GB798626A - Control of supply of feed-liquid to distillation apparatus - Google Patents

Abstract

Liquid is supplied to a still 10, at a rate proportional to the volume of vapour-delivery, by means of a vessel 1 which is divided into two communicating compartments 3 and 4 by cylindrical wall 5 and weir 6; the liquid flows from compartment 3 through an orifice 7, which is at the same level as the top of the weir, and then passes down through pipe 16 into the still. An orifice-plate 12 is mounted across the vapour-line 11 of the still; and a pipe 13 connects the vapour-line just below plate 12, to compartment 4. The low pressure end of line 11 and compartment 3 are both at atmospheric pressure. A pressure-difference between compartments 3 and 4, corresponding to the pressure-differential across orifice-plate <PICT:0798626/III/1> 12, is established and maintains a head of liquid in compartment 3. Liquid is supplied continuously to compartment 3 via line 14; and excess liquid (i.e. that which does flow to the still via orifice 7) overflows the weir 6 and is withdrawn by line 15 through a trap. The size of orifice 7 may be varied by needle 8 carried by spindle 9. Condensation in line 13 is prevented by introducing a gas, e.g. air, into it through line 17. When the low-pressure end of line 11 is not at atmospheric pressure, compartment 3 must be closed and connected to the low pressure end of line 11 by pressure-equalizing means.