JPH0913110A - Permeability evaluation method of charging layer in vertical furnace - Google Patents
Permeability evaluation method of charging layer in vertical furnaceInfo
- Publication number
- JPH0913110A JPH0913110A JP16342095A JP16342095A JPH0913110A JP H0913110 A JPH0913110 A JP H0913110A JP 16342095 A JP16342095 A JP 16342095A JP 16342095 A JP16342095 A JP 16342095A JP H0913110 A JPH0913110 A JP H0913110A
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- furnace
- raw material
- charged
- pressure
- charge
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、竪型炉における装入
物層の通気性評価法に関し、高炉操業などの竪型炉操業
において、操業安定化のための重要な指針である装入物
層の通気性を的確に評価しようとするものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating the permeability of a charge layer in a vertical furnace, and is an important guideline for stabilizing operation in a vertical furnace operation such as a blast furnace operation. It is intended to accurately evaluate the breathability of the layer.
【０００２】[0002]
【従来の技術】近年、高炉の稼働基数の低下に伴い、残
存高炉での出銑比を増加し、溶銑コストを削減するため
に、安価な細粒原料の使用量が増大しているが、これに
伴い、高炉に装入される鉄原料の通気性の厳密な管理が
重要となっている。というのは、出銑比の増加により、
炉内を通過するガス量が増大し、高炉上部での圧力損失
が増大するが、このような過度な圧力損失の増加は、装
入物の流動化、吹き抜け等を生じ、炉頂ガス利用率の変
動、装入物の降下不順、棚吊りなどの高炉操業上の問題
を惹起するからである。2. Description of the Related Art In recent years, with the decrease in the number of operating blast furnaces, the amount of inexpensive fine-grain raw materials has been increased in order to increase the tap ratio in the remaining blast furnace and reduce the hot metal cost. Along with this, it is important to strictly control the air permeability of the iron raw material charged into the blast furnace. Because the increase in the tap ratio,
The amount of gas passing through the furnace increases and the pressure loss in the upper part of the blast furnace increases.However, such an excessive increase in pressure loss causes fluidization of the charging material, blow-through, etc. This causes problems in blast furnace operation, such as fluctuations in temperature, irregular descent of charges, and hanging.
【０００３】特に、鉄原料を製造している焼結工場にお
ける工程変動によって、装入原料の通気性が変動した場
合には、その変動が高炉の操業変動を引き起こすため、
通気性の変動は事前に検知、制御する必要がある。ま
た、安価な細粒原料を多量に使用した場合には、同一の
炉内通過ガス量でも生じる圧力損失が大きくなるため、
原料の通気変動が同様に高炉の操業変動を引き起こす。In particular, when the gas permeability of the charging raw material changes due to the process variation in the sintering plant producing the iron raw material, the variation causes the operation variation of the blast furnace.
Fluctuations in breathability must be detected and controlled in advance. Further, when a large amount of inexpensive fine-grain raw material is used, the pressure loss that occurs even with the same amount of gas passing through the furnace increases,
Fluctuations in raw material aeration also cause fluctuations in blast furnace operation.
【０００４】さて、高炉に装入される原料は大別する
と、焼結鉱、塊鉱石、ペレットなどの鉄原料とコークス
等の副原料に区分される。一般に、鉄原料は副原料に比
較して粒径が小さいことから、高炉上部塊状体すなわち
炉内表層部における通気性を支配する主要因となってい
る。従って、炉内において、装入物の通気性の変動に起
因する高炉操業の変動を防止するには、鉄原料の通気性
を的確に評価することが重要になる。The raw materials charged into the blast furnace are roughly classified into iron raw materials such as sinter, lump ore and pellets and auxiliary raw materials such as coke. In general, the iron raw material has a smaller particle size than the auxiliary raw material, and thus is a main factor controlling the air permeability in the blast furnace upper mass, that is, in the surface layer of the furnace. Therefore, in order to prevent fluctuations in the operation of the blast furnace due to fluctuations in the air permeability of the charge inside the furnace, it is important to accurately evaluate the air permeability of the iron raw material.
