US3219097A

US3219097A - Radiant gas burner

Info

Publication number: US3219097A
Application number: US136309A
Authority: US
Inventors: Fred J Prince; Szell Charles
Original assignee: Hupp Corp
Current assignee: SCHWANK Inc; Hupp Corp
Priority date: 1961-09-06
Filing date: 1961-09-06
Publication date: 1965-11-23
Anticipated expiration: 1982-11-23

Description

N0V 23, 19654 F. J. PRINCE ETAL RADIANT GAS BURNER Original Filed April l2, 1956 INVENTORS /m J/w @MP/es @geen ATTORNEYS` United States Patent O RADIANT GAS BURNER Fred J. Prince, Euclid, and Charles Szell, Bedford Heights, Ohio, assignors to Hupp Corporation, Detroit, Mich., a corporation of Virginia Continuation of application Ser. No. 577,762, Apr. 12, 1956. This application Sept. 6, 1961, Ser. No. 136,309 7 Claims. (Cl. 158-114) This is a continuation of application Serial No. 577,762, filed April 12, 1956.

The present invention relates to improvements in perforated plate type radiant gas burners and more particularly to improvements in burners of that type which are of longitudinally elongated construction, that is to burners in which the length of the radiant surface is suiiiciently greater than its width to make uniformity of distribution of fuel and air to all portions of that surface a problem. An example of a burner of this type is disclosed in United States application Serial No. 470,467 led November 22, 1954, by Gunther Schwank for Incandescent Gas Heater, assigned to the assignee of the present application and now abandoned.

Perforated plate type radiant gas burners may be formed by assembling together a plurality of rectangular perforated burner units or elements in juxtaposition to provide a radiating Wall having an external radiant surface when the burner is in operation. The presently commercially available burner units are approximately 2.565 inches by 1.800 inches by .451 inch and are formed with approxi` mately one thousand through perforations approximately .0510 inch in diameter. These burner units may be either ceramic tiles of the type disclosed in application Serial No. 214,468 filed March 8, 1951, by Gunther Schwank for Radiation Burners, now Patent No. 2,775,294, or of the metal plate type disclosed in application Serial No. 563,319 filed February 3, 1956 by William M. Day for Gas Burner, assigned to the assignee of the-present application and now abandoned.

In certain installations where it is desired to heat a relatively long narrow area either within a building or out of doors, the burner assembly is formed by providing a single row of these perforated ceramic plates disposed in juxtaposed end to end relation to define the radiating surface, a row of eight of such plates being the most usual commercial form.

In the operation of longitudinally elongate perforated plate type radiant gas burners, particularly those utilizing but a single row of perforated burner elements, it has been extremely difficult to achieve the necessary distribution of the combustible air-gas mixture over the inner non-radiant face vof radiating wall in order to produce uniform radiance of the entire radiant surface of the radiating wall throughout the length of the burner. Flat batiies mounted in uniformly spaced relation to the radiant wall have been used heretofore to effect distribution of the air-gas mixture but have proved ineffective for this purpose. The improper distribution of the combustible air-gas mixture resulting from the use of flat baies, either perforate or imperforate, produces spots or areas over the radiant face which are not heated to radiant temperature and thus materially reduces the overall efficiency of operation of the burner. When proper distribution of the air-gas mixture is achieved, the fluid pressure at the inlet end of each of the approximately one thousand combustion chambers in each of the burner elements is substantially uniform `over ICC the entire radiant wall. Under this condition, all portions of the radiant surface of the radiant wall are equally radiant during burner operation.

With the foregoing general considerations in view the principal objects of the present invention are to provide:

(1) A longitudinally elongate perforated plate type radiant gas burner having uniformity of radiation of the entire radiating surface thereof during operation;

(2) A longitudinally elongate perforated plate type radiant gas burner embodying fluid ow guide and control structure therein which is effective to so distribute a combustible mixture of air and gas over the entire surface of the radiant wall thereof as to achieve substantially uniformity of radiation of the radiant surface of such wall;

(3) A longitudinally elongate perforated plate type radiant gas burner having a baflie structure therein which in cooperation with the burner housing, is effective to so distribute a combustible air-gas mixture received through a centrally located inlet in that housing as to establish a substantially uniform pressure within the chamber of the burner over the entire length of the radiant Wall thereof;

