Abstract:

Hawthorn was dried with an air-impingement jet dryer, and the effects of drying temperature, air velocity, drying
box width and distance from nozzle to material box on the drying characteristics and effective diffusion coefficient were
studied. In addition, the drying data were fitted to 7 drying mathematical models and the best drying model was screened
out. The results showed that air-impingement jet drying of hawthorn was a rate-falling drying process. The drying curve
and drying rate curve were significantly affected by air temperature but not significantly by air velocity, drying box width
or distance from nozzle to material box. The effective diffusion coefficient was increased with increasing air temperature
and air velocity, but decreased with increasing drying box width and distance from nozzle to material box. The maximum
effective moisture diffusion coefficient was 9.271 × 10-8 m2/s. The Page model and Modified Page model were the most
suitable for describing air-impingement jet drying behavior of hawthorn in the experimental conditions used in this study.

Key words: hawthorn, air-impingement jet drying, drying characteristics, drying model