Influence Of Temperature Of Raw Material Into Rotary Kiln On Material Reaction Characteristics And Temperature Profiles Of Clinker Calcinations System

Precalcining system has been the mainstream of cement clinker calcine process over the past decades.However,as a bottleneck,the residual decomposition of calcium carbonate and the slowly temperature rising process in the kiln limited the capacity to keep growing and the energy consumption to keep reducing.As the main contradiction,the rate of the heat transferred and needed for the clinker burning is hugely imbalanced.According to the previous research,if the temperature of raw material into rotary kiln increased from 900?to 1000¹200?,both the solid-phase reaction and liquid-phase reaction took place in the kiln would be significant increased.In other words,the above process of enhancing the calcinations for the raw material in the calciner took advantages of the efficient heat transfer under the suspension state,and the results were certificated to help increase the clinker production significantly.Through literature analysis and theoretical calculation,it helped to improve cement rotary kiln production by improving temperature of raw materials into rotary kiln.Moreover,the improvement effect of temperature of raw material into rotary kiln on cement rotary kiln production was more significant than that of the raw material.Through calcination condition comparison,this paper studied effect on the cement clinker physical and chemical reaction process of different temperature of raw material into rotary kiln.With the increase of calcination temperature,the higher reactivity of new phase can obtain.The activity of new phase product obtained around 1100?was 1.31¹.45 times that under 900?.When the temperature of raw material into rotary kiln varied from 900?to 1000?,the reaction rate fastened nearly ten times?C₂S for 2.6¹0.7 times,C₃A for 2.0¹0.0 times,raw material for2.8 times?.If the temperature of raw material into rotary kiln further raised 1100?,the reaction rate fastened nearly twenty times?C₂S for 9.0¹9.3 times,C₃A for 2.7²6.6 times,raw material for 4.0 times?.If higher temperature and/or higher decomposition rate of raw material into rotary kiln can be used to prepare the clinker,the reaction rate of clinker formation will be increased greatly.For mastering effect of temperature of raw materials into rotary kiln on the thermal characteristics of calcination system,this paper studied temperature field distribution and energy configuration of kiln inlet system and rotary kiln through mathematical model basing on heat transfer,mass transfer,momentum transfer and chemical reaction process in calcination system.When the ratio of calciner feed coal varied from 60%to 70%,the temperature of raw material into rotary kiln can vary from 886?to 1070?.Shorter L/D kiln type can obtain more stable temperature field calcining zone when the temperature of raw material into rotary kiln was 1070?.The highest solid temperature of the temperature of raw material into rotary kiln being 1070?was higher than 80?that of 886?,and high temperature region?>1450??length was 2 times that of 886?,which was good for clinker burning and higher clinker quality.The influence of that on the key thermal equipment of precalcining system was analyzed.These studies provided theoretical support for further engineering research of preclinkering technology.When the temperature of raw material into rotary kiln increased,the design of calciner should meet the increase the ratio of material/gas retention time?t_m/t_g?,extend the requirement of material retention time and meet the needs of pulverized coal fully dispersed and good combustion.The inner tube of C6 cyclone preheater can be used for ceramic tube cyclone preheater.The design of rotary kiln can adopt the scheme of large slope,large diameter and small L/D.The ingredients scheme can adopt the"two high one middle",and can better adapt the lower burn ability raw materials.Through the system study on the basis of precalcining kiln process,the temperature of raw materials into rotary kiln can reach 1000¹100?.When the ratio of calciner feed coal is about70%,the temperature and the decomposition rate of raw material into rotary kiln are 1070?and97.1%,respectively.The kiln production is increased by 95%,the theory heat consumption of clinker formation is reduced by 53.0 kJ/?kg·cl?,the process heat consumption of clinker formation is reduced by 236.1 kJ/?kg·cl?and thermal efficiency is increased by 3.6%.