CN204664000U - A kind of twayblade denoising draught fan - Google Patents

Abstract

The utility model discloses: a kind of twayblade denoising draught fan, comprise spiral case and the first impeller, snail tongue is provided with between spiral case and air outlet, hush pipe is connected with at air outlet end, hush pipe 1/2nd inwall near snail tongue side is provided with the first noise reduction part, remaining 1/2nd inwalls of hush pipe are fixed with the second noise reduction part, the peak of the first noise reduction part is A apart from the distance of hush pipe inwall, the peak of the second noise reduction part is B apart from the distance of hush pipe inwall, and meets A > B; Also comprise baffle circle, the first impeller has earial drainage gap, and the just lower end to baffle circle, described earial drainage gap. In the utility model, the first noise reduction part can be eliminated the Rotation Noise of the high-decibel that the air-flow of speed and the effect of snail tongue produce, the second noise reduction part can be eliminated the Rotation Noise of low decibel, by the differentiating and processing of the airflow layer to friction speed in spiral case, ensure that the air-flow at air outlet place is quiet and export stably.

Description

A kind of twayblade denoising draught fan

Technical field

The utility model relates to ventilation equipment, specifically refers to a kind of twayblade denoising draught fan.

Background technology

Centrifugal fan is primarily of the first impeller, casing, shaft coupling, axle. The first impeller is the main acting parts that produce blast and transferring energy; Casing is mainly used to introduce gas and Exhaust Gas, the part kinetic energy of gas is become to pressure energy simultaneously; Shaft coupling is used for connecting motor and blower fan, carry-over moment; The first impeller is installed and fixed to axle, by shaft coupling and motor.

Gas between centrifugal fan blade is when the first vane rotary, be subject to centrifugal action acquisition kinetic energy (dynamic head) to discharge from the first impeller periphery, through the guiding of scroll casing shape casing, make it to ventilation blower output flow, thus form negative pressure at the first impeller central position, outer gas stream is flowed into continually supplementary, thus make blower fan energy Exhaust Gas. Motor is passed to blower fan first impeller by axle power, the first vane rotary is given air energy transferring, under the effect of rotation, air produces centrifugal force, the blade that air prolongs blower fan first impeller spreads towards periphery, now, blower fan first impeller is larger, and the energy that air accepts is larger, and namely the pressure head of blower fan (blast) is larger. If the first large impeller is cut little, air quantity can not be affected, only blast can be reduced.

Produce strong noise but also can be accompanied by ventilating, bring serious noise pollution to environment. The noise that blower fan produces in the running mainly comprises the Gas-solid Coupling noise that aerodynamic noise, mechanical noise and gas and Elastic Solid System interaction produce. Wherein, aerodynamic noise accounts for 45%, and mechanical noise accounts for 30%, and Gas-solid Coupling noise accounts for 25%. Aerodynamic noise mainly comprises rotational noise and vortical noise, air power noise in ventilation blower is exactly the result that both superpose mutually, when blower fan rotates, rotate the blade path exit on the first impeller, stream pressure and air velocity vertically all vary widely, when the gap of snail tongue and blade exit edge part is less, when the blade path of rotation skims over snail tongue place, just there will be periodic pressure and velocity fluctuation, the noise that pulsation produces is called as rotational noise. Rotational noise is contaminated environment not only, and the stability of first impeller work can be affected, and therefore how to solve rotational noise very important.

Utility model content

The purpose of this utility model is to provide a kind of twayblade denoising draught fan, the Rotation Noise producing when reducing blower fan running, and then reaches protection of the environment and improve the object of blower fan job stability.

