US1982101A - Gas igniting and burning device - Google Patents

Description

Nov. 27, 1 934. e. HERB'STER GAS IGNITING AND BURNING DEVICE Filed Jan. 30, 1933 2 Sheets-Sheet 1 TTORNEY3 Nov. 27, 1934. HERBSTER 1,982,101

GAS IGNITING AND BURNING DEVICE Filed Jan. 30, 1933 2 Sheets-Sheet 2 '14 TTORNE Xi Patented Nov. 27, 1934 UNITED STA GAS IGNITING AND BURNING DEVICE George Herhater, Cleveland, Ohio, assignmto The Cleveland Cooperative Stove Company, Cleveland, Ohio, a corporation of Ohio Application January 30, 1933, Serial No. 654,162

Claims. (01.158-115) This invention relates to an apparatus for eifecting more efllcient firing relation between a service burner'and pilot burner.

One of the principal objects of the present invention is to insure substantially instantaneous ignition'of the servicebumer by the pilot burner under the most adverse conditions.

Another object is to provide an ignition burner in firing relation to both the pilot and-service burners, which ignition burner will operate substantially instantaneously with the introductionof fuel thereto.

A more specific object resides in the provision of a new and improved service burner having iii combination therewith an ignition burner for the purpose described.

Another specific object is to provide a new and improved valve for supplying fuel through different nozzles directly from the feed line both to the service burner and to the ignition burner.

Still another object is to provide a valve for this purpose adapted, upon turning in a given direction, first to introduce fuel to the ignition burner, and upon subsequent turning in the same 5 direction, to maintain the flow of fuel to the ignition burner and introduce fuel to'the service burner, whereby the ignition burner may be supplied with fuel'before and concurrently-with the supply to the service burner, and adapted, upon operation of the valve in the opposite direction to discommunicate the gas supply to the service burner, and subsequent thereto to discommunicate the ignition burner.

Other objects are to provide a valve of this character with a new and improved clutch means betweenthe operating stem and plug for rendering the valve more safe from interference by children, and to provide a means for positively locking the valve in a position to supply gas to the service burner so as to maintain a' simmering flame thereon. 7

Other objects and advantages will become apparent from the following specification wherein reference is made to the drawings.

In the drawings, Fig. l is a plan view of a service and ignition burner and control valve embodying the principles of the present invention.

Fig. 2 is a side elevation of the burners and valve shown in Fig. 1, part of the burners being shown in section for cleamess in illustration.

Fig. 3 is an enlarged sectional view illustrating the relation between the ignition burner and a pilot light, part being taken on a plane indicated 4 by the line 3--3 of Fig. 1.

56 Fig. 4 is an enlarged sectional view of the com 'trol valve and is taken on a plane indicated by the line 44 of Fig. 2.

Fig. 5 is a sectional view of the valve taken I on a plane indicated by the line 5-501 Fig. 4; Figs. 6 and 7 are sectional views of the valve taken on planes indicated by the lines 66 and 7-7 of Fig. 5.

Figs. 8, 9, 10 and 11 are sectional views of the valve taken on a plane indicated by the line 88 01' Fig. 5, showing different operating positions of the valve plug; v ig.8 showing the position of the plug when both burners are out 01f; Fig. 9 the ignition burner on and the service burner on; Fig. 10 the ignition burner on and the service 'burner at simmering position, and Fig. 11 both burners fully on. v

Fig. 12 is a fragmentary sectional view showsiigg a modified form of clutch and simmering Fig. 13 is a fragmentary sectional view of a service burner and a modified type of ignition burner.

In my copending application, Ser. No. 654,161 filed January 30, 1933, the advantages of a plurality of service burners ignited from a common pilot through the medium of firing tubes have been fully described. In the said application, it also has been pointed out that it is desirable to provide an ignition burner for insuring firing relation between the pilot and service burners, the ignition burner and service burner being controlled by the same valve and arranged so that upon turning the valve from the closed position in one direction, gas is'first introduced to the ignition burner and subsequently to the service burner, the supply to the ignition burner being maintained during the operation of the service burner and being cut off after the supply to the service burner has been cut off. Further, in my copending application I described a particular discharge nozzle forthe ignition burner to insure lighting thereof and of the service burner consequent upon a flashing through the firing tube.

