scholarly journals An Experimental Study and Analysis on Solar Drying of Bitter Gourd Using an Evacuated Tube Air Collector in Thanjavur, Tamil Nadu, India

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
AR. Umayal Sundari ◽  
P. Neelamegam ◽  
C. V. Subramanian

The objective of this research work is to design and develop a forced convection solar dryer using evacuated tube air collector and study its performance on bitter gourd in Thanjavur District, Tamilnadu, India. The designed solar dryer consists of a drying chamber, evacuated tube air collector, a blower, and a chimney. Drying parameters, moisture ratio and drying rates, are calculated and their performance is compared with natural sun drying. The results of the present study show that the proposed solar dryer has greater efficiency, and the moisture content of bitter gourd is reduced from 91% to 6.25% in 6 hours as compared to 10 hours in natural sun drying. In this solar dryer, the products are uniformly dried, and the moisture content of the sample is controlled. It is found that the quality of the dried bitter gourd using solar dryer is higher than the natural sun-dried bitter gourd.

2014 ◽  
Vol 953-954 ◽  
pp. 16-19 ◽  
Author(s):  
Yuttachai Keawsuntia

This research paper presents the experimental results of drying of chili by using the active solar dryer and sun drying because of chili is a commercial agricultural product of Thailand. The active solar dryer consisted of a solar collector, a drying chamber and a chimney. The small fans were installed in the solar collector of active solar dryer to provide the air flow circulated in the solar collector and a drying chamber. Drying of chili of 20 kg from moisture content 84 percent wet basis to 10 percent wet basis following the Thai Agricultural Standard (TAS 3001-2010) showed that the use of the active solar dryer to make the drying time reduced about 28.7 percent compared with sun drying because of the hot air temperature inside the drying chamber higher than the ambient temperature about 10 to 15 . The quality of dried chili from the active solar dryer better than dried chili from sun drying.


2015 ◽  
Vol 787 ◽  
pp. 147-151 ◽  
Author(s):  
R. Manivel ◽  
S. Sivakumar ◽  
T. Rajagopal

An indirect type solar dryer is fabricated with the components like evacuated tube collector, drying chamber and blower. The performance of the drier is evaluated by carrying out drying experiments with copra at Coimbatore district Tamilnadu, India. A short survey of these showed that applying the indirect type solar dryer not only significantly reduced the drying time but also resulted in many improvements in the quality of the dried products. The temperature of the drying chamber ranges from 55°C to 75°C while the ambient temperature ranges from 28°C to 38°C. Nine basic solar drying models were used to fit the experimental data of copra. For experimental results, the logarithmic model showed the best curve fitting with highest correlation coefficient (R2) and lowest value of RMSE (Root Mean Square Error). Solar dried copra obtained is free from smoke, dust, bird and rodent damage.


2003 ◽  
Vol 60 (3) ◽  
pp. 471-475 ◽  
Author(s):  
Angela Maria Maluf ◽  
Denise Augusta Camargo Bilia ◽  
Claudio José Barbedo

The physiological quality of seeds of native species is important to produce healthy saplings and therefore guarantee the success of programs to recover disturbed vegetation. This reinforces the necessity for investigating the physiological quality of those seeds. To evaluate the effects of different drying rates on the germination, moisture content and storability of Eugenia involucrata diaspores, mature fruits collected at Mogi Guaçu, SP, Brazil had their epi- and mesocarps removed by washing and were dried at 30, 40 or 50ºC until their water content was reduced from 57% (fresh diaspores) to 13% (final drying), totaling six drying levels. In a second experiment, diaspores had their moisture content reduced from 57% to 49%, at 30ºC, totaling six drying levels (0h, 1h, 2h, 3h, 4h and 5h), and were kept for 180 days in plastic bags under cold storage. The drying rate had no effect on tolerance to desiccation by E. involucrata diaspores; water contents lower than 51% decreased both germinability and storability. Diaspores can be stored for up to 180 days as long as their water content is reduced to 53% and they are kept inside plastic bags under cold storage.


2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Waseem Amjad ◽  
Muhammad Waseem ◽  
Anjum Munir ◽  
Abdul Ghafoor ◽  
Furqan Asghar ◽  
...  

