Marygold Flower Drying Machine Performance with Cooling
Dehumidification System Using a Refrigeration Machine
I Nyoman Gede Baliarta, Sudirman, Putu Darmawa and Suarta
Politeknik Negeri Bali, Indonesia
Keywords: Cooling Dehumidification, Refrigeration, Drying Machine.
Abstract: The purpose of this research is to make a drying machine for Marygold Flowers (Tagetes ercta L) which
operates below 60 degrees Celsius. Serves so that the color, aroma and components contained in gemitir
flowers are not damaged or greatly reduced due to high drying temperatures. The drying machine is made
using a cooling dehumidification system using a refrigeration machine as the main component. This dryer
operates at a temperature of 30-40 degrees Celsius with a humidity of 40-50%. This machine operates for 24
hours, producing dried flowers with a weight reduction of 90% and the smallest moisture content of 5%.
1 INTRODUCTION
Drying with a dehumidifier basically combines air
conditioning with a dryer/heater. The air conditioner
consists of a compressor, condenser, expansion valve,
evaporator and fan to produce air flow. In a
dehumidifier dryer the air coming out of the
evaporator pumps up to a temperature of 30
o
to 57
o
C
(Minea, 2012) (Acar & Dincer, 2014). An increase in
temperature will increase the rate of heat transfer to
the material being dried and the rate of air diffusion
in the material being dried. The low relative humidity
of the air ultimately aids the movement of air from the
dried material (Zamzami and Muhammad, 2017).
Here are some air dehumidification technologies,
such as refrigeration dehumidification, membrane
dehumidification, absorption dehumidification, and
adsorption dehumidification (G. D. da Silva, at al,
2016) This dehumidification cooling technology is
widely used in industrial and residential
dehumidification fields because of its compactness
and high safety (Caihang Liang, 2014). However,
conventional dehumidification cooling systems are
energy intensive. Energy costs will skyrocket if
ventilation rates are high to control IAQ (Indoor Air
Quality). As a result, a new dehumidification system
was needed (Yu-Cheng Chu, et al, 2017). The
advantage of dehumidifier drying compared to drying
drying is that it is easy to control temperature and air
drying so that it can be used over a wide temperature
range (Chin, et al, 2018).
The process of removing moisture from
agricultural materials is very energy-intensive.
Process energy use is quite large about: 20-25% of the
energy used by the food processing industry or 10-
25% of the energy used in all industries in developed
countries (Ziaforoughi and Esfahani, 2016).
Therefore, energy along with time efficiency is one of
the most significant design and operating parameters
in food processing (Chong, et al, 2014). The low
thermal conductivity and hardening of the material
are the main factors responsible for slowing down the
convective drying
There have been many advances in drying in
recent years, including pretreatments, techniques,
equipment and final product quality. Pretreatments,
for example, are used with the aim of accelerating the
drying process, improving quality and increasing
food safety (G. D. da Silva, at al, 2016).
2 MATERIAL AND METHODS
2.1 Equipment
The drying machine is made with a scheme like
Figure 1. Where the main equipment of the machine
made consists of a compressor, condenser, expansion
valve and evaporator. Additional equipment is a
heater element that functions to heat the air coming
out of the evaporator. The working scheme of this
dehumification cooling drying machine at Fig 1.
794
Baliarta, I., Sudirman, ., Darmawa, P. and Suarta, .
Marygold Flower Drying Machine Performance with Cooling Dehumidification System Using a Refrigeration Machine.
DOI: 10.5220/0011884700003575
In Proceedings of the 5th International Conference on Applied Science and Technology on Engineering Science (iCAST-ES 2022), pages 794-797
ISBN: 978-989-758-619-4; ISSN: 2975-8246
Copyright © 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)
Figure 1: Schematic of the cooling dehumidification dryer.
2.2 Procedure Experiment
The Dryer that will be made uses a Refrigeration
system component with a capacity of 1/2 Pk, with the
evaporator and evaporator fan placed on the inside of
the dryer, while the compressor, condenser and
expansion valve are placed outside the dryer.
The Drying Machine is divided into 2 rooms, the
first room has a shelf as a place for the bitter flowers
to be dried, while the other room functions as a return
air channel to the evaporator which will be cooled
again by the evaporator. The air that is cooled by the
evaporator will decrease in humidity, because in the
evaporator there will be air condensation after passing
through the gemitir flowers to be dried. The cold and
dry air coming out of the evaporator is then heated by
an electric heater. The hot, dry air then flows past the
flowers on the drying racks. Bitter flowers placed on
a drying rack will experience dehumidification, i.e.
the moisture content contained in them will be taken
up by dry and warm air that passes around them. The
air that absorbs moisture from the bitter flower will
be flowed back to the evaporator. And so on until the
bitter flowers that are on the drying rack will become
dry.
