US2418098A - Fuel control mechanism for fog generating machines - Google Patents

Description

March 25, 1947. A w RUFF 2,418,098

` FUEL CONTROL MECHANISM FOR FOG GENERM f' MACHINES Filed April 17, 1945 PRIMNG Tsessfsssp o H .24 A f 2f M `GAsoLsNE PUMP BLOWER.

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'Z4- f 25 26 d 16 Z5 27 1 :Snoentor AlonzoW. Ruff Bin 'il/f Cttorneg Patented Mar. 25, 1947 FUEL CONTROL MECHANISM FOR FOG GENERATING MACHINES Alonzo W. York, Pa., assignor to York- Shipley, Inc., York, Pa., a corporation cf Dela- Application April 17, 1945, Serial No. 588,825

'Y Claims.

This invention relates to a unied and simple control mechanism, by means of which a fog generating machine can be properly placed in operation, to the end, that the machine will function, as intended, in the shortest possible time. Machines of the general type herein disclosed are now in extensive use in both military and naval operations, and since the use of these machines is almost always in an emergency, it will be apparent that there is need for a control set-up which is practically fool proof, and does not require the services of an expert or experienced operator to get the machine into operation when there is urgent need for the laying-down of a smoke screen. Heretofore, in the operation of starting these machines, the various control valves were required to be operated in a denite sequence, and special operators had to be trained to know and to remember this sequence for use in the emergency. It has frequently happened that the prompt starting of these machines in emergencies has been prevented due to absence of a trained operator, and improper handling of the controls, at starting, has been responsible for ineffective use of the machine as well as failures of the machine to function with any appreciable results.

Accordingly, it is the primary object of this invention to provide a control mechanism which is simple to operate, which precludes improper starting operations, and one which is so organized that its action is positive and its falureto respond is practically eliminated. Other objects of the invention will be apparent from the following description of the apparatus when taken in connection with the accompanying drawing which latter forms a part of this disclosure.

In the drawings,

Figure 1 is a showing, partly in diagram, of a fog generating unit and the several uid supply lines that are required to be controlled, in the starting and operation of the machine.

Fig. 2 is a sectional view, in elevation, of the multiple valve arrangement which controls the operation of the machine.

Fig. 3 is a view, in section, of the control lever, together with its operating shaft and cam.

Fig. 4 is a front view showing the dial plate, in association with the operating handle, the dial showing the several stations to indicate the definite steps in the starting operation.

Fig. 5 is a detail View of the operating lever and its connection with a control wire or rod, by means of which the. R. P. M..oi the prime mover of the unit (not shown and which may be either a gas engine or electric motor) is regulated in the starting and during operation of the machine.

Fog generating machines, of the kind to which this invention relates, comprise generally a heater for vaporizing the fog oil, and a prime mover for operating one or more pumps and a blower by means of which the several uids (oil, gasoline and air) are supplied, under pressure, to the heater. the showing of Fig. 1, the heater is shown at the right. It comprises a cylindrical combustion chamber l at the base, with a pressure burner 2, the nozzle of which is preferably arranged to discharge atomized liquid fuel (gasoline or other fuel) in a direction that is tangential to the inner wall of the combustion chamber. Air for combustion (primary and secondary) supplied by the blower 3, is delivered through a pipe Il which surrounds the burner 2, and is likewise tangentially directed into the combustion chamber l.

The mid-section of the heater is of reduced diameter to form a throat portion 5, the latter being in direct communication with an upper expanding, vaporizng chamber or dome 6 with outlet nozzles 'l that radiate from the top thereof and constitute a multiple outlet for discharging the vaporized fog oil. A series of nozzles 8 are arranged to spray fog oil into the throat 5 of the heater. This oil is supplied under a suitable pressure which insures its atomization by the spray nozzles 8. The combustion chamber I is preferably water jacketed, and the resulting steam, when the heater is operated may be condensed and returned as a condensate to maintain a desired water level in the water space of the jacket. Also a heating coil may be used in the water space of the jacket to preheat the fog oil supply in order to raise the temperature of the oil and thereby reduce its Viscosity.

When the machine is in full operation, the combustion chamber discharges into the throat 5 large volumes of highly heated air and combustion products. By venturi action, these gases sweep the throat 5 at high velocity and entrain the atomized fog oil. The latter is whirled and vaporized in the dome Vii, while suspended in the hot air and combustion products, and the resulting fluid mixture is discharged to atmosphere, at high velocity, through the multiple nozzles i, in the form of a densev fog. The controls for starting this machine and for determining its rate of operation will now be described.

It is to be understood that the motor (gas engine or other prime mover) must first be started.

