US3095705A - Monofuel reaction chamber apparatus - Google Patents

Description

y 1963 G. TABBERER ETAL 3,095,705

' MONOFUEL REACTION CHAMBER APPARATUS Filed April 26. 1961 v 2 Sheets-Sheet 1 5 1; c TIP/C ELE c Tea M467VET7C l a my VAL v: 2

GEORGE 7745555 51? DEREK Hf/WLHCE ,4 7 TOFF/VE Y July 2, 1963 G. TABBERER ETAL MONOFUEL REACTION CHAMBER APPARATUS Filed April 26, 19 61 2 Sheets-Sheet 2 GEO/Q65 TQBBE/ FEFP DEREK H T TOP/VF Y tinuing supply of monofuel.

United States PatentO i r 3,095,705 MONOFUEL REACTION CHAMBER APPARATUS George Tabberer and Derek Henry Wallace, Coventry, England, assignors to Associated Electrical Industries Limited, Irond'on, England, a British company Erled Apr. 26, 1961, Ser. No. 105,668 Claims priority, application Great Britain May 9, 1960 4 Claims. (Cl; 6039.46)

This invention relates to apparatus for the'production, by the decomposition of a mono-fuel, of a flow of gaseous working fluid for operating a prime mover, such as a turbine starter for a gas turbine, or other internal combustion apparatus.

Apparatus for producing a flow of working fluid by decomposition of a mono-fuel in a reaction chamber is known, in which the decomposition of the fuel is initiated by supplying to the reaction chamber a starting mixture of monofuel and free-oxygen-c-ontaining gas in such proportions "as to provide an ignitable composition, and then eftecting combustion of the starting mixture by means of an electric discharge, the flow of gaseous products of combustion being maintained by the self-sustaining decomposition of the continuing supply of monofuel, the supply of free-oxygen-containing gas and the electric discharge being terminated by an automatic control actuated by the operation of a pressure switch by that pressure within the reaction chamber which is sufiicient to maintain the self-sustaining decomposition of the con- In the known apparatus, a single reservoir containing the supply of f-ree-oxygen-containing gas was utilised. The quantity of gas released from the reservoir each time the decomposition in the reaction chamber was initiated was therefore not closely regulated, and the condition could arise that the supply of gas be exhausted before the estimated number of operations of the prime mover provided for by the volume of the reservoir was reached.

The object of the present invention is to provide an arrangement for initiating a plurality of flows of gaseous working fluid from a reaction chamber utilising cartridges of an oxygen-containing gas under pressure.

In apparatus for producing a flow of gaseous working fluid by the decomposition of a monofuel within a reaction chamber, ignition of the monofuel supplied to the reaction chamber being initiated by the heated gaseous products of combustion obtained from an ignited mixture of monofuel and a free-oxygen-containing gas, according to the invention, the pressure developed by the release of gas from a cartridge containing the oxygen-containing gas, is applied through a shuttle valve, both to the reaction chamber and to the low pressure side of a pressure intensifier, the high pressure side of which is connected to the fuel supply .to the combustion chamber, so as to cause the injection of fuel into the chamber, the shuttle valve being so constructed that as the pressure obtained by the release from the cartridge of its contents diminishes and the pressure produced in the reaction chamber increases by the decomposition of monofuel therein, the shuttle valve operates to terminate the supply of gas from the cartridge and leave the combustion chamber directly connected only to the low pressure side of the pressure intensifier, the pressure developed in the reaction chamber being utilised, on its rising to a predetermined value, to

- open a main .valve permitting a continuing supply of monofuel to be admitted to the reaction chamber from' the high pressure side of the pressure intensifier.

Air will, hereinafter, be referred to as the convenient free-oxygen-containing gas.

