MODEL OF THE QUALITY-POWER INDICATOR OF A ROTARY DRUM MIXER

На основании экспериментальных исследований в статье изложены вопросы повышения качественных показателей работы барабанного смесителя кормов, представлено описание его конструкции и принцип работы. Исследования проводились в соответствии с действующей методикой и материалами, представленными в статье. По результатам аппроксимации исходно рассчитанных значений качественно-мощностного показателя получена статистическая модель данного качественно-мощностного показателя (0,01 %∙кВт). Осуществлен анализ величины ошибок расчетных данных на предмет соответствия исходным данным. После обработки полученных экспериментальных данных приведено описание графических зависимостей по влиянию конструктивных параметров рабочего органа барабанного смесителя на качественно-мощностной показатель. Увеличение высоты установки лопастей нежелательно свыше 0,16 м, а увеличение количества лопастей свыше восемь штук приводит к резкому ухудшению количественно-мощностного показателя. Даны соответствующие выводы по применению исследуемых конструктивных и режимных параметров при работе барабанного смесителя. Based on experimental studies, the article presents the issues of improving the quality indicators of the drum feed mixer, describes its design and operating principle. The research was conducted in accordance with the current methodology and materials presented in the article. Based on the results of approximation of the initially calculated values of the quality-power indicator, a statistical model of this quality-power indicator (0.01% kW) is obtained. The value of errors in the calculated data is analyzed for correspondence with the initial data. After processing the obtained experimental data, the description of dependence diagrams on the influence of the design parameters of the working body of the drum mixer on the quality and power indicator is shown. An increase in the height of the installation of blades is undesirable over 0.16 m, and an increase in the number of blades over eight leads to a rapid deterioration in the quantity-power indicator. The relevant conclusions on the application of the studied design and operating parameters in the working of the drum mixer are presented.

Regression model of the influence of the height of drum mixer blades on the quality of mixture

The aim of the research was to establish the influence of the number and height of blades of a drum mixer on the quality of the prepared mixture of concentrated feed. The research method of the drum mixer provided for the experimental determination of the coefficient of variation (unevenness) of the mixture with a three-level combination of the blades height and their number. The absence of an extremum according to the obtained data required the use of a fourth level of the number of blades. Computer processing of the results made it possible to establish a functional dependence of the influence of design factors on the quality of the mixture. The implementation of the used research methodology for the operation of the drum mixer made it possible to establish an adequate functional dependence of the influence of the number of blades and their height on the quality of the mixture. The number of blades used practically does not affect the coefficient of variation of the content of the control component. The values change less than experimental error. However, existing trends indicate a slight (about 1%) decrease in the coefficient of variation of the mixture with an increase in the number of blades from 2 to 8 pcs. For 50 kg of feed in a drum capacity of 0.26 m3, the height of the blades is about 0.15 m. The increase or decrease in the height to 0.125 m or 0.175 m affects the quality of the mixture, increasing the coefficient of variation from 20.6% to 34-50% at the proportion of the control component of 1% and the mixing time of 200 seconds.

Cohesion-driven mixing and segregation of dry granular media

Granular segregation is a common, yet still puzzling, phenomenon encountered in many natural and engineering processes. Here, we experimentally investigate the effect of particles cohesion on segregation in dry monodisperse and bidisperse systems using a rotating drum mixer. Chemical silanization, glass surface functionalization via a Silane coupling agent, is used to produce cohesive dry glass particles. The cohesive force between the particles is controlled by varying the reaction duration of the silanization process, and is measured using an in-house device specifically designed for this study. The effects of the cohesive force on flow and segregation are then explored and discussed. For monosized particulate systems, while cohesionless particles perfectly mix when tumbled, highly cohesive particles segregate. For bidisperse mixtures of particles, an adequate cohesion-tuning reduces segregation and enhances mixing. Based on these results, a simple scheme is proposed to describe the system’s mixing behaviour with important implications for the control of segregation or mixing in particulate industrial processes.