T204 feed pumps, reflux pump bearings and bushings Hugging many times and pump vibration larger phenomenon. P2401 feed pump axle phenomenon due to the pressurized T204 tower, the tower pressure control indicators 0.6MPa, during plant operation due to operational problems, and affect the vapor pressure of the ultra-high pressure will cause the tower, when the pressure exceeds 0.77MPa, by Height of the feed pump head can not meet the conditions of the feed, equivalent to pump outlet valve closed state, since the material is methanol and dimethyl carbonate, after long-term operation, cavitation in the pump body, the graphite bearings and shaft liquid film between the sets bubbles, shielding medium pumping is to lubricate and cool the bearings of the cooling of the motor plays a very important role, therefore, when the circulating fluid is not continuous, it will lead to bearing and sleeve flow liquid film between the bearing and the thrust plate is destroyed, the heat generated in the bearing not go, accelerated bearing wear. Time is too long will cause the graphite sleeve bearings dry grinding, leading axle phenomenon.

P2402 reflux pump axle phenomenon (1) P2402 pump for the high temperature, the cooling coil frozen cold fluid circulating cooling plays an extremely important role, since dimethyl carbonate circulating water system problems, structural phenomenon more in the pipeline system serious, cooling coil thin, over time, slowly clogging coil, circulating water flow rate is slower, the temperature of the circulating fluid can not be effectively reduced, accelerating the cooling coil blockage, while the pump body also appears cavitation, resulting in hold axis phenomenon occurs. (2) P2402b in the maintenance process, once found impeller cracks, in order to prevent impeller damage in the course of the operation, after welding crack at re-polish, it is precisely because of this reason the original break rotor balancing, resulting graphite bearing severe wear, and ultimately short bearings, thrust plate damage, graphite bearing and sleeve locking.