Experience has proven that the device therein described operates in a very few seconds. How-, ever, it is desirable that the same operate almost instantaneously, or about as promptly as the service burner would be ignited were a lighted match held at the discharge vents.

The present invention provides a means for effecting a more prompt introduction of gas to the ignition burner so that a flame is established substantially coincident with the discharge of gas mm the service burner.

vents 3. Communicating interiorly with the head 1 is a mixing chamber 4 having at its inlet end a mixing bell 5 into which gas is discharged for supplying the burner.

The ignition burner comprises a hollow burner head 10 having a mixing chamber 11, the chamber 11 having a mixing bell 12 at the inlet end for reception of gas and air supplied to the ignition burner. The burner head 10 may be formed, as described, integral with the service burner, preferably as a continuation of one of the arms 2 thereof. The burner 10 and chamber 11, however, are discommunicated from the interior of the head 1 and chamber 4 except, however, in some cases, a by-pass duct 13, for purposes later to be described, is provided. The ignition burnr head 10 is provided with a large vent 15 adapted to receive the neck of a discharge nozzle, later to be described, and better illustrated in Fig. 3, the vent 15 preferably being spaced a distance from the end of the outermost vent 3 of the arm of the burner with which associated. Intermediate the vent 15 and the particular vent 3 described, are a plurality of vents 16, these vents being arranged to be ignited consequent upon flashing of gas from the firing'tube and ignition of the jets issuing from the discharge nozzle provided in the vent 15'.

As more fully described in my copending apnlication, this discharge nozzle, designated at 20, is provided withan upright duct 21 which communicates with the interior of the ignition head 10, and a transverse duct 22, communicating with the duct 21 and discharging directly into the firing tube 23. The firing tube in turn discharges at the opposite end near the pilot burner 24. A second transverse duct 25 which likewise communicates with the duct 21 and preferably dischargesat to the duct 22 is provided in the nozzle 20. Mounted on the nozzle 20 is a movable head 26 provided with a baffle 27 which depends from the head in spaced relation to and in front of the discharge opening of the duct 25. The head is preferably mounted as illustrated, by means of a screw 28 so that item be positioned to deflect gas discharged from the duct 25, both toward the firing tube and discharge point of the duct 22 and toward the passages 16 of the ignition burner, so as to-insure a flame from the end of the firing tube to the ignition vents 16.

For introducing gas into the bells 5 and 12 and thus to the respective ignition and service burners, a gas cock or valve, the body of which is indicated at 30, is provided. -As more fully described hereinafter, this valve is provided with ducts directly communicating with a main gas supply pipe and with nozzles 31 and 32 respectively, the nozzle 31 discharging into the bell 5 and the nozzle 32 discharging into the bell 12- off position,.as it is turned in the direction for communicating the service burner with the gas supply, gas is first introduced from such supply to the nozzle 32 and consequently to the ignition burner. Upon additional turning in the same direction, gas is supplied to the service burner through the nozzle 31, the supply to the ignition burner continuing, and, upon additional turning in the same direction, the ignition burner continues operation and the flow to the service burner is increased. Since the outlet vents of the ignition burner are relatively small, if a large amount of gas is supplied through the nozzle 32, it cannot readily pass to the vents 15 and 16 due to the air and back pressure within the mixing passage 11. By increasing the fiow of gas to the nozzle 32, this air can be rapidly expelled but too large a supply of gas through the ignition burner would thereafter exist "during continuous burning. Furthermore, there would ,be a tendency for the gas to fill the tube 11 more quickly than the air was expelled and consequently, part of it would back out of the open end of the bell 12.

Again, a small flow of, gas introduced into the comparatively largehead 1 requires some few seconds to fill the head and issue from the vents 3. Consequently, it is desirable that a large flow be introduced to the service burner when first cut on and, in fact, the operator usually opens the valve to full open position when first starting the burner.

Since the service burner is provided with a large number of outlets 3, this large volume of gas from the nozzle 31 readily passes into the service burner, and-substantially no back presthat from the nozzle 31 more promptly passes to the service burner so that gas issues from the service burner at an interval before it issues from the ignition burner. To overcome this objection, and to insure a prompt fiow of gas to the ignition burner, the by-pass passage 13, above mentioned, is provided. This passage 13 communicates the interior of the ignition head with the interior of the service burner head, and is preferably arrahged well below the vents l5 and 16 of the ignition head and in a position out of the direct path of movement of the main stream of gas. This opening is sufiiciently large so that air in the tube 11 may readily pass into the service burner, wherefrom it will be exhausted and relieve any back pressure in the chamber 11, and consequently, will permit a rapid initial flow of gas from the nozzle 32 into the head of the igniting burner. When the gas in the tube 11 reaches the igniting burner, substantially all the air has been expelled, a small amount only re.- maining in the head. Since the gas is lighter than air, any remaining air will be easily dis-. placed downwardly through the passage 13, permitting the gas to flow readily to the passages 15 and 16 without objectionable back pressure.

