Heat-exchange roll and method of making

Claim 1

A HEAT-EXCHANGE ROLL FOR TREATING WEBS OF SHEET MATERIAL SUBSTANTIALLY UNIFORMLY ACROSS THE WIDTH THEREOF, COMPRISING A CYLINDRICAL ROLL BODY CONSTITUTED BY HELICALLY COILED TUBE MEANS OF RECTANGULAR CROSS SECTION AND PROVIDING AT LEAST A PAIR OF HELICAL PASSAGES THERETHROUGH, MEANS ON THE ENDS OF SAID ROLL BODY FOR ROTATIVELY SUPPORTING SAID BODY, THE FLAT ADJACENT SIDES OF THE COILS OF SAID TUBE MEANS BEING IN HEAT EXCHANGE ENGAGEMENT SUBSTANTIALLY THROUGHOUT THEIR AREA, FLUSH WELDS JOINING THE OUTER PERIPHERAL EDGES OF SAID COILS AND FILLING ANY CREVICES THEREBETWEEN, THE OUTER PERIPHERAL SURFACES OF SAID COILS AND SAID WELDS BEING FINISHED TO BE TRUE AND FUNCTION AS THE WORKING SURFACE OF THE ROLL, SAID PASSAGES BEING INCLINED IN THE SAME DIRECTION, MEANS DEFINING AN INLET FLUID PASSAGEWAY AT ONE END OF EACH HELICAL PASSAGE AND RESTRICTING FLUID FLOW ONLY INTO THE RESPECTIVE PASSAGE WITH THE INLET OF THE TWO PASSAGES BEING LOCATED IN THE ROLL BODY AT RELATIVE OPPOSITE ENDS THEREOF, AND MEANS DEFINING AN OUTLET AT THE END OF EACH HELICAL PASSAGE OPPOSITE THE RESPECTIVE INLET, WHEREBY FLUID IS FED THROUGH ONE OF THE HELICAL PASSAGES IN ONE ROTATIONAL DIRECTION AND THROUGH THE OTHER OF THE HELICAL PASSAGES IN AN OPPOSITE ROTATIONAL DIRECTION TO OFFSET FRICTIONAL DRAG ON THE ROLL BODY DURING ROTATION OF THE ROLL.