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June 7, 1938. M. A. POWERS ET AL " 2,119,830 APPARATUS FOR BURNTNG LIQUID FUELS Filed Oct. 2, 1954 _ a: a /7 /a 2 Sheets-Sheet 1 ' Qwu'wvboo ?ll/ran A. Powers dab/r A. VVi/aon June 7, 1938. M._ A. POWERS El‘ AL 2,119,330 APPARATUS FOR BURNING LIQUID FUELS Filed Oct. 2, 1934 H_w\ \ 2 Sheets-Sheet 2 1.3 //////// /’//// / ///// /////f2? 66 . .24. J5 41/71'0/2 A. Pan/era Jo/m A. M/i/san' MW 9A Gamma/l4! Patented June "7, 1938 2,119,830 UNITED ' STATES PATENT OFFICE 2,119,830 APPARATUS FOR BURNING LIQUID FUELS Milton A. Powers and John A. Wilson, Detroit, Mich., assignors, by mesne assignments, to The Timken-Detroit Axle Company, a corporation of Ohio Application October 2, 1934, vSerial No. 746,582 14 Claims. The present invention relates to methods of and apparatus for burning‘liquid fuels. More particularly the present invention relates to methods of, and apparatus for igniting and com busting liquid fuels in burners of ‘the wall ?ame type, whereby such burners are enabledv to func tion reliably and economically ‘while using fuel oil of poorer quality and higher viscosity than has heretofore been thought possible of use. In co-pending Powers application for a “Metal 10 hearth ring", application No. 620,373, dated July _(Cl. 158—4)- , into suf?ciently small droplets to wet the hearth periphery evenly. To attempt to atomize the oil I or to break it into particles smaller than sum cient to meet this requirement is distinctly un desirable as ?nely atomized oil will burn rapidly in the presence of air and di?iculty will be en countered in holding the ?ame at the periphery. Under conditions of excessive atomization the rate of ?ame propagation towardthe distributor 1 will exceed the outward velocity of the oil and the ?ame will accordingly burn or “?ash" back to 1, 1932, and Wilson application No. 682,374, dated ‘ the distributor causing trouble; July 27, 1933 for a Grill, will be found a full de scription of the operation and characteristics of an oil burner having a metal hearth ring con- struction in comparison with the conventional refractory clay segments heretofore universally used. Further investigation has disclosed ‘that the use of such metal constructions in special 20 ized forms, and in accordance with the methods of combustion of our invention which are about to be formulated, opens heretofore unsuspected possibilities in the effective burning of lower quality oils with the wall ?ame burner. During 2 the ?rst few years of use of the wall ?ame burner, and in fact until only comparatively recently, it was considered impractical to recommend oils in 30 ferior in quality to the No. 1 grade (United States Commercial Standards) for reliable domestic use in automatic burners of this types Later develop ments in ignition devices and segment form en abled the same burners to operate with the better commercial grades pf No. 2 oil. The recent rapid introduction of the metal segment construction 35 disclosed in our previously mentioned applica tions has warranted the recommendation of even the poorest grades of No. 2 611 without quali?ca _ The ?rst re quirement, therefore, is to wet the ?ame rim with liquid oil. There will be su?icient splatter result-i ing/from the oil striking the face of the segment to propagate the ignition ?ame around the pe riphery. Thereafter the wet oil is vaporized by the heat in the ?ame ring segments received from the burning oil, the vapors are mixed with the out?owing air stream and combustion oc 20 curs. At normal operating temperature the rate of vapor production is so high that the flame is unable to maintain itself in the immediate vicin ity of the vaporizing oil and "rises” to the top of the segment where it burns in suspension over the metal segments, around the grills, (if grills 25 are used in the installation) and in close proxim ity to the boiler wall. y It is therefore evident that the vaporizing zone or region is ?lled with rich vapors and no ?ame 30 can exist, because very little if any air or oxygen is present. Hence a "reducing” atmosphere, as contrasted with an “oxidizing” atmosphere is present in-this zone. ' Consequently (except for a short time in starting andafter stopping) no con 35 ditions exist in the oil impinging zone for remov ing the oil and its residue from-the ?ame ring tion. In fact good grades of No. 3 oil are burned except the heat of vaporization. with complete satisfaction in numerous installa The specification for a No. 1 oil calls fora dis tions. Continued development‘ in the laboratory > tillation/range, with all of the oil evaporated, at with poor grades of both No. 3 and No. 4 011 gives a temperature not to exceed 600° F. A ?ame rim indications of fair success with the No. 3 but segment temperature" of this degree or higher is almost hopeless results with the low quality No.