The standard range of rectangular splitter type sound attenuators/silencers have been developed to give virtually any attenuation required in normal practice, in any air handling situation. They are designed for use in industrial ventilation systems, where axial or centrifugal fan noise must be reduced. They are also ideally suited for use as cooling air inlet and outlet silencers for diesel generator sets, compressors, etc. , where they can simply fitted into builders work openings or mounted onto acoustic enclosure. When an installation has external facing walls, our range of fixed blade weatherlouvres, motorised weatherlouvres or gravity operated louvres, can be readily incorporated, to give maximum protection against ingress of rain and to prevent through draughts when the plant is not in operation.
Acoustic and aerodynamic performance is determined in accordance with the recommendations of BS 4718 1971 'Method of Test for Silencers in Air Distribution Systems.' The attenuation is calculated by comparing the sound levels from a sound source, with and without the silencer installed in the duct work between the source and the point of measurement.
Acoustic measurements are carried out without airflow and the attenuation which is measured in dB, in the octave bands from 63Hz to 8KHz, is termed the 'Static Insertion Loss (S.I.L.) . The acoustic performances of our standard range of silencers are shown below.
The silencers are constructed with a 1.6mm thick welded galvanised or zinc coated steel outer skin, with pre drilled, 50 x 50 x 5mm thick rolled steel angle flanges. The internal acoustic splitters are constructed using 1.6mm thick steel casings, with a heavy density rockfibre acoustic infill having a scrim cloth facing to prevent fibre erosion, in turn being retained in place behind 0.7mm thick perforated galvanised sheet steel. The complete assembly can have an external primer/undercoated paint finish, suitable for additional paint treatment if required. The heavy density rockfibre acoustic infill is inert, vermin proof and non-hygroscopic. It has a Class 1 Spread of Flame Certificate to BS 476, part 6.
Where arduous conditions prevail, such as with chemically contaminated processes or offshore applications, the range of silencers can be modified in construction by using heavier gauges of materials, stainless steel materials, hot dip galvanising, specialist paint finishes, etc.