Categories
Relatively speaking, some users have higher requirements for the degree of automation of the reverse osmosis pure water system. As the manufacturer of the reverse osmosis pure water system, VOLARDDA recommends PLC logic programming control to achieve fully automatic operation. The operation and monitoring of reverse osmosis pure water equipment is automatically monitored and executed by PLC and instruments. The panel has a touch screen for operation, and is equipped with manual operation buttons and control room operation buttons; the system has interlock protection function and alarm indication function.
One. Process requirements of instrument and PLC in the operation process of reverse osmosis pure water equipment
1. The dosing amount adopts the proportional adjustment method, and the metering pump is automatically adjusted for proportional dosing according to the signal sent by the water flow meter.
2. The metering box is equipped with an on-site level gauge, and an alarm is given with a low level signal to ensure that the dosing will not be interrupted due to the presence or absence of the medicine in the dosing box.
3. There is an on-site instrument panel, which is equipped with a flow indicator and a flow accumulation meter, a conductivity meter, and a PH value indicator. There is also a water supply pressure gauge. The parameter signals from the flow meter, the conductivity meter and the pH meter are sent to the PLC central control room for continuous recording; at the same time, the signal from the flow meter controls the metering pump for proportional dosing; the high and low alarm signals from the pH meter are sent to the PLC The central control room gives an alarm.
Two. The inlet and outlet sides of the high-pressure pump are equipped with low-pressure and high-pressure switches respectively.
When the inlet pressure of the high-pressure pump is lower than the limit value, the low-pressure switch closes and sends a signal to the PLC, and the PLC alarms and automatically stops the operation of the high-pressure pump; when the outlet pressure of the high-pressure pump is higher than the limit value, the high-pressure switch closes and sends a signal After the PLC, PLC delays for a certain time, if the pressure of the high pressure pump is still higher than the limit value, the PLC will output an alarm and automatically stop the operation of the high pressure pump. If it is higher than the switch and return to the off state within the delay range, the PLC will automatically Cancel the input signal.
Three. The outlet of the high-pressure pump is equipped with an electric slow-open valve.
After the high-pressure pump is started, the slow-open door opens automatically and slowly to ensure that the RO membrane element is not damaged by water hammer. If the slow-open valve fails to open within the specified time, the outlet pressure of the high-pressure pump increases, and the pressure switch outputs an alarm signal. PLC automatically stops the operation of the high-pressure pump.
