Characteristics Mathematical Model For Infrared Radiation Drying Of Carrot Slices

With the characteristics of higher efficiency, more energy saving and more environmental, the far-infrared heating and drying technology are widely used in the processing of agricultural and sideline products. However, the infrared drying process is a more complex unsteady heat and mass transfer process, the change of the test conditions has a very significant effect on the drying rate and the quality of the dried products. Various aspect factors was acted on the processing of infrared drying, several controlled test conditions with carrot slices selected to test in order to analyze the drying characteristics. Moreover, there has a in-depth research in carrot slices infrared drying model, and several common drying mathematical model was analyzed and contrasted for establish the most suitable mathematical model to describe the processing of carrot slices infrared drying.Aimed at the effective diffusion coefficient in the of mathematical model, derivation and analysis was realized for explain effective diffusion coefficient in the different conditions. This is all for provide a guidance in the processing of carrot slices infrared drying.The main contents and conclusions are as follows:Firstly, characteristics of infrared drying in carrot slices. Irradiation distance,slice thickness and drying temperature selected as the test conditions to analyze the influence on infrared drying rate; the appropriate factor levels should be selected for orthogonal test, for the sake of analyze moisture change and the rate of drying of sliced carrots in the different experimental conditions used to looking for optimal experimental conditions. Therefore, there are more important impact for the improvement of the test bed to achieve the purpose of energy saving and high quality.By calculating moisture diffusion coefficient in condition of drying,,the effective moisture diffusion coefficient of 4.4632×10-10 and 9.55459×10-10 m2/s.The results food drying process side of the effective diffusion coefficient of 10-9 and 10-10m2/s reported by Madamba is very match.by comparing the changes in the effective moisture diffusion coefficient under the respective conditions,that can be conclude that more higher the drying temperature, more greater the slice thickness, less lower the irradiation distance, the effective moisture diffusion coefficient Deff increases more, and the drying temperature have the greatest impact on the diffusion of water.The results showed that in three different test conditions, the irradiation distance, the slice thickness and the drying temperature. The maximum influence on drying rate was caused by drying temperature, the slice thickness was next,irradiation distance was the minimal impact in infrared drying.Secondly, select comparing the size of the R2 and RMSE values in three common dry mathematical model, a more suitable drying model used to describe the infrared drying process of carrot slices.The results showed that, among the single diffusion model,the index model and Page model three common dry mathematical model,the Page model had the highest simulation degree, the maximum error of the predicted values with the experimental values of only 6.53%, can be very good infrared drying process is used to describe the carrot slices.Thirdly, carrot slices infrared drying model. Compare eight different drying model, choose the most suitable model equation is used to describe the the carrot slices infrared drying process.The results showed that Midilli equation fitting by comparing the 8 different mathematical models R2 and RMSE values, preferably, R2 and between 0.9998 and 0.9999, RMSE values was between 0.001681 and 0.005021, the most suitable to describe the process of carrot slices infrared drying.