Drying apparatus

Claim 1

IN A SYSTEM FOR DRYING A COHERENT LAYER OF MATERIAL, THE COMBINATION COMPRISING A PLURALITY OF CLOSED SPACED DRUMS ADAPTED TO BE TRAVERSED BY SAID LAYER INCLUDING AT LEAST ONE UNDERSHOT DRUM AND AT LEAST ONE OVERSHOT DRUM ROTATABLE ABOUT PARALLEL HORIZONTAL AXES, SAID DRUMS BEING PROVIDED WITH PERFORATED PERIPHERAL WALLS; FIRST AND SECOND FLUID-CIRCULATING MEANS EACH HAVING AN INTAKE PORT COMMUNICATING WITH THE INTERIOR OF SAID UNDERSHOT AND SAID OVERSHOT DRUM, RESPECTIVELY, FOR SUBJECTING SAME TO SUCTION, EACH OF SAID FLUID-CIRCULATING MEANS HAVING AT LEAST ONE OUTLET PORT; DRIVE MEANS FOR ROTATING SAID DRUMS IN UNISION AND ADAPTED FOR CARRYING A LAYER OF MATERIAL TO BE DRIED ON THE UNDERSIDE OF SAID UNDERSHOT DRUM AND ON THE TOPSIDE OF SAID OVERSHOT DRUM; SHIELD MEANS WITHIN EACH OF SAID DRUMS REGISTERING WITH PORTIONS OF SAID WALLS NOT ADAPTED TO BE COVERED BY SAID LAYER, THEREBY RENDERING THE RESPECTIVE CIRCULATION MEANS INEFFECTIVE AT SAID PORTIONS; AND GUIDE MEANS FOR DIRECTING THE OUTFLOW OF SAID OUTLET PORTS ONTO THE OUTER SURFACES OF SAID DRUMS AT LOCATIONS ADAPTED TO BE COVERED BY SAID LAYER, THE SUCTION FORCE CREATED BY SAID FIRST FLUID-CIRCULATING MEANS IN SAID UNDERSHOT DRUM BEING GREATER THAN THE SUCTION IN SAID OVERSHOT DRUM, SAID GUIDE MEANS BEING POSITIONED TO DIRECT THE OVERFLOW OF THE OUTLET PORT OF THE SECOND CIRCULATING MEANS THROUGH BOTH OF SAID DRUMS AND TO DIRECT THE OUTFLOW OF THE OUTLET PORT OF SAID FIRST CIRCULATING MEANS THROUGH SAID UNDERSHOT DRUM ONLY.