Gas Burning Batch Oven - Two heating system

The Oven has two system to provide heat source: gas burning, and electricity.
The hot air are force to recirculated in a designed way to dry and heating the parts in the robust oven. Gas burning to provide a fast temperature rising.
Natural Gas will be burned in the burning chamber, to heat the air and them blow the air into oven chamber. For electrical heating, the air will be heated by heating pipe, and then blow in to the heating chamber.