Mechanical power noise: it refers to the low and medium-frequency noise caused by running, vibration, friction and collision of equipment.
Pneumatic power noise: it refers to the low, medium and high-frequency noise caused by high-pressure airflow, capacity expansion, tangential flow, exhaust steam, and air leakage in various sorts of fans, air ducts and steam tubes, among which the exhaust steam produces high-frequency noise and has remarkable influence on environment.
Combustion noise: it refers to the low and medium-frequency noise caused in the processes of combustion, vaporization, exhaust gas movement and convection in boiler.
Electromagnetic noise: it refers to the low and medium-frequency noise caused by motor, exciter, transformer and other electrical equipments in the alternating process of magnetic field.
Traffic noise: it refers to the noise caused by the transportation vehicles within the factory, among which the horn sound and the siren are of high-frequency noise.
Other noise: it refers to the noise caused by hydrodynamic force (such as the sound of cooling tower), broadcast and human activity, among which the noise of cooling tower has huge influence on the environment outside of the factory, and is hard to control. Currently, as for most power plants which noise produced within the factory boundary fails to meet the noise control requirement , most of its noise is caused by the cooling tower.
Control over Equipment Noise
The low-noise equipment must be given priorities as much as possible when designing; and the sound insulation hood to be particularly installed for the coal mill, steam turbine and other equipment, and mufflers to be installed at the air supply outlet of draught fan and the exhaust gas outlet of boiler to reduce noise strength.
When designing the overall layout, the buildings producing too much noise can be arranged in the center of the factory, the other noise sources can be arranged far away from the factory boundary; such layout and arrangement can help minimize the influence of industrial noise on external environment.