The cause of complaints about environmental noise levels was traced to this dual fuel burner boiler on a Heinz site. The company contacted us to assess the noise control options as the conventional palliative noise control techniques for this sort of problem involve fitting large silencers into the stack and converting the boiler house into an acoustic enclosure – eye-wateringly expensive with extensive downtime (which would have caused serious production problems).
The source was diagnosed as a 116Hz low frequency “drone” – a very common type of burner noise control problem – with a stunning simple alternative solution that comprised a set of aerodynamic modifications that fitted inside the combustion head. The initial trials were conducted using an adapted yoghurt pot fitted inside the burner head – as far as we know, this is the only known yoghurt-based noise control application… The modified pot reduced the drone by 16dB, completely eliminating the problem.
The cost? Less than £2k with a downtime of a few hours (aluminium version of the yoghurt pot). This new approach and technology can be an incredibly cost-effective solution to many burner or combustion noise problems.
Industrial boiler burner noise attenuation
There are usually only 2 noise sources on industrial boilers and burners:-
- combustion fan: broadband and/or tonal noise at the fan blade pass frequency. Easily controlled using a simple silencer and/or aerodynamic fan noise control technology
- combustion noise in the boiler burner: broadband sound - but very often with a pronounced low-frequency signature (and sometimes pure tones) that can travel large distances (a common cause of complaints). Traditionally, the suggestion is often to spend a large fortune to turn the boiler house into an effective acoustic enclosure. Our alternative is to address the problem at the source - as above...
