Heat gun with high performance jet pump and quick change attachments

• US 6,010,329 A
• Filed: 11/07/1997
• Issued: 01/04/2000
• Est. Priority Date: 11/08/1996
• Status: Expired due to Term

• Current Assignee: AF Gloenco, Inc. (AFG Holdings, Inc.)
• Original Assignee: Battenfeld Gloucester Engineering Co., Inc., Shrinkfast Corporation
• Inventors: Zagoroff, Dimiter S.
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): LEE, DAVID B
• Application Number:
  US08/966,293
• Time in Patent Office: 788 Days
• Field of Search: 431/158, 431/154, 431/181, 431/185, 431/255, 431/264, 431/266, 431/344, 431/345, 431/354, 239/296, 126/405, 126/407, 417/183, 417/163, 417/167, 417/171
• US Class Current: 431/158
• CPC Class Codes: B01F 2101/503 Mixing fuel or propellant and water or gas, e.g. air, or other fluids, e.g. liquid additives to obtain fluid fuel
• CPC Class Codes: B01F 25/312 with Venturi elements; Details thereof
• CPC Class Codes: B01F 25/31242 the main flow being injected in the central area of the venturi, creating an aspiration in the circumferential part of the conduit B01F25/31243 takes precedence
• CPC Class Codes: B01F 25/312533 Constructional characteristics of the diverging discharge conduit or barrel, e.g. with zones of changing conicity
• CPC Class Codes: B01F 35/71 Feed mechanisms with proportioning B01F35/80
• CPC Class Codes: B01F 35/712 for feeding fluids
• CPC Class Codes: B01F 35/7179 using sprayers, nozzles or jets
• CPC Class Codes: F04F 5/463 with provisions for mixing
• CPC Class Codes: F04F 5/466 with a plurality of nozzles arranged in parallel
• CPC Class Codes: F23D 14/08 with axial outlets at the burner head
• CPC Class Codes: F23D 14/38 Torches, e.g. for brazing or heating nozzles F23D14/48
• CPC Class Codes: F23D 14/64 with injectors
• CPC Class Codes: F23D 2207/00 Ignition devices associated with burner
• CPC Class Codes: F23D 2210/00 Noise abatement
• CPC Class Codes: F23D 2210/101 using noise dampening material
• CPC Class Codes: F23D 2900/00013 with means for spreading the flame in a fan or fishtail shape over a melting bath
• CPC Class Codes: F23D 2900/14642 with jet mixers with more than one gas injection nozzles or orifices for a single mixing tube

Abstract

A jet pump for a heat gun includes an elongate hollow pump body lying along a longitudinal axis. The pump body has an inlet, a mixing section and an outlet. A nozzle unit is axially aligned with the inlet for directing pressurized fuel into the inlet of the pump body. Movement of the pressurized fuel into the inlet causes air to be drawn into the inlet to mix with the fuel within the pump body. A disk shaped air diverter is axially spaced away from the inlet of the pump body. The diverter has a length and a diameter. The diameter of the diverter is greater than the length of the diverter and larger than the inlet of the pump body. A housing is radially spaced from and surrounds the diverter forming a first annular gap therearound for air outside the housing to pass therethrough. The air moves around the diverter then changes direction between the diverter and the inlet of the pump body before entering the inlet.

Claims

1. A jet pump for a heat gun comprising:

an elongate hollow pump body lying along a longitudinal axis having an inlet with an inlet opening diameter, a mixing section and an outlet;

a nozzle unit axially aligned with the inlet for directing pressurized fuel into the inlet of the pump body, movement of the pressurized fuel into the inlet causing air to be drawn into the inlet to mix with the fuel within the pump body;

a disk shaped air diverter axially spaced away from the inlet of the pump body, the diverter having a length and a diameter, the diameter of the diverter being greater than the length of the diverter and larger than the inlet opening diameter of the pump body;

a housing radially spaced from and surrounding the diverter forming a first annular gap therearound for air outside the housing to pass therethrough, the air moving around the diverter then changing direction between the diverter and the inlet of the pump body before entering the inlet.

2. The jet pump of claim 1 in which the nozzle unit is mounted to the diverter.

3. The jet pump of claim 1 in which the jet pump housing is radially spaced from and surrounds the pump body forming a second annular gap between the housing and the pump body, the housing including an opening positioned radially relative to the pump body such that air outside the housing can enter through the opening and pass through the second annular gap to enter the pump body inlet.

