Abstract: A heat exchanger includes an electrolytic bath and a control section. The electrolytic bath has first and second channels. A first fluid can flow through the first channel. A second fluid adapted to exchange heat with the first fluid can flow through the second channel. At least part of the first and second channels of the electrolytic bath is partitioned by anode and cathode plates to which a given potential is applied from a power source. The control section applies the given potential to the anode and cathode plates and performs polarity reversal adapted to reverse the polarity of the anode and cathode plates after having applied the given potential at given time intervals.

Abstract: A cooling water circulation apparatus is capable of limiting attachment of microorganisms and scale in an environmentally friendly manner. An electrolytic device 10 is provided on a cooling water circulation route R1. In the arrangement, mineral contents such as calcium ions and magnesium ions contained in cooling water W are deposited as scale S on an electrode 12A or 12B in an electrolytic step, thereby enabling the mineral contents to be removed from the cooling water W. Even if the hardness of the cooling water W is increased by evaporation of the water with elapse of time, the hardness can be reduced by the electrolytic processing. Thus, the deposition of the scale S in the circulation route R1 can be reduced. Further, the scale S deposited on the electrode 12A or 12B can be easily separated by operating while reversing the polarities of the electrodes 12A and 12B at predetermined time intervals.