JP2006283065A - Gas-blowing tuyere - Google Patents
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本発明は、高温溶融金属を精錬する転炉などの精錬容器内にガスを吹き込むために精錬容器に設置される羽口に関するものである。 The present invention relates to a tuyere installed in a refining vessel in order to blow gas into a refining vessel such as a converter for refining high-temperature molten metal.
精錬容器で溶融金属を精錬する場合、攪拌による反応促進などの目的で溶融金属にガスを吹き込むことがある。例えば、鉄鋼業の転炉における溶銑の脱炭精錬では、転炉の底からＡｒガスや窒素ガスなどの不活性ガスを吹き込んでいる。また、この転炉においては、羽口を内管と外管とからなる二重管構造とし、内管から酸素ガスを吹き込み、内管と外管との間隙から羽口冷却用のガスとしてプロパンガスなどの炭化水素ガスを吹き込むタイプのものもある。 When refining molten metal in a refining vessel, gas may be blown into the molten metal for the purpose of promoting reaction by stirring. For example, in the decarburization and refining of hot metal in converters in the steel industry, an inert gas such as Ar gas or nitrogen gas is blown from the bottom of the converter. Further, in this converter, the tuyere has a double pipe structure composed of an inner pipe and an outer pipe, oxygen gas is blown from the inner pipe, and propane is used as a tuyere cooling gas from the gap between the inner pipe and the outer pipe. There is also a type that injects hydrocarbon gas such as gas.
一般的には、吹き込みガス流量を増加することにより、溶鋼内に誘起される溶鋼流が増大し、これにより攪拌が強化され、精錬時間の短縮や鉄スクラップ溶解時間の短縮などがなされるのみならず、スラグとメタルとの攪拌も強化されるため、Ｍｎなどの合金鉄歩留まりの向上が図れる。そのため最近では、これら冶金特性の向上や生産性向上の必要性から、吹き込みガス流量を増量する要求が高まっている。 In general, by increasing the flow rate of the blown gas, the flow of molten steel induced in the molten steel will increase, which will strengthen the stirring and reduce the refining time and iron scrap melting time. In addition, since the stirring of slag and metal is strengthened, the yield of alloy iron such as Mn can be improved. Therefore, recently, demands for increasing the flow rate of the blown gas have increased due to the need for improvement of metallurgical properties and productivity.
溶融金属中にガスを吹き込む羽口の構造としては、単管タイプ或いは上記の二重管タイプが一般的であるが、その他に特許文献１に開示された羽口がある。特許文献１では、吹き込みガス流量を広い範囲で制御可能とし且つ羽口の損耗を抑制することを目的として、中心部に位置する軸心部の外側に、外管を、前記軸心部との間に適当な間隙を設けて固定設置し、リング状のガス吐出流路を有する羽口（以下、「環状羽口」と称する）を開示している。この環状羽口は、比較的構造が簡単で且つ製作コストも比較的安価であるという特徴を有する。 As a tuyere structure for injecting gas into the molten metal, a single tube type or the above-mentioned double tube type is common, but there is a tuyere disclosed in Patent Document 1. In Patent Document 1, for the purpose of making it possible to control the flow rate of the blown gas in a wide range and to suppress the wear of the tuyere, an outer tube is connected to the outer side of the shaft center located at the center portion. There is disclosed a tuyere (hereinafter referred to as “annular tuyere”) having a ring-like gas discharge flow path which is fixedly installed with an appropriate gap therebetween. This annular tuyere is characterized by a relatively simple structure and a relatively low manufacturing cost.
