US3267984A

US3267984A - Burner assembly producing radiant heat

Info

Publication number: US3267984A
Application number: US410375A
Authority: US
Inventors: Robert D Reed; Goodnight Hershel; Zink John Smith
Original assignee: John Zink Co
Current assignee: Zinklahoma Inc
Priority date: 1964-11-12
Filing date: 1964-11-12
Publication date: 1966-08-23
Anticipated expiration: 1983-08-23
Also published as: DE1261621B; FR1453169A

Description

Aug. 23, 1966 R, D, REED ETAL 3,267,984

BURNER ASSEMBLY PRODUCING RADIANT HEAT Filed Nov. 12, 1964 2 Sheets-Sheet 1 INVENTORS ROBERT D. H RSHEL GOOD/V JOHN SMITI-l ZINK B ab;

ATTORNEY United States Patent 3,267,984 BURNER ASSEMFBLY PRGDUQHNG RADlANT HEAT Robert D. Reed, Hershel Goodnight, and dohn Smith Zinir, all of Tulsa, Okla, assignors to John Zinlr Company, Tulsa, Girls", a corporation of Delaware Filed Nov. 12, 1964, Ser. No. 410,375 4 (Jlainis. (Cl. 1581.5)

The present invention relates to a burner assembly for the combustion of liquid fuel or gaseous fuel wherein a burner head unit is arranged in such relationship with respect to a shaped ceramic structure that the fuel burns and spreads along an annular'surface of the ceramic structure and provides a source of heat which radiates from a large area of the refractory structure.

An object of the invention is to provide a burner assembly adapted for the combustion of liquid fuel or a gaseous fuel mixture including means inducing the burning fuel to move along the surface of a ceramic structure surrounding the combustion zone whereby the burning fuel clings to the ceramic surface and minimizes or substantially eliminates projection of flames of burning fuel away from ceramic surfaces of the assembly.

A more detailed object of the invention is to provide a burner structure wherein the major portion of an air supply is directed into the burner assembly in such a manner as to set up a spinning mass of air into which the burning fuel is drawn by the low pressure developed in the whirling air to thereby promote movement of the burning fuel in a circumferential path along the surface of a ceramic member which forms a component of the burner assembly.

Other objects and features of the invention will be appreciated and become apparent to those skilled in the art to which the invention pertains as the present disclosure proceeds and upon consideration of the accompanying drawings taken in conjunction with the following detailed description wherein an embodiment of the invention is disclosed.

In the drawings:

FIG. 1 is a vertical elevation-a1 view of the forward end of the burner assembly mounted in a refractory wall.

H6. 2 is a sectional view taken on the line 22 of FIG. 1.

FIG. 3 is a sectional view on a larger scale and taken on the line 3-3 of FIG. 1.

FIG. 4 is a fragmentary sectional view of two walls of a heating chamber showing a plurality of the burner assemblies in relation to liquid carrying tubes.

FIG. 5 is a sectional view taken on the line 55 of FIG. 3.

The present invention pertains to a burner assembly which has utility for supplying heat to the exterior of tubes which carry fluids or liquids such as employed in the process industries and the heat supplied thereto is for conversion of the fluid to the required products. While heat generating equipment is known for supplying heat to water tubes or the like the burner assembly of the present application is designed to drive ultimate quantities of heat through the walls of each increment of such fluids carrying tubes and the quantity of heat supplied is in excess of that provided by prior equipment and without the flame of the burning fuel playing on or engaging exterior surfaces of such tubes to thereby avoid deterioration of the fluid carrying conduits. A burner assembly embodying the invention develops radiant heat over a large area of its refractory components and has utility for purposes in addition to delivering heat to fluid carrying tubes.

Referring to the drawings and to FIG. 1 there is shown at a wall formed of refractory material in which a generally rectangular shaped tile member 11 formed of ceramic material is mounted. The tile member 11 may have a thickness substantially equal to that of the wall 10 as shown in FIG. 4. The outer face of the tile member ll may be covered with sheet metal as indicated at 12 in FIG. 3. An openng 14 extends through the central portion of the ceramic member 11 and this opening is cylindric-ally shaped throughout more than one-half the thickness of the Wall structure. The opening 14 flares outwardly from the end 16 of the cylindrical portion of the opening 14. The outwardly flared surface 17 is also of arcuate convex shape when viewed in section and this arcuate surface merges flush with the inner face 18 of the tile member 11 and which is desirably in the same plane as the inner face 19 of the wall ll).

