US2547276A - Gas burner with gas preheating chamber and flame nozzles - Google Patents

Description

H. H. MARSH AL.

GAS BURNER WITH GAS HEA CHAMBER AND FLAME NOZZLE Filed Feb. 28, 1947 pril 3, 1951 mmf m @MW O m@ A i MMM. f

Patented Apr. 3, 1951 GAS BURNER WITH GAS PREHEATING CHAMBER AND FLAME NOZZLES Herbert H. Marsh and Glenn G. Short, Denver, Colo.v

Application February 28, 1947, Serial No. 731,576

` is simple in construction, highly efficient in operation and economical to manufacture.

l Still another object is to so construct a gas burner that the gas, prior to combustion, will be considerably expanded by heat from the gas which is in the process of combustion.

A further object is to so construct an iinproved gas burner that jet members or tubes having individual inlets for mixing air with the gasd can be eiciently employed.

A still further andmore specific object is to produce a gas burner having a chamber for re-` ceiving unmixed gas only from the fuel source and a plurality of burner jet members or tubes provided with individual air inlets and in which the chamber is so constructed and the jet members so associated therewith that heat can be transferred from the flames to the chamber without interference of direct air currents passing in between jet members from the direction of the sideof the burner remote from the jet members.v

A further object is to provide improved means for associating a pilot jet member with a gas burner.

Yet another object is to produce an improved pilot jetmember for agas burner.

Other objects of our invention will become apparent from the following description taken in connection with the accompanying drawings in which:

Figure 1 is a top view of a gas burner embodying the invention;

- Figure 2 is a cross sectional view of the gas burner shown in Figure 1; f

Figure 3 is a sectional view taken on. the line 3-3 of Figure 1 and showing details of the burner jet member;- and Figure 4 is a sectional view taken on the lin belief-Figure 1 showing the improved pilot jet member. Y Y

Referring to the drawings in detail and first to Figures-fl and 2, the gasfburner disclosed, by wayoffexaifnple as embodying our invention, is generallyindicated by theletter B and is shown as circular in shape. ,The burner comprises a 2 Claims. (Cl. 158%104) cylindrical gas receiving chamber I formed by a cylindrical side wall 2, a convex top wall 3 (as viewed from the exterior) and a bottom wall 4. The walls may be separately formed and then welded together, or the side wall may be formed as a flange on either the top or bottom wall and then the remaining wall Welded to the side wall. The walls are preferably made from sheet metal. The concave top wall is provided with a plurality of spaced apart threaded openings 5 and. into each of these openings is screwed a burner jet member 6 shown in detail in Figure 3. The 'jet 'members are of the type which are provided with individual air inlet openings for mixing with the gaseous fuel which is fed to the jet from the chamber I.

`The spacing of the jet members may be in anyl 'desired manner, but preferably there is provided a circular row of jets closely adjacent the ciricular outer edge of the top wall to insure a series -of flames close to the outer edge of the burner.

The other jet members in the top wall. may be regularly or irregularly spaced within this outer circular row of jet members and may or may not cover the entire top wall of the burner. In some instances it may be desired only to provide jet members closely adjacent the outer edge of vthe top wall of the burnerand when suchis done the jets can take the form of two circular rows with the outer row closely adjacent the edge, as indicated in Figure Land the next row just inwardly of this outer row, but with the jet members so spaced that they will be on radial lines which pass between adjacent jet members c of the outer row. The two rows of jets will then assume a staggered relation, all as indicated in Figure 1. 'l

Each jet member 6, as disclosed in the section view Figure 3, is of known construction and com'- prises a tubular element 1, f'the lower end of which is threaded so as to permit it to bescrewed into the hole 5 of the top wall of the burner. At the lower end of the passage 8 there is formed a conical passage 9, the large end of which forms the inlet for the jet and the small end of which communicates with-the passage 8 which extends to the outer upper end of the jet.y Just above the point where the small end of the/conical passage 5 enters the passage 8 a plurality of radial' nected to an opening in the bottom wall there-i of. The gas comes directly from `the Pressure supply line and enters the chamber in .an funmixed condition, that is, there is no air mixed with the gas prior to its entering the chamber.

Although the supply pipe is shown as connected to the center of the bottom wall; ofjthehami ber, it could 'enter through a side wall Aiff such p is desired. The circular burner is to be mountf ed below any structure that it may be desired to heat such las, for example, a boiler. As in- -dicated in Figure 2 :by vdotted lines, the :burner can'rest upon ledges I5 extending from the side lwalls :I5 of 4the base :of the boiler-or other structure.

