Stopson Italiana’s Enclosures soundproof the new Grastim trigeneration plant

4 Acoustic Enclosures installed to Ferentino energy plant (FR – Italy). A solution consisting of a 2.7 MW engine, a recovery boiler, and an absorption system.

Grastim chooses Stopson Italiana’s solutions for the soundproofing of the new Ferentino plant, owned by Froneri.
The joint venture between Nestlè and R&R has – in facts – allocated to the company specialized in efficiency for the industry, a considerable amount for the supply of the energy service within the European Gelato Motta pole.

The typology of the plant is “trigeneration”, a particular field of cogeneration systems. In addition to producing electricity, it allows the use of thermal energy recovered from the thermodynamic transformation, also to produce refrigerating energy, that is chilled water for air conditioning or for industrial processes, up to a temperature of -60 degrees.

The plant is equipped with a 2.7 MW motor, recovery boiler and an ammonia absorption plant. Thanks to it, Froneri will save significant annual energy cost, reducing CO2 emissions.

The installation – completed at the end of 2018 – concerns 4 enclosures with different applications:

  • N.1 Acoustic Enclosure for cogenerator
  • N.1 Acoustic Enclosure for air outlet and tank room
  • N.1 Acoustic Enclosure for air exhaust silencer
  • N.1 Insulated Enclosure for auxiliaries

 

With dimensions 13.3 x 3.1 x 3.5 m (Length x Width x Height), the main soundproof cabin is designed to be installed outside on a concrete floor. The structure is made of galvanized carbon steel sheet, containing a rock wool mat, and protected by an expanded galvanized carbon steel sheet.

The sound-absorbing material – in addition to having soundproofing characteristics – provides properties of rot-proofness, incombustibility and unalterability. The structure was designed by a team of structural engineers to withstand different weight levels and any seismic risks too.

The soundproof cabin guarantees a residual average sound pressure level in the free field of 65 dB(A), measured at 10 meters from the cabin and 1.5 meters from the floor.

 

Stopson Italiana has been present for decades in the world market of soundproofing as one of the leading producers of acoustic enclosure and control cabins.

The soundproofing solutions reduce noise pollution due to various sources, including the main turbines, auxiliary engines, internal combustion engines and generating sets, mobile power generators (mounted on trailers) for the production of electricity, cogeneration plants, natural gas compression units, starting and vacuum pumps, blowers, fans, mills, presses, vibrating devices, power transformers and boilers.

 

Stopson Italiana’s enclosures offer:

  • Noise reduction from 15dB (A) to 50dB (A) +
  • Vibration dampers, anti-shock systems with sound emission control settings
  • Combustion air intake unit with optional air filtration
  • Removal of exhaust gases from combustion engines
  • Internal / external applications
  • Natural, induced or forced ventilation system
  • Integrated lighting, fire protection systems, air conditioning
  • Modular solutions
  • Easy access for operation and maintenance with removable panels or sliding hoods
  • Installation service

 

⟶ For More Information about Enclosures and Barriers click HERE 

The Importance of Silencing Offshore Noise operations

How and why to consider Noise Reduction as essential on offshore platform operations. Risks, rules and due diligence for the welfare of Oil and Gas workers.

Health and safety are a crucial aspect of any offshore operation. Several companies across the Oil and Gas industries are highlighting the importance of preserving the better condition of their workers in the last decades.

One of the most challenging issues is – in facts – operating in such a hazardous environment within a noiseless condition.

As reported by Offshore Europe Journal “Offshore workers are daily exposed to helicopters, loud turbines, and several mechanical noises for an extended time. Despite strict rules imposing the use of hearing protection, noise is still inducing hearing loss. Only in the Norwegian Oil and Gas industry, 600 cases/year of hearing loss are reported.

Nevertheless, researchers from the Health and Safety Executive (HSE) estimate that over 30% of workers in the offshore sector are exposed to noise levels in excess of the action limit. This induces a forecast of 120 million people worldwide with disabling hearing difficulties. For example, new fields – often in deeper waters – are continually being discovered. These often require equipment operating at higher pressures and temperatures, creating even more difficult and noisy conditions in which to operate.

