Abstract: The ring tube axial flow pump is an important conveying equipment of polypropylene plant. Current fluctuations, power fluctuations, and inlet pumping-out often occur during pump operation, which affects the normal operation of the device. Two key test points Z1 at the pump drive end and Z2 at the pump inner bearing of a domestic axial flow pump are selected to test the actual operating parameters of the pump such as temperature, current and noise. The time domain and frequency spectrum are used to analyze the vibration data of the two key test points. The analysis results show that the effective value of vibration velocity in the Y-axis direction of the three-axis direction at the pump drive end Z1 is 3.940 mm/s which is the largest. The vibration energy in the Y-axis direction is high, and the pump body is slightly loose; there is no obvious impact feature in the test data of the two axial directions at the Z2 position in the pump inner bearing; the overall vibration amplitude is relatively small, and the internal liquid flow is relatively stable. The analysis results indicate that the vibration value of the pump is within the range specified in the relevant standards and will not affect the stable operation of the pump unit; the current power fluctuations and inlet pumping-out of the unit are mainly caused by sudden changes in medium density, speed and gas volume. According to the above phenomenon, this paper proposes corresponding solutions, which can provide reference for solving similar faults.

Key words: ring tube axial flow pump, vibration test experiment, spectrum analysis