US1633502A - Control system for liquid-fuel burners - Google Patents

Description

June 21 1927.

A. c. STALEY coNTRoL SYSTEM on LIQUID FUEL BURNERS Filed Dec. 7. 1921 gnvflfoz Allen C Scaley Patented June 21, 1927.

UNITED STATES PATENT OFFICE. v

ALLEN O. STALEY, OF LA FAYETTE,

CONTROL SYSTEM FOR LIQUID-FUEL BURNER Application filed December 'I, 1921.

The object of myinvention pertains to a system to automatically control the combustion of liquid hydrocarbon fuel, so as to maintain predetermined conditions of .temperature and pressure or both in a steam oiler or generator.

In the drawings,-I illustrate various improved structures which embody my invention, also the piping, wiring, etc., in operative relation to the various units connected therewith.

Other objects of my invention will appear hereinafter.

Referring to the accompan ing drawings, which are made 9. art hereo and on which similar reference 0 aracters indicate similar parts,

Figure 1 is a diagrammatic sketch of the control system embodying my invention the various mechanisms lnvolved being shown in their operative relationship, and

Figure 2 is a vertical section of the blower, burner, pressure control device, combustion chamber, and steam generator shown in operative relation.

The system shown is particularly adaptable to use in steam driven automotive apparatus but not necessarily limited to this application. This-class of service demands exceedingly simple and stur'dily reliable mechanism,

capable of operation by mechanically unskilled operators, and this, as well asother objects hereafter pointed out are attained in this system.

Referring to Fi re 1, reference numeral 10 is an electric ynamo of a capacity usually found on internal combustion engined automobiles, having for illustration, a charging rate of 10 to 15 amperes at 6 volts, at average car speeds. Reference character 11 represents a reverse current relay-of us-- ual design, to prevent discharge of battery through the dynamo, when the car is stationary, or the voltage generated by the dynamo is less than that of the battery. A 6-v0lt storage battery 12 is provided of any desired capacity, such as 80 to 100 ampere hours, which is ample to handle the system. A startin switch 13 operates starting motor 14 whic is provided with an engaging clutch 15 so as to drive air blower or fan 16, fuel pump 17, and small steam engine or turbine 18 which are all connected permanently so as to rotate together as one Serial No. 520,680.

unit. When the startin switch 13 is opened, stopping the motor, t e clutch 15 automatically disengages and when steam is up the blower, pump, etc., are driven from the small steam engine 18.

A steam generator re resented as 19 is provided and a steam line 20 leads therefrom to supply steam to the engine 18, the steamline 20 having in its length a hand valve 21 for shutting off the supply of steam to the en 'ne 13. A vibratin spark coil 22 is of ord i nary construction or producing a spark-sufficient to ignite primary or nozzle burner 23. The spark producing means is so arranged as to be operative only when starter switch 13 is closed, as it receives its sup ly of current from the same in Figure 2. The'spark plug 24 is so located as to ignite the spray of finely atomized fuel emitted from nozzle 23. The main nozzle or burner 25 receives its fuel from a source of supply represented by tank 26 through feed piping 27. A float chamber or other suitable means 28 is ada ted to control the fuel level at nozzle 25 1f this is of the aspirating type as describe Fuel pump 17 which supplies the rimary nozzle 23 is shown receiving fuel in the same supply tank as the secondary nozzle 25 but in case different fuels are used, separate tanks or other sources of supply may be furnished for each nozzle.

In starting up the plant when it is cold, the mode of o oration is as follows: Starting switc 13 is closed energizing motor 14 which is caused'to rotate rapidly, operating through engaging clutch 15, the blower 16, the fuel pump 17 and the steam engine 18. Thespark-coil 22 is at the same time energized to produce a spark at the plug 24. The pump 17 is operated to force fuel to nozzle 23 and the blast of air from the fan 16 creates a flow of fuel from aspirator nozzle 25. The fan 16' and nozzles 23 and 25 are arranged within a suitable casing 29 as best shown in Figure 2. .Air is forced passage 30 is provided with a valve 33 which Will later be described in detail; This valve regulates the flow of air from the fan 16 to the nozzle 25. The sparking of the plug 24 will start the combustion at nozzle 23 and spread thence to the nozzle 25, the combined combustion of the fuel from both nozzles extending through the common passage 34 and into the main combustion chamber 35 of the generator 19. I

Owing to the special design of the steam generator suflicient pressure is raised in less than one minute to operate blower pump etc., from the steam engine 18. Starter switch 13 is then opened causing spark coil and motor 14 to cease to function and clutch 15 is disengaged.

