POWDER JET PUMP

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.

[0004] WO 96 09122 (D1) discloses a powder jet pump, comprising a main body having a particle inlet and an outlet connector.

SUMMARY

[0005] 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.

[0006] In one aspect, the present disclosure provides 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.

[0007] As used herein:

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

the term "nozzle throat" refers to an area of minimum cross section of a nozzle.

[0008] 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

[0009] 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:

FIG. 1 is a perspective drawing of exemplary powder jet pump 20 according to the present disclosure;

FIG. 2 is side cross section view of powder jet pump 20, taken along section lines 2-2 in FIG. 1;

FIG. 2A is an enlarged view of region 2A in FIG. 2;

FIG. 2B is an enlarged perspective cross-sectional view of region 2B in FIG. 2; and

FIG. 3 is a side view of powder jet pump 20.

[0010] 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 of the principles of the disclosure. The figures may not be drawn to scale.

DETAILED DESCRIPTION

[0011] The present disclosure describes a powder jet pump for the introduction of particles into a gas stream.

[0012] 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.

[0013] 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.

[0014] Typical gauge pressures for the pressurized gas are 1 to 10 psi (6.9 to 69 kPa). Other gauge pressures may also be used.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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

[0023] In a first embodiment, the present disclosure provides 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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).

[0031] 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).

[0032] 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).

[0033] 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

[0034] Unless otherwise noted, all parts, percentages, ratios, etc. in the Examples and the rest of the specification are by weight.

EXAMPLE 1

[0035] 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.

[0036] 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.

Claims

1. A powder jet pump 20, comprising:

a main body 22 having a particle inlet 24 at a first end 27 and an outlet connector 44 at a second end 29, the particle inlet being in fluid communication with an inlet chamber 28;

a nozzle 42 defining a passage in fluid communication with the chamber and outlet connector, characterized in that the nozzle includes a nozzle throat 40;

at least one suction inlet 26 in fluid communication with the chamber;

an annular plenum 32 positioned around the main body having a gas inlet 34; and

at least two jet passages 52 each having an inlet opening 56 into the annular plenum 32 and an outlet opening 36 within the nozzle throat 40.

2. The powder jet pump of claim 1, wherein the gas inlet 34 is configured to impart a direction of rotation within the annular plenum 32 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 36 of the at least two jet passages 52 are helically advanced in the direction of rotation relative to their respective inlet openings 56.

4. The powder jet pump of claim 1, wherein the nozzle throat 40 has a nozzle throat inner wall 46, and wherein the at least two jet passages 52 are configured such that a portion of each jet passage adjacent to its respective outlet opening 36 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 52 are configured such that a portion of each jet passage adjacent to its respective outlet opening 36 is disposed at an angle of 1 to 10 degrees relative to the longitudinal axis of the nozzle throat 40.

6. The powder jet pump of claim 1, wherein the nozzle throat 40 has an inner diameter, wherein the nozzle has a maximum inner diameter 41, 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 20 is unitary.

8. The powder jet pump of claim 1, wherein the nozzle throat 40 has a minimum inner diameter 41 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 52 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 52 have respective lengths in the range of 0.10 inch (0.25 mm) to 1.00 inch (2.54 cm).

Ansprüche

1. Eine Pulverstrahlpumpe 20, umfassend:

einen Hauptkörper 22, der einen Teilcheneinlass 24 an einem ersten Ende 27 und einen Auslassverbinder 44 an einem zweiten Ende 29 aufweist, wobei der Teilcheneinlass in Fluidverbindung mit einer Einlasskammer 28 steht;

eine Düse 42, die einen Durchgang in Fluidverbindung mit der Kammer und dem Auslassverbinder definiert, dadurch gekennzeichnet, dass die Düse einen Düsenhals 40 aufweist;

mindestens einen Saugeinlass 26 in Fluidverbindung mit der Kammer;

eine ringförmige Kammer 32, die um den Hauptkörper herum angeordnet ist und einen Gaseinlass 34 aufweist; und

mindestens zwei Strahldurchgänge 52, die jeweils eine Einlassöffnung 56 in die ringförmige Kammer 32 und eine Auslassöffnung 36 innerhalb des Düsenhalses 40 aufweisen.

2. Die Pulverstrahlpumpe nach Anspruch 1, wobei der Gaseinlass 34 konfiguriert ist, einem Gas, das durch den Gaseinlass und in die ringförmige Kammer strömt, eine Drehrichtung innerhalb der ringförmigen Kammer 32 zu verleihen.

3. Die Pulverstrahlpumpe nach Anspruch 2, wobei jeweilige Auslassöffnungen 36 der mindestens zwei Strahldurchgänge 52 in der Drehrichtung relativ zu ihren jeweiligen Einlassöffnungen 56 spiralförmig hervorstehen.

4. Die Pulverstrahlpumpe nach Anspruch 1, wobei der Düsenhals 40 eine Düsenhalsinnenwand 46 aufweist und wobei die mindestens zwei Strahldurchgänge 52 so konfiguriert sind, dass ein Abschnitt jedes Strahldurchgangs, der an seine jeweilige Auslassöffnung 36 angrenzt, in einem Winkel von 1 bis 10 Grad relativ zur Düsenhalsinnenwand angeordnet ist.

