An Indirect Passive Solar Dryer for Drying

2011 ◽  
Vol 367 ◽  
pp. 517-524
Author(s):  
A. F. Alonge ◽  
O. O. Oniya
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Solar Drying ◽  
Drying Time ◽  
Sun Drying ◽  
Two Samples ◽  
Drying System ◽  
Average Size ◽  
Local Materials ◽  
Drying Chamber

A solar drying system designed on the principles of convective heat flow, constructed from local materials was employed in drying yam (Dioscorea Alata). A glass collector having an efficiency of about 0.63 was used along with an absorber for absorbing the heat energy. The drying chamber consisted of drying trays. A chimney fitted at the top centre of the drying chamber enhanced airflow. Air passing through the collector heated up and dried the foodstuff in the drying chamber. The latitude of Ilorin is 8.26oN and the collector angle could be varied . 56o C, 41o C and 71o C were obtained as the maximum attainable temperatures for the drying chamber, ambient and collector respectively. Two samples of yam chips, each weighing 1560g and having an average size of 1cm thick, were dried both inside the dryer and outside the dryer within its surrounding. The initial moisture content of the yam was 70.3% (wet basis) and its final moisture content was 9% (wet basis).The result was compared to natural sun drying. It was observed that the drying time was reduced from 52 hours for sun drying to 45 hours for solar drying. The total cost of the construction was 6, 105 Naira.

scholarly journals Energy Analysis of a Hybrid Solar Dryer for Drying Coffee Beans

2020 ◽  
Vol 9 (1) ◽  
pp. 131-139
Author(s):  
Suherman Suherman ◽  
Hasri Widuri ◽  
Shelyn Patricia ◽  
Evan Eduard Susanto ◽  
Raafi Jaya Sutrisna
Keyword(s):  
Moisture Content ◽  
Solar Collector ◽  
Energy Analysis ◽  
Initial Moisture Content ◽  
Solar Drying ◽  
Drying Method ◽  
Drying Time ◽  
Solar Dryer ◽  
Coffee Beans ◽  
Drying Chamber

In this study, hybrid solar drying of coffee beans was performed, and energy analysis was carried out, to assess the system’s performance, in terms of energy efficiency, compared to solar drying and the open sun drying method. The dryer has three compartments: solar collector for collecting solar radiation, drying chamber, and a Liquid Petroleum Gas burner, which acted as an auxiliary heater to assist the thermal energy. The drying chamber has four trays for placing the dried product. The initial moisture content of coffee beans was 54.23% w.b and was reduced to the final moisture content between 11-12% w.b. The coffee beans dried faster when subjected to the solar hybrid drying method, compared to other methods, with the dryer temperature of 40°C, 50°C, and 60°C. Results indicated that the coffee beans’ drying times varied from 10 to 14 hours. However, at temperature 50°C and 60°C for the 1st tray, the water content was reduced more rapidly compared to the other tray. From the results of this study, we can see the different efficiency of solar collector that shows of 54.15% at variable temperature 60°C for drying time 12:00 to 14:00 p.m for hybrid solar drying and for the solar drying process is 50.07% at the range of drying time 12:00 to 14:00 p.m. Mathematical modelling shows that Page model is the most suitable for describing the coffee beans’ drying behaviour using a hybrid solar dryer. The effective diffusivity values found in this experiment are all in the acceptable range for most agricultural products. ©2020. CBIORE-IJRED. All rights reserved

scholarly journals Development of an Automated Solar Powered Hot-air Supplemented Dryer

2019 ◽  
pp. 1-14
Author(s):  
O. Taiwo Aduewa ◽  
S. Ajiboye Oyerinde ◽  
P. Ayoola Olalusi
Keyword(s):  
Solar Energy ◽  
Moisture Content ◽  
Initial Moisture Content ◽  
Climatic Conditions ◽  
Solar Drying ◽  
Drying Time ◽  
Drying Temperature ◽  
Hot Air ◽  
Solar Powered ◽  
Drying Chamber

