US3322179A

US3322179A - Fuel burner having porous matrix

Info

Publication number: US3322179A
Application number: US271772A
Authority: US
Inventors: Paul H Goodell
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-04-09
Filing date: 1963-04-09
Publication date: 1967-05-30
Anticipated expiration: 1984-05-30

Description

y 1967 P. H. GOODELL 3,322,179

FUEL. BURNER HAVING POROUS MATRIX Filed April 9, 1963 4 SheetsSheet l INVENTOR i a 74 501672 l::] EIL 5/ May 30, 1967 P, H. GOODELL FUEL BURNER HAVING POROUS MATRIX 4 Shets-$heet Filed April 3, 1965 A .n a?

May 30, 1967 F. H. GOODELL. 3,322,179

FUEL BURNER HAVING POROUS MATRIX Filed April 1963 4 Sheets$heet 5 A; 9 if 44 A! l INVENTOR. 7%2/7 /7," 00 61 Z7 M y 1967 P. H. GOODELL.

FUEL BURNER HAVING POROUS MATRIX 4 Sheets-Sheet 4 Filed April 9, 196-3 INVENTOR United States Patent 015 3,322,179 Patented May 30, 1967 ice 3,322,179 FUEL BURNER HAVING POROUS MATRIX Paul H. Goodell, 21655 Cottonwood Drive, Rocky River, Ohio 44116 Filed Apr. 9, 1963, Ser. No. 271,772 Claims. (Cl. 158-99) This invention relates to gaseous burners and particularly to a gaseous fuel burner in which a porous matrix assists the combustion process and contributes to the eventual release of energy in the form of electromagnetic radiation on the one hand and inert gas on the other hand.

The burner of the present invention comprises a body, or shell, with one or more connections for fuel and air mixture and a porous cover or matrix, through which gaseous products may be defused through a multitude of inner-connected passageways preparatory to, or directly associated, with the intended exothermic reaction. The cover, or matrix, may simply serve as a flameholder providing the multiplicity of interconnected passageways for the release of fuel to form an external flame front of given area, size and thermal capacity. When operating in this manner the matrix will normally remain in the dark color region and the flames will be readily visible with a major portion of its energy being carried away from the matrix for release as convection heat in the resulting products of combustion.

The matrix may be so constructed as to operate in a manner to assist combustion on or near its heated face raising the temperature of this face to incandescence, thereby causing a substantial portion of the thermal energy to be released as radiation. Since the interconnected passageways permit flow of fuel entirely through the matrix, some energy will also be released as convection heat in the discharged products of combustion. The ratio or the amount of this energy in relation to the radiated energy will depend primarily upon the temperature and emission characteristics of the matrix and its surrounding environment, the depth behind the face at which combustion is occurring and the related ability of the matrix to conduct the released energy to its heated face.

The matrix may be constructed and operated in such a manner that its fuel passageways may not open directly to the external atmosphere at the heated face, but rather to an exhaust passageway which limits the energy emanation from the burner face to electro-magnetic radiation and permits the remaining convected energy to discharge to an exhaust flue or to intermediate heat exchange surfaces as may be provided. With this arrangement the device may have for its prime purpose the collection of the inert combustion gases as released under stoichiometric operation discarding or absorbing as a byproduct the emitted radiated energy in any convenient manner. Thus the matrix may be used to produce an inert gas which may be collected and used as a primary product.

As pointed out above, the burner matrix may be operated in various ways with only minor differences in construction, the several functions that occur within its environment, however, are more complex. These functions embody a fuel pressure equalization zone to aid uniform delivery to fuel to all matrix passageways; foreign matter disassociation, fuel preheating and backward flame retarding zone, .a molecular adjustment or crack ing zone, primary reaction or combustion zone, reaction cleanup and primary radiation emitting zone, and secondary energy dissipation zone including radiation emission from CO to H O vapors. To accomplish these functions, an infrared or radiating type burner matrix must provide a variety of qualities such as dwell time for fuel preheating and disassociation of the fuel molecules into their respective elements (usually carbon and hydrogen) followed by provision for their recombustion with oxygen for the intended thermal reaction. This process may be aided by heat transfer counterfiow to the direction of gas movement and by the presence of certain cracking and oxidation catalysts. It must firmly insulate the combustion zone from the fuel supply chamber and accelerate the rate of fuel flow between these zones to a velocity exceeding the rate of backward flame propagation to avoid pre-i-gnition of fuel in the supply chamber. It must provide efficient conversion of thermal energy to electromagnetic or infrared radiation at its heated face as the flame itself is limited in this capacity. Construction materials presenting high surface area and emission characteristics are thus required in addition to freedom from oxidation or other undesirable side effects as may occur at the intended operating temperatures. It must provide suitable porosity to permit the flow of the fuel-air mixture at permissible pressures, while assuring a gas-tight seal to the burner holder or shell.

