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Tech Update: Kiln Control Equipment

Compiled by Mel-Lynda Andersen

Drystar Computer Kiln Controller

From American Wood Dryers comes the Drystar Computer Kiln Controller, which the company claims is state-of-the-a rt , user-friendly, and so affordable that mills can purchase separate computers to control each kiln. With the Drystar system, each kiln is controlled by its own dedicated, rack -mounted Intel Pentium computer.

Each computer features a high-resolution colour graphics monitor, 540 Meg hard disk, colour printer and multiple input/output (I/0) modules. The 540-Meg hard disk allows each computer to hold data-logging, schedule-editing, storage and systems-function info rm ation. The I/O modules provide modulating control to regulate temperatures in proportion to the difference between actual and set-point conditions. In multi-kiln systems, any individual kiln computer can act as the host computer, providing unified schedule libraries and on-line help to the entire system.

The temperature sensors are fully interchangeable platinum RTDs with stainless steel jackets for protection from corrosion. Drystar options include integrated, variable-frequency fan speed-control software, resistance moisture-probe circuits, remote modem-communications hardware and software, electronic scale with interface to compute and record moisture content of oven-dried sample boards, and an uninterruptible power supply.

Custom Dry Kiln PLC

Custom Dry Kiln Company's PLC operating system combines industry standard PLCs with non-proprietary, off-the-shelf, windows PLC software, resulting in a program that its manufacturers claim is user-friendly, maximizes productivity and quality, and reduces energy use.

This operating system features the customer's choice of off-the-shelf, brand-name software, automatic temperature control and scheduling from computer, PLC cabinet location or remote location via modem, and automatic or manual on/off from computer, temperature control from screen, solenoid control from screen, PLC cabinet, or remote location via modem, and alarm monitoring. Additional features include fully modulated dampers, valves and burners, zone control, and an energy-management upgrade.

Historical strip charts, logging and archiving of kiln data, detail, overview, historical and schedule screens with instant support are among the reported advantages of this Custom Dry Kiln system, along with on going energy-use and consumption reports, schedules by customer's choice of control (for example, depression or TDLA), and choice of distributed or central control strategy. The manufacturer claims that this system can help improve productivity, lower operating costs and improve overall product quality.

Winkiln Control System

Salton Fabrication Ltd. announces its new kiln control system, Winkiln, which incorporates colorful, easy-to-operate screens and a multitasking Windows operating environment. According to the manufacturer, Winkiln's aim is to increase kiln productivity simply and dependably.

It can control up to 20 kilns, includes 60 drying schedules, and works with any type of kiln and heating system, including direct or indirect fired, single or double track, and side loading. Its data-management system allows a kiln operator to t ra ck drying variables and recall information on demand.

The company claims that Winkiln's ability to control up to 12 zones in a multi-zone configuration means better quality lumber and higher profits. Winkiln uses industry-standard equipment, including Opto22 hardware, a PC with a 486 processor with 8 Meg RAM and Windows 3.1. Technical-support services include a 24-hour-a-day, seven-day-a-week on-line diagnostic service, schedule monitoring and program upgrades by telephone or modem connection to Vancouver, Portland or Montreal.

Lignomat USA Ltd.

With over 800 units in operation throughout the world, Lignomat's kiln-control systems can be retrofitted on existing dry kilns or incorporated into new systems for the best possible control of the drying environment. Hardwoods and softwoods can be dried with fewer defects and a more uniform final moisture content, according to the manufacturer.

By increasing yields with shorter drying cycles, the Lignomat controls protect the lumber with a stepless drying curve and controlled moisture loss. Up to 16 probes in each kiln send moisture content data to the LSA kiln control. The controller follows a moisture-content-based schedule.

The Operators Interface in Microsoft Windows enables the user to access more information easily to help run the kiln efficiently. With multi-tasking capabilities, the system can run other Windows or DOS-based programs while operating the kilns. Lignomat also reports a new correction method that generates more accurate wood probe readings above the fibre saturation point. At the beginning of each drying cycle, results from an oven dry test are entered into the kiln schedule information.

The controller determines an individual correction factor for each sample board. From there on, the controller corrects the wood probe readings automatic ally. University studies have proven that green wood can be measured more accurately following the integrated procedures used by Lignomat.

