摘要:

Analytical solutions are developed for temperature and moisture distributions in a capillary-porous medium by using Luikov's model and applying a solution methodology based on the decoupling of simultaneous heat and mass diffusion problems. A parametric survey is made to illustrate the relative importance of various dimensionless parameters affecting drying.

ISSN:0737-3937    

DOI:10.1080/07373938808916400

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

In this paper we have examined the influence of gravity on the moisture transport process during the isenthalpic drying period, and we have considered the use of diffusion models both to predict saturation pro- files and to extract apparent diffusivities from experi- mental data. For granular or unconsolidated porous media, the one-dimensional moisture transport process can be characterized by two dimensionless groups that account for capillary forces, gravitational forces and viscous forces. Detailed numerical solutions of the saturation transport equation indicate under what circumstances the diffusion model can be used with confidence, and under what circumstances the diffusion model can be used to predict saturation profiles even though it is an incorrect representation of the moisture transport process. In addition to exploring the predictive capabilities of the diffusion model, we have

ISSN:0737-3937    

DOI:10.1080/07373938808916401

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

In designing cascading rotary dryers, it is important to size the flights correctly in order to ensure that they can adequately accommodate the contents of the drum. A set of equations has been derived to calculate the solids holdup on angular and extended-circular flights in such dryers. Three examples of the practical use of these equations are presented. These include estimation of the design holdup of the dryer, selection of the number of flights, and exploration of the flight cascade characteristics.

ISSN:0737-3937    

DOI:10.1080/07373938808916402

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The main objective of the experiment in thispaper is to investigate the influence of the ratio of the thickness of the plate and that of the film, and initial condi- tions on the conductive drying characteristics of thin films of gelatinized rice starch on a hot plate under constant heat and mass transfer to the surroundings. The plate was. supported on one arm of a sensitive balance which measured and recorded the weight loss due to drying. Tbennocouples situated at the upper and lower surfaces of the plate recorded the respective temperatures. The gelatinized starch was prepared by cooking a slurry of rice starchin a heated and agitated vessel at slightly above the gelatinization temperatureof the starch 70C. The film was applied after the plate was heated to its initial temperature which ranged from 70C to 119C. The weight 10s and the temperature of the upper and lower surfaces of the plate were recorded. The m3isture content of the dried sample was determined by measuring the weight loss after heating it in an oven at 90C for 24 hours.The dimensionless average moisture content was fitted to the drying rate eauation of the form The dimensionless temperature of tbe filmplate interface data was fitted to the following equation It was found that the critlcal moisture content Xc increases when both the intial temperature level and the ratio of the thickness of the plate to that of the film are raised. The dimensionless avenge moisture content profiles against dimensionless time and the dimensionless drying rate ploti against the dimensionless moisture content are not affected at all by this ratio. There was an initial cooling period fol lowed by a continuous rue in temperature. The dimensionless temperature is independent of the ratio of the thickness of rbe plate to that of the film. The dimen

ISSN:0737-3937    

DOI:10.1080/07373938808916403

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

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.

ISSN:0737-3937    

DOI:10.1080/07373938808916404

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A convection wen drying technique was used to develop a modified method for moisture content determination in corn and soybeans. Samples of corn and soybeans in the moisture ranges of 10–27% w.b. and 9–23% w.b.. respectively. were exposed to different temperatures for varying periods of time in a forced air convection wen. A correlation was developed beheen the reference moisture content of the samples of corn and soybeans and the moisrure content after a drying time of one hour. The predicted results were in close agreement with the standard air oven test results in the range of moisture contents studied.

ISSN:0737-3937    

DOI:10.1080/07373938808916405

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938808916406

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938808916407

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938808916408

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938808916409

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor