资源描述:
分类号 TD451 单位代码 10618 密 级 公 开 学 号 622180040012 硕士学位论文 反击式破碎机反击式破碎机破碎作用分析破碎作用分析及及对对集料集料 颗粒颗粒形状形状的影响研究的影响研究 研研 究究 生生 姓姓 名名 廖廖 科科 导师姓名及职称导师姓名及职称 曹源文曹源文 教授教授 申请学位类别 工学硕士 学位授予单位 重庆交通大学 一级学科名称 机械工程 论文提交日期 2021 年 4 月 15 日 二级学科名称 机械设计及理论 论文答辩日期 2021 年 6 月 02 日 2021 年 6 月 12 日 万方数据 Analysis of Impact Crushers Crushing Effect and its Impact on Aggregate Study on the Influence of Particle Shape A Dissertation ted for the Degree of Master CandidateLiao Ke SupervisorCao Yuanwen Chongqing Jiaotong University, Chongqing, China 万方数据 万方数据 I 摘要 集料颗粒主要是借助于颚式、圆锥式、反击式破碎机等破碎机械设备,经过一 系列的加工工艺破碎而成,是道路、矿山、建筑等工程施工中重要的基础材料。集 料颗粒形态取决于破碎机械设备的结构和加工母岩的物理特性,如果骨料中针片 状颗粒占比大时,会影响到如沥青混合料内部结构的抗压、水稳等性能。传统的针 片状颗粒的检测通常是人工检测, 效率低且受检测人员主观操作等影响, 数字图像 处理技术作为一种新兴的技术,可以实现快速采集和分析,提高检测效率,保证集 料质量。 反击式破碎机往往作为集料破碎加工的最后一步工序, 其生产破碎的成品 将直接运用于工程施工中, 因此为了更好的提升反击式破碎机的集料破碎质量, 本 文依托云南省交通厅科技项目,开展反击式破碎机的破碎作用分析及对集料颗粒 形状的影响研究,完成以下工作 (1)通过对破碎机理、破碎强度理论分析,选取适用于岩石破碎作用分析研 究的理论与准则;基于赫尔兹理论,完成对岩石破碎运动的反击速度、时间以及力 学分析;基于总体平衡理论,建立影响破碎颗粒形状的关系模型,确定影响破碎颗 粒形状的主要因素为岩石特性、破碎机结构参数、工作参数,并提出用于评价仿真 颗粒形状质量的指标颗粒形状质量指数。 (2) 通过对反击式破碎机结构分析, 完成破碎机的选型以及结构参数的确定, 并通过 CATIA 完成反击式破碎机破碎腔室三维模型的创建;通过对小颗粒坐标的 获取,完成 API 插件的制作,最终创建起适用于模拟岩石破碎的岩石颗粒;进而 完成反击式破碎机破碎过程离散元模型的建立。 (3)基于反击式破碎机破碎腔室离散元模型,选用单一因素研究法,讨论岩 石特性、破碎机结构参数、工作参数对破碎作用和破碎效果的影响;研究发现随 着岩石强度的增加,破碎产品粒形变差;随着转速、导料板倾角的增加,破碎产品 粒形变好; 随着第一反击板角的增大, 破碎产品粒形质量呈现先升高后降低的趋势; 随着第二反击板角的增大,破碎产品粒形质量呈现先略微降低再逐步升高的趋势。 基于正交试验方法搭建起以颗粒形状质量指数为评价指标的 L934正交仿真方案, 得出了影响颗粒形状质量的主要因素为转子转速; 其敏感度大小关系为 转速>第 一反击板角>导料板倾角>第二反击板角;其最佳参数组合为导料板倾角为 54、 第一反击板角为 15、第二反击板角为 66、转速为 700r/min,与现实工况基本吻 合。 万方数据 II (4)利用高清相机完成集料颗粒的图像采集,借助 MATLAB,利用图像处理 技术对集料颗粒进行二值化、高通滤波、分水岭分割、形态学处理、凸壳重建以及 外接拟合椭圆处理,提取颗粒的形状特征数据;基于颗粒形状特征评价指标,完成 工程实测中不同种类岩石对破碎颗粒形状质量的分析, 得出了强度较小时, 岩石发 生更多细碎,其粒形质量相对更好的结论,进一步验证了仿真结果的准确性。 关键词破碎作用,edem,粒形质量,正交试验,图像处理 万方数据 III ABSTRACT Aggregate particles are mainly crushed by a series of processing techniques with the aid of crushing machinery such as jaw, cone, and impact crushers. They are important basic materials in the construction of roads, mines, and buildings. The shape of aggregate particles depends on the structure of the crushing machinery and the physical characteristics of the processed parent rock. If the proportion of needle-like particles in the aggregate is large, it will affect the internal structure of the asphalt mixture, such as compressive resistance and water stability. The traditional detection of needle-like particles is usually manual detection, which is low in efficiency and is affected by the subjective operation of the inspector. As an emerging technology, digital image processing technology can achieve rapid collection and analysis, improve detection efficiency, and ensure aggregate quality . The impact crusher is often used as the last step of the aggregate crushing process, and the crushed products produced by it will be directly used in engineering construction. Therefore, in order to better improve the aggregate crushing quality of the impact crusher, this article relies on the Yunnan Provincial Communications Department. Scientific and technological projects, to carry out the impact analysis of the impact crusher and the impact on the shape of aggregate particles, and complete the following tasks 1 Through theoretical analysis of crushing mechanism and crushing strength, select theories and criteria suitable for rock crushing analysis and research; based on Hertz theory, complete the counterattack speed, time and mechanical analysis of rock crushing movement; based on overall balance theory Establish a relationship model that affects the shape of crushed particles, determine that the main factors affecting the shape of crushed particles are rock characteristics, crusher structure parameters, and working parameters, and propose an index for uating the shape and quality of simulated particlesparticle shape quality index. 2 Through the structural analysis of the impact crusher, the selection of the crusher and the determination of the structural parameters are completed, and the creation of the three-dimensional model of the crushing chamber of the impact crusher is completed through CATIA; the API is completed by obtaining the coordinates of the small particles The production of the plug-in finally created rock particles suitable for simulating rock crushing; and then completed the establishment of the discrete element model of the crushing process of the impact crusher. 