Does the DCS configuration use function blocks to keep the liquid level within a certain range?
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May I ask how to use Zhejiang University’s Zhongkong configuration to keep the liquid level within a certain range? For example: There is a liquid level LI101, and the solenoid valve SV101 at the inlet is used to keep this liquid level within a certain range, such as 40%–60%. What should be done in this case?
Control the valve based on the liquid level. 40 start, 60 stop
It’s sufficient to simply perform a liquid level check as the condition for controlling the on/off valve
If a comparison module is used, which one should be considered between 40 and 60? It’s turned on if the value is less than 60, and turned off if it’s greater than 60. What about values greater than 40? Should it be turned on or off?
This post was last edited by jlshnlhj on 2021-10-20 at 18:38 with a similar one.
If a solenoid valve is used, it will open and close frequently, leading to rapid wear, short maintenance cycles, and a high failure rate. Choosing a pneumatic control valve is the best option.
Is that interesting then? If the container is large, it’s manageable; but if it’s small, the solenoid valve keeps operating – is that acceptable? Since the liquid level needs to be stabilized, why not use a control valve? Was it designed this way?
Use RS, or a set/reset coil.
If high regulation requirements or frequent switching are needed, it is recommended to use a control valve.
Use the emergency shut-off valve in this way: it cuts off flow when the liquid level is too high or too low. If normal level control is required, it’s better to use a control valve.
Actually, an RS flip-flop will do; a value below 40% triggers the valve to open, while a value above 60% causes it to reset and close the solenoid valve. As for the range between 40% and 60%, there’s no need to worry about it