Based on the even mat model, the influence of unevenness of wool mat on the overall performance of suction-drum dryer is analysed numerically, and a mathematical model for expressing the mat thickness distribution is proposed. The results show that the uneven distribution of wool mat on the drums will cause an increasing of average moisture content in the product and a decreasing of throughput of the dryer, so that the practical design capacity of the dryer must be larger than the capacity calculated by the...