The world is facing two major challenges: one is to meet the exponential growing demand for energy particularly in developing and underdeveloped countries and other is to deal with global, regional and local environmental impacts resulting from supply and use of conventional energy. The cost-effective technology for solar drying that can be easily adopted among the rural farmers of developing countries needs to be developed in areas where solar energy is abundantly available. As cheap as the solar energy could be, there are associated problems with the stability of the energy for different purposes due to instability of climatic conditions. For this research, a solar powered hot-air supplemented dryer (SPHSD) with a capacity of 20 kg of sliced yam was designed and developed. The SPHSD has three sections which are solar collector chamber, drying chamber and hot-air supplement chamber which is powered with two 150-watt solar panel and a 200 amps solar battery for continuous operation during bad weather. All data were logged digitally for accuracy and test was done using yam slices. Difference in drying time and stability in drying temperature was evaluated using SPHSD and indirect solar dryer. The result shows stability of temperature in the drying chamber when SPHSD was used while the drying temperature fluctuates throughout the indirect solar drying test period. Drying experiment was conducted for 481 minutes (between 0910 hrs to 1713 hrs) reducing the moisture content from 71.91%, 72.1% and 72.8% to 27.95%, 25.78% and 28.23% for MC1, MC2 and MC3in wet basis respectively. Drying experiment was conducted for 832 minutes (between 0901 hrs to 2257 hrs) reducing the moisture content from initial moisture content levels of 72.66%, 71.48% and 71.48% to 13.47%, 12.53% and 12.54% for MC1, MC2 and MC3in wet basis respectively.

Performance of a Solar Drying System Driven by a Hybrid Power System

2012 ◽  
Vol 455-456 ◽  
pp. 139-146
Author(s):  
Hao Zhong ◽  
Zhi Min Li ◽  
Tong Wu ◽  
Ming Jiu Yu ◽  
Run Sheng Tang
Keyword(s):  
Power System ◽  
Early Stage ◽  
Initial Moisture Content ◽  
Agricultural Products ◽  
Solar Drying ◽  
Test Results ◽  
Drying Time ◽  
Drying System ◽  
Drying Chamber

To increase the production and improve the quality of dried agricultural products, a new drying system with a hybrid driving power system was developed and tested. The system with total collector area of 100m2 is consisted of 10 drying units and each of them is consisted of 5 identical air collectors and a greenhouse-like drying chamber. Each of collectors in the system is equipped with a DC fan, powered by either 120W solar modules or a 300W wind turbine, and an AC fan, directly powered by the electricity from grid. Such drying system can operate in all time of any day and avoid any possible spoilage of dried products as found in conventional solar dryers due to the formation of mould on the surface of dried materials in the events of consecutive rainy days. Field test for the drying of 9 fruits was conducted from November to December in 2005. The results indicated that the system was very effective for the drying of fruits and the solar drying time for most of the materials to be investigated was only one third of that required in the natural sun drying. Test results also showed that the nocturnal ventilation of drying chambers at the early stage of drying exercise was necessary for materials with high initial moisture content in order to further shorten the solar drying time.

scholarly journals Thermal Analysis of Tilapia Fish Drying by Hybrid Solar Thermal Drying System

2021 ◽  
Vol 90 (1) ◽  
pp. 115-129
Author(s):  
Hussain Al-Kayiem ◽  
Tadahmun Ahmed Yassen ◽  
Sundus Al-Azawiey
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Solar Thermal ◽  
Injection Technique ◽  
Solar Air Heater ◽  
Solar Drying ◽  
Sun Drying ◽  
Rainy Weather ◽  
Thermal Drying ◽  
Drying Chamber

The present work presents a hybrid solar thermal drying of Tilapia fish to improve the product quality and satisfy the importers. The developed hybrid dryer utilized direct solar drying, a solar air heater and a thermal backup unit which sustains the drying process during the night, cloudy and rainy weather conditions. Besides, a new feature of the developed dryer utilizes the flue gas exhausted from the thermal unit to enhance the updraft in the drying chamber by re-injection of the flue gases in the chimney. The initial moisture content of the Tilapia fish used in the investigation was 246.6% on a dry basis, equivalent to 74% on a wet basis. The investigations were repeated three times on different days. Experimental results showed that the moisture content was reduced to an average final of 17.0% db (5.0% wb) within 17.5 hours, while in the open sun drying, it required around 48-72 hours. Hybrid solar drying required around 72% shorter time than open sun drying. The average overall drying efficiency of the developed system for drying Tilapia fish was 13.0%. The Re-injection technique used in the present hybrid solar-thermal system has excluded the need for an electric source for air extraction from the drying chamber, which is highly desired in the rural and fishery regions.

scholarly journals Cherry Tomato Drying: Sun versus Convective Oven

Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 40
Author(s):  
Vincenzo Alfeo ◽  
Diego Planeta ◽  
Salvatore Velotto ◽  
Rosa Palmeri ◽  
Aldo Todaro
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Drying Process ◽  
Drying Time ◽  
Oven Drying ◽  
Sun Drying ◽  
Different Temperatures ◽  
Final Water Content ◽  
Drying Curves ◽  
Drying Conditions