Kiln Dry Systems

SII Dry Kilns offers a family of computerized control systems which can link up to 32 kilns into a unified, mill-wide network. Because Kiln Dry systems are modular, it is possible to buy kilns with manual controls today and inexpensively tie them together with computerized control at any point in the future. Both the 8000 and 9000 series control systems consist of central computers that gather information on wood-moisture content from either sample weights or MC probes.

The Kiln Dry 8000 communicates with each kiln through a digital circular chart recorder-controller; standard circular charts from the recorder-controllers provide a record for each charge. The Kiln Dry 9000 utilizes an industrial pro-grammable logic controller to control all kilns.

The computers for both systems store drying schedule data for each kiln, gather performance info rm ation for report and allow operators to easily control multiple kilns.

The Frank Control System

Airodyne Industries has announced what it claims is the "only true process control" system available. Where many controllers use a scheduling sch e m e, the Frank Control continuously monitors and controls the temperatures and relative humidity in the kiln. The unit's use of the Allen Bradley DF1 protocol allows the PLC to communicate and assume more control of the system. The user then has the flexibility to use process drying or schedule drying, as selected from the desktop computer or the PLC.

AKC, a user-friendly, mouse-driven menu system, provides graphical operator interface. The program also features report generation and graphical data trending, up to five weeks of info rm ation stored in the data base and the use of high-level mathematics for process control.

The object is to regulate the rate of evaporation off the wood surface and attain the optimum moisture and temperature gradients within the wood. The Frank system does not need to run on a schedule or set time; this is why its manufacturers call it a true pro-cess control system. Airodyne also offers on-line monitoring to ensure grade quality and prevent down time and costly on-site service.

Series 22M Computerized Multi-Zone Kiln Control

The Series 22M computerized dry kiln-control system is designed to meet today's demand for quality lumber drying, say its makers at Coe Manufacturing. The 22M automatically controls the drying process from startup to shutdown while giving the operator flexibility in scheduling based on time, Temperature Drop Across the Load (TDAL), moisture probes or load cells.

System inputs include resistance temperature devices, control by either entering or exiting air flow, moisture meter informa-tion, steam flow and pressure, vents, condensate level and fan status. The Series 22M system is designed to utilize a PLC for the control functions of the drying process and a personal comput-er for the operator interface.

This system combines the advantage of the industrial hardness of a PLC with the user friendliness of a modern personal computer.

Brunner Hildebrand

The Brunner B9400 Comp is the latest version of Brunner Hildebrand 's B7000/B 9000 system, applying the industry's latest hardware and software developments. The B9400 Comp system is operated with simple, user-friendly on-screen dialog boxes and colour graphics.

Dialogue and screen text is available in several languages. The manufacturer claims the B 9400 Comp is the only control system available that utilizes the drying gradient, an important safety feature for drying valuable, high-grade lumber.

The computer calculates the data and optimizes the drying schedules with up to 16 dry kilns at the same time, conventional kilns and High Vac vacuum-dry kilns. The company also claims that one computer system is sufficient for several dry kiln types, presenting a cost saving for monitoring and maintenance.

The Brunner work station can be set up in conjunction with company software to allow calculating of drying costs, energy costs, cost analysis, and the use of other compatible software. Interface with other computer systems allows kiln monitoring and control from several different locations.

The system is equipped with a built-in telephone modem, which can be con-nected to the company's central computer for monitoring and data transmission , enabling factory lumber-drying technicians at Brunner to check the system operation. New software can also be instantly transmitted.

Drying Technology, Inc.

The ideal kiln-control system should be able to compare MC between zones and shut down the kiln when the MC has reached the target value; otherwise, unnecessary degrade losses will occur. Drying Technology, Inc. invented and patented Temperature Drop Across the Load (TDAL).

The company claims TDAL functions well on continuous dry-ers, but points out the system is ineffective as the basis for a dry kiln-control system because individual zones cannot be accurately compared and endpoint MC cannot be accurately measured using this parameter.

Enter the new Delta T kiln control system, which uses drying rates for comparing zone drying. According to the manufacturer, the system also offers a menu of 10 parameters, including drying rates, which may be used alone or in combination as the basis for automatically shutting down the kiln when the setpoint MC value is reached.

Wagner 778

Wagner 's new 778 In-Kiln Moisture Monitoring System measures the hardest-to-reach portion of each load with the highest accuracy, according to the manufacturer. The 778 features broad-field moisture measurement that correctly samples a statistically significant portion of each kiln load.

