GB1348959A - Apparatus for heat-treatment of filaments - Google Patents

Abstract

1348959 Heating fibres EI DU PONT DE NEMOURS & CO 21 April 1972 [23 April 1971] 18671/72 Heading D1F In an open or enclosed apparatus for continuously heating running filaments an array 1 thereof passes over guides 12 to be maintained a desired distance above a planar surface 4 of a jet base 5 and between side walls 8. Hot pressurised fluid 13 e.g. air or steam, entering one or two ports as at 6, flows through slot orifice 7 which is bounded by surfaces 14 and 15 intersecting surface 4 at sharp edges 17 and 18, the angle 16 being 15-45‹. Fluid emerging at supersonic velocity from the orifice passes upwardly through the filaments, effecting a separating and heating action thereon, then downwardly through the filaments and thereafter flows along and parallel to surface 4 and whilst continuing to heat the filaments. Hot fluid also circulates in low pressure zone 19. Spent fluid is diverted from the filaments by a coanda surface 9 having side walls 10. In the fluid entry passage, distribution plates (or slot orifices) 23 and 24 may follow a plenum chamber 22. According to other embodiments of apparatus, Figs. 3-5 (not shown) the bounding surfaces such as 14 and 15 provide successively converging and diverging passages optionally with a parallel sided throat therebetween and the edge, as at 18, may be chamfered. In passing through the apparatus the filaments may be drawn e.g. with a draw ratio of 4.2.