Control and Optimized Management of Grain Drying in Forced-Aerated Bins

Author(s):  
Alexey Nicolaevich Vasiliev ◽  
Alexey Alexeevich Vasiliev ◽  
Dmitry Budnikov ◽  
Dmitry Tikhomirov ◽  
Asan Bekeshovich Ospanov

In the chapter, both informational and system-based approaches have been applied to the analysis of grain drying process as an interaction of two systems, namely, “drying agent” and “grain layer.” It made it possible to evaluate the information content of the process. Analytic expression has been obtained for grain layer informational entropy variations which enabled to make the conclusion that an adequate physical description of grain drying process has to include ambient air parameters control, as well as that of drying agent's parameters in its exit out of a grain layer, as well as parameters of both drying agent and grain in one point of grain layer. A mathematical model of heat-and-moisture exchange in dense grain layer has to be applied. As a result of modeling, it has been proved that the sensors of both drying agent and grain parameters have to be located at a distance of 10 to 11 cm from the central cylinder of the forced-aerated drying bin.

2021 ◽  
Vol 250 ◽  
pp. 6-12
Author(s):  
P.S. Ageev ◽  
◽  
S.A. Sutyagin ◽  
V.I. Kurdyumov ◽  
A.A. Pavlushin ◽  
...  

When creati ng modern eff ecti ve complex technical systems that realize the processes of thermal impact on bulk agricultural materials with the required quality and at a high energy level, it is important to know the conditi ons of heat and moisture transfer. The target functi on of our research was scienti fi c substanti ati on of the main thermophysical parameters of the studied process of thermal eff ect on the drying product as a whole, as well as identi fi cati on of the eff ect of the created temperature regime of the drying unit on the temperature gradient when heati ng the treated seeds, and, ulti mately, on the effi ciency of the enti re process. In case of contact drying of small-seeded crops, both external heat and moisture exchange processes are carried out - from the surface of the treated seeds to the external environment, and internal - the migrati on of heat and moisture inside the seeds. The main quanti tati ve factor that most fully describes the mechanism of moisture transfer is the Bio criterion (Bim). This criterion establishes a relati on between such parameters of the contact drying process as the intensity of moisture exchange on the surface of the processed grain and its moisture conducti vity. The descripti on of the process is reduced to solving an internal problem for the moisture contained in the processed grain, when considering the latt er as a colloidal body, Bim = 0.16. In this case, the removal of moisture with its transformati on into steam directly depends on the energy consumpti on for the heat treatment process. The driving force of this process is the temperature gradient arising from thermal acti on. Studies have established that the kineti c coeffi cient, which most fully describes this phenomenon, is the thermal and moisture conducti vity coeffi cient or the thermal gradient coeffi cient δ. This parameter characterizes the moisture content change in the processed grain at a temperature gradient equal to one degree Celsius. In order to confi rm the above theoreti cal dependencies, experimental studies were carried out to identi fy the features of contact thermal eff ects on various small-seed crops. Based on the results of the studies, it was revealed that the following operati ng parameters have the greatest infl uence on temperature regime during grain drying in the developed contact type grain dryer: the temperature of the heati ng surface and the rotati on frequency of the transporti ng working body. In this study, the rotati on frequency of the transporti ng working body was changed from 30 min-1 to 110 min-1, and the temperature of the heati ng surface - in the range from 40 ºС to 100 ºС. It was revealed that the temperature gradient of grain heati ng in the developed installati on for grain drying at appropriate drying modes is 9 ... 12 ºС and does not signifi cantly depend on the type of processed seeds. When improving the operati ng parameters of the drying process of seeds of one crop, it is possible to operate the developed grain dryer without loss of quality during heat treatment of small seeds of other crops.


2001 ◽  
Vol 6 (1) ◽  
pp. 9-19 ◽  
Author(s):  
A. Buikis ◽  
J. Cepitis ◽  
H. Kalis ◽  
A. Reinfelds ◽  
A. Ancitis ◽  
...  

The mathematical model of wood drying based on detailed transport phenomena considering both heat and moisture transfer have been offered in article. The adjustment of this model to the drying process of papermaking is carried out for the range of moisture content corresponding to the period of drying in which vapour movement and bound water diffusion in the web are possible. By averaging as the desired models are obtained sequence of the initial value problems for systems of two nonlinear first order ordinary differential equations. 


2019 ◽  
Vol 110 ◽  
pp. 02142
Author(s):  
Sergey Morozov ◽  
Konstantin Kuzmin ◽  
Denis Pogodin ◽  
Lyudmila Kochetkova ◽  
Anna Rogozhina

The article discusses the VisSim program, which allows simulating microwave grain drying process. Its capabilities and methods of development are shown, the structure of a mathematical model for management of the drying process and individual blocks is provided. It is noted that offered modeling of the grain drying process makes it possible to evaluate it as a technological process, as well as to show the possibility of its optimization. It should be noted that this method is environmentally friendly and less energy intensive than others.


Author(s):  
Alexey Nicolaevich Vasiliev ◽  
Alexey Alexeevich Vasiliev ◽  
Dmitry Budnikov ◽  
Gennady Samarin

This chapter presents an analysis of factors influencing the heat and moisture exchange for their further use in experimental research to study the process of grain drying with active ventilation. The temperature and velocity of the drying agent and grain moisture content are determined. One centimeter (1 cm) thick layer is considered to be a thin layer. This size appears to be very manageable to transfer the regularities of the drying process to a thicker layer when modeling the drying process in a thick layer. The experiment was carried out for three drying modes: classical mode (i.e., drying of grains with natural and heated air), with a constant concentration of air ions in the drying agent, with cyclic (periodic) presence of air ions in the drying agent. Using the regression equations produced a so-called electro-activation criterion can be described. The dependencies obtained would help to optimize the drying process with respect to drying time criterion.


