... working principle of: hanging drying tunnel using far infrared heating tube heating, the electrical energy into heat energy, heat from ... Diameter size: width 1400mm × 1400m × length high-48000mm, cabinet type 1 units. Material: a, drying tunnel wall galvanized steel, ... insulation thickness of 100mm.3, drying electric heating system Material: a, far outside the heating tube of red iron pipes used with ...