Molecular distillation Hickman still

Hickman still, molecular distillation, 427 HIGEE fractionator, 399 Homogeneous gas reactions, 592 HTU (height of a transfer unit), 401,404, 422... 

Figure 13.30. Molecular distillation and related kinds of equipment, (a) Principle of the operation of the falling film still (Chemical Engineers Handbook, McGraw-Hill, New York, 1973). (b) Thin-layer evaporator with rigid wiper blades (Luwa Co., Switzerland), (c) The Liprotherm rotating thin film evaporator, for performance intermediate to those of film evaporators and molecular stills (Sibtec Co., Stockholm), (d) Centrifugal molecular still [Hickman, Ind. Eng. Chem. 39, 686 (1947)].

Mixers. See also Agitation blend time, 290 dimensionless groups, 290 gas dispersion, 296-301 in line type, 300,301 liquids, power and speed need, 293,295 powders and pastes, 301,303,304 power number, 290-292 quality characterization, 290-292 suspension of solids, 295-299 tank desien. 287.288 Moisture c tent, critical, 237 Molecular distillation, 425-427 equipment sketches, 427 Hickman still, 427 operating conditions, rate of evaporation. 

Short path and molecular distillation were developed in the 1930s and 1940s mainly in the UK and in the USA. Different types of apparatus were developed. A still with a disk, rotating at high speed, is named after Hickman, one of the pioneers [2]. In this machine the centrifugal force is used to distribute the feedstock as a thin film on a heated disk. Exposure time is less than a few seconds ... 

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