Atmospheric steam silencers are designed to cut the noise generated by the expansion of steam from an elevated pressure to atmospheric pressure.
The noise produced is a combination of ‘shock noise’ generated by the rapid reduction in pressure across the relief device and the noise created by the turbulent flow of steam downstream.
The Trust Well-designed steam silencers consists of an inlet diffuser, an expansion chamber and an absorptive section.
The vented steam enters the inlet diffuser of the silencer and expands across a series of small holes in the diffuser body as it proceeds into the expansion chamber.
From there it flows into the absorptive section before being passed into the atmosphere. The diffuser forces the vented steam to pass through small radial holes normal to the initial steam flow.
This breaks the single axial steam jet into a series of smaller radial jets, increasing the frequency of the generated noise so that it can be better attenuated by the absorptive section of the silencer.
In circumstances where the steam velocity in the inlet pipe is low, a simple open pipe and a target plate can be used in place of the multi-holed diffuser. The pressure at the inlet diffuser of the Trust Well design of steam silencer is never more than 0.5 barg to ensure exemption from the requirements of the Pressure Equipment Directive.
This some time necessitates an inlet diffuser diameter greater than the vent line. The two can be connected by a transition section. The cross-sectional area of the silencer is a function of the flow rate of the steam to be handled, while the length of the silencer controls its acoustic performance.
Steam silencers are used in areas where it is necessary to:
Suppress the noise generated by safety relief valves, process vents, dumping steam to atmosphere during compressor or boiler set-up sequences, de-pressurising lines for maintenance, ejector discharges and steam exhausts, and the blow down of pipelines for cleaning purposes.
Join the team of winning people.