US2402826A - Control means for jet propulsion apparatus - Google Patents

Description

June 25, 1946. 1. LUBBOCK CONTROL MEANS FOR JET PROPULSION APPARATUS Filed July 7, 1943 euprueqazz q/a/ks /4 Mr M. 1 W m w pm a: a W Z w an 05 g a H a 2 A v .m... W 0 m m e mi. 2 3 an a a "mm I (I Horney Patented June 25, 1946 CONTROL MEANS FOR JET PROPULSION APPARATUS Isaac Lubbock, Great St. Helena, London, England, assignor to The Asiatic Petroleum Company Limited, London, England Application July I, 1043, Serial No. 493,801

In Great Britain November 7, 1941 4 3 Claims. 1

This invention relates to improved control means for the supply of liquids in combustion apparatus, especially jet propulsion apparatus of the type wherein a liquid fuel is used in combination with an oxidant in liquid form such as liquid oxygen.

The object of the invention is to ensure the arrival, timely in relation to the operation the ignition means, and steady feeding of the liquids over the time of operation of the apparatus.

Another object is to secure the regulation of the initial flows to prevent excessive pressure in the combustion chamber.

According to the invention, the operation of the apparatus is initiated by actuating means causing the liquids rapidly to arrive in the combustion chamber in automatic timed relationship coordinated with the actuation of the igniting means.

In carrying out the invention there is preferably employed a rapidly acting valve operated by an explosive charge-for example a valve as described in the specification of co-pending application Serial No. 464,832-which releases a propelling gas such as nitrogen through a reducing valve simultaneously to the vessels containing the respective liquids.

To prevent the possibility of the liquids prematurely mixing with each other. the propelling gas lines to the liquid vessels, and also the liquid feed lines to the burning nozzles, may be fitted with seals or diaphragms which will automatically rupture at pressures substantially below the operating pressures. The rupturing seals or diaphragms in the liquid iced lines. will of course be sufiiciently strong to withstand the gravity heads of the liquids themselves with a margin of safety. Diaphragms may be employed which are constructed as described in the specification of copending application Serial No. 498,442 (now abandoned).

The rapidly acting valve is preferably operated conjointly with the igniter, for example by electrical coupling, so that the apparatus can be started almost instantaneously by the operation,

for example, of a single electrical switch. There will be therefore substantially no delay period such as is usually associated with jet propulsion apparatus of the liquid combustion type. The control means according to the invention will assure the arrival of the liquids in the combustion chamber in a fraction of a second after the valve and igniter have been actuated. The igniter may be constructed as described in the specification of co-pending application Serial No. 464,833.

By using a reducing valve in the gas line leadins to the liquid vessels and by setting this valve at the appropriate pressure for metering the liquids through their respective nozzles against combustion chamber pressure, the change in pres-- sure of the propelling gas, on the high pressure side, as it becomes spent has no eflect on the rates of delivery. The nozzles for the liquids may be constructed as described in the specification of co-pending application Serial No. 493,800.

During the extremely short initial period before full pressure is established in the combustion chamber the nozzles will necessarily pass more than the steady amount but by introducing suitable chokes in the liquid and gas lines the amount of excess pressure at starting can be kept down to negligible proportions apart from the fact that the combustion chamber pressure as it builds up opposes the fiow through the nozzles.

The desired timed relationship of the arrivals of the respective liquids in the combustion chamber is obtainable by setting at calculated distances from the mixing nozzles the burster valves or diaphragms in the respective liquid lines. Preferably the setting is such that the liquid oxidant will arrive just before the liquid fuel.

Water, or other suitable liquid diluent, may be delivered into the combustion chamber to reduce the maximum, temperature of combustion and to improve the thermal efiiciency of the apparatus, a described in the specification of copending application Serial No. 493,802. The means for propelling the diluent liquid may be the same as for propelling the combustion liquids, including, if desired, a burster valve or diaphragm in the diluent liquid line set at a distance from the delivery nozzle or nozzles appropriate for securing delivery in proper timed relation with the deliveries of the combustion liquids.

The invention is illustrated by way of example in the accompanying diagrammatic drawmg.

Referring to the drawing. I indicates a combustion chamber, e. g. a combustion chamber for jet propulsion apparatus. 2 indicates ignition means for initiating combustion of liquids in the combustion chamber. 3 indicate nozzles for admitting liquids into the combustion chamber. 4 is a high pressure gas cylinder containing an inert gas such as nitrogen. 5 is an explosive operated rapidly opening valve such as described in application Serial No. 464,832. 8 is a reducing valve and I is a gas choke. The gas line has branches 66 leading to the liquid containers 8, 3 and It. In

the branch lines are rupturabie diaphragms al, a2, a3. Container 8 contains liquid oxidant, container 9 liquid fuel and container Ill water or other suitable liquid diluent.

From the containers issue liquid lines H, l! and i3 which lead to the nozzles 3.

In these liquid lines respectively are liquid choke Bi, B2, B3, and further along the respective lines are liquid rupturable diaphragms Al, A2, A3. These diaphragms are at different distances from the nozzles.

In operation, the igniting means 2 and valve 5 are conjointly operated by electrical means. The valve 5 rapidly opens and high pressure gas passes through the reducing valve 6 and gas choke i into the gas line whence it proceeds into the branch gas lines and immediately ruptures the diaphragms ai, a2, a3. Thereupon the containers 8, 9 and ID are subjected to high gas pressure and the liquids in'the liquid lines II, I! and I3 burst the rupturable diaphragms Al, A2, A3. The parts of the lines between these diaphragms and the nozzles were originally empty and therefore a very short period of time elapses before the liquids reach the nozzles after the diaphragms have been ruptured. The difierential distancing. of the diaphragms from the nozzles ensures that the liquid oxidant from con-- tainer 8 will be led into the combustion chamber Just before the liquid iuel arrives from the container 0. Very quickly after combustion has been initiated between these liquids. the water or other liquid diluent arrives through its nozzle.

I claim:

1. Control means for the supply of liquids to combustion apparatus comprising a source of propellant gas pressure, a plurality of containers for said liquids, a valve controlling the sup p y or propellant gas from said source to said containers, and lines connecting the respective containers with said apparatus, said lines containing automatically rupturable seals and the seals being located at diflerent distances from said apparatus so that the respective liquids reach said apparatus in a predetermined sequence.

2. Control means as defined in claim 1, said lines comprising liquid chokes located between the respective containers and rupturable seals.

3. Control means as defined in claim 1 wherein one of said containers holds a liquid fuel and another holds a liquid oxidant, the rupturable seal for said fuel being located further from said apparatus than the rupturable seal for said oxidant.

ISAAC LUBBOCK.

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