Because industrial drying is one of the most energy-intensive batch unit operations

a scheduling plan of multi-effect drying was studied. Based on the rate of drying curve

operation time in each effect of multi-effect drying process was designed to be the same. An optimal plan and scheduling of multi-effect drying model was established. Defining the number of effects and the drying time as the decision variables

the minimum annual cost model of the batch n-effect drying process could be expressed as a mixed-integer non-linear programming (MINLP)problem

which could be solved by the GAMS software. An example of slit drying process (effect from 1 to 5) was analyzed with the model. The results indicated that the 4-effect drying was the optimal

and it could save 26% of the cost each year compared to the 1-effect drying. Optimal Gantt chart of scheduled process was also presented. According to the Gantt chart

the least period and the optimal operation process could be determined. It indicated that the batch multi-effect drying process could achieve continuous production.