4. The jet pump of claim 1 in which the diverter is axially spaced from the pump body about 0.5 inches.

5. The jet pump of claim 4 in which the ratio of the diverter diameter to the inlet opening diameter is about 4.

6. The jet pump of claim 4 in which the ratio of the diverter diameter to the diverter length is about 2.

7. The jet pump of claim 1 in which the pump body has inner walls, the nozzle unit comprises a series of elongate nozzle tubes, the nozzle tubes extending into the inlet of the pump body and angled radially outwardly for directing the pressurized fuel towards the walls of the pump body.

8. The jet pump of claim 7 in which the nozzle tubes each have a stem portion with a first inner diameter and a first wall thickness, the nozzle tubes also having a tip portion with a second inner diameter and a second wall thickness, the second diameter at the tip portion being smaller than the first diameter of the stem portion.

9. The jet pump of claim 8 in which the wall thickness at the tip portion is less than the wall thickness of the stem portion.

10. The jet pump of claim 9 in which the wall thickness at the tip portion is about 0.003 inches and the wall thickness at the stem portion is about 0.005 inches.

11. The jet pump of claim 9 in which the nozzle tubes are about 0.437 inches long with the tip portion being about 0.06 inches long.

12. The jet pump of claim 11 in which the tip portions are positioned along a circle having a diameter of about 0.28 inches.

13. The jet pump of claim 7 in which the nozzle tubes are at an 12°

angle relative to each other.

14. The jet pump of claim 8 in which the ratio of the first diameter to the second diameter is about 1.6.

15. The jet pump of claim 1 further comprising a combustor system, the combustor system comprising:

a first spring loaded button protruding radially from the pump body;

a combustor attachment for combusting an air/fuel mixture received from the outlet of the pump body, the combustor attachment capable of being releasably coupled to the pump body and having an ignition device for igniting the air/fuel mixture, the combustor attachment including a first hole capable of engaging the first spring loaded button for locking the combustor attachment to the pump body in a first position and a second hole capable of engaging the first spring loaded button for locking the combustor attachment to the pump body in a second position.

16. The jet pump of claim 15 in which the combustor system further comprises a first electrical connector positioned in the pump body outlet for providing an electrical charge to the ignition device.

17. The jet pump of claim 16 further comprising a charge dissipator for dissipating residual electrical charges in the ignition device.

18. The jet pump of claim 15 in which the combustor system further comprises a hollow extension piece having proximal and distal ends capable of being positioned between the pump body and the combustor attachment, the extension piece including a second electrical connector at the proximal end for engaging the first electrical connector and a third electrical connector at the distal end for engaging the ignition device of the combustor attachment, the second and third electrical connectors being electrically connected together by an electrical conductor, the extension piece includes a proximal hole at the proximal end capable of engaging the first spring loaded button for locking the extension piece to the pump body, the extension piece also having a second spring loaded button capable of engaging one of the first and second holes of the combustor attachment for locking the combustor attachment to the extension piece.

19. The jet pump of claim 18 in which the extension piece is telescoping.

20. The jet pump of claim 1 in which the air and fuel mix to form an air/fuel mixture, the jet pump further comprising an expanding diffuser within which the air/fuel mixture is pressurized.

22. The jet pump of claim 19 in which the inlet has an inlet opening diameter, the jet pump further comprising:

a disk shaped air diverter axially spaced away from the inlet of the pump body, the diverter having a length and a diameter, the diameter of the diverter being greater than the length of the diverter and larger than the inlet opening diameter of the pump body; and

a housing radially spaced from and surrounding the diverter forming a first annular gap therearound for air outside the housing to pass therethrough, the air moving around the diverter then changing direction between the diverter and the inlet of the pump body before entering the inlet.

23. The jet pump of claim 22 in which the nozzle unit is mounted to the diverter.

24. The jet pump of claim 22 in which the jet pump housing is radially spaced from and surrounds the pump body forming a second annular gap between the housing and the pump body, the housing including an opening positioned radially relative to the pump body such that air outside the housing can enter through the opening and pass through the second annular gap to enter the pump body inlet.

25. The jet pump of claim 22 in which the ratio of the diverter diameter to the inlet opening diameter is about 4.

26. The jet pump of claim 22 in which the ratio of the diverter diameter to the diverter length is about 2.

27. The jet pump of claim 19 in which the nozzle tubes are at an 12°

angle relative to each other.

28. The jet pump of claim 19 in which the nozzle tubes each have a stem portion with a first inner diameter and a first wall thickness, the nozzle tubes also having a tip portion with a second inner diameter and a second wall thickness, the second diameter being constant and smaller than the first diameter, the second wall thickness being less than the first wall thickness.

29. The jet pump of claim 28 in which the ratio of the first diameter to the second diameter is about 1.6.

30. The jet pump of claim 28 in which the second diameter of the tip portion has a length, the length to diameter ratio of the second diameter being at least about 2.

