The influences of hot-air temperature

speed

relative humidity and blowing way(parallel and vertical)on drying characteristics of camphor were studied on a self-built hot air drying test bench.The results show that the whole drying process includes two phases

the constant speed phase and the declining speed phase.The hot air temperature is the main factor affecting the drying process

and vertical flow can increase the drying rate.This result was confirmed by Fluent simulation.On the basis of the test data

nonlinearly fitting was also conducted for four drying models.Comparison between the value of relative correlation FR2

the residual sum of squares FRSSand the root mean square error FSDindicates that the Page model is the optimal model for describing camphor hot air drying process at low temperature.The effective moisture diffusion coefficient Deffis affected greatly by the temperature

it increases with the temperature

while the hot air humidity

speed and blowing mode have little effects on the Deff.