US1249382A - Device for and method of mixing gas and air for combustion. - Google Patents

Description

S. HpHALE.

DEVICE FOR AND METHOD 0F MIXING GAS AND AIR FOR COMBUSTION. APPucATloN nm) APR. 5. 191.1`

hm@ mw, 14#- Pmemedvm. 11,1917.

i "Mmmm stadtus yra MNT @Flffm STEPHEN HUGH HALE, OF KANSAS CITY, MISSOURI.

i DEVICE FOB, METHOD 0F MIXING GAS AND AIR FOR COMBUSTION.`

naiasea.

gas and air mixing and delivering devices.

One of the objects of the invention is to provide devices which are so constructed and have their parts so related that the` flame produced in the combustion region will have its most efficient part constantly maintained Vin a given predetermined position notwithstanding such variations `as may be madein the quantity of gas which is introduced to the mixer and then to the burner.

Heretofore, in mixing, controlling and burner mechanisms there has not, to my knowledge, been provision made for modifying the character of the flame and simultaneously maintaining at predetermined points the efcient parts thereof. Numerous devices have been used, and others proposed, for varying the quantity of air in relation to the quantity of gas that is being consumed at successive times. But I have found that this is by nomeans sufficient in order to make available to the utmost the heatwhich is generated by the combustion. lt is well known, as concerns gas flames, and can be readily observed, that each comprises two distinctly defined sub-flames, each approximating, in general shape,la conical conformation, one being termed the inner cone and the other the outer cone; matters which will be referred to more yfully below. i

lt is further well establishedthat, in respect to a vertically disposed flame, there is one horizontal plane where it develops the extreme of available heat, and that a Superjacent object positioned to have a surface lying in that plane will receive and absorb to the greatest-degree the `heat units generated. In flames that are quite common (those having an inner coneof two and a half inches) this plane is about one-quarter of an inch (with variations) above the apex of the inner cone. The position of this plane at any instant depends upon the char- Speccation of Letters Patent.

Patented Deo. Ml, 191%. j

Application inea April 5, 1915. serial No. 19,306.

acter ofthe combustible gas and uponthe i proportion 0f the air (the efficient part of which is the oxygen component) that is commingled with the gas and is delivered to the interior of the dame. As the` quantity of oxygen-carrying air which reaches the interior of the flame (generally termed the primary air) relatively increases or decreases, the inner cone .(and with it the outer) lengthens or shortens, and the posi-` tion of the plane above referred to (which will be herein termed the heat zone) is correspondingly carried upward or downward.

One of the objects of the present `invention is as above noted to introduce into the assemblage of parts which effect the admitting and the mixing of the gas and air, factors which will insure` that at all times the heat zone shall constantly remain in one relative position within approximately fixed limits. a

Another object of the invention is to provide parts by which, when a maximum volume of 4mixture is being delivered and consumed at the burner, its constituents shall be in predetermined proportion, and. ,by which, as the gas is reduced in volume, the air will also be continually reduced but `at a rate which is greaterthan` the rateof decrease in gas.

In the drawings: i

Figure 1 isa plan view of a portion of a gas stove having parts embodying my irnprovements.

FFig. 2 is a section on the `line 1--1 of 4ig.1.

Fig. 3 is a vertical section, on a larger scale, of the arts which control the gas and air that are introduced to the mixing chamber. i

Fig. llis a side view of the parts in Fig. 1.

Fig. 5 is a top view..

Figs. 6, 7 and 8 are diagrams.

Fig. 9 isa partial side view of a mixer and burner, showing also the flames resulting from different adjustments of the regulating devices. i

` 1 indicates a mixing chamber, 2 a gas supply duct connected to the manifold 2a; 3 a

` gas valve bearing or socket, l the gas valve therein, 5 a nipple or short duct extending laterally from the valve socket 3; 6 i a delivery nozzle extending from the nippleI 5 toward the mixing chamber 1,7 a tube surring a v.wide end edge-12, converging side edges 13 and anapex 14.M 15 Vindicates theA Aburner which isY shown -as being a tube section atright angles'to the' tube of theY mixing chamber 1, and having opening 17 through which pass, the gases to be inflamed.

