Noise pollution in cement plant has always been a major problem in cement industry, which is mainly due to the large number of noise equipment in cement plant, such as vertical grinding, raw material grinding fan, high temperature fans in raw material grinding area, all kinds of fan equipment in kiln head area, coal grinding and Roots fan equipment in coal grinding workshop, as well as cement grinding workshop, homogenization storehouse area in air compressor rooms, the noise of these noise equipment is generally more than 85 decibels, some even more than 110 decibels. This results the noise characteristics of cement plants large scale, high strength and long time, and also makes the noise problems in cement plants very serious and complex.
When we consider the problem of factory noise, we usually start from two perspectives: factory boundary noise and factory area noise. The former is managed by the environmental and ecological department and mainly solves the problem of environmental assessment of the factory. The latter is concerned by the safety supervision department and solves the occupational health problem. From these two perspectives, different noise reduction requirements will be obtained, and the final scheme will be different.
Today's analysis mainly considers the noise control of cement plant from the point of view of factory boundary noise. This is a cement plant located in Jiangsu Province. The noise in the north of the factory is beyond the standard. Our company has carried out detailed on-site survey. The maximum noise of the factory boundary on the north side of the company exceeds 66 dB (A), which does not meet the three types of acoustic environmental standards in GB 12348-2008: day ≤ 65 dB (A) and night ≤ 55 dB (A).
We have carefully investigated the noise sources at the northern factory boundary, and found that the noise sources affecting the northern factory boundary are mainly 2 # grinding air compressor, 1 # grinding dust collector, 1 # grinding powder elevator, 1 # grinding tail elevator and 1 # grinding and separating fan, which are mainly used in production at night。 We measured these noise sources in detail, set up 21 measuring points, and obtained detailed noise data。
By analyzing, calculating and simulating the noise data, we design the appropriate acoustic structure, adopting one or more technical means such as sound absorption, sound insulation and noise elimination to reach the noise reduction requirement。
For 2 # grinding air compressor, we adopt sound absorption and insulation cover, and adopt intake muffler louver and exhaust muffler, in which the axial flow fan is used for active exhaust。
For the 1 # grinding dust collector, we use the muffler to guide the exhaust direction to the South side, and replace the room door with a professional sound insulation door to achieve good sound insulation effect.
For 1 # grinding powder hoist and 1 # grinding tail hoist, we installed sound absorption and insulation board in the machine room, and strengthened the sealing treatment of the machine room.
For the 1 # grinding and separating fan, we installed sound absorption and insulation board in the maintenance wall near the northern factory boundary to enhance the sound insulation of the maintenance wall, and installed sound absorption body in the machine room, replacing the door of the machine room as the sound insulation door.
Through the above measures, the boundary noise of the cement plant met the national requirement of 55dB (A) at night and passed the EIA。
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