U.S. patent application number 16/603114 was filed with the patent office on 2020-12-10 for powder jet pump.
The applicant listed for this patent is 3M INNOVATIVE PROPERTIES COMPANY. Invention is credited to Saurabh Batra, Karl K. Stensvad, Eric A. Vandre.
Application Number | 20200386243 16/603114 |
Document ID | / |
Family ID | 1000005038324 |
Filed Date | 2020-12-10 |
United States Patent
Application |
20200386243 |
Kind Code |
A1 |
Stensvad; Karl K. ; et
al. |
December 10, 2020 |
POWDER JET PUMP
Abstract
A powder jet pump that is effective for creating a smoothly
flowing gas stream with well dispersed particles.
Inventors: |
Stensvad; Karl K.; (Inver
Grove Heights, MN) ; Vandre; Eric A.; (Roseville,
MN) ; Batra; Saurabh; (Minneapolis, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
3M INNOVATIVE PROPERTIES COMPANY |
St. Paul |
MN |
US |
|
|
Family ID: |
1000005038324 |
Appl. No.: |
16/603114 |
Filed: |
March 27, 2018 |
PCT Filed: |
March 27, 2018 |
PCT NO: |
PCT/US2018/024518 |
371 Date: |
October 4, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62483753 |
Apr 10, 2017 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04F 5/42 20130101; F04F
5/14 20130101; F04F 5/463 20130101 |
International
Class: |
F04F 5/14 20060101
F04F005/14; F04F 5/46 20060101 F04F005/46; F04F 5/42 20060101
F04F005/42 |
Claims
1. A powder jet pump, comprising: a main body having a particle
inlet at a first end and an outlet connector at a second end, the
particle inlet being in fluid communication with an inlet chamber;
a nozzle defining a passage in fluid communication with the chamber
and outlet connector, wherein the nozzle includes a nozzle throat;
at least one suction inlet in fluid communication with the chamber;
an annular plenum positioned around the main body having a gas
inlet; and at least two jet passages each having an inlet opening
into the annular plenum and an outlet opening within the nozzle
throat.
2. The powder jet pump of claim 1, wherein the gas inlet is
configured to impart a direction of rotation within the annular
plenum to a gas travelling through the gas inlet and into the
annular plenum.
3. The powder jet pump of claim 2, wherein respective outlet
openings of the at least two jet passages are helically advanced in
the direction of rotation relative to their respective inlet
openings.
4. The powder jet pump of claim 1, wherein the nozzle throat has a
nozzle throat inner wall, and wherein the at least two jet passages
are configured such that a portion of each jet passage adjacent to
its respective outlet opening is disposed at an angle of 1 to 10
degrees relative to the nozzle throat inner wall.
5. The powder jet pump of claim 4, wherein the at least two jet
passages are configured such that a portion of each jet passage
adjacent to its respective outlet opening is disposed at an angle
of 1 to 10 degrees relative to the longitudinal axis of the nozzle
throat.
6. The powder jet pump of claim 1, wherein the nozzle throat has an
inner diameter, wherein the nozzle has a maximum inner diameter,
and wherein the ratio of the inner diameter of the nozzle throat to
the maximum inner diameter of the nozzle is in the range of 1:2 to
1:10.
7. The powder jet pump of claim 1, wherein the powder jet pump is
unitary.
8. The powder jet pump of claim 1, wherein the nozzle throat has a
minimum inner diameter in the range of 0.03 inch (0.76 mm) to 0.11
inch (2.79 mm).
9. The powder jet pump of claim 1, wherein the at least two jet
passages have respective inner diameters in the range of 0.01 inch
(0.25 mm) to 0.05 inch (1.27 mm).
10. The powder jet pump of claim 1, wherein the at least two jet
passages have respective lengths in the range of 0.10 inch (0.25
mm) to 1.00 inch (2.54 cm).
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to the introduction
of fine particles into a gas stream, and more particularly to an
efficient powder jet pump.
BACKGROUND
[0002] Certain industrial processes require the introduction of
particulate matter into a gas stream. Powder jet pumps (i.e., jet
pumps that are suitable for entraining powder into a fluid) can be
used for the introduction of powder into a gas stream. They use a
motive (pressurized) fluid to induce flow in a suction fluid (or
fluid containing powder in the case of a powder jet pump). These
devices are commonly used to move bulk solids or fluids containing
solids. They are often ideally suited to this task because of their
simplicity and robustness. Typically, they have no moving parts.
