1,Overview
A unit of Closed-loop water ring vacuum system consists of a set of closed-loop vacuum unit including one or several water ring vacuum pumps with motors, a unit of separator, a unit of heat exchanger, and a set of accessory including instrument, valves, piping fittings and internal piping. The equipment is supplied in a assembly unit. 2BE series and 2BV series liquid ring vacuum pump both can make up a closed-loop water ring vacuum system(unit).
2,Process explanation
The gas：The process gas flows into the water ring vacuum pump and the gas will be compressed and flows into the separator with the working liquid. The gas will discharge from the top of the separator.
Working liquid：The working liquid flows into the vacuum pump unit through the making up piping. After the system operates, the working liquid flows from the separator into the condenser, and then it returns to the vacuum pump. The level of the separator can be observed by the magnetic flap level gauge. Meanwhile, the level transmitter transmits the separator's level signal to DCS. If the separator's level is lower than the set value, the automatic making up valve will open to make up water. If the separator's level is higher than the set value, the automatic discharge valve will open to discharge the extra water.
3,Control strategy
3.1,Separator's level：A level transmitter is installed at the separator to monitor the separator's level and it transmits the detected signals to DCS for display, alarm and control. The level transmitter, the automatic making up valve and drain valve work together to control the working liquid's level and maintain the system's level.
3.2,The flow and temperature of the working liquid: A monitor sight glass is set at the working liquid piping to monitor the working liquid which flows into the liquid ring vacuum pump. Meanwhile a temperature transmitter is set at the working liquid piping to monitor the working liquid's temperature and it transmits the detected signal to DCS for display and alarm.
3.3,The pressure and temperature at the inlet and outlet. A pressure transmitter is set at the vacuum pump's inlet and outlet to monitor the pressure at the inlet and outlet and it transmits the detected signals to DCS for display and alarm. Meanwhile, it works with the manual return flow regulating valve to return the flow in the system. A temperature transmitter is set at the separator's discharge port to monitor the discharge temperature. And it transmits the detected signals to DCS for display and alarm.
All the control strategy stated above is operated by the user's DCS.
The description stated above can be changed according to user's requirements. It's subject to the scope of supply.
