JP6468272B2 - Lance protection method in blast furnace tuyeres lance - Google Patents
Lance protection method in blast furnace tuyeres lance Download PDFInfo
- Publication number
- JP6468272B2 JP6468272B2 JP2016231055A JP2016231055A JP6468272B2 JP 6468272 B2 JP6468272 B2 JP 6468272B2 JP 2016231055 A JP2016231055 A JP 2016231055A JP 2016231055 A JP2016231055 A JP 2016231055A JP 6468272 B2 JP6468272 B2 JP 6468272B2
- Authority
- JP
- Japan
- Prior art keywords
- blowing
- tuyere
- lance
- reducing material
- blown
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims description 19
- 238000007664 blowing Methods 0.000 claims description 91
- 239000000463 material Substances 0.000 claims description 67
- 230000008093 supporting effect Effects 0.000 claims description 7
- 239000003245 coal Substances 0.000 description 58
- 239000007789 gas Substances 0.000 description 38
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 34
- 238000002485 combustion reaction Methods 0.000 description 26
- 238000010926 purge Methods 0.000 description 20
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 19
- 229910001873 dinitrogen Inorganic materials 0.000 description 17
- 239000003345 natural gas Substances 0.000 description 17
- 230000000052 comparative effect Effects 0.000 description 11
- 239000000571 coke Substances 0.000 description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 9
- 239000001301 oxygen Substances 0.000 description 9
- 229910052760 oxygen Inorganic materials 0.000 description 9
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- 239000000446 fuel Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 238000006722 reduction reaction Methods 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 3
- 239000002737 fuel gas Substances 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910000805 Pig iron Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Landscapes
- Manufacture Of Iron (AREA)
Description
本発明は、高炉の羽口に接続するブローパイプに設置された、高炉羽口から微粉炭などの還元材を炉内に吹き込むための羽口吹き込みランスにおけるランス保護方法に関し、詳しくは、高炉羽口への還元材などの吹き込みを停止する際に、微粉炭や熱風などが羽口吹き込みランス内に逆流して羽口吹き込みランスを損傷させることを防止するためのランス保護方法に関する。 The present invention relates to a method for protecting a lance in a tuyere blowing lance installed in a blow pipe connected to a tuyere of a blast furnace and for blowing a reducing material such as pulverized coal from the blast furnace tuyere into the furnace. The present invention relates to a lance protection method for preventing pulverized coal, hot air, etc. from flowing backward into a tuyere blowing lance and damaging the tuyere blowing lance when stopping blowing of a reducing material into the mouth.
近年、高炉におけるコークスの消費量を抑えるために、微粉炭や易燃性還元材（天然ガス、コークス炉ガスなど）などの還元材を羽口から吹き込む高炉の操業方法が実用化されている。微粉炭や易燃性還元材を用いた高炉の操業方法では、熱風を高炉内に供給するブローパイプを通して、微粉炭や易燃性還元材が、熱風とともに高炉内へ供給される。このブローパイプには、ブローパイプ内に微粉炭や易燃性還元材を吹き込むための羽口吹き込みランスが設けられ、微粉炭や易燃性還元材がブローパイプ内を流れる熱風によって吹き込まれる構成となっている。羽口吹き込みランスから吹き込まれた微粉炭や易燃性還元材は、ブローパイプ内及び高炉内部のレースウェイと呼ばれる燃焼空間内で燃焼することにより、コークスの代替として機能する。 In recent years, in order to suppress the consumption of coke in a blast furnace, a method of operating a blast furnace in which a reducing material such as pulverized coal or a flammable reducing material (natural gas, coke oven gas, etc.) is blown from a tuyere has been put into practical use. In the blast furnace operation method using pulverized coal and flammable reducing material, pulverized coal and flammable reducing material are supplied into the blast furnace together with hot air through a blow pipe that supplies hot air into the blast furnace. The blow pipe is provided with a tuyere blowing lance for blowing pulverized coal and flammable reducing material into the blow pipe, and the pulverized coal and flammable reducing material are blown by hot air flowing in the blow pipe. It has become. The pulverized coal and the flammable reducing material blown from the tuyere blowing lance function as a substitute for coke by burning in a combustion space called a raceway in the blow pipe and in the blast furnace.
微粉炭と易燃性還元材とを羽口から吹き込む高炉の操業方法の例としては、たとえば、特許文献１には、同一の羽口から高炉炉内に微粉炭と気体燃料とを吹き込む高炉操業において、気体燃料の原単位を、微粉炭の原単位、微粉炭中の固定炭素の質量比率、微粉炭中の揮発分の質量比率から定められる値以下に制御し、未燃チャーの発生による炉況の悪化を抑制する高炉操業方法が提案されている。 As an example of a method of operating a blast furnace in which pulverized coal and a flammable reducing material are blown from the tuyere, for example, Patent Document 1 discloses a blast furnace operation in which pulverized coal and gaseous fuel are blown into the blast furnace from the same tuyere. In the furnace, the basic unit of gaseous fuel is controlled to a value determined from the basic unit of pulverized coal, the mass ratio of fixed carbon in the pulverized coal, and the mass ratio of volatile components in the pulverized coal. Blast furnace operation methods that suppress the deterioration of the situation have been proposed.
