Loud noise levels in the offshore oil industry torment workers with hearing damage and tinnitus.
Many workplaces have noise levels that are too loud for the human ear. In the long term, a loud working environment can consequently be damaging to your hearing health, therefore it affects workers’ productivity and accuracy.
Offshore oil rigs and platforms are examples of such noisy workplaces. In 2001, more than 800 workers in Norway reported hearing damage or tinnitus as a result of their line of work.
A study from 2009-2011 by PSA, the Petroleum Safety Authority of Norway, shows that 37% of workers in offshore oil productions are affected by damage to their hearing.
Organizations need to carefully think about the design of their workplace and how to manage noise levels. The negative effects of noise on employees can have financial impacts comparable with the positive impact of investing in acoustic improvements. Therefore, it makes good business sense to invest.
The impact of noise on performance
The British Journal of Psychology published a study that asked workers to perform two tasks, firstly tested without noise and then with a recording of general noise. The test with noise showed a decrease in the accuracy of their work by almost 67%. This test was made introducing noise at levels there are very low compared to offshore plants’ noise, it’s logic to predict that this percentage would increase when speaking of high-noise environments such as power generation plant or offshore platform.
Noise is very stressful and it can leave workers physically and mentally shaken. Prolonged exposure to loud noises can trigger physiologic stress responses in our bodies, including high blood pressure and an increased heart rate.
Studies show that workers are almost 65% less productive in a noisy work environment than employees who work in much quieter workplaces.
Moreover, HLF underlines that a person with reduced hearing is more likely to become physically exhausted at the end of a workday.
Acoustic solutions to mitigate noise
Stopson Italiana has been present for decades in the world market of soundproofing as one of the leading producers of acoustic enclosure, control cabins, and silencers.
Soundproofing solutions reduce noise pollution due to various sources and efficiently respond to any client’s needs.
SILENCERS Absorptive for cold and hot gases, reactive for engines or small boilers exhaust, combined absorptive and reactive for venting systems. Circular or rectangular shape, atmospheric or pressurized for any gas, temperature range, and applications, providing sound attenuation up to 70 dB and reduce residual noise to a sustainable level.
BARRIERS & ENCLOSURES Shaped around noisy equipment, indoor or outdoor, on-base or off-base, designed to provide optimum noise attenuation in any critical environment. Made of modular acoustic panels and linings for sound isolation while ensuring equipment maintenance, ventilation, weather protection, and fire safety.
On-Site tests to make facilities/plants compliant
Together with its soundproofing products, Stopson Italiana provides on-site services making sure to fulfill the customer needs and meet the highest quality standards.
⟶ For More Information about Stopson Italiana soundproofing solutions click HERE
The science behind the sound mitigation solution applied to power plants.
Soundproofing refers to the processes involved in checking the sound from entering or leaving a specified area by absorbing and/ or mitigating the sound. Soundproofing mechanisms can be employed in several situations, especially industries notorious for sound pollution mostly attributed to the use of heavy-duty machinery, Power Generation plants are part of these.
Noise pollution source in power generation plants
There are numerous main sources of noise within a power plant and only a few of the major causes are taken in the exam here.
The sound power level from equipment can spread from about 120 dB to over 155 dB depending on the size and type of machine. There is no easy method to generally categorize one unit as being noisier than another, in fact, the amount of MWs turbine produce does not directly affect the noise they produce. However, diesel engines are more predictable, and generally, the higher the horsepower or kilowatt rating, the higher the noise level because more cylinders and fuel are needed.
Here is a list of some of the common noise source in power plants:
Combustion turbine (CT)
Heat recovery steam generator
Diesel engine
Superchargers on diesel engines
Steam generators, regulators, by-pass and control valves and piping
Air-cooled condensers (ACC)
Cooling towers, produce fan and gearbox noises
Fuel gas pressure regulating, metering and valve stations
Main step-up transformers
Condensate pumps, condenser units, and associated piping
Piping and pipe hangers not acoustically isolated from structures
Blow-off and venting processes
Remote water-pumping stations.
The sound emissions from power generation equipment can be reduced by applying noise control devices.
