摘要:

A new approach is developed for mass transfer by making use of the statistical model of a porous body based on the methods of the kinetic theory of gases. The collision integral in the one-dimensional kinetic equation is replaced by the effective “external” force, which is the result of the collective interaction of gas molecules with the motionless particles. Evaporation from a recessed boundary and gas filtration in a porous layer are considered. Simple expressions are obtained for the permeability coefficient and pressure jump (output resistance) at the gas-porous medium boundary as a function of the Kn number. Theoretical and experimental results are compared.

ISSN:0737-3937    

DOI:10.1080/07373938708916535

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The sorption and desorption characteristics of raw, parboiled and other heat treated stabi1ized rice bran were studied in the relative humidity range of 20.0 to 75.8 per cent at the storage temperatures of 25°, 30° and 40°C. Results indicate that the equilibrium moisture contents (emc) of both raw and various heat treated rice bran increased with the increase of relative humidity and decrease of storage temperature. The emc is the highest for the raw bran and the lowest for the wet heat treated bran at any temperature and relative humidity. In general the rate of either sorption or desorption of raw and heat treated rice bran increases as storage temperature increases at a constant relative hmidity.

ISSN:0737-3937    

DOI:10.1080/07373938708916536

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

High intensity drying occurs when one web surface is heated to the thermodynamic saturation temperature corresponding to the local hydraulic pressure. Rapid vapor generation causes the process to be driven by a total pressure gradient, so vapor leaves the web by a bulk flow mechanism rather than a slower diffusion mechanism. Vapor pressure build-up promotes rapid web heating and offers the opportunity for liquid removal by displacement. Lower energy usage can result if only a part of the moisture is evaporated.

ISSN:0737-3937    

DOI:10.1080/07373938708916537

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The influence of air flow rate on the kinetics of drying 10x10x10 mm carrot cubes is presented. For this geometry kinetic equations are available, for the first falling rate drying period.

ISSN:0737-3937    

DOI:10.1080/07373938708916538

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The residence times of solids flowing through a fluidized bed dryer exhibit dispersion about the mean. In this paper, expressions for the probability density functions of solids moisture content in the various stages of a multi-stage dryer are derived. A simple recurrence relationship for the moments of the distribution is also presented. The analysis is applied to the drying of cereal grains, and it is shown that the degree of drying increases with the number of stages in the dryer. Probability density functions of the moisture content are presented.

ISSN:0737-3937    

DOI:10.1080/07373938708916539

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In the analysis and solutions of heat and mass diffusion problems governed by the Luikov system of linear partial differential equations subject to linear type boundary conditions, the existence of complex roots has been overlooked in almost all of the solutions available in the literature. A methodology is presented for establishing the existence of complex roots in such systems. The effects of complex roots on the results on temperature and moisture distributions are illustrated with a specific example on contact drying of a sheet of moist porous material on a hot plate.

ISSN:0737-3937    

DOI:10.1080/07373938708916540

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938708916541

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938708916542

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938708916543

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938708916544

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor