BIPC fluidized bed PVC dryer was studied numerically in this research. Control volume method and standard k-? turbulence model has been used in order to simulate drying process and a UDF (User Defined Functions) has been adopted for moisture transfer modeling between phases. Velocity, temperature and humidity field have been calculated and results show a good agreement with results from PVC dryer in BIPC. Effects of inlet air velocity, inlet PVC velocity and heat exchanger capacity on velocity, temperature and humidity were checked. Outlet PVC moisture content was decreased with increased inlet air velocity and inlet air temperature. Flow structure investigations illustrates places which may result to occur dark PVC particles and presents circulating areas that normally increase residence time of PVC particles and which again create dark PVC particles. Some further modification on dryer also suggested based on flow structure, heat and mass transfer results.