If a gas engine is used as prime mover, it may be started by manual cranking or other means, and is first to be operated at idling speed. This motor is in driving connection with a pump for supplying liquid fuel to the heater, and another pump for supplying the fog oil to the heater. Both liquids are required to be supplied to the generator under a suitable pressure. Also the motor is connected to drive the air blower 3 which" latter discharges into the combustion chamber I. With the motor in operation, at idling speed, the fuel for the burner and the fog oil supply will be placed under sufficient pressure for starting the fog generation operation, and it is the control of the pressure supply of these liquids to the fog generator which constitutes the principal part of my present invention.

In Figure 1, the valve control means shown at the center, is illustrated diagrammatically in connection With the two supply lines, and shows the fog oil lines, under control of a valve, in the upper part of valve casing, this casing being indicated generally by the reference character 38. The supply of fuel to the burner nozzle 2 is regulated by a valve in the middle part of the casing 3 8; `and a rotary cam by means of which both valves are operated and controlled is shown mounted in the lower section of the valve casing.

The details of the dual valve assembly are shown more clearly in Fig. 2. The casing is constructed of two separable parts, an upper part 9 and a lower part I8, these two parts being detachably secured together by bolts, one of which is shown in dotted lines at II. The upper part ofthe casing houses the valve I2 for controlling the fog oil line. The fog oil line extends from the topof the heating coil surrounding the combustion chamber I to the intake of the casing 9 of the valve assembly, as indicated by the dotted lines and the legends in Figure 1. Conventional means (not shown) conduct the surplus oil in the fog oil line back to the fog` oil drum. The valve I2 is urged toits seat by a spring I3, and the pressure of the fog oil is effective on the top of this valve, which adds to the spring pressure in giving a closing bias to the valve. The valve I2 is provided with a vertically arranged stem, which extends above and below the valve. The upper stem extension |4 extends into an aligned guide opening in the plug I5, this plug serving as a removable closure for the valve cavity in the casing 9, and its central bore serving to guide the movement of the valve I2. The Valve cavity beneath the valve vI2 includes an outlet opening I6 for discharge of the fog oil when the Valve I2 is raised from its seat. The valve stem I'I beneath the valve, extends into the central valve cavity in the lower part III of the casing 38, and is guided by a bushing or sleeve I8 which practically closes the fluid communication between the upper and lower valve cavities. In order to make a duid-tight seal between the valve cavities of the sections 9 and I8, the lower end of the valve stern I'I, within the cavity of the section I8, is completely surrounded by a Sylphon type of bellows which is'preferably welded or brazed to the under side of the bushing I8, and, at the lower end is similarly connected to a metallic disk I9,

which latter abuts the lower end of the valve The control valve for the liquid fuel supply (e. g. gasoline) to the burner is mounted in the lower `section I8 of the casing. It is shownat 20, and is vertically alined with the valve I2. Like that valve,'it is also biased to the closed position 4 by a coiled spring 2 I, and by the pressure of the uid which it controls, this fluid entering the valve cavity above the valve discharges, when the valve 20 is opened, through a lateral passage 22, that is beneath the valve.

The. valve 20 has a depending, vertically disposed stem 23, the lower end of which extends into a cylindrical recessed portion 24 within and adjacent the lower end of the section I8. In this recess 24, the bottom of the stem 23 is engaged by a rotary cam 25, and rotation of this cam, in the direction of the arrow, Fig. 2, is operative to first lift the valve 28 from its seat. Continued rotation of the cam raises the valve 28 to a point where the stem I1 of valve I2 will be engaged and that valve will then be lifted from a closed to an open position.

As shown in Fig. 3, the cam 25 is secured upon the inner end of a shaft 26, the latter being rotatably supported in a packed bushing 21 which closes the cylindrical recess 24, in the lower end of the casing 38. The packing of this bushing is eiective to prevent loss of any liquid fuel that may leak into the recess 24 along the valve stem 23, when the valve 20 is opened. For rotating the cam shaft 28, I provide a lever arm 28 which is secured to the outer end of the shaft 28 and is provided at its opposite end with a handle 29, Figs. 4 and 5. This handle carries a spring detent 38 designed to engage the upper edge of an arcuate dial plate 3| which is suitably supported, as shown in Fig. 4, in front of the valve casing 38. 'I'he upper edge of the plate 3| is notched at predetermined intervals which correspond, by their angular spacing, to valve settings which are determinative of the proper and desired operation of the fog generator. The dial plate 3|, at each notched position, displays marking or indicia to indicate to an operator, the condition of the machine that corresponds to that particular angular position of the operating lever 28. The latter lever is also provided with an arm-extension 32 (Fig. 5), the purpose of which is to coordinate engine speed (R. P. M.) with the valve actuation. At the outer end of arm 32 provision is made for operatively engaging one end of a bell-crank lever 33, the other end of the lever 33 being ilexibly connected, as by a wire or rod 34 to a suitable device for regulating the speed of the motor. Such a regulator may be the throttle valve of a gas engine. Displacement of the arm 32, to the left in Fig. 5, will rock the bell-crank lever 33 and thereby produce a limited movement of the rod or wire 34 in a direction to increase the speed of the motor until it is operating at full speed. The amount of movement of the operating lever 28 from the station Idle to station Run is without effect on the control valves, due to the design (shape) of the cam 24, which is made with a dwell portion corresponding tolthis amount of angular displacement of the lever 28. When the bell-crank lever 33 has been rocked `to the limit of its engagement with the arm 32,

