Patent GB-191111817-A (GB)
Filed: 1911-05-16
Granted: 1912-05-16
Abstract: 11,817. Humphrey, H. A. May 16. Direct explosion apparatus. - Relates to internal-combustion pumps and compressors of the reciprocating liquid column type wherein the pressure of delivery exceeds the mean effective pressure applied to the column by the expansion of the ignited combustible mixture, and consists in utilizing the combustion chamber itself as the intensifier necessary in such apparatus, the fluid being delivered on the return stroke of the liquid column which acts in such a manner as first to compress an elastic cushion and then to deliver fluid. The whole of the energy may be stored on the out-stroke to effect the return stroke, or a certain amount of liquid may be delivered during the out-stroke in the manner described in previous Specifications relating to pumps of this class and the remaining energy stored to effect the return stroke. The delivery may thus be effected at two different pressures. The method of working can be applied to pumps working either on a two or four stroke cycle. Fig. 1 illustrates a fourstroke-cycle pump, in which delivery of liquid is effected only on the return stroke. When explosion occurs in the combustion chamber 1, the delivery valves 3 are locked shut by valvegear which may be controlled by the movements of the exhaust valve 6, and the water is forced along the play pipe 4, 4<a> into an air-vessel 11 having a dip-pipe 13 and non-return valve 12. The air escapes freely through the valve 12 until the valve is shut by impact of the liquid, whereupon the remaining air is compressed, bringing the column to rest and effecting the return stroke. Water is drawn into the apparatus through the valves 2 during the later portion of the out-stroke, and the exhaust valve 6 opens by its own weight during the same period, setting free the valves 3. The return flow of the liquid column then occurs, and exhaust gases are first expelled through the valve 6 until the valve is shut by impact of liquid, whereupon a cushion of gas is compressed in the top of the combustion chamber, and, as soon as the pressure reaches that of the delivery head, the valves 3 open and liquid is delivered through the delivery pipe 10. As soon as the flow of liquid ceases, the valves 3 shut and the admission and compression strokes are effected in the well-known manner by the expansion of the compressed cushion of gas. Fig. 8 shows an air - compressor working on a similar cycle. During the out-stroke, air is forced at a low pressure from the air-vessel 32 into the reservoir 37 until the valve 34 is closed by impact of the liquid, whereupon a cushion of gas is compressed in the top of the vessel 32 to effect the return stroke. During the later portion of the outstroke, the exhaust valve 44 is opened by a spring, and the compressed air in the reservoir 37 enters the combustion chamber through the valve 39, expelling the burnt products. During the return flow, the column of liquid gains velocity while expelling air through the valve 44 until this valve shuts by impact of the liquid, and the air remaining in the combustion chamber is then compressed and delivered through the valves 41, 42 until the valve 41 is shut by impact, whereupon a cushion of gas is compressed in the top of the chamber to effect the admission and compression stroke in known manner. The following modifications are described. (1) The locking-gear for the valves 3 may be dispensed with, in which case some of the water is delivered during the explosion stroke while the explosion pressure is in excess of the delivery head. (2) The return stroke may be effected by the pressure of water raised in the play pipe instead of by an air cushion. (3) When the return flow is effected according to (2), the end of the play pipe may rise above the bottom of a delivery tank, so that the liquid delivered cannot return and the energy for effecting the return stroke may thus be limited. (4) The volume of the cushion of gas in the combustion chamber for effecting the admission and compression stroke may be adjusted by means of an open-ended pipe surrounding the exhaust valve and passing some distance down the chamber with an adjustable valve at the foot. (5) The air-vessel for effecting the return stroke may be in two parts separated by a valve closed by impact of the liquid, so that the return 'is effected at two different pressures. (6) Double combustion chambers may be used as described in Specification 19,341/07. (7) The air-vessel at the foot of the delivery pipe 10 may be dispensed with, in which case the momentum of the liquid in the delivery pipe may be utilized to produce a continuation of the flow. (8) The play pipe may be made U-shaped with an air cushion at the top of the arm remote from the combustion chamber. (9) The play pipe may be of variable cross-section. (10) The play pipe may pass vertically downwards to an air-vessel beneath. (11) Combustion chambers fitted with inlet and delivery valves may be situated at both ends of the play pipe, so that in the case of a two-stroke cycle pump every movement of the liquid column is brought about by a separate explosion. (12) In the arrangement just described, a liquid delivery valve may be situated at the middle of the play pipe where the pressure remains most nearly constant. (13) In a two-stroke-cycle air-compressor, the air is pumped from a bell dipping down into the combustion chamber, the combustion gases remaining entirely in the annular space between the bell and the outer walls of the combustion chamber. (14) Differential solid pistons may be fitted at the end of the play pipe for compressing gases to different pressures than would be attained by the use of the liquid column alone.