US2898979A - Gas-fueled burner - Google Patents

Description

P. l. HOLLMAN ET AL GAS-FUELED BURNER Aug. 11,4959 9 s Sheets-Sheet 1 Filed Aug. 18, 1955 Al1g- 1959 P. l. HOLLMAN ETAL I 2,898,979

GASFUELED BURNER Fi led Aug. 18, 1955 5 Sheets-Sheet 2 Aug. 11,- 1959 P. 1. HOLLMAN ETAL GAS-FUELED BURNER Filed Aug. 18, 1955 3 Sheets-Sheet 3 jrlflew/ars 7x4, 4? MM game /8 J7) Q M W United States l atent GAS-FUELED BURNER Peter I. Hollman and Lionel R. Jensen, Rockford, 111., assignors, by mesne assignments, to Geo. D. Roper Corp., a corporation of Delaware Application August 18, 1955, Serial No. 529,119

4 Claims. (Cl. -158116) This invention relates to a gas burner and particularly to a burner adapted for use with a temperature responsive burner control system.

One object of this invention is to provide an improved burner construction having a channel formed therearound and communicating with the several burner ports to receive gas therefrom and spread the gas in the channel between the main burner ports at low flame levels, to thereby facilitate ignition of all of the burner ports.

Yet another object of this invention is to provide an improved burner having an intermediate burner arranged to feed a combustible gas mixture into the channel to burn thereat and effect ignition of any gas from the main burner port which enters the channel.

Still another object of this invention is to provide a burner construction which is simple and economical to manipulate and which is reliable and automatic in use.

These, together with various ancillary objects and advantages of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description when taken in connection with the accompanying drawings wherein:

Figure 1 is a side elevational view of a preferred form of burner and control system therefor with parts broken away and shown in section to illustrate details of construotion;

Fig. 2 is a top plan view of the burner shown in Fig. 1, with parts broken away and shown in section;

Fig. 3 is a vertical sectional View taken on the plane 3-3 of Fig. 2;

Fig. 4 is a fragmentary elevational view of the burner showing the intermediate burner and the mixer therefor;

Fig. 5 is a fragmentary horizontal view taken on the plane 5-5 of Fig. 3;

Fig. 6 is a fragmentary vertical sectional view taken on the plane 6-6 of Fig. 5;

Fig. 7 is a top plan view of a further modified form of burner, with parts broken away to illustrate details of construction;

Fig. 8 is a side elevational view of the burner shown in Fig. 7; and

Fig. 9 is a front side elevational view of the burner of Fig. 7.

Reference is now made more specifically to the preferred embodiment of the invention illustrated in Figs. 1-6 wherein the burner control system is illustrated in the form of a top burner unit, it being understood that,

the burner control system is also adaptable for use in ovens and the like.

The burner control in general comprises a main burner designated by the numeral 20, a mixertube 21 connected to the main burner and a valve 22 for controlling the flow of gas to the main burner and including a main shut-01f valve 220! and a temperature responsive flow regulator 22b arranged to gradually open and close to regulate the flow of gas to the main burners in response In ac-- to 'the temperature at the sensing element 24. cordance with the present invention, provision is made for ice burning the small quantities of gas which are fed to the main burner, as the temperature regulating valve is opened and closed, and for this purpose there is provided a channel 26 in the main burner which extends therearound and communicates with the main burner ports 27 to re ceive gas therefrom. A novel intermediate burner, designated generally by the numeral 28 is provided for supplying a combustible gas mixture to the channel 26 to burn thereat and thereby ignite any gas which enters the channel from the main burner ports and, preferably, the intermediate burner has a preselected quantity of gas supplied thereto sufficient to maintain the minimum desired temperature at the object or in the space to be heated.

