Improved thermoradiative belt dryer with air recuperation and autonomous ventilation

This study considers the process of IR drying of organic raw materials and semi-finished products of mixed composition. A limitation of this process is the insufficient uniformity of drying and preservation of biologically active substances. To address this challenge, the structure of a film-like electric heater of radiating type has been improved by combined heat supply and conductive drying under autonomous ventilation conditions (15…30 W). A universal conveyor belt with replaceable modules expands the range of organic agricultural raw materials and semi-finished products of mixed composition during low-temperature drying (45…65°C). The drying duration is reduced by 30…35% with an increase in the residual content of biologically active substances by 15…20% compared to the base device. For apples of the Gala variety, the residual content of vitamin C after IR drying was 82.0 ± 3.1 mg/100 g, which is 20% more than in the prototype (68.0 ± 2.5 mg/100 g). In carrots of the Shantane variety, the residual content of β-carotene after IR drying was 87 ± 2.5%, which is 17% higher than in the prototype (70 ± 3%). In chokeberry, the preservation of anthocyanins is 92 ± 3%, in contrast to the prototype (76 ± 4%), in parsley, the preservation of chlorophylls is 82 ± 4% (the prototype is 65 ± 5%). In meat and vegetable semi-finished products, the preservation of antioxidant activity is 84 ± 2% (versus 72 ± 3%). The combination of film-like heating, recovery of secondary warm air, autonomous ventilation by Peltier elements, solar collector, and photovoltaic panel with battery contributes to resource saving (20…30%) and stabilization of the temperature field (ΔT = 12…18°C). The results confirm the functional and modular properties of the improved device for the “from farm to fork” system for the production of functional semi-finished products with a high degree of readiness.