【０００５】鉄原料の通気性が高炉操業に及ぼす影響
は、従来から良く知られている。例えば、鉄鋼便覧（鉄
鋼便覧第３版、II、製銑、製鋼編、 P.251〜252)では、
高炉の通気性に及ぼす焼結鉱粒度の影響が開示され、高
炉の生産性向上のため、高炉鉱石槽下に篩を設置し、篩
い分けを行うことにより、下限粒度を管理する例が報告
されている。また、高炉装入時や炉内での破壊ならびに
製鉄所内での輸送および処理過程での破砕を防止するた
めの落下強度、回転強度等の冷間強度の管理が示されて
いる。なお、従来の鉄原料の通気性の管理は、焼結工場
における２〜８時間毎の製品のサンプリングあるいは高
炉鉱石槽下における１回／日のサンプリングによる粒
度、強度測定に基づき行っていた。The effect of the air permeability of the iron raw material on the operation of the blast furnace has been well known. For example, in the Iron and Steel Handbook (Iron and Steel Handbook 3rd Edition, II, Ironmaking, Steelmaking Edition, P.251-252),
The effect of the particle size of the sintered ore on the air permeability of the blast furnace is disclosed.In order to improve the productivity of the blast furnace, an example of controlling the lower limit particle size by installing a sieve under the blast furnace ore tank and performing sieving has been reported. ing. Also, the control of cold strength such as drop strength and rotation strength is shown to prevent destruction during blast furnace charging, inside the furnace, and crushing during transportation and processing in the steel mill. In addition, the conventional control of air permeability of the iron raw material was performed based on the measurement of particle size and strength by sampling the product every 2 to 8 hours in a sintering plant or once per day in the blast furnace ore tank.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、従来法
に従う通気性の管理は、高炉側から見た場合に、以下の
ような問題を抱えていた。 (1) 測定が間欠的なだけでなく、測定対象とする鉱石が
通常20槽ある鉱石槽のうちの１〜２槽のみであるため、
鉱石装入物の全体の通気性の変化を知ることが難しい。
また、測定に多大な要員と費用を必要とする。 (2) 装入前の原料の測定では、炉頂装入系での原料の粉
化あるいは炉内へ装入後の堆積状態に起因した通気性の
悪化を知ることができない。However, the control of air permeability according to the conventional method has the following problems when viewed from the blast furnace side. (1) Not only the measurement is intermittent, but the ore to be measured is only 1 or 2 of the 20 ore tanks,
It is difficult to see changes in the overall permeability of the ore charge.
Also, the measurement requires a large number of personnel and costs. (2) In the measurement of the raw material before charging, it is not possible to know the deterioration of the air permeability due to the pulverization of the raw material in the furnace top charging system or the accumulation state after charging into the furnace.
【０００７】なお、炉内装入物の通気性を知る方法とし
ては、たとえば特公昭55-38004号公報に開示されている
ように、高さ方向に複数のシャフト圧力計を設置し、得
られた圧力損失から装入物の通気抵抗を測定する方法が
知られている。しかしながら、上記した従来法で測定さ
れる圧力損失は、炉内ガス量の変動、測定場所のガス温
度など多くの外乱要因を含んでいるため、装入物自体の
通気性、その結果としての堆積層の安定性を評価するこ
とは困難であった。As a method for determining the air permeability of the interior of the furnace, a plurality of shaft pressure gauges are installed in the height direction, as disclosed in, for example, Japanese Patent Publication No. 55-38004. It is known to measure the ventilation resistance of the charge from the pressure drop. However, since the pressure loss measured by the above-mentioned conventional method includes many disturbance factors such as fluctuations in the amount of gas in the furnace and gas temperature at the measurement location, the permeability of the charge itself, and the resulting accumulation of deposits. It was difficult to assess the stability of the layers.
【０００８】この発明は、上記の問題を有利に解決する
もので、装入物自体の通気性およびその結果としての堆
積層の安定性を的確に評価することができる竪型炉にお
ける装入物層の通気性評価法を提案することを目的とす
る。The present invention advantageously solves the above-mentioned problems, and the charge in a vertical furnace capable of accurately evaluating the air permeability of the charge itself and the resulting stability of the deposited layer. The purpose is to propose a method for evaluating the breathability of layers.
