Centrifugal fan and range hood using the centrifugal fan

Abstract

The invention discloses a centrifugal fan, which comprises a volute, an impeller arranged in the volute and a motor for driving the impeller to rotate, the volute includes a ring wall, and is characterized in that: the volute is provided with a The waveform conversion device for converting the noise spherical wave generated by the motor vibration into a plane wave, the waveform conversion device includes at least two waveform conversion units, and each waveform conversion unit is attached to the inner side of the ring wall. Also disclosed is a range hood applied with the centrifugal fan. Compared with the prior art, the advantage of the present invention is that the characteristics of the noise source signal with a wide frequency and whose amplitude changes with the propagation path are "equivalent" to a noise signal whose amplitude in a specific frequency range does not change with the propagation path through the waveform conversion structure The plane wave, so that the amplitude of the sound wave does not change with the distance of propagation, so that the noise amplitude at any position from the motor to the volute wall is the same, and the accurate noise amplitude at the same reference value can be used for noise reduction, which can greatly improve the noise reduction effect .

Description

technical field [0001] The invention relates to a power device, in particular to a centrifugal fan and a range hood using the centrifugal fan. Background technique [0002] The range hood uses the principle of fluid dynamics to work, sucks and exhausts the range hood through a centrifugal fan installed inside the range hood, and uses a filter to filter some grease particles. The centrifugal fan includes a volute, an impeller installed in the volute and a motor that drives the impeller to rotate. When the impeller rotates, a negative pressure suction is generated in the center of the fan, and the oil fume under the range hood is sucked into the fan, and after being accelerated by the fan, it is collected by the volute and guided out of the room. [0003] The survey results show that the experience perception of the user during the cooking process depends mostly on the noise and air volume of the range hood, but the increase in air volume and the reduction in noise are contra...

AI Technical Summary

Problems solved by technology

In the fan system, the sound propagates from the excitation source to the outside layer by layer. In this process, the motor as the excitation source is a spherical wave that radiates outward with the wave front as a spherical surface. The amplitude of this spherical sound wave is inversely proportional to the propagation distance. , which leads to different noise amplitudes at different positions in the volute, so whether it is using sound-absorbing cotton or active noise reduction, it is impossible to perform selective noise reduction for different positions, and the effect of noise reduction is not ideal. of

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