Abstract:  This study focuses on addressing the issues of low fragmentation rate of Gleditsia shell and the resulting low separation efficiency due to sieve hole blockage in the process of striking shell seeds. The influence of roller speed on the separation of Gleditsia shell seeds is investigated. The HertzMindlin with bonding model (HertzMindlin with bonding) was established using the discrete element method based on the study of the mechanical properties of the Gleditsia shell, and the bonding parameters of the model were calibrated. The normal stiffness, tangential stiffness, critical normal stress, and critical tangential stress of the Gleditsia shell bonding model were determined as 1.8MPa, 1.35MPa, 1.41MPa, and 0.59MPa, respectively. EDEM software was used to simulate and analyze the separation process of Gleditsia sinensis shell seeds. The simulation results showed that the fragmentation rates of Gleditsia sinensis shell were 41.7%, 65.96%, 88.3%, 94.52%, and 94.8, when the roller rotation speed of 200r/min, 360r/min, 400r/min, 500r/min, and 1 000r/min, respectively. When the rotational speed was 500r/min and 1 000r/min, there was no significant change in the fragmentation rate. The primary forms of shell fragmentation were impact crushing and extrusion crushing, resulting in three material forms: dust, filamentous, and incomplete fragmentation. Prototype testing confirms that a roller speed of 500r/min yields a higher fragmentation rate of Gleditsia shell and promotes the formation of filamentous materials, which facilitates the separation of Gleditsia shell seeds and reduces sieve clogging.

Key words: Gleditsia sinensis, shell seed separation, discrete element method, parameter calibration

摘要： 针对打击式壳籽分离过程中存在皂荚壳破碎率低，以及皂荚壳易堵塞筛孔，造成壳籽分离效率低等问题，研究滚筒转速对皂荚壳籽分离的影响。通过对皂荚壳力学特性进行研究，基于离散元法建立皂荚壳离散元模型（HertzMindlin with bonding），并对皂荚壳离散元模型进行粘结参数标定；得到皂荚壳粘结模型法向刚度、切向刚度、临界法向应力、临界切向应力为1.8MPa、1.35MPa、1.41MPa、0.59MPa。采用EDEM软件对皂荚壳籽分离过程进行仿真分析，仿真结果表明，在滚筒转速为200、360、400、500、1000r/min时，皂荚壳破碎率分别为41.7%、65.96%、88.3%、94.52%、94.8%，滚筒转速在500r/min和1000r/min时，破碎率无明显变化，皂荚壳主要破碎形式为冲击破碎和挤压破碎，破碎后物料形态包括粉尘、丝状、未完全破碎3种。样机试验亦表明滚筒转速为500r/min时，皂荚壳破碎率较高，且易于形成丝状物料，有利于皂荚壳籽分离和减小筛孔堵塞。

关键词: 皂荚, 壳籽分离, 离散元法, 参数标定