Abstract Batch type food dryers are common for drying agricultural produce due to simple in design, but they are prone to nonuniform drying and significant heat cost exclusively if they fall in the medium to large size range. The current study illustrates a solar hybrid food dryer using a gas burner and solar collector (evacuated tube collector, ETC) as heating source along with an inline perforation inside the drying chamber to obtain spatial drying homogeneity. Air distribution was assessed through three-dimensional simulation using computational fluid dynamics (CFD) analysis. Performance trials were conducted under three heating options (ETC, gas, and dual) using green chilies at 60 °C. Throughout drying chamber, under all heating modes, the average difference in drying rates ranged from 0.61 to 1.30 kg water/kg dry matter, demonstrating homogeneous drying. Simulated and experimental results of air distribution were found to be in agreement with each other. Using three options for thermal heating (ETC, gas, and dual) and an overall 58% efficiency for evacuated tube collector, the specific energy for moisture evaporation was found to be 4.5–5.7 MJ/kg and specific product energy 19.2–24.9 MJ/kg. In case of dual heating option, the energy supplied by solar and gas sources for a 20 hours period was 50.64% (160.22 MJ) and 49.35% (156.13 MJ), respectively. Compared with dual heating option, energy cost can be reduced by 68% if only solar energy is used as a heating option but with a protracted drying time.


2017 ◽  
Vol 13 (7) ◽  
pp. 6369-6375
Author(s):  
S. Kesavan ◽  
T.V. Arjunan ◽  
S. Vijayan

This paper involves with the experimental performance study of a triple pass solar flat plate collector integrated with  thermal energy storage medium for drying of blanched bitter gourd slices. The experimental setup consists of a blower, triple pass flat plate collector and a drying chamber. The experimets were carried out in the meterological conditions of Coimbatore, Tamil Nadu, India. The mass flow rate of air through the system was set as 0.06 kgs-1. From the results, it could be comprehended that, (i) triple pass arrangement of air improves the performance of flat plate collector (ii) thermal energy storage medium played an important role in consistent outlet air temperature and the thermal efficiency (iii) triple pass solar dryer took 5 hours to reach the final moisture content of bitter gourd (9% on wet basis) which is 29 % and 37.5% faster than without thermal storage and open sun drying system. It could be concluded that triple pass solar air collector performs better than without thermal storage and open sun drying.


Author(s):  
Mohammad Ali Basunia ◽  
Hamid H. Al-Handali ◽  
Mohammed Issa Al-Belushi ◽  
Mohammad Shafiur Rahman ◽  
Osman Maghoub

Taking into consideration the date harvesting and landholding capacities of the marginalized rural farmers in Oman, a 12 meter long and 2 meter wide tunnel was designed and constructed to dry about 180-200 kg of freshly harvested dates per batch. Half of the tunnel base was used as a flat plate air heating solar collector and the other half as a dryer. The drying air was forced from the collector region (South side) to the drying region (North side) of the half circled tunnel where the product is to be dried. The drying temperature could be easily raised by some 5-30 oC above the ambient temperature inside the tunnel at an air velocity of approximately 0.5 m/sec. The test was conducted with 190.2 kg freshly harvested dates with initial moisture content of 32.8% (wet-basis) to analyze the performance of the dryer. The dates were dried to a final average moisture content of 18.6% (wet-basis) within two days (20 hours). The results indicated that the drying was faster in a solar tunnel dryer than the natural open air sun drying. It was possible to reach the moisture content level for safe storage within less than two days (20 hrs) with a solar tunnel dryer and 5-7 days in open air natural sun drying. The improvement in the quality of dates in terms of color and brightness was distinctly recognized. 


