US1766243A - Process for burning liquid fuel - Google Patents

Description

June 24, 1930. w. CANNON 1,766,243

PROCESSFOR BURNING LIQUID FUEL Original- Filed May 29, 1925 '3 Sheets-Sheet 1 WMW June 24, 1930. J. w. CANNON PROCESS FOR BURNING LIQUID FUEL Original Filed May 29, 1925 3 Sheets-Sheet 2 INVENTOR 3 sheet-shea 5 J. w. CANNON PROCESS FOR BURNING LIQUID FuEp June 24, 1930.

Patented June 24, 1930 rarer PROCESS FOR BURNING LIQUID FUEL Original application filed May 29, 1925, Serial No.33,6 26. Divided and this application filed February 1,

1928. Serial No. 85,400.

This invention relates to a process of burning liquid fuel, such as oil, and has for its general object to secure complete combustion of such fuel and to obtain maximum heating efficiency therefrom. Further and more limited objects of the invention will be pointed out in the specification. The process set forth herein is realized in and through an apparatus which has been found to be particularly adapted for house-heating purposes and in conjunction with a centrifugal type of burner for oil-hereinafter referred to specifically as typifying the liquid fuel employed.

Claims drawn for improvements in the burner structure are covered in my application Serial No. 33,626, filed May 29, 1925 of which this application is a division.

Referring to the drawings, Fig. 1' represents a view partly in section and partly in side elevation of a system or apparatus embodying my invention and by means of which my process is realized; Fig. 2 is a central vertical section of the burner employed in such apparatus; Fig. 8 is a plan view of the burner, the cap being removed and certain parts being broken awa Fig. 4 is a vertical sectional view through the diaphragm valve which controls the flow of water to the steam generator; Fig. 5 is a detail view in vertical section through a part of the burner; and Fig. 6 is a similar view through the bypass tank for the oil supply to the burner.

Describing the various parts by reference characters, 1 represents the main oil tank of the system, connected by pipes 2 and 8 with a smaller-elevated siphon check tank 4, from the lower part of which a pipe 5 leads to the inlet side of a pump 6 driven by a motor 7, the motor indicated being any standard electric motor and driving the pump 6 through a shaft 8. The pipe 2 is provided with a downwardly seating check valve 2*, and is connected with the pipe 5 through the tank 4 by means of an elbow 5 The elbow is pro vided with a small vent 4 for preventing any siphoning of the liquid from the tank 1 and the tank is provided with a filling plug 4 The numeral 9 designates a pipe for delivering oil from the outlet side of the pump to the bypass tank 10, shown in detail in Fig. i

other pipe 12 leads to the top of the tank 4 for the pu-pose of conveylng excess fuel in the bypass tank 10 to the tank 4. A pipe 13 leads from the pipe 9 to the upper end of a diaphragm valve-chamber 14, the lower end of said chamber being provided with a pipe 15 for delivering Water from any source of supply, as the city main. From the delivery side of the diaphragm valve-chamber, {2L pipe l5 conducts the water passing therethrough to a steam generator 16, positioned within the fire pot of a furnace or heater 17, the particular furnace shown being indicated as an ordinary vapor or steam generator having an annular chamber or water leg 18. The pipe 15 is provided with a globe valve 15', whereby the Water supplied to the generator may be controlled by the diaphragm valve and also regulated by such hand-operated valve From the generator 16, a pipe 19 conducts the steam to the atomizer B within the burner A. y

The burner is of the centrifugal type, and the one illustrated herein comprises generally a cover which is secured to a vertical shaft 20, and a bottom plate, the bottom plate of the burner being spaced from'the top or cover of the burner to provide a slot therebetween for the discharge of the combustible mixture by centrifugal action, the cover and bottom being connected by fan blades. The bottom of the shaft 20 is provided with a bevel gear 20? meshing with a bevel pinion 21? attached to. the shaft 21 and driven by the motor 7.

