GB745256A - Improvements in or relating to the pumping of liquefied gases and to apparatus therefor - Google Patents

Abstract

745,256. Making and pumping liquified gases. AIR PRODUCTS, Inc. Aug. 7, 1953, No. 21814/53. Classes 8(2) and 102(1). In pumping a low boiling gas in the liquid phase, the suction line 29 is fitted with a cooler 24 and the pump cylinder 32 is cooled by a cooler 21 each supplied with separate cold fluid streams having a temperature below that of the boiling point of the liquid gas at the minimum inlet pressure of the pump so as to prevent gas lock in the pump. Fig. 1 shows a fractionating plant for producing oxygen in which compressed air is supplied at 16 to a heat interchanger A and passes to a boiling coil 15 in a fractionating column B and then to the cooler 21 through an expansion valve 20; the cooler 21 is connected to the column B by pipe 22. The nitrogen is conducted from the column B through pipe 23 to the cooler 24 and then passes through pipe 26 to the interchanger A to leave by outlet 27. The oxygen 18 passes from the column B through the pipe 28, cooler 24 and is pumped through pipe 41, interchanger A to the collecting space 43. Fig. 2 shows a fractionating column B having a high pressure section 47 and a lowpressure section 48. The boiling coil 54 is connected through an expansion valve 57 to an intermediate point in the section 47 and the nitrogen collected in pool 59 passes through the expansion valve 61 to the top of the section 48. The crude oxygen 55 in the section 47 passes through cooler 63, expansion valve 66 to the cooler 67 surrounding the pump cylinder 79 and then through pipe 68 to an intermediate point in the section 48. Nitrogen from the section 48 passes through the pipe 69 -to the cooler 70, cooler 63 and interchanger A. The liquid oxygen 58 passes through pipe 75 to the cooler 70 and the pump cylinder 79. The system may be used to treat natural gases to remove liquid petroleum gas fractions. Specification 573,383 is referred to.