高炉の操業において、羽口からの還元材吹き込み量は必ずしも一定ではなく、状況に応じて変化しうる。たとえば、高炉操業において炉内圧力損失の上昇が起こった際、操業安定化のためにコークス比を上げ、同時に、微粉炭や易燃性還元材の吹き込みを停止することがある。その際、高炉は高圧設備であるために、羽口吹き込みランスを取り替えたり、取り外したりすることは容易ではない。そこで、使用されない羽口吹き込みランスにおいては、逆流を防止するために窒素ガスや空気がパージガスとして使用されている。 In the operation of a blast furnace, the amount of reducing material blown from the tuyere is not necessarily constant, and may vary depending on the situation. For example, when an increase in furnace pressure loss occurs during blast furnace operation, the coke ratio may be increased to stabilize the operation, and at the same time, the blowing of pulverized coal or a flammable reducing material may be stopped. At that time, since the blast furnace is a high-pressure facility, it is not easy to replace or remove the tuyere blowing lance. Therefore, in a tuyere blowing lance that is not used, nitrogen gas or air is used as a purge gas in order to prevent backflow.
たとえば、特許文献２には、微粉炭の燃焼不良やレースウェイへの装入物降下が起こった際に、吹き込んだ微粉炭が逆流して送風支管の耐火物を破損するという問題を回避するために、送風支管の風量値が規定値以下となったときは微粉炭の吹き込みを停止し、代わりにパージガスとして窒素ガスを吹き込む方法が提案されている。 For example, in Patent Document 2, in order to avoid the problem that the pulverized coal blown backflows and damages the refractory of the blower branch pipe when a combustion failure of the pulverized coal or a charge drop to the raceway occurs. In addition, there has been proposed a method in which the blowing of pulverized coal is stopped when the air volume value of the blower branch pipe becomes equal to or less than a specified value, and nitrogen gas is blown as a purge gas instead.
また、特許文献３には、酸素高炉において微粉炭の吹き込み量が規定値以下となったときに、コークス炉ガスなどの燃料を吹き込んで操業を持続する方法が提案されている。 Patent Document 3 proposes a method of continuing operation by injecting fuel such as coke oven gas when the amount of pulverized coal injected in an oxygen blast furnace becomes equal to or less than a specified value.
特許文献２に示されるように、パージガスは設備保全上不可避なものであるが、高炉操業の観点から見ると、パージガスは、微粉炭の燃焼性を阻害したり、炉内の還元性ガスの濃度を下げて還元速度を低下させたり、また、低温ガスの流入による炉下部の熱量低下を引き起こしたりすることから、高炉にとって好ましくないものである。 As shown in Patent Document 2, the purge gas is unavoidable in terms of facility maintenance. From the viewpoint of blast furnace operation, the purge gas inhibits the combustibility of pulverized coal or the concentration of reducing gas in the furnace. This is not preferable for the blast furnace because the reduction rate is lowered to lower the reduction rate, or the amount of heat in the lower part of the furnace is lowered due to the inflow of the low temperature gas.
特に、羽口吹き込みランスから微粉炭と易燃性還元材や支燃性ガスとを同時に吹き込む複合吹き込み型の羽口吹き込みランスにおいては、易燃性還元材や支燃性ガスの供給を停止して窒素ガスや空気でパージすると、低温のパージ用窒素ガスやパージ用空気が同じ羽口吹き込みランスから吹き込まれている微粉炭と熱風との接触を阻害してしまうために、微粉炭の燃焼性を悪化させてしまうという問題が起こる。したがって、パージガスは可能な限り使用しないことが好ましい。 In particular, in the compound-inlet type tuyere blowing lance, in which pulverized coal and flammable reducing material and supporting gas are simultaneously blown from the tuyere blowing lance, supply of the flammable reducing material and supporting flame gas is stopped. When purging with nitrogen gas or air, the low temperature purge nitrogen gas or purge air hinders contact between the pulverized coal blown from the same tuyere blowing lance and hot air, so the pulverized coal combustibility The problem of getting worse. Therefore, it is preferable not to use purge gas as much as possible.
高炉の操業変化などにより易燃性還元材や支燃性ガスを停止する場合は、特許文献２と同様に、羽口吹き込みランスを窒素ガスや空気でパージすることが一般的である。つまり、従来技術ではパージガスによる操業悪化を避けることができない。 When stopping the flammable reducing material or the combustion-supporting gas due to a change in operation of the blast furnace or the like, it is common to purge the tuyere blowing lance with nitrogen gas or air, as in Patent Document 2. That is, in the prior art, deterioration of operation due to purge gas cannot be avoided.
