CFD aided design of integrated spray pyrolysis furnace for liquid ore exploitation

Abstract

Traditional spray pyrolysis of liquid ore includes the two processes of spray drying and calcination. A novel spray pyrolysis furnace was designed to integrate the two processes into one unit operation and separate solid particles from the furnace gas at the same time. Computational fluid dynamics was used to aid the design and investigate the flow pattern, which had the characteristic of co-axial swirling stratified flow. The mass flow rate distribution of the hot air was calculated under different boundary conditions and structural sizes to optimize the structure and flow field of the furnace. An injection model was built to simulate the hollow cone spray. The temperature and species distribution of the continuous phase, and the separation efficiency and residence time of the dispersed particles were obtained. Simulation results proved that the evaporation and pyrolysis process were divided in the upper and lower parts of the furnace chamber with continuous flow. The separation efficiency and mean residence time of the particle product was more than 95% and 6s, respectively. Preferred operation conditions and structure parameters are recommended for extensive application of spray pyrolysis of different liquid ores.