Sound Field Definition
To analyze noise from equipment, we need to define the sound field – that is, how the sound will propagate from the equipment or the sources of noise. Near field, far field, free field, and reverberant field are frequently mentioned. These are regions that describe certain characteristics of sound propagation as illustrated in the Figure.
Descriptions according to ISO 12001:2009
Near field
The near field of a source is the region close to a source where the sound pressure and acoustic particle velocity are not in phase.
Far field
The far field of a source begins where the near field ends and extends to infinity. Note that the transition from near to far field is gradual in the transition region. In the far field, the direct field radiated by most machinery sources will decay at the rate of about 6 dB each time the distance from the source is doubled.
Free field
The free field is a region in space where sound may propagate free from any form of obstruction.
Reverberant field
The reverberant field of a source is defined as that part of the sound field radiated by a source that has experienced at least one reflection from a boundary of the room or enclosure containing the source.
Fundamentals of Noise Control
Noise control or mitigation involves several steps, and the amount of noise reduction is driven by having to meet an environmental noise limit or some regulatory limit, not to mention workers’ safety. A simple model using the classical approach to noise control (shown below) allows the examination of the options for effective and economical noise control:
source of noise → path of noise →received noise
Solutions
Applying noise control involves affecting one of these three elements. Most often it is the ‘path of noise’ that is controlled by the use of acoustic enclosures, barrier walls, silencers, and other similar noise control treatments. This method is the most widely used as the degree of noise control can be tailored depending upon the noise requirements and generally it is the more economical approach. The control on the ‘source of noise’ can be expensive because it may require a complete redesign and retooling process which takes time and money.
For new plants, examine the structure arrangement and locate the noisiest equipment or operations away from noise-sensitive areas. Grouping smaller sources together can be beneficial in that a common noise barrier or enclosure can solve a lot of small problems.
Stopson Italiana Soundproofing Solutions
Enclosures and Barriers
Shaped around noisy equipment, indoor or outdoor, on-base or off-base, designed to provide optimum noise attenuation in any critical environment. Made of modular acoustic panels and linings for sound isolation while ensuring equipment maintenance, ventilation, weather protection, and fire safety.
Noise abatement by 15dB(A) to 50dB(A)+
Vibration absorbers, anti-shock systems with noise control settings
Combustion air intake Unit with optional air filtration
Soundproofing Materials: 10 Steps to choose the right one and how to test their effectiveness in the Industrial context.
Soundproofing refers to the processes involved in checking the sound from entering or leaving a specified area by absorbing and/ or mitigating the sound. Soundproofing mechanisms can be employed in a number of situations, some of which may include private homes, religious centers, offices, studios, and most especially industries notorious for sound pollution mostly attributed to the use of heavy-duty machinery.
Over the years, it has been discovered that noise pollution has the potential of causing damage to our health than we initially conceived. And as a result of these findings, employers of labor owe their employees good working conditions and a safe working environment, which typically involves a working area that dissipates noise levels below standardized noise thresholds.
What’s more, it’s common knowledge that a noisy environment negatively affects concentration and attentiveness, and would drastically reduce productivity and the quality of service.
More negative effects
Noise pollution doesn’t stop there, it also targets the psychological health of its victims and can trigger health issues such as high blood pressure, hearing impairments, stress, and insomnia. In truth, the list is inexhaustible.
Most industries the world over understand the importance of the health of employees, yet cannot afford to get rid of such heavy-duty machinery due to a lack of quieter alternatives. To solve this problem, it is best to lock in the noise that these machines produce by the installation of quality soundproofing materials.
Soundproofing Materials and How They Work
As was earlier stated, soundproofing simply refers to mitigating the noise within a certain area. This is achievable by installing certain materials (insulators) that trap sound and absorb them.
There exist different types of soundproofing materials and you’d need to consider a lot of factors like the kind of building to be soundproofed and the intensity of noise to be absorbed among many other factors.
Here are a few soundproofing materials used in for industrial soundproofing applications:
Mineral Wool (Rockwool Rockboard)
Soundproof Fiberglass (Owens Corning 703)
Acoustic Fiberglass.