`-18 indicates the ame 'as an entirety, the

Tlinefl9 passing Vtherethrough indicating the planel ofhigliest available heat-or the Yhigh f .This llame is shown as composed of the inner 'cone 2O and the outer cone 21.y The innercone isV producedV by the partial combustionr or oxidizing of the carbon of the -inixture and, generally, also of a minor porfrom the combustion. n

Forv certain; common; grades ofy fuel .gas

tifon of the hydrogen, the principal resultl ofthe chemicalreaction at the surfacel of i this cone'being' the production of carbon monoxid (which becomes visible at that surface) together with a small amount of water vapor.' The oxygen that effects these 4reactions in this region is that which is carriedinwi-th the primary air entering `theinixing chamber through ports 11 Vand passing with the hydrocarbon gas to the burner mouth. The carbon monoxid water vapor and remaining.hydrogenpass from the inner cone 20 outward and, being highly heated, they unitev withoxygen derived from the surround-ing massoff atmospheric ailij, the quantum of 'oxygen so. derived beingsuilicientzto. carry'the carbon inonoxid into the carbondioxid Vform and also effect thevcomplete 'oxidizing of; the hydrogen,

that lis, assuming that the combustion has been'carried suitably far at the iiinercoiie.

The oxygen required for complete combustion of hydrocarbongases (of the characters commonly used for fuel) is that which isfoundin a volume of atmospheric air that is approximately ten times the volume of the gasvtobe burned. A. relativelysmally part of this oxygen is taken in with the primary air, and the larger quantity isfsuppliedl from the atmosphere surrounding the llame, termed tlie'secondary air. lhese rela-tive volumes of primary air (with its oxygen); and. ofthe secondary air, Ijhave found must be varied to correspond! with dilferent fuel gasesfin orderto utilize, with the-.utmost economy, theiheat units resulting (such as numerous natural gases composed `lafngelfy, of methane) I have found that of the total ten volumes. of atmospheric air rclquired; for complete combustion in relation to a unit volume' of gas) vapproximately three. and a half volumes-'should be taken in as; primary air'and mixed withl thegas' before.. itreachesthe flame: region", that iS,

v In such case, the secondary oxygen is derived from about seven. and a half volumes of' the flame-.surrounding atmosphere. But there are manifest limits in this mattei' of Y varying the relative proportions ofthe pri mary and the secondary air masses.

rIhe best results, as concerns complete combustion of the various possible flows ol gas, can be attained, as I have discovered, only by nicely proportioning that part of the total `quantity of necessary oxygen which passes through the mixing tube and thence to the interior ofthe llame region, on the one hand, and that part of the total quantity' which is to be derived from the atmosphere surrounding the llame. If the Vvolume of primary air, in relation to. the

vol-unie of gas which is passing at any time becomes toov great there is danger of back tiring into the mixing chamber. If, on the other hand, the air at any adjustment ot gas is. too low, more or less of the carbon ofthe gas passes beyond the inner cone surface without oxidizing to the inonoxid form, and this cone becomes yellow, and this is followed by delivery of too much carbon to one part or another of the outer flame cone.