Solar drying and convective oven drying of cherry tomatoes (Solanum lycopersicum) were compared. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during the drying process. Drying curves were fitted to several mathematical models, and the effects of air temperature during drying were evaluated by multiple regression analyses, comparing to previously reported models. Models for drying conditions indicated a final water content of 30% (semidry products) and 15% (dry products) was achieved, comparing sun-drying and convective oven drying at three different temperatures. After 26–28 h of sun drying, the tomato tissue had reached a moisture content of 15%. However, less drying time, about 10–11 h, was needed when starting with an initial moisture content of 92%. The tomato tissue had high ORAC and polyphenol content values after convective oven drying at 60 °C. The dried tomato samples had a satisfactory taste, color and antioxidant values.

scholarly journals Effect of Pads and Thickness of Paddy on Moisture Removal under Sun Drying

2021 ◽  
Author(s):  
A. Narmilan ◽  
G. Niroash ◽  
M.I.M. Mowjood ◽  
A.T.A. Akram
Keyword(s):  
Sri Lanka ◽  
Moisture Content ◽  
Removal Rate ◽  
Initial Moisture Content ◽  
Storage Period ◽  
Moisture Removal ◽  
Drying Time ◽  
Sun Drying ◽  
Regular Time ◽  
Paddy Farmers

Background: Sun drying is a popular post-harvest operation to maintain rice quality during the storage period. Farmers use different pads and thicknesses for sun drying of paddy in Ampara district, Sri Lanka. A study was conducted to evaluate the suitability and effectiveness of the drying pad and thickness as practiced by local paddy farmers during the sun drying process.Methods: The grain with an initial moisture content of 28% (dry basis) was sun dried with four types of drying pads and five levels of thickness of grain. This experiment was conducted between 8.30 am and 4.30 pm at the South Eastern University of Sri Lanka in August 2020. The moisture contents of the grain were measured at regular time intervals.Result: It was found that the duration of drying of paddy from 28% to 13% moisture content on a dry basis was 300 to 540 minutes depending upon the drying pad and thickness. The tarpaulin is reasonable at shallow thickness with less time to reach the necessary moisture level than other drying pads. Black polythene and fertilizer bag can be utilized for sun drying of paddy at 4 cm thickness with 130 minutes. It was found that with an increase in the thickness of paddy from 0.5 cm to 4 cm, the drying time increases. A statistically significant interaction was obtained between drying pads and thickness level on moisture removal of paddy. Therefore, the moisture removal rate differs with the drying pad and thickness of the paddy under open sun drying.

scholarly journals Performance of hybrid solar-biomass dryer

2017 ◽  
Vol 5 ◽  
pp. 61-69
Author(s):  
M.K. Mishra ◽  
K.R. Shrestha ◽  
V Sagar ◽  
R.K. Amatya
Keyword(s):  
Moisture Content ◽  
Test Performance ◽  
Initial Moisture Content ◽  
Load Test ◽  
Sun Drying ◽  
Solar Dryer ◽  
Sunny Weather ◽  
Drying System ◽  
Overall Efficiency ◽  
Continuous Heat

Drying of agriculture product is energy intensive and traditional open sun drying is associate with many problems. Use of solar dryer is one of the alternative options. However, it is problematic in rainy and cloudy days. In order to measure the efficiency of solar/biomass hybrid dryer was proposed. A solar/biomass hybrid dryer was fabricated in RECAST Lab. Wood blocks were used as fuel for the gasifier stove. Biomass burning gasifier stove was integrated with solar dryer as an auxiliary heat source through a heat exchanger. The hybrid system of biomass with solar dryer ensures to provide continuous heat when needed. Due to the intermittent nature of sun, especially in rainy or cloudy season, food materials being processed get spoiled. A hybrid solar/biomass drying system solve such problems. Experiments were conducted to test performance of hybrid solar dryers by drying chili and banana. During the load test, conducted for chili, 16 kg of ripen chili with initial moisture content 72.58% (w. b.) was dried to moisture content of 7.13% (w. b.) in 20 hours. The result indicated that drying of chili was faster, within 20 hours (2 days), in natural sunny weather, against 48 hours (5 days) in open sun drying during April, in Kathmandu. Overall efficiency of drying system was found to be 4.29%.

