GB176838A - An improved method of & apparatus for generating power by combustion - Google Patents

Abstract

176.838. Shannon, D. M. Nov, 5, 1920. Generating combustion products under pressure.-Apparatus for generating power by combustion comprises a combustion chamber having an inlet valve for the mixture and an ignition device and located at one end of a tubular vessel having a large ratio of length to area. The gases resulting from the explosion of a mixture of air and fuel in the combustion chamber pass along the tubular vessel and by their momentum create a partial vacuum and draw a fresh charge into the chamber. A portion of the gases passes through an outlet at or near the remote end of the tubular vessel and is used for driving a turbine &c. or stored under pressure; the remainder is caused bv reflection from the end of the vessel to travel back towards the combustion chamber and compress the fresh charge therein. Fig. 2 shows one form of apparatus, in which mixture is supplied past the valve d, compressed in the combustion chamber a by gases reflected from the end b of the tubular vessel c and ignited by a sparking-plug e, the circuit of which is made by a plunger e<1> operated by the pressure in the chamber a. The gaseous combustion products pass along the vessel c and out through an outlet f near to the end. A portion of the gases is trapped in the space v between the outlet f and the end b of the vessel c, and travels back along the tube, compressing the fresh charge which has been drawn in by the partial vacuum created in the chamber a during the outward movement of the combustion products; the cycle is then repeated. Cones k may be fitted in the outlet pipe f to reduce inward leakage when the wave reflected from the end b passes the outlet. Air may be delivered bv automatic valves i in front of the charge to prevent leakage of charge through the outlet f; this air may be drawn from a jacket i which surrounds the vessel c and keeps it cool by air circulation. A similar jacket q may surround the combustion chamber and supply the air for combustion. The outlet f may be made adjustable in distance from the end b. In the modification shown in Fig. 2<B>, it is formed by a tube l screwed into the end b and projecting axially into the vessels c; in further modifications a comparatively small outlet opening or a spring-loaded valve is arranged in the end b, the result in all cases being that a portion of the combustion products passes back along the vessel c. In a simple form of the apparatus for propelling aeroplanes, vehicles or ships by the reaction of the issuing gases, the end of the vessel c is open and the compression is obtained owing to the oscillations set up in it. Other forms of the apparatus cnmprise: two tubular vessels c in one line with a common combustion chamber a between them: two combustion chambers, one at each end of the vessel c with two outlets f near the centre: the ring-like arrangement of a single combustion chamber with two expansion vessels shown in Fig. 5; a form in which the two vessels c are straight and parallel to one another with a common combustion chamber joining them at one end; the form shown in Fig. 7 in which the combustion products pass down a central tube s and thence up an annular space between the tube s and an outer tube s1, resulting in a shortening of the apparatus. In the form shown in Fig. 8 the outlet valves m are in the combustion chambers, a portion of the gases from each explosion being retained and compressing the charge in the other chamber; in a modification of this form a single inlet valve for the mixture is arranged at the centre of the tube c. To promote rapid combustion the charge may be rendered turbulent by vanes such as q, Fig. 2<G>, arranged in the entrance of the combustion chamber; these vanes may be pivoted at q1, so that they may move under the action of the gases between stops q2, q3 to offer small resistance to gases passing out whilst taking up a spiral direction when the column is moving into the combustion chamber. Fig. 2<H> shows a form of the apparatus in which the compression wave acting on a piston r and plunger r1 forces fuel into the chamber through a jet r7, air only being drawn in through the valve d. The use of pulverized solid fuel is referred to.