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Cement Companies Combat Heavy Dust with Industrial Vacuum Cleaners

September 27, 2007
Cleanup around boot seals is more effective with air-operated industrial vacuum cleaners (above) than with shovels and wheelbarrows (below).

In an industry that has its roots in ancient Roman times and turns mountains to dust with rugged equipment that pounds, crushes, and grinds, a vacuum cleaner seems almost unnatural. However, with recent supply shortages and tighter EPA and OSHA regulations, Portland cement manufacturers are finding vacuum cleaners to be ideal for reclaiming product and complying with health and safety regulations. As a result, industrial vacuum cleaners are being used in nearly every step of the manufacturing process, from the cement plant to the lab, in loading and unloading terminals, and in bagging operations.

Each step in the manufacturing and distribution process has its own pains and thus requires unique solutions. In the lab environment, a little dust is a big problem and may require a dedusting system for quality control measures, but a cement plant that spans many floors and produces 1000 lb of dust per day may require a central vacuum system with a piping network to each floor. For bagging operations where dust is difficult to control, a continuous-duty vacuum system is ideal. In areas where spillage is minimal, such as loading and unloading stations, a single portable air-operated vac may work for periodic cleanup.

Industrial vacuum cleaners are more sophisticated than their cousin, the shop-type vac that has been labeled “asthmatic” when up against the savage conditions in the cement industry.

“We tried shop vacuums, but they just wouldn’t last,” says Andy Rodgers, terminal manager at Buzzi Unicem USA’s Pensacola, FL, terminal. “The dust just eats everything up, and the motors don’t last.”

Air-Operated Vacuum Cleaners and Cleanup for Railcar Unloading

The Pensacola terminal unloads Portland cement from bottom-dump railcars into silos via a boot connector with foam seals. The boot seal connects hopper-car unloading gates to a pit where a screw conveyor transfers cement to bucket elevators that dump into the silos.

“Sometimes these foam seals blow out, they start leaking, or maybe one of the boots will drop and then cement will hit the ground instead of [landing] in the pit,” says Rodgers. “The shop vacuums weren’t powerful enough to clean up 500 to 600 pounds of cement, so we used a lot of shovels and wheelbarrows.”

The Lafarge 3302E system from Vac-U-Max. Air-powered vacuums operate on the Venturi principle. By design, they create their own vacuum without the use of motors or moving parts.

When Rodgers was searching for a more effective method of cleanup, John White, VP logistics at Buzzi Unicem USA, suggested he look at Belleville, NJ–based Vac-U-Max, which introduced the first air-operated vacuum cleaner in 1954. White was familiar with the company from earlier in his career, saying, “The company said that you could pick up a bowling ball with [the company’s vacuum] and we actually tried it once and it really worked.”

What impressed Rodgers most about the industrial vacuum was that it is powered by air and not electricity. “All these terminals have air compressors,” he said. “Air operates our valves. It operates our boot connectors. That is how we move the material—by air.”

The air-powered vacs operate on the Venturi principle and, by design, create their own vacuum without motors or moving parts, making them intrinsically safe and ideal for use with abrasive cement particles that can damage electrical equipment over time. “It works perfect for these big terminals,” says Rodgers.

Rodgers is only one of 31 Buzzi Unicem USA terminal managers who have a competitive tradition of tracking who has the cleanest terminal. After presenting his solution at last year’s annual meeting, the competition escalated. “That next week I had 30 e-mails asking me where I got this thing.”

Centralized continuous-duty vacuum systems, such as this one by Vac-U-Max at California Portland Cement Co., are precisely engineered for maximum efficiency in automated test labs where dust control and accuracy are essential to quality control.

Dissatisfied with using brooms, shovels, and air hoses that just blow around debris, Mike Glaze, terminal manager at Buzzi Unicem USA’s Indianapolis terminal that unloads fly ash and slag, was the next to get Vac-U-Max’s MDL 55. “We use it for several different things here,” Glaze says.

Like the unit in Pensacola, Glaze’s unit is mounted on a dolly with wheels that allows it to be moved around easily. “We clean our bucket elevator and our screw conveyors and use it to clean around our boot seals,” he says. “It’s really handy and easy to use.”

The unit has a unique pulse-jet filter cleaning system that, with the push of a button, backwashes the filter, eliminating the need to manually clean the unit and virtually eliminating clogging. Glaze says, “Like anything else, if you take care of it, it will last a long time. You just push a button on top of the vacuum mechanism to keep the filters clean.”

Glaze also appreciates that using ear protection is not necessary with the unit. “There is just no noise to it at all,” he says. The units are equipped with noise mufflers and guards to keep sound levels below 80 dbA. Pensacola’s Rodgers agrees. “You don’t even know this thing is running unless you put your hand on the end of the hose,” he says.

Beyond the friendly competition of keeping their terminals clean, reclaiming hundreds of pounds of material each day is important to the terminal managers. “That was one reason we wanted this, because the barrel was so easy to maneuver around,” says Rodgers. “We just vacuum it up, roll it over to the pit, and put it right back into the system, we don’t lose anything.”

Central Vacuum Systems and Cleanup for Bulk Transport Loading

Without air-operated vacuum cleaners such as those made by Vac-U-Max, heavy cement must be shoveled away from boot seals and adjacent areas.

Buzzi Unicem USA is sensitive to environmental issues and is proactive in adhering to OSHA and MSHA regulations as well as local EPA guidelines. Thus, the Stockertown, PA, plant utilizes two Monobloc centralized vacuum systems to remove product buildup around the hatches of bulk tankers and railcars that are loaded from above, ensuring that no dust is spread when the trucks are leaving the facility or traveling through neighborhoods.

These stationary Monoblocs include strategically placed piping throughout the facility, allowing hoses to be connected to clean multiple areas simultaneously.

Centralized vacuums are also used in clinker plants early in the cement manufacturing process and capture a half-ton of dust per day during the grinding process. In large grinding operations with multiple floors, the vacuum is centrally located on the ground level with piping routed to each floor for easy cleanup. Centralized vacuums are also used in more-sophisticated environments where continuous duty is essential for quality control purposes.

Continuous-Duty Vacuum Systems for Quality Control in Automated Labs

In automated labs where constant operation of multiple stations and materials produces fine, smoke-like dust, vacuum systems can easily become overwhelmed, skewing test results. In order to maintain accurate results, automated labs require central continuous-duty vacuum systems that are precisely engineered.

Considerations such as floor space, pickup points, collection capacity, the need for manual vacs, and other parameters must be weighed. When Lehigh Cement Company’s European-made central vacuum system wasn’t performing as well as expected, the company turned to Vac-U-Max. The company sent an engineer and a demo truck equipped with a 20-hp vacuum to perform an audit and make recommendations that delivered desired results.

Continuous-Duty Vacuums for Bag Filling Reclamation

Continuous-duty vacuums, although less sophisticated than the central vacuum systems used in the lab, are also used to capture and reclaim cement in the bagging process.

In cement bagging operations it is difficult to avoid dust spillage. Texas-based Featherlite uses a Vac-U-Max continuous-duty vacuum to avoid product loss with its bag-filling machines. The unit captures the spillage and puts it back into the packaging machine to maximize profit.

In rugged industrial applications where environmental safety, ergonomics, and productivity matter, vacuum cleaners designed specifically to withstand harsh 24/7 operation can deliver consistent performance that adds to a company’s bottom line.

For more information, contact Vac-U-Max, Belleville, NJ, at 800-822-8629 or www.vac-u-max.com.