We prefer to lead the air from the cartridge by way of the shuttle valve into the reaction chamber, and to pro- 3,095,705 Patented July 2, 1963 'ice vide for the supply of monofuel which is to form with the 'air an ignitable mixture by way of a device known as a torch igniter or a separate atomiser and spark plug. Ignition of the ignitable mixture is then obtained by producing a spark across the spark plug when the air and monofuel are initially introduced into the reaction chamber, When a deflagrant is injected into the reaction chamber, the heat developed by the deflagrant will generally be suificient to ignite the atomised monof-uel injected into the reaction chamber without the necessity of producing a spark across the spark plug. The control of the continuing supply of monofuel into the reaction chamber, necessary to produce the flow of working fluid therefrom, is provided for 'by the opening of the main fuel control valve in response to the pressure developed in the reaction chamber by the ignition of the monofuel initially injected into the reaction chamber.

Means may be provided for indicating the number of cartridges which have been expended, or the number remaining as may be most convenient.

In order that the nature of the invention may be more readily understood, reference will now be directed to the accompanying drawings which show in FIG. 1 an arrangement in accordance with the invention, in which air cartridges are employed to initiate decomposition within the reaction chamber, FIGS. 2 and 3 showing a construction of shuttle valve.

Referring to the drawings, the reaction chamber is shown at l1. It is supplied with mouofuel from a tank '2 which is connected by Way of a conduit 3 containing non-return valves 4, 5, which leads through a combined atomiser and spark plug 6 into the reaction chamber 1. The-re is also led into the reaction chamber 1, by Way of shuttle valve 7 and non-return valve 8, compressed air from a plurality of cartridges 9. The cartridges may be mounted in a breech by which the air contained in the separate cartridges can be released in succession into the reaction chamber. Shuttle valve 7 is also connected to the low pressure side of a pressure intensifier 9, the high pressure side of which is connected to the conduit 3 below the non-return valve-4. Pressure exerted on the low pressure side of the pressure intensifier is effective to force fuel by way of the conduit 3 and the non-return creased, to a value such as to ensure continued decomposition of the fuel introduced through the control valve 10. Shuttle valve 7 is so constructed that as the pressure obtained by the release of its contents from a cartridge 9 diminishes, and the pressure produced in the reaction chamber increases, the valve operates to close a port to terminate the supply of air from the cartridge and leave the reaction chamber 1 directly connected only to the low pressure side of the pressure intensifier 9 Thereafter the injection of monofuel into the reaction chamber is produced by the increased pressure developed by the pressure intensifier forcing fuel into the reaction chamher through the control valve '10..

The construction and operation of the shuttle valve whereby the required control effect is exercised, will be understood from the following description of FIGS. 2 and 3.

In these figures the shuttle valve is shown as having a body portion 20 in which slides a floating valve member 21. The valve member is of cylindrical shape and is formed at one end with an enlarged head 22 and at the other end with a second removable enlarged head 23. Head 23 is made removable in order to enable the valve member to be inserted in the body portion 20 of the valve. The valve member 21 is provided internally with a longitudinal passage 24 leading to a transverse passage 25. Passage 24 opens into a chamber 26 located at the end of the body portion 20 in which the head '23 is located, whilst passage 25 opens into a recess 27 communicating with an outlet conduit 28 leading from the body portion 20. A further chamber 29 is formed in the body portion 20 in which the head 22 of the valve member is located. A vent 30 to atmosphere leads from the body portion 20 and communicates with the part of the body portion in which slides the valve member '21. The diameter of the head 22 is such that this head is a close fit in the recess 27. In use the body portion is connected so that the chamber 26 leads to the non-return valve 8, the outlet conduit 28 leads to the pressure intensifier 9, while the remaining passage of the valve connects the chamber 29 to the reaction chamber 1.

