1. A PLATE TYPE BRAZED HEAT EXCHANGER COMPRISING A PLURALITY OF SEPARATOR PLATES OF GENERALLY SIMILAR CONFIGURATION SPACED IN SUPERPOSED SUBSTANTIALLY PARALLEL RELATIONSHIP ALONG A FIRST AXIS; MEANS SEALINGLY CONNECTING ADJACENT SEPARATORY PLATES ALONG THE MARGINS THEREOF THEREBY DEFINING FLUID PASSAGES BETWEEN SAID SEPARATOR PLATES; MEANS FOR CONDUCTING HEAT EXCHANGE FLUID FROM ONE END TO THE OTHER END OF EACH OF SAID PASSAGES IN A DIRECTION GENERALLY PARALLEL TO A SECOND AXIS EXTENDING PARALLEL TO SAID SEPARATOR PLATES; A BAFFLE PLATE DISPOSED IN ONE OF SAID PASSAGES INTERMEDIATE THE ENDS THEREOF INTERPOSED IN SPACED SUBSTANTIALLY PARALLEL RELATIONSHIP TO SAID SEPARATOR PLATES THAT DEFINE SAID ONE PASSAGE; A FIRST HEAT EXCHANGE FIN PACKING MEMBER DISPOSED IN SAID ONE PASSAGE AT ONE FACE OF SAID BAFFLE PLATE AND ORIENTED TO CONDUCT HEAT EXCHANGE FLUID IN A DIRECTION GENERALLY PARALLEL TO SAID SECOND AXIS; A SECOND HEAT EXCHANGE FIN PACKING MEMBER DISPOSED IN SAID ONE PASSAGE AT THE OTHER FACE OF SAID BAFFLE PLATE ORIENTED TO CONDUCT HEAT EXCHANGE FLUID IN A DIRECTION GENERALLY PARALLEL TO A THIRD AXIS EXTENDING PERPENDICULAR TO SAID FIRST AXIS AND TRANSVERSE TO SAID SECOND AXIS; A THIRD HEAT EXCHANGE FIN PACKING MEMBER DISPOSED IN SAID ONE PASSAGE DOWNSTREAM OF SAID BAFFLE PLATE AND HAVING FINS EXTENDING FROM ONE SEPARATOR PLATE TO THE OTHER ONE OF SAID SEPARATOR PLATES DEFINING SAID ONE PASSAGE; AND A PORT EXTENDING THROUGH SAID SEALING MEANS ADJACENT TO AND COMMUNICATING WITH SAID SECOND HEAT EXCHANGE FIN MEMBER.