The noise point source of boiler fan is many and the decibel is high, which is an important factor to cause environmental petition. Starting from the prevention and control of boiler fan noise, this paper discusses the harm of fan noise and the comprehensive treatment technology of noise reduction and energy saving. At present, in many enterprises, due to industrial production and heating demand, the installation and use of boilers are very popular. However, due to the poor site selection and fan performance of many boilers, the noise of boilers affects the quiet working and living environment of the surrounding residents, damages people's health, and often causes disturbing events and disputes. Therefore, the noise control of boiler fan is increasingly important.
What harm does the noise of boiler fan do to us?
Harm of environmental noise pollution: the impact and harm of noise on human body can be generally divided into two aspects: labor protection and environmental protection. The former refers to harm to human health, leading to the occurrence of various diseases, and the latter refers to interference with the environment and quiet, affecting people's normal work and life. The harm of noise to human health is mainly manifested in the following aspects: hearing impairment, noise induced deafness; cortical excitation and imbalance, cerebrovascular function damage, leading to neurasthenia; cardiovascular system damage, causing digestive system disorders, affecting endocrine; interfering with people's normal life, rest, language conversation and daily work and study, distracting attention and reducing work Efficiency.
The formation of noise pollution is mainly caused by three factors: sound source, media and receiver. Only when these three elements exist at the same time can they interfere with the listeners. From these three aspects, the purpose of noise control can be achieved by reducing the sound source, limiting the transmission of noise and blocking the reception of noise. In the specific noise control technology, four measures can be adopted, namely sound absorption, sound insulation and noise elimination.
1. Sound absorption:
When the sound wave incident on the surface of the object, part of the sound energy will be absorbed by the object and converted into other forms of energy, which is called sound absorption. The sound absorption performance of the material is expressed by the absorption coefficient. The larger the sound absorption coefficient is, the better the sound absorption performance of the material is. The sound absorption properties of materials are related to the properties and structures of materials, the incident angle of sound waves and the frequency of sound waves. The sound absorption mechanism of porous sound-absorbing materials is: there are innumerable small interconnected holes in the material. When the sound wave incident on the surface of these materials and then into these small pores, the air in the pores will move. The air close to the hole wall and the fiber surface is not easy to move due to friction and viscous motion resistance, so that the sound energy is converted into heat energy and consumed. Therefore, the sound-absorbing material with good performance should be porous, and the holes should be connected with each other, and the through holes should be connected with the outside, so that the sound wave can enter the inside of the material.
The sound absorption coefficient of 10 cm thick ultra-fine glass wool is 0.87.
2. Sound insulation:
The method of sound insulation is to close the noise source and control the noise in a small space. This kind of sound insulation structure is called sound insulation cover. When the sound wave meets the shield, due to the change of the characteristic impedance of the interface, part of the incident sound energy is reflected and absorbed, and part of the sound energy penetrates into the shield and continues to propagate. The sound insulation performance of materials can be expressed by sound transmission coefficient. The smaller the sound transmission coefficient is, the less the sound energy is, the better the sound insulation performance of the material is. The sound insulation performance of the material is related to the structure and property of the sound insulation body and the frequency of the incident sound wave.
3. Silencing:
In order to reduce aerodynamic noise, porous sound absorption material is fixed on the inner wall of the airflow channel or fixed in the pipe in a certain way, so as to reduce aerodynamic noise. The noise reduction amount can reach 10-50 dB.
On 2018-08-08 11:45:46
