The drying kinetics data of sludge in a paddle dryer were utilised for scaling up of batch dryer and continuous dryer. In the scaling up of batch dryer, the drying kinetics data can be directly used for drying area calculation. The moisture content of sludge at different drying time can also be easily determined. In the scaling up of continuous dryer, the dryer was partitioned into a series of drying units. Thus the the average drying rate in different drying unit can be calculated based on the drying kinetics data, as well as the important design parameters such as drying surface area, evaporation capacity and moisture distribution in continuous dryer.