Hi Air - Mercury Emissions Spread Overland!.

Hi Air - Mercury Emissions Spread Overland!.

Hi Air / Water; A national study finds that mercury has spread, even to areas considered to be pristine.

Fig A Above;

Although generally low in concentration, a study of mercury levels in fish from 21 Western national parks did find some locations where mercury concentrations exceeded health thresholds for potential impacts to fish, birds and humans, according to a recent publication by U.S. Geological Survey (USGS) and National Park Service (NPS) researchers. This study, the first of its kind, detected mercury in all of the fish sampled, even from the more pristine areas of the parks.

What is Mercury?

Mercury is a toxic, global contaminant that threatens ecosystem and human health. It is a naturally occurring element and the only metal that exists as a liquid at room temperature. Mercury is also used in industrial practices, mostly for the manufacture of industrial chemicals and for electrical and electronic applications.

The EPA sets standards for safe consumption of fish for human health in regard to mercury levels. In addition, EPA and the U.S. Food and Drug Administration have issued a joint advisory regarding recommended consumption of fish and shellfish due to mercury contamination levels. More than 16 million lake acres and one million river miles are under fish consumption advisories due to mercury in the United States, and 81 percent of all fish consumption advisories issued by EPA are because of mercury contamination.

Where Were These Fish Found?

More than 1,400 fish were collected between 2008 and 2012 from hard-to-reach, high-elevation lakes and streams in 21 national parks in the Western United States and Alaska.  Investigators sampled 16 species, with a focus on sport fish such as brook trout, rainbow, cutthroat and lake trout, as well as smaller prey fish eaten by birds and other wildlife.

How Did Mercury Migrate?

Although there are natural sources of mercury, such as emissions from volcanoes, the majority of the mercury in these high elevation areas arrives from man-made sources such as coal-burning power plants, waste incinerators, oil and gas wells, and mining operations. The mercury can originate many miles from the national parks, as it travels through the atmosphere as tiny particles or gases. It then settles to the ground carried by falling rain or snow, or landing on the ground as dust particles. In wetlands, atmospheric mercury can be transformed into methylmercury, a more dangerous form to living organisms.

Methylmercury levels can accumulate in animals over time and actually increase in concentration up the food chain, resulting in very high levels in larger animals. This process is known as bioaccumulation and happens when predators eat prey animals that already have mercury in them. The mercury in the prey animals is then stored in the tissues of the predator.

Dangerous to Human and Animal Health!!!

During their research, the scientists found that the mercury levels in fish greatly varied between parks and between sites within each park. In most parks, mercury concentrations in fish were moderate to low in comparison with similar fish species from other locations in the Western United States. Mercury concentrations were below EPA’s fish tissue criterion for safe human consumption in 96 percent of the sport fish sampled.

There were, however, particular areas that researchers identified elevated fish mercury concentrations, including levels that exceed safe human consumption or wildlife health benchmarks. Some sport fish exceeded the EPA human health criterion at Lake Clark, Lassen Volcanic, Mount Rainier, Rocky Mountain, Wrangell-St. Elias, Yellowstone and Yosemite national parks.

Mercury concentrations in individual fish also exceeded the most conservative fish toxicity benchmark at Capitol Reef, Lake Clark, Lassen Volcanic, Mount Rainier, Rocky Mountain, Wrangell-St. Elias, Yosemite and Zion national parks. Mercury levels in some fish exceeded the most sensitive health threshold for fish-eating birds at all parks except Crater Lake, Denali, Grand Teton, Great Basin, Great Sand Dunes, Mesa Verde and Sequoia-Kings Canyon national parks.

Start with Science!!!

Although risk of harm to humans and wildlife may be low in many locations, there are substantial concerns about the locations with high risk. 

This study identified areas where additional research is needed to better understand the risk to all national park units, and other remote landscapes or understudied environments.

Ultimately, advisories and related warnings consider both the risks and benefits of consuming fish. 

