US3303652A

US3303652A - Method for operating a jet propulsion engine with solid fuels

Info

Publication number: US3303652A
Application number: US413159A
Authority: US
Inventors: Maas Friedrich Julius
Original assignee: Kemenczky Establishment
Current assignee: Kemenczky Establishment
Priority date: 1963-11-23
Filing date: 1964-11-23
Publication date: 1967-02-14
Anticipated expiration: 1984-02-14
Also published as: CH436846A

Description

F. J. MAAS 3,303,652

METHOD FOR OPERATING A JET PROPULSION ENGINE WITH SOLID FUELS Feb. 14, 1967 Filed Nov. 23, 1964 I IIII IIIIIIIIIIIIIIIIII F/GZ United States Patent 3,303,652 METHOD FOR OPERATING A JET PROPULSION ENGINE WITH SOLID FUELS Friedrich Julius Maas, Zurich, Switzerland, assignor to Kemenczky Establishment, Vaduz, Liechtenstein, a corporation of Liechtenstein Filed Nov. 23, 1964, Ser. No. 413,159 Claims priority, application Switzerland, Nov. 23, 1963, 14,376/ 63 2 Claims. (Cl. 60204) The present invention relates to a jet propulsion engine for watercraft. Jet propulsion engines of this type are known in different designs and described per example in US. Patent No. 3,060,682 or in the pending Swiss applications Serial Nos. 6,538/ 63 and 7,337/ 63 assigned to the same assignee as the present application.

A jet propulsion engine for watercraft of the mentioned type are provided with a thrust tube being filled up with water through a check valve at the tubes entrance. The thrust tube is connected to a pressure chamber by a valve of suitable construction through which successive gas shocks are passed into thrust tube for expelling the column of water therein and for exercising a corresponding force in opposite direction to the engine. For producing the gas shocks the jet propulsion engines of the type similar to US. Patent 3,060,682 are using a liquid fuel and a carburator to prepare in a combustion chamber an explosive fuel/ air mixture, which is ignited in successive time intervals. According to the above mentioned pending Swiss application Serial No. 6,538/ 63 the carburator may be replaced by a fuel injection equipment. As described in the above mentioned pending Swiss application Serial No. 7,337/63 the combustion chamber may be filled up with high pressure steam from a separate water steam boiler and connected to the thrust tube in successive time intervals for producing the desired gas shocks.

The main object of the present invention is to replace the use of liquid fuels as well as the separate steam boiler by a method for operating a jet propulsion engine for watercraft provided with a thrust tube being filled with water through a check valve at the entrance and being connected to a pressure chamber by a valve means through which in successive time intervals gas shocks are passed into the thrust tube for expelling the water column therefrom. The invention is characterized by gas shocks produced by disintegration of a solid fuel.

These and still further objects of the present invention will become more apparent from the following detailed description thereof to be read with reference to the accompanying drawings in which:

FIG. 1 shows a longitudinal section of an embodiment of a jet propulsion engine operated according to the present invention by solid fuel;

FIG. 2 shows another embodiment of a jet propulsion engine for watercraft suitable to be operated by solid fuel according to the present invention.

The jet propulsion engine shown in FIG. 1 is provided with a pressure chamber 17 and valve means for intermittent connection to the thrust tube 100 similar to the corresponding parts described in the pending Swiss application Serial No. 7,337/ 63. During operation of the engine the thrust tube is below the water level 11 and provided with a check valve per example consisting of the blades 12 radially extending from a spindle-shaped rotation shaft 13. By this

check valve

12, 13 the entrance of the thrust tube 10 is open for a water stream only in the direction 14 but closed for the outlet of the water column from the thrust tube 10 in opposite direction.

The thrust tube 10 is connected to the pressure chamber 17 through a circular opening 15 which is closed against gas or water flow by a disk-shaped valve head 16. The pressure chamber 17 and the valve head 16 together with its mechanism are a common structure arranged in the .heat insulated inner space 20 of a streamline shaped support 19 for the thrust tube 10. The upper part of the support 19 is provided with a chamber 70 for accumulating high pressure gas.

The high pressure gas used for operating the jet propulsion engine is supplied from the gas chamber 70 through the connection 22 into the pressure chamber 17. The orifice of the connection 22 is arranged in the pressure chamber 17 above the cone shaped valve seat 23 constituting together with the cone shaped ring 24 at the stem 25 an inlet valve for the high pressure gas stream. This inlet valve 23, 24 is closing the gas supply from the connection 22 to the pressure chamber 17 after having lifted the stem 25 high enough to press the ring 24 to the valve seat 23.

