This invention relates to a new and improved industrial oven having means for recirculating air to produce a hot air curtain for effectively minimizing the loss of hot air through one or both of the access openings through which the articles to be heat treated are conveyed into and out of the oven.
Typically, a mechanical conveyor is employed to carry a continuous series of the articles to be heat treated into the oven through one access opening, through the tunnel space in the oven, and out of the oven through another access opening. Some of the hot air in the oven tends to escape through the access openings, which must be kept continuously open. The escape of the hot air causes wastage of energy. Moreover, the interior of the oven is cooler near the access openings than in the central portion of the oven. Furthermore, the escaping hot air raises the room temperature outside the oven, in the vicinity of the access openings, so that uncomfortably hot working conditions may be produced in the room.
One object of the present invention is to provide an industrial oven having new and improved means for minimizing the escape of hot air from the oven through the conveyor access openings, so as to minimize the wastage of energy, while also reducing the ambient temperature in the room outside the oven and improving the uniformity of the high temperature within the oven.
A further object is to provide a new and improved heat retention system which is readily applicable to both new and existing industrial ovens, at low cost.