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  • Ескіз
    Документ
    Improving the ecological safety of potato chips production by devising a method for wastewater treatment and recycling
    (PC Technology Center, 2021) Hetta, Oksana S.; Shestopalov, Oleksii; Duhanets, Viktor; Shubravska, Olena; Rudkovskyi, Oleksandr; Paraniak, Nаdiia; Riazanova-Khytrovska, N. V.; Maksimenko, Olena
    The study deals with determining the effectiveness of mechanical and physical and chemical methods for the treatment of wastewater of potato chips enterprises. It was established that the wastewater that is formed at different stages of production differ in composition. Wastewater after washing and peeling potatoes is contaminated mainly with suspended soil substances of about 500 mg/l, which are not settled, and also has soluble organic substances with a value of COD of about 1,000 mg/l. It was found that the use of coagulation-flocculation treatment makes it possible to get clear water suitable for reuse for washing potatoes. Coagulant – aluminum sulfate in the amount of 250 mg/l turned out to be effective to destroy the stability of the dispersed system. To intensify the sedimentation of coagulated flakes of suspended particles, non-ionogenic flocculant, which is recommended to be dosed after the introduction of coagulant in the amount of 2.5 ml/l, was selected. Analysis of clarified water indicates a decrease in the concentration of suspended particles up to 26 mg/l and a decrease in COD and BOD5 to values of 262 mg/l and 176 mg/l, respectively. The completed studies made it possible to propose a circuit of treatment of wastewater after washing potatoes, which consists of pre-filtering, reagent treatment, water clarification, and sediment dehydration. This circuit makes it possible to intensively clean the water to the standards of its discharge into the sewage network. However, additional disinfection of water with oxidizers, for example, ozone, was proposed for the reuse of clarified water to wash vegetables at an enterprise itself. The use of the proposed circuit of intensive water treatment will allow increasing the environmental safety of the production of potato chips by preventing environmental contamination through reducing the volume of tap water consumption.
  • Ескіз
    Документ
    Devising an engineering procedure for calculating the ductility of a roller bearing under a no-central radial load
    (PC Technology Center, 2019) Gaydamakа, A.; Kulik, G.; Frantsuzov, V.; Hrechka, I.; Khovanskyi, S.; Rogovуі, A.; Svуnarenko, M.; Maksimova, M.; Paraniak, N.
    Known theoretical approaches to calculating the ductility of rolling bearings include rather complicated analytical dependences and require cumbersome computation. That makes it a relevant task to undertake a research aimed at the development of an engineering approach to the calculation of radial ductility of bearings. The current study proposes an engineering method for determining radial ductility using cylindrical roller bearings as an example. It accounts for the radial gap, contact deformation of parts, the deformations of bending and misalignment of rings for cases when a bearing is exposed to the action of a central radial load and a radial load with eccentricity. The adopted simplified linear calculation model for determining the angle of rings misalignment is valid for small angles when contact is maintained over the entire length of the roller. Computation of radial ductility of roller bearings under a no-central radial load is based on determining the sum of variable elastic deformations in a contact between rings and the most loaded roller. The values for elastic deformations are determined from known formulae for solving the contact problem in elasticity theory taking into consideration a mismatch between the geometric centers of outer and inner rings. Adequacy of the proposed engineering procedure has been confirmed by results from calculating the specific ductility of the cylindrical roller bearing 2211 with a central radial load. By using the proposed methodology, we have derived values for specific ductility that are 3...4 % lower compared to similar results obtained from a known procedure. By using the cylindrical roller bearing 42726 as an example, we have investigated structural parameters considering a no-central radial load. A decrease in the bearing 42726 ductility with an increase in the number of rollers and rigidity of the outer ring has been shown, as well as with a decrease in the eccentricity of a radial load. The ductility of rolling bearings must be known when constructing dynamic models of certain machines: machine tool spindles, shaft-gears at large-size reducers, crane structures. Therefore, the proposed engineering procedure for determining the ductility of roller bearings at small angles of rings misalignment could be applied in the practice of designing machines and mechanisms for which the elastic characteristics of all their components are important.