scholarly journals Teknologi Kolektor Surya Berlubang tanpa Kaca Transparan untuk Mengeringkan Daun Gaharu

2018 ◽  
Vol 38 (2) ◽  
pp. 227
Author(s):  
Irwin Bizzy ◽  
Budi Santoso ◽  
Muhammad Zahri Kadir
Keyword(s):  
Wind Tunnel ◽  
Moisture Content ◽  
Solar Collector ◽  
Input Parameter ◽  
Agricultural Products ◽  
Solar Irradiation ◽  
Efficiency Evaluation ◽  
Collector Plate ◽  
Engineering Department ◽  
Simple Technology

The perforated solar collector technology is a highly potential solution to take advantage of renewable energy in tropical countries such as Indonesia. This technology can be applied as a simple technology for drying of agricultural products. This study aims to determine the rate of the decreased moisture content of gaharu leafs. In this study, the perforated solar collector equipped with four ribs was used. The efficiency evaluation of perforated solar collector plate was conducted in Wind Tunnel-Rig, Basic phenomenon Laboratory of Mechanical Engineering Department, Sriwijaya University. The dimension of the plate is 850 mm × 300 mm × 1.5 mm, which has 1018 holes with 2.5 mm in diameter. The results show that the drying rate for achieving the 10% moisture content of the gaharu leafs, can be reached in 2–3 days. This condition occurs when the weather is sunny, or not cloudy and rainy. In other condition, when the sunshine with an average solar irradiation on the surface is greater than or equal 500 W/m2. The efficiency tests of the perforated  aluminum plate solar collector using wind velocity as input parameter show that the blackened plate resulted in better performance (12,83%) than the colorless one in (6,36%). ABSTRAKTeknologi kolektor surya berlubang ini merupakan salah satu solusi untuk dapat memanfaatkan energi baru terbarukan yang peluangnya sangat besar untuk dikembangkan di negara beriklim tropis seperti negara Indonesia. Teknologi ini dapat digunakan sebagai teknologi tepat guna untuk mengeringkan produk-produk pertanian. Tujuan penelitian ini adalah untuk menentukan laju penurunan kadar air daun gaharu. Dalam pengujian pengeringan ini digunakan kolektor surya berlubang bersayap empat. Evaluasi efisiensi pelat kolektor surya berlubang dilakukan di Wind Tunnel Laboratorium Fenomena Dasar, Jurusan Teknik Mesin, Universitas Sriwijaya. Dimensi dari pelat kolektor surya berlubang adalah 850 mm x 300 mm x 1,5 mm, dengan jumlah lubang 1.018 buah yang berdiameter 2,5 mm. Hasil penelitian menunjukkan bahwa laju pengeringan daun gaharu untuk mencapai kadar air 10 % dapat dihasilkan dalam 2 ¸ 3 hari.  Kondisi ini terjadi bila cuaca cerah, tidak hujan dan tidak berawan. Dalam kondisi lain, ketika matahari bersinar dengan radiasi matahari rata-rata yang mencapai permukaan lebih besar atau sama dengan 500 W/m2. Pengujian efisiensi kolektor surya pelat alumunium berlubang dengan parameter kecepatan udara, menunjukkan bahwa pelat berwarna hitam menghasilkan performansi yang lebih baik (12,83%) dibandingkan dengan pelat tanpa warna (6,36%).

Impact of drying method of figs with small-scale flat-plate solar collector

2016 ◽  
Vol 13 (5) ◽  
pp. 407-412 ◽  
Author(s):  
Fahim Ullah ◽  
Min Kang ◽  
Lubna Hassan ◽  
Ninghui Li ◽  
Jun Yang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Flat Plate ◽  
Solar Collector ◽  
Agricultural Products ◽  
Ficus Carica ◽  
Solar Irradiation ◽  
Small Scale ◽  
Content Type ◽  
Flat Plate Solar Collector ◽  
Drying Chamber