Future collaborations between research groups would map patterns of mercury across national parks in greater detail, supporting resource managers’ decisions to protect both national park visitors and the wildlife they come to see.

The USGS’s website at  provides many fascinating stories and information, click the link here to visit the site. 

- "Their tag line is “science for a changing world.”

Fig B. Above; Spatial distribution of the 21 national parks sampled in this study. Size of circle represents percentage of total dataset.

Fig C. Above; A NPS researcher holds a brook trout in Mount Rainier National Park. Image credit: Collin Eagles-smith, USGS.

Hi Financial Incentives For Green Retrofits.!

Hi Financial Incentives For Green Retrofits.!

"Did you know a green roof not only helps you cut your facility’s cooling bills in the summer but it can also help you reduce your heating bills in the winter."

In fact, a green roof  can help you reduce your cooling bill by up to 75% compared to conventional roofing, and it can help you save between 5.63% and 5.95% – up to 61% for upper floors – on your heating costs.

A green roof is a “living roof.” It’s either fully or partially covered with vegetation and a growing medium, and it has a waterproofing membrane. 

Additionally it may contain drainage and irrigation systems.

Green roofs can be installed on a range of commercial buildings. 

Thanks to some new financial incentives, green roofs may become increasingly affordable for more facilities.

Building.com

Bishop Loughlin Memorial High School turned its original rooftop (left) into a green roof (right) with help from a DEP grant.
PHOTO CREDIT: DEPARTMENT OF ENVIRONMENTAL PROTECTION.

" Green roofs serve several purposes, but first and foremost they offer shade and remove heat from the air through evapotranspiration – the movement of water to the atmosphere from places like the soil or vegetation. This reduces the temperature of the surface of the roof as well as of the surrounding air."

The "EPA" says these are the benefits of a green roof:

1. Reduces energy usage: Because green roofs absorb heat and insulate buildings, they reduce the energy needed for heating and cooling.
2. Reduces pollution and greenhouse gas emissions: When air conditioning demand is lessened, so is the production of air pollution and greenhouse gas emissions.
3. Improves occupant health and comfort: Green roofs reduce heat transfer, lowering the heat stress usually experienced during heat waves and improving indoor comfort.
4. Better stormwater management and water quality: Greens roofs slow stormwater runoff and filter rain water pollutants.
5. Quality of life: Green roofs provide habitats for many species.

Download EPA .PDF Document.

Green Roofs Chapter (PDF) (29 pp, 4.2MB) from EPA’s Reducing Urban Heat Islands: Compendium of Strategies.

One example of a green roof financial incentive program is the Green Infrastructure Grants from the New York City Department of Environmental Protection (DEP). 

The grants can cover the startup costs for commercial building owners to retrofit their facilities with green roofs.

Two projects serve as examples of what’s possible with the grant funding.

Bishop Loughlin Memorial High School, a Catholic high school in Brooklyn, installed 13,300 square feet of vegetated mats on its building after receiving a $235,700 Green Infrastructure Grant. About 90% of the roof is covered in green material that will help the building handle the expected 435,000 gallons of stormwater that falls on the school’s roof every year.

The South Bronx nonprofit Osborne Association installed a green rooftop system to absorb rainwater and improve air quality. The system is expected to reduce runoff by 32% during a typical storm. The NYC DEP contributed $288,000 to the project via a Green Infrastructure Grant.

The upfront costs of a green roof retrofit are higher when compared to the installation of conventional materials, but facility owners can offset the costs over time through the savings achieved by using less energy and saving stormwater management costs.

Read more about..., "NYC’s Green Infrastructure Grant Program."

Consult your local government office for more information on what incentives may be available to facilities that invest in green roof retrofits.

NYC Green Infrastructure Video.

Hi Court; "Upholds EPA Emission Standards."

WASHINGTON (AP) -- A federal appeals court on Tuesday upheld the Environmental Protection Agency's first emission standards for mercury and other hazardous air pollutants from coal- and oil-fired power plants.

In its ruling, the court rejected state and industry challenges to rules designed to clean up chromium, arsenic, acid gases, nickel, cadmium as well as mercury and other dangerous toxins.