(4) To provide in a longitudinally elongate perforated plate type radiant gas burner having an elongate mixing chamber one wall of which is formed by a row of perforated radiant burner elements, a single economically manufactured bafe member mounted within the housing of the burner and effective to so control the flow of a combustible mixture of air and gas received through a centrally disposed inlet over the entire radiant wall of the burner as to achieve substantial uniformity of radiation over the entire external surface of such wall; and

(5) A baflie for use in a longitudinally elongated perforated plate type radiant gas burner which when assembled in such a burner is effective to control the iow of combustible air and gas mixture in such burner as to establish uniformity of radiation over the entire external surface of the radiant wall thereof and which is in assembly asymmetrical relative to the burner housing and is so constructed that it can be assembled in such housing only in its proper relationship thereto and is effective to cooperate with such housing to properly direct and distribute the air-gas mixture introduced therein.

These and other objects of the present invention will become more fully apparent by reference to the appended claims and as the following detailed description proceeds in reference to the accompanying drawings wherein:

FIGURE 1 is a longitudinal section view of a burner embodying the present invention;

FIGURE 2 is a right end view of the assembly of FIG- URE 1;

FIGURE 3 is a fragmentary sectional view of the assembly of FIGURE 1 taken substantially along the lines 3 3 of FIGURE l;

FIGURE 4 is a fragmentary sectional view taken substantially along the line 4-4 of FIGURE 1; and

FIGURE 5 is a fragmentary sectional view taken substantially along the line 5 5 of FIGURE l.

The burner 8 comprises basically a housing member 10 formed with an interior concave face 12 and a peripheral wall 14 formed with a rectangular opening 16 in which is mounted a row of perforated radiant burner units or heating elements 18 which cooperate to form a Wall 20. Elements 18 are all of one of the types of elements described above. The Wall 20 formed by the elements 18, the peripheral wall 14 and the concave face 12 define an elongate chamber 22 which is of such length relative to its width and depth that uniformity of distribution of a combustible gas-air mixture therein is a problem. An aperture 24 is formed through the member 10 centrally of the concave face 12 opposed to wall 20 to permit introduction of intermixed gas and air into the chamber 22 from a venturi 26. A hood or shade 28 is attached exteriorly of housing member to the end of the peripheral wall 14 of the housing 10 and extends around the wall 20. Hood 28 shields the exterior surface 30 of wall 20 from winds or breezes when the burner 8 is installed out of doors and confines the radiant energy from the burner elements and reflects it in a concentrated form on the definite desired area. The burner 8 is adapted for wall mounting by the provision of wall brackets 32 and 34 upon which the housing 10 is pivotally mounted by coaxial bolts 36 and 38.

The venturi 26 is formed by a casting 40 provided with a longitudinally extending passage 42 having a central section 43 of uniform cross-section, an inlet section 44 converging in the direction of ilow (indicated by the arrow 46) and an outlet section 48 diverging in a direction of flow which terminates in an elbow shaped conduit section 50 directing the intermixed gas and air downwardly through the aperture 24 in the housing 10. The common axis of the venturi sections 43, 44 and 48 is parallel to the longitudinal axis of the chamber 22 and to the surface 31 of wall 20. An orifice assembly 52, terminating in a discharge nozzle 54 directed coaxially through the venturi passage 42, is mounted upon the casting 40, as shown and is connected to a gaseous fuel supply pipe 56 (FIGURE 2). Air is admitted into the venturi 26 through an opening 58 in the casting 40 located radially outward of nozzle 54 and through a shield assembly 60 formed by a U-shaped shield 62 and a pair of deflector plates 64 and 66 which coact to permit the entrance of air into the venturi passage 42 through the inlet opening 58 while shielding the opening 58 from winds or breezes which would force an excessive amount of air through the opening 58. In indoor installations, shield assembly 60 functions as a dust cap.

In burners constructed in the manner thus far described it has been found, prior to the present invention, extremely diflicult to control the distribution of the combustible mixture of gas and air introduced through the inlet port 24 to effect a uniform distribution of that mixture throughout the entire chamber 22, that is so that the pressure is substantially uniform over the entire interior surface 31 of wall 20. The absence of such a uniform distribution results in unequal flow of the air-gas mixture through all of the perforations in the elements 18 and, thereby, nonuniformity of heating of the radiating elements 18 and variations in the radiation from various parts of the radiating surface 30. As has been pointed out above, flat ballles, both perforate and imperforate lying in substantially parallel adjacently spaced relation to wall surface 31 have been used in the past but are ineffective in providing the required uniformity of distribution of the air-gas mixture. In order to overcome this difliculty, we have provided a baflle assembly 68 of novel and improved construction which is effective to maintain a uniform distribution of the combustible gas and air mixture throughout the entire chamber 22 and thus provide a uniform pressure over the interior face 31 of the radiating wall 20 of the burner 8. The baffle 68 comprises a strip of metal having coplanar imperforate flat sections 70 and 72 extending toward each end of the chamber 22 and terminating in

