JP5741319B2 - Pulverized coal injection method - Google Patents
Pulverized coal injection method Download PDFInfo
- Publication number
- JP5741319B2 JP5741319B2 JP2011180594A JP2011180594A JP5741319B2 JP 5741319 B2 JP5741319 B2 JP 5741319B2 JP 2011180594 A JP2011180594 A JP 2011180594A JP 2011180594 A JP2011180594 A JP 2011180594A JP 5741319 B2 JP5741319 B2 JP 5741319B2
- Authority
- JP
- Japan
- Prior art keywords
- pulverized coal
- particle size
- size distribution
- distribution measuring
- coal
- 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
- 239000003245 coal Substances 0.000 title claims description 287
- 238000000034 method Methods 0.000 title claims description 35
- 238000002347 injection Methods 0.000 title description 35
- 239000007924 injection Substances 0.000 title description 35
- 239000002245 particle Substances 0.000 claims description 160
- 238000009826 distribution Methods 0.000 claims description 142
- 238000007664 blowing Methods 0.000 claims description 45
- 238000004519 manufacturing process Methods 0.000 claims description 44
- 230000032258 transport Effects 0.000 claims description 32
- 238000010298 pulverizing process Methods 0.000 claims description 20
- 238000005070 sampling Methods 0.000 claims description 10
- 238000005259 measurement Methods 0.000 description 21
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 14
- 239000000571 coke Substances 0.000 description 7
- 229910052757 nitrogen Inorganic materials 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 239000002184 metal Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000012159 carrier gas Substances 0.000 description 5
- 230000008859 change Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000000227 grinding Methods 0.000 description 5
- 230000007704 transition Effects 0.000 description 5
- 238000012546 transfer Methods 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000002834 transmittance Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000007561 laser diffraction method Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000011017 operating method Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000011112 process operation Methods 0.000 description 1
- 230000036962 time dependent Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Landscapes
- Manufacture Of Iron (AREA)
- Blast Furnaces (AREA)
Description
本発明は、補助還元材としての微粉炭を高炉に安定的に吹き込む微粉炭吹込み方法に関するものである。 The present invention relates to a pulverized coal blowing method for stably blowing pulverized coal as an auxiliary reducing material into a blast furnace.
高炉操業においては、還元材であるコークスの一部の代わりとして微粉炭を高炉羽口から吹き込む、微粉炭吹込み高炉操業が行なわれている。高炉への微粉炭吹込み操業は、高炉用コークスに比べて微粉炭が安価であるために、大きなコスト低減効果が得られる。また、高炉への微粉炭吹き込み量を増やすことにより高炉用コークスの製造設備であるコークス炉の負荷軽減を図ることができ、コークス炉の延命にも寄与する。
そこで、高炉操業においては、より一層多量の微粉炭を吹き込むための操業技術開発が要請されるに至り、現在では１２０ｋｇ/Ｔ以上の微粉炭多量吹込み操業が行われている。
In blast furnace operation, pulverized coal injection blast furnace operation is performed in which pulverized coal is injected from a blast furnace tuyere instead of a part of coke as a reducing material. The operation of injecting pulverized coal into the blast furnace provides a significant cost reduction effect because pulverized coal is less expensive than blast furnace coke. In addition, by increasing the amount of pulverized coal injected into the blast furnace, it is possible to reduce the load on the coke oven, which is a blast furnace coke manufacturing facility, and contribute to the extension of the life of the coke oven.
Therefore, in blast furnace operation, the development of operation technology for injecting a larger amount of pulverized coal has been requested, and at present, a large amount of pulverized coal injecting operation of 120 kg / T or more is performed.
このような、微粉炭の高炉内への吹込み処理の流れを図１４に基づいて概説する。微粉炭の高炉内への吹込みは、ヤードにストックされた石炭１を石炭ホッパ２に貯留し、その石炭ホッパ２に貯留されている石炭１をフィーダ３で切出して、微粉炭製造装置４に供給する。石炭１は、複数銘柄（石炭種）からなり、微粉炭製造装置４へは、各銘柄の石炭を所定の比率で供給・混合して粉砕すると共に乾燥し、所定の粒度分布に調製する。 The flow of such pulverized coal injection into the blast furnace will be outlined with reference to FIG. The pulverized coal is blown into the blast furnace by storing the coal 1 stocked in the yard in the coal hopper 2, cutting out the coal 1 stored in the coal hopper 2 with the feeder 3, and supplying it to the pulverized coal production apparatus 4. Supply. Coal 1 is composed of a plurality of brands (coal species), and each brand of coal is supplied to, mixed with, and pulverized into a pulverized coal production apparatus 4 and dried to prepare a predetermined particle size distribution.
こうして調製された微粉炭５を、主管６を通してバグフィルタ７へ気流輸送する。バグフィルタ７で捕集された微粉炭５はコールビン８で貯留され、更に吹込みタンク９へ輸送する。吹込みタンク９に輸送された微粉炭５を気送により分配器１０へ供給し、更に分配器１０から複数の枝管１１を通して高炉１２下部の多数の羽口１３部まで分配気送する。熱風炉１４から各羽口１３部のブローパイプ１５に供給される熱風中に、微粉炭５を吹込みノズルから噴射し、熱風と共に各羽口１３から高炉１２内に吹き込み、燃焼させる。 The pulverized coal 5 thus prepared is air-transported to the bag filter 7 through the main pipe 6. The pulverized coal 5 collected by the bag filter 7 is stored in the coal bottle 8 and further transported to the blowing tank 9. The pulverized coal 5 transported to the blowing tank 9 is supplied to the distributor 10 by air feeding, and further distributed to the many tuyere 13 at the lower part of the blast furnace 12 through the branch pipes 11. In the hot air supplied from the hot air furnace 14 to the blow pipe 15 of each tuyere 13 part, the pulverized coal 5 is injected from the blowing nozzle, and blown into the blast furnace 12 from each tuyere 13 together with the hot air and burned.
このように、微粉炭５を高炉１２の炉内へ吹き込むまでには、いくつかの配管系やバルブ、吹込み装置等を経由させなければならない。ところが、多量吹込みが要請される今日の微粉炭吹込みの高炉操業においては、微粉炭が配管系等の内部に付着し、更にはそれらを閉塞させることもある。
このような微粉炭の配管系等における付着や閉塞が発生した場合には、正常な高炉操業を継続することができなくなる。例えば、吹込みタンク９から分配器１０までの間で閉塞した場合には、高炉１２の全羽口からの微粉炭吹込みが不可能となり、炉頂からのオールコークス装入操業に切り替えなければならず、炉内状況を安定化させるためには長時間を要する。あるいは、分配器１０以降の複数の枝管１１のいずれかで閉塞すれば、炉内円周方向についての微粉炭吹込み量にバラツキが発生し、溶銑の成分変動や炉況不調の原因となる。特に、微粉炭吹込み量が多い高炉操業の場合には、減風や休風を余儀なくされて、減産その他大きな問題となる。
このように、配管系等における微粉炭の付着や配管系の閉塞は高炉操業に多大な損失を与える。したがって、微粉炭吹込みにおいては、微粉炭がその配管系等に付着したり、閉塞したりすることなく、スムーズに流れることが強く要請される。
Thus, in order to blow the pulverized coal 5 into the furnace of the blast furnace 12, it is necessary to pass through several piping systems, valves, blowing devices, and the like. However, in today's blast furnace operation with pulverized coal injection, which requires a large amount of injection, the pulverized coal adheres to the inside of the piping system or the like, and may even block them.
When such pulverized coal is attached or blocked in a piping system or the like, normal blast furnace operation cannot be continued. For example, in the case of blocking between the injection tank 9 and the distributor 10, pulverized coal injection from all the tuyere of the blast furnace 12 becomes impossible, and it is necessary to switch to all coke charging operation from the furnace top. It takes a long time to stabilize the in-furnace situation. Or if it obstruct | occludes in any of the several branch pipes 11 after the divider | distributor 10, variation will generate | occur | produce in the amount of pulverized coal injection | throwing in the circumferential direction in a furnace, and it will become a cause of the component fluctuation | variation of hot metal, and a furnace condition malfunction. . In particular, in the case of blast furnace operation with a large amount of pulverized coal injection, it is forced to reduce the wind and pause, which causes a reduction in production and other major problems.
Thus, the adhesion of pulverized coal in the piping system or the like and the blockage of the piping system cause a great loss to the blast furnace operation. Therefore, in the pulverized coal injection, it is strongly required that the pulverized coal flows smoothly without adhering to or blocking the piping system.