【０００９】[0009]
【課題を解決するための手段】さて発明者らは、上記の
目的を達成すべく、高炉上部に設けた炉内観察装置を用
いて炉内堆積層の挙動を詳細に観察したところ、炉内に
通気性の悪い原料が装入された場合には、装入物の堆積
角が低下すると共に高炉中心部へ原料が流れ込む現象が
観察された。従って、装入物層の通気性を判断するに
は、装入物自体の通気性のみならず、炉内における堆積
形状の変化に起因した通気抵抗の変化を正確に把握する
ことが重要である。この発明は、上記の知見に立脚する
ものである。Means for Solving the Problems In order to achieve the above object, the inventors observed the behavior of the in-reactor deposited layer in detail using an in-reactor observation device provided in the upper part of the blast furnace. When a raw material having poor air permeability was charged into the furnace, it was observed that the deposition angle of the charged material decreased and the raw material flowed into the center of the blast furnace. Therefore, in order to judge the air permeability of the charge layer, it is important to accurately grasp not only the air permeability of the charge itself but also the change in the air flow resistance due to the change in the deposition shape in the furnace. . The present invention is based on the above findings.
【００１０】すなわち、この発明は、竪型炉に装入され
た原料装入物層の通気性を評価するに当たり、基準装入
物表面からの距離が炉口半径の 1.5倍以内の位置におけ
る炉内圧力と炉頂部空間の圧力との差圧を直接測定し、
得られた値とサウンジングで測定した実際の装入物表面
の位置に基づいて炉内に装入された装入物層の通気性を
判断することを特徴とする竪型炉における装入物層の通
気性評価法である。That is, according to the present invention, in evaluating the air permeability of the raw material charge layer charged in the vertical furnace, the furnace at a position where the distance from the standard charge surface is within 1.5 times the radius of the furnace opening is used. Directly measure the differential pressure between the internal pressure and the pressure in the furnace top space,
Charge layer in a vertical furnace characterized by determining the air permeability of the charge layer charged into the furnace based on the obtained value and the actual position of the charge surface measured by sounding Is a method for evaluating air permeability.
【００１１】この発明において、差圧の測定に当たって
は、竪型炉の円周方向にわたる複数の位置で測定するこ
とが好ましい。In the present invention, it is preferable to measure the differential pressure at a plurality of positions in the circumferential direction of the vertical furnace.
【００１２】また、この発明において、竪型炉が高炉で
ある場合には、炉頂差圧の測定を、鉄原料装入から３分
以内に行うことが有利である。Further, in the present invention, when the vertical furnace is a blast furnace, it is advantageous to measure the differential pressure at the top of the furnace within 3 minutes after charging the iron raw material.
【００１３】[0013]
【作用】以下、この発明に従う装入物層の通気性評価法
を従来法と比較して説明する。図１に、この発明に従う
装入物通気抵抗指数の測定、算出要領を、また図２に
は、従来法に従う装入物通気抵抗指数の測定、算出要領
をそれぞれ示す。まず、従来法に従うシャフト圧力計に
よる装入物通気抵抗指数の測定、算出要領を、図２に基
づいて説明する。図２では、高炉シャフト１の基準装入
物表面からの距離Ｌの位置に取付けたシャフト圧力計２
によって装入物層の圧力Ｐ2 を測定し、データ収録・演
算装置３にてデータを収録する。ここで基準装入物表面
とは、炉口部上部に設けられる基準面である。一方、炉
頂部の排ガス流路であるアップテイク４に取付けた炉頂
圧力計５を用いて炉頂部空間の圧力Ｐ1 を測定し、同様
にデータ収録・演算装置３にてデータを収録する。さら
に、このデータ収録・演算装置３では、各圧力Ｐ1,Ｐ2
の30秒間隔の定時測定結果を用いて、平均の圧力さらに
はその結果から炉頂部の圧力差ΔＰを算出すると共に、
炉頂温度計６によって測定した炉頂部空間の温度から高
炉炉頂部の平均炉口ガス速度を算出し、これらの値から
装入物通気抵抗指数Ｋを求める。The method for evaluating the air permeability of the charging layer according to the present invention will be described below in comparison with the conventional method. FIG. 1 shows the measurement and calculation procedure of the charge ventilation resistance index according to the present invention, and FIG. 2 shows the measurement and calculation procedure of the charge ventilation resistance index according to the conventional method. First, the procedure for measuring and calculating the charge ventilation resistance index by the shaft pressure gauge according to the conventional method will be described with reference to FIG. In FIG. 2, a shaft pressure gauge 2 mounted at a distance L from the surface of the standard charge of the blast furnace shaft 1
The pressure P 2 of the charging layer is measured by and the data is recorded by the data recording / calculating device 3. Here, the reference charge surface is a reference surface provided at the upper part of the furnace opening. On the other hand, the pressure P 1 in the furnace top space is measured using the furnace top pressure gauge 5 attached to the uptake 4, which is the exhaust gas flow path at the furnace top, and data is recorded by the data recording / calculation device 3 in the same manner. Further, in the data recording / calculating device 3, the pressures P 1 , P 2
The average pressure and the pressure difference ΔP at the top of the furnace are calculated from the 30-second regular measurement results, and
From the temperature in the furnace top space measured by the furnace top thermometer 6, the average gas velocity at the furnace top of the blast furnace is calculated, and the charge ventilation resistance index K is determined from these values.