Burner construction the underface thereofin which an annular which will now be described.

plate 26 is secured by means of suitable rivets 26 The plate 22 has secured thereto the upper ends of the fan blades 27, the blades being such as are used with centrifugal fans. Each blade 27 is provided with a step 27, a short distance below the plate 26, and these steps support the peripheral portion of the bottom plate of the burner, indicated generally at C, the blades extending through the peripheral portion of the bottom plate and having their bottoms fastened to an annular plate 28 surrounding and spaced from the bottom plate C.

The bottom plate C as shown herein is given a conformation which not only provides a comparatively narrow peripheral slot C with the ring or plate 22, but admits air freely to the space between the top and bottom members and prevents the mixture delivered to such space from being drawn out of the burner by action of the lower fan provided by the blades 27 and the plate 28 and the peripheral portion 29 of the plate C. It will be noted that the peripheral part 29 of I the lower plate is substantially parallel to the plate 26, providing therewith a narrow peripheral slot for delivering the mixture into the fire pot D. From the inner end of such peripheral portion 29, the plate C extends downwardly and inwardly as shown at 30, and is then bent upon itself, at 31, and extends upwardly parallel with the axis of the shaft- 20 and spaced therefrom, the upwardly extending portion of the plate being shown at 32, thus providing a trough C at the central portion of the plate. The burner is located above an opening 33 in a deck or floor 33 which closes the bottom of the fire pot, except for the said central opening. The opening is approximately of the same diameter as the diameter of the upper and lower plates of the burner. The space between the plates 22 and C is supplied with a mixture of oil and steam from the atomizer B, the details of As pointed out hereinbefore, water is conducted to the generator 16, it being noted that this generator is shown as a simple receptacle into the bottom of which water is delivered through the pipe 15 and from the top of which steam is taken by the pipe 19 to the atomizer B.

It will be noted that, by supporting the burner from the shaft 20 by means of arms 24, connected to the fire ring 22, a practically free and unobstructed open center is provided for the supply of air to the mixture of steam and atomized oil delivered between the upper and lower burner plates and against the bottom of the central depression of the lower plate. The burner constructed as described gives a complete admixture of air with the steam and atomized oil between the upper and lower plates of the burner and produces an intense concentrated flame to the fire ring 33' and extending upwardly from said ring in the fire pot. This not only secures perfect combustion of the oil, without the accumulation of carbon or soot within or upon the burner and boiler, but also prevents the destruction of or injury to the burner and the boiler and the parts thereof by the tlan'ie. Furthermore, by constructing and operating the burner in the manner described. I am enabled to run the burner at a materially reduced speed, as compared with burners of similar types, thereby enabling me to prolong the life of the moving parts and economize in the use of current for the motor without sacrificing any of the advantages pointed out hereinbefore.

Reference has been made heretofore to the particular shape of the bottom plate 0 of the burner. In small installations, it will be given the shape shown herein, with the deep trough C formed by the walls 30 and 32, surrounding the shaft 20. In larger installati ons, however, this trough may be comparatively shallow. In both cases, however, the construction prevents the combustible mixture between the plates 22 and C from being drawn around the inner edge of'the part 32 by virtue of the action of the lower fan which is provided between the peripheral portion 29 of the lower plate and the plate 28. In both and small installations, a narrow airway will be provided between the top of the inner wall 32 of the trough and the inner edge of the ring 22. Because of the fact that the superheated steam and atomized oil are delivered forcibly into the trough in the form of a mist, there is danger that the large fan provided beneath the bottom plate C by the blades 27 will draw the fuel mixture from the inside of the burner beneath the plate C. By extending the inner wall 32 of the trough upwardly so as to provide a narrow passageway between its upper edge and the inner edge of the plate 22 this undesirable action will be prevented.

