Oven with air convection combustion, more particularly for bakehouses

Claim 1

A baking oven with air convection combustion comprising: a baking chamber having walls and a door opening; a fire-box; a burner operatively disposed in said fire-box; a vertical primary exhaust duct connected to said fire-box for exhausting the hot gases therefrom and forming a primary circuit therewith; a closed heating duct adjacent the baking chamber surrounding said fire-box and said exhaust duct and forming a secondary circuit for providing secondary air heated to about 200°-300° C. by contact with said exhaust duct and fire-box; a plurality of adjustable input nozzles mounted on the oven in spaced relationship over the height of and on one side of the baking chamber operatively connecting said heating unit to said chamber for conducting air from said secondary circuit to said chamber; adjustable exhaust nozzles mounted on the side of said baking chamber opposite the intake nozzles for exhausting said chamber; a chamber exhaust duct operatively connected to said exhaust nozzles for collecting the secondary air from said exhaust nozzles and returning it to said heating duct; a turbine mounted on a horizontal axis situated above said fire-box and operatively connecting said chamber exhaust duct to said heating duct for recycling said secondary air; a vapor producing humidifier means; a vertical ramp mounted within said baking chamber adjacent the input nozzle side thereof; a humidifier duct connecting said humidifier means with said ramp; and bore holes disposed along said ramp to inject vapor produced by said humidifier means into said baking chamber in the vicinity of said input nozzles.