US 3881858 A
A radiant gas burner having an upper elongated refractory body is secured to and supported by an underlying metallic manifold body. The manifold body comprises a metallic stamping formed of aluminized sheet metal and a vent bar cast of oxidation resistant metal seated in the stamping beneath the refractory body with a series of burner vents of narrow width formed in said vent bar for discharging the fuel mixture directly against the bottom of a series of transversely extending ceramic vanes in the upper refractory body. The metal stamping has reduced weight, is lower in cost, and is more resistant to oxidation than grey iron castings heretofore used. The preferred metal for the burner vent bar has a superior resistance to the formation of oxidized material which sometimes closed similar burner vents in grey iron castings of the prior art.
Claims available in
Description (OCR text may contain errors)
United States Patent [1 1 Fitzgerald May 6,1975
[ RADIANT GAS BURNER  Inventor: Carl E. Fitzgerald, 8901 Mango Ave., Morton Grove, Ill. 60053  Filed: Apr. 19, 1974 21 Appl. No.: 462,390
 US. Cl. 431/348  Int. Cl. F23d 13/12  Field of Search 431/348, 171; 126/92 R,
126/92 B, 92 RC  References Cited UNITED STATES PATENTS 3,136,354 6/1964 Fitzgerald 431/348 Primary ExaminerCarroll B. Dority, Jr. Attorney, Agent, or Firm-Fitch, Even, Tabin & Luedeka [5 7 ABSTRACT A radiant gas burner having an upper elongated refractory body is secured to and supported by an underlying metallic manifold body. The manifold body comprises a metallic stamping; formed of aluminized sheet metal and a vent bar cast of oxidation resistant metal seated in the stamping beneath the refractory body with a series of burner vents of narrow width formed in said vent bar for discharging the fuel mix- I tore directly against the bottom of a series of transversely extending ceramic vanes in the upper refractory body. The metal stamping; has reduced weight, is lower in cost, and is more resistant to oxidation than grey iron castings heretofore used. The preferred metal for the burner vent bar has a superior resistance to the formation of oxidized material which sometimes closed similar burner vents in grey iron castings of the prior art.
13 Claims, 11 Drawing Figures PATENTEUHAY 61975 SHEET 10F 4 IZI hlll.
F/ JO PATENIEDMM ems 3,881,858
sum as? 4 i an improved radiant gas burner of the general kind disclosed in US. Pat. No. 3,136,354 which is widely used for radiant process heating operations in various industries for such diverse operations as food processing, baking of enamel or paint, drying of inks or paper webs,
' curing of plastics, area heating, etc. Radiant burners of this kind are generally modular shaped in the form of elongated rectangular units which may be assembled adjacent one another to form large areas or zones in various shapes as needed for the particular radiant process heating operation. For instance, the modular radiant burners may be elongated with a ceramic burner face about three inches in width and twelve inches. in length with several burners arranged side by side or end to end to provide a wider and/or longer radiant refractory burner face. The radiant burners are fed with a mixture of oxygen and gas and efficiently convert the gaseous fuel into radiant heat with a usual capacity range of 4,000 to 40,000 BTUs per hour for a single burner unit.
In general, radiant burners of this kind have an all upper ceramic construction for the radiating surface with a lower metallic gas manifold body which is not exposed to the high temperature zone. In the aforementioned patent, the manifold body is an integral casting of cast iron having a gaseous fuel inlet port centrally located at the bottom of an elongated manifold chamber which distributes the gaseous fuel mixture to a multiplicity of narrow milled slots constituting burner vents extending transversely along the length of a central longitudinally extending member at the top of the manifold casting. The upper'surface of manifold casting was covered with a ceramic sheet or insert having similar slots cut therein to match the burner vents. The sheet formed a lower ceramic surface for the combustion chamber and insulated the casting from the high temperature combustion zone.
Mounted on the top of the manifold casting and suitably secured thereto was an elongated ceramic burner body having a plurality of transversely extending ceramic'vanes located over each of the burner vents to be impinged directly by the gas issuing from these vents in the manifold body. The vanes are spaced and provide combustion areas or chambers between the vanes within which the combustion occurs and the entire ceramic body becomes a radiant incandescent radiator of heat. Complete combustion is effected in these radiant burners because all the oxygen required for the complete burning of the gas fuel was previously mixed with the gas in proper ratios prior to entry of the fuel mixture into the radiant burner.