The purpose of this utility model is achieved through the following technical solutions:

A kind of twayblade denoising draught fan, the first impeller that comprises spiral case and be fixed in spiral case, the second impeller, the both sides of described spiral case offer respectively the air inlet of horizontal direction and the air outlet of vertical direction, described the first impeller and the second impeller are crisscross arranged, snail tongue is provided with between described spiral case and air outlet, the tip of the tongue of described snail tongue is to the lopsidedness near the first impeller, hush pipe is connected with in described air outlet end thread, hush pipe 1/2nd inwall near described snail tongue side is provided with the first noise reduction part, remaining 1/2nd inwalls of hush pipe are fixed with the second noise reduction part, the longitudinal section of described the first noise reduction part and the second noise reduction part is circular arc, and the peak of the first noise reduction part is A apart from the distance of hush pipe inwall, the peak of the second noise reduction part is B apart from the distance of hush pipe inwall, and meet A > B. during blower fan work, the air speed-raising that air inlet is poured into by the first wheel rotation, it is discharged by air outlet place fast, in the operation process of the first impeller, the particularly blade path exit on rotation the first impeller, stream pressure and air velocity vertically all vary widely, when the gap of snail tongue and blade exit edge part is less, when the blade path of rotation skims over snail tongue place, just there will be periodic pressure and velocity fluctuation, pulsation can produce rotational noise, and rotational noise can be discharged along the runner in spiral case from air outlet with air-flow, severe contamination the environment around blower fan,

During utility model works, the air that pour into by the first impeller outside moves to the air outlet of blower fan fast, and the rotational noise that the snail of gas shock simultaneously tongue produces also is discharged by air outlet thereupon, the Rotation Noise that the hush pipe that is threaded with air outlet can subtend transmits outward is processed, in spiral case near the air-flow speed of service at the first vane edge place for the air-flow at spiral case inwall place, its speed obviously increases, therefore the first noise reduction part on 1/2nd inwalls of hush pipe, is fixed with, remaining 1/2nd inwalls of hush pipe are fixed with the second noise reduction part, the longitudinal section of the first noise reduction part and the second noise reduction part is circular arc, and the peak of the first noise reduction part is greater than the peak of the second noise reduction part apart from the distance B of hush pipe inwall apart from the distance A of hush pipe inwall, comparatively speaking, the first noise reduction part that thickness is larger can be eliminated the Rotation Noise of the high-decibel that the air-flow of speed and the effect of snail tongue produce, and less the second noise reduction part of thickness can be eliminated the Rotation Noise of the low decibel that slow air-flow and the effect of snail tongue produce, by the differentiating and processing of the airflow layer to friction speed in spiral case, to avoid the Rotation Noise contaminated environment entrained by air outlet place air-flow, improve the efficiency of noise reduction processing simultaneously, ensure that the air-flow at air outlet place is quiet to export stably,

Wherein, the utility model is provided with two coaxial impellers, and the first impeller and the second impeller are staggered fixing, namely the blade of the first impeller is between two blades of the second impeller, the first impeller and the second vane rotary generation air-flow in spiral case are different phases along the pressure that snail tongue produces, at snail tongue place, partial cancellation can be carried out, and then reach the object that reduces noise; In common blower fan, the edge of snail tongue is normally parallel with axis, but the tip of the tongue of snail tongue is obliquely installed by the utility model, and then makes to act on the air pulse phase shifting on snail tongue, then reduce the impulsive force on snail tongue, also reach the object that reduces blower fan rotational noise simultaneously.

Further, described the first noise reduction part and the second noise reduction part are sponge, tapetum fibrosum or aluminium silicate wool. As preferably, the material that the first noise reduction part and the second noise reduction part all adopt erasure effect good, i.e. sponge, tapetum fibrosum or aluminium silicate wool, by the absorption processing to Rotation Noise at air outlet place, and then reaches that the air-flow at fan outlet place is quiet to be exported stably.

Further, the angle that the described snail tongue the tip of the tongue tilts is 15 ° ~ 35 °. The angle of inclination of the snail tongue the tip of the tongue is arranged within the scope of 15 ° ~ 35 °, the air-flow that rotation on the first impeller and the second impeller is flowed out can be applied on snail tongue simultaneously, and then the air pulse phase shifting that makes to act on snail tongue, then reduce the impulsive force on snail tongue, also reach the object that reduces blower fan rotational noise simultaneously.