The EPA's determination in 2000 that regulating emission standards is appropriate and necessary, and the agency's reaffirmation of that determination in 2012, 'are amply supported by EPA's findings regarding the health effects of mercury exposure,' said the court.

Congress did not specify what types or levels of public health risks should be deemed a hazard under federal law. 

By leaving this gap in the statute, Congress delegated to the EPA the authority to give reasonable meaning to the term 'hazard,' said the court.

In the majority were chief judge Merrick Garland and judge Judith Rogers, both appointees of President Bill Clinton. 

Judge Brett Kavanaugh, an appointee of President George W. Bush, joined most of the decision, but he parted company with his colleagues on the issue of cost - specifically, whether the EPA is obligated to consider industry costs in deciding whether regulation of hazardous air pollutants from power plants is appropriate.

'The problem here is that EPA did not even consider the costs,' Kavanaugh said. 'And the costs are huge, about $9.6 billion a year - that's billion with a b - by EPA's own calculation.'

In response, the majority said the EPA properly decided that the decision whether to regulate mercury should be based on health risks, not compliance costs. 

The majority added that the EPA had determined that benefits of the rule exceeded costs by a factor of at least 3 to 1. Some industry groups have said the EPA was overstating the benefits.

It is only in the first stage of rulemaking that the EPA doesn't industry costs, said the majority opinion. 

It added that the second stage leads to standards that are more restrictive and that, when setting those, the EPA does consider costs.

The new regulations are designed to remove toxins from the air that contribute to respiratory illnesses, birth defects and developmental problems in children.

Most companies operating power plants will have until March 2015 to meet the standards, but a state could grant an additional year and the EPA could extend the deadline until 2017 if the unit was critical for reliability.

- "The EPA proposed the rules in 2011."

Tuesday's ruling is 'a giant step forward on the road to cleaner, healthier air,' said Fred Krupp, president of the Environmental Defense Fund, which was a party in the case.

The EPA called the decision 'a victory for public health and the environment.'

'These practical and cost-effective standards will save thousands of lives each year, prevent heart and asthma attacks, while slashing emissions of the neurotoxin mercury, which can impair children's ability to learn,' the EPA said.

Laura Sheehan, senior vice president of communications for the American Coalition for Clean Coal Electricity, said that due in part to regulations like the one in Tuesday's ruling, almost 300 coal-fueled generating units in 33 states have announced they will shut down, costing the electricity sector roughly $200 billion in compliance costs and destroying at least 544,000 jobs.

Sheehan said that impacts of EPA's rulemaking processes aimed at coal have already been seen this past winter, with coal power plant retirements leading to increased reliance on natural gas - a just-in-time fuel source subject to volatile price spikes that many consumers and small businesses bore the brunt of. 

She said such impacts will only increase as more coal units are retired, especially next spring, the deadline for complying with the mercury standard.

The coalition says industry has invested $130 billion to reduce major emissions from coal-fueled power plants by nearly 90 percent and that it plans to invest another $100 billion over the next decade on clean coal technology.

National Mining Association President and CEO Hal Quinn said the federal rule 'imposes enormous costs upon households and businesses but provides little additional environmental benefit. The court recognized the EPA has the authority to consider costs but upheld EPA's decision to ignore them.'

Hi Scope; - "OSHA schedules meeting of the Advisory Committee on Construction Safety and Health."

Hi Scope; - "OSHA schedules meeting of the Advisory Committee on Construction Safety and Health."

WASHINGTON -- The Occupational Safety  & Health Administration will hold a meeting of the Advisory Committee on Construction Safety and Health May 7-8, 2014, in Washington, D.C. Work groups will meet May 7 and the full committee will meet May 8.

ACCSH(Advisory Committee on Construction Safety and Health),established under the Contract Work Hours and Safety Standards Act and the Occupational & Safety and Health Act of 1970, advises the secretary of labor and assistant secretary of labor for occupational safety and health on construction standards and policy matters.

