Liquid film evaporation type heat exchanger

A liquid film evaporation type heat exchanger in which a medium in a liquid state flows downwardly in the form of a film along heat transfer surfaces, the heat exchanger comprising:

• at least two heat transfer units arranged within a housing at locations spaced apart from each other in a direction in which the medium in the liquid state flows, each of said heat transfer units including a plurality of flat heat transfer ducts each formed with a plurality of warm water passageways extending substantially perpendicular to the direction of flow of the medium in the liquid state, and a plurality of liquid distributing beams which block a medium in a gaseous state, each of said beams is formed with a plurality of cutouts through which said medium in the liquid state flows downwardly, said flat heat transfer ducts and said liquid distributing beams being alternately arranged in the respective units;
• guide plate means disposed inside said housing and surrounding lateral sides of said heat transfer units to define a vapor passageway between said guide plate means and said housing;
• a liquid medium sump located above an uppermost heat transfer unit for supplying the medium in the liquid state into said heat transfer units;
• a chamber provided in said housing below said heat transfer units and filled with the medium in the liquid state;
• another heat transfer unit disposed in said chamber and including a plurality of flat heat transfer ducts each formed with a plurality of warm water passageways extending substantially in the same direction as the warm water passageways formed in the heat transfer ducts of said at least two heat transfer units;
• and
• port means positioned between the at least two heat transfer units and communicating a space inside said guide plate means with said vapor passageway for releasing the medium in the gaseous state within said space into said vapor passageway.