CN2695702Y - Silencer for axial fan - Google Patents

Abstract

The marine axial fan muffler is a wind muffler suitable for marine axial fans and small spaces. The muffler is composed of a sound-absorbing air cylinder (1) and a sound-absorbing cone (2); the sound-absorbing air cylinder is in the shape of a through-heart circular tube, and the large head of the cone in the sound-absorbing cone is located at one end of the air inlet outside the sound-absorbing cylinder , and leave a certain distance to form a circle of air inlet (3) between the wind of the sound-absorbing tube, the small head of the cone is located in the sound-absorbing tube, and the sound-absorbing tube and the sound-absorbing cone are located on the same axis. The sound-absorbing wind cylinder is made up of casing (11) and sound-absorbing material (12), and sound-absorbing material (12) is positioned at the inboard of casing (11), and the inwall of sound-absorbing cylinder is arc shape outside the air inlet. The sound-absorbing cone is made up of sound-absorbing material (21), bracing frame (22), and guard plate (23), and sound-absorbing material and bracing frame are arranged inside the guard plate, and the cone surface (24) is in the shape of a parabola. The muffler has the advantages of simple structure, small size, light weight, small resistance loss and good effect.

Description

Axial fan muffler

Technical field

The utility model relates to a muffler, in particular to a fan muffler suitable for an axial flow fan used in ships and in an environment with a small space.

Background technique

Shipbuilding companies use a large number of axial flow fans and other aerodynamic equipment in the production process. The operating noise of the axial flow fans is as high as 115dB(A), which seriously affects the hearing health and safety of the staff. In order to reduce noise pollution, improve work efficiency, and protect the health of workers, it is very necessary to equip axial flow fans with a muffler.

The muffler is a device that allows airflow to attenuate the noise energy in the airflow, and is installed in the pipeline through which the airflow passes or the inlet and exhaust pipes. According to the noise reduction mechanism, the mufflers are mainly divided into two types: resistive and resistive. However, for different equipment, resistive mufflers and resistive mufflers have many structural forms. The resistive muffler uses porous sound-absorbing material as the sound-absorbing body. When the airflow passes through the sound-absorbing body, the noise energy in the airflow is effectively absorbed, thereby reducing the noise at the air inlet and outlet. Generally, resistive mufflers are more suitable for medium and high-frequency airflow noise, and their noise reduction is generally around 10dB/m, which is related to the noise frequency in the airflow and the required resistance loss. The higher the frequency, the greater the noise reduction, and the allowable resistance loss The greater the noise reduction, the greater the amount. Resistive mufflers use the reflection, interference, and resonance of sound waves to consume noise energy. It does not require sound-absorbing materials, but its noise reduction is relatively small, and its resistance loss is large, and it is more suitable for low-frequency noise control.

Regardless of the type and structure of the muffler, its performance is mainly determined by the following aspects: first, the amount of noise reduction should be large; second, the resistance loss to the airflow should be small; third, the volume of the muffler should be large Small; fourth, the cost-effectiveness of use should be high; fifth, it is suitable for the use environment and use process.

Contents of Invention

Technical problem: The utility model muffler is designed for the characteristics of high noise in the operation of the marine axial flow fan, small cabin space, and frequent movement of the fan, and provides a marine axial flow muffler with simple structure, small size, light weight, small resistance loss and good effect. Fan muffler.

Technical solution: The muffler for the axial flow fan of the utility model is made of sound-absorbing material. The muffler is composed of a sound-absorbing air cylinder and a sound-absorbing cone; The big head of the middle cone is located at one end of the air inlet outside the sound-absorbing tube, and there is a certain distance between it and the wind of the sound-absorbing tube to form a circle of air inlet. The small head of the cone is located inside the sound-absorbing tube. The sound cones are on the same axis.

The sound-absorbing air cylinder is composed of a shell and a sound-absorbing material, the sound-absorbing material is located inside the shell, and the inner wall of the sound-absorbing cylinder outside the air inlet is arc-shaped. The sound-absorbing cone is composed of sound-absorbing material, support frame and protective panel. The sound-absorbing material and support frame are arranged inside the protective panel, and the cone surface is in the shape of a parabola.

Beneficial effects: compared with the usual resistive muffler, the utility model mainly has an improvement in the design structure, specifically as follows: 1. The air inlet channel of the muffler is designed in an arc shape, which can increase the muffler's noise reduction, and at the same time can Reduce resistance loss; 2. The conical surface of the sound-absorbing body of the muffler is in a parabolic shape, so that the thickness of the sound-absorbing body changes gradually, because for porous sound-absorbing materials, the product of the thickness of the sound-absorbing body and its first resonance frequency is one Constant, which expands the sound-absorbing frequency bandwidth of the muffler, thereby improving the sound-absorbing effect. The distance between the sound-absorbing cylinder and the sound-absorbing cone can be adjusted according to the specific noise reduction requirements and the limitation of resistance loss, so that the muffler is more practical.

