Abstract: A titanium sheet (4) serving as an anode-forming member is fixed on a tube plate (1a) of a heat exchanger (1) via a insulting sheet (5) and an insulating adhesive (6). The sheet (4) is coated with a film (3) of an electrochemically active, stable electrical catalyst. A dc power unit (7) has a positive electrode (7a) electrically connected to the sheet (4), and a negative electrode (7b) electrically connected to the tubes (1b). The inner surfaces of the tubes (1b) are used as a cathode for electrolysis for oxygen generation. An automatic potential controller (7c) adjusts potential difference between the electrodes (7a, 7b) such that oxygen is generated in seawater while generation of chlorine in seawater is suppressed. An external dc power unit (40) and a cathodic protection electrode (41) supply a cathodic protection current to the tubes (1b).

Abstract: An antifouling system (20) for a structure exposed to seawater has an anode forming member (4) bonded to the seawater-exposed surface to be wetted with seawater (15) of the structure via an insulating adhesive (6). The anode forming member 4 is coated with an electrical catalyst film 3 of an electrochemically active and stable electrical catalyst. A conductive member (8) is disposed so as to be wetted with seawater (15). An external dc power supply (7) has a positive terminal (7a) connected to the anode forming member (4) and a negative terminal (7b) connected to the conductive member (8). The external DC power supply (7) is provided with a built-in automatic potential controller (7c) that controls the potential difference between the positive terminal (7a) and the negative terminal (7b) such that oxygen can be generated in seawater suppressing the generation of chlorine in seawater.