Study On Drying Technology Of Thomson Seedless, Jujube And Apricot With The Equipment Of Drying Fruits And Vegetables By Series Parallel Solar Energy

Solar drying is an energy-saving method of drying fruits and vegetables. The article had introduced the equipment of drying fruits and vegetables by series parallel solar energy, The the main materials of study were Thompson Seedless, Ha Mi Jujube and apricot. The change trend of temperature were studied in this paper ,including the import temperature of equipment, the export temperature of equipment, the temperature of environment and the temperature of the airing house; The change trend of relative humidity were also studied in this paper, including the import relative humidity of equipment, the export relative humidity of equipment , the relative humidity of the environment and the relative humidity of the airing house; The moisture content changes of Thompson Seedless, Ha Mi Jujube and apricot; The wind speed changes of the equipment was also researched . The process of Thomson seedless Jujube and apricot were introduced and the drying mechanism was preliminary studied. The results of study as following:Drying results of Thompson Seedless:(1)From September 18 to October 17, 2007, the import temperature of equipment was higher than the environment, the average temperature was 18.5℃, the import temperature of equipment was higher than the airing house, the average temperature was 21.1℃, the average temperature of Import and Export of the Equipment was 8.5℃. the effect of solar equipment was obvious, increased the use of solar energy widely. The import temperature of equipment > The export temperature of equipment > The temperature of environment >The temperature of the airing house. The import relative humidity of equipment < The export relative humidity of equipment < The relative humidity of the environment<The relative humidity of the airing house. The drying cycle of Thompson Seedless grapes by the equipment < The drying cycle in the environment < The drying cycle by the airing house. The drying cycle of Thompson Seedless grape was 15d. The drying equipment prevented insect and dust from contaminating. The drying quality was also highly raised. The equipment may accommodate grapes about 3t. The dry product of raisins was about 0.75t. The excellent product rate raised from 35 percent to 79.19 percent.(2) The temperature of Ha Mi region in September was significantly higher than October, the best period of Thompson Seedless grape-drying was September. (3) The general trend of the wind speed at entrance of the equipment was: first increased and then decreased, temperature raised, wind speed raised, temperature reduced , wind speed is also reduced.(4) The drying rate curve of Thompson Seedless grape, refleced the process of drying rate changes, mainly divided into three stages, the moisture content changes from 77% to 74%, was adjust phase; the moisture content changes from 74% to 51%, was the constant speed stage ; water content dropped to 25% from 51% was the deceleration phase, the drying rate gradually declined, until the end of drying.Drying results of Ha Mi Jujube:(1) From September 11 to October 2, 2008, the Ha Mi Jujube drying time were 21 days, The import temperature of equipment > The export temperature of equipment > The temperature of environment. The import relative humidity of equipment < The export relative humidity of equipment < The relative humidity of the environment. During the period of Measurement, the average temperature of Import and Export of the Equipment was 3.8℃.(2) Because of the same harvest time, Jujube and Thompson Seedless grapes were dried together. Ha Mi jujube was placed on the tray, compared with Thompson Seedless grapes, the air resistance was more smaller, therefore the utilization of hot air is relatively low. Changes of the wind speed at entrance of the equipment was the same as Thompson Seedless.(3)The curve of Jujube's moisture content, reflected the moisture content changes during the drying process in the trend. Jujuba moisture content reduced to 64% from 14%. Drying curve was mainly divided into three stages, the moisture content changes from 64% to 61%, was an adjustment phase; Change from 59% to 48%, was mainly remove combined water, drying rate gradually increased; from 48% to 14%, was the descending speed stage.Drying results of Apricot:(1)From June 20 to July 2, 2008, the apricots drying time were 12 days, The import temperature of equipment > The export temperature of equipment > The temperature of environment. The import relative humidity of equipment < The export relative humidity of equipment < The relative humidity of the environment.(2) During the period of Measurement, the average temperature of import and export of the Equipment was 0.7℃.The air resistance was more bigger, the utilization of hot air was relatively higher. Therefore, Thompson Seedless grapes had better drying effect than Ha Mi jujube and Apricot. Changes of the wind speed at entrance of the equipment was the same as Thompson Seedless. (3) The curve of apricot's moisture content, reflected the moisture content changes during the drying process in the trend. Moisture content of fresh apricots changes from 78% to 15%. Apricot drying process was relatively slow, Drying curve was mainly divided into three stages, the moisture content reduce from 78% to 75%, was the adjust drying stage; Change from 75% to 62% to become stable; from 62% to 15% was the deceleration phase.The test tested the equipment of drying fruits and vegetables by series parallel solar energy, provided a theoretical basis for the equipment, which made a solid foundation for the equipment spread further in Xinjiang in future.