An Investigation Into Cyclone Preheater Performance In Condition Of High Temperature And High Solid-gas Mass Ratio

Cyclone preheater is the key device of clinker burning system in cement industry. High solid-gas mass ratio cyclone preheater is an advanced invention, hanving high efficiency energy saving characteristics,worthing to research and develop.In the condition of high temperature and high solid-gas mass ratio, the author has measured the pressure drop over the heat exchange tube, the pressure drop over the cyclone, the total pressure drop across the whole preheater, graded separation efficiencies of each particle size increaments and the overall efficiency and discussed the influnces of temperature,gas velocity and solid-gas mass ratio to the performance of the preheater.The following conclusions have been drawn from the experements.1.The Investigation into Pressure Drop over Heat Exchange TubeIn the cace of solid-gas mass ratio Z<1 the pressure drop increased with the gas temperature increasing at a given gas velocity and the gas tempreture being lower than 200℃.At the gas tempreture of 200℃the pressure drop reached a maximum.After that the pressure drop decreased as the tempreture further increasing.At the condition of fixed gas velocity and the solid-gas mass ratio Z≥1.5,the pressure drop decreased slowly with the gas tempreture increasing and the pressure drop reched a minimum at 600℃.Then the pressure drop increased slightly as the tempreture further increasing. The pressure drop over heat exchange tube always increased with the gas velocity increasing and increased with solid-gas mass ratio increasing.2. The Investigation into Pressure Drop over CycloneThe pressure drop increased with the gas temperature increasing at a given gas velocity, a fixed solid-gas mass ratio and the gas tempreture being lower than 200℃.Between 200℃and 400℃the pressure drop reached a maximum.After that and as the temperature further increasing the pressure drop decreased gradually.The pressure drop increased with the gas velocity increasing. The pressure drop decreased gradually with the solid-gas mass ratio increasing and reached a minimum between Z=1.5 and Z=2.0. Aross this point, the pressure drop increased with the the solid-gas mass ratio further increasing.3. The Investigation into Total Pressure Drop across Whole PreheaterIn the cace of the solid-gas mass ratio Z<1.5 the total pressure drop increased with the temperature increasing at a given velocity and reched a maximum between 200℃and 400℃.After that it decreased gradually as the tempreture further increasing. At the condition of solid-gas mass ratio Z≥2.0 the total pressure drop decreased with the temperature increasing and reached a minimum near at 600℃. After that it increased slightly as the tempreture further increasing.The total pressure drop always increased with the gas velocity increasing or with the solid-gas mass ratio increasing.4. The Investigation into The Overall Efficiency of CycloneThe overall efficiency decreased with the temperature increasing and increased with the gas velocity increasing or with the solid-gas mass ratio increasing.5. The Investigation into Graded Separation EfficiencyIn the case of the raw meal powder diameter dp=1μm about,"fish hook effect" is obviously.The critical particle size decreased with the gas velocity increasing or the solid-gas mass ratio increasing.The thesis has the following features.High Temperature and High Solid-gas mass ratio - The study results of cyclone preheater monomer in hot state and high solid-gas mass ratio hadn’t been reported in last many years.Comprehensive - The thesis comprehensively expoited the influnces of temperature, gas velocity and solid-gas mass ratio to the performance of cyclone preheater monomer.