GB613938A - Improvements in and relating to the removal of liquids from liquid-containing systems - Google Patents

Abstract

Samples or portions of predetermined volume are removed from a main stream of liquid by diverting the stream to a vessel of volume adequate to hold the portion required, the vessel being provided with (a) an overflow from which the liquid normally returns to the main stream; (b) a conduit leading to a sampling or off-take receiver; (c) a connection to a source of pressure (gas), the connections being arranged so that on application of pressure (1) flow from <PICT:0613938/III/1> the main stream ceases; (2) the portion or part thereof collected in the vessel is driven over into the collecting receiver. Automatic operation to remove samples at predetermined intervals is provided. The process is described with reference to a distillation process carried out in a column 1 provided with an off-take 3 cooled by condenser 2 so that condensate formed is fed through line 5 to a vessel 4 from which the condensate returns normally through line 6 to the column 1 as reflux. The vessel 4 is provided with a central baffle plate 7, a U tube 8 leading through line 9 to the sampling receiver 27, and a pipe 10 through which the gaseous pressure agent is supplied. The pipe 10 is connected (a) to a tube 24 through which nitrogen is supplied through a sulphuric acid bubbler 22 and trap 23; (b) to a lute 25 provided with a variable head of liquid which can be varied in height according to the quantity of sample required; (c) by a bent end portion so as to dip into a U tube 11 filled with mercury 12 and provided with a glass float 14 containing a soft iron armature 17, the corresponding part of the U tube being surrounded by a solenoid 18 connected into an electrical circuit 19 closed by tilting a mercury switch 20. On closing the circuit, the solenoid is energized and depresses the float 16, thus causing the mercury to flow up the limb of the U tube and close the end of pipe 10. The pressurizing gas is thus forced to flow into the vessel 4, whereupon flow of condensate through pipe 5 ceases and the sample collected in vessel 4 is evacuated into the receiver 27.