Large Particle Fluidized Cement Clinker Calcining Process Heat Mode Test - Firing Dynamics

An experimental project of clinker calcinations was carried out by using aflnuidized device of laboratory-scale. The tested raw meal was the nodulized feedfor use in a shaft kiln of black meal process. The fluidization behavior of thecoarse partticles in the tested device was studied. The optimum process parametersof fluidization occurred in the device were discussed. A set of operatingprocedures of the device was developed, for properly manipulating the system.Some operating and structural problems of the device were identified. A numberof modifications to the system are suasested.The experimental results indicate that close, strict and systematic control overthe mass flow rate of the raw meal into the fluidized bed, and flow rate of the fueland air is required for continuous and stable operation. For fluidization of thecoarse particles the flow velocity is higher than that of small particles. Significantdisintegration of the nodulized feed was observed. The top level of the bed variedviolently. The range of operating velocity is relatively strict. High fluctuation inpressure drop across the fluidized bed was recorded. It was easy to form slugging 西实建筑科技人学倾上论文 一 bed． For the particles 3．omm to 7．omm in diameter,the critical gas velocity of fluidization of4．33mlsandthep ieessuredropacrossthebedr ngingfrom2000to 3000Pa were observed．It was recognized that operating velocity in the range of (1．4—2．0)umr was desirable and the expansion ratio of＊theion bed was rangingnom 1．3toZ．3．Gastemperaturefroml380℃tol430℃andresidencetimeofthemeal in the iuidized bed of 乞bout 25～35 minutes resulted in clinker．The主 28d－compressive strength of5I．6MPa and the free CaO below．0％were detected from the clinker produced in the project．...