We have introduced open impellers before. Today we will talk about closed impellers and the differences between open impellers and closed impellers.
A closed impeller has cover plates on both the front and rear sides of the blade, giving it greater strength. This also reduces the thrust load on the shaft, increases bearing life and operational reliability, and reduces shafting costs. However, due to this more complex design, closed impellers are more difficult to manufacture and more expensive than open impellers. In the application of our slurry pumps, small pumps tend to use open impellers, while large pumps mostly use closed impellers. Closed impellers work better over a wider speed range than open impellers.
Now let’s cover some differences between open and closed impellers: Closed impellers can compensate for thermal expansion of the shaft, but if there is too much axial expansion, the blades may not be perfectly aligned with the outlet nozzle. Open Impellers When the pump is at operating temperature and all axial thermal expansion occurs, the gap between the impeller and the volute or backing plate must be adjusted.
Closed impellers are the most commonly used impellers in the industry because they can handle volatile and explosive fluids. Open impellers If you handle volatile and explosive fluids, the impeller must be made of soft, non-sparking material, which is not very practical. A closed impeller is initially very efficient, but as the wear ring wears and the clearance increases, its efficiency will decrease. Open impellers maintain efficiency by adjusting the impeller clearance. Closed impeller If the particles in the pumped slurry are larger or more viscous, the impeller may become clogged. It is difficult to remove these solids from between the cover and blades. Open impellers are less likely to become clogged by solid particles, but if clogged, they are easily cleaned. Closed impellers are difficult to cast because the inner blades are concealed, making them difficult to inspect for defects. All parts of the open impeller are visible, so it is easy to check for wear or damage.
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Shijiazhuang Pansto Pump Industry is a manufacturer of slurry pumps in Shijiazhuang. It mainly designs, manufactures and sells slurry pumps and accessories. Mainly engaged in mud pumps, submersible pumps, foam pumps, desulfurization pumps and many other series.
www.panstopump.com, laurashi@panstopump.com, 0086-15732149758