GB370942A - Treatment of divided non-gaseous material in suspension in a gaseous medium - Google Patents

Abstract

<PICT:0370942/III/1> <PICT:0370942/III/2> Non-gaseous materials such as solid or liquid materials contained in solution or suspension in liquid material, e.g. milk products, salt solutions, &c. are treated to dry them or evaporate them in suspension in a gaseous medium by introducing the materials into an inner gaseous zone and passing them outwardly into an outer annular gaseous zone in which the gaseous medium is maintained in a continuous swirling movement by continually withdrawing the medium from the outer zone and reintroducing it thereto in a tangential direction. The material to be dried is introduced through a spray 18 into a current of hot gases supplied from a furnace 4 through a pipe 5 and a distribution conduit 6, to an inner zone 7 bounded by a conical partition 8, the materials being delivered into the chamber 1 through helically inclined vanes 11 located in an annular opening 12. The housings 15, 20 of the rotary sprayer 18, Fig. 3, and the partition 8 are prevented from getting too hot by introducing cold gases between a plate 25 and the wall 2 and through an annular passage formed between partitions 8, 32. The outer gaseous zone is formed by extracting gases from the chamber through a tangential flue 38 and reintroducing them by a blower 39 through a tangential flue 41, the direction of the flow of gases in the outer zone being preferably opposite to that in the inner zone. The dried materials are removed from the chamber through a flue 43 by a blower 44 to collecting devices. Solid materials tending to collect on the walls of the chamber are removed by chains 47 connected to a framework 50 rotated mechanically or by the gaseous p current. In a modification the hot gases of combustion are used to warm air or other neutral gas in a series of heat exchangers and this gas is then introduced through the zone 7.