なお、特許文献１のように、羽口吹き込みランスから気体燃料のような燃焼性ガスを吹き込む方法は多数提案されているが、これらは、いずれも安定した操業時に、高炉への還元材の供給や微粉炭の燃焼促進の目的で行っているものであり、高炉の操業変化まで想定した時の易燃性還元材の活用方法については、述べていない。 In addition, as in Patent Document 1, many methods for injecting a combustible gas such as gaseous fuel from a tuyere injecting lance have been proposed. However, these methods all supply a reducing material to a blast furnace during stable operation. This method is used for the purpose of promoting combustion of pulverized coal, and it does not describe how to use the flammable reducing material when assuming changes in blast furnace operation.
また、特許文献３においては、微粉炭吹き込みランスとは別個の燃料吹き込み系を併設しておき、微粉炭吹き込み量が規定値以下となった時に、もう一方の吹き込み系からコークス炉ガスなどの燃料を羽口へ吹き込むことで、羽口先の火炎温度の変動を抑制し、操業を安定化させている。しかし、この方法では、吹き込みを止めた微粉炭吹き込み系とは別の場所に別途もう１箇所の吹き込み系を予め用意しておき、その場所から燃料ガスを吹き込む方法であるため、代替として吹き込んだ燃料ガスは元の微粉炭吹き込み系の設備保護には寄与せず、したがって停止した微粉炭などの吹き込みランスにおいては設備保護のための窒素パージが別途必要となり、特許文献２と同様にパージガスによる操業悪化が避けられない。 Further, in Patent Document 3, a fuel injection system separate from the pulverized coal injection lance is provided, and when the amount of pulverized coal injection becomes a specified value or less, fuel such as coke oven gas is supplied from the other injection system. By blowing into the tuyere, fluctuations in the flame temperature at the tuyere are suppressed and the operation is stabilized. However, in this method, another blowing system is prepared in advance in a place different from the pulverized coal blowing system in which blowing is stopped, and fuel gas is blown from that place. Fuel gas does not contribute to the protection of the original pulverized coal injection system, and therefore a nitrogen purge for the protection of the facility is separately required for the stopped pulverized coal injection lance. Deterioration is inevitable.
また、特許文献３においては、吹き込み停止させた微粉炭と同程度の質量の燃料ガスを吹き込むことになるので、結果として羽口からの還元材吹き込み量は微粉炭停止前と変わらず、たとえば高炉の圧力損失が増加した際に、還元材比一定でコークス比を上げて羽口吹き込み還元材比を下げることで通気を改善させるような操業変更には適用できないという問題もある。 Further, in Patent Document 3, since the fuel gas having the same mass as that of the pulverized coal stopped to be blown is blown, as a result, the amount of reducing material blown from the tuyere is not different from that before the pulverized coal is stopped. When the pressure loss increases, there is also a problem that it cannot be applied to an operation change that improves aeration by raising the coke ratio and reducing the tuyere blowing reductant ratio at a constant reductant ratio.
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、高炉羽口への還元材などの吹き込みを停止する操業変更の際に、窒素ガスや空気などのパージガスを用いずに、微量の易燃性還元材を活用することで、微粉炭や熱風などが羽口吹き込みランス内に逆流して設備を損傷することを防止することのできるランス保護方法を提供することである。 The present invention has been made in view of the above circumstances, and the object of the present invention is to use a purge gas such as nitrogen gas or air when the operation is changed to stop the blowing of reducing material into the blast furnace tuyere. It is to provide a lance protection method that can prevent pulverized coal or hot air from flowing backward into the tuyere blowing lance and damaging the equipment by utilizing a small amount of the flammable reducing material.
上記課題を解決するための本発明の要旨は以下のとおりである。
［１］羽口吹き込みランスを具備する高炉において、羽口吹き込みランスの少なくとも１つの吹き込み部位から、各羽口あたり１０Ｎｍ３／ｈ以下の易燃性還元材を吹き込むことを特徴とする、高炉の羽口吹き込みランスにおけるランス保護方法。
［２］通常操業では羽口吹き込みランスから、還元材及び／または支燃性ガスを吹き込む高炉において、前記還元材及び／または支燃性ガスの吹き込みを停止する際に、前記還元材及び／または支燃性ガスを停止した羽口に対し、前記還元材及び／または支燃性ガスの代わりに１０Ｎｍ３／ｈ以下の易燃性還元材を吹き込むことを特徴とする、高炉の羽口吹き込みランスにおけるランス保護方法。
The gist of the present invention for solving the above problems is as follows.
[1] In a blast furnace equipped with a tuyere blowing lance, a flammable reducing material of 10 Nm 3 / h or less is blown into each tuyere from at least one blowing site of the tuyere blowing lance. Lance protection method for tuyere blown lances.