Wagner claims this process avoids the pitfalls of calculating moisture content using Temperature Drop Across the Load (TDAL) moisture monitoring, which has been proven ineffective in many kilns. Pins, which could damage wood or break off within the stacks and cause problems, are not used.

Wagner claims their electro-magnetic wave technology provides com-prehensive monitoring, in contrast to single-board pin-type moisture -detection schemes.

Cathild CH 11Z

The CH 11Z is one of a series of kiln control systems developed and manufactured by Cathild. The CH11Z can simultaneously control up to 54 dryers and can control from six to 36 probes; the company claims it is the only commercialized computer that offers management of probes placed in the timber.

This system also offers automatic depolarization and manual guidance with or without probes, retaining the average value of the most humid indicator probes. According to the manufacturer it is the only commercialized computer capable of calculating and manipulating drying speed according to the amount of water extracted. The CH 11Z yields an economy of 10 to 15 per cent.

Dryline Systems Inc.

Dryline manufactures controllers for all applications of lumber drying. For larger systems, Dryline offers its Series 3000MC. The 3500MC operates in Dry bulb/wet bulb mode or on a programmable time-based schedule. It can control several kilns at once and comes complete with software to monitor and control the drying process.

For smaller DH and steam applications, Dryline Systems offers the Series 1000MC, which offers wet/dry bulb or depression-based control. It comes complete with three and lumber-drying schedules.

Energie FEI Inc. Kiln Controller

Energie FEI Inc. of St. Bruno, Quebec intro-sensors duces their new kiln controller, which the company claims offers improved flexibility and performance. Utilizing the latest computers and a minimum of 8 Mb of Ram, the new FEI kiln controller functions in a Windows environment and offers kiln operators the most flexible way of drying lumber, softwoods or hardwoods, according to the manufacturer.

The system can predetermine and produce a temperature-time profile, indicate temperature drops across the load and provide feedback to the operator using eight drive-in electrodes. This new kiln controller also offers the possibility of cycling in each step, to accommodate sudden changes in dry bulb temperature, and features variable-speed fans, built-in database software for drying statistics, and distance monitoring.

MPB Drying Master

MPB Tech nologies Inc. introduces the Drying Master as a local area network designed specifically to help mill managers, superintendents and quality control personnel optimize the lumber drying process.

The company claims it is the only system that includes data analysis for every parameter relevant to a strategic lumber drying program. The Drying Master uses an advanced algorithm which describes the rel ation ship between initial moisture content characteristics, species properties, drying char-a cteristics and rates of degrade.

Each sling is tracked from the green chain to the yard, to the kiln and to the dry chain, enabling the Drying Master to pinpoint any potential problems and print out a comprehensive report to mill personnel. Data from the environmental sensors, green and kiln-dried lumber moisture sensors, kiln drying schedules and grader readers are also analyzed and compared to a historical profile by the Drying Master.

April 1996 articles - Forest Expo Show Guide

  • New Deere Buncher
    Eastern and western contractors assess the new 653E.
  • Riverside Forest Products
    A $17 million upgrade produces a 12-percent recovery gain
  • OSB Fast Track
    Ainsworth opens its second OSB plant in as many years.
  • Caribou-Friendly Harvesting
    A look at a working study in BC's Chilcotin region.
  • Eye on the Orient
    With a confusing Timber West/Fletcher Challenge ownership behind it, the Elk Falls lumber mill invests $16 million to retool for Asian markets.
  • Unmasking the Eco-Myths
    Ex-Greenpeace activist Patrick works these days to counter the forestry myths and misinformation put forth by radical environmentalists. Most don't have a clue what they are talking about, says Moore.
  • Ancient Enterprise Still Thriving
    The oak forests and processing industry of France predate the Romans. LSJ's peripatetic editor Reg Barclay takes us inside a highly efficient plant in Burgundy, France.
  • Diploma Mill with a Difference
    A Crestbrook Forest Industries program that combines on-site industrial training with high school completion courses is well-accepted by employees.
  • Marketplace: Supplier NewsLine
    Equipment information including the Implemax Equipment skid steer grapple, the Dynaweld detachable trailer model, the Imac PowerSwivel, the Morbark Model 1300 Tub Grinder, and more.
    This month: Kiln controls including Drystar Computer Kiln Controller, Winkiln Control System, Custom Dry Kiln PLC and more.
  • New Era in Bush Communications
    Forest companies working in remote locations will welcome TMI Communications' new mobile satellite communications network.

Return to the April 1996 - Table of Contents

Last modified 6/10/96

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