US1911067A - Steam raiser - Google Patents

Description

W. DOBLE May i933.

EAM BAISER Filed Nev. 18, 1930 A TTORNEYS.

Patented May 23, 1933 vPATENT OFFICE WARREN DOBLE, 'OF`EMERYVILLE, CALIFORNIA STEAM BAISER Application led November 18, Y1930. Serial No. 496,455.

This invention relates to means, herein termed a steam raiser, for enabling the very rapid generation of steam, or other vapor, in a boiler or other vapor generator. While the invention will be described in connection with steam `generation, it is applicable to the generation of other vapors as well.. The present invention has proven of particular value where a relatively, light, compact,

l@ iiexible and eiiicient heat system is desirable. Such systems are employed for automotive and vehicular purposes in general as well as for industrial and process utilization.

It is a desirable feature that the generating system be capable of starting from cold `very rapidly to supply continuously a relatively large quantity of steam efficiently and substantially at a predetermined pressure and temperature. In one such generating system which has proven successful in automotive practice, heat for the boiler is furnished by passingr an air stream from an electr1cally driven'blower through a carburetion device and igniting the resulting combustible mixture. Since the size and weight of the system as a whole are necessarily restricted, the amount of electric power available for the blower motor is practically confined to that furnished by a usual size of storage battery.

This amount of power is small so that the quantity of heat furnished the boiler by the electric motor driven blower is meagre. The feasible rate of extraction of power from a battery is such that the rate of heat supply is low and considerable time is required to arrive at normal operating conditions.

In accordance with the present invention, the electric motor driving the blower is supplemented, while it can also be relieved of its load under proper conditions.

In general it is the broad object of the present invention to obtain the various advantages of a steam raiser which will enable a boiler to furnish steam rapidly at the desired temperature and pressure. However, the invention possesses other advantageous features and objects some of which will appear in the following where I have outlined the preferred form of the steam raiser of my invention.

, eluded in series with a source of E. M'. F.

Figure 1 of the drawing is a diagrammatic showing of a steam raiser of m invention, incorporated in a system which have found very successful in automotive practice.

Figure 2 is a fragmentary view showing in 55 cress section the valves 56 and 8l in closed posltion.

Figure 3 is a cross section showing the valve 74 in closed position.

Figure 4 is a cross section showing the valve 604 7 4 in open position.

In this system a bniler 6 or other vapor generator is provided. This boiler can have the construction and form illustrated in my co-pending application, Serial No. 415,997, filed December 23, 1929, wherein a heated tube of relatively great length is employed for steam generation, water being introduced into one end of the tube while steam is discharged from the other end.

Fuel is supplied to the boiler by an air blower 7 aspirating fuel from a carburetion device 8 positioned at the throat 9 of a Venturi'tube 10 through which the blower 7 discharges into the boiler. A spark plug 11 ignites the air and fuel mixture as it enters the boiler. The blower 7 includes a rotor 12 mounted upon a shaft 13 carried by a bearing 14 in a housing 16. In order to operate the rotor 12, an electric motor 21 is connected to the shaft 13.

Means are provided for controlling the generation of steam by controlling the supply of fuel to the boiler. The supply of fuel, in turn, preferably is subject to devices responsve to boiler conditions, for instance steam pressure and steam temperature. To this end a pressure responsive means 26 and a temperature responsive means 27 are insuch as a storage battery 28 which is grounded, a main switch 29, contacts 31 and 32 upon the pressure responsive device, and contacts 33 and 34 upon the temperature responsive device. The contact 34 is joined by a eon- 5 ductor 36 to the grounded motor 21 and by a conductor 37 to a make and break device 38 operated by the shaft 13 for supplying a high tension current from coil 41 to the grounded spark plug 11.

The operation of the describedJ system when the boiler is started from cold is as follows: i

When the temperature is low and there is little or no pressure in the boiler, the pressure responsive device 26 and the temperature responsive device 27 are so conditioned that their respective contacts are closed. Energization of the motor 21 upon closure of the main switch 29 results in rotation of the blower 7 so that fuel is withdrawn from the carburetion device 3 and is ignited, upon blowing over the concurrently energized spark plug 11, to supply heat to the boiler. When the desired temperature o r desired pressure is reached the circuit is interrupted by the opening of either one of the responsive devices so that the motor 21 and the spark plu 11 are de-energized with the result that t e furnishing of heat ceases.

Due to the desired compactness and necessity for observing restricted space and weight requirements iiiA such a system, particularly one-intended for automotive use, the storage` battery 28 is limited in size to one of those available commercially; preferably one of rather small size and weight. The power which this battery can deliver for a sustained eriod is relatively small and the speed of the blower is therefore restricted with the result that the quantity oi air supplied for combustion is limited and the rate of heat supply to the boiler is low. To increase the storage battery capacity by using a larger size battery is to require one of special manufacture, an undesirable feature, while to use a multiplicity of batteries is to increasagreatly the weight of the power plant. While either of these solutions for the increase in power desired for driving the blower is capable of being utilized, the present invention contemplates and provides a source of power for driving the blower at greatl increased speed without the necessity of ad itional or special batteries. y

In my invention I contemplate the utilization of the steam being generated and used and, therefore, provide means for utilizin exhaust steam from a luid engine connecte to the boiler for supplementarily driving the blower. Thus, I mount a. steam motor of any suitable sort such as a turbine wheel 4 46 within the housing 16 and upon the shaft 13. Steam is brought from the boiler by' an outlet conduit 48 through a throttle valve 49 to the iuid engine 52 from which exhaust steam flows through a pipe 53 to a low pressure nozzle 54. Since the period of air supply by the blower 7 does not necessarily correspond with the period of operation of the engine 52, there is provided means for controlling the flow of air. This may be accomplished in any suitable manner, in the resent instance by shutting down the blower by by-passing the exhaust steam -about the turbine 46 whenever the blower should be shut down.v

