Study on Particles Residence Time Distribution in Low-temperature Chlorinator

Based on the cold model of low-temperature chlorination furnace for Pangang titanium-bearing blast furnace slag,the conductivity method was employed to research the pulse tracer particles,and the effects of internal baffles,feed rate and apparent gas velocity on the particles Residence Time Distribution （RTD） in the low-temperature chlorination furnace were investigated. The results show that the baffles lengthwise separate the internal space of the furnace to eliminate short circuits,which is beneficial to efficiently mixing between the particles and fluidized gas. The RTD of carbonized slag in the furnace is more concentrated with double baffles （variance σ_t² reduces to 0.50 from 0.67）. When the feed rate decreases from 1.9 to 1.1 g/s the average residence time of the material doubles and the reaction time of carbonized slag increases. With the apparent gas velocity increased to 0.15 m/s,the concentricity of RTD for carbonized slag is weaken to some extent,but the contact and reaction between the particles and gas is enhanced by back-mixing which insures the fluidization conditions of the materials and is in favor of improving the chlorination efficiency of carbonized slag.