The Mechanism Research For Anti-fouling Of Spiral-flow Fluidization Technology

Transfer equipments due to many reasons inevitably emergefouling in chemical industry. Fouling can result in enormous economicloss directly, such as material consumption energy consumption and so on.So the effective cleaning of equipments has always been a topic scholarsconstantly explore.In view of comprehensive analysis for the fouling measuresand methods at home and abroad. The paper put forward the automaticcleaning technology of spiral-flow fluidization. Its technical principle is；A particle carries out quick rolling with slow sliding under spiral-flow.High-speed rolling destroys temperature near boundary layer,crystallization rate occurred in wall becomes slow. The inhibition offouling can be achieved eventually. Slow-speed sliding of particle canscraping the wall continually so that the generatedcrystallization fouling can be removed.We built dynamical model of fluidized pellet after making somesimplifications and assumptions. According to the analysis of forcesand torques on spheres coming from fluid and pipe wall, we got that:When a pellet started rolling for overcomes rolling friction firstly in thecondition of small flow rate, Eventually fluid viscous resistance couldexcess decreasing sliding friction, the pellet began to slip, that was pelletcarried out composite motion of rolling and sliding. On the other hand,because of fluid viscous resistance when flow velocity was Larger, thepellet could overcome sliding friction and start rolling and sliding.The trace method is used to investigate the motion trail of spiralmotion of fluid interpolated by steel wire. The result shows that theparticles conduct the helical motion under the river diversion of spiralsteel wire and the motion is influenced by flow rate and particle size. Wedesign tests to analyze the kinematic velocity and rotate speed of helicalflow of different particle sizes in tubes with diverse roughness. The resultshows that the rotate speed of Φ3mm spheres reaches up to2300n/minand the slip only occupy3.4%when the flow rate exceeds0.60m/s,indicating that the particles indeed take high speed rolling as the principal and low speed sliding as the supplement.On the basis of the above theory and experimental study, we performa simulation for the anti-fouling effect of liquid rotary fluidization. Itdemonstrates that the heat transfer coefficient under liquid rotaryfluidization reaches up to1000w.m^-2.K^-1and always maintain stabilization,it is10times as that of stable space-time tube and3.4times as that ofinterpolation steel wire spiral. And the three reliability heat transferexperiments also prove the fluidization rolling spheres have goodanti-fouling effect.