The process unit supplied by ASIO, spol. s r.o. consists of two water softening filters, where each of them is designed for the flow rate of 14 m ³ per hour at the softening level from 4 mmol to 2 mmol per litre, which is the value recommended by the regulation for the remaining water hardness. The filters designed by us can cope with the flow rate of 7 m ³ per hour at the complete softening capacity. The filtering efficiency is over 99%.

The filters are set as a duplex system, i.e. while one filter is in the regeneration mode, then the other filter is in the standby mode waiting for its operation. This means that once one of the filters is regenerated, the second one replaces it. This guarantees a continuous supply of the softened water even if one of the filters is regenerated. The system can be also arranged in series, by which the flow rate capacity of the softened water could be increased up to 28 m ³ per hour.

The whole system is placed upstream from the accumulation tank, where the flow rate of about 14 m ³ per hour is assumed. The system is designed for the filtration rate of 30 m per hour and the flow rate through the softening filters can be increased up to the level of 50 m per hour. However, the preset value is recommended as the optimum one for correct filter functioning and compliance with the safe hold-up time necessary for the ion exchange process. The filtration unit is placed upstream the accumulation tank, because it is necessary to keep a constant rate of the tank replenishment with water. If the filtration unit were placed downstream the tank, the filtration would have to be dimensioned for potentially high fluctuations in the instantaneous water demand. Each filter is capable of softening of 55 m ³ of water before it is necessary to regenerate it.

Ing. Michal Šubrt
http://www.asio.cz/en/water-treatment