By virtue of this by-pass, a larger amount of gas may be supplied through the'nozzle 32 for accelerating the initial flow to the ignition burner and any excess gas will pass through the bypass 13 and into the adjacent arm 2 of the service burner and thus be discharged through the ducts 3 nearest to the ignition burner. As a result, the flame from the firing tube or the nozzle 20 and issue of gas from the ventsds will occur substantially at the same time that gas'ilr'st issuing from adjacent vents 3 of that particular burner arm, so that firing relation is assured. These jets 16 provide sufllcient gas to form a continuous path between the discharge nozzle 20 and the burner arm so that'the flame may be formed from the nozzle to the vents 3. Obviously, when a large supply of gas is provided to both the ignition and service burners, this supply can substantially equalize through the by-pass 13 so that the two act as a single large burner with a few additional vents. During the period of high flame on the service burner, a venturi effect is produced tending to draw gas from within the ignition burner into the service burner through the by-pass. I

In order to effect the proper flow of gasto the respective nozzles 31 and 32, a valve, such as illustrated in Figs. 4 to 11 inclusive may be provided. This valve comprises a body having a suitable plug receiving bore 34 in which is mounted a rotatable plug 35. The body is'provided with a plurality of ducts, one of which, designated at 36, communicates with a gas supply and with the bore 34, the others being discharge ducts 37 and 38 which communicate with the bore 34 and respectively with the discharge nozzles 31 and 32. The plug 35 is provided with a radial duct 39, positioned axially of the plug to register with the duct 36 in one rotated position of the plug, The plug is also provided with an axially extending duct communicating with the duct 39 and with ducts 41 and 42 respectively, the ducts 41 and 42 being adapted for registry with the respective ducts 37 and 38 in various rotated positions of the plug 35. The ducts 41 and 42 may be coaxial, the axis thereof being ofiset transversely of the plug from the plug axis, or, if desired, one of said passages only may be offset, the axis of the other intersecting and being normal to the plug ,axis. hand burner in which the mixing chambers lead-.-

In event the valve is used with a lefting to the respective burners are positioned oppositely from the burner illustrated, the passages would be offset in the opposite direction for efiecting the same operating relation when the valve-- is turned in the same direction. The reason for offsetting the passages 41 and 42 in the manner described is best illustrated by reference to Figs. 8 to 11 inclusive.

in the ducts 41 and 42 respectively are offset from the ducts 37 and 38, the duct 39 being ofiset'frol'n" If the valve plugis rotated in a the duct 36. counter-clockwise direction, it first assumes a position illustrated in Fig. 9, wherein the duct 39 is communicated with the duct 36 to supply gas into the axial duct 40, the duct 40 being in communication through the duct 42, with the duct 38 leading to the ignition burner nozzle 32 and the duct 41 leading from the duct 40 being discommunicated from the duct 37 leading to the service burner. Consequently, gas will first be supplied only to the ignition burner. Upon continued rotation to the position illustrated in Fig. 10, a slightly increased flow is provided through the duct 42 to the ignition burner and a sufllcient For example, referring to Fig.. 8, the plug is shown in the cutoff position, where- '3 ting thereof, the registry of a small amount of the 'duct 42 with the duct 38 will supply as much gas to the ignition burner nozzle 32 as will be discharged thereby. Consequently, a full flow is maintained from the instant that the duct 42 is slightly in register and during the entire period of operation of the service burner, regardless of the degreeofflow to the latter.

Obviously, the plug passages and plate 60, later to be described, can be reversed, if circumstances so require, so that the same order of operation is obtained by turning the valve clo'clrwise.

. In order to rotate the plug and yet to render it comparatively safe from operation by children or uninstructed persons who might inadvertently turn on the gas supply, there is provided a clutch device for, eiiecting a connection between the valve stem and the plug, which device normally .is' disconnected and which for connection requires that the stem be moved axially inwardly and thence rotated while held in this inward position.