[2] In normal operation, in the blast furnace in which the reducing material and / or the combustion-supporting gas is blown from the tuyere blowing lance, when the blowing of the reducing material and / or the combustion-supporting gas is stopped, the reduction material and / or A tuyere blowing lance for a blast furnace, characterized in that a flammable reducing material of 10 Nm 3 / h or less is blown in place of the reducing material and / or the supporting gas for the tuyere where the supporting gas is stopped. Lance protection method in Japan.
本発明によれば、窒素ガスや空気などのパージガスの代わりに羽口吹き込みランスから各羽口あたり１０Ｎｍ３／ｈ以下の少量の易燃性還元材を吹き込むので、易燃性還元材の燃焼反応によって羽口吹き込みランス先端の圧力を高圧に確保することができ、これによって、羽口の圧力変動が起こっても、窒素ガスや空気などのパージガスを用いなくても微粉炭や熱風などの羽口吹き込みランス内への逆流を防止することができる。また、窒素ガスや空気などではなく易燃性還元材を吹き込むので、微粉炭の燃焼阻害や炉内還元反応の阻害を引き起こさない効果も得られ、更には、吹き込む易燃性還元材の量は少量で十分であり、操業への影響も小さく、コスト増大も引き起こさない。 According to the present invention, since a small amount of flammable reducing material of 10 Nm 3 / h or less is blown from each tuyere from the tuyere blowing lance instead of purge gas such as nitrogen gas or air, the combustion reaction of the flammable reducing material The pressure at the tip of the tuyere blowing lance can be secured at a high pressure, so that the tuyere of pulverized coal or hot air can be used even if the tuyere's pressure fluctuates or a purge gas such as nitrogen gas or air is not used. Backflow into the blowing lance can be prevented. In addition, since a flammable reducing material is injected instead of nitrogen gas or air, the effect of not inhibiting the combustion of pulverized coal and the reduction reaction in the furnace is obtained, and furthermore, the amount of the flammable reducing material to be injected is Small amounts are sufficient, have little impact on operations, and do not increase costs.
以下、本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail.
本発明では、複数の羽口吹き込みランスを具備する高炉において、高炉の操業中に、窒素ガスや空気をパージガスとして使用せずに、天然ガス、プロパンガス、コークス炉ガス、高炉ガス、転炉ガス、水素ガスなどの易燃性還元材を、１箇所または２箇所以上の吹き込み部位（吹き込み流路）を有する羽口吹き込みランスの少なくとも１つの吹き込み部位から、各羽口あたり１０Ｎｍ３／ｈ以下の流量で吹き込む。吹き込んだ少量の易燃性還元材は、羽口吹き込みランスの出口位置で熱風中の酸素ガスと燃焼反応を起こして急膨張する。これにより、羽口吹き込みランス先端で局所的に高圧な状態を形成することができ、羽口内のガスなどが羽口吹き込みランス内に逆流することが防止できる。 In the present invention, in a blast furnace having a plurality of tuyere-injection lances, natural gas, propane gas, coke oven gas, blast furnace gas, converter gas are used during operation of the blast furnace without using nitrogen gas or air as a purge gas. A flammable reducing material such as hydrogen gas is supplied at least 10 Nm 3 / h per tuyere from at least one blowing site of a tuyere blowing lance having one or two or more blowing sites (blowing channel) Blow at flow rate. The small amount of the flammable reducing material that has been blown up rapidly undergoes a combustion reaction with the oxygen gas in the hot air at the exit position of the tuyere blown lance. As a result, a locally high pressure state can be formed at the tip of the tuyere blowing lance, and the gas in the tuyere can be prevented from flowing back into the tuyere blowing lance.
羽口吹き込みランスが単管の場合は、該単管から易燃性還元材を吹き込み、羽口吹き込みランスが２重管以上の多重管構造の場合は、そのうちの少なくとも１つの吹き込み部位から易燃性還元材を吹き込む。 When the tuyere blowing lance is a single pipe, a flammable reducing material is blown from the single pipe, and when the tuyere blowing lance is a multi-pipe structure of a double pipe or more, flammable from at least one of the blowing parts. Inject a reductive material.
本発明を用いれば少量の易燃性還元材でパージ効果を発揮することができ、且つ、窒素ガスや空気を吹き込まないので、微粉炭の燃焼性や炉内の還元反応を阻害することがない。また、易燃性還元材を用いており、羽口吹き込みランスの先端で燃焼膨張するため、易燃性還元材の吹き込み流量が少量であっても、十分に逆流防止効果を発揮することができる。 If the present invention is used, the purge effect can be exerted with a small amount of flammable reducing material, and nitrogen gas and air are not blown, so that the flammability of pulverized coal and the reduction reaction in the furnace are not hindered. . In addition, since a flammable reducing material is used and combustion expansion occurs at the tip of the tuyere blowing lance, even if the blowing flow rate of the flammable reducing material is small, the effect of preventing the backflow can be sufficiently exerted. .
