US2898874A

US2898874A - Vane adjusting assembly for pulverized fuel type burner unit

Info

Publication number: US2898874A
Application number: US657657A
Authority: US
Inventors: Jr Henry Crewdson
Original assignee: American Viscose Corp
Current assignee: Robert Bosch GmbH; Akzo Nobel UK PLC
Priority date: 1957-05-07
Filing date: 1957-05-07
Publication date: 1959-08-11
Anticipated expiration: 1976-08-11

Description

v H. CREWDSON, JR VANE ADJUSTING ASSEMBLY FOR PULVERIZED Aug. 11-, 1959 VANE ADJUSTlNG ASSEIVELY FOR PULVERIZED FUEL TYPE BURNER UNIT Application May 7, 1957, Serial No. 657,657

6 Claims. (Cl. 110-28) The present invention relates to a control or adjusting assembly for adjusting the vanes which control the angle of feed of pulverized fuel such as coal to a boiler or a furnace.

In the past, when the operator found it necessary to adjust the burner vanes or blades which control the angle of feed of such fuel to the boiler or furnace, it was necessary to remove the boiler or other heating unit from service, remove the burner unit and then adjust the vanes of the burner unit in manual manner using pliers or other suitable tools. The burner unit then had to be reassembled within the furnace or boiler before the entire unit could be put back into service. This process had to be repeated until a satisfactory flame shape was obtained. This method of adjusting the burner vanes is strictly a hit or miss proposition and is not satisfactory in that much time is consumed, and it is not always possible to have the boiler or other furnace unit out of service for the required time to adjust the blades. Such adjustment is frequently required in view of the change in fuel or air mixture entering the burner.

It is therefore one object of my invention to provide a new and novel burner vane adjusting assembly wherein the blades or vanes may be easily adjusted as desired from a point lying, externally of the boiler or furnace unit.

Other objects and advantages of my invention will become apparent from a study of the following description and drawing wherein:

Figure 1 is an elevation partially in section of the adjustable burner assembly;

Figure 2 is a section taken along lines IIII of Figure 1; and

Figure 3 is a detail in section on an enlarged scale showing the relationship of the adjustable vane burner assembly with respect to the boiler or furnace unit.

Briefly, my invention relates to a hollow shaft which supports through its periphery a plurality of adjusting vanes or blades at the furnace end of the shaft which blades are pivoted by means housed within the shaft bore which means are moved from a point externally of the shaft at the opposite end of the shaft. The blades are arranged in a fan-like formation around the periphery of the hollow shaft whereby a plurality of small channels are provided in the path of the incoming pulverized fuel passing along the shaft periphery.

As seen in Figure 3 of the drawing, an outer shell or sleeve 1 is supported in an opening within the wall 3 of a boiler or furnace 4. The periphery of the shell or sleeve forms a tight seal through suitable welding with the boiler or furnace wall 3. Supported concentrically within the shell or sleeve 1 is a tube 5 which is of somewhat smaller diameter than the shell or sleeve 1 whereby a first annular passageway 6 is provided, the purpose of which will be hereinafter explained. A hollow shaft '7 is concentrically supported within the tube 5 to provide a second annular passageway 8 through which the pulverized fuel such as coal is fed to the furnace or boiler.

atent dice To add oil to the fuel mixture entering the furnace, if so desired, an oil atomizer 9 (Figure 3) is supported in a centered relationship within the hollow shaft 7. The atomizer 9 is affixed to an oil supply pipe 11. g

As further seen in Figure 3, the hollow shaft 7 supports a plurality of angularly constructed vanes or

blades

13, 13 which extend within the second annular passageway 8. The adjustable feature of these

blades

13, 13 will now be described in detail with specific reference to Figures 1 and 2 of the drawing.

As seen in Figure 1, each blade 13 is affixed to a pivotable stem 15. Each stem 15 extends through a complementary drilled hole or opening 17.

As seen more clearly in Figure 2, the base of each stem 15 is permanently secured to an enlongated arcuate shaped shoe 19. The base of the blades 13, as seen in Figure 1, lie almost flush with the periphery of the hollow shaft 7.

It is now evident that the angle of each blade 13 may be pivoted or angularly adjusted Within the annular passageway 8 by merely pivoting or rotating the shoes 19; 19. To rotate the shoes 19, 19, a shoe positioning assembly 20 is provided within and at the furnace end of the shaft 7. The positioning assembly 20 is formed of two opposed and spaced apart ring members 21, 23 which are joined together by

connectors

25, 25. In direct alignment with one another and extending inwardly from the opposed faces of the ring members 21-, 23- are projections or bosses 27, 27. As seen better in Figure 2, each shoe 19 is elongated sufficiently so that a portion of the shoe extends beyond each vane stem 15. The shoe adjusting assembly 20' is so positioned Within the hollow shaft 7 with respect to the shoes 19, 19 that the opposed bosses 27, 27 lie on either side of and are in direct alignment with that portion of the shoe extending beyond the stem 15.

By axially moving the shoe positioning assembly 20 toward the furnace end of the shaft 7, it is obvious that the bosses 27, 27 of the ring element 21 will contact the elongated portions of the shoes 19 to pivot the shoes and vanes in a clockwise direction. By axially moving the shoe positioning assembly 20 in the opposite direction, it is understood that thebosses 27, 27 of the ring member 23 will contact the extended portions of the shoes 19, 19 to' pivot the shoes and vanes in a counterclockwise position. Stop

pins

29, 29 positioned on either side of the shoe positioning assembly 20 limit the axial movement of the positioning means 20 within the shaft 7.

