Gas recirculation appts. for filling and emptying of tanker vehicles - includes electronic pump controller responsive to sensors of reservoir and tank liq. levels, pressures, pump temp. and leakage

摘要

A control head (16) provided with an eyelet (47) for suspension from a roof or mast incorporates a coupling (17a) for attachment to its counterpart (17b) mounted with a ball-cock (21) around the gas vent (22) on top of the tanker. Safety limit switches (29) cooperate with encoded contacts (28) on the coupling. A pressure transducer (34) monitors the venting of dangerous gas through a port (32) into a pipe (15) leading to the reservoir from which liq. is pumped into the tank (18). Reed switches (44) are operated by an annular magnet (45) rising and falling with a dipstick (41) when the ball-cock is open (20). USE/ADVANTAGE - In transfer of isocyanates or similar aggressive liqs., environment is protected by closed circuit from which escape of gas, vapour or aerosol is effectively prevented.