Designing, manufacturing and performance evaluation of small scale solar dryer for parboiled rice drying

Berihun, Walelign

dc.contributor.author	Berihun, Walelign
dc.date.accessioned	2020-06-04T06:02:11Z
dc.date.available	2020-06-04T06:02:11Z
dc.date.issued	2019-12-17
dc.identifier.uri	http://hdl.handle.net/123456789/10867
dc.description.abstract	An indirect mode convectional solar cabinet dryer consisting of a solar air heater and dryer chamber is designed, manufactured, simulated and tested for its performance. It plays a major role in reducing postharvest loss of grains and opens a way to food preservation. The dryer was designed based on the climatic conditions of Bahir Dar, Ethiopia. The average ambient conditions were 22ºC air temperature and 67% relative humidity with daily global solar radiation incident on horizontal surface of about 600w/m2. This study describes the design considerations and results of calculations of design parameters. A minimum of 2.91m2solar collector area was required to dry a batch of 50kg rice grain in 7 hours under natural convection from the initial moisture content of 23% to final moisture content of 13% wet basis. Using similarity laws a dryer with collector area of 0.7m2was fabricated and used in experimental drying tests. The average thermal efficiency of the solar collector is calculated to be 36% in natural convection at air flow rate of 0.0096 kg/s and 62% in forced convection at air flow rate of 0.07kg/s . Besides the maximum temperature of the solar dryer attained at the absorber plate is 75°C at 1:00 am in natural convection experiment and when the solar radiation intensity reached 1200 W/m² during no load test. The CFD simulation is very useful tool to predict the air velocity, temperature and pressure inside the chamber and collector plate. The maximum plate temperature in both natural and forced convection CFD simulation are 81oC and 74.7oC respectively. The maximum temperature in both natural and forced convection inside the drying chamber is 60.4oC and 37oC respectively.	en_US
dc.language.iso	en	en_US
dc.subject	Energy Center	en_US
dc.title	Designing, manufacturing and performance evaluation of small scale solar dryer for parboiled rice drying	en_US
dc.type	Thesis	en_US