I need help with calculating the side pressure on the impeller of a double-end face seal.
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Hello, teachers. I have a question for everyone. In the 53A flushing mode, the pressure in the sealed chamber is 1–1.5 MP higher than the pressure on the back side of the impeller. May I ask the experts here: how is the pressure on the impeller side of the pump calculated?
What you mean is how to calculate the pressure in the sealed chamber. Of course, the pressure on the back side of the blades can also be calculated; it can be determined by integrating from the mouth ring outward to the outer diameter of the impeller； The pressure in the sealed chamber with a flange can be approximated as inlet pressure + 0.3 MPa, while the pressure in the sealed chamber without a flange is approximately equal to the outlet pressure ； For the flushing pressure in 53A, it only needs to be higher than the pressure in the sealed chamber; 1-1.5 MPa is not necessarily required
53 Provide isolation fluid to the pressurized double seal through an external reservoir. During normal operation, circulation is maintained by the pumping ring. The pressure in the reservoir is higher than the pressure of the liquid in the sealed chamber. (Generally, the back side of the impeller refers to the inlet pressure.) If you want to calculate the pressure in the sealing chamber, an empirical formula is as follows: for a cantilevered single-stage pump, the sealing chamber pressure = inlet pressure + head/3; (in our company, we usually add 0.3–0.5 MPa to the inlet pressure.)
But, teacher, how can we calculate it without a pressure gauge at the inlet?