螺旋卸船机垂直输送机理及试验研究

发布时间：2019-04-02 00:58

【摘要】：随着世界船舶运输业散装化的飞速发展，螺旋卸船机作为一种性能优良的连续型散货卸船机械，以其环保、节能等综合优势受到广大港口的青睐。螺旋卸船机的垂直输送机理研究是该领域的核心问题，目前正受到相关学者的高度关注和重视。本文以螺旋卸船机的垂直输送为对象，分别采用散体力学理论模型分析方法、接触力学离散元理论的仿真方法、样机试验方法，对其垂直输送机理进行了全面深入的研究，其主要工作和取得的创新性研究成果如下：（1）应用散体力学、连续介质力学及颗粒群理论，建立了垂直螺旋卸船机内物料颗粒群稳定运动的散体力学模型，创新性地对螺旋槽内物料颗粒群的转速作出了沿径向变化的假设。通过对物料的运动分析，，确立了物料的运动特征参数。研究确定了输送机纵向截面的物料自由表面类型及其判别、求解的方法与物料颗粒群对输送管壁及螺旋面的压力分布规律，建立了物料的运动特征参数、生产率与螺旋轴驱动功率的计算模型并给出数值计算方法。应用垂直输送机理分析模型，对输送机相关设计参数与性能参数的变化规律进行了描述，为垂直螺旋输送机主要参数的确定提供了科学的理论支撑。（2）应用离散元理论及EDEM软件，对物料的相关物性参数、物料的垂直螺旋输送过程、物料在输送机底部的进料过程及其在滚动间隔式中间支撑处的运动过程进行了系统的仿真。对不同充填率及不同螺旋转速下垂直螺旋底部的取料、垂直输送及物料在中间支撑处的运动过程进行了离散元仿真分析，获取了垂直螺旋输送性能参数的变化特性、取料装置供料能力随自转转速及集料螺旋转速的变化关系，验证了物料在滚动间隔式中间支撑处的通过性，并给出了滚动间隔式中间支撑的设计准则。（3）以L型螺旋卸船机的取料及垂直输送机头作为试验研究的平台，对螺旋卸船机垂直输送机理及相关的取料过程、物料中间支撑通过性进行了试验研究。研究开发了螺旋卸船机垂直输送及取料机理试验台，制定了相关性能测试的试验方案；对输送机进料能力、输送性能参数随螺旋转速及充填率的变化关系、取料性能参数随取料螺旋转速及料堆高度的变化关系进行了试验研究，验证了物料在中间支撑处的通过性及理论模型和仿真模型的一致性。试验研究结果揭示了输送机进料口极限进料量的规律，获取了垂直输送及取料过程的相关变化曲线，验证了理论模型的正确性和仿真模型精度的局限性。本文提出的螺旋卸船机垂直输送机理的研究方法和结论，为新型螺旋卸船机的开发提供了理论支撑和设计准则，为不同特性散体物料的螺旋输送研究提供了新的思路。
[Abstract]:With the rapid development of bulk loading in the world shipping industry, spiral ship unloader, as a kind of continuous bulk cargo unloading machine with excellent performance, has been favored by the majority of ports for its comprehensive advantages of environmental protection and energy saving. The research on the vertical transport mechanism of spiral ship unloader is the core problem in this field, which is being paid close attention to by the relevant scholars at present. In this paper, the vertical conveying mechanism of spiral ship unloader is studied comprehensively and deeply by means of theoretical model analysis of bulk mechanics, simulation method of discrete element theory of contact mechanics and prototype test method. The main work and innovative research results are as follows: (1) based on the theory of bulk mechanics, continuum mechanics and particle group, the mechanical model of the stable movement of particles in vertical spiral ship unloader is established. The rotating speed of particle group in spiral groove was creatively assumed to vary along the radial direction. Through the motion analysis of the material, the motion characteristic parameters of the material are established. The free surface type and its discrimination of the longitudinal section of the conveyor are studied and determined. The method of solving the problem and the pressure distribution law of the material particle group on the conveying pipe wall and the spiral surface are studied, and the moving characteristic parameters of the material are established. The calculation model of productivity and driving power of screw axis is given and the numerical calculation method is given. Based on the analysis model of vertical conveying mechanism, the variation law of the design parameters and performance parameters of the conveyor is described, which provides a scientific theoretical support for the determination of the main parameters of the vertical screw conveyor. (2) based on the discrete element theory and EDEM software, the physical parameters of the material and the vertical spiral conveying process of the material are studied. The feeding process of the material at the bottom of the conveyor and the movement of the material at the middle support of the rolling spacer are systematically simulated. In this paper, the discrete element simulation is carried out to simulate the feeding process of the bottom of the vertical screw, the vertical transport and the movement of the material at the middle support under different filling rates and different screw speeds, and the variation characteristics of the performance parameters of the vertical spiral conveying are obtained. The relationship between the feeding capacity of the reclaimer and the rotating speed of the rotating speed and the screw speed of the aggregate is given. The passage of the material at the intermediate support of the rolling spacer is verified and the design criterion of the intermediate support of the rolling spacer is given. (3) taking L-type screw ship unloader as the experimental platform, the mechanism of vertical transportation and the related feeding process, and the passage of the intermediate support of the screw ship unloader are experimentally studied in this paper. The mechanism of the vertical transport of the screw ship unloader and the passage of the intermediate support of the material are studied experimentally. The vertical conveying and taking-off mechanism test-bed of spiral ship unloader is studied and developed, and the test scheme of related performance testing is worked out. The relationship between the feed capacity, the conveying performance parameters and the screw speed and the filling rate of the conveyor, and the relationship between the feed performance parameters and the screw speed and the height of the pile of the conveyor are studied experimentally. The consistency of theoretical model and simulation model is verified. The experimental results reveal the rule of the limit feed quantity of the conveyer inlet, and obtain the relevant curves of the vertical conveying and feeding process. The correctness of the theoretical model and the limitation of the accuracy of the simulation model are verified. The research methods and conclusions of vertical conveying mechanism of spiral ship unloader presented in this paper provide theoretical support and design criteria for the development of a new type of spiral ship unloader, and provide a new way of thinking for the study of helical transport of bulk materials with different characteristics.
【学位授予单位】：武汉理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U653.928.1

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