Patent GB-190812565-A (GB)
Title: Improved Method of Compressing Air or Gases, and Apparatus therefor.
Inventor: HUMPHREY HERBERT ALFRED
Filed: 1908-06-11
Granted: 1909-06-10
Abstract: 12,565. Humphrey, H. A. June 11. Compressing ; exhausting. - In a method of compressing or exhausting air or other elastic fluid by means of a liquid descending from a higher to a lower level, or set in motion by fluid pressure, the column of liquid first attains velocity and then its energy is utilized partly to deliver air under pressure and partly to store energy in an elastic cushion, which produces a reverse movement of the liquid and thereby causes a fresh charge of air to enter the apparatus. The air-compressor chambers and valves may conveniently be of the type described in Specification No. 22,646, A.D. 1907, in which a liquid piston is set in motion by the energy of expansion of an ignited combustible ; and valve mechanism, such as is described in Specifications Nos. 18,594, 18,595, and 19,341, A.D. 1907, [Abridgment Class Air and gas engines], for introducing a mixture of gas and air into a combustion chamber may be employed for introducing air into the air-compressor chambers. The compressing-chamber 1, Fig. 1, is fitted with an inlet valve 7, a discharge valve 8, a supplementary discharge valve 9 adapted to be seated by impact of liquid, and an inwardly-projecting discharge pipe 10 forming a cushioning-space, all as set forth in the aforesaid Specification. The cycle of operations is as follows. Liquid descending from a high-level reservoir 3 to a low-level reservoir 6 on attaining a certain velocity is adapted to close a spring-shaped valve 5, and then compress air in the chamber 1. Part of the air is delivered past the valve 8. and, whether or not the liquid rises sufficiently high to close the valve 9, part of the air is compressed into the cushioning-space. The cushioning-air effects a reversal of the flow of the liquid, thus permitting a fresh charge of air to be drawn in, and, a reduction of pressure in the pipe 2 taking place, the valve 5 reopens, allowing liquid to pass from the chamber 1 into the reservoir 6 until the condition for the commencement of a new cycle is established. An alternative position of the reservoir 6 is shown in dotted lines. In this, during the reverse movement, the liquid flows from the reservoir to the pipe 2, instead of vice versa as above. Modifications are described in which (1) a non-return valve similar to the valve 5 is additionally provided between the reservoir 3 and the pipe 2, this valve being located below an air-vessel enlargement of the pipe for preventing shock ; the cycle of operations is much the same as above, save that the closing of one of the valves 5 effects indirectly the opening of the other. (2) Cushioning takes place in a separate vessel arranged in parallel with the compressing-chamber. (3) Two chambers arranged in parallel, side by side, are adapted to function alternately as compressing and cushioning chambers. (4) The valves 5 are controlled by the pressure in the delivery pipe, so that they may close earlier as the receiver pressure rises, thus diminishing the mass of the moving liquid per cycle and therefore the air compressed per cycle, and so that they remain closed when a predetermined pressure is attained, thus stopping the compressor. For this purpose, the receiver pressure is admitted to act upon a piston connected to the valve stem. The volume of the air compressed per cycle may be varied as described in the aforesaid Specification by varying the level at which liquid rising in the compressing-chamber cuts off communication with the atmosphere; for this purpose, the liquid is adapted to close by impact a supplementary inlet valve located in a verticallyadjustable pipe within the chamber. Fig. 6 shows a similar device for varying the volume of the cushion space. The pipe 29, containing the impact valve 9 which closes the chamber to the receiver, is formed as a sleeve surrounding the pipe containing the delivery valve 8, and is vertically adjustable by means of a fixed nut and hand-wheel 23. Measured charges may be compressed per cycle, and the effective length of the liquid column varied, as described in the aforesaid Specification. It is not always necessary that there should be a reversal of the flow between the chamber and the high-level tank, and Fig. 12 shows a device in which the varying volume in the compressing- chamber is effected by means of a reversal of flow between the chamber and the low-level receiver. The compressing-chamber 1 is located between the receivers and much nearer thu low-level receiver 6. The waste valve 5 is locked, by meaos of spring pawls 51 engaging the curved valve stem 46, until the normal cushion pressure is attained in the chamber 1, whereupon the tension of the spring 49 is overcome, the valve is held open, the liquid level falls in the chamber 1, a fresh charge of air is drawn into the chamber 1, and a point is reached at which liquid commences to flow from the receiver 6 to the chamber, whereupon the valve is again closed by impact of liquid and locked to enable a new cycle to commence. The number of compressing-chambers, cushioning-vessels, and receivers used in combination with each other may be varied, and the valves 5 may be duplicated to any required extent in large compressors. In this case, one of each set of valves may be adapted to act as a pilot valve which closes a little before the others and ensures their prompt closure by the extra rush of fluid past them occasioned by the first closure. The high-level receiver may be replaced by a closed tank subjected to fluid pressure. The elastic cushion may be obtained by the use of spring-controlled pistons, or by the compressed air through the medium of a piston.