The burner assembly includes a generally cylindrical housing member 21 which is accommodated within the cylindrical shaped portion of the opening 14 as shown in FIG. 3. A flange 22 carried by the housing member 21 overlies the outer face of the wall 10 around the mouth of the opening 14 and provides means for supporting the burner assembly on the refractory structure. An annular element 23 is mounted within the housing member 21 and has a frusto-conical shaped intermediate portion 24 which flares outwardly in proceeding downstream of the burner assembly. A cylindrical shaped sleeve 26 is carried by the larger diameter end of the frusto-conical shaped portion 24. An annular rib 27 projects radially from the element 23 and this rib may be attached to the housing member 21 in any suitable manner such as by welding as indicated at 28. The small diameter end portion of frusto-conical portion of the element 23 provides a throat 25 for accommodating the forward end of a burner head unit. A cup-shaped upstream end portion of the element 23 includes a cylindrical shaped annular wall 31 as shown in? FIG. 3 of materially larger diameter than the throat 2.).

A conduit 32 extends into the upstream end of the housing 21 as shown in FIG. 3. Air is admitted to the conduit 32 through a laterally disposed fitting 33 depicted Ill]. FIG. 2. An annular wall 34 closes the upstream end of the housing 21 with respect to the perimeter of the conduit 32. The conduit 32 desirably has substanially the same external diameter as the annular wall 31 of the element 23 and the conduit 32 may be secured thereto in any suitable manner such as by welding indicated at 36.

A burner head unit indicated generally at 38 extends into the throat 25. The burner head for gaseous fuel is formed by a guide tube 39 and a sleeve 41 which surrounds the guide tube 39 in spaced relationship and provides an annular space 42 between the guide tube 39 and the sleeve 41. This burner head is supported within the annular element 23 by means of a plurality of radially disposed lugs 43 which are carried by a collar 44 which surrounds the sleeve 41. The outer ends of the lugs 43 engage the inner surface of the annular wall 31. A plurality of discharge ports 46 are arranged in a circular row at the downstream end of the burner head for gaseous fuel. The exterior of the sleeve 41 is spaced from the throat 25 to provide an annular passage for air to move over the exterior of the burner head unit. A baffle 47 is carried by the sleeve 41 adjacent the downstream end thereof and near the discharge ports 45 to restrict the area of the annular passage within the throat 25.

A pipe 51 is attached to the upstream end of the sleeve 41 and extends beyond the outer end of the conduit 32. A gaseous fuel mixture is supplied into the pipe 51 through a conduit fiting 52 shown in FIG. 2. The guide tube 39 extends outwardly and upstream beyond the end of the pipe 51. The gaseous fuel mixture supplied into the pipe 51 moves through the annular passage 54 provided between the interior of the pipe 51 and the exterior of the guide tube 39 and into the annular passage 42 for escape through the discharge ports 46. The burner head unit includes a nozzle 56 for liquid fuel and this burner tip is accommodated within the guide tube 39. The forward end of the nozzle 56 is provided with discharge apertures 57 for discharging liquid fuel as small droplets downsream from the nozzle 56 in a substantially conical pattern. The liquid fuel is supplied to the burner tip through a pipe 58.

A plurality of openings 61 are provided through the Wall of the conduit 32 whereby a major portion of the air admitted through the fitting 33 escapes outwardly through the openings 61 as indicated by the arrows 62 into the plenum 63 formed exteriorly of the element 23 with this air confined therein by the housing member 21. A plurality of apertures 64 extend through the frustoconical portion 24 of the element 23 near the rib 27. The apertures 64 have their axes disposed tangentially with respect to the cylindrical sleeve 26 and all of these apertures slope in the same direction in proceeding in one direction circumferentially of the assembly. A minor portion of the air admitted into the conduit 32 moves in the direction of the arrows 66 and through the throat 25 and over the downstream end of the burner head unit 38.

In operation and when liquid fuel is to be burned such fuel is supplied into the pipe 58 at relatively high pressures. The liquid is discharged through the apertures 57 as tiny droplets and in a conical pattern as represented by phantom lines in FIG. 3. Air at relatively high pressures is supplied through the conduit fitting 33 and this air moves into the combustion zone in two separate paths. The major portion of the air flows from the annular space 68 through the openings into the plenum 63 and thence through the tangentially disposed apertures 64. The apertures 64 are designed to provide a maximum pressure drop across each aperture so that the air attains a maximum velocity in passing through the apertures 64. The high velocity of this air develops a rapidly spinning mass of air within the cylindrical sleeve 26 to create a substantially dough-nut shaped mass of whirling air in an annular pattern as indicated at '71. A minor portion of the air in the annular space 68 moves in the direction of the arrows 66 and flows through the throat 25 over the periphery of the burner unit and over the perimeter of the baffle 47. There is no circumferential component imparted to this air and it does not spin. This portion of the air controls the zone at which the droplets of liquid fuel are subjected to the action of the violently spinning air mass 71. The quantity of air moving through the throat 25 may vary from five to ten percent of the total air quantity.