Click Here Or Image Above For Further Information On ACCSH.

The full committee agenda includes remarks from Dr. David Michaels, assistant secretary of labor for occupational safety and health, updates on rulemaking projects from OSHA's Directorate of Construction, discussion on the proposed rule on Beryllium: Alternatives for Construction and on updates to OSHA's standard on eye and face protection in construction and proposed amendments and corrections to OSHA's Cranes & Derrick standards. 

In addition, the committee will discuss items from the proposed Standards Improvement Project IV and a presentation on 29 CFR 1926, Subpart V, Power Transmission and Distribution.

Work groups and the full committee will meet in Room N-3437 A-C, U.S. Department of Labor, 200 Constitution Ave., N.W., Washington, DC 20210.The following work groups will meet May 7: Health Hazards, Emerging Issues, and Prevention through Design from 10 a.m. - noon; Temporary Workers from 1-3 p.m.; and Training and Outreach from 3:15-5:15 p.m. 

The full committee meeting will be held from 9 a.m. – 4 p.m., May 8. All meetings are open to the public.

Comments and requests to speak may be submitted electronically at http://www.regulations.gov, the Federal e-Rulemaking Portal. 

Click Here Or The Image Above To Access the Federal e-Rulemaking Portal. 

Comments may also be submitted via mail or facsimile. 

See the Federal register notice for details by clicking the link here.

Comments and requests to speak must be submitted by April 18, 2014.

Under the Occupational Safety and Health Act of 1970, employers are responsible for providing safe and healthful workplaces for their employees. 

OSHA's role is to ensure these conditions for America's working men and women by setting and enforcing standards, and providing training, education and assistance. 

For more information, visit www.osha.gov.

Click Here Or Image Above For Further OSHA Information By Visiting OSHA Website.

Hi Energy Tips – Process Heating & Dust Collector Explosion Protection

Process heating applications involving flammable solvent removal use large amounts  of energy to maintain safe lower flammable limits (LFL) in the exhaust air. National  Fire Protection Association (NFPA) guidelines require the removal of significant amounts of exhaust air to maintain a safe, low-vapor solvent concentration. If LFL monitoring equipment is used to ensure proper vapor concentrations, these guidelines allow for less exhaust air removal. LFL monitoring equipment can improve the efficiency of the solvent removal process and significantly lower process  energy requirements.

Free access to all NFPA Codes & Standards

Flammable solvents used in industrial production processes are typically evaporated in industrial ovens. Higher oven temperatures evaporate solvent vapors more quickly, allowing for faster production. Because the vapors are flammable, the exhaust air is discharged (along with the heat) to prevent the accumulation of the vapors in the oven.  As the oven temperatures increase, plants have to maintain higher ventilation ratios to  reduce the solvent vapor concentration levels and maintain the respective LFL.

For example, the NFPA ventilation safety ratio for batch-loaded ovens operating  below 250ºF is 10:1 and xylol has an LFL of 1%. Therefore, exhaust ventilation  needs to be added to the vapor until the solvent concentration reaches 0.1%, meaning  that the plant has to exhaust 10 times the amount of air required by the process to  meet the NFPA requirement. If the process operates above 250ºF, the required safety  ratio rises to 14:1, the LFL goes down to 0.07%, and the plant has to exhaust 14 times the amount of air required to keep the process from becoming flammable.

The non-uniform rate of solvent vaporization is one of the reasons why LFLs are so stringent. Solvent vaporization is inherently non-uniform mainly because of wall losses and load characteristics; this causes periodically high solvent concentrations in  the oven during the vaporization process. As a result, safe ventilation ratios are calculated using the theoretical peak needs of ventilation based on the highest vapor concentrations that can accumulate during the vaporization process.

