Performance study of solar vacuum tubes type dryer

Abstract

In the present work, a solar vacuum tubes type dryer is designed, fabricated, and tested for drying of different fruit and vegetable samples. The selected fruits and vegetables such as pineapple, apple, banana, guava, beans, brinjal, carrot, lady finger, and potato were dried separately by the open sun drying and by the solar dryer under consideration, and the drying efficiencies of the two methods were compared with each other. While conducting experiments on fruit samples, the solar air heater efficiency varied from 59% to 80% and the corresponding solar dryer efficiency and open sun drying efficiency were found to vary in the range of 55%–78% and 3.0%–5.0%, respectively. Similarly, while conducting experiments on vegetable samples, the solar air heater efficiency varied from 73%–84% and the corresponding solar dryer efficiency and open sun drying efficiency were found to vary in the range of 70%–79% and 3.0%–3.6%, respectively. The solar dryer reduces the average moisture content from 0.32 to 0.85 kg for drying fruits and from 0.36 to 0.71 kg for drying vegetables. The time taken by open sun drying is almost 1.5 times that taken by vacuum tubes type dryer under consideration and the final moisture content of the product in open sun drying is also higher. Therefore, in terms of utilisation of solar energy, solar vacuum tubes type collector dryer may be considered to be the best method for drying fruits and vegetables within a short period of time.

Application of ANN and prediction of drying behavior of mushroom drying in side hybrid greenhouse solar dryer: An experimental validation

“…This phenomena increase the efficiency of this types of collectors [19], [20], [21], and therefore performance of drying system would be higher assisted with ETSC as compared to FPC in term of efficiency. A few numbers of researchers conducted investigation on drying system assisted with ETSC [22], [23]. A number of experiment have been carried out on drying behavior of different foodstuff product for example rice [1], cassava [2] ginger [24], [25] pork strips [26], prickly pear cladode [27], tomato [28], onion [29], and grapes [30], [31], [32], [33].Further, literature has also stated that no study has been conducted on the drying of mushroom in solar drying with ETC.…”

Efficient solar drying techniques: a review

“…In a FPC convection heat loss is more as well as it can be used with applications that require moderate temperatures. Mahesh et al (2012) fabricated the forced convection indirect type solar dryer using an ETC integrated with a cylindrical drying chamber as shown in Fig. 8a.…”

“…As adequate food preservation methods are not available, farmers have to spread their products to be dried in thin layers on open grounds or on mats where they are exposed to sun and wind. Mahesh et al (2012) reported that significant losses may occur during natural sun drying because of various influences, such as rodents, birds, insects, rain, storms and microorganisms. The quality of the dried products by the open sun drying may also be degraded Responsible Editor: Philippe Garrigues significantly.…”

“…Fig.8Forced convection indirect type solar dryer using (a) an ETC without energy storage(Mahesh et al 2012) and (b) an ETC attached with shell and tube heat exchanger and drying chamber(Singh et al 2018) …”

Development and Performance Analysis of New Solar Dryer with Continuous and Intermittent Ventilation

“…This leads to extensive research on renewable energy applications including solar drying. Compare to open sun drying, solar dryers put the product being dried in closed space which gives better and hygienic results (Mahesh et al 2012). Solar drying is becoming a popular option to replace the mechanical thermal dryers due to costly, limited, and non-environmentally friendly of fossil fuels.…”