Purpose The purpose of the study was to develop a performance flat-plate solar collector that would be used as a solar drier for fruit fig (Ficus carica L). This study proposes how and why solar energy is important for drying the agricultural products. This study aims to expand the domain of solar collector for different purposes and, most important, for agricultural resource normally found in the literature. Design/methodology/approach The paper opted for an exploratory study using the flat-plate solar collector with drying chamber for drying purposes of agricultural products. During the experiment, the data were collected with moisture content, drying rate of the product and solar irradiation falls on the collector. Findings This paper describes that how flat-plate collector works for agricultural products and how to reduce the moisture content in the product (fig). Efficiency of collector was evaluated under the ambient temperatures of 24°C. Efficiency also significantly increased from 53 to 55 per cent with an increase in ambient temperature from 22 to 24 °C. Figs (Ficus carica L) were dried in the drying chamber of the flat-plate solar collector. The products were dried at temperature of 55-65°C and 15 to 20 per cent humidity. Research limitations/implications Because of this research chosen, the research results are beneficiary for agricultural users for drying purposes. Therefore, the researchers are encouraged to dry the agricultural product with flat-plate solar collector, because it reduced the moisture content of the product very fast. Originality/value This paper fulfills an identified need to study that how flat-plat solar collector can be used.

scholarly journals Design, Building and Performance Evaluation of a Mixed-Mode Solar Dryer for Agricultural Products

2020 ◽  
Vol 15 ◽  
Keyword(s):  
Performance Evaluation ◽  
Relative Humidity ◽  
Moisture Content ◽  
Ambient Temperature ◽  
Solar Collector ◽  
Mixed Mode ◽  
Ambient Air ◽  
Agricultural Products ◽  
The Third ◽  
And Performance

This research work presents the detailed explanation of the design, construction and performance evaluation of mixed-mode solar agricultural products dryer. The experimental set up used for testing the performance of the mixed-mode solar agricultural products dryer and determining the influence of various drying methods on the drying behaviour of agricultural products. Evaluation of the dryer was centered on the moisture content reduction, temperatures and relative humidities variations. 1680 g of freshly potato slides were used for evaluation. The test results gave that the temperatures inside the dryer cabinet and the solar collector were much higher than the ambient temperature during most hours of the daylight. The temperature inside the solar collector was up to 27 o C approximately higher than the ambient temperature. The temperature inside the drying cabinet was up to 22 o C approximately higher than the ambient temperature for about three hours immediately after 12.00 h (noon). The relative humidity in the solar collector and drying cabinet were lower than the ambient air relative humidity, with the ambient air recording the highest relative humidity at each reading followed by the drying cabinet and finally by the solar collector. Because of the decreased relative humidity inside the dryer, all the time, the temperature inside the dryer was high which is sufficient enough to dry the potato at an early time. Based on the results obtained during the test, temperature above 65 o C was recorded inside the drying cabinet. This high temperature in the drying cabinet causes 419 g of moisture to be removed on the first day, 257 g on the second day, 191 g on the third day, 136 g on the fourth day and finally 108 g on the fifth day. At the end of the five days of drying process, the mass of 1680 g of potato was reduced to 569 g. Total amount of moisture removed was 1111 g and total moisture loss was 66.1 %, which is the required amount of moisture to be removed for safe drying of freshly potato slides. The moisture content of the freshly potato slides was 24.9 % at the end of drying for the first day at about 5:00 pm, 20.4 % at the end of drying for the second day, 19 % at the end of drying for the third day, 16.7 % at the end of drying for the fourth day and finally 15.9% at the end of drying for the fifth day. It was observed that the drying rate increased from the end of one day to another, which shows the earlier and faster removal of moisture from the dried item.

