Electrohydrodynamic Grains Drying on Pilot Equipment with Continuous Flow

Introduction: Modern grain drying technologies aim to improve energy efficiency while preserving the quality characteristics of the final product. The energy performance of drying processes directly influences the technological and economic competitiveness of grain processing enterprises. In the context of increasing volumes of processed raw materials and the associated rise in energy consumption, the need for alternative drying methods is becoming increasingly relevant. At the same time, the application of electrohydrodynamic (EHD) flow in grain drying processes remains insufficiently explored, indicating a scientific and technological gap that necessitates further research in this area.

Purpose: To study the drying process of grain material in the EHD flow on pilot equipment with continuous flow and to determine drying efficiency, energy consumption and the possibility of scaling the equipment. 

Materials and Methods: Feed grain of wheat was used as the drying object. A pilot drying unit with a capacity of 50 kg/hour was used as an EHD-flow drying technology. The equipment operates on a cyclic principle, acting on the feed grain of wheat alternately with a corona and spark discharge, repeatedly passing the grain material through the electrode blocks until a preset moisture level is reached. The electric field strength in the treatment area reached 8 kV/cm. The drying efficiency was analyzed by evaluating the drying kinetics, total energy consumption, and exergetic drying index. All experiments were repeated three times, and the results were statistically processed using ANOVA analysis methods.

Results: It is shown that the superposition of electrohydrodynamic flow on grain material causes a combination of the effects of "etching" the grain surface with the appearance of a fine-mesh structure and promotes volumetric heating due to Joule heat. When drying grain using electrohydrodynamic flow, the decrease in grain moisture in one pass in the equipment was 0.28%. The unit cost of the proposed equipment is 1.85 kW/kg of moisture, which is 30% lower than traditional drying using a thermal agent under similar temperature conditions. 

Conclusions: The equipment for drying grain material with the application of electrohydrodynamic flow can be used in low-productivity technical lines for the purpose of drying or full-fledged drying of grain material. The results obtained can be used in the development of new drying plants and the modernization of existing technologies in agriculture and food industry.

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