HEAT EXCHANGER FOR DEHUMIDIFYING GAS

PURPOSE:To make a gas passage difficult to be closed by frosting and make it possible to defrost rapidly by providing a plurality of baffle boards axially in a cylindrical vessel with an appropriate distance between them and heat transfer tubes for defrosting with little of concave and convex marks on the outer surface along the inner face axially of the cylindrical vessel which face the opening of a gas passage. CONSTITUTION:The inner face of a cylindrical vessel 2 which faces an opening through which a gas passes has U-shaped heat transfer tubes 15 for defrosting along the axis of the cylindrical vessel 2. The both opening ends of the tube 15 open in the lower section chamber 5a and upper section chamber 5c of a flow passage chamber 5. When a gas to be dehumidified is supplied from a gas inlet 13, the gas is cooled while it passes through a gas passage by heat exchange of the gas with the cool brine through heat transfer tubes and the moisture in the gas forms frost on the heat transfer tubes 3 and their fin surfaces to dehumidify the gas. The frost attached to the inner face of the cylindrical vessel 2 which is posistioned away from the heat transfer tubes facing an opening 10 for gas passage and lumps of frost that fell from the heat transfer tubes 3 receive heat from the hot brine which passes through heat transfer tubes 15 for defrosting and melt rapidly. It is possible thereby to defrost in a short time and efficiently.