Accordingly, the main objects of the invention are: to provide an infrared burner matrix having layers of minute particles to provide a multiplicity of interconnected, random passageways for the gaseous fuel, to provide layers of small particles which are bonded together in a manner to provide interconnected random passageways through the body of the matrix formed thereby; to provide the uniform delivery of gas fuel to the burning zone at the same rate and pressure even though some of the passageways become plugged; to support catalysts and/or radioactive materials within the passageways to assist intended chemical or thermal reactions, to incorporate optical control within the matrix construction to assist, minimize, or, in many applications, to eliminate the need for external optical devices; to provide collecting means for entraining the products of combustion including carbon dioxide and Water vapor as they are released from the matrix with or without unburned or partial products of combustion; to provide a burner matrix which will convert all of the products of combustion into heat, either radiated or convected, absorbing the radiated component as a byproduct While the inert gas produced thereby is collected as a desired product, and in general, to provide a matrix for a burner which is simple in construction, positive in operation and economical of manufacture.

Other objects and features of novelty of the invention will be specifically pointed out or will become apparent when referring, for a better understanding of the invention to the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is an enlarged sectional view of a fixture containing two burners of the present invention illustrating a simple application thereof; f

FIG. 2 is an enlarged plan view, with a part broken away, of a burner illustrated in the fixture of FIG. 1;

FIG. 3 is a broken, sectional view of the burner illustrated in FIG. 2, taken on the line 3- 3 thereof;

FIG. 4 is an enlarged sectional view of the burner illustrated in FIG. 2, taken on the line 4-4 thereof;

FIG. 5 is .an enlarged brokenyiew of the matrix of the burner illustrated in FIG. 2;

FIG. 6 is a sectional view of the structure illustrated in FIG. 5, taken on line 6-6 thereof, with the particles in elevation;

FIG. 7 is a view of structure, similar to that illustrated in FIG. 4, showing another form thereof;

FIG. 8 is an enlarged view of the matrix of the burner illustrated in FIG. 7, as viewed within the circle 8 thereof;

FIG. 9 is an enlarged, broken plan view of the structure illustrated in FIG. 7;

FIG. 10 is a reduced perspective view of an oven having series of burners disposed in staggered relation on opposite walls thereof;

FIG. 11 is an end view of a burner, similar to that illustrated in FIG. 1, showing another form thereof;

FIG. 12 is a broken end view of a burner, similar to that illustrated in FIG. 11, showing still another form which the burner may assume;

FIG. 13 is a sectional view of a burner, similar to that illustrated in FIG. 4, showing still another form thereof;

FIG. 14 is a view of a burner, similar to that illustrated in FIG. 4, showing still another form of the invention;

FIG. 15 is a sectional view of a burner within a housing having an emitting face of substantially increased area; and

FIG. 16 is a broken view of structure, similar to that illustrated in FIG. 15, showing another form of the invention.

The basic concept of the present invention is to produce a matrix that will have multiple, random passageways permitting gas fuel flow, not only parallel and perpendicular, but also at all angles to the heated face. The changing of the course of the delivered fuel at several points from the entrance to the exit faces of the matrix, facilitates heat transfer between the passagway walls and the fuel by impingement and also increases the dwell time within the matrix and assures more intimate contact between the gas molecules and the active catalyst surfaces. Concurrently, the construction is also intended to provide the maximum attainable temperature gradient, or temperature difference from the entrance to the exit faces by more efficient heat transfer to the fuel while permitting the use of various construction materials and additives such as catalysts which offer special advantages at different levels or zones, the combination presenting minimum resistance to the intended flow rate of the fuel-air mixture.

