Fan system and silencer thereof

Abstract

The utility model provides a fan system and a silencer thereof. The silencing device comprises a box body, a sinking pressure cavity and a streaming cavity which are communicated with each other are formed in the box body, the sinking pressure cavity is used for being communicated with an exhaust outlet of a fan to be silenced, a silencing material layer is arranged on the inner side wall of the sinking pressure cavity, a streaming plate is arranged in the streaming cavity, one end of the streaming cavity is communicated with the sinking pressure cavity, and the other end of the streaming cavity is communicated with the silencing material layer. And the other end is communicated with the outside and serves as an air outlet of the silenced air. The silencing device provided by the embodiment of the utility model is simple and durable in structure, can adapt to severe use conditions, is large in ventilation quantity, is small in resistance to a main fan, is low in manufacturing cost, and can be widely applied to noise reduction of an air outlet of a centrifugal fan in a dust removal system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sound attenuation equipment, in particular to a fan system and a sound attenuation device thereof. BACKGROUND

[0002] At present, bag type dust collectors have been widely used in various industries, but the fan pressure head and air volume of the dust collector are large, and the fan noise is getting louder and louder, especially when the fan is overloaded, which can easily produce extremely strong noise and cause harm to the physical and mental health of production workers. As the most important measure for noise control, silencers are also widely used, and various standardized series of silencer products are more widely used. However, there is no mature and inexpensive product for the design and application of large air volume large silencers, especially for dustproof and other special types of silencers. In addition to the obvious noise reduction effect, the silencer also needs to have small resistance to the main fan and can run well in harsh conditions such as high dust and high temperature. Such a sound attenuation device plays an important role in improving the environment and protecting the physical and mental health of workers. CONTENT OF THE INVENTION

[0003] The first aspect of the embodiment of the present application provides a sound attenuation device of a fan, which comprises a box body, a communication sink pressure cavity and a flow around cavity are formed in the box body, the sink pressure cavity is used for communicating with the exhaust port of the fan to be attenuated, the inner side wall of the sink pressure cavity is provided with a sound attenuation material layer, the inside of the flow around cavity is provided with a flow around plate, one end of the flow around cavity communicates with the sink pressure cavity, and the other end communicates with the outside and serves as an air outlet of the sound-attenuated gas.

[0004] In some optional embodiments, the flow around plate is a plurality of plates, and the plurality of plates are arranged in the airflow direction and are spaced apart in a direction perpendicular to the airflow direction.

[0005] In some optional embodiments, the flow around plate comprises a support and a sound attenuation material layer arranged on the surface of the support.

[0006] In some optional embodiments, the support of the flow around plate is a metal mesh.

[0007] In some optional embodiments, the flow around plate comprises a first support, a second support, and a sound attenuation material layer clamped between the first support and the second support.

[0008] In some optional embodiments, the edge of the support is fixedly connected with the inner side wall of the box body through a connecting piece.

[0009] In some optional embodiments, the sound attenuation material layer is sound-absorbing cotton.

[0010] In some optional embodiments, the material of the sound-absorbing cotton is polyester fiber.

[0011] In a second aspect, the embodiments of the present application provide a fan system, which comprises a fan and the sound attenuation device as described above. The exhaust port of the fan is connected to the sink cavity of the sound attenuation device through a pipeline.

[0012] In some optional embodiments, the airflow direction of the airflow in the pipeline into the sink cavity is perpendicular to the extension direction of the sink cavity.

[0013] The sound attenuation device provided by the embodiments of the present application has simple and durable structure, can adapt to harsh use conditions, has large ventilation volume, has small resistance to the main fan, has low manufacturing cost, and can be widely applied to the noise reduction of the centrifugal fan exhaust port in the dust removal system. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0015] Figure 1 is a schematic diagram of the overall structure of an embodiment of the fan system of the present application;

[0016] Figure 2 is Figure 1 is a schematic diagram of the structure of the sound attenuation device in the embodiment;

[0017] Figure 3 is a schematic diagram of the structure of a single flow guide plate and a box;

[0018] Figure 4 is Figure 3 is an enlarged schematic diagram of the local structure at A in the embodiment;