upturned portions

74 and 76 at the opposite ends of the baflle 68, interconnected apertured upwardly inclined flat sections 78 and 80 which are interconnected at their adjacent ends and connected at their outer ends to the sections 70 and 72 respectively. The portions of the baflle assembly 68 thus far described, that is sections 70, 72,

end portions

74 and 76 and apertured sections 78 and 80 are formed from a single stamped strip in the preferred form of the invention. This strip is mounted upon the housing 10 by screws 82 and -84 which extend through suitable l apertures formed in the sections 70 and 72 and are threaded into bosses 86 and 88 respectively. As is apparent from FIGURES 3 and 5, the bosses 86 and 88 are substantially smaller than the width of the sections 70 and 72 and thus form very little impedance to the flow of gas. Sections 70 and 72 are disposed in adjacently spaced parallel relation to the surface 31 of wall 20 while sections 78 and are upwardly inclined toward inlet port 24 to provide greater spacing thereof from surface 31 than that between surface 31 and sections 70 and 72. The wide spacing between portions 78 and 80 and the face 31 provides a deep mixing chamber adjacent the inlet port 24 for diffusion of the mixture over the central portion of face 31 at a uniform pressure.

A deflector plate or partition 90 is attached to the section 80 of the baille assembly 68 and projects upwardly through the aperture or inlet port 24 and the aperture of gasket 92, which is interposed between the casting 40 and the housing 10 to provide a fluid tight connection therebetween, Gasket 92 is formed of asbestos and is designed to remain effective for temperatures up to 650 F. The detlector plate 90, as is best shown in FIGURE 4, extends transverse to the longitudinal dimension of chamber 22 through the aperture 24 in contact with the opposite walls thereof and thus divides the aperture 24 into two openings 94 and 96. The top edge 98 of dellector 90 abuts the casting 40 at its opposite edges to establish proper alignment of the deilector 90 within the aperture 24.

Outwardly of boss 88 an angle member 100 is attached to the top of the section 72 of the baflle 68. This angle member is so spaced relative to the aperture in the section 72 for screw 84 that the baflle member 68 can be mounted in the housing 10 only in the position illustrated in FIGURE 1. If by inadvertence one should attempt to mount the baflle assembly 68 in its reverse position, the angle member would abut the boss 86 and thus prevent mounting of the baflle assembly 68 in that position.

Since the baflle 68 is formed of a long strip which is bent to the desired shape, it is possible in manufacture for this strip to be bent so that it is not in the exact configuration shown in FIGURE 1. In order to maintain the proper spacing of the baflle from the surface 31 and the concave face 12 of the housing 10, the

end portions

74 and 76 have been provided so that, if the sections 70 and 72 are bent an excessive angle relative to the sections 78 and 80,

end portions

74 and 76 will abut the concave surface 12 and maintain the sections 70 and 72 in proper spaced relation to that surface 12. Similarly the end surface 98 of the dellector 90 abuts at its opposite ends the casting 40, as illustrated in FIGURE 4, to maintain proper alignment of the central sections 78 and 80 relative to the concave face 12.

As is apparent from FIGURE 1, the opening 96 into chamber 22 is smaller than the opening 94. The air-gas mixture in leaving the venturi section 48 and passing through the elbow section 50 has an inertial tendency to continue in its axial direction. This tendency produces a greater density of the mixture in opening 96 than in opening 94. The partition 90 is so located that substantially equal masses (or Weights) of the mixture pass through the openings 96 and 94 and thus establishes a distribution of equal amounts of the air-gas mixture to the opposite halves of the chamber 22.

This design may be modified so that inlet port 24 is not in the center 0f the burner housing but is moved to the right, as viewed in FIGURE l, to favor this end of the burner. In such a case, the juncture of the inclined baille portions 78 and 80 may lie in the center of inlet port 24 and partition 90 is unnecessary.