Turning tothe drawings, I have indicated, conventionally, in Fig. 9, by lines at 2Qv and 2li, as aforesaid, what I am referring to as the iame cones which are produced at the time of the completel combustion of a maximum mixture passing through a mixer and burnerl of substantially the dimensions indicated, the gas having a pres sure of from one tol three ounces. 1 ,In using any gas burner of the ordinary sorts under theV conditions indicated, a llame of this character can be produced. Moreover,

`all earlier burners. have been adapted to cut down the flow of gas by valve devices oi` their equivalent. And in some cases it has been proposed to simultaneously vary the flow of gas and the inflow of air. But in all cases, so far as known to me, where there was a simultaneous modifying of both the gas flow and ofthe air flow, the parts havey been so constructed and related that the air flow either was decreased without any predetermined relation at all of theliow of air to the flow of gas, or else was decreased at a rate substantially equal; to the rate of decrease of @Maese the gas', the ratio between'the volumes inthe llatter cases being constant. 'And my obseras to produce disadvantageous flame characteristics. t That is to say, in all` cases that I have observed, the cutting down of the gas has been followed' immediately by aI shortening vof the inner `flame cone 20 as well asthe Vouter cone 21. No provision has been heretofore made for simultaneously modifying the air supply in relation to the decreasing gas supply in such way that thelength, vertically, of the innerflame cone `(and, with it, the Zone 19 of" highest heat) will remain practically fixed, irrespective of theA quantity of gas flowing tothe flame region.

Thelengths ofthe flame cones and the position'of theheat zoneA 19 are established (with a gas of given constitution and pressure) by the above described relative proportions of primary air "and secondary air, or, in other terms, in `proportion to the quantities of oxidizing work that are beingedected at the flamecone'surfaces respectively. Thus,if the supply of primaryair and its oxidizing efliciency be reduced, while the gas supply is constant, the inner part 2O of the flame instantly responds by lengthening upwardthat it may avail itself of more secondary oxygen',l Vice versa,if the quantity of primary air, with its oxygen, should` be, at any time, 'increased while the gas remains the same at the burning points, the flame cone 2U quickly answers by shortening, vertically, as

it then requires less oxygen fromthe second ary, orouter,aii".j 4 Thusit will be seenthat, to maintain thehighest heatzone 19 in a fixed Aplane vertically, the abovementioned nicety or' proportioning of the primaryand the secondary air supplies must, at all times, be attained. And it willbe also seen thatas the flow ofy gas is reduced in volume at the burning points (which, asaboveexplained, is followed byjl'olwering the flame'cone 20 and the Y heat'l zone 19) the air commingled therewith must not onlybe also reduced inrelative volume, but mustvbe reduced ata relatively greater rate; which variation in rates, however, should always keep the ratio of the two gasV volumes between" those limits, above noted, where perfect combustion' is attainable. C

,Foriexaniple,4 if thequantity of air mingledfwith the gas, at the time of complete combustion of thev maximum gas supply, is in the ratio of approximately three anda half of air toone volume of gas, as above described, it will still `be possible to have practically` complete combustion with a some what smaller relative volume ofv air passing through the mixer,'because` the balance of the requisiteoxygen, as above described will be then derived from the secondary or surrounding atmosphere.

And the same is true of a mixture wherein l the quantity ofgas is decreased from the maximum.` For example, if the gas should be cut down, say, two-thirds of the possible maximum, the volume of the air can be simultaneously cut down to two-thirds of the maximum of air which flows at the time of com lete combustion of the maximum' but as above noted, the flame cones will be shortf ened and theheat zone 19 will be lowered,

although complete combustion is occurring.`

But I aim to have the heat zone fixed. Consequently, when I cut down the gas to twothirds of its possible maximum I prevent the flame from shortening and the heat zone from lowering by supplying less than twol thirds of the maximum possible primary air, this smaller quantity of air causing the length of the inner part 20 of the flame and the heat zone to remain xed. i

And, for further illustration, if the gas volume is further reduced to, say, onefourth of its possible maximum it is necessary (in order to keep the flame cone and the heat zone in their predetermined positions) to lower the volume of mixture air to a quantityconsiderably below one-fourth of the possible maximum primaryair in order t0 induce the flame cone 20 to elongate itself relatively to the quantities of gas in its effort to secure sufficient oxygen.

