Розглянуто методи моделювання руху сипкого матеріалу в дозувальному обладнанні безперервної дії. Встановлено, що моделювання пульсацій та розривів у потоці сипкого матеріалу можна здійснити за допомогою методу дискретних елементів. На його основі створена модель системи, що складається з бункера циліндрично-конічної форми та тарілчастого живильника безперервної дії. Частинки сипкого матеріалу представлені у вигляді сфер із постійним радіусом, між яким діють сили тертя та пружності. В результаті моделювання визначено швидкості руху та положення кожної частинки у поперечному перерізі системи «бункер-тарілчастий живильник» та на поверхні тарелі живильника. Визначено зони із характерними швидкостями руху сипкого матеріалу та продуктивність системи. Найбільша швидкість частинок спостерігається у зоні вихідного патрубка бункера, вздовж його центральної вісі та у зовнішньому шарі матеріалу, який знаходиться на поверхні тарелі. Найменші швидкості спостерігаються біля стінок бункера та в центрі тарелі. Встановлено, що у процесі роботи живильника спостерігається збільшення радіусу конусу сипкого матеріалу на 15,2 %, який знаходиться на поверхні тарелі. Експериментальне дослідження системи здійснено із використанням дослідного стенду, що складався з конічно-циліндричного бункера, тарілчастого живильника безперервної дії та системи збору даних. Визначено продуктивність живильника в усталеному режимі роботи. Встановлено, що вона має пульсуючий характер, який співпадає із результатами аналітичних розрахунків на основі розробленої моделі. Висновок про відповідність отриманих результатів зроблено на основі рівності дисперсій продуктивності, яку перевірено за допомогою критерію Фішера. Отримана модель може бути застосована для аналізу усталеного режиму роботи тарілчастих живильників безперервної дії у випадку, якщо сипкий матеріал надходить в центр тарелі Ключові слова: циліндрично-конічний бункер, тарілчастий живильник, сипкий матеріал, метод дискретних елементів, взаємодія частинок UDC 621:004.94

The processes to form the compositions of loose materials in centrifugal mixers of continuous action have been considered. Based on the method of discrete elements, a mathematical model of the movement of particles in the rotor of the centrifugal mixer was built, taking into consideration their geometric and physical-mechanical parameters. To assess the extent of influence of these parameters on the nature of particle movement, a well-known mathematical model in the form of a system of differential equations was used, which was built on the basis of classical laws of mechanics. The process of mixing particles of two loose materials under different initial conditions of movement was modeled. The trajectories of individual particles along the bottom and side wall of the rotor were calculated. The results of the research reported here have established that the model built on the basis of the discrete element method makes it possible to improve the accuracy of determining the parameters of the movement of loose materials in the mixing zone. Calculations that involved this method show that the length of the particle trajectory is 2.9, and the movement time is 9 times greater than those calculated by the system of differential equations. The built and known mathematical models demonstrated the same nature of the distribution of components in the mixer. The value of the Pearson correlation coefficient between the calculated values of the coefficients of variation is 0.758. The best homogeneity is achieved by separating the flows of the mixture components and reducing the distance between their centers. The experimental study was carried out using a centrifugal mixer of continuous action with a conical rotor. Particle trajectories were constructed; it was established that the shape of the trajectory built by a discrete element method is closer to the experimental one. The results reported in this paper make it possible to predict the impact of the structural and technological parameters of the mixers of continuous action on the uniformity of the mixture

The article presents the architecture and operation principles of the system for collecting and analyzing information from strain gauges. These systems are used to determine the equipment performance for transporting a variety of materials. In particular, they are used to control the movement of bulk materials mixtures components. For such technological processes, it is fundamentally important to ensure constant flows intensity. The paper identifies three variants of sensor connection schemes, analyzes their advantages and disadvantages. It is established that the structure “one ADC – several sensors” allows to reduce equipment costs and at the same time to provide the minimum parameters influence of a transmission line on a useful sensor signal. The “one-to-one” scheme provides the connection of each sensor to its own ADC. “Circuit with multiplexer” allows to increase the number of sensors connected to one ADC. It is established that the best option in terms of reducing the interference effects on the analog signal and the cost of creating a system is the scheme “one ADC – several sensors”. The algorithm of information transfer from ADC to microcontroller (MC) is analysed. It is calculated that HX711 ADC chips provide the maximum data rate of 18.5 values/s. It is proposed to transfer data between the MC and the server using the TCP protocol because it avoids data loss and provides the necessary data transfer speed. The structure and formats of data that are transmitted from the mass sensor to the ADC, microcontroller, web server and database are proposed. The main speed, design parameters, advantages and disadvantages of wired and wireless data network between MK and the server are determined. Recommendations for the design of such a network depending on the characteristics of the premises in which the data collection system will be used have been developed.

Studying the influence of continuous centrifugal mixers design features on their smoothing ability. The methods used are discrete elements, mathematical modeling and regression analysis. The paper considers five continuous centrifugal mixers designs with conical and parabolic rotors. The mixers design features are determined, allowing to change their smoothing ability. Mathematical models of the bulk materials particles movement inside each mixer have been developed based on the discrete element method. The considered mixers reaction to a step change of the key component amount is investigated. The transients parameters are calculated and the particles average residence time in the mixer is determined. It is established that the introduction of turbulizers in the mixers design increases the particles kinetic energy, which leads to a decrease in their residence time in the mixer. Moreover, the absence of a turbulizer leads to a decrease in the mixing intensity. It was also found that the most effective way to increase the mixer smoothing ability is the introduction of additional rotors. In terms of the technological and design parameters combination, the use of mixers with a conical rotor and a turbulizer is the most effective from the point of view for increasing the smoothing ability. On the discrete element method basis, the bulk materials particles movement models in continuous centrifugal mixers of five designs have been developed. The influence of the mixers design features on their smoothing ability and average mixing time is determined. The results obtained allow us to select the appropriate mixer design according to the specified requirements for smoothing ability.

The  aim  of  the  work  is  to  improve  the  work  of  hair  styling  devices,  which  is  aimed  at increasing  the  efficiency  of  hair  styling  under  the  action  of  sufficiently  high  temperatures  with  the  least damage to it. To achieve this goal, the following tasks were solved: the relationship between the physical properties  of  hair  and  temperature  regimes  of  curling  was  analyzed;  experimentally  investigated  the distribution of curling temperature during heating and cooling; the distribution of the temperature of the curling iron when heated with dry hair and with moist hair was experimentally studied. Methodology. The methods of mathematical modeling, methods of mathematical physics, methods of experimental researches with processing of results of experiment by means of a modern software product and computer equipment are used in the work. Findings. Analytical and experimental studies have shown the need for a uniform temperature field on the surface of the work surface to achieve the desired result. The necessity of temperature regulation in devices for work with hair is proven. Originality.  The  possibility  of  using  the  installation  for  experimental  evaluation  of  temperature control  in  devices  for  working  with  hair  is  substantiated,  which  will  significantly  increase  the  time  of continuous operation of the device and reduce electricity consumption. Practical value.  A stand for research and analysis of different temperature regimes of electrical appliances has been developed. The thermostat circuit for temperature control in devices for work with hair is applied. It has been proven that you need to choose the temperature in relation to the condition and type of hair, so as not to cause great harm. Due to its small size, economic and technical indicators, this stand is easy to use when studying the temperature conditions in devices for working with hair in the work space, which contributes to more modern and demonstrative training. It is proposed to use the two-position law of temperature regulation for the surfaces of the working bodies.