Referring to Figs. 4 to 7, an operating stem 45 is mounted for independent rotary and axial movement in a suitable sleeve46 which may be formed in the end closure cap 47 secured to the body 30. The inner end of the stem protrudes inwardly of the valve body and into a suitable coaxial recess or bore 48 in the plug 35. The inner endof the stem is provided with a bore 49 coaxial with the bore 48. In the walls of the stem bore 49 are,longitudinally extending slots 50 which may be positioned diametrically opposite to each other, and which open at the inner end of the stem. Mounted in the slot 50 is a dental clutch member 51 which may be in the form of an H-shaped bar extending diametrically of the stem 45 and protruding laterally beyond the limits of the stem, the clutch member being positioned against the end wall of the slots 50 and secured in place by a suitable pin as illustrated in Figs. 5 and 6. The ends of the clutch member terminate each in a pair of oppositely disposed clutch teeth, such as indicated at 52 and 53, preferably extending longitudinally of the stem. A spring 54 is mounted in the stem bore, oneend of the spring abutting the end wall of the bore 48 in theplug and the opposite end abut- 'ting the dental clutch member 51 so as to urge it and the stem away from the plug. The plug 35 is provided with, suitable means adapted for engagement with the inwardly disposed clutch teeth 520! the clutch'member so as to effect rotation of the plug consequent upon rotation of the clutch. In the form illustrated, such means may comprise recesses, as indicated at 55, adapted for reglstrywith and to receive snugly the clutch teeth 52 when the same are aligned therewith and, moved axially toward the plug.

Referring to Fig. 6, the backing plate 4'7 isprovided with recesses 57 positioned for registry with the outwardly extending clutch teeth 53 and adapted to receive these teeth. The recesses 55 and 57 are positioned relative to each other and to the fuel ducts in the plug so that when the plug is in the cut-off position, the recesses 55 and 57 are in axial alignment. Consequently, due to the action of the spring 54, the clutch member is moved axially away from the plug to dispose the teeth 53 within the recesses 57, thus allowing the clutch member 51 to move away from the plug a suflicient distance so that the teeth 52 are disengaged from the recesses 55. In this position, the stem is locked and cannot be rotated except upon sufficient inward movement of the stem to disengage the teeth 53 from the recesses 5'7; this amount of-movement being likewise sufficient to engage the teeth 52 with the recesses 55 of the plug. Obviously, when the handle is moved axially inwardly to effect this disengagement and then rotated a slight amount, the outer ends of the teeth 53 may bear against the plate 4'7, thus holding the teeth 52 in engagement with the recesses in the plug and permitting "rotation of the plug and handle together without further inward movement or holding of the stem inwardly by the operator.

To stop rotation of the stem and plug in off position when moving, from the on position, so that clutch teeth 53 are aligned with and may enter the passages 5'7, stops or nibs 58.-better illustrated in Fig. 6, may be provided on the plate 4'7, these nibs being conveniently formed from the metal 61 to the body 30 of 'passed the stops 65,

stamped out to form the passages 57.

In some instances, it may be desirable to provide a positive stop and locking means positioned so that after the valve plug has been rotated to fully opened position it may be stopped upon return to maintain the flame on the service burner at a suitable height for simmering. For accomplishing this purpose, a stop plate 60 may be provided, this plate being secured by a-suitable screw the valve and being provided with a slot 62 to permit rotation of the same relative to the valve body for effecting proper adjustment relative to the clutch for the particular size of simmering flame required. This plate is provided with recesses 63 alignable with the recesses 5'7 and elongated slots 64. The metal intermediatethe recesses 63 and slots 64 provides stops 65 which lie inthe path of the teeth 53 when the teeth 53 extend through the slots 64 with their ends bearing against the plate 4'7. The duplicate recess, slot, and stop engagement with the respective clutch member.

