GB350726A - Improvements in and relating to the treatment of vessels to render them suitable forbleaching textile goods - Google Patents

Abstract

Vessels used for bleaching textile goods with hydrogen peroxide are treated with a thin internal coating containing mainly free lime with a comparatively small quantity of Portland cement, the coating being allowed to stand until partly dry and then washed with an aqueous solution containing alkali silicate and carbonate. In an example, 4 parts of burnt lime were slaked into a cream with water. 1 part of Portland cement and 1 part of finely-divided magnesia were separately made into a cream with water and the three components mixed and filtered. The internal surfaces of the vessel had applied to them a thin layer of the slurry so formed by painting or spraying. The vessel was allowed to stand for about 20 hours and then, before the coating was set, an aqueous solution containing 1 \ba1/2\be per cent silicate of soda solution of 80 DEG Tw. and 0,75 per cent of soda ash was placed in the vessel and boiled for about 6 hours. On being drained out, the mixture of alkali silicate and carbonate carries with it any loosely adhering particles of the layer which form a thin coating on the interior of the outlet pipes and pumps. It is stated that, if a second coating is required, it should be put on before the first has dried. Specification 352,690 is referred to.ALSO:Vessels used for bleaching textile goods with hydrogen peroxide are treated with a thin internal coating containing mainly free lime with a comparatively small quantity of Portland cement, the coating being allowed to stand until partly dry and then washed with an aqueous solution containing alkali silicate and carbonate. In an example 4 parts of burnt lime were slaked into a cream with water. 1 part of Portland cement and 1 part of finely divided magnesia were separately made into a cream with water and the three components mixed and filtered. The internal surfaces of the vessel had applied to them a thin layer of slurry so formed by painting or spraying. The vessel was allowed to stand for about 20 hours and then before the coating was set an aqueous solution containing 1 1/2 per cent silicate of soda solution of 80 DEG Tw. and 0,75 per cent of soda ash was placed in the vessel and boiled for about 6 hours. On being drained out, the mixture of alkali silicate and carbonate carries with it any loosely adhering particles of the layer which form a thin coating on the interior of the outlet pipes and pumps. It is stated that, if a second coating is considered necessary, it should be put on before the first has dried. Specification 352,690 is referred to.