.Oz'Z atomz'zng and mixing device The oil atomizing and mixing device is located within the central part of the burner and between the vertical flange 32 of the lower plate and the shaft 20. It may be a metallic block, as indicated, having therein a vertical passage 19 constituting a cont-inuation of the steam pipe 19, and a vertical passage 11 constituting'an extension of the oil pipe 11. Steam is delivered from the top of the passage 19 into a transverse or horizontal passage 3 1, which passageway has a relatively restricted inlet end 34 but is of increasing cross-sectional area toward its intersection with the top of the passage 11. This arrangement enables the steam which is delivered from the top of the passage 19 to expand as it flows through the passage 34 and enables the steam to operate in a. most efiicient manner upon the oil delivered from Q1: nu

the top of the passage 11 to secure the atomization thereof. The duct comprising the passages 34, 34 and 34 delivers the mixture into a nozzle 35, the lower end of which projects downwardly within the space between the walls 30 and 32, as indicated at 35 lhe nozzle is shown as connected to the mixer B by means of a threaded recess 36 forming an enlarged extension of the passage 34, with a bushing 37 surrounding the flanged end 35 of the nozzle 35, the said bushing being threaded into the seat 36. This construction enables the nozzle to be conveniently connected to and disconnected from the mixer B and provides the nozzle with a flared receiving end for the mixture delivered thereinto from the passages 34, 34".

By-pass tank In order to insure efiicient operation of the burner under all ordinary incidents of use, the pump should be capable of supply ing a sufiicient quantity of oil to enable the burner to operate at and below its maximum capacity. In order to' accommodate the system for variations in burner oil-supply without the necessity for changing the speed at which the pump is driven, I provide the bypass tank referred to, such by-pass tank enabling oil which is pumped from the tanks 1 and 4, but which is not required for the burner, to be delivered back into the tank 4 and thence into the tank 1.

The by-pass tank, indicated generally at 10 (see Fig. 6) is provided with an inlet connection 38 with which the pipe 9 communicates, the wall of the tank having suchconnection being provided with a passage 39 extending downwardly from said connection and then inwardly, as shown at 39, a short distance above the bottom of the tank. Across the upper part of the tank and below the top thereof there extends a rib 40 provided with a passage 41 the delivery end of which communicates with a connection 42 for the pipe 11 leading to the atomizer B. I'he passage 41 is provided with a pair of valves 43 and 44, each provided with a cover, indicated at 45, which covers can be locked in place so that one of the valves may be set in a position to prevent more than a certain quantity of oil from passing to the mixer or atomizer. The passage '41 receives oil from the chamber therebeneath through a vertical passage 41 formed in the rib and in a bushing 46, the lower end of which bushing cooperates with a valve seat 47 carried by the short arm 48 of a bent lever the long arm 49 whereof projects in front of the delivery end of the passage 39, 89 the lever being pivoted near the rib 40, as shown at 50. A partition 51, extending from the tank wall having the connection 38 and partition wings 52 carried by the lever 49 provided an downturned valve seat 64 tank 1 without entering the passage 41 and The wall of the tank 10 which the burner. is opposlte the connection 38 is provided with a vertlcal passage 54 extending from v the bottom of the tank to the top thereof and having its upper end connected to the pipe 12 which leads to the siphon check tank 4.

In the top '01? the by-pass tank is a chamber 55 which delivers air liberated from the oil into the passage 54 through a port 55*. The

valve arrangement ensures the closing of the passage 41 as soon as the pump stops, thereby preventing siphoning of oil to the burner; it also preventsthe valve 47 from sticking.

