Utilization of Solar Energy for Drying Sugar Beet Tops (original) (raw)

Experimental analysis of solar drying system for vegetable and fruits

Journal of Thermal and Fluid Science, 2020

A performance analysis of a sun drying system for vegetables and fruits is the subject of this study (Grapes, Potato, Onion and Banana). Drying 5 kg of Vegetable & Fruits using the dryer Study the influence of drying, as well as environmental and operational conditions, on the performance of the drier. The experiment was conducted both with and without a reflecting mirror, and the results were compared. In the absence and presence of reflecting mirrors, the highest collector outlet temperature was 66 o C and 81 0 C, respectively. According to the results, ginger can tolerate a maximum of 65 0 C in a dryer without a reflecting mirror, but not one with one. The maximum temperature for ginger is 65 0 C when the dryer has a reflective mirror installed. On average, efficiency without and with a mirror was 53.14% and 79.39% whereas it was 53.14% when using a mirror and 61.84% when using a mirror, respectively Reflectors enhance the average efficiency of the collector by 8.04%, according to the study. Ginger's original moisture content was 82.95%, and it required 16 hours of daytime drying in a solar dryer to achieve its equilibrium moisture level of 12%, and 48 hours of open sun drying with 8 hours of drying each day to reach the same level. Fruits and vegetables dried in a dryer took 66.7% less time and had better quality than those that were sun-dried.

A study of drying rate of some fruits and vegetables with passive solar dryers

The two passive solar dryers designed and constructed were with available local materials. The passive solar dryers which were direct and indirect type was tested with pepper, okro and vegetables in order to know the drying rate of these produce. 180g of freshly harvested pepper with moisture content of 78.9 % (w.b) were reduced to 24.0 % (w.b). The drying rate in the direct passive solar dryer was found to higher than the indirect passive solar direct. 1000 g of okro with initial moisture content of 92 % (w.b) was reduced to 20% (w.b) The drying rate in the direct passive solar dryer was found to higher than the indirect passive solar direct. 400 g of vegetable with initial moisture content of 90 % (w.b) was reduced to 20 % (w.b). The drying rate in the direct passive solar dryer was found to higher than the indirect passive solar direct. During the course of drying after the crop is kept inside the drying system the temperature of each drying was monitored after one hour interval, the moisture content of the crop was also monitored after three hours interval until there is no more change in the weight of the crop. The crop dried inside the direct solar dryer dried faster than the indirect passive solar dryer. As result of highest temperature attained in the direct passive solar dryer the rate of moisture removal was high in this dryer

Drying rates of some fruits and vegetables with passive solar dryers

Two passive solar dryers were designed and constructed with available local materials. The passive solar dryers which were direct and indirect types were tested with pepper (Capsicum annum L.), okro (Abelmoschus esculentus L.) and vegetables (Amaranthus hybridus L.) in order to evaluate the drying rate of these produces. The moisture content of 78.9% (w.b.) for 180 g freshly harvested peppers was reduced to 24.0% (w.b.). The drying rate in the direct passive solar dryer was found to be higher than the indirect passive solar dryer. The initial moisture content of 92% (w.b.) for 1000 g okro was reduced to 20% (w.b.). The drying rate in the direct passive solar dryer was also found to be higher than in the indirect passive solar dryer. The initial moisture content of 90% (w.b.) for 400 g vegetable was reduced to 20% (w.b.). The drying rate with the direct passive solar dryer was found to be higher than that with indirect passive solar dryer. During the course of drying, after each crop was kept inside the drying system, the temperature of the drying was monitored at an-hour interval; the moisture content was also monitored at a three-hour interval until there was no more change in the weight of the crop. The crops dried faster with the direct passive solar dryer than with the indirect passive solar dryer. As a result of the highest temperature attained in the direct passive solar dryer, the rate of moisture removal was the highest in this dryer.

Effect of Drying Conditions on Properties of Dried Sugar Beet

2010

Drying behavior of sugar beet was investigated in a bench scale fluidized bed dryer with an energy carrier (3 mm glass beads) and a freeze dryer. The effect of the type of dryer (fluidized bed dryer & freeze dryer) on the rate of drying and properties of dried sugar beet were studied. It was found that drying could be useful for the storage of sugar beet for a long time before processing, but the removal of more than 90% of its initial water content is necessary for the dried sugar beet to conserve its sugar content and other properties during storage. The results of experiments in two different dryers showed that drying time in a fluidized bed dryer with energy carriers is much less than that of a freeze dryer, but the dried matter obtained by the freeze dryer has a better appearance in comparison to fluidized bed dryer. Also, the shrinkage of drying material with a change of moisture content was investigated and it was seen that a linear relation with reasonable error between thes...

A review of solar drying technology for agricultural produce

The Indonesian Journal of Electrical Engineering and Computer Science (IJEECS), 2023

Agriculture contributes to large export earnings for many countries and provides food all over the world. However, most agricultural products need some post-harvest processing, such as drying, to extend their shelf life while still maintaining their respective nutrient quality. One popular post-harvest processing method is drying using solar energy. It is a type of renewable energy that is abundant and free. Conventional dryers use grid electricity and can be expensive to operate. Consequently, there is a growing need for costeffective solar-powered agricultural dryers that is reasonable for smaller-scale farmers. Although current solar dryers are still not on par with modern electricity-powered dryers, solar dryers have lower running costs and are sustainable and able to generate electricity. They can also be used practically anywhere with abundant solar energy. As numerous solar drying technologies have been proposed over the past decade, it is necessary to assess the current state of solar drying technology in the agricultural sector to identify current advancements and potential research gaps. In this paper, a review of existing solar dryers mechanism and the state of the art of solar drying technology research for agricultural products is presented.

Performance characteristics of solar drying system for agricultural products

Drying has important influences on agricultural products' quality and storage. Drying characteristics of different agricultural products vary. Temperature and velocity of drying airflow affect greatly drying quality and drying efficiency of agricultural products. Two types of solar drying systems for different drying temperature requirement were designed and characterized in this paper: solar air drying system with plate air collector and solar parabolic trough concentrating drying system. In solar air drying system with plate air collector, the drying oven has two ventilation modes. With top inlet and bottom outlet ventilation mode, the overall temperature in drying oven is relatively high, however large vertical temperature difference exists in drying oven. With bottom inlet and top outlet ventilation mode, the temperature in drying oven is uniformity, however relatively low. In notoginseng drying experiment, the drying time is shortened to half of that in nature drying. The average thermal efficiency is 66.5%. The solar trough concentrating drying system utilizes a low cost and reliable V-type metal cavity to collect solar irradiation. In the system, the heat conducting oil can be heated to 230℃, and the air flow from heat exchanger reaches above 200℃. The tobacco shred drying experiments verifies that the drying temperature of the system meets the tobacco shred drying requirement. Solar trough concentrating drying system matchts the drying temperature scope of 80℃~200℃.

Intensification of the Plant Products Drying Process by Improving Solar Dryer Design

Journal of Engineering Thermophysics, 2018

The article presents the rationale for production of dried fruits and vegetables using a solar drying unit. To intensify the drying process, convection of drying agent flow in the proposed drying chamber is studied using Navier–Stokes equations. Numerical methods are used for solving equations describing the process of convective heat transfer. As a result, graphical interpretations of isolines of drying agent flow are obtained and location of passive zones in the dryer chamber are identified. Uniformity of the temperature zones in the chamber is ensured by supplying additional drying agent into the passive zones. Temperature values at various levels of the drying chamber are experimentally obtained. Results for drying cut-up mass of vegetables and fruits are presented.