' In coming down thus from the possible maximum quai'itities of gas and air to, say, twothirds, and then to, say, one-fourth Vof such maximum quantities, I have found that `the rate at whichthe air decreases in relation to therate of gas decreasefis nota constant, but an increasing, one. if n 0f course, Jche upper and the lower limit defining complete combustion must be had in mind. As already observed at no point.

should the air be decreased in relation to the gas to an extent beyond the lower limit for a combustion at the surface of the inner cone as complete as is desired at that place 5` for ifthat limit be passed in decreasing the rate of primary air at any pointthe flame, instead Aof maintaining its predetermined length with complete combustion, will Velongate upward in its eifort to find secondary 'oxygen and will at once display unconsumed ,a

yellow carbon. ,l l

above remarked, I have found that at any point in descending from the maximum quantities of gas flow, I can attain practically complete combustion `until the proportion' of the air has been lowered to.approxi Iio@ plished by devices constructed and relatively arrangedfas shown in the drawings.

The gas valve 4 is rotated'in its'seaty 3 vby means of a handle 22. The air valve is a sleeve23 fitted'to the exterior of the tube 7 and adapted to cover and to open the air orifices 11. 24 is a link which connects the air'valve toa crank arm 25 secured tothe l treme open vposition as in fullv lines, Fig. 9,

the air Will enter at a predetermined maximum rate, vvhich rate (having in mind the assumptions in the above illustrations) `Will be such that at the iiame region there Will be ysupplied three and a half volumes of primary air to one volume of gas, and the flame cones then produced can be regarded as illus` tratedrby the lines at 20 and 21, Fig. 9..

If now it be desired to cut down the flow vof gas to, say, tvvo thirds of its maximum,

the lgas valve handle 22 is turned to .bring the gasvalve to the position, approximately, shovvn in Fig. 6. The link. 24 vcauses the air valve sleeve 23r to move to the position in Fig. 6. And the air orifices 11 are so formed (as concerns their length, their Width at 12, `and the angle of divergence of theirl side edges 13) that, (in conjunction with the predetermined relations of the crank arm 25,

the link 24 and thevvalves 4 and 23) When the valve 23 is in the position shown in Fig. 6, it cuts down the flow of air to a quantity considerably less than tivo-thirds of the maximum of air. Thesey air orifices are carefully :designed'in relation to the injector action of the gas jet.' The lateral dimensions of the air orifices vary from line to line trans? versely, each` orifice narrowing in a backvvard direction relatively to the .path oi vthe gas. As more and more gas is ad- Vmitted its in-dravving povver is increased,

and therefore the cross area of the air orifices is relatively decreased; in other Words', `more air is drawn through .a relatively small increase in air entrance area as the air valve opens because of the gradually increasing efficiencyV of the gasa-sv a factor lin drawing inl the air.. Inasmuch as gas pressures vary When that from one locality or from one source of supply is comparedivith another, it is impossible to'lay doi'vnv any positive data for the dimensions of the air orifices 11;` these are determined from the several governing data, including the constitution of `the ygas and the pressure at vvhichit is supplied. The devices forfstoring and conducting gas and supplying it` to,

and controlling it at, the burners are generally standard and duplicates of each other. Consequently gas is delivered and burned at an elevated point, say at Denver, Colorado, 'for example,v with the same devices as those With which it is delivered and burned at sea level, for example, at New York. But the error here involved is apparent upon mention, as no difference in ther pressures is taken into consideration. Because of these differences in the devices, there will be a difference in the quantity of gas consumed at. one place when passed through, and controlledfby a certain set of devices, when compared. with the quantity consumed at another place, where it passes through duplicate devices, so far as con- 1cerns the production of a given amount of ieat.

One of the objects of my invention is` to provide devices which Willy supply, and control, gas at the time ofV consumption in such way that, regardless of the level of the place Where consumed, the full amount of possible heat will be generated by so Varying the air inlets and the air controlling devices that` the necessary quantities of the two bodies Will be provided for perfect combustion.

