A Problem-Oriented System of Control and Optimization of Basic Parameters of Technical Complex Systems

: The paper proposes a methodology for the development of a control and optimization system, which is used to solve the design problems of technical complex systems. The systems developed on the basis of this methodology are easy to use and create more accurate estimates of the values of the parameters of technical complex systems than using traditional methods based on solving empirical equations. An example of the implementation of the proposed methodology is a problem-oriented system designed to optimize the parameters of a two-blade mixer of a vertical capacitive apparatus.

DESIGNING A MIXER OF PROTEIN, MINERAL AND VITAMIN ADDITIVES

To ensure the eff ective use of protein-mineral-vitamin supplements in the diets of dairy cows, a mixer design has been developed for their preliminary mixing before adding to the main mixing process. Based on the structural-morphological analysis, alternative structural elements of the mixer design have been considered and conventional symbols were assigned to them. A morphological matrix of solutions has been compiled to off er a set of alternative options. The mixer drive was chosen by the ability to ensure high speed, rotational speed control, user-friendly operation and cost. The design uses an electromechanical drive combined with a V-belt drive. This solution meets all the specifi ed requirements and allows protecting the drive from possible overloads. The working tool was chosen based on the requirement to contact the material actively throughout the chamber volume and to avoid the formation of stagnant zones. A blade mixer with variable blade positioning was found the most eff ective tool for the high-speed mixing of bulk materials. The designed mixer will be operating at a continuously varying speed in the range from 500 to 1500 min-1. This will off er the advantages of high-speed mixing while reducing the infl uence of negative factors on the fi nal mixture quality. The resulting decision matrix will allow determining the most promising areas for further designing, which makes it possible to improve the quality of the developed technical means.

Pengembangan Butiran Premiks untuk Fortifikasi Zat Besi dalam Beras

Iron-fortified rice potentially increases iron consumption in order to overcome anemia in Indonesia. Premix kernel can be applied as a fortificant vehicle being formulated into rice. The premix kernel is processed by mixing rice flour and iron source and extruded to yield rice-like extrudate. This research aimed to develop iron premix kernel using a double screw extruder and evaluate the fortificant homogeneity during mixing and stability due to washing as well as overall sensory acceptability of fortified rice. The premix kernel was made by mixing rice flour (1000 g), pyrophosphate ferries (containing 5,000 mg Fe), and GMS (10 g) for 5, 10, 15, 20, 25, and 30 minutes, added with water (450 mL) and passed into an extruder at 80°C. The dry-mixed for 20 minutes yielded a homogenous premix kernel (6,030±135 mg/kg with RSD of 2.25%). The mixing of premix kernel and Pandanwangi rice (1:100) for 25 minutes using a blade mixer yielded fortified rice with iron content of 39 mg/kg and RSD of 13.56%. The washing process of fortified rice decreased iron content, and the percentage of iron loss was affected by the washing frequency. Raw and cooked fortified rice did not differ organoleptically from those without fortification. Keywords: anemia, fortified rice, ferric pyrophospate, homogeneity, premix kernel

Investigation of the Efficiency of Wet Biodiesel Purification

The main research aim is to verify the efficiency of wet methods of biodiesel cleaning and to establish optimal and rational parameters for biodiesel purification and disposing of its cleaning waste. The efficiency of biodiesel washing was studied by means of volumetric, bubble and aerosol washing. Volumetric washing of biodiesel was carried out with the use of a blade mixer with three blades on a shaft and a four-blade agitator with sloping blades. One of the three methods of biodiesel washing studied can be recommended for practical use – aerosol washing with medium- and large-grained washing to be carried out for at least 4-5 hours, while fine-grained – for a longer time. The use of waste from the purification of biodiesel as a cosubstrate in biogas plants will almost double the output of biogas, which will significantly reduce the payback period of biogas plants.

