Zinc Concentrate Boiling Roaster Waste Heat Boiler Fouling Numerical Simulation Studies

Flue gas of zinc concentrate fluidized roaster boiler has a lot of waste heat, which can be utilized by waste heat boiler. However, there is much ash in flue gas which is easy to deposit, so ash depositing in waste heat boiler is very common. Ash depositing not only influences heat transfer, but also induce tube burst, flue block, production stop and so on. Therefore, ash depositing has a bad influence on production of waste heat boiler with economy and security. Accordingly, deeply research on ash depositing in waste heat boiler is very necessary. Particularly, it is more important to forecast tendency and degree of ash depositing, then the forecast is help to provide the technical support for ash depositing alleviate or avoid.Ash depositing of boiler is a complex physical-chemical phenomenon which contains multiphase flux, heat transfer and mass transfer, etc. Ash depositing is highly related with the flue gas characteristics, structure and operating condition of boiler. With the theory of ash depositing and the technology of zinc concentrate fluidized roaster, the text does research on the formation of ash deposit in waste heat boiler of zinc concentrate fluidized roaster boiler. Specially, the text does analysis on influence of ash characteristics, temperature field, fluid dynamic field and chemical reaction.The method of numerical simulation of ash depositing in boiler was discussed and foundation of models, including ash transportation model, ash conglutination and ash deposition model, was elaborate intensively in the text. Then Fluent was carried out the numerical simulation to the waste heat boiler for ash depositingFirstly, geometric model and boundary conditions were foundation on the basis of structure and operating condition of a waste heat boiler which exists in engineering practice, then turbulent model was applied to flow and heat transfer of the gas phase, and fluid dynamic field and temperature field are given the detailed analysis. Secondly, stochastic particle trajectory model of the method model was applied to simulate motion and collision of particle. Thirdly, conglutination model was applied to compute conglutinate proportion of the particle. Finally, situation of the ash depositing was discussed. The result shows that the method of numerical simulation in the text can predict ash deposit with a certain degree of precision. It lays a foundation in the further development of numerical model. It also does a job in paving the way for complex simulation of the ash depositing process physical-chemical reactions.