Although the above described radiant burners have proved to be eminently satisfactory for many operations, the manifold casting had several shortcomings in that the castings could not be held to close dimensional tolerances and the castings were heavy and rather costly. Also, the transversely milled slots forming the small burner vents in the upper convex wall of the casting are subject to becoming closed after the burner has been in use for a long period of time. More specifically, after prolonged use of the burner, the gray iron manifold casting oxidized and formed hard glass-like material which ultimately closed many of the small, viz.,
0.035" burner slots. This glass-like oxidized material or scale was extremely hard and difficult to remove except by sandblasting which caused erosion of the burner slot metal changing their shape by forming undesirable round corners for the slots. Also, gray iron manifold castings are subject to rusting and have been coated with aliminum paint to retard such oxidation. But, the paint chips as a result of the heating and cooling cycles and sometimes due to an attack of a caustic cleaning solution used in the food industry.
Accordingly, a general object of the invention is to provide a new and improved radiant gas burner of the foregoing kind.
Another object of the invention is to provide a gas burner of the foregoing kind which can be manufactured economically and will have improved life.
Other objects and advantages of the invention will become apparent in the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of a radiant burner embodying the novel features of the invention;
FIG. 2 is an exploded perspective view of the radiant burner of FIG. 1;
FIG.- 2a illustrates an anchoring strip;
FIG. 3 is a side elevational view of a manifold vent bar;
FIG. 4 is a cross-sectional view taken substantially along the line of 4-4 of FIG. 3;
FIG. 5 is an elevational view of a manifold body with a portion broken away;
FIG. 6 is a cross-sectional view taken substantially along the line 6-6 of FIG. 5;
FIG. 7 is a partially sectioned perspective view of an igniter as used with the radiant gas burner of FIG. 1;
FIG. 8 illustrates a tandem arrangement of gas burner units attached to a common gas inlet pipe; and
FIGS. 9 and 10 illustrate various gas inlet adapters and valve arrangements for use with the radiant burner of FIG. 1.
As shown in the drawings for purposes of illustration, the invention is embodied in a radiant burner 11 comprising a lower generally box-like gas manifold body 12 having a gas inlet adapter 13 at the bottom thereof for gas to flow upwardly therein for distribution to a ceramic burner body 14 having a plurality of spaced combustion chambers 15 at which the comcally, as best seen in FIGS. 2 and 7, the gas and oxygen fuel mixture in the manifold body 12 flows through burner slots or vents 16 in the top of manifold body 12 and through aligned slots 17 in a ceramic sheet 19 to impinge directly on the lower ends of vanes 21 in the ceramic body, the vanes separating adjacent combustion chambers '15 in the ceramic body. The ignited air fuel mixture in the combustion chambers 15 causes the ceramic burner body 14 to become a radiant encandescent radiator of heat and the ceramic strip 19 likewise becomes an incandescent radiator of heat. Herein, the combustion occurs in an overall combustion chamber which is ceramic throughout with the ceramic sheet 19 insulating the metal manifold body 12 so that there are no metallic surfaces exposed to the high temperatures, for example, as high as 2000 F.
In the radiant burner disclosed in US. Pat. No. 3,136,354, gas issued from the manifold body through a multiplicity of transverse milled narrow slots each having a width of about 0.035 inch with the slots being formed in a convex bar integral with the remainder of the cast manifold body. Because of the combustion process and after a period of considerable usage, some of these narrow burner slots may become closed and prevent combustion in its associated combustion chamber above the closed slots. The closing of these slots was the result of oxidation of the gray iron casting which scaled to form a glassy, hard oxidized material which is extremely hard to remove. The oxidized material was too hard to be cut and could not be chipped away easily. Sandblasting of the scale will effectively remove the same; but sandblasting wore down the edges of the burner vent slots resulting in an undesirable flow characteristic from the gas issuing therefrom. Moreover, the casting of iron presented other problems. They require the use of cores to form the interior manifold chamber and relatively heavy thick crosssectional walls which are subject to warping, making it difficult to maintain dimensional tolerances, in all instances. Also, the exterior of the manifold body casting oxidizes rapidly in these high temperature emvironments and had to be coated, in most instances, with an aliminum paint to retard such oxidation. Because of the heating and cooling cycles and because of the use of caustic cleaning solutions, as often found in the. food processing industry, the aluminum paint often chipped from achieved casting.