The control valve 22 may be any of the conventional oven control valves of the type having the main shut-off valve and a temperature responsive flow regulating valve arranged to gradually open and close, one form of which valve is shown in the patent to Weber 2,303,011. Briefly, the control valve 22 includes a valve body 31 having a passage 32 formed thereat and communicating with the gas supply manifold 33. A main shut-off valve in the form of a plug 34 is disposed in the valve body and has a port 35 adapted to register with the passage 32 when the control knob 36 is turned. An axial passage 37 is formed in the plug 34 and conveys the gas entering through the port 35 to the chamber 38. A valve disk 39 is disposed in the body and cooperates with the valve seat 41 to regulate the flow of gas from the chamber 38 to the outlet 42 leading to the main burner. As is conventional, the valve disk 39 is slidably and non-rotatably connected by means of a stem 43 to the control knob 36 and is threadedly interconnected as indicated at 44 to the pressure responsive diaphragm 45 whereby the valve disk is moved away from the seat 41 as the control knob 36 is turned to a preselected temperature setting, to an extent determinedby the temperature setting of the knob. A spring 46 is provided for yieldably urging the valve disk to its open position and the valve disk is moved against the bias of the spring by the diaphragm 45 to throttle the flow of gas to the main burner as the temperature sensed by the element 24 approaches the temperature setting of the control knob 36.

The gas flow to the outlet 42 to the main burner is thus controlled by both the main shut-off valve 22a formed by the plug 34 and the temperature responsive flow regulating valve 22b formed by the disk 39, connected in the order named between the manifold 33 and the outlet 42. The gas from the outlet 42 is supplied through a burner spud 47 to the mixer tube 21 of the main burner to supply an air-gas mixture to the main burner.

The main burner comprises an annular outer body 51 having an inwardly-extending rim 52 on the upper end thereof and formed with a flat top wall 53. An inwardly extending flange 54 is formed on the lower end of the outer body and is threaded as indicated at SS for the re ception of the threaded lower end of the tubular inner, body 56. The inner body 56 projects above the outer body and has a portion 57 which extends outwardly over the top of the outer body member and a depending portion 58 spaced from the body 56 and extending downwardly into engagement with the flat upper face 53 on the rim 52 'of the outerv body to thereby form an annular chamber 59 between the inner and outer body members. A mixer extension 61 is formed on the outer body 51 and communicates with the chamber 59 and a flange 62 is provided on the mixer extension for attaching the same to the mixer drilled in the depending portion 58 of the inner body 56 and extend from the chamber 59 to the outer side of the burner. Conveniently, the channel 26 for receiving the gas from the main burner ports is formed by undercutting the outer periphery of the depending portion 58 adjacent the lower edge of the depending portion so that the latter engagm the flat top Wall 53 of the rim 52 at a point spaced inwardly from the outer periphery thereof to define a lower ledge 53a. The undercut in the depending portion defines an upper ledge 64 which extends outwardly from the depending portion and in spaced relation to the lower ledge to define the channel therebetween. The channel is arranged to spread the gas between adjacent main burner ports, as the gas issues therefrom at the low flow rates encountered when the flow regulating valve gradually begins to open and as it approaches its closed position, to facilitate ignition of each main burner port from an adjacent main burner port.

An improved arrangement is provided for igniting the gas in the channel to assure proper combustion of any gas collected therein and for this purpose there is provided an intermediate burner 28. Conveniently, the intermediate burner may be cast integrally with the main burner, and in the form shown in Figs. 1-6, includes an upstanding body 66 formed on the outer body 51 and defining an elongated passage 67 which enters from the lower end of the outer body and terminates at its upper end in a port 68-spaced inwardly from the outer edge of the ledge 53a and located adjacent the base of the channel 26. A connection 69 is formed at the lower end of the body .66 to receive an air-gas mixture. Gas is supplied to the intermediate burner under the control of the main shut-off valve 34 and independent of the temperature responsive flow regulating valve 23. As best shown in Fig. 1, a passage 71 is formed in the valve body and communicates with the chamber 38 between the plug 3 and the valve disk 39 and an adjustable valve element 72 is provided for regulating the flow of gas from the passage 71 to the outlet 73 for the intermediate burner. Gas from the outlet 73 is supplied through a conduit 74 to a mixer 75 attached to the connection 69 on the body 66. Any suitable mixer assembly may be provided for supplying an air-gas mixture to the intermediate burner, and as best shown in Fig. 4, the mixer includes a mixer tube 76 having ports 79 and an orifice 77 for directing a stream of .gas into the tube. The stream of gas from the nozzle draws air in through the ports 79 and mixes therewith to supply an air-gas mixture to the intermediate burner. An air control member 78 is adjustably mounted on the mixer to permit adjustment of the amount of primary air in the mixture to the intermediate burner.

