US3199570A

US3199570A - Industrial burner

Info

Publication number: US3199570A
Application number: US283807A
Authority: US
Inventors: John R Williams; Feng Chung Liao
Original assignee: Selas Corp of America
Current assignee: Selas Corp of America
Priority date: 1963-05-28
Filing date: 1963-05-28
Publication date: 1965-08-10
Anticipated expiration: 1982-08-10

Description

1965 J. R. WILLIAMS ETAL 3,199,570

INDUSTRIAL BURNER Filed May 28, 1965 INVENTOR JOHN ROGER WILLIAMS CHUNG LIAO FENG ATTORNEY.

United States Patent ,0

3,199,570 INDUSTRIAL BURNER John R. Williams, Ambler, and Chung Lian Feng, Horsham, Pa., assignors to Salas Corporation of America, a corporation of Pennsylvania Filed May 23, 1953, Ser. No. 283,887 6 Claims. (Cl. 158-104) The present invention relates to industrial burners, and more particularly to a high intensity radiant'heat burner.

Burners have previously been made with screens in front of them, which screens were heated in some manner to radiate heat. These burners have been relatively ineflicient in that the heat from the hot products of combustion has not been completely utilized for transferring heat to the screen. In addition, the screens in most cases, have been unevenly heated and have had a tendency to warp, thereby producing uneven heating of work placed in front of them.

The burner of the present invention is provided with a tightly woven metal screen that is heated both by heat radiated from a refractory surface, and by the passage of products of combustion flowing through the screen under pressure. In assembling the burner, the screen, and various other parts, are held loosely in place so that they may expand and contract under changes in heat without warping and without placing a strain upon adjacent parts.

It is an object of the present invention to provide a radiant screen burner in which the screen is heated evenly over its surface, It is a further object of the invention to provide a radiant screen burner which is easy to assemble and which may be assembled in units to provide a burner of any desired and practical length.

A further object of the invention is to provide a radiant screen burner which utilizes efliciently the available heat of the fuel burned therein.

The various features of novelty which characterize our invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which we have illustrated and described a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a view, partly in section, lengthwise of the burner,

FIG. 2 is a view taken on line 2-2 of FIG. 1, and

FIGS. 3 and 4 are enlarged views showing the manner in which the screen is held in place.

Referring to the drawings, there is shown a manifold 1 which is mounted in a position for use by attaching a flange 2 that is formed on it to a similar flange 3 on a fuel supply pipe 4. The manifold is provided with a distributing chamber 5 into which fuel is supplied from pipe 4 past a baffie 6, immediately in front of the entrance to the chamber, in order to distribute evenly the fuel. The top of the manifold consists of a plate '7 which, with a pair of side plates 8, as shown in FIG. 2, form a trough in which various burner parts are received. These parts include a plurality of refractory cup'bloclts 9, each of which has a cup-shaped depression 16 formed in its upper surface with the various cups bein connected by grooves 12. Ceramic parts 11 are used to space the cup blocks from plates 3, and to locate them along the trough.

Each block 9 is provided with an opening extending from the base of the depression to be aligned with a similar opening provided in the plate 7. A tip holder 13 extends through each of the block openings and is threaded into the plate to hold the cup block in place. These tip holders each receive a refractory tip 14 that is provided with axially extending passages 15 on its surface through which a fuel mixture is discharged from the manifold as a plurality of radially directed jets across the surface of the depression. The manifold is shown as supporting three of the cup blocks although it will be apparent that a different number of cup blocks could be mounted on each manifold if it were so desired.

Each end of the burner trough is closed by a refractory plate 16 having a metal backing 18 that is bolted to the end of the manifold. The end plate 16 is separated from the adjacent cup block, and the cup blocks are separated from each other, and the blocks 11 are separated from the side plates 8. The spaces between these various parts are covered or filled in by high temperature fibrous material 17 which will give slightly so that the parts can move slightly relative to each other without damage to the refractory and to prevent gas leakage between them. One of the end plates of the burner, as shown on the right of FIG. 1, is provided with a hole 19 which is aligned with one of the grooves 12. Extending through this hole is a pilot burner 21 which is used to ignite the burner. A flame detecting electrode 22 also extends into the block adjacent to the pilot flame. If desired a number of the burners can be mounted end to end. When thisvis done adjacent end plates will be omitted'and the burner blocks 9 on separate manifolds will be moved against each other as shown at the left of FIG. 1. The two abutting manifolds will be held in alignment with respect to each other by a pin 23 extending through holes provided therein, which pin is held in place by a cotter pin.

An enclosed combustion space is formed above the various blocks by means of a closely woven screen 24 of a heat resisting metal. The screen, as shown in FIG. 2, is held in place by the side plates 8 which are bent over as indicated at 26, with the plates being provided with retainers 27 into which the lower edges of the screen are received. In order to prevent buckling of the screen, due to expansion and contraction, the screen is made in sections, each of which is substantially the width of one of the cup blocks. It is noted that the plates 8 are also made in sections for the purpose of providing expansion joints and each plate has in it a slot 25 as shown in FIG. 1 for the same purpose. The edges of the screen sections adjacent to each other are held in alignment and the joint between them is closed, by retainers including a lower metal strip 28 which has pins 29 welded to and projecting upward from it. This strip underlies adjacent screen edges with the pins extending between the edges of the screens. An upper retaining metal strip 31 is laid over strip 28 with the pins 29 extending through it and bent over to hold these strips in place.

Strips

28 and 31 are not attached to the screen sections, but merely keep them in alignment. The edges of the screen at the ends of the burner are loosely held in place by hoods 32 that are bolted to end plates 13 by bolts 33.

The construction of the entire burner is such that the refractory parts are separated so that they can expand and contract relative to each other. The metal parts forming the combustion chamber, including the screens 24, are so fastened to the side plates that a substantially gas-tight point is formed between the two and between sections of the screen. The various parts are held in place loosely so that they can expand and contract relative to each other without buckling and causing gaps to form in the screen as a whole. The screen, as indicated above, is made of a heat resisting alloy such as 309 stainless steel and is tightly woven of about 16 x 200 mesh so that about 6%, but no more than about 20%, of its area is open.

In the operation of the burner a fuel supply in the form of a combustible mixture of gas and air flows into the manifold and through the slots 15 to be discharged radially across the surfaces of the depressions 10. The

' ucts of combustion.

fuel is ignited and burns to heat the refractory surface to incandescence. The products of combustion escape through the openings in the screen. Since the total open area of the screens is so small, a pressure is built up in the combustion space, thus insuring that the combustion products will be discharged evenly over the whole surface of the screen. The screen is heated both by radiant heat from the surface of the refractory and by convection heat given up by the products of combustion as they flow through the screen. In this fashion the screen is heated to incandescence evenly over its entire area. Changing the amount of fuel that is supplied to the burner causes a rapid change in the incandescence of the surface of the refractory cup blocks as well as the volume of prod- Since the outer face of screen 24 is radiating to the atmosphere, any change in the temperature of the refractory back of it, or volume of gases discharged through it, will permit a rapid change in its temperature. Consequently the temperature of the screen and the heat radiated by it will vary rapidly and in proportion to the fuel supply. This ability to change rapidly is enhanced by the low heat inertia of the screen. A large percentage of the heat of the gases is given up to the screen so that a very high percentage of the total heat developed by the burning gases is transferred into radiant heat which can be projected from the burner for useful purposes.

From the above it will be seen that we have provided a burner which is so designed that the various parts can move relative to each other as the temperature of the burner is changed thereby insuring a long trouble free life. In addition the combination of the refractory surface and the fine mesh screen insures that the screen will be heated evenly over its entire area and the useful heat from the fuel, in the form of radiant heat will be directed outwardly from the burner.

While in accordance with the provisions of the statutes we have illustrated and described the best form of embodiment of our invention now known to us, 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 set forth in the appended claims, andthat in some cases certain features of our invention may be used to advantage without a corresponding use of other features.

What is claimed is:

1. An industrial burner comprising a plurality of refractory blocks, each block being provided with a cup-shaped depression on one surface thereof, structure including side plates supporting said blocks side by side with said surfaces exposed flexible means to separate said blocks from each other and from said side plates. means extending through said structure and blocks into the base of each depression to hold said blocks on said structure and through which fuel is supplied to burn along the surfaces of said depressions, a screen extending over each of said blocks, said screens being closely woven thereby to retard the flow of combustion gases therethrough, means to fasten said screens loosely to said side plates at opposite sides of each block, and means to fasten said screens loosely to each other above said surfaces to form an enclosed combustion space above said depressions.

2. In an industrial burner, means forming a manifold and having on one side thereof a flat surface, a plurality of burner blocks mounted side by side on said surface, each of said blocks being provided on the side opposite said surface with a cup-shaped depression, and a trough connecting said depressions, fuel distributing means extending from the base of each depression to said manifold operative to hold said blocks on said surface and to supply fuel across the faces of said depressions to burn thereacross and heat them to incandescence, means including a tightly woven screen extending from side to side of said blocks across the front thereof above said depressions to form a space, means to close the ends of said space, holding means extending from said surface on opposite sides of said blocks, and means cooperating with said holding means to fasten said screen in position with a loose, substantially gas-tight connection over said blocks and with said end closing means.

3. The combination of claim 2 including a pilot burner to ignite the gas flowing into said depression, and means to mount said pilot burner in one of said end closing means.

4. The combination of claim 2 in wtu'ch said screen is formed in sections with a section over each block, and means loosely joining said sections to each other.

5. In an industrial burner, means forming a manifold having on one side thereof a flat surface, a plurality of refractory blocks placed side by side on said surface, the side of each of said blocks opposite said surface being formed with a cup-shaped depression, fuel distributing means extending through each block from the base of said depression into said manifold, said means being operative to hold said blocks in position on said surface and to discharge fuel along said depressions where it is burned to heat the blocks to 'incandescence, side plates attached to said manifold and extending up the sides of said blocks, flexible material between each of said blocks and between said blocks and said side plates, a closely woven screen extending between said side plates and over said blocks, and means loosely to attach said screen to said side plates with a substantially gas tight connection, the arrangement being such that the several blocks and screen can move relative to each other and to said side plates due to expansion and contraction as a result of changes in the temperature thereof.

6. The combination of claim 5 in which said closely woven screen has no more than twenty percent of its area open whereby said screen will retard the flow of combustion products from the space between said depressions and said screen.

References Cited by the Examiner UNITED STATES PATENTS 1,237,780 8/17 Hicks.

1,294,999 2/19 Brickman 158ll2 1,451,716 4/23 Sharpe l58104 1,944,350 1/34 Kuhner 1l097 2,302,751 11/42 Don Howe 158l04 2,980,104 4/61 Patrick et al 1581l4 X 3,073,379 1/63 Martin l58ll4 3,098,477 7/63 Lotter 15 899 FOREIGN PATENTS 1,175,620 11/58 France.

JAMES W. WESTHAVER, Primary Examiner.

FREDERICK L. MATTESON, JR., Examiner.

Claims

1. AN INDUSTRIAL BURNER COMPRISING A PLURALITY OF REFRACTORY BLOCKS, EACH BLOCK BEING PROVIDED WITH A CUP-SHAPED DEPRESSION ON ONE SURFACE THEREOF, STRUCTURE INCLUDING SIDE PLATES SUPPORTING SAID BLOCKS SIDE BY SIDE WITH SAID SURFACES EXPOSED FLEXIBLE MEANS TO SEPARATE SAID BLOCKS FROM EACH OTHER AND FROM SAID SIDE PLATES. MEANS EXTENDING THROUGH SAID STRUCTURE AND BLOCKS INTO THE BASE OF EACH DEPRESSION TO HOLD SAID BLOCKS ON SAID STRUCTURE AND THROUGH WHICH FUEL IS SUPPLIED TO BURN ALONG THE SURFACES OF SAID DEPRESSIONS, A SCREEN EXTENDING OVER EACH OF SAID BLOCKS, SAID SCREENS BEING CLOSELY WOVEN THEREBY TO RETARD THE FLOW OF COMBUSTION GASES THERETHROUGH, MEANS TO FASTEN SAID SCREENS LOOSELY TO SAID SIDE PLATES AT OPPOSITE SIDES OF EACH BLOCK, AND MEANS TO FASTEN SAID SCREENS