequately compressed the nitrogen to a proper level, the
DGAN
compressor 124 may transmit the compressed nitrogen to the combustor 120 of
the
gas turbine engine 118. The nitrogen may be used as a diluent to facilitate
control of
emissions, for example.
[00301 As described previously, the compressed nitrogen may be transmitted
from
the DGAN compressor 124 to the combustor 120 of the gas turbine engine 118.
The
gas turbine engine 118 may include a turbine 130, a drive shaft 131 and a
compressor
132, as well as the combustor 120. The combustor 120 may receive fuel, such as
syngas, which may be injected under pressure from fuel nozzles. This fuel may
be
mixed with compressed air as well as compressed nitrogen from the DGAN
compressor 124, and combusted within combustor 120. This combustion may create
hot pressurized exhaust gases.
[00311 The combustor 120 may direct the exhaust gases towards an exhaust
outlet
of the turbine 130. As the exhaust gases from the combustor 120 pass through
the
turbine 130, the exhaust gases force turbine blades in the turbine 130 to
rotate the
drive shaft 131 along an axis of the gas turbine engine 118. As illustrated,
the drive
shaft 131 is connected to various components of the gas turbine engine 118,
including
the compressor 132.
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[0032] The drive shaft 131 may connect the turbine 130 to the compressor 132
to
form a rotor. The compressor 132 may include blades coupled to the drive shaft
131.
Thus, rotation of turbine blades in the turbine 130 may cause the drive shaft
131
connecting the turbine 130 to the compressor 132 to rotate blades within the
compressor 132. This rotation of blades in the compressor 132 causes the
compressor
132 to compress air received via an air intake in the compressor 132. The
compressed
air may then be fed to the combustor 120 and mixed with fuel and compressed
nitrogen to allow for higher efficiency combustion. Drive shaft 131 may also
be
connected to load 134, which may be a stationary load, such as an electrical
generator
for producing electrical power, for example, in a power plant. Indeed, load
134 may
be any suitable device that is powered by the rotational output of the gas
turbine
engine 118.
[0033] The IGCC system 100 also may include a steam turbine engine 136 and a
heat recovery steam generation (HRSG) system 138. The steam turbine engine 136
may drive a second load 140. The second load 140 may also be an electrical
generator for generating electrical power. However, both the first and second
loads
134, 140 may be other types of loads capable of being driven by the gas
turbine
engine 118 and steam turbine engine 136. In addition, although the gas turbine
engine
118 and steam turbine engine 136 may drive separate loads 134 and 140, as
shown in
the illustrated embodiment, the gas turbine engine 118 and steam turbine
engine 136
may also, be utilized in tandem to drive a single load via a single shaft. The
specific
configuration of the steam turbine engine 136, as well as the gas turbine
engine 118,
may be implementation-specific and may include any combination of sections.
[0034] The IGCC system 100 may also include the HRSG 138. High pressure
steam may be transported into the HSRG 138 from the syngas cooler 107. Also,
heated exhaust gas from the gas turbine engine 118 may be transported into the
HRSG
138 and used to heat water and produce steam used to power the steam turbine
engine
136. Exhaust from, for example, a low-pressure section of the steam turbine
engine
136 may be directed into a condenser 142. The condenser 142 may utilize a
cooling
tower 128 to exchange heated water for chilled water. The cooling tower 128
acts to
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provide cool water to the condenser 142 to aid in condensing the steam
transmitted to
the condenser 142 from the steam turbine engine 136. Condensate from the
condenser 142 may, in turn, be directed into the HRSG 138. Again, exhaust from
the
gas turbine engine 118 may also be directed into the HRSG 138 to heat the
water from
the condenser 142 and produce steam.