Any suitable means may be provided for igniting the gas supplied to the channel through the intermediate burner port 58. In the apparatus illustrated in the drawings, the intermediate burner igniting means includes a pilot burner 81 which may be of the constantly burning type and having a gas supply thereto through a conduit 32 from the gas supply manifold 33. A laterally extending ignition port 84 is formed in the body 66 and has a nozzle 85 mounted therein, the outlet port 86 of the nozzle being directed toward the flame of the pilot burner 81 to be ignited thereby. A saw slot 87 is formed in the nozzle 85 between the port 86 and the juncture of the nozzle with the body 66 and a vertically extending saw slot 88 is formed in the body between the nozzle and the port 68. The gas in the passage 67 which escapes through the saw slots 87 and 88 is ignited by the flame at the port 86 and in turn ignites the gas issuing from the intermediate burner port 68 into the channel.

As is apparent, the gas issuing from port 68 in the intermediate burner passw into the channel before it is ignited so as to thereby enrich the mixture in the channel and to burn thereat in spaced relation to the base of the channel.

This maintains a flame at the channel, whenever the main shut-off valve is opened, and independent of the position of the valve disk 39. As the latter begins to open, the gas issuing from the main burner ports 27 flows into the channel and is ignited by the intermediate burner flame in the channel. In the preferred form of the invention, the channel is made wider than the diameter of the main burner ports. More particularly, the channel is made sufliciently wide to permit suflicient secondary air from around the burner to mix with the gas mixture adjacent the open end of the channel to provide a mixture within the channel and adjacent the open end thereof which has suflicient air to support combustion part way in the channel. Preferably, the width of the channel is made substantially equal to the minimum width at which the flame will burn at least partially inside the channel adjacent itsouter edge. It has been experimentally determined that a channel width of the order of .150 inch permits burning of the minimum quantity of gas in the burner. The channel is made sufliciently deep to prevent the flame at the open end of the channel from burning at the base of the channel to thereby provide an annular chamber between the base of the channel and the flame front in which the gas issuing from the main burner ports at very low flow rates may diffuse and spread between adjacent ports. A channel depth of .190 inch has been found satisfactory. In a burner of the type shown having a 3-inch diameter and 32 main burner ports, gas flows of from 225 to 300 B.t.u. per hour have been ignited and burned with negligible unburned gas escaping from the main burner, when the channel width is substantially .150 inch. Obviously, if the size and number of ports in the main burner is either increased or decreased, the minimum heat outputs as well as the maximum heat outputs obtainable will be correspondingly changed. Such gas flows through the aforementioned burner are insuflicient to maintain a steady flame around the entire burner. However, the steady flame at the side of the burner, produced by the intermediate burner, ignites the gas as it collects in the channel. In operation, the flame at such low flow rates flickers and appears to travel around the burner; burning the gas as it accumulates in the channel. The flames travel around the burner at a rapid rate so that negligible unburned gas can escape from the channel. As the gas input to the burner is increased, the flickering of the flame diminishes until the gas burns in the channel in one continuous flame at a gas flow rate somewhat higher than the minimum flow rate. As the gas input to the burner is further increased for high heat output, the gas issues from the several main burner ports at a higher velocity and does not difluse appreciably in the channel. The gas from each port then burns in separate streams and, since the channel is wider than the diameter of the main burner ports, the individual gas streams will tend to burn at the base of the channel. By dimensioning the channel so that the secondary air can enrich the gas adjacent the open end of the channel sufiiciently to support combustion, it is thus possible to burn the gas in the channel with the flame located at least partially within the channel. The channel therefore protects the flame from drafts and since the gas is burned before it leaves the channel and diffuses into the surrounding air, the burner is effective to burn gas inputs to the burner which are insuflicient to maintain a steady flame around the entire burner. It is preferable to make the width of the channel the minimum at which the aforementioned burning of the gas partially within the channel occurs since, as the width of the channel is increased beyond this minimum, the flame area at the open end of the channel is similarly increased. It has been found that the amount of gas which need be supplied to the main burner with a somewhat wider groove correspondingly increased the minimum quantity of gas which would be burned by the burner. When the width of the channel is made sufliciently small so that the flame burns outside of the channel, it has been found that the minimum quantity of gas which the burner can properly burn is that quantity which will maintain a steady flame around the entire burner.

As previously described, the channel is wider than the fiiain burner ports and when the gas issues from the latter at a high velocity, the gas stream does not diffuseappreciably in the channel. Therefore, thegas streams from the main burner ports burn in separate flames at high heat outputs. In order to adapt the single main burner 20 for operation also at high flame levels, that is, when the gas issues from the main burner ports at a velocity above the velocity of flame propagation of the gas mixture supplied to the burner, there are provided a plurality of auxiliary ports 89 having a diameter smaller than the main burner ports 27 and located between adjacent main burner ports. The auxiliary ports are designed to have a flow impedance which is high as compared to the flow impedance of the main burner ports so that the auxiliary ports will throttle the flow of gas therethrough, at high flame levels, and reduce the velocity of the gas issuing fromthe auxiliary ports to below the velocity of flame propagation of the gas mixture. The gas issuing from the auxiliary ports will therefore burn adjacent the outer ends thereof, at high flame levels, and thus serve to ignite the gas which issues at a relatively higher velocity from the main burner ports 27. In this manner the flame front at each of the main burner ports is prevented from moving away from the burner head at high flame levels. At low flame levels, the high flow impedance of the intermediate ports is such that very little gas flows therethrough and the latter have negligible effect.

The control apparatus is particularly designed in a top burner unit of a gas stove and accordingly the main burner 20 is made hollow so that the temperature sensing element 24 may extend therethrough in spaced relation to the main burner and out of thermal contact therewith. The sensing element 24 is provided with a resiliently mounted head 24a engageable with the underside of a pan (not shown), disposed upon the burner grate 91, so as to be actuated in response to the temperature of the pan. The sensing element may be of any convenient construction and is connected through a tube 92 to the diaphragm 45 to actuate the latter in accordance with the temperature detected by the sensing element. Alternately, the control system may be utilized for controlling the temperature in a confined space such as an oven and under these conditions the expansion bulb type of temperature sensing element would be located at a suitable spot in the space to be heated, instead of within the burner.

Referring more specifically to Figs. 7-9, the burner includes an outer body 150 having an inwardly extending flange 151 at its lower edge which is threaded to receive the threaded lower end of the inner body member 152. A head portion 153 is formed on the upper end of the inner body 152 and overlies the upper end of the outer body 150 in sealed relation therewith. The inner and outer bodies define a main gas chamber 154 therebetween to which gas is supplied through the integral mixer extension 155 adapted for connection to the mixer tube 21. A plurality of annularly spaced main ,burner ports 156 are formed in the head 153. An annular channel 157 is formed in the outer periphery of the head and extends completely therearound to receive gas from each of the several main burner ports.

In this form of the invention, the intermediate burner is arranged to burn along an arcuate segment of the main burner and for this purpose the outer body member is formed with an arcuate wall 153 spaced from the outer body 150 and sealed thereto along the bottom and side edges to define an intermediate burner compartment 159 therebetween. The head 153 overlies the upper end of the compartment 159 and forms a closure therefor, and gas is supplied to the compartment 159 through a connector 161 which communicates therewith and is arranged for connection to the outlet of the mixer 75.

