US1671822A - Oil-burning system - Google Patents

Description

May 29, 1928.

B. GREENFIELD OIL BURNII JG SYSTEM Filed Oct. 23, 1922 SIM/13mm Patented May 29, 19.28.

UNITED STATES PATENT oFF cE.

BENJAMIN GREENFIELD, OF BARTLESYILLE, OKLAHOMA, ASSIGNOB TO DOHER TY BE- SEARCH COMPANY, 01 NEW YORK, N. Y., A. CORPORATION OF DELAWARE.

OIL-BURNING SYSTEM.

Application filed October 23, 1922. Serial No. 596,436.

This invention relates to an oil burning system and more particularly to a method of' and apparatus for controlling combustion in oil tired furnaces in which the feed of oil to the burner is controlled by a vacuum.

The oil burning combustion regulating system of the present invention is of the same type as the oil burning systems disclosed in my Patent 1,423,764 granted July 25, 1922, and my application, Serial No. 48l,141, filed July 12, 1921. In these systems the oil is fed to a burner under a low pressure which is developed by means of steam. The steam circulates through comparatively long sections of piping, and under some conditions such as are encountered by the portable locomotive type'boiler used in oil well drilling, the use of steam often ,causes trouble in operation of the combustion regulating system. For example, the water often contains oils and alkaline earth salts-which when carried into the regulator pipes soon clogs them. Also, the condensation of the steam in the pipe lines requires that the lines be carefully positioned to drain the condensation water. In cold weather this condensation Water will read ily freeze in the lines that are not heated by the boiler, thus breaking the lines and stopping the operation of the system. Further, the development of oil feeding pressure requires a substantial volume of steam, and

thus increases the cost of operating the system.

The primary object of the present invention is to provide a process and apparatus wherebya positive feed of oil may be attained which is reliable and certain in its ()Ptl'tliiUll, and whch will overcome'the objections noted above.

ll'ith this object in view, one feature ofthe invention contemplates the use in an oil burning system of a steam injector burner wh ch will create a vacuum pressure for feeding oil to the burner so that steam does not enter the piping of the combustion regulating system.

A further object of the invention is to provide an oil burning system by which ,oil may be fed to a furnace burner by a vacuum pressure in such a manner that the air and steam used for combustion may be supplied at a rate proportional to the oil feed to obtain the most efficient and complete combustion.

With this object in view another feature of the invention contemplates the'provision in an oil burning system employing a vacuum pressure for feeding oil to the burner, of a mechanism for controlling the air supply to the furnace and the steam supply to the burner which is directly controlled by the oil feeding vacuum pressure.

Another object of'the invention is to provide an apparatus wllich'is simple in construoton and operation so that it may be in stalled and operated by operators Who are not skilled in furnace combustion regulation.

lVith these and other features and objects in view, the invention consists in the improved method of and apparatus for controlling combustion hereinafter described and particularly defined in the claims.

The various features of the invention are illustrated in the accompanying drawing, in which:

Fig. 1 is a view in side elevation partly in section of a locomotive type steam boiler provided with a combustion regulating system embodying the preferred form of the invention;

Fig. 2 is a vertical sectional view of the automatic steam regulating valve, and

Fig. 3 is a vertical sectional view of the automatic vacuum pressure regulating valve.

The steam boiler illustrated in the drawings is the usual type of locomotive field boiler which is used in drilling oil wells.

. Such field boilers are usually provided with wheels by which they may be transported from place to place, but in the drawings the boiler 10-is shown as being mounted upon a sub-furnace 12 to provide/an increased combustion space for the oil. A burner 14 projects through an opening 16 in the rear end of the sub-furnace 12 and the combustion products passing forwardly through the sub-furnace .from the burner, pass up through the tire box space 18 of the boiler 10, thence through the fire tube space 20, and How out through a stack or exhaust fine 22. The air for supporting combustion flows through 'the opening 16 and also through a grate or damper 24 and opening 20 into the sub-furnace. The volume of air flowing into the sub-furnace for combustion is controlled by means of a damper 28 mounted in the stack .22.