2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Erik W. Aslaksen

The paper presents a basic model of the flash drying process, as it is applied in a number of industrial applications, and illustrates this by means of a particular application: the drying of subbituminous coal. Besides its economic importance, that application is representative of those where the product is combustible, so that the drying needs to be conducted in an inert atmosphere, which is achieved by recycling some of the drying gas. A novel feature of the model is that it takes explicit account of the transport of heat and moisture within the coal particles. The model provides the basis for the development of a tool to support the design of a flash drying plant.


Author(s):  
A. I. Ol’shanskii ◽  
A. S. Marushchak

The methods of approximation of the curve of the drying rate of fabrics according to the methods of A. V. Lykov and V. V. Krasnikov are described. The results of processing experimental data on convective tissue drying are presented. Equations are given for determining the drying time of fabrics, the density of heat flows and the temperature of fabrics during the drying process. The equations for determining the drying coefficient and the relative drying rate are given. An analytical method for determining the temperature for the period of falling drying rate is considered. The comparison of the temperature values according to the results of analytical solutions with the values obtained by the experimental formula is given. It is shown that the number of Bio during drying of fabrics is less than one, and the main limiting factor is the external heat and moisture exchange of the evaporation surface from the surface of the material with the environment. Verification of the reliability of the calculated values obtained with experimental ones is presented. The discrepancy between the values is within 5 % of the accuracy of the experiment and processing.


Author(s):  
N. Zanko ◽  
◽  
T. Gaidai ◽  
S. Stepchenko ◽  
N. Nilova

Aim. Investigation of the influence of natural factors on the quality of grain drying in a grain modular dryer. Methods. Experimental studies in operational conditions and graphical modeling of dried grain moisture depending on natural factors. The results. The change in the environmental conditions causes a certain influence on the return of the spent waste dryer to the environment and the processes of drying the grain in it. This causes the production of undried grain and reduced drying efficiency. The influence of natural factors - temperature and humidity, atmospheric pressure and wind speed on the humidity of corn grain during its drying with a single-module grain dryer has been studied. The output of the refrigerant with moisture vapor is carried out through the perforated panels of the dryer circuit and at the same time experiences some resistance from atmospheric pressure. The results show that the reduction of atmospheric pressure helps to reduce the resistance for the exit of the coolant through the surface of the dryer housing. As a result, the coolant in the chamber is more efficiently spent on the grain drying process. This is evidenced by the simultaneous decrease in pressure and humidity of the dried grain The dryer is also affected by the wind: its body experiences cooling, and the drying temperature and drying conditions of the grain deteriorate. Thus, during the research period, the wind speed decreased from 5,3 m / s to 4,4 m / s, and the humidity of the dried grain decreased from 15,2 % to 13,9 %. That is, the reduction of the effect of wind on the surface of the dryer has a positive effect on the drying process of grain. The ambient air is characterized by the moisture present in it. Its reduction in atmospheric air promotes better moisture yield from corn grain and the "filling" of this air moisture: the humidity of the dried grain decreases. The positive temperature of the atmospheric air causes additional thermal action on the dryer and the drying process in it. In this case, the heat supplied to the working chamber of the dryer is more productively used for the drying process: in accordance with the increase in atmospheric air temperature, the humidity of the dried grain decreased from 15,2 % to 13,9 %. Based on the results of experimental studies, graphical dependences of the humidity of dried corn grain on humidity, pressure, temperature and velocity of atmospheric air are constructed. The grain harvester is a system adapter for Conclusions. Conclusions. The process of grain drying and the moisture content of the resulting dried grain of modular grain dryers depends on the influence of objective natural factors. These include, in particular, the weather conditions during the operation of dryers. With an increase in humidity, pressure and air velocity, the quality of drying deteriorates: when the moisture content of the grain decreases from 18,5 ° C to the regulated 14 %, with a single pass through the dryer, the moisture content of the dried grain exceeds the regulated one and vice versa. Drying grain in conditions of positive ambient air temperatures, especially at an air temperature of more than 21 °C, is most favorable for obtaining grain with a moisture content that is significantly less than 14 % and vice versa. Low wind speed, dry and warm atmospheric air with low pressure contribute to the production of dried grain with regulated humidity. For the maximum elimination of the unfavorable influence of natural factors on the quality of operation of modular dryers according to the criterion of the moisture content of dried grain in the conditions of the forest-steppe zone of Ukraine, it is advisable to carry out the drying process in the period from late September to early October.


2003 ◽  
Vol 8 (2) ◽  
pp. 103-112 ◽  
Author(s):  
R. Čiegis ◽  
T. Leonavičiene ◽  
V. Skakauskas ◽  
O. Suboč

In this paper we consider the mathematical model which describes the grain drying process. The air and grain moisture and temperature are described by a system of PDE. A finite difference scheme is proposed for finding a numerical solution. The convergence of the discrete solution is proved for a simplified model, when the temperature is assumed to be given a priori. Results of numerical experiments are presented.


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