it disengages from its connection with that arm, and remains in a position corresponding to full speed for the motor until this arm 33 is reengaged and restored to the position of Fig. 5, with the return of the lever 28 to the position of Fig. 4, in discontinuing or shutting-down operation of the fog machine.

In installations which may use an electric motor in lieu of a gas engine, as the prime mover, the starting switch for the motor can be closed, by operation of the lever 28 in moving from its initial or "01T" position to the position correspond# amants ingto` the initial opening of the fuel line to the burner, which position or station is indicated as Fire on the dial plate 3|. In such an installation,'the switch may be operated, directly, by the lever 28, and does not necessarily require the ex tension arm 32; that is useful in gas enginefinstallations.

With the above explanation `and description of the structural details, it only remains to describe the control operation which is asfollows:

Assuming that the control lever 28 is in the position shown in Fig 4, that the motorhas been started and is operating at idling speed; then the lever 28 is moved counterclockwise until the detentV 3i) drops into the next radial notch. As already explained this, amount of movement of the control lever acts only to bring the motor up to full operating speed, both valves 20 and l2 remaining closed, Continued movement of the control lever, in the same direction `to the next dial station, brings the cam 25 into action to lift the valve 2|] from its seat and thereby initiate the supply of liquid fuel, under pump. pressure, to the iburner nozzle 2. Ignition of the fuel, adjacent the nozzle 2, is effected by an elec- -tric spark from an ordinary spark plug mounted in the tube A, the circuit for which is the same as that of the spark plugs for the gas engine prime mover. This burner igniter plug furnishes a spark discharge continuously, so long as the gas engine is operated, and functions to ignite the fuel. as soon as the fuel supply valve 20 has been sufficiently opened by the operation of the control lever 28. This continuous operation of the spark plug is a safety feature and intended v to relight the burner, in event the same, for any reason, should be extinguished during normal operation of the fog generator. v'I'his means (spark plug) for igniting the burner is conventional and, therefore, is not illustrated -in the drawing. When the burner is in operation (this fact being audi-bly apparent), the control lever is advanced to the next notch. In this movement of lever and cam, the valve 2i] has continued to be lifted until it has contacted the disk I9 and has thereby lifted valve l2 from its seat in order to initiate the flow of fog oil, under pressure, to the nozzles 8 in the throat 5 of the generator. At this station of control the valve l2 is only partially opened, while the combustion rate of burner 2 has been somewhat increased by a wider opening of the valve 2E. At the sulbsequent positions of the control lever, the rate of supply of fog oil is increased until the generator is in full capacity operation. This occurs l when the lever occupies the final position indicated as Fog-3. In the shutting-down operation of the generator, the control lever is simply returned by clockwise movement to the position shown in Fig. 4, the effect of which is to put the cam 25 in the position shown in Fig, 2 and nally to reduce the R. P. M. of the motor to idling speed. The counterclockwise movement of the control lever to place the generator in operation should preferably be at a slow, step-by-step rate, but its reverse movement, in shutting down the generator, can be quickly done and without regard to the station markings on the dial plate 3l.

From the foregoing, the construction, operation, and the many advantages of my invention will be apparent to those skilled in the art without further description, and it will be understood that various changes in the size, shape and proportion and minor details of construction may be resorted to without departing from the spirit tion which is defined by the following claims.

WhatI claim is:

1. In a fog generating machine of the type in which oil under pressure is atomized and projected into a confined and rapidly moving column of a mixture of hot products of combustion and heated air, supplied by a burner; means for controlling the .sequence of the starting, rate of operation, and shutting down of the machine, comprising: a valve for controlling the flow of liquid fuel, under pressure, to the burner that supplies the heated air and hot products of combustion for vaporizingthe fog oil; a second valve for controlling the supply of fog oil, under pressure, to the generator; and a single, manuallyoperable means for controlling both valves, the operation of said means, by movement in one direction, functioning `to progressively open the said valves, sequentially, with the first said named valve opening in advance of the said second named valve, and the movement'of said means in the reverse direction functioning to effect the closing of the valves in the reverse order of their opening.

