Abstract: The heat exchanger has a zig-zagged liquid-flowing passage and an overflowed-liquid escaping conduit. When an excessive amount of cooling water is supplied to the heat exchanger, a part of cooling water flows into the overflowed-liquid escaping conduit through a dam formed between the liquid-flowing passage and the escaping conduit. The heat exchanger is formed by assembling a plurality of heat exchanging partition plates formed by molding. The heat exchanging partition plates have the same shape and the same dimensions, and they are easily engageable with and detachable from each other.

Abstract: A cross-flow type cooling tower comprises a cooling tower main body, a water tank placed at the upper part of the main body, a plurality of closed type heat exchanging units arranged in the main body in substantially horizontal manner and in parallel to each other in multi-stage below the water tank, a supplying header placed near an air discharge opening of the main body, which is detachably connectable to supplying ports of the heat exchanging units, a discharge header placed near an air intake opening of the main body, which is detachably connectable to discharge ports of the heat exchanging units, wherein the water tank is divided into a first water receiving part near the air intake opening and a second water receiving part near the air discharge opening by way of a partition wall, and a switching valve is provided at at least a water feeding pipe to the second water receiving part.