旋转闪蒸干燥机分级轮动力学及静强度分析

发布时间：2018-04-30 12:03

本文选题：闪蒸干燥机 + 动力学　；参考：《东北大学》2014年硕士论文

【摘要】：旋转闪蒸干燥机具有结构简单、干燥时间短、物料温升低、适用特殊物料干燥等特点,在传统的旋转闪蒸干燥机的基础上增加旋转分散装置(分级轮),能很好的解决产品的再次团聚问题,提高分散能力,保证干燥产品达到一定的粒度要求。分级轮是在高转速及中高温的环境下工作,结构上位于立筒式干燥室的顶端,其振动会很大程度上影响到整个机体的稳定性,严重时甚至不能正常工作。所以针对该转子系统进行了动力学特性的分析和分级轮与热流体的耦合作用分析,判断出该分级轮系统不能满足正常的工作需求,需要做出调整或优化。首先,选用离散质量模型和有限元两种方法对分级轮进行了转子动力学的特性分析,特别是考虑了陀螺效应对高速转子的影响,经过相互验证发现数学模型对高阶模态有较大误差,而有限元法则对分级轮笼式结构有较好的模拟结果。其次,通过模态分析及谐响应分析验证了转子的工作转速小于但很接近其一阶临界转速,瞬态不平衡响应分析也显示了在转子启动过程中接近工作转速时振动急剧增大到很大的位移值,所以为了避免过大振动,应该对转子系统进行调整优化。同时,本文分析并得到了干燥室内的热气流与分级轮之间的相互影响,以及分级轮转速对物料颗粒逸出率的影响关系。最后,通过热-结构耦合分析对分级轮结构强度的验证和流场压力对轮盘结构的影响,选择提高转子系统临界转速的方案对其进行结构优化,并得到了满意的结果。
[Abstract]:The rotary flash dryer is characterized by simple structure, short drying time, low temperature rise of materials, suitable for drying of special materials, etc. On the basis of the traditional rotary flash dryer, the addition of rotary dispersion device (grading wheel) can solve the problem of product reunion again, improve the dispersing ability, and ensure that the dry product can meet certain particle size requirements. The classifier is working in the environment of high rotating speed and medium and high temperature. The structure is located at the top of the vertical cylinder drying chamber. Its vibration will affect the stability of the whole body to a great extent and even can not work normally when it is serious. Therefore, the dynamic characteristics of the rotor system and the coupling analysis between the stage wheel and the thermal fluid are analyzed, and it is concluded that the classifier wheel system can not meet the normal working requirements and needs to be adjusted or optimized. Firstly, discrete mass model and finite element method are used to analyze the rotor dynamics of the stage wheel, especially considering the influence of the gyroscope effect on the high-speed rotor. After mutual verification, it is found that the mathematical model has a large error to the higher-order mode, and the finite element method has a good simulation result for the stepped wheel-cage structure. Secondly, modal analysis and harmonic response analysis show that the rotor speed is less than but close to its first order critical speed. The transient unbalance response analysis also shows that the vibration increases sharply to a very large displacement value when the rotor starts close to the working speed, so in order to avoid excessive vibration, the rotor system should be adjusted and optimized. At the same time, the relationship between the thermal air flow in the drying room and the classifier wheel and the influence of the speed of the classifier wheel on the particle escape rate are analyzed and obtained. Finally, through the thermal-structural coupling analysis to verify the strength of the stage wheel structure and the effect of the flow field pressure on the wheel structure, the scheme of increasing the critical speed of the rotor system is selected to optimize the structure, and the satisfactory results are obtained.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB4

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