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Think Quiet—Design for Noise Control in Industry
Published in John D. Constance, Controlling In-Plant Airborne Contaminants, 2020
The greatest benefits in noise control are derived from quieting the source. Surveys have shown that more than 50% of power generating and other industrial machines produce at least 90-100 dBA of noise, and 50% of all plant working areas have noise levels of between 85 and 95 dBA. The ideal approach is noise reduction through new machinery design. This will prove to be the most economical in the long run since, even though there may be some choice, the design engineer may be forced to confine location of equipment because of the nature of the operation. On the other hand, such equipment as valves and piping can be designed to control noise propagation by devices and pipewall lagging applied to the outer surface of the equipment. Gear noises, loose bearings, noisy conveyors, escaping steam, and compressed-air sources can be quieted through engineering knowhow at the drawing board stage.
Fundamentals and Basic Terminology
Published in David A. Bies, Colin H. Hansen, Engineering Noise Control, 2017
David A. Bies, Colin H. Hansen
A common method of noise control is a barrier or enclosure and in some cases this may be the only practical solution. However, experience has shown that noise control at the design stage is generally accomplished at about one-tenth of the cost of adding a barrier or an enclosure to an existing installation. At the design stage the noise producing mechanism may be selected for least noise and again experience suggests that the quieter process often results in a better machine overall. These unexpected advantages then provide the economic incentive for implementation, and noise control becomes an incidental benefit. Unfortunately, in most industries engineers are seldom in the position of being able to make fundamental design changes to noisy equipment. They must often make do with what they are supplied, and learn to apply effective “add-on” noise-control technology. Such “add-on” measures often prove cumbersome in use and experience has shown that quite often “add-on” controls are quietly sabotaged by employees who experience little benefit and find them an impediment to their work.
Hearing, Sound, Noise, and Vibration
Published in R. S. Bridger, Introduction to Human Factors and Ergonomics, 2017
Noise control can reduce noise levels and extend machine life, since the same processes that give rise to noise also give rise to wear. Narrowband frequency analysis can be used to locate the part of the machine giving rise to the noise, if the operating frequency of the components is known. Scannel gives some examples of cost-effective interventions: The flywheel of a 10 ton power press was found to generate bell-like tones, due to resonance. Dynamic vibration absorbers were attached to the flywheel to damp the resonant frequencies. The costs were $50 for materials and 1 day's pay for a fitter. The life of the machine was extended by 8 years and the noise levels dropped from about 96 to 86 dB.Aluminum castings being worked on a capstan lathe emitted 94 dB(A) at the operator's ear. The cutting tool was causing the product to vibrate which not only caused noise but also affected the smoothness of the cut. Vibration damping straps were made at $5 each and fitted onto the castings before they were machined. The noise dropped to 78 dB(A), the tool life was increased, and the machining cycle time was reduced.
Experimental and computational analysis of acoustic characteristics of warp-knitted spacer fabrics
Published in The Journal of The Textile Institute, 2020
Razieh Abedkarimi, Hossein Hasani, Parham Soltani, Zahra Talebi
Control of noise is of paramount importance in a wide variety of applications in environmental engineering such as transportation, industrial noise control, architectural design, passenger vehicles and convention halls. Engineering of sound absorbers and insulation materials to meet full or partial requirements of the above-mentioned applications has become a significant challenge to material designers (Talebi, Soltani, Habibi, & Latifi, 2019). Most sound absorber materials used in these applications are porous. They can be classified as granular materials (e.g. porous concrete), cellular materials (e.g. foams) or fibrous structures (Yang, Xiong, Mishra, Novák, & Militký, 2018).
Noise source identification of high-speed motion mechanism of textile equipment based on equivalent source method
Published in The Journal of The Textile Institute, 2020
Yang Xu, Angang Li, Xiaowei Sheng, Ziyu Zhang
The newly revised GB/T 50087-2013 Code for Design of Noise Control in Industrial Enterprises stipulates that the noise limit of production workshop is 85 dB. However, at present, the noise of most textile workshops in China is above the standard limit. Textile workers are exposed to this environment for a long time, and their physical and mental health will be seriously harmed. If the location of noise source can be identified accurately, pertinent measures can be taken to reduce vibration and noise, and noise can be predicted even at the stage of product design to achieve low-frequency noise control.
Analysis of the effect of fiber cross section and different bonding methods on sound absorption performance of PET fiber based nonwovens using Taguchi method
Published in The Journal of The Textile Institute, 2020
Handan Palak, Burçak Karagüzel Kayaoğlu
Noise control is essential in automobiles or other vehicles, industrial machines and constructions since noise pollution can lead to several problems such as loss of hearing, reduced efficiency and tiredness and even psychophysiologic problems. Noise control can be achieved with acoustic materials such as sound absorbers, sound barriers and silencers, by redesigning of sound sources and hearing protection aids such as earplugs (Nayak & Padhye, 2016).