CN2359508Y

CN2359508Y - Centrifugal fan casing

Info

Publication number: CN2359508Y
Application number: CN 99235291
Authority: CN
Inventors: 游斌; 罗嘉陶
Original assignee: Shunwei Electric Appliance Co
Current assignee: Guangdong Sunwill Precising Plastic Co Ltd
Priority date: 1999-02-01
Filing date: 1999-02-01
Publication date: 2000-01-19
Anticipated expiration: 2009-02-01

Abstract

The utility model relates to a centrifugal fan spiral casing. The inner wall molded lines of the spiral casing (1) and a spiral tongue (2) are inclined outwards with respect to the rotation centre line of an impeller or the inner wall molded lines of the spiral casing (1) are parallel to the rotation centre line of the impeller and only the spiral tongue (2) is inclined outwards with respect to the rotation centre line of the impeller. An inclining angle range is 2 DEG-20 DEG. The utility model has the function of fan noise decrease under the condition of air quantity increase or no air quantity decrease.

Description

Centrifugal blower volute

The utility model relates to a kind of centrifugal blower volute.

The effect of centrifugal blower inner spiral casing is the gas that leaves impeller is concentrated, water conservancy diversion, and change the part kinetic energy diffusion of gas into static pressure, the spiral case inwall profile and the impeller shaft line parallel of tradition centrifugal blower, the impeller of rotation and the gap between the static spiral case do not change along the impeller axial direction, simultaneously on arbitrary fixing circumferential position, blade equates all that with the horizontal equivalent of spiral case inwall profile the radius of volute tongue does not in axial direction change.During the impeller rotation, because non-permanent interference and blade between impeller and the snail tongue have periodically just produced a kind of revolution noise by the minimum clearance of impeller and snail tongue, again owing to impeller and minimum clearance between the snail tongue equate on whole axial direction just to make that the noise stack of same frequency produces the resonance peak noise, cause rotational noise higher relatively, become a kind of main noise of multi-wing centrifugal fan.

The purpose of this utility model be to provide a kind of air quantity increase or undiminished situation under reduce the multi-wing centrifugal fan spiral case of fan noise.

The utility model is to realize like this, all the rotation centerline of impeller is outward-dipping relatively for the inwall molded lines of this centrifugal blower volute and snail tongue, the perhaps rotating center line parallel of the inwall molded lines of spiral case and impeller, only the snail tongue portion is outward-dipping, and range of tilt angles is 2 °～20 °.

Because centrifugal blower volute is outward-dipping along the axial rotary of impeller, it has axially changed the gap length between impeller and the snail tongue, alleviated the wake effect that produces owing to non-permanent interference effect between impeller blade and the spiral case housing, make the noise that produces between blade and the snail tongue that certain phase difference be arranged, the resonance noise of having avoided the stack of same frequency noise to be brought, thereby reduced the rotational noise of impeller.

The utility model is described in further detail below in conjunction with drawings and Examples.

Fig. 1 is the structural representation of known spiral case;

Fig. 2 is the structural representation of the utility model;

Fig. 3 is the plan view of the another kind of mode of execution of the utility model.

Embodiment 1: as shown in Figure 2, the inwall molded lines of spiral case (1) and snail tongue (2) are outward-dipping along the rotation centerline of impeller, and range of tilt angles is 2 °～20 °.

Embodiment 2: as shown in Figure 3, the inwall molded lines of spiral case (1) and the rotating center line parallel of impeller, only snail tongue (2) part of impeller is outward-dipping, and the plane of inclination angular range is 2 °～20 °, and the plane of inclination of snail tongue is three-dimensional sector.

Claims

1. centrifugal blower volute, it is characterized by: the inwall molded lines of spiral case (1) and snail tongue (2) are outward-dipping with respect to the rotation centerline of impeller.

2. centrifugal blower volute is characterized by: the inwall molded lines of spiral case (1) and the rotating center line parallel of impeller, snail tongue (2) part of spiral case (1) is outward-dipping with respect to the rotation centerline of impeller.

3. centrifugal blower volute according to claim 1 and 2 is characterized by: range of tilt angles is 2 °～20 °.