CN2195384Y - Ultralow noise cooling tower axial-flow fan - Google Patents

Abstract

The utility model relates to an ultra-low noise cooling tower axial flow fan, which belongs to a ventilating device of a cooling tower in the field of a fluid machine, and is composed of four forwardly inclined blades 1 with wide outer part and narrow inner part. The four blades 1 are distributed with unequal space, the included angles between the blades 1 are between 79DEG and 101DEG, a blade wheel is directly connected and driven by a multiple stage motor with low rotation speed, and an air intake of the fan adopts a streamline type. The ultra-low noise cooling tower can omit to be provided with a silencing sound insulating device and other additional facilities with adopting the utility model, so the fan maintenance is convenient, the flow resistance is reduced, and the sound pressure level can be reduced by 5 dB (A) compared with a low noise fan. Therefore, the utility model has the advantages that the energy is saved by 20%, and the material is saved by 20%.

Description

Ultralow noise cooling tower axial-flow fan

Ultra-low noise cooling tower axial flow blower is that the cooling tower that belongs in the field of fluid machinery ventilates fully.

In prior art, the main method of administering cooling tower buzz is to adopt additional noise elimination sound arrester, ultra-low noise cooling tower as Guangzhou Chinese-foreign joint venture adopts is equipped with silencer at top of tower, and air inlet has acoustic screen, owing to adopt acoustic screen and silencer, cost is increased, blower fan maintenance difficulty, the drag overall of tower increases, air quantity reduces, and air quantity is not reduced must increase power of motor.And can cause the increase of noise again.

Outside the deficiency that overcomes cooling tower noise reduction in the prior art, the purpose of the present utility model be under the prerequisite that does not add noise elimination, sound arrester the design a kind of noise ratio silent ventilator reduce 5DB(A again) the ultra-low noise cooling tower blower fan.

The content of the utility model blower fan of cooling tower invention is that draught fan impeller is made up of 4 FC blades wide outside and narrow inside, be unequal-interval between 4 blades and arrange that it is streamlined that air inlet is, fan static pressure is low, the pressure coefficient height, available slowspeed machine drives or belt drives.

Fig. 1 is the fan impeller blade layout drawing

1 is blade among the figure, the 2nd, and blade outer rim, the 3rd, blade inner edge, the 4th, blade center of gravity, the 5th, blade centreline, the 6th, impeller diameter.

The concrete enforcement of the utility model blower fan is that draught fan impeller is made up of 4 FC blades 1 wide outside and narrow inside, and 41 in blades are unequal-interval and arrange.Blade 1 is proclined, and blade centreline 5 does not overlap with impeller diameter line 6, has only blade center of gravity 4 on impeller diameter line 6, and impeller radius is greater than blade center of gravity 4, and blade 1 tilts to the impeller direction of rotation.Blade outer rim 2 is wide, and blade inner edge 3 is narrow, the blade profile of this moulding uniqueness, blade outer rim 2 places are had higherly boost, blade inner edge 3 places boost lowlyer so that might obtain to boost more greatly under same peripheral speed condition, and blade 1 load is less relatively, lower than sound pressure level, the peripheral speed loss is less relatively.

1 in four blades of draught fan impeller are unequal-interval and arrange, the angle that blade is 1 is not 90 ° but 79 ° and 101 °, this unequal-interval blade arrangement can reduce the humorous intensity of wave of maximum noise, eliminated because the caused regular intensity of pressure of equidistant blade is disturbed, make compression shock little, suppressed rotational noise, it is lower than sound pressure level value that blower fan is had.

Air inlet adopts streamlined (1/4 ellipse) that air-flow can be quickened gradually along wall, enters impeller equably, reduces the eddy current of air-flow at the air inlet place, can reduce the eddy current crack 1.5～2.0dB(A) at air inlet place.

To the blower fan of impeller diameter greater than 2 meters, do not adopt gearbox drive and belt pulley transmission, but adopt multipole several Low speed electric motor direct connection to drive, as 200 tons/time cooling tower adopt 24 utmost point motor direct connections to drive, eliminated the noise and the flimsy disadvantage of belt pulley of gear-box.

Adopt the utility model axial flow fan in cooling tower, can make ultra-low noise cooling tower remove the additional facilities such as installing noise elimination sound arrester from, make maintenance of fan make things convenient for flow resistance to reduce, reduce again 5dB(A than the comparable silent ventilator of sound pressure level), have energy-conservation 20%, material-saving 20%, noise reduction 5dB(A) characteristics.

Claims (3)

1, a kind of ultra-low noise cooling tower axial flow blower of forming by impeller and motor, it is characterized in that draught fan impeller is made up of 4 FC blades 1 wide outside and narrow inside, being unequal-interval between 4 blades arranges, blade centreline 5 does not overlap with impeller diameter line 6, has only blade 1 center of gravity 4 on impeller diameter line 6, impeller radius is greater than blade center of gravity 4 places, blade 1 tilts to the impeller direction of rotation, blade outer rim 2 is wide, blade inner edge 3 is narrow, 1 in 4 blades forming impeller are unequal-interval and arrange that 1 angle of blade is not 90 °, but 79 ° and 101 °.

2,, it is characterized in that blower fan adopts multipole several Low speed electric motor direct connection to drive by the described ultra-low noise cooling tower axial flow blower of claim 1.

3,, it is characterized in that air inlet adopts streamlined (4/1 ellipse) by claim 1 or 2 described ultra-low noise cooling tower axial flow blowers.

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