Kyoji Okabe

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Empirical Formulae for the Gas Pressure Drop and the Liquid Holdup for the Counter-current Region of Gas-liquid Flow in the Dropping Zone of a Blast Furnace

Tetsu-to-Hagane (1980)

Tsuyoshi Fukutake Kyoji Okabe

The Ergun-type pressure loss equation was extended to the flows in irrigated packed beds on the basis of the assumption that, in the case of irrigated beds, the bed is composed of solid particles and hypothetical liquid droplets. Dimensionless empirical formulae for the quantity and the size of liquid in the bed were obtained by using experimental data on gas pressure drop and liquid holdup obtained under simulating flow conditions of the dropping zone of a blast furnace.Flooding gas velocities as well as gas pressure drop and liquid holdup over entire region of gas velocity up to the flooding could be calculated by use of the above formulae with reasonable accuracy.The pressure loss equation was further extended to the flow of two liquid phases in the dropping zone of a blast furnace. A sample calculation confirmed the result of earlier study that the fluidization of the coke bed would start before the onset of flooding of the slag.

Fluidization

Dimensionless quantity

Wet gas

10.2355/tetsutohagane1955.66.13_1947

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Citations (14)

Heavy Oil Combustion in Blowpipe and Tuyere of Blast Furnace

Tetsu-to-Hagane (1976)

Toshihiro Inatani Kyoji Okabe Tetsuji Nishiyama Yasunori Serizawa Hiromitsu Takahashi

The injection of large quantities of auxiliary fuels to reduce the coke rate at blast furnaces is an economic necessity because of the shortage of coke and its increasing cost. One of the reasons of the limitation of the amount of injected heavy oil is incomplete combustion with unacceptable soot formation.Firstly, the authors observed the phenomena in the raceway by using the experimental model and, secondly, they analyzed the combustion process in the real raceway on the basis of the gas composition measured by the probe inserted through the tuyere.The heavy oil is generally injected from the tip of oil nozzle settled near the tuyere at the oxygen excess ratio (μ) over 1.1. A great part of injected oil burns simultaneously with coke in the raceway and soot formation begins with increasing the amount of injected oil.In order to gasify the heavy oil in the blowpipe and tuyere before the beginning of the coke combustion, the nozzle tip was moved backward 1.75 or 0.75m away from the tuyere nose. The test of the new injection system was carried out at No. 6 tuyere of No. 2 blast furnace in Chiba Works and its results were also discussed. Much quantity of heavy oil could be gasified without soot formation on the condition of μ=0.9.

Raceway

Tuyere

Fuel oil

10.2355/tetsutohagane1955.62.5_514

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Circulation of Elements in Blast Furnace Estimated by Thermodynamics and Vapour Pressure Measurement

Tetsu-to-Hagane (1978)

Yoshiyasu TAKADA Mitsuo SUMITO Nobuo TSUCHIYA Kyoji Okabe

The circulation behaviour of Fe, Mn, Si, Mg, Zn, Na, K, S, and Cl in blast furnace is studied. The compounds of circulating elements and the region of the circulation are quantitatively estimated by thermodynamic calculations using gas compositions measured by the vertical probes at a working blast furnace. The probable vapour pressures of circulating species are quantitatively estimated by the mass spectrometric analysis of Knudsen effusates from pig iron, slag, and coke.

Slag (welding)

Circulation (fluid dynamics)

10.2355/tetsutohagane1955.64.8_1114

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Bell-less Top Operation at Chiba No. 2 Blast Furnace

Transactions of the Iron and Steel Institute of Japan (1981)

Junsaku Kurihara Hiromitsu Takahashi Kazuo Okumura Yoichi KARIKOME Kyoji Okabe

A bell-less top has been installed for the fourth campaign of Chiba No. 2 blast furnace, Kawasaki Steel Corp., in consideration of its high flexibility in controlling burden distribution in the furnace. Before blowing-in, tests were conducted to obtain comprehensive information about the burden distribution by using the full-scale top for No. 2 blast furnace.ITV-system and mechanical profile meter for observing the motion and piling behavior of burden materials have been developed and installed to full utilize the flexibility of the bell-less top. Various charging patterns were tried in the actual operation. As a results, the control method of the burden distribution has been established to meet any operational requirement, either for full-capacity or reduced for the production of steel making pig iron as well as for the production of foundary pig iron. Furthermore, the charging method for small size sinter has been newly developed to reduce the overall cost of pig iron.

Pig iron

Full scale

10.2355/isijinternational1966.21.192

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Influence of Operational Factors on Thermal and Chemical Conditions at Lower Part of Blast Furnace

Tetsu-to-Hagane (1978)

Seiji TAGUCHI Nobuo TSUCHIYA Yoshiyasu TAKADA Kyoji Okabe

The operational data of blast furnace performance for longer periods are analyzed by the following parameters as adiabatic flame temperature, height for heat exchange and height of melting level, as well as indices of the thermal state RSi and the reduction behavior of ferrous oxide RS and RMn at the lower part of blast furnace. The results are as follows.(1) The temperature of melts changes with the adiabatic flame temperature and height for heat exchange, and is related to the heat balance.(2) RSi gives the same expression as that for thermal state representing the extent of coke reserve zone.(3) With lower quality coke, RSi, RS and RMn decrease markedly even in a regular operation; this indicates increasing FeO content in slag at the hearth.(4) The increase of sulfur content in injected oil decreases the S distribution ratio between slag and metal. On the other hand, the increase of sulfur content in coke has no influence on it. These differences are caused by the transfer mechanism to gas phase.