ところで、配管系等における付着や閉塞の要因として微粉炭の粒度分布が影響していることが知られている。
そこで、特許文献１においては、配管系における付着や閉塞が微粉炭の水分含有量にも関係することに着目して、微粉炭の５〜５０質量％が粒径１〜20μｍの微粉炭粒子であり、かつ前記微粉炭が水分を１〜８質量％含有する高炉への微粉炭吹き込み方法が開示されている。
また、吹き込み経路において閉塞を生じないような流動性が確保された微粉炭の製造方法として、特許文献２には以下のような反応炉内吹込み用微粉炭の製造方法が開示されている。
「単一種の石炭又は複数種の石炭から製造された微粉炭を、微粉炭製造装置からキャリアガスによって配管系内を経由して輸送し、こうして輸送された当該微粉炭を微粉炭吹込み装置から反応炉内へ吹き込んで燃焼させるための微粉炭を、微粉炭製造装置により製造する方法において、前記反応炉に吹き込まれる前記微粉炭の粒度分布の制御を、当該微粉炭製造に用いる石炭の粉砕性をパラメーターとし、前記微粉炭製造装置において当該石炭に負荷する粉砕力を調整すること、により行なうことを特徴とする、反応炉内吹込み用微粉炭の製造方法。」（特許文献２の請求項１参照）
By the way, it is known that the particle size distribution of pulverized coal has an influence as a cause of adhesion or blockage in a piping system or the like.
Therefore, in Patent Document 1, paying attention to the fact that adhesion and blockage in the piping system are also related to the moisture content of the pulverized coal, 5 to 50% by mass of the pulverized coal is pulverized coal particles having a particle diameter of 1 to 20 μm. There is disclosed a method for blowing pulverized coal into a blast furnace in which the pulverized coal contains 1 to 8% by mass of moisture.
In addition, as a method for producing pulverized coal in which fluidity is ensured so as not to cause clogging in the blowing path, Patent Document 2 discloses the following method for producing pulverized coal for in-reactor blowing.
"Pulverized coal produced from a single type of coal or multiple types of coal is transported from the pulverized coal production device via the inside of the piping system by carrier gas, and the pulverized coal thus transported is transferred from the pulverized coal blowing device. In a method for producing pulverized coal for blowing and burning into a reaction furnace using a pulverized coal production apparatus, control of the particle size distribution of the pulverized coal to be blown into the reaction furnace is used to produce pulverized coal. And adjusting the crushing force applied to the coal in the pulverized coal production apparatus. ”(Patent Document 2 claim) 1)
特許文献１、２においては微粉炭の閉塞を生じないための微粉炭の粒径や製造方法が開示されているものの、実際に吹き込まれている微粉炭の粒径の測定に関しては詳細な開示はないが、恐らく輸送管等からサンプリングして測定室に設置されたレーザ回折法により測定をするといういわゆるバッチ方式によって行われていると推察される。 Although Patent Documents 1 and 2 disclose the particle size and manufacturing method of pulverized coal so as not to cause clogging of the pulverized coal, detailed disclosure regarding the measurement of the particle size of pulverized coal actually blown is disclosed. Although it is not, it is presumed that the measurement is performed by a so-called batch method in which sampling is performed from a transport pipe or the like and measurement is performed by a laser diffraction method installed in a measurement chamber.
しかしながら、輸送管を流れる微粉炭の粒度分布を常に適切な粒度分布になるように管理するためには、微粉炭の粒度分布の経時変化を測定することが要請される。
微粉炭粒度を連続測定するための微粉炭粒度測定装置、微粉炭製造システム、高炉操業方法としては例えば特許文献３に開示されている。
However, in order to manage the particle size distribution of the pulverized coal flowing through the transport pipe so as to always have an appropriate particle size distribution, it is required to measure the change in the particle size distribution of the pulverized coal over time.
For example, Patent Document 3 discloses a pulverized coal particle size measuring device, a pulverized coal production system, and a blast furnace operating method for continuously measuring the pulverized coal particle size.
特許文献３に開示された微粉炭の粒度分布測定装置は、微粉炭を高炉羽口へ気流輸送する輸送管と、該輸送管を流れる微粉炭をキャリアガスと共に取り出すバイパス路と、該バイパス路に設けられて該バイパス路に流入する微粉炭の濃度を希釈する希釈手段と、該希釈手段で希釈された微粉炭の粒度分布を連続的に測定するレーザ回折式粒度分布測定装置とを備えたことを特徴とするものである。 The pulverized coal particle size distribution measuring apparatus disclosed in Patent Document 3 includes a transport pipe for air-transporting pulverized coal to a blast furnace tuyere, a bypass path for taking out the pulverized coal flowing through the transport pipe together with a carrier gas, and A dilution means for diluting the concentration of the pulverized coal that is provided and flowing into the bypass passage, and a laser diffraction particle size distribution measuring device for continuously measuring the particle size distribution of the pulverized coal diluted by the dilution means It is characterized by.
配管系等における付着や閉塞の要因として微粉炭の粒度分布が影響しており、適切な粒度分布の微粉炭の粒度分布やその製造方法の開示はあるものの、そのような粒度分布の微粉炭を製造するには、実際に吹き込まれている微粉炭の性状を適切にオンラインで知ることが必要であり、それを前提として初めて適切な微粉炭吹込みが実現できるのである。
しかしながら、特許文献３に開示された微粉炭の粒度分布測定装置は、流路の圧力調整が複雑なため微粉炭の取り出しが安定せず、微粉炭の粒度分布を正確に測定するのは難しいという問題があった。すなわち、最大9kg/cm2程度の高圧となっている吹込みタンクから輸送管を通して微粉炭は輸送されるが、吹込みタンクの圧力が変動すると輸送管内圧力も変動するためエジェクタ差圧が変動し、エジェクタ効果により取り出しされるキャリアガス量および微粉炭量が変動することになる。レーザ回折式粒度分布測定装置は、透過率が所定の範囲内にあることが要請されるところ、取り出されるキャリアガス量および微粉炭量が変動するとキャリアガス中の微粉炭濃度が変化し、それ故に透過率が変化して、安定した測定が難しいという問題がある。
また、吹込みタンクの圧力が変動してエジェクタ差圧の変動が大きい場合には、微粉炭の取り出しが困難になることも考えられる。
さらに、特許文献３に開示された方法は、高圧で気流輸送中の微粉炭を、バイパス路やエジェクタ等を設けて輸送管から取り出すため、取り出し流路が複雑でバルブ等が多数必要となり、設置およびメンテナンスの費用が多大となる問題もあった。
Although the particle size distribution of pulverized coal has an influence as a cause of adhesion and blockage in piping systems, etc., and there is disclosure of the particle size distribution of pulverized coal with an appropriate particle size distribution and its manufacturing method, pulverized coal with such particle size distribution is In order to manufacture, it is necessary to know the property of the pulverized coal actually blown on-line appropriately, and appropriate pulverized coal blowing can be realized only on the premise of this.
However, the pulverized coal particle size distribution measuring device disclosed in Patent Document 3 is difficult to accurately measure the particle size distribution of the pulverized coal because the pressure adjustment of the flow path is complicated and the extraction of the pulverized coal is not stable. There was a problem. In other words, pulverized coal is transported through the transport pipe from the injection tank, which has a maximum pressure of about 9 kg / cm 2, but if the pressure in the injection tank fluctuates, the pressure in the transport pipe also changes, so the ejector differential pressure fluctuates. The carrier gas amount and pulverized coal amount taken out due to the ejector effect will fluctuate. The laser diffraction particle size distribution measuring apparatus is required to have a transmittance within a predetermined range. When the amount of extracted carrier gas and the amount of pulverized coal fluctuate, the concentration of pulverized coal in the carrier gas changes. There is a problem that the transmittance changes and it is difficult to perform stable measurement.
Further, when the pressure of the blowing tank fluctuates and the fluctuation of the ejector differential pressure is large, it may be difficult to take out the pulverized coal.
Furthermore, the method disclosed in Patent Document 3 is provided with a bypass passage, an ejector, etc., to take out the pulverized coal being transported at high pressure from the transport pipe. In addition, there is a problem that the maintenance cost becomes large.
このように、特許文献３に開示された粒度分布測定装置によって吹き込まれる微粉炭の粒度分布をオンラインで測定したとしても、正確な粒度分布の測定が期待できないため、この装置を特許文献１，２のものと組み合わせたとしても適切な微粉炭吹込み方法を実現することはできない。 Thus, even if the particle size distribution of the pulverized coal blown by the particle size distribution measuring device disclosed in Patent Document 3 is measured online, accurate measurement of the particle size distribution cannot be expected. Even if combined with the above, it is not possible to realize an appropriate pulverized coal injection method.
