Two Cedar Mills Turn to Lignomat for Computerized Kiln Controls and In-Line Moisture Meters
By Alan Froome
Contributing Author
BEAVERCREEK, Oregon — The staff of Lazy S Lumber Co. engineered and built the company’s dry kilns, but they recognized that the real ‘smarts’ in kiln drying is in the control system. For up-to-the-minute computerized kiln controls and in-line moisture meters, Lazy S turned to Lignomat-USA.
“The main payback for us has been improved lumber value due to less checking, splitting and cupping,” said Lazy S general manager Tony Maben. “This is resulting from the fact that we can now control the drying process much better.”
The Lazy S sawmill is a secondary breakdown mill, resawing softwood cants into 23 different products, including bevel siding, channels and decking. Finished sizes range from 3/4 to 8/4 in 6, 8 and 10-inch widths. Lazy S ships random lengths from 6 to 20 feet in even lengths.
The company buys cedar cants up to 12×12 and 20 feet long from other sawmills in a region ranging from northern California to British Columbia.
Lazy S is situated near Oregon City, southeast of Portland. The company and an affiliated mill, Columbia Cedar in Kettle Falls, Wash., are owned by president and CEO Ralph Schmidt and his wife, Merry.
Ralph’s father and two uncles built a small sawmill in 1952 as a sideline to their farming business — the Lazy S ranch — in order to supply themselves and their neighbors with custom cut lumber. The sawmill business grew rapidly.
Today the two mills process 100% cedar and specialize in bevel siding, fencing and decking. The company’s products are shipped all over the U.S. and Canada and to some offshore markets.
The company recently went through a major technological upgrade at both mills, installing computerized optimization equipment for primary break-down and edging and also two new dry kilns with Lignomat computerized controls and in-line moisture meters.
Most of the improvements were made to Columbia Cedar, the company’s flagship mill. It is a primary breakdown mill, running on raw logs. Columbia also has dry kilns using Lignomat controllers and has planers and resaws for the same remanufacturing capabilities as Lazy S. Two new kilns with computer controls are also being added at the Lazy S mill to double drying capacity to 300,000 board feet.
The two mills employ a combined 110 workers. Tony is one of the original employees and has been with the company for 22 years. Two other employees with the longest service are planerman Mike Foster and production manager Rob Giesler, who was recently named plant manager at Kettle Falls.
Production is about 120,000 board feet per day from one shift at Lazy S and 160,000 at Columbia.
The mill is equipped with considerable proprietary machinery that was designed by company personnel.
Kilns and Controls
The Lazy S dry kilns, designed by Ralph, Rob and Tony, have a steel structure and aluminum cladding with direct- fired propane heating. Each kiln has 75,000 board feet capacity. Loads pass through on cars that move on rail tracks.
“We dry to 19 percent moisture content or less,” said Tony. The Lignomat system, controlled by the in-line moisture meters, automatically adjusts the drying schedule. “We only need to adjust the basic schedules on a seasonal basis,” he said.
The new kilns will be operational by the fall. Steam will be vented through the end of the building, using fixed speed fan motors and heat exchangers to recycle some of the heat.
The control system supplied to Lazy S, a Lignomat LMS-16 G system, is fully automatic with in-line moisture meters. The same system also will be used to control the new kilns when they begin operating. (The dry kilns at the Columbia Cedar mill also are equipped with Lignomat controls.)
“The system can control a complex of up to 16 separate kilns and has two basic types of drying schedule, time or moisture,” said Peter Brinsek, production manager at Lignomat’s factory in Portland, Ore.
The Lignomat system at the Lazy S uses a personal computer as the user interface and an MP16 master controller. The control software runs in a user-friendly Windows program.
The system at Lazy S was installed two years ago and has been updated since then. The latest upgrade will enable it to control four kilns.
The Lignomat system features:
• Moisture sensors-transmitters (wireless battery operated) that convert analog values into digital at the point of measurement.
• Temperature sensors-receivers and receiver station, two for each kiln.
• KCU process control and input-output modules (microprocessor based), with one mounted on each kiln.
• Relay interface with discrete relays to operate fan motors and actuators.
• MP16 Master controller, single board programmable computer.
• Graphical operator interface, running on a personal computer in a Windows based program. This allows the operator to run the kilns in manual or fully automatic mode, with error notification and drying status using a graphic display on the personal computer.
• Software package, customized to mill requirements with schedule editor, drying history, options to jump, link or hold schedule, export to spreadsheet etc.
Drying Process
The Lazy S drying schedules are controlled automatically by an in-kiln measuring system. The operator places wireless battery powered moisture sensors in the lumber stack before drying starts (six normally are used), and the sensors transmit readings to two receivers mounted on each side of the kiln. The receivers are wired to the kiln control unit (KCU) using high temperature rated cable — the only cable that enters the kiln. A separate KCU is used for each kiln, and they are connected to the central MP16 master controller. This is a single board computer that is programmable to suit each kiln’s individual parameters. The operator can monitor the drying process and kiln status from the interface personal computer. A buzzer will sound to alert the operator if the temperature increases too much.
The Lignomat in-line moisture meters use a patented dual frequency measuring method that is not dependant on lumber density. The system at the Lazy S has
a three-dimensional graphical display
that shows moisture values in accordance with the position of each package in the kiln. Data from the kiln control program may be transferred to other database programs, and management and performance reports are available to monitor the entire kiln operation.
Lignomat has sold more than 3,000 computerized kiln controllers to sawmills all over the world for drying all kinds of softwoods and hardwoods.
For more information on Lignomat, call Lignomat USA president Uli Heimerdinger at (503) 257-8957 or e-mail uli@lignomat.com.
