Composite sorption filter bags with fibre and disperse fillers

Abstract

677.66:621.763 and M. A. AskarovThe essence of the structure and formation of a fibre-or dispersely filled knit composite filter bag was revealed. Handbook process parameters and the results of tests on experimental samples are presented. The applicability of the technology for manufacturing sorption composite filter bags with fibre and disperse fillers was demonstrated.Textile fabrics are a strong support in mechanical filtration in capturing industrial emissions. Harmful toxic substances can only be captured with adsorbents incorporated in the filter material by impregnation (solutions of functionally active polymers and copolymers), spraying, application on the surface or inside in spinning the material, and by formation of the base of active fibres itself [1].Information on the successful use of pilot-industrial units with chemisorption fibres for removal of toxic emissions (HF, HCl, NH 3 , CO, SO 2 , acid aerosols) from air; capture of copper, nickel, cobalt, lead, and zinc ions in electrolysis; extraction of silver, gold, platinum, palladium, and lithium from aqueous medium in different sectors; treatment of drinking water to remove heavy metal ions and radionuclides, sulfate, nitrate, chloride anions, bacterial pathogens, etc., is reported in [2]. The author drew the attention of investigators to the necessity of obtaining materials with a higher content of chemically active groups while preserving the mechanical properties that ensure their processing into textile articles.Sorption, chemisorption in particular, fibres have low mechanical properties, which makes it difficult to spin yarn from them for fabricating fabrics. All attempts to increase the mechanical properties (increasing the number of punctures, the adhesive binder content or content of strong fibres in nonwovens) are accompanied by worsening of the sorption properties of the filter materials.In view of the important pressure loss of fabrics in filtration, the insufficiently high mechanical properties of nonwovens, and the labor intensity of forming the finished bag shape, we developed [3, 4] technology for production of seamless composite filter bags made from cross-knit honeycomb cloth on circular knitting machines. The size and parameters of the fabric cells are regulated within the technological possibilities of the machines. The fabric is formed by alternating layers of single weaves and a double row that joins them, and until binding of the binder weave, between single layers, filler weft is fed to the cell. The filler weft can be a heterogeneous porous ribbon, a bulky yarn or knitted tube previously filled with fibre or disperse substances.The essence of the proposed technical solution consists of forming honeycomb cloth in two-bed circular knitting machines. The cell sizes and parameters are regulated within the processing possibilities of the machines. The cloth is formed by alternating layers of single weaves and binding a double row, and before binding the binding weave, a filler weft is fed between single layers into the cell. The ...