 

The Noise impact on Offshore workers

Prolonged exposure to excessive noise levels has the potential to create a wide range of long term and often-irreversible health impacts. Beyond these: permanent hearing loss, cardiovascular diseases, sleep disturbance, stress, brain impairment, and mental health issues.

The effects for business should also not be underestimated where the requirement to limit noise levels often leads to lower productivity levels, with a need for increased staffing or shorter hours of operation. At a time when the offshore Oil and Gas industry is seeking to access deeper complex fields, the challenges remain significant and the opportunities for improved occupational health of staff and overall business productivity greater.

 

How the Noise Regulation has changed

Regulatory changes are also helping the industry to make significant steps towards safer practices. The key pieces of legislation applicable to noise within offshore installations within the UK are the Control of Noise At Work Regulations 2005 implemented under EU Directive 2003/10/EC) and HSE publication OTR2001/068 which outlines technical recommendations for the way in which noise and vibration should be taken into account in the design of offshore platforms. Exposure limits within the Norwegian sector are in line with EU legislation and NORSOK S002 sets similar standards to OTR 2001/068 for living and working areas.

The Control of Noise – as reported on Work Regulations 2005 – reduced the upper and lower action levels by 5 dB from 90 and 85 dB (A) in the previous directive to 85 and 80 dB (A) and introduced a new exposure limit of 87 dB (A).

Equally fundamental, the latest regulations move away from a focus of earlier legislation on assessment, quantification of exposure levels and consequent hearing protection, to a philosophy of controlling noise at source wherever possible.

Within the offshore industry, the move to access deeper fields, coupled with the close proximity pumps, compressors, valves and pipes, and noisy hand tools on a space-constrained single platform, means that specific expertise is required to accurately diagnose and treat platform noise control issues.

 

Acoustic Enclosures in offshore applications

Due to the increasing demand for higher performance of machinery, offshore manufacturers always seek for packaged acoustic enclosure options to mitigate the noise risk and save space.

Stopson Italiana can rely on more than 50 years of experience with a number of solutions ranging from on-skid mounted acoustic enclosures, on-skid acoustic screening, and both skids mounted and deck mounted fully encompassing acoustic enclosures, designed to be accessible by personnel for equipment maintenance purposes.

In line with the specification, packaged enclosure options include hazardous area compliant ventilation systems and filtration, hazardous area lighting and emergency back-up lighting. The can be equipped with full electrical fit out and terminated at internally or externally mounted junction boxes, as well as fire and gas detection and suppression systems.

In certain applications, it is necessary to consider accidental loads in conjunction with environmental loads. In relation to the design of acoustic enclosures, the most critical accidental loads to be considered in most offshore applications are blast loads. Stopson Italiana can engineer manufacturing enclosures that are designed to meet the specification requirements for the most onerous of blast load incidents.

Beyond the noise pressure levels, these designs need to take into account the spatial limitations in terms of access from/to/around the rig.

With raised health and safety standards within the offshore industry, the requirement for Oil and Gas companies to be compliant to noise control solutions has never been more central. Moreover, a recently changed law which places more crucial emphasis on ensuring employee welfare, noise treatment need to be prioritized through the design and development of offshore suppliers.

Enel Green Power soundproofs the Generation Group No. 3 of hydroelectric power plant in Bordogna with Stopson Italiana’s Acoustic Enclosures

Included in the supply are the ante-operam surveys, the design, the construction, the installation and the phonometric measurements of an acoustic booth, for the historic plant in Moio de Calvi, val Brembana.

 

The soundproofing intervention consisting of an acoustic enclosure for the Enel Green Power plant in Bordogna has recently been completed.

The acoustic cabin was designed to be installed inside the beautiful power plant built in 1932 which, exploiting a useful jump of 546.55 meters and a maximum derivable flow of 12 square meters/sec through two forced pipes that feed 3 hydraulic turbines Pelton is in able to provide efficient power of around 47,000 KW.

Acoustic Enclosure, Bordogna Hydroelectric Plant (Italy)

With a size of 11.6 x 11.1 x 3.8 m, the structure has been made accessible and completely removable by means of a bridge crane in its upper part, in order to facilitate the management of the turbine components.

The air outlet from the system has been designed using an electric fan, which, when coupled to a silencer, expels air outside the plant through an opening located on the central window.