Consequently the flame cone 20, instead of shortening, Will remain with approximately the length shown inFig. 9 and the heat zone 19 will remain in the same position. If the air valve 23, and its moving parts, and the air orifices 11 had been, so related that the front vedge of the valve 23 would have stopped at, say, the line y-y Fig. 6 (the line atfWhich tivovtlirds of' the maximum of air would enter the ports 11) the flame cone 20 would have shortened" and the heat zone 19 would have dropped. But, with the parts constructed as described the decrease in air is relatively` greater than the decrease in gas, and therefore the Colle 20 must extend upward to derive secondary oxygen,

The lines 20a can be regarded as indicating the defining lines of the inner fiame vcone when the, gas andv air are reduced with the peculiar relationship in volumes` attained bythe devices shown in Fig. (i. The inner flame cone at 20 is thinner' than that indicated by 20, but is of the same length vertically. At such time the outer part 21 of the flame is considerably reduced 1n size and its boundary lines may be regarded as indicated' at 21a.

In Fig. 7 I have shown diagrammatically ,the relative positions of the controlling devices for theA gas and the air when the gas is cut down to say one-quarter of Aits possible maximum. The air valve 23k is then ad vanced over the orifices 1]; in the manner illustrated in this Fig. 7 .c If itwere to. stop at'the line e-e Fig., 7, one-half of the possible maximum` of air would enter; but in the gas, the ratio betweenthe volumes in the latter cases being constant. jAndl my observations ofearlier Vdevices of all sorts 1n this class haveshown me that when they werein `operation 'and the gas supply `was decreased v outer cone '91. No provision has been heretofore made for simultaneously modifying the air supply'in relation to the decreasing gas supply in'such way that the length, vertically, ofthe innerjliame cone (and, with it, the zone 19 of highest heat) will remain practically fixed, irrespective of the quantity ofgasliowing to the flame region.

The lengths ofthe flame'cones and theposition ofthe heat zone 19 are established (with a gas of given 'constitution and pressure) by the above described relative proportions of primary air and secondary air, or, in otherterms, vin proportion to the quantities of oxidizing work that are beingeffected at the flame cone'surfaces respectively. Thus, if ,the supply ofprimary air and its oxidizing efficiency be reduced, while the gas supply is'constant, the inner part 2O of the flame instantly responds by lengthening upward that it may avail itself of more secondary oxygen. Vice versa, if the vquantity of primary air, with its oxygen', should be, at any time, increased while the gas remains the same at `the burning points, the fiame cone 20 quickly answers by shortening, vertically, as it then'requires less oxygen from the secondary, or outer, air. I Thus it will be seen that, to

maintain `thehighest heat zone 19 in a xed plane vertically, the above mentioned nicety of proportioning of the primary and the secondary air supplies must, at all times, be attained.` And it willbe also seen that as the flow of gasfis reduced inv volume at the burning points (which,` as above explained, is followed by lowering theflame cone 20 `and the heat zone 19)1 the air vcommingled therewith must not only "be also reduced in relative volume, but must be reduced at a relatively `greater rate; which variation inrates, however, should always keep the ratio of the two gas A volumes between those y limits, above noted, where perfect `combustionis attainable. f

` For examplenif the quantity of air mingled with Athe gas, `atthe time of complete combustion ofthe maximumlgas supply,"is

in the 'ratio of approximately three and a half of air tofone volume of gas, asabove described, it will still' .be possible to have practically complete combustion with a somewhat smallerjrelative volume ofair passing 'M65 through the"inixer,"because` the balance of the requisite oxygen, asabove described will bethen derived from the` secondary or `surrounding atmosphere. y

