Drying kinetics of brick in a convective hot air dryer
In this study, drying characteristics of brick have been investigated experimentally. Evaluating experimental results under these circumstances diffusion coefficients and drying diagrams were determined. Экспериментально исследованы характеристики сушки кирпича. По этим данным были вычислены коэффиц...
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2005
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| Zitieren: | Drying kinetics of brick in a convective hot air dryer / Ahmet Cihan, Dinser Akal, Kamil Kahveci // Промышленная теплотехника. — 2005. — Т. 27, № 6. — С. 47-50. — Бібліогр.: 4 назв. — англ. |
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Ahmet Cihan Dinser Akal Kamil Kahveci 2014-05-06T15:30:18Z 2014-05-06T15:30:18Z 2005 Drying kinetics of brick in a convective hot air dryer / Ahmet Cihan, Dinser Akal, Kamil Kahveci // Промышленная теплотехника. — 2005. — Т. 27, № 6. — С. 47-50. — Бібліогр.: 4 назв. — англ. 0204-3602 https://nasplib.isofts.kiev.ua/handle/123456789/61497 66.011 In this study, drying characteristics of brick have been investigated experimentally. Evaluating experimental results under these circumstances diffusion coefficients and drying diagrams were determined. Экспериментально исследованы характеристики сушки кирпича. По этим данным были вычислены коэффициенты диффузии и построены диаграммы сушки. Експериментально досліджено характеристики сушіння цегли. За цими даними було обчислено коефіцієнти дифузії та побудовано діаграми сушіння. en Інститут технічної теплофізики НАН України Промышленная теплотехника Теория и практика сушки Drying kinetics of brick in a convective hot air dryer Кинетика сушки кирпича в конвективной сушилке горячим воздухом Article published earlier |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine |
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DSpace DC |
| title |
Drying kinetics of brick in a convective hot air dryer |
| spellingShingle |
Drying kinetics of brick in a convective hot air dryer Ahmet Cihan Dinser Akal Kamil Kahveci Теория и практика сушки |
| title_short |
Drying kinetics of brick in a convective hot air dryer |
| title_full |
Drying kinetics of brick in a convective hot air dryer |
| title_fullStr |
Drying kinetics of brick in a convective hot air dryer |
| title_full_unstemmed |
Drying kinetics of brick in a convective hot air dryer |
| title_sort |
drying kinetics of brick in a convective hot air dryer |
| author |
Ahmet Cihan Dinser Akal Kamil Kahveci |
| author_facet |
Ahmet Cihan Dinser Akal Kamil Kahveci |
| topic |
Теория и практика сушки |
| topic_facet |
Теория и практика сушки |
| publishDate |
2005 |
| language |
English |
| container_title |
Промышленная теплотехника |
| publisher |
Інститут технічної теплофізики НАН України |
| format |
Article |
| title_alt |
Кинетика сушки кирпича в конвективной сушилке горячим воздухом |
| description |
In this study, drying characteristics of brick have been investigated experimentally. Evaluating experimental results under these circumstances diffusion coefficients and drying diagrams were determined.
Экспериментально исследованы характеристики сушки кирпича. По этим данным были вычислены коэффициенты диффузии и построены диаграммы сушки.
Експериментально досліджено характеристики сушіння цегли. За цими даними було обчислено коефіцієнти дифузії та побудовано діаграми сушіння.