As will be noted in reference to FIGURE 1, baille section 78 is provided with three

apertures

102, 104 and 106 and baflle section 80 is provided with three

apertures

108, 110 and 112. The section 78 is inclined upwardly from the section 70 to a position closely adjacent the housing member 10 at the aperture 24 and the sectionl 80 is upwardly inclined from the section 72 closely adjacent the oppositeend of the aperture 24 of the housing 10. The portion of the section 78

intermediate apertures

104 and 106 coacts with `the adjacent end face of the aperture 24 to deiine a relatively small oriice through which intermixed gas and air is discharged at a relatively high velocity toward the end of the chamber 22 to which the section 70 extends. Similarly the portion of section 80

intermediate apertures

108 and 110 coacts with the adjacent portion of the housing and aperture 24 to deiine a relatively large orifice through which intermixed gas and air passes at a lower velocity but which is directed toward the end of the chamber 22 toward which the baille section 72 extends. The apertures 102 through 112 are large diameter openings to permit diilusion of gas and air through the sections 78 and 80 without material acceleration of the gas and air particles. The portions of sections 78 and 80 in which these apertures 102 to 112 are formed are upwardly inclined from the inner face 31 of the radiant wall 20 to space those apertures suiliciently from face 31 so that the gas and air mixture within the portion of 22 between baille sections 78 and 80 and the interior wall 31 is free of streams of gas and air directed against the Wall face 31.

By this construction, the stream of intermixed gas and air from venturi passage 42 is divided by partition 90 into two streams of substantially equal mass. A portion of each stream is directed toward an end of the chamber 22 above the baille sections 70 and 72 and accelerated in its movement to assure its distribution to the extreme end of the chamber. A further portion of each stream is allowed to diiluse through the

large openings

102, 104 and 106 or 108, 110, and 112 toward the central portion of the wall surface 31. The wide spacing of openings 102 to 112 from surface 31 is important to provide equal pressurization of all portions of the surface 31.

As is apparent from FIGURES 3 and 5 the baille assembly 68 is narrower than the chamber 22 so that the gas and air mixture directed toward the opposite ends of the chamber 22 between the baille assembly 68 and the concave surface 12 of the housing 10 in the manner previously described gradually diffuses through the space deiined between the peripheral wall 14 of the housing 10 and the lateral edges of the baille assembly 68 along the sections 70 and 72 thereof.

End portions

74 and 76 effect further diffusion of these streams.

The baille constructed in accordance with the foregoing description assures distribution of gaseous fuel and air mixture throughout the chamber 22 along its entire length to establish substantially uniform pressure within the chamber 22 along the interior surface 31 of the radiant wall 20. This assures substantial uniformity of gas pressure at the inlet ends of all of the perforations in the radiatingl elements 18 and uniformity of radiation over the entire radiant surface 30.

The invention may be embodied in other specific forms Without departing from the spirit or essential characteristics thereof. The present embodiment is therefor to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come Within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a perforated plate type radiant gas burner, a housing, a perforated radiating wall cooperating with said housing to deiine a chamber of such elongate construction that uniformity of distribution throughout said chamber of intermixed gas and air from an inlet is a problem, said housing having an inlet port -formed centrally in the Wall thereof -opposed to said radiating wall, an air-gas mixing venturi assembly mounted on said housing with its axis substantially parallel to the interior surface of said wall,

a conduit interconnecting the outlet of said venturi assembly and said housing inlet port in iluid communication, and means mounted in said chamber for controlling the distribution throughout said chamber of intermixed gas and air passing through said inlet port, said means comprising a partition mounted in said inlet port and extending across said inlet port in a direction transversely of said chamber and off-set from the center thereof toward -the side thereof opposite said venturi assembly to divide the iluid discharged from said venturi into two streams, a baille mounted in said chamber on said housing having first and second portions adjacent each end of said chamber extending substantially parallel to the interior face of said radiating wall and edges thereof spaced from said housing and third and fourth portions extending respectively between said iirst and second portions and said partition, said third and fourth portions being formed with a plurality of ports therethrough and more remotely spaced from said radiating all interior face than said iirst and second portions.

2. The combination defined in claim 1 wherein said baille is a single metal strip having upturned end sections at the outer ends of said rst and second baille portions adapted to abut the wall of said housing opposed to said radiating wall to establish a predetermined spacial relationship of said baille relative to said radiating wall.

3. The combination defined in claim 1 wherein said partition is mounted on said baille adjacent the junction of the third and fourth portions thereof and on the side thereof opposite said radiating wall.

