GB806883A - Apparatus for dyeing, bleaching and other liquid treatment of a material in granular or fibrous form or threads - Google Patents

Abstract

<PICT:0806883/IV (c)/1> Apparatus for dyeing or bleaching comprises a container 1 for the material, an expansion vessel 3 in which the liquor is heated by steam coils to 110 DEG C., and a vacuum and compressor pump 5 connected via a four-port valve 8 and conduits to the container and vessel. In operation for dyeing, the container 1 is exhausted for the purpose of removing air from the material by opening a valve 7 and the four-port valve 8 so that communication is set up between conduits 6 and 9 and the vacuum pump 5, a valve 10 to atmosphere being also opened. When the desired degree of vacuum is obtained the valve 10 is closed and a valve 19 opened so that the heated dye liquor may flow from vessel 3 into the container 1 until a float valve 21 is closed. The valve 8 is now operated by an impulse transmitting device (not shown) to allow the high-pressure side of the air pump 5 to communicate alternately with the container 1 through valve 7 and conduit 6, and with the vessel 3 through valve 15 and conduit 14, thus pulsating the liquor which however always covers the material. The liquor can either flow through the valve 16 and the conduit 17 to the outside of the perforated material support 2, or may flow through conduit 18 and valve 19 to the interior of the support 2. The system may be subjected to a certain constant superatmospheric pressure during pulsation by opening a valve 12 in a pressure conduit 11, a valve 13 being provided between the high- and low-pressure sides of the pump 5 so that a suitable pressure difference may be maintained between the two sides, and if desired an amount of liquor may be passed through a non-return valve 22 and conduit 23 into the container without passing through the material. After 10-15 minutes pulsation the dyeing process is complete, the spent liquor may be drained from the system through valves 16, 24, and the liquor residual in the material may be removed by air blown therethrough via an opened valve 25, pump 5, valve 8, and conduit 6. The material may be rinsed by water introduced into the container through valve 26 and drained in a repetitive sequence, or the water may be allowed to flow through continuously. To examine the material during the treatment the liquor is forced back into the vessel 3, valves 16, 19 then being closed and valve 24 opened so that the pressure drops to atmospheric and the temperature to 100 DEG C. The lid of the container 1 may then be raised. The vessel 3 may however be cooled by passing cold water through the coils 4. Normal bleaching may be carried out as above for dyeing, but a more rapid bleaching operation may be performed by replacing the pulsation step by air and steam blown through the material. For this purpose steam is introduced through valve 27 and air through valve 25; the moisture content being high so as not to dry the material. After heating, the valves 7, 24 and 27 are closed and the material allowed to remain in the container for 40-60 minutes.