本発明はかかる課題を解決するためになされたものであり、微粉炭の粒度分布の経時的な変化を正確に測定して適切な微粉炭吹込みができる微粉炭吹込み方法を提供することを目的としている。 The present invention has been made to solve such a problem, and provides a pulverized coal injection method capable of accurately measuring the change over time in the particle size distribution of pulverized coal and performing appropriate pulverized coal injection. It is aimed.
（１）本発明に係る微粉炭吹込み方法は、微粉炭製造装置によって石炭を粉砕して製造された微粉炭をバグフィルタに気流搬送して、該バグフィルタで回収した微粉炭をコールビンに貯留し、該コールビンに貯留された微粉炭を吹込みタンクに切り出して高炉羽口に向けて気流搬送する微粉炭吹込み装置を用いた微粉炭吹込み方法であって、
前記微粉炭製造装置によって製造された微粉炭を搬送経路から取り出して粒度分布測定装置で周期的に測定する粒度分布測定工程と、該粒度分布測定工程で測定された測定値と目標値との偏差を用いて前記微粉炭製造装置における石炭粉砕力を調整する粉砕力調整工程とを有し、
前記粒度分布測定工程は、
前記バグフィルタと前記吹込みタンクとの間に設けられ、微粉炭を自然落下によって搬送する搬送管に取り付けられて該搬送管内を移動する微粉炭を採取する採取装置と、該採取装置によって採取された微粉炭を微粉炭気送装置によってレーザ回折式粒度分布測定装置に気送して前記レーザ回折式粒度分布測定装置で粒度分布を測定することを特徴とするものである。
(1) The pulverized coal injecting method according to the present invention is a method in which pulverized coal produced by pulverizing coal by a pulverized coal production apparatus is air-flowed to a bag filter and the pulverized coal collected by the bag filter is stored in a coulbin. Then, a pulverized coal blowing method using a pulverized coal blowing device that cuts the pulverized coal stored in the coal bottle into a blowing tank and conveys the air toward the blast furnace tuyere,
The pulverized coal produced by the pulverized coal production device is taken out of the conveyance path and periodically measured by the particle size distribution measuring device, and the deviation between the measured value and the target value measured in the particle size distribution measuring step A pulverization force adjusting step of adjusting the coal pulverization force in the pulverized coal production apparatus using
The particle size distribution measuring step includes
A sampling device that is provided between the bag filter and the blowing tank and that is attached to a transport pipe that transports the pulverized coal by natural fall and collects the pulverized coal that moves within the transport pipe, and is collected by the sampling device. The pulverized coal is fed to a laser diffraction type particle size distribution measuring device by a pulverized coal air feeding device, and the particle size distribution is measured by the laser diffraction type particle size distribution measuring device .
（３）また、上記（２）に記載のものにおいて、前記粒度分布測定装置は、前記機械式サンプラーと前記微粉炭気送装置における吸入口との間に振動フィーダを備え、該振動フィーダによって前記吸入口側に向かって供給される微粉炭を前記吸入口で吸入するようにしたことを特徴とするものである。 (3) Further, in the above (2), the particle size distribution measuring device includes a vibration feeder between the mechanical sampler and a suction port of the pulverized coal infeed device, and the vibration feeder supplies the vibration feeder. The pulverized coal supplied toward the suction port side is sucked through the suction port.
（４）また、上記（２）又は（３）に記載のものにおいて、前記微粉炭気送装置は、微粉炭の吸入量を調節する吸入量調節機能を有することを特徴とするものである。 (4) Further, in the above (2) or (3), the pulverized coal air-feeding device has an intake amount adjusting function for adjusting an intake amount of the pulverized coal.
本発明の微粉炭吹込み方法においては、前記微粉炭製造装置によって製造された微粉炭を搬送経路から取り出して粒度分布測定装置で周期的に測定する粒度分布測定工程と、該粒度分布測定工程で測定された測定値と目標値との偏差を用いて前記微粉炭製造装置における石炭粉砕力を調整する粉砕力調整工程とを有し、前記粒度分布測定工程は、前記バグフィルタと前記吹込みタンクとの間に設けられ、微粉炭を自然落下によって搬送する搬送管に取り付けられて該搬送管内を移動する微粉炭を採取する採取装置と、該採取装置によって採取された微粉炭を微粉炭気送装置によってレーザ回折式粒度分布測定装置に気送して前記レーザ回折式粒度分布測定装置で粒度分布を測定するようにしたので、安定的に微粉炭粒度分布の測定ができ、これにより微粉炭粒度を精度良く制御し微粉炭吹込み配管の閉塞を抑制し、実質的に微粉炭吹込み量を増やし低コストの高炉溶銑の製造を実現可能にできる。 In the pulverized coal injecting method of the present invention, the pulverized coal produced by the pulverized coal production device is taken out of the conveyance path and periodically measured by the particle size distribution measuring device, and the particle size distribution measuring step. A pulverizing force adjusting step of adjusting a coal pulverizing force in the pulverized coal production apparatus using a deviation between the measured value and the target value, wherein the particle size distribution measuring step includes the bag filter and the blowing tank. And a sampling device that is attached to a transport pipe that transports pulverized coal by natural fall and collects the pulverized coal that moves in the transport pipe, and pulverized coal that is collected by the sampling device Since the apparatus is pneumatically fed to the laser diffraction particle size distribution measuring device and the particle size distribution is measured by the laser diffraction particle size distribution measuring device, the pulverized coal particle size distribution can be measured stably. The pulverized coal particle size accurately controlled to suppress the clogging of the pulverized coal blown pipe can feasible the production of substantially lower cost of the blast furnace hot metal to increase the pulverized coal blowing amount by.
本実施の形態に係る微粉炭の吹込み方法は、微粉炭製造装置１６によって石炭を粉砕して製造された微粉炭をバグフィルタ７に気流搬送して、該バグフィルタ７で回収した微粉炭をコールビン８に貯留し、コールビン８に貯留された微粉炭を吹込みタンク９に切り出して羽口１３に向けて気流搬送する微粉炭吹込み装置を用いた微粉炭の吹込み方法であって、
微粉炭製造装置１６によって製造された微粉炭を搬送経路から取り出して粒度分布測定装置４０で周期的に測定する粒度分布測定工程と、該粒度分布測定工程で測定された測定値と目標値との偏差を用いて微粉炭製造装置１６における石炭粉砕力を調整する粉砕力調整工程とを有している。
以下、各工程及び各工程に使用される機器について詳細に説明する。
The method of blowing pulverized coal according to the present embodiment is such that the pulverized coal produced by pulverizing coal by the pulverized coal production apparatus 16 is conveyed to the bag filter 7 by air flow, and the pulverized coal recovered by the bag filter 7 is recovered. A method for injecting pulverized coal using a pulverized coal injecting device that stores in the coal bin 8 and cuts the pulverized coal stored in the coal bin 8 into an injection tank 9 and conveys the air toward the tuyere 13.
A particle size distribution measuring step in which the pulverized coal produced by the pulverized coal production device 16 is taken out from the transport path and periodically measured by the particle size distribution measuring device 40, and the measured value and the target value measured in the particle size distribution measuring step. A pulverization force adjusting step of adjusting the coal pulverization force in the pulverized coal production apparatus 16 using the deviation.
Hereinafter, each process and the equipment used in each process will be described in detail.
＜粒度分布測定工程＞
粒度分布測定工程は、微粉炭製造装置１６によって製造された微粉炭を搬送経路から取り出して粒度分布測定装置４０で周期的に測定する工程である。
粒度分布測定工程においては、同一粉砕条件で周期的に測定した連続１０点の測定値の標準偏差が１％以内である粒度分布測定方法を用いることが必要である。
そのため、本実施の形態では、上記の条件を満たす粒度分布測定方法とするために、粒度分布測定装置４０や粒度分布測定装置４０を取り付ける部位を工夫している。
<Particle size distribution measurement process>
The particle size distribution measurement step is a step in which the pulverized coal produced by the pulverized coal production device 16 is taken out from the conveyance path and periodically measured by the particle size distribution measurement device 40.
In the particle size distribution measuring step, it is necessary to use a particle size distribution measuring method in which the standard deviation of 10 consecutive measured values measured periodically under the same grinding conditions is within 1%.
Therefore, in this Embodiment, in order to make it the particle size distribution measuring method which satisfy | fills said conditions, the site | part which attaches the particle size distribution measuring device 40 and the particle size distribution measuring device 40 is devised.
