 Open Access
 Total Downloads : 1036
 Authors : Shweta Goyal, Swati Gargust, Mandeep Guleria
 Paper ID : IJERTV2IS2246
 Volume & Issue : Volume 02, Issue 02 (February 2013)
 Published (First Online): 28022013
 ISSN (Online) : 22780181
 Publisher Name : IJERT
 License: This work is licensed under a Creative Commons Attribution 4.0 International License
Simplified Approach for Paper Drying Modeling Using Matlab
International Journal of Engineering Research & Technology (IJERT)
ISSN: 22780181
Vol. 2 Issue 2, February 2013
Shweta Goyal, Swati Gargust, Mandeep Guleria
MTech in Instrumentation & Control GRAPHIC ERA UNIVERSITY DEHRADUN
Index TermsIntroduction, Factors affection drying process, what is Matlab, Model Equation, Matlab Models,results
Abstract
In this proposed work model for the paper drying process has been designed in Matlab Simulation toolbox developed, for modeling ,the drying section divides into component such as PAPER,CANVAS,AND CYLINDERS. The
dynamic model of these component are represented as lumped parameter system and connected to each other to model the entire paper drying process. Matlab simulation helps in developing model for paper dryer. simulation studies are carried out to study the effect of grade change and other process variables on the final moisture of the paper. the novel approach of modeling the paper dryer as lumped parameter system reduced he numerical complexity of the model
Introduction
Paper is used for printing and writing, for wrapping and packaging and for a variety of other application ranging from kitchen towel to the manufacture of building material , it simply comes in an enormous variety of quantities. Some common types of paper qualities include the following:

Copy paper for printer

Newsprint

Cardboard

Lightweight coated paper for magazines

Wrapping and packaging paper

Currency paper
The function of a paper machine is to form the paper
sheet and remove the water from the sheet. A paper machine is divided into three main parts, the wire section, the press section and the drying section shown in fig 1.1, when a stock enters the head box in the wire section it contains roughly 1% of fiber or less. The viscous mix is dispensed through a long slice onto the wire. As it travels on the wire, mu of the water drains way by gravitational forces or is pulled away by suction from underneath. As a water disappears, the cellulose fiber starts to adhere to one another by hydrogen bonds and form a paper web. when the paper web leaves the wire section and enters the press section ,the dry solids content around 20%. In the press section, the newly formed
sheet is pressed between rotating steel rolls and water is displaced into a press felt. After a few press nips the web enters the drying section with a solid content of approximately about 50%. It now encounters the dryer cylinders. These are large hollow metal cylinders, heated internally with steam, which dry the paper as it passes them, Finally the paper wound up on a big roll and removed from the paper machine .the moisture content is now roughly 510%.
Figure :basic principle of paper machine
Introduction of Drying section:
Paper dryer is an important equipment in paper making process. The dryer section is the last part of the paper machine which consist of series of steam drums. The most common way to evaporate water from the paper web is to use the latent heat of vaporization in steam. A steamfilled dryer is a cost effective method to transfer heat into the sheet. The moist paper web is rolled on these steam fed drums. Where the steam is used to evaporate the moisture from the web. The heat to the paper web is controlled by the steam pressure in the drum. The drying section consumes 70% of the total steam used in the paper mill. During grade transition, the drying section consumes energy without producing desired quality of paper.
1.4) FACTORS AFFECTING ON THE MOISTURE IN THE PAPER :
There are large number of variables that determine the moisture in the paper sheet,shown in fig1.4. To indicate the complexity of the problem some of them are listed below.

Production speed Affects the amount of steam needed, since high production also involves higher vaporization.

Dry weight A thick sheet is more difficult to dry than a thin sheet at the same production speed.

Inlet moisture The moisture content of the sheet after the press section is a
disturbance variable that normally is unknown.

Degree of Refining The parameter naturally affects both the freeness and the ability to dry the sheet

Air dew point A high dew point inhibits effective evaporation.

Dryer Fabric Condition An old fabric can be clogged and give a higher evaporation resistance.

Bulk High bulk means that the water inside the web has a longer transport distance to the surface and ambient air.

Web Tension High web tension increases the heat transfer coefficient and the drying rate.