羽口から易燃性還元材を多量に吹き込み過ぎると、羽口先温度の異常低下などの高炉操業の制御に問題を引き起こす懸念があり、また、吹き込み材の過剰使用によりコストアップを引き起こす懸念もあるが、本発明では、羽口あたり１０Ｎｍ３／ｈ以下の少ない流量の易燃性還元材を吹き込むので、これらの問題は未然に防止される。 If too much flammable reducing material is blown from the tuyere, there may be a problem in controlling the operation of the blast furnace, such as abnormal lowering of the tuyere temperature, and there is also a concern that the use of the blowing material may increase the cost. However, in the present invention, since a flammable reducing material having a small flow rate of 10 Nm 3 / h or less is blown per tuyere, these problems are prevented.
また、上記説明は、通常操業では微粉炭などの還元材を吹き込んでいて、トラブルなどにより操業条件が変化した時に微粉炭などの還元材の吹き込みを停止するケースを想定した説明であるが、もちろん、その他のケースでも本発明は成り立つ。 In addition, the above explanation is based on the assumption that in normal operation, a reducing material such as pulverized coal is blown, and when the operating conditions change due to troubles, the blowing of reducing material such as pulverized coal stops. In other cases, the present invention holds.
たとえば、通常は微粉炭のみを吹き込む操業をしており、銑鉄の生産量を一時的に増やしたいときのみ易燃性還元材と微粉炭との同時吹き込みに切り替える操業なども想定できる。このときは、最初から二重管ランスを高炉に設置しておき、そして、易燃性還元材の吹き込み部位（吹き込み流路）には本発明の方法で少々の易燃性還元材を流し、逆流防止を施した状態を確保しておく。そして、生産量を増やすタイミングとなったら、必要量の易燃性還元材の吹き込みを行うようにすればよい。 For example, an operation of blowing only pulverized coal is usually performed, and an operation of switching to simultaneous blowing of a flammable reducing material and pulverized coal can be assumed only when it is desired to temporarily increase the production amount of pig iron. At this time, a double-pipe lance is installed in the blast furnace from the beginning, and a small amount of the flammable reducing material is caused to flow into the flammable reducing material blowing portion (blowing flow path) by the method of the present invention, Ensure that the backflow is prevented. Then, when it is time to increase the production amount, a necessary amount of the flammable reducing material may be blown.
また、通常操業では、羽口吹き込みランスから、易燃性還元材を吹き込まずに、微粉炭などの還元材及び／または酸素ガスや空気などの支燃性ガスを吹き込んでいる場合には、以下のように対処することができる。 Also, in normal operation, when a reducing material such as pulverized coal and / or a combustion-supporting gas such as oxygen gas or air is blown from the tuyere blowing lance without blowing a flammable reducing material, Can be dealt with.
つまり、何らかの理由で、羽口吹き込みランスからの還元材及び／または支燃性ガスの吹き込みを停止する際には、前記還元材及び／または支燃性ガスの代わりに羽口あたり１０Ｎｍ３／ｈ以下の易燃性還元材を吹き込むようにする。 That is, for some reason, when stopping the blowing of the reducing material and / or the combustion-supporting gas from the tuyere blowing lance, 10 Nm 3 / h per tuyere instead of the reducing material and / or the combustion-supporting gas. The following flammable reducing material is blown.
なお、羽口吹き込みランスが、多重管構造であって、吹き込み部位（吹き込み流路）が２つ以上あり、２つ以上の吹き込み部位から還元材を吹き込んでいて、これらの還元材を同時に停止する場合は、羽口吹き込みランスの各吹き込み部位に対し、各吹き込み部位の断面積で均等分割して羽口あたり合計１０Ｎｍ３／ｈ以下の易燃性還元材を吹き込むようにすればよい。 The tuyere blowing lance has a multi-tube structure, and there are two or more blowing parts (blowing flow paths). Reducing materials are blown from two or more blowing parts, and these reducing materials are stopped simultaneously. In such a case, the flammable reducing material of 10 Nm 3 / h or less per tuyere may be blown evenly by dividing each blown part of the tuyere blown lance by the cross-sectional area of each blown part.
易燃性還元材の吹き込み量の下限は、特に規定する必要はないが、安定して逆流防止効果を得るためには、１Ｎｍ３／ｈ以上とすることが好ましい。 The lower limit of the amount of the flammable reducing material to be blown in is not particularly required, but is preferably 1 Nm 3 / h or more in order to stably obtain the backflow prevention effect.
