Coating for ceramic chimney tubes

摘要

Ceramic chimney tubes are coated by immersion in an aq. soln. contg. (a) Na or K Me-siliconate as hydrophobic impregnation agent and (b) Me-cellulose. Only the outside of the tubes is allowed to come into contact with the impregnating soln. and the immersion time is just sufficient for a partial impregnation of the tube wall. The impregnating agent pref. contains 0.1-1.0%, esp. 0.5% Me cellulose. The impregnating agent is diluted with water in ratio 1:10-100, esp. 1:50. The immersion time is esp. 5-25 sec. The tube is internally pressurised. Immersion depth is regulated by immersion time and/or the internal pressure.