-With a gas burner constructed vas Vjust described, it will be seen that there is provided a `gas receiving chamber of Vconsiderable volume and which 'is provided with a top wall having considerable continuous area. Mounted on `this top wall are upwardly extending jet members v.which arefsupplied with unmixed gas from the chamber. The jets are .so constructed that air :is lindividually mixed Yat-feachjet.` -fSince there 'is fa :single chamberonly .which :is supplied with 9 unmixed gas from the gas line and the 'tcp wall tof this single chamber continuous between :all lof the jet members, .it will -be :impossible for Y any upward currents .of air .to pass from a point below .the bottomwall of .the chamber .directly upward .and in between the jet members. .Consequently, with the elimination of .such currents o'f it will be possible for considerable heat :from the burning jet membersto 'be transferred by radiation .to the top wall of the chamber. Such transfer of heat will result in an expansion pf fthe unmixed gas entering the chamber I. This gas, in its expanded :condition when mixed with air upon entering 'the passages of the jet members and becoming ignited at. the upper end of the jet members, will cause the burner to have a higher eiciency. It is also to be noted in this connection that thev air. when mixed with the gas, will be preheated -as it must pass over ithe ltop wall of the `burner before entering the air inlets of each bur-ner member 6. Due to the fact that-the gas is expanded in the chamber I from radiated heat froifn the-burning jet members, less gas-will be lcon'sumed yet the B. t. u. heat produced vby each iiame will be greater than would be possible where no expansion chamber was `pres'e'nt'o'r there was such a small chamber that little expansion ltakes vplace prior to the Vair mixing and burning. Actual installations Lof burners embodying the con' vstruction disclosed have-proven that as high as fior-ty ypercent greater heating 'efiiciency per unit of gas consumed is possible than by presently known types of` burner construction. The TB.' rt; ru.s `of heat lobtained 'with applicants iburner` per cubic 'foot Lof 'gasl consumed 'is con'- siderably higher thanburners 'which 'are 'known ias-'the Vmanifold type, that .'is, vwher'ea 'chamber iS ilmvidedwith .burner holes'iinjitsuppen walls and gas. :mixedv witnrairibyra .manifoldfbetween the source and the chamber having the jet holes. In such known prior burners the chamber is relatively small and is generally so irregular in shape that air can pass directly upwardly from below the burner to the top thereof and create an upward draft between jets. By mixing the air with the gas by use of a manifold positioned Vahead nf 'the chamber which is provided with the jet openings, there will be little expansion of the gas and it is further prevented from any lappreciable expansion by the cooling effect of the upward draft between the jet openings.

iFh'e chamber being small, consequently the gas will move directly to the jet openings and be ignited bef-ore Aany appreciable expansion takes place. Also, with the manifold type burners,

:cool -air 'is mixed with the gas, thusalso tendbers having individual iair mixing `openings ob;-

tains improved results `is further evidenced by the Eact that it is :considerably more .efficient than a burner which is constructed to .have cross piping or radial piping Aas the .gas receiving chamber with `jet members .extending upwardly from this piping. In such a burner the .chambers formed bythe pipes .are small ,and vthe small top wall areas receive little heat from the ignited gas. Consequently there will be no .appreciable amount of expansion of gas before it is consumed. Expansion will further .be held vto a minimum by the fact that cold .currents of air are constantly moving upwardly between the pipe chambers and `jet members and thus interfere with radiation .of heat, together with the fact that relatively cool air will be mixed withthe gas. i f

With a convex top wall provided for our im proved 'bur-ner, expansion of the gas in the chamber will be efliciently compensated Vfor without any undue stresses being present. Furthermore, with the convex wall, dirt and foreign matter will have a tendency to roll o'if the top wall, thus aiding in keeping the burner clean. It is, of course, obvious that 'the burner may .take shapes 'besides the cir cular one shownby way of example. However, to be efficient the chamber of the burner `must be considerable volume and its top lwall must be vof considerable area and continues between, any and all iet members tothus eliminate updrafts of air currents. Y

In order to provide an eicient Ipilot Aiet member for igniting our improvedjgas burner, there is extended through the gas receiving chamber l a tube Il. The upper end of this tube is'welded or otherwise sealed in an lopening in the upper ^wal l 3 and its lower end is welded inte an aligned open'- 'ing in the 'bottom wall 4. `With this arrangement of the tube -a passage is provided through the chamber from the bottom of the burner'to the topi and within thev'outline 'of-the' burner. 1-he lower end 'of the 'tubefis connected by a conduit 5I8 tothe gas supply so as tofurnishgas to the Pilot :'je't' member 'I9 which iis-threaded into fthe upnr'endof the tube and or Vsuch height that its llame end yis above' the top ofthesurrounding jet members 6. The pilot jet I9 is of special construction so as to eiliciently ignit the jet members 6 when gas is allowed, by suitable valving, to :dow to said jet'members'through the chamberY I. The positionbf the tube Il, which provides the pas'- sage through the chamber I, is preferably located closely adjacent and just inwardly of the second circular row' of thejet members. The pilot jet member isfof special construction so as to insure that the jet members 6 will be fully and enicient- 1y ignited. As clearly shown in Figure 4, the pilot jet I9 is oftubular construction providing a passage 20 which is arranged to be connected at vits lower e'nd .tothe tube Il through a small orice 2I formed in a plug 22. Just above the plug the tubular jet member is provided with two small airv inlet openings 23, thus causing the gas com-i ing from the-source of supply to be mixed with air. The openings 23, if desired, can be replaced by a single opening of larger area. The upper end of the passage 20 of the pilot jet is closed off by an end wall 24 which is provided with an extension 25 so as to provide a baille in the form of an annular flange at the top of the pilot jet member. Just below this baille at the upper end of the pilot jet member. there is provided small outlets 26 which extend in a radial direction.

With this construction of the pilot jet member I9, it will be seen that unmixed gas will be conducted intov the jet members where it will be mixed withrrair and then forced out of the small bring gasto the pilotjet members.` The pilot jet varrangement insures for. efcient lighting of the burner which could not be accomplished by the usual practice of placing pilot jets at theside. of the burner.

Being aware of the possibility of modillcationsr 1. A burner for the burning of gas fuel frcm a supply conduit withoutvr any introductionof air into the gas coming from the fuel line and-prior to entry into the burner, said burner comprising radial outlet openings 26 just below the baille 25 at the upper end. When this gas is ignited, small flames will shoot out in various horizontal direc-` tions and since the length of the pilot jet member is such that the flame openings 26 are somewhat above the Qlevel of the upper ends of the burner jet members 6, the gas coming from these j etmembers will be ignited. The annular baille 2,5

will protect the radial pilot ames from any vertical draftsof air and thus prevent the flames from being blown out. The pilot jet member I9 is what can be termed a manual pilot jet and is allowed to burn at all times.

This manual pilot ,iet I9 should, for safety, be associatedwith an automatic pilot ,iet member and such a jet is shownV at 21 in Figure 1, pref.- erably being placed diametrically opposite the pilot jet I9 and just insidethe second row of circular ,iet members 6. This automatic pilot ,ietr

member may be of any known construction and is arranged to control the gas being conductedwto both it and the manual pilot ,iet I9. 'I'he auto,-

matic pilot jet member can be mounted at the upper end of a tube which `extends through the chamber I in a manner similar to the tube I1, ora larger tube can be provided through the chamber I and a conducting tube with the automatic pilot jet member connected thereto and arranged to extend through this larger tube. The automatic pilot will be arranged to cut oil the supply of gas to both it and the manual pilot I9 in the event the llame of the automatic pilot goes out, as is Well known practice in connection with the operation of combined manual and automatic pilot iet members. With the two pilot jet members associated with the burner jet members 6 in the manner shown, it will be seen that the burners can be quickly and efliciently lighted. The pilots are arranged to be positioned inwardly of the outer two rows of iet members 6 and by providing tubes, such as I1, through the burner chamber, there will be no necessity of extending y,conduits across the top of the burner in' order to a chamber for rreceiving gaseous fuel and having a depth which is substantially-less than one-half of any crosswise dimension ofl its top walland said chamber also having its outer peripheral wall so constructed tllatnol portion of such wall can be intercepted by a direct line drawn across the chamber between'any two spaced points Yon the outer peripheral wall, means providing a gas inlet to the chamber for connection with the supply conduit for furnishing gas unmixed with air to said chamber from the source of supply with the area of said inlet being a small fraction of the area of the top wall, and tubular spaced jet members mounted ,on said top wall for receiving gas directly from the chamber and being distributed in closely spaced relationthroughout the entire area of the top wall and without obstructions therebetween, said jet members each having an air intake adjacent the top wall and a flame end thereabove but spaced closely to the top wall in order to effect transfer of heat from said llame end to the top wall, said top wall having continuity in order to assure that the jet members when ignited are capable of transmitting heat to the entire top wall and therethrough to the gas in the cham-ber all without interference from any air currents moving directly upward in a vertical direction outside the peripheral wall from below the bottom of the chamber to the top thereof, the number of jet members being such in relation to the volume of the chamber and also the size of the supply conduit being such in relation to the size of the chamber that unmixed gaseous fuel passing through the cham-ber from the conduit to the burner will remain in the chamber a suiiicient period of time as to have appreciable expansion due to heat radiated from the burners.

2. Aj burner for the burning of gas fuel from a supply conduit without. any introduction of air into the gas coming from the fuel line and prior to entry into the burner, said burner comprising a chamber made from sections of sheet metal welded together for receiving gaseous fuel and having a circular top wall curved to present a convex exterior surface and an annular straight side wall and said chamber havinga depth which is substantially less than one-half of any crosswise dimension of its top wall and said cham'- ber being free of any obstructions between any two points on its side wall, means providing a gas inlet'to the chamber for connection with the supply conduit for furnishing gas unmixed with air to said chamber from the source of supply with the areeJ of said inlet being a small fraction of the area of the top wall, and tubular spaced jet members mounted on said top wall for receiving gas directly from the chamber and being distributed in closely spaced relation throughout the er1-

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