The AutoBox ABX-PRO (ProDrive) robotic lance-cleaning system from StoneAge exemplifies the push for more automated equipment that keeps employees out of harm’s way at Thompson Industrial Services.

The company owns a large fleet of the machines, which are used to clean tubes in heat exchangers in refineries, paper mills and petrochemical plants. They’re also used to clean evaporators, mostly in paper mills, says Chris Meldrim, director of automation and outage management at the company, headquartered in Sumter, South Carolina.

The remote-controlled ProDrive hose tractor eliminates the need for manual lancing. The ProDrives are used with either a ProPositioner or XY Positioner from StoneAge, which attaches the unit to the equipment being cleaned. The positioners also help guide the lance into the tubes, he explains.

The machines typically are paired with diesel-engine-powered Jetstream hydroblasting pumps, capable of generating water pressure anywhere from 10,000 to 40,000 psi and flow up to 80 gpm, he says.

The ProDrive can clean pipes from 1 to 18 inches in diameter. Tubes in heat exchangers can range from 1/2 to 1 inch in diameter and anywhere from 8 to 50 feet long. The tubes in evaporators usually are 1-1/2 to 2 inches in diameter and anywhere from 20 to 50 feet long.

“The exchangers get filled with residue from the heat-removal processes,” Meldrim says. “And the evaporators recycle the ‘black liquor’ used in the paper mills, which builds up inside the tubes.” (Black liquor is a waste product generated during the paper-making process.)

“These tubes usually are plugged solid,” he says. “It’s almost like they’re filled with concrete.”

Operators run the pneumatically powered ProDrive from a safe distance via a remote control that can move the lance up and down, left and right and in and out of the tubes. “It’s like an old Pac-Man video game with a joystick,” he says. “You can train someone to run it in about a week.”

Not only is the robotic cleaner much safer to use, it works about 25% faster than manual lancing, depending on the diameter and length of the tubes and how badly they’re clogged.

“It doesn’t wear down like a human being and it doesn’t take breaks, either,” he says.

Furthermore, the ProDrive cleans at a consistent speed, while manual operators tend to vary the rate of cleaning as fatigue sets in. It also reduces manpower requirements. Typically, a crew lancing the tubes manually might need at least eight operators on site, with one group of four working for a certain number of hours then another group of four to relieve the first group.

“Now we need only four guys per crew,” Meldrim says. “The labor savings allow us to bid more competitively while still maintaining our profit margins.”