US1761537A - Oil burner and method of effecting the combustion of oil fuels - Google Patents

Description

June 3, 1930 w. F. RAVENOR 6 OIL BURNER AND METHOD OF EFFECTING THE COMBUSTION OF OIL FUELS Filed Dec. 3, 1924 In Ven 60 2. r61 fe a/s fififmvr Z a Pate nted' June a, Yieao UNITED STATES PATENT OFFICE OIL BURNER AND METHOD EFFECTIIQ' G THE COMBUSTION OF OIL FUELS Application filed December 8, 1924. Serial No. 753,670.

My invention relates to improvements in oil burners and the method of efi'ecting the combustion of oil fuels, and the ob'ect of my invention is to devise a burner for eavy fuel oil in which the oil is fractionally vaporized in an enclosed retort which characterizes the burner at high temperature without the accumulation of free carbon and ash'so that choking of the burner due to carbon and ash deposits is entirely prevented, enabling it to operate continuously with great cleanliness, economy and efliciency. In oil fuels there is a tendency when subjected to heat for the more volatile fractions to form vapors and 1 for the less'volatile fractions to retain their liquid state, and I refer to these two fractions of the oil-fuel, respectively, as vaporized and non-vaporized portions of the oil fuel.

A further object is to provide a burner ofthis character in which the entering oil is subject to a moderate temperature and in which all the surfaces subjected to high temperature are kept moist so that thefree gases do not contact with any dry hot surface. A

still further object is to provide an oil burner in which the lighter fractions only of the oil are vaporized, provided with means whereby the heavy residual fractions flow from the burner outlet into the furnace in the form of a drip to carry the free carbon and ash out of the burner which normally tend to choke it, an additional characteristic of the burner being that the flame is formed specifically into an oxidizing flame directed to a point on which the heavy residual drip falls so that complete combustion throughout is efiected in a highly practicalmanner. A still further ob ect is to devise a retort burner which functions to vaporize the volatile fractions from the oil designed and arranged so that the remaining residual oils are then cooled below their point of vaporization by directing them past surfaces cooled b the incoming oil and are further coole by passing them around the surface of a pipe maintained at a low temperature by an air current induced by the draft of the furnace so that the residual oil at its outlet point is below its kindling temperature.

The method of effecting the combustion of oil fuels at present in oil burners is to provide a motor driven fan or a jet to force air to the fuel to supplly for its'combustion. t is well recognized that merely allowing oil fuel to drip, without be: ing under pressure,from a nozzle will not provide for its combustion, but will result-in the accumulation of free carbon and soot about the nozzle that will very quickly clog the device. A primary object of my 1nven-- introducing the non-va orized portion to the oxidizing point of the ame,be it noted, not the-reducing portion of the flame. I utilize the non-vaporized portion to carry off any soot or ash that might result at the time of the separation of the vaporized from the non? vaporized portion of the oil fuel. attain these objects by the construction illustrated in the accompanying drawings in which'- Fig.1 is a view of the burner, in sectional elevation.

Figs. 2 and 3 are front and side views respectively of the burner as embodied in a furnace, the furnace being. indicated in dotted outline.

the necessary oxygen Similar figures of reference indicate similar parts throughout the several views.

1 indicates an open-ended cyiindrical shell perforated as shown to provide a plurality of air inlet apertures 2, in the upper end of which is fitted a shorter open-ended cylindrical shell or cover 3 the lower end of which projects a short distance into the shell 1 as at 4 and has its outer periphery Within the shell reduced in diameter so that a space 5 is provided between the shells while disposed in close proximity to the lower end of the shell 1 to provide an air inlet 39 thereinto is a ring 6 having a bore 7 of less diameter than the bore 8 of the shell 1, as shown more particularly in Fig. 1.