Oil is supplied to the burner from a float chamber or container 30 shown as provided iltl with a spout whose discharge orifice 52 is on a level with the oil level adapted to be maintained within the container in any suitable manner as by a float 54 which operates a supply valve. Oil which flows from the spout passes down to the burner 14 through a conduit or pipe 50. A vacuum chamber 32 is preferably provided between the spout and conduit'to permit a more uniform suction effect to be maintained on the oil supply. Oil is caused to flow to the burner under a regulated suction efl'ect maintained in the vacuum chamber This suction effect is preferably produced by means of a steam injector the steam whereof serves to atomize the oil flowing to the burner. As shown the injector consists of a steam nozzle 34 and an injector throat 36 formed in the burner 14. The steam supplied to the injector is taken :from a boiler steam line 38 andflows through a pipe 40, strainer 42, constant pressure regulator 44, a control valve 46, and a steam line 48 connected with the nozzle 34. The conduit 50 is connected to the burner 14 at the rear of the steam nozzle 34, so that the .oil will be drawn into the burner by the steam passing through the injector throat 36, and will thus be thoroughl mixed with steam so that it will be comp etely atomized'when the steam and oil mixture leaves the burner. It will now be appreciated that sub-atmospheric pressure prevails in the vacuum chamber 32 by reason of the suction effect produced by the steam injector. The oil in the container 30 is subject to atmospheric pressure. The oil feeding pressure is therefore the difference in pressures prevailing on the oil in the'container and in the vacuum chamber 32. Due to the arrangement of the oil container above the burner only a comparatively low degree of vacuum need be maintained in the vacuum chamber to cause the oil to feed as will be readily appreciated. The .arrangement also permits the discharge orifice 52 in the spout to be made relatively lai'ge to avoid its becoming clogged by dirty o1 The volume of oil supplied to the burner is varied in accordance with the steam demand on the boiler, so that as the demand for steam increases the volume of oil supplied will increase and as the steam demand decreases the supply of oil will be cut down. To accomplish this a vacuum regulator 56, (see Fig. 3) is connected by means of a pipe 58'with the steam line 38 and by means of pipes 60 and 62 with the vacuum chamber 32. The regulator 56 is provided with a diaphragm 64 at its upper end, which directly communicates with the live steam or the boiler through the pipe 58. A spring 66 below the diaphragm normally tends to seat a valve 68 upon a seat 70 to close communication between the vacuum pipe 60 and an airpipe 7 2. The live steam pressure acting upon the diaphragm 64 works against the spring 66 to open the valve 68. This permits air to enter the normally closed vacuum circuit with the result that the effect of the vacuum is correspondingly modified. As the steam pressure increases the pressure on the diaphragm increases, tending to .open the valve 68 and when the steam demand has decreased to such an extent that the full boiler steam pressure is attained, the valve 68 will be open sufliciently to reduce the vacuum in the chamber to such a point that only a sutficient amount of oil will flow to the burner to maintain a flame. On the other hand, when the steam demand increases to such an extent as to reduce the pressure below the maximum boiler steam pressure, the valve 68 will be varied in accordance with the steam pressure to control the extent or value of the vacuum in the chamber 32.