2. In a, fog generating machine of the type in which oil under pressure is atomized and projected into a confined and rapidly moving column of a mixture of hot products of combustion and t heated air supplied by a burner; means for controlling the sequence of the starting, rate of operation, and shutting down of the machine, comprising: a valve for controlling the flow of liquid fuel, under pressure, to the burner that supplies the heated air and hot products of combustion for vaporizing the fog oil; a second valve for controlling the supply of fog oil, under pressure, to the generator, the said second valve being so positioned that its movement is dependent upon the movements of the rst named valve; and a single, manually-operable means for controlling both valves, the operation of said means, movement in one direction, functioning to progressively open the said valves, sequentially, with the rst said named valve opening in advance of the said second named valve, and the movement of said means. in the reverse direction functioning to eniect the closing of the valves in the reverse order of their opening.

3. The combination recited in claim 2 in which the two control valves are of the reciprocating type mounted within an enclosing casing and having their stems arranged in axial alinenient with the stem of the fog oil control valve projecting into the path of movement of the: fuel control valve and being so positioned relative thereto that after partial opening of said fuel control valve the latter will engage the stem of the fog oil valve and progressively raise said valve from its seat with continued opening of said fuel valve, and the said manually-operable means for controlling both valves comprises a cam element engaging directly with the stem of the fuel valve.

4. In a fog generating machine of the type in which oil under pressure is atomized and projected into a confined and rapidly moving column of a mixture of hot products of combustion and heated air supplied by a liquid fuel burner, a valve assembly and operating means therefor to control the sequence of the starting, rate of operation, and shutting down of the machine; a fluid-tight casing for housing the valves and their operating means, said casing being formed of two separable parts connected in duid-tight relation, a reciprocating fog oil supply valve mounted within one part of said casing, an operating stem therefor which extends into the adjoining part of said casing, means flexibly enclosing said stem Within said adjoining part to provide a fluid seal between said separable parts of the casing, a reciprocating liquid fuel supply valve mounted in the adjoining part of said casing in axial alinement with the fog oil valve and having its head when gated spaced from the bottom of the stem of said fog oil valve, an operating stem for said fuel supply valve, a valve operating cam mounted within the casing and positioned adjacent the end of the stem of the fuel supply valve, and means extending outwardly of thev casing for operation of said cam to first open the fuel supply valve and to thereafter openthe fog Voil valve by engagement of the one valve head with the stem of the other, the sequential opening of the valves being effective to start the operation of the burner and heat the same before admitting fog oil to the generator.

5. The combination as recited in claim 4, in which both supply valves are manually biased to their closed positions by spring action assisted by the iluid pressure of the respective fluids that are controlled by these valves.

6.- The combination as recited in claim 4, in which the means for operating the cam includes a lever and operating handle secured thereto;A

and an arcuate dial plate positioned in front of said lever and having circumferentially spaced indicia markings thereon which serve to indicate, by the position of the lever handle with reference thereto, the sequential steps in the operation of the fog generating machine.

7. In a fog generating machine of the type in which oil to be vaporized for producing the'fog is atomized under pressure, and projected into a conned, rapidly moving column of a mixture of hot products of combustion and heated air supplied by a forced draft burner, and a prime mover is employed to supply the several fluids used under suitable pressures; a valve assembly for fluid-tight relation; a reciprocating fog oil-sup- A ply valve mounted for operation in one part of"v said casing and having an operating stem which extends into the adjoining partof said'casing;

means flexibly enclosing said stem within said' adjoining part of the casing to provide a iluid seal between said parts of the casing; a reciprocating liquid fuel supply valve mounted in said adjoining part of the casing in axial alinement with said fog oil supply Valve and having its head, when seated, normally spaced from the adjacent end of said stem of the fog oil supply valve an operating stem for said fuel supply valve; a valve operating cam mounted within the casing and positioned therein to operatively en gage the end of said stem of the fuel supplyvalve; a cam operating shaft extending outwards ly of the casing in fluid-tight connection therewith; a lever and operating handle secured to said shaft' for turning said cam; an arm extension on said lever; and means cooperating therewith' to control operation of the prime mover as the operating handle is moved to control thefoperation of the machine, the turning of .the cam by` REFERENCE S CITED The following references are of record in le of this patent:

UNITED STATES PATENTS Name Date Means May25, 1909l Collins July 29, 1936 Number Jernberg Apr. 10, 1928 FOREIGN PATENTS Country Date French ---nr Apr. 4, 1936 Number the Kerrick Apr. 11, 1939'f Oglesby DSC. 23, 1930

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