Precise laboratory fractionation an automatically controlled column

This paper discusses a method of reducing heat losses from laboratory fractionating columns. A differential thermocouple in the lagging detects radial heat flow and controls the current passing through an electrical heater winding in the lagging, by means of a galvanometer, lamp and photocell relay system. Thermal and electrical characteristics are calculated for equipment required to maintain a number of columns adiabatic by intermittent inspection and control. In the second part of the paper construction and operation of a column lagging jacket, controller and inspection unit arc described. Heat losses are reduced to negligible dimensions and up to six jackets have been controlled simultaneously at temperatures up to 265° c. The equipment has been in use for three years with little attention.