Pump auto-start
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The design flow rate of the feed pump for the reboiler at the bottom of the tower is 1900 m3/h. The designed interlock mechanism is for automatic startup, and our logic is as follows: 1. The inlet shut-off valve closes; 2. If the liquid level in the tower is too low, the pump stops. If the outlet pressure is low, the standby pump will start automatically. Let’s all discuss such a design approach
1. The inlet shut-off valve is closed. 2. The tower liquid level is very low. Are these two conditions for shutting down the pump? It is unclear whether the pump is installed at the inlet or outlet of the tower: the positions of the inlet shut-off valve, the tower, and the pump are not clear. The outlet pressure of the pump is low, so it’s no problem for the standby pump to start automatically.
This pump must also be related to flow rate, right? Doesn’t the flow rate play a role in controlling the pump? And since the stop valve is involved in the conditions for shutting down the pump, why isn’t it considered in the conditions for starting the pump? Surely, the pump can only be started when the stop valve is open!
Our interlock system was designed by a foreign patent holder. Flow is not subject to control; instead, the pump outlet pressure is used, and a backup pump starts automatically when the outlet pressure is low. The first two are conditions for stopping the pump, aimed at protecting the pump.
There should be a low flow interlock for furnace feed to prevent dry burning of the furnace tubes; when this interlock activates, the furnace stops firing (with a pilot light kept lit) + steam is blown into the furnace tubes, in addition to the pump shutdown interlock. It is believed that the pump shutdown interlock signal should also trigger the feed low flow interlock action; depending on the specific circumstances, it is possible that in some cases the flow measurement response may be slow. If a minimum flow circuit is provided for the pump, it is not necessary to stop the pump when the inlet shut-off valve (assuming this inlet refers to the pump outlet or the furnace inlet) is closed. This way, the recovery process is faster. The startup of the low-pressure standby pump is relatively independent, but the interlock signal for shutting down the pump has a higher priority. This post was last edited by RainWolf on 2009-2-19 11:31]
What is used to measure pressure?:) Logical control needs to be implemented through a PLC
First, write a plan for everyone to review, so that you can improve
Someone upstairs asked, “What is used to measure pressure?” I don’t understand what you mean. Pressure means pressure detection, transmission, and transmission to the ESD via a safety barrier