The steam flowing through the burner is used not only for creating an oil feeding vacuum pressure but is also used to atomize the oil. Also the steam enters into combustion with the oil. If too much steam is ad mitted to the burner, it will tend to reduce the flame temperature and to cool and dilute that steam at a substantially uniform pres-- sure is delivered to the line 74 as indicated .by the pressure gauge 7 6. At the time the steam reaches the controlling valve 46 its pressure is independent of the fluctuating pressure in the steam line 38 and the volume of steam admitted to the burner by the control valve 46 is varied in accordance with the vacuum in the oil feeding piping system. To accomplish this the pipe 62 is connected by a pipe 78 with a diaphragm chamber 80 of the control valve 46. (See Fig. 2.) The vacuum in the line 7 8 acts on the adjacent side of a diaphragm 82 in the chamber 80 and tends to open double poppet valves 84 mounted over valve seats 86 in the casing of the valve 46. The valves 84 are connected by means of a stem 88 with the diaphragm 82, and a spring 90 surrounding the stem 88 normally When controlling combustion the supply of air is generally regulated to maintain a slight over-ventilation in the furnace. \Vith an over-ventilation there is always sufiicient supply of oxygen to burn the fuel in the furnace. If too large an excess volume of air is used the flame temperature in the furnace will be lowered, and the combustion products will be diluted and a very large amount of heat will be lost by the exhaust flue gases. To maintain the proper and an efficient combustion in the furnace the sup ply of air in the present invention is controlled by the oil feeding vacuum pressure so as to be directly proportional to the volume of oil supplied to the burner. To this end a pipe 92 is connected between the pipe 78 and a damper motor 94 located at the rear of the boiler immediately below the stack 22. The damper motor 94 consists of a chamber 96 having a plunger 98 mounted in the upper portion of the chamber and arranged to form a closed space within the chamber by means of a cylindrical diaphragm 100. The plunger 98 is connected by means of a rod 102 and cable 104 with a sheave wheel 106 mounted on a shaft 108 upon which the damper 28 is fixed. When the pressure in the vacuum lines 60, 78, and 92 is substantially atmospheric pressure, the damper will be held in closed position as illustrated in Fig. 1 by means of Weights 110 mounted on the rod 102 and weights 112 secured to a cable which is attached to and positioned in a groove in the sheave wheel 106, the weights 110 and 112 being proportioned to hold the damper in a balanced position. When the space below the plunger 98 and diaphragm 100 is placed under a vacuum the plunger will tend to move downwardly to open the damper 28, and as the vacuum increases, due to an increased demand for steam in the boiler, the damper will tend to move to full open position. The balancing of the damper by means of weights and the movement of the damper in accordance with the oil feeding pressure so as to maintain a proportional relation between the flow of air through the furnace and the volume of oil supplied to the burner has been fully developed and explained in my copending application, Serial No.1 84,141, referred to above. Reference is hereby made to this application for a detailed explanation of the proportional relation existing between the angular position of the damper and the oil feedingpressure. It is apparent however thatwhen the damper motor of the present invention is operated by a vacuum its movement is the reverse of the movement when gas under pressure is used below the piston for operating the motor. In both cases however the law of operation of the motor is the same.

When burning oil it is comparatively easy to supply too much oil and thus injure the boiler fire box and to waste fuel. To avoid injury to the boiler the damper motor is used to place a maximum limit upon the supply of oil to the burner, regardless of the demand of the steam on the boiler. To accomplish this a conical valve 114 is mounted in a valve chamber 116 formed in the plunger 98, and a stem 118 projects downwardly from the valve 114. If the plunger 98 moves downwardly under an increase in the vacuum of the system a suliicient distance to bring the stem 118 in contact with the bottom of the chamber 96, the valve 116 will be raised to permit air to enter the space in the chamber 96 through an opening 120 and reduce the vacuum pressure. In this way the maximum vacuum may be limited and thereby the maximum feed of oil may be determined.

With the construction outlined above it will be apparent that the steam generated in the boiler is used for creating the pressure by which the oil fed to the burner, by which the supply of steam to the burner is controlled, and by which the flow of air through the boiler furnace is controlled. The steam used for creating a vacuum pressure flows directly through the oil burner and therefore throughout the system the pipes contain only air and there is no chance for them to become clogged or frozen. FllItllGlII'lOlG, all of the steam which is used for creating the pressure is also used in atomizing the oil and in supporting combustion, and therefore no steam is lost in developing the oil feeding pressure. Since there is no condensation in the combustion regulating system it is not necessary to arrange the piping so that water may be drawn therefrom.

The combination regulating system of the present invention controls the volume of fluid fuel supply, the volume of air supply and the volume of steam supply to the furnace in a unit of time. In other words, the regulating system controls the rate of liquid fuel, air and steam supplies to the furnace and maintains a proportional relationship between them.