The soundproof cabin was designed to guarantee an average residual sound pressure level of 78 dB (A), measured at 1 m from the cabin and 1.7 m from the floor.

Stopson Italiana acoustic enclosures are modeled around every type of noisy equipment, internal or external, on skid and on the ground. They are designed to provide excellent attenuation of sound emissions in any critical environment. The realization takes place in modular acoustic panels and coatings for noise insulation, guaranteeing at the same time the maintenance of the equipment, ventilation, weather protection and fire safety.

 

The typical applications of acoustic enclosures are:

  • Energy production systems, including gas turbine steam turbines, traditional and industrial recovery boilers, diesel generators;
  • Cogeneration plants (CHP);
  • Natural gas compression networks and facilities;
  • Manufacturing and process industry: for example the automotive industry, paper industries, printing houses, etc.

 

⟶ More information about Stopson Italiana Acoustic Enclosures here.

 

Noise Reduction in Power Generation Plants

Power Generation Plant and Soundproofing – a brief introduction

Over the years, there has been a general increase in the use of power plants, from smaller generating plants owned by individuals to large industrial power generation plants. This increase may be attributed to the trends of development which seems to be taking over the global front currently.

With these changes with regards the need for more power, there is the prevailing issue of noise pollution by power generation plants which has been ever-present but is gradually becoming a point of concern for communities and individuals who suffer the effects of noise pollution, especially those emanating from the power generation plants.

While innovations such as industrial soundproofing and industrial silencers have played a role in curbing some of the issues associated with noise pollution from power generation plants, many other factors continue to serve as bottlenecks towards an effective campaign against noise pollution. Some of these factors include:

  • Lack of scalability of power plants
  • Insufficiencies in the design of power plants
  • Challenges with heat management in power plants due to soundproofing materials

 

Why Noise Reduction is important

Noise reduction in power plants is of utmost importance owing largely to the issues associated with persistent noise pollution, especially with regards health. Common noise sources include:

  • Compressors
  • Turbine
  • Fan Intake & Exhaust (PA, ID, FD fans)
  • Generators
  • Piping and ducts
  • Steam Exhaust
  • Motors
  • Centrifugal Blowers

 

Noise reduction in power plants is of grave importance as the employees are exposed to health issues which may not manifest immediately. Some of these issues include:

  • neurobehavioral change
  • psychological stress
  • unhappiness
  • reduced speech intelligibility,
  • permanent hearing loss

These factors may also affect those who may be directly affected by the noise from power generation plants.

 

When Noise reduction in the industry is crucial (limits and tolerance)

According to the Occupational Safety and Health Administration OSHA, the permissible thresholds or permissible exposure limit for noise exposure is set at 90Dba over the course of 8 hours.

To grasp a full understanding of what 90 Dba is, a whisper perhaps between two friends is approximately 30dBA. A regular conversation between two parties is set at approximately 60dBA while a mower operates at 80dBA.

Based on OSHA standards, a noise level increase of 5 Dba translates to an exposure period of half the time. This implies that a worker who is exposed to 95dBA should work for only four hours under such conditions.

Below is a table to ensure better understanding:

Source: https://www.healthlinkbc.ca/health-topics/tf4173

 

 

How is this covered by international standards

A number of health and safety organizations around the world have set certain thresholds, mostly within the aforementioned ranges. Some of these organizations include the ISO, ANSI ad WHO to mention but a few.

 

Which solutions are implementable

Thanks to technological advancements, there are solutions to the menace of noise generation in energy plants. The most common of these solutions, especially for individuals and small-scale business owners are industrial silencers and industrial soundproofing. Some other solutions include:

Duct Silencers – These components offer an incredibly high level of sound reduction in airflow applications. It is mainly applied in stacks, larger ID fans, building ventilation and so many other applications.

Mufflers –While these share a similar concept to the duct silencers above, its mode of operation differs in that it ensures noise reduction in energy plants in that the mufflers are applied to motors or compressed air pipings within the system in a bid to eliminate exhaust noise. Some of the more common applications of mufflers include blowers, compressors and generators.

