GB639408A - A process and contrivance for the treatment of water for the feeding of steam boilers and the like - Google Patents

Abstract

639,408. Purifying water. KOPECKY, F., and VONDRUSKA, F. May 24, 1947, No. 13998. [Class 46] In the treatment of water for feeding steam boilers and for removing silicic acid therefrom, clear saturated lime-water is prepared from the whole of the water and subsequently is saturated with carbonic acid gas or gas mixtures containing it, whereupon precipitated calcium carbonate is removed by sedimentation or filtration, the process being chiefly characterized in that saturation with carbonic acid gas occurs at 75‹ to 100‹ C., at which temperature the gas is insoluble in water, so that no calcium bicarbonate can form. Crude water entering by the pipe 1 is preheated at 2 and 4 to about 100‹ C., and passes to a vessel 5 where air escapes at 6, and milk of lime is introduced from a vessel 7. The water is then pumped tangentially into a reaction cone 8 having radial baffles 9, and becomes a clear saturated solution of calcium hydroxide, passing via a filter 11 to a saturator 13, where it is finely divided by a distributer 16 and iron shavings on sieves 17. Cleaned smoke gases containing carbon dioxide are introduced at 18, and hot steam at 19, the waste steam escaping at 32 serving to pre-heat the crude water. Calcium carbonate is formed in the saturator 13, and the now-turbid water passes into an equalizing vessel 21, and thence tangentially into a settling tank 23 consisting of two truncated cones 24, 25, the latter having radial baffles 33. The inner cone 24 becomes filled with sludge which acts as a filter, excess sludge flowing into the outer cone and being discharged at 28. The purified water is finally discharged through a filter 30 filled with marble or graphite pieces. Specification 639,460 is referred to.