US1997036A - Gas burner construction - Google Patents

Description

3 Sheets-Sheet 1 M4 W N X mfi my m V T N T If A w H W. Q m! ilm m6 Ill April 9, '1935.

' H. A. ATWATER GAS BURNER CONSTRUCTION Filed June 27, 1931 April 9, 1935. H. A. ATWATER GAS BURNER CONSTRUCTION Filed June 27, 1931 5 Sheets-Sheet 2 I N VEN TOR. Harry /7. flfn afcc' A TTORNE Y.

April 9, 1935. H. A. ATWATER 1,997,036

GAS BURNER CONSTRUCTION Filed June 27, 1951 s Sheets-Sheet s G O 3 z INVENTOR:

I Harv" y 1 7. HIM/afar;

A TTORNE Y.

Patented Apr. 9, 1935 UNITED STATES PATENT 1 OFFICE it V 71,997,036 g I L GAS BURNER CONSTRUCTION Harry A. Atwate'r, Kansas City, Mo. Application June 27, 1931, Serial No. 547,219

13J0laims. (01 158-104) My invention has relation to combustion apparatus, with particular reference to gas burning equipment, and the primarybbject in view-is to;

devise an improved gaseous fuel burning construction for furnaces of; various types, andin which the combustion peration is carried out more economically and efiiciently and with a greater degree of heat transference from the burner unit to the heat absorbing surfaces of the burner.

To this end I have devised alnovel Eben:

burner construction to which the gaseous fuelis conducted without premixing of air, andwithcorresponding elimination of snap back actionor back firing from the burner, as .wellfjas ,in-'

the air by an improved arrangement of the gas jet orifices by which the. gas is discharged in the path of the air at substantially right angles to the direction of the airflow pastthe orifices, with the result that a more ideal and effective combustible mixture is produced I A. further improvement lies in the provision of a novel and greatly improved-type of combustion zone around thefiame orifices, to the end that ample space is provided for the expansion of the combustion gases and all pinching or smothering of the combustion zone is eliminated, as a result of which the process of combustion is promoted in the highest degree for thepurpose of maintaining as hot temperatureconditions in the combustion zone as possible. 1

This condition is further promoted by an improved arrangement of 'the'refractory block unit whereby more effective heat reflection angles are maintained, both asregards reflection of heat back into the combustionzone as'well as in the direction of the heat absorption surfaces of the fire chamber; and in this connection a most-important object of the invention is to insure the highest possible degreeof heattransfer'by direct my invention is chamber.

type, in which a gas burning structure is substi- 5 tuted for original equipment, and the present im proved construction is designed to enable the same to be installed under such conditions with the greatest possible convenience and facility by ordinary workmen and with practically notools 10 of any description. U 1 i With the foregoing general objects in view, as well as various minor objects which will appear in the course of the detailed specification,- the invention will now be described by referenceto-l5 the accompanying drawings illustratingatypi cal furnace installation equipped with a gas burner construction embodyingthe variousf ea tures of improvement, after which those-fea-L tures and combinationsdeemed to be novel and patentable will be duly set forth and claimed, a In the drawings V ,g

Figure 1 is a sectional perspectiveview illus trating a portion of a warm air furnace equipped with a gas burner construction embodying: the present invention; 4 Figure 2 is a vertical longitudinal sectional View, showing the burner structure on a largerscale;

Figure 3 is a horizontal sectional. view; and 9,

Figures 4 and 5 are transverse sections, repre senting sections taken on the lines 3- 3; 4-.-4

and 55, respectively, of Figure 2;

Figure 6 is a detail section taken on the line 6-6 of Figure 4; 3

Figure 7 is a. plan View of the sectional ring castings forming the base shell of the burner;

Figure 8 is a plan view of the sectional ring castings forming the burner. ring,- one ofthe sections being partly broken away; Figure 9 is a perspective view of the refractory block sections forming the top of theburner, the same being illustrated in separated relation;

Figure'lOis bottom. plan view of the same in assembled relation; and -Figure 11 is a side elevation of thejcombina tion burner supporting stand and gas supply'con' nection for uniting the gas ring sections.

In the various kinds of gas burner installa 5Q,

tions commonly metwith, whether of the warm" air, hot water or steam type, gas burner castings are provided, having orifices for thedi'schargeot the gas at approximately the bottom of the lire The prevailing practice is to premix the gas with certain proportions of air as the gas travels through the burner or. before it discharges from the burner orifices, while in some instances, in addition to thisprimary air, a certain amount of secondary air is conducted to the combustion zone separately from the primary air. in either case, the combustion process produces the wellknown Bunsen type of blue flame, burning with a relatively short flame body, and the practically universal practice is to employ what are commonly known as leaning radiants of refractory or metallic material for the purpose of deflecting the burning gases over against the inside surfaces of the fire chamber. The advo oates of such constructions also claimv that this. radiant material becomes d thereby promotes the transfer of heatfrom the" surfaces of the radiant material to that of the incandescent and walls of the fire chamber by the principle of direct radiation.

