Stychynskyi Y. Increasing the efficiency of separation of sugar production suspensions by improving the filter cloth

The thesis is devoted to the scientific substantiation of increasing the efficiency of the main and control filtration of juice of the first and second carbonization, thick juice (syrup) in sugar production by improving the structure of filter fabrics. A priority in the sugar industry is the development and use of rational filter fabrics for separating suspensions of intermediate products, which will have a lower cost compared to foreign-made fabrics and provide not only high filtration performance but also the required quality of the filtrate. It has been established that it is advisable to start studying the filtration properties of suspensions by determining the filtration rate. It has been shown that currently the best way to produce filter partitions is by fabric knitting. This technology makes it possible to produce filter elements for various types of automated filtering equipment. The structure of the filter cloth is determined by the structure and diameter of the yarns used, the nature of their weave, and the density and thickness of the cloth. The nature of the yarn weave affects the strength of the filter cloth, specific throughput and filtering fineness. It has been established that the most rational for separating sugar production suspensions is the manufacture of filter cloth using a combination of multifilament (complex) yarns for the warp and textured yarns for the weft. The use of plain weave for the manufacture of filter fabrics is advisable in order to obtain high quality filtrate with a slight decrease in its flow rate. By using a complex twill and plain weave and a combination of polyamide complex yarns for the warp and polyamide textured yarns for the weft, filter fabrics recommended for separating carbonized suspensions and thick juices (syrups) (Satex-9; Satex-14; Satex-18; Satex-19; Satex-25, Ditex-1, Ditex-2 and Ditex-4) were developed. The dispersive composition of sugar production suspensions and their turbidity in quantitative units were studied under production conditions using the laser diffraction method. Using a compact device for determining the filtration rate, the effective lime consumption for lime-carbonation in the case of purification of raw (diffusion) juices of different quality and under conditions of suspension separation using the developed Satex-14 filter cloth was investigated. Using the generalized optimization criteria, it was determined that the rational consumption of lime for lime-carbonation is: for juice with a purity of 83.0% - 0.62...0.66% CaO; for better juice with a purity of 87.0% - 0.55...0.60% CaO to the amount of juice. It is proved that using the developed filter cloth Satex-14 and the established consumption of lime for liming-carbonization, it is possible to use thickening filters and filter presses for separation of preliminary lime-carbonated juice. It has been experimentally proved in production conditions that the developed filter fabrics Satex-19, Satex-14, and Satex-9 provide sufficient filtration rate for separation of juice of the first carbonization. In terms of filtration rate, Satex-19 and Satex-14 outperform the Valmet (Poland) factory fabric by 1.3 and 1.2 times, respectively, and Satex-9 filter fabric has almost the same filtration rate and sediment separation properties as the Valmet factory fabric. At the same filtration rate of second carbonization juice compared to the Valmet fabric, the manufactured Satex-25 filter cloth provides 24 times lower turbidity of the filtrate. At the same time, the average particle size of the solid phase is 10 times smaller compared to juice filtered through Valmet fabric.