DRYING RESEARCH AND DEVELOPMENT IN CZECHOSLOVAKIA

This paper provides general information on drying R 6D activities in Czechoslovakia. This survey report lists the main topics in drying according to individual industrial sectors in which drying plays an important role. Drying R 6D carried out in Czechoslovak Universities is also cited. The paper includes an extensive list of references, mainly proceedings of national drying conferences, symposia, and meetings     

DRYING RESEARCH AND DEVELOPMENT IN THE GERMAN DEMOCRATIC REPUBLIC

A summary is given of papers published in the GDR in the field of drying including drying theory, dryer models, sensor development, and analysis of industrial dryers.

Today in the GDR more than 10 000 dryers using 280 000 TJ/a are operated. So drying research and development mainly is driven by practical considerations, but there are pure theoretical approaches to dryer modelling and development of sophisticated drying sensors of general intereet too.     

DRYING RESEARCH AND DEVELOPMENT IN THE GERMAN DEMOCRATIC REPUBLIC

A summary is given of papers published in the GDR in the field of drying including drying theory, dryer models, sensor development, and analysis of industrial dryers.

Today in the GDR more than 10 000 dryers using 280 000 TJ/a are operated. So drying research and development mainly is driven by practical considerations, but there are pure theoretical approaches to dryer modelling and development of sophisticated drying sensors of general intereet too.     

DISSERTATIONS AND THESES IN DRYING WRITTEN IN CZECHOSLOVAKIA IN THE PERIOD 1975 - 84

Research and development of drying processes and equipmect has a long tradition in Czechoslovakia (1). There are at least 10 top reoearch centers where drying of varicus materials has been studied. Remarkable attention to drying theory and application is also paid at Czechoslovak universities which yields numerous theses dealing with various aspects of the drying process. The total of 52 M.Sc. theses oriented to drying and/or dryers had been published in the last decade. Moreover, 22 Ph.D. theses were carried out in the same period. This represents an important source of theoretical and experimental results. However all theses had been mitten in the Czech or Slovak language, and therefore their wide international application is rather limited. They are summari-zed in the following list.     

DISSERTATIONS AND THESES IN DRYING WRITTEN IN CZECHOSLOVAKIA IN THE PERIOD 1975 - 84

Research and development of drying processes and equipmect has a long tradition in Czechoslovakia (1). There are at least 10 top reoearch centers where drying of varicus materials has been studied. Remarkable attention to drying theory and application is also paid at Czechoslovak universities which yields numerous theses dealing with various aspects of the drying process. The total of 52 M.Sc. theses oriented to drying and/or dryers had been published in the last decade. Moreover, 22 Ph.D. theses were carried out in the same period. This represents an important source of theoretical and experimental results. However all theses had been mitten in the Czech or Slovak language, and therefore their wide international application is rather limited. They are summari-zed in the following list.     

RECENT DEVELOPMENT OF GHE SOLAR DRYING IN INDONESIA

Prototypes of greenhouse effect GHE solar dryer have been tested and their technical performances for drying of tropical products have been obtained. Quality of the dried products was comparable to the existing standard used in estate plantation. The latest drying experiment with fermented cocoa beans using mechanical stirrer, and with a stationary rectangular bin for coffee berries, showed that the developed drying system was capable of reducing the total specific energy to 6.2 MJ/kg and 5.2 MJ/kg water evaporated, respectively. Therefore, the results of the study suggest that the current design could now be used in helping the farmers and fishermen to produce better quality products.     

炭材料在生物及医学应用中的研究进展

炭材料在生物和医学方面的实验研究,证实了炭与生物有很好的相容性,在医学方面有一定的实用价值,研究工作上此制造出炭质人造心脏瓣膜,人造牙极,人造骨,活性炭吸附剂等生物和医用材料,为炭材料在生物和医学方面的应用研究开拓了新的领域。     

SLURRY DRYING IN GAS-PARTICLE CONTACTORS: FLUID-DYNAMICS AND CAPACITY ANALYSIS

The fluid-dynamic characteristics and evaporation capacities of several substrates (pure water, a mixture of water and carbohydrates, and apple pulps with maltodextrines) for conical spouted bed, fluidized bed and pneumatic dryers was compared.

For fluidized and spouted beds, the presence of fluids increased the fluid-dynamics parameters over the values when only inert particles were present in the beds. In both cases it was proposed correlations to predict those effects. In the spouted bed drier, increasing the load of inert particles resulted in a slight increase of the water evaporation capacity, while in the fluidized bed drier the effect was more marked. For fluidized and spouted beds, under similar operation conditions, the maximums of the suspension drying capacities are lower than the values of water evaporation, but for pneumatic drying this effect was the opposite. In general terms, the maximal capacities of fluidized bed dryers are higher than those observed in the spouted bed dryers.     

德国煤炭能源化工研究与开发的现状和前景

本文介绍了德国从事煤炭能源化工研究与开发的机构和学术团体，主要研究方向和由政府资助的若干研究课题，有炼焦，燃烧，热解，气化和微生物加工等，并对今后的发展进行了分析。     

喷动床发展与现状

介绍了流化床的一个分支——喷动床的发展与现状。首先简述了喷动床的发展史，然后着重讲解了有关喷动床的几个基本概念，并对喷动床的流动特性及其与传统流化床的异同点作了描述。给出了一些喷动床的床型变化及应用实例，并提供了一份有关喷动床研究的较完整的文献清单     

DRYING OF CARROTS IN A FLUIDIZED BED. I. EFFECTS OF DRYING CONDITIONS AND MODELLING

Drying curves were determined in a mechanically agitated fluidized bed dryer, at temperatures between 70°C and 160°C, air velocities between 1.1 m/s and 2.2 m/s and stirring rates between 30 rpm and 70 rpm for batch drying of 3 kg lots of carrot slices, measuring the moisture content and shrinking of the particles in time. This was complemented by a study of the rate and degree of swelling of dried carrot particles in water between 20 and 75°C. Drying kinetics were modeled by Fick's second law, for which an optimal agreement with the experimental data was obtained when the effective diffusivity (D_e) was determined by a correlation based on the air velocity (v), the air temperature (T) and the dimensional moisture content of the carrot particles (X/X_o). Loss of carotenes is minimized when dehydration is carried out at about 130°C with a drying time below 12 min.     

