In the import and export of material in the process of the diaphragm around both sides of the force, the maximum 4800kN, due to the continuous alternating force, easy to damage and cracking, the diaphragm design life of 8000h diaphragm pump, the working pressure is 6MPa, the reason is easy to damage the pump diaphragm are as follows:
The 1 air chamber is not clean, the gas volume varies with the change of liquid pressure, promote the formation of air hammer, diaphragm local stress increases, the diaphragm will break.
2 of the diaphragm chamber volume, if the feed is not stable, low pressure, the feed compensator level below 1 2m, voltage stabilizing device the material level is not normal, slurry separation gap is formed in the pump feed, cause the lack of material, air pump, impact hammer or even produce cavitation, increasing so, under the diaphragm stress frequency increases, causing the diaphragm fatigue damage or breakdown.
3 feed containing 3-8mm pebbles or solid bulk material and slurry mass percentage of more than 2%, caused by card valve, resulting in pump pressure fluctuations, or because the valve assembly, valve cone positioning, caused by stab valve, diaphragm causing momentary force increase caused by rupture.
4 feed temperature exceed 100 C, accelerated aging diaphragm, at the same time, steam bubbles in the slurry gas into the diaphragm chamber or unloading valve leakage, hydraulic pressure is reduced, causing the diaphragm uneven stress, fatigue damage.
Feed 5 of the diaphragm chamber and the discharge through the probe detection control rod position control of the times, if the magnetism control rod of the weak, the probe cannot detect the signal, not timely discharge of oil filling, caused by excessive force and unilateral diaphragm rupture.
6 diaphragm control rod supporting sleeve wear, the control rod eccentricity, sinking, diaphragm stress increase, easy to rip the diaphragm.
7 unit pressure difference, causing the diaphragm pump overpressure, diaphragm withstand instantaneous force increase caused by rupture.
Loose 8 crosshead and piston or cylinder liner, crosshead, crosshead guide bearing caused by incorrect installation of the piston hammer, will cause the hydraulic imbalance; pump frequent jump stop, also can make the diaphragm instantaneous stress reached the limit, caused by rupture of the diaphragm.
9 nitrogen pack is pre filled with 2 2MPa nitrogen, which has better damping effect. Operation when the pressure gauge pressure is reflected on the operating pressure rather than nitrogen pressure (packet only when the pump stops to see if the operation), the package is damaged or nitrogen pressure decreased in diaphragm pump without damping condition, will cause the hydraulic imbalance, prone to hit and damage the diaphragm.