In accordance with the present invention, the closing of the transversely extending burner vents 16 by scale has been substantially eliminated and the problems of oxidation, as well as the problems of the cost and difficulty in maintaining dimensional tolerances for the manifold body have been eliminated by the development of a composite manifold body 12 comprising an upper separate vent or orifice bar 30 of scale-resistant material and a lower sheet metal manifold body stamping 31 carrying the vent bar 30. More specifically, the vent bar 30 is preferably a Ni Resist casting having a tenfold increased resistance to such scaling and oxidation over a gray iron casting and still having sufficient depth for its vent slots 16 to provide the desired flow characteristics for the gas and fuel mixture. The Ni Resist metal bar 30 also has good corrosion resistance at high temperatures. The elimination of many of the problems with gray iron castings has been achieved by stamping with a die press a sheet of aluminized metal to form the box-like manifold body shaped to close dimensional tolerances; the aluminized metal will not readily oxidize and need not be painted. Moreover, the cost and weight reductions achieved are also significant factors and advantages of the manifold body stamping 31 over the casting manifold body of the aforesaid patent.
Referring now in greater detail to the individual elements of the invention, the illustrated manifold body stamping 31 is formed of a thin metal sheet, for instance, a l l 6 inch thick aluminized metal sheet which has been shaped by a die press into a complex shape, such as illustrated and described hereinafter. Preferably, the lower portion of the manifold body stamping 31 includes a pair of downwardly sloping bottom walls 33 joined at the lower ends to a central common bottom wall 35 having a down-turned circular flange 37 as best seen in FIGS. and 6. The latter defines an open-- ing of about ll inches diameter and is shaped to bear tightly against a frustro-conical surface 38 (FIG. 2) of the gas adapter 13. The bottom walls 33 and 35 are relatively narrow, for example, 15/ 16 of an inch in width. As best seen in FIGS. 5 and 6, a pair of vertically extending side walls 41 and 42 define with the bottom walls 33 and a hollow chamber 39 containing the air and gas fuel mixture for distributing the latter uniformly to each of the gas fuel vents 16 in the gas vent bar 30.
For receiving and supporting a lower portion of the gas vent bar 30, the manifold stamping 31 is formed with an indentation or seat conformed to the bottom portion of the vent bar and defined by a pair of longitudinally extending vertical side walls 45 and 46 joined at opposite ends to short end walls 50 and 51 with these side walls and end walls joined at their lower ends to horizontally extending short shelf 48. The peripheral edges of bottom surfaces 52 of the vent bar 30 will rest on the shelf 48.
As will be explained in greater detail hereinafter, an upper and encircling tray-like portion 53 is provided on the manifold stamping 31 to support the ceramic body 14. Herein, the tray-like portion 53 comprises a surrounding shelf defined by a horizontally extending shelf or wall 55 which is joined to a pair of longitudinally upstanding parallel walls 57 and to a pair of opposite parallel end walls 59. The shape of the manifold stamping may be changed from that described above and still fall within the purview of the claims of this invention.
The preferred scale resistant metal is Type 1 Ni Resist cast iron alloy identified by International Nickel Company as having 14 percent Ni; 6 percent Cr and 2 percent C. The width, length and depth of the slots 16 may be varied according to gas volume and flow characteristics desired for each burner slot. Herein, the slots 16 have a 0.035 inch width and are spaced uniformly at distances of about /2 inch with the slots 16 having a depth of about inch, which is the preferred wall thickness between the outer convex surface 60 and the inner surface 61 shown in FIG. 4. The convex surface 60, in this instance, has a radius of about A inch with the inner surface 61 having a radius of about 5 8 inch at the center thereof leading to a pair of downwardly and outwardly sloped walls defining a generally longitudinally inverted V-shaped groove 63 extending the length of the bottom of the orifice bar 30. In this instance, the bar is of a width to fit into the seat 40 in the manifold body stamping 31 and is about l-3/ 16 inch in width and about 1 linches in length. The lower portion of the vent bar 30 nests in the seat 40 and for this purpose has a pair o;f longitudinally extending side walls 65 which are about the height of the seat walls 45 and 46, in this instance, about inch in height and curved end walls 66 at opposite ends thereof.
