How Industrial Silencers work in HVAC systems

Crucial factors to take in account when silencers have to be installed in HVAC plants.

One of the most frequent application of soundproofing technology (like Acoustic Louvers and Intake Silencers) encompasses definitely the installation on HVAC plants. These installations release sound emission into the environment, often exceeding the allowed thresholds.

That’s because of the noise created by airflow produced by motors or fan. In other cases, the sound waves tend to break out through the walls of the ductwork and spill out into a room. Often, the noise travels the length of the ductwork and spill out the mouth at the vent.

Acoustic EnclosuresAccording to their functions, these machines are arranged in outdoor places, like courtyards and terraces. Hence, the first step is to evaluate the area in which the HVAC systems should be set. That means an accurate mapping process of noise propagation, including ventilation of buildings, enclosures, and equipment rooms. Integration of noise control measures such as silencers and louvers, into the system design requires careful consideration of space constraints, fan selection and aerodynamic pressure losses.

The need is, one one hand, to reduce the noise generated by air or gas flow. On the other, to avoid of compromising the air or gas flow itself, with keeping the pressure drop as low as possible too. For these reason the Stopson Acoustic Louvers, Intake Silencers and Acoustic Enclosures can be considered suitable for these multiple industrial applications. The silencers can be added on the ventilation circuit and combined with the machine, in order to completely acoustically isolate it in any direction.

The HVAC silencers are an excellent choice for applications requiring maximum insertion loss (noise reduction), low static pressure drop, low maintenance, and quick delivery. Stopson’s offer encompasses the design and engineering assistance to integrate the HVAC system with its attenuators. Both ready-made silencers and custom built solutions are offered. The benefits are: durability, surface finishing, ease to operate.

C.O.R.U. Project Moscow

Stopson Italiana delivers Vent Silencers for Refinery and Petrochemical Projects in Russia

EAC certified vent silencers successfully supplied for Oil & Gas projects in Moscow and Kingisepp

Stopson Italiana has recently completed delivery of 10 silencers to be installed at Combined Oil Refinery Unit (CORU), in the Moscow Refinery and 9 vent silencers to be installed at the new Ammonia plant under construction in Kingisepp, Russia, according to the data below:

  • C.O.R.U. Project – no. 10 SPM and PSP vent silencers for the Combined Oil Refinery Unit, with flow rates from 0,4 to 46 t/h. Temperatures from 150 °C to 450 °C, noise levels 80 dB(A) @ 1 m.
  • Kingisepp Project – No. 9 SPM vent silencers for the Ammonia plant, i.e. Steam and CO2 with flow rates from 1 to 130 t/h. Temperatures from 110 °C to 515 °C, noise level 85-110 dB(A) @ 1 m.

9 SPM Vent Silencers Ammonia PlantAll silencers have engineered according to the highly demanding EPC and end user’s technical specifications. They have been manufactured in Italy in special materials, including stainless steel for internal components, and certified in accordance with EAC TR CU 010 standards for Russian market.

Stopson’s Vent Silencers can be installed downstream any device acting as a link between a container of pressurized gaseous fluid and the atmosphere. The vent silencer can also provide high or low back pressure relief for the system ensuring proper operation.

SPM Vent Silencers, used for higher flows and back pressure, are based on a combined reactive and absorptive principle for noise reduction. The gases expand to atmospheric pressure through a perforated diffuser, providing a first important step in attenuation. The flow evolves into a sound-absorbing lining section to further contribute to reach required noise residual level.

PSP Vent Silencers, used for lower flows and back-pressures, feature an expansion chamber upstream the final absorptive section with no diffuser at the inlet.

A special sound-proofed weather hood is finally heading flow and noise upward, while delivering an effective rain protection and drainage.

Vent silencers can be reactive, absorptive or combined type depending on applications and required attenuation, which can reach as much as 75 dB(A).

Typical Applications for vent silencers are:

  • Safety Valve (PSV)
  • Relief valve (PRV)
  • Control valve
  • Ejector
  • Start up valve
  • Snort-valve
  • Flash and Blow Down Tanks