摘要:

The first part o f this paper deals with technology issues. These ye megorised as ( i) fundamental aspects. specifically susoension characteristics and dewatcrinn mechanisms along with process modelling and control; ( ii) pre-treatment procedures, both physical and chemicd, that optimise the dewatering characteristics, ( iii) types of dewatering devices based on centrifuges, vacuum and pressure filters with particular reference to various combined field approaches using two or more complentary. driving forces to achieve better performance. The second part of the paper ( attributed principally to the fim-named author) deals with related R & D issues. namely economic assessments and justification for particular R & D strategies, including benchmarking and operational factors that apply in industrid environments Dewaterine operation and R & D needs are also analysed from the perspective of matching and integration into overall proccss flowsheets, and in the context of alternative processing or utilisation strategies which avoid the dewaering step. The analysis concludes with a discussion on effective identification and utilisation of existing knowledge, and the R & D management process. Although the paper draws heavily on experiences relating to the coal industry, much of the material is relevant to fine suspensions in general.

ISSN:0737-3937    

DOI:10.1080/07373939608917145

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Experimental and theoretical research and development studies are preposed and presented in important areas of the freeze drying process. The practical importance of the synergistic integration of advanced theoretical models and experiments is indicated, and the potential contributions of the proposed

ISSN:0737-3937    

DOI:10.1080/07373939608917146

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

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.

ISSN:0737-3937    

DOI:10.1080/07373939608917147

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

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.

ISSN:0737-3937    

DOI:10.1080/07373939608917148

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Drying processes affect the quality of the final food biopolymer product. The texture, density, wetability, caking, rehydration capacity and mechanical properties of the dried food biopolymer depend on: the product properties, the drying process conditions and the product residence time distribution in the dryer. The interrelationship between dried product quality and drying process conditions is not sufficiently explored in literature because of limited understanding of the physico-chemical mechanisms affecting product quality, and of the effect of these mechanisms on transport properties. Recent ad- vances in material and polymer science research, however, provide the tools and methodologies needed to understand in depth the quality changes dur-ing drying. The current work reviews the approaches of conventional drying theories and presents recent advances in polymer science on modelling solvent absorption by glassy polymers based on the glass-transition theory. Oppor- tunities presented by the glass transition theory towards explaining quality changes during drying are identified and the framework of a recent rnathe- matical model that can be used to integrate the drying and polymer-science approaches is then presented.

ISSN:0737-3937    

DOI:10.1080/07373939608917149

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Recent published literature (1990–1995) on the subject of grain drying and drying of forages is reviewed. Research priorities regarding crop drying tends to be regionalized. responding at times to differences in socio-economic conditions, at times to the status of energy research and environmental policy. Because grains have recently become much more important feedstocks for various food and industrial products, drying research has gradually shifted towards the study of drying-induced changes in microstructure and physico-chemical propenies of plant material. Future research will focus on issues related to texture modification, innovative techniques for dryer control, improved drying models end technologies that reduce the need for non-renewable sources of energy.

ISSN:0737-3937    

DOI:10.1080/07373939608917150

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Importance of Solar Drying is increasing worldwide, especially in areas where the use of the abundant, renewable and clean solar energy is essentially advantageous. In the developing countries and in rural areas the traditional open-air drying methods should be substituted by the more effective and more economic solar drying technologies.

ISSN:0737-3937    

DOI:10.1080/07373939608917151

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

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.

ISSN:0737-3937    

DOI:10.1080/07373939608917152

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The efficient dryer design and the optimization of existing drying processes require both effective drying models and hygrothermal properties. Following extensive research during the previous decades, today's existing models for the drying process are mostly adequate. Thus.most of the requirements for appropriate process design and operation depend on the existence of data for the various properties. The correct estimation of properties is of fundamental importance for the design.optimization and control of the process. The existing knowledge is adequate regarding the hygrothermal properties of the drying medium (air). Most of the efforts should address the problem of finding and standardizing appropriate measuring techniques and selecting and compiling the existing data, concerning hygrothermal and quality properties of the product being dried. The article identifies those areas, where adequate data not exist and future research is needed or data banks should be created.

ISSN:0737-3937    

DOI:10.1080/07373939608917153

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Research in the field of drying should include aspects of bask or fundamental research and applied research related to the product and process as well as development to meet the needs of the customer. Research might be better categorized as government, industry, and university, with each organization defining the approprlate role for its mission, The linear model of research is not appropriate for engineering. It should be recognized that ideas can come from many different sources and should be sought by the researcher. The single most important need is ideas. Instruments, equipment, and laboratories stimulate the generation and experimentation of pertinent ideas. Several suggestions for ‘new’ ideas are made that illustrate the expanding opportunities in an ‘old’ field.

ISSN:0737-3937    

DOI:10.1080/07373939608917154

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor