Hybrid Technology of Beet Pulp Dewatering with Process Intensification in a Convection Dryer as an Element of Sustainable Processing of Agro-Industrial Waste into Bioenergy

Abstract

In the studied process of moisture removal there is an increase in the driving force, due to centrifugation during rotor rotation, the emergence of electroosmotic pressure when creating conditions for one-sided diffusion, the filtering of the technological mass of the load through the rotor perforations, as well as the introduction of low-frequency oscillations of the dryer’s actuators. Therefore, the purpose of this scientific study is to substantiate theoperating modes of the vibration convective dryer by evaluating the amplitude–frequency parameters of the beet pulp dehumidification process. According to the results of the studies, the use of the angular velocity of the drive shaft of the vibrator in the range of 80. . .110 rad/s and the amplitude of oscillations within 2.5. . .3.0 mm allow the process to be carried out at maximum energy consumption of about 700. . .750W. The developed technology involves the sequential implementation of vibration, filtration, and electroosmotic technological action, which allows for a reduction in the duration of beet pulp processing during dehumidification by almost two times compared to the duration when performing filtration moisture removal in a stationary layer of products. Low-frequency oscillations with force field acceleration (of the order of 2. . .3 g) are used to create a pseudo rapid layer of products before convective processing, and when this parameter is reduced to (0.9. . .1.0 g), they ensure maximum compaction of the pulp mass, which significantly increases the efficiency of electroosmotic moisture removal. Such a combination of the noted physical and mechanical factors makes it possible to reduce the specific energy consumption for the removal of 1 kg of moisture by 2.7 times compared to traditional convective drying.