In systems heretofore used on steam automobiles, the electric motor continues to function at all times that the fire is in operation, requiring large and expensive motor, dynamo, and storage battery. By means of this system much smaller and less costly units are required, the starting motor usin but 30 to 40 amperes for a comparativdl short period. Steam havin been. raised the system is entirely indepen ent of the electrical system, an extremely valuable characteristic of my invention.

Also, in case of failure of the electrical system the blower may be provided with a hand crank for cold starting and the burner thus ignited by other than electrical means, which gives the user of this system a confidence not heretofore secured by .use of the electrical control exclusively.

The first phase of starting the fire and raising the steam having been secured, as explained above, the second phase of operation, entirely automatic, and independent of the operators attention, is disclosed in the following:

Referring to Figure 2, piston housing 35 is secured adjacent the casing 29. Within the housing 35 is a piston or diaphragm 36 forced downwardly by spring 37. The under face of the piston is exposed to the pressure of the steam from the generator which is introduced through pipe 38. The pistonor diaphragm is so arranged that at any predetermined pressure in the boiler or steam generator, the pressure therein is communicated through pipe 38 to the piston 36 whose motion is opposed by spring 37, capable of adjustment to any required range 'or scale of operation.

As the pressure gradually approaches this predetermined point or condition, the move-' ment of the piston or diaphragm against the spring, actuates a shutter or damper valve 33, by means of the connecting linkage 39, 40 and 41 causing a reduction in the flow of air past the burner nozzle 25 which if of the aspirating type as shown reduces the fuel in like proportion so as to maintain at all times a completely combustible mixture of fuel and air.

the delivery of fuel in definite relationship to the volume of air passing the shutter 33.

When the predetermined high pressure, as mentioned above, is reached, the flow of fuel from nozzle 25, is practically stopped, the shutter 33 being in a closed position and stopping the flow of air from fan 16 past the nozzle 25.

The pilot or primary nozzle 23 continues, however, in operation and is of relatively small capacity as compared with that of the intermittently operating and graduated burner nozzle 25, the fuel from the primary nozzle being of sufficient amount to maintain the steam in the generator at a working pressure with the car stopped, supplying the necessary heat to overcome the radiation and other losses from the steam generating plant and connecting piping, as well as, to supply the steam to the engine 18 to operate the lower or fan engine.

-As the demand for steam increases due to the operation of the main engine of the car, or other cause; the pressure in the steam generator falls, and the steam piston is reversed in its motion by the action of the resisting spring, opening the shutter and cansing fuel to flow from the secondary nozzle. 4

When any predetermined required pressure is secured as determined by the adjustment of the spring 37 and connecting linkage the shutter, 33 is wide open and the burner is operating at its maximum capacity and gencrating the maximumquota of steam.

It is to be particularly noted that this system does not operate on the well known cut in and cut out principle, as used in many designs, but a graduated fire is furnished at all times in proportion to the demand 'for steam with the following desirable results.

Itv is a well known fact that when steam generating, superheating, and other surfaces, such as combustion chamber linings, etc., are subjected to sudden temperature changes as caused by the cut in and cut out method of plant is called upon for less than its full capacity,'the fire operates at a correspondingly reduced rate and deterioration of boiler, superheater, and other surfaces subjected to the heat of combustion are more than correspondingly reduced by the comparatively moderate heat-to which they are subjected the greater portion of the time, as in the cut in and cut out system of combustion where the intensity of combustion is always a maximum whatever the load, the steam generation being controlled by the time be tween or duration of firing periods only.

Furthermore, when superheating coils are used with the cut in and cut out method of operation, there is a decided tendency to secure a wide variation in steam temperature with a consequent more rapid deterioration of coil surface, engine, and valves, as well 'as difficulties in lubrication.