4. The combination defined in claim 1 wherein said venturi assembly includes a casting having a through passage of converging-diverging form in the direction of iluid flow therethrough and wherein said conduit is an integral extension of said casting, the outlet end of said conduit being of lesser cross sectional area than the inlet port of said housing and the edge of said partition remote from said baille abutting the face of said casting surrounding the outlet of said conduit to establish proper spacial relationship of said partition relative to said inlet port and of said third and fourth baille portions relative to the walls of said chamber.

5. The combination defined in claim 1 wherein said baille is asymmetrical relative to the juncture of said third and fourth baille portions and wherein cooperating means on said housing and on said baille are provided for preventing improper mounting of said baille on said housing.

6. For use in a perforated plate type radiant gas burner of such elongate construction that uniformity of distributi-on .throughout the chamber thereof 4of intermixed gas yand a-ir is a problem, la baffle comprising an elongated metal strip .having coplanar imperforate end regions interconnected by ,a pair of interconnected ilat central regions angularly inclined from the planes of said end regions and relative to each other, each such centnal region being forme-d with a plurality of spa-ced ports to permit passage of intermixed gas =and air therethrough, and 4a plate parti- 4tion mounted on said strip ald-jacent the juncture of said central regions on the side thereof opposite the plane of said end regions and ladapted to be received in the inlet port of such a burner to divide such port into two distinct openings.

7. In a perforated plate-type radiant gas burner comprising an elongated perforated radiant wall and a housing cooperating with said -wall to define an elongated chamber and provided with ian inlet port opposed to said wall located intermediate the ends of said chamber, a baille of substantially uniform thickness fixed within and extending over the major portion of the length of said chamber and having end regions substantially parallel to and .adjacent the interior face -of said wall and mounted with its longitudinal edges in spaced relation to said housing and connected by central portions inclined from said end .regions away from said wall .to their regi-on of interconnection at said inlet port, said baille central portions 7 8 each being formed with a plurality of ports oriented to References Cited by the Examiner lpermit fluid cpmmunicationthrough .said central portions UNITED STATES PATENTS -m mutually mclmed directions -lncllned relative to said Wall, the discharge ends of said baille ports being more 22281114 1/1941 Hess 158-99 remotely yspaced from said Wall than said end regions, 5 215411428 2/1951 Leo et al' 158` 116 whereby portions of `the stream of gaseous mix-ture flowing ythrough said inlet port are deflected lin opposite direc- FOREIGN PATENTS tions valong the wall of said .housing opposed t0 said 387,871 2/ 1933 Great Britain.

radi-ant walil and portions of such dellected stream portions are permitted to diffuse through said central por l JAMES W' WESTHAVER Pnmay Examiner' `tion toward said Wall. 0 PERCY L. PATRICK, Examiner.

Claims

1. IN A PERFORATED PLATE TYPE RADIANT GAS BURNER, A HOUSING, A PERFORATED RADIATING WALL COOPERATING WITH SAID HOUSING TO DEFINE A CHAMBER OF SUCH ELONGATE CONSTRUCTION THAT UNIFORMITY OF DISTRIBUTION THROUGHOUT SAID CHAMBER OF INTERMIXED GAS AND AIR FROM AN INLET IS A PROBLEM, SAID HOUSING HAVING AN INLET PORT FORMED CENTRALLY IN THE WALL THEREOF OPPOSED TO SAID RADIATING WALL, AN AIR-GAS MIXING VENTURI ASSEMBLY MOUNTED ON SAID HOUSING WITH ITS AXIS SUBSTANTIALLY PARALLEL TO THE INTERIOR SURFACE OF SAID WALL, A CONDUIT INTERCONNECTING THE OUTLET OF SAID VENTURI ASSEMBLY AND SAID HOUSING INLET PORT IN FLUID COMMUNICATION, AND MEANS MOUNTED IN SAID CHAMBER FOR CONTROLLING THE DISTRIBUTION THROUGHOUT SAID CHAMBER OF INTERMIXED GAS AND AIR PASSING THROUGH SAID INLET PORT, SAID MEANS COMPRISING A PARTITION MOUNTED IN SAID INLET PORT AND EXTENDING ACROSS SAID INLET PORT IN A DIRECTION TRANSVERSELY OF SAID CHAMBER AND OFF-SET FROM THE CENTER THEREOF TOWARD THE SIDE THEREOF OPPOSITE SAID VENTURI ASSEMBLY TO DIVIDE THE FLUID DISCHARGED FROM SAID VENTURI INTO TWO STREAMS,