GB1345453A - Heat treatment apparatus - Google Patents

Abstract

1345453 Yarn-stretching apparatus AKZO NV 26 April 1972 [4 May 1971] 19326/72 Heading B5B [Also in Division D1] Apparatus for heat treating a plurality of elongate elements (e.g. yarns of synthetic filaments in a hot stretching process) at a temperature above 100‹ C. comprises a heat treatment zone 1 formed with a plurality of heating chambers 9 passing therethrough, the number of chambers 9 corresponding to the number of elongate elements to be treated, each treatment chamber having a lateral pipe 4 for the introduction of steam or other treatment medium and pressure locks 13 formed at its inlet and outlet ends. As illustrated the heating chambers are preferably formed by laterally spaced, parallel tubes 2 passing through an outer chamber 5, tubes 2 and chamber 5 being fed with steam under pressure from steam source 17 via inlets 7 and 4 respectively. At their downstream end each treatment chamber 9 is preferably provided with a compressed air ejector 14 for re-threading any yarns which break during the heating process. The pressure locks 13 preferably include throttle members which allow the cross-sections of flow ducts passing therethrough to be altered as required. In the preferred embodiment (Figs. 3-17, not shown) the adjustable throttle members are formed by rotatable cylinders formed with recesses having a cross-section equal to that of the flow duct and mounted in bores perpendicular to the flow ducts, alternate cylinders along the length of the flow ducts being separated by bores which form turbulence zones. These cylinders are rotatable between a position in which only a narrow channel for passage of the yarn is present and a position, used when re-threading of a yarn is necessary, in which the whole cross-section of the flow ducts are open. The apparatus allows filaments of, for example, nylon to be hot stretched using steam at 152‹ C. with a higher yarn throughput than conventional apparatus.