The gas vent slots 16 are formed curved surfaces67 formed by milling with a 2 inches radius cutter, with depth of the cut, as shown by the dimension X in FIG. 4, being about 7/16 inches. The depth of the milling out also varies the area and dimension of the vent slots 16 and thereby the burner output capacity (in BTUs/hr.) at a given manifold feed pressure or for a given fuel mixture. Thus, the small vents extend transversely about the entire width of the bar with the fuel mixture flowing transversely and expanding as it moves into a slot 16 from the underlying manifold chamber 39. Herein, the vent 30 is secured in place by a central retaining set screw 68, FIG. 2, having an upper head seated in a bore 69 in the vent bar 30 with the lower end of the screw 68 threaded into a threaded bore 70 formed in the top of the gas inlet adapter 13. This screw also holds the gas inlet adapter with its surface 38 engaged with the encircling flange 37 on the manifold body stamping 31 to provide a gas tight joint therebetween. Additionally, it is preferred to use additonal fastener means suchasscrews 76 for securing the orifice bar 30 to the manifold body stamping 31. As best seen in FIG. 7, the heads of the screws 76 are external of the bottom wall 33 and project through openings 77 therein and are threaded in threaded bores 78 in the bottom of the orifice bar 30.
In accordance with another aspect of the invention, it has been found that the heat conduction between the vent bar 30 and the manifold body stamping 31 is generally insufficient without a means for heat transfer therebetween. The preferred heat transfer means 70 shown inFlG. 2 is a coating of furnace cement which is coated on the walls 52, 65 and 66 of the vent bar 30; and, when the latter is inserted, it fills any space between the vent bar side walls and the respective walls 45, 46, 48, 50 and 51 on the manifold body stamping 31. By transferring heat from the vent bar 30 to the manifold body stamping 31, the temperature of the bar 30 may be maintained at a lower temperature than it would. be if air spaces were present between the vent bar 30 and the manifold body stamping 31. A preferred form of furnace cement is a Calcinated Cement manufactured by Ferro Corporation, Gem Refractory Plant, Sebring, Ohio.
The ceramic sheet 19 for covering the top convex surface 60 of the vent bar 30 is preferably formed from a rectangular sheet of Fiberfrax" ceramic made of silica fiber. The slots 17 in the sheet 19 are preferably wider than the fuel vents 16, e.g., about 0.125 inch in width with a pair of slots 17 aligned over each fuel vent 16. The thin ceramic sheet is usually moistened to become limp and conforming to the convex shape and is sufficiently wide to have a pair of outer longitudinally extending flange portions 71 thereon extending laterally of the vent bar sides 65 and engaging the shelf wall 55 of the manifold body stamping 31. As will be explained in greater detail, the lower longitudinally extending bottom walls 73 of the ceramic body 14 will rest on the ceramic sheet flange portions 71 and insulate the same from the underlying metallic walls 55 of the manifold body stamping 31. The ceramic sheet insert 19 will become radiant thereby increasing the radiant heat output; and it also covers the bottom of the combustion chamber so that the metallic convex surface 60 of the vent bar 30 will not be directly exposed to the high temperature of the combustion chambers. The insert 19 also serves as a gasket between the refractory body 14, the metallic vent bar 30 and the manifold body stamping 31.
The ceramic body 14 is generally rectangular in shape and is similar to that described in the aforesaid patent and is preferably formed in two identical half sections 14A and 143, as seen in FIG. 2. The ceramic body has a pair of upper vertical walls 80 and 81 extending longitudinally and joined to end walls 82 and 83. As best seen in FIG. 7, the vanes 21 are integrally joined at opposite ends thereof to the longitudinally extending walls 80 and 81 and are formed with upwardly sloping sides 88 which provide a wider or thicker cross section at the lower portion of the vanes that at the upper portion of the vanes. Each of the vanes 21 terminates at a lower edge 89 which is positioned directly above the vent slots 16 and 17 so that the fuel mixture flowing through the vent slots impinges directly against the vane edge 89 and then flows upwardly along the vane sides 88. The combustion occurs in the combustion spaces 15 between the pairs of adjacent vanes. The bottom edges 89 of the vanes are spaced upwardly of the ceramic insert 19, as shown in FIG. 7, and are in a horizontal plane and define the top of a generally stepped central groove 93, as best seen in FIG. 2, formed to extend longitudinally along the bottom of the ceramic body.
