GB1012501A - Improvements in or relating to the distribution of viscous liquid substances in pipes - Google Patents

Abstract

1,012,501. Spinning composition supply system. BRITISH NYLON SPINNERS Ltd. Feb. 28, 1964 [March 22, 1963], No. 11378/63. Heading B5B. [Also in Division F2] A spinning solution (or melt) supply system (Fig. 1) comprises a supply pipe or manifold M fed with the viscous liquid material under pressure and having successive sections 1-4 of decreasing diameter, and stripping junctions T 1 -T 3 for branch pipes at intervals along the pipe designed to remove an outer annular portion of liquid, so spaced and constructed that the times of transit of the liquid material from the supply pipe inlet to each of the withdrawal positions (P 1 -P 4 ) are at least substantially equal. Thus the extent of thermal degradation of a polymer, e.g. hexamethylene adipamide, withdrawn at each point is substantially the same. Thus, in Fig. 1, the volumetric flow u at each position is the same and is a quarter of that (4u) at the input of the manifold, the dotted lines within the manifold showing the boundaries between the streams flowing to the respective positions. By reversing the direction of flow of liquid through the apparatus, it may be used for providing a viscous liquid material from a plurality of sources of supply to a common outlet. In Fig. 2, a manifold M is connected to a twin branch stripping junction T having three branches B 1 , B 2 , B 3 , the upstream end portion of the smaller diameter pipe of branch B 3 protruding backwardly into the manifold. In Figs. 3 and 4, a manifold M is connected to a single stripping junction T having a branch pipe B. In Fig. 3, division of the stream takes place upstream of the junction, as in Fig. 2, by virtue of the backward protrusion of the inner pipe of the stepped down portion of the manifold. In Fig. 4, division of the stream takes place downstream of the branch B, the outer annulus of the stream of liquid being reversed in direction before flowing down the branch pipe. Figures 5 and 6 illustrate the use of an annular metering slot at the stripping junction leading to an annular plenum chamber C. In Fig. 6 a sufficiently large plenum chamber enables the asymmetric arrangement of branch pipes B 1 and B 2 to be used if desired. Fig. 7 illustrates a four-branch junction. Branch pipes B 1 -B 4 are equal in diameter to the manifold M so that they more than cover the circumference of the manifold at the tapping station T. This overlap is necessary if proper stripping of the entire annulus is to take place by the action of meter pumps extracting an equal flow in each of the branch lines.