[0019] Figure 5 is a schematic diagram of an embodiment of the flow guide plate of the present application;

[0020] Figure 6 is a schematic diagram of another embodiment of the flow guide plate of the present application. DETAILED DESCRIPTION

[0021] The present application will be described in further detail below with reference to the drawings and embodiments. It is particularly pointed out that the following embodiments are only used to illustrate the present application, but do not limit the scope of the present application. Similarly, the following embodiments are only some embodiments of the present application, not all embodiments of the present application, and all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0022] The terms "first", "second", "third", etc. in the embodiments of the present application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly. The terms "include" and "have" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or components inherent to the process, method, product or device.

[0023] In this document, the term "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it independent or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] The embodiments of the present application provide a fan system, please refer to Figure 1 , Figure 1 is a schematic diagram of the overall structure of an embodiment of the fan system of the present application, which includes but is not limited to a fan 100 and a silencer 200, wherein the exhaust port 110 of the fan 100 is communicated with the silencer 200 through a pipeline 300.

[0025] Specifically, please refer to Figure 2 , Figure 2 is Figure 1 the structure of the silencer in the embodiment, wherein the silencer 200 in the embodiment includes a box 210, a sink cavity 211 and a flow cavity 212 are formed in the box and communicated, and the exhaust port 110 of the fan 100 is communicated with the sink cavity 211 through the pipeline 300, wherein the airflow direction (arrow Z in the figure) of the airflow in the pipeline 300 entering the sink cavity 211 is perpendicular to the extension direction (arrow X in the figure) of the sink cavity 211.

[0026] The inner side wall of the sink chamber 211 is provided with a sound-absorbing material layer 201, and the internal wall of the flow-around chamber 212 is provided with a flow-around plate 213. One end of the flow-around chamber 212 is in communication with the sink chamber 211, and the other end is in communication with the outside and serves as an air outlet for the sound-absorbed gas. In some other embodiments, the internal wall surface of the flow-around chamber 212 can also be paved with a sound-absorbing material layer, which is not shown in the figure.

[0027] Optionally, the flow-around plate 213 in the embodiment is a plurality of flow-around plates, which are arranged in the direction of the air flow (the arrow X in the figure) and are spaced apart in a direction perpendicular to the air flow. Please refer to Figure 3 and Figure 4 , Figure 3 is a structural schematic view of a single flow-around plate cooperating with the box body, Figure 4 is Figure 3 is an enlarged schematic view of the local structure at A in the embodiment, in which the edge of the flow-around plate 213 is fixedly connected to the inner side wall of the box body 210 through a connecting member 214 (such as a square steel pipe or the like). Please refer to Figure 1 and Figure 2 , the middle part of the flow-around plate 213 can be fixedly connected to the inner side wall of the box body 210 through an angle steel 215.

[0028] Please refer to Figure 5 , Figure 5 is a structural schematic view of an embodiment of the flow-around plate of the application, in which the flow-around plate 213 in the embodiment includes a support member 2131 and a sound-absorbing material layer 2132 arranged on the surface of the support member 2131. The edge of the support member 2131 can be fixedly connected to the inner side wall of the box body 210 through a connecting member.

[0029] Optionally, the support member 2131 in the embodiment can be a metal mesh, such as a steel wire mesh. The sound-absorbing material layer 2132 and the sound-absorbing material layer 201 arranged on the inner side wall of the sink chamber 211 can be the same or similar materials, such as sound-absorbing cotton, which can be 100% polyester fiber that is heat-pressed in a cocoon-shaped structure through high technology.

[0030] Please refer to Figure 6 , Figure 6 is a structural schematic view of another embodiment of the flow-around plate of the application, in which the flow-around plate 213 in the embodiment includes a first support member 21311, a second support member 21312, and a sound-absorbing material layer 2132 clamped between the first support member 21311 and the second support member 21312. The first support member 21311 and the second support member 21312 can both be metal meshes.

