CN2059192U

CN2059192U - Low noise axial-flow blower

Info

Publication number: CN2059192U
Application number: CN 89219249
Authority: CN
Inventors: 任世瑶
Original assignee: Shanghai Jiao Tong University
Current assignee: Shanghai Jiao Tong University
Priority date: 1989-12-09
Filing date: 1989-12-09
Publication date: 1990-07-11

Abstract

The utility model discloses a low noise axial-flow blower which belongs to a ventilator in the field of fluid machinery pneumatic acoustics. The blades of present general axial-flow blower adopt a single circular-arc blade type designed by equal circulation negative index, and the present general axial-flow blower has the defects of multiple blade number, high specific pressure level, and high noise. The fan blade of the utility model adopts a non-single-circular-arc blade type designed by variable circulation negative index, and the utility model has the advantages of less blades and low noise. The blade profile is additionally provided with a plurality of circular arc-shaped convex and concave ribs, so the fundamental frequency and the sound power level of second harmonic are reduced. The low noise axial-flow blower is especially suitable for reforming traditional blowers to achieve the effects of noise reducing and energy saving. As for pipeline blowers, the casing can be made into two half pieces for convenient maintenance.

Description

Low noise axial-flow blower

Low noise axial fan belongs to ventilation equipment in the fluid machinery aeroacoustics field.

The general axis flow fan all is outer narrow interior wide blade profile both at home and abroad at present, and the number of blade is more relatively, than sound pressure level height, though or drive with higher rotation speed, as external T35-11,30K4-11, West Germany sieve cuts down blower fan, U.S. BAC, all there are poor efficiency, the high disadvantage of making an uproar in COLTD blower fan, the former making atmosphere of news service of Japanese Chi machine, and domestic silent ventilator is low because of rotating speed, blast is low, and application surface is narrow.It is big that old blower fan is all changed required expense.

Make an uproar in order to overcome existing blower fan poor efficiency, height, the shortcoming of big energy-consuming, and the old blower fan of traditional design carried out the noise reduction reducing energy consumption, the utility model blower fan adopts change circular rector negative exponent to design non-single circular arc profile, and the blade FC vane type line that is wide outside and narrow inside is non-single circular arc.On blade, be provided with the concavo-convex muscle of several circular arcs, can improve blade stiffness, reduce vane thickness, in order to saving aluminium.In order to reduce the tail eddy current, improve fan efficiency, in blade inner edge outlet port, blade one angle air-flow is crooked in the other direction.This blower fan adopts few number of blade, can replace original 4 blade blower fans with 2 blades, can replace former six blade blower fans with three blades, and original blower fan is undergone technological transformation, and only need the transposing blade, and the motor of former blower fan and shell can utilize all.

Needs are installed in pipeline fan in the pipeline, and for overhauling conveniently, this model utility blower fan can be made flow blower casing 2 half slit bamboo or chopped woods, and an end connects with hinge, and the other end connects with screw.Electric machine support is contained in rotatable half slit bamboo or chopped wood.

Fig. 1 is the low noise axial fan structural representation that shell can be made into two slit bamboo or chopped woods;

Fig. 2 is a low noise axial fan blade front view;

Fig. 3 is a low noise axial fan leaf type line chart.

1 is blade among the figure; The 2nd, electric machine support; The 3rd, shell; The 4th, hinge; The 5th, screw; The 6th, concavo-convex muscle; The 7th, the blade outer rim; The 8th, the blade inner edge; The 9th, blade inlet edge; The 10th, trailing edge; The 11st, the blade chord length; The 12nd, the maximum sagitta of blade.

The concrete enforcement of this model utility blower fan is, blower fan adopts and becomes the circular rector negative exponent and design non-single circular arc blade profile, and it is wide outside and narrow inside that blade is, and blade 1 outer rim 7 is wide, and inner edge 8 is narrow, and the maximum sagitta 12 of blade 1 molded lines is from blade inlet edge 9 30～45% chord length 11 places.On blade 1 profile, set up the concavo-convex muscle 6 of several circular arcs, at the B of blade inner edge 8 ₃C ₂B ₂It is once molding formed that (promptly crooked to air-flow) blade 1 usefulness alloy aluminium sheet is made and is bent downwardly at the place in the other direction.Blower fan adopts few number of blade, replaces the old blower fan of original 4 blades with two blades 1, replaces original six blade blower fans with three blades 1, and old blower fan is undergone technological transformation, and only need the transposing blade, and the shell of former blower fan and motor can utilize all.Flow blower casing 3 can be made 2 half slit bamboo or chopped woods to the pipeline fan that is installed in the pipeline for maintenance is convenient, an end connects with hinge 4, and an end connects with screw 5, and electric machine support 2 is contained in rotatable half slit bamboo or chopped wood, only need take screw 5 during machine maintenance apart, then around hinge 4 rotations.

This utility model blower fan, because fan blade adopts change circular rector negative exponent to design non-single circular arc blade profile, compare with the blower fan blade profile of traditional design, the pressure coefficient height, it is little to reverse loss, and noise is low, the efficient height, and set up the concavo-convex muscle of several circular arc types on the blade profile, can use thinner aluminium alloy plate and do not reduce blade stiffness, greatly saved aluminum alloy materials. Blade inner edge B₃C ₂B ₂Make and be bent downwardly at the place, can reduce the tail eddy current, improves fan efficiency. Blower fan adopts few number of blade can reduce the acoustic power level of fundamental frequency and second harmonic, and noise significantly reduces. This utility model is specially adapted to the noise-reduction energy-saving transformation of the old blower fan of traditional design, only need the transposing blade, and the motor of former blower fan and shell can utilize all, have small investment, the characteristics that economic benefit is high. For pipeline fan, shell is made 2 half slit bamboo or chopped woods, is beneficial to maintenance.

Claims

1. An axial flow fan composed of a motor, a casing and blades, characterized in that the fan blade 1 adopts a non-single-arc blade shape designed with a negative index of variable circulation, and the maximum arch height of blade 1 is 12 in front of the blade. Edge 930～45% chord length 11 places, several arc-shaped concave-convex ribs 6 are added on the surface of blade 1, and B ₃ C ₂ B ₂ on the inner edge 8 of the blade are made to bend in the opposite direction of air flow, and the fan casing is made of 3 Become two half valves, one end is connected with hinge 4, and one end is connected with screw 5, and motor support 2 is contained in the rotatable half valves.

2. The axial flow fan according to claim 1, characterized in that the blade 1 is formed by one-time compression molding of an alloy aluminum plate.

3. The axial flow fan according to claim 1, characterized in that the number of fan blades 1 is 2 or 3.