【作者】 王旭；

【导师】 王春光；

【作者基本信息】 内蒙古农业大学 ， 农业机械化工程， 2017， 硕士

【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。更多还原

【Abstract】 Gravity separation is one of the most important methods for seed cleaning and grading.The original seed of Alfalfa contains more sand,and it is not full of shriveled seeds.Alfalfa is the king of grass,it has a large area of cultivation,and the amount of seeds and processing equipment is also large.Also gravity separator is one of the most complex equipment in the sorting equipment.It needs to adjust the number of working parameters,resulting in increased dificulty in use.Therefore,it has practical significance to study the gravity separation of Alfalfa seeds.In this paper,the theory of the movement of seeds is analyzed.The gravity separation property of alfalfa seeds was studied.First of all,According to the analysis of gravity separator related documents,determine the property index of gravity separator,mainly the cleanliness,selected rate,productivity,the light impurityremoval rate,the heavy impurityremoval rate.The influencing factors are vibration frequency,amplitude,wind speed,longitudinal inclination and transverse angle.With the performance index as the evaluation index and the influence factor as the variable,the single factor test was carried out to get the best value of each influencing factor.On the basis of the optimum value,the orthogonal experiment was carried out to determine the frequency of vibration,wind speed and longitudinal inclination of 3 factors.Respectively,the productivity,clarity,selection rate were used as the evaluation indexes to determine the importance of the order of the 3 factors and the optimal level combination.On this basis,and then consider the balance of 3 evaluation indexes,finally get the optimal level combination of these factors,it is the vibration frequency of 368r/min,wind speed of 2.8m/s,vertical angle of 5 degrees,the corresponding index for clarity is 97.6%,the rate is 95.4%,the productivity is 62.9kg/h.The theoretical analysis and experimental research of this paper can provide data for the design of related equipment,and provide guidance for the use of gravity separation of Alfalfa seeds更多还原