DRYING OF CARROTS IN A FLUIDIZED BED. I. EFFECTS OF DRYING CONDITIONS AND MODELLING

ABSTRACT

Drying curves were determined in a mechanically agitated fluidized bed dryer, at temperatures between 70°C and 160°C, air velocities between 1.1 m/s and 2.2 m/s and stirring rates between 30 rpm and 70 rpm for batch drying of 3 kg lots of carrot slices, measuring the moisture content and shrinking of the particles in time. This was complemented by a study of the rate and degree of swelling of dried carrot particles in water between 20 and 75°C. Drying kinetics were modeled by Fick's second law, for which an optimal agreement with the experimental data was obtained when the effective diffusivity (D _e ) was determined by a correlation based on the air velocity (v), the air temperature (T) and the dimensional moisture content of the carrot particles (X/X _o ). Loss of carotenes is minimized when dehydration is carried out at about 130°C with a drying time below 12 min.     

DRYING OF BIOMASS PARTICLES IN FIXED AND MOVING BEDS

ABSTRACT

The drying of biomass fuel particles in fixed and moving beds with hot gas or steam is considered both experimentally and theoretically. A single particle drying model is coupled with a model describing beat and moisture transfer in The gas phase of the bed. The size of the bed to reach a certain degree of drying depends mostly on the following parameters: particle size, panicle moisture content, gas inlet temperature, gas inlet moisture content and gas mass flow rate.     

RECENT DEVELOPMENT OF DRYING TEORY AND COMPUTING METHODS IN CZECHOSLOVAKLA

The survey on recent development of the drying technology research in Czechoslovakia is confined to major achievements in drying theory and dryers design in NRIMD Praha. Selected works deal with moisture bond and moisture transport in dried material, modeling of advanced dryers systems like the vibrofluidized bed and impact drying. Methods of the dryer design and computing of drying process parameters used in NRIMD are outlined.     

A NUMERICAL AND EXPERIMENTAL STUDY OF MICROWAVE DRYING USING A RECTANGULAR WAVE GUIDE

The drying of a capillary porous packed bed of glass beads by microwave energy using a rectangular wave-guide was investigated numerically and experimentally. The effects of moisture content, particle size and microwave power level on the drying kinetics were examined. Most importantly, this work focuses on the prediction of the distribution of the electromagnetic field as well as the temperature and moisture distribution within the capillary porous medium. The model, which combines the electromagnetic, temperature, and moisture fields, predicted results which were in good agreement with the experimental data.     

A NUMERICAL AND EXPERIMENTAL STUDY OF MICROWAVE DRYING USING A RECTANGULAR WAVE GUIDE

The drying of a capillary porous packed bed of glass beads by microwave energy using a rectangular wave-guide was investigated numerically and experimentally. The effects of moisture content, particle size and microwave power level on the drying kinetics were examined. Most importantly, this work focuses on the prediction of the distribution of the electromagnetic field as well as the temperature and moisture distribution within the capillary porous medium. The model, which combines the electromagnetic, temperature, and moisture fields, predicted results which were in good agreement with the experimental data.     

THE DRYING OF SOYBEAN SEEDS IN COUNTERCURRENT AND CONCURRENT MOVING BED DRYERS

ABSTRACT

The aim of this work was to analyze the simultaneous heat and mass transfer between air and soybean seeds in countercurrent and concurrent moving bed dryers by simulation. The technique chosen was based on modeling from mass and energy conservation equations for the fluid and particulate phases. The equilibrium, heat transfer and mass transfer equations were taken from specific studies. The equation representing drying kinetics was obtained by means of a thin-layer study, whereas the equilibrium equations was chosen from rival model discrimination, based on nonlinearity measures. Hence, the model parameters were defined by the respectives studies. The profiles for temperature and humidity of the fluid and the temperature and moisture of the seeds were obtained by numerical solution of the model. This model consisted of ordinary differential equations and the solution was obtained by a specific code. The simulated results indicated a significant.     

抗静电剂及其开发研究进展

就静电的产生与防止理论以及抗静电剂的分类与特征进行了论述,并对国内外抗静电剂的市场概况及品种进展与研究开发方向进行了较详细的介绍,针对我国抗静电剂的研究开发、生产提出了几点建议。     

丁羟胶的研究及开发概况

详细地介绍了端羟基聚丁二烯（丁羟胶）的国内外合成及开发概况，侧重叙述了丁羟胶的多种阴离子合成方法。     

R—SMA共混合金的研究进展

无规苯乙烯-马来酸酐共聚树脂(R-SMA)可作为塑料合金中提高耐热性、易加工性等性能的树脂组分,其本身又是塑料合金的相容剂,且具有成本低的优势。本文较详细地介绍了R-SMA与PVC、ABS、聚碳酸酯(PC)、聚酰胺(PA)、聚对苯二甲酸丁二醇酯(PBT)等通用及工程树脂的塑料合金的技术进展。