BURNER SUPPLY TUBE WITH FUEL CHANNEL

Abstract

A burner supply tube, and a burner arrangement having such a burner supply tube, which includes a tube wall extending having a tube diameter and at least one integrated fuel channel extending from a fuel input at an upstream tube end to a fuel output at a downstream tube end. To enable an integrated design, the fuel channel is along the majority of the tube length helical with a gradient of at least 0.5 times and at most 5 times the tube diameter.

Claims

1.-17. (canceled)

18. A burner arrangement having a burner and a tube arrangement, which is attached to the burner at its upstream side and which is comprising an outer protection tube, a first inner fluid supply tube, optionally a second inner fluid supply tube, and a burner supply tube arranged between the outer protection tube and first fluid supply tube, wherein the burner supply tube comprises: a tube wall extending from an upstream tube end to a downstream tube end along a tube length further having a tube diameter and a wall thickness, wherein the tube length is at least 2 times and at most 20 times the tube diameter and the wall thickness is at least 0.01 times and at most 0.2 times the tube diameter, and comprises at least one integrated fuel channel extending from a fuel input at the upstream tube end to a fuel output at the downstream tube end, which has an equivalent diameter of at least 0.3 times and at most 3 times the wall thickness, wherein the fuel channel is helical along a majority of the tube length with a gradient of at least 0.5 times and at most 5 times the tube diameter, wherein a thickening due to the fuel channel is arranged on an inner side and/or on an outer side of the tube wall.

19. The burner arrangement according to claim 18, wherein a local thickness of the burner supply tube at the fuel channel is at most 3 times the equivalent diameter; and/or wherein a local thickness of the burner supply tube at the fuel channel is at most 3 times the wall thickness.

20. The burner arrangement according to claim 18, wherein the tube length is at least 4 times and/or at most 10 times the tube diameter.

21. The burner arrangement according to claim 18, comprising one or two fuel channels.

22. The burner arrangement according to claim 18, wherein the distance from a fuel input to the helical form and from a fuel output to the helical form is at most 1 time the tube diameter.

23. The burner arrangement according to claim 18, wherein the fuel input and/or the fuel output are arranged on the outer side of the burner supply tube.

24. The burner arrangement according to claim 18, wherein the fuel channel is arranged with its center between the middle and the inner side of the tube wall.

25. The burner arrangement according to claim 18, wherein the outer protection tube is firmly connected with the burner, and firmly connected at the upstream tube end with a terminal block and comprises bellows.

26. The burner arrangement according to claim 25, wherein the burner supply tube is firmly connected to the burner and firmly connected at the upstream tube end with a terminal block; and/or wherein the first fluid supply tube and/or the second fluid supply tube is/are firmly connected with the burner while a thermal expansion is possible at the upstream tube end at a terminal block.

27. The burner arrangement according to claim 18, wherein an annular fluid channel is defined between the burner supply tube and first fluid supply tube with a channel width between the burner supply tube and first fluid supply tube, wherein the channel width is at least 0.05 times and at most 0.3 times the tube diameter.

28. The burner arrangement according to claim 18, wherein the local distance from the first fluid supply tube to a thickening at the fuel channel is at least 0.2 times and at most 0.7 times the channel width.

29. The burner arrangement according to claim 18, wherein the wall thickness is at least 0.02 times and/or at most 0.1 times the tube diameter.

30. The burner arrangement according to claim 18, wherein the equivalent diameter is at least 0.6 times and/or at most 1.5 times the wall thickness.

31. The burner arrangement according to claim 18, wherein the gradient is at least 1 time and/or at most 2.5 times the tube diameter.

32. The burner arrangement according to claim 25, wherein the distance from a fuel input to the helical form and from a fuel output to the helical form is at most 1 time the tube diameter.

33. The burner arrangement according to claim 25, wherein the fuel input and/or the fuel output are arranged on the outer side of the burner supply tube.

34. The burner arrangement according to claim 18, wherein the fuel channel is arranged with its center between the middle and the inner side of the tube wall.

35. The burner arrangement according to claim 22, wherein the distance from a fuel input to the helical form and from a fuel output to the helical form is at most 0.5 times the tube diameter.

36. The burner arrangement according to claim 25, wherein the outer protection tube is firmly connected with a mounting frame.

37. The burner arrangement according to claim 27, wherein the channel width is at least 0.1 times and at most 0.2 times the tube diameter.

38. The burner arrangement according to claim 28, wherein the local distance from the first fluid supply tube to a thickening at the fuel channel is at least 0.3 times and at most 0.6 times the channel width.

39. The burner arrangement according to claim 32, wherein the distance from a fuel input to the helical form and from a fuel output to the helical form is at most 0.5 times the tube diameter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In the following figures an example of an inventive tube arrangement with an inventive burner supply tube is shown:

[0040] FIG. 1 shows an example of a tube arrangement in longitudinal section;

[0041] FIG. 2 shows the exemplary inventive burner supply tube;

[0042] FIG. 3 shows in detail the fuel channel of the burner supply tube.

DETAILED DESCRIPTION OF INVENTION

[0043] In FIG. 1 exemplary tube arrangement 31 located between a burner 32 at the downstream tube end and a terminal block at the upstream tube end 03 is shown in a longitudinal section. The tube arrangement 31 comprises at the outer side and outer protection tube 33 which 33 is firmly connected with the burner 32 on the downstream side 04 and also firmly connected to the terminal block at the upstream tube end 03. To prevent terminal stress inside the tube arrangement 31 the outer protection tube 33 comprises a bellow. Further the mounting frame is attached with further bellows in-between with the outer protection tube 33.

[0044] Next to the outer protection tube 33 the exemplary burner supply tube 01 is arranged. This 01 is also firmly connected with the burner 32 on the downstream tube end 04 and with the terminal block at the upstream tube end 03. The burner supply tube 01 comprises an integrated fuel channel 11, which has almost of the length helical shape.

[0045] Inside the burner supply tube 01 first fluid supply tube 34 is arranged. This is also firmly connected with the burner 32. To prevent terminal stress the first fluid supply tube 34 is connected with the terminal end at the upstream tube end 03 with the ability of terminal expansion. Between the burner supply tube 01 and the first fluid supply tube 34 in annular channel is defined.

[0046] In this example inside the first fluid supply tube 34 a further second fluid supply tube 35 is arranged. This leads to the possibility to guide a further medium from the upstream tube end 03 to the burner 32 at the downstream tube end 04.

[0047] In FIG. 2 the exemplary burner supply tube 01 used in the tube arrangement 31 of FIG. 1 is shown, wherein in FIG. 3 a detail on the fuel channel is sketched. The burner supply tube 01 comprises a thin tube wall 05 with the tube length 06 and the tube diameter 07, which is the diameter on the outer side of the tube wall 05. The tube length 06 is in this example about 4 times the tube diameter 07. The tube wall 05 is quite thin compared to the size of the burner supply tube 01 and has a tube thickness 08 of about 0.05 times the tube diameter 07.

[0048] The burner supply tube 01 comprises as a key feature the fuel channel 11. This has a fuel input 12 at the upstream tube end 03 and a fuel output 13 at the downstream tube end 04 (the fuel output 13 is offset in circumferential direction and therefore not directly visible in this section). After a short distance of 17 from the fuel output 13 and analogue after a short distance from the fuel input 12 the fuel channel 11 comprises the helical shape with the gradient 14. In this example the gradient 14 of the fuel channel 11 is about 1.5 times the tube diameter 07.

[0049] The integration of the fuel channel 11 inside the burner supply tube 01 leads to the necessity to arrange thickening 15, 16 in this case on the inner side and on the outer side of the tube wall 05. The inner thickening 16 leads to a decrease of the distance the first supply tube 34. Due to the helical shape of the fuel channel 11 the inner thickening 16 does not hinder the fluid stream inside the annular fuel channel. In this example it is preferred that the fuel channel 11 is arranged with its center in a radial direction at the inner side of the tube wall 05. This leads to a smaller outer thickening 15 on the outer side of the tube wall 05 and the higher thickening 16 on the inner side of the tube wall 05.