INFLUENCE OF A NUMBER OF IMPACTS OF LOW-SPEED MIXER BLADES ON CONCRETE QUALITY BEING PREPARED

The paper presents purpose equations describing the uneven mixing depending on the number of the mixer blade impacts per unit of concrete weight as well as the weight of the mixture that have an impact on blades of the slow-speed mixer. Based on the literature review and analysis of the mixing process conducted in the Samara State Agricultural Academy, the design of the blade mixer was developed. The mixer consists of a body where there is a horizontal shaft with working bodies, made in the form of radial blades of helical shape. There are received equations that allow determining the concrete uniformity depending on a number of the impacts of the mixer blades per unit of the concrete weight as well as on the concrete weight that act on the blades of the slow-speed mixer. The power function is adequately described by the experimental results of 98 % confidence probability. In the studied areas of changes in independent factors rational values of the number of impacts per unit of the concrete weight is not less than 800 PCs/kg, as well as the concrete weight having impact on the blade of the slow-speed mixer is not more than 0,001 kg/PC.

ANALYTICAL DESCRIPTION OF THE MIXER PERFORMANCE FOR BULK MATERIALS WITH SCREW BLADES

The aim of the study is to reduce the energy consumption of the blade mixer for bulk materials in regard to its de-sign parameters. Preparation of feed mixtures is carried out mainly by mixers of various designs, as well as extrud-ers and other auger equipment. Widespread horizontal mixers with blades mounted on a rotating shaft are wide-spread and used. They are distinguished by the ability to achieve the necessary smooth mixture within short oper-ating time. The main purpose of the proposed mixer is the preparation of dry mixtures of bulk feed components. The intended use of the mixer is the preparation of concentrated animal feed n agricultural production. In Samara SAA, the design of the blade mixer with screw blades was developed based on the literature review and analysis of the technological process of mixers. The mixer consists of a body with a horizontal shaft with radial trapezoidal screw blades. The proposed blades allow to direct forces in such a way that the total (resulting) projection of the resistant force of the material along the shaft will tend to zero due to the changing angle of the profile and width of the blades. At the same time, an axial force will be created at the edge of the blade at a certain radius, which facili-tates to unload mixer through the discharge opening. The expressions of specific energy consumption for mixing, as well as the work duration of the mixer cycle are given. An expression allowing estimation of an average flow rate of bulk material from the discharge opening of the mixer is obtained. It is established that the position of the gate regulating the area of the discharge opening can affect the volume of the portion simultaneously processed by the mixer, filling volume of mixer and the quality of the mixture.

INFLUENCE OF DESIGN OPERATING AND TECHNOLOGICAL PARAMETERS OF AUGER-BLADE MIXER ON POWER CONSUMED BY IT

The purpose of the study – is the equipment improvement for dry mixing of crumbled feed with substantiation of de-sign and operating parameters. The use of complete feed mixtures is possible only with the use of special techno-logical equipment – feed mixers, producing mixture homogeneity meeting livestock requirements. The costs of pur-chasing, operating and maintaining mixers ultimately affect the cost of livestock production. Accordingly, it is neces-sary to aim efforts at the reduction of these costs. This can be achieved by reducing the specific energy costs for the mixing process, which largely depend on the mixer design, its working parts operation and the efficiency of the mix-ing process and power consumption needed for mixing process. No method of power consumption estimation of mixers with combined working parts according to theoretical studies obtained, having alternating in regard to exe-cution and purpose areas. Power consumption needed for the mixing process is one of the main components of the operating costs for the mixing equipment, ultimately determining the specific energy costs for the mixing process – is one of the important specification of any mixer. The research methodology provided a theoretical basis for the relationship of the mixer parameters on the power consumption during mixing process. Equations for determining the power consumption for the parts were submitted in regard to auger conveyor, the first and the second transport-ing and throwing blades. The expression for determination of power consumption for mixing process from the an-gle of installation mixing and transporting blades, the filling ratio of the mixer and the frequency of rotation of the working parts have been received. The obtained and given expressions allow to determine the power values for the mixing process with an error of no more than 5%, with the values of the studied parameters of the mixer within the boundaries of the experiment.