Gantrol of water (53 oil pressure Reference has been made hereinbefore to the control of the water to the generator 16 by the pressure of the oil delivered from the pump 6. The manner in which this result is obtained will be explained in connection with Fig. 4 wherein 14 denotes the lower or 1 body portion of the diaphragm valve chamber and 14 the cover for said chamber, the diaphragm 56 being clamped between the parts 14 and 14 5? denotes a rod which is connected to a disk 5"? on the bottom of the diaphragm and which extends through a stufiing box 58 at the bottom or". said chamber and carries a yoke 59 having the valve 60, the yoke being provided with an extension 6O guided within a bushing 61 which is threaded into the bottom of the chamber 62 to which water is supplied through the'pipe 15. The inner end 01" the pipe 15 communicates with an extension 63 which has a cooperating wit the valve 60. This construction prevents water troinbeing supplied to the generator 16 until the pump has created a predetermined pressure of oil. When the pump is shut down and the fire extinguished, the

. valve 60 will engage its seat, but there will too be a delivery of steam for a short time through the burner slot, which will ensure the burning or" any oil vapors that may remain, and the cleanness of the burner parts.

With the parts constructed and arranged as described, the operation will be as follows: the motor 7 being started, the shafts 8 and 21 will be driven, the former shaft operating the pump which will deliver oil from the storage tank 1 into the tank 4 and thence to the pump inlet. Oil from the pump outlet will be delivered through the pipe 9 into the bypass tank 10, whence the quantity nece sary for the operation of the burner will be conducted to the atomizing and mixing device B through the pipe 11, the remainder of the oil, in excess of such burner supply, being delivered from the by-pass tank through the pipe 12 into the tank 4, whence any excess of oil may flow into the tank 1. In its passage through the tank 10, any sediment that may be in the oil is kept out of the burner pipe-line 11, and surging, or fluctuations in pressure, of the oil delivered into the burner are avoided. Part of the oil delivered from the pump will fill the pipe 13 and will operate the diaphragm 58 to open the valve 60, permitting water from the main (or other source of supply) to flow through the pipe 15 and past the globe valve 15 into the generator 16.

Prior to operating the burner, the generator may be heated by an source of heat, as a torch, to provide steam necessary for the initial atomizing of the oil; or the burner may operate, as is the case with burners of this general type, with a mixture of oil and air until the generator is heated suiiicicntly by the flame from the burner to generate superheated steam, after which the steam will atomize and be mixed with the oil in the manner described hereinbefore, and the mixture of steam, air and atomized oil will be thrown from the slot C provided between the upper and lower plates, this action being facilitated by constructing the burner on the principle of a Sirocco fan. The additional air for completing the combustion will be thrown into the fire pot, beneath the flame, by the fan provided by the lower portions of the blades 27 and the plates 28 and 29.

In practicing my process with the apparatus described herein, a mixture of steam (preferably superheated) with atomized oil and air is supplied to a burner, preferably of the revolving centrifugal type, and this mixture is so treated as to insure complete combustion thereof within a limited space, with an elimination of the roaring or drumming noise which is usually attendant upon the operation of burners of this kind and with a complete combustion of the oil, without any deposit of carbon or soot within the burner or within the parts of the boiler or other apparatus heated thereby and without injury to the burner and the boiler by the flame. Furthermore, the use of steam in the manner described, in burners of this type, positively prevents any flashing bacl"of the flame within the burner, an action which has characterized burners of the general type shown and described herein. The prevention of flashing back is further insured by the velocity of the fuel mixture through the space provided between the upper and lower burner members. The mixture of atomized oil, air and superheated steam enters the space at great velocity, is greatly expanded in such space; and flows through the narrow slot C at such velocity as will prevent the propagation of flame into such space.

Furthermore, in the practice of my process, by using superheated steam (at a temperature not in excess of 1000 F. and preferably not lower than 500 F.) I am enabled to at omize the coil thoroughly and deliver it, in such atomized condition and mixed with steam, into the burnerat a sufficiently high temperature to enable the mixture of oil, air and steam to be quickly and completely gasifled in the burner throughthe heat to which the latter is subjected by reflection and radiation in the combustion chamber. This gasification is facilitated by the heating of the upper burner plate 22 and cap 23 by the combustion within the fire pot and the transmission of the heat from these parts to the gasifying mixture within the burner. By locating the atomizer B within the burner and particularly in the central portion there of, the atomizer is protected fronr destruction, through the parts 22 and 23 thereabove, by the extreme heat within the combustion chamber, being also cooled by the air which flows upwardly within the inner'wall 32 of the trough A. Furthermore, the parts are located so that only a short nozzle or conduit 35 need be employed to deliver the superheated steam and atomized oil into the burner trough.

