共查询到18条相似文献,搜索用时 171 毫秒
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对同向啮合型双螺杆挤压机内挤压过程进行了研究,并分析不同双螺杆挤压机之间的关系和影响因素,从公式中推出挤压机内物料完全充满段对挤压机生产和设计的影响。 相似文献
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双螺杆食品挤压机的应用日益广泛。本文介绍了双螺杆食品挤压机的应用、双螺杆食品挤压试验的系统分析模型、双螺杆食品挤压机挤压机理的研究进展。 相似文献
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物料在双螺杆挤压机中停留时间分布的研究 总被引:3,自引:1,他引:2
阐述了物料在双螺杆挤压机中停留时间分布的理论,从设计模型和检测方法方面描述了物料的停留时间分布,并指出了影响停留时间分布的因素,为更好地选择和控制挤压机系统和操作提供了依据。 相似文献
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近来人们对食品挤压工艺的兴趣已集中于双螺杆挤压机及其解决在食品挤压方面所产生许多问题的能力。双螺杆挤压机由于其结构特点,可更有效地使物料连续流动。使用这种挤压机,许多配方在加工时存在的脉动和浪涌的程度降低了。双螺杆装置的起动和关机过程比单螺杆挤压机更为简单和可靠,并可减少清理时间。另一方面,双螺杆挤压机通常比相同生产率的单螺杆挤压机成本高,至少其初始费用是较高的。 相似文献
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本文讨论了零件参数设计与制造成本的关系。利用概率的理论 ,假设各零件的参数服从正态分布 ,从而给出非线性规划问题的目标函数。参数标定值的选取是离散的 ,用计算机数值计算能力采用网格搜索最优解。并结合实例 ,介绍了食品挤压机双螺杆零件参数的优化设计 相似文献
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食品物料在双螺杆挤压机中流动状态分析 总被引:2,自引:0,他引:2
本文对同向啮合型双螺杆挤压机在挤压加工过程中食品物料流动状态进行了探讨 ,分析了双螺杆挤压机内存在的四种漏流形式。根据物料充满程度不同 ,沿轴向将双螺杆挤压机内整个轴向区域划分成物料部分充满段和完全充满段二段 ,通过理论分析可知模头压力与机筒内的完全充满段长度有关 ;为了简化流动方程的求解 ,沿径向将物料的流动分成输送区和啮合区两个区域 ,通过求解不同区域的方程并结合边界条件和约束条件 ,可对双螺杆挤压机内物料的流动进行模拟。 相似文献
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螺杆挤压机及其应用研究现状 总被引:2,自引:0,他引:2
综述了螺杆挤压机挤压加工的原理以及单螺杆、双螺杆、三螺杆挤压机和超临界二氧化碳挤压膨化机几种挤压加工设备,并简介了螺杆挤压机的应用。 相似文献
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Effect of moisture content, screw rpm and β-amylase dose on the rate of maltose production in a Baker-Perkins twin screw food extruder has been studied. Fifteen experiments were conducted using a fixed screw configuration at a fixed mass flow rate of 15 kg/h, under isothermal conditions (t=57°C) and a pH of 5.5. Each of the three variables was found to have a significant effect (P<. 05) on maltose production. Using response surface regression analysis on the experimental data, a quadratic objective function was derived. the function was optimized, subjecting it to three explicit boundary conditions, using the adaptive complex method. the optimization process yielded a maximum maltose production of 34% at 54% moisture content, 30 rpm screw speed and 157 units of enzyme/g of starch. the extent of saccharification was about 30%. 相似文献
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《Journal of food engineering》1988,7(3):223-246
A method is presented for modelling flow in a twin-screw extruder. Computer-aided treatment of results obtained from residence-time distribution experiments enables the assessment, in the Fourier domain, of the intrinsic transfer function of an extrusion system. This characteristic function is then fitted to the theoretical transfer function of a particular prediction model by frequency response analysis, the terms of which are adjusted by multivariable optimization.This method is compared with other methods of response results analysis. Among the different flow models tested, the GAMMA model, i.e. Plug Flow Reactor (PFR) + series of Continuous Stirred Tank Reactors (CSTR), represents the best compromise between the accuracy of modelling and a reasonable number of optimization terms. It also appears to give a realistic approximation to the flow behaviour in a twin-screw extruder by quantifying its capacity both for positive displacement and for axial mixing. 相似文献
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Wheat starch was processed in a co-rotating twin-screw extruder, at moisture contents 25% and 30%, screw speeds 200 and 300 rpm, feed rate 30 kg/hr, and barrel temperature settings 100, 120, 140, and 160°C. Degree of starch gelatinization at each point along the extruder channel was determined by sampling and analyzing material inside the extruder. Kinetics of the gelatinization during extrusion was investigated. A first-order rate equation was developed to predict degree of starch gelatinization during extrusion. The rate constant was a function of both temperature and shear stress. 相似文献