US1835297A - Oil burner - Google Patents

Description

W. S. GRANT nec. s, 1931.l

OIL BURNER original Filed Deo.

5, 1.927 2 Sheets-Sheet l I Patented 1.931-

UNITED, l STATES PATENT.' orrics .wmmnn s. emr, or nn'raorr. meinem, assmnon fro my D.- mmm r- DETROIT, meinem on. BURNER,

- This invention relates to oil burners for various types of furnaces or heating apparatus, the principal object being the provision` of a new and novel oilburner and particu 3 larly a fire -pot used in connection therew1th,g

v through the fire pot.

- and is a division of my application for Letters Patent of the United States forimprovements vin oil burners led December 5, 1927 and serially numbered 237,947.'A

10 Another object is the provision pf a new and novel oil 'burner pot for oil burnlng apparatus so designed and constructed as to preclude the passagev of unvaporized fuel partlcles out of the same into the combustion cham; .15 ber of the boiler or other apparatus for which the heat is being provided, 'and so fermedlas to provide withoutjany mechanical ald of any description'a relatively flat and wide spreadA llame. 2 Another object is the provlsion ef a burner apparatus for oil burning mechamsms so designed and constructed as not to depend upon an excess of air su plied to the same for the complete lvaporiz'atlon of the oil being burned. 25 A further object is the provision of -a ir'e pot for oil burning mechanism in which a refractory lining is provided and so mounted with respect to the shell of the fire pot as to quickly brought to an incandescent condition tively long time after discontinuance Aof la 'heating medium, by the prevention of heat jects in view. 1 Y

In the accompanying drawings which illustrate a suitable embodiment ofthe present invention andl in which like numerals refer to v1ews,-

Fig. 1 is a plan view of the oil burning apparatus the furnace being 'shown in the horizontal section. 'l0 Fig. 2 isa side elevation of Fig.A 1 partially and maintained in Such condition for a relalike parts throughout the several diiferent 1927, serial no. 237,947.' Divided and uns appnauon ma August ao, 192s. serial No. 300,773.

in section, the muler being removed to better illustrate the construction of the same.

' Fig. 3 is an enlarged vertical sectional view taken on line 3.-3 of Fig. 1, lon 'tudinally -through the oil bur-ner. nozzle an centrally Fig. 4 is a vertical sectional view taken on the line 4-4 of Fig. 1 and illustratesthe form of iiame obtained by theuse of the fire pot illustrated.

In the drawings is shown a conventional type of furnace 15 which may be especially designed for use in connection withthe present lnvention or ma be of the usual coal burning type which as been converted into -an oil burning type by the use of the present invention. Within the ash .pit 16 of the furnace is a fire pot designated generally in Figs. 1 and 2 as. 17, which is supported from the floor of `the ash pit by the standard 18v which adjustably engages the a er- .tured boss 19 formed on the outer sur ace ofthe fire pot 1 7, the iire pot 17 being locked in vertical adjusted position by means of the set screw 20. Integral with the fire pot 17 is the nozzle or' venturi 21 which enters the fire pot at a tangent to the interior surface thereof. Supported exteriorly of thefurnace on the legs 22 is the stand 23' which supports the-.electric motor 24. On 'one end of the motor 24 is secured a fan or blower 25 which may be of any conventional type, but for the purpose of illustration is shown as a centrifugal type of blower,

it being provided with-a disc r passage 26.which extends through the for 27 of vthe ash` it 16and-is socketed in the outer end of t e venturi 21. The air intake for the' fan 25 extends axially from the fan casing on the side-thereof opposite the motor 24 and receives at its free end a mullier or silencer 29. This serves to mulile the sound of the air rushing through the fan and its passages and also serves to mule the noise of combustion of the gases in the lire pot 17 which tendsto travel back through the passage 26 and'out through the fan 25.

