Numerical Simulation And Optimization Of Gaseous Combustion Process In Anode Furnace With Different Burners

ABSTRACT:The anode furnace is the key equipment in copper refining process. Production practice indicates that burners of different structures have different combustion performances during the anode refining process. Simulations have been carried out in this dissertation of the combustion processes with two different burners. Comparisons were made of the combustion features in two operational stages of the refining process, aiming to explore optimizations in both the burner structure and organization of the combustion process. The results are also expected to provide a theoretical guidance and technical supports for achievements of stable and uniform temperature distributions inside the furnace, and furthermore, of a highly efficient copper anode refining process.The simulation was carried out with the commercial software Fluent6.3. The physical model was developed and the boundary conditions were determined on the basis of practical structure and operational parameters of a copper anode furnace in production. The basic conservation equations, the standard k-ε model, the species transport model and the P-1radiation model are applied to the simulation of the flow, temperature and concentration fields. Main conclusions of the dissertation are summarized as follows.(1) The reliability of the numerical model presented in the dissertation was validated by comparing the simulation results to data obtained in an industrial test in the same furnace and the same operational condition.(2) When equipped with the1#burner, a larger recirculation can be found near both sides of the burner in the heat preservation period. The recirculation effectively strengthens the circulation and mixture of gas and increases the stability of the combustion. The highest temperature in the furnace at this stage is2311K. While in the oxidation period, a swirl is formed on the right side of the burner, and the flame is found deflected to the right side accordingly. The highest temperature in the oxidation stage is2506K. Furthermore, the entire combustion process is concentrated within the range of the2times the furnace radius from the burner exit. The natural gas and oxygen are completely consumed.(3) When equipped with the2#burner, strong recirculation flows can be found near both side of the burner as well in the heat preservation period. However, in the oxidation period, a swirl only appears on the right side of the burner, causing the flame to deflect to the right side. The highest temperature in the furnace is2800K. The combustion process is completed within the scope of the1.5times the furnace radius from the burner exit, the concentration of the remainder oxygen is about5%when the reaction is complete.(4) Optimization for parameter and structure of the1#burner equip on copper anode furnace. The results show that combustion in the furnace is better and the temperature distribution is uniform without localized hot spots when the ethylene flux is0.1times as much as the natural gas flux. The simulation results reveal that the fire segregation phenomenon disappears when the oxygen lance is located below the natural gas lance. When decreasing the angle between the burner and the horizon direction further, the temperature distribution becomes more uniform.