When steam, air, natural gas, nitrogen, oxygen or any other process or hydrocarbon gas is vented to atmospheric pressure, if released from a pressure higher than only a few Psi, or KPa, then a harmful noise level will happen that can be injure nearby workers, or disturb local residents.
Whether the pressure release is planned or unexpected, Flo-Dyne can offer the most economical silencing solution by optimising silencer design to produce a noise level that is acceptable for nearby workers or residents.
Flo-Dyne's vent silencers comprise of two key components, the inlet diffuser and the absorptive pack.
The inlet diffuser provides back pressure onto the inlet pipework and controls the flow through the silencer. It's importance is that is that it provides attenuation, primarily of low frequency and is often a pressure retaining part, and 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.
The structural design of the Flo-Dyne Vent Silencer is given the same thorough attention as its acoustic design, with external forces such as wind, nozzle and seismic loads all being considered in the design.
The external shell is constructed of seamless pipe in smaller sizes or continuously welded rolled plate in larger diameter silencers. NDT examination such as x-ray, dye pen or magnetic particle examination is regularly used to prove the integrity of our welding.
Units may be mounted horizontally or vertically, with pads or cradle type supports being supplied as standard for easy installation.
A variety of weather-hoods are available to keep out rain, snow and sand.
Should you require, we can provide inlet nozzles with moving inlets that provide a significant range of axial and lateral displacement as well as allowing bending and rotational movement.
All of Flo-Dyne's atmospheric vent silencers can be supplied with or without an inlet diffuser. However, when silencers are supplied without an inlet diffuser this usually result in a larger silencer as the absorptive pack has to make up for the acoustic attenuation that the diffuser would have provided.
Where a silencer is provided with an inlet diffuser then the diffuser then we can help choose a suitable pressure drop (back pressure) and we will then constructed the diffuser accordingly.
Back pressure is sometimes seen as a bad thing, however this is not always the case. Because it is impossible to have a silencer with zero pressure drop, because there would then be no flow, why not choose a pressure drop that improves the cost and efficiency of the system.
When the back pressure is chosen carefully then the noise generated at the upstream valve will be reduced, less noise will be radiated by the pipework leading up to the silencer, the flow velocity in the pipework between the valve and the silencer can be reduced, as can the pipe size, as well as achieving an overall smaller size of silencer.
When required, we can help examine the pressure losses through the pipework between the venting valve and the silencer and recommend the most suitable silencer pressure drop for your system.
Equipment is available in a variety of materials, but most commonly in ordinary carbon steels, 3104(L) and 316(L) stainless steels.
