You need JavaScript to view this

An experimental and theoretical study of multi-cylinder paper drying

Thesis/Dissertation:

Abstract

A mathematical model was developed for the drying of paper in a multi-cylinder drying section. The model is based on the unsteady state, one-dimensional heat conduction equation, which is applied to both the cylinder shell and the paper web. No internal mass transfer phenomena were modelled explicitly. A lumped parameter, the effective thermal conductivity of the paper, implicitly takes these phenomena at least partially into account. Great emphasis was placed on finding the proper heat and mass transfer coefficients that are a part of the boundary conditions of the unsteady state heat conduction equation. Three of these boundary conditions were investigated in detail: * contact heat transfer at the cylinder-paper interface was studied experimentally, * mass transfer at the paper-fabric-air interfaces was also investigated experimentally, and * laminar condensate flow inside the cylinders was studied using a computational fluid dynamics program. Based on the mathematical model, a simulation program was developed. The data predicted by the program compared favorably with measured data from nine different industrial paper dryers. The model applied just as well as lighter paper grades such as newsprint as to heavier grades such as paper board. Two parameters were used to tune the output of the program  More>>
Authors:
Publication Date:
Jan 01, 1995
Product Type:
Thesis/Dissertation
Report Number:
LUTKDH-TKKA-1001-1-164
Reference Number:
SCA: 320303; PA: SWD-95:007025; EDB-95:028994; SN: 95001320512
Resource Relation:
Other Information: TH: Doctoral thesis (TeknD); PBD: Jan 1995
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; PAPER; DRYING; DRYERS; MATHEMATICAL MODELS; COMPUTERIZED SIMULATION; PARAMETRIC ANALYSIS; HEAT TRANSFER; MASS TRANSFER; EXPERIMENTAL DATA; 320303; EQUIPMENT AND PROCESSES
OSTI ID:
10114489
Research Organizations:
Lund Univ. (Sweden). Dept. of Chemical Engineering
Country of Origin:
Sweden
Language:
English
Other Identifying Numbers:
Journal ID: ISSN 1100-2778; Other: ON: DE95737670; TRN: SE9507025
Availability:
OSTI; NTIS
Submitting Site:
SWD
Size:
171 p.
Announcement Date:
Jun 30, 2005

Thesis/Dissertation:

Citation Formats

Wilhelmsson, B. An experimental and theoretical study of multi-cylinder paper drying. Sweden: N. p., 1995. Web.
Wilhelmsson, B. An experimental and theoretical study of multi-cylinder paper drying. Sweden.
Wilhelmsson, B. 1995. "An experimental and theoretical study of multi-cylinder paper drying." Sweden.
@misc{etde_10114489,
title = {An experimental and theoretical study of multi-cylinder paper drying}
author = {Wilhelmsson, B}
abstractNote = {A mathematical model was developed for the drying of paper in a multi-cylinder drying section. The model is based on the unsteady state, one-dimensional heat conduction equation, which is applied to both the cylinder shell and the paper web. No internal mass transfer phenomena were modelled explicitly. A lumped parameter, the effective thermal conductivity of the paper, implicitly takes these phenomena at least partially into account. Great emphasis was placed on finding the proper heat and mass transfer coefficients that are a part of the boundary conditions of the unsteady state heat conduction equation. Three of these boundary conditions were investigated in detail: * contact heat transfer at the cylinder-paper interface was studied experimentally, * mass transfer at the paper-fabric-air interfaces was also investigated experimentally, and * laminar condensate flow inside the cylinders was studied using a computational fluid dynamics program. Based on the mathematical model, a simulation program was developed. The data predicted by the program compared favorably with measured data from nine different industrial paper dryers. The model applied just as well as lighter paper grades such as newsprint as to heavier grades such as paper board. Two parameters were used to tune the output of the program to the values measured. Both parameters were assigned physically reasonable values confined to a rather narrow range. Studies of the effect of certain input data of the program were also performed. These indicated, for example, that the condensate coefficient and the contact coefficient were the most influential of the heat transfer coefficients, but that the mass transfer coefficient of the dryer fabric was of only slight influence. The potential for simulating different operating conditions was illustrated by several examples. 113 refs}
place = {Sweden}
year = {1995}
month = {Jan}
}