A BP refinery in the USA had been quoted $1.25 million for five 1.5MW double entry ID combustion fan silencers to address the cause of extensive noise complaints. Their acoustic consultant had come across our aerodynamic fan noise control technology on the web and contacted us for advice. He sent his noise data to us by email and we identified that our technology would be ideal as an alternative to fitting fan silencers.
We used the information provided to design the aerodynamic modifications to generate drawings that would allow the components to be made by local contractors. After an installation process that required a tiny fraction of the downtime associated with fitting attenuators, the 180Hz blade pass tone had been completely eliminated (>12dB reduction), preventing any further noise complaints.
The quotation for fitting conventional silencers or mufflers totaled $1.25 million with additional costs associated with the extensive downtime required to fit the attenuators plus increased running costs.
The total project cost for all the aerodynamic modifications not only saved over $1,000,000 from the $1.25 million quotation for conventional silencers, but, in contrast with traditional mufflers, the modifications had no effect on fan efficiency (reduced running costs) and will last the lifetime of the fan with zero maintenance.
No site visits were required, saving time, resources and carbon (transatlantic flights etc). A very self-financing project...