Defect and microstructural evolution during drying of soapnut-based alumina foams

The present study demonstrates the use of soapnut, a naturally occurring surfactant for producing alumina ceramic foams. A range of slurry compositions with soapnut amounts ranging from 2 to 20 wt% in water, alumina loading of 35–55 vol% were studied. Though all slurry compositions foamed when subjected to mechanical agitation the formation of green ceramic foams free of macroscopic defects was found to be strongly dependent on conditions during drying of foamed slurries. Addition of guar gum to the slurries was shown to enhance foam stability and thus produce defect-free foams from compositions that otherwise either collapsed or resulted in other macroscopic defects during drying. Drying conditions also had a strong effect on microstructural parameters such as cell size and cell connectivity. Soapnut-based foams appear to have a greater connectivity between cells than foams produced by other comparable processes.     

Use of triboelectric probes for on-line monitoring of liquid concentration in wet gas-solid fluidized beds

The objective of this study was to validate the effectiveness of a novel method employing triboelectric probes for accurate on-line solid moisture measurements in fluidized beds. Liquid injections were conducted in a fluid bed of glass beads and the resulting solid moisture was monitored during the whole drying stage by acquiring triboelectric signals generated from several locations inside the bed. For various superficial gas velocities and amounts of injected liquid, the bed drying end point and the fraction of sprayed liquid involved in the formation of slow-vaporizing stable agglomerates were estimated performing fast signal analysis by means of the W statistic.     

Discrete pore network modeling of superheated steam drying

A nonisothermal two-dimensional pore network model is developed to describe the superheated steam drying of a capillary porous medium. The complex void space is approximated by a network of spherical pores interconnected by cylindrical throats. In this model, the condensation of water vapor at the network surface as well as the network drying are taken into account. During the network drying period, the liquid transport is driven by capillary action, whereas vapor transport occurs because of convection. The condensation of water vapor within the pores is modeled based on newly formulated liquid invasion rules. The simulation results, presented as temperature and moisture content profiles over time, indicate qualitative agreement with available experimental observations. The inclusion of the liquid invasion rules is shown to accommodate more of the condensed water mass compared to earlier models, in which condensation is only partly treated. Due to the viscous vapor flow, the vapor overpressure within the network, which is the driving force of vapor transport, is reproduced in these simulations. The influence of vapor overpressure on the disintegration of the liquid phase is also discussed.     

多孔介质干燥孔道网络模型的研究进展

建立在物质微观传输基础上的孔道网络干燥理论，通过完全离散化的方法在孔道等级上对干燥过程进行研究，描述了多孔介质内部结构参数对干燥过程的影响。介绍了建立孔道网络模型的原理和方法，阐述了基于单元体上孔道网络研究的内容及目的，综述了基于产品等级上孔道网络研究的最新进展，阐明了孔道网络模型方法对干燥理论研究的重要意义。指出，进一步提高网络模型中孔道的拓扑等价性、形状的不规则性及尺寸的相关性，探索网络构建新方法以及增加孔道网络信息量，是孔道网络干燥理论的主要发展方向，并应加强同分形、渗流理论的进一步结合。     

湿磨干烧新工艺的设想

用于工业实践的湿磨干烧工艺与全干法的预分解窑相比,因烘干破碎机的存在,电耗较高。从造纸业中回收石灰石的湿浆脱水真空过滤新工艺得到启发,设想出不需烘干破碎机的湿磨干烧新工艺,新工艺烧成系统与原带有烘干的破碎机的系统相比电耗降低5kWh/t以上。     

Sun Creator在研究生管理信息系统中的应用

本文研究Java环境下的可视化Web开发。以高校研究生管理信息系统为例,探索Sun Java Creator的数据源配置、可视化Web组件、行集、Session Bean等在Java Web中的应用。     

皂化淀粉丙烯腈接枝共聚物干燥前处理研究

考察了洗涤介质、洗涤前pH值、干燥前pH值和洗涤次数对皂化淀粉丙烯腈接枝共聚物的吸水能力的影响。结果表明：洗涤方法、洗涤前pH值、干燥前pH值和洗涤次数对干燥后产物的吸水能力均有影响。其中，直接用异丙醇沉淀、经多次洗涤后将pH值调到6．5左右，干燥后产物的吸水能力可达到较高的水平。     

粮食真空低温干燥新技术的优势

真空低温干燥技术是近年来被广泛应用的一项新技术。就近年来真空低温干燥技术在东北玉米干燥方面的应用研究及其进展作了综述。探讨了真空干燥技术在玉米方面的应用前景。     

A Simulation Tool for the Optimization of Lumber Drying Schedules

A two-dimensional wood drying model based on the water potential concept is used to simulate the convection batch drying of lumber at conventional temperature. The model computes the average drying curve, the internal temperature and moisture content profiles, and the maximum effective moisture content gradient through board thickness. Various scenarios of conventional kiln-drying schedules are tested and their effects on drying time, maximum effective moisture content gradient, final moisture content distribution within and between boards, and energy consumption are analyzed. Simulations are performed for two softwood species, black spruce (Picea mariana (Mill.) B.S.P.) and balsam fir (Abies balsamea (L.) Mill.). The simulation results indicate that the predictive model can be a very useful tool to optimize kiln schedules in terms of drying time, energy consumption, and wood quality. Such a model could be readily combined with intelligent adaptive kiln controllers for on-line optimization of the drying schedules.     

干湿循环下高液限土力学特性研究

路基填料的承载比大小反映土体局部抵抗剪切破坏的能力,是评价路基填筑质量的重要检测标准之一。本文以实际工程高液限土改良方案确定为背景,通过一系列的室内试验研究了具体明显地区特征的掺砂高液限粉土和高液限黏土的承载比影响因素,获得了高液限土在不同掺砂量下,不同干湿循环次数后的吸水量、膨胀率、脱水量对土体的CBR值的影响规律,得出有益结论：水是引起土体膨胀、收缩及CBR值差异的主要原因;在干湿循环初期以“砂化作用”为主,后期以“裂缝作用”为主;高液限土应填筑在较深的93区;掺砂改良后,其可以填筑在相对较浅的94区。