__ accordingly all that is necessary to completely 4 oil. An analysis of the difficulties proved that change all of the liquid oil to a vapor. The rigid 45 an entirely different angle of attack was neces sary for a successful outcome and the following line of reasoning was responsible for the success attained by the’fuel burning‘ methods and con structions of our invention to be described later. In the ?rst place let us brie?y analyze the modus operandi of the present ‘day wall ?ame burner. Oil is thrown by centrifugal forces from" the distributor head to the ?ame or combustion rim at the periphery of the boiler. The most im 55 portant requirement is that this oil be divided speci?cationsms to free carbon, ash, sulphur, and so‘ on practically assures their absence from fuels of No. 1- speci?cation nowon the market. Hence operation may continue inde?nitely without ac cumulation of carbon or foreign matter while 'using No. 1 oil-and continued good combustion 50 a burner of the character shown by the previ ously mentioned applications will operate with will result. These are the conditions under which high quality, sediment free oils. ’ The next poorer grade oil, a No. 2 presents 2 2,119,830 a somewhat di?erent story. The distillation re quirements specify that 90 percent of the 011 must vaporize below 620° F. In other words a some‘ what higher temperature is needed to vaporize even the lighter nine tenths of the oil, but there is no speci?c limitation as to the vaporizing range of the last 10 percent of the oil. It is as sumed, of course, that said remainder would con tlnue in conformity with the quality of the ?rst 90 percent although there is no limitation to re quire this. And moreover a further di?icul-ty attending use of No. 2 oil resides in the fact that much oil has been sold as No. 2 oil in which this last 10 percent necessitated much higher vapor izing temperatures than would be expected It is not unknown for No. 2 oil to be delivered from trucks which have not been cleaned after carry ing very heavy grades of oil. As a result oils mar keted as corresponding to the No. 2 speci?ca 20 tions may contain an appreciable percentage of tarry products almost entirely unvaporizable un der normal operating temperatures. Accordingly, when using some No. 2 oils, under short periods of operation, segment temperatures do not reach a maximum, residue collects and burner ignition and operation soon becomes erratic. 7 Under these circumstances (short periods of operation), when attempts were made to-burn a poor grade of No. 4 oil with its considerable pro portion of heavy tarry ends, free carbon, and ash, there was a most rapid accumulation of such matter. At times a few minutes operation was su?‘icient to build up an inwardly projecting wall of solid matter sufficient to prevent further combustion of acceptable quality. Such were conditions at the beginning of the present development of the invention, and it was realized that a radical departure from the usual methods of combustion with the wall ?ame burner 40 would be necessary for progress to be made. The vaporizing zone on the wall ?ame burner, as mentioned earlier, is entirely surrounded by rich vapors with very little if any air.present, and it was found when using No. 4 oils, that any collection of unvaporized material remained un It is another object of the invention to provide a fuel burning apparatus of the character having a carbureting surface against which liquid fuel impinges, with means for directing a supply 01' air at theface of fuel impingement, to establish a combustion zone of oxidizing character for con suming fuel that fails to vaporize. ' A further. object of the invention is to devise novel methods for combusting fuels, which result in employing only slightly more combustion sup porting air than that calculated as required for oxidation of the fuel. It is ‘another object of the present invention to devise novel methods for burning heavy liquid fuels which comprises utilizing a part of the. 15 heat of the fuel to vaporize the same, the heat for this purpose being obtained from the com ponentsof the fuel that are difficult if not im possible to vaporize. - The present invention also aims to devise novel 20 means for initiating combustion in liquid fuel burning apparatus, which is so designed as to make feasible the combustion of heavier fuels than) heretofore believed capable of use. Further objects of the present invention will 25 become apparent as vthe detailed description thereof proceeds in connection with the annexed drawings, and from the appended claims. In the drawings: , Figure l is a vertical sectional view of a boiler 30 equipped with a fuel burning device constructed in accordance with the present invention. Figure 2 is a front view of one of the carburet ing ring segments as it appears when removed from the device shown in Figure 1. Figure 3 is a sectional view taken on the line 3-3 of Figure 2; and also diagrammatically il lustrates the combustion conditions that exist in the device. ‘ Figure 4 is a view similar to Figure 3, but il 40 lustrates a slightly modi?ed form of air directing member. Figure 5 is a front view of a modi?ed form of segment assembly also forming part of the pres affected and accumulated until it caused com ent invention. 45 Figure 6 is a sectional view taken on the line bustion failure. It was discovered however, that 6-6 of Figure 5. by directing relatively large quantities of com bustion air directly at the base of the vaporizing 50 zone a surprising change in combustion condi tions took place. It was found that su?lcient air to initiate combustion was now present below the oil impingement line, and a very active roll- . ing ?ame continued to burn in the trough por 55 tion of the combustion ring segments, with result ing greatly increased operating temperatures. The metal parts in proximity to the ?ame at tained a bright cherry temperature (about 1700‘ F.) and remained so during operation. This high temperature eliminated all chance for incom plete vaporization of high boiling point portions and thereby rendered it entirely feasible to burn oils of No. 3 and No. 4 speci?cations. , It is accordingly a primary object 'of the pres 65 ent invention to devise" methods and apparatus for e?iciently burning heavier liquid fuels than have heretofore been used. ‘ -~ Figure 7 is a view similar to Figure 6, but il lustrates a modi?ed form of carbureting ring assembly segment. ' 50 Figure 8 is a front view of a still further modi ?ed form of carbureting ring segment. Figure 9 is a sectional view-taken on the line 9—8 of Figure 8. . Figure 10 is a sectional view illustrating a fur ther form of carbureting ring assembly. 