【００１４】従来は、上記のような手順で装入物通気抵
抗指数Ｋを求め、これによって通気性を評価していたの
であるが、かような方法では、必ずしも満足いくほど厳
密に通気性を評価することはできなかった。そこで、そ
の原因を解明すべく検討を重ねた結果、その原因は (1) シャフト圧力計の取付け位置および (2) 実際の装入物表面と基準装入物表面とのずれ にあることを究明した。Conventionally, the charge ventilation resistance index K was obtained by the above-mentioned procedure, and the air permeability was evaluated by this. However, in such a method, the air permeability is strict enough to be satisfied. It could not be evaluated. Therefore, as a result of repeated studies to clarify the cause, it was clarified that the cause was (1) the mounting position of the shaft pressure gauge and (2) the difference between the actual charge surface and the reference charge surface. did.
【００１５】まず、上記の原因(1) について説明する
と、シャフト圧力計は、シャフト上部に取り付けられ、
その装入物表面（ただし基準装入物表面）からの距離Ｌ
は、通常炉口部の半径Ｒの 1.5倍よりも大きい。すなわ
ち、シャフト圧力計の取り付け位置は、通常、炉体の冷
却装置であるステーブ７に設けられた圧力測定口であ
り、Ｌ＞1.5 Ｒである。しかしながら、この領域での圧
力損失は、装入物の平均温度に左右されるため、高炉炉
頂部の昇温挙動に影響され易い圧力損失しか得られな
い。このため、鉱石、コークス等の装入物８の装入物通
気抵抗指数を従来法で算出しても、高炉の操業状態に影
響されたバラツキの大きいデータしか得られない。ま
た、各圧力の絶対値を測定し、その測定結果から圧力差
ΔＰを算出しているので、測定誤差、データ採取タイミ
ングによるデータのバラツキが極めて大きい。たとえ
ば、炉頂部での代表的な圧力は0.30MPa であるのに対し
て、シャフト上部における圧力差は0.015MPa程度であ
り、圧力の測定精度が問題となる。First, the cause (1) will be explained. The shaft pressure gauge is attached to the upper part of the shaft.
Distance L from the surface of the charge (however, the surface of the standard charge)
Is usually greater than 1.5 times the radius R of the furnace mouth. That is, the mounting position of the shaft pressure gauge is usually a pressure measurement port provided in the stave 7 which is a cooling device for the furnace body, and L> 1.5R. However, since the pressure loss in this region depends on the average temperature of the charge, only the pressure loss that is easily affected by the temperature rising behavior of the blast furnace furnace top is obtained. For this reason, even if the charge ventilation resistance index of the charge 8 such as ore and coke is calculated by the conventional method, only data having large variations affected by the operating state of the blast furnace can be obtained. In addition, since the absolute value of each pressure is measured and the pressure difference ΔP is calculated from the measurement result, there are extremely large variations in data due to measurement errors and data collection timing. For example, the typical pressure at the top of the furnace is 0.30 MPa, whereas the pressure difference at the upper part of the shaft is about 0.015 MPa, which poses a problem of pressure measurement accuracy.
【００１６】次に、上記の原因(2) について説明する
と、従来は測定基準位置として、基準装入表面を設定
し、操業中における装入面の変動にかかわりなく、この
基準装入面からシャフト圧力計取り付け位置までの距離
を一定値Ｌとして演算に利用していたので、実際の装入
面の変動による誤差が大きかった。Next, the cause (2) will be explained. Conventionally, the reference charging surface is set as the measurement reference position, and the shaft is moved from this reference charging surface regardless of the fluctuation of the charging surface during the operation. Since the distance to the pressure gauge mounting position was used for the calculation as the constant value L, the error due to the actual fluctuation of the charging surface was large.