LFL Monitoring Equipment

LFL monitoring equipment can reduce energy used in solvent removal by adjusting  the ventilation ratio according to the fluctuations in vapor concentration. The equipment continuously tracks the solvent extraction rate in real time and controls the rate of ventilation air based on real needs, thereby maintaining a safe ratio throughout the process. LFL monitoring equipment can employ several technologies including catalytic systems, infrared sensors, ionization systems and combustion sensors. LFL monitoring equipment has self-check functions and uses a calibrated test gas for periodic self-calibration. Because the vaporization process depends on the intake and exhaust air, linking the LFL controller to an adjustable speed drive on the exhaust system fan can improve process efficiency even further (damper adjustments can also be used).

Suggested Actions

Evaluate energy costs, process load and production requirements to determine the economic feasibility of LFL monitoring equipment.

Examine process energy requirements to confirm the flammable solvent load. If this 

load has changed over time, ventilation rates may need to be adjusted.

Using a booster oven can reduce the evaporation requirements in the main oven, thus reducing its exhaust requirements

Consider a professional outside evaluation to determine the technical and economic feasibility of additional improvements including reducing wall losses, installing heat ex-changers and fume incinerators, and recuperating exhaust air to capture the heat value of exhaust air.

Check all relevant NFPA and other applicable codes, regulations, and standards before adding equipment or making adjustments and consider consulting with an expert.

Example

The NFPA safety ventilation ratios are significantly lower when LFL monitoring equipment is used than when such equipment is absent. This lowers the energy requirements for the process because less air needs to be exhausted to keep the process from becoming flammable. For a continuous strip coating process requiring 46 gallons of xylol with a maximum oven temperature of 800ºF and ambient air temperature of 70ºF, the safety ventilation ratio is 4:1 without LFL monitoring equipment. This results in an exhaust requirement of 8,330 standard cubic feet per minute and energy consumption of 6.7 million British thermal units (MMBtu) per hour. At a cost of $8/MMBtu assuming a two-shift operation, this process costs approximately $214,000 annually. Installing LFL monitoring equipment would reduce the ratio to 2:1, halving the exhaust and energy requirements. Annual energy savings would total $107,000. With an installed cost of $12,500 for an LFL controller, the simple payback is very attractive at less than 1.5 months.

Understanding Dust Collector Explosion Protection

Many production operations generate combustible dusts that are highly flammable and explosive under the certain conditions. A combustible dust is defined as any finely divided solid material, 420 microns or less in diameter, that presents a fire or explosion hazard when dispersed and ignited in air or other gaseous oxidizer. Plastic, agricultural, food, pharmaceutical, carbonaceous and metal are some of the dusts that can be explosive.

Combustion occurs when dust and air mix together in the proper quantities in the presence of an ignition source. When combustion takes place in a confined space, an explosion occurs accompanied by an increase in pressure inside the confined space. If the confined space is strong enough, the explosion will be contained.

The National Fire Protection Association (NFPA) has issued a number of publications related to the prevention of industrial dust explosions. These standards and guides should be reviewed in detail if your dust control system handles combustible dust. Some of these standards have been made part of state safety codes and should be incorporated in your dust control system specifications and design. 

View The National Fire Protection Association Standards NFPA 654 Click Here

The purpose of NFPA 654, is the prevention of fire and dust explosions in the chemical, dye, pharmaceutical and plastics industries and to prescribe reasonable requirements for safety to life and property from fire and explosion and to minimize the resulting damage should a fire or explosion occur. Some highlights from this standard are:

1. A continuous industrial exhaust system shall be installed for processes where combustible dust is liberated in normal operations.
   
   
2. The industrial exhaust system shall incorporate a dust collector. Industrial exhaust system components including the duct-work and dust collector must be so constructed such that dust does not leak out of the system components when the system is shut down.
   
   
3. The dust control system shall comply with the requirements of NFPA 91, Standard for Exhaust Systems for Air Conveying of Materials.
   