3 Based on the discrete element model of the crushing chamber of the impact crusher, a single factor research is selected to discuss the impact of rock characteristics, crusher structure parameters, and working parameters on the crushing action and crushing effect; the research found that as the strength of the rock increases , The particle shape of the crushed product becomes worse; with the increase of the rotation speed and the inclination of the guide plate, the particle shape of the crushed product 万方数据 IV becomes better; with the increase of the angle of the first counterattack plate, the particle shape quality of the crushed product shows a trend of first increasing and then decreasing; With the increase of the angle of the second counterattack plate, the grain shape quality of the crushed product shows a tendency to decrease first and then gradually increase. Based on the orthogonal experiment , the L934 orthogonal simulation scheme with the particle shape quality index as the uation index was built, and the main factor affecting the particle shape quality was the rotor speed; the sensitivity relationship was speedfirst Counterattack angle guide plate inclination angle second counterattack angle; the best combination of parameters is that the guide plate angle is 54 , the first counterattack angle is 15 , the second counterattack angle is 66 , and the speed is 700r /min, basically consistent with the actual working conditions. 4 Use a high-definition camera to complete the image acquisition of aggregate particles, and use MATLAB to use image processing technology to per binarization, high-pass filtering, watershed segmentation, morphological processing, convex hull reconstruction, and external fitting ellipse processing on the aggregate particles with the help of MATLAB. Extract the particle shape feature data; based on the particle shape feature uation index, complete the analysis of the shape and quality of the broken particles of different types of rocks in the engineering measurement. It is concluded that when the strength is lower, the rock will be more finely broken, and the particle shape quality is relatively better The conclusion further verifies the accuracy of the simulation results. KEY WORDS fragmentation, edem, grain shape quality, orthogonal experiment, image processing 万方数据 V 目录 摘要摘要 ............................................................................................................... I ABSTRACT .............................................................................................. III 第一章第一章 绪论绪论 ............................................................................................... 1 1.1 研究背景及意义 ................................................................................................ 1 1.2 国内外研究现状 ................................................................................................ 2 1.2.1 集料破碎技术国内外研究现状 ............................................................... 2 1.2.2 集料颗粒形状检测技术国内外研究现状 ............................................... 4 1.3 本文主要研究内容 ............................................................................................ 5 第二章第二章 反击式破碎机的破碎机理和破碎数学模型反击式破碎机的破碎机理和破碎数学模型 .............................. 7 2.1 反击式破碎机的结构及工作原理 .................................................................... 7 2.2 破碎机理分析 .................................................................................................... 7 2.2.1 经典破碎理论 ........................................................................................... 7 2.2.2 热力学和原子结构破碎假说 ................................................................... 9 2.2.3 层压破碎理论 ......................................................................................... 10 2.3 岩石力学特性及强度理论 .............................................................................. 10 2.3.1 岩石的物理力学性质 ............................................................................. 10 2.3.2 岩石强度理论 .......................................................................................... 11 2.3.3 岩石碰撞动力学分析 ............................................................................. 14 2.4 反击式破碎机破碎作用数学模型 .................................................................. 18 2.4.1 基于总体平衡的破碎粒度分布模型 ..................................................... 18 2.4.2 分级函数的确立 ..................................................................................... 19 2.4.3 破碎函数的确定 ..................................................................................... 20 2.4.4 破碎影响因素关系数学模型 ................................................................. 21 2.4.5 颗粒形状质量指数的确定 ..................................................................... 21 2.5 本章小结 .......................................................................................................... 21 第三章第三章 反击式破碎机破碎腔室离散元模型的建立反击式破碎机破碎腔室离散元模型的建立 ............................ 23 3.1 离散单元法基本算法及接触模型 .................................................................. 23 3.1.1 离散单元法基本算法 ............................................................................. 23 3.1.2 离散单元法接触模型 ............................................................................. 25 3.2 岩石颗粒离散元模型的建立 .......................................................................... 28 3.2.1 几何壳体的建立 ..................................................................................... 