The Simulation Of Temperature Field During The Sintering Of MnZn Ferrite

The process of sintering of MnZn ferrite in tunnel kiln protecting by 29M nitrogen was studied in this paper.3-D model of kiln chamber was set up and meshed in the professional pre-processor GAMBIT of CFD. And then Reynolds stress model was selected as the mathematical basis of the temperature field judging from the motion of gas in the kiln chamber. Then Fluent, the professional CFD software, was used to compute the problem, the 3-D temperature field in the kiln chamber was obtained finally. The characteristics of the temperature field and the influence of flow to the distribution of the temperature field were analyzed; the difference of temperature field among actual gas flow, no gas flow, variations of inlet speed, inlet pores of different positions and ring inlet pores was compared.The simulation results show that:the distribution of temperature field in kiln chamber is non-uniform. The flowing cold air absorbs and removes heat, the temperature of middle ferrite is higher than that of surrounding ferrite, because the heat loss of middle ferrite which is under the protection of surrounding ferrite is small; in addition, the temperature of lower surface of ferrite region is higher than that of upper surface which contact with the cold air.Reducing of inlet speed can improve the uniformity of the temperature field of kiln chamber, on the contrary, increasing of inlet speed will make the uniformity worse. The cold gas will take less heat, and the heat transport can be more fully while the inlet speed is small, otherwise, the heat transport will be inadequate and the distribution of temperature field will be non-uniform. Changing the position of inlet pores will change the characteristic of the temperature field of kiln chamber, but won't change its uniformity. When pores located in the middle position, the cold gas spread symmetrically, the circumferential motion of it is slow. The heat transport of the ferrite which is away from the pores is fully, because the effects to those ferrite by the cold gas is small. When the pore is ring, the temperature field will become more uniform for the cold gas spreading quickly.