Patent ID: 9464844
Filing Date: 2016-10-11
CPC Classification: D01F,F27B,F27D

Claim Text:
1. An oven comprising: an oven chamber through which a product passes to be treated, wherein the product is exposed to a desired processing temperature and a process gas within the oven chamber; an oven wall defining a plurality of apertures through which the product passes to enter and exit the oven chamber; a vestibule chamber that is adjacent to the oven wall and is at least partially separated from the oven chamber by the oven wall, the vestibule chamber comprising at least one aperture through which ambient air enters the vestibule chamber from an ambient environment of the oven; a return air duct disposed within the vestibule chamber that draws in an air curtain gas comprising a portion of at least one of: at least one nozzle disposed externally of the vestibule chamber and separated from the oven chamber by the vestibule chamber, the at least one nozzle being located adjacent to the at least one aperture of the vestibule chamber and in fluid communication with the return air duct to receive at least a portion of the air curtain gas drawn in by the return air duct and to direct the air curtain gas generally toward the at least one aperture of the vestibule chamber to form an air curtain adjacent to the at least one aperture, wherein the air curtain interferes with the flow of at least one of the process gas and the ambient air outward into the ambient environment from the vestibule chamber through the at least aperture of the vestibule chamber, and the return air duct is in communication with the ambient environment to draw in a combination of the process gas and the ambient air as the air curtain gas to be directed by the at least one nozzle generally toward the at least one aperture of the vestibule chamber to form the air curtain.