To provide this axial movement of the shoe positioning assembly 20 within the shaft '7, a pair of small elongated connecting shafts 33, 33 are permanently secured to the assembly 20. These bars 33, 33 run in opposed fashion along the inner wall surface of the hollow shaft 7. The opposite end of each shaft 33 is in turn permanently afixed to a threaded sleeve 35. As seen in Figure 1, the threaded sleeve 35 extends partially within the hollow shaft 7 but does not contact the shaft wall. A threaded hand wheel 37 is threaded onto the free end of the sleeve 35. To axially move the positioning assembly 20 within the hollow shaft 7, the hand wheel 37 may be rotated in either a clockwise or counter-clockwise direction depending upon the direction of axial movement desired. As the hand wheel is rotated, the sleeve 35 is moved axially of the shaft '7. Rotation of the sleeve 35 and shafts 33, 33 during rotation of the hand wheel is prevented by limiting

pins

39, 39.

After the desired adjustment is achieved, this position may be permanently set through locking bolt and nut assemblies 41, 41 which cooperate with a lock washer 43, a flange 45 of the hand wheel 37 and a collar 47 around shaft 7 to firmly set the adjusted position of the shoe positioning assembly 20.

3 Not constituting a specific feature of my invention except as used in combination with the subject matter heretofore disclosed, there is supported on the perlphery of the tube 5 to lie within the first annular channel 6 a slidable collar 50 having a rim portion 52 which slants backward and upwardly from the collar hub. This rim 52 cooperates with an annular bafile plate 54 which extends inwardly into channel 6 from the inner surface of the outer shell 1 to form an annular passageway 53. The collar 50 may be moved axially of the tube 5 by means of a lever 56 which is loosely secured to the collar 54) and which extends externally of the bore of shell 1. By this means, the channel 53 defined by the annular baffle 54 and the collar rim 52 may be enlarged or diminished in size as desired to adjust the amount and the angle of introduction of a quantity of secondary air introduced into the furnace unit 4 through the annular passage 6. Further, by this means, a controlled method is provided for scattering the pulverized fuel entering the furnace unit through the annular channel 8.

From the above description, it is obvious that I have provided a new and novel as well as practical means for the simple adjustment of the

burner blades

13, 13.

While preferred embodiments of the invention have been shown and described, it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A control assembly for a pulverized fuel type burner unit as used with a furnace or boiler comprising a sleeve which extends through an opening in the furnace wall, a main fuel feeding tube of-somewhat smaller diameter than the sleeve supported within said sleeve, the outer periphery of said tube and inner surface of said sleeve forming a substantially annular passageway through which a fuel scattering medium may be passed, a hollow shaft supported in concentric manner within the main fuel feed tube, at least one pivotable means extending through the shaft periphery at the furnace end of the shaft, a deflecting vane mounted on said pivotable means and extending within the bore of said main fuel feed tube with the base of said vane lying substantially flush with the'periphery of said hollow shaft, an elongated arcuate shaped shoe fixed to said pivotable means so as to lie within. said hollow shaft, a shoe positioning assembly formed of a pair of spaced apart, opposed and joined together ring members between which said shoe is positioned, shoe contact means mounted upon the opposed faces of each ring member which means lie directly opposite the shoe, and means secured to the shoe positioning assembly which is movable longitudinally of the shaft bore to urge the ring members axially of the shaft whereby the shoe contact means will pivot the shoe, the pivotable means and the vane.

2. A control assembly for a pulverized fuel type burner unit used in a furnace or boiler unit according to claim 1 wherein the shoe contact means consist of bosses extending from the opposed faces of the ring members.

3. A control assembly for a pulverized fuel type burner unit used in a furnace or boiler unit according to claim 1 wherein a plurality of aligned vanes, vane pivotable means, shoes and shoe contact means are provided with the vanes disposed in fan-like formation around the hollow shaft and within the main feed tube bore.

4. A control assembly for a pulverized fuel type burner unit according to claim 1 wherein the means for moving the shoe positioning members back and forth within the hollow shaft comprises an opposed pair of elongated shafts afiixed to the shoe positioning assembly which shafts lie adjacent opposing sides of the inner surface of the hollow shaft, and means secured to the elongated shafts for moving the shafts axially within the hollow shaft.

5. A control assembly for a pulverized fuel type burner assembly according to claim 4 wherein the means for effecting axial movement of the opposed shafts comprises a nonrotatable threaded sleeve to which the shafts are secured and which lies partially within the end of the hollow shaft opposite the vane end, and a complementary threaded hand wheel which supports the sleeve in position and which is threaded onto the free end of the threaded sleeve whereby when the hand wheel is rotated, the threaded sleeve and the shafts secured thereto will be moved axially within the hollow shaft depending upon the direction of rotation of the hand wheel.

6. A control assembly for a pulverized fuel type burner assembly according to claim 5 comprising means for preventing the threaded sleeve from rotating within the hollow shaft.

References Cited in the file of this patent UNITED STATES PATENTS.

1,086,713 Irish Feb. 10, 1914 1,879,652 Blizard Sept. 27, 1932 2,136,777 Andrews Nov. 15, 1938 2,271,587 Haynes Feb. 3, 1942