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Experimental and computational evaluation of mass transfer resistance of paper dryer fabrics

Wilhelmsson, B. and Stenström, Stig LU (1995) In Nordic Pulp & Paper Research Journal 10(3). p.174-182
Abstract
The mass transfer aspects of synthetic dryer fabrics used in multi-cylinder paper dryers were investigated both experimentally and computationally. Experiments were performed in a convective dryer to determine which characteristics of the fabric are instrumental in controlling the drying rate. Results obtained from twelve different fabrics showed that neither the permeability nor the porosity of the fabrics can be used alone to quantify the reduction in mass transfer (evaporation) from a completely moist surface. It was indicated that the microscopic structure of the fabric plays a major role. The fabrics reduced the mass transfer coefficient from the wet surface by about 30-50 %. The reduction is quantified by a new parameter called the... (More)
The mass transfer aspects of synthetic dryer fabrics used in multi-cylinder paper dryers were investigated both experimentally and computationally. Experiments were performed in a convective dryer to determine which characteristics of the fabric are instrumental in controlling the drying rate. Results obtained from twelve different fabrics showed that neither the permeability nor the porosity of the fabrics can be used alone to quantify the reduction in mass transfer (evaporation) from a completely moist surface. It was indicated that the microscopic structure of the fabric plays a major role. The fabrics reduced the mass transfer coefficient from the wet surface by about 30-50 %. The reduction is quantified by a new parameter called the Fabric Reduction Factor or FRF. Calculations indicated the reduction in the corresponding heat transfer coefficient to be practically negligible. Computer simulations of the multi-cylinder dryer section were also performed. In the simulations the geometry of the paper machine was varied. The results showed that, regardless of the geometry, the value of the FRF had only a slight influence on the total evaporation occurring in the dryer section. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nordic Pulp & Paper Research Journal
volume
10
issue
3
pages
174 - 182
publisher
Arbor Publishing AB
ISSN
0283-2631
DOI
10.3183/NPPRJ-1995-10-03-p174-182
language
English
LU publication?
yes
id
12322bcb-66be-4d66-9b57-90a1a47193bc (old id 3918293)
date added to LUP
2013-07-08 09:45:06
date last changed
2016-04-16 03:20:25
@article{12322bcb-66be-4d66-9b57-90a1a47193bc,
  abstract     = {The mass transfer aspects of synthetic dryer fabrics used in multi-cylinder paper dryers were investigated both experimentally and computationally. Experiments were performed in a convective dryer to determine which characteristics of the fabric are instrumental in controlling the drying rate. Results obtained from twelve different fabrics showed that neither the permeability nor the porosity of the fabrics can be used alone to quantify the reduction in mass transfer (evaporation) from a completely moist surface. It was indicated that the microscopic structure of the fabric plays a major role. The fabrics reduced the mass transfer coefficient from the wet surface by about 30-50 %. The reduction is quantified by a new parameter called the Fabric Reduction Factor or FRF. Calculations indicated the reduction in the corresponding heat transfer coefficient to be practically negligible. Computer simulations of the multi-cylinder dryer section were also performed. In the simulations the geometry of the paper machine was varied. The results showed that, regardless of the geometry, the value of the FRF had only a slight influence on the total evaporation occurring in the dryer section.},
  author       = {Wilhelmsson, B. and Stenström, Stig},
  issn         = {0283-2631},
  language     = {eng},
  number       = {3},
  pages        = {174--182},
  publisher    = {Arbor Publishing AB},
  series       = {Nordic Pulp & Paper Research Journal},
  title        = {Experimental and computational evaluation of mass transfer resistance of paper dryer fabrics},
  url          = {http://dx.doi.org/10.3183/NPPRJ-1995-10-03-p174-182},
  volume       = {10},
  year         = {1995},
}