Search / Korean Journal of Chemical Engineering
HWAHAK KONGHAK,
Vol.36, No.4, 576-583, 1998
코크스 시험로에서 석탄 건류시 석탄 팽창압 거동 특성
Coking Pressure Behaviour during Coal Carbonization in a Movable-Wall Test Coke Oven
코크스 오븐에 장입된 석탄의 건류과정에서 발생하는 석탄 팽창압의 특성을 파악하기 위해 이동벽이 있는 코크스 시험로(0.2W×0.4H×0.45L)에서 여러 종류의 석탄에 대한 건류 실험을 행하였다. 또한 단일탄 및 배합탄의 유동도 특성과 이들로부터 제조된 코크스의 품질을 평가하였다. 단일탄의 유동도는 휘발분 함량에 따라 증가하였으나, 배합탄의 유동도는 휘발분 함량보다는 단일탄의 유동도 특성 경향을 나타내었다. 석탄 등급이 증가함에 따라 단일탄의 CO2 반응성은 감소하였으나, 반응후강도(CSR)는 증가하였다. 점결성이 강한 석탄의 양이 증가함에 따라 배합탄의 반응후강도는 증가하나 CO2 반응성은 감소하였다. 석탄의 건류과정에서 발생하는 팽창압 측정에서 유동도가 높은 석탄(PH, DP)들이 높은 팽창압을 나타내었으나, 상대적으로 낮은 유동도를 갖는 NP탄의 경우 가장 높은 팽창압을 나타내었다. 8-9wt%의 수분을 갖는 석탄을 5-6wt%의 수분을 갖도록 건조하였을 경우 장입밀도는 13-20% 증가하며, 건조된 점결탄의 팽창압은 습탄에 비해 2배 이상 증가하였으며, 석탄내 가스압은 습탄에 비해 높은 값을 나타내었다.
Coal carbonization for various kinds of coals has been carried out in a movable-wall test coke oven(0.2W×0.4H×0.45L) to investigate the variation of coking pressure when dried coal is charged in the coke oven. Also fluidity properties of single coals and coal blends have been determined in a Gieseler plastometer. Fluidity of single coal increases with increasing volatile matter content. Fluidity of coal blends is largely depended on that of single coal rather than volatile matter content of coal blends. CO2 reactivity and coke strength index after reaction with CO2(CSR) of coke produced from single and coal blends also have been evaluated. With increasing the amount of strong-coking coal, CSR of the coal blend increased but CO2 reactivity of the coal blend decreased. Effects of coal rank and moisture content on coking pressure in a 30kg of test coke oven were determined. Coals(PH, DP) with high fluidity exhibit high coking pressure but despite of low fluidity a coal(NP) represents the largest coking pressure among the coals tested. Bulk density of the dried coal(5-6 wt%) is 13-20% higher than that of the wet coal(7-9 wt%). Coking pressure of the dried strong-coking coal is approximately two times as high as that of the wet coal and internal gas pressure in the dried coal charge center is also much higher than that in the wet coal charge center.
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