Acoustical Louvers – Due to the challenges associated with poor designs of some power generation plants and a resulting inability to inculcate a sound proofing system without risking rising temperatures, acoustical louvers provide sound reduction with little to minimal restriction of airflow within the power plants. For the most part, acoustical louvers are used in place of standard louvers for a high level of noise reduction while retaining the effective ventilation of their system.

Duct and Pipe Lagging – While this sounds pretty hands on, it is quite the process to go through with. it simply refers to eliminating breakout noise which is being generated from pipe and ductwork. Hence, the piping or ductwork is neatly wrapped with a barrier absorber composite to keep noise within safe thresholds.

Sound Enclosures – Sound enclosures are arguably the most effective solutions noise control in power generating plants, especially amongst newer designs. With sound enclosures, the power generating plant is simply enclosed, while access for heat dissipation as well as maintenance are made readily available. Sound enclosures are particularly effective in Enclose blowers, pumps, fans or other equipment generating high noise levels.,

Absorptive Panels – Absorption panels serve as an active form of noise reduction in Energy plants. In most cases, these panels are available as an additional feature to generating sets, especially industrial based sets. To large extents, it significantly reduces noise levels in areas of application. It is normally installed to either side of the wall of the generating power plant in a bid to mitigate the noise effects from the power plant.

All in all, the need to match up with the world’s seemingly unchecked noise generation levels in light of increasing power generation cannot be understated. Hence the need for all hands to be on deck in an effort to ensure that noise reduction, particularly in energy plants becomes a reality that everyone embraces.

 

Blow-Off and Steam Vent Silencers successfully installed in re-converted Paper Mill in Northern Italy

Stopson Italiana’s solutions soundproof the restored historical newsprint mill in Mantua.

Beyond Power Generation and Oil and Gas, Stopson Italiana’s soundproofing solutions embrace the manufacturing sector as a whole.
One of the last relevant projects concerns the soundproofing of the recently converted paper mill in Mantua, Lombardy, performed with two types of silencers for different services: Blow-Off and Steam Vent.

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 an horizontal configuration, located laterally to the body of the silencer, is built with higher thicknesses and usually three metal layers. It consists of a pipe with a closed end with a certain number of large holes to allow proper expansion of the fluid and any debris passing through the holes with no damages at the same time.

The silencer – which has a size of Ø 2500 mm x H 7000 mm – has been conceived to achieve a sound pressure level of 100 dB (A) at 20m, which is more challenging than the ordinary soundproofing capacity for this type of silencers.
Discharge conditions: maximum flow rate 135 T / h at 330° C

Due to its capabilities, the typical applications regard the pipes blowing and cleaning processes, as well as the resistance to huge water flows.

The second silencer – that was supporting a larger supply delivered by our partner Tecnoterm Energy S.r.l. – comprised the design, production and installation of a Steam Vent Silencer (SPM model).
The model chosen was specific to reduce the sound emissions generated by the medium and low pressure valve groups.
Produced with a dimension of Ø 2200 mm x H 2900 mm, the silencer provides a residual noise level of 85 dB (A) at 1 m, with a sound attenuation of 50 dB(A) (delivery scheduled for the end of January).

  • Discharge conditions: Maximum flow rate 135 T / h at 160 ° C for the low pressure; 430° C for medium pressure.

The typical applications of this type of silencer are the Revamping Mill Plants and Cogeneration Plants.

 

Our offering for Paper Mill application

Stopson Italiana has a wide range of product for Paper Mill applications, including Air Filtration, Duct Silencer, Acoustic Enclosures and Barriers, Steam Vent Silencers.
Our Vent Silencers are designed to reduce noise level of exhaust piping to the atmosphere for pressurized gaseous fluids, such as air, vapour, natural gas, nitrogen, oxygen, carbon dioxide, etc. They 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.
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
  • Blow-off

Stopson Italiana’s offering for plant Blow-off cleaning does also include additional services and materials as described below:

  • Engineering
  • Steam blow flange
  • Spectacle flanges with gaskets
  • Demi water pumps
  • Gate and globe valves
  • Thermocouples
  • Temperature and Pressure transmitters
  • Pneumatic target plates inserters
  • Installation
  • Blow-off Supervision

Stopson Italiana delivered Blow-Off Services to 2 Power plant in Egypt

Blow-off Equipment, including Silencers, and Supervision from Stopson Italiana supported New Assiut and West Damietta Single to Combined Cycle Power Plants conversion in 2018

Stopson Italiana has successfully completed the supply of steam blow-off silencers and cleaning equipment, including pumps, valves, spectacle flanges, instrumentation and pneumatic target plates system, and provision of supervision services for the blow-off operations of two Combined Cycle Power Plants (CCPP) performed in parallel.