In FIG. 2, the valve member 21 is shown in the position which it occupies during the initiation of the starting cycle. Air from a cartridge, acting on the valve member 21, forces the head 23 against the shoulder 31 present at the end of the chamber 26. Air under pressure passes through passages 24 and 25 and reaches the pressure intensifier by way of outlet conduit 28 and the reaction chamber by way of chamber 29. The arrows show the direction of air travel. As pressure builds up in the reaction chamber with the initiation of combustion therein, the air pressure from the cartridge gradually falls. When the reaction chamber pressure reaches a predetermined value, its excess of pressure over that of the air from the cartridge causes the valve member 21 to be displaced to the position shown in FIG. 3. In this position, the reaction chamber pressure is diverted to the outlet conduit 28 whence it is passed to the pressure intensifier 9' and serves to maintain the flow of fuel into the reaction chamber 1. At the same time, the remaining air from the cartridge is diverted via passages 24, 25 to the vent 30 and to atmosphere. 7

In order to control the release of air from a cartridge 9, an electrical control unit, indicated at 11, is provided. The control unit is supplied from a suitable supply 12, conveniently of direct current, and is connected to an electro-magnetic valve, indicated at 13, associated with a breech in which the cartridges 9 are carried. Control unit 11 is also connected through an ignition unit 14 by which the ignition of the atomised fuel directed through the torch igniter 6, or separate atomiser and ignition plug, is brought about. Control unit '11 will be arranged to operate the electro-magnetic valve 13 and, at the same time, to supply current to the ignition unit 14 and to the coil of the bypass valve 15 to close it. Closure of the bypass valve 15 is to prevent the pressurised fuel from being forced back into the tank 2, and keeping it closed for the duration of the starting cycle, which is terminated by the operation of the starter control switch, or the time control unit 11 breaking the supply of current to the coil of valve 15 which then opens to bypass fuel back into the fuel tank 2.

Pressure intensifier 9' will be arranged on its high pressure side to accommodate sufficient monofuel to provide for a flow of gaseous working fluid from the reaction chamber estimated to secure a single operation, e.g. the starting of a gas turbine.

If desired, the'equipment may have provision for at least a stand-by cartridge containing a deflagrant for use as an alternative to the air cartridges for starting purposes. This addition is shown in interrupted lines. A cartridge 16 of defiagrant is connected through a pipe 17 to the chamber 1, the cartridge 16 being fired, when desirable or necessary, by way of an additional electrical connection 18 to the control unit 11.

What We claim is:

1. Apparatus for producing a flow of gaseous working fluid comprising a reaction chamber in which decomposition of a monofuel takes place to provide said flow, a source of monofuel, a connection between said source and said chamber, said connection including a main valve, a pressure intensifier, a connection between the high pressure side of said pressure intensifier and said source to enable fuel under pressure to be injected into said chamher through said main valve, a cartridge containing an oxygen-containing gas, a shuttle valve having a floating valve member, conduit means connecting said shuttle valve to the low pressure side of said pressure intensifier, to said reaction chamber and to said cartridge, said shuttle valve in one position of said floating valve member connecting both said reaction chamber and said pressure intensifier to said cartridge, electrical control means for initiating the flow of oxygen-containing gas from said cartridge, and ignition means for igniting the resulting mixture in said reaction chamber of said gas and said monofuel, said shuttle valve being so constructed that as the pressure obtained by the release of the contents from said cartridge diminishes and the pressure produced in the reaction chamber increases by the decomposition of monofuel therein, the floating valve member of 'said shuttle valve moves to another position to connect the supply of gas from the cartridge to the atmosphere and connect the reaction chamber directly to the low pressure side of the pressure intensifier, the pressure developed in the reaction chamber being utilized, on its rising to a predetermined value, to open said main valve permitting a continuing supply of monofuel to be injected into said reaction chamber from the high pressure side of the pressure intensifier.

2. Apparatus as claimed in claim 1, in which said fioating valve member has at its ends enlarged heads subjected to pressure of gas from said cartridge and from said reaction chamber, respectively, said valve member being moved in one direction when the pressure of the gas from said cartridge exceeds that from said reaction chamber to connect the gas supply from said cartridge to said pressure intensifier, and in the other direction to connect said reaction chamber to said pressure intensifier when the pressure in said reaction chamber exceeds that of the gas from said cartridge by a predetermined amount.