55 Figures 11 and 12 illustrate a variation in the construction shown in Figure 10. Figure 13 is a fragmental sectional view through the device shown in Figure l butillus trates a modi?ed form of electrode assembly as sociated therewith, also forming part of the pres ‘ .ent invention. _ Figure 14 is a fragmental sectional view taken on the line I.4-ll of Figure 13. Figure 15 is a fragmental sectional view taken on the line l5--l5 of Figure 14, and Figure 16 is a diagrammatic illustration of the A further major object of the inventionis to ‘transformer and circuit utilized with the igniting devise a fuel burning apparatus having a reduc 70 ing combustion zone and an oxidizing combustion zone, the zones being so located that fuel that fails to vaporize in the reducing zone will auto device shown in Figures 13, 14 and 15. 70 with continued. reference to the drawings, wherein like reference characters have been em ployed to designate like parts throughout the ,, ._ matically ?nd its way to the‘ oxidizing zone} several views thereof, we have illustrated our fuel is where it is efficiently combusted. vburning apparatus shown as being incorporated 15 3 2,119,880 in a boiler having a base portion II and a water section II. - de?ecting members II cooperate with the ‘air . streams projected from distributor It in a man Mounted on -. an inwardly extending ?ange l2 ner to be hereinafter described. ' of base I0, is a hearth member it which con .sists of a refractory clay mass which may be Combustion of the liquid fuel may be ini tiated in any suitable; manner, the ignition mechanism of the device-shown in Figure 1 tak molded in place in the boiler. Extending through a centrally disposed aperture in hearth I3 is a . ing the form of a pair of electric rcs. Prefer . ably disposed at diametrically op to points prising a stand I4, a motor l5, and a distributor of the carbureting ring assembly .areelectrodes head IS, the latter being provided with a plu-. 31, each of which preferably consists of an in rality of nozzles I1 and a plurality of fan blades timately mixed mass of carborundum and re l8. The distributor assembly forms no part of fractory material disposed in a metallic container the present invention, and its operation will secured to the segments.‘ The carbureting ring therefore be only brie?y described. The dis is provided with apertures opposite electrodes 15 tributor head rotates at motor speed and throws 31 in order to allow an arc to pass from the sur 15 unatomized droplets of oil upwardly and out- _ face of the carborundum to an electrode II ' wardly, and it discharges an outwardly and which is molded in the hearth opposite each liquid fuel and air distributor assembly,' com downwardly extending blast of air, the streams electrode 31. Electrodes 10 are ‘connected by of oil and. air being combusted in a manner to 20 be hereinafter described. The distributor as means of leads 3! across the high side of a trans former 40. The voltage across the high side of 20 the transformer 40 preferably lies in the neigh borhood' of from 12,000 ‘to 15,000 volts and the sembly is adapted to be automatically controlled in accordance with temperature changes by mechanism disposed in a control stand‘Zi. current produced thereby goes through ‘one ' ‘Disposed- on the upper surface of hearth i3 is electrode I8 and jumps across the gap in the 25 a carbuzeting ring assembly,\and in the present form of a ?aming arc, enters, one electrode 31. 25 instance it consists of a plurality of metal seg travels through the connected segments of the ments which are welded or otherwise suitably carbureted ring and into the other electrode,” secured together to‘ form a unitary whole. With particular reference to Figures 2 and 3, each 30 segment consists of a body 22' preferably of pressed- metal. Although any suitable material may be employed for the segments, the high tem ' peratures to which the metal portions of the burner are subjected necessitates the use of a special heat resisting steel unaffected by oxidiz ing conditions in the burner, and it has been then through another ?aming are into the other electrode 30. It is therefore seen that the arcs or spark gaps are disposed in series vwith the "30 result that. the voltage across each gap will be one;half‘ of the voltage across the high tension terminals. - Before proceeding to a detaileddiscussion of the modi?ed forms of the invention, a. descrip tion of the operation of the construction just found that a chromium steel having a chromium described will now be set forth. The controlling content of from 20 to 28% is suitable for' the mechanism for the burner is preferably arranged so that the motor is started simultaneously with energization of transformer 40 with the result that the oil, or other liquid fuel; is thrown out Each segment 22 is provided with a vertical wardly from the head, (illustrated as droplets-in impact _wall 23, which ‘provides a vaporizing Figure 3) and strikes portions 23 of the segment surface; a gutter portion 24, into