Qenos Plastics has accepted five noise complaints between 10-13 May 2013 related to a tonal noise generated from a low speed gear box fitted to the Reactor 1 Recycle Gas Compressor in Mid April.

The gear box was generating a tonal noise @ 800 hz at the complaint locations in Blythe Street, Civic Parade and Galvin Street in Altona which was confirmed during the investigations.

Two complaints were received on Friday 10 May with a further three complaints on Monday 13 May. Qenos arranged shutdown of the compressor on Monday evening to replace the noisy low speed gearbox with the previous gear box, which has removed the tonal noise. The low speed gear box was installed as part of an ongoing program (included in Qenos EIP) to reduce the energy consumption of the Recycle Gas Compressors and has already reduced power consumption from 1040kw to 850kw from previously installed gear boxes, by reducing the compressor speed from 6625 rpm to 5960.

The final speed reduction step to 5760 rpm can reduce the energy consumption to around 750 kw. Previous attempts at this speed had failed within days, due to the development of vibration, with the latest gear box having effected further enhancements to address the vibration issues experienced.

The compressor came on line on April 17 with the latest gear box and there was no hint of there being any noise issues on site with the gear box until the first noise complaint about offsite noise on Friday 10 May. Detailed evaluations of the noise were already in progress when the three further complaints were received and the decision was made to shutdown the compressor.

A Qenos Incident Report has been raised and will be investigated with a report on the findings being sent to all ACNCG members.