[00351 In combined cycle systems such as IGCC system 100, hot exhaust may
flow from the gas turbine engine 118 and pass to the HRSG 138, along with the
steam
generated by the syngas cooler 107, where it may be used to generate high-
pressure,
high-temperature steam. The steam produced by the HRSG 138 may then be passed
through the steam turbine engine 136 for power generation. In addition, the
produced
steam may also be supplied to any other processes where steam may be used,
such as
to the gasifier 106. The gas turbine engine 118 generation cycle is often
referred to as
the "topping cycle," whereas the steam turbine engine 136 generation cycle is
often
referred to as the "bottoming cycle." By combining these two cycles as
illustrated in
FIG. 1, the IGCC system 100 may lead to greater efficiencies in both cycles.
In
particular, exhaust heat from the topping cycle may be captured and used to
generate
steam for use in the bottoming cycle.
[00361 As mentioned above, the IGCC system 100 may include one or more solid
feed pumps 10. FIG. 2 is a cross-sectional side view of an embodiment of the
solid
feed pump 10, further illustrating operational features of the solid feed pump
10. As
shown in FIG. 2, the solid feed pump 10 includes a housing 214, inlet 200,
outlet 202,
and rotor 204. The rotor 204 may include two substantially opposed and
parallel
rotary discs 206 and 208, which include discrete cavities defined by
protrusions to
drive solids there between. The rotary discs 206 and 208 may be movable
relative to
the housing 214 in a rotational direction 216 from the inlet 200 towards the
outlet 202.
The inlet 200 and the outlet 202 may be coupled to a curved passage 210 (e.g.,
circular or annular passage). A curved passage 210 may be disposed between the
two
rotary discs 206 and 208 and within the housing 214. A solid feed guide 212
may be
disposed adjacent the outlet 202. In some embodiments, the solid feed guide
212 may
be disposed adjacent the inlet 200 or at both the inlet 200 and the outlet
202. The
solid feed guide 212 may extend across the curved passage between rotary discs
206
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and 208. The solid feed guide 212 may include an upper portion 218 and a lower
portion 220. The lower portion 220 of the solid feed guide 212 may include a
guide
wall 222 and a surface 224 that interfaces with the rotor 204. To ensure
efficient
performance of the solid feed pump 10, the rotor interfacing surface 224 of
the solid
feed guide 212 may be tightly contoured to the shape of an outer surface 226
of the
rotor 204. Together the guide wall 222 and the rotor interfacing surface 224
may
form a tip 228 at the lower portion 220 of the solid feed guide 212. The rotor
interfacing surface 224 near the tip 228 may contact the rotor surface 204
while the
rest of the rotor interfacing surface 224 may include a slight gap between the
rotor
interfacing surface 224 and the rotor surface 204 that gradually increases
from the tip
228 towards the opposite end of the rotor interfacing surface 224. The outlet
202, or
in some embodiments the inlet 200, may provide a fixed support to the upper
portion
218 of the solid feed guide 212. As discussed in detail below, the discussed
embodiments include one or more discrete contacts between the surfaces 224 and
226,
thereby reducing friction, heat generation, and stresses.
[00371 As particulate matter is fed through an opening 230 of the inlet 200,
the
solid feed pump 10 may impart a tangential force or thrust to the particulate
matter in
the rotational direction 216 of the rotor 204. The direction of flow 234 of
the
particulate matter is from the inlet 200 to the outlet 202. As the particulate
matter
rotates through the curved passage 210, the particulate matter encounters the
guide
wall 222 of the solid feed guide 212 disposed adjacent the outlet 202
extending across
the curved passage 210. The particulate matter is diverted by the solid feed
guide 212
through an opening 236 of the outlet 202 into an exit pipe 238 connected to a
high
pressure vessel or into a conveyance pipe line.
