1、外文文献Failure analysis of centrifugal pumpAbstract Cause defects in process system of centrifugal pump failure according to their causes can be divided into mechanical fault, pump and pipeline pump is composed of pump abnormal vibration, noise fault. Causes of failure after class is relatively hidden,
2、 not easy to find. Through some examples, encountered in the work, the fault of centrifugal pump leads to the design process and pipeline system is analyzed, and puts forward the corresponding countermeasures.Keywords: vacuum degree analysis of mechanical faults of centrifugal pump1 centrifugal pump
3、 suction inlet Because of the gas density is far less than the liquid, gas through the impeller,head head can be far less than the liquid through the impeller. In the different positions of the impeller of the pressure distribution, different, when the liquid is mixed with gas bubbles in the pressur
4、e, the uneven, after the first expansion compression, produced a similar impact of cavitation, the last may be crushed or broken. The impellers are exciting force will be severe vibration and noise pump outlet pressure in the closed system along with the liquid circulation flow, unable to discharge
5、system, if the gas entrained in quantity is more, the pump will appear abnormal vibration. The closed system of gas sources are mainly in two aspects:(1) system design is not reasonable to exhaust the dead angle, each to the system into the liquid of these dead area has a large number of residual ai
6、r, and in the cycle of these air may be brought into the pump.(2) the working fluid system in the long process cycle of non condensable gas due to lack of gas-liquid separation system, emissions of non condensable gas ac cumulation in the system. If the heating system of heat medium and other organi
7、c matter in the long time use will produce gaseous substances due to oxidation and other reasons. The above two kinds of circumstances in the closed system, the gas first as soon as possible to discharge system, secondly to accurately determine the source of gas to gas in the system existence; not s
8、top, to a gas-liquid separation device in the system increases and regularly discharge. Obviously for the closed cycle system, in the appropriate part of the system installed gas collection (storage system pressure, and low (or, discharge device (such as pipelines highest point)strengthen inspection
9、 regularly on exhaust system is essential A drying drum heating system (Fig. L) in the 1 B41 5 H M 0506 satellite shielding pump found that volatility pump severe vibration noise outlet pressure test.Exclusion of mechanical and electrical fault pump itself after study of the heat medium system, find
10、 that the system of Jin wheel drum (L) without exhaust system filling heat medium, drum heating jacket in the air does not come out. When driving, air is sucked into the failure of shielding pump. So in the Jin wheel stalled on the exhaust valve, exhaust gas of high restart shielding pump in the nor
11、mal functioning of the system when the heating medium. For the open cycle system, gas produced in the system can be directly discharged into the atmosphere will not accumulate in the system. So into the gas pump is mainly caused by the inlet pipeline pump suction from the outside. This fault and the
12、refore should be focused on checking the suction pipe. If a chilled water circulation system is an open system, circulating pump as shown in Figure 2 the (model 15150 a 125 a 400, head for the 45m, flow rate of 190m3/h) is the 1 single stage single suction centrifugal pump. Found in operation began
13、to pump start there is no abnormal starting about Z min after the periodic oscillation, outlet pressure gauge pointer large radial swing, serious when systematic pipe rack will shake. Experiments were repeated, the same phenomenon. After inspection of the pump running parts no problem. And frozen wa
14、ter level higher than the pump suction pipe on the pump body, hydraulic loss is very small, the pump cavitation does not occur. Exclude factors, consideration might be inhaled the gas pump, and the pump suction line on inspection, check the water tank that return water tank DN250 pipe located just a
15、bove the pump suction pipe, water tank liquid level from 0.3m LM, from the mouth of the suction pipe. High speed into the backwater pool of liquid entrainment from a large amount of air into the pump The suction, the pump inhalation of air, resulting in pump body vibration.Therefore the pump suction
16、 pipe extending 1.Sm to the pool, avoid water backwater port, the failure to eliminate. 2 centrifugal pump export pipeline gas block In the circulation system, aggregation is higher or larger process upper valve is easy to produce gas pipeline. Centrifugal pump operation in these areas will form the air bag, liquid flows through the region of the flow resistance increases, the partial pressure increases, the compressed gas,