図１は、本実施の形態に係る微粉炭吹込み方法に用いる粒度分布測定装置４０が取り付けられる部位を説明するための説明図であり、バグフィルタ７と吹込みタンク９との間の配管等を詳細に示している。
まず、図１に基づいて、バグフィルタ７と吹込みタンク９との間の配管等を詳細に説明する。
図１に示されるように、バグフィルタ７の下部にはバグフィルタ７で回収された微粉炭を切り出すためのスクリューフィーダ１７が設けられている。また、スクリューフィーダ１７で切り出された微粉炭をコールビン８に搬送するための２本の搬送管１９がスクリューフィーダ１７とコールビン８との間を連結するように設けられている。各搬送管１９にはバグフィルタ７の機密性を確保するためのロータリーバルブ２１が設けられている。
コールビン８の下方には中間タンク２３が設けられ、中間タンク２３の下方には吹込みタンク９が設けられている。
FIG. 1 is an explanatory diagram for explaining a part to which a particle size distribution measuring device 40 used in the pulverized coal blowing method according to the present embodiment is attached, such as piping between the bag filter 7 and the blowing tank 9. Is shown in detail.
First, the piping and the like between the bag filter 7 and the blowing tank 9 will be described in detail with reference to FIG.
As shown in FIG. 1, a screw feeder 17 for cutting out the pulverized coal recovered by the bag filter 7 is provided below the bag filter 7. Further, two transport pipes 19 for transporting the pulverized coal cut out by the screw feeder 17 to the coalbin 8 are provided so as to connect between the screw feeder 17 and the coalbin 8. Each transport pipe 19 is provided with a rotary valve 21 for ensuring the confidentiality of the bag filter 7.
An intermediate tank 23 is provided below the colebin 8, and a blowing tank 9 is provided below the intermediate tank 23.
上記のように構成されたバグフィルタ７から吹込みタンク９までの構造において、バグフィルタ７で回収された微粉炭が吹込みタンク９に供給されるまでの流れを説明する。
バグフィルタ７で回収された微粉炭は、スクリューフィーダ１７で切り出され、スクリューフィーダ１７の下部に設けられた搬送管１９内を自由落下してコールビン８に貯留される。コールビン８に貯留された微粉炭は中間タンク２３を経由して吹込みタンク９に供給される。
In the structure from the bag filter 7 to the blowing tank 9 configured as described above, the flow until the pulverized coal recovered by the bag filter 7 is supplied to the blowing tank 9 will be described.
The pulverized coal recovered by the bag filter 7 is cut out by the screw feeder 17, freely falls in the transport pipe 19 provided at the lower portion of the screw feeder 17, and is stored in the coal bin 8. The pulverized coal stored in the coal bin 8 is supplied to the blowing tank 9 via the intermediate tank 23.
次に粒度分布測定装置４０の構造について説明する。
粒度分布測定装置４０は、図２に示すように、バグフィルタ７とコールビン８との間に設けられた搬送管１９に取り付けられて搬送管１９内を落下する微粉炭を採取する採取装置としての機械式サンプラー４１と、採取装置によって採取された微粉炭をレーザ回折式粒度分布測定装置３５に気送する微粉炭気送装置２７とを備えている。
以下、粒度分布測定装置４０の構成を詳細に説明する。
Next, the structure of the particle size distribution measuring apparatus 40 will be described.
As shown in FIG. 2, the particle size distribution measuring device 40 is attached to a transport pipe 19 provided between the bag filter 7 and the colebin 8 and serves as a sampling device that collects pulverized coal falling in the transport pipe 19. A mechanical sampler 41 and a pulverized coal feeding device 27 for feeding pulverized coal collected by the collection device to the laser diffraction particle size distribution measuring device 35 are provided.
Hereinafter, the configuration of the particle size distribution measuring apparatus 40 will be described in detail.
＜採取装置＞
本実施の形態に係る採取装置は、搬送管１９に挿入された機械式サンプラー４１によって構成される。
機械式サンプラーとしては、上面が開放された筒体内にスクリューを設置したスクリューフィーダ等を用いることが出来る。上面が開放したスクリューフィーダを用いる場合、スクリューの一部を搬送管１９に挿入し、スクリュー上に落下した微粉炭を搬送管１９の外に定量的に取り出すことが可能となる。
機械式サンプラー４１によって取り出された微粉炭は、微粉炭気送装置２７によってレーザ回折式粒度分布測定装置３５に導入される。
<Collecting device>
The sampling device according to the present embodiment is configured by a mechanical sampler 41 inserted into the transport pipe 19.
As the mechanical sampler, a screw feeder or the like in which a screw is installed in a cylinder whose upper surface is open can be used. When a screw feeder having an open upper surface is used, a part of the screw can be inserted into the transport pipe 19 and the pulverized coal falling on the screw can be quantitatively taken out of the transport pipe 19.
The pulverized coal taken out by the mechanical sampler 41 is introduced into the laser diffraction particle size distribution measuring device 35 by the pulverized coal infeed device 27.
＜微粉炭気送装置＞
微粉炭気送装置２７は、先端側が吸入ノズル２５に連結された吸入管２９と、吸入管２９の他端に取り付けられたエジェクタ３１と、エジェクタ３１に吸入用のガスとなる窒素を供給する窒素供給管３３とを備えている。吸入管２９におけるエジェクタ３１の上流側には、レーザ回折式粒度分布測定装置３５が設けられ、レーザ回折式粒度分布測定装置３５にはＰＣ３７（パーソナルコンピュータ）が接続され、さらにＰＣ３７にはプロセスコンピュータ３９が接続されている。
<Pulverized coal feeding device>
The pulverized coal feeding device 27 includes a suction pipe 29 having a distal end connected to the suction nozzle 25, an ejector 31 attached to the other end of the suction pipe 29, and nitrogen for supplying nitrogen as a suction gas to the ejector 31. And a supply pipe 33. A laser diffraction particle size distribution measuring device 35 is provided upstream of the ejector 31 in the suction pipe 29, and a PC 37 (personal computer) is connected to the laser diffraction particle size distribution measuring device 35, and a process computer 39 is connected to the PC 37. Is connected.
上記のように構成された微粉炭の粒度分布測定装置４０を用いて微粉炭の粒度分布を測定する方法を説明する。
バグフィルタ７で捕集された微粉炭はバグフィルタ７下部のスクリューフィーダ１７により搬送管１９に切出される。搬送管１９に切り出された微粉炭は、コールビン８に貯留され、中間タンク２３を経て吹込みタンク９へと搬送される。
ここで、バグフィルタ７から吹込みタンク９間は、ほぼ大気圧であり、微粉炭は自然落下しているため、搬送管１９から微粉炭を取り出す場合には、複雑な圧力調整が必要ない。
A method for measuring the particle size distribution of pulverized coal using the pulverized coal particle size distribution measuring apparatus 40 configured as described above will be described.
The pulverized coal collected by the bag filter 7 is cut out by the screw feeder 17 below the bag filter 7 into the transport pipe 19. The pulverized coal cut out in the transfer pipe 19 is stored in the coal bin 8 and transferred to the blowing tank 9 through the intermediate tank 23.
Here, since the pressure between the bag filter 7 and the blowing tank 9 is almost atmospheric pressure, and the pulverized coal is naturally falling, no complicated pressure adjustment is required when the pulverized coal is taken out from the transfer pipe 19.
搬送管１９を落下する微粉炭は機械式サンプラー４１における筒体内に落下してスクリューによって定量的に切り出され、ホッパ４３を介して吸入管２９の吸入口４５に供給される。
他方、微粉炭気送装置２７における窒素供給管３３に窒素を供給すると、エジェクタ３１の作用によって吸入口４５に供給された微粉炭が吸入ノズル２５から吸入される。吸入された微粉炭は、レーザ回折式粒度分布測定装置３５に供給される。レーザ回折式粒度分布測定装置３５は、搬送管１９から吸入されて分散飛翔状態で流れる微粉炭粒子群にレーザ光を照射することによって生ずる回折光の空間強度分布を測定し、その測定結果に基づいて微粉炭粒子群の粒度分布を測定する。
レーザ回折式粒度分布測定装置３５によって測定された測定結果はＰＣ３７に出力され、ＰＣ３７によって所定の演算がなされ、プロセスコンピュータ３９にさらに出力され、プロセス操作室等でモニターされると共に微粉炭製造装置１６の制御装置５５に入力され、微粉炭製造装置１６における粉砕力制御に使用される。
The pulverized coal falling on the transport pipe 19 falls into the cylinder in the mechanical sampler 41, is quantitatively cut out by a screw, and is supplied to the suction port 45 of the suction pipe 29 through the hopper 43.
On the other hand, when nitrogen is supplied to the nitrogen supply pipe 33 in the pulverized coal feeding device 27, the pulverized coal supplied to the suction port 45 by the action of the ejector 31 is sucked from the suction nozzle 25. The sucked pulverized coal is supplied to the laser diffraction particle size distribution measuring device 35. The laser diffraction particle size distribution measuring device 35 measures the spatial intensity distribution of the diffracted light generated by irradiating the pulverized coal particles that are sucked from the transport pipe 19 and flow in a dispersed flight state, and based on the measurement result. To measure the particle size distribution of the pulverized coal particles.