3. Apparatus as claimed in claim 2, in which said valve member is provided with an internal passage which is arranged to pass gas from said cartridge into said reaction chamber and into said pressure intensifier when said valve member is in one position during the initiation of combustion in said reaction chamber, and to pass gas from said cartridge to a vent to atmosphere when said valve member is in said other position.

4. Apparatus as claimed in claim 3, in which an auxiliary cartridge containing a defiagrant is connected directly to the reaction chamber to serve as a standby.

References Cited in the file of this patent FOREIGN PATENTS 947,657 France Jan. 17, 1949 1,150,928 France Aug. 19, 1959 784,121 Great Britain Oct. 2, 1957 816,752 Great Britain July 15, 1959

Claims (1)

1. APPARATUS FOR PRODUCING A FLOW OF GASEOUS WORKING FLUID COMPRISING A REACTION CHAMBER IN WHICH DECOMPOSITION OF A MONOFUEL TAKES PLACE TO PROVIDE SAID FLOW, A SOURCE OF MONOFUEL, A CONNECTION BETWEEN SAID SOURCE AND SAID CHAMBER, SAID CONNECTION INCLUDING A MAIN VALVE A PRESSURE INTENSIFIER, A CONNECTION BETWEEN THE HIGH PRESSURE SIDE OF SAID PRESSURE INTENSIFIER AND SAID SOURCE TO ENABLE FUEL UNDER PRESSURE TO BE INJECTED INTO SAID CHAMBER THROUGH SAID MAIN VALVE, A CARTRIDGE CONTAINING AN OXYGEN-CONTAINING GAS, A SHUTTLE VALVE HAVING A FLOATING VALVE MEMBER, CONDUIT MEANS CONNECTING SAID SHUTTLE VALVE TO THE LOW PRESSURE SIDE OF SAID PRESSURE INTENSIFIER, TO SAID REACTION CHAMBER AND TO SAID CARTRIDGE, SAID SHUTTLE VALVE IN ONE POSITION OF SAID FLOATING VALVE MEMBER CONNECTING BOTH SAID REACTION CHAMBER AND SAID PRESSURE INTENSIFIER TO SAID CARTRIDGE, ELECTRICAL CONTROL MEANS FOR INITIATION THE FLOW OF OXYGEN-CONTAINING GAS FROM SAID CARTRIDGE, AND IGNITION MEANS FOR IGNITING THE RESULTING MIXTURE IN SAID REACTION CHAMBER OF SAID GAS AND SAID MONOFUEL, SAID SHUTTLE VALVE BEING SO CONSTRUCTED THAT AS THE PRESSURE OBTAINED BY THE RELEASE OF THE CONTENTS FROM SAID CARTRIDGE DIMINISHES AND THE PRESSURE PRODUCED IN THE REACTION CHAMBER INCREASES BY THE DECOMPOSITION OF MONOFUEL THEREIN, THE FLOATING VALVE MEMBER OF SAID SHUTTLE VALVE MOVES TO ANOTHER POSITION TO CONNECT THE SUPPLY OF GAS FROM THE CARTRIDGE TO THE ATMOSPHERE AND CONNECT THE REACTION CHAMBER DIRECTLY TO THE LOW PRESSURE SIDE OF THE PRESSURE INTENSIFIER, THE PRESSURE DEVELOPED IN THE REACTION CHAMBER BEING UTILIZED, ON ITS RISING TO A PREDETERMINED VALUE, TO OPEN SAID MAIN VALVE PERMITTING A CONTINUING SUPPLY OF MONOFUEL TO BE INJECTED INTO SAID REACTION CHAMBER FROM THE HIGH PRESSURE SIDE OF THE PRESSURE INTENSIFIER.

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