本発明者等は、この環状羽口について鋭意研究した結果、リング状ガス吐出流路を形成する外管（以下「管状部」と記す）の内径を４０ｍｍ以上とすることで、羽口の損耗速度が飛躍的に減少することを見出した。しかし、損耗速度を低減するべく管状部の内径を４０ｍｍ以上とした場合、溶銑の脱炭処理を行う転炉などの高温で精錬するプロセスに適用した際には、管状部側面や管状部上面の受熱面積が大きくなるため、管状部を形成する羽口金物の温度が上昇し、時には溶融して損耗する場合があることが分かった。 As a result of diligent research on the annular tuyere, the present inventors have determined that the inner diameter of the outer tube (hereinafter referred to as “tubular portion”) forming the ring-shaped gas discharge flow path is 40 mm or more, so that the tuyere wears out. We found that the speed decreased dramatically. However, when the inner diameter of the tubular part is set to 40 mm or more in order to reduce the wear rate, when applied to a process for refining at a high temperature such as a converter for decarburizing hot metal, It has been found that since the heat receiving area increases, the temperature of the tuyere metal forming the tubular portion increases and sometimes melts and wears.
この対策の１つとして、ガス流量を増大させて冷却の強化を図る方法がある。しかしながら、ガス流量を増加させると、羽口周囲の溶鉄流動速度の増加に起因する、或いは、溶鉄流の底叩き現象（青木：鉄と鋼，７６（１９９０），vol.１１，p.１９９６，参照）の増加に起因するなどして、却って損耗速度の増加を招いてしまう。
本発明は上記事情に鑑みてなされたもので、その目的とするところは、精錬容器にガスを吹き込むために設置される環状羽口の管状部の内径が４０ｍｍ以上と大きい場合であっても、管状部を構成する羽口金物の溶損の恐れがなく、長期間安定して使用することのできるガス吹き込み羽口を提供することである。 The present invention has been made in view of the above circumstances, and the purpose of the present invention is that even when the inner diameter of the tubular portion of the annular tuyere installed to blow gas into the refining vessel is as large as 40 mm or more, It is an object of the present invention to provide a gas blown tuyere that can be used stably for a long period of time without fear of melting of the tuyere metal constituting the tubular portion.
上記課題を解決するための第１の発明に係るガス吹き込み羽口は、溶融金属を精錬する精錬容器に設けられ、ガスを精錬容器内へ吹き込むガス吹き込み羽口において、該羽口は、羽口の精錬容器側の先端部が、管状部と該管状部の内側に設けられる軸心部との間隙からガスを噴出する構造であって、前記管状部の内径が４０ｍｍ以上であり、且つ、吹き込まれるガスが不活性ガスと炭化水素ガスとの混合ガスであることを特徴とする。 A gas blowing tuyere according to a first invention for solving the above-mentioned problems is provided in a refining vessel for refining molten metal, and in the gas blowing tuyere for blowing gas into a refining vessel, the tuyere is a tuyere The tip of the refining vessel has a structure in which gas is ejected from the gap between the tubular portion and the axial center provided inside the tubular portion, and the tubular portion has an inner diameter of 40 mm or more and is blown The gas to be produced is a mixed gas of an inert gas and a hydrocarbon gas.
第２の発明に係るガス吹き込み羽口は、第１の発明において、不活性ガス及び炭化水素ガスのそれぞれの流量は、下記の（１）式によって定まる流量以上であることを特徴とする。但し、（１）式において、Ｑ1 は不活性ガスの流量（ｍ3 （標準状態）／分）、Ｑ2 は炭化水素ガスの流量（ｍ3 （標準状態）／分）、αは不活性ガスの冷却能（R1）と炭化水素ガスの冷却能（R2）との比（R2／R1）、Ｌは管状部内壁の周長さと軸心部外壁の周長さとの和（ｍ）である。 The gas injection tuyere according to the second invention is characterized in that, in the first invention, the flow rates of the inert gas and the hydrocarbon gas are equal to or higher than the flow rate determined by the following equation (1). However, in equation (1), Q1 is the flow rate of inert gas (m 3 (standard state) / min), Q2 is the flow rate of hydrocarbon gas (m 3 (standard state) / min), and α is the inert gas flow rate. The ratio (R2 / R1) of the cooling capacity (R1) and the cooling capacity (R2) of the hydrocarbon gas, L is the sum (m) of the peripheral length of the inner wall of the tubular portion and the peripheral length of the outer wall of the axial center portion.