微粉炭燃焼実験炉を用いて実機羽口を模擬した条件を作成し、検証実験を行った。微粉炭燃焼実験炉の外観の概略図を図１に示す。微粉炭燃焼実験炉１は、ブローパイプ２と、このブローパイプ２に接続する燃焼室４とで構成され、燃焼室４内のコークス充填層５に、ブローパイプ２から熱風を供給するとともに、ブローパイプ２に設置した２重管構造の羽口吹き込みランス３から微粉炭を供給し、供給した微粉炭の燃焼状態を調査する装置である。 Using a pulverized coal combustion experimental furnace, conditions were simulated to simulate the actual tuyere, and a verification experiment was conducted. A schematic diagram of the appearance of the experimental pulverized coal combustion furnace is shown in FIG. The pulverized coal combustion experimental furnace 1 is composed of a blow pipe 2 and a combustion chamber 4 connected to the blow pipe 2. While supplying hot air from the blow pipe 2 to the coke packed bed 5 in the combustion chamber 4, It is a device for supplying pulverized coal from a tuyere blowing lance 3 installed in a pipe 2 and investigating the combustion state of the supplied pulverized coal.
なお、酸素過剰率を０．７程度とする条件で実験を行った。ここで、酸素過剰率とは、羽口から吹き込んだ微粉炭や天然ガスなどの吹き込み材が燃焼反応を起こす際に、吹き込み材が全て完全燃焼してＣＯ２及びＨ２Ｏになる際に必要となる酸素量に対して、実際に羽口に吹き込んだ酸素量の比率を表す指標である。完全燃焼後に酸素が余る条件では酸素過剰率が１．０以上となり、酸素が不足して不完全燃焼となる条件では酸素過剰率が１．０未満となる。 In addition, it experimented on the conditions which make oxygen excess rate about 0.7. Here, the oxygen excess rate is necessary when the blowing material such as pulverized coal or natural gas blown from the tuyere undergoes a combustion reaction, and all the blowing material is completely burned to become CO 2 and H 2 O. This is an index representing the ratio of the amount of oxygen actually blown into the tuyere to the amount of oxygen. Under conditions where oxygen remains after complete combustion, the excess oxygen ratio is 1.0 or more, and under conditions where oxygen is insufficient and incomplete combustion occurs, the excess oxygen ratio is less than 1.0.
また、図２に示すように、２つの吹き込み部位を有する２重管構造の羽口吹き込みランス３の内管７から微粉炭６を吹き込み、外管８から易燃性還元材として天然ガスを吹き込んだ。具体的には、内管７から１８０ｋｇ／溶銑-t相当の微粉炭を吹き込み、且つ、外管８から５ｋｇ／溶銑-t相当（７０Ｎｍ３／ｈ相当）の天然ガスを吹き込み、この吹き込み条件をベース条件とした。この条件をベースとして、外管８からの天然ガスの吹き込みのみを停止し、その後、外管８からのガスの吹き込み条件を切り替える試験を行った。 Further, as shown in FIG. 2, pulverized coal 6 is blown from the inner pipe 7 of the tuyere blow lance 3 having a double pipe structure having two blow parts, and natural gas is blown from the outer pipe 8 as a flammable reducing material. It is. More specifically, pulverized coal equivalent to 180 kg / molten metal-t is blown from the inner pipe 7 and natural gas equivalent to 5 kg / molten metal-t (corresponding to 70 Nm 3 / h) is blown from the outer pipe 8. Base conditions were used. Based on this condition, a test was performed in which only the natural gas blowing from the outer pipe 8 was stopped, and then the gas blowing conditions from the outer pipe 8 were switched.
本発明例１；外管からの天然ガス吹き込みの停止後、外管から３Ｎｍ３／ｈ相当だけ天然ガスを吹き込む
本発明例２；外管からの天然ガス吹き込みの停止後、外管から１０Ｎｍ３／ｈ相当だけ天然ガスを吹き込む
比較例１；外管からの天然ガス吹き込みの停止後、外管から２０Ｎｍ３／ｈ相当だけ天然ガスを吹き込む
比較例２；外管からの天然ガス吹き込みの停止後、外管には何も吹き込まない
比較例３；外管からの天然ガス吹き込みの停止後、外管に１０Ｎｍ３／ｈ相当だけ窒素ガスをパージガスとして吹き込む
比較例４；外管からの天然ガス吹き込みの停止後、外管に５０Ｎｍ３／ｈ相当だけ窒素ガスをパージガスとして吹き込む
これらの結果を表１に示す。
Invention Example 1: After stopping the natural gas blowing from the outer pipe, the natural gas is blown by 3 Nm 3 / h equivalent from the outer pipe. Invention Example 2: After stopping the natural gas blowing from the outer pipe, 10 Nm 3 from the outer pipe. Comparative example 1 after natural gas blowing from the outer pipe is stopped and then natural gas is blown from the outer pipe by an amount equivalent to 20 Nm 3 / h Comparative example 2 after natural gas blowing from the outer pipe is stopped Nothing is blown into the outer pipe. Comparative example 3; after stopping the blowing of natural gas from the outer pipe, nitrogen gas is blown into the outer pipe as a purge gas by an amount equivalent to 10 Nm 3 / h. Comparative example 4; natural gas is blown from the outer pipe. After stopping, nitrogen gas is blown into the outer tube as a purge gas by an amount corresponding to 50 Nm 3 / h.
