Image
Buzzi Unicem USA's terminal in Pensacola, Fla., reclaims 500 to 600 pounds of portland cement every other day with air-operated vacuums.
Image
Centralized, continuous duty vacuum systems, like this VAC-U-MAX system at California Portland Cement Co., are precisely engineered for maximum efficiency in automated test labs where dust control and accuracy are essential.

Concrete production's roots date back to ancient Roman times. Our ingredients come from processes that transform mountains into dust with rugged equipment that pounds, crushes, and grinds. Fugitive dust and material spills, although they are infrequent, still can bring clutter to our operations.

In the last few years, cement manufacturers have discovered that vacuum cleaners are the ideal solution to reclaim product. Vacuums can be viewed as a best management process to help plant managers comply with EPA and OSHA regulations.

Some concrete producers have used industrial vacuum cleaners in almost every step of the manufacturing process. You can find these units in the production facility, the lab, in loading and unloading operations, as well as in bagging operations.

Each step in the production process has its own pains that require unique solutions. In the lab environment, a little dust is a big problem, requiring a de-dusting system for quality control. A production area that can span many floors and produce 1000 pounds of dust per day may require a central vacuum system with a piping network on each floor.

The bagging operation is often the location where dust is the most difficult to control. Many producers use a continuous duty vacuum system. Where spillage is minimal, like loading and unloading stations, a single portable air-operated vac may be sufficient for periodic cleanup.

Better tools

Industrial vacuum cleaners are more sophisticated than their cousin, the shop-type vac. Some producers have labeled these lightweight units as asthmatic when up against the savage conditions in the cement and concrete industries.

“We tried shop vacuums, but they just wouldn't last,” says Andy Rodgers, terminal manager at Buzzi Unicem USA's Pensacola, Fla., terminal. “The abrasive dust just wears away the operating parts, and the motors don't last.”

Rodgers manages the Pensacola terminal that unloads 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 powder 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 in the pit,” Rodgers explains. “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.”

When Rodgers was searching for a more effective cleanup method, John White, vice president of logistics at Buzzi Unicem, suggested he consider an air-operated vacuum cleaner, which was introduced in 1954.

Rodgers was impressed that the industrial vacuum is powered by air and not electricity. “These terminals have air compressors,” he says. “Air operates our valves and 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. This makes them intrinsically safe and ideal to use with abrasive cement particles that can damage electrical equipment over time.

Cleaning terminals

Buzzi Unicem tracks which of its 31 terminals is the cleanest. After presenting his solution at last year's annual meeting, Rodgers received 30 e-mails asking him where he got it.

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.

Like the unit in Pensacola, Glaze's is mounted on a dolly with wheels so crews can move it around easily. “We clean our bucket elevator and our screw conveyors, and we use it to clean around our boot seals,” he says. “It's handy and easy to use.”