|
| issn |
0204-3602 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/61497 |
| citation_txt |
Drying kinetics of brick in a convective hot air dryer / Ahmet Cihan, Dinser Akal, Kamil Kahveci // Промышленная теплотехника. — 2005. — Т. 27, № 6. — С. 47-50. — Бібліогр.: 4 назв. — англ. |
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AT ahmetcihan dryingkineticsofbrickinaconvectivehotairdryer AT dinserakal dryingkineticsofbrickinaconvectivehotairdryer AT kamilkahveci dryingkineticsofbrickinaconvectivehotairdryer AT ahmetcihan kinetikasuškikirpičavkonvektivnoisušilkegorâčimvozduhom AT dinserakal kinetikasuškikirpičavkonvektivnoisušilkegorâčimvozduhom AT kamilkahveci kinetikasuškikirpičavkonvektivnoisušilkegorâčimvozduhom |
| first_indexed |
2025-11-26T01:47:59Z |
| last_indexed |
2025-11-26T01:47:59Z |
| _version_ |
1850606981035851776 |
| fulltext |
ISSN 0204�3602. Пром. теплотехника, 2005, т. 27, № 6 47
ТЕОРИЯ И ПРАКТИКА СУШКИ
Introduction
Brick is supposed to be base item of the construction
sector in developing countries. Brick production is one
of the highly energy consumed production method and
85;90% of used energy during its production is con;
sumed for its baking and drying processes. Usage of
appropriate drying method in the brick production
highly affects cost, brick durability and production
time. The performance of the drying process depends
on many parameters such as condition of the drying air,
dimensions of the kiln, speed of the drying line and
number of the bricks to be dried. Generally, tunnel type
of kilns is used for brick drying. This type of kiln works
according to principles of the cross flow heat exchang;
er and temperature of the each zone of the kiln is meas;
ured and controlled. Bricks are get moved to opposite
direction of the air flow. Brick pass is controlled through
the regions of the kiln with definite temperature in
defined period. The advantage of this system over the
others occurs due to controlled drying systems. The
kiln was continuously checked by measuring and con;
trolling the temperature, flow rate, humidity and pres;
sure then required modifications were done if necessary.
There are some studies concerning investigation and
improvement of brick drying in the literature.
Prasersan [1] observed experimentally that time and
energy are saved when smaller and low loaded capaci;
ty kilns with high temperature are used. Suresh et al. [2]
used turbulent air in their experiment and concluded
that drying process realizes in short time and with low
cost when turbulent air flow is used. Palekar et al. [3]
pointed out that bricks are dried fast in vertical kilns.
In this study, drying behavior of the brick which is
dried in the tunnel type kiln was investigated experi;
mentally. Effects of drying conditions on the behav;
ior of the drying of the brick were determined. In
addition, effective diffusion coefficient of the brick in
experimental conditions was calculated.
Materials and Methods
Schematic view of the tunnel type of the kiln used
in this study is shown in Figure 1. Experimental
measurements were taken in the kilns of the Kale
Brick Factory in Turkey. Inlet temperature of the dry;
ing air was 154oC. Drying air is obtained by mixture of
fresh air and air coming from bakery kiln. This mixed
air is flown into kiln by a fan from the side of the kiln
in which bricks being dried exit. The reason of the
opposite movement of the brick and air is to prevent
high temperature difference. Thus, crack formation
Експериментально досліджено ха+
рактеристики сушіння цегли. За цими
даними було обчислено коефіцієнти ди+
фузії та побудовано діаграми сушіння.
Экспериментально исследованы ха+
рактеристики сушки кирпича. По этим
данным были вычислены коэффициен+
ты диффузии и построены диаграммы
сушки.
In this study, drying characteristics of
brick have been investigated experimen+
tally. Evaluating experimental results under
these circumstances diffusion coefficients
and drying diagrams were determined.
УДК 66.011
AHMET CIHAN, DIN ER AKAL, KAMIL KAHVECI
Mechanical Engineering Department, Trakya University, Turkey
DRYING KINETICS OF BRICK IN A CONVECTIVE
HOT AIR DRYER
D – diffusion coefficient;
L – length;
m – mass;
T – temperature;
t – time;
x – moisture ratio;
ρ –density.
Subscripts
b – brick;
d – dryw;
w – moisture;
0 – initial.
48 ISSN 0204�3602. Пром. теплотехника, 2005, т. 27, № 6
ТЕОРИЯ И ПРАКТИКА СУШКИ
and brittle behavior of the brick are not permitted.
