Swimming pool water filter has filter tank with bulk grain horizontal filter layers on a water permeable base under top layer of active carbon granules

摘要

A swimming pool water filter has a filter tank containing a series of bulk grain horizontal filter layers (7-9) on a water permeable base (6) under a first top layer (10) of active carbon granules. The second layer (9) is sand or gravel over a third layer (8) of high-density grains with a filter sharpness of down to 1m. The third layer is about 200 mm thick and rests on a fourth layer (7). The third and fourth layers (8, 7) are aluminium silicate with the chemical formula Fe(3AL(2(SiO(4) (essentially 37% SiO(2, 21% AL(2O(3, 29% FeO). The grain size of the third layer (8) is in the range 3 - 0.6 mm. The grain size of the fourth layer (7) is 1.4-2.5 mm. The density of the aluminium silicate grains is 4.1 g/cm. The filter tank has an inlet pipe for a disinfecting solution delivered to the filter layers. The agent may be introduced during or prior to the normal the normal water filtration process. Also claimed is an operating process in which the disinfecting agent is introduced to the tank either continually or intermittently. From time to time filter operation is suspended and the filter cleaned by back flushing, thereby expelling disinfected particles.