Plate type heat exchanger

A plate type heat exchanger having a shell containing a plurality of heat exchange elements, each of said heat exchange elements being composed of two plates for exchanging heat between an internal fluid flowing inside said heat exchange element and an external fluid flowing outside said heat exchange element characterized in that:

• peripheral portions of said two plates being sealedly connected together to form an internal space in which said internal fluid flows and an external space in which said external fluid flows;
• an introduction passage and a discharge passage being connected to said plates and communicating with said internal space for allowing said internal fluid to flow inside said two plates;
• and
• an introduction passage and a discharge passage being connected to said shell and communicating with an interior of said shell for allowing said external fluid to flow as a liquid film on surfaces of said plates within a space between the outside of said plates and said shell,
• wherein at least one of said introduction passage and said discharge passage for said internal fluid connected to each of said plates comprises a plurality of passages, and
• said passages including a sprayer provided above the heat exchange elements for spraying said external fluid on said plates to form a liquid film on the surfaces of said plates.