US2806521A

US2806521A - Furnace wall gas burner

Info

Publication number: US2806521A
Application number: US292696A
Authority: US
Inventors: Blaha Emil
Original assignee: Selas Corp of America
Current assignee: Selas Corp of America
Priority date: 1952-06-10
Filing date: 1952-06-10
Publication date: 1957-09-17
Anticipated expiration: 1974-09-17

Description

Sept 17, 1957 E. BLAHA FURNACE WALL. GAs BURNER 5 Sheets-Sheet 1 Filed June l0, 1952 FIG.

INVENTOR EMIL BLAHA Blz @www ATTORN EY.

Sept 17, 1957 E. BLAHA 2,806,521

FURNACE WALL GAS BURNERI ATTORNEY.

INVENTOR. EMIL BLAHA BXX4/wr n sept 17, 1957 E, BLAH/1 2,806,521

FURNACE WALL. GAS BURNER Filed June 10, 1952 3 Sheets-Sheet 3 F|G.9 l Flaw 56 INVENTOR.

M BLAHA ATTORNEY.

United States Patent O FURNACE WALL GAS BURNER Emil Blaha, Cheltenham, Pa., assigner to Selas Corporation of America, Philadelphia, Pa., a corporation of Pennsylvania Apparaten am@ in, 1952, serai No. 292,695

s params. (ci. iss- 116) The present invention relates to gas burners, and more particularly to gas burners of the type in which the fuel and air are mixed immediately prior to the time they are discharged into the combustion space.

Burners of the type with which the present invention is particularly concerned are disclosed in Furczyk Patent 2,561,793, issued July 24, 1951, although the present improvement can be used with other types of burners. In that patent, there is disclosed a distributing member for the fuel mixture including a ceramic part having a plurality of radially directed ports through which the fuel is discharged. The distributor terminates in a relatively heavy cap that extends into a cup shaped combustion space where the fuel is burned. Apparatus of this type performs in a satisfactory manner, but is expensive to manufacturebecause of the shapes of the ceramic parts that are required. K v A l It is an object of the present invention to provide an improvement yon burners of theA above mentioned type. It isa further object of the invention to provide a burner having a distribuer member for fuel, with the portions that are ,subjected to heat being formed of small parts that will not be affected by thermal stresses.

Itis a further object of the invention to provide a large capacity burner in which the fuel and combustion air are discharged into .the combustion space ina substantially axial direction; The cup shaped combustion space is so formed that'the axiallyV directed jets are bent in a radial direction to be burned along the surface of the cup.

It isa further object of the invention to provide a large Y capacity gas burner which is inexpensive to manufacture and easy to assemble, and one in which the combustion process is carried out in an efficient manner.

In accordance with the present invention, there is provided a burnerV block having a cup shaped depression inone face thereof and an opening extending from the base of the depression to an opposite face of the block.

Extending through the opening, almost tothe base of the( cup', 'is an alloy distributor member provided with pas- Y sagesthrough which fuel and air are discharged into the combustion space. The end or tip of the distributor which faces the combustion space is formed of a pluraiity v of small ceramic pieces. With this construction, the various parts of the burner may be assembled easily into a rigid unit that is readily inserted into and removed from the burnerV block. The block is located in and forms part of the furnace wall.

The various features of novelty which characterize my invention are pointed out with particularity in Vthe claims annexed to and forming a part of this specification,v For Y 2,806,521 Patented Sept. 17, 1957 ice tributor on a larger scale taken on line 2-2 of Figure 3; Figure 3 is an end view of the distributor; Figure 4 is a section view taken on line 4 4 of Figure 2; f

' Figures 5 and 6 are top and side Views, respectively, of

Y one ofthe distributing tip members;

` and reference is made thereto.v The distributor is sub- Figures 7 and 8 are top and side views, respectively, of another of the distributing tip members;

' Figure 9 is a section view corresponding to Figure 2 of the discharge end of a modified form of the distributor; Figure 10 is a section view corresponding to Figure 2 of the discharge end of still a different form of distributor taken on line 10-10 of Figure l1;

- Figure ll is an end view of the distributor of Figure 10; and Y Figures 12 and 13 are top and side views, respectively, of the distributing tip members used in connection with the form o'f the `invention shown in Figure l0.

