Arrangement in heat exchangers of the plate-type

Claim 1

A PLATE TYPE HEAT EXCHANGER FOR TWO FLUID MEDIA, COMPRISING A STACK OF A PLURALITY OF THIN PLATES DISPOSED IN SPACED AT LEAST GENERALLY PARALLEL RELATIONSHIP, MEANS FOR SEALING THE BORDERING EDGES OF ADJACENT PLATES TOGETHER TO FORM A SUCCESSION OF CLOSED FLUID RECEIVING CHANNELS, EVERY SECOND CHANNEL CONSTITUTING A FIRST SET OF CHANNELS ADAPTED TO RECEIVE A FIRST ONE OF SAID FLUID MEDIA AND THE REMAINING CHANNELS CONSTITUTING A SECOND SET OF CHANNELS ADAPTED TO RECEIVE THE SECOND OF SAID FLUID MEDIA, THE TWO SETS OF CHANNELS BEING ISOLATED FROM EACH OTHER, A SET OF INLET PORTS AND A SET OF EXHAUST PORTS COMMUNICATING WITH EACH CHANNEL OF THE FIRST SET OF CHANNELS, AND A SET OF INLET PORTS AND A SET OF EXHAUST PORTS COMMUNICATING WITH EACH CHANNEL OF THE SECOND SET OF CHANNELS, THE PORTS IN EACH SET THEREOF BEING ALIGNED AND BEING FORMED BY A TAPERED COLLAR ON EACH PLATE DISPOSED ABOUT AN OPENING THROUGH THE PLATE, THE COLLARS PROJECTING AND CONVERGING IN THE SAME DIRECTION WITH RESPECT TO THE PLATES IN THE STACK, ALTERNATE COLLARS FORMING EACH SET OF PORTS BEING LONG, THE REMAINING COLLARS FORMING SAID SET OF PORTS BEING SHORT, THE FREE ENDS OF THE LONG COLLARS BEING TELESCOPED WITHIN THE SHORT COLLAR ON THE NEXT ADJACENT PLATE, THE FREE ENDS OF THE SHORT COLLARS BEING SPACED RADIALLY INWARDLY FROM THE ROOTS OF SHORT COLLARS ON THE NEXT ADJACENT PLATE TO FORM SAID PORTS, AND FUSION WELDS SEALINGLY CONNECTING THE TELESCOPED CONTACTING SIDE SURFACES OF THE LONG AND SHORT COLLARS.