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全旋流分离马铃薯淀粉试验研究及计算机模拟

Experimental Research and Computerized Simulation of Full-hydrocyclone-networks for Separating Potato Starch Milk

【作者】 李树君

【导师】 李里特;

【作者基本信息】 中国农业大学 , 食品科学, 2002, 博士

【摘要】 本文在深入实践和广泛查阅国内外有关马铃薯淀粉旋流分离资料的基础上,对单级水力旋流器分离马铃薯淀粉进行旋流管分离性能的实验研究、建立了水力旋流器单因素和多因素分离模型、提出了全旋流系统优化设计方案并对较优全旋流系统进行了计算机模拟。 旋流管是全旋流系统进行分离的核心,本文首先对水力旋流管分离性能进行了实验研究,定性分析出进料压力、底流口直径及进料淀粉浓度三个因素对生产能力、分股比以及分离效率等三个指标的定性影响规律。通过对实验结果的分析可获知应用于马铃薯淀粉分离的水力旋流器的性能指标随着各参数变化的规律,得出一定条件下最佳分离状态的各参数值。后又得出随底流直径变化,旋流管对淀粉分离效率的影响与对蛋白和渣分离效率的影响相矛盾,要依据进料浓度和分离任务来选择合适的旋流管,以获得良好的分离效果。 在马铃薯淀粉分离的实验研究中根据多年的生产经验和实际的实验条件来确定参数和指标,在实验台上创造相似的实验条件进行正交实验。针对全旋流系统运行中进料压力、底流直径和进料浓度三个可调节因素,通过试验研究具体分析了它们对生产能力、分股比、分离效率以及底流浓度的定量影响,将这些指标和参数之间的关系由Matlab拟合成曲线即单因数影响数学模型;通过应用相似理论对马铃薯淀粉分离进行模化实验,并应用相似准则对数据进行整理,对整理后的数据应用逐步回归的方法建立起一组反映单级水力旋流器分离马铃薯淀粉效果的具有较高精度的多因素影响数学模型。该模型可以对分离作出预测,并为放大设计和优化提供依据。 本文的编程计算基本思想基于物料衡算法。通过编程计算,得出在简化情况下全旋流系统中各级旋流器的工作状态参数与单级旋流器底流分率和分离效率的函数关系,以及整个系统的最终分离效率。在综合分析系统的构成及实测与计算结果的基础上,本文首次提出了可行的系统设计思路,为高效节能的全旋流分离系统的开发提供了必要的理论依据。研究结果表明,适当的改进旋流管配置,提高单级旋流器的分离效率,可以有效的提高系统的分离效果,简化系统构成。最后通过计算比较得出全旋流分离马铃薯淀粉的较优系统。 网络计算机模拟方法即在对较优网络系统充分分析的基础上,根据近几年的生产实践经验、实验测量的数据,应用单级马铃薯淀粉分离数学模型,利用Matlab数学应用软件中强大的Simulate功能,模拟仿真实际生产过程。通过计算机模拟,可以得出在已知进料流量、淀粉含量、进水量以及各级配置的情况下得出各级的分离状况以及整个网络系统分离状况,以达到预测的目的;通过计算机模拟,可以为调试安装节省大量的人力和物力;通过计算机模拟,可以为设计提供检验的手段。 本论文对水力旋流器应用于马铃薯淀粉分离进行的试验研究和普遍适用的单因素、多因素分离模型的建立以及对网络进行的计算机模拟的完成填补了国内外在该领域研究的空白,为该项技术的推广和生产应用提供了理论依据和指导,具有较高的实际意义。

【Abstract】 Based on the deep practice and wide collection of literature in this field, the theoretical analysis of the individual hydrocyclone separation was studied, the separation models for hydrocyclone were established, the full-hydrocyclone-network was studied by experiments and the whole system is simulated through computer. The main contents as follows:Firstly, experimental studies were made on relationships among adjustable parameters hi the working system (input pressure, underflow diameter and input concentration) and separation performance measured by feed flow rate, underflow percentage and separation efficiency. The optimal parameters were formed.Secondly, in potato separation experiments, the parameters and targets were decided by the rich experiences and conditions provided by the reality. There are so many parameters affecting the separation of potato starch. The similar conditions were made to perform orthogonal experiments. The results of the experiments were displayed by figures and the data were fitted to be curves with Matlab. The change characteristics of the parameters and the optimal parameters under certain conditions were found. And the underflow diameter of hydrocyclone can give contrary effect on starch separation efficiency and protein & dregs separation efficiency. To achieve better separation performance, hydrocyclones with different underflow diameter had to be chosen according to the duty of separation and the concentration of feed materials. Dealing with the data gained from experiments with similarity theory and applying mathematical stepwise regression method a series of equations could be established. These equations reveal the effect of separating potato starch precisely. These equations were also used to predict the performance of separation and provide a foundation for the amplification and optimization of the designing of separation operation.Thirdly, it is the first time in China the working states of each stage and the outputs of the whole system were calculated by mass balance calculations. The system will besimplified before simulation. With calculations and the analysis of the whole system we provided a method to design optimization system. And through comparison we found out which network is the best.Fourthly, the computerized simulation method is that based on the analysis of the best network of separating potato starch and the experience of production and the separation characteristics gained from experiments, the process of separation can be simulated with the strong toolbox SIMULATE of mathematical software MATLAB. With the computerized simulation, the separation situation of each hydrocyclone and full-hydrocyclone-networks can be obtained only if the quantity of input per hour, the content of starch, the quantity of input water per hour and the structure parameters of each hydrocyclone are provided. The predicted results fit well with experimental data. With the computerized simulation the separation performance can be predicted and the expenses of erecting and trying a new production line can be decreased. It also provides the reliable tool to check the design of new hydrocyclones and networks. It is particularly valuable for the optimization of alternative designs or arrangements for a given duty. Strategies to design multistage hydrocyclones are also proposed. The research work shows that it is possible to achieve even better separation performance or less number of multi-hydrocyclone stages by properly improving the scheme of hydrocyclone so as to the higher separation efficiency of single stage.

  • 【分类号】TS236
  • 【被引频次】12
  • 【下载频次】401
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