Referring to Figure l of the drawing, there is shown a furnace wall made of suitable refractory material that is backed up in the usual manner by a steel plate 2. This plate has fastened to it, and extending along the same in a direction parallel to a row of burners, a first channel 3 Vthat 4forms a passage for gas and a second channel 4 that forms afpassage for air to be burned in the burners. Located in and forming part of the furnace wall is a burner block 5V of refractory ceramic material that is provided on its face with a cup shaped depression 6. The depression is formed near its bottom portion with apair of parallel and concentric ridges '7 immediately above a recessedportion 8 which forms the entrance to an Vopening 9. The opening extends to the rear face: of the burner block, and is continued through the refrac tory of the furnace wall and an opening made in the:

metal sheet 2.

Extendingthroughthe opening 9 and almost to the:

base of the cup is a cylindrical distributing member 11. of heat resisting alloy having a spider 10 in its discharge: end for supplying the fuel and air that are to be burned in the cup in a plurality of jets. This distributing member is attached to a burner body 12 mounted on the ex terior of the furnace wall. The connection between ther distributor and the burner body includes a collar 13y formed on the back end of the distributor which is engaged by a flange on a ring 14. Bolts 15 extend through the ring and into the burner body 12 to hold the distributor and bodytogether as a single rigid assembly. The burner body in turn is fastened to the furnace wall by means of bolts 16 which extend through a flange 17 onvthe body and which are threaded into a flange 1S extendingrradially from a ring 19. This ring is welded into position in the opening formed in the backing 2 of the furnace wall and is concentric with the opening 9 in the burner block. The space betweenring 19 and the distributor 11 is filled with a suitable cement 20 to prevent infiltration of air past the distributor.

The burner block 12 includes an air chamber 21 to which air is supplied from the channel d through a pipe 22 and a flexible connection taking the form of a bellows 23. The burner body also includes an annular gas charnber 24 that is supplied from the channel 3 through a pipe 25 and a liexi'ole connection in the form of a bellows 26. A platey 27 is used to close the rear end of the chamber 21. Air is introduced into the burner body through the pipe 22 and flows through the distributor to be discharged in a manner to be described below. Gas flows into the chamber 24, and through a series of tubes 28 extending from this cham-ber to the discharge end of the distributor in a manner to be described below. Y

'The discharge end of the distributor 11, or the left end in Figure 1, is shown more Vclearly in Figures 2 to 8,

stantially closed at its end by the spider portion 10. This portion is provided with a plurality of short passages 31 located in a ring concentric with the distributor as shown in Figure 4. The spider portion `also has a plurality of longer passages 32 that are radially displaced frornpassages 31 and intok the inner ends of which extend the outer ends of the tubesl 28, as best shown in the drawin-gs.- The end of the distributorl and the spider areprotected, and radially displaced openings 31- and 32 are4 grouped into aplurality of channels by a cap which iszforrned of a plurality of smallV refractory

ceramic pieces

33 and 34. Each of the pieces 33 as shown in vFigures 5 and 6 includes a wedge shaped part 35 that is undercut on each side at substantially 45 as shown at 36 andis provided with a groove 37. The central part of the member has a projection 38 which extends radially outward between the undercut por-tions. The lower edge of thisy projection is provided with a tongue 39. Each piece 34 shown in Figures 7 and 8 is substantially rectangular in plan and is provided with undercut portions 41 and a groove 42 which are similar to the undercut portions 36 and grooves 37 ofthe members 33. The lower outside edge of this member is provided with a tongue 43.

When live of the pieces 33 and ve of the pieces 34 are assembled as shown in Figure 3, they form a cap which is in the shape of a complete circle. The pieces areplaced in the end of the distributor 11 beyond the lends of the

openings

31 and 32 in the spider with the

tongues

39 and 43 being received in a groove 44 formed on the inner surface of the distributor. After the

members

33 and 34 have been assembled, a refractory ceramic bolt 45 is inserted through an opening left in the center of the assembled parts with the bolt being threaded into a refractory ceramic nut 46 that is received in a socket located concentrically in the end of spider 10. The bolt acts like a wedge or cam to force the

ceramic pieces

33 and 34 radially outward as .shown best in Figure 2. The pieces are thereby held rigidly as a unit between the bolt head and the nut in position in the end of the distributor. It is desired that these pieces be aligned in a predetermined relation to the openings formed in the spider port-ion. To this end, each of the pieces is provided on its lower face with a projection 47 that is received in a depression 48 formed on the end of the spider between openings 32. It will be seen that when the parts are assembled as described above and as best shown in Figures 2 and 3 of the drawings, there are provided a plurality of passages or channels formed by the

undercut portions

36 and 41 extending substantially in an axial direction with cach channel being directly above l and in communication with one of the openings 31 and one of the openings 32. The projection 38 of members 33 and the members 34.are so arranged that they separate completely the passages 32 from eachother, while the

grooved portions

37 and 42 of

members

33 and 34 respectively form an annular passage which connects all of the passages 31.

