| Ceramic kiln is one of the most important part in the entire ceramic production process.In recent years, with the national pay more and more attention on people’s lives environment, put higher pressure on the enterprise "carbon emissions",Ceramic enterprises are facing "energy conservation" problem. A wide-body roller kiln with the excellent quality of its high production efficiency, low energy consumption per unit,land use efficiency, energy saving and environmental advantages than traditional ones,it gradually boarded the stage of history.Ceramic industry define effective wide above3.1metres of the roller kiln as super wide-body roller kiln.But currently, widened the kiln’s wide makes wide-bodied kiln preheating zone lack of heat temperature,causing the burner not easy to control,easy to exceed setted temperature range,leading to oxidation insufficient,or make products into the reduction phase in advance,and lead to produce defects like black core,foaming,etc.This article through analyzing preheating zone for heat balance calculation and analysis of energy consumption of the wide-body kiln compare with ordinary one.reach a conclusion that the wide-bodied preheating zone need more energy consumption than conventional kiln for energy consumption,based on the principle of fluid mechanics,heat transfer,and combining with working principle of the kiln,we increase the gas flow channel area appropriately and reduce the gas flow resistance,to improve the part of the gas temperature effectively,so as to increase the convective heat transfer and the effect of the heat accumulation capacity of this part.by using the fluid dynamics software CFD modeling numerical simulation analysis,obtained under different heat storage layer structure of the distribution of temperature field and velocity field, further explain the heat storage layer structure, fix the best heat storage layer structure.numerical simulation makes the following conclusions:①the top heightened kiln(model B series) or the top heightened-bottom lower (model C series),the two heat storage layer structure can make kiln gas temperature higher than no heat storage layer structure (model A).②Model B series:rollers of heat storage layer’s top and bottom temperature is smaller than the model C series, when the heat storage layer in the same length condition, model B series’s effect is better than model C series③Comprehensive analysis of the temperature field and velocity field from section X=1.55m, different cross section Y value and cross section of Z=0.25m, Z=0.25m can obtain top-bottom temperature difference of model B61, B62, B63are smaller than other model,temperature gradient are small, exit temperature all around900k.particularly model B62better than B61/B63,its regenerative effect is more obvious.Through comparing each model, the heat storage layer space is too large, easy to cause the roller gap is too big, to reduce the roller on the upper resistance, makes too much heat flow through the upper, and makes the furnace roll on roll temperature under the temperature difference is bigger, so increase roller space on the upper appropriately to improve heat capacity.Analysis can be drawn from the results that the best regenerative effect model is model B62,namely, high box in preheating zone in heat storage layer length is6units (12.6m), the heat storage layer is two layer brick high (0.134m). |
PDF Full Text Request