Jet pumps typically have a mixing region where the motive and
suction fluids meet before they enter a nozzle. While a nozzle is a
common design feature of jet pumps, the function is distinctly
different from a Venturi pump in that pressure drop is created by
energy transfer from the motive fluid to the suction fluid. In a
true Venturi pump, suction is created by the pressure drop in the
nozzle itself.
[0003] Powder jet pumps may be used to introduce powder at a powder
inlet port and mix it with a gas stream (e.g., air), then emit
well-dispersed powder particles entrained in the gas stream. In
some applications, subsequent gas handling devices can cause gas
stream pressures at the powder jet pump outlet (i.e., back
pressure) to be high or fluctuate to high pressure, thereby cause
the powder jet pump to stall, or reverse the flow direction. This
problem has been generally overcome by various designs that use
high output gauge pressure from the powder jet pump, but such high
pressure are not always desirable. There remains a need for powder
jet pumps that can operate effectively at relatively low gauge
pressure.
SUMMARY
[0004] The present disclosure provides a powder jet pump that is
notably energy efficient and effective at creating a smoothly
flowing gas stream with well-dispersed particles. The powder jet
pump may impart rotational angular momentum to the gas/particle
mixture to improve the dispersion and resist agglomeration at low
gas stream gauge pressures (e.g., 1-10 psi). Advantageously, the
powder jet pump has improved resistance to stalling at higher back
pressures than prior designs.
[0005] In one aspect, the present disclosure provides a powder jet
pump, comprising:
[0006] a main body having a particle inlet at a first end and an
outlet connector at a second end, the particle inlet being in fluid
communication with an inlet chamber;
[0007] a nozzle defining a passage in fluid communication with the
chamber and outlet connector, wherein the nozzle includes a nozzle
throat;
[0008] at least one suction inlet in fluid communication with the
chamber;
[0009] an annular plenum positioned around the main body having a
gas inlet; and
[0010] at least two jet passages each having an inlet opening into
the annular plenum and an outlet opening within the nozzle
throat.
[0011] As used herein:
[0012] the term "gauge pressure" refers to a relative pressure
measurement which measures pressure relative to outlet pressure and
is defined as the absolute pressure minus the outlet pressure;
and
[0013] the term "nozzle throat" refers to an area of minimum cross
section of a nozzle.
[0014] Features and advantages of the present disclosure will be
further understood upon consideration of the detailed description
as well as the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The disclosure may be more completely understood in
consideration of the following detailed description of various
embodiments of the disclosure in connection with the accompanying
figures, in which:
[0016] FIG. 1 is a perspective drawing of exemplary powder jet pump
20 according to the present disclosure;
[0017] FIG. 2 is side cross section view of powder jet pump 20,
taken along section lines 2-2 in FIG. 1;
[0018] FIG. 2A is an enlarged view of region 2A in FIG. 2;
[0019] FIG. 2B is an enlarged perspective cross-sectional view of
region 2B in FIG. 2; and
[0020] FIG. 3 is a side view of powder jet pump 20.
[0021] Repeated use of reference characters in the specification
and drawings is intended to represent the same or analogous
features or elements of the disclosure. It should be understood
that numerous other modifications and embodiments can be devised by
those skilled in the art, which fall within the scope and spirit of
the principles of the disclosure. The figures may not be drawn to
scale.
DETAILED DESCRIPTION
[0022] The present disclosure describes a powder jet pump for the
introduction of particles into a gas stream.
[0023] Referring now to FIGS. 1-3, exemplary powder jet pump 20
comprises a main body 22 has a particle inlet 24 at a first end 27
and an outlet connector 44 at a second end 29. Particle inlet 24 is
in fluid communication with inlet chamber 28. Nozzle 42 defines
passage 48 in fluid communication with inlet chamber 28 and outlet
connector 44. Nozzle 42 includes nozzle throat 40. Suction inlets
26 are in fluid communication with inlet chamber 28. Annular plenum
32 is positioned around main body 22 has gas inlet 34. While shown
as a torus, it will be recognized that other shapes of the annular
plenum that accomplish the technical effect of feeding the jet
passages may also be used (e.g., polygonal plenums). Hollow jet
passages 52 each have a respective inlet opening 56 (see FIG. 2B)
into the annular plenum 32 and an outlet opening 36 within nozzle
throat 40. Optional braces 38 add structural reinforcement to
powder jet pump 20.
