Fan volute tongue

Abstract

The invention discloses a fan volute tongue which comprises a volute tongue body and is characterized in that a first rotary column and a second rotary column are mounted at a tongue tip part of the volute tongue body in a sagittal direction of the volute tongue body; the first rotary column corresponds to a front disk area of the volute tongue; the second rotary column corresponds to a central disk area of the volute tongue; the first rotary column and the second rotary column can rotate synchronously; and a rotary speed of the second rotary column is higher than that of the first rotary column. The fan volute tongue has the advantages that the first rotary column and the second rotary column are mounted at the tongue tip part of the fan volute tongue; the first rotary column is arrangedin the front disk area of the volute tongue; the second rotary column is arranged in the central disk area of the volute tongue; the rotary speed of the second rotary column is higher than that of thefirst rotary column; gas circulation layers in different speeds can be generated on the front side and rear side of the volute tongue to adapt to a change of speed at an impeller exit from front to back, so that more stable air volume and air pressure are achieved; and the noise reduction is also facilitated.

Description

technical field [0001] The invention relates to a fan volute tongue. Background technique [0002] Multi-blade centrifugal fans are widely used in range hoods due to their advantages of compact structure, high pressure coefficient, large flow coefficient and low noise. The centrifugal fan of the existing range hood is provided with a volute near the outlet of the volute, and the function of the volute is to prevent part of the gas from circulating in the volute. It is found through experiments that the impact of the airflow at the outlet of the impeller on the volute tongue is relatively strong, and the gas flow near the volute tongue is more complicated and has a greater impact on the performance of the fan. In addition, the rotation of an object in the air can drive the surrounding fluid to rotate, and the circulation generated by the rotation interacts with the fluid, so that the fluid velocity on one side of the object increases and the fluid velocity on the other side ...

AI Technical Summary

Problems solved by technology

At present, the improvement of fan volute tongue structure is mainly considered from the angles of reducing fan noise and eliminating vortex, such as the Chinese invention patent application with application number 201210210890. Volute case, volute tongue", the volute tongue includes an inner concave surface, and the inner concave surface is a smooth curved surface, so that the airflow at the volute tongue is smoother, which is beneficial to reduce noise, although the improved volute tongue is designed as an inner concave surface structure It considers the law of changing the impeller outlet speed from front to back, but it does not consider how to improve the volute tongue structure from the perspective of effectively increasing the air volume and wind pressure

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