[00381 The guide wall 222 may substantially block the curved passage 210. In
some embodiments, the guide wall 222 may only partially block the curved
passage
210. The guide wall 222 extends radially outward from the rotor 204. The guide
wall
222 may be angled in a radial direction relative to the rotor 204. For
example, the
radial angle (i.e., angle between guide wall 222 and the rotor 204) may range
between
approximately 0 to 90 degrees, 0 to 60 degrees, 30 to 60 degrees, 0 to 45
degrees, 30
to 45 degrees, 0 to 30 degrees, or 0 to 15 degrees, or any angle therebetween.
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further example, the radial angle may be approximately 30, 35, 40, 45, 50, 55,
or 60
degrees, or any angle therebetween.
100391 The impact of the particulate matter on the solid feed guide 212 may
create
a load pressure on the guide wall 222. The load pressure may increase the
sliding
friction between the rotor interfacing surface 224 and the outer surface 226
of the
rotor 204. The increase in friction may result in an increase in heat
generation at the
rotor interfacing surface 224 near the tip 228 of the solid feed guide 212.
Besides
increasing friction, the load pressure created by the particulate matter on
the solid feed
guide 212 may increase the high stresses experienced by the solid feed guide
212,
particularly at the tip 228. Together, the high heat generation and the high
stresses
may accelerate the rate of tip wear. However, as discussed below, the
disclosed
embodiments include one or more discrete contacts at the surfaces 224 and 226
to
reduce friction, heat generation, and stresses.
[0040] FIGS. 3-10 illustrate embodiments of the solid feed guide 212 with
unique
contacts that may reduce the heat generation and stresses experienced by the
solid
feed guide 212. The contacts discussed below are disposed on the surface 224
of the
solid feed guide 212. FIG. 3 illustrates a cross-sectional side view of an
embodiment
of the solid feed guide 212. As mentioned above, the solid feed guide 212 may
include upper portion 218 and lower portion 220. The lower portion 220 of the
solid
feed guide 212 may include the guide wall 222, rotor interfacing surface 224,
and tip
228. In addition, the lower portion 220 may include multiple discrete contacts
250
distributed along the rotor interfacing surface 224. Each of the multiple
discrete
contacts 250 may present a curved or arcuate surface when interfacing with the
outer
surface 226 of the rotor 204. The extent to which the multiple discrete
contacts 250
extend out from the rotor interfacing surface 224 may vary. The size and shape
of the
multiple discrete contacts 250 also may vary. For example, the contacts 250
may be
spherical, cylindrical, or any suitable curved shape. The multiple discrete
contacts
250 may be arranged in a pattern or randomly distributed on the rotor
interfacing
surface 224.
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[00411 The illustrated multiple discrete contacts 250 are movable. For
example,
the multiple discrete contacts 250 may roll in the rotational direction 216 of
the rotor
204. In addition, the multiple discrete contacts 250 may be made of a low-
friction
material and have a rolling friction coefficient less than the sliding
friction coefficient
experienced by the rotor interfacing surface 224 in the absence of the
multiple
discrete contacts 250. For example, the low-friction material may include high
alloy
steel, stainless steel, chrome steel, ceramic, plastic, or a combination
thereof. Thus,
the multiple discrete contacts 250 may generate less heat and may reduce the
total
heat generated between the solid feed guide 212 and the rotor 204. Besides
reducing
friction, the multiple discrete contacts 250 may provide extra support to the
lower
portion 220 of the solid feed guide 212, particularly the rotor interfacing
surface 224.
As a result of this additional support, the high stresses experienced by the
lower
portion 220 of the solid feed guide 212 may be reduced, particularly the
stresses near
the tip 228. Other embodiments may include both movable and static discrete
contacts 250.
[00421 In some embodiments, the multiple discrete contacts 250 may be
stationary.
