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Serbian version
Russian version
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CONTROL OF THE DRYING PROCESS |
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Automatic control unit used for drying process control in small capacity conventional wood dryers (kilns)
Automatic control unit MC-412 is a device that automatically controls drying process in small capacity conventional kilns produced by "NIGOS - elektronik". It can also be used in other kilns for modernization of old manual kilns. This is simplest controller to turn your old manually controlled wood drying kiln into modern fully automatic wood dryer. Device achieves optimal drying conditions in the chamber through air temperature and humidity control. This controller support only conventional drying mode where hot water or steam heating is used. It is very simmilar to it's ancessor MC-411R but do not support dehumidifying drying. On the other hand, it has functionality and brand new software simmilar to one used in MC-502R. Automatic and semiautomatic control mode are supported. Drying process is divided into several phases. When drying process is started, automatic controller starts with measurement phase, no mater which operation mode is selected. In semiautomatic mode this phase lasts 20 sec which is required for measurement to stabilize. In automatic mode this phase lasts until average wood MC is calculated. After this controller advances to heating phase in case measured temperature is lower than first temperature in selected regime. During heating phase temperature is increased according to heating ramp rate until minimal temperature in regime is reached. At this point controller can enter core heating phase in case user has set the time for core heat phase to any value other than 0 hours. During this phase controller will maintain constant temperature (equal to minimal temperature from drying regime) for the time set by user (in hours). When this time elapses controller will advance into drying phase. In automatic mode controller will follow temperature and EMC curves from drying regime. In semiautomatic mode controller will disregard regime and only maintain values for temperature and EMC set by user. This is the longest phase, and it lasts several days until desired average wood moisture content is reached, when drying process ends. After drying phase, if it is enabled, system starts conditioning phase as the last phase of drying process, which provides equalization of wood moisture content inside the wood and on the wood surface. In case conditioning phase is disabled or when it is finished, cooling phase starts. During cooling phase only air exchange system (dampers i.e. flaps) is enabled. System decreases temperature in the kiln until the final temperature, set by user, is reached. Transition from automatic to semiautomatic control mode and reverse is possible at any time. When such transition is made, drying process starts from a beginning. If automatic-to-semiautomatic control mode transition is made in the middle of drying, values for temperature and humidity that are measured in that moment become setpoint values for semiautomatic control mode until user change them manually. In reverse situation (semiautomatic-to-automatic control mode transition), automatic control unit measures average wood moisture content in that moment, and uses this value to calculate setpoint values for air temperature/humidity according to a chosen regime. After a power failure has occurred, drying process is interrupted and upon power supply reconnection MC-412 continues with drying starting from the drying point determined after measurement stage is finished. Technical data of a MC - 412 automatic control unit are given in the following tables:
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- heating (2-pin; 8A / 250 Vac)
- conventional drying (3-pin;8A / 250 Vac)
- humidifying (2-pin; 8A / 250 Vac)
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 ©2011 NIGOS-elektronik |
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18000 Nis • Srbija • Borislava Nikolica - Serjoze 12 Phone/fax. +381 18 / 211-212, 217-468 • E-mail: office@nigos.rs |
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