scholarly journals Design consideration of smart solar dryer for precision drying

2021 ◽  
Vol 8 (2) ◽  
pp. 135-138
Author(s):  
TH BIDYALAKSHMI DEVI ◽  
YOGESH B KALNAR

A sensor based solar dryer was designed to control the drying environment for precision drying of agricultural produce. The system entirely used solar energy utilizing both thermal and electrical effect. Paraffin wax (PCM) was used for storage of thermal energy whereas solar battery was used to store the electrical energy. Hot air blower was also provided to supply heat when there is less or no solar radiation. Temperature sensors were provided to control the environment of drying chamber. The exhaust fan started operating depending on the set temperature and thus control the drying environment. Load cells were provided below each tray to measure the dry weight. The drying chamber was made of mild steel with glass wool insulation. The capacity of the designed dryer was 10-15 kg with 6 trays. The designed dryer has target temperature of 55-60oC.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
A. O. Adelaja ◽  
B. I. Babatope

Solar dryers are imperative for the tropical and sub-Saharan African countries, which are faced with the duo challenges of inadequate electrical energy supply, which has severely limited the application of conventional refrigeration as a means of preservation of agricultural produce, and the need to make produce competitive in the international market. In this study, a cost-effective natural convection solar dryer was developed; the thermal and drying analyses were done and tested to obtain some performance evaluation parameters for the system in order to examine its efficiency and effectiveness by drying some plantain fillets. The collector and system efficiencies are found to be 46.4% and 78.73%, respectively, while a percentage moisture removal of 77.5% was achieved at the 20th hour in order to give final moisture contents of 15.75% in the product, which still maintained its integrity. With a cost of about $195.00, it has been affordable for the small- and medium-scale enterprises as well as for private use in domestic applications.


2011 ◽  
Vol 367 ◽  
pp. 745-752
Author(s):  
C.O. Ilechie ◽  
G.F. Aibangbee ◽  
S.R. Ogblechi ◽  
B.O. Abikoye

In this work an electrically operated thermostatic multipurpose dryer is developed and evaluated. It measures 2,300mm long, 600mm wide and 1,100mm high and consists of 50mm x 50mm mild steel angle iron and aluminium sheet wrapped all over it. The interior of the dryer is painted black to ensure maximum heat retention within the system for faster drying. The multipurpose dryer is constructed with the incorporation of vents to enable uniform air circulation within the system. This is to facilitate uniform drying of specimens. The development of the dryer is to help minimize losses of agricultural produce by drying them to the required moisture content that will enable them to be kept in storage. The dryer was used to determine the moisture content of coconut meat and it was found to be 53.47% and 1.15% wet and dry basis respectively. The dryer could be used to dry all agricultural produce to the required moisture content that will enable them to be preserved. This is achieved by selecting the appropriate temperature graduated on the dryer. The equipment has hot air at a velocity of 18.7m/s distributed uniformly across specimen trays in the drying chamber. As the hot air passes over agricultural produce in trays, the drying process takes place. It has been found that the multipurpose dryer is suitable for drying agricultural produce and other allied produce to the required moisture content up to a maximum temperature of 1100C. The dryer efficiency was determined to be 75%.


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.


2013 ◽  
Vol 770 ◽  
pp. 80-83 ◽  
Author(s):  
Nattapon Srisittipokakun ◽  
Keerati Kirdsiri

This paper describes a mixed mode natural convection of solar dryer. The dryer was designed for small-scale commercial producers of agricultural products in non-electrified locations. The products to be dried are placed in multi layer on a wire mesh in the drying tunnel to receive energy from both hot air supplied from the collector and incident solar radiation on products. Temperatures in the drying chamber varied from 28.0° C to 55.0° C depend on the weather conditions. To investigate its performance, the dryer was used to dry 30 kg of Centella asiatica in December 2012. The dryer could be used for Centella asiatica of 80% (wb) moisture content, and they could be dried within 4 hours, with 0% (wb) remaining moisture. In addition, the Centella asiatica being dried in the solar tunnel drier were completely protected from rain, insects and dust, and the dried Centella asiatica were high quality dried products terms of flavor, color and texture. The drying efficiency of the solar component alone was found to be 39.18%.


Author(s):  
Barki. E ◽  
Ukwenya J ◽  
Idoko F

Solar dryer with backup incinerator was fabricated with the aim of improving the efficiency of the drying rate of selected agricultural products. The dryer consist of three main parts, the collector, the drying chamber and the incinerator. 1000g of chill pepper was sun dried and 1000g was charged into the dryer for the experiment. Drying using solar drying process was carried out during clear weather while incinerator drying process was carried out during cloudy weather and at nights The collector, dryer and incinerator energy efficiencies were determined and reported elsewhere. Exergy analysis of the dryer was carried out for both solar drying and incinerator drying using the experimental values. The average exergy inflow and outflow during solar drying was found to be 266.97 KJ/Kg and 20.85 KJ/Kg respectively. The average exergy loss at airflow velocity of 2.7 m/s was found to be 269.3 KJ/Kg for incinerator drying. The exergy efficiency of the incinerator fluctuates as it starts from 7.9, 11.1, 5.2, 13.5, 8.0 and 3.6 % for 8.00, 10.00, 12.00, 14.00, 16.00, 18.00 hrs respectively. The result also shows exergy efficiency of 83.1, 85.9, 91.7, 92.4, 89.0 and 73.4 % for 8.00, 10.00, 12.00, 14.00, 16.00, 18.00 hrs respectively during solar drying. The experimental and analytical temperatures values were observed to be solar radiation intensity dependants and are directly proportional with it. Although the heat losses are high for both drying processes, the dryer is suitable for drying agricultural produce during clear, cloudy weather and at nights.


