Temperature distribution of solids in one novel screw extruder

摘要

A novel nested double-screw extruder with higher solid conveying capability is introduced.From the previous pressure model considering centrifugal force and solid compressibility, and Tadmor-Broyer's non-isothermal model in solid conveying zone, solid temperature is more accurately predicted. Simulating results of the two single screw extruders with the diameters of 90mm and 30mm respectively are consistent with the experimental values. The present is the effects of barrel temperature and friction coefficient on temperatures of solids in the axial direction and in the channel depth for the novel nested double-screw extruder. The local pressure and the length of solid conveying zone can further be calculated. Three interface temperatures exponentially vary along axial distance due to the chosen exponential function of density as pressure. The length of solid conveying zone for inner screw is longer than that of outer screw. Temperature rise predominately occurs in about one millimeter, ca. 15% to 20%of the channel depth from the outer screw surfaces or from the barrel in radial direction by heat conduction from barrel or friction with screws.