Several obstacles to attaining the, desired efficiency are apparent in such constructions, of which are inherent in the burner principle itself, for in all 'air premixing ype tseraahg on the injection action of theventuri tube, any

effective premixing action depends upon a'carefnl observance of very-definite and pre'c'is'eproporr tions, including a" definite -fixedgas pressure at the mixer nozzle, and properly propjoiftionedfflows: of air and gas to correspond t o that pressuli'e.

, For any given set of values fortheseffactorsthe' physical dimensions of the proper mixer may-be determined froin' specific formulae, and anyjinaterial variation from the predetermined {rate of air and gas now will very appreciably a'fft-ict mixers performance. As a matter of act, it is demonstrated in actual practice thatthese mixingburner designs give satisfactory perform ance only when'limited to relatively narrow ranges of pressure and now. 7 Moreover, the presence of a"combustiblfeniixture-in the burner in advance of the name orifices is "constantly atte'nded'by 'inorefor less frequent 'snap" backs or back'firin'g towardthe mixer.

Thenext most serious obstacle to obtaining the desired"degre or efficiency in hese types "of burner constructions in in the character and position or arrangement of the radiant devices used as of the equipment. fSi'n'ce in thse designs the radiants are' 'placed in angularpenum directly overlying the 'c'ombustion'zone, they arethus subjected to severe temperature 'conditlons, causing those of refractory material to spell and break ofi and other types to warp and break t of shape, with theresult that the entire radiant assembly is disarra'n'ged, often to the point of obstructing the flow of gas from the burner'orifices,so thatthe installaltion "suffers a marked reduction in efficiency "iml'ess properly serviced and'the deterioration of the radiant structure given the necessary attention and repairs; Another difficulty attending the use of. I the 'leaning 'type .of radiants is the restriction'pf the combustion zone by =,the .overlyingradiant elements. which results in u'nburne'dgas, being allowed to escape past the radiantsinto. zones of lower temperature where there is'little likelihood V of ;-complete combustion j taking place. This crowding of the combustion space reaches aggravated state whenever the rate of the gas mands from the boiler or heater.

Another effect of the useof leaning radiants'isfthe tendency to bottle up the heat of combustion and concenis stepped up to meet excessiveheatlde trate it about the gas burner rings and other castings comprising the burner structure proper;

such overheating of these parts of the burner in- I area of heat absorbing surfaces acting to keep down the combustion temperatures to a correspondingly low point, result in operating conditionswhich do not favor any very marked degree of radiant transmission in such installations. Moreover, it is apparent that the angle of these r'a'c'iiant'elementsis "such as to restrict the greatest part ofthe heat transfer to that portion of the fire chamber lying below the tops of the radiants, whlchi'n itself greatly reducesthe heat transfer into the relatively larger area of heat absorbing surfaces withinthe fire chamber above thi's' level, and to that extenttherefore the full effect of exposing the entire area "of the fire bowl surface for'such directradiant heat 'absorption is lost.

'Ii'he present invention aims toprovide a c0n'' struction inwhich the various difiiculties'be'for'e' mentioned are largely overcome, and in the accompanying drawin'gs the improved construction is, as' above indicated, illustrated as 'inst'alled in a warm air furnace of the conventional type comprising the ash p'it chamber "l2, and the fire bowl t3, from which the'usual grates are re moved, It is to be understood however that while thety'pe of furnace illustrated is of -rounddesign,

the-improved burner construction is applicable to either round, rectangular, "or' other forms of fire boxes, the gas burner orifice structure being simply: changed in shape in whatever way may benecessary 'tocOnform firebox. V I V ,Extendirig from the outsid'e'of the furnace and into't-he-a'shpit chamber is :an' air box casing M through which a controlled supply of air is conducted to the-burner, and the opening into the ash pitptherwise closed,yor walled in, in any suitable manner as indicated at .15 "(Figure 1).

