GB784584A - Improvements relating to ammonia stills - Google Patents

Abstract

<PICT:0784584/III/1> Ammonia is stripped from ammonia liquor, such as is obtained in coke oven plants, by passing the liquor through a still counter-currently to a mixture of vapours and combustion gases which has been formed by burning a mixture of air and gas, obtained by carbonization of coal, in direct contact with the stripped liquor withdrawn from the still. In the apparatus shown, stripped liquor from the base of column-still 2 flows through pipe 11 into combustion chamber 8. Coke oven gas and air are forced by compressors, via pipes 5 and 6 respectively, to vertical pipe 7 which is open at the base and deeply immersed in the liquor in chamber 8. The gas and air mixture is ignited, e.g. by means of a sparking-plug, and burns beneath the surface of the liquor. The heat of combustion vaporizes a part of the liquor; and the mixture of steam and combustion gases, so obtained, passes through pipe 9 into the lower part of column 2. The mixture of steam and gases flows up the column, and strips the ammonia from liquor flowing down the column from the level of inlet-pipe 1. A mixture of gases and ammonia leaves the top of the column through pipe 10. The over-flow from chamber 8 passes through pipe 12 into vessel 13 which is so arranged that the liquor-level in chamber 8 is maintained at a predetermined level while the overflow from vessel 13 is led away by pipe 14.