共查询到20条相似文献,搜索用时 109 毫秒
1.
凹版印刷机干燥箱的作用是在数秒时间内完成对印品的强迫干燥工作。干燥箱内热风动力学特性及干燥箱结构参数对干燥效果有直接影响,而干燥均匀性是表征热风动力学特性的主要指标。因此,论文对传统干燥箱热风流动进行建模,采用计算流体力学的理论与方法对热风温度均匀性进行分析。计算结果显示传统干燥箱的干燥均匀性较差。论文还对干燥箱进行了优化设计。通过对改进后的干燥箱热风流动进行建模、计算和仿真分析,并与传统干燥箱的计算结果对比,得到了改进后的干燥箱热风温度均匀性较传统干燥箱有较好改善的结论。 相似文献
2.
目的对FR-300凹版印刷机干燥箱进行数值模拟与改进研究,为企业提供改进模型最优的方案。方法采用数值模拟方法,建立干燥箱的三维物理模型,对干燥箱内部的速度场、压力场及温度场进行研究。得到干燥箱热风流动迹线图及切面迹线图,并针对其内部热风流动特性和结合干燥箱结构特点,对干燥箱排风口结构进行改进,确定新的干燥箱结构。结果改进后的干燥箱对印品的干燥效果更佳,出口压力更小(-330 Pa和-150 Pa),更有利于负压风机的选择。结论为干燥箱的设计及改进研究提供了参考。 相似文献
3.
目的研究凹版印刷机热风干燥系统的工作特性,确定最佳干燥工艺参数。方法以FR400凹印机干燥装置为研究对象,从油墨溶剂阶段性挥发的干燥机理出发,建立多束气体冲击平面射流干燥模型;通过Fluent完成干燥箱的流体场数值计算,基于干燥箱几何结构研究热风的复杂流动状态,分析湍流产生原因及对干燥效果的影响;通过数值切片技术,提取印刷品表面热风速度和温度值,研究干燥参量波动的范围和特征,讨论不同位置处热风不均匀特征和产生机理,以及不同区域干燥过程中风速和温度的变化特征。结果干燥箱左腔体导流板两侧及右腔体上端产生湍流,风嘴之间形成了间隔分布的涡流区域;干燥箱中间区域风嘴的热风速度较为均匀,上、下两侧较差,中后部风嘴处热风温度较高,左侧区域效果较差。结论热风干燥系统的几何结构对干燥效果的影响显著,合理的干燥箱结构设计和印刷图文布置有利于印品的干燥,为干燥系统优化改进与创新设计提供了依据。 相似文献
5.
凹版印刷机自动套色系统的控制方法与实现 总被引:17,自引:8,他引:9
针对凹版印刷机的工作特点,提出了一种新颖的凹版印刷机自动套色控制系统的控制与实现方法,并采用多片80C196KC单片机与一台PC机实现该控制系统。该控制系统在实际应用中证明,其能大大提高各类凹版印刷机的套印精度和印刷速度,因而具有广泛的应用前景。 相似文献
6.
7.
无轴凹版印刷集版辊传动和套色控制于一体,提高了凹版印刷的灵活性和操作性,提高了凹版印刷机的自动化水平,降低了凹版印刷机的机械成本;适应了当今印刷行业复杂工艺生产的要求,提高了印刷品质,节约了生产成本,适应了印刷行业市场的发展,实现了安全生产和环保生产。 相似文献
8.
9.
10.
11.
A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling. 相似文献
12.
V. T. Bublik A. I. Voronin E. A. Vygovskaya V. F. Ponomarev N. Yu. Tabachkova O. V. Toropova 《Inorganic Materials》2011,47(14):1563-1568
An analysis of anisotropy of the properties of a Bi2Se0.3Te2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal
expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological
fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained
using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied. 相似文献
13.
O'Brien RS 《Radiation protection dosimetry》2003,105(1-4):95-100
Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides. 相似文献
14.
15.
16.
17.
Development is continued of the empirical method for the calculation of the heat of combustion of organic compounds and, in particular, of hydrocarbons of different structures by the additive scheme based on their chemical structure. 相似文献
18.
An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a
rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate
agreement is demonstrated between the derived relations and experimental data. 相似文献
19.
本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。 相似文献
20.