Directly beneath the fire bowl Hi, the .top of the inner end of .the air'bo'x is provided with an opening surrounded by a vertical flange 11 upon which is mounted the base shell or-cast'ing' of the burner, comprising a. pairof ring sections or castings l8 '(see Figures 2 and '7) ,the lower edge of which is telescoped into the'flange H of the air box, the'sections of saidring castingscombining to form'a-bowl extending outwardly and upwardly from the air box, with which it is also engaged by external lugs projecting downward into engagement with the outer face ofsaid flange (see Figure 5). The meeting portions of the ring sections are also provided with interlocking means comprising an external lug 21 on each "section projectingpast the meeting edge of' the companion section for seating in a notch 22 in an" external lug 23 on said companion section (compare Figures 3 and 7), in which interli icked relation the parts are held by means of yoke-shaped clips 24 (Figures 1 and 3).

The upper: interior of each ring section 18 is tothe shape of the formed with a plurality of angle lugs 25 provid-- as indicated at 33, for positioning and retaining engagement with a lug 46 projecting up from the stiffening rib 21, and the outer vertical facesof the rims are providedwith horizontal or outwardly directed and equally spaced gas jet orifices,

. 34, adapted to discharge the gas (which is as yet unmixed with air) in jets directed substantially at right angles to the air whichfiows up vertically past the outer faces of said rims, or through the passages 35'between the gas rim and the base ring sections (Figure 2). A flow of gas is supplied equally ,to the gas burner sections through a fitting 31 having a pair of tapered and machined elbow nipples 38 engaging both the sleeves 32 (providing smooth and gas-tight joints) and formed as part of a supporting stand 39 mount.- ed on the floor of the air box (see Figures 2 and 5). This fitting 31 is tapped for connection with the gas flow line 40 leading out through the front end of the air box as shown in Figure 3.

Above the gas ring is mounted a block'structure comprising two front and rear sections 42, 43, of suitable refractory material, with their meeting faces joined in ship-lap fashiongas indicated at 44 (Figures 1 and, 2). The outer margins of the block sections are supported on the. rims 30 of the gas ring sections, and the central,

portion of the block structure projects downwardly sufiiciently for support uponthose parts of the ring sections which connect with thefitting 31 and stand 39; at the same time the rear block section 43 is provided with a bottom recess 45 for positioning and retaining engagement with the upper end of the lug 46 already referred to,

assembly being of approximately the same diam-: eter as the gas ring, and said curvaturereceding from the outer rimedge of the gas ring,

and flaring again to the top of the block as,

sembly, which is of thesame diameter as its base (as clearly illustrated in Figures 1 and 2).

The gas flow connections and controlling equipment for the burner comprise the following construotion assembled with relation to, the outer end of the air box. The gas supply pipe 40 (Figure 1) is equipped with a manual control valve 53, pressure regulating device 54, electric flow-V regulating valve 55, and also a variable flow orifice unit 52 of the type illustrated in my Patent No. 1,913,149 of June 6, 1933, filed June 22, 1931 for adjusting and setting'therate of gas flow to the burner. The pilot burner tube 48 is provided with a gas supply tube 51,:connected with the gas flow line 40, as .at thepressure regulator 54, and also with an electric automatic control structure comprising a thermostat device 56 having a control connection58 with safety cutoff switch 59 which controlsthe op-' eration of the flow regulating valve in a manner well-known. The pilot assembly. is supported by the framework 60 at thefrontend of the air box and by an. open hanger structure.

filiconnecting thetop and'oneiof theside walls of th'eair box (see Figure 5), which facilitates the: location of the pilot assembly into. proper position, in which the tube 51 and thermostat device 56 are located in a recess 62 and between lugs 63 formed on the interior of the bowed portion. of thefront base ring or shell section 18 (Figures 3 and 7).

The air flow through the air box I8 is also automatically controlled or regulated by the electricunit: 55, which is provided with an automatically actuated arm 65 having a connection .66 with a swinging damper plate 61 which is hinged. at .68 within 'a frame 69 at the front end of the casing I4; I

. The damper opens inward by gravity. and the extent of its opening movement; is adjusted or regulated by means ofga bolt 10 adjustably mounted in the frame 69, asshown in Figure. 4, said bolt extending between a pair of lugs H dependingffrom the plate 61, and its inner end or head 12 forming an adjustable stop for engaging said lugs and thereby limiting the maximum opening movement of the damper.

