Search / Korean Journal of Chemical Engineering
HWAHAK KONGHAK,
Vol.29, No.2, 127-133, 1991
기-고 유동층에서 입자크기가 축방향 압력요동에 미치는 영향
Effects of Particle Size on Pressure Fluctuations along the Axial Direction in a Gas Fluidized Bed
내경이 0.109m인 기-고 유동층에서 입자크기가 각각 0.715, 0.359 및 0.194mm인 세종류의 균일 크기의 모래입자를 사용하여 축방향에 따른 압력요동을 차압전달기로 측정하여 통계학적 특성치의 하나인 표준편차와 power spectrum의 분포를 이용하여 분석하였다. 입자크기가 압력요동에 미치는 영향을 유속과 초기층높이에 따라 규명하고 이를 이용하여 기포의 운동과 입자 혼합 등의 유동층 내부의 거동을 예측하였다. 실험결과 입자의 크기가 압력요동에 큰 영향을 미쳤으며 일정 유속에서 압력요동의 크기가 최대값을 갖는 위치에서 spectrum의 분포가 가장 넓고 복잡하게 나타났으며 이것으로부터 이 지점에서 기포가 가장 결렬한 운동을 하며 입자의 혼합이 가장 좋음을 알았다.
The pressure fluctuations along the axial distance above the distributor were measured by a differential pressure transducer in a 0.109m ID fluidized bed of sand particles(0.715, 0.359 and 0.194mm). The pressure fluctuations were analyzed by the standard deviation and the distribution of power spectrum. The effect of particle size on the pressure fluctuations was investigated with different gas velocities and static bed heights to interpret the fluidized bed behavior such as bubble motion and particle mixing. The amplitude of pressure fluctuation was greatly affected bythe particle size and exhiibited a maximum value at which the distribution of power spectrum has the most wide and complicate peaks, thus, the most vigorous bubble motion and particle mixing took place at that position in a fluidized bed.
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