The measurement result measured by the laser diffraction particle size distribution measuring device 35 is output to the PC 37, subjected to a predetermined calculation by the PC 37, further output to the process computer 39, and monitored in the process operation room or the like, and also the pulverized coal production device 16 Is used for controlling the crushing force in the pulverized coal production apparatus 16.
本実施の形態の微粉炭吹込み方法に使用する粒度分布測定装置４０においては、バグフィルタ７と吹込みタンク９との間にある搬送管１９に機械式サンプラー４１を設けて、搬送管１９内を落下する微粉炭を取出してレーザ回折式粒度分布測定装置３５に導入するようにしたので、搬送管１９内はほぼ大気圧であることから、搬送管１９から微粉炭を取り出すに際して、複雑な圧力調整が必要ない。そして、安定的かつ確実に微粉炭を取り出すことができるので、散飛翔状態の微粉炭濃度を安定させることができ、微粉炭の粒度分布の経時変化を正確に測定することができる。
その結果、同一粉砕条件で周期的に測定した連続１０点の測定値の標準偏差が１％以内である粒度分布測定方法を実現できる。
In the particle size distribution measuring apparatus 40 used in the pulverized coal blowing method of the present embodiment, a mechanical sampler 41 is provided in the conveying pipe 19 between the bag filter 7 and the blowing tank 9, and the inside of the conveying pipe 19 Since the pulverized coal falling is taken out and introduced into the laser diffraction particle size distribution measuring device 35, the inside of the transfer pipe 19 is almost at atmospheric pressure. No adjustment is necessary. And since pulverized coal can be taken out stably and reliably, the concentration of pulverized coal in a scattered state can be stabilized, and the time-dependent change of the particle size distribution of pulverized coal can be measured accurately.
As a result, it is possible to realize a particle size distribution measuring method in which the standard deviation of 10 consecutive measured values measured periodically under the same grinding conditions is within 1%.
また、本実施の形態では、バグフィルタ７とコールビン８との間に設けた搬送管１９に微粉炭を取り出す機械式サンプラー４１を設けたので、吹込みタンク９側の圧力の影響が少なく、より好ましい。もっとも、バグフィルタ７と吹込みタンク９との間であれば、コールビン８と吹込みタンク９との間、例えばコールビン８と中間タンク２３の間にある配管に機械式サンプラー４１を設けるようにしてもよい。 Further, in the present embodiment, since the mechanical sampler 41 for taking out the pulverized coal is provided in the transfer pipe 19 provided between the bag filter 7 and the coal bottle 8, there is less influence of the pressure on the side of the blowing tank 9, preferable. However, if it is between the bag filter 7 and the blowing tank 9, a mechanical sampler 41 is provided in a pipe between the colebin 8 and the blowing tank 9, for example, between the colebin 8 and the intermediate tank 23. Also good.
なお、レーザ回折式粒度分布測定装置３５による微粉炭の粒度分布の測定に際し、微粉炭濃度を調整するには、微粉炭気送装置２７における窒素供給管３３への窒素の供給量を調整して微粉炭の吸入量を変化させることで対応できる。 In order to adjust the pulverized coal concentration when measuring the particle size distribution of the pulverized coal with the laser diffraction particle size distribution measuring device 35, the amount of nitrogen supplied to the nitrogen supply pipe 33 in the pulverized coal air-feeding device 27 is adjusted. This can be done by changing the amount of pulverized coal intake.
本実施の形態の粒度分布測定装置４０の測定精度を検証するために、微粉炭製造装置１６を用いて代表的な粉砕条件で微粉炭を製造して得た微粉炭標準試料（−７４μｍ割合：約７０％、−４４μｍ割合：約５０％）を、オフラインの搬送管中に自然落下させ、粒度分布測定装置４０によって粒度分布測定を行った。図３、図４はその結果を示すグラフであり、図３は、横軸が経過時間を示し、縦軸が微粉炭粒度分布（-７４μｍ割合（％））を示している。
また、図４は、横軸が経過時間を示し、縦軸が微粉炭粒度分布（−４４μｍ割合（％））を示している。図３、図４のグラフを見ると、測定値の上下への変動が少ない。
１０点の標準偏差は、図３（−７４μｍ割合（％））では０．８％、図４（−４４μｍ割合（％））では０．７％であり、本発明の測定値の安定性が１％以下の条件を満たし、微粉炭粒度分布の経時変化を正確に測定できていることが読み取れる。
このように本実施の形態の粒度分布測定装置４０によれば、微粉炭採取装置として機械式サンプラー４１を用いたので、微粉炭の粒度分布を安定的、かつ正確に測定することができ、標準試料の測定値の標準偏差を１％以内にすることができる。
なお、上記の例では標準試料の測定値の標準偏差を求める計測値のデータとして連続する１０点（図３、図４参照）を用いたものを示したが、測定値のデータ数はこれに限られず、１０点以上のデータ数であれば測定値の安定性を評価できる。
In order to verify the measurement accuracy of the particle size distribution measuring apparatus 40 of the present embodiment, a pulverized coal standard sample (ratio of -74 μm: obtained by manufacturing pulverized coal under typical pulverization conditions using the pulverized coal manufacturing apparatus 16). About 70%, -44 μm ratio: about 50%) was naturally dropped into an off-line conveying tube, and the particle size distribution measurement was performed by the particle size distribution measuring device 40. 3 and 4 are graphs showing the results. In FIG. 3, the horizontal axis indicates the elapsed time, and the vertical axis indicates the pulverized coal particle size distribution (-74 μm ratio (%)).
In FIG. 4, the horizontal axis represents elapsed time, and the vertical axis represents pulverized coal particle size distribution (-44 μm ratio (%)). Looking at the graphs of FIGS. 3 and 4, there is little fluctuation in the measured value up and down.
The standard deviation of 10 points is 0.8% in FIG. 3 (-74 μm ratio (%)) and 0.7% in FIG. 4 (−44 μm ratio (%)), and the stability of the measured value of the present invention is It can be seen that the change over time of the pulverized coal particle size distribution can be accurately measured while satisfying the condition of 1% or less.
As described above, according to the particle size distribution measuring apparatus 40 of the present embodiment, since the mechanical sampler 41 is used as the pulverized coal collecting apparatus, the particle size distribution of the pulverized coal can be measured stably and accurately. The standard deviation of the measured value of the sample can be within 1%.
In the above example, ten consecutive points (see FIGS. 3 and 4) are used as the measurement value data for obtaining the standard deviation of the measurement value of the standard sample. The stability of the measured value can be evaluated as long as the number of data is 10 points or more.
＜粉砕力調整工程＞
粉砕力調整工程は、粒度分布測定工程で測定された測定値と目標値との偏差を用いて微粉炭製造装置１６における石炭粉砕力を調整する工程である。
微粉炭製造装置１６の構成を説明する。
<Crushing force adjustment process>
The pulverization force adjustment step is a step of adjusting the coal pulverization force in the pulverized coal production apparatus 16 using the deviation between the measurement value measured in the particle size distribution measurement step and the target value.
The configuration of the pulverized coal production apparatus 16 will be described.
微粉炭製造装置１６は、石炭を装入するための装入部６３と、装入部６３から装入された石炭を受け止めるターンテーブル６５と、ターンテーブル６５を囲むように設置された竪型のローラータイヤ５１と、ローラータイヤ５１における粉砕力を調整するための油圧シリンダー５３と、油圧シリンダー５３の押圧力を制御する制御装置５５と、所定の粒度の石炭が通過できる開口隙間が形成された粒度分級調整盤５７と、粒度分級調整盤の開口隙間を通過した微粉炭が排出される排出口５９と、粉砕室に高速の温風を供給する温風供給管６１とを備えている。 The pulverized coal production apparatus 16 includes a charging unit 63 for charging coal, a turntable 65 for receiving coal charged from the charging unit 63, and a bowl-shaped unit installed so as to surround the turntable 65. The roller tire 51, the hydraulic cylinder 53 for adjusting the crushing force in the roller tire 51, the control device 55 for controlling the pressing force of the hydraulic cylinder 53, and the particle size in which an opening gap through which coal of a predetermined particle size can pass is formed. A classification adjustment board 57, a discharge port 59 through which pulverized coal that has passed through the opening gap of the particle size classification adjustment board is discharged, and a hot air supply pipe 61 that supplies high-speed hot air to the grinding chamber are provided.
