Commercial EO water generators can be divided into three major types based on their automatic control sys- tems. The first type of EO water generators, made by the ARVÒ and the AmanoÒ companies, allows the users to select brine flow rate while the machines adjust voltages and/or amperages automatically. The second type of EO
water generators, made by the HoshizakiÒ Company, allows the users to select amperages and/or voltages, while the machines change brine flow rate accordingly. The third type of EO water generators, made by the ToyoÒ and the Nippon IntekÒ companies, allows the users to select a pre- set chlorine concentration level of EO water from a display panel and the machines change brine flow rate and amper- ages and/or voltages automatically (Hsu, 2003).
Hsu (2003) investigated relationship among water flow rate, water temperature and salt concentration on electrol- ysis efficiency, and separation efficiency of an EO water generator. He made following conclusions: (1) electric potential (7.9–15.7 V) and power consumption (16– 120 W) of electrolysis cell were not affected by water flow rate, water temperature or salt concentration in the feed solution; (2) electric current changed with water tempera- ture and water flow rate; and (3) electrolysis efficiency of the electrolysis cell and separation efficiency of the ion exchange membrane were significantly decreased by the increases in water flow rate and salt concentration in the feed solution. Later, Hsu (2005) also reported that ORP decreased with increases in water follow rate and free chlo- rine increased with increases of salt concentration and decrease of water flow rate.