For the purpose of anchoring the ceramic body 14 to the manifold body 12, a pair of elongated retainer anchoring strips 101 and 102 of generally channel shape, as best seen in FIG. 2a, have upper intumed securing flanges 103 for insertion into horizontal, longitudinally extending slots 105 (FIGS. 1 and 2) formed in the longitudinal sides of the ceramic body with lower portions of the strips 101 and 102 secured to the manifold body. More specifically, the slots 105 are located beneath a downwardly and inwardly tapered wall 107 extending from the upper walls and 81 to a lower vertical, longitudinally extending side wall 109, the slots being located at the junction of the side walls 107 and 109.
The anchoring strips 101 and 102 include a vertically extending web 113 which is adapted to abut the lower longitudinally extending side wall 109 of the ceramic body and have their outer web surfaces abutting the tray walls 57 on the manifold body stamping 31.
Herein, the anchoring strips 101 and 102 may be secured in either one of two manners to the manifold body 12. In the manner described in the aforesaid patent, a plurality of circular tabs are formed in the anchoring strips web 113 to be punched and deformed for insertion through apertures 117 in the walls 57 of the manifold body stamping 31. The tabs 115 are punched on a larger radius than the openings 117 in the body wall 57 with the upper edge of each tab 115 being accessible to a punch or awl inserted through the aperture 117 at its top. These tabs are deformed outwardly and downwardly by the awl or punch with the tabs 115 expanding and engaging sides of the apertures 117 below its diameter thereby securing the anchoring strip 101 or 102 to the manifold body. The above described tab connection is generally satisfactory except in instances where the ceramic body splits longitudinally with the vanes 21 separating at the center portions thereof. In such instances, the split vane portions may pivot outwardly with the anchoring strips 101 and 102 no longer retaining the ceramic body 14 in proper position on the tray.
In accordance with another aspect of the present invention, the anchoring strips 101 and 102 are provided with tabs 121 formed in their bottom flanges 111 for punching out in a downward direction for insertion through two pairs of slots 123', as best seen in FIG. 2, in the shelf 55 adjacent the upstanding tray walls 57. The lower ends of these tabs 121 are pushed through the slots 123 and the lower edges are twisted as with a pliers to form ends 124 bent out of the vertical plane of the tabs 121 to prevent the tabs 121 from being lifted directly upward through the slots 123. Alternatively, the lower edges of the tabs 121 may be bent inwardly to form a flange parallel to the flange 111. This latter manner of fastening the strips 101 applies a downward force through their upper flanges 103 to the ceramic body 14 at the slots 105 therein to hold the bottom surfaces 73 of the ceramic body in engagement with the horizontal shelf 55; and this prevents the pivoting of the anchor strips 101 and 102, which was sometimes experienced when the tabs 115 were used with the openings 117 and the vanes 21 split longitudinally down the center portions of the ceramic body.
The adapter 13 is a tubular metal member having a lower end formed with a pipe thread 130 for threading into a manifold gas pipe or tube 131, as shown in FIG. 8, with the tubular member thus serving to support and hold upright the radiant burner 11. The gas tubes 131 have a wall thickness of at least 3/16 inch and come in various sizes and shapes, for example, the illustrated 3 inch by 5 inch tube shown in FIG. 8, or more square cross-sectional shapes shown in FIGS. 9 and 10. Other means than the adapter may be used to support the radiant burner. The adapter 13 has a hollow interior with a central longitudinally extending bore through which the fuel mixture flows from the lower open end of the bore disposed within the gas tube 131 upwardly to a series of exit ports 133 in the form of a series of radially extending apertures formed in the upper cylindrical portion of the adapter. The fuel mixture flows uniformly from six ports 133 equally spaced from each other and into the manifold chamber 39 in the manifold body 12.
When a pair of modular radiant bueners 11 is used in a tandem or side-by-side relationship, such as shown in FIG. 8, it is preferred to provide protective anchoring strips 101a and 102a which extend the full height of the ceramic body 14 to prevent adjacent side walls 80 and 81 of the tandem ceramic bodies 14 from firing together. More specifically, the illustrated anchoring strips 101a and 102a have lower flanges 111a functioning in the same manner as the flanges 111 above described and likewise have the bent lower tabs 121a and the bent ears 124a in the manner above described. The I upper portions of the anchoring strips 101a and 102a have inclined portions 137 to abut the inclined wall 107 on the ceramic body 14 and an upper vertical section 139 having at its upper end an inturned retaining flange 141 extending over the top upper edge of the longitudinally extending side walls 80 and 81 of the ceramic body 14. The slots 105 in these ceramic members are empty. As the preferred anchoring strips are made of stainless steel, they can withstand the high temperatures and will prevent fusing or firing together of adjacent side walls of the ceramic bodies 14'.
In a number of instances, the fuel tubes connected to the adapters 13, are of different sizes or provide gas flow rates varying from that desired. As will be described in connection with FIG. 10, a fuel control means 143 may be used to control the fuel mixture flow from a manifold tube 145 into the lower threaded end 130 of the adapter 13 which may be secured to a radiant burner 11 in the manner above described. As will be explained, the illustrated fuel control means 143 comprises a threaded orifice control pin 147 which may be shifted vertically to change the flow rate of fuel into the bore of the adapter 13 by changing the effective area of the orifice.
In the embodiment of the invention shown in FIG. 10, the orifice control pin 147 has an exterior thread 148 threaded into an interior thread in an orifice con trol tube 149. By turning the control pin in the thread, it will shift longitudinally within the orifice control tube and shift its upper pointed end 151 relative to fuel inlet ports 153 in the form of circular aperutures in the upper end of the orifice control tube 149. The covering or uncovering of the circular apertures varies the effective area for fuel flow from the pipe into the hollow bore of the orifice control tube 149. The orifice tube 149 has an interior pipe thread 155 on its upper end for threading onto the pipe thread of the adapter 13 to provide a substantially gas tight joint and has a head 159 exterior of the fuel pipe with flats thereon to assist in turning the same for threading. Preferably, the orifice control tube has an arcuate shoulder 160 immediately above its head portion 159 for abutting the lower opening in the manifold pipe 145 to provide agas tight seal therewith after turning the tube to abut the arcuate shoulder with the fuel pipe. A lock nut 161 may be threaded onto the control pin 147 and tightened to abut the head 159 of the orifice control tube to lock the pin at a given position.
.To adjust the fuel flow and thereby the flame height in the radiant burner 11 with the flow control means 143 shown in FIG. 10, the lock nut 161 is loosened and the orifice pin 147 is turned by insertion of a tool into a slot 163 in the lower end thereof to turn the same in the thread in the stationary orifice control tube 149 with the pointed end 151 moving vertically in the tube 149. In this manner, the pointed tip 151 effectively pipe wall 167 of fuel pipe 145a. The upper end 151a of the pin may be moved vertically into or from the central bore of the adapter 13 to vary its effective inlet orifice cross-sectional area and thereby control the flow I of fuel into the adapter. 4
In accordance with another aspect of the invention, the radiant burner 11 may have attached thereto an 'additional means 170, as shown in-FIG. 7, for automatic fuel ignition or sensing a flame condition. More specifically, as shown in FIG. 7, the means 170 may include a bracket 171 secured in a suitable manner such as welding or bolting to the manifold body 12 for supporting a pair of electrical conductors 173 and 175, which project through openings in the side wall 59 of the manifold body stamping 31 and into the space of the combustion chambers 15. The illustrated electrical conductor tubes function as fuel ignitors, and similar but longer conductors (not shown) may be used to sense the flame. Since such flame sensors and flame starters are well known in the art, they will not be described in any greater detail herein.
From the foregoing, it will be seen thatthe present invention provides a new and improved radiant burner unit which has a composite manifold body including a cast metal orifice bar and a metallic stamping body for distributing the fuel to burner vents in the orifice bar.
The orifice bar is preferably made of a Ni Resist metal which solves the problem of closing the burner vents by scaling at the burner vents. The manifold body is preferably aluminized metal which provides a lighter weight and less expensive manifold which need not be painted to reduce oxidation thereof.
While a preferred embodiment has been shown and described, it will be understood that there is no intent to limit the invention by such disclosure but, rather, it is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims.
1. A radiant gas burner comprising an elongated upper refractory ceramic body having a series of transversely extending vanes spaced longitudinally from each other and defining therebetween separated combustion chambers,
a manifold body disposed beneath and supporting said refractory body, said manifold body comprising a metal stamping having an elongated manifold chamber and a separate metallic burner vent bar mounted on said metal stamping, means providing a fuel inlet port into said manifold body,
a refractory means covering a portion of said vent bar exposed to said combustion chambers to protect said metallic vent bar and to provide combustion chambers of substantially all refractory material,
a series of burner vent slots of narrow width spaced longitudinally in said vent bar and aligned with and beneath said transversely extending vanes in said refractory body, said slots being in fluid communication with said manifold chamber to discharge the fuel mixture therefrom directly against said vanes for flowing thereabout and into said combustion chambers,
said vent bar having a cross-sectional thickness greater than said cross-sectional thickness of said metal stamping and being supported in said metal stamping, said vent bar being cast of a scale resistant metal to retard closing of said vent slots with oxidation of said cast metal of said vent bar.
