Mitigation of noise pollution in compressed air installations through the use of an air collection system in the expansion process

Despite the many advantages of pneumatic systems, one disadvantage is the noise accompanying the expansion of the exhaust air. In pneumatic exhaust systems, the pulse jet generates the impulse noise. The A-weighted sound pressure levels of exhaust system impulse noise can reach 96 to 108 dBA, or even up to 130 dBA. On the other hand, attempts to reduce pneumatic noise involve loss of performance by reducing the torque and speed of the pneumatic tool. Commonly used mufflers do not reduce the noise level below 85 dB. Our research introduces a novel air collection system, details its technical implementation, and conducts thorough experimental analysis comparing its noise reduction effectiveness and mechanical efficiency impact with traditional mufflers. In the study we conducted experimental tests on the noise level and mechanical properties of a pneumatic screwdriver in an anechoic chamber, and presenting the operational characteristics and sensitivity analysis of the air collection system geometry. Next the industrial implementation shows that a standard screwdriver produces levels of 90.7 dBA, while a screwdriver with a collection system produces levels of 82.8 dBA. Our findings indicate that the selection of the design parameters of an air collection system allows for the removal of acoustic energy from the area affecting the worker’s exposure to noise, without compromising the efficiency of the production process. By eliminating this component of the noise associated with the air exhaust, the noise generated by the mechanical components of the screwdriver is exposed and becomes audible.