Slag (welding)

Adiabatic flame temperature

10.2355/tetsutohagane1955.64.6_691

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Development of a Mathematical Model of Silicon Transfer via SiO in the Blast Furnace

Tetsu-to-Hagane (1982)

Seiji TAGUCHI Hideho KUBO Nobuo TSUCHIYA Kazuo Ichifuji Kyoji Okabe

A mathematical model for the simulation of Si transfer process in the blast furnace was developed. The whole regions of the furnace from the stock level to the hearth were one-dimensionally simplified, and mass and heat transport and main reaction rates in each region were included in the simulation. The feature of the model is that instead of the slag-metal reaction in the hearth the reaction between SiO-gas and iron-droplets in the dropping zone is exclusively taken into account as the Si transfer reaction. When the temperature distribution is so simulated as to be well coincide with the actual in-furnace distribution, the calculated Si contents in hot metal are proved to be in good agreement with the observed values.

Hearth

10.2355/tetsutohagane1955.68.15_2303

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Citations (17)

Gasification reaction of lump coke for blast-furnace use. [Lump cokes packed in ceramic tube and gasified for maximum of 3 hr at 1000-12000/sup 0/ in upward streams of CO/sub 2/--CO and CO/sub 2/--N]

S. Taguchi Kyoji Okabe

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Investigations of Oil Combustion in the Race Way of the Blast Furnace

Transactions of the Iron and Steel Institute of Japan (1974)

Mikio Kondo Toshihiro Inatani Kyoji Okabe

I n order to clarify the phenomenological challges in the blast furnace accollljlanied wilh the iruection of heavy oil through the tz!yeres, the reaction gas in th e race way was sampled by the li se of a hori~ontal jJl"obe and analysed.i n the case withollt oil irUection, the CO 2 content gradually increased with decreasing content of ox)'gen along Ihe inward direction, and the COli tents of co and H 2 increased in the region passed through the maximum point of CO 2 ' A s the injection rate of heavy oil increased, this trend was more intensified and it was accomplished in a shorter range.When the nozzle head 'If the oil burner was fillt back in the blow pljle, the decrease in the content of oxygen occurred even in the blow flipe.Th e decrease in the length of the racewlry accomflallied with the increase ill the rate of oil injection was found also b.y the bar-test.The distributions of gases al the top of the shaft were measured by a fHobe /zori ::ontally installed at the stockline level and Ihe qjicienry of gas was calcula ted.

10.2355/isijinternational1966.14.267

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Citations (3)

Theoretical and Experimental Studies of the Scale-up Conditions for the Gas Flow in Packed Beds

Transactions of the Iron and Steel Institute of Japan (1976)

Tsuyoshi Fukutake Kyoji Okabe

I n order to clarify the conditions Jor the scale-up oj the flow through packed beds, dimensional analysis is applied to the flow equatiolls which are derived Jrom the mass and the momentum balances Jor the" macro" flow or the main stream in the beds.The p ressure distribution in a two dimCllsional reclangular model wilh a gas inlet installed on the side wall is measured and is also calculated numerically by the use oj a mathematical simulation model in order to verilY the scale-up conditions obtained and to evaluale Ihe applicability oj Ihe mathematical simulation model.R esults obtained are summariz.edas Jollows:(1) B esides Ihe distribut ions q! porosity and particle siz.e, scale-up conditions are shown by two dimensionless numbers R epo = Podoco Vo l f.1and Reb o=poV~/Ro D .(2) Except at the place near the gas inlet, Ihe dimensionless pressure defined by Eq. ( 6) does not change in deJ)endently oj Ihe flow conditions and that calculated agrees well wilh.Ihat oj experiment.(3) Among Ihe scale-up conditions, R epo mainly influences Ihe dimensionless pressure at Ihe gas inlet .(4) Near Ihe gas inlet, the calculated dimensionless pressure differs from Ihat oj experiment by up 10 10°" .

10.2355/isijinternational1966.16.189

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Citations (2)

Potassium absorption and degradation of metallurgical coke

Mikio Kondoh Yukio Konishi Kyoji Okabe

In the present work, the mechanism of potassium absorption by coke, the formation of lamellar compound, and the crack formation and subsequent disintegration of coke particle were studied under the conditions similar to those in the blast furnace. Potassium and carbon in coke form the reaction product close to the lamellar compound. This brings about undesirable results to coke properties such as crack formation and particle disintegration. No evidences of these phenomena could be found at the dissection survey of chiba No. 1 blast furnace because of low potassium load. In case of high alkali load, potassium attack to coke is undoubtedly a serious problem of the blast furnace operation. 19 figures, 4 tables.

Particle (ecology)

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