The Research Of The Veneer-Dry Auto-Control System Based On PLC

In recent years, with the increasing development of home decoration design, our country plywood productivity has created new high. However, many of our country plywood production enterprises are mid & small-scale enterprises. The technical equipment is backward and the automatization degree is low. When examining veneer moisture content, many enterprises still follow artificially stochastically samples the moisture content of the veneer surface, depending on the experience to carry on the appraisal to the veneer dry quality. The error is finally big, causing the product quality to drop and affect the plywood production enterprise's economic efficiency.In view of above situation, this topic, which is based on the introduction and absorption of overseas advanced veneer moisture content on-line examination technology, has developed the veneer moisture content on-line examination instrument independently, and has made up domestically in the veneer moisture content on-line examination research aspect blank. Besides, this topic has set up a set of veneer dry automatic control system. This system selects OMRON Corporation C200H PLC as the control core, examines and controls the temperature and humidity condition of the wet air on-line. It changes the wet air discharge from disorderly to regularly and reduce the energy resume. In addition, through the on-line examination of veneer end moisture content, it can control the net belt speed of veneer dryer, while improving the veneer dry quality, in certain degrees it may also enhance the output of product, which increases the economic efficiency of mid & small-scale enterprise.On the constructs of article system, taking "PLC + IPC +PT" as the foundation, take the collection control thought as the instruction, this topic completes veneer drying automatic control system, which has achieved the concentrated monitor and disperser control. Through the touch screen, establishes the good human-machine dialogue control interface, achieves the real-time monitor of the production, the dynamic demonstration, the accident alarm, production report and ect., enormously enhances the automatization degree of the veneer dry in enterprise.Through cooperation with Dong-sheng wood science company in, the control system has been successfully installed on plywood production line in this company. At present, this control system works well, the enterprise'energy consume has fallen and the veneer dry quality has distinct enhancement. In May, 2007 this automatic control system smoothly passed the check by the national forestry organization's expert group, and obtained the good praise.