Acoustic Foam Panels.
Echo Absorber™ Acoustic Cotton.
Fabric Wrapped Acoustic Panels.
Fire Rated Foam.
Ten Steps towards choosing the right soundproofing material
There are no wrong materials when it comes to soundproofing, it really just depends on what you aim to achieve. We have, however, come up with 10 guidelines to be followed when choosing soundproofing materials in order to get the best out of soundproofing.
The level/Source of Noise: The level of noise that is to be locked out or in, goes a long way in deciding the kind of materials to use. For minimal noise, soft, specially designed foams can help to absorb the noise, but for noise emanating from heavy-duty machinery, more advanced noise insulators may be adopted.
Propagation of Noise: Noise can either be airborne or structure-borne. To get the best materials for soundproofing, you would need to first determine how the noise travels from the original source to the receiver. This is because some insulators are suited for airborne noise transmission and may be quite ineffective for noise that is structured-based and vice versa.
What are these materials are made of: Some soundproofing materials are more eco-friendly than others, and should generally influence the choice of materials. Some others may include flammable agents which may not be suitable for certain applications.
Thermal Insulation: Some soundproofing materials carry with them some thermal insulation features, which helps to reduce heat also. It is advisable to get these types of soundproofing materials for cost-effectiveness and the added advantage, especially in an industrial setting.
Ease of Installation and Maintenance: When choosing soundproofing materials, it’s advisable that opt for the ones that are easier to install for time maximization. For example, when decoupling walls and ceilings to keep sound front traveling through them, it is best to make use of the resilient sound clips instead of resilient channels because they are easier to install.
Why are you soundproofing? In choosing the right materials, you must understand the purpose for which you are soundproofing in the first place. If the aim is to lock sound in, you should not consider soundproofing materials like the mass loaded vinyl which is specifically designed to keep sound out.
Additional soundproofing: If you are looking to cover the loopholes that may remain after general soundproofing, you should consider getting additional soundproofing such as the under door draft stopper as it seals the small gap between the bottom of the door and the floor, and ensures that there are no under-door spaces that could let noise penetrate or escape.
What parts of the area are most important? You should also determine what parts of the noise prone workspace you want to focus on when soundproofing, as this will help to decide the kind of materials to look out for. For example, the weather stripping can only be used to seal gaps around doors and windows, hence it should not be considered for soundproofing walls.
The best material wins: It is of paramount importance to purchase the best quality materials affordable. You can seek expert opinion in deciding what materials are of the best quality based on your proposed applications. Low-quality materials will only bring you discomfort in the long run and in some cases a potential industrial hazard.
Soundproofing windows: When soundproofing windows, the use of double-glazed windows may fail miserably to effectively mitigate noise pollution, hence, you may opt for thick glass as a more functional alternative. The thicker the glass, the better the results.
How to Test the Effectiveness of Your Soundproofing Materials
To ensure that you are purchasing the best and most effective soundproofing materials for your industry, it is best to run a series of tests. Here are some methods to employ in testing the effectiveness of soundproofing materials:
Making use of Impedance tools: The impedance tube is pretty much a tube with circular ends. There are different types based on size, shape, and material used in making it. This tube can be used in free field situations to test the transfer of sound in a bid to understand the specific soundproofing needs.
The impact insulation class: This is used to test sound-blocking floor soundproofing products. There are other products such as the impact insulation class that test other soundproofing efficiency of other parts of a workspace.
If your industry related noise challenges require that you test how effective sound-blocking materials are for ceilings and walls, you may use the CAC and STC respectively.
For sound absorption material testing, the NRC is your best method. NRC is the comparing of different sound absorption levels through the use of speakers and microphones.
Stopson Italiana produces customized solutions according to the client’s needs. The main soundproofing solutions can be collected in 2 categories:
Silencers
Absorptive for cold and hot gases, reactive for engines or small boilers exhaust, combined absorptive and reactive for venting systems. Circular or rectangular shape, atmospheric or pressurized for any gas, temperature range , and applications providing sound attenuation up to 70 dB and reduce residual noise to a sustainable level.