[0031] The purpose of the embodiment of the present application is to solve the problem of how to cheaply make a large wind volume large silencer and the problem of how to simply install the large wind volume large silencer. The silencer is a device for reducing aerodynamic noise, which is installed on an air flow passage of an aerodynamic equipment or in an air inlet and exhaust system to reduce air flow noise. The silencer can block the propagation of sound waves while allowing air flow to pass through, and is an effective tool for controlling aerodynamic noise. The embodiment of the present application belongs to an impedance composite silencer, which is internally designed with two sections of a pressure sink cavity and a flow around cavity, and the inner wall surface of the box is paved with sound absorbing cotton. The outlet of the centrifugal fan is directly inserted into the top end of the box through a metal round pipe, connected to the pressure sink cavity inside the silencer, and the sound absorbing cotton is installed on the side wall of the pressure sink cavity to reduce air flow impact and noise propagation. At the same time, the gas jet at the outlet does not directly impact the structure at the inlet of the tail pipe, and the sound waves are reflected and interfered by the expansion of the cross section of the pressure sink cavity, and then continue to propagate along the box to achieve the purpose of silencing.

[0032] The flow around cavity inside the silencer of the embodiment of the present application can be installed with six rows (or other number, not specifically limited here) of flow around plates and paved with sound absorbing cotton, and the sound energy is absorbed by the resistive material (mainly porous material) installed in the middle to achieve the purpose of reducing noise. When the sound waves pass through the flow around cavity paved with sound absorbing material, the sound waves excite the vibration of air molecules in the numerous small holes in the porous material, and due to the frictional resistance and viscous force, a part of the sound energy is converted into heat energy and dissipated, thereby playing a silencing effect. The air flow is divided and weakened by the flow around plates, and the air flow at the outlet can approach the national emission standard of plant boundary noise. The impedance composite silencer has a resistive structure in front and a resistive structure in back, which first eliminates low-frequency sound and then eliminates high-frequency sound, and the total silencing amount can be considered as the sum of the two. The use of resistive sound absorbing material: on the one hand, the peak value of the sound absorption spectrum is reduced, but the total silencing amount is improved, and this effect mainly occurs in the high frequency range; on the other hand, due to the effect of the resistive sound absorbing material, the sound absorption spectrum is shifted, and this effect mainly occurs in the low frequency range. The silencer in the embodiment of the present application achieves good silencing effect in high, medium and low frequency ranges.

[0033] The silencer in the embodiment of the present application can be a silencer transformed from a standard container, which is connected to the original outlet of the centrifugal fan through a metal round pipe (pipe), internally designed with two sections of a pressure sink cavity and a flow around cavity, and the sound absorbing cotton can be installed on the side wall of the pressure sink cavity and the inner wall of the flow around cavity, thereby using the original cavity in the container and the added sound absorbing cotton to achieve the effect of reducing noise, which is a method of realizing effective resource reuse. Compared with other large wind volume large silencers, the silencer in the embodiment of the present application is installed on site, does not need to be installed on the pipe, and does not need to be made into a large support, which has the advantages of low installation cost, low manufacturing cost, convenient maintenance, etc.

[0034] By looking up the literature, the results of the stable airflow-based research show that the strategies for controlling the occurrence of airflow noise in the muffler include the following five points: reducing the jet flow speed from the cavity inlet, and forming a structure that does not directly hit the tail pipe inlet; in order to avoid the occurrence of a sharp contraction, implementing a large curvature radius processing such as a horn at the top end of the tail pipe inlet is also effective; in the through-hole type muffler, the shape of the final hole of the perforated pipe must be fully considered, and at the same time, selecting a material with high sound transmission and less airflow through the through-hole is also effective. These effective strategies for reducing noise can be mostly applied to the design and manufacturing process of large wind volume and large mufflers. Generally, the outlet pipe of a large centrifugal fan is between 900 mm and 1200 mm, and the outlet pipe enters the muffler in the embodiment, the airflow first enters the sink cavity with a length of 6 meters, a height of 2.5 meters, and a width of 2.4 meters, the air jet flow speed and pressure rapidly decrease, the jet flow direction is perpendicular to the container outlet, the sound waves in the sink cavity reflect and interfere to achieve the purpose of noise reduction, and the sink cavity side wall is provided with sound-absorbing cotton to also reduce airflow impact and noise propagation. After the airflow at the outlet enters the flow-around cavity, it is divided by the sound-absorbing cotton (multiple flow-around plates), the sound waves excite the vibration of air molecules in the small holes in the porous material in the sound-absorbing cotton, and due to the friction resistance and viscous force, a part of the sound energy is converted into heat energy and dissipated. In the flow-around cavity, the air resistance is small, and the permeability is good, so that the airflow at the outlet can approach the national emission standard of factory boundary noise.

