Treating water for use in dishwasher - by passing through filter and then a water-softener to remove calcium salts

摘要

Water treatment for dish-washing machines is effected by passage through a pre-filter, for removing suspended matter, then through a water-softener to remove calcium salts; it then passes through activated carbon before the final demineralisation process by reverse osmosis with hollow fibre membranes. Used for special purposes, such as cleaning crystal glass or surgical instruments, the pH of the water should be adjusted to 7.2. The water leaving the water-softener should have a total hardness of 3-4 French degrees (30-40 ppm.). The simple and efficient treatment of the washing machine water solves many problems encountered in restaurants, hotels and canteens and avoids the formation of deposits on porcelain and glasses.