   
4. Dust collectors for industrial dust control shall be located outside of buildings. Dust collectors may be located inside of buildings if they are located near an outside wall, are vented to the outside through straight reinforced ducts not exceeding 10 feet in length, and have explosion vents designed according to information in NFPA 68, Venting of Deflagrations. Some think that installing an explosion vent on a dust collector prevents an explosion. This is not the case. The vent relieves the pressure of an explosion. Dust collectors can be installed safely inside buildings only under one of the following conditions:
   
   
   
   
   
   
   
   * The dust collector is protected by an explosion suppression system meeting the requirements of NFPA 69, Explosion Prevention Systems.
   
   
   * The dust collector has an explosion relief vent meeting the requirements of NFPA 68, Venting of Deflagrations, and the vent is properly ducted in accordance with NFPA 68 through a nearby outside wall.

   Choosing Methods of Dust Control, Dust Collection, and Dust Explosion Protection

   

   
   

   It is not normally practical to build a dust collector strong enough to fully withstand the maximum pressure of a dust explosion. Other methods of protection are usually taken. Suppression or venting or a combination of both can be used to minimize the safety hazard and property damage caused by a dust explosion in the dust collector.

   
   

   
   

   The most important factor in determining the best method of dust explosion protection is a proper analysis of the dust. Samples of the dust should be tested by a qualified lab to determine dust explosion severity and the minimum ignition concentration for explosion. Tests following ASTM E1226, Standard Test Method for Pressure and Rate of Pressure Rise for Combustible Dusts, will provide details about your dust's explosive characteristics. It is important to note that the sample tested must be a sample of collected dust and not a sample of your powdered product. The explosion characteristics of the two are usually different with the collected dust being more explosive because of smaller particle size.

   
   

   

   
   

   You should also realize that changes in powdered product composition, particle size or moisture content, and, as a result, the collected dust may affect dust explosion severity and the minimum concentration for explosion. Don't use someone else's test data. Analyze your own test information to set correct specifications. Test the collected dust, not the product powder, periodically after installation to confirm that safe conditions continue to exist. If conditions have changed, the explosion suppression system and/or explosion venting may need to be upgraded.

   Dust Explosion Suppression

   NFPA 69, Explosion Prevention Systems, 1992 Edition, defines dust explosion suppression as the technique of detecting and arresting combustion in a confined space while the combustion is in its incipient stage, thus preventing the development of pressures that could result in an explosion. Explosion suppression systems will be successful in cases where the suppressant can be effectively distributed.

   
   

   VIEW NFPA 69: STANDARD ON EXPLOSION PREVENTION SYSTEMS cLICK HERE

   
   

   

   
   

   The design of every dust explosion suppression system must be thoroughly analyzed with respect to the equipment to be protected, dust characteristics, type and location of detectors, suppressant chemistry and the installation and operation of the dust explosion control system and the related process. Although some explosion suppression systems are more expensive to install and to maintain as compared to explosion venting, suppression systems may be the only choice when venting cannot be properly installed.

   There are three dust explosion suppression system manufacturers in the United States who can advise you on applying dust explosion suppression systems to your dust collector as part of your industrial dust control system. Your specification must provide enough details so that the suppression system manufacturer can select the proper system configuration.

   
   

   

   Dust Explosion Venting

   NFPA 68, Venting of Deflagrations, applies to equipment or enclosures needing to withstand more than 1.5 psig pressure. Most dust collectors need additional reinforcement for that capability. The maximum pressure that will be reached during an explosion will always be greater than the pressure at which the vent device releases. NFPA 68 calls for a pressure differential of at least 50 lbs./ft2 or 0.35 psi between the vent release pressure and the resistive pressure of the dust collector (enclosure). This NFPA guide lists the following basic principles that are common to the venting of deflagrations. You should become familiar with these principles so that you can correctly specify the conditions the dust collector and explosion vent must satisfy.

