Shungo Natsui 교수

Low reducing agent operation of the blast furnace is an essential method for mitigating CO2 emissions in ironmaking. Because the coke rate is reduced in low reducing agent operation, gas permeability tends to deteriorate. Recently, blast furnaces with inner volume larger than 5000 m3 have become usual not only in Japan, but also in other Asian nations. Under these conditions, detailed information on in-furnace phenomena is required to attain stable operation.In the present study, a combination m

In order to mitigate CO2 emissions from steel industry, decreasing coke rate by shaft gas injection such as top gas recycling is a favorable way. The conception based on oxygen blast furnace is able to bring several profits for intensifying gas reduction and decreasing coke rate by massive coal injection. In these processes, gas injection from auxiliary tuyere plays an important role to inject reducing gas or make up heat balance in the upper part. Therefore, the effect of shaft gas injection is

A low coke rate operation in blast furnace is desired to decrease the carbon input and mitigate global warming problem. However, low coke rate operation tends to cause the gas permeability to deteriorate. The mixing of small-size coke (nut coke) including high reactivity coke in ore layer is considered to be a promising way to improve permeability and increase reaction efficiency in a blast furnace. Although adding a nut coke mixing to an ore layer is predicted to be empirically effective in low

Since the solid flow in blast furnace is composed of each particle motion, the discontinuous phenomena of burden descending can be occasionally observed. Understanding of the solid flow is important for blast furnace operation. Discrete Element Method (DEM) can offer the behavior for each particle of burden in the furnace. Three dimensional analysis of solid motion containing the ununiform region became possible with using DEM.In the present study, a blast furnace of 2000 m3 inner volume with 16

Abstract Blast furnace technology is currently aiming at low reducing agent operation so as to decrease CO 2 emissions. At the same time, the inner volume of blast furnaces has frequently been enlarged so as to increase production rate in some countries, including Japan. Operating conditions designed for low reducing agent in a large blast furnace tend to cause unfavorable phenomena such as slipping of the burden and gas channeling due to the decrease in coke rate. Mathematical models help to cl

Shaft gas injection of reducing gas in the blast furnace is one of favorable ways to greatly decrease CO2 emissions from steel works, and this approach is used for the top gas recycling and oxygen blast furnace processes. In these processes, the penetration effect of the gas injected from the auxiliary tuyeres is important for attaining effective gas reduction or making up the heat balance in the upper part, and so it is useful to analyze the dynamic behavior of the gas injected into the shaft.

A newly developed computational fluid dynamics (CFD) model based on a multi-phase particle method is presented for predicting the entrainment behavior of liquid metal into slag due to rising single bubble. By comparing results calculated using this model against experimental data, it was found that the transient behavior of bubbles and the two immiscible liquids can be accurately estimated by this method. The rupturing of the thin water film surrounding the bubble was less reliably predicted, bu

A high-resolution numerical model was performed for a detailed understanding of packed-bed structures constructed by actual scale cokes, and the molten slag (SiO2–CaO–Al2O3) trickle flow characteristics in the lower part of an actual blast furnace. Smoothed particle hydrodynamics (SPH) simulations can track the motion of liquids containing dispersed droplets, and the discrete element method (DEM) with a multisphere approach makes possible to simulate non-spherical solid-particle motion. We carri

Analysis of solid motion in the vicinity of raceway of the blast furnace has been carried out by discrete element method (DEM). The physical properties of particle for DEM calculation are important factors to simulate precisely the solid motion in the blast furnace. In order to represent the feature of burden such as coke in the lower part of the blast furnace, the rolling friction was cautiously determined. Through the simulation results, it was found in the result of simulation that the contac