Process and apparatus for treatment of water and for keeping it clean

摘要

A process for treating and purifying water for swimming pools uses water softeners, filters, pumps and pipes for circulating water. The water is treated with ion exchangers (6) to remove acids and water hardness components and the softened water is used to fill a pool (1). Lime water (8), comprising a clear saturated solution of (hydrated) lime in water, is added to the pool to create a lime-carbonic acid equilibrium which converts any carbon dioxide in the water into carbonate in order to precipitate phosphate and sulphate as sparingly soluble calcium salts, as well precipitating body substances (eg. dead skin), creams and bath oils as lime soaps. Inorganic oxidation products generated by sunlight are precipitated as calcium ions, and small suspension or sediment solids not normally capable of being filtered are adsorbed onto calcite. The water is passed continuously through a cycle consisting of pipes (13, 19, 20) , pumps (17), valves (14, 18) and filters, forcing at least some of the water to flow a bed of crushed limestone to keep pH above 7. More limewater is optionally added to maintain the lime-carbonic acid equilibrium. Lost water is replenished with fresh acid- and hardness-free water to prevent water in the pool becoming too salty. The apparatus is also claimed.