Thermal block for heat exchanger tube sheet

Claim 1

THE COMBINATION FORMING A HEAT EXCHANGER INCLUDING A CLOSED SHELL, A TUBE SHEET DISPOSED WITHIN AND CONNECTED ABOUT ITS PERIPHERY TO SAID SHELL AND DIVIDING THE INTERIOR OF THE SHELL INTO A TUBE SIDE AND A CHAMBER SIDE, A PLURALITY OF TUBES DISPOSED WITHIN SAID SHELL ON THE TUBE SIDE OF SAID TUBE SHEET AND THE ENDS OF SAID TUBES BEING FITTED INTO SAID TUBE SHEET, THE IMPROVEMENT COMPRISING: (A) A METAL PLATE VERY THIN IN COMPARISON WITH SAID TUBE SHEET POSITIONED WITHIN SAID SHELL ON THE TUBE SIDE OF SAID TUBE SHEET, (B) SAID PLATE CLOSELY SPACED FROM SAID TUBE OPEN SPACE FORMING A CHAMBER COMPRISING A NARROW OPEN SPACE LOCATED BETWEEN SAID TUBE SHEET AND PLATE AND EXTERIORLY OF THE TUBES EXTENDING THEREBETWEEN, (C) SAID TUBES PASSING THROUGH AND IN CLOSELY FITTING CONTACTING RELATIONSHIP WITH SAID METAL PLATE FORMING A PERVIOUS JOINT THEREBETWEEN, AND, (D) THE PERIPHERAL EDGE OF SAID METAL PLATE ARRANGED IN CONTACT WITH THE INNER WALL OF SAID SHELL ABOUT ITS ENTIRE PERIPHERY FOR SECURING THE PLATE IN POSITION WITHIN THE SHELL WHEREBY A RELATIVELY QUIESCENT FLUID ZONE IS SET UP IN THE OPEN SPACE OF SAID CHAMBER BETWEEN SAID METAL PLATE AND TUBE SHEET.