Cross-flow fan

Abstract

The present invention relates to a cross flow fan. The cross flow fan comprises a cross flow wind wheel, a chassis scroll casing and an outtake-frame scroll casing; wherein, the sectional shape of the chassis scroll casing comprises a chassis drainage line, a rear guiding scroll casing curve and a chassis air outlet-shaped line; the sectional shape of the outtake-frame scroll casing comprises a scroll casing tongue part and a front guiding scroll casing curve; and the distance valve between the scroll casing tongue part parallel to the axial direction of a rotary shaft and the outer edge of a vane wheel of the cross flow fan is variable. The scroll casing tongue part (4) is axially toothed, corrugated or skewed and twisted. Through the axial change of the volute structure and the function of the wind wheel, the cross flow fan can axially generate inconsistent (trend) pressure fluctuation to inhibit the large ultraharmonics components generated by the cross flow fan and the wind wheel in order to eliminate the harsh sound caused by the ultraharmonics contained in noise, and meanwhile, by changing the axial structure of the cross flow fan, the axial flow of a flow field in the cross flow fan can help to inhibit the generation and development of end wall corner vortexes, swirls in the clearance flow of the wind wheel, and the like, thus reducing aerodynamic noise and finally improving the sound quality of the whole machine and controlling the noise level of the whole machine.

Description

technical field [0001] The invention is a cross-flow fan, which belongs to the transformation technology of the cross-flow fan. Background technique [0002] Compared with the axial flow fan and the centrifugal fan, the cross-flow fan has a higher total pressure coefficient under a certain flow coefficient, and its requirement for the radial size of the wind wheel is very small (small volume); it can be freely used according to the requirements of the air volume The choice of impeller length, and the characteristics of uniform and concentrated air supply and low noise, although its efficiency is low compared with axial flow and centrifugal fans, it is used in low-pressure ventilation and ventilation occasions such as household appliances, laser instruments, and agriculture. Material cleaning and other aspects have been widely used. With the improvement of industrial production, science and technology, and people's requirements for the cleanliness and comfort of working and ...

AI Technical Summary

Problems solved by technology

Therefore, in the vicinity of the volute tongue, it is easy to generate consistent (trend) pressure pulsation in the axial direction of the conventional wind wheel, so it is easy to generate large high-order harmonic components. If this harmonic is included in the noise, it will easily become harsh.

[0005] The currently used constant-pitch volute tongue (collectively referred to as straight-line volute tongue) cross-flow fans, as the tongue gap decreases, the flow rate increases, but the noise also increases accordingly

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