In the operation of a burner constructed in the above described mann'er, fuel and air lin proper proportions to form a combustible mixture are supplied to the

channels

3 and 4. The air flows through pipe 22, chamber 21, the distributor and through each of the

openings

31 and 32 in the end thereof. Gas ows from the supply channel through pipe into annular chamber 24. From here, the gas flows through the tubes 28 into each of the passages 32. The diameter of tubes 28 is 'so proportioned with respect to the diameter of passages 32 that a rich mixture of gas and air will be discharged into theseY passages. This mixture is too rich to burn by itself, but will be diluted in the channels to a combustible mixture by the air owing through passages 31, and a co-mplete mixture will be produced in the channels formed jointly by the projections 38 and the ceramic pieces 34. This combustible mixture is discharged in a plurality of substantially axially directed jets into the end of: the opening 9 of the burner block. As these jets move outwardly toward the combustion space formed by cup shaped depression 6, they are ignited and bend in a substantially radial direction to burn along the surface of the depression to heat it to incandescence. It would normally be expected that when the gas and air mixure is discharged into the opening 9 that the jets would burn directly outwardly toward the interior of the furnace, This is not the ease, however, since the dynamic flow of these jets past the recess 8 apparently creates a low pressure area around the outside of the jets which draws them radially outwardly across the surface of the cup. This low pressure area in connection with additional low pressure areas created by the ridges 7 cause the jets of gas and air to move along and burn along the surface of the depression 6 to heat the same to incandescence.

The ceramic tip is formed by the

parts

33 and 34, each of which is of a small enough mass so that it is not subjected to thermal stresses suiiciently to, cause breakage thereof; Furthermore, the parts can move relative to each other sufficiently to compensate for any inequalities in thermal expansion that mayk take place.

Burners of this type having a cup diameter of l0.

inches have been operated in the open with a cup ternperatureof 2600c F. whereas the temperature of the tip, as nearly as it could be measured, was not above 2300 F. In order toobtain this temperature, gas was supplied to the burner at 231/2 inches water column, and air was supplied at 16% inches water column. f Sufficient air and gas of 700 B. t. u. per cubic foot were supplied atthese pressures to liberate 900,000 B. t. u. per hour in a single burner. It was found, that when gas and air were supplied at a much lower pressure, namely below a 1/2 inch water column for both the gas and the air, with a B. t. u. release in the neighborhood of 150,000 B. t. u. per hour, that the jets of fuel delivered through the channels of the tip would burn axially without wiping the surface of the cup. As soonas the pressure of the fuel and the air was increased above thisy value, however, the low pressure area adjacent to the recess- 8 increased to a suflcient vialue, so that the jets of fuel mixture bent radially outward to burn along the surface of the cup in the manner described above.

Figure 9 shows another form that the distributor may take. This form differs from that previously described, in that the spider portion inthe end of the distributor 11 is formed separately therefrom and of a refractory ceramic material, vwhereas in the previously described embodiment, the spider portion havingthe fuel and air openings was integral with the distributor. Referring to Figure9, it will `be' seen that the spider is shown at 51 and includes short passages 31a and long passages 32a that are radially displaced therefrom. Passages 32a take the form of U- shaped'slots` on the surface of spider 51. The spider is also provided with a central opening 52 through which a bolt 45a extends. Nut 46 is, in this case, below the spider so that the bolt will hold the spider rigid with

ceramic pieces

33 and 34.