` The oil is conducted through! theJ pipe 42 to a valve mechanism having a .casing 43 andlthenthro'ugh the pipe 44 to another valvemechanism having a casing 45. From the casing the -oil is conducted through the pipe 46 to a third valve mechanism, the casing of which is indicated as 47, and thence through the pipe 48 into the interior of the fan passage 26, the pipe 48 terminating inv the nozzle end 49l which is provided with a pluralityof radial openings 50 for the escape of the oil. The purpose of the foregoing valves which are inserted in the oil line will be described later.

As set forth in the objects-of the present invention, the construction herein disclosed employs no pilot light, the fire never being extinguished, but instead, being merely checked when the room or other space being heated has reached a desired maximum temperature, the mechanism being constructed to provide a high and'low fire. It is obvious that in attaining such a result the air and the fuel being fed to the mechanism will at no time be completely shut ofi', but that` in changing from high to low fire a lesser amount of air and o1l will necessarlly have to be fed to the mechanism than for high fire conditions. My method of controlling the air is to provide the fan 25 of such capacity that at full speed of the motor 24 the desired amount of air for high fire conditions is being fed to the burner, and I prefer to allow the motor 24 to run at a constant speed and to reduce the amount of air bein passed by the same to the burner for low re conditions by throttling the amount of air which the fan 25 may draw into the same. I accomplish this result by positioning a butterfly valve 51 on the shaft 52 within the intake passage 28 of the fan 25 and securing to the upper end of the shaft 52 above the passage 28 a lever 53. Rotatably secured to the shaft `52 above the lever 53 is a second lever member 54 provided with a slot 55 as indicated in Fig. l. The screw 56 projects downwardly through the slot and threadedly engages the lever` 53 and thereby locks the levers 53 28 I provide a third lever 57 secured thereto,

the free end of the lever being provided with a screw 58 which is a-dapted'to bear against the boss 59 formed on the lower surface of the casing 28 to control the low fire or minimum volume of air being passed through the fan 25, the screw 58 being threaded inwardly or outwardly to regulate the positionof the butterfly valve 51 for this condition and thus determining the amount of space between the edges of the butterfly valve 51 .same into the pipe 44. A needle valve provided with a suitable indicating and controlling head 66 cooperates with the valve 63 to limit the amount of oil which may flow through the openin 63 under the constant head provided for y the supply reservoir, this serving to regulate the amount of fuel flowing to the burner for high fire conditions when the maximum amount of 'oil is being used. A suitable pointer 67 is preferablyprovided in conjunction with the control head 66 for visual location of the needle valve 65 with respect to the opening 63. The oil from the pipe 44 flows'through the solenoid controlled valve 45 which is connected in series with the solenoid valve 62 for the air supply .fan and the supply of current to both of which is controlled by one or more suitable thermostats (not shown) located in the room or rooms. heated by the furnace, as will be readily understood. The valve member 45 is so constructed that when the main flow of oil through the same for high 4fire conditions is shut off upon operation of the solenoid, sufficient oil is by-passed past the valve to the pipe 46 to take care of low fire conditions, as is fully explained in my previous patent application above referred to.

As this far described, the mechanism for providing a maximum and minimum amount of oil and air has been explained, it being understood of course, that the solenoids 73 and 62 are so controlled as to furnish a maximum amount of air for the maximum amount of oil and vice versa. The construction of the lire pot and burner nozzle and venturi will now be described.

