Abnormally high pressure at the pump outlet in the tank area; seeking online assistance
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This post was last edited by sssaw on 2019-3-30 at 12:39. Exception 1: With valves 2, 3, 4, 5, and 6 closed, the pressure at the pump outlet rises slowly, at a rate of approximately 0.01 MPa/min (the length of the closed pipe section is about 3 m); the maximum pressure can reach over 0.4 MPa. Abnormal condition 2: When valves 2, 3, 4, and 5 are closed, valve 6 is opened, and valve 7 is closed, the pressure at the pump outlet rises rapidly, at a rate of approximately 0.3 MPa/min (with the length of the closed pipeline section being around 90 m); the pressure can reach over 0.6 MPa. Interlock settings: FISQ0101 is used to set the flow rate; once this set value is reached, valve 2 and the isopropanol pump are closed simultaneously, with valve 7 being closed after a 10-second delay. Materials: Isopropyl alcohol; the isopropyl alcohol pump is a magnetic pump with a flow rate of 25 m3/h and a head of 32 m.
The operating point of a centrifugal pump is determined by the pump’s performance curve; a high pressure indicates high resistance at the outlet
The problem is that the pump is turned off; as a result, the pressure in the closed pipeline rises abnormally. The pressure gauge is new, and the surface temperature of the pipeline is also normal
What is the pressure in the reactor? Is the valve leak-free?
The valve is closed, the pump is also off, and the reaction vessel is at atmospheric pressure
If you create a confined area, won’t the pressure increase?
The problem is that there’s no source of pressure, right? Does isopropanol expand so significantly in a closed pipe?
Have any engineers on site encountered this situation? Let’s see how to resolve it
Looking at the drawings, the storage tanks and low-level tanks are equipped with balance pipes. The reaction vessel operates at atmospheric pressure; an increase in pressure at the pump outlet can be attributed only to the vaporization of the material. There are heat sources at the site that cause heat transfer in the closed pipelines; nothing else comes to mind. If the original poster manages to solve the problem, please share the solution.
Add a check valve downstream of valve 7, and modify the interlock mechanism as follows: FISQ0101 sets the flow rate; once that set flow rate is reached, valve 7 shall be closed simultaneously and the isopropanol pump shall be stopped. Give it a try.