From the foregoing it isapparent that a burner structure is provided in which all premixing of the gas with primary air is eliminated, with back firing action, as well as dispensing .with

the necessity for the precise design required for any premixing tube as well as making it possible ,to operate over a wide range of rates of The design and construction of the refractory,

blockunit also possesses several features'of advantage. In the first place, the concave design of the outer exposed faces of' the block provides for a greatly increased volume for the combustionzone, and hence correspondingly less restric-.

tion or opposition tothe expansion of the combustion gases, thereby resulting inimuch more complete combustion than is possible with the leaning or other types of radiant elements -pro-.

jecting into positions overlyingthe combustion zone, or even with refractory blocks having straight vertical faces above the'bumer. I o

The improved concave design alsopror'notes higher temperature conditions within the area of greatest combustion in a manner similarfto the heat bottling effect secured by the use v of dutch ovens or refractory arches in-the combustion chambers of industrial furnaces. This higher temperature range, coupled with the increased volume or size of combustion space made available, makes for a very marked increase'in the efliciency of the complete combustion process.

It will also be apparent that the concave curvature of the refractory block assembly .also has the effect of imparting a pronouncedoutward direction of flow to the combustionga'ses asthey pass the upper edge of block, without the necese' sity of producing this deflecting action by a crowding of the gases over against the fire. bowl surface by masses of inclined radiant'material:

This advantage; of a r-controlof :the combustion: gas movement is alse secured without'sacrific'ing the benefit of ample combustion space within the combustion zone; and there is also a marked advantage in this construction in that it permits the use of i one certain :sizeof refractory iblock assembly for. different fire'bowl diameters, it is evident that even with larger :s'izes of fire chambers no difficulty :is experienced in securing the-"proper deflection of the :combustion gases 1 in'the direction of the 'interior surfaces of the fire bowl. i j

Since the principle of the use :of Cleaning i'baffles=or radiant elements requires an assemblyeoi' such'elements of diametrical proportions almost equaling the diameter :"of the fire bowl :(in order to wheat the radiant structure to anyappreciable; degree :bf incandescence), it.is apparent that oneiof {the essential conditions-necessary for any efiicient'propagation of "heat transfer by -direct racli'ationds lost, since such direct radiating action {must occur in straight line -paths ."em'anating from the source for l radiation.-

Obviously, inthe caseof the leaning or =overlying "baffle types rofidesignax'the "burning. flame bodyJitself is'en'tirely shut ofi from direct line radiant transmission .to any point .of'the fire bowl "surface beyond -the outer limits 'or topsof the radiant elements. T By the present improved design, however, there is made possiblefa vastly increased; degree of he'at transfer activity by directradiation froni' the flame body to pra'c tically the .en'tire surface of the fire chamber; due to the opening up of. the combustion zone by=the removal of all overlying portions of the radiants or refractory assembly. The operation OfFthiS principle of direct radiationis further enhanced in the improved construction by the fact that the combustion flameiis purposely made of a brilliantly luminous character, by the" elimina-- tionof all -premixing of thegas with primary air, as it is well known that the blue orBunsen type of-fiame possesses nowher'enearthe heat radiating power of flames having brilliantly luminous properties. 7 V 3 i in the interestiof convenience, and expediting the installation operation, theiimproved burner structure is so arranged'as'to facilitate its instal lationin thefusual small type of'domestic'heating opening and; assembled in place as illustrated.

The'various guides lug'sand fittings, insure the assembly being made in 1 only one correct "manner and without thehuse or'toms for the purpose, thus-simplifying the installation to the-greatest possible extent and making the same practically 'fool proof. 7. I Itswillthus be seen that a very-practical-and comparatively simple burner apparatus :or ,very superior efiiciencyhas been devised for carrying out the variousobjects of the invention as herein setsforth, and while atypical arrangement and construction have beensshow'n and described for illustrating one \proposedi 'embodiment of 'the several improvements, I desire to bexunderstood as expressly reserving the 'rightto; make "whatever changes or lmodifications .mayifairly' fall within the scope ofythe appended claims.

-Having described myinventi on, what I claim' to :be nw andzdesire to secure by Letters Pat:- 7

en'tzisr. V,

'1. A gas burner equipmentcomprisingga burn-1 er casting having :a plurality of'aoutwa'r dly directed gasv jet :orifices, 'mea n's ifor.conducting a flow of gasunmixed with primary air for dis-.-

charge outwardly through said iorifices, means for conducting a fiow i-oi air ex'te'rio'rlyito said orificesrforimixing-with the gas emitted therefrom, and means providing'an annular combustion 'zone directly above said orifices having un restricted space forfdirect heat radiation .from

the combustion flames infiall directions upward ly and outwardly from SQld ZOIlG.

2. {A gas burner'equipment comprising a burner casting' having "a plurality'jof outwardly directed gas jet' "orifices, 'r'neans for conducting a flow of gas unmixed-with primary air fordischarge outwardly "through said orifices, means for conducting a now of air exteriorly to said;

orifl'ce's for niixing' with'the gas emitted there from, and a blockst'ructure of 'refraetory-niate-* rial of'a horizontal diameter approximating that of'the' bu'rner casting a'nd "overlying-the same,

said block structure havi-ng 'concave lateral 1 faces; forming the' irine-r boundary of'the combustion zone and providing ampleexpansiorrspace for the 1 combustion gase's while p'ermitting direct heat radiation from the-combustion flan'iesfreely in "all directions up'wrardly and outwardly from I c said combustion Zone. I

3'. Gas burning equipment 'for "furnace fire chambers; cor'nprising aburner base housingrnember, =a burner orificeunit andrefractory block:structure adapted' to be assembled in su perposednelation within the fire chamber, said housing member having interior spaced shoul ders supp 'rting the outer margins crane orifice] unit in slightlyys'pa'ced relation to the interior surface of said housing rnember; and means-pro viding a; 'combination ce'ntralsupport and gas supply connection for-said orifice unit.

"4; Gas burning equipment for furnace fire chambers, comprising a sectional burner orifice unit adapted to be assembled within the'fi're chamber, and a combination supporting standa-rd and gas supply fitting comprising a 'floor pedestal portion form'ed integrally with a gas supplyelbow having spaced vertical nipples for engaging and supporting both sections of said orifice unit in matched "assembled relation.

" 5.::Ga's burning"equipmentlfor furnace The chambers; comprising'ia burner base member; a burner orifice unit, and a refractory block structure all constructed in'chalf sections 'inse'rtable through'the bottom-opening of: the fire chamber for assembly in :superpo'sed relation therein, and

a pilot structui'e adapted to'be mounted in operativerelationito said o'rificeunit, and engaging means ifor'med as a part of said base member for positioning andretaining said pilot structure in-said operative relation.

:6. Gas burning equipment for furnace the chambers, comprising a burner base member, a burner orifice unit, and, arefractory block structure a1l;constructed in half. sections insertable through thefbottom opening of-the fire chamber c for' assembly; in superposedrelation therein, one

of; said, refractory block sections having a I pilot tube recess anda pilot structure includinga pilot flame-tube projecting within saidreces's, the other refractory; block section and corresponding base member section having interengagingportionsfor* positioning and holding the said base memberand block structure in a predetermined assembled relation.

7. A gas burner construction comprising a base shell casting, and a gas burner member enclosed by said base casting and provided with laterally directed gas jet orifices, said base casting having interior shoulders supporting said burner memher in spaced relation to the inner surface of the base casting to provide a passage for the upflow of air vertically past said orifices.

j 8. A gas burner construction comprising a base shell casting, a gas burner member enclosed by said base casting and provided with laterally directed gas jet orifices, said base casting having interior shoulders supporting said burner member in spaced relation to the inner surface of the base casting to provide a passage for the upfiow of air vertically past said orifices, and a refractory block structure mounted over said burner member and extending in position to provide ample combustion space While permitting direct radiant heat transmission in all directions both upwardly and outwardly therefrom.

9. A gas burner construction comprising a base shell casting, a gas burner member enclosed by said base casting and provided with laterally directed gas jet orifices, said base casting having interior shoulders supporting said burner mem-- her in spaced relation to the inner surface of the base casting to provide a passage for the upfiow of air vertically past said orifices, and a refractory block structure mounted over said burner member and provided with concave lateral faces providing an ample combustion zone space and leaving unobstructed the vertical upward and outward paths for direct radiant heat transmission above said combustion zone.

10. Gas burning equipment comprising an air box for furnace ash pit chambers, said box having a top opening at its inner end, a burner base charging the gas in jets at right angles tothe air flowing between said burner unit and base casting, and a refractory block structure mounted over said burner unit andformed with concave lateral faces providing an ample combustion zone space above the burner unit and leaving unobstructed the vertical upward and outward paths for direct radiant heat transmission above said combustion zone.

11. Gas burning equipment comprisinganair' box for furnace ash pit chambers, said box having a top opening at its inner end, a' burner base shell casting fitting over said opening, a burner orifice unit enclosed by said basecasting in spaced relation thereto and provided with outwardly directed gas orifices, a laterally concave faced refractory block structure mounted over said burner unit and formed with a pilot tube recess opening into the combustion space above the burner unit,

bled relation, and a refractory block structure having its base seated upon those portions of the burner sections which connect with said nipples.

13. A fluid fuel burner comprising a pipe elbow with twoseparate pipes forming one arm of the elbow, a base connected to and supporting said elbow with the double pipe arm extending up-

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