Why is a minimum flow control valve installed on the high-pressure feed pump? What should be noted when starting the reaction feed pump?
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Why is a minimum flow control valve installed on the high-pressure feed pump? What should be noted when starting the reaction feed pump? Because it operates at low flow rates, the high-pressure pump may experience the following problems: ① Rising temperature and increased saturated vapor in the liquid, leading to intensified cavitation. ②As the temperature rises, the rotor temperature increases accordingly, leading to wear. The installation of a minimum flow control valve ensures the economic efficiency and safety of the feed pump during long-term operation. When starting the high-pressure feed pump, the operator should first bypass the minimum flow protection button for the reaction feed pump, set the output signal of the minimum flow regulator for the pump to be started at the specified value (50%), and set the output signal of the fresh feed flow controller to 0.1%. Once the pump starts operating properly and the outlet valve is opened, adjust the pump’s minimum flow setting to the normal value, and then reset the minimum flow protection button for the reaction feed pump. Before starting the pump, the operator on site should check whether the low-point valves on the hydrogen flushing line, the sludge oil line, and the pump outlet pipeline are closed, whether the blind flanges are in place, whether the manual valves upstream and downstream of the feed control valve are open, and whether the bypass valves are closed. After the pump starts and the outlet valve is opened, it is necessary to check for any leaks along the flow path as well as to ensure that the lubrication system is functioning properly. This post was last edited by The wise are free from confusion on 2009-3-26 11:32.]
The minimum flow control valve is primarily used when the pump starts up or shuts down. When starting the pump, it is necessary to open the minimum flow control valve first; this serves two purposes: one is to prevent the pump from being under high pressure, and the other is to ensure that there is a certain amount of flow returning to the pump at the beginning of operation, thereby preventing the buffer tank upstream of the pump inlet from being emptied. This aspect is also taken into consideration during shutdown. Why is it necessary to first open the bypass of the minimum flow control valve at startup? It seems to be because flow must be present after the minimum flow control valve before it can be activated! ! !
Agree with the person above; this is the biggest difference from turning ordinary pumps on and off!