HEAT EXCHANGER AND WATER COOLING SYSTEM USING IT

PROBLEM TO BE SOLVED: To positively carry out drain of fore and aft piping of a heat exchanger for the purpose of freeze proofing during non-usage without using an air pump or the like. SOLUTION: Multipoint connection of a branch pipe 7 with a length of ≥5M is carried out vertically downward with respect to an outlet side passage of the heat exchanger 3, and a drain valve 4 is provided on its tip. Water of a cooling pipe in the heat exchanger 3 and a passage of its periphery is quickly and positively drained by a suction pressure caused by a height difference A of the branch pipe 7 during drainage. During drainage, an opening and closing switch SW is pressed, or each valve (solenoid valve) is automatically, remotely, and simultaneously opened and closed by a temperature switch TS to drain water. COPYRIGHT: (C)2004,JPO