Papers by Keyword: Solar Dryer

Abstract: Performance of solar dryers were tested. In the past, to study the efficiency of solar dryers. A dryer with one drying chamber was built and tested by changing the conditions. In each experiment, the solar irradiance value is different, which can cause the results to be inaccurate. Therefore, in this study, a number of drying chambers are designed according to the number of experimental conditions to be studied during the same period. To reduce factors that will cause discrepancies in the experimental results. The solar dryer with 4 drying chambers was constructed in 1 unit and tested the performance of passive solar dryer (PSD) and active solar dryer (ASD). Air flowrate of ASD varied at 0.03 m³/s (ASD0.03), 0.06 m³/s (ASD0.06) and 0.09 m³/s (ASD0.09). Pork was selected as testing material with initial moisture content of 265% dry basis. Drying rate, solar dryer efficiency and specific energy consumption are criteria to evaluate of solar dryer performance. Result from the experimental was found that the performance of PSD is lowest compared with ASDs. Furthermore, it was revealed that the drying rate of ASD0.06 is higher than that for PSD, ASD0.03 and ASD0.09 by 22% 10% and 8%, respectively. Results from the experimental reveal the ASDs performance are higher than that of PSD. Moreover, it was found that the drying rate of ASD0.06 is higher than that for PSD, ASD0.03 and ASD0.09 by 22% 10% and 8%, respectively. Whereas, specific energy consumption of ASD0.06 is lower than that PSD, ASD0.03 and ASD0.09 by 26%, 11% and 9%, respectively. Finally, it was also found that solar dryer efficiency of PSD, ASD0.03, ASD0.06 and ASD0.09 are 11.68%, 13.34%, 14.89% and 13.73%, respectively.

Abstract: The current work presents about the development of thermal energy storage (TES) using paraffin wax as a phase change material (PCM). In order to investigate the performance of TES as a supplemental heat source for solar dryer when no sunshine, the TES was connected with solar dryer having maximum capacity for 10 kg of fresh chilies. The TES unit consists of 28.35 kg PCM and copper tube inside the cylindrical tank. The charging process of the TES is carried out with the help of electrical heater. The paraffin wax in the TES starts to melt and absorb the energy till it turns to liquid state. For heat discharging process during the off sunshine hours, air with mass flow rate of 0.0023 kg/s at ambient temperature can be passed through the copper tube in the TES in order to provide hot air for the dryer. From the performance analysis results, it is observed that the temperature of drying chamber can be maintained about 40-50 °C for 3 hours at least after sunset and higher than ambient temperature about 16.72 °C. The novel design of TES successfully increases the performance of the drying systems and reduces the time for drying process.

Abstract: This paper presents the results obtained in the process of drying bananas using solar energy, in order to spread the culture of renewable energy and to promote sustainable development. The use of solar energy is important because of its characteristics of being clean and widely available throughout Brazil, mainly in the Northeastern part of Brazil. Developing equipments using solar energy as an energy source in the Northeastern region of Brazil contributes to promote social-economic growth, thereby reducing social inequalities in the region. Among the various types of fruits produced in Brazil, we chose bananas because of its large domestic production, and its economic and nutrition contribution. Bananas have great postharvest losses, since it is extremely perishable. The study aims to change fresh bananas in dried bananas, which has high added value. The solar drying of banana with the use of indirect radiation dryers turns to be a viable alternative to small, medium and large bananas producers. We present data obtained from experiments on drying bananas through the solar dryer developed in UFCG. The experiments showed statistical significance, and the used empirical model proved to be reliable and representative because of the high values of the correlation coefficients that approached 0.99. In this work, we also present the constructive and operational characteristics of the equipment under development.

Abstract: 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.

Abstract: 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 8.26^oN and the collector angle could be varied . 56^o C, 41^o C and 71^o 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.

Abstract: The photovoltaic (pv) forced convection solar dryer comprises the solar collector, dryer and pv assemblies. It is designed for a continuous operation throughout the day. The direct solar irradiation is utilized during sunshine hours and it automatically switches power supply to the battery during cloud covers and non-insolation periods. The inclusion of a heat reservoir enables heat transfer to continue during this period. In this study, thermal and dryer analyses were done. Experimental investigations were carried out to evaluate the performance of the system by drying plantain chips. The useful power collected was found to be, 391.50W, collector efficiency, 65.6%, dryer efficiency, 39.6%, average drying rate during insolation, 0.0169kg/hr and total drying time was 23 hours. The maximum temperature attained was 55oC. The average drying non insolation period was 0.0112kg/hr. The capital cost is less than $350.

Abstract: This solar conversion system incorporates a suction fan powered by a solar PV module. Located at the outlet of the chamber is the d.c suction fan utilised to achieve forced air circulation without the use of external power supply like grid electricity, fossil fuel and battery. Simple thermal energy balance equations and heat transfer equations were employed in the design of the system. The operational efficiency of the collector is 83.2% and mass flow rate 1.58kg/min, the maximum temperature achieved in the chamber was 58oC. The system was used to dry vegetable, hydrophylum. The capital cost is less than $150.