The 230 t/h capacity silencers are equipped with 16 bara design pressure diffuser in a carbon steel casing 6 meters high with 2.5 meters diameter, capable to achieve a residual sound pressure level of 90 dB(A) at 3 m from equipment. Stopson Italiana’s blow-off silencers are based on a combined reactive and absorptive principle for noise reduction: the gases expand to atmospheric pressure through an horizontal large-holes perforated diffuser, providing a first step in attenuation while allowing any debris to flow out, then evolves into a sound-absorbing lining section to further contribute to reach required noise residual level.

The 1 GW New Assiut plant and 500 MW West Damietta plant have gone through a substantial upgrade with the addition of steam turbine modules recovering heat from existing Gas Turbines. This 750 MW addition over the two plants will take the total capacity to 2.25 GW, further contributing to helping meet the increasing demand for power in the country.

 

Stopson Italiana’s offering for plant Blow-off cleaning does include a various range of products and services:

  • Engineering for Blow-off
  • Blow silencers
  • Steam blow flange
  • Spectacle flanges with gaskets
  • Demi water pumps
  • Gate and globe valves
  • Thermocouples
  • Temperature and Pressure transmitters
  • Pneumatic target plates inserters
  • Installation
  • Blow-off Supervision

Stopson Italiana exhibits at Gastech 2018 – Barcelona

With more than 50 years of activity in industrial soundproofing, Stopson Italiana will bring its expertise gained in 20 thousand projects worldwide, most of them accomplished within the Oil & Gas sector.

The Milan based company will present the technological features of its soundproofing products – like Vent Silencers, Engine Exhaust Stack, In-line Silencers and many more, in the world’s leading conference and exhibition for the European Power Generation industry.
For all those attending, Stopson Italiana will make available its technical expertise to support any demanding requirements to develop new sound-proofing and noise abatement solutions in the Gas Industry.

For over 45 years, the Gastech exhibition and conference has been at the forefront of the international gas, LNG and energy market. This world renowned event is regarded as the most significant meeting place for upstream, midstream and downstream gas and LNG professionals, where they convene to do business.

 Visit us at Gastech Barcelona, Spanish Pavilion – Booth G160!

➡ CLICK HERE
TO DOWNLOAD YOUR FREE PASS!

Gastech has fast become a next generation energy event, hosting major NOCs, IOCs, integrated energy companies, global utilities, EPC contractors, shipbuilders, pipeline companies, manufacturers, technology providers and service companies all of whom play an active role in the global energy value chain. Gastech has been at the forefront of the gas and LNG business for more than four decades, with each edition being supported by a host partner since 2002.

With more than 3.500 International Conference Delegates, 1.200 C-Level & Ministerial Attendees and 350 speakers (regarding upstream, midstream and downstream value chains), the event encompasses also a Conference consisting of the Plenary Stage, Strategic conference and Technical conference streams, and four Specialist Conferences.

Gastech’s four-day, multi-streamed conference is regarded as the industry’s most important platform to debate and discuss the global issues and challenges facing the gas and LNG community in 2018 and beyond. The program features ministerial sessions, CEO panel sessions, and commercial sessions, along with the world’s largest technical conference.

Gastech 2018 will take place in Barcelona (Fira Gran Via), September 17-20, and Stopson Italiana will be exhibiting in the Spanish Pavilion – Booth G160.

Stopson Italiana exhibits at Electrify Europe 2018 in Wien

Stopson Italiana will present the technological features of its soundproofing products in the world’s leading conference and exhibition for the European Power Generation industry

In its inaugural year as Electrify Europe, the re‑imagined event (previously “Power Gen”) will be dedicated to the convergence underway between the power generation and the transmission and distribution sectors, driven by digitalization, decarbonization, decentralization and electrification.
For all those attending, Stopson Italiana will make available its technical expertise to support any demanding requirements to develop new sound-proofing and noise abatement solutions in the Power Industry.

