COOLANT LIQUID STERILIZING DEVICE

PURPOSE:To provide a coolant liquid sterilizing device capable of being continuously used for a long time with a simple and economical structure. CONSTITUTION:A coolant liquid sterilizing device is assembled with a metal pipe body 31 and a metal rod body 33 inserted therein through an insulating space to compose both electrodes of the metal pipe body 31 and metal rod body 33, and provided with an electrode part 3 having the space between the metal pipe and metal rod communicating with the outside and a power supply controlling section 5 for supplying polarity alternating DC to both electrodes of the electrode part. The electrode part is interposed in a forcibly circulating flow path leading to a coolant liquid storage tank T. When the coolant liquid having a mixture of water, hydrogen ion and hydroxide ion flows in a space in which polarity alternating DC is supplied to both electrodes, metal ion is deposited from the positive electrode side to sterilize the coolant liquid while being combined with hydroxide ion to provide hydroxide and be discharged as impurities together with the coolant liquid to the storage tank.