ANALYSIS OF POWER AND ENERGY PARAMETERS OF THE CONVEYOR INFRARED DRYER OF OIL-CONTAINING RAW MATERIALS

. Infrared drying of bulk agricultural products is becoming increasingly widespread in processing and food industries due to energy efficiency, compactness of technological equipment, and ease of operation. The purpose of the presented research is to determine the influence of the technological parameters of the process of infrared drying of the moving layer of oil-containing raw materials. An experimental model of a vibro-conveyor dryer and a set of measuring equipment were developed to solve the problems. The scientific novelty of the work is the confirmation that in the conditions of a vibro-liquefied layer of products, unique conditions are created for the constant renewal of heat exchange surfaces and, accordingly, the leveling of the negative thermal radiation effect on the products, the possibility of advancing the product layer along the working zone, reducing the forces of internal friction in the technological mass, which leads to a decrease in energy consumption on the process Laws have been established regarding the effect of the number of thermoradiation blocks, the load on the flexible belt of the wave conveyor, the speed of product advancement on the belt on the dynamics of infrared drying of soybeans and rapeseed. The practical value of the work was the substantiation of the operating modes of thermoradiation drying with the help of a vibrating wave conveyor installation based on the energy saving of the technological impact, high intensification of the process and minimization of the negative effect on the properties of the processed products


Introduction
The drying process is one of the most complex mass transfer processes, which is a complex complex of interconnected elements that includes heat transfer during the transfer of heat to products through the boundary layer; evaporation during phase transformation; heat and mass transfer during the transfer of moisture and heat inside the material; heat and mass transfer during the transfer of moisture and heat from the surface of the material to the environment through the boundary layer by diffusion or molecular transfer; filtration or molar transfer under convection conditions; thermodiffusion, that is, the transfer of moisture under the influence of a temperature gradient, for which the direction of the thermodiffusion density of the substance mass flow corresponds to the direction of the heat flow density. When justifying the structural and technological scheme of the equipment for the implementation of the presented stages of heat and mass transfer, it is necessary to conduct an analysis of energy costs to ensure their implementation, to assess the technical and economic feasibility of the process and its impact on the change in the physical and chemical properties of the processed raw materials. It is the power and energy characteristics of the process that ensure the dynamics of the development of these factors [5,9,12,19,25].
Among the main factors of intensification of the drying process of bulk material, it is possible to note the transfer of heat of the product from the source of radiant energy and the creation of a fluidized layer of products to increase the heat and mass exchange surface. In the process of heat exchange, the radiant flow partially penetrates into the capillary-porous bodies to a depth of 0.1...2 mm and is almost completely absorbed due to a series of reflections from the walls [1,10,12,21,25,27]. At the same time, the heat exchange coefficient has a significant value and the duration of the drying process is reduced by 30...100 times compared to the convective or conductive method [1,8,21,22]. The vibration of the executive bodies of the dryer ensures the movement of the particles of the loose medium at a constant speed or at a slowly changing speed. This leads to driftdisplacement of the equilibrium positions of such particles and to the appearance of one or more discrete positions of their quasi-equilibrium; as a result of which there is an almost 10-fold decrease in the effective coefficient of friction in the product mass, which increases the coefficient of thermal contact with the product to 100%, significantly reduces the time of technological action and indirectly leads to a 3-5-fold decrease in energy consumption for the process [8,23,11,17,26,18].
To carry out the investigated process in modern technologies, vibrating transport and technological machines are used. The main disadvantages of vibro-conveyor systems with an undeformed conveying body remain high metal consumption and energy consumption, structural imbalance and, accordingly, high dynamic loads on support nodes [8,4,20,24,16]. The presence of a transport device in the form of a flexible conveyor in dryers allows to eliminate the indicated shortcomings and to create energy-saving product processing schemes with prospects for the implementation of automated modes [2,3,7,28,6]. However, it is the presence of a flexible transport element that greatly complicates the design of the machine, makes it difficult, and in some cases, eliminates the possibility of adjusting the operating modes of the vibrating installation.
Thus, the power and energy characteristics of the researched process determine both the possibilities and the efficiency of its implementation, the degree of influence on the surface of the loose product and the corresponding provision of the required properties, which determines the relevance of these studies in the design of infrared technological equipment.

