https://sci.ldubgd.edu.ua/jspui/handle/123456789/61 2026-11-13T11:35:39Z https://sci.ldubgd.edu.ua/jspui/handle/123456789/19513 Title: Математична модель надійності деревообробних верстатів за критерієм технологічної точності Authors: Дзюба, Лідія Федорівна; Чмир, Оксана Юріївна 2026-01-01T00:00:00Z https://sci.ldubgd.edu.ua/jspui/handle/123456789/19511 Title: Modeling the impact interaction of wood chips with the screen of a drum-type wood-comminuting machine Authors: Дзюба, Лідія Федорівна; Ребезнюк, І.Т.; Чмир, Оксана Юріївна 2026-01-01T00:00:00Z https://sci.ldubgd.edu.ua/jspui/handle/123456789/19509 Title: Substantiation of the design parameters of a sectional screen for a drum-type wood chipping machine Authors: Dziuba, Lidiia; Rebeznyuk, I. T.; Chmyr, Oksana; Barabash, B.Z. Abstract: The production of wood chips for the pulp-and-paper, wood-based panel, and bioenergy industries requires ensuring stable granulometric composition (stable particle-size distribution) of the product. A promising direction for improving chip quality is the optimization of screening systems in drum wood chippers. The aim of this study is to develop a mathematical model of the interaction between wood chips and the screen and to substantiate its rational design parameters. The study was conducted using the methods of solid-body motion mechanics, mathematical modeling, and experimental testing. A mathematical model of the impact interaction between wood chip particles and the screen was developed, taking into account the kinematic parameters of particle motion and the physical and mechanical properties of the material. A relationship for determining the number of sections of a stepped screen was derived, and the patterns governing particle movement within the inter-drum space were established. The influence of the number of screen sections and the radial distance between the screen and the drum on the efficiency of wood chip sizing has been experimentally investigated. It was found that the use of a sectional screen improves the separation of substandard particles and the fractional composition of the output product. The optimal parameters are 11 screen sections and a radial spacing of 15 mm. Under these conditions, the proportion of the substandard fraction is 8–15%, whereas for a plate-type screen it is 25–32%. The obtained results may be used in the design and modernization of drum wood chippers. Description: Based on the developed mathematical model of the impact interaction of wood chips with a steel screen, it was found that for a drum chipper with the drum radius of 200 mm, it is most appropriate to use screens with 8 to 12 sections for the production of wood chips smaller than 6 mm. With an increase in the drum radius to 300 mm, the number of sections on the screen can be increased from 10 to 16, depending on the distance of the screen from the drum and the moisture content of the wood. The experimental studies have shown that the smallest percentage of industrial chips with a size exceeding the required 6 mm is obtained when the screen is placed at a distance of 15 mm from the drum. Positioning the screen with 11 sections at the indicated distance produces the best results in terms of the percentage of the required chips at a wood moisture content of 40%. Therefore, for practical application, it is advisable to use screens of this type in drum chippers. 2026-01-01T00:00:00Z https://sci.ldubgd.edu.ua/jspui/handle/123456789/19478 Title: Диплом переможця конкурсу, сертифікати Authors: Гембара, Тарас Abstract: У файлі фотокопії 2026-01-01T00:00:00Z