Patent GB-454678-A (GB)
Title: Improvements in or relating to a method of or apparatus for dyeing, washing or bleaching yarns or other material
IPC: D06B5/00
Filed: 1935-06-22
Abstract: <PICT:0454678/IV/1> <PICT:0454678/IV/2> A dyeing &c. vat of the kind provided with means for introducing compressed air in order to agitate and circulate the vat liquor, is provided also with means for introducing steam or heated vapour and with means for controlling the supply of air and steam to the said means, whereby simultaneous or successive jets of air and steam may be obtained automatically and periodically, so that streamline circulation of the liquor is avoided and heat is evenly distributed.  The <PICT:0454678/IV/3> <PICT:0454678/IV/4> vat 10 is of wood, with a lining 11 of stainless steel, and has an inwardly projecting flange 12.  Horizontal plates 13 spaced from the lining 11 and separated by slots 14 are supported by angle pieces 15 which form, at each corner of the vat, a pocket extending from the top to the bottom of the vat.  The plates 13 act as weirs for circulation purposes, and define, with the lining 11, four separate air-lift spaces 16.  The liquid level in the vat, according to the quantity of yarn &c. to be treated, is maintained just below the upper edge of one of the plates 13.  At the bottom of each space 16 are arranged perforated steam and air distribution pipes 17, 18 connected by vertical pipes 19, 20 to suitable sources of supply.  Further pipes 21 for the distribution of air and/or steam are arranged across the dyeing space within the weir plates 13. Control of the supply of steam and air to the pipes 19, 20 is effected by two valves 25, Fig. 6, each comprising a casing 26, connected to a supply main 24 or 23 and to the pipes 19 or 20, and a piston 27.  The two pistons are rotated simultaneously by gearing from an electromotor 31 or by a fluid motor driven by the main supply of air or steam, and comprise a series of ports 28 for registration with the pipes 19 or 20. According to the arrangement of the ports 28, a predetermined combination or sequence of discharges of steam and/or air may be produced at the pipes 17, 18.  The pipes 19 and/or 20 include throttle valves whereby the volume of steam and/or air supplied may be reduced as the temperature of the vat liquor rises. These valves may be controlled by hand or thermostatically. Alternatively, each distributing pipe 17, 18 may be formed of thermostatic material such that the cross-section of its discharge openings is reduced automatically as the temperature rises, for example, by forming the pipe in two telescoping sections with overlapping openings which pass partly out of register as the sections expand.  One corner pocket 40 is connected to an external standpipe whereby the height of the liquor in the vat may be observed and regulated.  A pocket 42 used for the addition of toning colour to the vat is connected to sparge pipes in the vat. A pocket 52 is used for introducing fresh dye liquor.  The hanks or the like to be treated are supported by a swift, Fig. 9, comprising uprights 45, a cover 47, cross-pieces 46, and angle plates 49 formed with keyhole slots 51 for receiving the reduced ends of poles 48.  The poles may be pivoted at one end.  The hanks may be supported on the poles in superposed layers, as shown in Fig. 9, or otherwise.  After treatment of the hanks, the swift may be supported by its uprights 45 on the flange 12, for draining purposes.  The connecting pipes to the pipes 19, 20 are arranged below the flange 12.  In operation, the vat is filled to the required level, and the standpipe connected to the pocket 40 maintains the liquor at this level, by valved openings or otherwise.  Air may now be forced into one section 16.  This sets up a rising current and raises the liquor level above the weir at this side, producing a circulation of liquor from the section to the body of the vat.  Simultaneously, steam is introduced, at a lower pressure, into the opposite space 16, causing a heating of the liquor in this space but no circulation to the body of the vat.  The supplies are now reversed, so that the air jets circulate the liquor from the heated space to the body of the vat, and the opposite space is heated.  This cycle is then applied to the other two opposite spaces 16, and the cycles may be repeated periodically.  Various cycles may be produced by suitable arrangements of the ports 28 in the valves 25; at times, air may be supplied simultaneously to all the pipes 18 and 21, or continuously to the pipes 21 and intermittently and in succession to the pipes 18.  The spaces 16 may be subdivided by vertical baffles, and several vats may be operated by a common valve gear. A single distributing pipe, in place of the two pipes 17, 18, may be used in conjunction with a suitable controlling valve; or the distributing device may consist of an elongated box with irregular openings for the discharge of the air and steam.  Several vats of the kind described may be assembled in a large vat with liquor common to the smaller vats.  Where a readily oxidized dyestuff is used, nitrogen may be employed instead of air. Alternatively, Fig. 11, the atmosphere above the dye bath may be used as the agitating medium.  The upper end of the vat is enclosed by a hood 58, from which the atmosphere is withdrawn by an injector 60 supplied with vat liquor by pipes 62, 61 and a pump 63.  The atmosphere and liquor are discharged into the vat by a distributing pipe at the bottom thereof.  In a modification, the atmosphere is withdrawn by an injector operated by a separate water stream, is separated by a suitable separator, and is then forced into the vat.