上記のように構成された微粉炭製造装置１６においては、装入部６３から給炭された石炭は、複数個のローラータイヤ５１とターンテーブル６５とで囲まれた空間領域に供給され、ローラータイヤ５１とターンテーブル６５の隙間において両者によって破砕・粉砕される。粉砕された石炭は、ターンテーブル６５の上面とローラータイヤ５１の下端面との隙間から、ターンテーブル６５の盤面上を周円部に移動し、はじき出される。はじき出された粉砕石炭は、高速温風に乗ってターンテーブル６５の周縁から舞い上がり、大部分の粉砕石炭は、粒度分級調整盤５７の開口隙間を通過して当該装置上部の排出口５９から温風によって排出される。
他方、粒度分級調整盤５７の開口隙間を通過できなかった粉砕石炭は、落下してローラータイヤ５１の間隙に供給され、再度、破砕・粉砕される。
In the pulverized coal manufacturing apparatus 16 configured as described above, the coal supplied from the charging unit 63 is supplied to a space region surrounded by the plurality of roller tires 51 and the turntable 65, and the roller tire In the gap between 51 and the turntable 65, both are crushed and crushed. The pulverized coal moves from the gap between the upper surface of the turntable 65 and the lower end surface of the roller tire 51 to the circumferential portion on the surface of the turntable 65 and is ejected. The pulverized coal that has been ejected flies from the periphery of the turntable 65 by riding on high-speed hot air, and most of the pulverized coal passes through the opening clearance of the particle size classification adjustment panel 57 and passes through the outlet 59 at the top of the apparatus. Discharged by.
On the other hand, the pulverized coal that has failed to pass through the opening gap of the particle size classification adjusting plate 57 falls and is supplied to the gap between the roller tires 51, and is crushed and pulverized again.
微粉炭製造装置１６における粉砕加圧力はローラータイヤ５１を支持する支持部に設けられた油圧シリンダー５３の圧力を制御することによって制御される。つまり、油圧シリンダー５３の圧力を高くすることで粉砕力を高め、微粉炭の粒度を細かくでき、逆に油圧シリンダー５３の圧力を弱くすることで微粉炭の粒度を粗くすることができる。
油圧シリンダー５３の圧力は、粒度分布測定工程で粒度分布測定装置４０によって測定された測定値と目標値との偏差を用いて制御装置５５によって調整される。
調整方法の一例を示すと、下式（１）によって調整される。
Pn＋1＝Pn＋A×（Xｔ−Ｘn）・・・（１）
但し、Ｘn：粒度分布（-４４μｍ割合（％））測定値
Xｔ：粒度分布（-４４μｍ割合（％））目標値
Pn+1：調整後の加圧力（MPa）
Pn：調整前の加圧力（MPa）（粒度分布Ｘn測定時）
Ａ：定数（ＭＰａ／％）
The pulverizing pressure in the pulverized coal production apparatus 16 is controlled by controlling the pressure of the hydraulic cylinder 53 provided in the support portion that supports the roller tire 51. That is, by increasing the pressure of the hydraulic cylinder 53, the pulverization force can be increased and the particle size of the pulverized coal can be made finer. Conversely, by reducing the pressure of the hydraulic cylinder 53, the particle size of the pulverized coal can be made coarser.
The pressure of the hydraulic cylinder 53 is adjusted by the control device 55 using the deviation between the measured value measured by the particle size distribution measuring device 40 and the target value in the particle size distribution measuring step.
An example of the adjustment method is shown by the following equation (1).
P n + 1 = P n + A × (X t −X n ) (1)
However, X n : Particle size distribution (-44 μm ratio (%)) measured value
X t : Particle size distribution (-44 μm ratio (%)) target value
P n + 1 : Applied pressure after adjustment (MPa)
P n : Pressure before adjustment (MPa) (when measuring particle size distribution X n )
A: Constant (MPa /%)
［実施例］
本発明の効果を確認するために、羽口が４０本の高炉で、計画出銑量に対し［１５０ｋｇ／ｔ−溶銑］の微粉炭比で高炉内へ微粉炭を吹込む操業を実施した。
各羽口の微粉炭吹込み配管が閉塞した場合は、微粉炭吹込み配管の負荷が変わらないように羽口1本当たりの微粉炭吹込み量を変えず実質の微粉炭比が変わるようにし、その分コークス比を調整した。
吹込む微粉炭の粒度分布の管理値は、「４５％≦―４４μｍ≦５０％、＋７４μｍ≦４０％」とした。
[Example]
In order to confirm the effect of the present invention, an operation was performed in which pulverized coal was blown into the blast furnace at a blast furnace with 40 tuyere at a pulverized coal ratio of [150 kg / t-molten iron] with respect to the planned amount of dredging.
If the pulverized coal injection piping at each tuyere is blocked, the actual pulverized coal ratio should be changed without changing the amount of pulverized coal injection per tuyere so that the load on the pulverized coal injection piping does not change. The coke ratio was adjusted accordingly.
The management value of the particle size distribution of the pulverized coal to be blown was set to “45% ≦ −44 μm ≦ 50%, +74 μm ≦ 40%”.
上記の操業条件で粒度分布測定装置４０を用い、その測定結果に基づいて微粉炭製造装置１６で石炭に負荷する粉砕力を、前述の（１）式を満たすように調整して、微粉炭の粒度分布の制御を実施する試験操業を行った。微粉炭粒度は１２分毎に測定し、（１）式を用いた粉砕力の調整も１２分毎に行った。なお、Ａ＝０．０１（ＭＰａ／％）、Xｔ＝４８％とした。 Using the particle size distribution measuring device 40 under the above operating conditions, adjusting the pulverization force applied to the coal with the pulverized coal production device 16 based on the measurement result so as to satisfy the above-mentioned formula (1), A test operation was performed to control the particle size distribution. The pulverized coal particle size was measured every 12 minutes, and the pulverization force was adjusted every 12 minutes using the formula (1). A = 0.01 (MPa /%) and Xt = 48%.
粉砕力を調整した結果、Ｘn、Ｙn、Ｐnの推移を図６のグラフに示す。図６のグラフは、左縦軸が粒度分布であり、また右縦軸が加圧力（ＭＰａ）であり、横軸が経過日数である。また、微粉炭吹込み配管の閉塞本数を調査した結果を図７のグラフに示す。微粉炭吹込み配管の閉塞本数とは、各羽口の閉塞（微粉炭吹込み停止）時間を２４時間で割った値の羽口本数（４０本）分の総和を、日毎に示した値である。図７のグラフにおいて、縦軸が閉塞本数であり、横軸が経過日数である。 As a result of adjusting the crushing force, the transition of X n , Y n and P n is shown in the graph of FIG. In the graph of FIG. 6, the left vertical axis is the particle size distribution, the right vertical axis is the applied pressure (MPa), and the horizontal axis is the elapsed days. Moreover, the result of investigating the blockage number of pulverized coal injection piping is shown in the graph of FIG. The number of closed pulverized coal injection pipes is the sum of the number of tuyere (40) divided by 24 hours divided by 24 hours of each tuyere (stop of pulverized coal blowing). is there. In the graph of FIG. 7, the vertical axis represents the number of obstructions, and the horizontal axis represents the number of days elapsed.
実験の結果、粒度分布Ｘnの変動幅が４８±２％であり、極めて小さい変動幅での微粉炭吹込みが実現され、粒度分布Ｘnの管理値である「４５％≦―４４μｍ≦５０％」に調整できた。
なお、粒度分布Ｙn（-７４μｍ割合（％））の管理値は４０％以下であるが、３８％を目標値とし粒度分布Ｙnが目標値より高い場合には、微粉炭製造装置１６に吹き込む温風の流量を減らして、また目標値より低い場合には、温風の流量を増やして粒度分布Ｙnを管理値内に調整した。
As a result of the experiment, the fluctuation range of the particle size distribution X n is 48 ± 2%, pulverized coal injection with an extremely small fluctuation range is realized, and the control value of the particle size distribution X n is “45% ≦ −44 μm ≦ 50. % ".
The management value of the particle size distribution Y n (ratio (−74 μm (%))) is 40% or less. However, if the particle size distribution Y n is higher than the target value with 38% as the target value, the pulverized coal production apparatus 16 When the flow rate of the hot air to be blown was decreased and the flow rate was lower than the target value, the flow rate of the hot air was increased to adjust the particle size distribution Y n within the control value.
［比較例］
本発明の実施例の効果を検証するため、実施の形態で用いた粒度分布測定装置４０とは異なる形態の粒度分布測定装置２４を用いた場合について同様の実験を比較例として行った。
まず、比較例として使用した粒度分布測定装置２４について図８に基づいて説明する。
比較例の粒度分布測定装置２４は、採取装置として機械式サンプラー４１を用いるのではなく、吸入ノズル２５を搬送管１９に直接挿入して搬送管１９内を落下する微粉炭を吸入して採取するようにしたものである。
[Comparative example]
In order to verify the effect of the example of the present invention, the same experiment was performed as a comparative example in the case of using the particle size distribution measuring device 24 having a form different from the particle size distribution measuring device 40 used in the embodiment.
