Науково-прикладні основи вдосконалення машин для подрібнення м’ясної сировини: автореф. дис. на здобуття наук. ступеня д-ра техн. наук: 05.18.12 - процеси та обладнання харчових, мікробіологічних та фармацевтичних виробництв

Abstract

Дисертація присвячена розробці науково-практичних основ вдосконалення машин для подрібнення м’ясної сировини, а саме кутерів, вовчків і емульситаторів, на базі вироблення і використання концепції вдосконалення машин для подрібнення м’ясної сировини, яка ґрунтується на взаємоузгодженні гідродинаміки сировини, процесу її подрібнення, напружено-деформованого стану та параметрів зношування робочих органів машин. За результатами виконаного комплексу теоретичних та експериментальних досліджень отримано залежності і виявлено закономірності, що розвинули положення про вплив основних конструктивних і кінематичних параметрів кутерів, вовчків і емульситаторів на процес подрібнення м’ясної сировини. На основі наведеного розроблено нові конструкції вовчків, кутерів, емульситаторів і їх робочих органів з узгодженими характеристиками, які мають підвищену питому продуктивність, покращену енергоефективність і працездатність. Результати роботи впроваджено на підприємстві ТОВ «Черкаська продовольча компанія».

The dissertation is devoted to the development of scientific and practical bases for improving machines for grinding of raw meat, namely bowl cutters, meat grinders and emulsifiers, based on the development and use of the concept of improving machines for raw meat grinding, which is based on the coordination of raw material hydrodynamics, grinding process, stress-strain state and wear parameters of the working bodies of machines. According to the results of a complex of theoretical and experimental research, dependences were obtained and regularities were revealed that developed the position on the influence of the main structural and kinematic parameters of bowl cutters, meat grinders and emulsifiers on the process of raw meat grinding. The regularities of hydrodynamics of raw material movement in the working zones of bowl cutters, meat grinders and emulsifiers depending on the structural and kinematic parameters of the working bodies and working zones of these machines and the structural and mechanical properties of raw meat are established. Based on the analysis of the obtained amount of scientific information and developed methodological principles of improvement of machines for raw meat grinding acquired further development of the provision on the influence of basic structural and kinematic parameters of meat grinders, bowl cutters and emulsifiers and structural and mechanical properties of raw material on the overall efficiency of grinding processes. The necessity, levels and methods of mutual coordination of constructive and kinematic parameters of feed and grinding systems are substantiated, which provide a significant increase in the overall efficiency of grinding processes in meat grinders, bowl cutters and emulsifiers and, accordingly, determine the basic directions of improvement and development of meat grinding machines. The dependence of the limit of fatigue strength (endurance) of the bowl cutter knives at alternating loads on the type of firming processing and on the features of the geometric shape of the knives is established. By mathematical modelling using numerical methods, it is established that bowl cutter knives of all studied types, when used in modern high-speed machines, work in the range of oscillation frequencies close to resonant. The influence of the constructive parameters of knives on their resonant frequencies is found out. Quantitative characteristics of the influence of vibration loads on the stress-strain state of knives are obtained. For knives of the most common types, even when performing their construction with the maximum specific thickness, there is an increase in the coefficient of dynamism in the range β = 1,04–2,24, which causes a proportional increase of deformation and stress. Using the obtained research results, a set of constructive (a series of new constructions of bowl cutter knives, a fabricated construction of the meat grinder plate, a new construction of the knives of the meat grinder with blades placed only in zones of intensive feed of raw material by the screw, a new design of the emulsifier cutting mechanism, a structure of a protective tray (pallet) of the meat grinders) and technological (method of strengthening of bowl cutter knives by high-frequency forging, application of wear-resistant metal-ceramic covering WC-Co 88/12 on the blades of the knives and the plates of the emulsifiers by pulsed plasma method) measures are offered, substantiated and implemented, that provided an increase of wear resistance up to 3,4 times, mechanical strength up to 34% and fatigue endurance up to 2,5 times of the working elements of meat grinders, bowl cutters and emulsifiers. Based on the above, new designs of meat grinders, bowl cutters, emulsifiers and their working bodies with agreed characteristics have been developed, which have high specific productivity, improved energy efficiency and working capacity. 8 patents of Ukraine for inventions and 7 utility patents of Ukraine were obtained for the proposed new constructive solutions. Developed technical solutions of improvement of bowl cutters provide a 2,8 times higher increase in productivity, 62% decrease in capital investments and 75% reduction in operating costs. The productivity of meat grinders increases by 1,8-2,2 times, emulsifiers – 1,4 times. The durability of the cutting tool of the meat grinders increases by 1,9-3,2 times. The heating of the raw material in the emulsifier can be reduced by 4 °C, and the wear resistance of the cutting tool is increased by 3,4 times. New methods of calculating of the basic design and kinematic parameters of bowl cutters, meat grinders and emulsifiers, which allow taking into account their influence on the process of grinding of raw meat. The economic effect, depending on the applied technical solutions is: for bowl cutters UAH 1304 300, for meat grinders up to UAH 344 000, for emulsifiers UAH 220 000. The results of the work were implemented at the Cherkassy Food Company LLC. The calculation of the economic effect from the use of the developed designs of bowl cutters, meat grinders and emulsifiers confirms the feasibility of their introduction into production.