GB1238325A - - Google Patents

Abstract

1,238,325. Drying compressed gas. AIR TECHNIQUES Inc. 2 Aug., 1968, No. 37119/ 68. Heading B1L. Moist compressed gas, particularly air, from compressor 10 is passed by line 14 through separator 18 where droplets are removed, and thence through drying chamber 26 packed with desiccant, e.g. silica gel, activated alumina, molecular sieve. The major part of the effluent dry gas is then passed by line 38 to tank 46, while a minor part is passed by adjustable valve 68 and unidirectional checkvalve 84 to secondary tank 92. When pressure in tank 46 reaches a predetermined valve, switch 52 switches off motor 54 driving compressor 10 until sufficient gas has been removed for use through line 48 for the pressure to have fallen to a second predetermined valve at which switch 52 switches motor 54 on again. During the period during which motor 54 is inoperative, compressed air in chamber 26 vents to atmosphere through separator 18 carrying moisture from chamber 26 with it, check valve 40 preventing decompression of tank 46. Air also flows back from secondary tank 92 through pressure regulating valve 106, which is set so that the volume of air effluent therefrom is the same as the volume of compressed air which has passed through drying chamber 26 since the previous cycle. This dry return stream flows through chamber 26, regenerating it, and is vented through separator 18, vent valve 58 being controlled by switch 52. Before the system is brought into use, valve 120 is opened so that compressed gas in tank 46 passes along line 116 to supplement the gas in tank 92 being refluxed through chamber 26; this ensures that desiccant 28 is completely dry at the outset. Valve 120 is then closed.