This result is effected automatically by the provision of a nearly balanced valve 56 controllingdirect communication between chambers 57 and 58 on opposite sides of the turbine wheel 46. The valve closes u on valve seats 62 and 63 in the casin 16, an has a stem 64 which extends throug the casing to a solenoid having a coil 66. The solenoid coil is included by a conductor 67 in the electrical circuit so that upon de-energization of the circuit, as by the opening of one of the devices 26 or 27, the solenoid is likewise de-energized. The slight unbalance in the valve is suflicient, when the solenoid is de-energized, to move the' valve to open position to by-pass steam through an outlet 68 preferably to another portion of the system, such as a condenser. The solenoid however, is sufiiciently strong when energize to maintain the valve 56 in closed position.

Since no exhaust steam is available until the engine 52 operates, and the engine cannot operate until supplied byl the boiler, the initial steaming of the boiler from cold with the system as thus far described is dependent solely upon, the energy extractable from the battery 28. In practice, therefore, the initial steaming ability of the boiler is restricted. In accordance with my invention I provide means for augmenting the motor 21 even before' exhaust steam is available. To this end I preferably utilize steam directly from the boiler as soon as any is obtainable. In starting from cold the boiler generates steam, first'ata very low pressure which gradually increases until a pre-determined pressure is reached at which the control 26 operates. The initial low pressures are not nearly suficient to operate 'the'en'gine' 52, `especially if it must be started under a heavy load. Such initial pressures are, however, potentially effective upon the turbine wheel 46. I therefore provide mechanism for conductin steam directly from the boiler to the turbine.

This introduction of steam from the boiler is preferably so controlled and regulated that it takes place only when the operator particularly desires it, as when the boiler is cold or the pressure or temperature is very low. In the embodiment illustrated I make use of the steam engine control shown in Wilson Patent No. 1,558,657 wherein a valve is positioned inthe boiler outlet line so that when the vehicle emergency brake approaches a brake applying position, steam can pass directly into the exhaust pipe instead of entering the engine. Thus an emergency brake lever 71 actuates a brake rod 72 connected to a lever 73 secured to a control valve 74 so that when the brake lever 72 approaches or is in a brake applying position, steam can pasa through a pipe 76 to a high pressure nozzle 77 in casing 16.

.manipulation of the main throttle 49 the With the arrangement as thus far described, the operator during the steaming from cold period, or ait any other time, can set the brake lever 71 to open the valve 74 establishing communication between pipes 48 and 76. Then, when the main throttle 49 is partly or entirely opened, steam, if avail-y able or as soon as available, can flow directly from the boiler to the nozzle 77. The turbine thereupon augments the motor 21, and more heat is supplied to the boiler to accelerate the rate of steaming. In practice, the irst fluid iiowing to the turbine nozzle 77 is found to be water which has previously condensed in the pipe and very wet steam. These fluids are relatively dense and have a material impellin important benefit of this arrangement, the pipe 48 is cleared of water and is heated so that when the engine 52 is to be operated, it need not initially function disadvantageously on a large amount of water or wet steam.

It is usually impractical to design the nozzle 77 and the wheel 46 so" that they can operate satisfactorily throughout ythe entire range of. boiler pressures, which often is a span of 2000 pounds per square inch. l I cons'equently'fashion the turbine to function 011 steam iowmg through the nozzle 77 at pres? sures ranging up to a maximumsomewhat lessthan the boiler maximum. By proper pressure in pipe 76 can be kept below this desired maximum, but preferably I employ automatic means for this purpose. 'Such `means conveniently takes the form of a pressure relief mechanism and includes a conduit 7 8 communicating with the pipe 76 and with the chamber 57. A valve 81 controls flow through the conduit 78 yand is seated by a spring 82 on the terminus 83 of the conduit. Whenever the pressure on the nozzle 77 exceeds the bias of the spring 82, the valve 81 lifts from its seat and relieves thev excess pressure by permitting discharge of steam into chamber 58.

Since it may occur during the time the nozzle 77 is functioning that the blower 12 should'be shut down, I preferably utilize for this purpose the control mechanism already provided. To this end the valve 81 is carried by the valve 56 and, although free to open against the bias of spring 82 even when the valve 56 is closed, it must necessarily open when the electrical circuit is opened and the solenoid is de-energized.

While I have indicated that the electric blower motor and the steam blower motor are energized at the same time and are deenergized at the same time, it is possible to reduce the work` of the battery 28 when some steam is available by cutting out' the electric motor entirely so that the blower plies air upon power derived directly from the boiler.` The individual de-energization sup- , for supplying said motor with low pressure steam, and means responsive to boiler Steam temperature for simultaneously disabling both of said steam supplying means.

2. A steam raiser comprising a steam boiler, means for supplying heat to said boiler including an air blower, a steam turg bine for driving said blower, a steam engine l eect on the wheel 46. As an incidental but adapted to operate on steam from said boiler, a steampipe for conducting boiler steam to said engine, an exhaust pipe for conducting steam from said engine to saidturbine, a steam conduit for conducting boiler steam from said steam pipe to said turbine, a bypass conduit connected to said steam conduit and by-passing said turbine, a by-pass pipe connected to ,said exhaust pipe and by-pass-v ing said turbine, and means `responsive to boiler steam temperature. for simultaneously controlling communication through said bypass conduit and said by-pass pipe. t'

In testimony whereof, I have hereunto set m hand.

y WARREN DOBLE.

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