Leakage air The air from the machine room is cooler that the preheated supply air and therefore impair the drying condition

Ply loading In paperboard, different layers consist of different pulps, hence different physical properties. This influences the drying
FIGURE 1.4 factors affecting on the moisture in the paper during drying process
The name MATLAB stands for Matrix Laboratory. MATLAB was written originally to provide easy access to matrix software developed by the LINPACK (linear system package) and EISPACK (Eigen system package) projects. MATLAB is a highperformance language for technical computing. It integrates computation, visualization, and programming environment. Furthermore, MATLAB is a modern programming language environment: it has sophisticated data structures, contains builtin editing and debugging tools, and supports objectoriented programming. These factors make MATLAB an excellent tool for teaching and research.MATLAB has many advantages compared to conventional computer languages (e.g., C, FORTRAN) for solving
technical problems. MATLAB is an interactive system whose basic data element is an array that does not require dimensioning. The software package has been commercially available since 1984 and is now considered as a standard tool at most universities and industries worldwide. It has powerful builtin routines that enable a very wide variety of computations. It also has easy to use graphics commands that make the visualization of results immediately available. Specific applications are collected in packages referred to as toolbox. There are toolboxes for signal processing, symbolic computation, control theory, simulation, optimization, and several other fields of applied science and engineering.
Introduction of Matlab
Introduction to MATLAB for Engineering Students" is a document for an introductory course in MATLAB RÂ°1 and technical computing. It is used for freshmen classes at Northwestern University. This document is not a comprehensive introduction or a reference manual. Instead, it focuses on the specific features of MATLAB that are useful for engineering classes. The lab sessions are used with one main goal: to allow students to become familiar with computer software (e.g., MATLAB) to solve application problems. We assume that the students have no prior experience with MATLAB.The availability of technical computing environment such as MATLAB is now reshaping the role and applications of computer laboratory projects to involve students in more intense problemsolving experience. This availability also provides an opportunity to easily conduct numerical experiments and to tackle realistic and more complicated problems.
Modelling Of Steam dryer
Inlet paper web is to be dried to a desired moisture content using steam heated drums. To support and transport the paper web, it is covered with canvas or paper fabric. The canvas is also used to provide good thermal contact between the web and the cylinder. the drying section is enclosed within a drying hood to provide controlled ambient condition. The exhaust air from the hood removes
the evaporated water and preheated air is fed to the
Wth = RSLWth( w w) WA (7)
hood to maintain controlled environment for paper i o
drying process. This results in better heat
utilization and less variation in the paper quality. The basic configuration of a dryer shown in fig.
FIGURE:input output stream of dryer
MODEL EQUATION The mathematical modeling of a dryer is based on mass/energy balance equation. In this case the assumptions are outer surface area and inner surface area of the dryer.
Outer surface area of cylinder is DA=rL (1)
Corresponding outer surface area of web and
similarly mass balance for moisture Wth
w wat w wat
w wat w wat
RSLWth(i MTin o MTo ) WA (8)
Heat energy balance on web –
W
W
SHo Wth=
W w w w w W
W w w w w W
WHDDA(DTTOW)WCHWA(TOWTOC)+RSLWth
(SHi i Ti o To SHO ) WAevH (9) heat balance on the cylinder
DthDSHD =
SaSDh (DTTOW)r(2)LDAh(DTdT) (10)
heat balance on canvas
C SH =W WC (T WT C)
canvas over cylinder th C C A
h O O
wA=(r+wth)L (2)
cA= (r+ wth +cth)L (3) Inner surface area of cylinder
Sa=(rDth)L (4)
The density of the web depends on its moisture content
w w w
w w w
i =265(1MTi )+1000 MTi (5)
MASS balance on the web is
= min mout WA (6) where
w
w
i o
i o
min= RSLDth w , M= w, mout=RSL Dtho
CACAh(TOCDT)+WRSCthLSHC(T CTOC) (11)
i
i
Amount of steam required is given by total heat demand divided by the latent heat of condensation of steam
Relation between steam pressure and steam temperature
ST=100((P+SP)/105)0.25 (12)
Specific heat capacity of the web=
w) w
w) w
SHOW= (0.321.366asr+MTo / 1+MTo (13)
The evaporation rate,
=[WAh(Shuhu)]/SHA+ ShuSHv (14) where air humidity is
Shu = ,
Substituting these values in mass balance equation
the exhaust air moisture given by soinien and karlosson
hu
22
Constant
22.04
Constant2
Add
2
Constant6
Divide1
560
Constant5 100
Constant7
Product1
Add1
Product
158
158
Constant1
Divide
1
m 5307
m1
2
Out1
(15)
From antoine equation the vapour partial pressures Pa AND Ps are
ap=105(105.11564)
SP= )
The heat of evaporation, Hev is the sum of the latent heat of vaporization and heat of sorption
evH= Vaph+Sh (16) where
2.74
2.72
2.7
2.68
heat amount
heat amount
2.66
2.64
2.62
2.6
2.58
2.56
32
Constant4
amount of heat required
Scope
Vaph = 505.3747(1RT)
reduced temprature
0.354
+269.658(1RT)
0.456
2.54
0 1 2 3 4 5 6 7 8 9 10
time
o
o
RT =T W/373.95
Sh=0.10085R()MTW1.0585WET2
Relative humidity of air
FIGUREAMOUNT OF STEAM REQUIRED(ms)
Fig; represents the simulation model and simulated result for relation between steam pressure and steam temperature
1 In1
70
Constant Add
(17)
u
uv
1.27e+005
1.27e+005
Divide
Heat transfer coefficient between air and web
5
Constant1
10
Math Function
0.25
Constant2
Math Function1
100
Product
TS1 1
Out1
wa k B R nexp(k B NnMT W)+k B R nexp(k B
Constant3
WRS OW
WRS OW
h= 1 W S