Positioned within the shell 1 at a suitable height above its lower end and concentrically therein is a small cylindrical chamber 9 closed at its lower end as at 10, its upper end being open, which chamber is termed, for the purpose of this specification, the retort, and expanded at its upper end to form an oil expansion chamber B, and extends to a point above the upper end of the shell 3, as indicated by the numeral 11, and is provided intermediate its height with an integral exterior annular lip 12, positioned a short distance below the upper end of the shell 3 so as to lie within the shell, and surmounting and substantially enclosing the upper end of the chamber 11, which is open, and suitably spaced therefrom is a hood 13 the lower edge of which is flanged outwardly, as at 14, this flange 14 being spaced close to the lip 12 hereinbefore mentioned, so that an annular orifice, outlet or nozzle 15 is provided from the interior of the chamber formed by the hood 13 and the enlarged upper end 11 of the retort 9. Between hood 13 and cover 3 is disposed suitable air port 52 preferably annular in form which functions to maintain a high air velocity induced by the draft of the furnace.

Secured concentrically to the bottom of the retort 9 and of less diameter than the same is a vertical tube 16 the upper end of whichis open and extends substantially to 1 the same level as that of the orifice 15 while within the tube 16 is a sealing pipe 16 of smaller diameter the upper end of which is secured to the underside of the hood 13 and the lower end of which extends to within a short distance of the bottom of the retort 9 and within the pipe 16 is a smaller open ended air pipe 17 the upper and lower ends of which extend respectivel through the hood l3'and the bottom 10 o the retort, the projecting lower end of the pipe 17 being surrounded by a ring 18 secured concentrically to the bottom of the retort, which ring forms the inner wall of an air cooling chamber 19 formed by the ring 18 and a cylindrical casing 20 disposed around the retort 9 and the ring and spaced 2. suitable distance therefrom, the lower end edge of the casing 20 being flan ed inwardly as at 21 to extend to within a s ort distance from the ring 18 so that an annular opening 22 is provided in the bottom of the chamber 19.

The pipe 17 is provided with a downwardly directed internal pipe 23 the mouth of which extends through the pipe wall and is-spaced a short distance below the level of ghe upper end of the tube 16, as indicated in 2 5 indicates a fuel pipe passed through the burner shell 1 and connected at one end to the retort 9 close to the bottom of the same its opposite end being formed as a receptacle 25 to receive a regulated oil supply from a fuel pipe 26 and maintain a constant oil level in the retort 9, since the oil level in the receptacle 25 is controlled at the same level, while 27 indicates an air duct passed through the shell 1 and connected at its inner end to the air cooling chamber 19 which surrounds the retort 9, as hereinbefore stated. The annular space between the walls 1 and 3 and the axially disposed walls 11 and 20 constitutes a flame chamber 51.

28 indicates a box inserted into the front of the furnace the furnace being indicated by the dotted lines and numeral 40 in Figs. 2 and 3, usually in the furnace door opening, which box has the top 29, bottom 30, sides 31 and 32 and back 33, the front of the box being open and the bottom 30 provided with an opening 34, as indicated in Fig. 3, the position of the box when in place being such that the opening 34 lies over a an 35 placed on firebrick 36 covering the fire ars 37. The box 28 is enclosed in a larger open-fronted box 41 havin an opening 42 with which the opening 34 of box 28 registers and. the space between the boxes is filled with a layer of asbestos 43.

The manner in which the burner is used and operates may be briefly described, it being understood that there are mainly, three chambers within the burner, namely, the retort chamber 9, which receives the unvaporized fuel oil from the pipe 25 and now identified by the letter A, the boiling oil chamber identified by the letter B and which extends from the oil level as maintained constant in the retort to the level of the upper end of the tube 16, and the gas chamber identified by the letter C, which is the space above the boiling oil level B1 enclosed by the hood 13, and that these chambers A, B and 'C, are surrounded by the shells 1 and 3 and are in communication with the interior of these terior thereof with which communication is established only through the opening 34 and thus the burner functions in the outside atmosphere. Oil being fed into the retort 9, that is, the chamber A, which is kept comparatively cool by the surrounding air chamer l9, boils when the burner is operating, into the chamber B, the boiling oil rising to the level B1, and, the lighter fractions being vaporized, gas forms andcollects in the gas chamber C, from which it passes through the outlet orifice 15 and mixes with the down draft of air passing the orifice 52 which en'- ters the upper end of the bore of the shell 3, the combustible gas and air mixture then passing down through the bores 8 and? of the shell 1 and ring 6, and through the opening 34 in the bottom of box 28 and registering opening 42 of box 41 into the furnace where it burns continuously as long as the burner remains in operation, the length of the flame, which is indicated by the numeral 45, being limited by the pan 35 which is placed under the flame at the oxidizing point ofthe same.