The preferred .form ofthe invention having been thus described, what is claimed as new is:

1. In an oil burning system, means for feeding oil to a burner by steam injector action in proportion to the steam demand, and means for transmitting the vacuum produced by the said steam injector action to a regulating means to control the steam passing to the said burner and to control the air supply to the furnace to burn the said oil.

2. In an oil burning system, a steam boiler and furnace, oil burning means in the said furnace, means for producing a vacuum in the system, means for feeding oil to the oil burning means in proportion to the said vacuum, means for regulating the said vacuum in accordance with the steam demand from the said boiler, means dependent on the said vacuum for controlling steam supply to the said vacuum producing means, and means for maintaining a flow of steam to the said burning means when the vacuum in the said system is at a minimum.

3. In an oil burning system, a steam boiler and furnace, oil burning means in the said furnace, vacuum producing means connected with the said burning'means in the said system, means for feeding oil to the oil burning means in proportion to the said vacuum, means for regulating the said vacuum in accordance with the steam demand from the said boiler, means dependent on the said Vacuum for controlling steam supply to the said vacuum producing means, means for supplying steam to the said controlling means at a substantially constant pressure, and'means for maintaining a flow of steam to the said burning means when the vacuum in the said system is at a minimum.

4. Inan oil burning systen'i, a steam boiler and furnace, an ejector type oil burner in the said furnace, means to produce a. vacuum in the said system, an oil burner trap, means for feeding oil to the said trap, means in the said trap for controlling the oil feed thereto in accordance with the level of oil therein, an orifice chamber connected to the said trap, a conduit connecting the said orifice chamber with the oil burner to feed oil thereto, a conduit connecting the said orifice chamber with a second conduithaving a vacuum relief valve, a diaphragm chamber, a diaphragm within the said diaphragm chamber connected to the said relief valve, a conduit connecting the diaphragm chamber with the steam boiler to transmit boiler pressure thereto, and thereby to control the operation of the said vacuum relief valve to vary the vacuum within the said orifice chamber, a diaphragm chamber connected with the said second conduit, a diaphragm within the last named diaphragm chamber, a conduit connected to the oil burner with the steam boiler to conduct-steam thereto, a valve in the last named conduit. means connecting the said valve with the last named diaphragm, a stack, a damper in the stack, a damper motor, means connecting the damper motor with the damper to vary the position of the damper with variations in the damper motor, a conduit connected to the damper motor with the said sccond conduit, and means in the damper motor to limit the vacuum in the said system when the said damper is in its fully open position.

5. In an oil burning system, a boiler, a furnace for the boiler, an exhaust flue con: nected to the furnace, an oil burner for the furnace, means for feeding oil to the burner under pressure, means for controlling the oil feeding pressure in accordance with the steam demand, a damper in the exhaust flue, a damper operating motor'connected with the damper, a connection between the oil feed regulating means and the motor, and means mounted on the motor for controlling the oil feeding pressure by the motor movement. 1

6. The method of regulating combustion in oil fired furnaces to generate steam in a boiler, which comprises feeding steam under regulated pressure from the boiler into a vacuumproducing burner, feeding oil to the burner in accordance with the degree of vacuum produced by the said burner, regulating the vacuum in accordance with the steam demand on the said boiler, and regulating the steam supply to the said oil burner in accordance with the said vacuum.

7. The method of regulating combustion in oil fired furnaces to generate steam in a boiler, which comprises atomizing oil into a furnace by means of steam injector action, feeding oil to the atomizing means by means of a vacuum produced by the said injector action, controlling the steam injector action in accordance with the steam demand on the boiler, and controlling the draft and air admission to the said furnace by means of the said vacuum.

8. The method of regulating combustion in oil fired furnaces to generate steam in a boiler, which comprises controlling the flow of oil to a burner by means of a vacuum produced by a constant pressure jet of steam regulating the vacuum in accordance with the steam demand on the boiler, and maintaining a minimum limit on the vacuum to maintain a flame at the burner.

