US2250164A - High pressure cylinder - Google Patents

Description

July 22, 1941. o. MINDER HIGH PRES SURE CYLINDER Filed Oct. 20, 1939 2. Sheets-Sheet 1 MV/lI/Ifld. I I III ATTORNEY-5 Patented July 22, 1941 UNITED STATES PATENT, OFFICE HIGH PRESSURE CYLINDER out Minder, Winterthur, Switzerland, assignm- 'to Sulzer Frres, Socit Anonyme, Wintei'thur,

Switzerland Application October 20, 1939, Serial No. 300,405 In Switzerland October 27, 1938 3 Claims.

This invention relates to high-pressure cylinders, and particularly to cylinders of the type employing a single acting piston. The high pressure cylinder of the invention comprises at least two parts, one part being at the head-end where the fluid medium undergoing compression is subjected to the greatest pressure; the other part (hereinafter called the low-pressure'cylindel -portion is connected to the head-end, portion and extends to the vicinity of the lower dead point of the piston, the pressure in this portion of the cylinder being relatively low. The invention contemplates the provision of an improved cylinder .for the compression of fluid media at pressures, for example, over one thousand atmospheres capable of resisting corrosion resulting from the conditions prevailing in certain portions of the cylinder.

Repeated attempts have been iacture such compression cylinders, which are subject to high stresses, of steel which'is suitable forj tempering. However as these, without exception, for construction reasons show very -great differences with respect to the cross sections and material aggregations or agglomerations cannot be avoided, whereby a temperingwhich is uniform and free from stresses is impossible, these attempts did not lead to the resultexpcted. In

accordance with the invention, therefore only that part ofthe working surface which is e posed to corrosion is made of steel suitable-fortempering. 7

In subjecting certainfluid media to extremely high pressures in cylinders, there is a relatively rapid corrosion of the cylinder in the vicinity of the lower dead point of the piston caused by a corrosion phenomenon generally attributed to accumulated acid residues. The relatively low temperature and pressure at thispart of the cylinder seem to produce conditions most favorable to corrosion. The'invention aims to provide made to manu- The apparatus illustrated in Fig. 1 comprises a head-end cylinder-portion I formed of a rela-- tively thick pie'ce of, metal, for example, steel,

to withstand the excessive pressures when the piston 2 is in the position shqwn at the upper end of its compression stroke. The head-end portion I has suitably mounted therein a suction valve 3 and a pressure valve 4 which are connected to intake and exhaust'conduits 5 and 6 respectively, The low-pressure cylinder-portion I 0 is so connected to the head-endportion I as to form a continuous cylinder for the reciprocation'therein of the piston 2.' The cylinder portion III has relatively thin walls in comparison with the relatively thick walls of the head-end portion I and is formed 0! a heat treated corrosion resisting alloy, such as stainless steel or the like.

. The .low-pressure'cylinder is attached to or I mounted upon a frame II and has a stufling box I2 attached to the lower outside portion of the 5 cylinder I 0. The 'stufllng box comprises a packing I3 and a bushing II made, for example, of

\ bronze, which butts up against the cylinder and a high-pressure cylinder in'which the head-end portion is relatively thick and a low-pressure cylinder-portion. having a relatively thin wall formed of a heat treated metal capable of resists ing the corrosive action just described. The lowpressure cylinder-portion, which is the part exposed to the most active corrosion, is made in the simplest possible form, for example, as a solid of revolution. symmetrical, or with equal thickness of wall. It is preferably formed of a corronon resisting steel alloy, for example: I

or a steel containing one or' more of the following metals: nickel, chromium, vanadium, aluminum, silicon, manganese, molybdenum. copserves as a guide for the piston rod 2. The stuffing box has a cover Ii-ior compressing'the packing I3 by means of the bolts I6. I -.As shown in the drawings, the piston I is in the upper dead-end pist'onleaving a clearance I! in which the fluids are compressed. Wh piston moves on the downward stroke. it r ches the lowerdead-end piston shown in. the dotted lines within the bushing II. The low-pressure cylinder portion shown in Figs. 2 and 3 has upper and lower flanges II and 0 2|, respectively. .ylhich are square in cross-section and the lower flange is larger in diameter.

but of the same thickness as the upper flange. The central body portion 22 is'preferably cylin- -drical.

'55 The low pressure cylinder-portion shown ,in-

Figs. 4 and 5 comprises upper and lower flanges the 25 and 26, respectively, which are of approximately the same thickness but the lower flange is of larger diameter. The central portion 21 is cylindrical as are the flanges, this cylinder being formed as a solid of revolution.

The low-pressure cylinder-portion shown in Fig, 6 comprises upper and lower flanges 30 and 3|, respectively, in the central portion 32. This cylinder is made symmetrical with respect to they plane 33.

The low-pressure cylinder-portion shown in Fig.3 comprises upper and lower flanges 35 and 36, respectively; and a central portion 3"1'. This cylinder is made as a symmetrical solid of revolution with equal thickness of wall.

In view of the different kinds of metals used in forming the cylinder and stuffing box, there is a tendency for electrolysis to be set up with resulting decomposition of one or more of the metals. In forming the low temperature cylinder portion of the heat treated corrosion resisting metal, the destructive action resulting from electrolysis is very efiectively suppressed.

I claim:

1. A high-pressure cylinder which comprises a head-end portion wherein a fluid medium undergoing compression is subjected to the highest pressure attainable in the cylinder, valves for the intake and exhaust or gas mounted in the headend portion, a low-pressure portion having relatively thin walls with respect to the thickness of the walls of the head-end portion and a flange at each end, saidlow-pressure portion being formed of heat treated alloy steel which is highly resistant to the corrosive action in the cylinder and being connected by means of the flange at one end tothe head-end portion and by means of the flange at the other end to a stuffing box, a piston reciprocable in ,the high-pressure cylinder, and means operatively connected to the stufiing box to guide the piston.

2. A high-pressure cylinder according to claim 1 in which the central portion of the low-pressure portion of the cylinder is about the 'same thickness as the flanges.

3. A high-pressure cylinder according to claim 1 in which the low-pressure portion is symmetrical with walls of uniform thickness.

o'r'ro MINDER.

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