The position of rest of the valve head 16 carried by the stem 25 is shown in FIG. 1 and in this position the connection between the pressure chamber 17 and the thrust tube 10 is closed. Accordingly the inlet valve 23, 24 is opened and high pressure gas is 'fiowing from the connection 22 into the pressure chamber 17. Through a conduit 26, the needle valve 27 and a bore 28 the pressure chamber 17 is connected to a control chamber 29 being closed at the top with a piston plate 30 carried by the stem 25. In the rest position the needle valve 27 is closed and the connection between the conduit 26 and the bore 28 is interrupted. Only when the gas in the pressure chamber 17 comes up to a predetermined value the needle valve 27 is opening the connection from the pressure chamber 17 through the conduit 26 and the bore 28 to the control chamber 29 which acquires the same gas pressure. Because the area of the piston plate 30 exposed to the control chamber 30 is larger than the area of the valve head 16 the upward force against the piston plate 30 and the stem 25 is overbalancing the downward force on the stem 25 carried out by the valve head 16. Accordingly the stern 25 is moved upward by the piston plate 30 and the valve head 16 is lifted opening the connection between the pressure chamber 17 and the thrust tube 10.

The upward motion of the stem 25 is finished as soon as the cone shaped valve ring 24 is pressed against the valve seat 23 closing the inlet valve for the gas supply connection 22. Before the stem 25 reaches this upper end position the pressure in the pressure chamber 17 is decreased far enough that the needle valve 27 is again closed interrupting the connection between the pressure chamber 17 and the control chamber 29. In the upper end position of the stem 25 the curved rear surface 31 of the valve head 16 is contacting the edge 32 in the pressure chamber 17 closing the upper part of the pressure chamber 17 as well as the inlet valve 23, 24 and the orifice of the conduit 26 against the lower part of the pressure chamber 17. Furthermore in this upper end position of the stem 25 the outlet valve 33 arranged below the piston plate 30 is lifted from its seat and hence the control chamber 29 is connected through the conduit 35 to the lower part of the pressure chamber 17.

At the moment the valve head 16 is lifted by the stem 25 a gas shock is directed through the opening 10 upon the water column in the thrust tube 10 from the high pressure gas filling of the lower part of the pressure chamber 17. The gas from the lower part of the pressure chamber 17 as well as from the control chamber 29 is flowing through the opening 15 into the thrust tube 10.

After the expellation of the water column from the thrust tube 10 is finished, the gas pressure in the lower part of the pressure chamber 17 becomes lower than in its upper part which is closed by the rear of the valve head 16 contacting the edge 32 so that a downward force is arising upon the valve head 16 and the stem 25. This force is increased by the pressure of the gas in the connection 22 upon the valve ring 24. As a result of these forces increased by the own weight of all the parts carried by the stem 25 the valve head 16 is falling down and closing again the opening 15 between the pressure chamber 17 and the thrust tube furthermore the

outlet valve

33, 34 of the control chamber 29 is closed and the high pressure gas is flowing from the connection 22 through the open inlet valve 23, 24 into the pressure chamber 17. Now the mechanism is again in the position of rest shown in FIG. 1.

By the above described action of the valve mechanism successive gas shocks are passing the opening and exercised to the water column in the thrust tube 10. The valve mechanism is a self interrupting push-pull valve at the connection 22 supplying the high pressure gas into the pressure chamber 17 and at the opening 15 between the pressure chamber 17 and the thrust tube 10. Besides the dimensions of the mechanism the adjusting of the needle valve 27 is responsible for the operation frequency of the self interrupting push-pull valve; hence the frequency is continuously variable within a broad range. An embodiment of a suitable needle valve 27 is described in detail in the above mentioned Swiss application Serial No. 7,337/63; the highest operation frequency is 40 to 50 cycles per second and lower frequencies are adjustable. I

The valve mechanism described above in connection with FIG. 1 is a preferred embodiment of a mechanical self-interrupting push-pull valve having an operating frequency adjustable by the response pressure of the needle valve 27. Nevertheless other embodiments of valve mechanism are suitable; per example the pressure responsible needle valve 27 may be replaced by a control means not pressure responsible but arranged to connect the conduit 26 and the bore 28 from the pressure chamber 17 to the control chamber 29 at predetermined time intervals. Such a control means may be responsible, per example, to the pressure pulses arising in the thrust tube 10 during the water column is expelled therefrom. Also an external controlled valve means may be used, per example a magnet controlled valve which is operated by electric control pulses with a frequency adjusted according to the desired operating frequency of the valve mechanism. Moreover in a mechanism comprising the valve head 16 and the gas inlet valve 23, 24 the control chamber 29 may be avoided and replaced by suitable spring means. Also a magnetic operation of the valve head 16 and the gas inlet valve 23, 24, may be used and the operating frequency adjusted by exciting the magnet coils by suitable electric current pulses.

The high pressure gas necessary for the operation of the jet propulsion engine shown in FIG. 1 is supplied to the gas chamber 70 through the connection 71 from a gas generator 72 for solid fuels. The gas generator 72 comprises, per example a case containing gun powder in the form of pressed rods 73. Similar high pressure gas generators suitable for solid fuels are well known in different types as rocket drives. After having ignited the solid fuel, per example by an electrically heated filament (not shown), the suitable prepared gun powder rods 73 are burning with constant speed without an explosion. The burning process of the rods 73 is producing a large gas amount and high pressure and the gas is supplied through a sieve plate 74 and the connection 71 into the gas chamber 70. Normally the burning process cannot be stopped after the ignition. The amount and pressure of the produced gas may be influenced by the shape and arrangement of the solid fuel in the generator 72 and the duration of the burning process is determined by the fuel amount contained in the case.

