Noise emission from belt conveyor systems and stockyard equipment for handling bulk materials – preliminary calculations and noise reduction measures
Dipl.-Ing. R. Wirtz, ThyssenKrupp Fördertechnik GmbH, St. Ingbert, Germany
Increasing environmental awareness among the public as well as international and national laws on emission control are making it more and more difficult to operate large industrial plants, particularly near residential areas. In the specific case of handling bulk materials in coal power stations, cement plants and steel works the understandable demands with respect to complying with limits for the emission of dust, odour and, in particular, noise require a modern, environmentally friendly design using very low-noise plants. Industrial plants for processing raw materials can only be operated cost-effectively if they are used 365 days a year 24 hours a day. This means that careful acoustic design of the individual plants and the complete system is of great importance as a preliminary to any new capital investment. Starting from the basic principles of acoustic physics this article will go into the acoustic aspects of handling bulk materials with belt systems and large stockyard equipment for handling coking coal in a German steel works. In this specific case the governmental approval authorities had defined noise measuring positions outside the works’ terrain and in residential areas located very close to the works’ terrain at which the sound pressure levels were not allowed to exceed the specified limits by day or night. The permissible sound pressure levels for the individual units were calculated as requirements for the plant from the sound pressure levels defined at the points affected by immission. Part of the plant described here is a stockyard for receiving different types of coal. A stacker and two rail-mounted reclaiming machines are in use there. Most of the coal reaches the harbour about 1 km away by pusher barge. The barges are unloaded by a grab-type ship unloader. The coal is then supplied from the harbour by a pipe conveyor and other belt conveyor systems either directly to the feed hoppers in the coking plant or to a stockyard serving as an intermediate buffer.
Summary CEMENT INTERNATIONAL 04/2011 pp 42-57
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