Apparatus for heat treatment of synthetic yarns and fibers

摘要

For heating synthetic yarns and fibers an elongated vessel filled with saturated steam is provided through which the yarn is continuously drawn. The steam condensates on the yarn and transfers its condensation heat to the yarn. For sealing the vessel (3) at the inlet (2) and the outlet (4), several apertures (6-9, 13-16) are provided in a pair of tubes (5,12) surrounding the traveling path of the yarn (1). The space between the first aperture and the opening adjacent the steam vessel (3) is connected to a blocking liquid supply pipe (30) and the space between the last aperture (9,16) and the inlet hole (10) and the outlet hole (17), respectively, for the yarn is connected to a blocking liquid return pipe (31). The blocking liquid supply pipe is kept under a pressure which is somewhat higher than the pressure within the steam vessel (3). The blocking liquid pressure is reduced stepwise by the apertures connected in series and the blocking liquid return pipe (31) ports into a blocking liquid collector tank (32) which is under atmospheric pressure. Preferably water is used as blocking liquid.