There are 6 canals in the kiln used in the experiments
and bricks were put into these canals. Brick samples
used in the experiment are in the dimensions of about
290mm×190mm×135mm. The weight of the brick
samples before entering the kiln was varied between
6.212 – 6.252 kg. The speed of the line which carries
the bricks from inlet to exit was 6.33 m/h. Total length
of the kiln is 57 m and there are 3 windows along the
canal to take measurements. The weight of the bricks
dropped to 4.254 – 4.566 kg after drying. The drying
experiments took 9 hours and the weight of the sam;
ples and time required for drying were determined by
measuring the temperature of the drying air at the
inlet, exit and 3 windows in the kiln.
Results and Discussion
In this study, drying of brick with forced convec;
tion of hot air has been investigated experimentally by
making measurements in working conditions.
Moisture ratio is defined as;
, (1)
where m is the mass of the brick before drying and md
is the mass of dried brick.
Brick is porous and nonhigroscobic item and diffu;
sion coefficient is defined in [4] as;
, (2)
where T is temperature of drying air, ρb is density of
the brick, ρw is amount of moisture in unit volume.
Moisture ratios obtained from the measurements
during the drying period are given Table 1. Drying
process was carried out using 6 bricks to minimize the
error of measurements, the values given in Table 1 is
mean values of these 6 bricks. Drying diagrams of the
bricks are plotted by using experimental humidity rates
and given in Figure 2 and 3. Variation of the moisture
3 2737,35 10
273 0,35
ρ+= ⋅
ρ
w
b
TD
=
d
dmmx
m
Figure 1. Schematic view of the brick drying kiln.
Figure 2. Variation of the moisture ratio of brick with
drying time.
ISSN 0204�3602. Пром. теплотехника, 2005, т. 27, № 6 49
ТЕОРИЯ И ПРАКТИКА СУШКИ
ratio of the brick with time is given in Figure 2. Figure 3
shows variation of moisture ratio with the distance from
the inlet of the kiln. The variation of the drying air
which is the most important parameter in the brick dry;
ing along with length of the kiln is given in Figure 4. As
seen from Figure 2;3, the big amount of the moisture in
the brick is removed in the first 20 m of the kiln in first
2 hours. The moisture on the surface of the brick and
very near the surface is removed quickly at the begin;
ning of the drying process. Meanwhile, removal of the
moisture in the deep part of the brick is mostly related
to internal structure of the brick rather than external
conditions. Because brick is porous item and movement
of the moisture depends on the internal structure.
Therefore moisture removal from the brick is very slow
after a certain stage even if the temperature of the dry;
ing air is very high. The values of diffusion coefficients
related to temperature of the measurements points are
given in Table 2. As seen from Table 2, diffusion coeffi;
cients are dependent on the temperature and the high;
er the temperature the bigger the value of the diffusion
coefficient. The temperature of the drying air is not
increased to prevent the crack formation in the brick
due to thermal stress. Experimentally obtained results
show that the drying performance does not change
much when the length of the kiln is kept shorter. The
Ta b l e 1 .
Ta b l e 2 .
big amount of the drying occurs at the first 20 meter dis;
tance of the kiln. Drying in the other part of the kiln
almost does not affect the moisture ratio of the brick.
As a result, keeping the shorter kiln length or faster
band speed for the temperature of the drying air
which experiments done does not change the per;
formance of the drying but it provides merit in terms
of time and cost.
References
1. Prasersan, S., Energy Saving in Making, 1995,
Thailand.
2. Suresh, H. N., Murugesan, K., Narayana, A.
And Seetharamu, K. N., Drying of Porous Material
Using Finite Element Method, Second International
Conference on CFD in the minerals and Process
Industries, 1999, CSIRO, Melbourne, Australia.
3. Palekar, A. And Date, A. W., Drying of Brick,
Technology Project Report, 1993, Indian Institute of
Technology, Bombay, India.
4. Mujumdar, A. S., Handbook of Industrial
Drying, 1995, Marcel Dekker Inc.
Получено 30.08.2005 г.
50 ISSN 0204�3602. Пром. теплотехника, 2005, т. 27, № 6
ТЕОРИЯ И ПРАКТИКА СУШКИ
Figure 4. Variation of the air temperature along the
kiln length.
Figure 3. Variation of the moisture ratio of brick along
the kiln length.
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