As shown best in Figs. 3 and 4, the fire pot comprises a cup-shaped metal part or por tion 76 and a refractor lining 77 conforming in shape to the port1on'76, the refractory dished upper surface of the diaphragm 78 is shown as formed Complementary to a substantially spherical surface and as receding from a thin inner edge thereof in an upwardly curved manner,-the bottom of this flange being shown as flat and as disposed in substantially the same plane as a circular upper edge of cup 76. I prefer to so form a cylindrical wall and bottom wall of the lining 77 with respect ito the corresponding walls of the cup 76, that when these two Vaseline? parts are in cooperative relationship a dead air space such as 79 is formed between the ad]acent walls of the same, this bein an important feature as will be later described. As previouslydescribed, the ire 'nozzle or 'venturi is formed integral with the rtion 76 of the re pot and extends into t e interior thereof in a direction tangential to the.' interior side face of the refractory material 77, the nozzle being modified in cross `section ,from a circle at its rear end to an ellipse at the discharge end within the fire pot in order toimpart greater velocity to the'gas being e'ected from the same intol thefire pot.

ormed in the bottom Wall of the fire nozzle as shown in Fig. 3, is what maybe termed a well or receptacle 79 provided with a baille 80 extending upwardly and inwardly from the bottom interiorv wall of the nozzle 21 at the rear end of the well 79 over the rear portion thereof, thus'forming a hood over such portion. This baiile or hood 80 is provided with a plurality of openings 80 through the same for the pur ose of conductin a metered amount of air throu h the ba e for apurpose to be described ater. I'he metal along the edges of the well 79 is formed to provide inwardly extending flange portions 81, and received within the well 79 under the i'anges 81 is an absorbent pad 82 which 'may be formed'of suitable fibrous asbestos mate` rial, or other suitable material, and a screen such as 83 is rovided over the up er sur- .face of the pad)` 82 for maintaining t e same in place and providinga ready passage for oil'to the pad and the gases vaporlzed 01T of the pad 82 into .the nozzle. 'As indicated in Fig. 3, the oil nozzle 49 is positioned substantially in line with the inner edge ofthe bae 80 so that the oil being discharged from the same through -the openings 5() will fall upon the pad 82. The designl of the nozzle 'and fire pot is such that in operation the oil from the nozzle 50 is deposited upon the pad 82 which absorbes the same, the heat from the fire pot is conducted back through absorbe thereby to be given oif inthe form of a vapor'which is picked up by the air`from the tire nozzle 21 and heats the pad 82 to a relativel high degreewhi'ch causes the oil thefan 25 and isV carried into the fire. pot. In o eration the [ire actually extends over the pa 82 and in' low fire operation all of the oil that enters thevre pot is in the form of vaporized gas coming solely from l-thepad 82. During high re operation when the maximum blast of air from the fan 22 is passed through the'iire nozzle v21, a certain amount ofunvaporized oil particles in the form of a mist may be carried directly into the fire pot without having had the opportunty of bein de osited upon Athe pad 82,

and absorbed t ere to. be laterheated and vaporizedeintogthe rm of .a readily combustible gas. YInasmuch as the pad. 82 is `of,

-asto a relatively substantial area, vthe baa is lprovided at the rear of the same in order to as may occur whenv the butterfly valve 51 is suddenly opened, -and'thus prevents ssible blowingl out of the ame above it. he pad 82v in t is construction not only serves'the purpose of the pilot light used in the con- Ventional oil burner system. but in addition.

serves as the sole means of supplying oil in roduce no.

purpose is best 'determlnedby protects the pad 82 from any sudden blasts ofair such.l