Referring to Fig. '7, assuming the teeth 53 lie within the passages 5'7; while so received they extend through the recesses 63 in the plate 60. The stem must be moved axially inwardly to disengage the teeth 53 from the passages 57 and when in this position, engage the recesses 55 in' the plug so that upon turning the stem, the plug is turned. This inward movement should be sufficient to dispose the teeth 53 inwardly from the recesses 63 and stops 65 so that the plug may be fully opened. As soon as the clutch teeth have if the stem is then released, the teeth 53 will be urged into contact with the plate 4'7 while still in engagement with the plug teeth 53 of the .recesses 55, and thus held engaged. When so held, if the stem is rotated in the opposite direction, i. e., toward the cutoff position, the teeth 53 will engage the stops 65, the stops 65 being so positioned to effect this engagement when the plug has been rotated to cause a simmering flame on the service burner. To completely close the valve, it is necessary to again shove the stem inwardly to carry the teeth 53 inwardly'from the stops 65,

and turn the same slightly toward cut-off position, after which the stem may be released and the teeth 53 will engage and slide along the plate 4'7 until the teeth again pass into alignment with the openings 5'7 and snap into place therein to lock the valve in the closed position. For clearness in illustration, radial lines, indicated at P P P and P have been shown on Fig. '7, the lines showing the rotated position of the clutch for different operating positions of the plug, the clutch being in position P when the plug is in are placed for simultaneous the flow of gas to both the service and igniting v burners, the flow to the latter being suflicient to permit only a simmering flame, as illustrated in Fig. 10, and in position P when the'plugis in the open position for full operation of both burners, as illustrated in Fig. 11.

In some instances, it is desira le to provide a means for stopping rotation of the plug in aposition to maintain the simmering condition of the service burner, as described above, which means will not only positively stop and hold the plug at this position but, if suflicient torque were exerted on the stem to damage the plug or clutch, would disengage and permit rotation of the plug to closed position. Such an arrangement will assure the operator that the simmering position is reached more effectively thanthe usual snap action which permits easy additional turning, and at the same time, will-prevent damage to the valve by undue twisting of the stem by an uninstructed operator. Such a means is illustrated in a modification shown in Fig. 12, wherein the parts corresponding to the parts above described are indicated by prime numbers corresponding to the numbers above used. Thus the clutch teeth 53 may be provided on the edge leading in the direction of rotation for'cutting off the gas with a comparatively steep cam surface 70, which,

upon engagement with the bridge or lug 60' will arrest rotation of the clutch, but which, when an extremely heavy torque is exerted on the stem, will lift up over the lug 60 and pass to the position in which the plug would cut off completely the supply of gas to both burners.

As above explained, the ignition burner insures lighting of the service burner promptly. In order to more effectively utilize the fuel discharged therefrom, the ignition burner may be in the form illustrated inFig. 13, wherein parts corresponding to the parts illustrated in Figs. 1 to 3 are designated by corresponding primed numerals. In this embodiment, the part of the top wall of the ignition burner in which the nozzle 26'- is mounted is stepped down below the level of the remainder of its top wall and the top wall of the burner arm 2, In this lower portion of the top wall of the ignition burner and in the upper por-.

.toward the firing tube 23'. The offset between the top wall portions is such as to bring the firing tube in position to discharge over the upper surface of the burner arm 2'. Due to the vents 80, a body of fuel is maintained from within the discharge end of the firing tube over the surface of the ignition burner and burner arms 2', thus insuring a flash between the tube and burners. For a reason now unknown but apparently because of swirling of the gas entering the head of the ignition burner, the discharge of gas therefrom is at a higher pressure or rate of flow than from the service burner, even when the by-pass 13 is provided. and operating, but too great an excess of fuel to the ignition burner will be relieved through the by-pass and pass to the I r 1,989,101 7 that the invention provides an efllcient means for increasing the rapidity of the ignition oi the service burner from the pilot burner and for eil'ectively controlling the operation of the respective;g burners from a single operating valve or gas coc 7 Having thus described my invention, I claim:

1. In a gas burning device, a pilot burner, a service burner, an ignition burner in firing relation to the pilot burner and having a discharge vent in igniting relation to the service burner, individual mixing tubes leading one to the ignition burner and one to -the service burner, separate means for discharging gas into the respective mixing tubes, and means for passing excess air and gas from the ignition burner into the service burner. g

2. Ina gas burning device, a pilot burner, a service burner head, an ignition burner. head in firing relation to the pilot burner and having a discharge vent in igniting relation to the service burner head, individual mixing tubes leading one to the ignition burner head and one to the service burner head respectively, each of said tubes and its respective burner head defining a chamber separate iromthe other tube and its respective burner head, separate means for discharging gas into the respective mixing tubes, and means for discharging excess air and gas from one of saidchambers into the other.