The muffler for the axial flow fan of the utility model has a relatively simple structure and a sense of streamline; it is small in size, light in weight and less in consumables; the muffler has a wide range of muffler frequencies; and the muffler per unit length is 2-3 times that of a general resistive muffler.

Description of drawings

Fig. 1 is a structural schematic diagram of the muffler for an axial flow fan of the present invention. Wherein there are sound-absorbing air cylinder 1, sound-absorbing cone 2, air inlet 3, shell 11, sound-absorbing material 12, sound-absorbing material 21, support frame 22, protective panel 23, cone surface 24.

Fig. 2 is a sectional view along I-I direction in Fig. 1 .

Detailed ways

According to the actual use status of the axial flow fan in the production workshop of the shipbuilding enterprise, the length and width of the muffler must not exceed the length and width of the axial flow fan, that is, 600mm, so as to facilitate frequent movement and displacement; the designed noise reduction frequency should be suitable The main frequency band of the axial flow fan; the total noise reduction should reach 15 decibels.

The muffler for the axial flow fan of the present utility model is composed of the sound-absorbing air cylinder 1 and the sound-absorbing cone 2; One end of the outer air inlet, and a certain distance is left between the sound-absorbing tube wind 1 to form a circle of air inlet 3, the small head of the cone is located in the sound-absorbing tube 1, the sound-absorbing tube 1 and the sound-absorbing cone 2 on the same axis. The sound-absorbing air cylinder 1 is composed of a casing 11 and a sound-absorbing material 12, the sound-absorbing material 12 is located inside the casing 11, and the inner wall of the sound-absorbing cylinder 1 outside the air inlet 3 is arc-shaped. The sound-absorbing cone 2 is composed of a sound-absorbing material 21, a support frame 22, and a protective panel 23. The sound-absorbing material 21 and the support frame 22 are arranged inside the protective panel 23, and the conical surface 24 is in a parabolic shape.

The structure of the muffler is shown in Figure 1. It is mainly composed of a sound-absorbing air cylinder and a sound-absorbing cone, and an air inlet channel is formed between the two. The air inlet is located on the side, and the air outlet is connected with the axial flow fan.

When the original airflow enters the fan outlet, the fan noise is radiated back to the external environment. After adding this muffler, the airflow can still enter along the air inlet of the muffler, but the running noise of the fan is only transmitted to the external environment through the air inlet of the muffler. Since the air inlet duct is surrounded by sound-absorbing bodies, the sound energy is absorbed in a large amount in the air inlet duct, thereby reducing the noise at the air inlet of the fan.

The two are made respectively when the utility model muffler is made, and then the two are connected into a whole with a flat iron. According to the air supply volume of the axial fan and the selected air velocity, the cross-sectional area of the air inlet is determined, and the total length of the muffler is determined according to the requirements of the noise reduction.

The axial fan muffler designed in a certain shipyard is 500mm long and 600mm in diameter, and the muffler's noise reduction (transmission loss) is 17dB(A).

Claims (3)

1, a kind of axial-flow blower silencing apparatus is made up of the sound absorbing material structural member, it is characterized in that this silencing apparatus is made of sound absorption air duct (1) and sound absorption cone (2); Sound absorption air duct (1) is the pipe shape of a logical heart, the major part of circular cone is positioned at outer intake grill one end of sound absorption tube (1) in the sound absorption cone (2), and and sound absorption tube wind (1) between leave certain distance and form a circle intake grill (3), the microcephaly of this circular cone is positioned at sound absorption tube (1), and sound absorption air duct (1) and sound absorption cone (2) are positioned on same the axis.

2, axial-flow blower silencing apparatus according to claim 1, the air duct (1) that it is characterized in that absorbing sound is made up of shell (11) and sound-absorbing material (12), sound-absorbing material (12) is positioned at the inboard of shell (11), and the inwall of sound absorption tube (1) is a camber line shape outside intake grill (3).

3, axial-flow blower silencing apparatus according to claim 1, the cone (2) that it is characterized in that absorbing sound is made up of sound-absorbing material (21), supporting frame (22), protection slab (23), be provided with sound-absorbing material (21) and supporting frame (22) in the inside of protection slab (23), the conical surface (24) is parabolic shape.

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