[0035] According to the number and air discharge volume of the centrifugal fan that needs to reduce noise, a 6-meter or 12-meter long standard container is selected as the main body of the sound-absorbing device. The sound-absorbing device made of a 12-meter long standard container is suitable for an exhaust pressure of 0.014 MPa and an air discharge volume of 250,000 m3 / h or less. The sound-absorbing device made of a 6-meter long standard container is suitable for half of the air discharge volume. Taking the 12-meter long sound-absorbing device as an example, the inside is designed to have a sink cavity and a flow-around cavity, the sink cavity is provided with sound-absorbing cotton on the inner side wall, the flow-around cavity is provided with six rows of flow-around plates with a length of 6 meters, a height of 2.5 meters, and an equal spacing, and the flow-around plates are provided with polyurethane sound-absorbing cotton. The sound-absorbing cotton selected in the embodiment can be composed of 100% polyester fibers that are hot-pressed by high technology and in the shape of cocoon cotton, and the sound absorption coefficient reaches 0.94 in the noise range of 125-4000 Hz. The sound-absorbing cotton contains polyester fiber fireproof material and has excellent fireproof performance, and passes the national B1 level fireproof test. The noise reduction amount of the muffler meets the requirement that the noise is less than or equal to 60 dB(A) at a distance of 1 meter from the muffler.

[0036] It is known from the literature that the aerodynamic noise of a centrifugal fan is the noise generated during the flow of gas, mainly due to the unsteady flow of gas, that is, the disturbance of the gas, the noise generated by the interaction of the gas with the gas and the object. The aerodynamic noise of the fan is mainly composed of two parts: rotating noise and vortex noise. If the fan outlet is directly discharged into the atmosphere, there is also exhaust noise. The power of the exhaust noise is proportional to the eighth power of the speed of the fan outlet discharged into the atmosphere. The resistance loss of the design or selection of the silencer should be paid special attention to. The sound attenuation amount of the silencer meets the sound attenuation requirements, and the resistance loss cannot exceed the allowed range. In order to make the system work in a high-efficiency and low-energy state, the resistance loss of the designed or selected silencer should be as small as possible, and the installation of the sound attenuation cotton should not be too dense. The airflow sound attenuation of the silencer should be avoided to be too large, and the airflow speed of the industrial fan silencer should be controlled at 10-20 m / s. The silencer is preferably installed at the inlet and outlet of the fan, that is, close to the noise source, to prevent the fan noise from exciting the pipeline vibration. The silencer in the embodiment of the application is arranged outdoors and placed on the ground, and the centrifugal fan is installed indoors and connected through the air pipe. The rotating noise is difficult to penetrate the wall for propagation, and the noise can also be conducted to the ground for dissipation through exciting the pipeline vibration. The rotating noise and vortex noise are discharged into the atmosphere through the pipeline, and the sound attenuation device in the embodiment of the application is added at the outlet of the centrifugal fan, so that the effect of reducing the aerodynamic noise can be achieved, thereby meeting the national standard emission standard (the national emission standard of plant boundary noise ≤60 decibels). The design and manufacture of the container type silencer are in accordance with the GB150-98 standard, and the welding seam inspection of the silencer is in accordance with the JB4730-94 "Nondestructive Testing of Pressure Vessels".