Control This Marygold flower dryer uses a
thermostat to control the heater element at a
temperature of 40 degrees Celsius and uses a
humiditystat to control the compressor which will
turn on at 50% relative humidity and turn off at 40%
relative humidity.
Figure 2: Thermostat and humiditystat installed on the
Smart control panel.
The gemitir flowers are to be dried, the Marygold
flowers are removed from the stems first, then
weighed, each shelf contains 500 grams of flowers.
The drying chamber contains 7 shelves. The flowers
that have been removed from the stems are placed on
a shelf, then put into the drying chamber. The data
logger is installed in the drying chamber and on the
refrigeration system piping. Press the ON push button
so that the dryer starts. Smart control is set at 40
degrees Celsius and humidity at 40%. And leave the
dryer in the dryer for 24 hours.
Figure 3: Marigold flower dried in the drying chamber.
The temperature and humidity conditions of the
dryer are monitored by data loggers and computers.
Fresh flowers and dried flowers were weighed and the
Marygold Flower Drying Machine Performance with Cooling Dehumidification System Using a Refrigeration Machine
795
moisture content was measured using a moisture
meter
Figure 4: Data logger and computer to get test data.
3 RESULTS AND DISCUSSION
The results of the marigold flower research that have
been carried out are shown below.
3.1 Marigold Flower Drying Results
The results of the research that has been done where
there are 7 shelves where dried flowers are made
Table 1.
Table 1: Results of drying research of Marygold flower.
Figure 5: Comparison graph of the weight loss of each shelf.
Flowers on shelf number 7 lost more weight
(90%) than flowers placed on other shelves, because
shelf number 7 was the first shelf to receive dry air
coming out of the evaporator and heated by the
heater. Following rack numbers 6, 5, 4 and so on.
Circulating air conditions in the dryer are depicted
in Figures 6, 7 and 8.
On the condition of the second to 1750 seconds.
Figure 6 shows the air coming out of the evaporator
with a temperature of about 34
o
C and a humidity of
55%, after passing through the heater element the air
temperature will increase to 50
o
C and the humidity is
around 35% (Figure 7). After the drying air passes
through the heater, it then passes through the flowers
on the shelves, taking moisture from the marygold
flowers. The air temperature increased by about 50
o
C
with the humidity also increasing to 43%. (Figure 8).
Figure 6: Graph of the condition of the air in the drying
chamber coming out of the evaporator (point 5).
Figure 7: Graph of the air condition in the drying chamber
after passing through the heater element (point 11).
Shelf
Number
Weigh Fresh
Flower
Weight Dry
Flower
Weiht Loss
(Gram)
Weiht
Loss (%)
1 150 25 125 83,33
2 150 25 125 83,33
3 150 25 125 83,33
4 150 25 125 83,33
5 150 25 125 83,33
6 150 20 130 86,67
7 150 15 135 90,00
83,33
83,33
83,33
83,33
83,33
86,67
90,00
1
2
3
4
5
6
7
Shelf Number
20
30
40
50
60
70
80
20
25
30
35
40
45
50
55
60
0 250 500 750 1000125015001750
RH (%)
Temperatur (⁰C)
Time (minute)
Temperature°C
iCAST-ES 2022 - International Conference on Applied Science and Technology on Engineering Science
796
Figure 8: Graph of the air condition in the drying chamber
after passing through rack number 1. (point 8).
Figure 9: Moisture content of dried marigold flowers on
each shelf.
The smallest moisture content is on the 7th shelf,
because the flowers on that shelf are the first to
receive the air heated by the heater element. Because
in addition to the hot air that hits it causes the water
vapor contained in the flowers to be easily released
and also floats up towards the shelves above.
4 CONCLUSIONS
The results of drying marygold flowers are quite
satisfactory, because the water content of dried
flowers produced on average is below 10%, but not
all of them show good results. Also the time it takes
is still too long about 24 hours. It is necessary to make
improvements to the machine, so that the results of
the dried flowers are evenly distributed and the time
required is under 24 hours.
ACKNOWLEDGEMENTS
This research can be carried out well, because of the
generosity of the Director of the Bali State
Polytechnic through the Center for Research and
Community Service (P3M PNB) providing sufficient
funds.
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20
30
40
50
60
70
80
20
25
30
35
40
45
50
55
60
0 250 500 7501000125015001750
RH (%)
Tmperatur (⁰C)
Time (Minute)
Temperature°C Humidity%
10
9,3
8,80
8,5
8,3
7,5
5
0
1
2
3
4
5
6
7
8
9
10
1 2 3 4 5 6 7
Moisture conten
(%)
Shelft Number
Marygold Flower Drying Machine Performance with Cooling Dehumidification System Using a Refrigeration Machine
797