(Ｑ1＋α×Ｑ2)／Ｌ＝10 …（１） (Q1 + α × Q2) / L = 10 (1)
本発明によれば、高温溶融金属の精錬において使用される環状羽口から、不活性ガスに加えて炭化水素ガスを吹き込むので、炭化水素ガスの熱分解による吸熱効果により、管状部を構成する羽口金物が冷却されて、羽口金物の温度上昇、つまり溶損が防止される。また、炭化水素ガスの冷却効果は大きく、少量の炭化水素ガスを混合させるだけで目的とする冷却効果が得られるので、環状羽口周囲の溶融金属自体の流動速度の上昇は少なく、また溶融金属流による底叩き現象の増加も少ない。そのため、環状羽口先端部の損耗速度の増加も抑制される。その結果、環状羽口の溶損を防止し、長期間の安定した吹き込みが可能となる。 According to the present invention, since the hydrocarbon gas is blown in addition to the inert gas from the annular tuyere used in the refining of the high-temperature molten metal, the feathers constituting the tubular portion are formed by the endothermic effect due to the thermal decomposition of the hydrocarbon gas. The base is cooled, and the temperature rise of the tuyere, that is, melting damage is prevented. In addition, the cooling effect of the hydrocarbon gas is large, and the desired cooling effect can be obtained just by mixing a small amount of hydrocarbon gas, so the increase in the flow rate of the molten metal around the annular tuyere is small, and the molten metal There is little increase in bottom hitting phenomenon due to flow. For this reason, an increase in the wear rate of the tip of the annular tuyere is also suppressed. As a result, melting of the annular tuyere is prevented, and stable blowing over a long period of time becomes possible.
以下、本発明を具体的に説明する。 The present invention will be specifically described below.
羽口構造として比較的吹き込みガス流量の調整範囲が広く、ガス吹き込み量の増加を図ることのできる環状羽口に着目し、その損耗速度低減について鋭意検討と実験を重ねた。その結果、環状羽口でも、ガス流量を増大させた場合に損耗速度が大きくなる原因として、前述した非特許文献１で指摘されているように、吹き込まれたガスが羽口出口で急激に膨張し、一部の上昇しきれない気泡とそれに随伴する溶融金属流とが、羽口煉瓦部を叩くことによって損耗することが確認され、損耗速度を抑えるには、これを低減することが重要であるという結論に至った。 Focusing on the annular tuyere, which has a relatively wide adjustment range of the blown gas flow rate as a tuyere structure, and can increase the amount of blown gas, we conducted extensive studies and experiments on reducing the wear rate. As a result, even in the annular tuyere, as pointed out in Non-Patent Document 1 mentioned above, the gas blown in rapidly expands at the tuyere outlet as a cause of increasing the wear rate when the gas flow rate is increased. However, it has been confirmed that some of the bubbles that cannot be raised and the molten metal flow that accompanies them are worn by hitting the tuyere brick part, and it is important to reduce this in order to reduce the wear rate. I came to the conclusion.
ここで、環状羽口について説明する。図１は、環状羽口を転炉などの精錬容器に設置した状態を示す概略断面図、図２は、図１のＸ−Ｘ’矢視による概略図である。但し、図２では精錬容器の耐火物を省略している。 Here, the annular tuyere will be described. FIG. 1 is a schematic cross-sectional view showing a state where an annular tuyere is installed in a refining vessel such as a converter, and FIG. 2 is a schematic view taken along arrow X-X ′ in FIG. 1. However, the refractory in the smelting vessel is omitted in FIG.
図１及び図２に示すように、環状羽口１は、内管３と内管３の内面側の耐火物充填層４とからなる軸心部２と、この軸心部２の外側にリング状の間隙６を隔てて固定される管状部５とで構成される。環状羽口１の稼動面側の反対側には、風箱７及び風箱７に設置されるガス導入管８が備えられており、ガス導入管８から導入されたガスは風箱７で分散し均圧され、リング状の間隙６を通って精錬容器９の内部に供給されるようになっている。図１において、１０は精錬容器の鉄皮、１１は精錬容器の耐火物、１２は環状羽口１を鉄皮１０に取り付けるための取付金物である。 As shown in FIG. 1 and FIG. 2, the annular tuyere 1 has an axial center portion 2 composed of an inner tube 3 and a refractory-filled layer 4 on the inner surface side of the inner tube 3, and a ring outside the axial center portion 2. And a tubular portion 5 fixed with a gap 6 between them. On the side opposite to the operating surface side of the annular tuyere 1, a wind box 7 and a gas introduction pipe 8 installed in the wind box 7 are provided, and the gas introduced from the gas introduction pipe 8 is dispersed in the wind box 7. The pressure is equalized and supplied to the inside of the refining vessel 9 through the ring-shaped gap 6. In FIG. 1, 10 is an iron skin of a refining container, 11 is a refractory material of the refining container, and 12 is a fitting for attaching the annular tuyere 1 to the iron skin 10.
そこで、発明者等は、環状羽口１の損耗速度を低減するべく、各種寸法の環状羽口１のモデル実験を行い、吹き込みガスの羽口出口での広がり防止、並びに随伴流の低減方法について検討した。その結果、環状羽口１の径を大きくすることで、具体的には、管状部５の内径（Ｄ）を４０ｍｍ以上とすることで、環状羽口１の損耗が低減することを見出した。この効果が発現するのは、次のような理由であると考えられる。即ち、吹き込みガス流量が一定の場合には、ガスに随伴する溶融金属量は一定になる。環状羽口１の径が大きい場合には、随伴する溶融金属を補う表面積が大きくなるため、誘起される溶融金属の流速は小さくなる。また、環状羽口１の径が大きくなるほど、羽口出口における気泡の膨張が抑制される。誘起される溶融金属の流速が小さくなること、及び、気泡の膨張が抑制されることの両者の効果によって、環状羽口１の損耗が低減されると考えられる。 Therefore, the inventors conducted a model experiment of the annular tuyere 1 having various dimensions in order to reduce the wear rate of the annular tuyere 1, and a method for preventing the spread of the blown gas at the tuyere outlet and reducing the accompanying flow. investigated. As a result, it has been found that wear of the annular tuyere 1 is reduced by increasing the diameter of the annular tuyere 1, specifically by setting the inner diameter (D) of the tubular portion 5 to 40 mm or more. It is considered that this effect appears for the following reason. That is, when the flow rate of the blown gas is constant, the amount of molten metal accompanying the gas is constant. When the diameter of the annular tuyere 1 is large, the surface area of the accompanying molten metal is increased, so that the induced molten metal flow rate is reduced. Further, as the diameter of the annular tuyere 1 increases, the expansion of bubbles at the tuyere outlet is suppressed. It is considered that the wear of the annular tuyere 1 is reduced by both the effects of the reduced flow rate of the molten metal induced and the suppression of bubble expansion.
しかし、管状部５の内径（Ｄ）を４０ｍｍ以上とすると、管状部５の側面面積及び上面面積が大きくなり、受熱面積が増加することによって、管状部５を形成する羽口金物の温度上昇を招くことが判明したので、更に、検討を加えた。 However, when the inner diameter (D) of the tubular part 5 is 40 mm or more, the side surface area and the upper surface area of the tubular part 5 are increased, and the heat receiving area is increased, thereby increasing the temperature of the tuyere metal forming the tubular part 5. Since it was found to invite, further examination was added.
酸素ガスを底吹きする羽口においては、羽口を二重管構造とし、内管と外管との間隙から冷却用ガスとして炭化水素ガスを吹き込んでいる。これは、炭化水素ガスは顕熱に加えて熱分解時の吸熱による冷却効果があり、この熱分解時の吸熱による冷却効果を利用したものである。 In the tuyere where oxygen gas is blown to the bottom, the tuyere has a double pipe structure, and hydrocarbon gas is blown as a cooling gas from the gap between the inner pipe and the outer pipe. This is because hydrocarbon gas has a cooling effect due to heat absorption during pyrolysis in addition to sensible heat, and utilizes the cooling effect due to heat absorption during pyrolysis.