表１には羽口吹き込みランスの外管に流すガスの種類及び吹き込み量とともに、微粉炭の燃焼率と実験後の目視確認によるランス状態とが示されている。ここで微粉炭の燃焼率は、微粉炭における可燃成分のうち、レースウェイ位置においてどれだけ燃焼して消費されたかを示す指標である。微粉炭の燃焼率η（％）はレースウェイ位置にサンプリング管を差しこんでレースウェイ内の微粉炭を取得し、レースウェイ内の微粉炭に含まれる灰分割合ash（質量％）と、吹き込み前の元の微粉炭の灰分割合ash0（質量％）とから、下記の（１）式によって算出することができる。 Table 1 shows the combustion rate of pulverized coal and the lance state by visual confirmation after the experiment, together with the type and amount of gas flowing through the outer tube of the tuyere blowing lance. Here, the combustion rate of pulverized coal is an index indicating how much of the combustible components in the pulverized coal are burned and consumed at the raceway position. The combustion rate η (%) of pulverized coal is obtained by inserting a sampling pipe into the raceway position to obtain the pulverized coal in the raceway, the ash content ash (mass%) contained in the pulverized coal in the raceway, and before blowing The ash content ratio ash 0 (mass%) of the original pulverized coal can be calculated by the following equation (1).
本発明例１及び本発明例２では、それぞれ３Ｎｍ３／ｈ相当、１０Ｎｍ３／ｈ相当の天然ガスを外管から吹き込んで逆流防止を行った。試験後、羽口吹き込みランスの状態を確認したところ、どちらも健全な状態であることが確認できた。 In the present invention Example 1 and Inventive Example 2, respectively 3 Nm 3 / h equivalent, was blown by backflow preventing 10 Nm 3 / h equivalent natural gas from the outer tube. After the test, when the state of the tuyere blowing lance was confirmed, it was confirmed that both were in a healthy state.
比較例１では、外管から２０Ｎｍ３／ｈ相当の天然ガスを吹き込むようにした。このときも羽口吹き込みランスは健全な状態を保てているが、一方でレースウェイにおける理論燃焼温度が２０℃程度下がってしまった。これを実機の状態に置き換えると、溶銑温度の低下や炉冷などの操業不安定を引き起こす懸念があり好ましくない。この結果から、逆流防止のための天然ガス吹き込み量は１０Ｎｍ３／ｈ以下が最適であることが確認できた。 In Comparative Example 1, natural gas equivalent to 20 Nm 3 / h was blown from the outer tube. At this time, the tuyere blowing lance was still in a healthy state, but on the other hand, the theoretical combustion temperature in the raceway had dropped by about 20 ° C. Replacing this with an actual machine is not preferable because it may cause unstable operation such as lowering of hot metal temperature and furnace cooling. From this result, it was confirmed that the natural gas blowing amount for preventing the backflow was optimally 10 Nm 3 / h or less.
比較例２は、外管から何も吹き込まない条件である。実験後の羽口吹き込みランスを確認したところ、高熱負荷を受けた状態が羽口吹き込みランスに確認できた。したがって、比較例２では羽口吹き込みランスの損傷の懸念がある。 Comparative Example 2 is a condition in which nothing is blown from the outer tube. After checking the tuyere blowing lance after the experiment, it was confirmed that the tuyere blowing lance was subjected to a high heat load. Therefore, in Comparative Example 2, there is a concern of damage to the tuyere blowing lance.
比較例３は、外管から１０Ｎｍ３／ｈ相当の窒素ガスをパージガスとして吹き込んだ条件である。実験後の羽口吹き込みランスを確認したところ、比較例２と同様に、高熱負荷を受けた跡が確認できた。つまり、同じ１０Ｎｍ３／ｈのガスを吹き込んだとしても、燃焼しない窒素ガスでは逆流防止効果がなく、燃焼性を有する易燃性還元材を用いる必要のあることが確認できた。 Comparative Example 3 is a condition in which nitrogen gas corresponding to 10 Nm 3 / h was blown as a purge gas from the outer tube. When the tuyere blowing lance after the experiment was confirmed, a trace of being subjected to a high heat load was confirmed as in Comparative Example 2. That is, even when the same 10 Nm 3 / h gas was blown in, nitrogen gas that did not burn did not have a backflow prevention effect, and it was confirmed that it was necessary to use a flammable reducing material having combustibility.
