Solid-liquid separators

A solid-liquid suspension flows along the inside of a fixed perforate tube 1 from inlet 9a while gas fed in through inlet 9 is caused by vanes 17 to swirl, inducing a similar swirl in the suspension so that centrifugal forces force the liquid component through the tube wall to outlet 11. In Fig. 2 a second, heated whirling gas stream is admitted further down the tube, so that almost dry solids reach outlet 16. In Figs. 3, 4 vanes outside tube 1 induce whirling there, and in Fig. 5 the gas from outlet 12 and from another outlet below plate 13 is recycled. Figs. 6, 7 show two-stage separators. The gas may be air, heated or not, for drying polymer particles. When crystals are being recovered from a solution, steam-humidified gas is used, to preclude evaporation of liquid and consequent fine crystal formation.