   
   

   View NFPA 68: STANDARD ON EXPLOSION PROTECTION BY DEFLAGRATION Click Here

   

   
   

   
   

   1. The vent design must be sufficient to prevent deflagration pressure inside the dust collector from exceeding two-thirds of the ultimate strength of the weakest part of the dust collector, which must not fail. This criterion does anticipate that the dust collector may deform. So do expect some downtime with the dust control system after an explosion.
   2. Dust vent explosion operation must not be affected by snow, ice, sticky materials or similar interference's.
   3. Dust explosion vent closures must have a low mass per unit area to reduce opening time. NFPA recommends a maximum total mass divided by the area of the vent opening of 2.5 lbs./ft2.
   4. Dust explosion vent closures should not become projectiles as a result of their operation. The closure should be properly restrained without affecting its function.
   5. Vent closures must not be affected by the process conditions which it protects nor by conditions on the non-process side.
   6. Explosion vent closures must release at over pressures close to their design release pressures. Magnetic or spring-loaded closures will satisfy this criterion when properly designed.
   7. Explosion vent closures must reliably withstand fluctuating pressure differentials that are below the design release pressure.
   8. Dust explosion vent closures must be inspected and properly maintained in order to ensure dependable operation. In some cases, this may mean replacing the vent closure at suitable time intervals.
   9. The supporting structure for the dust collector must be strong enough to withstand any reaction forces developed as a result of operation of the dust explosion vent.
   10. Industrial exhaust system duct-work connected to the dust collector may also require explosion venting.

   
   

   
   

   Dust Explosion Vent Ducts

   Dust collectors that are vented for dust explosions should be installed in an outdoor location with vents directed safely away from persons and property. When there is no alternative to locating a dust collector inside a building, vent ducts should be installed to safely direct the vented flames, gases and debris from the dust collector to the outside of the building.

   
   

   

   
   

   You must be aware of the fact that adding a vent duct to a dust collector will change the conditions that the dust collector will be exposed to during an explosion. The use of explosion vent ducts will significantly increase the pressure in the dust collector during venting. The vent duct must have a cross-section at least as great as that of the vent itself. A vent duct with a cross-section larger than that of the vent will result in a smaller increase in the maximum pressure produced during venting. NFPA 68 includes a graph showing the increase in over pressure (within the dust collector) due to the use of vent ducts as a function of straight duct length.

   
   

   Dust explosion vent ducts should be kept under 3 meters in length and as straight as possible. Any changes in vent duct direction increases the over pressure developed during venting. In all cases, the vent duct must be made as strong as the dust collector. The vent duct configuration must be submitted to the dust collector manufacturer with the dust collector specification for proper design.

   Dust Control Explosion Prevention System Inspection and Maintenance

   Inspection and maintenance of suppression and venting systems should be done in accordance with the manufacturer's recommendations and NFPA standards.

   
   

   For dust explosion suppression systems, NFPA 69 states that suppression systems shall be thoroughly inspected and tested at 3-month intervals by personnel trained by the system's manufacturer. In the event of suppression system operation, all components shall be inspected, replacement parts installed if necessary, and the system tested prior to restoration to full operating condition. See NFPA 69 for more details.

   
   

   

   
   

   For dust explosion vents, NFPA 68 calls for visual verification that the vent closure is in place and able to function as intended. This is done by ensuring that the vent closure is properly installed, that it has not operated or been tampered with, and that there is no condition that might hinder its operation. Maintenance includes preventive and remedial actions taken to ensure proper operation of the vent closure. See NFPA 68 for more details.

   
   

   

   
   

   
   

   An important activity often neglected is the periodic sampling of the collected dust for an explosibility determination. If the process has changed so that the particle size or shape of the collected dust has changed, dust explosibility may be affected. If the chemistry of the processed product has changed, dust explosibility may again be affected. If the collected dust shows an increase in explosibility above the level for which the installed explosion suppression or venting system was designed, immediate action must be taken to correct the deviation from the design condition.
   
   

   Product Highlight

Click to Email & Contact Hammam Industries & Co. Egypt, Regional Supplier of The Market Leader Donaldson Torit Dust Collectors & Filters in Egypt or Click Here To Visit Donaldson Torti Website.

Exactly what you need for dust, fume & mist collection, Donaldson Torit's broad range of collectors and filters gives the customers interviewed in this video exactly what they need for dust, fume and mist collection. 

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