Browsing by Author "Dhananjay Singh"

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Computational study of the performance of a solar dryer for improvement in the shelf life of the food materials
(Springer, 2024) Mukul Sengar; Dhananjay Singh; Pradeep Kumar Mishra; Deepak Singh; Balendu Shekher Giri
In this study, the thermal and drying characteristics of a thin layer food sample were investigated. An indirect type, simple, efficient, and economically feasible solar dryer was fabricated and used for food preservation. However, a dynamic model of a fabricated solar dryer was also presented to gain a better insight into the drying and thermal actions. This model consists of thermal modeling of the drying chamber, solar collector, and solar-dried food sample. The law of conservation of energy was applied to evaluate the temperature at different sections of the solar dryer with respect to drying time. All listed model equations were solved in the MATLAB environment. This study helps to examine the influence of solar radiation on the collector plate temperature, drying chamber temperature, food sample temperature, and performance parameters such as thermal efficiency with respect to drying time. Model data was found in good agreement with experimental data within a 4% error. It is concluded that the drying of food material is affected by air temperature, the collector temperature, mode of heat transfer, and material characteristics such as dimension and mass of the food sample. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
Drying kinetics, thermal and morphological analysis of starchy food material: Experimental investigation through an induced type solar dryer
(Elsevier B.V., 2023) Mukul Sengar; Reeta Rani Singhania; Deepak Singh; Pradeep Kumar Mishra; Dhananjay Singh; Manish Kumar; Balendu Shekher Giri
Solar drying is a green and clean energy-based technique for food preservation. In this study, drying kinetics and thermal, and morphological analyses of food material have been investigated. A mathematical model has also been studied and modified to validate experimental findings. An induced-type solar dryer setup has been fabricated and experiments have been conducted with potatoes as food samples. The weight loss and temperature variations were monitored in all three types of food samples. The average drying efficiency of the dryer has been found as 20.3 %. Scanning electron microscopy analysis has also been done to examine the surface morphology of the solar-dried food samples. The spherical-shaped sample has shown interesting results and they have the quality to attain maximum temperature due to the small surface area among all three shapes. The fabricated experimental setup has an initial cost and better payback period of $ 205.78 and 1.50 yr respectively. © 2023
Nelumbo nucifera leaves as source of water-repellent wax: Extraction through polar and non-polar organic solvents
(Elsevier B.V., 2022) Aradhya Dev Srivastav; Vireshwar Singh; Deepak Singh; Sunita Singh; Suresh Kumar Patel; Dilip Kumar; Sudeep Yadav; Balendu Shekher Giri; Dhananjay Singh
Nelumbo nucifera leaves are rich source of natural wax possessing super-hydrophobic properties. It provides protection to them from ecological turbulences and climatic wear and tear. In this study, various experiments have been conducted to observe the yield of extraction and the determination of various functional groups, which are present in natural wax, derived from Nelumbo nucifera leaves. The natural wax has been extracted from lotus leaves through non-polar (hexane) and polar (ethanol) solvent via different extraction methods. The superhydrophobic wax has been successfully extracted with hexane. Whereas, ethanol did not extract the water-repellent wax of lotus leaf. Considering the cumulative amount, i.e. (desired + undesired), the maceration shows the extraction of 2.9% (%w/w, through hexane) and 10.2% (%w/w, through ethanol), while it was found 2.5% (%w/w, cycle period 15 min) and 9.0% (%w/w, cycle period 26 min) respectively, in case of Soxhlet extraction technique. For this specific case of natural wax recovery from biomass (lotus leaf), the maceration (traditional method) resulted a little bit superior extraction yield in comparison to the Soxhlet extraction method for extraction of crude wax. In the case of non-polar solvent (hexane), an extraction yield of 1.97% (%w/w) through maceration method was observed while in the case of non-polar solvent (ethanol), an extraction yield of 1.62% (%w/w) through Soxhlet extraction was observed. The TLC analysis on both types of extracts was performed. For the detection of various hydrocarbon chains in the crude wax extracts, FTIR was also performed. Topography of wax surface and wax-coated waterproof fabric was compared through SEM. © 2022 Indian Chemical Society
Performance comparison of single and double slope solar still by experimental investigation
(Walter de Gruyter GmbH, 2025) Vinay Mishra; Dhananjay Singh; R. S. Singh; Balendu Shekher Giri
Life can't sustain without water. Sustainable development goal (SDG-6) emphasizes on access of suitable quality water to all. The amount of available freshwater on earth is very low and declining further. Human health, life quality and environment can be severely affected by the rising water scarcity. Desalination is the most widely adopted method to meet the global water demand. However, the adverse environmental impacts of existing desalination techniques necessitate the quest of sustainable methods. Solar distillation can be used for production of drinking water in a sustainable and economic manner. The current work evaluates and compares the performance of a small size single and a double slope solar still under similar climatic conditions. Both the stills are made of galvanized iron sheet and basin area is 0.36 m2. The productivity of single slope solar still (SSSS) and double slope solar still (DSSS) are found to be 2.58 L/m2 and 3.19 L/m2 respectively. The water yield of double slope solar still is observed to be 23.7 % higher than that of single slope solar still. Hence, the double slope solar still is observed to exhibit better performance. © 2025 Walter de Gruyter GmbH, Berlin/Boston.
Performance evaluation of solar dryer integrated with solar panel for drying of carrot (Daucus carota) vegetable
(Taylor and Francis Ltd., 2024) Mukul Sengar; Dhananjay Singh; Pradeep Kumar Mishra
Solar energy is a well-known and economically efficient energy source. Solar energy is harvested in two modes: one is direct and another is indirect. In the direct type, the global radiation is used directly to dry the food samples, while in indirect mode, solar energy is converted into electricity to operate the integrated exhaust fan for enhancement of the drying rate. Thermal analyses of the various components of the PVT hybrid dryer have been incorporated into this performance evaluation. Carrot has been chosen as a food sample because it has good moisture content and is used for nutritive purposes. The maximum ambient temperature has been monitored as 41°C at maximum global radiation conditions. The effect of the PVT system with solar dryer in both cases i.e. natural convection and forced convection have also been discussed in terms of temperature profiles of the drying chamber, sample temperature, and thermal efficiency. The thermal efficiency has been found as 55.3% for forced convection and 53.4% for natural convection. Similarly, a 3°C temperature increment has been found in food samples. Results have been supported and analyzed by the comparison between outcomes of natural and induced convection. © 2024 Indian Institute of Chemical Engineers.
Potable water production through a low-cost single chamber solar still in north India
(Springer, 2024) Vinay Mishra; Dhananjay Singh; Ram Sharan Singh; Deepak Singh; Eldon R. Rene; Balendu Shekher Giri; Sarthik Sharma; Anurag Mishra; Harishchandra Shukla
The main aim of this study is to evaluate the performance of a single slope solar still and to assess the effect of nanofluid on its performance. A single basin single slope solar still was designed and fabricated at the Department of Chemical Engineering, IET Lucknow. Its performance was assessed in terms of the yield of potable water. The effect of various climatic parameters was also studied. Al2O3 nanofluid was used to enhance the yield of the solar still. In the presence of nanofluid, the total yield of the solar still improved by 16.6%. Its economic feasibility was analyzed and reported. The portability of the small size of solar stills, its better economics, easy fabrication, and good performance make them very useful for industrial as well as household purposes. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.