It is desired to call attention to the fact that the pilot light or primary burner 23 does not necessarily serve as an ignition jet, nor is this a rich mixture process of combustion as is used in certain other systems which have been developed. The operation of the burner is more fully described in a co-pending application, Serial No. 540,551, filed March 2, 1922, and it is to be noted that this primary burner is in continuous operation at all times when the plant is in service. l' he secondary burner or nozzle is also i continuous operation at all times that the main engine is in'operation, although never fully open except when the plant is loaded to its maximum capacity. In other words the system is composed of two general parts,

the system warm and steam up ready for a I quick start. In milder weather, and owing to the quick initial start possible with properly designed steam generators, it is better practice to shut off the fire entirely. This is readily accomplished by closing the hand valve 21, Fig. 1, which stops the flow of steam to the blower engine, stopping th fuel pump and consequently all combustion. In starting again with pressurestill up in the steam generator, this valve is opened at the same time that the starter switch '13 is pressed and the fan and pump are immediately brought up" to speed and the fire lighted by the spark in the usual manner. By making the steam engine so as to be nonstarting except when dranked by the motor there is no danger of the fuel being delivered to the combustlon without at the same time putting on the spark for ignition. This is readily accomplished by suitable design of the fan engine valves.

A summary of the outstanding features of the system as described, is as follows:

1. Extreme simplicity and sturdiness of all parts. 1 a

2. Freedom from spark delay devices, differential pressure control for out in and out sulting in long life of the associated parts and securing high efiiciency of the steam generating plan 5. Constant steam temperature and pressure at any particular load or set of operating conditions.

It will be evidentto those skilled in the art that numerous modifications can be made in my advice without departing from the spiritof the invention and therefore I do not limit myself to the specific embodiment of the invention shown in the drawin and described in the specification but DDT; as indicated in the appended claims.

having thus fully described my said invention, what I claim as new an desire to secure by Letters Patent, is:

1. A control system for liquid fuel vapor pressure generators comprising a primary fuel nozzle, a secondary aspirator fuel nozzle, a pump for supplying fuel under pressure to the primary nozzle, a float controlled chamber for controlling the supply of fuel to the secondary nozzle, means for supplying air to both nozzles, means for diminishing the 'air supply to the aspirator nozzle as the va or pressure increases beyond a predetermlned point, and an auxiliary prime mover operated by the vapor, said auxiliary prime mover being arranged to operate the fuel pump and. air supplying means at times when the secondary nozzle is inoperative, substantially as set forth.

2. In a steam driven vehicle, a steam generator, a burner therefor including a liquid fuel nozzle, a pump for supplying fuel to the nozzle, an air blower for supplying air to said burner, an auxiliary steam driven prime mover having driving connection with the air blower and the fuel pump, an electric starting motor detachably connected with said air blower and fuel pump, means for producing an electric spark adjacent said nozzle, means for simultaneously causing the electric motor to operate said fuel pump and the air blower to generate an initial steam pressure, and means for causlng the auxillary prime mover to operate the air blower and the fuel pump to maintain steam pressure at all times including times when the vehicle is at rest, substantially as set forth.

3, A liquid fuel burner comprising a cas ing having a chamber at the upper end, a fan in the chamber, a passage at one side of the casing extending downward from the chamber intersecting the first passage, a primary burner in the second passage, a secondary burner in the first passage adjacent the auction of the two, a spark plug immediately below the primary burner, a partition above the primary burner having a perforation of limited extent immediately above the nozzle of said burner, and a valve in the first-named passage for adjustment of the air current therein, substantially as set forth.

4:. A liquid fuel burner comprising a casing having a chamber at the upper end, a fan in the chamber, a passage at one side of the casing extending downward from the chamber intersecting the first passage, a pressure-operated prlmary burner in the second passage, a suction-operated secondary burner in the first passage adjacent the junction of the two, a spark plug immediately below the primary burner, a partition above the primary burner having a perforation of limited extent immediately above the nozzle of said burner, and a valve in the first-named passage for adjustment of the air current therein, substantially as set forth.

In testimony whereof I aflix my signature.

' ALLEN C. STALEY.

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