FIG. 4 illustrates a cross-sectional side view of another embodiment of the
solid feed
guide 212. Similar to FIG. 3, the solid feed guide 212 includes the upper
portion 218
and the lower portion 220 that may include guide wall 222, the rotor
interfacing
surface 224, and the tip 228. The rotor interfacing surface 224 also may
include
multiple discrete contacts 250. The multiple discrete contacts 250 illustrated
are static
discrete contacts 260. As illustrated, the static discrete contacts 260 are
integral to the
solid feed guide 212 and may be made of a low-friction material. For example,
the
low-friction material may include high alloy steel, stainless steel, chrome
steel,
ceramic, plastic, or a combination thereof. Alternatively, the static discrete
contacts
260 may be affixed to the rotor interfacing surface 224. If the static
discrete contacts
260 are affixed to the solid feed guide 212, then the static discrete contacts
260 may
be made of the same constituent material as the solid feed guide 212. In other
embodiments, the affixed static discrete contacts 260 may be made of a low-
friction
material different from the constituent material of the solid feed guide 212.
Each of
the static discrete contacts 260 may present a curved or arcuate surface when
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interfacing with the outer surface 226 of the rotor 204. The extent to which
the static
discrete contacts 260 extend out from the rotor interfacing surface 224 may
vary. The
size and shape of the static discrete contacts 260 may also vary. For example,
the
contacts 260 may be semi-spherical, convex, partial cylindrical, disc-shaped,
or any
other curved protruding shape. The static discrete contacts 260 may be
arranged in a
pattern or randomly distributed on the rotor interfacing surface 224. Also,
similar to
the discrete contacts 250 embodied in FIG, 3, the static discrete contacts 260
may
similarly reduce the high stresses experienced by the lower portion 220 of the
solid
feed guide 212, particularly the tip 228.
[00431 As mentioned above in FIG. 3, the multiple discrete contacts 250 may be
movable. FIG. 5 illustrates a cross-sectional side view of an embodiment of a
bearing
270, as shown within line 5-5 of FIG. 3, of the solid feed guide 212. The
illustrated
embodiment shows a portion of the rotor interfacing surface 224 of the solid
feed
guide 212 and the bearing 270 disposed in a recess 272 of the rotor
interfacing surface
224. The recess 272 may be concave in order to allow the bearing 270 to rotate
within the recess 272 when the bearing 270 rotates in a direction opposite the
rotational direction 216 of the rotor 204. The dimensions of the recess 272
may vary
with the size of the bearing 270. The bearing 270 may be spring loaded into
the
recess 272 or captured between the surfaces 224 and 226. The bearing 270 may
be
made of a low-friction material with a rolling friction coefficient less than
the sliding
friction coefficient of the rotor interfacing surface 224 in the absence of
the bearing
270. For example, the low-friction material may include high alloy steel,
stainless
steel, chrome steel, ceramic, plastic, or a combination thereof.
100441 FIG. 6 is a partial face view of an embodiment of a solid feed guide
212,
taken along line 6-6 of FIG. 3, illustrating cylindrical shapes of the
bearings 270. The
illustrated embodiment shows multiple cylindrical bearings 280 disposed along
the
rotor interfacing surface 224 of the solid feed guide 212. The rotor
interfacing surface
224 may include a top portion 282 and a lower portion 284. The lower portion
284 is
nearest the tip 228. As mentioned above, the cylindrical bearings 280 may be
spring
loaded into the concave recess 272 or captured between the surfaces 224 and
226.
The cylindrical bearings 280 may be disposed along the entire width 286 of the
rotor
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interfacing surface 224, or less than the entire width 286. The length 288 and
diameter 290 of each cylindrical bearing 280 may be uniform or non-uniform.
Likewise, the length 288 and diameter 290 may be the same or different from
one
bearing 280 to another. In some embodiments, the multiple cylindrical bearings
280
may occupy the same longitudinal axis. In other words, each illustrated
bearing 280
may be segmented into multiple cylindrical bearings across the width 286.
Furthermore, spacing 292 between cylindrical bearings 280 may be constant or
vary.
