GB360817A - Improvements in and apparatus for carrying out distillations - Google Patents

Abstract

<PICT:0360817/III/1> Liquids particularly those containing a multiplicity of constituents e.g. hydrocarbon oils are distilled by heating to about the mean boiling-point of the required distillate preferably under slight pressure in an externally heated coil 5, injecting the heated product through a pipe 11 into a fractionating column 2, withdrawing the unevaporated portion through a pipe 12 and allowing it to trickle from a distributer 13 in thin layers over an indirectly heated tubular system, and passing the vapours evolved back into the column 2 through a pipe 10. The liquid may be initially preheated in a heat exchanger 3 and a coil 19 which with a cooling coil 18 controls the fractionation of the vapours. The tubular heating system is preferably situated in the same furnace as the coil 5, and comprises a number of ribbed tubes 8 containing guide tubes 6 through which gases from the burner 23 are passed, the gases flowing back in countercurrent through the annular passages 7 formed between the tubes 6, 8, and then passing through a pipe 25 and the heating jacket 30 over the tubes 5 which also are heated by gasses passed directly through a pipe 28. The tubes 8 are preferably covered with aluminium or other good conductive material.