2014 ◽  
Vol 979 ◽  
pp. 11-15 ◽  
Author(s):  
Nattapon Srisittipokakun ◽  
Keerati Kirdsiri

Pineapple was dried using a mix mode solar dryer developed in the Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom, Thailand. The dryer was designed for small-scale commercial producers of agricultural products in non-electrified locations. The products to be dried are placed in multilayer on a wire mesh in the drying tunnel to receive energy from both hot air supplied from the collector and incident solar radiation on products. It is constructed in local materials then tested experimentally in food stuffs drying pineapple. With this dryer, 40 kg of pineapple can be dried within 4 days. The dryer reduces drying losses as compared to sun drying and show lower operational costs than the artificial drying. Temperatures in the drying chamber varied from 28.0 °C to 57.0 °C depend on the weather conditions. The dryer could be used for pineapple of 83% (w.b.) moisture content, and they could be dried within 4 days, with 15% (w.b.) remaining moister. In addition, pineapples being dried in the solar tunnel dryer were completely protected from rain, insects and dust, and the dried.


Food Research ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 62-66
Author(s):  
H.S. Song

In order to explore the change of lipid oxidation of half-dried eels treated with green tea extracts and stored frozen, acid values, peroxide values, carbonyl values, and TBA values were measured. The eels were placed into the plastic bag and soaked for 1 hr in the solution mixed with distilled water and green tea extracts, and also vacuumed and stored frozen at –18 ∼ –20°C for 9 months after being dried with a hot-air blower for 15 hrs at 35°C (Aw 90-91). The control consisted of eels prepared in the same way without any pretreatment. At the end of the 1st month, 3rd month, 6th month, and 9th month, eel oil obtained from the samples were tested for its lipid oxidation. The activity of green tea extracts 1 mL was very similar to Vitamin C 500 μM 0.8 mL. The acid values, peroxide values, carbonyl values, and TBA values of eels treated with green tea extracts were lower than those of the control during 9 months of frozen storage (p<0.05). While the acid values and peroxide values of the control and eels treated with green tea extracts highly increased after the first month of frozen storage, the TBA values increased greatly on the third month of frozen storage. Compared to the control, the pre-application of green tea extracts to half-dried eels meaningfully prevented the generation of TBA compound during the frozen storage (p<0.01). In conclusion, pre-application of green tea extracts was effective in delaying early-stage peracid inducement and preventing the generation of secondary oxidation compounds, such as carbonyl compound and TBA compound, in the course of the drying and frozen storage


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 350 ◽  
Author(s):  
Wengang Hao ◽  
Shuonan Liu ◽  
Baoqi Mi ◽  
Yanhua Lai

A new hybrid solar dryer was designed and constructed in this study, which consisted of a flat-plate solar collector with dual-function (DF-FPSC), drying chamber with glass, fan etc. The DF-FPSC was firstly applied in drying agricultural products. The innovative application of hybrid solar dryer can control the drying chamber air temperature within a suitable range by different operation strategies. Drying experiments for lemon slices in the hybrid solar dryer were conducted by comparing open sun drying (OSD). Eight mathematical models of drying characteristics were employed to select the most suitable model for describing the drying curves of lemon slices. Furthermore, energy, exergy economic and environment (4E) analysis were also adopted to analyze the drying process of lemon slices. The results show that under the same experimental condition, the drying capability of the hybrid solar dryer was stronger than that of OSD. Meanwhile, it was found that the Two term and Wang and Singh models were the most suitable for fitting the lemon slices’ drying characteristics inside the hybrid solar dryer. The drying chamber air temperature can be controlled under about 60 °C during the process of lemon slices’ drying. The experimental results show the feasibility and validity of the proposed hybrid solar dryer.


2013 ◽  
Vol 135 (3) ◽  
Author(s):  
S. Shanmugam ◽  
P. Kumar ◽  
AR. Veerappan

This paper presents a mathematical model for drying agricultural produce using a solar dryer capable of oscillating its bed while kept at an inclined position with respect to vertical. A model of the solar dryer with double-pass flat plate collector and an oscillating-bed has been fabricated and tested for drying agricultural produce (sunflower seeds). The model can predict the change in the absolute humidity of air across the bed, the temperature of the air, the moisture content, and the dryer thermal efficiency. Sunflower seeds were dried on a physical model of the solar dryer with its bed tilted at different angles and oscillated at different frequencies. The predicted and the experimental results are in good agreement. The average error and standard deviation for the absolute humidity of air across the bed is 1.74 and 1.55%, the exit temperature of air leaving the bed is 1.11and 1.21%, and the dryer thermal efficiency is 0.78 and 1.33%, respectively.


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