And the Same is true of a'mixture wherein the Aquantity of gas is decreased from the maximum. `For example, if the gas should be cut down,`say, two-thirds of the possible maximum, the volume of the air can be simultaneously cut down to two-thirds of the maximum of air which fiows at the time of? complete combustion of the maximum but, as above noted, the flame cones will beshortened and the heat zone 19 will be lowered, although complete combustion is occurring. But I aim to have the heat zone fixed. Consequently, when I cut down the gas to twothirds of its possible maximum I prevent the llame from shortening and the heat zone from lowering by supplying less than twothirds ofthe maximum possible primary air, this smaller quantity of air causing the length of the inner part 2O of the flame and the heat Zone to remain lixed.

l And, for further illustration, if'the gas volume is further reduced to,say, one-fourth of its possible maximum it is necessary (in order to keep the flame cone and the heat Zone in their predetermined positions) to lower the. volume of mixture air to a quann tity considerably below one-fourthv of the possiblev maximum primary air in orderto induce the flame cone 20 to elongate itself relatively to the quantities of Agas in its effort to secure suilicient oxygen.

In coming down thus from the "possible maximum quantities of gas and air to, say, two-thirds, and then to, say, one-fourth of such maximum quantities, I have found that the rate at which the air decreases in relation to the rate of gas decrease is not a constant, but an increasing, one.

Of course, the upper and the lower limit defining complete combustion must behad vin mind.` As already observed at no point should the air be decreased in relation to the gas to an extent beyond the lower limit for a combustion at the surface of the inner cone as complete as is desired at that` place; for if that limit be passed in decreasing the rate of primary air at anyp'oint the flame, instead of maintaining its predetermined length with complete combustion, will elongate 4upward in its eort to find secondary oxygen and will at once display unconsumed y yellow carbon.

As above remarked, I have found that at any point in descending from the `maximum quantities of gas flow, I can attain practically complete combustion until the proportionof theair has been lowered to approximately two and a half volumes to a unit volume (at that point of supply) of gas; i

This regulating of the primary air and varying itsrate of decreasein relation to vthe decrease in the flow ofgas areaccom- "ibo ica

ilo

its

plished by devicesv constructed and relatively arranged as shovvnin the drawings.

The gas valve 4 1s rotated. 1n its seat 3 by means of a handle 22. The air valve 1s a.

lsleeve 23 fitted to the exterior `of the tube 7 and .adapted to cover and to `open the air orifices 11. 2,4 is. alink which connects the air valve to a Vcrank arm secured to the handle 22 or to the stem of the valve 4.

- The gas valve 4 when fully open as shown in Fig..3 permits the maximum flow of gas.

The vlatter'enters the nozzle 6 and escapes be such that at the fiame region there lWill be supplied three and a half volumes of primary air to one volume of gas, and the flame cones then produced can be regarded as illus- `trated by the lines at 20 and 21, Fig. 9.

y If now it be desired to cut down the flow of gas to, say, two thirds of its maximum,

the gas valve handle`22 is turned to bring the gas valve to the position, approximately, shown in Fig. 6.` The link 24 causes the air valve sleeve 23 tofmove to the position in Fig. 6.] And the air orifices 11 are so formed (as concerns their length, their Width at 12, and. the anglel of divergence of their side edges 13) that, (in conjunction with the predetermined relations of the crank arm 25, the link 24 and the valves 4and 23) vvhen the valve 23 is in the position shown in Fig. 6 it cuts dovvnthe fiow of air to a quantity considerably less than two-thirds of the maximum of air. `Theseair orifices are carefully designed in relationl to thel injector actionof vthe gas ljet. The lateral dimensions of the air orifices vary from line `to line transversely, each orifice narrowing in. a backward direction relatively tothe path 0i theV gas. As ymore. andmore gas is admitted its Vviii-drawing power is increased, and therefore thecross area of the air ori,- fices is. relatively decreased; in other Words, more air is` drawnthrough a relatively small increase in air entrance area as the air valve, opensbecau'se of the gradually injcreasing efficiency of vthe gas va factor in dravving in the air.V linasmuch as gas pressures. vary when that from one1local1ty or A from one source of supplyis compared'rwith another, it is impossible tof'lay down any positive. data for the dimensions of they air orifices 11;A these are'd'etermined from the several governing data, including the con` stitution .of the' gas and. the pressure at f'vvhich. it is supplied. The devices for' storing vand conducting gas and supplying it to,