Visit us at EE2018, Italian Pavilion – Hall A Booth R52

CLICK HERE ⇦
TO DOWNLOAD YOUR FREE PASS!

With the aim to attract over 11.000 delegates and attendees from more than 85 countries, Electrify Europe represents the industry’s premier conference and exhibition dedicated to the power generation, renewable and alternative energy and transmission and distribution industries. In this year of rebranding, the trade show has extended its conference program including keynote and plenary sessions addressing key issues affecting the sector. Among these: E‑mobility, Cybersecurity, AI, Blockchain, Demand Side Response and Energy Storage. Read full program here.

This year, Electrify Europe will address such topics as:

  • Transforming power economics & management
  • Advances in power generation technology
  • Operations & maintenance in a digital age
  • Sustainability & environmental protection
  • Energy storage & e-mobility
  • Intelligent infrastructure & cybersecurity
  • Empowering the customer
  • Distributed energy & systems
Since 1965 Stopson Italiana has been considered one of the largest provider of noise control solutions such as silencers, enclosures, vent equipment and test facilities for any industrial applications.


The Electrify Europe will take place on 3 days from Tuesday, 19 June to Thursday, 21 June 2018 in Wien and Stopson Italiana will be exhibiting at Hall A Booth R52 (Italian Pavilion)

Silenziatori a Sfiato

An in-depth Analysis about Industrial Silencers Manufacturing

How and what you need to know to soundproof properly your plant

Some basics about noise

Noise is commonly defined as unwanted sound. A typical noise control problem includes three basic components: the noise source (machines, fans, pumps, processes etc.), the receiver (persons subjected to the noise); and the path (the route the noise travels between the source and the receiver indoors or outdoors).

Noise can be classified in two different forms: airborne and structure-borne.

The first one goes from a source to a receiver as a differential in atmospheric pressure, traveling in all directions. Structure-borne instead is unwanted vibration, which is transmitted from a vibrating source to a receiver through a solid material and regenerated as airborne noise. Once the three main elements (source, path and receiver) have been identified, four ways can be adopted to control the noise: absorption, barriers (blocking), damping and vibration isolation.

Perhaps the greatest single contribution of unnecessary noise is the lack of proper maintenance and corresponding preventive maintenance intervals. Equipment that is poorly maintained eventually becomes inefficient. One manifestation of inefficiency is noise (misdirected energy), which, ultimately, becomes the subject of replacement. Typical energy wasters and noise producers are:

  • Steam leaks
  • Slipping belts
  • Worn bearings/gears
  • Improperly aligned belts
  • Unbalanced rotating parts
  • Reciprocating striking parts
  • Insufficiently lubricated parts
  • Contact between moving and stationary parts
  • Compressed air leaks
  • Vibrating sheet metal, such as streamlining
  • Improperly adjusted linkages or cams

 

How to choose the most appropriate Steam Vent Silencer provider

Which are the most relevant data to be considered in order to identify the correct roles within the supply chain of acoustic manufacturers. Understanding all of the factors involved could simplify the selection of the rightest vent silencer for the application required. But first, it’s important to introduce vent and blowdown silencers, reviewing the factors involved in predicting the noise generated by high-pressure vents.

Here below a list about the blowdown and vent applications that require silencers:

  • Steam venting in power generation applications
  • Process control and relief valves in industrial applications
  • Pipeline blowdowns and Natural Gas compressor station
  • Blowdown tanks and autoclaves
  • Bypass valves on blowers and compressors
  • Discharge of high-pressure gas to substantially lower pressure environment (atmosphere).
  • Steam ejectors and hogging vents

 

Vent Silencers and their applications

Stopson Italiana’s Steam Vent Silencers

The terms “vent silencer” and “blowdown silencer” refer to the relative application for which each one is used. For both of them the design is similar, since we refer to vent silencers when being used to vent at a constant flow rate, for a period of time. The word silencer is instead referred to as blowdown, when they are blowing down a finite volume of gas starting at a high pressure, and ending at a low pressure over a given time. Vent silencers are sized for constant flow and blowdown silencers are sized for maximum flow.