In assembling the part-s forming this embodiment of the invention, the spider 51 is moved into the end of the distributor 11 and the

ceramic pieces

33 and 34 are assembled with their

respective tongues

39 and 43 in the groove 44. Bolt 45a is then placed in position and the nut 46 threaded to the end of the bolt. The entire assembly is then held rigidly together and is held in place in the end of the distributor by the tongue and groove connection. The distributor with the assembly in its end is then moved from the outside of the furnace through the opening 9 in the burner block to a position similar to that shown in Figure 2. The operation of this embodiment of the burner is exactly the same as the operation of the previously de` scribed embodiment.

The embodiment of the invention shown in Figures 10 to 13 inclusive differs from thosel previously described in the manner in which the ceramic pieces used to form the channels or passages through which the fuel mixture ows to the cup are shaped. As shown in this embodiment of the invention, the spider 51 is ceramic and 1s separate from the distributor tube 11 as was the case with the embodiment shown in Figure 9. The ceramic pieces forming the passages in this case are best shown in Figures 12 and 13 at 54, and are substantially wedge shaped. There is one of these pieces provided to be placed between each of the pairs of

openings

31a and 32a. Each of these pieces is provided with a tongue 55 to tit in the groove 44 and with a projecting wedge 56 on its lower surface that is received in a complementary depression formed in the surface of the spider 51. The wedge shaped projection, rather than a small round pro jection such as 47 in the previous embodiments, is required since these individual pieces do not engage each other and therefore require a more accurate means of aligning thembetween the fuel and air passages. Each of the pieces is provided with a slanting edge 58 that is engaged by the lower face of a funnel shaped ceramic member 59. It will be noted from Figure of the drawing that when the funnel is in position forcing the ceramic pieces 54 toward the distributor tube 11, there is a passage 57 formed i bove the openings 31a corresponding to the passage 42 in the previous embodiments.

In assembling the parts of ,this type of burner, the spider is moved into position in the end of distributor tube 11. The ceramic pieces 54 are then placed in position and are held in position by the funnel shaped member 59. Thereafter, bolt 45a is inserted through the funnel and opening 52 of the spider and threaded into the nut 46. When the bolt is drawn up tight, the various parts ofthe tip assembly yare forced radially outward and locked into position, and in effect form a single member operating to direct the jets of fuel mixture toward the cup. As described above, the spider 51 in this embodiment 1s separate from the distributor tube 11. If desired, however, the spider could be formed integrally with the tube .11 as was the case in the embodiment of Figures 2 to 8 inclusive.

From the above description, it will be seen that I have provided a burner in which the cover for the tip of the fuel and air distributing partis made of ia number of small ceramic pieces which are easily for-med and easily assembled into the desired arrangement. When the assembly is complete, the parts are locked together so that there is no possibility of dislodging them in the normal use of the apparatus. Since the various parts forming the tip are independent of each other, they can move relative to each other as a result of thermal expansion. Thus, practically no stresses are set up in the parts during operation of the burner. Furthermore, the design which produces substantially axially directed jets of the fuel mixture into a cup having the recess adjacent to the point where the mixture enters into the 'cup permits the distributor to be withdrawnv to a point below the base of the cup. This position of the distributor means that it is cooler than would be the case if it were moved forward in the cup. Consequently, the parts of the distributor are not heated to the extent that they would otherwise be. This reduction in temperature of the parts contributes a longer life to the burner.

The distributor and tip or cap of the present burner have been described as being used as part of a burner in which mixing of the fuel and air takes place adjacent to the discharge end thereof. It will be obvious, however, that the invention can also be used Where a complete mixture of fuel and air is introduced into the cylinder 11.

While in accordance with provisions of the statutes, I have illustrated and described the best forms of my invention now known to me, it will be apparent to those skilled in the art that #changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of the invention as set forth in the appended claims, and that in some cases certain features 6 of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

l. A fuel distributor for a burner comprising in cornbination a tubular member having a groove around the inside thereof adjacent to one end, spider means within said member adjacent to `said groove and formed with a plurality of axially extending passages arranged in a ring, a plurality of lceramic parts each having a portion thereof adapted to extend into said groove, cooperating means on each of said parts and on said spider means between adjacent passages therein to locate definitely said parts between said passages, means to lock said parts in position on saidk member, said parts being shaped to form channels between said parts each of which is axially aligned with one of said passages, and means to supply fuel to said member to pass through said passages and channels into a combustion space in a plurality of jets.