andxcontrolling it at, the burners are generally standard and duplicates of each other. Consequently gas is delivered and burned at an elevated point, say at Denver, Colorado, for example, with the same devices as those With which it is delivered and burned at sea level, for example, at New York. But the error here involved is apparent upon mention, as no difference in the pressures is taken into consideration.

Because ofy these differences in the devices,

there will be a difference in the quantity of gas consumed at one place When passed through, and controlled: by a certain set of devices, when compared. with the quantity consumed` at another place, Where it passes through duplicate devices, so far as concerns the production of a given amount of' heat.

One of the objects of my invention is to provide devices Which will supply, and control, gas at the time of consumption in such Way that, regardless of the level of the place Where consumed, the full amount of possible heat will be 4generated by sovarying the air inlets and the air controlling devices that the necessary quantities ofv the two bodies Will be provided for perfect combustion.

Consequently the flame cone 20, instead of shortening, Will remain` with approximately the lengthshown in Fig. 9 and the heat zone 19 will remain in the same position. If the air valve 23, and its movin-g` parts, and the air orifices 11 had been. so. related that the front edge of theY valve 23 would have stopped at, say, the line yf-y. Fig.L 6 (the line at which .tivo-thirds of the maximum. of air would' enter the ports 11) the flame cone 2.0 would' have shortened andl the heat zone 19 would have dropped. But` with the parts constructed as described the decrease in air is relatively greater than the decrease in gas, and therefore the cone 2 0 mgust extend upward to derivev secondary oxygen.

lThe. lines 202l can be regarded as. indicating the defining, lines ofil the inner flame cone When the gas andv air are reduced With the peculiar relationship in volumes'attained by the devicesshown in Fig.. 6. The inner flame conev at 20a is thinner than that indi'- cated by 20, but is of the same length vertically. At such time the outer part. 21 of the flame is considerably reducedin size and its boundary lines may bc regarded as indicated at 21a.

'In Fig. 7 Iv have showndiagrammatically the relative positions of they controlling devices for the gas and the air when. the as is cut downto say one-quarter ofits possi le maximum.` The air valve 2 3. isthen ad yvan/cedl over the orifices 11- in the manner illustrated in this, Fig. 7 If it were toi stop .at the line ae 7, one-half odi' the possi- -ble maxinnimC of air would enter; but in such case the inner `fiame cone would drop because of the Jfull supply of primaryoxygen.y But as this air valve 23 is at this time carried beyond the line z-a, the quantity of primary oxygen is reduced, relatively, and the inner fiame cone 20 is reducedgfto relatively elongate itself so that its tip remains approximately in its earlier position and the heat zone at 19 is not lowered. Of course the flame cone 2O becomes considerably thinner or narrower as indicated at 2O.` And the outer part of the flame contracts and shortens and can be regarded as illustrated by the lines at 21".

In Fig. 8 there are illustrated at 11 air orifices of such sort that the air would be reduced at a rate in a constant ratio with the rate of the reduction of gas, and consequently the flame at 20 and the heat Zone would be thrown out of their desired positions. The velocity of the gas escaping through the nozzle at 6 is one of the most important factors governing the quantity and rate of air supply; this velocity varying with the fiow of gas. And the orifices l1 are formed so as to be peculiarly related to the velocity of the entering gas. If they were made of the shape and size indicated at 11a in Fig. 8, (the velocity of the gas remaining the same) too much air would be drawn in at any adjustment for gas. There is, indeed, a predetermined margin allowed in the capacity of the ports 11, this being governed also by the throw of the valve 23, in order to provide for relatively minor variations in the pressure and velocity of the gas.

