Patent GB-700111-A (GB)
Title: Improvements in and relating to the recovery of carbon disulphide in the processing of viscose rayon threads, fibres, filaments and the like
Inventor: MERRIMAN HORACE BARTLETT
IPC: D01F13/02
Filed: 1951-01-23
Abstract: <PICT:0700111/IV(a)/1> <PICT:0700111/IV(a)/2> Apparatus for the recovery of carbon disulphide from viscose rayon threads comprises a container for a heated liquid which is fitted with a continuous channel around its upper edge for containing a liquid, a bell mounted over the container so that it can be raised and lowered and so that, when in its lowest position, its edges are immersed in the liquid in the continuous channel to seal off the container, the bell having thread entrance and exit ducts so constructed that when it is in its lowest position the lower edges of the ducts are immersed in the heated liquid in the container and the ducts are sealed off, conveying mechanism fitted to the bell for passing the thread through the container and means for withdrawing carbon disulphide vapours from within the bell.  The heated liquid in the container may be water, spinning bath liquid or aqueous ammonium sulphate.  The liquid in the continuous channel is preferably cold water or cold liquors collected from godets ("channel liquor").  As shown a tank 1 is provided with a continuous channel 2 around its upper edge, and is divided down its centre by a similar channel 3 connected at its ends to the channel 2.  From the channel 3 a vertical partition 4 extends downwardly for about half the depth of the tank 1.  Thus two recovery units 5, 6 are formed, each having a continuous channel around its upper edge.  The tank 1 is nearly filled with hot water or other liquid by pipes 7, 8, and the channel is filled with a cold liquid. Each recovery unit is covered by a bell 9 formed with a peripheral lip 10 fitting into channels 2, 3 and forming a gas-tight seal.  The bell may be raised and lowered by an overhead crane hooked into eyes 26, 27.  The tow of filaments enters and leaves the bell by funnel-shaped openings 11, 12, wide enough to admit the hand, and so formed that their lower edges are below the level of the liquid in the tank when the bell is lowered.  Two sets of freely rotating rollers 13, 14 in fixed bearings are suspended below the underside of the bell close to the entrance and exit ducts.  A trap 24 is also formed in the bell and the carbon disulphide vapours which collect in it are drawn away by a pipe 25 to a recovery plant.  To operate, the bell is raised and a tow of freshly extruded filaments 15 is passed by hand through opening 11, round rollers 13, 14 and out through opening 12.  The bell is lowered on to the tank so that all edges and openings are sealed off.  A roller 16 at the entrance end and rollers 17, 18, 19 at the exit end are provided to assist the passage of the tow and to remove excess liquid therefrom.  Guides 20, 21 provided with slots to allow the passage of the tow 15 are placed near ducts 11-12 to direct gas bubbles formed near the ducts towards the centre of the tank.  A lid may be placed over the tank during setting-up. Specifications 170,817, [Class 2 (ii)], and 509,981 are referred to.