How to update the current (failing) noise risk management process to make it much more effective – and self-financing Noise Induced Hearing Loss claims of £400,000,000 per annum show that thousands of people are suffering hearing damage, most of which could be avoided by changing the way risk management is is carried out. A simple, innovative approach that dramatically improves the effectiveness of noise risk management was described at the BOHS
Reduce Product Noise and Vibration – the innovative and profitable way…
We have been extremely successful at applying engineering experience, intuition and technology transfer across a wide range of industries to eliminate product noise and vibration problems. Our clients have benefited both commercially and technically from this success.
Innovation, innovation, innovation… For experienced engineers, solving noise and vibration problems is as much an art as a science – we provide both to help with your product development. Our reputation for successful innovation is illustrated by the range of novel and elegant engineering solutions contained in our case studies.
Sample Past Project Arenas
air conditioning – axles – office products – pneumatic nozzles – trains – compressors – power presses – weighing machines – steering columns – vibratory filters – white goods – pneumatic tools – woodworking machines – fans – wrapping machines – vacuum cleaners – vacuum pumps – ships and yachts …
Product Noise Control Case Studies
Vax Vacuum Cleaner
During the re-design exercise for a new model, the noise from this vacuum cleaner was not only reduced by a factor of 10 (10dB(A)), but the subjective character of the noise was also substantially changed by eliminating tonal components to make it sound “nicer” (a specialist technical term in acoustics!). This also had the side effect of making the vacuum cleaner sound more powerful….vaxbeforafter
Quiet Compressor Development
As part of a continuous product development programme to maintain their world – leading reputation, CompAir asked us whether it would be feasible to re-design the noise control package on one of their compressors. The initial target was to remove the existing silencer element to reduce the overall size of the unit – without any increase in noise or a reduction in the performance of the cooling system. Source control modifications were developed for the cooling system which significantly reduced the overall noise from this element at source and also dramatically cut the tonal content (less “nuisance”). Coupled with modest flow and geometry changes, the new package reduced the overall “headline” noise from the compressor by 2 – 3dB(A), despite removing the standard silencer – and all without any cost or performance implications.compair before after
Engineering source control techniques have been developed for separators and filters that reduce the noise by 5-12dB(A) at very low cost and without compromising hygiene.
Cigarette Making Machine
An engineering noise control kit was developed for this Molins making machine. It reduced the noise by 4dB(A) at very low cost and without affecting normal access or operation. It was licensed by the manufacturer to provide a profitable retro-fit or overhaul option service. This illustrates the commercial opportunities inherent in the engineering noise & vibration control technology in which we specialise.
Cooling Down – HVAC
There is enormous competitive pressure on suppliers to develop quieter A/C and chiller plant. We’ve recently applied our engineering skills to reduce the noise from a new range of A/C units. As a result, they can now quote sound power levels that are at least 4dB(A) lower than before, at, quite literally, no additional cost to the units at all. This has provided the company with a significant commercial advantage and illustrates the benefits of introducing engineering noise control techniques during the development of new products.
Quoting the project manager “.. is the unit actually running?! .. That’s an amazing result over such a short timescale”.
We were asked to look at improving the acoustic design of Custom Design speaker stands for up-market Hi-Fi aficionados. As a result of vibration testing on the stands, we recommended replacing the top and bottom plates with laminated “dead-metal” versions. These reduced the vibration response of the stands by up to 40dB (a factor of x100). According to the review in Hi-Fi Choice
” .. switch to the acoustic steel plates and the sound is even better, with a deeper, quicker base and a more open mid-band. There’s definitely a neutralising effect with the acoustic steel that zaps a lot of colouration, giving a far more neutral sound … Top value upgrade .. 5 stars.”
Pick-and-Place Suction Fan Noise Reduction – a packet quieter…
This suction fan used in a newly designed, automated pick-and-place system for food packets on a production line generated high levels of noise. Conventional fan silencing would not only have posed a hygiene problem (attenuators make use of porous acoustic absorbent materials), but would also have required acoustic enclosure. We re-designed the fan mounting system (interestingly, the fan itself was designed for model aircraft engines) and modified the geometry slightly. This reduced the fan noise at source by 8dB(A) without affecting the efficiency.
Eurostar HVAC Fan Noise Control – no space, no spare capacity, no problem…
The noise from the Eurostar Nightstock HVAC module (140 had been built) was unacceptable in terms of overall noise and tonal content at the fan blade pass frequency. Conventional noise control techniques (silencers) from the manufacturer had been unsuccessful. Maintaining the fan performance was critical and space within the air conditioning system was severely limited and a retro-fit solution was needed very quickly.
The optimum solution involved a combination of Quiet Fan technology with a new 7 bladed impeller design that could be fitted very quickly at low cost and entirely within the existing HVAC unit i.e. no space implications. The whole project was completed within a few days.
As the fan noise reduction modifications reduced the noise at source, they simultaneously treated the intake, exhaust and break-out noise through the fan casing. Conventionally you would have needed separate attenuators for each transmission path that would have had a catastrophic effect on HVAC system performance. The fan modifications will last the lifetime of the unit without maintenance, cleaning or degradation of acoustic or aerodynamic performance. Despite the remarkably high 24dB reduction in tonal content and an overall noise reduction of 8dB(A), the flow was reduced by only 4.7%. This engineering approach is widely applicable to other HVAC plant where it can be used to reduce costs and improve system efficiency.