Object of investigation
The developed drying unit contains a flexible load-bearing body 1 (Fig. 1), on which a running or standing wave is created during the operation of mechanical vibrators 2, 3 [13][14][15]. Such a wave spreads along the belt 1, occurs as the transportation of products coming from the feeder 7, with a speed that is regulated by the amplitude-frequency characteristics of the vibrators, which leads to the emergence of a fluidized state of the processing material and its intensive mixing. translational movement. This ensures constant renewal of the surface of products with a thermal energy carrier and accordingly reduces the heat intensity on the surface layer while maintaining a sufficiently high flow rate. Oscillation of rollers 5, 6 ensures the advancement of loose material at a speed necessary to maintain the kinetics of the process under study. The aggregated mechanical vibration exciter in the support rollers 5, 6 of the dryer compactly and organically fits into the scheme of the wave conveyor, allows to reduce the oscillating mass of the drive and provides for the leveling of parasitic vibrations with the help of elastic elements 9. Such a scheme of the drive body, together with the presence of a wave conveyor with a deformable transport element, allows significantly improve the balancing system of the dryer. In addition, it is possible, together with the reduction of the metal and energy consumption of the device compared to existing designs of vibro-infrared dryers of the type "Uragan", "USK", UTZ-4 "M-500", "SVIK" [13], to provide conditions for regulated intensification of the removal process free and physically bound moisture from the processing material. The last factor is implemented by changing the power and energy characteristics of the "vibration field" due to the selection of the corresponding amplitude and frequency of oscillations of the support rollers 5 and 6.

Evaluation of the parameters of the investigated infrared drying process
In order to evaluate the desired parameters of the process of infrared irradiation of oily material (Fig. 2), the selection of equipment was carried out according to the following factors: ensuring the necessary level of activity of substances and humidity; implementation of constructive solutions for the organization of infrared irradiation to ensure the necessary energy and technological efficiency of the process; the choice of the method of mechanical action to ensure the transportation and mixing of the material [7,8,17,22].
The process of infrared drying of oil-containing products was carried out in two stages: first, processing of the product at the maximum temperature of the source of infrared radiation until the formation of a browning crust on the surface of the product; then bringing the product to full readiness at a reduced constant temperature of the generators. The temperature decrease in the second stage occurred with the help of reducing the electric power or increasing the distance of the product to the source of infrared radiation. Design solutions for the layout of the infrared lamp block and the generators themselves ensured the achievement of uniform irradiation according to the requirements of this treatment for the corresponding oil-containing material [2,3], including the content of anti-nutrients [28].
When conducting experimental studies, a certain amount of whole grain of rapeseed or soybeans was received on the tape, obtaining values of specific loading equal to 2.5, respectively; 3.5; 5 kg/m 2 . After that, they ensured the promotion of products on tape 2 (Fig. 2) at a speed of 0.13; 0.33 or 0.54 cm/s. At the same time, under the influence of infrared emitters 4, which were turned on individually and together, the product perceives radiation with a power of 100, 200, 300 W. The power of the emitters was adjusted by changing the current strength with the help of current clamps.

Fig. 2. Scheme of the experimental conveyor installation for infrared drying: 1drive roller; 2ribbon; 3tension roller; 4infrared irradiated; 5production
The temperature of the product layer was determined using a pyrometer through the windows in the casing of the installation, which are located after each of the emitters along the movement of the products on the belt.

Determination of the investigated parameters of infrared drying for the moving layer of products
On the basis of the conducted experiments, we obtained numerical data of the desired characteristics of infrared drying of rapeseed and soybeans in a moving layer of products, and built the dependencies presented in Figures 3, 4, 5.
When the speed of the conveyor belt increases from 0.0015 to 0.0285 m/s, the intensity of humidity changes for a fixed processing time decreases by 3 times (Fig. 3). With a 5-fold increase in the power of irradiation, the intensity of humidity changes increases by 8 times (Fig. 4a). When the load of products in the working area changes from 0.2 to 0.5 kg/m 2 , the intensity of humidity changes increases by 3.5 times (Fig. 4b). The dynamics of changes in the speed of infrared drying of rapeseed and soybeans depending on the number of radiating modules, with a change in the radiation power N op , loading in the working area P s , and the speed of the conveyor belt υ st are presented, respectively, in figures 5, 6.
According to the results of the experiments, the most optimal values of the speed of transportation of products were determined in the range from 0.15 to 0.3 cm/s, under the conditions of the power of infrared emitters of 400 -500 W. It turned out that a specific loading of more than 3.5 kg/m 2 is impractical to use due to the fact that a large layer of products does not allow infrared rays to carry out uniform processing of grains, especially at sufficiently high speeds of the belt movement. It was determined that it is more expedient to carry out the drying process with three successively located infrared emitters, to increase the amount of moisture removed, it is effective to reduce the power of the emitters from 500 to 300 W. 3) With the simultaneous operation of two vibration exciters, stable transportation of products by a wave conveyor while ensuring the necessary productivity and quality of processing is observed under the following operating modes of processing: speed of transportation of products in the range from 0.15 to 0.3 cm/s; power of infrared emitters in the range of 400 -500 W; the specific loading of the load-bearing body should not exceed 3.5 kg/m 2 . 4) Carrying out the drying process with three successively located infrared emitters while reducing the power of the emitters from 500 to 300 W made it possible to increase the amount of moisture removed per unit of time.