[0037] Working principle: In the dust removal system, high-pressure air with large air volume is discharged from the outlet of the high-pressure centrifugal fan or the medium-pressure centrifugal fan, and enters the container type silencer through the exhaust pipe. First, it enters the pressure sink chamber, expands to reflect and involve sound waves, and then continues to propagate along the container outlet to achieve a certain sound attenuation effect. The sound attenuation cotton installed on the side wall of the pressure sink chamber also plays a role in reducing airflow impact and noise propagation. The high-pressure air with large air volume enters the flow-around chamber after pressure reduction and sound attenuation in the expansion chamber. The airflow is divided and weakened by the flow-around plate, and when the sound wave passes through the flow-around chamber coated with sound absorption material, the vibration of air molecules in the numerous small holes in the porous material is excited by the sound wave. Due to the friction resistance and viscous force, a part of the sound energy is converted into heat energy and dissipated, thereby further attenuating the sound. After two times of sound attenuation, the effect of reducing the aerodynamic noise can be achieved, and the air discharged from the centrifugal fan enters the atmosphere, thereby meeting the national standard emission standard.

[0038] Generally, the muffler products are designed to be larger than the pipeline to facilitate installation in the middle of the pipeline or the air outlet, and the sound-absorbing cotton is installed on the pipe wall, while the muffler itself is small, and the noise reduction effect is poor, and the installation cost and maintenance cost are high. The muffler in the embodiment of the application is placed on the ground outdoors, does not occupy indoor space, does not need to be installed on the support, significantly reduces the installation materials and installation cost, and the transformation cost is lower than that of purchasing the same type of muffler. The noise reduction amount of the muffler meets the national emission standard of ≤55 dB(A) at a distance of 1 meter from the muffler, and the noise measured by the precision noise meter is ≤60 decibels.

[0039] The sound-absorbing device in the embodiment of the application has been applied to the air outlet of the high-pressure centrifugal fan of the calcium carbonate dry grinding dust removal system, the fan pressure head and air volume of the dust remover are large, the exhaust pressure is 0.014 MPa, the air discharge amount is 250000 m3 / h, and the fan noise reaches about 85 dB(A); and after the muffler is installed, the noise is 65.3 dB(A). The installation cost of the sound-absorbing device in the embodiment of the application is about 21% of the cost of the purchased muffler, and the installation time is the same. The sound-absorbing device in the embodiment of the application is easy to manufacture and install, convenient to maintain, low in cost, and has a relatively universal applicability.

[0040] The sound-absorbing device provided in the embodiment of the application has a simple and durable structure, can adapt to harsh use conditions, has a large ventilation volume, has a small resistance to the main fan, has a low manufacturing cost, and can be generally applied to the noise reduction of the air outlet of the centrifugal fan in the dust removal system.

[0041] The above only describes some embodiments of the application, and does not limit the protection scope of the application, and any equivalent device or equivalent process transformation using the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A sound attenuation device for a fan, comprising: The silencing device comprises a box, a communicating depression cavity and a flow-around cavity are formed in the box, the depression cavity is used for communicating with the exhaust port of a fan to be silenced, an inner side wall of the depression cavity is provided with a sound-absorbing material layer, an inner part of the flow-around cavity is provided with a flow-around plate, one end of the flow-around cavity communicates with the depression cavity, and the other end communicates with the outside and serves as an air outlet of the gas after being silenced.

2. The sound attenuating device of claim 1, wherein, The flow-around plate is multiple and is arranged along the airflow direction, and the multiple flow-around plates are arranged along the airflow direction.

3. The sound attenuating device of claim 2, wherein, The flow-around plate comprises a support and a sound-absorbing material layer arranged on the surface of the support.

4. The sound attenuating device of claim 3, wherein, The support of the flow-around plate is a metal mesh.

5. The sound attenuating device of claim 4, wherein, The flow-around plate comprises a first support, a second support and a sound-absorbing material layer arranged between the first support and the second support.

6. The sound attenuating device of claim 3, wherein, The edge of the support is fixedly connected with the inner side wall of the box through a connecting piece.

7. The sound attenuating device of any of claims 1-6, wherein, The sound-absorbing material layer is sound-absorbing cotton.

8. The sound attenuating device of claim 7, wherein, The material of the sound-absorbing cotton is polyester fiber.

9. A fan system characterized by, The fan system comprises a fan and the silencing device of any one of claims 1-8, and the exhaust port of the fan communicates with the depression cavity of the silencing device through a pipeline.

10. The fan system of claim 9, wherein, The airflow direction of the airflow in the pipeline into the depression cavity is perpendicular to the extension direction of the depression cavity.

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