そこで、環状羽口１についても、攪拌用の不活性ガスに加えて冷却用ガスとして炭化水素ガスを混合して吹き込むことを検討した。 Therefore, the annular tuyere 1 was studied to mix and blow hydrocarbon gas as cooling gas in addition to the inert gas for stirring.
先ず、環状羽口１の管状部５を形成する羽口金物の温度は、何に依存するかを実験及び伝熱計算により求めた。その結果、環状羽口１の管状部５を形成する羽口金物の温度は、間隙６を形成する管状部５の内壁周長さと、内管３の外径周長さつまり軸心部２の外壁周長さとを加えた和の単位長さ当たりのガス流量によって決まることが判明した。即ち、間隙６を流れるガス流量と、この間隙６を囲む周囲長さとによって決まることが分かった。 First, what depended on the temperature of the tuyere metal forming the tubular portion 5 of the annular tuyere 1 was determined by experiment and heat transfer calculation. As a result, the temperature of the tuyere metal that forms the tubular portion 5 of the annular tuyere 1 depends on the inner wall circumferential length of the tubular portion 5 that forms the gap 6 and the outer diameter circumferential length of the inner tube 3, that is, the axial center portion 2. It was found that it was determined by the gas flow rate per unit length of the sum of the outer wall perimeter. That is, it was found that the flow rate was determined by the flow rate of the gas flowing through the gap 6 and the peripheral length surrounding the gap 6.
更に、不活性ガスと炭化水素ガスとで流量を比較すると、炭化水素ガスは熱分解時の吸熱による冷却効果を有しており、窒素ガスやＡｒガスなどの不活性ガスに比較して冷却能が大きく、羽口金物を冷却するという観点からみると、炭化水素ガスの流量は不活性ガスの流量よりも大きく換算してよいことが分かった。つまり、不活性ガスの流量をＱ1 （ｍ3 （標準状態）／分）とし、炭化水素ガスの流量をＱ2 （ｍ3 （標準状態）／分）とし、不活性ガスの冷却能をR1（Ｊ）とし、炭化水素ガスの冷却能をR2（Ｊ）とし、更に、不活性ガスの冷却能（R1）と炭化水素ガスの冷却能（R2）との比（R2／R1）をαとすると、炭化水素ガス流量の換算値としては、実際の流量（Ｑ2 ）にαを乗算した流量換算値で表されることが分かった。 Furthermore, when comparing the flow rates of an inert gas and a hydrocarbon gas, the hydrocarbon gas has a cooling effect due to heat absorption during pyrolysis, and the cooling capacity is lower than that of an inert gas such as nitrogen gas or Ar gas. From the viewpoint of cooling the tuyere metal, it was found that the flow rate of the hydrocarbon gas may be converted to be larger than the flow rate of the inert gas. In other words, the flow rate of the inert gas is Q1 (m 3 (standard state) / min), the flow rate of the hydrocarbon gas is Q2 (m 3 (standard state) / min), and the cooling capacity of the inert gas is R1 (J ), The cooling capacity of the hydrocarbon gas is R2 (J), and the ratio (R2 / R1) of the cooling capacity of the inert gas (R1) to the cooling capacity of the hydrocarbon gas (R2) is α, It was found that the converted value of the hydrocarbon gas flow rate is represented by a converted flow rate value obtained by multiplying the actual flow rate (Q2) by α.