Shaped around noisy equipment, indoor or outdoor, on-base or off-base, designed to provide optimum noise attenuation in any critical environment. Made of modular acoustic panels and linings for sound isolation while ensuring equipment maintenance, ventilation, weather protection, and fire safety.
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.
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)
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.
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.
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.
How to limit the noise propagation (not only in Oil and Gas). Risks and countermeasures of a phenomenon as important as universally underrated.
The noise pollution’s matter has become a well-documented public domain anthology by now.
The World Health Organisation has reported that 40% of Europe’s population is exposed to noise levels in excess of 55dB. Moreover, noise pollution is ranked as second to air pollution, in terms of affecting our health and wellbeing, including diabetes, tinnitus and risk of heart disease.
Noise pollution in Oil and Gas
According to recent study achieved by PSE Healthy Energy and West Virginia University, some modern Oil and Gas techniques – such as hydraulic fracturing (or “fracking”) – produce noise that may increase adverse effects on human health.
Fracking can create noise at levels high enough to harm the health of people living nearby (source phys.org). “Oil and gas operations produce a complex symphony of noise types, including intermittent and continuous sounds and varying intensities,” argued PSE Healthy Energy Executive Director Seth Shonkoff.
An adequate set of policies should be specified, in order to safeguard residents and communities, such as particularly vulnerable populations (e.g. schools and hospitals). Noise mitigation techniques like perimeter sound walls, noise barriers and acoustic enclosures could represent the most appropriate solutions to hold back this phenomenon.
Noise impact on marine species
This is not all. A recent study led by International Fund for Animal Welfare, reveals the damaging impact of Oil
Noise pollution can damage marine species
and Gas noise pollution on whales and dolphins. In the report, they put in evidence how new technologies should reduce their impact on marine environment during the exploration phase (source: International Fund for Animal Welfare).
Noise and Diseases
Numerous epidemiological studies have linked noise to adverse health outcomes too. They include diabetes, depression, birth complications and cognitive impairment in children.
In facts, apart from damage to hearing, exposure to excessive and constant noise can cause other health problems including:
Headache
Sleep and heart disease
Stress
Elevated blood pressure
Fatigue
Irritability
Digestive disorders
Increased susceptibility to colds and other minor infections
Noise in Europe: limits and human tolerance
As we know, the loudness of noise is measured in decibels. Sensitivity to noise differs from one individual to the next, but experts believe that damage to hearing occurs when noise levels are higher than 85 decibels, which is about the loudness of heavy traffic.
Every year, 7 million people in Europe die from heart disease, which would put the toll from exposure to noise at around 210,000 deaths. In England heart disease kills 110,000 people annually, so the deaths linked to noise could be around 3,300.
2% of Europeans suffer severely disturbed sleep because of noise pollution. The researchers calculate that chronic exposure to loud traffic noise causes three percent of all cases of tinnitus, in which sufferers hear constant noise. Length of exposure is important too. In facts, it is not recommendable to listen to noises of 109 decibels for any longer than two minutes in row.
Noise and public health in U.S.
In US the noise phenomena has been studied deeply, causing a direct response by public health. The Health Impacts Project (HIP) provides since 2013 guidance for policy makers to identify the health consequences of potential projects by making public a national sample of health impact assessment.
Exposure Limits in U.S.
The U.S. EPA recommends an average 24-hr exposure limit of 55 A-weighted decibels (dBA) to protect the public from all adverse effects on health and welfare in residential areas. This limit is a day–night 24-hr average noise level (LDN), with a 10-dBA penalty applied to nighttime levels between 2200 and 0700 hours to account for sleep disruption and no penalty applied to daytime levels.
More info about the Noise sources and Soundproofing solutions in industrial sector can be found here.
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.
According 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.
The main principles that affects the engineering process of a soundproofed plant
The noise pollution is considered nowadays a crucial aspect in the selection and construction of manufacturing plants.
Noise is defined as, “the unwanted, unpleasant or disagreeable sound that causes discomfort to all living beings”. One dB is the faintest sound that a human ear can hear. Unless levels are above 85 decibels, noise pollution should not be a problem in the workplace. Federal occupational safety and health mandates state that if the noise produced by heavy machinery or equipment is in excess of these levels, employers must control noise pollution through engineering and administrative controls.
