Before investing in extensive sound-deadening materials, or requiring staff to wear personal protection equipment in affected areas, factory and processing plant owners along with facility owners and managers should look at relatively inexpensive ways to isolate the source of the trouble with simple inflatable or solid rubber mounts.
Inflatable Airmount Air Springs are proven globally in applications ranging from extreme isolation of operating tables in hospitals, computer and electronics installations, through to outstandingly effective dampening of the din and shaking created by huge and heavy shakers, crushers, metal stamping, compressors and generators in industrial plants.
Isolation efficiencies of up to 99 per cent have also been attained beneath common sources of NVH in buildings, ranging from emergency electricity generators and HVAC plants in high-rise buildings, through to, in one Australian instance, a swimming pool in an exclusive hotel.
The entire pool was mounted on air springs to ensure its glassy surface is isolated from disruptive trains rumbling by in nearby tunnels and other heavy vehicle traffic. Mounting the pool on air springs also ensured that the sounds of diving and aquatic cavorting did not transmit through to the hotel rooms below, often costing more than $1000 per day.
"It just makes sense to look at prevention before cure – preventing noise happening, and preventing vibration spreading," says James Maslin, National Marketing Manager for isolation and actuation specialist Air Springs Supply Pty Ltd.
The NVH problem is almost universal throughout the design, engineering and construction of industrial and commercial buildings. It is a workplace hazard to human occupants of buildings, disrupting employee comfort and safety; considering that the number of claims for industrial deafness has doubled since the start of the decade, prevention is vital.
Not only presenting as a workplace hazard to employees, NVH, in particularly bad circumstances, can disturb the daily function of instruments and computerised building systems, including automation, process control and materials handling systems.
"Years ago not many building specifiers and their clients gave a second thought to environmental NVH - it was just typical background noise in just about every industrial plant or commercial building," says Maslin.
"All that has changed radically over the last decade or so. Not only have state governments become aware of the health issues involved, but also a huge amount of electronic equipment has gone into industrial and commercial buildings as companies strive for efficiency and automation.
"Instead of being an afterthought, a quieter environment free of vibration and shock has become a necessity in many buildings which are heavily dependent on electronic equipment and computerised production," said Maslin.
Weight support of up to 40,000kg
Airmounts are available in an expanded range of sizes which can individually support weights extending from under 100kg up to more than 40,000kg. Models range from palm-sized to nearly a metre across, which have been used as actuators to lift mining draglines for maintenance.
"One of the beauties of isolators as simple as the Airmounts is that they contain no internal moving parts to wear, or metal springs or surfaces to corrode or break," says Maslin.
"They are extraordinarily tough, being manufactured by Firestone in exactly the same way as the Air Springs used in the suspensions of luxury coaches, heavy trucks, and express trains such as NSW’s XPTs and France’s TGVs."
