INDUCTION DRYER AND MAGNETIC SEPARATOR

摘要

Apparatus for inductively heating metal can lids (100) operates at medium frequency, with a many-turn induction coil (223) wrapped partly or entirely around the can closures. No focusing cores are required, nor need the conductors be water cooled. Can ends may be fed through the apparatus in-stick (208). IGBTs (230) are used in the H-bridge of the inverter. A control system (Fig. 19) minimizes peak current flow through the switches. The control system monitors the tank voltage phase angle and turns the switches on and off in optimal response thereto. Can lids (100) are separated magnetically while being motivated by sequentially switched electromagnets, and can bodies may be rotated by a split conveyor belt (210) while being transported. Close-loop temperature control apparatus may also be included to control AC power input and to prevent overheating of the can closures in the event of unintended stoppage of the production line.