Industrial Tunnel Oven

Overview

A tunnel oven bakes continuously: product rides a slow conveyor in one end of a long insulated tunnel and comes out baked at the other, instead of going into a fixed chamber and coming back out. The Insulated Tunnel holds the heat, the Conveyor System carries the product, and a series of Heating Zone sections set a temperature profile along the length. A Steam Injection system controls crust and colour, a Exhaust System removes moisture and flue gas, and the Zone Control System holds every zone to its setpoint. The whole oven sits on a Support Frame.

How it works

In a tunnel oven, time in the oven equals belt speed times tunnel length, so the same bake repeats for every piece with no door opening or batch handling. The Conveyor System runs a steel band or wire mesh around terminal drums, driven by the Conveyor Drive Motor through the Conveyor Gearbox; the Band Tensioner keeps the band taut as it expands with heat, and a line of rollers carries the long span. Around it the Insulated Tunnel is a double-wall steel structure packed with Insulation, with end vestibules that limit the heat lost where the band enters and exits.

Heat is applied in stages. Each Heating Zone runs its own Gas Burner or Heating Element and a Blower Motor circulation fan, so a typical profile is hot at the front for oven spring, hotter in the middle to set structure, and cooler at the exit to finish colour without burning. The Steam Injection manifold injects steam into the early zones, keeping the dough surface moist so the crust sets late, which gives better rise and gloss. The Exhaust System blower pulls combustion gases and baking moisture out through a damped stack, balancing humidity against flue draw. The Zone Control System runs a PID loop per zone, reads the zone probes, sets band speed for the target bake time, and switches the burners and elements through power relays.