Seeking advice on the automatic start-stop control of pumps
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Currently, the company transports the material from the large storage tanks to the intermediate tanks in the workshop; these intermediate tanks are equipped with high-level alarm valves； But the pumps in the large tank area are still running. Due to the great distance, it is not convenient to use level switches to trigger the shutdown of the pumps in a linked manner; with the pumps running, the solution heats up. Is there any way to enable the pumps to shut down automatically through such a linkage? (Such as based on changes in pump current after the valve is closed, or changes in pipeline pressure)
I’m not sure if the distance mentioned by the original poster refers to the range beyond which it’s impossible to install signal cables. Based on the pipeline pressure, the current seems very unstable. If the distance is too great and the pipe diameter is large, won’t the pressure change be minimal? The same is true for currents of the same type, right? In practice, if the distance is roughly the same, self-locking when the valve is closed should work as well.
Set how long to run before stopping the pump; calculate it based on flow rate, and then verify whether it’s feasible
It is linked to the pump’s outlet pressure; the pump shuts down when the pressure rises to a certain level
Simply install a flow meter or a flow switch (which is cheaper than a flow meter); using flow rate for interlocking is the most direct and reliable method.
With this design, the pump’s failure rate is high. Since the liquid is transported over long distances, the pressure is high, which results in high power consumption. Often, the pump runs idly after the valve is closed, leading to energy waste and damage to the pump. It is recommended to connect the tank level signal; internet cloud technology or wireless transmission can be used for this purpose
A pressure switch interlock is installed at the pump outlet; the pump stops when the pressure reaches a certain level.
It’s not necessarily necessary to use a level switch for participating in the interlock mechanism; a double-flange level gauge in the intermediate tank can also be used. A simple interlock can be set up on the DCS or SIS, and no on-site wiring is required. However, it is necessary to connect the wiring from the cabinet to the pump control circuit in the power distribution room. Is this distance short?