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.

 

Stopson Ventilation Silencers to be installed at Gas Compression stations in Northern Italy

Completed delivery of 12+8 combined Ventilation System Building for Gas storage plant in Sergnano and Minerbio (Italy)

 

Stopson has successfully fulfilled the delivery of 12+8 Ventilation System Buildings for the natural gas Compression Stations in Sergnano and Minerbio (Italy).

Ventilation System Building for Industry
Section of combined Filtered-and-silenced Inlet System (Cremona – Italy)

The supply service entails a total of twenty ventilation systems, composed by 20 filtered-and-silenced Inlet System together with the same number of Soundproofed Outlet Systems with forced extraction and fireproof dumpers.

The acoustic warranty covers a noise level reduction of 30 dB(A) SPL at 1mt.The order has been completed and tested phase in these past days.

In general, the plant consists of implementation of 3 turbo-compressor to be set within the Sergnano gas infrastructure. The operations necessary for the installation of the station will be completed as a whole by mid 2018.

The total investment amount is 0.6 bln € (between 2017-2021), aimed to increase the general safety and flexibility of the area, bringing a resources’ capacity increment of 7% circa.

Thanks to a 50 years of experience in the field of industrial soundproofing, Stopson’ technical department is able to deeply analyze and propose the rightest solutions to control noise produced by the extraction systems.

Some possible applications are:

  • Soundproofing of compressors
  • Soundproofing of pumps
  • Silencers for industrial fans
  • Soundproofing air expulsion chimneys
  • Silencers for ATU/air treatment units
  • Silencers for extraction systems
  • Soundproofing engine testing room
  • Silencers for side channel blowers

The main solutions consists of rectangular or circular silencers, designed taking into account of the different noise sources and sound spectrum. The installation can be made along the piping or chimneys of emission into the atmosphere.

They can be designed and produced in standard dimensions, or in any size on request and are equipped for external air intake, in addition to return from the filter system.

Everything You Need to Know about Noise Pollution

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 hydraulic fracturing (or “fracking”) – produce noise that may increase adverse effects on human health. 

A fracking well in Colorado, pictured in 2012

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.

A adequate set of policies should be specified, in order to safeguard residents and communities, such 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, that 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 per cent 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 healthThe 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.

 

 

ventilation silencer

Why control of noise is so important in manufacturing

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, Chennai reported, 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.

Check it out http://stopson.it/applications/