Study of Characteristic of Evacuated Flat Plate Type Solar Collector With Flow Boiling

2007 ◽  
Author(s):  
Masahiro Taniguchi ◽  
Shigeki Hirasawa ◽  
Shunsaku Nakauchi ◽  
Tadayoshi Tanaka
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Flow Boiling ◽  
Saturation Temperature ◽  
Solar Irradiation ◽  
Working Fluid ◽  
Collector Plate ◽  
Collector System ◽  
Heat Collector ◽  
Collector Efficiency

An evacuated solar collector system with flow boiling in tube has high collector efficiency of solar energy. In this paper, we present experimental and simulation results for characterizing an evacuated flat plate solar collector. By comparing the experiment results with six boiling heat transfer correlation equations, we found that Sani’s correlation is closest to our experimental results. Subsequently, this paper reports on how various factors impact collector efficiency. Collector efficiency decreases with decreasing flow rate of the working fluid, with decreasing solar irradiation, with reduction of thickness and thermal conductivity of the heat collector plate. Collector efficiency increases with decreasing saturation temperature of the working fluid, with decreasing vacuum pressure in the collector, with small bending angle of the heat collector tube. Collector efficiency does not change with change of inside diameter of the heat collection tube, and with change of inlet subcooling temperature of the working fluid.

scholarly journals Development of a Compact Solar Vegetable Dehydrator

2021 ◽  
Author(s):  
S. V Jadhav ◽  
S. S Wangikar ◽  
A. M Kulkarni ◽  
M. K Patil ◽  
A. A Bansode ◽  
...  
Keyword(s):  
Solar Energy ◽  
Moisture Content ◽  
Shelf Life ◽  
Flow Velocity ◽  
Solar Collector ◽  
Agricultural Products ◽  
Hot Air ◽  
Different Temperatures ◽  
Passive Solar ◽  
Time Required

Agricultural products, such as, vegetables are generally perishable and are difficult to store. Drying is one method to reduce the increase their shelf life. Dehydrators use different type of energy as per availability and requirement. Solar dehydrators are more popular since they use renewable solar energy. In this paper such a domestic passive solar dehydrator is designed and analysed for its utility and effectiveness. The dehydrator is designed for converting the perishable agricultural products into powders so that it can be stored and used for longer time. It is designed in two parts. The first part work as a solar energy collector and the second part works as the dehydrator. The heat from solar radiations is imparted to the air in the solar collector. This hot air is used in dehydrator foe drying agricultural products. The experimentation has been performed for different temperatures and flow velocity of air varying for different vegetables depending on their moisture content and time required to remove the moisture. It is observed that drying at different temperature is required for different vegetables to convert them into powder. The taste and colour of the powder produced are found to be good. Therefore, it is suitable and affordable even for farmers with lesser quantity of products.

Equilibrium moisture content of dead fine fuels of selected central European tree species

2013 ◽  
Vol 22 (6) ◽  
pp. 797 ◽  
Author(s):  
Christian Schunk ◽  
Clemens Leutner ◽  
Michael Leuchner ◽  
Clemens Wastl ◽  
Annette Menzel
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Input Parameter ◽  
Fire Danger ◽  
Pedunculate Oak ◽  
Salt Solutions ◽  
Test Procedures ◽  
Climate Chamber ◽  
Central European ◽  
Fine Fuels

Fine fuel moisture content is a key parameter in fire danger and behaviour applications. For modelling purposes, equilibrium moisture content (EMC) curves are an important input parameter. This paper provides EMC data for central European fuels and adds methodological considerations that can be used to improve existing test procedures. Litter samples of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), European beech (Fagus sylvatica L.) and pedunculate oak (Quercus robur L.) were subjected to three different experiments using conditioning in a climate chamber and above saturated salt solutions. Climate chamber conditioning yielded the best results and can generally be recommended, however saturated salt solutions are able to produce lower relative humidities, which are relevant to forest fire applications as they represent the highest fire danger. Results were within the range of published sorption isotherms for forest fine fuels. A fairly clear gradation was present with higher EMC values in leaf litters than in needle litters. These differences are in accord with values from the literature and suggest general differences in the sorption properties of leaves and needles, which may be caused by differing chemical and physical properties. The influence of temperature on EMC described in the literature could be confirmed.

