First, the working principle of shielding pump Shielding pump is a centrifugal seal pump, pump and drive motor are enclosed in a pumped medium filled pressure vessel, the pressure vessel is only static seal. This construction eliminates the need for rotary shaft seals in conventional centrifugal pumps to be completely leak-free. Shield pump pump and motor together, the motor rotor and pump impeller fixed on the same axis, the shield sleeve motor will be separated from the stator and rotor, the rotor is transported medium, the power through the stator magnetic field Pass to the rotor. Shield hydraulic end of the pump can be used in accordance with the general centrifugal pump structure and the relevant standards, design and manufacture specifications. Second, the characteristics of shielded pump 1, shielded pump advantages (1) compared with a sealed pump, eliminating the need for maintenance and replacement of the seal trouble, but also eliminates the need for coupling, the small number of parts (only mechanical seal pump 30 % Or so), high reliability. No rolling bearings and motor fan, do not need to add lubricating oil, and smooth operation, low noise [usually 60 ~ 65dB (A)]. Configurable bearing wear monitor to detect bearing wear. (2) compact structure, small footprint, low requirements on the base and the base, there is no coupling of the center of the problem, easy to install and low cost. Routine maintenance workload, low maintenance costs. (3) Normal operation without leakage in the vacuum system or "vacuum" and "positive pressure" alternately. The material can be fed directly from the vacuum tank to other vessels under high vacuum conditions. Wide range of use, for high temperature, high pressure, low temperature, high melting point and other conditions can meet the requirements. 2, the shortcomings of shielding pump (1) due to the use of sliding bearings, and with the media being transported lubrication, it is not suitable for poor lubrication of the shield pump delivery. Generally suitable for shielding pump medium viscosity range of 0.1 ~ 20cP. (2) Shielded pumps are generally less efficient than sealed centrifugal pumps. However, in the case of medium and low power, compared with the double-end seal pump, the latter has little difference in overall efficiency due to the increased power consumption of the cooling and flushing systems. (3) Centrifugal pump operation, the required flow should be higher than the minimum continuous flow. This is particularly important for shielded pumps because in the case of low flow rates, the pump is less efficient and can cause heat to evaporate and cause the pump to dry and cause damage to the plain bearings.