These requirements are simultaneously accomplished, according to the invention, by constructing the matrix in layers consisting of small spheres or particles bonded together at their contact points with suitable high temperature binders or cements of ceramic or other types leaving open spaces to form random passageways for the flow of the fuel. The closely related spherical or small particles, either solid or hollow, present the ideal forms for matrix construction. Uniform size spherical particles fill only 53% of the volume, leaving approximately 47% of the space therebetween uniformly available as the random fuel passageways. The point-to point contact between the particles reduces the rate of counterflow heat conduction to a minimum and the strength attained by nesting of the particles compares favorably with other usual forms of porous ceramic constructions. Heat resisting glass, quartz, silicon carbide, and various ceramic oxides such as A1 0 offer useful properties as basic particle materials for the construction of the matrix. They are cited by way of example and are not to be considered limiting.

In FIG. 1, a fixture 18 is illustrated having a heat resisting 19 containing burners 21 of the present invention which direct the radiant energy outwardly through louvers 22 of conventional form. The products of combustion are conducted from the burners and housing through a flue 23. The burner 21, as illustrated in FIGS. 1 to 6, comprises a housing or shell 24, which is attached in sealed relation to the burner element or matrix 25 by a filter element or gasket 26 on the intake side thereof. The matrix herein illustrated is constructed from a plurality of layers of spherical particles 27 which nest with each other and which are bonded together at the points of contact 28 by a high temperature ceramic or other bonding agent, or by fusion of the material from which the spheres are constructed. The spheres, for example, may be constructed of high temperature glass which, upon heating, will bond to each other at the points of contact 28 to form a porous matrix.

Precise control of the fuel passageway areas and the consequent permeability to the flow of gases or fuel mixtures at any given pressure is provided by selection of the size of the spheres or particles, representing the main cross-sectional dimension. Small particles nest closer than large particles, leaving smaller passageway areas and presenting more impingement points where the fuel flow must change direction in a matrix of given depth between the inlet and outlet faces. One basic size particle may be useful throughout the entire cross-section of the matrix, as illustrated in FIG. 7, or the size may be changed from one layer to another as illustrated in FIG. 4. Accurate nesting of the particles with each other provides greater strength and uniform permeability when the diameters of the small and large spheres are maintained in a ratio of three to one, providing a hexagonal geometry as illustrated more specifically in FIGS. 3, S and 6.

In the figures, a plurality of layers are made up of small balls or particles 29 while the top layer is made up of a plurality of larger balls or particles 31. This change from small to the large size balls or particles, is useful to provide a primary combustion zone Where the larger size passageways will facilitate rapid thermal expansion of the combustion gases provided by the oxidation reaction. Such an arrangement also increases the dwell time afforded to complete the combustion by surface reaction and will improve heat conductivity to the outward radiating face for a given length of combustion path. In the reverse or counterflow direction, this change in passage size is also useful in limiting or restricting the potential possibility of backward flame propagation or flashback since both thermal and static pressure conditions will favor initiation or continuation of a forward flame front. When it may be impractical to change particle size, the extension of the combustion paths and outward radiating surface areas may be provided by configuration of the heated matrix face, as illustrated in FIG. 7, to be later described.

A minimum of three layers of particles having a diameter or mean cross-sectional dimension of 0.065 to 0.135 inch has been found desirable for zone B with one similar layer for zone C, as illustrated in FIG. 6. It is to be understood that the invention is not to be limited to these specific dimensions as sizes may vary when forming a matrix other than for burner use Which is herein illustrated and described by way of example. Additional layers of the balls 29 may be added to the zone B to obtain greater mechanical strength and increase the insulating value at the intake face of the burner, which value is further increased When the particles are hollow. If similar size particles are used for zones D and E, a minimum of three additional layers is recommended with an extended surface arrangement such as that illustrated in FIG. 7. If, however, large size particles are used in the D and E zones, their diameter should be precisely three times that of the smaller size balls or particles for proper nesting and increased mechanical strength. The diameter range of these larger balls or particles would be from 0.195 to 0.406 inch. In any case, preference is given to particles having high emissivity and thermal conductance in the D and E zones while those in the B and C zones should be chosen to provide thermal insulation.

To form the matrix, loose particles are retained in layers in a form or mold of a desired size and shape and heat is applied thereto to soften the material of the balls or particles or the coating material thereon to a point of melting to such a degree as to leave the material fused together when cooled at the touching points 28 to unite all of the balls or particles into unit relation to each other. Alternately, a bonding material may be employed of any well-known type, such as those used for binding together the grits of grinding stones. To provide a catalyst coating on such particles as silicon carbide, A1 and the like, a mixture should be prepared containing the selected particles, a temporary binder, such as coal tar, a high temperature melting point glaze, such as flint or feldspar, and a lime .fiux. Preferably, the catalyst materials are added only to the balls or particles of specific layers so as to be present in the fuel passageways in a specific zone or zones.

