Centrifugal fan for range hood

Abstract

The invention discloses a centrifugal fan for a range hood, which comprises a volute and an impeller arranged in the volute, the impeller includes a plurality of blades, and the profile of the blades includes a first circle smoothly connected at the entrance. arc and a second arc at the exit, said first arc having a radius R 1 , the central angle is α 1 , the radius of the second arc is R 2 , the central angle is α 2 , characterized in that the ratio of the radius of the first arc to the second arc is 3.5≤R 2 / R 1 ≤4, the central angle of the first arc is 85°≤α 1 ≤90°. Select the more reasonable radius and central angle parameters of the two arcs of the blade profile, so that the degree of shrinkage at the outlet of the blade and the narrow length of the blade are larger, the speed of the impeller outlet is larger, and the vortex in the blade channel is less, so as to better adapt to The application environment of the range hood makes it easier for the fumes to be thrown out of the impeller, and there is less eddy current inside the fan.

Description

technical field [0001] The invention relates to a range hood, in particular to a centrifugal fan of the range hood. Background technique [0002] The range hood has become one of the indispensable kitchen appliances in modern families. The commonly used range hood is usually equipped with a fan casing on the fume collecting hood, and the fan casing is equipped with a volute, an impeller and a motor driving the impeller. centrifugal fan. [0003] At present, the blades of the commonly used multi-blade centrifugal fan impellers are usually single-arc-shaped. The single-arc shape has the advantages of compact structure, high pressure coefficient, large flow coefficient and low noise, and is widely used in many ventilation devices. , electronic equipment and air conditioning systems and other occasions. However, due to the relatively large width of the impeller of the multi-blade centrifugal fan, the inlet airflow is unevenly distributed along the axial direction. The pressur...

AI Technical Summary

Problems solved by technology

However, it is not suitable for use in range hoods. This is because the smoothness of the oil fume flowing in the leaf passage is more concerned about in the range hood. The flow in the blade path is smooth, and it can be thrown out of the impeller at one time as much as possible

In the existing double-arc blade profile, there are a lot of backflow and vortex between the blade flow channels. The pressure surface in the blade channel is higher than the suction surface pressure. Because the density and viscosity coefficient of the oil fume are higher than that of the air, the oil fume is easier to pass through. The pressure side flows to the suction side to form a vortex backflow, especially at the outlet, the airflow is blocked at the outlet and cannot go out, which not only increases the flow loss, but also makes the oil fume pollute the impeller

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