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정상상태 고로에 미치는 미분탄 취입의 영향

Effects of Pulverized Coal Injection on Blast Furnace at Steady State

김정희 박판욱¹ 정진경² 허완욱² 정용옥^†

Jung-Hee Kim Pan-Wook Park¹ Jin-Kyung Chung² Wan-Wook Huh² Yong-Ok Jeong^†

부경대학교 화학공학과, 부산 608-739 ¹부산대학교 화학공학과, 부산 608-735 ²포항제철 기술연구소, 전남 544-090

Dept. of Chem. Eng., Pukyong National University, Pusan 608-739, Korea ¹Dept. of Chem. Eng., Pusan National University, Pusan 608-735, Korea ²Technical Research Laboratories, POSCO, Cheonnam 544-090, Korea

HWAHAK KONGHAK, April 2002, 40(2), 169-178(10), NONE

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Abstract

미분탄 취입(pulverized coal injection; PCI)은 고로 내부의 분 축적을 가중시킨다. 특히 고로 하부에서 축적된 미연소 미분탄은 연소대 심도를 감소시키고 데드맨의 기체흐름을 저하시켜, 고로의 정상상태에 영향을 준다. 기체와 고체의 흐름 그리고 각 고체층에 상당하는 반응을 고려한 물질전달과 열전달로 모형화한 고로 내부 현상들은 유한요소법(Finite Element Method; FEM)을 사용하고, 철광석의 환원율 모형은 전진 차분법(Forward Euler Method)을 사용하여 수치해석하였다. 연소대의 심도 감소와 데드맨의 기체흐름저하는 모두 충진층 내의 압력강하를 증가시키고 고로 내부의 온도를 감소시킨다는 점에서는 비슷하였다. 그러나 데드맨의 기체 흐름 감소가 단지 고로 하부 온도만 감소시켰다. 이에 반해, 연소대의 심도 감소는 고로의 전체 평균온도를 저하시키고, 연소대 경계의 기체흐름을 증가시켜 노벽측 보쉬 부근의 고체온도를 상승시킨다. 따라서 철광석의 연화융착이 축 중심부에서 낮게 형성되고 노벽측에서는 높게 나타난다. 그 결과 연화융착대의 길이가 감소하여 기체흐름과 고로의 상태에 나쁜 영향을 미친다.

A pulverized coal injection increases the accumulation of fines in a blast furnace. The accumulation of fines in the lower part of the blast furnace diminishes the size of the raceway depth and gas flow into the deadman and, as a result, affects the steady state condition of the blast furnace. The state of the blast furnace, which depends on the gas and solid flow, chemical_x000D_ reactions, mass transfer and heat transfer, is numerically analyzed using a FEM (finite element method). But the ore reduction index model, which estimates the chemical state of ore in blast furnace, is made using Forward Euler method. The decrease in both the size of the raceway depth and the gas flow into the deadman results in increasing pressure drop and lowering the average temperature in the blast furnace. However the reduction of gas flow into deadman affects in only the lower part of the furnace, but the diminution of the raceway depth decreases the average temperature in the entire furnace, even though the solids on the upper raceway become hotter due to increasing gas flux through the raceway. So, the melting position is lowered in axial_x000D_ direction at center of blast. As a result the length of the cohesive zone is shortened to give permeability resistance on the gas flow and to make the furnace operation unstable.

Keywords

Pulverized Coal Injection Blast Furnace Numerical Analysis

References

Yun CK, Shim JD, Cho YS, Kang IS, Shim YT, "Mathmatical Modeling of Fluid Flow and Temperature Profile in a Blast Furnace," KAIST (1983)
Lee KS, Kim HS, "Analysis of Steady State Behavior of a Blast Furnace using a Two Dimensional Model," Sogang Univ. (1986)
Yagi J, Takeda K, Omori Y, Tetsu-to-Hagane, 66, 1888 (1980)
Takatani K, Inada T, Ujisawa Y, ISIJ International., 39, 15 (1999)
Chung JK, Huh WW, Park PW, HWAHAK KONGHAK, 37(5), 767 (1999)
Chung JK, Park PW, HWAHAK KONGHAK, 36(5), 743 (1998)
Chen J, Akiyama T, Nogami H, Yagi J, Takahashi H, ISIJ International., 33, 664 (1993)
Jeong YO, Ph.D. Dissertation, Houston Univ., Houston, U.S.A. (1989)
Austin PR, Nogami H, Yagi J, ISIJ International., 38, 246 (1998)
Hara Y, Sakawa M, Kondo S, Tetsu-to-Hagane, 62, 315 (1976)
Sato M, Murai R, Ariyama T, Maki A, Shimomura M, Mori K, Testsu-to-Hagane, 85, 717 (1999)
Austin PR, Nagami H, Yagi J, ISIJ International., 37, 748 (1997)
Miyasaka N, Kondo S, Tetsu-to-Hagane, 54, 1427 (1968)
Wang GX, Chew SJ, Yu AB, Zulli P, ISIJ International., 37, 573 (1997)