The embodiment of the jet propulsion engine shown in FIG. 1 comprises a high pressure gas generator using solid fuels; hence it is suitable only for purposes in which the propulsion force is desired only during a predetermined time interval. Per example, a jet propulsion engine of this type is suitable for water torpedos or similar purposes. After having burned down the solidfuel contained in the generator 72, the jet propulsion engine may be used again after having replaced at the gas generator 72 the empty fuel case by a fresh one.

Whilst the embodiment of the jet propulsion engine according to FIG. 1 is provided with a gas generator for continuously burning solid fuels a second embodiment shown in FIG. 2 uses granulated solid fuel and an explosion of predetermined quantities during successive time intervals. This second embodiment is described in detail below but is shown in FIG. 2 only diagrammatically and all less important parts are avoided.

The jet propulsion engine according to FIG. 2 is provided with a thrust tube having a rotating check valve 81 at the entrance of the type described above. The pressure 82 is connected to the thrust tube 80 through a valve means 83, preferably provided with a number of flat and pane like lamellae being arranged at small distances parallel one to another securing only a very small resistance against a gas flow from the pressure chamber 82 into the thrust tube 80 but at the same time preventsany passing of water from the thrust tube 80 into the pressure chamber 82. Additional to this valve means 83 the pressure chamber 82 is provided with a check valve, per example comprising a perforated plate 84 and a number of fiat spring plates 85 closing the openings in the plate 84 when in the position of rest shown in FIG. 2.

The pressure chamber 82 is also provided with several radial extending ribs forming a grill 86 carrying a tray suitable as a receptacle of one or more particles 87 of the granulated solid fuel. The grill 86 is also the support of a feeding 88 being connected to the storage case 90 through a dosage means 89 for the granulated solid fuel contained in the case 90. An insulating body 91 attached to the grill 86 is carrying a spark plug which is connected through an insulated lead in 92 to an electric current supply 93 outside of the pressure chamber 82.

In adjustable successive time intervals the receptacle of the grill 86 is supplied by the dosage means 89 and through the feeding 88 with one or more particles 87 of the granulated solid fuel from the storage case 90. The dosage means 89 and the feeding 88 may be operated pneumatically, per example. The fuel particles 87 are ignited by an electric spark and exploded. The pressure shock produced by this explosion passes the

check valve

84, 85 and the valve means 83 and is expelling the water column in the thrust tube 80 through the outlet. During the refilling of the thrust tube 80 through the entrance check valve 81 the

check valve

84, 85 is again closed and from the dosage means 89 a quantity of granulated solid fuel is fed into the empty tray on the grill 86 followed by the next ignition and explosion. The dosage means 89 is designed in a manner to keep off the pressure shocks produced by each explosion in the pressure chamber 82 from the storage case 90 and the solid fuel therein.

As solid fuels are all explosive materials suitable, which can be prepared in granulated form, per example as smalli balls or particles of other shapes. Per example the:

normal gun powder can be used after being mixed with:

a suitable oxygen carrying material and then granulated.

Also other solid fuels are suitable in granulated form, per

example nitrocellulose and other explosive substances. The Weight of the single particles or of the amount of particles fed into the tray for each explosion cycle are adjusted to produce a pressure shock by each explosion which is just sufficient to expell the water column in the thrust tube 80 therefrom.

The above described and in FIGS. 1 and 2 diagramfor other types of jet propulsion engines for watercraft provided with a thrust tube being connected to a pressure chamber by a valve means through which in successive time intervals gas or pressure shocks are passed into the thrust tube for expelling the water column therefrom. The gas or pressure shocks are produced by disintegrating a solid fuel. The fuel may be burned continuously to produce a gas of high pressure which is passed in successive intervals into the thrust tube. Also granulated solid fuel may be used to be exploded in predetermined quantities and in successive intervals to exercise pressure or gas shocks to the water column in the thrust tube.

What I claim is:

1. A method of operating a hydrojet engine having a thrust tube for receiving and expelling water, a check valve positioned in the forward end of said tube, a pressure chamber in valved, fluid communication with said tube downstream of said check valve and a gas producer in valved, fluid communication with said pressure chamber; comprising the steps of (1) continuously burning solid fuel in said gas producer to obtain a high pressure gas (2) intermittently supplying said high pressure gas to said pressure chamber and (3) intermittently passing said gas from said chamber to the thrust tube for expelling a column of water therefrom.

2. The method according to claim 1 further com-prising the step of providing a gas accumulator between said gas producer and said pressure chamber.

References Cited by the Examiner UNITED STATES PATENTS 730,042 6/1903 Okun 1l513 1,838,984 12/1931 Berkowitz 6035.6 2,463,820 3/1949 Stafford et al. (SO-35.6 2,903,850 9/1959 Lang 6035.6 3,157,992 11/1964 Kemenczky 60-3977 CARLTON R. CROYLE, Primary Examiner.