The post-harvest losses for agricultural products are around 30%-40% [1]. Drying is a one of the necessary processes for the preservation of agricultural products. Agricultural products require hot air of temperature above 40 ºC for drying. Open sun drying takes more time for drying of products due to slower drying rates. Also, various factors hamper the quality of the dried product. Due to the moisture content in the products bacterial attack is possible. India being the tropical region has good solar radiation. It is advisable to use the solar dryer to avoid spoilage of quality of products [2]. In this work, the compact and portable forced convection solar dryer designed and developed for drying chilies with thermal energy storage. Solar dryer is having capacity of 15 kg and it consists of the flat plate collector based air heating system with thermal energy storage. Paraffin wax used as phase change material (PCM). The CFD simulations carried out for the solar dryer to study the temperature distribution over the surfaces of the flat plate collector and inside the drying chamber, velocity of air and phase change behavior of paraffin wax inside the trays. The energy stored in the paraffin wax and time required for charging and discharging of paraffin wax is found out. The time for which temperature in the drying chamber is maintained above 40 oC is also found out. Results of CFD simulations validated with the experimental results.


2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Masnaji R. Nukulwar ◽  
Vinod B. Tungikar

Abstract The objective of this study is to find an optimized thin-layer mathematical model suitable for drying kinetics of turmeric. Turmeric has a high moisture content which necessitates effective drying. A 10 kg, sample batch, of turmeric was dried in a solar dryer. Drying air temperatures and air velocity were observed in the range of 55 °C–68 °C and 0.7 m/s–1.4 m/s, respectively, in the drying experiments. It is seen that the moisture content of the turmeric is reduced from 77% to 11.93% in 22 h when compared with open sun drying, which required 60 h for the same reduction in the moisture content. Scheffler dish was used to generate steam for the dryer. Seven thin-layer mathematical models, cited in the literature, had been used for the study. These models were applied for different trays placed in the dryer. The result of the research and experimentation showed that the Page model fits best for drying in the steam-based dryer and open sun drying. Experimental results showed 63.33% saving in drying time, and the drying efficiency was found as 29.85%. Uncertainty in the drying efficiency was observed as 0.67%. Experimental investigation and the findings from the mathematical modeling are presented in this paper.


2018 ◽  
Vol 34 (6) ◽  
pp. 2902-2912
Author(s):  
J. Saravanan ◽  
Kishan Singh Rawat ◽  
Sudhir Kumar Singh

Groundwater quality of Thiruvallur (district of Tamil Nadu) of coastal areas of the Bay of Bengal has been studied. Standard overlay analysis; techniques have been used for analyzing spatial data in Geographic Information System platform. For this research work, groundwater samples were collected from bore wells and open wells covering the whole study area. The collected samples were analyzed for physical, cations and anions. The thematic maps of groundwater quality parameters of the entire study area were prepared using Inverse Distance Weightage interpolation technique. Further, water quality index was computed for the region on a recommendation of standard permissible limitsrecommended by World Health Organization (WHO) 2006 for the suitability of groundwater for drinking purposes.


2018 ◽  
Vol 49 (2) ◽  
pp. 100-109 ◽  
Author(s):  
Muhammad Zakaria Hossain ◽  
Md Masud Alam ◽  
Md Faruq Bin Hossain ◽  
MSH Sarker ◽  
Md Abdul Awal ◽  
...  

A cabinet type solar dryer was designed and fabricated over a collector and dryer area of 4.00 m2 and 7.5 m2 respectively for the geographical condition of Bangladesh. Red pepper was used to test the performance of the dryer. The upper tray and lower tray pepper drying needed 36 and 41 h to reduce moisture from 73% (wet basis) to 10% (wet basis) respectively and found 9 kg dried pepper from 30 kg fresh red ripe pepper. In contrast, open sun drying needed 85 h to reduce moisture from 73% (wet basis) to 11% (wet basis) and produced 2.43 kg dried pepper from 8 kg red ripe pepper. The average global radiation was about 133 W/m2 while the flux incidence and flux absorbed on collector was about 128 W/m2 and 103 W/m2 respectively. The average collector and dryer efficiency was about 48% and 34% respectively. The average exergy efficiency was obtained 63%. The average rate of top, bottom and side collector loss was 37 W/m2, 20 W/m2 and 3 W/m2 respectively. The upper tray, lower tray and open sun pepper seed germination was 76%, 81% and 85% respectively (P≥0.01). The redness value of lower tray pepper (a*=27.1) was higher followed by upper tray (a*=24.7) and open sun pepper powder (a*=21.1), which means direct exposure of sunlight diminishes the quality of pepper colour. The redness value of fabricated solar drying was significantly (P≤0.01) higher than that of open sun drying.


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