そして更に、このようにして定めた不活性ガス流量と炭化水素ガス流量との和（Ｑ1 ＋α×Ｑ2 ）を、管状部５の内壁周長さと軸心部２の外壁周長さとを加えた和に対して、下記の（１）式により定まる値と同等以上にすることで、管状部５を構成する羽口金物の温度上昇が防止でき、羽口金物は容損しないことが分かった。即ち、下記の（１）式で定まる不活性ガス流量（Ｑ1 ）及び炭化水素ガス流量（Ｑ2 ）以上の不活性ガス及び炭化水素ガスをそれぞれ流すことで、羽口金物の温度上昇が防止でき、羽口金物は容損しないことが分かった。尚、（１）式におけるＬは管状部５の内壁の周長さと軸心部２の外壁の周長さとの和（ｍ）である。 Further, the sum (Q1 + α × Q2) of the inert gas flow rate and the hydrocarbon gas flow rate determined in this way is added to the inner wall circumferential length of the tubular portion 5 and the outer wall circumferential length of the shaft center portion 2. On the other hand, it was found that by making the value equal to or greater than the value determined by the following equation (1), the temperature increase of the tuyere metal constituting the tubular portion 5 can be prevented, and the tuyere metal is not damaged. That is, by flowing an inert gas and a hydrocarbon gas that are equal to or higher than the inert gas flow rate (Q1) and hydrocarbon gas flow rate (Q2) determined by the following equation (1), the temperature rise of the tuyere can be prevented, It was found that the tuyere hardware would not be damaged. In the equation (1), L is the sum (m) of the circumferential length of the inner wall of the tubular portion 5 and the circumferential length of the outer wall of the shaft center portion 2.
(Ｑ1＋α×Ｑ2)／Ｌ＝10 …（１）
不活性ガスの冷却能は顕熱量で定まり、炭化水素ガスの冷却能は顕熱量と熱分解による吸熱量との和で定まる。顕熱量は、各ガスを供給したときに羽口内を通過するまでに昇温するときの熱量と考えることができる。例えば２５℃から１６００℃までの温度上昇に必要な顕熱とすることができる。また、熱分解による吸熱量は、炭化水素ガスが羽口内で炭素及び水素或いはより低級な炭化水素ガスへと熱分解するのに必要な熱量である。例えば、使用する炭化水素ガスが常温で炭素、水素まで分解するのに必要な熱量で計算することができる。従って、使用する不活性ガス及び炭化水素ガスの種類によってαの値は決定される。不活性ガスとしては窒素ガスまたはＡｒガスを使用する。窒素ガスまたはＡｒガスでは顕熱に若干の差はあるが、羽口金物を冷却する観点からみれば無視できる程度の差でしかなく、従って、（１）式は不活性ガスとして窒素ガスまたはＡｒガスを使用する限り、両者に適用することができる。
(Q1 + α × Q2) / L = 10 (1)
The cooling capacity of the inert gas is determined by the amount of sensible heat, and the cooling capacity of the hydrocarbon gas is determined by the sum of the amount of sensible heat and the amount of heat absorbed by thermal decomposition. The amount of sensible heat can be considered as the amount of heat when the temperature is raised before passing through the tuyere when each gas is supplied. For example, the sensible heat required for temperature increase from 25 ° C. to 1600 ° C. can be obtained. Further, the endothermic amount due to thermal decomposition is the amount of heat necessary for the thermal decomposition of hydrocarbon gas into carbon and hydrogen or lower hydrocarbon gas in the tuyere. For example, the amount of heat required for the hydrocarbon gas used to decompose to carbon and hydrogen at room temperature can be calculated. Therefore, the value of α is determined by the type of inert gas and hydrocarbon gas used. Nitrogen gas or Ar gas is used as the inert gas. Nitrogen gas or Ar gas has a slight difference in sensible heat, but it is only a negligible difference from the viewpoint of cooling the tuyere metal fitting. Therefore, the equation (1) is an inert gas such as nitrogen gas or Ar. As long as gas is used, it can be applied to both.
また、炭化水素ガスとしては、メタンガス、プロパンガス、ブタンガスなどの常温でガス状態であるものが好適に使用できる。更に、ベンゼンなどの常温で液体のものであっても、不活性ガス中にミストとして吹き込んで羽口内で気化するものは、使用することができる。炭化水素ガスは過剰に混合させる必要はなく、炭化水素ガスの流量（Ｑ2 ）は不活性ガスの流量（Ｑ1 ）の１／５程度以下であればよい。 Moreover, as hydrocarbon gas, what is a gas state at normal temperature, such as methane gas, propane gas, butane gas, can be used conveniently. Furthermore, even if it is liquid at room temperature, such as benzene, it can be used if it is blown as a mist into an inert gas and vaporizes in the tuyere. The hydrocarbon gas need not be excessively mixed, and the flow rate (Q2) of the hydrocarbon gas may be about 1/5 or less of the flow rate (Q1) of the inert gas.
