Oxidation furnace

An oxidation furnace for the oxidative treatment of fibers comprising:

• a) a housing which except for passage openings for the fibers is gastight;
• b) a process chamber which is located in an interior of the housing;
• c) deflection rollers which guide the fibers in a serpentine manner such that they lie beside one another in the form of a fiber carpet through the process chamber, wherein the fiber carpet defines a plane between respective mutually opposite deflection rollers;
• d) an atmosphere generating installation, by way of which an operating atmosphere comprising heated air is generated, and which comprises a blower installation having at one or more exit windows through which the operating atmosphere is capable of being blown into the process chamber between two adjacent planes of the fiber carpet, each of the one or more exit windows being positioned on an outer side of the blower box facing the process chamber, each of the one or more exit windows being bound on a first side by a first guide rail and on a second side by a second guide rail, and extending to an access means at a third side, each of the one or more exit windows having a distinct first guide rail, a distinct second guide rail, and a distinct access means;
• wherein
• e) the operating atmosphere reaches the process chamber by way of a flow directing installation which is mountable to a periphery of the blower installation, wherein
• f) the flow directing installation comprises replaceable flow directing elements having flow passages, the replaceable flow directing elements being mountable in a removable manner through each access means into each of the first and second guide rails such that the removable flow directing elements extend across the at least one exit window of the blower installation and partially fill the outer side of the blower box comprising the at least one exit window, the flow passages forming a pathway for the operating atmosphere from the at least one exit window to the process chamber.