First, the particle size distribution measuring device 24 used as a comparative example will be described with reference to FIG.
The particle size distribution measuring device 24 of the comparative example does not use the mechanical sampler 41 as a sampling device, but sucks and collects the pulverized coal that falls inside the transport tube 19 by directly inserting the suction nozzle 25 into the transport tube 19. It is what I did.
微粉炭製造装置１６の粉砕条件や粒度分布測定周期は実施例と同様とした。
まず、粒度分布測定装置２４の測定精度を検証するために、前記実施の形態と同様の微粉炭標準試料（−７４μｍ割合：約７０％、−４４μｍ割合：約５０％）を、オフラインの搬送管中に自然落下させ、粒度分布測定装置２４によって粒度分布測定を行った。
図９、図１０はその結果を示すグラフである。図９は、横軸が経過時間を示し、縦軸が微粉炭粒度分布（-７４μｍ割合（％））を示している。また、図１０は、横軸が経過時間を示し、縦軸が微粉炭粒度分布（-４４μｍ割合（％））を示している。図９、図１０のグラフを図３、図４と比較すると、粒度分布測定装置４０に比べ、測定値の変動が大きい。
測定値における１０点の標準偏差は、図９（―７４μｍ割合（％））では１．４％、図１０（―４４μｍ割合（％））では２．５％であり、本発明の測定値の安定性として要求している１％以下の条件を満たしていなかった。
The pulverization conditions and particle size distribution measurement cycle of the pulverized coal production apparatus 16 were the same as in the example.
First, in order to verify the measurement accuracy of the particle size distribution measuring apparatus 24, the same pulverized coal standard sample (−74 μm ratio: about 70%, −44 μm ratio: about 50%) as in the above-described embodiment is used as an offline transport pipe. The particles were allowed to fall naturally, and the particle size distribution was measured by the particle size distribution measuring device 24.
9 and 10 are graphs showing the results. In FIG. 9, the horizontal axis indicates the elapsed time, and the vertical axis indicates the pulverized coal particle size distribution (-74 μm ratio (%)). In FIG. 10, the horizontal axis indicates the elapsed time, and the vertical axis indicates the pulverized coal particle size distribution (-44 μm ratio (%)). When the graphs of FIGS. 9 and 10 are compared with FIGS. 3 and 4, the variation in measured values is larger than that of the particle size distribution measuring apparatus 40.
The standard deviation of 10 points in the measured value is 1.4% in FIG. 9 (−74 μm ratio (%)) and 2.5% in FIG. 10 (−44 μm ratio (%)). The condition of 1% or less required for stability was not satisfied.
このような本発明の条件を満たさない粒度分布測定装置２４を用いて微粉炭吹込みを行った場合についてどのような結果が得られるかを確認するために、実施例と同様に羽口が４０本の高炉で、微粉炭を吹込む操業を実施した。
比較例の粒度分布測定装置２４を用いた場合は、粒度分布測定値Ｘnの変動が、粒度分布測定装置４０を用いた場合よりも大きいので、Ａ＝０．０１（ＭＰａ／％）とすると石炭に負荷する粉砕力が調整の度にＸnの変動の影響を受け変動し不安定であったため、Ａ＝０．００４（ＭＰａ／％）とすることで石炭に負荷する粉砕力を調整した。粒度分布Ｙnの調整は、実施例１と同様に行った。
In order to confirm what results are obtained when pulverized coal injection is performed using the particle size distribution measuring device 24 that does not satisfy the conditions of the present invention, the tuyere is 40 as in the example. The operation of blowing pulverized coal was carried out in the blast furnace.
When the particle size distribution measuring device 24 of the comparative example is used, since the variation of the particle size distribution measured value Xn is larger than that when the particle size distribution measuring device 40 is used, A = 0.01 (MPa /%) since grinding force load was unstable fluctuates under the influence of fluctuations in the X n each time adjustments to coal, to adjust the grinding force loading coal by the a = 0.004 (MPa /%) . The particle size distribution Y n was adjusted in the same manner as in Example 1.
実験結果であるＸn、Ｙn、Ｐnの推移を図１１に、微粉炭吹込み配管の閉塞本数を図１２に示す。
比較例の粒度分布測定装置２４を用いた場合には、粒度分布Ｘnの変動幅が４８±５％と実施例の場合よりも大きくなり、粒度分布Ｙnの変動幅もまた大きく、粒度分布測定装置２４のばらつき（測定値の安定性が低い）以上に、実際の微粉炭粒度の変動も大きいと推察される結果となった。
実施例と比較例の試験結果を表１に示す
FIG. 11 shows changes in X n , Y n , and P n as experimental results, and FIG. 12 shows the number of closed pulverized coal injection pipes.
When the particle size distribution measuring device 24 of the comparative example is used, the fluctuation range of the particle size distribution X n is 48 ± 5%, which is larger than that of the example, and the fluctuation range of the particle size distribution Y n is also large. As a result, it was assumed that the fluctuation of the actual pulverized coal particle size was larger than the variation of the measuring device 24 (the stability of the measured value was low).
Table 1 shows the test results of Examples and Comparative Examples.
理想では詰まり本数が０本／日であり、その場合に微粉炭比が［１５０ｋｇ／ｔ−溶銑］となるが、実施例では、１４日間の平均詰まり本数が０．３４本／日で、実質の微粉炭比が［１４９ｋｇ／ｔ−溶銑］と比較的良好であった。
一方、比較例では、１４日間の平均詰まり本数が３．６本／日で、実質の微粉炭比が［１３７ｋｇ／ｔ−溶銑］と低く、安価な微粉炭の使用量が減った上、閉塞した微粉炭吹込み配管の清掃作業の頻度が高く操業コストが高い結果であった。
このように、微粉炭粒度分布測定装置の測定値の安定性が１％以下の測定装置を用いて、微粉炭製造装置１６の石炭に負荷する粉砕力を調整することによって、微粉炭粒度を精度良く制御し微粉炭吹込み配管の閉塞を抑制し、実質的に微粉炭吹込み量を増やし低コストの高炉溶銑を製造できることが実証された。
Ideally, the number of clogs is 0 / day, in which case the pulverized coal ratio is [150 kg / t-molten metal], but in the examples, the average number of clogs for 14 days is 0.34 / day, The pulverized coal ratio of [149 kg / t-hot metal] was relatively good.
On the other hand, in the comparative example, the average number of clogs for 14 days was 3.6 / day, the actual pulverized coal ratio was as low as [137 kg / t-hot metal], and the amount of inexpensive pulverized coal used was reduced, and the blockage As a result, the frequency of cleaning the pulverized coal injection pipe was high and the operation cost was high.
In this way, the pulverized coal particle size distribution measuring device is used to adjust the pulverization force applied to the coal of the pulverized coal production device 16 by using a measuring device having a measurement value stability of 1% or less. It has been demonstrated that it can control well and suppress clogging of the pulverized coal injection pipe, substantially increase the amount of pulverized coal injection, and produce low-cost blast furnace hot metal.
なお、粒度分布測定装置の他の態様として、図１３に示す粒度分布測定装置４２のように、機械式サンプラー４１によって取り出した微粉炭を一時的に貯留するバッファタンク４７を設け、バッファタンク４７から吸入ノズル２５へフィーダ４９によって定量的に切出すようにしてもよい。このようにすれば、レーザ回折式粒度分布測定装置３５導入される分散飛翔状態の微粉炭濃度をより安定させることができる。フィーダ４９は、振動フィーダを用いると切出し量（供給量）の時間変動が少ないのでより好ましい。
この場合、フィーダ４９による供給量を調整することにより、微粉炭の吸入量を調節して、レーザ回折式粒度分布測定装置へ導入される微粉炭濃度を最適値になるように調製することもできる。
As another embodiment of the particle size distribution measuring device, a buffer tank 47 for temporarily storing the pulverized coal taken out by the mechanical sampler 41 is provided as in the particle size distribution measuring device 42 shown in FIG. The suction nozzle 25 may be quantitatively cut out by the feeder 49. In this way, the pulverized coal concentration in the dispersed flight state introduced by the laser diffraction particle size distribution measuring device 35 can be further stabilized. As the feeder 49, it is more preferable to use a vibration feeder because the amount of cutout (supply amount) varies little over time.
In this case, by adjusting the supply amount by the feeder 49, the amount of pulverized coal sucked can be adjusted, and the concentration of the pulverized coal introduced into the laser diffraction particle size distribution measuring device can be adjusted to an optimum value. .