W O

W S 4
nMT ) (18)
Heat transfer coefficient between drum and web
Scope
DW =c exp(c MT w)+c exp(c M w) (19)
1.295
5
x 10
relatin between steam pressure and temprature
h 1 2 o 3 4 o
Fig :represent the simulation model and simulated graph for a steam required ms depends upon heat demand latent heat of condensation of steam
1.29
steam temprature
steam temprature
1.285
1.28
1.275
1.27
0 1 2 3 4 5 6 7 8 9 10
steam pressure
5
x 10
1.295
The evaporation rate,
FIGRELATION BETWEEN STEAM PRESSURE AND TEMP. TS
Fig:represents the simulation model and simulated result for the specific heat capacity
1.29
EVAPORATION RATE
EVAPORATION RATE
1.285
1.28
1.275
1.27
0 1 2 3 4 5 6 7 8 9 10
specific heat
FIG: EVAPORATION RATE()
0.32
Constant
1.366
Constant1
2.33
Constant2
1.1
Constant3
1
Constant4
Product
Add
Add1
Divide
Scope
1
cpwo
0.8394
0.8394
cpwo1
Conclusion
This paper presents modeling and simulation of a paper drying machine. A SIMULINK model of the drying machine is developed considering the effcts of moisture,pressure and temperature. Modification of paper machine SIMULINK model is done to obtain the model of a drying process. The theoretically obtained characteristics of the paper drying experimentally verified for different ambient conditions.
1.295
1.29
specific heat output
specific heat output
1.285
1.28
1.275
5
x 10
Specific heat capacity of the web
Different drying system parameters were studied and it was concluded as a Matlab model. SIMULINK model was developed for a paper drying process. The performance of the system for different temperatures is analyzed. It was observed that a good matching can be achieved
Refrences
1.27
0 1 2 3 4 5 6 7 8 9 10
web moisture output
FIGURE SPECIFIC HEAT CAPACITY SHOW
fig represents the simulated model and simulation result for evaporation rate which depends air humidity with respect to time

Senthilmurugan, tarun Mthur,
Simplified Approach for Paper dryer Modeling TAPPI PaperCon09 Conference, May 31 June 3, 2009 St. Louis,
2
In2
200
Constant1
320
Product
1 In1
6600
Constant
Add
Add1
Divide
Product1
1
lamda
lamda1
MO
2.714
2.714

Johan Ã…kesson,Jenny Ekvall, parameter optimization of a paper machine model Department of Automatic Control Lund University BOX 118, 22100 Lund Network for Process Intelligence Mid Sweden University 89118 Ã–rnskÃ¶ldsvik
Constant2
Scope

Akadmijas laukums, A mathematical model of paper dryingJ. Cepitis Institute of Mathematics, Latvian Academy of Sciences and
University of Latvia, , Riga, LV1524,Version of record first published: 14 Oct 2010.

Johan Â°Akesson,Ola SlÂ¨atteke, Modeling, Calibration and Control of a Paper Machine Dryer Section Department of Automatic Control, Faculty of Engineering, Lund University, Sweden ABB Ltd.,