3. In a gas burning device, a pilot burner, a service burner, an ignition burner in firing relation to the pilot burner and having a discharge vent in igniting relation to the service burner, individual mixing tubes arranged side by side and leading one to the ignition burner and one to the service burner, separate means for discharging gas into the respective mixing tubes, a continuously open by-pass duct communicating the ignition and service burners, said duct being spaced below the level of the discharge vent of the ignition burner.

4. In a gas burning device, a pilot burner, a

service burner, an ignition burner in firing relation to the pilot burner and having a discharge vent in firing relation to the service burner, individual mixing tubes leading one to the ignition burner and one to the service burner, separate gas nozzles for discharging gas into the respective mixing tubes, and means for accelerating the initial flow of gas through the ignition burner mixing tube to the discharge vent oi the ignition burner said means comprising a by-pass duct directly communieatingwith the interiors of the ignition burner and the service humor.

6. In a gas burning device, a pilot burner, a service burner, an ignition burner in firing relation to the pilot burner and having a discharge vent in firing relation to the service burner, in-

dividual mixing tubes leading to the ignition and service burners respectively, separate means for discharging gas into the respective mixing tubes, and means for accelerating the initial flow of gas through the ignition burner mixing tube to the said discharge vent of the ignition burner, said means comprising a by-pass duct directly communicating with the interior of the ignitio'm'and service burners, the end of said duct in the ignition burner lying out of the path of direct flow or gas passing into the ignition burner.

7. In a gas burning\d evice, a pair of burner heads having discharge vents, individual mixing tubes communicating with the respective burner heads, a valve casing having discharge ducts discharging respectively into said mixing tubes and an inlet duct communicating the interior of the casing with a source of gas, a rotatable plug in said casing having a feed duct communicable with said inlet duct in one rotated positionot the plug and having plug discharge ducts extending transversely of the plug and communicating with said feed duct and respectively with the discharge ducts of the casing, said plug discharge ducts being of the same diameter and in substantially the same position longitudinally of the plug, and being positioned relative to each other and to the casing discharge ducts to effect communication of one with a casing discharge duct, both beiore and during communication of 'the other and its respective casing discharge ductconsequent upon rotation of the plug, whereby gas is introduced to one of said burners priorto and during the introduction of gas to the other.

8. In a gas burning device, a burner, a valve casing having ducts discharging into said burner and communicating with a gas feed conduit respectively, a rotatable plug in said casing adapted to vary the supply of gas discharged to said burner consequent upon rotation of the plug to predetermined positions, a stem carried by said casing and mounted for independent axial and rotary movement and operably connected to said plug for rotating the same, whereby saidw plug may be rotated to efiect a simmering flame on said burner, a stop rigid with said casing, and axially movable means rotatable by said stem and engageable with said stop-in one rotated position for stopping rotation of the plug, said means being positioned relative to the plug passages for stopping rotation of the plug in said simmering position when the plug is rotated from open toward a cut-off position, said means and stop being disengageable consequent upon axial movement of the stem whereby the plug may be rotated from the simmering position to cut-off position.

9. In a gas burning device, a. burner, a valve casing having ducts discharging into said burner and communicating with'a gas feed conduit respectively, a rotatable plug in said casing adapted to vary the supply of gas discharged to said burner consequent upon rotation of they plug to predetermined positions, astem. carried by said casing and mounted for independent axial and rotary movement and operably connected to said plug for rotating the same, whereby said plug may be rotated to effect a simmering flame on said burner, a stop rigid with said casing, and axially movable means rotatable by said stem and engageable with said stop in one rotated position for stopping rotation of the plug, said means being positioned relative to the plug passages for stopping rotation of the plug in said simmering position when the plug is rotated from open toward a cut-off position, said means and stop being disengageable consequent upon axial movement of the stem whereby the plug may be rotated from the simmering position to cut-oi! position, and means tor adjusting the position of 150 an ignition burnerintegral therewith, said burn-- ers comprising a hollow body having upwardly discharging exhaust vents and a. mixing tube leading into said body, a partition within said body and mixing tube, said partition extending longitudinally of said tube'and dividing the in- 1,982,101 'terior of the body into separate compartments and dividing said mixingtube into separate ehannels, one channel communicating with one compartment of the body and one communicating with the other, a by-pass passage in said partition .wall' near the burner compartments and spaced below-the discharge vents thereof.v

GEORGE HERBSTER;

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