１ ヤードにストックされた石炭
２ 石炭ホッパ
３ フィーダ
４ 微粉炭製造装置（従来例）
５ 微粉炭
６ 主管
７ バグフィルタ
８ コールビン
９ 吹込みタンク
１０ 分配器
１１ 枝管
１２ 高炉
１３ 羽口
１４ 熱風炉
１５ ブローパイプ
１６ 微粉炭製造装置（実施形態）
１７ スクリューフィーダ
１９ 搬送管
２１ ロータリーバルブ
２３ 中間タンク
２４ 粒度分布測定装置（比較例）
２５ 吸入ノズル
２７ 微粉炭気送装置
２９ 吸入管
３１ エジェクタ
３３ 窒素供給管
３５ レーザ回折式粒度分布測定装置
３７ ＰＣ（パーソナルコンピュータ）
３９ プロセスコンピュータ
４０ 粒度分布測定装置
４１ 機械式サンプラー
４２ 粒度分布測定装置（他の形態）
４３ ホッパ
４５ 吸入口
４７ バッファタンク
４９ フィーダ
５１ ローラータイヤ
５３ 油圧シリンダー
５５ 制御装置
５７ 粒度分級調整盤
５９ 排出口
６１ 温風供給管
６３ 装入部
６５ ターンテーブル
Coal stocked in 1 yard 2 Coal hopper 3 Feeder 4 Pulverized coal production equipment (conventional example)
5 Pulverized Coal 6 Main Pipe 7 Bag Filter 8 Coalbin 9 Blowing Tank 10 Distributor 11 Branch Pipe 12 Blast Furnace 13 Tuyere 14 Hot Blast Furnace 15 Blow Pipe 16 Pulverized Coal Production Equipment (Embodiment)
17 Screw Feeder 19 Transport Pipe 21 Rotary Valve 23 Intermediate Tank 24 Particle Size Distribution Measuring Device (Comparative Example)
25 Suction nozzle 27 Pulverized coal inflator 29 Suction pipe 31 Ejector 33 Nitrogen supply pipe 35 Laser diffraction particle size distribution measuring device 37 PC (personal computer)
39 Process computer 40 Particle size distribution measuring device 41 Mechanical sampler 42 Particle size distribution measuring device (other forms)
43 Hopper 45 Suction Port 47 Buffer Tank 49 Feeder 51 Roller Tire 53 Hydraulic Cylinder 55 Controller 57 Grain Size Adjustment Panel 59 Discharge Port 61 Hot Air Supply Pipe 63 Insertion Portion 65 Turntable
Claims (1)
前記微粉炭製造装置によって製造された微粉炭を搬送経路から取り出して粒度分布測定装置で周期的に測定する粒度分布測定工程と、該粒度分布測定工程で測定された測定値と目標値との偏差を用いて前記微粉炭製造装置における石炭粉砕力を調整する粉砕力調整工程とを有し、
前記粒度分布測定工程は、
前記バグフィルタと前記吹込みタンクとの間に設けられ、微粉炭を自然落下によって搬送する搬送管に取り付けられて該搬送管内を移動する微粉炭を採取する採取装置と、該採取装置によって採取された微粉炭を微粉炭気送装置によってレーザ回折式粒度分布測定装置に気送して前記レーザ回折式粒度分布測定装置で粒度分布を測定することを特徴とする微粉炭吹込み方法。
The pulverized coal produced by pulverizing the coal by the pulverized coal production apparatus is air-flow conveyed to the bag filter, the pulverized coal collected by the bag filter is stored in the colebin, and the pulverized coal stored in the colebine is blown into the tank. A pulverized coal blowing method using a pulverized coal blowing device that is cut into a gas flow toward the blast furnace tuyeres,
The pulverized coal produced by the pulverized coal production device is taken out of the conveyance path and periodically measured by the particle size distribution measuring device, and the deviation between the measured value and the target value measured in the particle size distribution measuring step A pulverization force adjusting step of adjusting the coal pulverization force in the pulverized coal production apparatus using
The particle size distribution measuring step includes
A sampling device that is provided between the bag filter and the blowing tank and that is attached to a transport pipe that transports the pulverized coal by natural fall and collects the pulverized coal that moves within the transport pipe, and is collected by the sampling device. A method for injecting pulverized coal, wherein the pulverized coal is fed to a laser diffraction type particle size distribution measuring device by a pulverized coal air feeding device and the particle size distribution is measured by the laser diffraction type particle size distribution measuring device .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011180594A JP5741319B2 (en) | 2011-08-22 | 2011-08-22 | Pulverized coal injection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011180594A JP5741319B2 (en) | 2011-08-22 | 2011-08-22 | Pulverized coal injection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2013043998A JP2013043998A (en) | 2013-03-04 |
| JP5741319B2 true JP5741319B2 (en) | 2015-07-01 |
Family
ID=48008141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2011180594A Active JP5741319B2 (en) | 2011-08-22 | 2011-08-22 | Pulverized coal injection method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5741319B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104745753B (en) * | 2015-03-26 | 2017-01-04 | 中国神华能源股份有限公司 | The blending method of a kind of pulverized coal injection into blast furna and pulverized coal injection into blast furna |
| JP6885282B2 (en) * | 2017-09-27 | 2021-06-09 | Ｊｆｅスチール株式会社 | Blast furnace operation method |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57101605A (en) * | 1980-12-16 | 1982-06-24 | Ishikawajima Harima Heavy Ind Co Ltd | Pulverized coal blower for blast furnace |
| JPH0650282B2 (en) * | 1986-01-30 | 1994-06-29 | 日機装株式会社 | Powder particle size online automatic analyzer |
| JP2528616B2 (en) * | 1993-11-24 | 1996-08-28 | 日機装株式会社 | Particle size analyzer |
| JPH08184548A (en) * | 1994-12-30 | 1996-07-16 | Horiba Ltd | Dry method particle size distribution measuring apparatus |
| EP1273901A1 (en) * | 2001-07-02 | 2003-01-08 | Université de Liège | Method and apparatus for automatic measurement of particle size and form |
| JP2005241480A (en) * | 2004-02-26 | 2005-09-08 | Jfe Steel Kk | Particle size distribution measurement device for pulverized coal, pulverized coal manufacturing system and blast furnace operation method |
| JP5541195B2 (en) * | 2011-02-24 | 2014-07-09 | Ｊｆｅスチール株式会社 | Method for measuring particle size distribution of pulverized coal |
-
2011
- 2011-08-22 JP JP2011180594A patent/JP5741319B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2013043998A (en) | 2013-03-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5365226B2 (en) | Sizing method of sintered ore aggregate | |
| JP5741319B2 (en) | Pulverized coal injection method | |
| WO2012115061A1 (en) | Powder supply apparatus and powder supply method | |
| JP2007175561A (en) | Apparatus for manufacturing pulverized coal and its method | |
| JP5541195B2 (en) | Method for measuring particle size distribution of pulverized coal | |
| JP6973321B2 (en) | Manufacturing method of pulverized coal for blast furnace blowing and its manufacturing equipment | |
| JP2020012132A (en) | Quality control method of blast furnace coke | |
| JP7183648B2 (en) | Pulverized coal blowing method | |
| JP2004035913A (en) | Method and device for controlling blowing of granular powder | |
| JP2005241480A (en) | Particle size distribution measurement device for pulverized coal, pulverized coal manufacturing system and blast furnace operation method | |
| JP2016113664A (en) | Airflow conveyance method of powdered coal, and powdered coal blowing method into blast furnace | |
| JP5469938B2 (en) | Manufacturing apparatus and manufacturing method of inorganic spheroidized particles | |
| JP7087534B2 (en) | How to perform PCI stably | |
| JP3513735B2 (en) | Char transfer device | |
| JP3209029B2 (en) | Granulation method of sintering raw material | |
| CN214988735U (en) | Limestone conveying device for desulfurization of incinerator | |
| KR100722383B1 (en) | Device for controlling vibration in pulverizer mill and controlling method thereof | |
| JP2008014504A (en) | Method and system for recycling coarse particle recovered from fluidized bed boiler fuel manufacturing and supplying equipment | |
| CN106276316B (en) | The system and method that powder crushes | |
| KR20130035765A (en) | Pulverized coal feeding system | |
| JP4088615B2 (en) | Pulverized coal fuel supply device | |
| JP3721090B2 (en) | Air flow transportation method of pulverized coal | |
| JP2024007329A (en) | Operation method for blast furnace and pulverized coal for blowing in blast furnace | |
| JP3863359B2 (en) | Blow operation method | |
| JP2003171014A (en) | Powder and particle processing apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20140220 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20150126 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20150203 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20150306 |
|
| 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: 20150331 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20150413 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5741319 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| 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 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |