Jae-Ek Son

The effect of fine particles on elutriation of coarse particles in a gas fluidized bed

The effect of fine particles on the elutriation rate of the coarse particles at the gas exit was investigated in a gas-fluidized bed (i.d.: 0.1 m, height: 1.97 m) with sand as bed material. The elutriation rate of the coarse particles increased with the gas velocity and the proportion of fine particles in the bed. It was found to increase nearly proportionally with the upward momentum of the fine particles calculated on bases of unit mass and composition of bed particles at a specified gas velocity. The effect of the fine particles on the elutriation of the coarse particles decreased as the gas velocity increased. The elutriation of the fine particles was not affected by the size distribution of bed particles. An improved correlation to determine the elutriation rate of the coarse particles has been proposed for sand particles.

Simultaneous experiments of sulfidation and regeneration in two pressurized fluidized-bed reactors for hot gas desulfurization of IGCC

Hot Gas Desulfurizarion for IGCC is a new method to efficiently remove H2S in fuel gas with regenerable sorbents at high temperature and high-pressure conditions. The Korea Institute of Energy Research did operation of sulfidation in a desulfurizer and regeneration in a regenerator simultaneously at high pressure and high temperature conditions. The H2S concentration at exit was maintained continuously below 50ppmv at 11,000 ppmv of inlet H2S concentration. The sorbent had little effect on the reducing power in the inlet gas in the range from 11% to 33% of H2. As inlet H2S concentration was increased, H2S concentration in the product gas was also increased linearly. The sorbent was maintained at low sulfur level by the continuous regeneration and the continuous solid circulation at the rate of 1.58× 10−3 kg/s with little mean particle size change.

Axial voidage profile in a cold model circulating fluidized bed

The axial voidage profile was measured in a cold model circulating fluidized bed (0.38 m in diameter and 9.1 m in height) of sand particles as bed materials. Voidage in the riser column increases along the height above the distributor plate with increasing the gas velocity. However, it decreases with an increase in solid circulation rate in the bed. Model correlations to predict the solid circulation rale and the axial voidage profile in the bed are proposed.

Effect of temperature on slug properties in a gas fluidized bed

Abstract 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 ( U mf ∼0.15 m/s) and temperature (25–400 °C). Air was used as fluidizing gas and fluid catalytic cracking (FCC) catalyst particle (Geldarts group-A particle, d p =0.071 mm, ρ p =1600 kg/m 3 ) 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.