摘要:

A previously developed computer program for depicting the heat and mass transfer behavior of heat pipe conduits, slightly open to a large ambient at their far ends, inside moist paper webs is developed further. The addition consists of accounting for the thermal dynamics of a hot metal slab from which the latent heat of evaporation corresponding to vapor generation in the hot end of the heat pipe is drawn. Values are used for the input parameters representing as closely as possible an approximately 40 % dry (by total weight) printing paper sheet being suddenly pressed against a hot steel or iron slab at l50°C or 200°C. These are conditions that could occur in Condebelt drying. Temperature distributions in the metal and inside the web, as well as the pressure distribution inside the web, are determined as functions of the distance from the hot surface and time. Important parameters are the initial metal and web temperatures, the interface Biot number, the structural geometry of the web, and the metal Fourier number. It is shown that there is a S to 25°C metal surface temperature drop in the first 100 μs after contact with the web. This can be significant in reducing possible web surface damage.

ISSN:0737-3937    

DOI:10.1080/07373939208916494

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Superheated steam drying of sintered spheres of glass beads with different diameters is investigated to reveal the effects of the gravitational force on drying rates. In a previous study, the drying rate curves of small samples with coarse glass beads in which the frictional resistance to flow of water and the effect of the gravitational force are negligible, were predicted by an evaporation zone model.In the present investigation, the drying rate curves of sintered spheres of glass beads with diameters ranging from 1.53×10-2m to 4.99×lO-2m are experimentally and theoretically obtained, and also the capillary pressure curves are measured by use of Haines' apparatus. The drying rate curves of large samples in which the effect of the gravitational force can not be negligible, are compared with those for small samples and the difference among these curves is discussed in terms of the moisture distributions which are estimated from the evaporation zone model with the observed capillary pressure curves.

ISSN:0737-3937    

DOI:10.1080/07373939208916495

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373939208916496

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The purpose of this investigation is to compare various drying models with respect to (a) the accuracy in calculating the material moisture content and temperature versus time and (b) the computation time required.

ISSN:0737-3937    

DOI:10.1080/07373939208916497

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373939208916498

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373939208916499

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373939208916500

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373939208916501

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373939208916502

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373939208916503

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor