Should the flow meter used for measurement be installed at the end or the beginning of the pipeline?
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Measurement of the feed volume from the tank area to the reaction vessels in the workshop: Currently, flow meters are installed in the workshop, at the end of the pipelines. After each feeding session, when the desired amount of fluid has been delivered and the pump stops, some excess liquid remains in the pipeline and flows into the reaction vessels; closing the valve immediately can cause pressure buildup. Considering installing it at the pump outlet of the tank area, would that be better? ?
There is a problem with the design. Of course, you can also make modifications on your own by adding a self-acting control valve in front of the reactor. The pump can be stopped when the cumulative flow approaches the required feed volume; the pipeline pressure will automatically drop and cause the valve to close once it falls below the pressure set by the self-acting control valve. Naturally, no excess material will enter the reactor anymore. For the specific parameter settings, either have the design institute do the calculations or try them out yourself gradually.
A check valve will work too. If there is pressure in the pipeline, the valve remains open. When the pump stops and the pipeline pressure drops, it shuts off automatically.
From the problem you described, it seems to have nothing to do with where the flow meter is installed. Without adding any equipment, it is possible to measure or estimate how much material will still flow in after the Shimonoseki pump; by taking this amount into account when setting the feed rate, more accuracy can be achieved.
Problems will still arise; when installed at the pump outlet, if you stop the pump, not all of the fluid in the pipeline will make it to the reaction vessel, which may result in an insufficient amount of fluid. It is best to maintain the status quo; after all, it is a reactive system that relies on accurate feeding into the reactor, with a shut-off valve installed after the flow meter. The problem of pressure buildup due to material remaining in the pipeline can be easily resolved; connecting it to the storage tank via a return line should solve it!
The flow rate triggers the automatic valve closure and pump shutdown; that’s how it’s generally designed. The suggestion for the 6th floor is great; adding a return pipe at the pump outlet will prevent pressure buildup. The deviation in the amount of material added is related to the question of whether the flow meter or the shut-off valve is placed first; generally, the design calls for the shut-off valve to be located after the flow meter.
For measurement purposes, there should be requirements regarding the length of straight pipe sections before and after it.
In terms of the operating conditions for flow meters, the situation at the pump outlet of a tank farm is not as favorable as that at the feed inlet of a reactor; the fluid at the pump outlet experiences pulsating flow and significant vibration, which hinders accurate flow measurement.
It cannot be installed at the pump outlet; an appropriate location must be chosen based on the pipeline structure and length, as well as the type of flow meter used. The pressure holding issue is a system design problem; add a pressure relief valve or a pump switch interlock.
The current installation location is correct