This study theoretically analyzed the cutting process of castor and determined the structural parameters of the key component of the castor disc-cutting device, aiming to obtain the optimal operation parameter combination and reduce the cutting resistance and power consumption during the harvesting process. The effects of the cutting-disc thickness, cutting-disc rotational speed, feeding speed, and edge angle on the cutting power consumption were studied using an orthogonal rotation combination experiment. The response surface method was used to optimize the parameters, and the mathematical relationship model between the cutting power consumption and each factor was established to determine the optimal parameter combination for disc cutting. The simulation results showed that the optimal combination of cutting parameters was cutting-disc thickness of 3 mm, cutting-disc rotational speed of 550 r/min, feeding speed of 0.6 m/s, and edge angle of 20°. Under these conditions, the cutting power consumption was 1.20375 J. The test results were basically consistent with the model prediction results. Therefore, this study provided a theoretical basis and reference for the design and improvement of castor harvesters.

Our study aimed to identify a design which would reduce cutting resistance during the harvesting of castor. This paper presents a theoretical study of the wave-type disc cutter, which plays an important role in castor harvesting. Based on the SPH–FEM coupling algorithm, a combined orthogonal rotation experiment was performed to study the effects of disc cutter thickness, edge angle, disc cutter rotation speed, and feeding speed on the maximum cutting force. The response surface method was used to achieve an optimal combination of all the test factors. Mathematical modeling of the maximum cutting force and influencing factors was utilized to obtain the optimal parameters for a cutting system consisting of wave-type disc cutters. The optimal results were obtained with a computer-simulated disc cutter rotation speed of 844.2–942.1 r/min, a feeding speed of 0.89–1.01 m/s, a disc cutter thickness of 2.71–3.15 mm, and an edge angle of 29.2–33.9°. Under these conditions, the maximum cutting force was less than 50 N. Finally, the experimental data and numerical computer simulation results were compared using cutting performance test verification. The analysis found that the test results and simulation results were largely consistent. Therefore, the simulation model was judged to be effective and reasonable.

To enhance the value of corn stalk and promote the utilization of corn stalk in pellet fuel, the pelletizing process of corn stalk rind using a flat die pelletizer was studied. A central composite design (CCD) methodology of four factors and five levels was applied to determine the effects of four process variables, i.e., material temperature, moisture content, die hole length-diameter ratio, and spindle speed, on responses such as pellet density and power consumption per ton. The statistical analysis of data was performed using Design-expert software and second-order polynomial models generated after analysis of variance applied for the responses. Using response surface methodology, the optimal range of process variable was obtained as follows: material temperature of 78.7 to 91.1 °C moisture content of 17.6% to 26.9%, die hole length-diameter ratio of 2.62–3.04, and spindle speed of 168.2–210.5 rpm. Under these conditions, the pellet density is over 1.0 g/cm3 and power consumption per ton is below 90 kW · h/t.