THEORETICAL JUSTIFICATION OF THE DESIGN- TECHNOLOGICAL SCHEME OF THE MODERNIZED THERMAL VACUUM EXTRUDER

Abstract

The article presents the results of theoretical studies on the justification of rational technical parameters of a single-screw thermal vacuum extruder. The chambers of preliminary and final drying of the extrudate were the object of the study. On the basis of modern views on the nature of the interaction of water steam and air flows in a limited volume of vacuum chambers of the extruder, the article proves one of the possible ways to increase the efficiency of the finished product dehydration. In order to simplify the design and increase the intensity of extrudate dehydration, the upgraded thermal vacuum extruder is proposed to be equipped with preliminary and final dehydration chambers with a uniform vacuum system. The conducted research has obtained equations that can be useful to determine the mass airflow rate introduced into the vacuum chambers of the machine. Its influence on the main design and technological parameters of the system also can be determined. It is the system that provides the thermal vacuum effect of the extrusion process. The analytical expressions presented in the article are the basis for calculating the area of cross-sections of the vacuum pipes connecting the preliminary and final dehydration chambers of the extruder with its vacuum system. The results obtained, along with the parameters received experimentally, make it possible to confirm its basic design and technological parameters with sufficient accuracy for the accepted values of the modernized extruder.

Keywords

• thermoplastic extrusion
• extrudate
• thermal vacuum effect
• vacuum chamber