Patent GB-1211596-A (GB)
Title: Apparatus for heterogeneous mixing of spinning solutions and other viscous liquids
IPC: B01F5/06
Filed: 1968-08-12
Abstract: 1,211,596. Spinning solution supply systems. INSTYTUT WLOKIEN SZTUGZNYCH I SYNTETYCZNYCH. 12 Aug., 1968 [16 Aug., 1967; 14 March, 1968], No. 38520/68. 'Heading B5B. [Also in Division B1] Apparatus for heterogeneously mixing spinning solutions and other viscous liquids by continuously introducing each of the solutions separately into a common chamber in the form of streams uniformly distributed over the whole cross-section of the chamber comprises a plate divider with a fitting having guide rings provided with vanes mounted thereon and also one or more perforated plates. Thus the mixer of Fig. 1 comprises a container 1 provided with lateral and bottom connector pipes, closed at the top with cover 2 clamped with flange 8. Pipe 6 in cover 2 having the divider 3 and pipe fitting 5 attached thereon divides the container into three chambers a, b and c so that chamber a is within chamber b. Guide rings 4 provided with vanes are mounted on the pipe fitting 5, and a perforated plate or plates 7 may be arranged in the bottom part of the container to effect stronger break up of streams where necessary. Divider 3 is provided with slots and/ or orifices of optional shape, hereinafter called slots, e.g. as in Figs. 5-11 (not reproduced) serving as outlets from chambers a and b to the chamber c. Desirably, the total surface area of such slots should not exceed 85% of the total surface area of the divider which is connected directly to the common chamber into which streams of different spinning solutions are introduced. The linear arrangement of slots as well as the distance between them, makes it impossible to form streams from the same solution with large cross-sections. The mixer of Fig. 3 comprises a central case 9 fitted with a lateral connector pipe, upper case 10 and bottom case 11 provided with perforated plate 12 positioned within and having slots whose axes may be perpendicular to the surfaces of the plate as shown or may besinclined provided they do not subtend angles greater than 80 degrees with the main axis of the mixer, the slots effecting cutting and mutual rearrangement of streams. This mixer also includes a divider 13 of plate-pipe type placed tightly within the cases 9, 10 and 11, thus dividing the apparatus into three chambers a, b and c. Plate-pipe divider 13 consists of plates 14 and 15 with slots and small pipes whereby some of the slots of plate 14 are connected with some of the slots of plate 15. One solution flows from chamber a through small pipes into chamber c, while the solution from chamber b flows directly through slots of the plate 14 into chamber c. As with the mixer of Fig. 1, the total surface area of slots in plate 14 should not exceed 85% of its total surface area. A ring assembly is advantageously provided, in order to obtain uniform size and shape of cross-section of particular streams and their uniform arrangement in the total cross-section of the solutions. Fig. 13 shows a mixer for two spinning solutions comprising a case 16 closed by cover 17 in which are common chambers 18 serving for separately introducing the spinning solutions. Figs. 17, 21 and 25 (not reproduced) show other patterns of mixer, the reference numerals having the same connotation as those of Fig. 13, The points of entry of the solutions are at the nozzles of pipes screwed into the cover 17. Ring assembly 20 defining ring chambers 19 is fastened to cover 17 by means of connector 21. The divider consists of ring assembly 20 with the connector 21. Rings 20 are provided with rows of slots so that slots of one row do not overlap or only partly overlap slots of the adjacent row. Thus spinning solutions flow from ring chambers 19 through slots as shown in Figures 15, 19, 23 and 27 (not reproduced) forming in the bottom part of the mixer a heterogeneous mixture which if necessary, is set in rotational motion by means of skew vanes 22 fixed in the bottom part of the mixer. The distribution of particular streams in the mixture of solutions using the mixer of Figs. 13, 17, 21 and 25 is shown respectively in Figures 16, 20, 24 and 28 (not reproduced). The mixer for three spinning solutions shown in Fig. 29 differs from that for two solutions only by the number of common chambers 18 and the mutual arrangement of slots in the divider shown in Fig. 31 (not reproduced). Advantageously a primary divider is used for uniform introduction of spinning solutions into appropriate ring chambers. Thus the plate divider 3 may be placed into the mixer, before ring assembly 20 as shown in Fig. 42 and in Fig. 43 (not reproduced) wherein slots of the plate divider are suitably connected with ring chambers 19 of the mixer. Spinning solutions are introduced separately into chambers 23 from where through suitable slots of divider 3 and through orifices in the plate 24 they flow into suitable ring chambers 19. The apparatus of the invention thus ensures the proper distribution of particular spinning solutions in relation to each other, thus enabling the production of two or multicomponent crimped fibres having novel and valuable properties. Thus polyacrylonitrile fibres having a stable spiral crimp and a high degree of curling may be obtained. The form of apparatus embodying the ring assembly enables streams of spinning solutions having cross-sections predetermined in respect of size and shape to be obtained, and ensures the orientation and uniform distribution of said streams in the total cross-section of the spinning solutions, so enabling two or multicomponent fibres having a more homogeneous three-dimensional crimp to be made.