The housing of the current collector with the impeller

In order to ensure the performance of the fan, it is especially necessary to ensure that the gap between the collector and the impeller of the fan meets the drawing standards. For some fans with higher gas temperature and larger size, in order to ensure that when the fan is running at a high temperature, the air inlet ring and the impeller will not friction after the casing is thermally expanded. The gap between the inlet ring and the impeller inlet is not completely uniform. generally big small, approximately uniform, the inlet adjustment ring and the impeller inlet port containing a gap, to ensure that the gap value satisfies drawing to requirements. The performance of the fan and the efficiency are mainly determined by the impeller, but the shape and size of the volute and the shape of the suction port will also affect it. The function of the volute is to collect the gas thrown from the impeller and make it flow to the exhaust port. During this flow, part of the dynamic pressure energy obtained by the gas from the impeller is converted into static pressure energy to form a certain wind pressure. . There is a tongue-like structure at the exit of the volute of a centrifugal fan, which is generally called a volute tongue. The volute tongue can prevent gas from circulating in the casing. The composition of the tongue .  

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