[0024] In use, pressurized gas (e.g., compressed air) enters gas
inlet 34, continues into annular plenum 32, and is directed through
jet passages 52 from annular plenum 32 to nozzle throat 40
positioned at the end of inlet chamber 28 opposite particle inlet
24. Throat 40 widens into nozzle 42, terminating in outlet
connector 44. Exemplary useful gases include air, nitrogen, and
argon. Other gases may also be used.
[0025] Typical gauge pressures for the pressurized gas are 1 to 10
psi (6.9 to 69 kPa). Other gauge pressures may also be used.
[0026] In the embodiment shown in FIG. 1, respective outlet
openings 36 of jet passages 52 are helically advanced in the
direction of gas stream rotation relative to their inlet openings
56, although this is not a requirement.
[0027] Preferably, the jet passages (which are tubes) have an inner
diameter in the range of 0.01 inch (0.25 mm) to 0.05 inch (1.27
mm), although this is not a requirement. Preferably, the jet
passages have respective lengths in the range of 0.10 inch (0.25
mm) to 1.00 inch (2.54 cm), although this is not a requirement.
[0028] Referring now to FIG. 2, particle inlet 24 has an annular
counterbore 45 which can receive, e.g., an O-ring seal to prevent
particle leakage during operation of powder jet pump 20 if
connected to a particle feed device (e.g., a screw feeder or
gravity hopper). Nozzle throat 40 has a nozzle throat inner wall
46. Jet passages 52 are helically configured such that a portion of
each jet passage 52 adjacent to its respective outlet opening 36 is
disposed at an angle of 1 to 10 degrees relative to the nozzle
throat inner wall 46. In this embodiment, the gas stream causes a
vortex to form in the nozzle throat, thereby reducing recirculating
flow in the gas stream emerging from nozzle. While the above
geometry is preferred, other angles of the jet passages relative to
the nozzle throat inner wall may also be used.
[0029] Nozzle throat 40 has an inner diameter 41, and nozzle 42 has
a maximum inner diameter 43 (see FIG. 2A). In some embodiments, the
ratio of the inner diameter 41 to the maximum inner diameter 43 is
in the range of 1:1 to 1:20, preferably 1:2 to 1:10, and more
preferably 1:4 to 1:7. Preferably, the nozzle throat has a minimum
inner diameter in the range of 0.03 inch (0.76 mm) to 0.11 inch
(2.79 mm), although this is not a requirement.
[0030] While the powder jet pump can be made from assembled parts,
in preferred embodiments, the powder jet pump is unitary (i.e., a
single part). This may be accomplished by a rapid prototyping
method such as, for example, fused deposition modeling or
stereolithography.
[0031] The various components of the powder jet pump may be made of
any suitable material(s), including, for example, metal, plastic
(including engineering plastics such as high density polyethylene,
polycarbonate, polyimide, polyether ether ketone, polyether
ketone), glass, and fiber reinforced composites, (e.g., fiberglass,
carbon fiber composites), and combinations thereof.
[0032] Powder jet pumps according to the present disclosure can be
used in powder coating applications including but not limited to
painting, powder dispersion, and the coating of woven and non-woven
articles.
[0033] Exemplary embodiments of the present disclosure may take on
various modifications and alterations without departing from the
spirit and scope of the present disclosure. Accordingly, it is to
be understood that the embodiments of the present disclosure are
not to be limited to the following described exemplary embodiments,
but is to be controlled by the limitations set forth in the claims
and any equivalents thereof.
Select Embodiments of the Present Disclosure
[0034] In a first embodiment, the present disclosure provides a
powder jet pump, comprising:
[0035] a main body having a particle inlet at a first end and an
outlet connector at a second end, the particle inlet being in fluid
communication with an inlet chamber;
[0036] a nozzle defining a passage in fluid communication with the
chamber and outlet connector, wherein the nozzle includes a nozzle
throat;
[0037] at least one suction inlet in fluid communication with the
chamber;
[0038] an annular plenum positioned around the main body having a
gas inlet; and
[0039] at least two jet passages each having an inlet opening into
the annular plenum and an outlet opening within the nozzle
throat.
