Month: <span>February 2022</span>

How to solve temporary noise reduction needs linked to Blow-off Operations

Nearly any high-pressure gas or steam application has the need to purge or evacuate a system at certain times or as a safety measure. When releasing high-pressure gases into the atmosphere, a large amount of kinetic energy is freed due to the pressure difference. The pressure difference causes a dramatic increase in velocity which results in high sound emissions which need to be reduced.

Stopson Italiana Blow-off Silencers are specifically designed to reduce the noise generated by the high differential pressure at the time of a release. The engineering and calculation processes require the following data: medium, mass flow, pressure, and temperature upstream of the valve. The acoustic design covers two main steps: the determination of the non-silenced sound power level and the calculation of the silencer itself.

The sound power level can be transmitted by the valve supplier or inferred by Stopson Italiana using a proprietary framework developed on international standards, and honed by Stopson Italiana’s scientists.

What is a Blow-Off Silencer

The Blow-Off type is a typical expansion and absorption silencer, which is used before the system’s enactment. The principal use is to clean the pipes, removing any solid bodies and residual debris after erection and installation. The expander has a horizontal configuration, located laterally to the body of the silencer, is built with higher thicknesses and usually three metal layers (Case Study: Stopson Italiana’s Blow-off installation in a reconverted paper mill in Italy here).

Soundproofing temporary installations

Profiting from almost sixty years of experience, Stopson Italiana has developed the most efficient silencers with the longest design life. For temporary installations – like steam purging of pipes before plant start-up or boiler/pipe system maintenance – suitable blow-off silencers for rent are now available.

Stopson Italiana’s Blow-Off Silencers cover a wide range of flow rates, pressures, and most common acoustical guarantee targets:

• 20 t/h up to 250 t/h flow capacity
• 4 bar to 8 bar Inlet pressure
• 100 dB(A) @ 1m residual SPL or
  95 dB(A) @ 10 m or
  85 dB(A) @ 30 m

In addition, they are designed to withstand typical blow-off temperatures and feature the following characteristics:

• Corten A body and structure for a longer resistance at high temperature
• AISI304 diffuser for clean fluid operations
• 12”/20” inlet connections with customized adapters available upon request
• T-joint to avoid larger debris flowing into the diffuser
• Supporting legs 1.5 meters high from the ground

Stopson Italiana Blow-Off silencers are currently available in three models to cover the entire range of flow rates:

• SPM 20-70/B: 20-70 t/h capacity range, from 1.2 bar inlet pressure
• SPM 70-120/B: 70-120 t/h capacity range, from 5 bar inlet pressure
• SPM 120-250/B: 120-250 t/h capacity range, from 8 bar inlet pressure

Blow-Off silencers can be also tailor-made for Sales against project and Customer specifications with flow rates up to 900 t/h. Stopson Italiana offers an important contribution to the early design process to optimize the system of valves, pipes, and silencers with regard to sizes and costs.

BLOW-OFF OPERATIONS SERVICES

To support plant blow-off operations Stopson Italiana provides a wide range of additional equipment and services:

Engineering Services:

• Hydraulic Engineering
• Instruction and Procedures
• Temporary Piping and Support Design
• Final Report

Equipment – Sales and Rental Services:

• Blow off silencers
• Manual/Pneumatic Target Plate Holder
• Target Plates
• Valves
• Pumps
• Accessories

On-site Services:

• Supervision
• Consulting Services
• Engineering
• Representation

Stopson Italiana’s extensive knowledge and experience providing A-Z soundproofing solutions to industrial facilities since 1965, ensure the supply of comprehensive acoustical solutions in support of meeting customer mandatory requirements and their soundproofing objectives, being temporary or permanent.