以上説明したように、本発明に係る環状羽口１は、その管状部５の内経（Ｄ）を４０ｍｍ以上とし、且つ、不活性ガスと炭化水素ガスとの混合ガスを吹き込むので、炭化水素ガスの熱分解による吸熱効果によって管状部５を構成する羽口金物が冷却されて温度上昇が妨げられ、その結果、環状羽口１の溶損を防止し、長期間の吹き込みが可能となる。間隙６の幅は、ガス吹き込み流量や溶融金属の密度に応じて、間隙６に溶融金属が差し込まず、所望のガス流量を吹き込むことができる寸法とすればよい。内管３及び管状部５は金属製（主にステンレス鋼）であり、その厚みは３〜１０ｍｍ程度とすればよい。 As described above, since the annular tuyere 1 according to the present invention has an inner diameter (D) of the tubular portion 5 of 40 mm or more and a mixed gas of an inert gas and a hydrocarbon gas is blown into the annular tuyere 1. Due to the endothermic effect due to the thermal decomposition of the gas, the tuyere metal constituting the tubular portion 5 is cooled and the temperature rise is hindered. As a result, the annular tuyere 1 is prevented from being melted and can be blown for a long time. The width of the gap 6 may be a dimension that allows a desired gas flow rate to be blown into the gap 6 according to the gas blow flow rate and the density of the molten metal. The inner tube 3 and the tubular portion 5 are made of metal (mainly stainless steel), and the thickness may be about 3 to 10 mm.
溶鉄における効果を把握するために、容量が５トンの試験転炉を用いて試験を実施した。試験では、攪拌用ガスとして窒素ガスを使用し、炭化水素ガスとしてプロパンガスを使用した（水準２，３）。また、比較のために、プロパンガスを使用しない試験（水準１）も実施した。脱炭精錬終点の溶鋼温度を１７００〜１７２０℃とし、上吹きランスから酸素ガスを吹き付けて１ヒートが２０分間の溶銑の脱炭精錬を２ヒート実施した。表１に水準１〜３の試験に用いた環状羽口の仕様及びガス吹き込み条件を示す。尚、プロパンガスを使用した場合のαは１０．２となる。 In order to grasp the effect on the molten iron, a test was conducted using a test converter having a capacity of 5 tons. In the test, nitrogen gas was used as the stirring gas, and propane gas was used as the hydrocarbon gas (levels 2 and 3). For comparison, a test (level 1) in which propane gas was not used was also conducted. The molten steel temperature at the end point of decarburization refining was set to 1700 to 1720 ° C., and oxygen gas was blown from the top blowing lance to carry out 2 heat decarburization refining of hot metal for 20 minutes. Table 1 shows the specifications and gas blowing conditions of the annular tuyere used in the tests of levels 1 to 3. When propane gas is used, α is 10.2.
各２ヒートの脱炭精錬の終了後、試験転炉から環状羽口を回収し、管状部を構成する羽口金物の損耗量を調査した。図３に、水準１〜３の各試験における羽口金物の損耗量を比較して示す。図３に示すように、前述した（１）式を満たす範囲で窒素ガス及びプロパンガスを吹き込んだ水準２及び水準３では、損耗量が２ｍｍ以下であり、本発明の底吹き羽口では羽口金物の損耗量を削減できることが確認できた。 After the completion of the decarburization refining for each of the two heats, the annular tuyere was recovered from the test converter, and the amount of wear of the tuyere hardware constituting the tubular part was investigated. In FIG. 3, the wear amount of a tuyere metal in each test of level 1-3 is compared and shown. As shown in FIG. 3, at level 2 and level 3 in which nitrogen gas and propane gas are blown in a range satisfying the above-described expression (1), the wear amount is 2 mm or less. It was confirmed that the wear amount of hardware can be reduced.
