By Staff Writer
Price Industries was founded in 1981 by John Porter Price as a result of in-house research and development done to equip his own chip mills in Monticello, Arkansas. The equipment that John installed in his facilities worked so well that he decided to bring it to the marketplace as one of his Price Industries companies.
Under John’s leadership, his company developed a broad range of advanced machinery for chipping and debarking, including a rotating drum tree debarking system, a transportable drum debarker, a rotary log crane system, and patented positive feed conveyors for moving material into the debarking system. John sold the company in 1992 when he decided to concentrate on an innovative approach to contract chipping for pulp and paper mills.
John sold the business to a partnership that operates the company under the name Price Systems. Today, Price Systems continues along the innovative trail that was blazed by John. It continues to adjust to changing conditions in the American chipping industry, according to Doyle Jones, a partner in the company.
The nature of the changes that are underway and the adjustments that suppliers like Price Systems must accordingly make to mill designs was illustrated last year. The original mill that John built in the early 1980s was redesigned and refitted by Price Systems to meet the new, changing requirements the mill faces.
One of the most important changes that has occurred is in the kind of wood that is chipped now and what was available two decades ago, Doyle noted. When the Monticello mill was first built, 100% of the wood being harvested was short wood. Today only a small percentage of the trees brought in is cut up into short length.
In addition to the change in tree length, there also has been a dramatic shift in tree diameter. In the past, Doyle pointed out, the minimum top diameter of wood accepted for chipping was often around 8 inches. By contrast, today the butt end of a stem is often not as large as 8 inches.
The ability to handle smaller stems means more income for the land owner and less wasted fiber left on the ground in the harvested area, according to Doyle, but it also means new challenges for the wood handling systems. “The changes in the wood supply have to be taken into account when designing chipping lines,” he said. “Gentler handling of the smaller wood is required to keep breakage to a minimum. Changes of wood flow direction have been eliminated as wood length has increased and plug-ups eliminated. Changing directions of wood flows with 6-foot wood is a lot different challenge than turning a 50-foot tree stem. All these things have design implications that must be addressed.”
The new Monticello mill incorporates equipment changes developed from years of experience as Price Systems mills have been constructed and operated throughout the U.S. The log deck, loader, and Precision brand 96-inch chipper and motor used in the old mill were retained, but most of the remaining equipment is brand new. Major new additions included a Price Systems patented positive feed conveyor, a 10-foot by 80-foot drum debarker, conveyors to handle the drum discharge, feed the chipper, and route bark, a new BM&M chip screen system, and a new bark bin. All the new equipment was designed into an integrated system.
In a chip mill, the flow of material is everything. Down time at any stage in the process impacts the entire system; if the chipper is operating at maximum capacity, down time cannot be made up. All elements of the mill must be compatible, said Doyle. “Many systems have
bottlenecks in them that keep them from a sustained, dependable through-put rate,” he said. In designing a mill, Price Systems looks at production rates over a shift or week, not a brief period of time.
Environmental issues are also an important part of modern mill design, Doyle said. “We do not use any hydraulic motors or drives on our equipment. We were, at one time, 100% dependent on hydraulics but have gone totally electric with the exception of the hydraulic loaders. This saves having to dispose of spent hydraulic fluids and filters as well as having to deal with on-site leaks.”
Another environmental advance of Price Systems was eliminating water usage, Doyle said. Traditional short wood water flume systems used between 30,000 and 40,000 gallons of water per minute to move wood. The new systems are totally mechanical.
“All transitions for bark and chips are sealed tightly to prevent the emission of fines to the extent possible,” Doyle added. “We continue to work on these areas with the goal of achieving 100% containage of all particles.”
Doyle believes the industry must do a better job of educating the public on its accomplishments in protecting the environment. For example, forest products businesses that have converted to whole tree systems are utilizing wood that once would have been left on the forest floor as waste. “This is not unique to Price Systems,” Doyle noted. “Some mills today are running totally on residue that 20 years ago would have been left in the woods. We need to band together as an industry and get the facts out about the positive modifications we are making.”
Like the modern sawmill, chip mills today have evolved over time. As one of the newest, and most modern mills in North America, the Price Companies’ new chip plant in Monticello, as designed by Price Systems, stands as an example of how innovation applied to technology can enhance profit for both a mill’s clients and for the mill’s owner. At the same time, innovative technology is leading to important gains in conserving natural resources