膨胀机故障的原因及处理和预防（Causes of failure of expander and its treatment and Prevention）.docVIP

膨胀机故障的原因及处理和预防（Causes of failure of expander and its treatment and Prevention） The cause of trouble and its treatment and Prevention Failure cause Tachometer indicator misalignment, there are two reasons: one is due to the expander itself caused by the fault of the tachometer indicates the exception, often accompanied by abnormal sound expander serious; two is caused by magnetoelectric sensor fault. Magnetoelectric sensor mounting cover in the middle of the brake fan end, composed of two permanent magnets with coils, the magnetic induction coil principle, if the destruction of the insulation on the short circuit or the internal moisture, when the rotor rotates cutting lines to generate induced current changes, resulting in no speed measurement. An accurate diagnosis can be made by using the ohmmeter to measure coil wiring, ground resistance and insulation. The expander tachometer can work normally at ambient temperature of 0~40 degrees centigrade. The temperature is too low or too high, which is harmful to tachometer measurement. In the fractionating tower heating without removing the expander, even in the exhaust vent valve is closed, due to the cold air blowing stage temperature is lower than 0 DEG C, heating the air temperature is higher than that of the late 40 C, the two large temperature difference between the gas filled with long time fan system, magnetic sensor coil affected the largest, repeated heating will produce damp coil insulation, not fault on the short circuit, in this case the tachometer indicator will slow and less than the actual speed. The failure of the tachometer itself is very rare. If the tachometer fails to correct, it may be judged whether the mechanical fault is due, and the expander shall be removed for examination. If the mechanical system is not abnormal, the operation can be carried out by experience. The speed is low, so there is no need to worry about the automatic stop of the expander because of the high speed. It will cause the to