振动给料机偏心振动下物料颗粒运动分析与纠偏研究

发布时间：2018-08-05 13:49

【摘要】：在转底炉直接还原工艺中,炉膛上含碳球团的厚度和分布效果对海绵铁的品质和生产效率有直接的影响。国内外学者通过研究,设计出了一类新型的振动给料机,可实现炉膛周向和径向上的等厚度布料。但由于振动给料机存在偏心,炉膛上的料层会出现厚度不均匀现象,达不到工艺要求。有鉴于此,本文以振动给料机为研究对象,对偏心造成的布料不均匀问题进行了系统的研究,从偏心状态下振动给料机的振动及物料颗粒运动特性两方面探究这一现象产生的机理,并寻找解决方案。在深入分析振动给料机的结构、原理及振动特性的基础上,将质心与激振力作用线不重合的现象定义为偏心,建立了振动给料机的五自由度振动模型,通过振型叠加法求解出了不同偏心状态下的稳态响应；并利用MATLAB进行数值计算,得到偏心与稳态振动幅值的关系曲线,分析了偏心对振动给料机稳态振动特性的影响。推导了直线振动条件下振动给料机中物料颗粒的运动理论,以此为基础,建立了一种适合于球团颗粒运动仿真的摩擦力模型；并通过FORTRAN77编写用户子程序将其嵌入到ADAMS中,对复杂振动条件下球团颗粒的运动进行了仿真,分析了偏心引起的振动变化对振动给料机中物料颗粒运动的影响。结合振动给料机的偏心振动特性及球团颗粒运动规律,分析了偏心对布料效果的影响,阐释了偏心造成振动给料机布料不均匀现象的内在机理；进而对偏心状态下的振动给料机进行多球团颗粒运动仿真,找到了偏心与振动台面上球团颗粒的分布状况之间的联系；以此为基础,提出了两种纠偏方案,并通过布料试验进行了验证。结果表明,水平方向上的偏心是造成振动给料机布料不均匀现象的根本原因；纠偏后,振动给料机的布料效果得到明显改善,证明了理论分析的正确性。
[Abstract]:In the direct reduction process of rotary bottom furnace, the thickness and distribution of carbon-bearing pellets on the furnace have a direct effect on the quality and production efficiency of sponge iron. A new type of vibrating feeder has been designed by scholars at home and abroad, which can realize the distribution of equal thickness in the circumference and radial direction of the furnace. However, due to the eccentricity of vibrating feeder, the thickness of the material layer on the furnace will be uneven, which can not meet the requirements of the process. In view of this, this paper takes the vibrating feeder as the research object, and makes a systematic study on the uneven distribution caused by eccentricity. In this paper, the mechanism of this phenomenon is explored from the vibration of the vibrating feeder under eccentric condition and the motion characteristics of the material particles, and the solution is found. Based on the deep analysis of the structure, principle and vibration characteristics of the vibrating feeder, the phenomenon that the action line between the center of mass and the exciting force does not coincide is defined as eccentricity, and the vibration model of the vibration feeder with five degrees of freedom is established. The steady state response in different eccentricity states is solved by mode superposition method, and the relation curve between eccentricity and steady vibration amplitude is obtained by using MATLAB, and the influence of eccentricity on steady state vibration characteristic of vibrating feeder is analyzed. In this paper, the motion theory of material particles in vibrating feeder under linear vibration is derived. Based on this theory, a friction force model suitable for pellet motion simulation is established, and embedded in ADAMS by user subprogram written by FORTRAN77. The movement of pellets under complex vibration conditions is simulated and the effect of eccentricity on the movement of particles in vibrating feeder is analyzed. Combined with the eccentric vibration characteristics of vibrating feeder and the movement law of pellets, the influence of eccentricity on the distribution effect is analyzed, and the internal mechanism of uneven distribution caused by eccentricity is explained. Then, the motion simulation of multi-pellet particles is carried out on the vibrating feeder in eccentric state, and the relation between eccentricity and the distribution of pellet particles on the vibrating table is found, and two kinds of rectifying schemes are put forward. It is verified by cloth test. The results show that the eccentricity in the horizontal direction is the fundamental cause of the uneven distribution of the vibrating feeder, and the distribution effect of the vibrating feeder is obviously improved after rectifying the deviation, which proves the correctness of the theoretical analysis.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH237.1

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