- It will be noted that additional air enters during operation through the apertures 2 and the inlet 39 between the shell 1 and the ring 6.

The heavy residual particles, being unvaporized in the chamber B, overflow the top of the tube 16 as a weir, and pass down between the tube 16 and the-sealing pipe 16 to the bottom of the tube 16 and then pass upwardly around the outside of theair ipe 17 to enter the outlet 23 and flow there rom in the form of a drip the temperature of which is below its kindling temperature due to the cooling of the residual flow by its passage around the sealing and air pipes respectively 16 and 17 from its overflow point to its outlet point, which drip, indicated by the numera1 44, carries with it the accumulation of free carbon and ash and drips on the pan 35, and as the point of contact of the drip with the pan is also the point of contact therewith of the oxidizing flame, combustion of the heavy residual fractions is instantaneously efl'ected from which it will be seen that choking of the burner by carbon and ash deposits is en tirely prevented, enabling it to function with great efficiency, cleanliness and economy.

I claim: v

1. The method of effecting the combustion of oil fuels, comprising heating the fuel to form vaporized and unvaporized portions thereof, separating said portions, burning the vaporized portion in a primary flame, while withholding the non-vaporized portion of the oil fuel from the said flame, and thereafter feeding the non-vaporized portion of the oil to said flame.

2. The method of effecting the combustion of oil fuels, comprising heating the fuel to form vaporized and unvaporized fractions thereof, burning the vaporized fraction;

temporarily withholding the non-vaporized fraction from the flame; maintaining the temperature. of said unvaporized fraction below its flash point; and then introducing the said unvaporized fraction to the flame.

3. In the method of eflectin the combustion of oil fuels, the ste s of continuously drawing ofi separately t e oil fuel in two portions, the vaporized and non-vaporized; and maintaining the temperature of said non-vaporized portion below its flash point and feeding it to the combustion flame in liquid form.

4. An oil burner embodying a shell; an oil retort within said shell; an oil expanding chamber communicatin with said oil retort; an annular flame cham er surrounding said oil retort and said oil expansion chamber; and a withdrawal chamber axially disposed within said oil retort and oil expansion chamber, and communicating with the former to receive unvaporized oil therefrom and having an outlet to the flame chamber to supply said unvaporized oil thereto.

, 5. An oil burner embodying a shell with air ports therethrough; an annular cover on said shell; an air jacketed oil retort in said shell and spaced from the wall thereof to form a flame chamber, an oil expanding chamber communicating with said retort from which the oil fuel is withdrawn in two separate portions, the vaporized and nonvaporized, and having an outlet for the former to said flame chamber, the cover having an air port of smaller area than the area of the flame chamber.

6. An oil burner embodying a shell; an oil retort operatively disposed therein; an oil expanding chamber communicating with said retort from which-the oil fuel is withdrawn in two separate portions, the vaporized ,and non-vaporized; nozzle means discharging from said chamber into the interior of the shell, and separate .means for delivering said non-vaporized portion of the fuel into the shell. 7

7. An oil burner embodying a shell forming a combustion chamber; an oil retort operatively disposed therein; an oil expanding chamber communicatin with said retort from which the oil fuel 1s withdrawn in two separate portions, the vaporized and nonvaporized; nozzle means for delivering said vaporized portions from said expanding chamber into one part of the shell; aseparate withdrawal means from the retort for said non-vaporized portion of the fuel; and

means for delivering said vaporized portion from said expanding chamber into the combustion chamber, a Withdrawal means from the retort for said non-vaporized portion of the fuel; an open ended air tube connected to said withdrawal .means and leading to said chamber, for delivering said non-vaporized portion of said oilfuel to the combustion chamber.