which unva and breaks up into smaller particles which drop ‘present device, while somewhat lower percent ages of chromium may also be used with reason able satisfaction. ' . . ' 45 porized. components of the .fuel may rest while " they are consumed by the oxidizing atmosphere therein; and an upwardly inclined air directing surface 25. Segments 22 are supported upon the \ hearth by means of a plurality of metal plates '50 26 which generally conform to the con?guration of segments 22 and are secured thereto by a welding or like‘ operation. ' _ >_ ~ down into the electric arc and are volatilized and ignited. The arcs, are intensely hot, and accord ingly heat the volatilized fuel- to a high tempera _ ture and ionize the air and oil vapor in the region ‘of the electrodes, with the result that the. vapor ignites._ It should be observed that while the above operation takes place the current ?owing ' ~ through electrode 31 heats it to a high‘ temper Although the mechanism perform satisfac ature. with the result that further atomized fuel. torily without them, each segment is preferably fdropping thereupon is readily volatilized. . provided with a grill 28, which comprises a When ignition has been initiated in the manner 55' - ?anged plate having a ‘plurality of openings 20 - formed therein. Each grill 28 is secured to its segment by means of a pair of brackets 3|. The just described, the ?ame propagates around the ring in both directions‘ thereby establishing’ a continuous ring. With combustion taking place forward arms 32 of brackets 3| are bifurcated ' around the entire periphery of the carbureting and straddle the vertical portions of the segment. the rear legs 33 of bracket 3| are disposed ring, segments 22 are heated, and as they are _ againstthe rear face of the segment. (“Brackets 3| may be welded or ‘otherwise suitably fastened ~ to the segments in order to make the construc tion more ‘rigid if desired. _ ~ v Thecarbureting, ring assembly just described is equipped with an air de?ecting, or an air re directing assembly, and although it may take any desired form and be supported on the hearth or "70, any other part of the burner, it is preferably mounted on the carbureting ring assembly itself and in the present instance it takes the form of a plurality of metallic members 35 which are horizontally disposed and have their ends 38 bent downwardly and welded to segments 22. 'fAir - so formed of relatively thin pressed metal they heat up rapidly and in a short time they attain a temperature sufficient to almost instantly vola tilize the droplets of oil striking their vertical portions 23. When the carbureting ring- attains 65 a temperature su?icient to'instantly volatilize the liquid fuel impinging thereagainst just de scribed, stea'dy combustion‘ conditions may be said to exist in the device and at this time an auto matic device .of any suitable character may 'be 70 employed to open the igniter circuit. Under steady combustion conditions, the uné I atomized fuel emanating from head l6v takes the paths illustrated by the upper row of .arrows in Figureyl, (illustrated as droplets in Figure 3),» 2,119,880 and strike portions 23 of the segments in a line which will hereafter be termed the impingement line. The air ?owing from head it curves down Wardly asit emanates .from head IS with the re sult that the fuel in its passage from head IE to the carbureting ring is isolated from the air and is accordingly incapable of burning for the reason that it is not supplied with sui?cient air to form a combustible mixture. With particular 1o tion of the solid matter. As the ?ame in the gutter. is continuously oxidizing in character dur ing normal operation of the burner,‘ the solid or unvaporizable part of the fuel is consumed as rapidly as it forms and breaks away from the impingement wall. There is therefore no pos sibility of the burner becoming so incrusted with solid matter asto cause combustion to fail. It was discovered during the course of experi of theair supplied to them for proper combustion, mentation that the high carbureting ring tem 10 peratures requisite for complete volatilization of liquid fuels of number 3 or number 4 speci?ca-7 tion causes the oil to crack into its component parts and the free carbon so released will precipi tate with amazing rapidity on any convenient 15 surface. The temperature of the collecting sur the ?ame in this region is of a reducing charac ter. A large part of the air issuing from the dis tributor strikes air de?ectors 35 and takes the face the faster the carbon collects thereon. . reference to Figure 3, part of the air issuing from the distributor, diagrammatically illustrated by arrows A, is thrown outwardly and upwardly and mixes with the vapors generated on surfaces 23 of segments 22 and starts to burn in this region. 15 However; as the vapors generated are in excess 20 path indicated by the arrows B and mixes with the vapors in the region below the impingement face itself does not seem to in?uence the rate of precipitation. If anything, the hotter the sur . - Two methods of correcting this dii?culty oc 20 curred atv the time of developing the present ap paratus; (1) provide no collecting surface until line. As the amount of air in this region is in excess of 'that required to ei?clently burn the vapors present in this region, the ?ame in this combustion of the fuel is complete or (2) main tain an oxidizing atmosphere over the surfaces‘ erably carefully adjusted so that when the gases pingement surfaces. of the reducing and oxidizing zones are mixed, there will be just su?icient, or only a slight excess, introduced be not in material excess over that 25 25 locality is of a highly oxidizing character. The ' in the region of the released. carbon. In view of the necessity for a vaporizing surface, the sec vapor streams are illustrated diagrammatically in Figure 3 by lines C. The ?rst described region ond solution of the problem was followed, and the or zone of combustion will be hereinafter termed present practical apparatus resulted. Therefore the reducing zone and the last described region it is seen that maintaining an oxidizing atmos 30 phere adjacent the line of fuel impingement not 30 will be described as the oxidizing zone. The gases in the reducing and oxidizing zone only produces efficient and complete combustion pass upwardly and strike grills 28 which serve of the solid matter in the fuel, but it also rapidly . to mix them, with the result that they burn above and completely oxidizes the free carbon that may the grill with a blue ?ame, and the quantity of be released as a result of the fuel cracking under the high temperatures encountered on the im 35 air supplied to the carbureting assembly is pref of oxygen present above the grill to thoroughly It is important that the total volume of air required to completely burn all of the fuel. The method, of the present invention therefore in 40 40 combust all of the fuel. ’ Fuels of number 3 and number 4 speci?cation, _ cludes directing the air in a manner to maintain as previously pointed out, not only contain sub stances that cannot be vaporized, but they also contain a certain percentage of solid matter. 45 Moreover a. certain percentage of solid matter is precipitated incident to cracking of portions of the oil that is vaporized in the device. When the burnergis operating under steady combustion conditions, the solid matter in the 50 oil, plus any solid matter precipitated incident to portions of the oil cracking under the high ‘ vaporizing temperatures existing in the segments, collect upon the surface of the segments at the line of oil impingement. This solid matter ac 55 .cumulates at a relatively rapid rate, depending an oxidizing condition in certain zones and upon certain'surfaces; thereafter mixing the vremain ing air with its unused oxygen, the unburned vapors, free hydrogen and oxygen, and the prod 45 ucts of combustion, in a manner to give e?icient combustion of the total mass. With reference now to Figure 4 of the drawings, there is illustrated a modi?ed form of construc tion, and the only difference therein over the con struction just, described, resides in the shape of the air de?ecting member 35a which in this in stance is of curved con?guration. This form of air de?ecting member may be used to advantage in some installations, depending upon the volume 55 of auxiliary air required. In fact the air de ?ecting member 35 of' the ?rst described con struction may be adjusted or progressively bent into the curved con?guration shown in Figure 4 to give the requisite balance between the air that .60 upon the quality of the oil being burned. Never theless, and for some reason‘not clearly under stood, such accumulated matter, after reaching a certain thickness, breaks into segments along its length. These segments upon being formed may drop at once to the bottom of the trough in the ‘ ?ows directly toward the impingement line and carbureting ring, or as is usually the case, they the air that is de?ected into the gutter. In view curl inward at their ends away from the surface of the fact that this form of the invention func of the metal until their weight acting against tions in precisely the same manner as that just 65 described it will not be set forth. 65 their weakening hold upon the impingement wall With reference to the carbureting ring con ?nally results in their dropping away into the trough. As previously described, the air ?owing struction shown in Figures 5 and 6, the carburet into the trough, by virtue of the air de?ectors, ing ring assembly is'provided with a series of im maintains a ?ame therein and the relatively pingement plates ll which are provided with preferably integrally formed ears 42. Ears 42 ex 70 70 large amount ofwair causes this portion of the tend rearwardly as seen in Figure 6 andrare then ?ame to be of a highly oxidizing character. Con ' sequently when the solid matter breaks off and bent downwardly to provide a vertical portion . drops into this zone as just described, the com‘ bination of excass oxygen and, high ?ame tem peratures causes the rapid and complete combus 43. Portions \43 of cars 42 are slitted vertically and are ?tted over vertical portions 23' of seg ments 22. . : , 2,119,830 This apparatus functions in a slightly different manner than those previously described in that no air de?ecting member is required. Assuming that plate 4| has been heated sufliciently to sub stantially instantaneously vaporize the fuel strik ing it, vaporization takes place as previously de scribed, and aircurrents A establish a reducing combustion zone adjacent the impingement line. The vapors below the line of impingement mix 10 with air current B and establishacombustionzone in the gutter, and the products of combustion pass upwardly behind plate 4| toward the grill 28. The upward movement of the gases in this com bustion zone establishes a_ partial vacuum in the lower part of the ‘ gutter, which ‘results in air currents 3- taking the path shown and which es tablish an ‘oxidizing zone.. However, if desired, air de?ecting members of the character shown ' in Figures‘3 and 4 may also be used to increase 20 the how of air into the oxidizing zone. It should be observed that the combustion of the gases taking place behind plate 4| serves to further ele . ' 5 of a continuous ring, as distinguished from the segments employed in the previously described forms of the invention. with continued refer ence to Figure 10, a' plurality of bracket mem bers 85 are disposed upon hearth l8 and~have ex tending tabs 66 molded therein. Secured to the upper face of each bracket 85, by means of a plurality of tabs 81 which are preferably struck therefrom,._is a clamp member 68 having up standingarms 88 and 10. A ring member -'||, 10 against which the fuel is adapted to impinge, is mounted on brackets 88 and is‘ secured thereto by bending the upper ends of arms 89 thereover.‘ A narrower ring 12 is secured to arms 18 of brackets 68. Grills 28 are secured to spaced portions of 15 ring ‘II by means of bracket members 14. An air de?ecting member 18, which may be continu- , ous or segmental in form, is secured to the upper edge of ring H by means of brackets 15. . In this'form'of the invention, air currents A pass upwardly and mingle with the vapors in the region of the oil impingement line on ring mem ber ‘H and establish a reducing zone in a man ner similar to ‘that effected in the previously de scribed constructions. Air currents B pass up vate the temperature of the vaporizing surface, with-the result that vaporization of the imping~ 25 ing fuel is greatly enhanced. The gases passing upwardly fi‘omthe reducing and oxidizing zones ' wardly and are de?ected downwardly by member‘ ' enter the grill wherethey are mixed and com 18 into the gutter formed between ring mem busted as previously described. ‘ bers ‘H and ‘I2 and establish an oxidizing zone With reference to Figure "l, a construction is wherein the solid or unvaporizable components 30 shown that. is very similar to, and, functions in of the fuel are consumed. The gases emanating the same manner as that Just described, but the parts are assembled in a different manner. Plate 4la at its lower end is welded to a bracket 45 which rests in a gutter 24 of the segment and is from the reducing and oxidizing zones pass uP— wardly and are mixed and consumed above the grills as in the previously described forms of the invention. 35 provided with a bifurcated upper end 48 which. The construction shown in Figures 11 and 12 is embraces theupper lip of segment 22. Segment 22 has been cut down as the impingement wall 28 is not necessary in this form of the invention. A pair of brackets 41 support grill 28, and is pro vided with a bifurcated end 49 which embraces the upper edge of plate Ila. =Rear legs 48 of brackets 41 engage behind'segments 22. - The modi?ed , carbureting ring construction shown in Figures 8 and 9 functions in the same 45 manner as those shown in Figures 5, 6 and 7. In this form of the invention the segments are re placed by a plurality of segments 52, which are secured together in end to end relationship as those employed in the previously described forms of the invention. Segments 52 are each pro vided with a vertical wall 58, a horizontal base 54 and an upwardly inclined frontwall 55. Plates 4|b are disposed within segments 52 and are pro-, vided at their lower ends with outwardly turned identically the same as that Just described except for the air de?ecting member, which in this in stance is integrally formed with the smaller of the carbureting ring members. ‘Inthis form of the invention ring 12a is‘slit horizontally along 40 edges 11 and TI’ to form air de?ecting mem bers 18,‘ which are connected to the ring at in tervals by integral supporting portions 18 of the ring. - \ ‘ In Figures l3, 14, 15 and 16 there is shown a 45 modi?ed form‘ of igniting device also forming part of the present invention, and it is particularly useful in the present apparatus as it is capable of initiating combustion of the heavier fuels. The igniting device has been illustrated in connection with the’ carbureting rlng assembly shown in Figures 1, 2 and 3, and although two igniter as semblies are used only one will be described. With particular reference to Figures 13 and 14, 55 tabs 58, which cooperate with the front walls 55 an aperture-88 is formed in__ segment 22 and a of the segments and inwardly turned tabs 51, box-likemember 8| is welded to segment 22 in which cooperate with the rear wallof the seg-' alignment with aperture 80. Secured to a down ment to maintain plates ‘ 4|b» properly spaced wardly projecting ?nger 82' of‘ member 8| is from the segment walls. A pair of U-shaped a clamp 88. Detachably carried by clamp 83 is an clamps 59, each having downwardly extending insulator 84 having an electrode 85 therein. Elec legs GI and 62, is mounted upon plate 4 lb and the trode'85 is insulated from member 8| and is pro rear wall 58 of segment 52 and supports grills 28 vided with an enlarged upper end 88 for a pur which are welded thereto. ._ pose that will presently appear. This form of the invention performs in precise Insulating material 8'|,_ _ preferably having ly the same way as the apparatus shown in Fig ures 5, 6 and '7, a part of the air stream A passing upwardly and establishing a reducing zone in the region of the impingement line and another part thermal as ‘well as electrical insulating proper 75 vention the carbureting assembly takes the form trodes .85 are provided with terminals 88. __Co ties, is disposed within member 8| and against 65 the rear face of segment 22. Molded in place within member 8| and projecting through the of the air stream B passing downwardly within opening 80 in segment 22 is a mass'vof conducting the segment and under plate 4|b to establish the _ material 88,lwhich preferably-consists of a mix 70 'oxidizing zone, where they solid matter is-con ture of carborundurn and a refractory binder of - sumed as previously described. preferably electrical insulating properties, so that‘ In Figure 10 there is illustrated a runner mod when current passes therethrough it, will heat up i?ed construction, andin this form of the in and volatilize the fuel. 'I'he‘lower ends of elec-~v 6 2,119,830 operating with one of the electrodes 85 is a metal lic hearth electrode that will now be described. Secured to a recessed portion 9| of Segment 22, as by means of a welding operation, is a clamp member 93 which is molded in‘ the hearth and which clamps an insulator member 94 in place. Disposed within insulator member 94, and se cured thereto at its lower end, is an inner in sulator 95 carrying an electrode 96 which curves upwardly and outwardly and terminates in a‘ somewhat blunt tip 91, which is disposed sufli--v ciently close to the carborundum electrode to 15 spects as illustrative and not restrictive, the scope ‘ of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come .within the meaning and range of equivalency of the claims are there fore intended to be embraced therein. What is claimed and desired to be secured by United States Letters Patent is: 1. In a liquid fuel burning apparatus compris- ‘i ing a combustion chamber having a hearth and 10 means for discharging liquid fuel in a path over said hearth, _a carbureting device mounted on form an are when a high voltage is impressed said hearth in the path of the discharged fuel. across the electrodes; said device comprising an upper, fuel impact wall " portion, a lower wall portion and a grooved or 15 ‘ The transformer and electric circuit preferably _ employed with the igniting device is illustrated in Figure 16. The transformer has a primary winding 99 ‘which, if the fuel burning apparatus is'mounted in a residence, is connected across 20 the regular 110 volt, '60 cycle line. The trans depressed imperforate portion. forming a sheltered gutter between said wall portions, means for pro jecting. a major draft of air against said lower wall portion and across said gutter, and means for projecting a minor air draft into said gutter. 20 2. In the combination defined in claim 1, the former is provided with two secondary windings IOI and I02. Winding l‘nl is connected across last mentioned means comprising a member car electrodes 85, and one end of winding I02 is con nected to electrode 96. Although the transformer ried by said device and constructed to form said minor air draft from a portion of the air of said 25 has been conventionally illustrated, winding llll is designed to cause a comparatively heavy cur rent, say, I80 \milliamperes to ?ow between the electrodes 86 with a drop in potential of approx imately two thousand volts, while winding I02 is 30 designed to have a greater number of ampere turns, so as to cause a current of say 18 milli amperes to ?ow between electrode 91 and elec trode 96. It is‘ accordingly seen that when the burner is 35 put into operation a heavy current flows between terminals 86 and-rapidly heats member 89, with the ‘result that when fuel particles gravitate downwardly on the hot surface of this member they are rapidly volatilized. Simultaneously an 40 arc is established between electrode 91 and mem ber 89, which serves to further volatilize the fuel and ignite it. It should‘be observed that while current is passing between electrodes 86, the heat generated in member 89 is conserved by reason of the insulating action of members 81,"which 45 also electrically insulates member 89 from the ring .segments. The heat generated in mem ber 99 is accordingly prevented from dissipating into segments 22 and accordingly promptly reaches a vaporizing temperature. 50 As previously mentioned, the carbureting ring assembly in this form of the invention is Provided with two. diametrically opposite igniter assem blies and although we have illustrated each igniter assembly as being provided with a sep 55 . arate transformer, it is to be understood that if major draft. - 3. In the combination de?ned in claim 1, the last mentioned means comprising a de?ector overlying said lower wall portion and said gutter. 4. In a liquid fuel burning apparatus, in com bination with a combustion chamber having a 30 hearth and an upright wall, fuel distributing means positioned to project. a liquid fuel stream toward said wall and means for directing a blast of air toward said wall, a refractory carbureting structure disposed between said wall and said distributing means, said structure comprising an imperforate gutter arranged transversely of and below the projected fuel stream, a member pro viding an air de?ecting surface in front of said gutter in the path of the air blast and positioned 40 to direct said blast upwardly, means providing ‘a fuel impingement surface above'said gutter in the path of the upwardly directed blast, and means for causing a part of the air blast to flow into said gutter during operation of the appara tus. 45 . 5. In the combination/de?ned in claim 4, said means providing said. fuel impingement surface being thin and of good heat conductivity and disposed forwardly of the rear side of said gutter. 50 6. In a liquid fuel burning apparatus; a heat exchange unit having a combustion chamber; a liquid fuel carburetin'g member providing a substantially vertical surface disposed in said chamber, means for projecting unatomized liquid ' 65 fuel toward‘ said surface for atomizing said fuel desired, the transformer may be made of greater by impact with said surface; means for project capacity and be connected in series or parallel to ing a draft of air toward said surface for ad .mixture with the atomized fuel for establishing both of the igniter assemblies. and maintaining a combustion zone adjacent said With reference to all of ‘the forms of the in 60 vention, it is to be understood that although ' vertical surface between said ?rst-named means and said vertical surface, and means for‘ causing various devices have been illustrated for de?ect ‘ing or re-directing a portion of the air emanating a part of the projected air draft to form an from the distributor head for establishing an oxidizing zone below and adjacent to 'said com 65 oxidizing zone in the carbureting assembly, air bustion zone. arate fan directing air directly to the carbureting ring gutter, and the appended claims are intend 70 ed to embrace the present invention when it as prises a de?ecting means for diverting a part of the air supplied said combustion zone to a region for this purpose may be independently supplied if desired, as for instance, by means of a sep sumes this form. . ' The invention may be embodied in other speci?c ‘ forms without departing from the spirit or essen tial characteristics thereof. The present embodi ments are therefore to be considered in all re ‘ 7. The liquid fuel burning apparatus set forth in claim 6, wherein said last named means com 70 8. In a liquid fuel burning apparatus, a mem ber having a substantially vertically disposed atomizing surface, means for projecting an air current and liquid fuel toward said atomizing surface, for causing said fuel to be atomized by ‘ below said combustion zone. 2,119,880 impact with said surface and to be mixed with a part of said air current and means for causing a portion of said air current to be de?ected to a region below said atomizing surface. 9. The fuel burning apparatus set forth in claim 8, wherein said last-named means com prises at least one air de?ecting member dis posed in the path of said air current. 10. In a device for burning liquid fuel, a heat 10 exchange unit having a combustion chamber; a fuel carbureting member disposed in said cham ber and providing a substantially vertically ex tending fuel atomizing surface and a gutter lo cated below said surface; means for causing liquid v15 fuel to impinge against said atomizing surface, means for causing an air current to ?ow past said gutter for admixture with the fuel atomized on said surface, and means for causing a current of air to ?ow into said gutter for combusting any fuel accumulating therein. _ 11. The liquid fuel burning apparatus set forth in claim 10, wherein said last named means com prises an air de?ecting element mounted on said carbureting member and disposed between said atomizing surface and the source of the air sup plied to the fuel atomized on said atomizing sur face. - 12. In a liquid fuel, burning device, a liquid fuel projector, a carbureting member providing a sub stantially vertically disposed atomizing surface in the path of the liquid fuel discharged by ~said projector, means for mixing air with said liquid fuel atomizing by impact with said atomizing surface for effecting combustion of said liquid fuel, in the region of said surface impacted by said liquid fuel, and means for causing hot gases of combustion to pass downwardly under ‘and thence upwardly with respect to said atomizing surface for simultaneously consuming any fuel 7 that fails to vaporize on said atomizing surface and for heating said atomizing surface. 13. In a liquid fuel burning apparatus com prising aqcombustion chamber having a hearth and means for discharging liquid fuel in a sub 5 stantially horizontal path over said hearth, a carbureting device mounted on said hearth in the path of the discharged fuel, said device com prising an upper fuel impact wall portion, a lower wall portion and a grooved or depressed imper 10 forate portion forming a sheltered gutter between said wall portions, means for projecting a major draft of air against said lower wall’ portion and across said gutter, and means for projecting a minor draft into said gutter comprising a down 15 ward extension provided on said fuel impact wall and projecting downwardly into said gutter. 14. In a liquid fuel burning apparatus, a com busti'on chamber having a hearth, an upright-fuel impact wall disposed adjacent the periphery of said hearth, said hearth being provided with an .aperture centrally thereof, a distributor mecha nism projecting upwardly through saidaperture and embodying means for projecting a sheet-like blast of air outwardly over said hearth toward said fuel impact wall and means for'projecting solid droplets of liquid fuel‘ against said impact wall for atomizing and vaporizing the, same, means located inwardly of said impact wall for de?ecting said blast of air upwardly and out wardly adjacent said impact wall, and means for deflecting at least a part of said air from its upward course comprising a plurality of thin members constructed of a metalv which is resist ant to destruction by heat and has good heat conductivity. - MILTON A. POWERS, JOHNA. WILSON. 30'