Centrifugal blower volute of range hood

Abstract

The invention relates to a centrifugal blower volute of a range hood. A molded line of the volute (1) consists of a first curve AB, a second curve BC, a log spiral CD and a straight line DE which are in smooth transition connection with each other, and the first curve AB and the second curve BC which form a volute tongue are front edge parts of a wing profile molded line, wherein the first curve AB is the front edge part of a wing profile upper airfoil molded line BAF, the second curve BC is the front edge part of a wing profile lower airfoil molded line BCF, and the upper airfoil molded line BAF and the lower airfoil molded line BCF form the wing profile molded line. The centrifugal blower volute uses the wing profile front edge parts with good streamline forms as the molded lines of the centrifugal blower volute tongue. The volute adopting the wing profile volute tongue can greatly reduce the probability of generating flow separations and back flows at the volute tongue and reduce impact losses, and is favorable for improving the wind quantity, the wind pressure and the efficiency of a centrifugal blower and reducing aerodynamic noises.

Description

technical field [0001] The invention relates to a centrifugal fan volute of a range hood, which belongs to the modification technology of the centrifugal fan volute of the range hood. Background technique [0002] Existing centrifugal fans have been widely used in range hoods due to their advantages of large suction, low noise, and compact structure. The volute is one of the core components of the centrifugal fan. Its function is to concentrate the gas leaving the impeller, guide it to the outlet of the volute, and convert part of the dynamic pressure of the gas into static pressure. There is a tongue-shaped structure near the volute outlet of the centrifugal fan, called the volute tongue, which is used to divert the airflow directed to the volute outlet and prevent part of the gas from circulating in the volute. The shape and form of the volute tongue have an important influence on the air volume, wind pressure, efficiency and noise of the centrifugal fan. The traditional...

AI Technical Summary

Problems solved by technology

Because the angle of attack between the airflow directed at the outlet of the volute and the volute tongue is relatively large, coupled with the expansion effect of the volute outlet, the volute tongue designed by the traditional design method is prone to flow separation near the outlet of the volute above it, forming The large reverse pressure gradient leads to the generation of backflow, causing some gas to circulate in the volute, reducing the air volume, wind pressure and efficiency of the fan, and increasing the eddy current noise

In addition, the volute tongue is closest to the blade of the rotating impeller. The volute tongue designed by the traditional design method has a blunt head, and the airflow has a greater impact on the volute tongue head, which will cause greater rotational noise.

[0003] Considering the important influence of the volute tongue on the aerodynamic and acoustic characteristics of the centrifugal fan, people have made some structural improvements to the volute tongue. For example, Chinese Patent No. CN200510060742.4 discloses an inclined volute tongue with variable R. In addition, China Patent No. CN200420020071.X discloses an equal-R inclined volute, and Chinese Patent No. CN00115736.1 discloses a stepped volute noise-reducing volute, although these improvements have been made in the aerodynamic performance or noise characteristics of the fan. Certain results have been achieved, but none of the above-mentioned design methods of the snail tongue has jumped out of the traditional design method of the snail tongue, and the design method of the snail tongue has not made breakthrough progress so far

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