【００１７】これに対し、この発明では以下の要領で装
入物の通気抵抗指数を算出することにより、上記の問題
を解決する。高炉シャフト１に取り付けたシャフト圧力
計２の導圧管をシャフト微差圧計９に導くと同時に、炉
頂部の排ガス流路であるアップテイク４に取付けた炉頂
圧力計５の導圧管をシャフト微差圧計９に導き、この微
差圧計９により両者の圧力差ΔＰを直接測定し、データ
収録・演算装置３にてデータ収録する。このデータ収録
・演算装置３では、さらに、装入物の表面位置を測定す
るサウンジング10による測定結果および炉頂温度６の測
定結果も同時に取り込んで、装入物通気抵抗指数Ｋを算
出する。この発明では、上述したように、差圧の直接測
定により測定に伴う誤差を少なくすると同時に、距離Ｌ
として通常の基準装入面と圧力計の距離ではなく、サウ
ンジング10で測定した実際の装入面とシャフト圧力計と
の距離Ｌs を用いて、圧力勾配ΔＰ／Ｌの精度を向上さ
せ得るので、従来に比し、炉頂に装入された装入物の通
気抵抗を精度良く評価することができるのである。On the other hand, the present invention solves the above problem by calculating the ventilation resistance index of the charging material in the following manner. At the same time as introducing the pressure guiding pipe of the shaft pressure gauge 2 attached to the blast furnace shaft 1 to the shaft fine differential pressure gauge 9, the pressure guiding pipe of the furnace top pressure gauge 5 attached to the uptake 4 which is the exhaust gas passage at the top of the furnace is used to make the shaft fine difference. The pressure difference ΔP between the two is directly measured by the fine pressure gauge 9 and the data is recorded by the data recording / calculating device 3. The data recording / calculating device 3 further incorporates the measurement result of the sounding 10 for measuring the surface position of the charge and the measurement result of the furnace top temperature 6 at the same time to calculate the charge ventilation resistance index K. In the present invention, as described above, the error due to the measurement is reduced by the direct measurement of the differential pressure, and at the same time, the distance L
Since the distance Ls between the actual charging surface and the shaft pressure gauge measured by the sounding 10 is used instead of the normal distance between the standard charging surface and the pressure gauge, the accuracy of the pressure gradient ΔP / L can be improved. Compared with the conventional method, it is possible to evaluate the ventilation resistance of the charging material charged on the furnace top with higher accuracy.
【００１８】ところで、シャフト上部の微差圧は、円周
方向における原料の堆積の不均一性および装入される鉱
石、コークスの割合の不均一性により、円周方向で異な
る値を示す。従って、これら円周方向の装入物通気抵抗
の不均一性を評価するために、円周方向の複数の位置に
圧力計９を設け、同様にデータ収録・演算装置で処理す
ることが望ましい。Incidentally, the slight differential pressure at the upper part of the shaft shows different values in the circumferential direction due to the non-uniformity of the deposition of the raw material in the circumferential direction and the non-uniformity of the ratio of the ore and coke charged. Therefore, in order to evaluate the non-uniformity of the charged material ventilation resistance in the circumferential direction, it is desirable to provide the pressure gauges 9 at a plurality of positions in the circumferential direction and similarly process them by the data recording / calculating device.
【００１９】次に、図３(a), (b)にそれぞれ、炉の高さ
方向の圧力損失および圧力勾配について調べた結果を示
す。実験は、２次元の層構造を考慮したガス流れ、伝熱
計算モデルを用い、小型の高炉模型により実施した。図
中、破線は通常の原料を使用した場合、また実線は安価
な細粒原料を炉頂部に装入し装入物８が平坦化した場合
の計算結果である。安価な細粒原料の装入により、炉上
部の通気抵抗が増大する。同時に、装入物の表面が平坦
化し、炉上部極く表面近傍の通気抵抗が増大する。この
ような高さ方向の圧力の両条件での差は、高炉下部にな
るにしたがって減少する。これは、圧力損失に対して、
ガスの流速を支配する温度の変化が主要因となるため、
装入物自体の炉頂での通気性の影響が小さくなることに
起因している。Next, FIGS. 3 (a) and 3 (b) show the results of examining the pressure loss and pressure gradient in the height direction of the furnace, respectively. The experiment was carried out by a small blast furnace model using a gas flow and heat transfer calculation model considering a two-dimensional layered structure. In the figure, the broken line is a calculation result when a normal raw material is used, and the solid line is a calculation result when an inexpensive fine-grain raw material is charged at the furnace top and the charge 8 is flattened. The charging of inexpensive fine-grain raw materials increases the ventilation resistance in the upper part of the furnace. At the same time, the surface of the charge is flattened, and the ventilation resistance near the surface of the upper part of the furnace is increased. The difference between the pressure in the height direction and the pressure in the height direction decreases toward the lower part of the blast furnace. This is
Since the change in temperature that governs the gas flow rate is the main factor,
This is because the effect of air permeability at the furnace top of the charge itself is reduced.
