Increasing the efficiency of transfer processes when using inhomogeneous fluidization

Abstract

The processes of dehydration and granulation are associated with the heat transfer to the solid particles from the gas coolant, which acts as a fluidizing agent and causes the stochastic movement of the granular material in the apparatus. To implement the layered structure mechanism of granulation of organic-mineral fertilizers it is necessary to ensure intensive circulation of granular material with intensive gradual passage through the appropriate technological zones of the apparatus. The main problem is the low efficiency of interphase exchange in the gas-liquid-solid system and the formation of agglomerates during granulation with the injection of a liquid heterogeneous solution into the bed of solid granular material. In this work the conditions for increasing the efficiency of the transfer processes when using an inhomogeneous jet-pulsating mode of fluidization were determined. Analysis of the intensity of renewal of the contact surface of the phases when using inhomogeneous jet-pulsating fluidization in the self-oscillating mode was carried out. It was established that the use of this mode of fluidization allows getting a significant intensification of heat and mass transfer processes due to the activation of diffusion-controlled processes and an increase in the dynamics of interphase contact exchange by 1.9÷2.9 m2/s, which is 27÷41% of the total surface of the material in device.