Further, described snail tongue is short tongue, and snail tongue is s apart from the distance of the first impeller peak, and the excircle of the first impeller is S apart from the distance of spiral case top inwall, and meets 0 < s < S. snail tongue refers to that the junction of centrifugal ventilator volute and gas outlet often has one to be formed by shell wall, shape " ligule " structure as tongue, its effect is at spiral case internal circulation flow for placement part gas, near the gas flow sweep snail tongue in the first impeller passage exit time, the tip of the tongue of snail tongue breaks it into two: most of air-flow has flowed to the outlet of blower fan along passage, small part air-flow is then flowed back to spiral case by the gap between snail tongue, the first impeller, returns to snail tongue place participate in new shunting in spiral case with the first vane rotary after reaching one week. wherein, snail tongue comprises flat tongue, short tongue, dark tongue and sharp tongue, namely the corner dimension by forming between the shell wall of spiral case body and the shell wall of air outlet judges, and angle is within the scope of 0 ~ 180 °, snail tongue is set to short tongue by the utility model, because its efficiency curve is comparatively smooth, economic work region is wider, is therefore applicable to the blower fan carrier that stability exports, and snail tongue is s apart from the distance of the first impeller peak, the excircle of the first impeller is S apart from the distance of spiral case top inwall, meet 0 < s < S simultaneously, namely a ventilation gap between snail tongue and the first impeller, is formed, ventilation gap width is s, in the first region, impeller passage exit, air-flow can produce stronger pressure fluctuation in ventilation gap, form also the first impeller blade by effective acoustic radiation of frequency and its harmonic wave, when this ventilation gap increases, air stream axle to VELOCITY DISTRIBUTION comparatively level and smooth, therefore the amplitude of the pressure fluctuation at snail tongue place also can reduce, namely Rotation Noise is reduce, this ventilation gap can not be excessive simultaneously, and after ventilation gap increases to a certain degree, noise no longer declines, and excessive ventilation gap can make the aeroperformance of blower fan reduce on the contrary, therefore the scope of s is determined within the scope of 0 ~ S.

The utility model compared with prior art, has following advantage and beneficial effect:

1, the first noise reduction part that in the utility model, thickness is larger can be eliminated the Rotation Noise of the high-decibel that the air-flow of speed and the effect of snail tongue produce, and less the second noise reduction part of thickness can be eliminated the Rotation Noise of the low decibel that slow air-flow and the effect of snail tongue produce, by the differentiating and processing of the airflow layer to friction speed in spiral case, to avoid the Rotation Noise contaminated environment entrained by air outlet place air-flow, improve the efficiency of noise reduction processing simultaneously, ensure that the air-flow at air outlet place is quiet and export stably;

2, the utility model first noise reduction part and the second noise reduction part material that all adopts erasure effect good, i.e. sponge, tapetum fibrosum or aluminium silicate wool, by the absorption processing to Rotation Noise at air outlet place, and then reach that the air-flow at fan outlet place is quiet to be exported stably;

3, the utility model is in the first region, impeller passage exit, air-flow can produce stronger pressure fluctuation in ventilation gap, the first impeller blade is by effective acoustic radiation of frequency and its harmonic wave, when this ventilation gap increases, air stream axle to VELOCITY DISTRIBUTION comparatively level and smooth, therefore the amplitude of the pressure fluctuation at snail tongue place also can reduce, and namely reduces Rotation Noise; .

Accompanying drawing explanation

Accompanying drawing described herein is used to provide the further understanding to the utility model embodiment, forms the application's a part, does not form the restriction to the utility model embodiment. In the accompanying drawings:

Fig. 1 is the structural representation of a kind of twayblade denoising draught fan described in the utility model specific embodiment;

Fig. 2 is the sectional view of a kind of twayblade denoising draught fan described in the utility model specific embodiment;

Fig. 3 is the structural representation of a silencing pot specific embodiment in a kind of twayblade denoising draught fan described in the utility model.