[00451 Alternatively, the bearings 270 may include ball bearings 300. FIG. 7
illustrates a partial face view of an embodiment of solid feed guide 212,
along the
rotor interfacing surface 224, as indicated by line 6-6 of FIG. 3. The
embodiment
illustrated shows multiple ball bearings 280 disposed along the rotor
interfacing
surface 224 of the solid feed guide 212. The rotor interfacing surface 224 may
include the top portion 282 and the lower portion 284 with the lower portion
284
nearest the tip 228. Also, as mentioned above, each of the ball bearings 300
bearings
may be spring loaded into a concave recess or captured between surfaces 224
and
226. The ball bearings 300 may be disposed in horizontal alignment along the
width
286 of the rotor interfacing surface 224 and vertical alignment from the top
portion
282 to the lower portion 284 as illustrated. Alternatively, ball bearings 300
may be
staggered or randomly distributed along the rotor interfacing surface 224. The
diameter 302 of the ball bearings 300 may be uniform or non-uniform from one
ball
bearing 300 to another. The horizontal spacing 304 and vertical spacing 306
may also
be uniform or non-uniform from one ball bearing 300 to another.
100461 In certain embodiments, the multiple discrete contacts 250 may include
wheels or rollers having a rotational axis or axle. FIG. 8 illustrates an
embodiment of
the solid feed guide 212 with rollers 316. The solid feed guide 212 may
include a
groove 318 running from the top portion 282 of the rotor interfacing surface
224
towards the lower portion 284. The groove 318 may terminate in the lower
portion
284 prior to the tip 228. The solid feed guide 212 may include multiple
rollers 316
disposed in alignment within the groove 318. Each of the rollers 316 may
rotate
along an axis 320 (e.g., an axle) in a direction opposite the rotational
direction 216 of
the rotor 204. For example, each axle 320 may extend through a roller 316
across the
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groove 318 from one side to another. The rollers 316 provide a curved contact
surface in the shape of a cylindrical surface. The diameter of the rollers 316
may vary
between embodiments. The spacing between the rollers 316 within the groove 318
may also vary. In addition, the number of rollers in the groove 318 may vary.
In
some embodiments, the rotor interfacing surface 224 may include multiple
grooves
318 for multiple series of rollers 316.
[00471 In some embodiments, the movable discrete contacts 250 may not be
located directly on the rotor interfacing surface 224 of the solid feed guide
212. FIG.
9 illustrates a side view of the solid feed guide 212 with the movable
discrete contact
250 located at an offset away from the surface 224, e.g., behind the solid
feed guide
212. Similar to embodiments above, the solid feed guide 212 may include the
upper
portion 218 and the lower portion 220 that may include the guide wall 222, the
rotor
interfacing surface 224, and the tip 228. In illustrated embodiment, the solid
feed
guide 212 includes an extension 330 that extends from a backside 332 of the
solid
feed guide 212 to the movable discrete contact 250. The movable discrete
contact
250 may include a curved contact surface (e.g., a spherical or cylindrical
shape) to
interface with the outer surface 226 of the rotor 204. For example, the
movable
discrete contact 250 may include the bearing 260 or roller 316. The bearing
260 may
include the ball bearing 300 or the cylindrical bearing 280. In embodiments
with the
roller 316, the roller 316 may be coupled to the extension 330 via an axle.
100481 As illustrated, the extension 330 may originate from the lower portion
220
of the backside 332 of the solid feed guide 212. In other embodiments, the
extension
330 may originate from the upper portion 218 of the solid feed guide 212. The
extension 330 may be angled in a radial direction relative to the backside 332
of the
solid feed guide 212. For example, the radial angle (i.e., angle between the
extension
330 and the backside 332 of solid feed guide 212) may range between about 0 to
90
degrees, 0 to 60 degrees, 30 to 60 degrees, 0 to 45 degrees, 30 to 45 degrees,
0 to 30
degrees, or 0 to 15 degrees. By further example, the radial angle may be about
30, 35,
40, 45, 50, 55, 60 or 65 degrees, or any angle therebetween.
