Heat and mass transfer mechanism of drum fertilizer dryer

Drying is a simultaneous transfer process of heat and mass transfer, and the two processes are closely related. When the drum fertilizer dryer is working, the contact between the material film and the outer wall of the rotary drum is quite good after the wet material film is formed on the outer wall of the rotary drum. This assumption does not cause a large error in the calculation of heat and mass transfer in the drying of liquid materials, so it can be considered that there is no heating resistance between the material film and the outer wall of the drum.
The heat transfer mechanism of drum fertilizer dryer consists of three parts: convection heat transfer of the heating medium in the drum, such as steam condensation heat transfer; Heat conduction of scale layer, drum wall and material film; Convective heat transfer outside the film.