The upper edge of the outer'wall 150 is recessed to provide a slot 162 between the body 150 and the head 153 through which gas may flow from the intermediate burner chamber 159. A plurality of saw slots 163 are formed in the head to communicate the chamber 159 with the channel 156 to thereby supply a combustible gas mixture to the channel. The gas issuing from the recess 162 and the gas which flows into the channel 156 through the saw slots 163 may be ignited in any desired manner and as shown there is provided a laterally extending nozzle 165 which communicates with the connection 161 to the intermediate burner mixer 75 to receive gas therefrom. An orifice 166 is formed in the nozzle to direct a stream of gas at the constant pilot burner 81, or other means for igniting the main burner, to be ignited thereby. Saw slots 167 and 168 are formed in the nozzle 165 and in the outer wall of the body for passing the flame from the nozzle 166 to the recess 162.

As is apparent, gas is supplied to the nozzle 165, and to the recess 162, and also through saw slots 163 to the channel 156 whenever the main shut-off valve is opened, and independent of the position of the flow regulating valve. The gas issuing from the several ports is ignited from the constant pilot burner 81 and the gas which flows through the recess 162 burns in a ribbon of flame below the main burner ports. The gas supplied to the channel through the saw slots 63 burns thereat and thereby facilitates igntion of any gas which passes through the main ports into the channel.

From the foregoing, it is thought that the operation of the burner control system will be readily understood. When the main gas valve 22 is turned on, gas is supplied to the intermediate burner and the latter is ignited from the constant pilot burner 81 or any other suitable means. In each of the forms of the burner, the intermediate burner produces a flame in heat transmitting relation to the object engaged by the sensing element. In the embodiments illustrated, the means for igniting the intermediate burner from the pilot, including the nozzle for directing a gas stream at the pilot and the vertical slot for producing a flame which extends from the nozzle to the intermediate burner, also tends to heat the object above the burner. However, because of the more remote location of these flames, the heating effect thereof is somewhat reduced. Preferably, the gas supply to the intermediate burner is adjusted so that the heat output of the intermediate burner and ignition means therefor is 'suflicient to maintain the object engaged by the sensing element at the minimum temperature desired for any cooking operation. The intermediate burner shown in Figs. 7-9 requires a predetermined minimum quantitytof gas. to be supplied thereto in order to safely and efiiciently ignite the gas issuing from the main burner, and the gas flows thereto should not be adjusted below the abovementioned minimum.

The control valve 22 is settable, by means of the knob 36, to a position in which only the main shut-off valve 22 is open. Under these conditions, gas is supplied only to the intermediate burner. As previously described, the flame at the'intermediate burner is preferably adjusted to maintain the minimum temperature desired. When the control knob is set for relatively higher temperatures, the valve disk 39 is moved to open the flow regulating valve 22b to supply gas to the main burner. The latter is ignited from the intermediate burner and, as the temperature of the pan resting on the sensing element approaches the set temperature, the temperature responsive valve operates to throttle the flow of gas to the main burner. At temperature settings only slightly above the minimum temperature, the temperature responsive valve 22b opens suflicient to provide a flame around the main burner. The control system tends to overshoot slightly, due to thermostatic lag, and the temperature responsive valve is then operated to extinguish the flame at the main burner until the temperature of the pan drops below the set temperature. At relatively higher temperature settings, the temperature responsive valve is operated to merely throttle the flow of gas to the main burner and does not completely extinguish the flame at the main burner when the desired temperature is reached.

