Air circulation and exhaust control system for commerical ovens

In an oven, an air circulation and exhaust control system comprising:

• means defining an oven enclosure;
• a multi-tier conveyor including side portions and circular end portions for transporting food products through the oven enclosure;
• a plurality of burners each located within the oven beneath a side portion of one of the tiers of the conveyor to heat the interior of the oven;
• inlet plenums extending to inlet apertures situated directly above the burners for receiving heated gases generated by operation of the burners;
• a pair of outlet passages;
• a plurality of discharge tubes each extending radially outwardly from one of the outlet passages and adjacent a tier of one of the circular end portions of the conveyor and having a plurality of outlet apertures therein;
• each tier of the conveyor having a discharge tube extending adjacent thereto also having a burner extending thereunder;
• means supporting each discharge tube for selective positioning of the outlet apertures with respect to the conveyor;
• circulation fan means for drawing heated gases into the inlet plenums through the inlet apertures thereof and for directing the heated gases through the outlet passages to the discharge tubes and outwardly through the outlet apertures thereof to effect heating of food products transported through the oven interior by the conveyor;
• at least one discharge port formed in the oven enclosure means;
• exhaust blower means for controlling the withdrawal of heated gases from the oven interior through the discharge port means;
• and
• means for monitoring the flow rate of combustion air and gaseous fuel to the burners and for operating the exhaust blower means at a speed to effect discharge of heated gases from the oven interior through the discharge port at a rate proportional to the rate of flow of combustion air and gaseous fuel into the oven interior.