Through careful observation of the working process of the diaphragm pump, it was found that when the working pressure exceeds 0.9 MPa, the vibration of the pump is great, and the amplitude of vibration of the output pipe is large. At this time, the inlet pressure of the buffer pressure relief device of the inlet of the adjustment pipeline and the pressure-reducing pressure tank on the outlet pipeline can not eliminate the vibration, and the foundation of the pump and the brackets of the fixed pipeline are all loosened for a long time, and the pump also follows the certain time. Shake and damage. After dismantling the pump, the diaphragm is damaged. The reason is that the diaphragm is pushed out of the limit position by the diaphragm connecting rod, which causes damage to the center of the diaphragm and the connecting rod of the diaphragm. The diaphragm connecting rod is thus deformed and can no longer be used. The piston rod assembly is due to the piston rod. The damage of the silk mouth caused the two fixing nuts to fall off, and the piston rod was also scrapped; the cylinder sleeve and the piston were mainly worn too much and caused the pressure to go up.
According to the results of the maintenance of the diaphragm pump, it was mainly because the manufacturer did not design according to the best working conditions of the pump when programming the pump. The occurrence of faults is due to the high speed of the pump during the high pressure operation. Therefore, the cause of the pump must be checked. The principle of electrical control of the diaphragm pump is as follows: Pressure signals from the inlet of the plate frame are taken to the Siemens S7-300 PLC, and a 4 to 20 mA analog current signal is sent to the frequency converter to control the operating speed of the diaphragm pump. The frequency is between 4Hz and 80Hz). Nothing is wrong with the surface of the pump. As the pressure rises, the speed of the diaphragm pump slowly decreases. Through the programming software, the block inspection of the control pump is called out and the entire process of the diaphragm pump operation is detected on-line.
When the pressure is 0~0.7MPa, the output frequency of the inverter is 80Hz; when the pressure rises from 0.7MPa to 1.0MPa, the output frequency of the inverter drops from 80Hz to 40Hz; when the pressure is 1.0~1.3MPa, the inverter The output frequency is always maintained at 40Hz. At this time, the vibration of the diaphragm pump is observed to increase. The output pressure oscillates between 0.9 and 1.4 MPa. The piping and the soft pipe at the outlet of the pump fluctuate by a large margin; the pressure is from 1.3. When MPa rises to 1.4MPa, the output frequency of the frequency inverter drops from 40Hz to 8Hz. This pressure is the normal use pressure. At this time, the vibration of the diaphragm pump and the pump outlet and the pipe and the soft pipe joint jitter are basically absent until the diaphragm pump stops working. A loop. When the working pressure is 1.0 ~ 1.3MPa, the diaphragm pump operating speed is too fast, that is, the frequency of the pump's piston back and forth is too fast, resulting in the diaphragm on both sides under high pressure force exceeds the limit, the whole pump body vibration increases, so that Diaphragm pumps produced more failures and accessories were damaged abnormally.