Plate and fin heat exchanger

A plate and fin heat exchanger in the form of a refrigerant evaporator for cooling an air stream flowing therethrough, comprising:

• a stack of formed plates,
• adjacent pairs of the plates providing alternately channels for flow of refrigerant and spaces for the flow of air,
• the adjacent pairs of plates having inlet and outlet headers at the ends thereof forming chambers in communication with the refrigerant flow channels,
• fin means within the air spaces,
• and a refrigerant inlet tube projecting through the inlet header chambers and isolating one from the other,
• the inlet tube having a plurality of discharge orifices with at least one orifice in each inlet header chamber in register with a refrigerant flow channel,
• wherein the improvement comprises:
• the orifices being oriented to discharge refrigerant laterally from the inlet tube toward the side of the heat exchanger first contacted by the air stream entering the fin means,
• the orifices being in longitudinal alignment along the length of the inlet tube and directed radially thereof at an acute angle below the horizontal.