scholarly journals Studies on drying characteristics and techno-economic analysis of sprouted moth beans (Vigna aconitifolia) in solar tunnel dryer

2019 ◽  
Author(s):  
C. M Badgujar ◽  
O. S. Karpe ◽  
S. R. Kalbande
Keyword(s):  
Moisture Content ◽  
Economic Analysis ◽  
Initial Moisture Content ◽  
Cost Benefit ◽  
Maximum Temperature ◽  
Drying Time ◽  
Sun Drying ◽  
Tunnel Dryer ◽  
Present Worth ◽  
Drying Efficiency

A commercial solar tunnel dryer (STD) was evaluated for drying of sprouted moth beans and also its techno-economic analysis was carried out. The maximum temperature 58ºC was recorded at 13:00h in STD during the drying process i.e. 41.0% (34.2ºC) higher than the maximum ambient temperature at the same time. A total drying time of 13:50h were required in STD to reduce the initial moisture content from 177.7% dry basis (d.b) to a final moisture content of 16.6% (d.b). However, the open sun drying took 16.5 drying hours to obtain desired moisture content. The net present worth and cost-benefit ratio of dryer was Rs.5,83,910.68/- and 1.19, respectively. However, the payback period for STD was 15 month 8 days. The cost economics of dried products were proved better for STD than open sun drying method. STD samples were found to be of good quality in terms of color, taste and aroma as compared to open sun dried (OSD) with an overall drying efficiency of STD was 19.7%. Therefore, the evaluated solar tunnel dryer were recommended for the drying of sprouted moth beans.

scholarly journals Experimental Analysis of Single Glazing, Double Glazing and Triple Pass Solar Dryer

2020 ◽  
pp. 70-73
Keyword(s):  
Moisture Content ◽  
Window Glass ◽  
Initial Moisture Content ◽  
Solar Drying ◽  
Average Value ◽  
Solar Dryer ◽  
Collector Efficiency ◽  
Drying System ◽  
Time Required ◽  
Drying Efficiency

Adjustable Multi glazing solar drying system is designed and fabricated for experimental study. The arrangement is made in the present model such that it can be wok as a single glazing, double glazing and multi-glazing solar dryer by adjusting the plain window glass (Glazing). The performance analysis and comparison of Single glazing (SGSD), double glazing (DGSD) and Triple pass solar drying system (TPSD) have been conducted by using red chilli. The performance curves show the effect of solar intensity on the collector efficiency, drying efficiency and pick-up efficiency of solar drying system. The collector efficiency of TPSD increased by 28.8% and 53% as compared to DGSD & SGSD respectively at average value of solar radiation 674.4 W/m² at 26.90 gm per second of air mass. The initial moisture content in red chili was measured and found 78.8 (wb) reduced to minimum moisture content 9.8% (wb). It could be concluded that, the time required to dry the red chilli in TPSD is minimum as compared to SGSD and DGSD.

scholarly journals Pengaruh kecepatan udara dan massa gabah terhadap kecepatan pengeringan gabah menggunakan pengering terfluidisasi

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
S. Syahrul ◽  
M. Mirmanto ◽  
S. Romdani ◽  
S. Sukmawaty
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
National Standards ◽  
Drying Process ◽  
Air Velocity ◽  
Drying Time ◽  
Grain Processing ◽  
Grain Moisture ◽  
Time Required ◽  
Drying Chamber

Grain processing does not meet the actual grain harvests. This is due to the unsuitable drying process. Milling grain entrepreneurs and farmers in Indonesia are currently conducting a drying process under the sun. Based on the National Standards Body (BSN), grain moisture content must be at 14% to maintain the grain at high qualities. The purpose of this study is to determine the effect of velocity and grain mass variations on drying times. The grain used in this study contains an initial moisture content of 22% ± 0.5%. The grain is dried by inserting it into the drying chamber and varying the air velocities and grain mass. The air velocities used are 4 m/s, 5 m/s, 6 m/s and the variations of the grain mass are 1 kg 2 kg and 3 kg. The results show that increasing the air velocity decreases the drying time. On the other hand, when the grain mass is increased, the drying time elevates. The air velocity and mass of the grain that results in the fastest drying time are 6 m/s and 2 kg. The time required for achieving the water content of 13.6% is 30 menit. At the air velocity of 4 m/s, and the grain masses of 1 kg, 2 kg, and 3 kg, to achieve moisture contents of 13.4%, 13.5% and 13.4% the drying time needs 50 minutes.

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