lf am aware, as above indicated, that it has been heretofore proposed to construct a gas mixing and burning device of the Bunsen burner class and to employ a sleeve shutter to slide over air openings adjacent to the gas inlet, these shutters or valves being connected to the plug valve 'for the gas by a link and crank union. But the air orifices were differently constructed, and the air shutters or valves were merely used to quickly open and quickly close the entire air orifice.

l am also aware that among the devices so proposed have been some in each of which there was to be provided a rotary gas element provided with a series of graduated apertures or with a series of sets of such apertures; the gas to flow, first, through a small aperture, and then, on moving the valve, to be out oli" until a larger aperture registered with the passage, then cut ofl' again until a still larger aperture registered, and so on. But lf believe myself to be the first to have arranged the gas feeding and air supplying devices, and their controllers, in such way that when the gas is to be cut down from its maximum the air is simultatu neously and automatically cut down with out interrupting the flow or fvelocity of the gas and the gas flow remaining continuous at. all-:times while the air is flowing; and the first to provide devices for cutting down the flow of gas and simultaneously cutting downthe flow lof air, but at a rate greater than the rate of decrease of the gas, and the parts so proportionedfthat the most efficient part of the flame is maintained 1n approximately one position, vertically. l have herein, for the sake of illustration and description, assumed proportions of gas volumes, pressures of gas, heights of flames, etc., but do not mean to be understood as limiting the essential features of the invention to the specific data so assumed for the purposes of description.

What lf claim is:

1. The combination of the mixing chamber, a duct adapted to deliver varying quantities of gas mixture therefrom to the combustion region, and two simultaneously acting gas control devices, one adapted to supply gas at a maximum rate to the mixing chamber and to decrease the supply of gas at a fixed rate, and the other adapted to deliver air to said chamber at a maximum rate, and to decrease the air supply at a fixed rate greater than the rate at which the gas is simultaneously decreased.

2. The combination of the mixing chamber, a burner supplied therefrom and adapt ed to form a combustion flame with a fixed heat zone and two simultaneously acting gas control devices one adapted to supply gas at a maximum rate to said chamber to produce a flame having said heat zone and also adapted to supply gas at either of several lower rates, and the other control device being adapted to supply air at a maximum rate to maintain a maximum flame having said heat zone and also adapted to supply air at lower rates respectively corresponding to said lower rates of gas supply, said lower rates of air supply, respectively, being such as to maintain the same heat Zone that is produced at maximum combustion.

3. The combination of the mixing chamber, a duct adapted to deliver varying quantities of mixture therefrom to a combustion region and two simultaneously acting gas control devices, one adapted to supply gas to the mixing chamber at a minimum rate for combustion and also adapted to increase at a fixed rate the supply of gas, and the other adapted to deliver air to said chamber at an increasing rate which is less than the rate at which the gas is simultaneously increased, the relative quantities of gas and air permitted by said simultaneously acting control devices to enter the mixing chamber being such as to insure complete combustion at all times.

4l. The herein described method of producing a combustion flame with varying lid@ that prevents the displacing of the heat zone of the flame.

In testimony whereof, I aflix my signature, in presence of two Witnesses.

. STEPHEN HUGH HALE.

Witnesses:

C. R. JONES, B. G. ARMBRUSTER.

quantities of combustible gas and 'establishing a fixed heat Zone therefor, consisting in mixing` Volumes of air and combustible gas, delivering the mixture to the ame region, decreasing the gas supply at a fixed rate, s- Inultaneous'ly decreasing the air supply and establishing a rate of decrease for the air relativertothe rate of decrease vofthe 'gas copies nf this patent may be obtained ornve cents each, by addressing me commissioner nf I'atents.

- Y Washington, D. C.

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