GB641000A - Improvements in or relating to ammonia evaporation plant particularly for refrigerated transportation systems - Google Patents

Abstract

In a stationary plant for separating ammonia from a strong aqueous solution formed in the absorbent holder of a mobile refrigerated container as described in Specification 639,271, [Group XIII], strong solution is introduced into a tower 10 through a tube 22 and falls through bubble-trays 71 where it is met by water vapour rising from the foot of the tower heated by a coil 11, the ammonia being thus distilled out of the strong solution, the ammonia vapour being led by a pipe 16 to the bottom of a similarly constructed rectifying tower 17 down which flows condensed ammonia, the rectified ammonia then proceeding to a condenser 28 from which part flows back to the rectifying tower and part flows to a storage tank 29. The bubble trays are pierced by several short pipes 73 having perforated conical hoods 74. Vertical fall pipes 72 feel liquid down the tower from tray to tray. Weak and strong solutions are withdrawn from the bottom of the distilling and rectifying towers respectively and the top of the tower 10 is fitted with a cooling coil 76. Connections 37 (Fig. 1) are connected to the absorbent holder on the mobile container and strong solution flows by a pipe 36, three-way valve 35 and pipe 38 to check-valves 39, 40 controlling the input to tanks 41, 42 which are connected by linked three-way valves 48, 50 to a pump 46. The pump 46 sucks solution into one of the tanks 41, 42 and discharges solution from the other through a pipe 45 to a storage tank 18 from which solution is pumped by a pump 21 through a heat-exchanger 23 and a <PICT:0641000/III/1> <PICT:0641000/III/2> pipe 22 to the tower 10. In the distilling tower, ammonia is driven off and passes through the rectifier 17 to the condenser 28 from which it flows to the storage tank 29. Water drains from the tower 10 by pipe 24, heat exchanger 23 and pipe 25 to a storage tank 26. The rectifier 17 is fed with condensate by a pipe 30 and drains to the tank 18 by a pipe 32. Non-condensable gases are removed from the tank 18 by a pipe 62 to a tank 64 where they are washed by water from the tower 10 entering by pipe 69 and leaving by pipe 65, the gases being snifted through pipe 67. To charge a mobile container with anhydrous ammonia and water, connections 37 are connected to the absorbent holder and hoses 61 to the refrigerated holder. Refrigerant, i.e. ammonia, flows from the storage tank 29 by pipe 51, precooling coil 58 and pipe 57 to the connections 61, some refrigerant being byepassed through a float control 54 to cool the coil 58 in a chamber 53, vapour being returned to the tank 18 by pipes 56, 45. Absorbent, i.e. water, flows from the storage tank 26 by pipe 33, three-way valve 35 and pipes 36 to the connections 37.