The addition of the catalyst to the radiant burner matrix is a distinct feature of this invention intended to permit operation at essentially stoichiometric condition. Whereas most infrared or radiant type burners require excess air for reliable and complete combustion of fuels such as natural gas or methane (CH.,), a proper application and use of the catalyst can eliminate this need because of the assistance they provide in attracting the reaction molecules to each other. Various metallic oxides of different materials may be employed for their known catalytic properties including cobaltic oxide, cerium oxide, chromic oxide, thorium oxide, vanadium pentoxide, neodymium, didymium, gadolium and praseodymium. One method of coating used with success is the spray application of a solution based on an ethylhexoate catalyst salt suspended in hydrocarbon solvent such as xylene. The soluble catalyst 34 thus provides limited penetration into the tar and binder mix 35 with undissolved oxides remaining on the surface thereby permitting a dual coating in a single operation. Normally, an amount less than 2% by weight will provide an effective catalyst surface. Permanent bonding to the matrix passageway is accomplished during a subsequent,

firing operation as portions of the catalyst particles are wetted by the bonding agent or glaze used to hold the matrix elements together. Basic improvements in burner performance is accomplished by the emission properties credited to cerium oxides and the wider turndown capability or lower temperature level at which complete oxidation of the fuel may be sustained by catalytic oxidation. This reduces the convection heat loss during the burner operation with or without a reduction of the combustion air volume and improves the energy release by radiation in specific emission zones relative to the catalyst employed.

The balls or particles are placed in a form or mold in distinct layers as illustrated in FIG. 6. The particles 29 in the layers in the insulating zone B being made of a heat softening material or having the coating 34 applied thereto. The particles 29 in the layer in zone C and possibly D have the coating 35 applied thereto to provide one or more layers having the catalyst in the passageways thereof. Thereafter the large balls or particles 31 with the coating 35 thereon are applied to form the top layer. A predetermined amount of pressure is applied to the assembly whether or not the ceramic inserts 32 have been used in the particular arrangement.

The ceramic inserts are normally prefired and coated with the high temperature glaze or coating 35 to conform to the material used for bonding the particles of the matrix together. The ceramic inserts have threaded apertures 36 therein for the reception of a screw 37. In this manner, all the components of the matrix are fused and bonded together in a single controlled heating cycle after being assembled together as pointed out above. By the use of the ceramic threaded elements 32 convenient means are provided for the replacement of the matrix in the field by the mere substitution of one matrix for another.

Due to limited strength in the green state, the matrix particles are normally supported during firing on a ceramic plate having the same contour as the back or intake face of the finished matrix. During firing, the temperature is progressively increased to vaporize the tar or temporary bonding constitutent after which the permanent bonding materials are liquefied and fluxed to the matrix particles. The latter operation is normally accomplished at temperatures several hundred degrees higher than the intended future service operating temperature as a radiant burner.

After a limited period at peak temperature, the furnace is allowed to cool and the matrix is removed as a rigid porous plate. After the matrix cools, the outer edge passages, or other areas where permeability to fuel flow is not desired, are sealed by the application of cold sealing ceramic cements such as Sauereisen or a silicate slurry of diatomaceous earth applied by spraying or brushing over the areas and edges which then become impervious.

The face element or matrix 25 of the burner is mounted within the shell 24 after the gasket or optional sheet of filter material 26 has been applied over the intake face thereof. The shell 25 is dish-shaped and of rectangular form. Sloping bottom sections 38 extend from a flat central portion 39 with ribs 41 disposed about the edges of the sloping sections and the central portions to provide strength thereto. The sides 42 of the shell have curved ledges 44 thereon upon which the gasket or filter material 26 rests and is clamped in sealed relation to the shell 24. The ledges have a side flange 45 extending thereabout located adjacent to the sealed edges 33 at the sides and ends of the matrix 25. The screws 37 extend through the side ledges 44 and are threaded in the thread 36 of the ceramic elements 32 to thereby securely clamp the matrix and filter material 26 to the shell in sealed relation thereto. A plurality of angle brackets 46 are supported on the shell 24 to provide mounting means on the burner which extend into rectangular mounting pockets 47 illustrated in FIG. 7. A boss 48 is deflected from ledge 44 adjacent to the aperture for the screw 37 for the purpose of supporting the angle bracket 46 in a manner to have the free leg disposed substantially parallel to the flange 45 of the shell. The curved ledge 44 at the ends and sides of the shell conforms to the accurate shape of the matrix and is readily sealed thereto.

