Experimental Investigation on the Heat Transfer Characteristics in Process of Printed Circuit Boards Pyrolysis Under Nitrogen Flow

A fixed bed pyrolysis experiment device was established and investigated experimentally under high temperature nitrogen flow. The temperature distribution of waste PCB particles layer was measured, and the heat transfer characteristics was investigated. The experimental results indicate that the size of the PCB particle has an obvious effect on the pyrolysis reaction time and the migration rate of pyrolysis. The larger the particle size is, the shorter the pyrolysis reaction time is and the faster the migration rate is. When the square particle sizes are 1.5 cm, 2.5 cm and 3.5 cm wide, the average migration rates of pyrolysis reaction zone along the vertical direction are 0.47 m/h, 0.50 m/h and 0.63 m/h, respectively. High temperature gas can make the whole material layer fully pyrolyzed. The particles in the middle part of the same level are uniformly in the same pyrolysis state, while the temperature and pyrolysis speed of materials near the furnace wall are lower than those of the central part. © 2019, Science Press. All right reserved.