SU662020A3

SU662020A3 - Method of protecting bottom tuyeres

Info

Publication number: SU662020A3
Application number: SU772459655A
Authority: SU
Inventors: Леруа Пьер
Original assignee: Крезо-Луар (Фирма)
Priority date: 1977-03-16
Filing date: 1977-03-16
Publication date: 1979-05-15

Description

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Изобретение относитс к металлургии и может быть использовано при продувке ванны кислородом через дно конвертера.The invention relates to metallurgy and can be used when blowing a bath with oxygen through the bottom of a converter.

Известны способы защиты донных фурм дл продувКй конверторной ваннь кислородом , окруженным защитной жидкостью {1 .There are known methods for protecting bottom tuyeres for blowing through a converter bath with oxygen surrounded by a protective liquid {1.

Наиболее близким по технической. сущности и достигаемому результату к описывае мому изобретению вл етс способ защиты донных фурм дл продувки конверторной ванны кислородом, окруженным защитной жидкостью, содержацхей углеводороды, BKJlroчающи .й регулировку расхода защитной жидкости 2.The closest technical. The essence and the achieved result to the described invention is a method of protection of bottom tuyeres for blowing the converter bath with oxygen surrounded by a protective fluid containing hydrocarbons, BKJrochuyuyuyu regulating the flow of protective fluid 2.

Недостатком известного способу вл етс больщой расход защитной жидкости и низка стойкость фурм.A disadvantage of the known method is the large consumption of protective fluid and the low resistance of the tuyeres.

Целью изобретени вл етс увеличение стойкости фурм.The aim of the invention is to increase the resistance of the tuyeres.

Указанна цель достигаетс тем, что -регулировку расхода защитной жидкости осуществл ют в три фазы, причем от начала продувки до содержани углерода в ванне 0,3-0,7°/о расход защитной жидкости поддерживают равным 0,4-0,6 Dn, до 90-95% общего времени продувки равным Dn и до конца продувки 1,5-2,0 Dn, где Dn- нормальный расход защитной жидкости, равный 0,08-0,15 литров в минуту на сантиметр средней длины окружности кольцевого прохода в фурме дл защитной жидкости.This goal is achieved by the fact that the adjustment of the flow rate of the protective fluid is carried out in three phases, and from the beginning of the purge to the carbon content in the bath of 0.3-0.7 ° / o the flow rate of the protective fluid is maintained at 0.4-0.6 Dn, up to 90-95% of the total blowing time equal to Dn and until the end of blowing 1.5-2.0 Dn, where Dn is the normal flow of protective fluid, equal to 0.08-0.15 liters per minute per centimeter of average circumference of the annular passage in tuyere for protective fluid.

Пример осуществлени способа.An example of the method.

Продувка велась в конверторе - 60 тонн, днище которого имело 7 двойных фурм, кажда из которых имеет трубку 28 мм/34 мм дл кислорода и трубку 36 мм/42 мм дл защитной жидкости. В данном случае защитной жидкостью вл етс мазут.The purge was carried out in the converter — 60 tons, the bottom of which had 7 double tuyeres, each of which had a tube of 28 mm / 34 mm for oxygen and a tube of 36 mm / 42 mm for a protective fluid. In this case, the protective liquid is fuel oil.

При фурмах этого размера нормальный расход мазута составит около 1,43 литров в минуту и 1,5 литров в минуту на фурму.With tuyeres of this size, the normal consumption of fuel oil will be about 1.43 liters per minute and 1.5 liters per minute per tuyere.

1-а фаза; с начала до объема продутоto кислорода в 2200 Нм, то есть 65% общего дуть . В этот момент содержание уг5 лерода э ванне не дозируетс , но оно составл ет около 0,500%. В течение всего этого первого периода расход мазута регулируетс 0,5 Dn 0,5x1,5 0,75 литров в минуту на фурму, то есть 5,25 литров в минуту на 7 1st phase; from the beginning to the volume of oxygen production in 2200 Nm, that is 65% of the total blowing. At this point, the carbon dioxide content is not dosed, but it is about 0.500%. Throughout this first period, the consumption of fuel oil is regulated by 0.5 Dn 0.5 × 1.5 0.75 liters per minute per lance, i.e. 5.25 liters per minute at 7

0 фурм. В насто щем примере перва фаза длитс 8,5 минут. 0 lances In the present example, the first phase lasts 8.5 minutes.

Claims

2nd phase; Starting from 2200 Nm of purged oxygen to 3200 Nm (i.e. 95% Blow), the consumption of fuel oil is the normal flow rate Dn, in this case 1.5 liters per minute for the tuyere, i.e. 10.5 liters per minute for 7 tuyeres. This second phase covers the termination of the decarburization, the transition and the main part of the removal of phosphorus from the bath. In the present example, this second phase lasts 3 minutes. 3rd phase; Starting from 3200 Nm of purged oxygen to 3,360 Nm, i.e., up to the end of the oxygen blowing, the consumption of fuel oil is a single flow rate of 1.6 Dn 1.6 X 1.5 2.4 liters per minute. that is, 16.8 liters per minute for 7 lances. In this example, this third phase lasts 30 seconds. The modulation technique, according to the present invention, of the flow rate of the tuyeres protective fluid has several important advantages. First of all, by limiting the modulus to three different phases, it retains the simplicity character, which makes it easily applicable in practice. Secondly, this method is well-adapted. changes in the rate of exposure in the hot state on the tip of the tuyeres of iron oxides, in accordance with the decrease in the carbon content in the metal bath, and as a result, it leads to the consumption of protective fluid, largely reduced in relation to the known method constant flow throughout the blow. Then, the excess flow of protective fluid relative to the normal flow, during the second phase, allows, in addition to the protection effect, to achieve a deoxidation effect, and even a very slight re-carburization of the bath at the end of the purge, due to carbon coming from the cracking of excess liquid. Claim Method A method of protecting bottom tuyeres for purging a converter bath with oxygen surrounded by a protective fluid containing hydrocarbons, including adjusting the flow of protective fluid, characterized in that, in order to increase the durability of the tuyeres, the flow of protective fluid is controlled in three phases, from the beginning of blowing to The carbon content in the bath is 0.3–0.7%; the flow of protective fluid is maintained at 0.4–0.6 Do; up to 90–95% of the total purge time is equal to Dn; and until the end of the blow, 1.5–2.0 Dn, where DH - normal flow of protective liquid ti, equal to 0.08-0.15 liters per minute per centimeter of the average circumference of the annular passage in the form of a liquid for liquids. Sources of information taken into account in the examination 1.Patent of France No. 2067143, cl. C 21 C 5/00, 1971.

2. Steel production using oxygen purging abroad Chermetinformatsi, series 6, vol. 8, 1974, p. 6-14.