We claim:

1. A gaseous fuel burner adapted for operation over a wide range of gas inputs thereto in combination with a pilot burner and including a burner body having an upstanding side wall and a large number of main burner ports in said side wall spaced therealong for producing a plurality of separate flames at high flow rates and requiring a preselected rate of flow of gas to the burner body to maintain a minimum steady flame at each main port, means for burning the gas which issues from said main ports at low flow rates when gas is supplied to said burner body at a rate below said preselected rate, said last-mentioned means comprising spaced upper and lower horizontally disposed ledges on said side wall extending therearound respectively above and below said main ports to define a channel therebetween for collecting the gas which issues from said main ports at said low flow rate, said lower ledge being spaced below said upper ledge a distance large enough to cause secondary air to enter only the radially outer portion of said channel and produce an inflammable air-gas mixture within the channel adjacent the open side thereof when the gas issues from said main ports at said low flow rates, the radial depth of said channel being at least as large as the axial width thereof to prevent the secondary air which enters the open end of the channel from mixing with the gas at the base of the channel when the gas issues from said main ports at said low flow rates to thereby cause the gas to burn at least partially within the channel at a point spaced from the base of said channel, said main burner ports being dimensioned to freely pass gas therethrough into said channel and to prevent flash back therethrough at said low flow rates, said main burner ports being spaced apart a distance less than twice the radial depth of said channel to cause the gas issuing from said main ports at said low flow rates to spread in the channel and merge with the gas issuing from an adjacent port to thereby feed gas in a substantially continuous sheet toward the open end of the channel for mixture with secondary air thereat, means defining an intermediate burner having an end port in said lower ledge spaced radially inwardly of the outer periphery of said ledges and directed at said upper ledge whereby unburned gas issuing from said end port impinges on said upper ledge and is spread thereby in said channel said intermediate burner also having a restricted side port smaller than said end port disposed between said pilot burner and said channel so as to carry flame to said channel.

2. The combination of claim 1 wherein said main ports have a diameter less than the vertical width of said channel and are spaced vertically from each of said ledges whereby the gas issuing from said main ports at high flow rates flows in separate streams to entrain large quantities of secondary air.

3. The combination of claim 2 wherein said side wall has at least one auxiliary port therein between each adjacent pair of main ports, said auxiliary ports having a diameter which is small as compared to the diameter of said main ports to substantially prevent flow therethrough when the gas issues from said main ports at said aforementioned low rates and to feed gas to said channel when the gas issues from said main ports at a high velocity whereby to provide a flame at said channel for igniting the gas issuing from the main ports.

4. In a gaseous fuel burner cooperating with a pilot burner, the combination of a burner body having an upstanding side wall and vertically spaced upper and lower horizontally disposed ledges extending around said side wall and defining a channel therebetween, said side wall having a plurality of spaced main burner ports therein located between said ledges and each arranged to direct a stream of gas substantially horizontally outwardly of said body between said ledges, said channel having a radial depth at least as large as the vertical width thereof to collect the gas issuing from said main ports at low rates of flow of gas from said main ports, said ports being annularly spaced apart a distance less than twice the radial depth of said channel to permit the gas to spread in said channel between adjacent main ports at low rates of gas flow, said burner body having a first passage means therein for supplying a gaseous mixture to all .of said main ports, means defining an intermediate burner having an end port directed transverse to the direction of gas flow from said main ports and at one of said ledges whereby unburned gas issuing from said end port impinges on said one of said ledges to be spread thereby in said channel, said intermediate burner alsohaving a side port extending between said pilot burner and said channel so as to carry flame to said channel, and a second passage means separate from said first passage means for supplying a gaseous mixture to said intermediate burner.

References Cited in the file of this patent f UNITED STATES PATENTS 1,416,500 Nicolaus May 16, 1922 1,884,764 Lonergan Oct. 25, 1932 1,918,872 Schmidt July 18, 1933 2,155,122 Fox Apr. 18, 1939 2,215,520 Burklin Sept. 24, 1940 2,215,711 Mueller Sept. 24, 1940 2,430,887 Ray Nov. 18, 1947 2,450,680 Mueller Oct. 5, 1948 2,573,502 Smith Oct. 30, 1951 2,595,739 Weseman May 6, 1952 2,642,934 Gunther et a1 June 23, 1953 2,764,145 Knight Sept. 25, 1956 FOREIGN PATENTS 10,638 Netherlands Nov. 17, 1923 164,036 Switzerland Nov. 16, 1933

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