5. Die Pulverstrahlpumpe nach Anspruch 4, wobei die mindestens zwei Strahldurchgänge 52 so konfiguriert sind, dass ein Abschnitt jedes Strahldurchgangs, der an seine jeweilige Auslassöffnung 36 angrenzt, in einem Winkel von 1 bis 10 Grad relativ zur Längsachse des Düsenhalses 40 angeordnet ist.

6. Die Pulverstrahlpumpe nach Anspruch 1, wobei der Düsenhals 40 einen Innendurchmesser aufweist, wobei die Düse einen maximalen Innendurchmesser 41 aufweist und wobei das Verhältnis des Innendurchmessers des Düsenhalses zum maximalen Innendurchmesser der Düse im Bereich von 1:2 bis 1:10 liegt.

7. Die Pulverstrahlpumpe nach Anspruch 1, wobei die Pulverstrahlpumpe 20 aus einem Stück besteht.

8. Die Pulverstrahlpumpe nach Anspruch 1, wobei der Düsenhals 40 einen minimalen Innendurchmesser 41 im Bereich von 0,03 Zoll (0,76 mm) bis 0,11 Zoll (2,79 mm) aufweist.

9. Die Pulverstrahlpumpe nach Anspruch 1, wobei die mindestens zwei Strahldurchgänge 52 jeweilige Innendurchmesser im Bereich von 0,01 Zoll (0,25 mm) bis 0,05 Zoll (1,27 mm) aufweisen.

10. Die Pulverstrahlpumpe nach Anspruch 1, wobei die mindestens zwei Strahldurchgänge 52 jeweilige Längen im Bereich von 0,10 Zoll (0,25 mm) bis 1,00 Zoll (2,54 cm) aufweisen.

Revendications

1. Pompe à jet de poudre 20, comprenant :

un corps principal 22 ayant une entrée de particules 24 au niveau d'une première extrémité 27 et un connecteur de sortie 44 au niveau d'une deuxième extrémité 29, l'entrée de particules étant en communication fluidique avec une chambre d'entrée 28 ;

une buse 42 définissant un passage en communication fluidique avec la chambre et le connecteur de sortie, caractérisé en ce que la buse inclut une gorge de buse 40 ;

au moins une entrée d'aspiration 26 en communication fluidique avec la chambre ;

un plénum annulaire 32 positionné autour du corps principal ayant une entrée de gaz 34 ; et

au moins deux passages de jet 52 ayant chacun une ouverture d'entrée 56 dans le plénum annulaire 32 et une ouverture de sortie 36 à l'intérieur de la gorge de buse 40.

2. Pompe à jet de poudre selon la revendication 1, dans laquelle l'entrée de gaz 34 est configurée pour communiquer un sens de rotation à l'intérieur du plénum annulaire 32 à un gaz circulant à travers l'entrée de gaz et dans le plénum annulaire.

3. Pompe à jet de poudre selon la revendication 2, dans laquelle des ouvertures de sortie respectives 36 des au moins deux passages de jet 52 sont avancées de manière hélicoïdale dans le sens de rotation par rapport à leurs ouvertures d'entrée 56 respectives.

4. Pompe à jet de poudre selon la revendication 1, dans laquelle la gorge de buse 40 a une paroi interne de gorge de buse 46, et dans laquelle les au moins deux passages de jet 52 sont configurés de telle sorte qu'une partie de chaque passage de jet à côté de son ouverture de sortie 36 respective est disposée à un angle de 1 à 10 degrés par rapport à la paroi interne de gorge de buse.

5. Pompe à jet de poudre selon la revendication 4, dans laquelle les au moins deux passages de jet 52 sont configurés de telle sorte qu'une partie de chaque passage de jet à côté de son ouverture de sortie 36 respective est disposée à un angle de 1 à 10 degrés par rapport à l'axe longitudinal de la gorge de buse 40.

6. Pompe à jet de poudre selon la revendication 1, dans laquelle la gorge de buse 40 a un diamètre interne, dans laquelle la buse a un diamètre interne 41 maximum, et dans laquelle le rapport du diamètre interne de la gorge de buse au diamètre interne maximum de la buse est dans la plage de 1:2 à 1:10.

7. Pompe à jet de poudre selon la revendication 1, dans laquelle la pompe à jet de poudre 20 est unitaire.

8. Pompe à jet de poudre selon la revendication 1, dans laquelle la gorge de buse 40 a un diamètre interne 41 minimum dans la plage de 0,03 pouce (0,76 mm) à 0,11 pouce (2,79 mm).

9. Pompe à jet de poudre selon la revendication 1, dans laquelle les au moins deux passages de jet 52 ont des diamètres internes respectifs dans la plage de 0,01 pouce (0,25 mm) à 0,05 pouce (1,27 mm).

10. Pompe à jet de poudre selon la revendication 1, dans laquelle les au moins deux passages de jet 52 ont des longueurs respectives dans la plage de 0,10 pouce (0,25 mm) à 1,00 pouce (2,54 cm).

Drawing