[0040] In a second embodiment, the present disclosure provides a
powder jet pump according to the first embodiment, wherein the gas
inlet is configured to impart a direction of rotation within the
annular plenum to a gas travelling through the gas inlet and into
the annular plenum.
[0041] In a third embodiment, the present disclosure provides a
powder jet pump according to the first or second embodiment,
wherein respective outlet openings of the at least two jet passages
are helically advanced in the direction of rotation relative to
their respective inlet openings.
[0042] In a fourth embodiment, the present disclosure provides a
powder jet pump according to any one of the first to third
embodiments, wherein the nozzle throat has a nozzle throat inner
wall, and wherein the at least two jet passages are configured such
that a portion of each jet passage adjacent to its respective
outlet opening is disposed at an angle of 1 to 10 degrees relative
to the nozzle throat inner wall.
[0043] In a fifth embodiment, the present disclosure provides a
powder jet pump according to any one of the first to third
embodiments, wherein the nozzle throat has a longitudinal axis,
wherein the at least two jet passages are configured such that a
portion of each jet passage adjacent to its respective outlet
opening is disposed at an angle of 1 to 10 degrees relative to the
longitudinal axis of the nozzle throat.
[0044] In a sixth embodiment, the present disclosure provides a
powder jet pump according to any one of the first to fifth
embodiments, wherein the nozzle throat has an inner diameter,
wherein the nozzle has a maximum inner diameter, and wherein the
ratio of the inner diameter of the nozzle throat to the maximum
inner diameter of the nozzle is in the range of 1:2 to 1:10.
[0045] In a seventh embodiment, the present disclosure provides a
powder jet pump according to any one of the first to sixth
embodiments, wherein the powder jet pump is unitary.
[0046] In an eighth embodiment, the present disclosure provides a
powder jet pump according to any one of the first to seventh
embodiments, wherein the nozzle throat has a minimum inner diameter
in the range of 0.03 inch (0.76 mm) to 0.11 inch (2.79 mm).
[0047] In a ninth embodiment, the present disclosure provides a
powder jet pump according to any one of the first to eighth
embodiments, wherein the at least two jet passages have respective
inner diameters in the range of 0.01 inch (0.25 mm) to 0.05 inch
(1.27 mm).
[0048] In a tenth embodiment, the present disclosure provides a
powder jet pump according to any one of the first to eighth
embodiments, wherein the at least two jet passages have respective
lengths in the range of 0.10 inch (0.25 mm) to 1.00 inch (2.54
cm).
[0049] Objects and advantages of this disclosure are further
illustrated by the following non-limiting examples, but the
particular materials and amounts thereof recited in these examples,
as well as other conditions and details, should not be construed to
unduly limit this disclosure.
EXAMPLES
[0050] Unless otherwise noted, all parts, percentages, ratios, etc.
in the Examples and the rest of the specification are by
weight.
Example 1
[0051] An apparatus generally as depicted in FIG. 1 was fabricated
by standard additive manufacturing techniques. The inner diameter
of the throat was 0.08 inch (2 mm). The jet passages had a length
of 0.55 inch (14 mm) and an inner diameter of 0.02 inch (0.5 mm).
Fine carbon particles were introduced into the particle inlet via a
twin-screw feeder at a rate of 1 g/min. Air was introduced at the
gas inlet at gauge pressures ranging between 1 and 10 psi (6.9 to
69 kPa). A fine dispersion of the particles in the gas/particle
mixture emerging from the outlet connector was observed over the
pressure range.
[0052] All cited references, patents, and patent applications in
the above application for letters patent are herein incorporated by
reference in their entirety in a consistent manner. In the event of
inconsistencies or contradictions between portions of the
incorporated references and this application, the information in
the preceding description shall control. The preceding description,
given in order to enable one of ordinary skill in the art to
practice the claimed disclosure, is not to be construed as limiting
the scope of the disclosure, which is defined by the claims and all
equivalents thereto.
* * * * *