粉体包装螺旋式密实输送研究

发布时间：2019-04-19 18:51

【摘要】：现代工业发展呈突飞猛进的态势,在包装生产领域,粉体包装的发展更是日益成熟。传统粉体包装机械存在着诸多问题,如粉体夹带气体,粉尘污染,生产效率较低等。如今,在保护环境以及机械自动化与智能化的新形势下,传统粉体包装机械已不能很好地满足包装需求。本研究针对充填包装中粉体物料的密实输送问题,提出解决密实问题的方法,设计密实输送装置的结构参数和包装工艺参数并验证结构参数的合理性,运用离散元软件对粉体物料的密实输送进行仿真模拟。分析粉体包装行业内包装机械的生产现状、机械化程度以及传统包装机械存在的问题,论述了粉体充填包装装置及相关领域的国内外研究现状与研究进展,对所研究粉体物料的概念及基本特性进行分析,多方面分析包装物料的特性、粉体夹带气体的原因及其影响,为粉体密实输送方法的提出提供依据。结合普通螺杆的参数设计原则、密实比等包装生产要求以及粉体螺旋输送理论,提出螺距组合式的密实输送螺杆,即将输送螺杆分为进料段、密实段、排气段以及卸料段。对密实输送螺杆的输送量、螺旋叶片的直径、螺距尺寸、螺旋轴直径、密实比、驱动功率等主要参数进行分析并计算,并运用三维实体软件对密实输送螺杆进行实体建模。理论分析密实输送螺杆的强度和刚度条件,并采用有限元的方法,以ANSYS Workbench为平台,对所设计的密实输送螺杆进行结构静力学分析和预应力模态分析,得到其工作时的应力应变分布情况以及固有频率和振型,并分析其分布规律,从而检验其主要参数设计的合理性。应用离散单元法对粉体在密实输送螺杆和包装容器的运动过程进行仿真分析,使得粉体颗粒在输送过程的运动状态和输送轨迹可视化。分析螺杆转速分别为90rpm、100rpm、110rpm、120rpm时,粉体的质量流量等变化规律。对密实输送螺杆的进料段、密实段、排气段以及卸料段等不同功能段处的粉体速度、运动密度变化情况进行分析。仿真模拟粉体充填至包装容器后,在不同振动幅度和频率的工艺参数下,分析粉体的振动密实过程。仿真结果一方面检验输送螺杆参数设计的合理性并对结构参数的优化提供指导,另一方面验证螺距组合式的输送螺杆和振动包装容器能够使输送过程的粉体变得密实。
[Abstract]:The development of modern industry is developing by leaps and bounds. In the field of packaging production, the development of powder packaging is maturing day by day. There are many problems in traditional powder packaging machinery, such as powder entrainment gas, dust pollution, low production efficiency and so on. Nowadays, under the new situation of environmental protection and mechanical automation and intelligentization, the traditional powder packaging machinery can no longer meet the packaging needs. Aiming at the problem of dense transportation of powder materials in packing and filling, this paper puts forward a method to solve the problem, designs the structural parameters and packaging technological parameters of the dense conveying device, and verifies the rationality of the structural parameters. Discrete element software is used to simulate the dense conveying of powder materials. The production status, mechanization degree and existing problems of traditional packaging machinery in powder packing industry are analyzed. The research status and research progress of powder filling packaging equipment and related fields at home and abroad are discussed. The concept and basic characteristics of powder materials studied are analyzed, and the characteristics of packaging materials, the causes and effects of entrainment gas of powder are analyzed in many aspects, which provides the basis for the proposal of dense conveying method of powder. According to the parameters design principle of the common screw, the packing production requirement of the density ratio and the screw conveying theory, the screw with screw distance combination is put forward, that is, the screw can be divided into the feeding section, the dense section, the exhaust section and the discharge section, which are divided into the feeding section, the dense section, the exhaust section and the discharging section. The main parameters of the dense conveying screw, such as the volume of the screw, the diameter of the screw blade, the pitch size, the diameter of the screw shaft, the density ratio and the driving power, are analyzed and calculated, and the solid modeling of the dense conveying screw is carried out by using the three-dimensional solid software. The strength and stiffness of dense conveying screw are analyzed theoretically, and the structural statics analysis and prestressed modal analysis of the designed dense conveying screw are carried out on the platform of ANSYS Workbench by using the finite element method. The stress-strain distribution, natural frequency and mode shape are obtained, and the distribution law is analyzed, so as to verify the rationality of the design of the main parameters. The discrete element method is used to simulate and analyze the movement process of powder in dense conveying screw and packaging container, which makes the movement state and transportation trajectory of powder particles visualize in the process of conveying. The changes of the mass flow rate of the powder were analyzed when the screw speed was 90 rpm, 100 rpm, 110 rpm and 120 rpm, respectively. The changes of powder velocity and motion density in different functional sections such as feeding section, dense section, exhaust section and unloading section of dense conveying screw are analyzed. After the powder is filled into the packaging container, the vibration compacting process of the powder is analyzed under different vibration amplitude and frequency. The simulation results, on one hand, verify the rationality of the design of the conveying screw parameters and provide guidance for the optimization of the structural parameters, on the other hand, verify that the conveying screw and the vibrating packaging vessel of the pitch combination can make the powder dense in the conveying process.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB48

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