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 current collector, an air inlet is formed on the volute, the collector is arranged at the air inlet, the impeller and The current collector has a common axis, and the current collector includes an annular mounting part connected to the volute and a guide part for guiding the airflow, and the guide part includes a radially inner side extending inward from the mounting part. The radial guide part and the axial guide part extending from the radial inner side of the radial guide part through the air inlet to the inside of the volute, the impeller includes a front ring, a rear ring, and a front ring and a rear ring The blades between them are characterized in that: on the axial section of the current collector, the axial guide part is a curve that gradually expands radially outward from the end connected to the radial guide part toward the direction of the impeller, and every Each blade is formed with a recessed portion at the end connected to the front ring, and the recessed portion is formed by indenting from the radially inner side to the radially outer side of each blade.

Description

technical field [0001] The invention relates to a power system, in particular to a centrifugal fan and a range hood using the centrifugal fan. Background technique [0002] The multi-blade centrifugal fan has the characteristics of high pressure and low noise. Therefore, the current society generally uses the multi-blade centrifugal fan system as the power source, and uses the high-speed rotating impeller to complete the two functions of acting and filtering in the volute. As it is commonly used in range hoods, the oil smoke is sucked and exhausted through the multi-blade centrifugal fan installed inside the range hood. The multi-blade centrifugal fan includes a volute, an impeller installed in the volute and a motor that drives the impeller to rotate. When the impeller rotates, the The center of the fan generates negative pressure suction, sucking the fumes under the range hood into the fan, and after being accelerated by the fan, it is collected by the volute and guided ou...

AI Technical Summary

Problems solved by technology

[0004] In the existing multi-blade centrifugal fan system, since the air flow enters the volute from the axial direction, it needs to turn a relatively large angle to flow out from the radial direction of the impeller, which increases the degree of turbulence of the air flow; It is close to the front ring of the impeller, and the position between the two is prone to eddy currents, thus forming edge sounds (howling sounds are formed when the frequency is appropriate)

In addition, there are other problems in the cooperation between the collector and the impeller: when the axial clearance is too small, the airflow cannot quickly change from axial to radial flow after entering the impeller, so that the front end of the impeller forms a low-speed vortex flow, and the impeller’s The working ability decreases; when the axial clearance is appropriately increased, although the airflow entering the impeller can better complete the change of speed direction, reduce the low-speed vortex flow, and improve the working ability of the front end of the impeller, the leakage flow between the collector and the impeller will Slightly increased, the working ability of the impeller also decreased

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