2. A distributorV member for a burner including in combination a hollow cylindrical member having a groove formed around the inside thereof adjacent to one end, a plurality of ceramic parts extending radially of said member and operative when assembled side by side to form a circular cap to close the said one end of said member, said cap having an opening in the center thereof, each of said parts having a radially extending portion received by said groove, and various of said parts being formed with cut-,out portions each of which forms a passage through said cap from the interior of said member to the exterior thereof, and means extending through said opening to hold said pieces rigidly together with said portions in said groove.

3. In a burner, a distributor for delivering fuel to the combustion space of the burner comprising in combination a hollow cylindrical member, means forming a plu- -rality of axially extending passages adjacent to one end of said member, said member being provided with a groove around the interior of said end beyond said passage forming means, a plurality of ceramic pieces extending radially of said member each having a radially extending portion to fit into said groove, said pieces forming a circular cap for the end of said member, various of said pieces being provided with a radially cut-back section axially aligned with a passage and adjacent to the periphery of said member whereby fuel can flow through said passages and cutback sections in a plurality of substantially axially directed jets arranged around the periphery of said member, and means for wedging said pieces radially outward tightly into engagement with the groove in said member.

4. The combination of claim 3 in which said means forming said plurality of passages is separate from said member, and in which said means for wedging is attached to said last mentioned means.

5. In a burner, the combination of a cylindrical distribu tor member having an inlet end and a discharge end and a groove around the interior adjacent to the discharge end, a plurality of ceramic parts extending radially of said member and `operative when placed side by side to form a ring substantially equal to the diameter of said member with an opening through the center thereof, each of said parts being provided with a radial projection to engage said groove when they are assembled in the end of said member, a bolt having a diameter `substantially equal to the diameter of said opening and extending through said central opening, a nut threaded on said bolt, said bolt and nut serving to lock said parts from radial movement in position in the end of said member, said parts being formed to provide passages extending from the interior of said member to the exterior thereof in a substantially axial direction, and means to supply fuel to the inlet of said member to pass therethrough and through said passages to be burned.

6. A distributor for use in a gas burner comprising a hollow cylindrical member having an inlet end and a discharge end said member being provided in its interior with means forming a plurality of radially displaced pairs of openings extending axially thereof adjacent to the discharge end, and a groove around the insideY of the periphery of the discharge end beyond said openings, a ceramic cap to cover the end of said member comprising a plurality of ceramic parts, each of said parts having a portion thereof to engage said groove, alternate ones of said parts being provided with undercut portions extending radially inward' beyond said openings, cooperating means on said member and parts operative to, position said parts with an undercut portion above each of said pairs of openings, means to lock said parts in position, andmeans to supply fuel and air to the inlet end of Said member. Y

7. A distributor tip for a gas burner comprising a hollow cylindrical member having a groove formed around the inner surface thereof adjacent` to one end, a plurality of sector shaped complementary ceramic parts operative to form a circular cap for the end of said member, each of said parts being formed with a projection operative to engage said groove and thereby locate said parts relative to said member, said parts being formed to provide between adjacent parts an aperture through which a fuel mixture may ow, and means to force said parts radially outward to lock them in position on said member by engagement between said projections and said groove.

8. In a burner for gas fuel, a cylindrical distributor member having an inlet. end and an outlet end, means forming a plurality of passages for gas and air in the outlet Iend of said member, and means forming discharge channels for the gas andair passing through said passages comprising aplurality of sector shaped ceramic parts located on the dischargeend-of said member between various of said passages, radially extending interlocking portionsy on said member and said parts to position said parts relative to said member, means to force said parts radially outward to lock them in position on said member byfsaidinterlocking portions, and means to supply gas and air to the inlet end of said member.

References Cited'in' the le of this patent UNITED STATES PATENTS 882,545 Von Wouwermans Mar. 17, 1908 1,910,020 Boutillier et al. May 23, 1933 2,070,859 Don Howe Feb. 16, 1937 2,398,398 Abbott Apr. 16, 1946 2,474,313 Hess June 28, 1949 2,499,218- Hess Feb. 28, 1950 2,543,688 Coriolis et al Feb. 27, 1951 2,561,793 Furczyk July 24, 1951 2,583,736 Hess- Ian. 29, 1952 2,669,300 Blaha Feb. 16, 1954 FOREIGN PATENTS 8,480v Great Britain Mar. 21, 1912 595,514 Germany Apr. 13, 1934