１ 環状羽口
２ 軸心部
３ 内管
４ 耐火物充填層
５ 管状部
６ 間隙
７ 風箱
８ ガス導入管
９ 精錬容器
１０ 鉄皮
１１ 耐火物
１２ 取付金物
DESCRIPTION OF SYMBOLS 1 Annular tuyere 2 Axial center part 3 Inner pipe 4 Refractory filling layer 5 Tubular part 6 Gap 7 Air box 8 Gas introduction pipe 9 Refining vessel 10 Iron skin 11 Refractory 12 Mounting hardware
Claims (2)
(Ｑ1＋α×Ｑ2)／Ｌ＝10 …（１）
但し、（１）式において、Ｑ1 は不活性ガスの流量（ｍ3 （標準状態）／分）、Ｑ2 は炭化水素ガスの流量（ｍ3（標準状態）／分）、αは不活性ガスの冷却能（R1）と炭化水素ガスの冷却能（R2）との比（R2／R1）、Ｌは管状部内壁の周長さと軸心部外壁の周長さとの和（ｍ）である。 2. The gas blowing tuyere according to claim 1, wherein each flow rate of the inert gas and the hydrocarbon gas is equal to or higher than a flow rate determined by the following equation (1).
(Q1 + α × Q2) / L = 10 (1)
However, in equation (1), Q1 is the flow rate of inert gas (m 3 (standard state) / min), Q2 is the flow rate of hydrocarbon gas (m 3 (standard state) / min), and α is the inert gas flow rate. The ratio (R2 / R1) of the cooling capacity (R1) and the cooling capacity (R2) of the hydrocarbon gas, L is the sum (m) of the peripheral length of the inner wall of the tubular portion and the peripheral length of the outer wall of the axial center portion.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005101682A JP2006283065A (en) | 2005-03-31 | 2005-03-31 | Gas-blowing tuyere |
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| Application Number | Priority Date | Filing Date | Title |
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| JP2005101682A JP2006283065A (en) | 2005-03-31 | 2005-03-31 | Gas-blowing tuyere |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101913410B1 (en) * | 2016-12-21 | 2018-10-31 | 주식회사 포스코 | Method of manufacturing high purity molten steel |
| WO2021177101A1 (en) * | 2020-03-04 | 2021-09-10 | 黒崎播磨株式会社 | Integrated tuyere for converter |
| WO2022048313A1 (en) * | 2020-09-03 | 2022-03-10 | 钢铁研究总院 | Annular-gap-type gas supply element, and gas supply method |
| CN115090867A (en) * | 2022-07-18 | 2022-09-23 | 江苏盐电铸业有限公司 | Casting pouring system and pouring method thereof |
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2005
- 2005-03-31 JP JP2005101682A patent/JP2006283065A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101913410B1 (en) * | 2016-12-21 | 2018-10-31 | 주식회사 포스코 | Method of manufacturing high purity molten steel |
| WO2021177101A1 (en) * | 2020-03-04 | 2021-09-10 | 黒崎播磨株式会社 | Integrated tuyere for converter |
| JP2021138997A (en) * | 2020-03-04 | 2021-09-16 | 黒崎播磨株式会社 | Integrated tuyere for converter |
| TWI773163B (en) * | 2020-03-04 | 2022-08-01 | 日商黑崎播磨股份有限公司 | Integrated tuyere for converter |
| WO2022048313A1 (en) * | 2020-09-03 | 2022-03-10 | 钢铁研究总院 | Annular-gap-type gas supply element, and gas supply method |
| JP2022042996A (en) * | 2020-09-03 | 2022-03-15 | 鋼鉄研究総院 | Annular slot type air supply means and air supply method |
| JP7284228B2 (en) | 2020-09-03 | 2023-05-30 | 鋼鉄研究総院 | Annular slot type air supply means and air supply method |
| CN115090867A (en) * | 2022-07-18 | 2022-09-23 | 江苏盐电铸业有限公司 | Casting pouring system and pouring method thereof |
| CN115090867B (en) * | 2022-07-18 | 2023-11-24 | 江苏盐电铸业有限公司 | Casting pouring system and casting pouring method thereof |
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