The shell 24 forms the fuel entry chamber for the burner to which fuel is delivered through a fitting 51 which is sealed within an aperture 52 in the central portion 39 of the bottom of the shell. The fitting embodies an externally threaded cylindrical section =53 and a cylindrical flange 54 disposed at right angles thereto which rest upon the top of the central portion 39 outwardly of the aperture 52. A sealing washer 55 is secured to the bottom side of the central portion 39 by a nut 56 which clamps the fitting 51 in sealed relation thereto. A deflector portion 57 is supported by a plurality of vanes 58 centrally of the cylindrical portion 53 for directing the fuel outwardly within the shell 24.

The construction of the entire burner provides a reliable sealed chamber for a lifespan of several years. The prethreaded ceramic inserts sealed within the matrix transmit substantial mechanical forces with minimum contact area for heat transfer between the matrix and the engaged surfaces. The retention elements and seal are designed to deliver pressure over tapered or multiplane surfaces of the shell 24 disposed at suitable angles to deliver compression components both parallel and perpendicular to the matrix faces thereby maintaining the ceramic structure under compression to minimize tension or fracture stresses in at least two planes. The tapered design of the shell opposes thrust components from normal heat stresses thereby providin g stability with light weight and low thermal capacity, permitting the use of thin matrix sections having twentyeight or more square inches of fuel distribution area without any substantial distortion or fracture hazard. This arrangement permits the use of the single filter layer of Fiberfrax or similar blanket or woven fabric of glass filaments or other material which serves as a parameter gasket between the matrix and shell and combines thermal insulation and flash arrester properties between the hot matrix and the incoming fuel-air mixture while serving as a dust removal or filter device to minimize possible contamination of the passageways through the matrix by foreign matter entrained in the fuel-air mixture.

Retained flame burners of this type afford little opportunity for entrainment of secondary combustion air at the radiating face. Accordingly, the needed oxygen supply for combustion must be available from the primary air introduced with the gas. For natural gas, as distributed by most utilities, this requires an air volume of 10.6 times the volume of gas used. When gas is available above approximately 0.5 p.s.i.g. pressure, a major portion in the combustion air can be inspirated through a standard venturi mixer from the kinetic energy in the gas stream. Since this arrangement is common to atmospheric type gas burners, specific details are omitted except for the fuel inlet where the venturi discharge should be attached. Alternately, single or multiple arrangements of these burners are often provided with premixed fuel and air in proper proportions and under suitable positive pressure (3 to 8 inches water column), from air jet mixers or a gas-air mixing blower. In any case, fuel should be introduced intothe shell 24 through the fitting 51 as illustrated in FIG. 4.

Referring to FIGS. 7, 8 and 9, a further form of matrix is illustrated wherein like size particles of substantially uniform diameter are employed to make up the various layers in the intake portion 59 of the matrix. The layers in the heated face of the matrix are interrupted by regular rectangular recesses 61 as illustrated more specifically in FIG. 9. The recesses provide projecting ribs 62 which become radiating portions of the burner as the gas is consumed in the area at the base of the recesses 61. In this particular arrangement the matrix is secured within the shell 24 by a rectangular frame 63 having an accurate upper flange 64 which forces the sealed edge portions 33 of the matrix into sealed relation with the filter layer 26. Securing fingers 65 are retained on the rectangular frame 64 by screws 66. The fingers extend into the rectangular pockets 47 on air ducts 67 having deflecting elements 68 which direct ventilation air into the heating zone of the oven or furnace for removal of unburned combustion products during cold starting, thereafter entraining oven process vapors and serving as a source for secondary burner air. The uniform disposition of the particles, which are bonded together in a manner as pointed out hereinabove and as illustrated in FIG. 8, provide a substantial area of interconnected passageways disposed in random relation between the layers so that the same pressure of fuel is provided at the burning face throughout the entire area thereof.