It should be noted that, in the operation of the apparatus to realize the process, the steam is delivered across the top of the oil passage 11 at substantially right angles thereto. The use of the by-pass enables me to feed the oil slowly, or under a comparatively light pressure, to the point at which the steam encounters the oil and thus enables the steam to operate in a most eflicient mannerin atomizing the oil. Furthermore, in the operation of such apparatus, it should be noted that the supply of water to the generator 16 (and hence the. supply of steam to the mixing and atomizing device B) is controlled in part by the pressure of the oil which is delivered to the said device. The apparatus and process described herein have proven to be of great eiiiciency in securing perfect combustion of oil without injury to the burners and theheating appliances with which the burners are associated, and in securing maximum efiiciency from the combustion of a given quantity of oil.

having thus described my invention, what I claim is 1. The process of burning oil in a furnace which consists in transmitting oil and water to said furnace, developing steam in a vessel exposed to the burning fuel and transmitting said steam wholly within the furnace, atomizingthe oilby means of the steam so developed, delivering the mixture of steam and atomized oil to the interior of a burner having a peripheral discharge outlet, supplying air to the interior of said burner to be admixed with said steam and atomized oil, rotating the burner, and igniting the mixture delivered by centrifugal action through said outlet.

2. The process of burning oil in a furnace which consists in transmitting oil and water to said furnace, developing steam and superheatin it in a vessel exposed to the burning fuel, transmitting said superheated steam wholly wi hin the furnace, atomizing the 011 by means of said superheated steam, delivering the mixture of steam and atomized 011 to the interior of a burner having a peripheral discharge outlet, supplying air freely to the central portion of such burner, rotating said burner, and igniting the mixture delivered from said outlet whereby complete and intense combustion of the mixture delivered from said burner is obtained.

3. The process of burning oil which consists in delivering oil, atomized by super heated steam, together with such atomizing steam to the interior of a burner'having a peripheral discharge outlet, supplying air to the interior of said burner for admixture with such atomized oil and steam, rotating.

the burner, and igniting the mixture delivered from said outlet.

l. The process of burning oil which consists in atomizing the oil by superheated steam under pressure, delivering the mixture of atomized oil and gas to the interior of a burner, igniting the mixture delivered by said burner, subjecting the burner to the heat developed by the combustion of said mixture whereby the mixture within said burner is gasified, and rotating the burner.

5. The process of burning oil which consists in atomizing the oil by superheated steam under pressure, delivering the said mixture at a sufficient velocity to the interior of a rotary burner, having a peripheral outlet, to prevent the propagation of flame 1nt-o the interior of said burner through said outlet, igniting the mixture delivered from said burner, and rotating said burner.

6. The process of burning oil in a furnace which consists in transmitting oil and water to said furnace, developing steam and superheating it in a vessel exposed to the burning fuel, transmitting said superheated steam substantially wholly within the furnace, atomizing the oil by means of said superheated steam, delivering the mixture thus formed to the interior of a burner, supplying air to the interior of the burner for admixture with the atomized oil and steam, igniting the mixture delivered from said burner, heating the burner by the ignited mixture whereby the mixture within the burner is gasified, and rotating the burner.

7. The process of burning oil which consists in delivering air, atomized oil and superheated steam to the interior of a burner having a peripheral outlet, rotating the said burner to deliver the mixture therefrom, ignlting the said mixture, and heating the burner by the ignited mixture whereby the mixture within the burner is gasified.

