Effect of temperature on slug properties in a gas fluidized bed

In order to understand the effect of temperature on slug properties, the onset velocity of slugging, slug rising velocity and slug frequency have been measured by a differential pressure method in an electrically heated gas fluidized bed of 0.1 m i.d. and height of 1.97 m and, with respect to variations in gas velocity (Umf∼0.15 m/s) and temperature (25–400 °C). Air was used as fluidizing gas and fluid catalytic cracking (FCC) catalyst particle (Geldartʹs group-A particle, dp=0.071 mm, ρp=1600 kg/m3) as bed material. The minimum slugging velocity was found to increase a little with bed temperature. The qualitative change in minimum slugging velocity was found to agree with the inverse of minimum fluidizing velocity as temperature was varied. As the bed temperature increased, slug frequency was found to decrease a little, whereas slug rising velocity increased. A correlation between slug rising velocity and bed temperature was proposed.