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WO 2011/133321 PCT/US2011/031315
[00491 The movable discrete contact 250 located on the backside 332 of the
solid
feed guide 212 may provide additional support to the solid feed guide 212 to
reduce
stresses experienced by the lower portion 220 of the solid feed guide 212,
particularly
the tip 228. Additionally, the backside 332 location of the movable discrete
contact
250 may allow a thickness 334 of the solid feed guide 212 to be reduced from a
thickness 336 of the standard solid feed guide 212. In certain embodiments,
the
thickness 334 of the backside supported solid feed guide 212 may be reduced by
at
least approximately 10, 20, 30, 40, or 50 percent compared to the thickness
336 of the
standard solid feed guide 212. For example, the thickness 336 of the standard
solid
feed guide 212 may be a factor of approximately 1.1 to 3 times greater than
the
thickness 334 of the backside supported solid feed guide 212. However, the
factor
may range between approximately 1 to 3, 1 to 2.5, 1 to 2, or I to 1.5. The
reduced
thickness of the solid feed guide 212 may reduce the area requiring a tight
tolerance
between the rotor interfacing surface 224 and the outer surface 226 of the
rotor 204.
[00501 In additional embodiments, the movable discrete contacts 250 may be
adjustable at the interface between surfaces 224 and 226. FIG. 10 illustrates
a cross-
sectional side view of the solid feed guide 212 with adjustable movable
discrete
contacts 250. Like the embodiments above, the solid feed guide 212 may include
upper portion 218 and lower portion 220 that may include the guide wall 222,
the
rotor interfacing surface 224, and tip 228. In addition, the illustrated solid
feed guide
212 includes rods 344 extending vertically from the upper portion 218 to the
lower
portion 220 of the solid feed guide 212. The rods 344 include at one end
threaded
portions 346 (e.g., male threads) and at the other end movable discrete
contacts 250.
An adjustment member 348 (e.g., female threads) may engage the threaded
portion
346 of the rod 344. The adjustment member 348 may include a nut. The
adjustment
member 348 enables adjustment of the distance between the movable discrete
contacts 250 and the rotor interfacing surface 224, as well as adjustment of
the
clearance between the contacts 250 and the surface 226. The number of
adjustable
movable discrete contacts 250 may vary. The adjustable movable discrete
contacts
250 may include a curved contact surface (e.g., spherical, cylindrical, semi-
spherical,
partial cylindrical, etc.) to interface with the outer surface 226 of the
rotor 204. The
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adjustable movable discrete contacts 250 may include the bearing 260 or the
roller
316. The bearing 260 may include the ball bearing 300 or the cylindrical
bearing 280.
The rod 344 may include a spring 350 located towards the end with the discrete
contacts 250 to spring load the bearings 260. In embodiments with a roller
316, the
roller 316 may be coupled to the rod 344 via an axle.
[00511 As mentioned above, a tight tolerance is provided between the solid
feed
guide 212 and the rotor 204 for efficient operation of the solid feed pump 10.
The
adjustable movable discrete contacts 250 may help ensure this tight tolerance.
The
adjustable movable discrete contacts 250 may allow the proper clearance to be
obtained between the solid feed guide 212 and the rotor 204 during initial
installation.
Also, as the movable discrete contacts 250 wear over time, the clearance
between the
solid feed guide and the rotor may be adjusted to ensure a tight tolerance.
[0052] This written description uses examples to disclose the invention,
including
the best mode, and also to enable any person skilled in the art to practice
the
invention, including making and using any devices or systems and performing
any
incorporated methods. The patentable scope of the invention is defined by the
claims,
and may include other examples that occur to those skilled in the art. Such
other
examples are intended to be within the scope of the claims if they have
structural
elements that do not differ from the literal language of the claims, or if
they include
equivalent structural elements with insubstantial differences from the literal
languages
of the claims.
1'