8. The steps in the process of burning oil in a furnace which comprise transmitting oil and water to said furnace, developing steam and superheating it in a vessel exposed to the burning fuel, transmitting said superheated steam substantially wholly within the furnaceto a nozzle, atomizing the oil by means of said superheated steam and draw ing in adjacent air by induction to form a combustible mixture, delivering said mixture to the interior of a burner, vaporizing the oil by heat conducted to the burner and controlling the supply of water delivered to the steam generator and superheater for atomizing purposes in accordance with the pressure of the oil supplied to the furnace.

9. The steps in the process of burning oil in a furnace which comprise transmitting oil and water to said furnace, developing steam and superheating it in a vessel exposed to the burning fuel, transmittingsaid superheated steam substantially wholly within the furnace to a nozzle, atomizing the oil by means of said superheated steam, delivering air and said steam and atomized oil to the interior of a burner, vaporizing the oil within said burner, and controlling the supply of superheated steam for atomizing purposes in accordance with the pressure of oil supplied to the furnace.

10. The steps in the-process of'burning oil in a furnace which comprise transmitting oil and water to said furnace, developing steam and superheating it in a vessel exposed to the burning fuel, transmitting said superheated steam substantially wholly within the furnace to a nozzle, atomizing the oil by means of said superheated steam, delivering air and said steam and atomized oil to the interior of a burner, vaporizing the oil within the burner, and controlling the amount of superheated steam supplied to the atomizer in accordance with the pressure of oil supplied to the atomizer.

11. The process described in claim 2 in which the burner is rotated at a constant rate independently of the amount of the fuel being used. v

12. The steps in the process of burning oil in a furnace which comprise pumping the oil through a cleansing and control chamber, delivering the oil under'pressure from said chamber to an atomizing chamber, delivering water in amounts proportioned by the oil pressure to a superheater, vaporizing and superheating said water within the furnace and in contact with the burning fuel, conducting said superheated steam to said atomizing chamber without exposure to the flames, discharging the atomized oil. into a rotating chamber, drawing in air adjacent the axis of rotation of the burner to mix with the atomized oil and discharging the resultant mixture through peripheral outlets in said last-mentioned chamber at high Velocity by means of thermal expansion and centrifugal force.

13. The process described in claim 12 in which the amount of steam delivered to the mixing chamber is automatically controlled by the pressure of the oil delivered from the cleansing and control chamber.

1 1. The process described in claim 12 in which the flame is distributed uniformly with respectto the central axis of the combustion chamber.

15. The method of operating an oil furnace which comprises pumping the oil into a cleansing and control chamber, regulating the flow of oil through said control chamber, by-passing the excess oil from said cleansing and control chamber to the main oil supply, automatically regulating the flow of water to a combustion chamber in accordance with the pressure of the oil delivered from said cleansing and control chamber, superheating steam from said water supply within the furnace in a vessel exposed to the flames, atomizing the oil delivered from the cleansing and control chamber by means of the superheated steam, said steam being conducted from the superheating chamber without exposure to the flames, delivering the atomized oil and steam into a rotatable chamber having a central inlet for induced air flow, .and rotating the last-mentioned chamber to throw out from its periphery the combustible mixture whereby uniform heating is obtained around the axis of rotation.

16. The process of operating a domestic furnace described in claim 12 in which the flowof water automatically stops when the oil supply is stopped. T

17. A process of burning liquid fuel which comprises the atomization of the fuel by means of steam superheated within the furnace, controlling the water supply for superheated steam automatically in accordance with the oil pressure supplied to the furnace, and automatically removing water from the furnace by steam pressure and vaporization when the oil supply is shut off, whereby the parts of the system within the combustion chamber are left substantially dry while the furnace is not in operation.

18. The process described in claim 17 in which air is supplied to the fuel by induction assisted by centrifugal action on fuel, steam and air.

In testimony whereof I hereunto afi'ix my signature.

JOHN lV. CANNON.

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