比較例４は、外管から５０Ｎｍ３／ｈ相当の窒素ガスパージガスとして吹き込んだ条件である。試験後の羽口吹き込みランスに異常はなく、逆流は抑止できた。しかしながら、窒素ガスによる燃焼阻害が起こり、微粉炭の燃焼率が低下した。この結果から、比較例４は望ましくないことが確認できた。 Comparative Example 4 is a condition in which nitrogen gas purge gas equivalent to 50 Nm 3 / h was blown from the outer tube. There was no abnormality in the tuyere blowing lance after the test, and backflow could be suppressed. However, combustion inhibition by nitrogen gas occurred, and the combustion rate of pulverized coal decreased. From this result, it was confirmed that Comparative Example 4 was not desirable.
１ 微粉炭燃焼実験炉
２ ブローパイプ
３ 羽口吹き込みランス
４ 燃焼室
５ コークス充填層
６ 微粉炭
７ 内管
８ 外管
DESCRIPTION OF SYMBOLS 1 Pulverized coal combustion experimental furnace 2 Blow pipe 3 tuyere blowing lance 4 Combustion chamber 5 Coke packed bed 6 Pulverized coal 7 Inner pipe 8 Outer pipe
Claims (2)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016059534 | 2016-03-24 | ||
| JP2016059534 | 2016-03-24 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2017179586A JP2017179586A (en) | 2017-10-05 |
| JP6468272B2 true JP6468272B2 (en) | 2019-02-13 |
Family
ID=60003806
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2016231055A Active JP6468272B2 (en) | 2016-03-24 | 2016-11-29 | Lance protection method in blast furnace tuyeres lance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6468272B2 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03260005A (en) * | 1990-03-12 | 1991-11-20 | Nippon Steel Corp | Method for operating blast furnace under unsteady state |
| JP4992235B2 (en) * | 2005-12-09 | 2012-08-08 | Ｊｆｅスチール株式会社 | Method and apparatus for injecting reducing material into blast furnace |
| JP5194504B2 (en) * | 2007-03-22 | 2013-05-08 | Ｊｆｅスチール株式会社 | Apparatus for injecting gas reducing material into blast furnace and operating method of blast furnace using the same |
| JP2013001934A (en) * | 2011-06-15 | 2013-01-07 | Jfe Steel Corp | Device and method for blowing reducing material into blast furnace |
-
2016
- 2016-11-29 JP JP2016231055A patent/JP6468272B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2017179586A (en) | 2017-10-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5522326B1 (en) | Blast furnace operation method and tube bundle type lance | |
| JP2006312757A (en) | Injection lance for gaseous reducing material, blast furnace and blast furnace operation method | |
| JP5971165B2 (en) | Blast furnace operation method | |
| JP5888435B2 (en) | Equipment for blowing oxygen from blast furnace tuyere and blast furnace operating method | |
| CN114787391A (en) | Method for operating blast furnace | |
| RU2586194C2 (en) | Method of heating blast-furnace air heater | |
| JP3176680B2 (en) | Blast furnace operation method | |
| JP4992235B2 (en) | Method and apparatus for injecting reducing material into blast furnace | |
| JP6468272B2 (en) | Lance protection method in blast furnace tuyeres lance | |
| JP2017061716A (en) | Method for increasing temperature of charging material and residual material in furnace at blast furnace bottom | |
| JP5770124B2 (en) | Blast furnace operation method | |
| JP5775476B2 (en) | Reducing gas blowing method and blowing lance from blast furnace tuyere | |
| JP4720260B2 (en) | Method and apparatus for injecting reducing material into blast furnace | |
| EP4339301A1 (en) | Gaseous reducing material blowing method and blast furnace tuyere | |
| JP4747662B2 (en) | Lance for blowing gas reducing material, blast furnace and blast furnace operating method | |
| WO2018180892A1 (en) | Method for operating blast furnace | |
| CN102147110B (en) | Method for combustion of a low-grade fuel | |
| EP3330387B1 (en) | Apparatus for blowing dust coal of melting furnace | |
| JP6604343B2 (en) | Preheating gas blowing method, blast furnace operating method, and oxygen blast furnace operating method | |
| KR101739861B1 (en) | Apparatus for injection the pulverized coal of melting furnace and this method | |
| JP4445479B2 (en) | Waste melting furnace tuyer purging method and apparatus | |
| CN103740873A (en) | Blast furnace ironmaking system | |
| JP4915074B2 (en) | Apparatus for injecting reducing material into a blast furnace, and blast furnace operating method using the apparatus | |
| WO2023233957A1 (en) | Blast-furnace operation method and blast furnace | |
| JPH04110405A (en) | Method for operating blast furnace |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20171024 |
|
| RD03 | Notification of appointment of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7423 Effective date: 20180502 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20180509 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20180918 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20181002 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20181122 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20181218 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20181231 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6468272 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: R3D04 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |