Design and Experiment of Pneumatic-Mechanical Combined Leaves Removing Machine for Artemisia selengensis

Abstract

Artemisia selengensis, whose edible part is stem and several fresh leaves at the top, is a characteristic vegetable in China. Most of the leaves need to be removed before the sale. However, it is hard to remove the easy folding leaves without damaging the fresh stem. Existing leaves removing operation of the Artemisia selengensis is still rely on the hand labor with high cost and labor consumption. To improve the mechanization level of leaves removing operation, a pneumatic-mechanical combined leaves removing machine for the Artemisia selengensis was designed. The effective removing of leaves from the stem was realized through the pneumatic adsorption guidance of leaves suction drum and the mechanical pulling of leaves pulling roller. Characteristics based on the defoliation machine was designed. The geometric parameters of Artemisia selengensis were statistically analyzed while the pull resistance of leaves in forward, normal, and reverse pulling were tested. It was indicated that the reverse pulling method was better to remove the leaves. The analysis of the structural parameters and operating parameters of the key components such as the leaves suction drum and pulling roller was carried out. The air flow field of the leaves suction drum was simulated based on CFD. Combined with the simulation orthogonal test, the axial spacing of the suction hole was determined to be 10mm, the circumferential distribution angle was 10°, the number of effective holes was 121, the diameter of the suction hole was 4mm with the depth of 4mm, and the relative height of the leaves pulling roller was 30mm. By taking the leaves suction drum speed, the leaves pulling roller speed and feeding rate as experimental factors, taking the removal rate and breaking rate of leaves as evaluation indexes, the quadratic regression orthogonal experiment was conducted. The regression mathematical model was established. The optimal parameter combination was obtained as leaves suction drum speed of 77r/min, leaves pulling roller speed of 65r/min,and feeding rate of 40mm/s. Under the optimal parameter combination condition, the leaves removal rate and breaking rate were 94.32% and 12.93%, respectively. The operation efficiency could reach 12.3kg/h, which met the production of the Artemisia selengensis. The research result could provide a reference for the structure improvement and optimization of leaves removing machine for Artemisia selengensis.

Keywords: Artemisia selengensis,  leaves removing machine, pneumatic suction, mechanical pulling