Clean Plasma Cutting

Shipbuilder Finds a Clean-air Solution for Plasma Cutting with a Modular Dust Collector

Jeffboat, Jeffersonville, Ind., uses dual torch plasma cutting systems to cut painted mild steel plate 3⁄8 in. to 2 in. thick and 10 ft. by 40 ft. long. The cut plate is used to make bulkheads and runners for barges. Challenged with keeping its work environment clear of dust and smoke generated by its plasma cutting operation, Jeffboat found a clean-air solution and an unexpected return on investment with a Gold Series modular dust collector from Camfil Farr Air Pollution Control, Jonesboro, Ark.

The manufacturing arm of American Commercial Lines Inc., Jeffersonville, Ind., Jeffboat is the largest inland shipbuilder and repair facility in the United States. The company occupies 68 acres, including 5,600 ft. of frontage on the Ohio River. Jeffboat designs and builds custom inland and ocean service barges ranging from towboats and hopper barges to tank barges with up to 30,000-barrel capacity for inland waterways or limited load line and oceangoing tank barges with 30,000 to 50,000-barrel capacity.

The Farr Gold Series modular dust collector is effective at removing the microscopic particles in plasma cutting smoke.

“Jeffboat tried several downdraft systems with disappointing results,” says Jonathan White, a mechanical engineer for PlasmaCraft Inc., Muscle Shoals, Ala. PlasmaCraft specializes in CNC plasma and oxy-fuel cutting equipment. The company is a longtime supplier for Jeffboat’s equipment, retrofit and service needs. “Jeffboat installed a water table, a more costly option when compared to downdraft systems, but it wasn’t very effective at collecting the plasma cutting operation’s residue,” says White.

With a water table, the metal plate typically is positioned on a bed of slats. Air is forced into or exhausted out of a chamber concealed below the slats, causing the water level in the table to rise or fall accordingly. Cutting plate about 3 in. below the water is best for reducing noise, glare and smoke, but most shops cut plate slightly above or just below the water level.

“Jeffboat is very safety-oriented,” White says. “They didn’t want any smoke being released into the air. A water table can remove smoke, but they found the system didn’t capture dust very efficiently and, once used, the water must be treated as waste water. The process for removal is quite costly, requiring the water to be sealed in barrels and picked up by an Environmental Protection Agency representative for proper disposal. The water table system also has a tendency to rust, creating the potential to leak waste water."