9. The method of regulating combustion in oil fired furnaces to generate steam in a boiler, which comprises controlling the flow of oil to a burner by means of a vacuum produced by a constant pressure jet of steam, regulating the vacuum in accordance with the steam demand on the boiler, and limiting the rate of firing to the capacity of the boiler irrespective of the steam demand on the boiler. I

10. The method of regulating combustion in oil fired furnaces to generate steam in a boiler, which comprises feeding oil to a burner in a furnace by means of a vacuum produced by a constant pressure jet of steam controlling the flow of oil to the burner by means of the said vacuum, regulating the said vacuum in accordance with the steam demand on the boiler, maintaining a minimum limit on the vacuum to, maintain a flame at the burner and limiting the rate of firing to the capacity of the boiler irrespective of the steam demand on the boiler.

11. The method of regulating combustion in oil fired furnaces to generate steam in a boiler which comprises controlling the flow of oil' to a burner by means of a vacuum, regulating the vacuum in accordance with the steam demand on the boiler, supplying air to the furnace for combustion, supplying steam to the burner, andlvarying the oil feed, the air supply, and the steam supply in accordance with the variations of the vacuum.

12. The combination with the steam boiler and furnace of a steam generating plant, of a nozzle through which liquid fuel and a fuel atomizing agent under pressure pass to thc furnace, a normally closed system in which the suction developed by the flow of the atomizing agent is effective, a fuel container forming part of said system and adapted to feed fuel to the nozzle proportionately to the suction, effective in said system, and means under the control of the boiler pressure for admitting air into said system.

13. The combination with the steam boiler and furnace of a steam generating plant, of

a nozzle through which liquid fuel and a fuel atomizing agent under pressure pass to the furnace, a normally closed system in which the suction developed by the flow of the atomizing agent is effective, a fuel container forming part of said system and adapted to feed fuel to the nozzle proportionately to the suction effective in said system, means under the control of the boiler pressure for admitting air into said system, and means controlled by the suction effective in said system for regulating 'the rate of flow of said atomizing agent.

14. The combination with the steam boiler and furnace of a steam generating plant, of a nozzle through which liquid fuel and a fuel atomizing agent under pressure pass to the furnace, a normally closed system in Which the suction developed by the flow of the atomizing agent is effective, a fuel container formmg part of said system and adapted to feed fuel to the nozzle proportionately to the suction effective in said system, means under the control of the boiler pressure for admitting air into said system, and means controlled by the suction effective in said system for regulating the fio'w of air for combustion of the fuel.

15. The combination with the steam boiler and furnace of a steam generatin plant, of a nozzle through which liquid f uel and a fuel atomizing agent under pressure pass to the furnace, a normally closed system in which the suction developed by the flow of the atomizing agent is effective, a fuel con tainer connected to said'system by a conduit whose upper end is on a level with the normal liquid level within the container and whose lower end is below such level, the top of the container being open to the atmosphere, and means under the control of the boiler pressure for admitting air into said system.

16. In an oil burning system, means for feeding oil to a burner by steam injector action in proportion to the steam demand,

and means for transmitting the vacuum produced by the said steam injector action to a regulating means to control the steam passing to the said burner.

17. The method of regulating combustion in oil fired furnaces to generate steam in a boiler, which comprises feeding steam under constant pressure from the boiler irrespective of pressure variations in the boiler into a vacuum producing burner, feeding oil to the burner in'accordance with the degree of vacuun'r produced by the said burner and regulating the vacuum in accordance with the steam demand on the said boiler.

18. A method of regulating combustion in oil fired furnaces to generate steam in a boiler comprising feeding oil into the furnace in an atomized condition, the fuel being fed into the furnace in accordance with the aspirating action developed by the atomizing agent, controlling the flow of the atomizing agent by the aspirating action developed by said agent, and controlling the aspirating elfect of said agent by the boiler pressure.

19. In an oil burning system, a burner, an oil container open to atmospheric pressure and having a spout extending upwardly from below a normal liquid level therein, a conduit into which oil discharged from the spout flows to the burner, means for passing a jet of atomizing fluid through the burner in such a manner that a suction is set up in said conduit, and means subject to the heat demands made on'the burner for modifying the suction effective in said conduit.

In testimony whereof I affix my signature.

BENJAMIN GREENFIELD.

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