GB521754A - Improvements in refrigerating systems - Google Patents

Abstract

521,754. Refrigerating. STATOR CORPORATION. Oct. 26, 1938, Nos. 30979 and 30980. Convention dates, Oct. 27, 1937, and May 11, 1938. [Class 29] Vacuum systems.-In. systems in which the vapour of aqueous refrigerant liquid is entrained and compressed by mercury vapour as set forth in Specification 292,812, [Class 29], the formation of mercury sludge on the low pressure side of the system is reduced by adding ethylene diamine or morpholine to the refrigerant or by heating the vapour delivery tube of the second stage aspirator, and any sludge formed is separated into mercury and refrigerant by pressure or suction. The system described comprises a heated mercury vapour generator 1 which supplies first and second stage aspirators 5a, 5b. The first stage is connected to the refrigerant evaporator 11 by a vapour pipe 8 and discharges into a chamber 7 from which liquid mercury particles drain through a conduit 49. Mercury vapour is condensed in a finned tube 12 drained at 14, while the other vapour after being cooled in a finned pipe 16 passes to the second stage aspirator, which discharges into a chamber 22 and tube 25. Uncondensed vapour passes into a tube 29 provided with internal baffles and heated by conduction through a plate 13 on the hot mercury vapour pipe 5. As the result of this heating effect mercury particles coalesce and flow down to a drain pipe 27. The refrigerant vapour passes on to the condenser proper 30 and the condensate flows through a pipe 34 and a liquid seal 42, 43, 44 into the evaporator. A sludge chamber 50 is connected to the wide bore pipe 44 from the bottom of the evaporator and through a vapour pipe 70 with the top of the evaporator, and is connected through a seal 53 with the drain conduits 49, 51 of the aspirators, from which mercury spills over into a tube 55 leading to the mercury vapour generator. Should refrigerant freeze in the upper part of conduit 44, the aspirator withdraws vapour mainly from the sludge chamber through conduits 70, 8, and the evaporator gradually warms up and melts the ice. Uncondensed gases in the refrigerarit condenser 30 flow through pipe 39 into a purge chamber'64 and are compressed by particles of mercury spilling over from pipes 27, 40 through a pipe 61 and a small bore drop tube 65 leading to a seal 67 open to the atmosphere. Mercury returns from this seal by a pipe 57 back to the generator 1. The sludge chamber 50 is preferably located to receive heat from the hot vapour pipe 5 In a modification the wide bore pipe 44 from the bottom of the evaporator is extended downwards to provide a heavy column to compress the sludge collected in it. This causes separation of the refrigerant and the mercury coalesces and flows freely to the drain conduit 49.