苜蓿种子重力分选性能试验研究

发布时间：2018-11-08 09:41

【摘要】：重力分选是种子清选和分级的重要方法之一,其作用是将种子按密度进行排列分级。苜蓿原种子含有较多沙子和不饱满的瘪种子,去石和除瘪种子是重力分选的特长。苜蓿是牧草之王,种植面积大,种子用量及加工设备需求也大。重力分选机是清选分级设备中最复杂的一种。其使用中需要多个工作参数的调节,造成使用难度增加。所以研究苜蓿种子重力分选有实际意义。论文从理论上对重力分选过程中,种子的运动进行了分析,重点研究苜蓿种子的重力分选性能。根据重力分选机有关文献分析,确定重力分选机的性能指标,主要有净度、获选率、生产率、除轻杂率、除重杂率,影响因素有转速、振幅、风速、纵向倾角、横向倾角。以性能指标为评价指标,以影响因素为变量,进行单因素试验,得到各影响因素的较优数值。以较优数值为基础,确定转速、风速、纵向倾角3个因素的水平,进行正交试验。分别以生产率、净度、获选率为评价指标,确定3个因素重要性的排列顺序和最优水平组合。在此基础上,再平衡考虑3个评价指标,最终得到因素的较优水平组合,即转速368r/min,风速2.8m/s,纵向倾角5.0°,对应指标为净度是97.6%,获选率是95.4%,生产率是62.9kg/h。论文的理论分析和试验研究能够为相关设备的设计提供数据,为苜蓿种子重力分选的使用提供指导。
[Abstract]:Gravity sorting is one of the most important methods of seed cleaning and grading, and its function is to arrange and classify seeds according to density. Alfalfa seeds contain more sand and less than full and flat seeds. The special strength of gravity sorting is to remove stone and desiccate seeds. Alfalfa is the king of forage. Gravity separator is one of the most complex cleaning and classifying equipment. It needs the adjustment of several working parameters in use, resulting in more difficulty in use. So it is of practical significance to study the gravimetric sorting of alfalfa seeds. In this paper, the movement of seeds in the process of gravity sorting is analyzed theoretically, and the gravity sorting performance of alfalfa seeds is mainly studied. According to the analysis of relevant documents of gravity sorter, the performance indexes of gravity separator are determined, including cleanliness, selection rate, productivity, light impurity removal rate, heavy impurity removal rate, influencing factors such as rotational speed, amplitude, wind speed, longitudinal inclination angle and transverse inclination angle. Taking the performance index as the evaluation index and the influence factor as the variable, the single factor experiment was carried out, and the optimum value of each influencing factor was obtained. Based on the optimal values, orthogonal experiments were carried out to determine the level of three factors, namely, rotational speed, wind speed and longitudinal inclination angle. Productivity, cleanliness and selection rate were used as evaluation indexes to determine the order of importance of three factors and the optimal level combination. On this basis, three evaluation indexes were rebalanced and the optimal horizontal combination of the factors was obtained, that is, the rotational speed was 368r / min, the wind speed was 2.8 m / s, the longitudinal inclination angle was 5.0 掳, the corresponding index was the cleanliness of 97.66.The selection rate was 95.4%. Productivity is 62.9 kg / h. The theoretical analysis and experimental study in this paper can provide data for the design of related equipment and provide guidance for the use of gravity sorting of alfalfa seeds.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S541

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