2. A radiant gas burner in accordance with claim 1 in which a heat conducting means is placed between said vent bar and said sheet metal stamping to enhance heat conduction therebetween to reduce the temperature of said vent bar.
3. A radiant gas burner in accordance with claim 2 in which said heat conducting means is a furnace cement positioned at the interface between said vent bar and said metal stamping.
4. A radiant gas burner in accordance with claim 1 in which said stamping is formed of aluminized steel to prevent rusting of said manifold body.
5. A radiant burner in accordance with claim 1 in which said manifold stamping is formed with a central lower seat for receiving and seating said vent bar therein and is formed with an upper surrounding tray for seating a lower portion of said ceramic body in said tray.
6. A radiant burner in accordance with claim 5 in which a pair of metallic anchoring strips anchors said ceramic body to said metal stamping and in which fasteners secure said vent bar to said metal stamping.
7. A radiant burner in accordance with claim 1 in which said vent bar is formed of a Ni-Resistant metal having an upper convex surface and a lower inverted V-shaped groove extending longitudinally thereof, said narrow width burner vent slots being cut by a circular 8. A radiant gas burner in accordance with claim 6 in which said anchoring strips each comprise an upper flange for engaging and applying a downwardly directed force to said ceramic body, a vertically extending web extends downwardly from the upper flange and along a longitudinally extending side wall of said ceramic body, and a lower flange connected to a lower end of said web, and in which a plurality of punch out tabs are formed in said lower flange for projecting through openings in said metal stamping and for being bent to non planar positions to hold the tabs against upward movement through said openings.
9. A radiant gas burner in accordance with claim 8 in which said webs extend to the top of said ceramic body with said upper flanges positioned over the upper edges thereof, said anchoring strip webs extending longitudinally and protecting the sides of the ceramic body from firing and fusing together with an adjacent side of an adjacent radiant burner.
10. A radiant gas burner in accordance with claim 1 in which said means providing a fuel inlet port includes an adapter secured to said manifold body and projecting downwardly from a central portion of said stamping, said adapter having a lower end for threading into a fuel pipe, and in which orifice control means is provided in said fuel pipe for controlling the flow rate of fuel from said pipe into and through said adapter.
11. A radiant gas burner in accordance with claim 10 in which said fuel control means includes an orifice control pin having an end extending externally from one side of said fuel pipe for turning the pin, means for threading and holding said pin at a predetermined position until turned, and an internally positioned and on said pin for movement to vary the effective orifice area for fuel flow into said adapter,
12. A radiant gas burner in accordance with claim 11 in which said fuel control means includes an orifice control tube having an upper end threaded onto said lower end of said adapter, said orifice control tube having a series of radially extending apertures therein, said orifice control tube having said orifice control pin extending longitudinally therein with the internally positioned end thereof movable across said apertures to vary the effective area of said apertures available for fuel flow from said pipe into said adapter.
13. A radiant gas burner comprising an elongated upper refractory ceramic body having a series of transversely extending vanes spaced longitudinally from each other and defining therebetween separated combustion chambers,
a metallic manifold body disposed beneath and supporting said refractory body, anchoring means anchoring said refractory body to said manifold body, said manifold body comprising a metal stamping forming anelongated manifold chamber and a separate metallic burner vent bar, said manifold chamber having an inlet port at the bottom central portion thereof and having upper portion closed by said metallic burner vent bar, said metal stamping having a seat formed by walls therein to seat said vent bar and a surrounding tray wall to receive a lower portion of said ceramic body,
a refractory sheet disposed over said vent bar to protect an upper surface of said metallic vent bar from exposure to said combustion temperatures,
said vent bar having an upper convexly curved surface,
eral times thicker than said cross-sectional thickness of said stamping to provide surfaces for directing fuel flow in a predetermined manner against the lower edges of said vanes, said vent bar being formed of a scale resistant metal to retard closing of said vent slots with oxidation of said metal of said vent bar.