Performance evaluation of modified forced convection solar dryer with energy storage unit for drying of elephant apple (Dillenia indica)

Abstract

The development and performance of a modified force convection solar dryer (MFCSD) for drying elephant apple slices have been presented in this research. The MFCSD consists of two solar collectors and a drying chamber of 20 kg drying capacity. The secondary collector is integrated with thermal energy storage unit using a phase change material-paraffin wax. Performance analysis of the MFCSD was studied for drying elephant apple (Dillenia indica) slices. The proposed design enhanced the collector thermal efficiency by 12% as compared to a conventional glass collector. Drying of elephant apple slices in MFCSD will limit exergy losses and increase exergy efficiency. The estimated uncertainty of the collector chamber and the drying unit of the proposed MFCSD were obtained as ±3.3% and ±1.0%. Quality analysis (proximity analysis and textural properties) of the fresh as well as samples dried in open sun drying, tray drying, and MFCSD was carried out. The contents of carbohydrates (47.85 ± 2.66) and protein (21.24 ± 1.68) were high in samples dried in MFCSD when compared to samples dried in other two methods. The ash content of the sample dried in MFCSD was found to be 10.25 ± 0.15%, which was higher than samples dried in tray dryer. The payback period for drying elephant apple in MFCSD is 2.56 years, which is lower than the lifetime period (20 years) of the dryer. Practical ApplicationsA traditional method practiced by small farmers for drying high-value perishable fruits is conventional open sun drying (OSD). Owing to slow drying rate and excessive heating, products dried under the open sun lose their nutritious and medicinal qualities. The present work details the construction of a low-cost solar dryer for the drying of elephant apple. The aim of the drying kinetics to develop the architecture aspects of the solar dryer is to refine the drying systems. The results showed that the performance of modified force convection solar dryer (MFCSD) assisted with thermal storage could improve the quality of dried elephant apple slices and reduce drying time in comparison with an OSD method and a tray drying method. MFCSD would Abbreviations: A, area (m 2 ); Cv, air volume heat capacity (J/kg K); A % , ash percentage (%); Cp, dry air heat capacity (J/kg K); Exeff, exergy efficiency (kW); Ex in , input exergy (kW); Ex loss , exergy loss (kW); F, mass flow rate of dry air (kg/s); Fc, fiber content in the drying sample; F % , sample fat (%); H, humidity (%); hc, convective heat transfer coefficient (W/m 2 K); M i , initial moisture content; m i , sliced elephant apple initial mass (g); m oven , mass of sliced-dried sample using oven (g); m s , mass of sliced sample dried in MFCSD (g); M t , moisture content at time (t); T, temperature ( C); Vd, dry air volume in dryer (m 3 ); W, weight (g).

Latent Heat Storage System Based Mixed Mode Indirect Solar Dryer for Drying Myrobalan

“…The collector mounted on an iron frame with an inclination angle of 23° along north-south for trapping maximum solar radiation. The unique feature of the collector was polycarbonate glazing cover and compared thermal conductance with the existing glass 03022-2 cover type-solar dryer [4]. The polycarbonate glazed sheet of 6mm mounted as a solar observer and 5mm thick aluminum sheet was acting as a heat-absorbing bottom plate, and the aluminum tubes were used to increase the thermal conductance in the collector.…”

Performance analyses of Modified Indirect Solar Dryer with Integrated Thermal Storage Material for drying of Dhekia (Diplazium esculentum) fern

“…The base plate and a rectangular partition in the collecting chamber were made of 0.5 mm thick aluminium sheet. To increase thermal efficiency, ambient air was drawn into the collector and routed along the zig-zag channel (Saikia et al, 2022). A flange section was supplied at the collector's top end (air output) to attach the flexible connector with nuts and bolts.…”

“…10, the TPC and TFC values decreased significantly during drying. This result could be attributed to bound phenolic compounds disengaging from cellular components and releasing free phenolic compounds (Saikia et al, 2022;Krishnan et al, 2020).…”

“…In a variety of local cuisines, the tender young shoots are used in stirfries and salads (Junejo et al, 2018;Archana et al, 2012). Dhekia is the name locally used to refer Diplazium esculentum fiddleheads in Assam, NER India (Saikia et al, 2022;Srivastava & Rao, 2019). The fern is said to have a variety of therapeutic benefits like antioxidant, antiinflammatory, anticarcinogenic, and hepatoprotective properties, as well as anti-diabetic and wound healing properties some of which have been scientifically proven (Koniyo et al, 2021).…”

“…Exergy study of a solar dryer offers extensive data on how thermal energy is used within the dryer and estimates the heat that is not used. A number of different approaches on the energetic and exergetic evaluations of solar drying of various farm produce were conducted, such as star fruit (Kondareddy et al, 2022), elephant apple (Kondareddy et al, 2022), rosemary leaves (Karami et al, 2021), valerian rhizomes (Bhardwaj et al, 2021), black pepper (Lakshmi et al, 2021), blood fruit (Kondareddy et al, 2021), stevia leaves (Lakshmi et al, 2019), black turmeric (Lakshmi et al, 2018), ghost chilli pepper and ginger (Rabha et al, 2017), Jackfruit leather (Chowdhury et al, 2011) and mulberry (Akbulut & Durmuş, 2010).…”