FIG. illustrates an application of the burners within a furnace. A plurality of the burners 71 are disposed in right angularrelation to each other to form a plurality of spaced zig zag rows 72 on the opposite side walls of the furnace. It will be noted further that the angular relation of the burners on one side wall are in staggered relation to those on the other side wall so as to provide a uniform area of heat over a length of material 73 to be treated. The material is carried rapidly through the furnace midway between the burners on a conveyor 70 disposed midway between the side walls. When a sheet of cloth, paper or other material is to be dried in a rapid manner, the sheet may be traveling at a very high speed through the heated furnace area so that substantially instantaneous drying will occur. Such chain or zig zag burner arrangements with any perimeter surface of one burner adjacent to any perimeter surface of other burners, whether grouped horizontally or vertically will permit chain ignition of the fuel across the entire group of \burners thereby permitting the use of one pilot or ignition source and one flame proving device for each such group. This provides substantial savings in the number of convections and burner accessory devices re quired for reliable and safe operation.

In FIG. 11, a further form of the invention is illustrated that wherein a shell 76 is similar to the shell 24 with the exception that the sealing ledge 77 is disposed in a common plane at the top portion thereof. A matrix 78 is formed of a plurality of layers of uniform particles which may be globular or substantially so, in shape, embodying the zones and the catalyst described hereinabove. It will be noted that the intake and heated faces of the matrix are located in parallel plane provided the multiplicity of random passageways between the particles which are sealed at the edges 33 in the manner hereinabove described. The side edge portions are provided with the ceramic elements 32 having threaded apertures 36 in which the screws 37 are secured to retain the matrix and the filter 26 in sealed relation with the ledge 77. The angle brackets 46 are secured by certain of the screws to the shell 76 for releasably supporting the burner in position when the extending arms of the angle brackets 46 project within the rectangular pockets of the elements 47. The heating surface in the flat plane may have the large balls or particles applied thereto when desired.

In FIG. 12, a still further form of burner is illustrated, that wherein the matrix 80 is constructed in the manner hereinabove described either with the same size spherical or irregular particles throughout the depth or with the larger particles on the outer face thereof. The matrix 80 has a convex shape to provide an optical arrangement which is the reverse of the burner of FIGS. 1 to 6.

Referring to FIG. 13, a still further form of the invention is illustrated, that wherein a matrix 83 has two portions, 84 and 85, disposed in angular relation to each other to form a convex or recessed area on the burner face. While this type of burner may also be constructed from spherical particles with large size particles on the outer face, irregular particles are herein illustrated for forming the various layers. The small irregular particles 86 are substantially of the same cross section size which is also true of the irregular larger particles 87. The particles are coated with bonding and catalyst material in the various layers as pointed out hereinabove, and are secured together after being assembled in layers by the use of heat, as above described. Ceramic elements 32 are bonded to the particles and the edge portions 33 are sealed by a filler material. The matrix functions as the burner element of the unit in the same manner as when regular particles are employed. It is, therefore, to be understood that irregular shaped particles of substantially similar size may be satisfactorily employed to form the matrix in place of the spherical particles.

In FIG. 14 a still further form of the invention is illustrated, that wherein a matrix 25 and sealing element 26 are secured to a shell 24 by the use of the ceramic elements 32 and screws 37, the edges of the matrix 25 may be sealed by being bonded to side flanges 93 and end flanges 94 of an enclosing element 95 which is spaced from the primary radiating surface of the matrix. The enclosing element 95 may be made of quartz, fused silica, high temperature glass or other material that will transmit the radiation released from the surface of the matrix and the combustion products while entrapping the latter which may be drawn off through a flue attached to a collar 96 in extension of an aperture 97 in one or both of the end walls 94. When all of the fuel constituents and oxygen are consumed at the face of the matrix 25, as in stoichiometric operation, the resulting gases will be inert and may be collected for use as a byproduct to the heat produced by the burner.

