Design of Double-Roller Anisotropic Force-Feeding Device for the D200 Single Screw Straw Fiber Extruder

A force-feeding device with a double-roller anisotropic was designed for the D200 single screw straw fiber extruder to keep the performance continuity of the system, which could improve the productivity of straw fiber. Four factors (the diameter of the auxiliary roll, the difference in linear speed of the two rolls, the gap between two rollers and the spindle speed as the test factors) were investigated to establish regression model to analyze the influence of the coupling of multiple factors on the test indexes. It was demonstrated that significant effects ( p < 0.05) on the feeding rate and material loss were produced by four factors according to the experimental results. The sequence of influence in descending order on feeding rate was spindle speed, linear speed difference, gap and auxiliary roller diameter. The effects on materials loss in descending order were auxiliary roller diameter, line speed difference, spindle speed and gap. The optimal combination of parameters was obtained by the response surface, which were an auxiliary roller diameter of 230 mm, a spindle speed of 104.49 rpm, a line speed difference of 2840 mm/s and a gap between the two rolls of 14 mm. The average feeding rate was 2.3798 t/h, and the loss was 1.908 kg/h, and the errors were within 3.28%, which satisfied the feeding requirements for rice straw fiber production with high feeding efficiency and low raw material losses. This study provided a reference for the forced compression feeding and fibrillation process of rice straw.