28 3.2.2EDEM 界面下模型的建立 ...................................................................... 28 万方数据 VI 3.2.3 颗粒模型的获取 ..................................................................................... 29 3.3 模型参数及属性设置 ...................................................................................... 31 3.3.1 接触模型设置 ......................................................................................... 31 3.3.2 材料属性参数设置 ................................................................................. 32 3.3.3EDEM 界面的其他设置 .......................................................................... 32 3.4 破碎机结构确定和破碎腔室几何模型的建立 .............................................. 33 3.4.1 结构参数、运动参数的计算 ................................................................. 33 3.4.2 破碎腔室几何模型的建立 ..................................................................... 34 3.5 集料颗粒破碎模型的参数反演与可靠性试验验证 ...................................... 35 3.5.1 冲击时间、破碎力的计算 ..................................................................... 35 3.5.2 颗粒仿真破碎力的确定以及模型可靠性分析 ..................................... 36 3.6 本章小结 .......................................................................................................... 37 第四章第四章 反击式破碎机破碎作用仿真分析反击式破碎机破碎作用仿真分析 ............................................ 39 4.1 仿真方案 .......................................................................................................... 39 4.2 破碎作用效果分析 .......................................................................................... 40 4.2.1 转速对破碎作用效果影响仿真分析 ..................................................... 40 4.2.2 岩石强度对破碎作用效果影响仿真分析 ............................................. 44 4.2.3 导料板倾角对破碎作用效果影响仿真分析 ......................................... 47 4.2.4 第一反击板角对破碎作用效果影响仿真分析 ..................................... 51 4.2.5 第二反击板角对破碎作用效果影响仿真分析 ..................................... 54 4.3 最佳方案的确定 .............................................................................................. 58 4.3.1 正交试验设计 ......................................................................................... 58 4.3.2 试验结果分析 ......................................................................................... 58 4.4 本章小结 .......................................................................................................... 61 第五章第五章 基于数字图像技术的集料颗粒形状实测结果分析基于数字图像技术的集料颗粒形状实测结果分析 ................ 63 5.1 数字图像技术基础 .......................................................................................... 63 5.2 图像的采集 ...................................................................................................... 63 5.3 集料颗粒形状的图像处理 .............................................................................. 64 5.3.1 集料颗粒数字图像预处理 ..................................................................... 64 5.3.2 集料颗粒的滤波处理 ............................................................................. 65 5.3.3 集料颗粒数字图像的形态学处理 ......................................................... 66 5.3.4 粘连颗粒分割处理 ................................................................................. 66 5.3.5 颗粒凸壳处理 ......................................................................................... 67 5.4 颗粒形状质量实测结果分析 .......................................................................... 67 万方数据 VII 5.4.1 颗粒形状质量评价指标 ......................................................................... 67 5.4.2 集料形状特征的提取 ............................................................................. 68 5.4.3 工程实测结果分析 ................................................................................. 69 5.5 本章小结 .......................................................................................................... 74 第六章第六章 结论与展望结论与展望 ................................................................................. 75 6.1 主要结论和成果 .............................................................................................. 75 6.2 展望 .................................................................................................................. 76 致谢致谢 ............................................................................................................. 77 参考文献参考文献 ..................................................................................................... 79 在学期间发表的论文和取得的学术成果在学期间发表的论文和取得的学术成果 ................................................ 83 万方数据 第一章 绪论 1 第一章 绪论 1.1 研究背景及意义 集料颗粒主要是借助颚式、圆锥式、锤式、反击式和立式等破碎机设备,经过 一系列的加工工艺破碎而成,是道路、矿山、建筑等工程施工中重要的基础材料。 资料显示,在沥青路面施工中,集料颗粒质量大约占到沥青混合料的 90以上[1]。 研究者对沥青路面早期损伤原因探究发现,骨料颗粒形状是关乎道路施工品质的 关键要素之一, 当针片状颗粒占比较大时会影响混合料骨架结构, 使混合料产生显 著的断裂,进而引起沥青路面发生垮塌凹陷,对路面酿成有害影响[2 、3],如图 1-1 所示。 a裂缝 b凹陷 图 1-1 沥青路面早期损伤 集料外框的三维长度中最长尺寸与最短尺寸进行作比,将商大于 3 的叫做针 片状颗粒。 针片状颗粒主要是通过破碎设备破碎时产生的, 其中破碎设备结构参数、 工作运动参数和加工母岩的物理特征都是影响针片状颗粒产生多少的主要因素。 破碎机械设备主要包括破碎腔室结构空间排布, 加工运动参数主要是转速, 加工母 岩的物理特性主要是岩石强度。反击式破碎机作为最后一道破碎加工工序[4],其生 产破碎的成品将直接运用于工程施工,这将会直接影响到如沥青路面内部结构的 抗压、水稳等性能;因而对反击式破碎机破碎作用研究分析、提高成品集料质量具 有很重要的意义。 大型机械设备的研发往往需要在大量实验数据的基础上进行优化,这种基
展开阅读全文