A fitting 98 is secured in the fiat portion 39 of the shell 24 in the manner above described. A fuel delivery conduit 99 has a valve housing 101 secured thereto and provided with a truncated spherical seat 102 against which a ball 103 is urged by a spring 104 into sealed relation therewith. The spring is supported by a retainer 105 which is threaded within the valve body 106. The upper end of the body has a cylindrical extension 107 provided with a truncated conical outer surface 108 which is disposed in parallel relation to an inner truncated conical surface 109 on the fitting 98. An O-ring 111 is maintained on the cylindrical portion 107 by an outwardly extending flange 112 at the top thereof. The slope of the surfaces 9 108 and 109 is such that when the O-ring is engaged by the flange 112, the lower end of the sloping surface 109 is disposed outwardly of and in spaced relation thereto. A deflector portion 113 of the fitting 98 carries a screw 114 having an arcuate head 115 which engages the ball and moves it from the seat 102 when the burner is secured to its support. The screw 114 is adjustable on the deflector portion 113 and is secured after adjustment by a nut 116. The adjustment regulates the flow of fuel through the sleeve 107 to thereby balance the flow of fuel delivered to a plurality of burners from a single manifold.

A burner supporting body 117 is of a truncated pyramidal shape having sloping

side walls

118 and 119 dis posed in opposite relation to each other. The sides form a dish-shaped element with a bottom web 121 which contains a hexagon opening which mates with the hexagon shape of the body 106 of the valve, except for the edges adjacent to the sides 119 which extend inwardly slightly toward each other. These inwardly extending portions rest upon oppositely disposed ledges 122 at the top of the body 106 and accurately locate the supporting body 117 on the body 106. The extending edges of the hexagon opening in the web 121 have tabs 123 projecting downwardly therefrom containing an aperture for a screw 124 which secures the body 117 in fixed position on the valve body 106. The side walls 118 have a flange 125 at each end for supporting a stud 126 within a threaded extension 127 of the flange. The shell 124 has spring securing clips 128 of conventional form having oppositely disposed clamping fingers 129 which engage the ball end 131 of the companion studs 126 for securing the burner on the body 117. The clip 128 is secured to a block or boss 132 on the flange 44 of the shell 24 by rivets 133. The burner may be removed from its supports by pulling it outwardly and releasing the spring fingers 129 from the ball ends 131 of the studs 126 and separating the fitting 98 from the Oring 111 at the time the ball 103 engages the seat 102 and cuts off the supply of fuel from the valve 101. Not only is the supply of fuel shut off from the burner at the time it is removed, but a safety feature is provided by automatically closing the outlet 99 from the manifold so that fuel cannot escape from valve 101 at any time the manifold is pressurized until the burner has been properly replaced.

In FIG. 15, a still further form of the invention embodies a burner 25 mounted within a sealed housing 135 having an outlet 136 in one of its faces for the withdrawal of the flue or inert gases therefrom. The front open face of the housing 137 is enclosed by a corrugated sheet 138 which is made of black stainless steel, or a similar radiation absorbing material, secured in a suitable manner to permit thermal expansion while providing a closure therefor. The closure is located in the path of the radiant heat 139 from the burner and provides several times the radiating area of the burner for efficient operation of such a secondary emitting face and by corrugating the material such increase in area is provided so that the black stainless face of the corrugated sheet 138 can emit or dissipate the radiant heat at substantially lower temperature than that of the burner matrix.

This arrangement may also be used to control the inward and outward flow of gases or liquids that are passed through the matrix for processing or bombardment by radio active materials supported in the matrix.

When the structure of FIG. is to be employed for collecting inert gas with the emitted heat as a byproduct, a closure 141 for the open face 137 may be provided with refrigeration tubes or may be made of double wall construction having inlet and outlet ports 142, 143 for the passage of cooling air, water, brine, a refrigerant or any other substance which will absorb the heat and carry it away from the enclosure as illustrated in FIG. 16.

When all of the energy and oxygen are consumed from the fuel-air mixture delivered to the burner, only inert gas and water vapors will remain and these can be drawn off 10 through the outlet 136 to thereby provide a useful inert gas product. Further treatment may be applied to the gases such as condensation or other moisture removing processes toprovide a degree of purification as may be desirable. Such further operations embody no part of the present invention.

It will be noted in FIG. 1 that the fixture 19 also em bodies a lighting fixture 145 having a housing 146 which is below and out of the path of the radiant heat from the burner 21 having light emitting elements 147 contained therewithin above a closure louver 148. Any type of energy may be employed for illuminating the elements 147.

What is claimed is:

1. In a burner, a hollow shell, a matrix being constructed from layers of substantially spherical particles, and means for bonding the particles of the layers at their points of engagement, the particles of the matrix adjacent to the intake face being small to provide an insulating area and the particles on the heated face. being substantially larger to form the emitting face, the ratio of the diameter of the small particles to that of the large particles being in the order of substantially three to one.