Mark and corresponding parts title in accompanying drawing: 1, spiral case, 2, air inlet, 3, air outlet, 4, the first impeller, 5, snail tongue, 6, hush pipe, 7, the first noise reduction part, 8, the second noise reduction part, 9, baffle circle, 10, earial drainage gap.

Detailed description of the invention

For making the purpose of this utility model, technical scheme and advantage clearly understand, below in conjunction with embodiment and accompanying drawing, the utility model is described in further detail, exemplary embodiment of the present utility model and explanation thereof are only for explaining the utility model, and negative actions is to restriction of the present utility model.

Embodiment 1

As shown in Figure 1 to Figure 3, the first impeller 4 that the present embodiment comprises spiral case 1 and is fixed in spiral case 1, the both sides of described spiral case 1 offer respectively the air inlet 2 of horizontal direction and the air outlet 3 of vertical direction, snail tongue 5 is provided with between described spiral case 1 and air outlet 3, hush pipe 6 is connected with in described air outlet 3 end thread, hush pipe 1/6th two inwall near described snail tongue 5 side is provided with the first noise reduction part 7, remaining 1/2nd inwalls of hush pipe 6 are fixed with the second noise reduction part 8, the longitudinal section of described the first noise reduction part 7 and the second noise reduction part 8 is circular arc, and the peak of the first noise reduction part 7 is A apart from the distance of hush pipe 6 inwall, the peak of the second noise reduction part 8 is B apart from the distance of hush pipe 6 inwall, and meet A > B, also comprise the baffle circle 9 being fixed on the first impeller 4, the first impeller 4 has earial drainage gap 10, and the just lower end to baffle circle 9, described earial drainage gap 10.

During utility model works, the air that pour into by the first impeller 4 outside moves to the air outlet 3 of blower fan fast, and the rotational noise that the snail of gas shock simultaneously tongue 5 produces also is discharged by air outlet 3 thereupon, the Rotation Noise that the hush pipe 6 that is threaded with air outlet 3 can subtend transmits outward is processed, in the interior air-flow speed of service near the first impeller 4 edge of spiral case 1 for the air-flow at spiral case 1 inwall place, its speed obviously increases, therefore the first noise reduction part 7 on 1/2nd inwalls of hush pipe 6, is fixed with, remaining 1/2nd inwalls of hush pipe 6 are fixed with the second noise reduction part 8, the longitudinal section of the first noise reduction part 7 and the second noise reduction part 8 is circular arc, and the peak of the first noise reduction part 7 is greater than the peak of the second noise reduction part 8 apart from the distance B of hush pipe 6 inwall apart from the distance A of hush pipe 6 inwall, comparatively speaking, the first noise reduction part 7 that thickness is larger can be eliminated the Rotation Noise of the high-decibel that the air-flow of speed and snail tongue 5 effect produce, and less the second noise reduction part 8 of thickness can be eliminated the Rotation Noise of the low decibel that slow air-flow and snail tongue 5 effect produce, by the differentiating and processing of the airflow layer to the interior friction speed of spiral case 1, to avoid the Rotation Noise contaminated environment entrained by air outlet 3 place's air-flow, improve the efficiency of noise reduction processing simultaneously, ensure that the air-flow at air outlet 3 place is quiet to export stably,

Wherein, the utility model is provided with two coaxial impellers, and the first impeller 4 and the second impeller 9 are staggered fixing, namely the blade of the first impeller 4 is between two blades of the second impeller 9, it is different phases that the first impeller 4 in spiral case 1 and the second impeller revolve 9 pressure that angry stream produces along snail tongue 5 of changing the line of production, at snail tongue 5 place, partial cancellation can be carried out, and then reach the object that reduces noise; In common blower fan, the edge of snail tongue 5 is normally parallel with axis, but the tip of the tongue of snail tongue 5 is obliquely installed by the utility model, and then makes to act on the air pulse phase shifting on snail tongue 5, then reduce the impulsive force on snail tongue 5, also reach the object that reduces blower fan rotational noise simultaneously.

