R & D Needs - Drying of Ceramics

ABSTRACT

New research and development needs for the drying of ceramics are prooosed. The researches on the ceramic drying are briefly reviewed and the role of the drying in the ceramic production process iS summarized. The drying must deal with molded materials and the problem is of significant difference from another drying with particulate materials. It means that the drying must be performed with keeping the molded feature and the insufficient completion of drying and the careless operation influence directly on the product quality The importnance of the R & D on the heat and moisture transfer. shrinking mechanism. the deformation behavior and the strain-stress formation in the molded clay issuggested. The subjects are also pointed out for the further improvement of the ceramic drying process and the precise design of molding with high quality.     

Global R&D Needs in Drying

This paper summarizes some recent advances and general trends in drying technologies of industrial interest. The process of innovation is applied to drying R&D. The conventional drying techniques are compared with the innovative technologies. Numerous emerging technologies are listed and some examples are discussed in detail. Potential application areas for the new technologies are identified.     

R&D Needs in the Drying of Coatings

The key technologies involved in the drying of coatings are first reviewed and then the factors that influence the drying process are identified, leading to a discussion uf future R&D needs. The drying mechanisms in the constant and falling rate periods are discussed. Present and nticipated estrictions on the use of solvents will result in aqueous systems replacing some solvent systems. and in wider use of high solids coatings and 100% solids coatings. Cross-linking reactions to solidify monomers and low-molecular polymers now become important. Dryers will become chemical reactors. Further development of models of drying, of diffusion, of surface solvent levels, and of solvent vapor pressures will be needed, along with those of dryer defects and drying stresses. To accurately simulate a wide range of coating systems more physical property data is needed. Nan-convection heating and environmental concerns complete the discussion.     

Global R&D Needs in Drying

This paper summarizes some recent advances and general trends in drying technologies of industrial interest. The process of innovation is applied to drying R&D. The conventional drying techniques are compared with the innovative technologies. Numerous emerging technologies are listed and some examples are discussed in detail. Potential application areas for the new technologies are identified.     

R&D Needs in the Drying of Coatings

ABSTRACT

The key technologies involved in the drying of coatings are first reviewed and then the factors that influence the drying process are identified, leading to a discussion uf future R&D needs. The drying mechanisms in the constant and falling rate periods are discussed. Present and nticipated estrictions on the use of solvents will result in aqueous systems replacing some solvent systems. and in wider use of high solids coatings and 100% solids coatings. Cross-linking reactions to solidify monomers and low-molecular polymers now become important. Dryers will become chemical reactors. Further development of models of drying, of diffusion, of surface solvent levels, and of solvent vapor pressures will be needed, along with those of dryer defects and drying stresses. To accurately simulate a wide range of coating systems more physical property data is needed. Nan-convection heating and environmental concerns complete the discussion.     

Review of R&D in Drying of Refractories

This article reviews the published research and development work on refractory drying. Current practice and potential problems are analyzed. Some selected important research results are presented. It is shown that significantly improved drying procedures can be achieved through computer simulation of the drying process.     

Recent R&D on Drying Technology in Japan

This article presents the outlook of the energy situation in Japan and reviews the recent R&D on innovative drying technologies performed in Japan. The overview of drying includes fundamentals as well as industrial technologies. The topics considered are drying characteristics of several materials, drying of hard-to-handle powders, drying of coatings, drying-induced strain-stress problems, drying modeling, and drying of agricultural wastes for functional recycling and noble dryers. An appropriate combination of heating methods and dryer type can result in significant enhancement of efficiency, drying rate, and/or material quality. The final goal of this article to contribute to providing an idea for development and evaluation of precise drying systems with a high performance and an effect of energy saving in drying.     

R&D Needs and Opportunities in Pulse Combustion and Pulse Combustion Drying

This short communication attempts to summarize briefly the authors’ opinions on R&D needs and opportunities for basic as well as applied research in pulse combustion and pulse combustion drying. It is not all-inclusive. Only minimal citations are made to relevant literature as readers interested in pro-actively pursuing this area can locate it reasonably easily. The objective in presenting this verview is to encourage new researchers in this fascinating and challenging field.     

Drying Characteristics of Malaysian Paddy: Kinetics & Grain Cracking Quality

Drying kinetics of Malaysian paddy dried in a laboratory scale batch rapid bin dryer was studied. Quality of paddy after drying at temperatures of 60 and 80°C, bed heights of 2 and 4 cm, and at different drying stages was presented in terms of cracking percentage. Moisture content of paddy reduced exponentially with time and became stable at equilibrium moisture content. Characteristic drying rate curves exhibited mainly falling rate period, with an induction period in deep beds, but without the constant rate period. A custom-made light box was built to visually analyze the cracking in paddy kernel. The extent of breakage is directly related to the crack percentage. The percentage of cracks increased with drying and tempering temperatures and was higher after 2 weeks of storage before milling. Bed heights did not significantly affect the head rice yield as much as tempering between two drying stages. Temperatures above 80°C caused severe cracking in paddy kernel and produced miserable yield of head rice after milling, which could be slightly improved by tempering. The use of a proper miller is also important in ensuring good head yield results and whiteness quality.     

DRYING R& D IN P.R. CHINA

A survey has been made of r6cent R& D activities in drying of solids in the People's Republic of China. Overall, the interest level appears to be rising in view of the increase in industrial development in the chemical, food, and other industries. Synopses are provided of selected recent publications     

R&D Needs-Drying of Sludges

Sludge management is very important subject for the environmental issue in many industrialized countries, because its generated volume is the largest in all generated wastes. In sludge management field, role of drying is becoming more needful as increase of difficulty for sludge disposal and need for sludge drying is expected in the future.

In this paper, the present status of drying of construction sludge, food industry sludge and municipal sludge are mentioned as concrete examples.

To respond these needs, it is necessary to advance further R & D     

卫生陶瓷快速干燥机理初探

1概述卫生陶瓷半成品干燥是卫生陶瓷生产中不可缺少的重要环节。由于卫生陶瓷产品器型较大,造型不规则,各部位厚薄不均匀,以及单、双面组合注浆成形形成的坯体各部位致密度不一致,导致了卫生陶瓷坯体的干燥过程较为复杂。传统的卫生陶瓷干燥方式大多采用热的干空气将热量传给坯体,坯体表面获得热量后,水分立即蒸发,并向外界扩散,同时引起坯体内部水分不断地扩散到表面,再由表面向外界干燥介质中蒸发,最终达到坯体水分与干燥介质的平衡,完成干燥过程。由于传统工艺干燥方式使坯体内外产生大的温度梯度,难以产生均匀的干燥和收缩…