Spray resistance type muffler, small hole muffler, fan silencer
1. Principle and product characteristics
Microperforated silencers are porous on the inner wall of the airflow channel or arranged in the pipeline in a certain way to form a resistant silencer. When the sound wave enters the resistant muffler, the sound energy is rubbed in the pore and dissipated into heat energy, which weakens the sound wave passing through the muffler. The resistance muffler is composed of the tube and chamber of the mutant interface, which seems to be an acoustic filter, similar to the electrical filter, each small tube chamber is a mesh of the filter, the air quality in the tube is equivalent to the electrical inductance and resistance, called sound mass and acoustic resistance. The volume of air in the chamber is equivalent to the electrical capacitance, which is called smooth. Similar to the electrical filters, each chamber with a tube has its own natural frequency. When the sound waves of various frequency components enter the first short tube, the sound waves of certain frequencies near the natural frequency reach the second short tube mouth through the mesh, and the noise of certain frequency components can be filtered out, and the appropriate tube and chamber can be selected for combination. So as to achieve the purpose of noise elimination. Resistance muffler is suitable for eliminating all kinds of high, medium and low frequency noise. Spray-resistance type mufflerSeries is a device that prevents the transmission of sound and allows the air flow through. It is an important measure to eliminate aerodynamic noise.
To measure the quality of muffler, the following two aspects are mainly considered: (1) the aerodynamic performance of muffler; (pressure loss, etc.) (2) the structural performance of muffler.(Size, price, life, etc.) The selection of muffler should be based on the requirements of fire prevention, moisture-proof, anticorrosion, cleanliness, and the space position of installation, the general situation is: the greater the diameter and pressure of the muffler, the greater the space of the muffler. For high temperature, high humidity, oil fog, water and gas environmental system generally choose microporous structure muffling equipment.
2. Depending on the use, the company has produced the following series
1, the boiler ignition and exhaust muffler
The working principle is the high temperature and high pressure steam and low pressure steam in the silencer after a capacity expansion and pressure reduction into the secondary pressure reduction body by large volume expansion and pressure reduction, forming low pressure or ultra low pressure steam after the ejection of a combination of multi-material composite structure of sound absorption cover. Again again and row into the atmosphere. The type of industrial noise reduction equipment has the advantages of high safety factor, large noise value, small equipment size, light weight and convenient installation.
2, steam safety door muffler
As is known to all, for the boiler forces of devices such as safety door, the exhaust steam should avoid excessive noise, more should let steam flow smoothly, therefore, the common multistage throttling and hole injection noise is unfavorable, this limitation has always been the one of the safety door silencer design difficulty, is also the cause of the safety door muffler noise effect is poor. The utility model muffler for the safety door also adopts the noise elimination principle of resistance, spray and resistance, in which the large hole expansion replaces the control hole with a small diameter, which strengthens the mechanism of resistance and resistance in the structure to achieve the ideal muffler effect.
3. Low-pressure steam muffler (TD type)
Various industrial and mining enterprises use a large number of low-voltage boilers of 0.13 Mpa and below. There are also a large number of low-voltage thermal devices in the thermal system of the power station, such as back pressure steam turbine, deaerator, auxiliary pump pump, boiler continuous sewage, regular sewage discharge, etc. The exhaust pipe of the above equipment should be equipped with light structure and more convenient installation of muffler. For different noise objects, the company designed special deaerator series, back pressure steam turbine series and other series products, can meet the requirements of users.
The muffler effect of the above muffler can meet the requirements of the "Noise hygiene Standard for Industrial Enterprises", and it has been widely used in China.
4, the fan muffler
(1) Brief introduction of the fan silencer
Fan muffler is a kind of equipment to make the air flow through the equipment to effectively reduce the noise. According to the different forms, the fan muffler can be divided into resistance, resistance, composite type and exhaust vent type four types.
Resistance silencer is a silencer that uses different structural forms of porous sound absorption material to absorb sound energy and reduce noise.
Resistant silencer is a silencer that reflects part of the acoustic waves to the echo source direction through the mutation of the acoustic characteristics in the pipeline. It is mainly suitable for reducing the noise of long wave and medium wave.
Composite type silencer is the combination design of different noise elimination principles such as resistance and resistance.
Fan muffler is used to control the aerodynamic noise formed by the fan to the environment. For all kinds of fans, blowers, centrifugal and axial flow ventilator in and out of the air channel noise elimination. The muffler series is of impedance sound flow type. According to the spectral characteristics obtained from the actual test of the noise source of various fans of the power plant, the data of how much noise is required in the spectral range is determined as the main basis for the design of the sound absorption piece structure and the fluid channel. Meanwhile, the narrow moment opening channel with a large material surface is adopted to enhance the absorption effect.
(2) Working principle
Fan muffler adopts the short and medium wave noise effect of resistance structure and resistance structure, according to the actual test of the spectral characteristics as the main basis of the design of the sound absorption body and fluid channel, at the same time with large sound absorption material surface of narrow rectangular channel, in order to enhance the absorption effect. In addition, when the noise source of the fan is at the maximum noise level, its spectrum value is often more than one, and for different spectrum bands, the noise suppression requirements are not the same. This series ventilation pipe muffler and drum induced fan muffler are impedance sound flow type, adopted the short and medium wave noise absorption effect resistance structure and for the medium and long wave noise sound reduction resistance structure, at the same time in the resistance channel adopted short wave and long wave sound absorption area, to maximize the widening noise band, in order to achieve good noise reduction effect.
Film muffler is a device that prevents the transmission of sound and allows the airflow to pass through. It is an important way to eliminate the aerodynamic noise. Patch muffler mainly uses the porous sound-absorbing material to reduce the noise. The sound absorbing material is fixed on the inner wall of the airflow channel or arranged in the pipeline in a certain way to form a piece of muffler. When the sound wave enters the chip muffler, a part of the sound energy is rubbed in the pores of the porous material and converted into heat energy and dissipated, which weakens the sound wave through the muffler.
For eliminating short and medium wave noise, it is not very effective for the elimination of long wave noise, the shape of the air channel, the air velocity, the length, the type, density and thickness of the protective panel material and its type also have great influence on the noise effect. The protective material can be soft and porous breathable fabric, such as glass fiber cloth, or perforated plate. The perforated plate for the protection is generally made of thin steel plate and stainless steel plate. In order to play the sound absorption performance of the sound absorbing material, the perforation rate of the perforating plate should be greater than 20%, and the pore diameter is 3~10m m.
(3) Manufacturing process
1. This equipment is a fan import and export muffler, with resistant chip structure silencer. The equipment is designed, produced and accepted according to GB1234-8 Noise Emission Standard for Industrial Enterprises.
2. During welding, necessary measures should be taken to prevent deformation and ensure the flatness and Angle of the four walls.
3. The distance between the straight panels is uniform, the hole distance is uniform, and there are no burrs at both ends.
4. The sound-absorbing packing should be selected strictly according to the requirements, and the installation density should meet the requirements of the drawings.
5. The docking flange should be smooth and smooth, and polished around without burrs and cutting defects.
6. The connection of muffler and fan pipe is flange connected.(With counterflanges and fasteners)
7. The dust content of the gas passing through the muffler should be low and 150 m g / m³, and the water mist or corrosive gas is not allowed to pass through, and the gas temperature should not be greater than 300℃.