scholarly journals Karakteristik Pengeringan Biji Jagung (Zea Mays L.) Menggunakan Alat Pengering Surya Adriyarkara Termodifikasi

2018 ◽  
Vol 3 (2) ◽  
pp. 351-360
Author(s):  
Athul Fadhli ◽  
Diswandi Nurba ◽  
Raida Agustina
Keyword(s):  
Zea Mays ◽  
Relative Humidity ◽  
Moisture Content ◽  
Zea Mays L ◽  
Initial Moisture Content ◽  
Solar Irradiation ◽  
Air Velocity ◽  
Drying Time ◽  
Average Temperature ◽  
Average Relative Humidity

Abstrak. Jagung merupakan tanaman penghasil karbohidrat terpenting. Pengeringan jagung pipil menggunakan alat pengering merupakan proses untuk menghasilkan jagung pipil yang siap diolah untuk pembuatan tepung jagung dengan batas kadar air tertentu sehingga menghaslkan jagung pipil dengan kualitas yang baik. Tujuan penelitian ini adalah untuk mengkaji karakteristik pengeringan biji jagung menggunakan alat pengering surya Termodifikasi. Metode penelitian  menggunakan 3,15 kilogram jagung pipil dengan kadar air awal 22% untuk proses pengeringan. Parameter yang dianalisis terkait alat pengering kolektor surya yaitu temperatur, kelembaban relatif, kecepatan udara dan iradiasi surya, sedangkan parameter yang dianalisis terkait bahan yaitu kadar air, lama waktu pengeringan, laju pengeringan dan organoleptik. Prosedur penelitian terdiri dari pengujian kosong dan pengujian dengan menggunakan jagung pipil. Hasil penelitian menunjukkan bahwa temperatur rata-rata dalam rak pengering sebelum dilakukan modifikasi yaitu 44,4oC, temperatur rata-rata setelah dilakukan modifikasi yaitu 55,5oC dan temperatur rata-rata rak pengering pada pengeringan menggunakan jagung pipil yaitu 46,96oC. Kelembaban relatif rata-rata dalam rak pengering sebelum dilakukan modifikasi yaitu 40,1%, kelembaban relatif rata-rata dalam rak pengering setelah modifikasi yaitu 35,1% dan kelembaban relatif rata-rata pengeringan menggunakan jagung pipil yaitu 44,45%. Dari hasil pengukuran tersebut menunjukkan bahwa nilai temperatur dan kelembaban pada alat setelah modifikasi lebih baik dibandingkan sebelum alat dimodifikasi. Pengukuran temperatur dan kelembaban relatif terdiri dari 4 titik pengukuran yaitu rak 1A,1B dan rak 2A, 2B. Kecepatan udara rata-rata yang diukur konstan yaitu 0,7 m/s pada ruang pengering, sedangkan lingkungan 1,1 m/s. Total iradiasi surya selama pengeringan yaitu 1848,84 W/m2. Kadar air jagung pipil masing-masing rak yaitu rak 1A 14,29%, rak 1B 14,47%, rak 2A 13,91% dan rak 2B 14,1%. Hasil dari pengujian organoleptik, panelis agak menyukai jagung pipil yang dikeringkan menggunakan alat pengering tersebut.Characteristics of Seed Drying (Zea mays L.) Using a Modified Adriyarkara Solar DryerAbstract. Corn is the most important carbohydrate plant. Drying corn using a drying tool is a process to produce corn that are ready to be processed for making corn flour with a certain water content limit so as to produce corn with good quality. The purpose of this study was to examine the characteristics of drying of corn kernels using a modified solar dryer. The research method used 3,15 kilogram of corn milled with the initial moisture content of 22% for drying process. The parameters analyzed in relation to solar collector dryers are temperature, relative humidity, air velocity and solar irradiation, while the parameters analyzed are materials such as moisture content, drying time, drying rate and organoleptic. The research procedure consists of unloaded testing and testing using corn. The results showed that the average temperature in the dryer tray before modification was 44,4°C, the average temperature after modification was 55,5°C and the average temperature of the dryer tray on drying using corn was 46,96oC. The average relative humidity in the dryer tray before modification is 40,1%, the average relative humidity in the dryer tray after modification is 35,1% and the average relative humidity of drying using corn is 44,45%. From the measurement results show that the value of temperature and humidity in the tool after modification is better than before. Measurement of temperature and relative humidity consist of 4 point of measurement that is tray 1A, 1B and tray 2A, 2B. Average mean air velocity measured is 0,7 m/s at the dryer room, while the environment is 1,1 m/s. Total solar irradiation during drying is 1848,84 W/m2. Moisture level of corn each shelves tray 1A is 14,29%, tray 1B is 14.47%, tray 2A is 13,91% and tray 2B is 14,1%. As a result of organoleptic testing, panelists rather like dried corn using the dryer.

