Abstract: An oven for treating web stock, especially a tentor for treating textile fabric, to remove volatile combustible substances therefrom in a manner that results in more rapid operation with less capital outlay for equipment, less fuel consumption, and controlled stack discharge. The oven employs a recycle circuit in which the temperature of the oven discharge gaseous stream is first raised by combustion of the volatilized substances therein, and then lowered by entry of cooler, supplemental air, after which part of the gaseous stream is returned to the oven and part used for stock preheating or post heating in other oven sections.

Abstract: Oven apparatus for heat treating web stock, especially a tentor for treating textile fabric, to remove volatile, combustible substances therefrom. The oven has a preheating entry section, a post-heating exit section, and intermediate sections, there being partial flow of gaseous materials from the intermediate sections to an incinerator outside of the oven chamber, and then to the entry and/or exit sections, and partial recirculatory flow by-passing the incinerator and propelled back to the intermediate sections, with the intermediate sections operating at a negative pressure relative to the entry and exit sections.