2. In a burner, a porous matrix forming the burner element, a filter element disposed over the inner face of said matrix, an element forming a chamber disposed in sealed relation to said filter and matrix, and a. fitting on said element through which fuel is conducted into said chamber, said matrix being constructed from a plurality of layers of discreet particles of substantially the same diameter disposed in bonded nested relation to each other to provide random interconnected passageways from the intake to the heating face of said matrix, means applied to the edges of the layers to provide an impervious periphery thereto, and elements bonded within the matrix adjacent to the edges having securing means thereon by which the matrix is attached to the element, said shell having sloping bottom portions and ribs to provide strength thereto and to reduce the warping thereof in the presence of heat.

3. In a burner, a porous matrix forming the burner element, a filter element disposed over the inner face of said matrix, an element forming a chamber disposed in sealed relation to said filter and matrix, and a fitting on said element through which fuel is conducted into said chamber, said matrix being constructed from a plurality of layers of discreet particles of substantially the same diameter disposed in bonded nested relation to each other to provide random interconnected passageways from the intake to the heating face of said matrix, means applied to the edges of the layers to provide an impervious periphery thereto, elements bonded within the matrix adjacent to the edges having securing means thereon by which the matrix is attached to the element, said shell having sloping bottom portions and ribs to provide strength thereto and to reduce the warping thereof in the presence of heat, releasable supporting means on said burner and shell, and a fitting on said shell releasably attachable to a fuel supply.

4. In a burner, a porous matrix forming the burner element, a filter element disposed over the inner face of said matrix, an element forming a chamber disposed in sealed relation to said filter and matrix, and a fitting on said element through which fuel is conducted into said chamber, said matrix being constructed from a plurality of layers of discreet particles of substantially the same diameter disposed in bonded nested relation to each other to provide random interconnected passageways from the intake to the heating face of said matrix, means applied to the edges of the layers to provide an impervious periphery thereto, elements bonded within the matrix adjacent to the edges having securing means thereon by which the matrix is attached to the element, said shell having sloping bottom portions and ribs to provide strength thereto and to reduce the warping thereof in the presence of heat,

:fitting on said shell releasably attachable to a fuel supply,

a valve within said fitting, and an unseating projection on said first fitting which opens the valve when the burner is mounted and adjustable on a support.

5. In a burner, a porous matrix forming the burner element, a filter element disposed over the inner face of said matrix, an element forming a chamber disposed in sealed relation to said filter and matrix, and a fitting on said element through which fuel is conducted into said chamber, said matrix being constructed from a plurality of layers of discreet particles of substanitally the same diameter disposed in bonded nested relation to each other to provide random interconnected passageways from the intake to the heating face of said matrix, means applied to the edges of the layers to .provide an impervious periphery thereto, elements bonded within the matrix adjacent to the edges having securing means thereon by which the matrix is attached to the element, said shell having sloping bottom portions and ribs to provide strength thereto and to reduce the warping thereof in the presence of heat, releasable supporting means on said burner and shell, and a fitting on said shell releasably attachable to a fuel supply, a valve within said fitting, and an unseating projection on said first fitting which opens the valve when the burner is mounted and adjustable on a support means on said unseating projection for changing the valve opening.

References Cited UNITED STATES PATENTS JAMES W. WESTHAVER, Primary Examiner.

MEYER PERLIN, FREDERICK L. MATTESON, JR.,

Examiners.

H. B. RAMEY, Assistant Examiner.

Claims

1. IN A BURNER, A HOLLOW SHELL, A MATRIX BEING CONSTRUCTED FROM LAYERS OF SUBSTANTIALLY SPHERICAL PARTICLES, AND MEANS FOR BONDING THE PARTICLES OF THE LAYERS AT THEIR POINTS OF ENGAGEMENT, THE PARTICLES OF THE MATRIX ADJACENT TO THE INTAKE FACE BEING SMALL TO PROVIDE AN INSULATING AREA AND THE PARTICLES ON THE HEATED FACE BEING SUBSTANTIALLY LARGER TO FORM THE EMITTING FACE, THE RATIO OF THE DIAMETER OF THE SMALL PARTICLES TO THAT OF THE LARGE PARTICLES BEING IN THE ORDER OF SUBSTANTIALLY THREE TO ONE.