Drying of wet powdery materials

Claim 1

A PROCESS OF DRYING POWDERY SYNTHETIC POLYMERS CONTAINING WATER WHICH COMPRISES INTRODUCING SAID POLYMER BY MEANS OF AN AIR STREAM INTO A CYLINDRICAL STREAM OF HOT AIR EXTERNALLY CONFINED BY THE WALLS OF A TUBE OF CONSTANT DIAMETER IN SUCH A MANNER THAT BOTH STREAMS FLOW CONCURRENTLY AND HAVE SUBSTANTIALLY THE SAME SPEED WHEN THEY JOIN, AND THE AIR STREAM CARRYING THE POWDERY POLYMERS IS SURROUNDED BY THE CYLINDRICAL STREAM OF HOT AIR, WHEREBY THE POWDERY POLYMERS ARE ENTRAINED BY THE COMBINED CYLINDRICAL AIR STREAM, KEEPING THE POWDERY POLYMERS IN THE COMBINED AIR STREAM UNTIL THE WATER HAS BEEN SUBSTANTIALLY EVAPORATED, AND THEREAFTER REMOVING THE POWDERY POLYMERS FROM THE COMBINED AIR STREAM, SAID CYLINDRICAL STREAM OF HOT AIR HAVING A TEMPERATURE OF FROM 40 TO 200* C. AT THE BEGINNING OF THE DRYING PROCESS, SAID POLYMER-ENTRAINING AIR STREAM HAVING A TEMPERATURE OF ABOUT 5 TO 60*C. AT THE POINT WHERE IT JOINS SAID CYLINDRICAL STREAM OF HOT AIR, SAID COMBINED STREAMS AT THE END OF THE DRYING PROCESS HAVING A TEMPERATURE OF ABOUT 20 TO 100*C., SAID SYNTHETIC POLYMER CONTAINING REACTIVE GROUPS SELECTED FROM THE CLASS CONSISTING OF OLEFINICALLY UNSATURATED GROUPS, NITRILE, CARBOXYL, CARBONAMIDE, ALDEHYDE, KETO, METHYLOL, METHYLOL ETHER, DIXOLANE, AND UREIDO GROUPS.