IMPROVING THE EFFICIENCY OF EXTRUDATE DEHYDRATION IN A VACUUM CHAMBER OF A MODERNIZED EXTRUDER

Abstract

The work of modern models of food extruders goes mainly with passing the extruded material into the environment, which, taking into account the processing of raw materials with high moisture content, leads to insufficient drying of the extrudate. Extrusion of raw materials in vacuum allows to eliminate this drawback. The article presents a theoretical justification for increasing the efficiency of extrudate dehydration in a vacuum chamber of a modernized extruder by computer simulation of the thermal vacuum effect. The Navier-Stokes equation averaged with the addition of Reynolds stresses and the laws of conservation of mass, moment, and energy were used to calculate the flow and heat transfer rates. Computer simulation of a simplified model of a vacuum chamber was performed using the SolidWorks Flow Simulation software module. Geometry was built in SolidWorks CAD. The data obtained by computer simulation of a simplified model of an extruder vacuum chamber confirmed the influence of the thermal vacuum effect on the characteristics of the extruded product. The created vacuum in the zone of ejection of the extruded vegetable raw material from the extruder matrix creates such fluid medium parameters that significantly increase the drying rate of the extrudate, increase its expansion index and contribute to more efficient removal of moisture from this zone.

Keywords

• extruder
• thermal vacuum effect
• matrix die
• explosion coefficient
• vacuum chamber
• volume flow rate