Convective drying of vinyl] chloride polymer - by feeding polymer and drying gas through a tube and then onto a non-heated cyclone drier without intermediate heating

摘要

Convective co-current stream drying of vinyl chloride polymer is effected by feeding the damp polymer in a heated gas stream co-currently with drying gas first into a tube (4) and then, without additional contact heating, onto a directly connected non-heated cyclone drier unit (6). The drying gas is air supplied at 15-50 m/sec. and 130-190 deg.C, from a fan or blower opt. via a protective filter. The loading of the stream with the damp polymer takes place directly after the entrance of tube (4) which is horizontal or vertical and has a dia. of 80-700 mm and a minimum length of 6-9 m. ADVANTAGE - Suspension polymerised PVC can be dried to controllable moisture content in a low energy process using simple appts. and with a short dwell time.