US2398883A - Liquid fuel burner - Google Patents

Description

Patented Apr. 23, 1946 UNITED STATES PATENT OFI-ICE AllckClarkson, Bloomingdale-Township, DuPage clll'ltylll. v

application Marsu s, 1944', sei-iai No. 525,201

' a claims. `(ci. 15e-Les) This invention relates to certain'newgand use- /cojnbustion mixture as it dips near or impinges e against the said bottom of the chamber.

ful improvements in liquid ,fuel burners and particularly burners embodying thev principles disclosed inmy copending application, SerialNo. 515,555,v filed December24, 1943.

`In my said c'opending application a liquid fuel porized atl atmosphericp'ressure-in a retort and simultaneously mixed with a quantity of air insunicient' to support 'combustionThe ricljrgaseous mixture, thus produced, passes into the dis-V tributing chamber of ar burner' memberyfromy through annular portsleach of which provides a concentric envelope of air .for'ajet of gas.

' A principall object of the present invention is to provides. liquid fuel burner of improved convburner is'illus'tratedv in ywhich a liquidy fuel is va- The present invention-'includes the basic .principles disclosed in lthe said copending application, but-provides dierent arrangements and constructions .wherebya blue quality flame and greater emciency isobtaine'd. y 4' In the present. apparatus the liquid fuel is vaporized in a retort in'the presence of'insufllcient air to support combustion. The rich gaseous mixf ture isthfengpassed in'to a distributing chamber of an invrtedburner. The gaseous mixture is directed downwardly toward the bottom of a combustion 'chamber so 'as to cut through the path of travel of the combustion ir being supplied to the into a combustion chamber.` The combi'istionl l struction which will operate to thoroughly vaporize the liquid fuel and to heat the combustionair both preliminary to and during the mixing operation so that the burner will function efficiently at all times.

r Anotherobject is to provide in a liquid fuel t burner improved constructions whereby the liquid fuel, -after'vaporization, is directed against or caused to movein close relation to a hot baille pas toeifect emcient'mixing thereof with the combustion air. e

furtherobject is to provide inan apparatus of theabove character improved arrangements and simplified constructions vwhereby the combustion air' for the burnermay be thoroughly heated and `mlxedwith Jthe gaseous mixture at locations which prevent the incoming air from cooling the burner member and the retort sumciently to cause condensation of the vaporized fuel.

combustionchamber. In this way the gaseous fuel and combustion air are thoroughly lnixed so.

as to burn as ablue flame. The bottoml ofthe combustion lchamber serves as a baille against which the ignited jets of gas impinge and are diverted upwardly. The name from the burner heats the baille so that the baille, in 'addition'to i defiecting the flame upwardly, serves also as a hot plate to preheat the combustion air before the latter comes intocontact with the vaporized fuel'.

It will bey observed, by inspection of the /drawing, that the said hot Vybaffle is so arranged ,thatv the incoming combustion airfmakes direct contact with thelower surface thereof before enter-.- ing the combustion chamber. This minimizes the possibility ofthe condensation of fuel inthezone where the rich gaseousmixture comes into conytactwlth the combustion air. The movement of the ilaine and hot gases of combustion in a downf ward and then in an upward path causes a relatively thin blanket of combustion air tobe drawn into the chamber and flow along the hot upper surface of the bottom wall of the chamber. This blanket of hot air serves tomix with and raise the temperature of the outer portion or strata of the The' invention is illustrated in the accompany-y ing drawing wherein:

Fig.` 1v is a vertical section through the lower portiony of a heater casing showing the burner structure of this invention installed therein.

Fig, 2 is a plan view of the structure illustrated in Fig. 1. i

Fig. 3 is a sectional view takenthrough the burner member on line 3-3 of Fig. 1 to illustrat the ring loi.' fuel discharge openings. f

Fig. 4 is akplan view of an air deector embodied in the structure shown in Fig. 1, and

1 Fig. 5 is aA fragmentary lsectional view illustrating the manner in which the baille of Fig. 4 is supported on the bottom of the combustion chamber ,of the burner.

The burner' of the present invention is s utable for use in manysltuations. However, for the purpose of simplifying the present disclosure,

the slaidlburneris shown renclosed in the lower vportion of ordinary heater casing. Ihe heater ,casingksi designated by the )reference numeral Ill 'and is formedfatasuitable distance from the bottom thereof with a` corrugation Il or other form of 'inwardly extendngprojectlon/which serves to support a'flre pot |2.2The repot I2 '50 .is preferably cylindricafin construction and vconstitutes thecombustion chamber of the present embodiment. The burner structure is designated generally by the reference numeral I3 and is ,located within the combustion chamber so that" it will be enveloped and/heated bythe flame andI the hot gases of combustion. Preferably the fire pot I2 is made of sheet metal and is formed at its upper end with an outurned flange I4 which seats on the corrugation II of the heater casing III.

When the burner structure is employed in situations where it is subject to substantial vibrations, for example on an automotive truck or other vehicle, the flange I4 may be spot-welded or otherwise suitably secured to the heater casing I so that the bottom portion of the re pot will be maintained in a`xed position relative to the burner member. The bottom l5 of the re pot is formed with a large, central opening I6 for the admission'of combustion air into the combustion chamber. The adjacent portion of the bottom is formed with a downwardly pressed annular groove I 1 which is concentric with the central opening and with the vertical walls of the combustion chamber. An air baille ring I8, hav-'- ing vertical and lateral anges I 9 and 20, is positioned in said central opening I6 with the latter lateral flanges of the ring overlying the top face of the bottom I5 of the combustion chamber. The vertical and lateral iianges of said ring, however, are spaced from the adjacent surfaces of the bottom wall I5 of the combustion chamber so as to provide a narrow circular passage 2l through which air is admitted into the combustion chamber and caused to iiow radially outward in close relation to the top face of the bottom wall of the combustion chamber. This current of air is shown by the feathered arrows indicated by the reference numeral 22. The baiiie ring I-8 may be supported on the bottom wall I5 of the combustion chamber by any suitable means, for example, by annular lugs 23 fixed to the baille ring and engaging the edge 24 of the central opening I6 together with the adjacent top surface of the bottom wall I5 of the combustion chamber. The annular lugs 23 may, if desired, be brazed to the bottom wall I5 of the combustion chamber so as to prevent the possibility of accidental displacement.

'I'he burner member I3 and the retort are preferably, though not necessarily formed as an integral structure having upper and lower chambers. The upper chamber 25 constitutes the retort in which the fuel is vaporized. The lower chamber 26 constitutes the distributing chain-` ber of the burner. This portion of the burner ,is circular in plan section, as indicated in Fig. 3, and is formed adjacent its outer wall with an annular channel 21 which extends a substantial distance below the bottom wall 23 of the distributing chamber. At the bottom of the channel 21 is formed a ring of discharge openings 23, through which the vaporized fuel is discharged in the form of downwardly extending jets into the combustion chamber. These lets of gaseous fuel, being directed downwardly toward the bottojm wall l5 of the combustion chamber are caused to cut across the path of the main stream of combustion air admitted through the air supply passage 33. In order to direct this main supply of air outwardly and away from the burner so as to minimize its cooling effect on the lower wall of the burner member, an upwardly flared deiiector disc 3l is interposed between the said air supply opening I6 and the bottom surface of the burner. The deiiector 3| is clamped in position between the burner member and a spacing sleeve 32 by means of a bolt 33, forming part of the central supporting structure of the burner member. The bolt 33 extends through an. ad-

` justable sleeve 32 which may be adjusted to raise and lower the burner so as to vary the size of the air supply passage 30 and thereby control the volume of combustion air. The distributing chamber of the burner member communicates through a', central opening 34 with the retort 25. The bottom surface 35 of the retort is curved 1 vto provide an annular groove extending around the chamber and curves upwardly toward the center so that the central opening 34 therein is above the lower portion of the groove. The top of the retort is closed by means of a cap 36 which may be brazed or otherwise suitably fixed sto the main portion of the burner casting. A

fuel and air supply duct is designated by the reference numeral 31. This duct is open to the atmosphere at its upper end 33, and inclines downwardly and communicates with the retort chamber 25. A fuel supply conduit 33 delivers liquid fuel in controlled volume onto a retarding surface 33a arranged inthe supply duct 31 so as to prevent the drops or beads of liquid fuel from dancing about on the heated surface. While the invention preferably utilizes a screen for this purpose so as tov form a series of pockets which tend to retain small pools of fuel, similar results vmay be obtained by providing absorbent surfaces, for example rock wool, cemented in position or by providing roughened surfaces made of granular material. 'I'he volume of fuel may be controlled by means of a hand valve 40 or by means of any of the various automatic controls nowknown. A baffle 4I is positioned opposite the lower end of the supply duct 31, so that the air entering the retort through the duct- 31 will be deiiected away from the opening 33 until it has traversed a portion of the retort and become thoroughly mixed with the vaporized fuel.

In operation the burner is preheated by permitting a quantity of liquid .fuel to flow into the combustion chamber. This fuel, when the burner i is cold, will drip from the small opening 31a yfrom entering at this place.

downwardly through the discharge openings 29 of the burner and into the channel portion I1 of the combustion chamber. When a suitable quantity of liquid fuel has collected in the said channel portion I1 a torch (not shown) may be inserted through the ignition duct 43. When the fuel is ignited, the removable cap 42 is again positioned on the ignition duct so as to prevent drafts of air When the burner structure is sufilciently heated to vaporize the liquid fuel, the vaporized -fuel mixes with the small quantity of air admitted into the retort through the supply duct 31. 'I'his air may be drawn into the retort'by the'stack or thermal drafts developed during the operation of the burner, or this air, together with the'supply of combustion air, may be forced into the heater by a suitable .blower (not shown). This rich gaseous mixture is passed from the retort 25 through the central opening 34 into the burner distributing chamber 26. From this chamber it is discharged into the combustion( chamber through the ring of openings 28. The gas is directed downwardly in the form oi separate streams or jets. 'I'hese streams are deflected upwardly by the curved portion of the bottom wall of the combustion chamber and bythe streams of combustion air drawn or forced into the combustion chamber through the passages 30 and2I. Additional combustion air is admitted into the combustion chamber through a ring of ports 44 positioned adjacent the vertical wall of the chamber. This air, while it funccient to support combustion, whereby the fuel is vaporized and mixed with said air to provide a f @ceases tions as auidliaryfcombustion air, also provides vina botttmwailtherecfffor-admitting a quantity an airfbla'nket along the inner face of the fcom-v bustion, chamber wall so as to hold the name and combustible products out of actual contact with v the wall.

fThe combustion air entering the combustion chamber is first caused to pass into the space 45 and thence into the space 46 beneath the burner.

In traversing -this space a large portion of the air is caused to ilow along thehot lower face of the combustion chamber bottom l5. The said air is thereby preheated before it'enters the combustion chamber. The upwardly moving flame and hot gases of combustion maintain the burner member and the retort associated therewith at a relatively/high temperature so as to insure complete vaporization oi.' the liquid fuel and prevent any likelihood of subsequent condensation thereof. `By the arrangement herein shown a thorough mixture of hot' gas and hot air is effected in the proper proportions to provide a blue flame. y

While the invention is illustrated herein in connection with certain specific structures, it will be obvious to persons familiar with this art that of combustion air, a retort arranged in the combustioncharnber to beheat'ed during the operation of the burner, meansgfor` delivering into the retort a controlled volume of liquid fuel and a quantity of air insuiilcient to support combustion, whereby the lfuel is vaporized and mixed with said air to provide a rich gaseous mixture, a burner member comprising a `chamber having an open top communicating with Ysaid retort to receive said gaseous mixture and formed with spaced dis-- charge openings positioned for discharging said gaseous mixture downwardly toward the. bottom of the combustion chamber, whereby the said bottom is heatedand a deector having a lateral ,-ilange -foridieetingsaid'combustion air into the downward, flow path of` said gaseous mixture, the bottomwallof "the, combustion chamber being positioned incluse relation to the said discharge openings land formed with a dished configuration which deflects the flame and hot gases of combustion upwardly in said chamber and the outer surface of said bottom wall being curved upwardthese various structures may bealtered in form and arrangement without departure from the pur-poseintended for the constructions shown. It is to be understood, therefore, that the invention contemplates all such changes in structure as come within the terms of the appended claims.

Iclaim: g

1. A liquid fuel burner comprising, in combination, a. combustion'chamber having an` opening for admitting a quantity of combustion air, a retort arranged in the combustion chamber to be heated during the operation of the burner, means for delivering into the retort a controlled volume of liquid fuel and a quantity of air insumrich gaseous mixture, anda burner member including an air deilector arranged above said combustion air opening so'as to deflectthe said air laterally and the burner member having an open top communicating with said retort to receive ly toward said combustion air opening so that air adjacent said outer surface is heated before it enters the combustion space.

4. A liquid fuel burner comprising, in combination, a combustion chamber having a bottom and side walls and having a central opening in its bottom wall for admitting combustion air, a

retort arranged in the combustion chamber to be heated during the operation of the burner, means for 'delivering into the retort quantities 0f fuel and air to provide a rich gaseous mixture, a

burner 'member positioned in said combustion chamber above said combustion air opening and formed to receive said richgaseous mixture from said retort and deliver it downwardly into the combustion chamber, a deflector for directing the combustion air `outwardly across the downward flow path of said gaseous mixture; the bottom of the covx'nbustionKVV chamber being formed with a curved4 upper surface heated by the flame and adapted to deflect the ame upwardly and formed with a lower surface which curves upwardly toward the combustion air opening, whereby airl" said gaseous mixture and formed with parts positioned to discharge said mixture in a downward direction intoA said combustion chamber and across the now path of said combustion air.`

2. A liquid fu'el burner comprising, in combination, a. combustion chamber having an opening in a bottom wall thereof for admitting a quantity of combustion air, a retort arranged in the combus-A tion chamber to be heated during the operation of the burner, means for delivering into the rel; torta controlled volumel of liquid fuel and a quantity of air insui'licient to support combustion, whereby the fuel is vaporized and mixed with said air to provide a rich gaseous mixture', a burner member comprising a, chamber having an open top communicating with said` retort to receive said gaseous mixture and /formed with spaced discharge openings positioned for discharging said gaseous mixture downwardly toward the bottom of the combustion chamber, and a deflector positioned above the said opening inY said bottom wall of the combustion chamber for directing said combustion air laterally into the downward iiow path l of said gaseous mixture, whereby the flame and hot gases of combustion are turned upwardly by a blanket of air near the bottom of said combustion chamber.`

3. A liquid fuel burner com rising, in combination, a combustion chambe adjacent said lower surface is heated and 'directed toward said combustion air opening.

5. A liquid fuel burner comprising,y in combination, a combustion `chamber havingbottom and vertical walls and having a central opening lin its bottom wall for admitting the main supply of combustion air and having` a ring of openings for supplying a blanket of air adjacent the vertical walls of the chamber, a retort and a burner member positioned in said combustion chamber above said central opening and adapted to vaporize the liquid fuel and deliver thevapor downwardly into said combustion chamber, the said burner memberbeing formedA with a ring of discharge openings from which said vaporized fuel is discharged, and a deilector positioned above said central opening to prevent the incoming combustion air from -cooling the maior kportion of the burner member and to direct said air outwardly across the flow path of said vaporized fuel.

6. A lliquid fuel burner comprising, in combination a combustion'chamber, a.v retort in said chamber having an inclined entrance passage, means for delivering into the entrance passageof theretort a 'controlled quantity 'of fuel to be vaporized, and a` quantity, of air insumcient to support combustion, a burner member positioned underneath the retort and .below Vthe inclined enf having an opening 'u trance passage so as to heatsaid passage, means comprising a reticular surface in said entrance passage for providing a plurality of pockets for retarding the movement of the liquid fuel and for retaining small quantities of said liquid fuel.

7. A liquid fuel burner comprising, in combination, a combustion chamber having a bottom wall, a retort in said chamber, means for delivering into the retort a controlled quantity of fuel to be vaporized and a. quantity of air insuicient to support combustion so that the vaporized fuel and air form a rich gaseous mixture, a burner member positioned below the retort adapted to receive vaporized fuel from said retort and deliver it downwardly into the combustion chamber in close relation with said bottom wall, the bottom wall being formed with an opening for admitting combustion air into the lcombustion chamber, and a deflector ring positioned in said opening and having a lateral flange overlying but spaced from the said bottom wall for directing a portion of said air along the top surface thereof.

8. In a heater of the character described, a casing provided on its inner surface with means for supporting a. re pot in spaced relation to the bottom of the casing, a cylindrical fire pot formed at its upper edge with an outturned flange engaging said supporting means and formed with a. bottom wall provided with a central opening therein for admitting combustion air into the nre pot and a burner member positioned in the nre pot .and provided with supporting means extending through the said central opening in said bottom wall of the nre pot to the bottom of the casing.

9. A liquid fuel burner comprising, in combination, a. combustion chamber having a bottom wall, a retort in said chamber, means for delivering into the retort a controlled quantity of fuel to be vaporized and a quantity of air insumcient to support combustion so that the vaporized fuel and air form a richl gaseous mixture, a burner member positioned below the retort adapted to receive said gaseous mixture from'said retort and deliver it downwardly into thecombustion chamber in close relation with said bottom wall, and means for admitting a stream of combustion air into the combustion chamber at `alocation beneath the burner adjacent the upper surface of said bottom wall and for directing a portion of said air stream into the -fiow path ofvsaid rich gaseous mixture and another portion of said air stream along said upper surface of the said bottom wall to form a moving air blanket for preventing the'ame from impinging against the said bottom-walks,V liiLICKI CLARKSON.

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