Flo-Dyne's blow down silencer will be built with two key components, the inlet diffuser and the absorptive pack.
The inlet diffuser provides back pressure onto the inlet pipework and restricts the flow through the silencer and will, like an orifice plate, control the blow down timing of the system. The diffuser also acts as an acoustic device because it provides attenuation, primarily at low frequencies and is often considered a pressure retaining part which must be built to the same standards as the incoming pipework. CE marking of this component is often mandatory.
The absorptive pack is the second component, it provides little resistance to flow, and is made from tubes and panels of perforated steel sheet that have a porous material, such as glass fibre or rock wool packed in between. The choice of materials, perforations, packing materials and flow passage arrangement is crucial to the overall performance of the silencer.