a vaporized vstate to the fire pot, 1t being such sitively preclude its being extinguishe by any blast of ainfrom the fan 25, and such as to provide a suicient fuel re' serve therein for continuous combustion fora substantial period of time, fpr instance, fifteen minutes to onehalf hour, depending upon the sizeand surface area of the pad 82, after the How of oil throu the nozzle 49 has completely stopped.- he flange projected into the re pot thi'ough the nozzle 21, and the combustible ixture which is carried thereby and has itdbombustion completed within the fire pot, because of the tangential direction-.in whichv it is introduced into the fire pot, is caused to swirl around f the same and radually rises upwardl into ontactwith t e diaphragm 78 and t en is nusr forced upwardly through the 4central opening of t e same. The flame and gases'in assng upwardly through the diaphragm 78 erm a low pressure area directly over the diaphragm 78 which acts to pull the ,flame outwardly and imparts to the 'same a iiat mushroomtype of swirl formation as indicated in Fig. 4. This Haine which may be regulated by proper adustment of the but-l teriiy valve 52 and .n le valve 65, may be 11| l controlled so ,as to approach closeto but out of contactwith the said walls of the furnace 15 so asto impart thev maximum amount of heat to the same without actual contact with it, which would otherwise act to corrode the walls ofthe furnace with which the flame came in contact. This construction also insuresthe hea'tof the combustloncomlng 1n contact .with the lower portion, ofthe heating surface of the furnace instead of; the dome thereof, as is the case in substantially las all of the conventional oil burner constructions, and 'as the dome usually com rises less than fty per centof the heat absor ing area l of the furnace, the importance of thisfeature will be readily recognized, and it will be further readil nnderstod that in obtaining this form of lfame I am enabled to obtain a stack temperature of as low as 200 F. as opposed to a stack temperature of between 600 and 700 F. obtained in the usual oil burning mechanism, the saving of heat as a result of this feature being enormous.

Under high fire conditions when the maximum amount of oil and air is being fed to the fire pot, a certain amount of oil from the nozzle 49, as previously described, may be carried into the fire pot in the form of a mist of unvaporized fuel particles such as the conventional constructions depend upon entirely for combustion. In such a case, these particles being heavier than the bulk of the combustible mixture being fed into the fire pot, and because of the rotary motion imparted to the mixture by the formation and location of the lire nozzle 21, the centrifugal force acting on the particles will throw them outwardly into Contact with the incandescent' refractory lining 77'which will quickly vaporize the same and they will thereafter be discharged through the diaphragm 78 in the form of a vaporized gas. Thediaphragm 78 serves to prevent any of these unvaporized fuel particles from being carried above the lire pot inasmuch as the centrifugal force acting on the particles confines the path of the particles to a point in the fire pot axially outwardly from the inner edge of the diaphragm 78. In forming the refractory lining 77 with the airspace 79 between the same and the metallic cup portion 76 I am enabled to heat the refractory material 77 to a substantially higher temperature and degree of incandescence than in the conventional constructions, inasmuch as the air space 79 serves as an insulation between the refractory mate rial 77 and the cup 7 6 and thereb cuts down the conduction and radiation o heat from the cup portion 76 to a minimum. It also serves as a means for allowing the refractory material 77to be brought to a point of incandescense in a much shorter period of time than in conventional constructions, and further serves to hold it at such temperature for arelatively greater period of time after the flame Within the fire pot has been extinguished.

In accordance with the laws of some States,

means must be provided in apparatus of this type such that should oil in liquid form accumulate within the fire pot the flow of oil to such pot will be stopped, this being a safety provision for eliminating ossibility of an explosion due to the accumu ation of a material body of oil. This provision is taken care of in the present invention by forming an upwardly projecting boss 84 on the floor of the cup portion 76 of the re pot and of such a height as to extend into flush relationship with the floor of the insulating material 77.

The boss 84 is shown as tapered favorably to a sealing fit and as provided with a central opening 84 the lower end of which is screw-A threaded for connection with the pipe 85 as indicated in Fig. 3. The pipe 85 in turn extends forwardly out through the door 27 of the ash pit 16 and terminates above the bucket 86 which is suspended from the free end of the lever 87 which actuates the trip valve 47. In operation, should for some reason or other an excess of liquid oil accumulate in the lire pot, the oil will pass down through the opening 84 into the pipe 85 and be drained into the bucket 86. The valve 47 is so arranged that when a predetermined weight of oil is drained. into the bucket 86, the weight of the oil and bucket acting through lthe arm 87 will actuate the valve 47 to stop the flow of oil to the burner.

A safety feature best shown in Fig. 3 comprises a thermostatic switch inserted in the electrical connections leading to the solenoids 62 and 7 3. This switch comprises the insulated base 104, the Contact member 105, and the strip of thermostatic metal 106 supported at one end on the binding post 107 Within the fire nozzle 21 and adjacent the open end of the same. The electrical current passing through the solenoids 62 and 73 is adapted to pass between the binding posts 105 and 107 through the thermostatic strip 106 which is so formed that when cold or relatively cold its free end is bent outwardly out of Contact with the binding post 105 and when heated straightens out and makes Contact u with the binding post 105 and thereby permits the passage of electricity between the posts 105 and 107. Under normal operation of theburner sufficient heat is supplied to the thern'iostatic strip from the gases burning above the pad 82 to insure contact of the tl1crmostatic strip 106 with the binding post 105, but if for any reason all flame should become extinguished within the lire pot of the lire nozzle 21, the Strip 106 will bend away from the binding post105 and thereby interrupt the flow of electricity to the solenoids and 73 and movcthe mechanism to low lire position.

The novel form of lire pot which I have provided serves to produce a flame within the furnace which much more economically coacts with the heating surface of the furnace than in the conventional constructions and this without the employment of any mechanical spreading means of any description whatsoever and, further, that complete burning of all the oil particles is assured and the formation of carbon prevented.

Although I have shown in the accompanying drawings and described a variety of separate and distinct features which I have combined to form an oil burner of novel construction and distinct formation it will be recognized, of course, that various of these devices may be eliminated under certain conditions or ma be employed in vconnection with devices o a different type, and I do not limit myself to the employment of the same to the specific assemblage with parts and to the exact construction shown and described, but desire to state that formal chan esmay be made in the specific embodiment o the in- `vention described without departing from the spirit or substance of the broad'invention, the sco e of which is commensurate with the appen ed claims.

What I claim is:

l. A fire pot foroil burning apparatus having a tangential inlet and comprising a cup-shaped member provided with .a substantially cylindrical wall and with an inwardly extendin flange adjacent an open upper end thereo the lower surface of said flange being substantially flat, the upper surface of said flange bein curved outwardly and upwardly, and said ange being thinnest at its inner edge. f

2. A fire pot for oil burning apparatus comprising a cup-sha ed member provided with an inlet dispose to impart a whirling movement to a mixture admitted therethrough and with an inwardly extending ange adjacent the o n end thereof, the upper surface of said ange bein dished to form a low ressure area over sai flange and said flange ing thinnest at its inner edge',

I whereby to spread the flame passing upwardly therethrough. j v

3. A fire pot for oil burning apparatus comprising a cup-shaped member having an inwardly extending integral annular .flange adjacent the open end thereof, the outer face of said flange being formed complementary to a part of an approximately s herical surface cup, and a refractory linin and means for introducing a combustible mixture into said cup below said Hange in a direction tangential to the interior surface of said cup. i

' 6. A tire pot for oil burning apparatus comprising, in combination, a metal cup hav-ing a tapered nozzle member integral therewith and disposed to discharge into said spaced from the sidesthereo the space between said cup and lining being sealed at the open edge of said cup and about said nozzle against the circulation of air.

WINFIELD-S. GRANT.

and the inner face of said ange being substantally flat, and means for introducmg acombustible mixture into said member in va direction tangential thereto and below said ange.

4. A fire pot for oil burning apparatus comprising a cup-shaped member provided with an inwardly extending integral annular flange adj aoent the open end thereof the surface of said llange most remote from the bottom of said cup being concave and curved outwardly and away from said bottom, and the surface of said flange more adjacent to said bottom being substantially dat and disposed in a plane substantially perpendicular. .to the axis of said cup; and means for imparting a whirling motion to a fuel mixture upwardlyadvancing past said ange.

5. A fire pot for oil burning apparatus comprising a cup-shaped member provided with an inwardly extending integral annular flange adjacent the open end thereof, the surface of -said angefmost remote from the bottom of said cupbeig concave and curved outwardly and away from said bottom, the

for 4said cup

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