가압순환유동층 적용을 위해 루프씰(loop-seal: 내경 0.10 m)을 갖는 고체재순환부(직경 0.10 m, 높이 2.25 m)에서 층 물질로 silica sand 입자(dp=240 μm, ρs=2582 kg/m3)를 사용하여 시스템 압력 변화(0.10~0.71 MPa)에 따른 고체흐름 특성을 연구하였다. 루프씰을 통한 고체질량플럭스는 공기주입량이 증가할수록 선형적으로 증가하였고, 동일한 공기주입속도에 대해 시스템 압력이 증가할수록 증가하였다. downcomer 내 압력변이는 시스템 압력이 증가할수록 동일한 공기주입속도에 대해 증가하였고, 흐름 내 고체속도 및 기체 속도 또한 증가하였다. 고체질량플럭스로부터 downcomer에서의 압력변이를 예측할 수 있는 상관관계식을 Transportation number와 Pressure drop number를 이용하여 제안하였다. 루프씰에서의 압력강하는 시스템 압력에 관계없이 고체질량플럭스가 증가할수록 증가하였다. 각각의 시스템 압력에서 공기주입속도 변화에 따른 고체질량플럭스 및 Transportation number를 예측할 수 있는 상관관계식을 제안하였다.

Solids flow characteristics have been determined in a pressurized solids recycle systems of silica sand particles for the application in a pressurized CFB(PCFB). The solids recycle system is composed of a downcomer(0.10 m i.d. 2.25 m high) and a loop-seal(0.10 m i.d.). The silica sand(dp=240 μm, ρs=2,582 kg/m3) particles were transported at room temperature and system pressure(Psys) up to 0.71 MPa using air. Solids mass flux(Gs) increases with increasing_x000D_ system pressure at constant aeration rate. Pressure gradient, solids velocity and actual gas velocity increase with increasing Psys at constant aeration rate. The Pressure drop number(Φ) on pressure gradient in downcomer has been correlated with Transportation number(Tr). Pressure drop across the loop-seal increases with increasing of Gs irrespective of variation_x000D_ of Psys. The obtained Gs and Transportation number(Tr) have been correlated with the experimental variables.

Circulating Fluidized Bed Solids Recycle System Loop-Seal System Pressure

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