Vent silencers find wide applications in high pressure vents, steam vents, safety relief valve outlets, system blow downs and purge outlets etc. Vent and blowdown noise is a function of upstream pressure and temperature, type of gas being vented, the valve size and type, plus the effect of downstream piping.

Stopson Italiana designs and manufactures high quality Vent Silencers that attenuate the high noise produced by the expansion of Gas, Steam or Air at elevated temperatures to atmospheric pressure.

When it’s required the installation of a Vent Silencer, here below all the data required in order to obtain a precise offer:

  • Application (Vent, Blow down, Relief)
  • Fluid Composition (Steam, Gas, Air)
  • Molecular Weight or Specific Gravity
  • Process conditions upstream of valve and units (lb/hr, SCFM, ACFM)
  • Temperature Pressure (P1)
  • Atmospheric pressure ( Pa ) / Temperature (T2)
  • Line size between valve and silencer
  • Line size from silencer discharge
  • Attenuation required (silencer performance)
  • Allowable pressure drop

 

Noise Generated by High-Pressure Vents

Over the years, there has been a good deal of work done in the field of predicting the noise generated by the high-pressure venting of gases.

Factors Influencing Noise Generated by High-Pressure Vents:

  • Mass flow – the higher the mass flow, the noisier it becomes.
  • The type of gas and its molecular weight/specific gravity – lighter gases are noisier.
  • Temperature – higher temperatures result in lighter gas flows, and therefore, higher noise levels.
  • Upstream versus downstream pressure – the higher the upstream pressure is relative to downstream pressure, the louder it will be.
  • Choke flow (critical flow or sonic flow) – occurs when upstream pressure is roughly two times or greater than downstream pressure, making things much noisier.
  • Orifice/opening size of valves, vents, orifice plates, diffusers, etc. – larger diameters result in low frequency noise, while smaller diameters produce higher frequency noise. For instance, diffusers create a shift in the noise spectrum from low frequency (one large vent opening) to high frequency (many smaller openings), which is much easier to attenuate.

Elements Creating Noise in High-Pressure Venting Systems

The noise at the end of a high-pressure vent pipe is a combination of the noise generated by the high-pressure-drop elements in the system. Essentially, any element that has a high-pressure drop across it or large change in area will create noise and should be included in the noise model to accurately predict overall noise level.

The major elements that create noise in high-pressure venting systems are:

  • Pressure relief and control values – present in virtually all venting systems.
  • Vent pipes/nozzles – last element in venting systems, except for those using high-pressure silencer diffusers.
  • High-pressure silencer diffusers – when included, usually designed to provide a specific backpressure at the rated flow (sometimes used as fail-safe device).
  • Orifice plates – included in many systems as a flow regulator or fail-safe device.
  • Enlargers (reducers), headers and abrupt transitions – included in pipe systems for various reasons. Shock Noise Versus Turbulent Mixing.

There are two phenomena that produce noise in a high-pressure venting system:

  • Shock noise – occurs when a choked flow condition exists
  • Turbulent mixing – caused by the ripping of the air as the vent gas decelerates to lower velocity, such as the atmosphere. Shock noise is the louder of the two. By adjusting the elements in a piping system it is possible to reduce the shock noise by reducing the magnitude or quantity of choked flow conditions present. Turbulent mixing, on the other hand, is always present, though less of an issue.

The Sound Vibration Control Magazine released a full report with all the specifications needed (listed in a Data Sheet) in order to proceed with the right purchase of a industrial silencer.

 

Industrial silencers: an increase of demand due to a more strict regulation for industries

An integral part of today’s industrial process and ventilation systems, industrial fans, blowers, and compressors are leading causes of noise problems. If unaddressed, these issues can lead to health and safety concerns, as well as environmental regulation violation. With the tightening of noise regulations, industrial facilities are required to stay in compliance with regulations. Industrial silencers are typical being used to attenuate noise coming from intake and exhaust systems of industrial facilities. These silencers may be built in limited space.  Inside an industrial area, fan installation is one of the most predominant source.

Industrial silencers are engineered to control noise in specific applications, and can alleviate problems in work facilities. With more than 50 years of experience Stopson Italiana soundproofed plants in a broad range of installations, such as:

  • Fan Silencers
  • Duct Silencers
  • Blower Silencers
  • Sound Enclosures

Gas Turbine Engine Exhaust Silencers

Silencers are required for almost all installations that particularly include gas turbines and heat recovery steam generators. Our Gas Turbine Exhaust Silencers are especially designed to work in an environment where they are simultaneously exposed to high temperatures and to high velocity turbulent flow.

Stopson Italiana provides full custom engineered Inlet Exhaust Silencers for Gas Turbines, DG sets Turbo Compressors and Turbo Blowers. They entail complete solutions in the field of Machinery filtration and acoustic solutions for Gas turbines and compressors.

Stopson Italiana Gas Turbine Silencers provide the ideal solution to keep noise at a manageable level, while maintaining the operating efficiency of your turbine intake system.

Stopson Italiana designs and manufactures all types of discharge silencers in compliance with the international quality standards. Our discharge silencers are very much effective in reducing the noise for entire systems that receives air for heavy engines & turbine.

 

Stopson Italiana engineers have been designing application-specific products and services for industrial plants and processes since 1965.
Each product manufactured is tested and inspected to meet all applicable industry standards in terms of quality, longevity and safety.

Stopson Italiana now certified ISO 9001:2015 in compliance with new rules for Quality Management System

Stopson Italiana has just achieved the new ISO 9001:2015 certification, pointing its ethical awareness towards a full compliant and updated Quality Management System.
The certification highlights the company’s focus on pursuing a policy of continuous improvements, constantly keeping all its operating units up-to-date, ensuring customers affordable performance, products and services.
We firmly believe in teamwork – said the CEO of Stopson Italiana -, for this reason, while adopting this new certification we ensure that stakeholders, such as customers, staff, suppliers feel more involved around common objectives”.
Defined by International Organization for Standardization, and provided in Italy by ICIM SpA (Istituto di Certificazione Italiano per la Meccanica), ISO 9001 is a standard that sets out the requirements for a quality management system. It helps businesses and organizations to be more efficient and improve customer satisfaction, sharing the culture of quality for the industrial mechanical sector.
The new version of the standard, ISO 9001:2015, has just been launched, replacing the previous version (ISO 9001:2008).

 

ISO 9001:2015 specifies requirements for a quality management system when an organization:

 

  • needs to demonstrate its ability to consistently provide products and services that meet customer and applicable statutory and regulatory requirements;
  • aims to enhance customer satisfaction through the effective application of the system, including processes for improvement of the system and the assurance of conformity to customer and applicable statutory and regulatory requirements.

 

The main difference with the previous certification

 

The most noteworthy change to the standard is represented by its new structure. In facts, ISO 9001:2015 follows the same overall structure as other ISO management system standards (also known as the High-Level Structure). As a consequence it is more expedient using multiple management systems. Another difference is the focus on risk-based thinking, since this new version gives it increased prominence.

 

Contextual Analysis as a new core issue

 

An other important element of novelty regarding the definition of quality concerns the identification of the context in which the company operates.
Context of the organization is analyzed considering both the internal and external issues that can impact strategic objectives and the planning of the QMS.
In facts, clause 4 of ISO 9001:2015 mentions how the organization needs to evaluate itself and the various elements that influence its context, such the company’s culture, objectives and goals, complexity of products, flow of processes and information, size of the organization, customers, markets, etc.

 

Internal context can include its approach to governance, its contractual relationships with customers, and its interested parties.
In order to determine the external context, a more in depth analysis on social, technological, ethical, political, legal, and economic environment is required.
Examples of external context can include:

 

  • Government regulations and changes in the law
  • Economic shifts in the organization’s market
  • Level of competition
  • Events that may affect corporate reputation
  • Changes in technology

 

The benefits in pills:

 

The new version  ISO 9001:2015 brings the user a number of benefits. Among the others:

 

  • A more relevant emphasis on leadership engagement
  • Support in terms of addressing organizational risks and opportunities within companies
  • Cross and multidisciplinary structure and language, useful in order to make use of multiple management systems (business continuity, environment, health & safety, social responsibility)
  • A deeper insight on supply chain management’s efficiency
  • Thought with a user-friendly approach in the service design

 

See more info about the Stopson Italiana’s certifications here.