【００２０】同図から明らかなように、炉頂部における
原料の通気性の差を検出するには、Ｌ＜7.5 ｍの位置す
なわちＬ＜1.5 Ｒを満足する位置に圧力計を設置するこ
とが肝要である。とくに、Ｌ＜1.0 Ｒでは、より一層感
度よく炉頂部の原料の通気性の差を検出することができ
る。ここに、Ｌ＝1.5 Ｒの範囲は、だいたい装入物の７
層分に相当する。従って、換言すると、炉頂部における
原料の通気性を的確に評価するには、装入物表面から７
層分以内の炉内圧と炉頂圧との差圧を利用することが重
要といえる。As is apparent from the figure, it is essential to install a pressure gauge at a position of L <7.5 m, that is, a position satisfying L <1.5 R in order to detect the difference in the air permeability of the raw materials at the furnace top. Is. Particularly, when L <1.0 R, the difference in the air permeability of the raw material at the furnace top can be detected with even higher sensitivity. Here, the range of L = 1.5 R is about 7 of the charge.
Equivalent to a layer. Therefore, in other words, in order to accurately evaluate the air permeability of the raw material at the furnace top, it is necessary to measure
It can be said that it is important to utilize the differential pressure between the furnace internal pressure and the furnace top pressure within a layer.
【００２１】図４に、炉頂微差圧計による測定結果の一
例を示す。なお、微差圧計は、ストックラインを基準と
し、この基準面から 5.0ｍの位置すなわちＬ＝1.0 Ｒの
位置に設置した。炉頂微差圧計の測定結果は、鉱石、コ
ークスの装入タイミングに伴う装入面の変化、サウンジ
ングで測定された装入物表面位置の装入物降下による変
化、装入された原料の炉頂での昇温および鉱石、コーク
スの通気抵抗の変化により周期的な変化を示す。すなわ
ち、鉱石、コークスの装入と共に炉頂温度が低下し、そ
の後、下部からの高温のガスによる昇温の結果、炉頂温
度が再度上昇し始める。装入物の表面はほぼ規則的に低
下し、所定の位置、本例では−1.0mになった段階で原料
が再装入され、装入物面が回復する。炉頂微差圧すなわ
ち圧力損失は、鉱石装入時に急激に上昇し、その後装入
物の降下と共に低下する。FIG. 4 shows an example of the measurement result by the furnace top differential pressure gauge. The differential pressure gauge was set at a position 5.0 m from this reference plane, that is, a position of L = 1.0 R, with the stock line as a reference. The measurement result of the furnace top differential pressure gauge is the change of the charging surface with the charging timing of ore and coke, the change of the charging surface position measured by sounding due to the dropping of the charging material, and the charging of the charged raw material in the furnace. It shows a periodical change due to the temperature rise at the top and changes in the ventilation resistance of ore and coke. That is, the furnace top temperature decreases as the ore and coke are charged, and then the furnace top temperature begins to rise again as a result of the temperature increase by the hot gas from the lower part. The surface of the charging material is lowered almost regularly, and the raw material is recharged at a predetermined position, in this example, at the stage of -1.0 m, and the charging surface is recovered. The furnace top differential pressure difference, that is, the pressure loss, rises sharply during ore charging and then decreases as the charge drops.
