Environmental Noise Control in the Pulp and Paper Industry

The number of external noise sources of a paper making line is typically around 80 pcs. The major ones are process and machine room ventilation and vacuum pump exhausts. The noise control targets will dictate the scope and costs of sound attenuation. Considerable cost reductions can be achieved if the noise control design starts at the early stage of a project. Additionally, depending on the noise level requirements, absorptive silencers, resonators or enclosures are used. Active Noise Control is yet another method of reducing noise, especially at the lower frequencies. The sensors and actuators are using ElectroMechanical Film (EMFi) technology. GENERAL TRENDS IN EXTERNAL NOISE LEVEL REQUIREMENTS The external noise level requirements in the paper industry have increased from the 80's till now. Already in the 80's some paper mills in the center of cities had very strict noise level requirements. The general overall trend, however, looks as shown in figure 1.