The pressure within the whirling air mass 71 is extremely low and the liquid fuel droplets are drawn into this violently spinning air. The turbulence and violence of the whirling air breaks the droplets of liquid fuel into smaller droplets of micron size and which are so small that the fuel particles then appear as smoke which burn with extreme rapidity. Initial ignition of the liquid fuel may be established in any conventional manner and combustion of the liquid fuel is maintained by the return of the hot gases as represented by the arrows 72 to elevate the liquid fuel to a temperature where stable auto-ignition is maintained. The spining fuel undergoing combustion burns with a bright blue color near the free end of the cylindrical sleeve 26. An annular shaped ceramic member 76 is provided within the housing 21 adjacent the downstream end of the sleeve 26. The inner annular surface 77 of the ceramic member 76 flares outwardly in proceeding downstream of the burner assembly and de sirably has curvature which merges smoothly with the arcuate surface 17 forming .the exit end of the opening in the tile member 11.

The flame developed in the spinning air mass 71 moves circumferentially of the assembly at a rapid rate. The pressure within this burning mass is low and the burning fuel and gases spin against the inner surface 77 of the ceramic member 76. This surface is solid and the low pressure within the burning fuel causes the burning fuel to cling to the surface 77 and cling to the surface 1.7 of the tile member 11. Centrifugal force urges the burning fuel against the surface 17 so that the flame clings tightly to the surface 77 and to the surface 17. The burning fuel moves along these arcuate ceramic surfaces and there is virtually no projection of the flame away from these arcuate surfaces. The downstream face 18 of the tile member 11 and the downstream face 19 of the wall 10 are scrubbed with heat. Heat is transferred to the tubes 79 (FIG. 4) as energy radiating from the wall it) and the tile member if. The flame does not play upon the external surfaces of the tubes 79.

The gaseous fuel mixture is supplied into the pipe 51 through the fitting 5'2 and the gaseous fuel mixture moves into the annular space 54 and escapes through the discharge ports 46 in the burner head unit. The pressure at which the gaseous fuel is supplied is controlled so as to provide for a suitable quantity of the gaseous fuel mixture to flow from the discharge ports 46 in a frustoconical pattern along the inner surface of frusto-conical portion 24 of the element 23 and into the spinning air mass 71. The air entering through the throat 25 mixes with the gaseous fuel. This fuel burns stably after ignition an suitable combustion is established by the time the burning gaseous fuel mixture arrives in the presence of the whirling air mass 71. The burning gaseous fuel moves along the inner surfaces of the ceramic member 76 and the tile member 11 in a manner similar to that described in connection with the burning liquid fuel.

While the invention has been described with reference to a particular burner assembly it will be appreciated that changes may be made in the elements as well as the overall combination. Such changes and modifications along with others may be made without departing from the spirit and scope of the invention as set forth in the appended claims. What we claim and desire to secure by Letters Patent 1. In a burner assembly for producing radiant heat, a refractory wall, a ceramic tile member mounted in said wall with the inner face thereof flush with the inner face of said wall, said tile member having an opening through the central portion thereof, a flared annular surface defining the exit end of said opening, said flared annular surface being of convex shape in section and merging smoothly with the inner face of side wall, a housing member within said opening, an annular element within said housing member having a throat of smaller cross section than other portions of said annular element, a burner head unit mounted with-in said throat, means for supplying fuel into said burner head unit for discharge in a flaring [pattern into the downstream end portion of said annular element, means guiding air over the exterior of said burner head unit and through said throat into the presence of the fuel discharged from the burner head unit to support combustion of the fuel, said annular element having a plurality of 'circumtferentially spaced apertures therethrough downstream of said burner head unit arranged generally tangentially of the annular element with the axes of all of said apertures sloping in the same direction in proceeding circumferentially of said annular element, means guiding air at pressures above atmospheric through said apertures, said aperture-s producing pressure drop in the air passing the-rethrough and directing the air in a circumferential swirl as a consequence of the tangentially disposition of the apertures whereby the burning fuel is drawn into the swirling air so that the burning fuel moves along said flared surface Without development of flames of any substantial extent away from said flared surface.

