GB214907A - High duty multi-stage compressors for compressing air or gases - Google Patents

Abstract

214,907. Nordberg, B. V. Sept. 10, 1923. Compound piston pumps.-A compressor. especially intended for costly, inflammable, or poisonous gases which are to be compressed to a high pressure, comprises a stepped cylinder and piston, in which the first stage is double-acting and the remaining stages single acting, all the spaces within the cylinder being active compression spaces, and a detachable cylinder head with a stuffing- box through which the piston rod, at the large end of the piston, passes, the piston being bodily removable through the large end by removal of the head without disturbing the mounting and the suction and discharge connections. Fig. 5 shows a four-stage compressor with two stepped cylinders cooled by water jackets. The spaces 5, 6 on either side of the large head 7 of the first cylinder form first-stage compression spaces connected through inlet valves 16 and a pipe 17 with a gas supply reservoir 18 and through discharge valves 20 and a pipe 21 with an intercooler 22 from which the gas passes through a valve 24 to the second stage space and below the small end of the cylinder. From the outlet valve 26 of this space, the gas passes through a cooler 28 to the compression space below the large head of the second cylinder and thence through a cooler 34 to the final space 12 at the small end from which it is discharged through a pipe 39. The idle space 42 at the head of the second cylinder is connected with the first intercooler 22 or another low pressure space. The cylinders are provided at their large ends with removable heads 45, 46 provided with stuffing boxes 47, 48 for the piston rods, which are fastened to cross-heads connected by parallel guided rods with cross-heads driven from a crank shaft; the cross-head may be disconnected from the shaft if power fails, and the compressor driven by a hand lever. Fig. 3 shows a suction valve comprising a cage 66 fitted in an opening in the cylinder wall, a separate and reversible seat section 67 formed with ports 68 controlled by a disc 69 which is pressed down by a spring 72 bearing on a seat 70 bolted to the port 67, and a cover 73 formed with an annular chamber 86 between jcint.s 84, 90 which may be of soft metal and rubber respectively. The annular chamber 86 receives any leakage and conveys it through piping 78, Fig. 5, to the reservoir 18. The discharge valves are similarly constructed and provided with leakage channels leading also to the piping 78 and the reservoir, and similar joints and leakage chambers are formed around the cylinder heads 45, 46. Above the stuffing boxes, hoods 76, 77 are provided on the heads to receive any escaping gas and lead it back to the reservoir. The smaller ends of the cylinders may be provided with separate, heads. A single-cylinder compressor having more than two stages may be employed.