31. The jet pump of claim 19 further comprising a combustor system, the combustor system comprising:

a first spring loaded button protruding radially from the pump body; and

a combustor attachment containing the combustor for combusting the air/fuel mixture which is received from the outlet of the pump body, the combustor attachment capable of being releasably coupled to the pump body and having an ignition device for igniting the air/fuel mixture, the combustor attachment including a first hole capable of engaging the first spring loaded button for locking the combustor attachment to the pump body in a first position and a second hole capable of engaging the first spring loaded button for locking the combustor attachment to the pump body in a second position.

32. The jet pump of claim 31 in which the combustor system further comprises a first electrical connector positioned in the pump body outlet for providing an electrical charge to the ignition device.

33. The jet pump of claim 32 further comprising a charge dissipator for dissipating residual electrical charges in the ignition device.

34. The jet pump of claim 31 in which the combustor system further comprises a hollow extension piece having proximal and distal ends capable of being positioned between the pump body and the combustor attachment, the extension piece including a second electrical connector at the proximal end for engaging the first electrical connector and a third electrical connector at the distal end for engaging the ignition device of the combustor attachment, the second and third electrical connectors being electrically connected together by an electrical conductor, the extension piece includes a proximal hole at the proximal end capable of engaging the first spring loaded button for locking the extension piece to the pump body, the extension piece also having a second spring loaded button capable of engaging one of the first and second holes of the combustor attachment for locking the combustor attachment to the extension piece.

35. The jet pump of claim 34 in which the extension piece is telescoping.

21. A jet pump for a heat gun comprising:

an elongate hollow pump body lying along a longitudinal axis having an inlet, a mixing section and an outlet, the pump body having inner walls;

a nozzle unit axially aligned with the inlet for directing pressurized fuel into the inlet of the pump body, the nozzle unit having a series of elongate nozzle tubes, the nozzle tubes angled radially outwardly for directing the pressurized fuel towards the walls of the pump body, the movement of the pressurized fuel into the inlet causing air to be drawn into the inlet to mix with the fuel within the pump body to form an air/fuel mixture;

an expanding diffuser in which the air/fuel mixture is pressurized; and

a combustor for combusting the air/fuel mixture.

40. The method of claim 21 further comprising the step of forming the nozzle tubes each with a stem portion having a first inner diameter and a first wall thickness, and a tip portion with a second inner diameter and a second wall thickness, the second diameter being constant and smaller than the first diameter, the second wall thickness being less than the first wall thickness.

41. The method of claim 40 further comprising the step of forming the nozzle tubes with a first diameter to second diameter ratio of about 1.6.

42. The method of claim 40 in which the second diameter of the tip portion has a length, the method further comprising the step of forming the second diameter with a length to diameter ratio of at least about 2.

43. The method of claim 21 further comprising the step of angling the nozzle tubes at an 12°

angle relative to each other.

36. A method of pumping an air/fuel mixture in a heat gun comprising the steps of:

providing an elongate hollow pump body, the pump body lying along a longitudinal axis and having an inlet with an inlet opening diameter, a mixing section and an outlet;

directing pressurized fuel into the inlet of the pump body with a nozzle unit axially aligned with the inlet, movement of the pressurized fuel into the inlet causing air to be drawn into the inlet which mixes with the fuel within the pump body;

diverting air into the inlet of the pump body with a disk shaped air diverter axially spaced away from the inlet, the diverter having a length and a diameter, the diameter of the diverter being greater than the length of the diverter and larger than the inlet opening diameter of the pump body, a housing radially spaced from and surrounding the diverter forming a first annular gap therearound for air outside the housing to pass therethrough, the air moving around the diverter changing direction between the diverter and the inlet of the pump body before entering the inlet.

37. The method of claim 36 further comprising the step of forming the diverter and the inlet with a diverter diameter to inlet opening diameter ratio of about 4.

38. The method of claim 36 further comprising the step of forming the diverter with a diameter to length ratio of about 2.

39. A method of pumping an air/fuel mixture in a heat gun comprising the steps of:

providing an elongate hollow pump body, the pump body lying along a longitudinal axis and having an inlet, a mixing section and an outlet;

directing pressurized fuel into the inlet of the pump body with a nozzle unit axially aligned with the inlet, the nozzle unit having a series of elongate nozzle tubes angled radially outwardly for directing the pressurized fuel towards the walls of the pump body, movement of the pressurized fuel into the inlet causing air to be drawn into the inlet to mix with the fuel within the pump body to form the air/fuel mixture;

pressurizing the air/fuel mixture within an expanding diffuser; and

combusting the air/fuel mixture within a combustor.