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Central Vacuum System Plays Critical Role in Silica Sand Clean-up

June 4, 2014

As a basic component of soil, sand, granite, and many other minerals, crystalline silica is found in many industrial facilities across the U.S. But, manufacturers must handle with care. This by-product has been recognized as a human carcinogen for close to 20 years. It is closely regulated by OSHA and watched by National Institute for Occupational Safety and Health (NIOSH), the EPA and CDC. And, recently, it’s making headlines on the top of OSHA’s regulatory agenda.
       OSHA's Notice of Proposed Rulemaking (NPRM) for Occupational Exposure to Respirable Crystalline Silica was published in the Federal Register on September 12, 2013. The new proposed permissible exposure limit (PEL) is 50 micrograms of respirable crystalline silica per cubic meter of air, averaged over an eight-hour day. The rule would apply to all industry, including construction and maritime. OSHA estimates the new PEL would prevent approximately 700 deaths per year.
       Not only is silica dust a major worker safety concern, but companies are facing hundreds of thousands of dollars in fines for failure to meet current PEL levels. So, keeping a clean, safe facility is a top priority for companies handling any form of silica by-product.
One of the largest independent oil and natural gas companies in the U.S. recently opened a sand processing facility where sand is washed, dried, and sent through a vibration and screening process to separate it by grain (mesh) size. This process involves the transfer of sand from containers to conveyors and back again, up and down seven levels of the plant. As you can imagine, the vibration and transport process results in excess materials and debris falling onto the mezzanines, equipment, and floor.
       “Silica sand isn’t only a nuisance to clean, but it is also highly regulated for health risks. It’s imperative that we keep our environment clean and dust out of the air,” said the production superintendent.
       The company quickly realized mops and brooms were not enough for the job, so the facility began investigating industrial vacuum solutions. Nilfisk Industrial Vacuums was asked to visit the plant for a full site assessment.
       “Sand is extremely abrasive and varies in bulk density and particle size,” said Rob Decker, application engineer, Nilfisk Industrial Vacuums. “It is important to assess each plant to make sure the solution we recommend not only meets our customer’s expectations for efficient, effective cleaning, but also helps them meet standards set by OSHA and other regulatory bodies.”
       After an in-depth project survey and analysis, which took approximately two weeks, the company decided to install a central vacuum system. The system includes a Nilfisk CFM CV15 HEPA central vacuum with approximately 115 ft of 11-gauge galvanized steel tubing to combat abrasion wear. The tubing leads to four ports along the upper mezzanine, allowing two users to operate the vacuum simultaneously. Users can clean quickly and easily with the attached 25-ft-long hoses. An estimated 6000 FPM air velocity delivers 125 CFM to properly collect sand of varying densities.
       The vacuum system is equipped with a hopper specially designed by Nilfisk’s global team to handle the abrasive, toxic nature of silica sand. It includes a cartridge purge system that automatically pulses the filter to keep suction at peak performance. It also includes a double-dump butterfly discharge valve, big-bag frame, maximum level indicator for emergency overfill stop, a deflector made of niploy, and stainless steel chamber body to collect and dispose of the materials safely.
       It took approximately two weeks to install the complete system, but only minutes to “fire it up” explained the staff. They also described it as extremely easy to use. The facility staff simply plugs a hose into an inlet and they can start cleaning immediately.
       “Previously, we would spend an entire 12-hour shift cleaning. Now, we can clean our upper mezzanine areas in 15 minutes,” said the production superintendent.
       Beyond the increased time efficiencies, this new central vacuum system is another step toward keeping their commitment to environmental stewardship and worker safety. With the help of a new central vacuum system, this sand processing plant is a clean, safe work environment.
    For more information, contact Nilfisk Industrial Vacuums at 800-645-3475 or visit www.nilfiskcfm.com.

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