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Gary Johnson's impression of the ARMEX/ACCUSTRIP process is succinct: "We're opening up a whole new field of cleaning." As owner and general manager of Coastal Contractors Ltd. of Springfield, Oregon, Gary has spent the past decades doing all sorts of cleaning for the pulp and paper industry---and he's seen just about everything. That's why he was so impressed when he first saw ARMEXâ Blast Media and the ACCUSTRIP SYSTEM® in action.

"In pulp and paper mills, we work with practically every material there is: aluminum, nickel, steel, stainless steel, porcelain, glass, tile. With the ARMEX/ACCUSTRIP process, we're not only replacing caustic chemicals and sandblasting in many areas, we're also cleaning areas with the ACCUSTRIP SYSTEM that used to be done by hand," explains Gary.

Specifically, work done includes the cleaning of dryer can heads, inside and outside, for magnetic particle testing. This was done at very low pressure, using about 30 lbs. of media per hour. "It's economical and it's the only way to do it."

Another very important application is cleaning the headbox and stainless steel piping of the Fourdrinier (papermaking) machine. Cleaning rust and scale from D.A. tanks (recovery boiler), removing pitch from chip conveyors and aluminum idler rolls, cleaning suction rolls and batch digesters for inspection and repair, cleaning oil leakage from floors and hydraulically-operated equipment, stripping paint from tanks and structural steel inside and outside the plant...all of this and more can be accomplished with the floor drains into the plant's wastewater treatment system. Which leads Gary to comment on another aspect of working in this particular industry. "Environmental and safety issues are very important in all the mills. With ARMEX and ACCUSTRIP, we've had no problem whatsoever. The men really like working with it, too."

Application Overview

A small New England-based paper mill produces nearly 100 tons per day of quality papers for business and industrial use. The mill operates continuously seven days a week to maximize its productivity and earnings. Every five to six weeks, the equipment requires a thorough cleaning so the mill can begin a new paper production run.

This "wash up" of the process residues from the pulp and the binding agents such as latex and clay presents a challenge because of the many intricate and difficult-to-reach areas.

Previous Methods

Traditionally, the cleaning was performed with sodium hydroxide (caustic soda) by spraying the chemical foam on the residue to help dissolve it. This method required 3 or 4 spray applications of foam followed by a 2500-psi pressure washer. The cleaning results were satisfactory, but not exemplary. The "wash up" required approximately four workers, including supervisory personnel, and 20 hours to complete (80 worker hours).

Substrate

The papermaking machine, commonly known as the fourdrinier, has a stainless steel platform covered by a nylon "web." Other applications include tank cleaning and general maintenance of pumps, motors and stainless steel hoods and pans.

Special Concerns

After incurring several workman's compensation claims due to chemical burn injuries and those from difficult-to-handle high pressure equipment, which operate at 2500-3000 psi, the project manager sought alternative cleaning methods.

Equipment Specifications

The new cleaning process is accomplished using the ACCUSTRIP SYSTEM® delivery device 12X, fitted with a #6 Water Injection Nozzle(WIN). The media used is ARMEX® Maintenance XL formula with SupraKleen® Rinse Accelerator.

The media is blasted wet at 60-70 psi at a distance of approximately 12-15 inches from the substrate. Other applications, like tank cleaning, are performed at 90-100 psi with a 15-20-inch nozzle distance.

Containment

No special containment is needed as the environmentally benign sodium bicarbonate is rinsed into the plant's waste treatment system, which helps buffer the wastewater.

Project Schedule

It is critical for the "wash up" to be performed effectively in the least amount of time. The project occurs eight to 10 times per year depending on the number of paper type switches required. With the ARMEX® Cleaning and Coating Removal System, the cleaning time takes approximately nine hours total.

Results/Benefits Summary

In addition to solving worker safety and environmental problems, the ARMEX technology provided numerous cost and productivity savings. By cutting the project schedule by 50 percent (worker hours were decreased from 20 to 10 hours), the mill yielded 80 more hours of annual production time. And there was no need for personnel to supervise worker safety. Savings for materials cost included: $18,200 dollars per year from barrels of caustic soda, which were reduced from 30 barrels to four barrels at $700 each; $3500 in special protective gear, which were no longer required; and the eliminated need to purchase soda ash to buffer the waste water, since ARMEX fulfilled that need.