MATERIAL RESPONSE-BASED KILN CONTROL SYSTEM

ABSTRACT

The origin of material response (changing shrinkage rates) during drying is changing stress levels within the lumber as was determined in a previous paper. The object of this research was to demonstrate that a kiln control system based on material response parameters can reduce the drying time while incurring no additional drying defects. One control run and two pilot runs were performed. The results showed that it is possible to advance the kiln schedule using only material response as the controlling parameter and maintain or improve the quality of the lumber. Accelerating the drying substantially reduced the residual stress levels in the final product.     

Shrinkage Characteristics of Potatos Dehydrated Under Combined Microwave and Convective Air Conditions

A study of the pysical structure and quality potatoes during microwave and air drying war undertaken. The effect of various experimental variables on volumetric shrinkage including microwove power levels, air temperature and velocity as well as sample geometry was investigated. In both microwave and air drying, the shrinkage of potatoes showed a linear behaviour in relation to different moisture content levels. Experimental data showedthat air velocity and microwave power had a major effect on the degree of shrinkage, also the shrinkage behaviour was independent of sample geometry and air temperature. The use of microwave produced smaller changer in volume (less shrinkage) and henee a better quality finished product.     

Shrinkage Characteristics of Potatos Dehydrated Under Combined Microwave and Convective Air Conditions

ABSTRACT

A study of the pysical structure and quality potatoes during microwave and air drying war undertaken. The effect of various experimental variables on volumetric shrinkage including microwove power levels, air temperature and velocity as well as sample geometry was investigated. In both microwave and air drying, the shrinkage of potatoes showed a linear behaviour in relation to different moisture content levels. Experimental data showedthat air velocity and microwave power had a major effect on the degree of shrinkage, also the shrinkage behaviour was independent of sample geometry and air temperature. The use of microwave produced smaller changer in volume (less shrinkage) and henee a better quality finished product.     

信息融合技术在陶瓷窑炉智能控制系统中的应用

将信息融合技术引入陶瓷窑炉智能控制系统，并提出了系统的控制模式。该控制模式被划分为六个层次，而六个层次中主要包括四个子系统。分析了各个组成部分的关联关系，并进一步分析了四个子系统的组成、功能和算法，对整个系统的控制方案和工作过程进行了分析。     

辊道窑温度监控系统分析与展望

对现有主要的辊道窑温度监控系统作了概括，分析了其构建原理和特点及其应用情况。指出分布式温度监控系统是当前发展的主流，基于现场总线的辊道窑温度监控系统是未来的发展方向，提出了利用工控组态软件和通用计算机开发辊道窑温度监控系统的新思路。     

PCD系列温湿度可编程控制(PLC)快速干燥系统

本文简要论述了国内外的陶瓷卫生洁具干燥技术发展概况,比较详细地介绍了PCD系列温湿度可编程快速干燥系统的原理和技术特点。     

VACUUM-PRESS DRYING OF THICK SOFTWOOD LUMBERS

ABSTRACT

In vacuum-press drying of softwood species, wood lemperaiure exhibited a low temperature gradient, and plateau temperature of core lasied during all stages of drying. The drying curves were close to “linear”. The drying rates of the short lumbers were higher for red pine and western hemlock, lower for white pine and similar for larch lumber compared to the long ones. Transverse and longitudinal moisture gradients were small for western hemlock and red pine, and great for larch and white pine lumber. Energy consumption curves were split into three sections: increasing moderately, fairly constant and increasing rapidly. Casehardening stress of dried lumber occurred very slightly. Dried lumbers exhibited strong tendency for fine end checking, slight surface checking and no internal checking. Shrinkage appeared to be low.     

钛液的酸度系数控制

控制钛液的酸度系数（Ｆ）,可提高钛白粉的产量、质量和回收率。提出了采用废酸返回用于酸解和浸取的工艺,使酸度系数Ｆ偏高（Ｆ１８～２．２）,既可提高钛液的稳定性,又可代替部分外加的硫酸,降低生产成本。     

Experimental Investigation and Practical Application of Superheated Steam Drying Technology for Softwood Timber

Due to several advantages, superheated steam drying of timber has attracted great attention. However, the technology is still restricted to some special cases, partly due to the lack of fully understanding of the drying process. In this work, experiments were conducted to dry radiata pine timber using superheated steam under vacuum and at pressure. In the first part of the experiments, softwood timber was dried in a superheated steam kiln with drying rates, steam temperature across the stack and wood temperature being measured during drying. In the second part of the work, experimental studies were performed to investigate potential applications of the superheated steam drying at ultra-high temperatures (UHT) and pressurized steam conditioning of kiln dried timber. Compared to normal drying temperatures, the UHT drying can reduce the drying time by a factor of 5 to 10 and it is also more energy efficient. The pressurized steam conditioning has been proven to be a promising technology to relieve drying stresses and to reduce twist of the dried timer.