As preferably, the angle that described snail tongue 5 the tip of the tongue tilts is 15 ° ~ 35 °. The angle of inclination of snail tongue 5 the tip of the tongue is arranged within the scope of 15 ° ~ 35 °, the air-flow that rotation on the first impeller 4 and the second impeller 9 is flowed out can be applied on snail tongue 5 simultaneously, and then the air pulse phase shifting that makes to act on snail tongue 5, then reduce the impulsive force on snail tongue 5, also reach the object that reduces blower fan rotational noise simultaneously.

As preferably, the material that the first noise reduction part 7 and the second noise reduction part 8 all adopt erasure effect good, i.e. sponge, tapetum fibrosum or aluminium silicate wool, by the absorption processing to Rotation Noise at air outlet 3 place, and then reaches that the air-flow at fan outlet 3 place is quiet to be exported stably.

Snail tongue 5 is set to short tongue by the utility model, and because its efficiency curve is comparatively smooth, economic work region is wider, is therefore applicable to the blower fan carrier that stability exports, and snail tongue 5 is s apart from the distance of the first impeller 4 peak, the excircle of the first impeller 4 is S apart from the distance of spiral case 1 top inwall, meet 0 < s < S simultaneously, namely between snail tongue 5 and the first impeller 4, a ventilation gap is formed, ventilation gap width is s, in the first impeller 4 channel exit region, air-flow can produce stronger pressure fluctuation in ventilation gap, form also effective acoustic radiation of the first impeller 4 blade passing frequency and its harmonic wave, when this ventilation gap increases, air stream axle to VELOCITY DISTRIBUTION comparatively level and smooth, therefore the amplitude of the pressure fluctuation at snail tongue 5 place also can reduce, namely Rotation Noise is reduce, this ventilation gap can not be excessive simultaneously, and after ventilation gap increases to a certain degree, noise no longer declines, and excessive ventilation gap can make the aeroperformance of blower fan reduce on the contrary, therefore the scope of s is determined within the scope of 0 ~ S.

Above-described detailed description of the invention; the purpose of this utility model, technical scheme and beneficial effect are further described; institute is understood that; the foregoing is only detailed description of the invention of the present utility model; and be not used in limit protection domain of the present utility model; all within spirit of the present utility model and principle, any amendment of making, be equal to replacement, improvement etc., within protection domain of the present utility model all should be included in.

Claims (4)

1. a twayblade denoising draught fan, comprise spiral case (1) and be fixed on the first impeller (4) coaxial in spiral case (1), the second impeller (9), the both sides of described spiral case (1) offer respectively the air inlet (2) of horizontal direction and the air outlet (3) of vertical direction, it is characterized in that: described the first impeller (4) is crisscross arranged with the second impeller (9), snail tongue (5) is provided with between described spiral case (1) and air outlet (3), the tip of the tongue of described snail tongue (5) is to the lopsidedness near the first impeller (4), hush pipe (6) is connected with in described air outlet (3) end thread, hush pipe (6) 1/2nd inwall near described snail tongue (5) side is being provided with the first noise reduction part (7), remaining 1/2nd inwalls of hush pipe (6) are fixed with the second noise reduction part (8), described the first noise reduction part (7) is circular arc with the longitudinal section of the second noise reduction part (8), and the peak of the first noise reduction part (7) is A apart from the distance of hush pipe (6) inwall, the peak of the second noise reduction part (8) is B apart from the distance of hush pipe (6) inwall, and meet A > B.

2. a kind of twayblade denoising draught fan according to claim 1, is characterized in that: described the first noise reduction part (7) is sponge, tapetum fibrosum or aluminium silicate wool with the second noise reduction part (8).

3. a kind of twayblade denoising draught fan according to claim 1, is characterized in that: the angle that described snail tongue (5) the tip of the tongue tilts is 15 ° ~ 35 °.

4. a kind of twayblade denoising draught fan according to claim 1 ~ 3 any one, it is characterized in that: described snail tongue (5) is short tongue, and snail tongue (5) is s apart from the distance of the first impeller (4) peak, the excircle of the first impeller (4) is S apart from the distance of spiral case (1) top inwall, and meets 0 < s < S.