GB727614A - Improvements in and relating to distilling apparatus - Google Patents

Abstract

<PICT:0727614/III/1> <PICT:0727614/III/2> <PICT:0727614/III/3> <PICT:0727614/III/4> <PICT:0727614/III/5> A two stage still, adapted for the distillation of acids from fatty acid stock, comprises a cylindrical shell divided by a depending vertical wall into two sections communicating with each other through the opening left between the depending wall and the base of the still, tubular heaters being provided in each section, and direct contact heat exchange with the feed being provided in the light end stripping section. The still 10 (Fig. 2) comprises a cylindrical shell 101 closed by end wall 11, 12 and divided into a light end stripping section A and a bulk distillation section B by a depending partition 20 shaped as shown in Fig. 7 and spaced from the still bottom to provide a communicating passage 131. The tubular heaters 15, 16 are disposed in a trough 13 which has cylindrical extensions 14, 141 lying outside the ends of the still. The trough (Fig. 5) is cylindrical in shape and with extending sides 21, 22 forms a vapour chamber 211. An entrainment eliminator 25, arranged in the path of the vapours, extends from the baffle 22 to the side of the still and is provided with a plurality of slots 25 inclined in opposite directions. Direct preheating of the feed supplied through pipe 53 is effected by flowing it over a series of spaced horizontal trays 28-31 delivering to a container 33 which feeds through conduit 37 into the trough 13 provided with perforated steam pipes 38, 39. A receiver 41 for the vapours from the stripping zone is formed by the partition 20 and walls 42, 43 and communicates through a vapour outlet 51 with the light ends condenser 40 located adjacent the shell 10. A vapour outlet 27 connects section B with the fatty acid condenser 58. The space 55 defined by the shell 10 and the trough 13 forms a bottoms receiver from which bottoms are drained through line 56. In operation (Fig. 1) vapours (diphenyl, diphenyl oxide or steam) generated in still 581 are circulated through the tubular heaters 15, 16 by lines 59, 60, 61, 62. Fatty acid stock supplied through line 53 is de-aerated and dehydrated by hot vapours formed in the section A while flowing over trays 28-31 to container 33 from which the stock passes to the part of the trough 13 in section A where it is stripped of light ends by contact with heaters 16 and direct steam from pipe 38, vapours formed passing to condenser 40. The stripped feed passes through opening 131 to section B where the fatty acids are evaporated, the bottoms flowing through space 55 to accumulator 68 and the vapours through line 27 to condenser 58.