The environmental noise has been doubling every ten years; The Indian Institute of Oto-Rino Laryngology, Chennaireported, in facts, that increasing industrial pollution damages the hearing ability by at least 20%.
Workers in steel industry, who work close to heavy industrial blowers are exposed to 112dB for eight hours suffer from occupational pollution.
Noise is classified as: Industrial Noise, Transport Noise and Neighbourhood noise. The first one is caused by industry machines, and it entails noise pollution caused by machines from machines in various factories, plants (e.g. Power Generation and Oil & Gas), industries and mills.
The preceding step to the selection and design of control measures, is to identify and carefully evaluate the noise sources. In order to set up the control strategy with the right approach, the following factors need be considered:
Type of sound
Noise levels and temporal pattern
Frequency distribution
Noise sources (location, power, directivity)
Noise propagation pathways, through air or through structure
Room acoustics (reverberation)
Additionally, other crucial factors have to be determined, such number of exposed workers, type of work, amount of time spent to the noise’s exposure etc. Where possible, noise levels should be evaluated at locations occupied by workers’ ears.
The noise control planning is based on a “A-weighted immission” (or noise exposure levels) for which the respect of standard ISO 11690-1 is recommended.
Any noise problem may be described in terms of source, transmission path and a receiver (e.g., a worker); thus a noise control plant needs to take into account the relative combinations of this different factors.
The better phase to project a soundproofing system lies in the original design. In fact, when noise control is included in the first design of a new plant (or factory), advantages both in terms of overall performance and costs’ reduction arise.
When noise cannot be controlled to an acceptable level at the source, attempts has to directed to control it at some point during its propagation path. For this reason, an important part of the process consists to identify noise sources and to sort them in terms of contributions to excessive noise.
When the requirements for noise control have been quantified, and sources ranked, it’s possible to consider various options for implementing the control, determining the cost effectiveness of the various options. Generally speaking, some studies put in evidence that the cost of enclosing a noise source is much greater than modifying the source or process producing the noise.
Stopson Italiana produces fully customized solutions for all type of plants and applications: Boilers, Heat Recovery Steam Generator (HRSG), Turbomachinery, Venting systems, Combustion engines and Industrial equipments.
Expectations and confidence: Goldman Sachs (GS) on the new Donald Trump policy to support crude oil prices.
Initially Donald Trump’s victory, the strengthening dollar, rising US crude oil rigs, and high crude oil, gasoline, and distillate inventories could limit the upside for prices.
Goldman Sachs (GS) expects that successful implementation of OPEC (Organization of the Oil Exporting Countries). Non-OPEC producers’ plan to cut production will reduce the oversupply in the market and support crude oil prices.
Goldman Sachs expects Brent to average $58 per barrel in 2017—compared to its previous forecast of $51.50 per barrel. Likewise, it expects WTI crude oil prices to average $57.50 per barrel for the same period.
However, a recent Reuters report may be showing there was more to the decision to cut production. While the supply imbalance was first the main reason for the cut, now reports are surfacing that prior production levels may have been testing capacity limits.
The Reduction forecast
OPEC agreed to slash the output by 1.2 million barrels/day from Jan. 1, with top exporter Saudi Arabia cutting as much as 486,000 barrels/day.
Non-OPEC oil producers (such as Azerbaijan, Bahrain, Brunei, Equatorial Guinea, Kazakhstan, Malaysia, Mexico, Oman, Russia, Sudan, and South Sudan) agreed to reduce output by 558,000 barrels/day. And this latter starting from Jan. 1, 2017 for six months, to take into account prevailing market conditions and prospects.
Nevertheless, the successful implementation of Donald Trump’s energy policies would lead to a rise in US crude oil production. The rise in non-OPEC production in 2017 would also pressure crude oil prices. A Wall Street Journal survey of major banks predicts that US and Brent prices will average $54 per barrel and $56 per barrel in 2017, respectively. It’s $1 per barrel more than the previous estimates.
Let’s see in June which effects of this policy in the oil market.
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