scholarly journals Entropy generation analysis for the design of a flat plate solar collector with fins

DYNA ◽  
2020 ◽  
Vol 87 (212) ◽  
pp. 199-208
Author(s):  
Milton Muñoz ◽  
Manuel Roa ◽  
Rodrigo Correa
Keyword(s):  
Flat Plate ◽  
Entropy Generation ◽  
Solar Collector ◽  
Entropy Generation Rate ◽  
Design Parameters ◽  
Outlet Temperature ◽  
Minimum Entropy ◽  
Airflow Velocity ◽  
Collector Plate ◽  
Flat Plate Solar Collector

This article describes the optimal design of a flat-plate solar collector with fins, based on the minimum entropy generation criterion. The design parameters were optimized, considering entropy generation due to heat transfer and airflow. The latter has not been considered in previous works. The flat plate in the collector is assimilated to a finned heat sink. The dimensionless entropy generation variation is analyzed to increase values of the number of fins, as well as for different plate thicknesses and heights. We also considered variations in airflow velocity. Our data shows that airflow velocity greatly influences entropy generation. Values other than the optimum found, caused a considerable growth of total entropy. For a collector area of 4 m2, and an outlet temperature of 50°C, the optimum parameters that minimize the entropy generation rate were: 9 fins on each side of the collector plate, a height of 5 x10-2 m, a thickness of 25x10-3m, and an air velocity variable between 0.015 and 0.046 m/s. This development is relevant to the design of flat plate solar collectors, for grain drying applications.

Experiment on Flow Boiling Heat Transfer in Tube and Study of Performance of a Vacuum Solar Collector

2007 ◽  
Author(s):  
Shigeki Hirasawa ◽  
Masahiro Taniguchi ◽  
Shunsaku Nakauchi ◽  
Tadayoshi Tanaka
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Boiling Heat Transfer ◽  
Solar Collector ◽  
Flow Boiling ◽  
Saturation Temperature ◽  
Collector Plate ◽  
Flow Boiling Heat Transfer ◽  
Boiling Heat Transfer Coefficient ◽  
Inclined Angle

A high-vacuum solar collector system with flow boiling in tube has high collector efficiency of solar energy. In this paper flow boiling heat transfer coefficient in tube was measured by changing mass flow rate (30–80 kg/m2s), heat flux (5–30 kW/m2) and inclined angle of collector plate. Inside diameter of tube is 4.4 mm, and saturation temperature is 100°C. Flow boiling heat transfer coefficient is about 8000 W/m2K and decreases at low flow rate. Effect of the inclined angle of collector plate is small. Experimental results of boiling heat transfer coefficients are similar to Sani’s correlation equation. The collector efficiency of vacuum solar collector systems with flow boiling in tube is analyzed and the efficiency is 69% at a standard calculation condition. There is 50°C temperature difference in the collector plate. Effects of the mass flow rate and the vacuum pressure on the efficiency are large. The efficiency decreases at high saturation temperature and at low solar radiation.

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