齿板碎矿过程与齿距对破碎性能的影响

Mineral Crushing Process of Jaw Crusher and Effect of Tooth Pitch on Its Crushing Performance

根据颚式破碎机的工作特点,应用数值模拟技术,采用脆性开裂材料模型建立三维模型。以朗金准则作为开裂探测原理,模拟和分析单颗粒物料在齿板作用下发生的破碎行为,获得单因素条件下齿距对破碎的影响,验证数值模拟方法研究物料动态破碎的可行性。模拟结果表明:单颗粒物料在单向压缩条件下破碎过程可分为断裂渐变期和断裂突变期,渐变期包含压实阶段及微裂纹萌生和拓展阶段;在其他齿形参数不变的情况下,齿板最大反作用力和最大应力随着齿距增加而增加,最大应力主要出现在齿顶圆角和齿根处,物料的裂解效果随着齿距增加而改善。基于灰色理论得到齿距和性能参数的关联度以及单因素条件下的最优齿距。

In order to simulate and analyze the fracture behavior of a single particle under linear movement,numerical simulation was carried out with the finite element analysis software,depending on the operation status of a jaw crusher. 3D models were built with the brittle cracking material,and the Rankine criterion was used to detect the cracking and verify the feasibility of numerical simulation for dynamic crushing behavior. Simulation results show that the single particle crushing under uniaxial compression can be divided into gradual cracking phase and catastrophic fracture phase. The gradual cracking phase includes compaction and micro-crack extension; the maximum counterforce and stress of the jaw crusher increase with increasing tooth pitch,while other parameters of the shape of the jaw crusher stay invariant. The maximum linear stress appears in the addendum arc and tooth root;the mineral crushing effect tends to be better as the tooth pitch increases. The relationships among tooth pitch,performance parameters and optimal tooth pitch under the single factor condition are obtained with the grey theory.