9. An oil burner embodying a shell forming a combustion chamber, an annular oil retort axially dis osed in said shell; an oil expanding cham er superimposed upon and communicating with said retort, from which the oil fuel is withdrawn in two separate portions, the vaporized and non-vaporized; an annular nozzle means for said vaporized portions discharging from the expanding chamber into the combustion chamber; an annular withdrawal chamber concentrically disposed within said retort into which the non-vaporized oil fuel may pass; an open ended tube concentrically disposed within said withdrawal chamber through which tube air may )ass to the combustion chamber, and a coniluit leading from said withdrawal chamber into said tube whereby said non-vaporized portion of said oil fuel may be introduced into said tube.

10. An oil burner embodying a shell; an

- oil retort within said shell; an oil expanding chamber communicating with said oil retort from which the oil fuel is withdrawn in two separate portions, the vaporized and non-vaporized; said shell forming an annular flame chamber surrounding said oil retort and expansion chamber; an air-jacket around said oil retort; and a withdrawal chamber axially disposed within said oil retort and oil expansion chamber, and provided with means whereby said non-vaporized oil may be conducted inwardly to said withdrawal chamber, and means to mix said non-vaporized oil with air and discharge same into the flame chamber.

11. An oil burner comprising a constant level fuel oil retort having its upper end extended to form an expansion chamber, and provided with an exterior lip intermediate its height, a hood surmounting the upper end of said chamber enclosing therewith a gas chamber receiving the vaporized light fractions from the boiling oil, said gas chamber having an outwardly extending flange at its lower end edge disposed adjacent the said exterior lip forming therewith an annular outlet from the gas chamber, an air pipe extending at its 0 posite ends respectively through the hoo and the bottom of the retort, said air pipe being provided with a downwardly directed internal pipe the mouth of which extends through the pipe wall below the normal constant oil level, a sealing pipe disposed around and spaced from the said air pipe" secured at its upper end to the under side of said hood and extending at its lower end to within a short distance of the retort bottom, and an openended cylindrical shell surrounding the said retort and chambers.

12. An oil burner comprising a constant level fuel oil retort having its upper end extended to form an expansion chamber, and provided with an exterior lip intermediate its height, a hood surmounting the upper end of said boiling oil chamber enclosing therewith a gas chamber receivin the vaporized light fractions from the boiling oil, said gas chamber having an outwardly extending flange at its lower end edge disposed adjacent the said exterior lip forming therewith an annular outlet from the gas chamber, an air pipe extending at its opposite ends respectively through the hood and the bottom of the retort, said air pipe being provided with a downwardly directed internal pipe the mouth of which extends through the pipe wall below the normal constant oil level, a scaling pipe disposed around and spaced} from the said air pipe secured at its upper end to the underside of said hood and extending at its lower end to the retort bottom and extending at its upper end to the normal oil level and an open-ended cylindrical shell surrounding the said retort and chambers.

13. The combination with a furnace, of a box inserted into the furnace front closed on all sides except the front which is open and having an aperture in the bottom forming theonly communication between the interior of the box and the firebox, an openended cylindrical shell seated in said box With its bore communicating with the box aperture, a fuel oil retort mounted within the shell having its upper end extended to form an expansion chamber, a hood surmounting the upper end of said chamber enclosing therewith a gas chamber, said gas chamber having a side outlet, a vertical air duct extending at its opposite ends respectively through the hood and the retort bottom, said air duct being provided with a downwardly directed internal discharge, the mouth of which is directed toward said aperture, a pipe disposed around and spaced from said air duct secured at its upper end to the underside of the hood and extending at its lower end below the said air duct discharge mouth to prevent escape of gas therethrough from the gas chamber, and a tube disposed around and spaced from said pipe secured at its lower end to the retort bottom extending at its upper end to provide a weir over which non-vaporized oil overflows.

14. The combination with a furnace, of a box inserted into the furnace front closed on all sides except the front which is open and having an aperture in the bottom forming the only communication between the interior of the box and the firebox, an openended cylindrical shell seated in said box with its open end communicating with the box aperture and a fuel oil retort mounted within the shell and having as and nonvaporized oil outlets into the s ell, the shell formin a flame chamber which discharges throng its open end and said aperture into the furnace. Dated at Vancouver, B. 0., this 24th day of November, 1924.

WILFRED FRANCIS RAVENOB;

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