2. In a burner assembly for producing radiant heat, a refractory wall, a ceramic tile member mounted in said wall with the inner face thereof flush with the inner face of said wall, said tile member having an opening through the central portion thereof, an annular surface flaring outwardly from the axis of said opening and merging smoothly with the inner face of said wall, a housing member within said opening, an annular element within said housing member providing an annular plenum between said housing member and said annular element, said annular element having a throat of smaller cross section than other portions of said annular element, a burner head unit mounted within said throat, means for supplying fuel into said burner head unit for discharge in a flaring pattern into the downstream end portion of said annular element, means guiding air over the exterior of said burner head unit and into the presence of the fuel discharged from the burner head unit to support combustion of the fuel, means supplying air into said plenum at pressures above atmospheric, said annular element having a plurality of circumferentially spaced apertures the-rethrough and located downstream from said burner head unit, said apertures being arranged generally tangentially of the annular element with the axes of all of said aperture-s sloping in the same direction in proceeding circumferentially of said annular element, said apertures producirrg pressure drop in the air passing therethrough and directing the entering air in a circular path along the inner surface of said annular element with the burning fuel drawn into the swirling air whereby the burning fuel moves around and along said flared surface without development of flames of any substantial extent away from said flared surface.

3. In a burner assembly according to claim 2 wherein the annular element in the portion between the burner head unit and said apertures has a firusto-conical shaped inner surface.

4. In a burner assembly according to claim 2 wherein a ceramic member within the downstream end of said housing member has an annular surface which fiares outwardly from the axis of the housing. member and guides the burning fuel onto the surface of said tile member.

References Cited by the Examiner UNITED STATES PATENTS 2,527,503 10/1950 Sinclair et al. 158-l.5l 2,969,833 1/1961 Bloom et al. 15811 3,133,731 5/1964 Reed 158-11 X 3,203,462 8/1965 Prowse 1581.5

FREDERICK L. MATTESON, JR., Primary Examiner.

E. G. FAVORS, Assistant Examiner.

Claims

1. IN A BURNER ASSEMBLY FOR PRODUCING RADIANT HEAT, A REFRACTORY WALL, A CERAMIC TILE MEMBER MOUNTED IN SAID WALL WITH THE INNER FACE THEREOF FLUSH WITH THE INNER FACE OF SAID WALL, SAID TILE MEMBER HAVING AN OPENING THROUGH THE CENTRAL PORTION THEREOF, A FLARED ANNULAR SURFACE DEFINING THE EXIT END OF SAID OPENING, SAID FLARED ANNULAR SURFACE BEING OF CONVEX SHAPE IN SECTION AND MERGING SMOOTHLY WITH THE INNER FACE OF SIDE WALL, A HOUSING MEMBER WITHIN SAID OPENING, AN ANNULAR ELEMENT WITHIN SAID HOUSING MEMBER HAVING A THROAT OF SMALLER CROSS SECTION THAN OTHER PORTIONS OF SAID ANNULAR ELEMENT, A BURNER HEAD UNIT MOUNTED WITHIN SAID THROAT, MEANS FOR SUPPLYING FUEL INTO SAID BURNER HEAD UNIT FOR DISCHARGE IN A FLARING PATTERN INTO THE DOWNSTREAM END PORTION OF SAID ANNULAR ELEMENT, MEANS GUIDING AIR OVER THE EXTERIOR OF SAID BURNER HEAD UNIT AND THROUGH SAID THROAT INTO THE PRESENCE OF THE FUEL DISCHARGED FROM THE BURNER HEAD UNIT TO SUPPORT COMBUSTION OF THE FUEL, SAID ANNULAR ELEMENT HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED APERTURES THERETHROUGH DOWNSTREAM OF SAID BURNER HEAD UNIT ARRANGED GENERALLY TANGENTIALLY OF THE ANNULAR ELEMENT WITH THE AXES OF ALL OF SAID APERTURES SLOPING IN THE SAME DIRECTION IN PROCEEDING CIRCUMFERENTIALLY OF SAID ANNULAR ELEMENT, MEANS GUIDING AIR AT PRESSURES ABOVE ATMOSPHERIC THROUGH SAID APERTURES, SAID APERTURES PRODUCING PRESSURE DROP IN THE AIR PASSING THERETHROUGH AND DIRECTING THE AIR IN A CIRCUMFERENTIAL SWIRL AS A CONSEQUENCE OF THE TANGENTIALLY DISPOSITION OF THE APERTURES WHEREBY THE BURNING FUEL IS DRAWN INTO THE SWIRLING AIR SO THAT THE BURNING FUEL MOVES ALONG SAID FLARED SURFACE WITHOUT DEVELOPMENT OF FLAMES OF ANY SUBSTANTIAL EXTENT AWAY FROM SAID FLARED SURFACE.