【００２２】ところで、鉱石装入後、約３分経過後にガ
スが集中している高炉炉中心部の鉱石層が加熱され炉頂
温度が上昇し始めるが、この炉頂温度の上昇に伴い、鉱
石層を流れるガスの流速が増加し、装入物が降下してい
るにもかかわらず、圧力損失の減少が停滞し、炉頂温度
の変化次第ではコークス装入前に圧力損失が上昇し始め
る。鉱石層の通気抵抗に比べるとコークス層の通気抵抗
は通常１／３程度であり、コークス層装入時の圧力損失
の上昇はそれほど大きくない。一方、鉱石層を通過する
ガスの温度は上昇し続けるため、圧力損失全体としては
緩やかに上昇し続ける。その後、約10分後に再度鉱石を
装入すると圧力損失が急上昇し、以後は同様な経過をた
どる。By the way, about 3 minutes after ore charging, the ore layer in the center of the blast furnace where the gas is concentrated is heated and the furnace top temperature starts to rise. With the rise of the furnace top temperature, the ore Although the flow velocity of the gas flowing through the bed increases and the charge drops, the decrease in pressure loss stagnates, and depending on the change in the furnace top temperature, the pressure loss begins to increase before charging the coke. Compared with the ventilation resistance of the ore layer, the ventilation resistance of the coke layer is usually about 1/3, and the increase in pressure loss when charging the coke layer is not so large. On the other hand, since the temperature of the gas passing through the ore layer continues to rise, the pressure loss as a whole continues to rise gradually. After about 10 minutes, when the ore was charged again, the pressure loss increased sharply and the same process was followed.
【００２３】さらに、これらの、炉頂温度：Ｔ（℃) 、
炉頂圧力：Ｐ1 (MPa) 、圧力損失：ΔＰ(MPa) 、装入面
と炉頂微差圧計取り付け位置間の距離：Ｌs(m)、炉頂ガ
ス量：Ｖ(Nm3/s) を用いて装入物の通気抵抗指数Ｋを次
式(1) に従い計算した。得られた結果を、図４に併記す
る。Further, these furnace top temperatures: T (° C.),
Furnace top pressure: P 1 (MPa), pressure loss: ΔP (MPa), distance between charging surface and furnace top fine differential pressure gauge mounting position: Ls (m), furnace top gas amount: V (Nm 3 / s) The ventilation resistance index K of the charging material was calculated by using the following equation (1). The obtained results are also shown in FIG.
【数１】 (Equation 1)
【００２４】同図に示したように、通気抵抗指数Ｋは、
鉱石装入後約３分間はほぼ一定の値を示すが、その後は
コークス層の装入に伴う装入面の変化、装入物の温度上
昇によるガス流速の変化により異なった値を示す。装入
物の昇温は下部から温度が上昇する非定数的な変化であ
り、炉頂温度Ｔではその効果を評価し、真の通気抵抗指
数を求めることは困難である。従って、装入物の温度上
昇の影響を受けない装入物の通気抵抗指数Ｋを求めるに
は、鉱石層装入後約３分以内の一定値を示す間にＫ値を
求めればよい。この通気抵抗指数には、その測定原理か
ら明らかなように、装入物、特に鉱石層の通気抵抗と、
炉頂に装入された際の半径方向への粒度の偏析の効果、
および炉頂での装入物の表面定常の変化、例えば装入物
の中心への流れ込み等の効果が含まれている。As shown in the figure, the ventilation resistance index K is
The value is almost constant for about 3 minutes after charging the ore, but after that, the value changes depending on the change of the charging surface due to the charging of the coke layer and the change of the gas flow velocity due to the temperature rise of the charging material. The temperature rise of the charging material is a non-constant change in which the temperature rises from the bottom, and it is difficult to evaluate the effect and obtain the true ventilation resistance index at the furnace top temperature T. Therefore, in order to obtain the airflow resistance index K of the charged material which is not affected by the temperature rise of the charged material, the K value may be calculated while it shows a constant value within about 3 minutes after the charging of the ore layer. This ventilation resistance index, as is clear from the measurement principle, the ventilation resistance of the charge, especially the ore layer,
Effect of particle size segregation in the radial direction when charged at the furnace top,
And effects of surface steady changes of the charge at the furnace top, such as the flow of charge into the center.
【００２５】かくして、出銑比の増加、溶銑コスト削減
のための安価な細粒原料の使用の際に要求される装入物
の通気性を厳密に管理できるようになる。すなわち、こ
の発明を適用することにより、迅速に装入物、特に鉱石
の通気性の変化を検出し、高炉の操業変動を引き起こさ
ない迅速な装入物分布制御、あるいは、細粒原料配合量
の変更が可能になるのである。なお、装入物の分布制御
は、炉頂装入装置としてベルレス装入装置を用いること
によって容易に達成することができる。すなわち、ベル
レス装入装置を用いれば、細粒原料を半径方向および円
周方向の任意の位置に装入することができるので、炉頂
部での装入物の通気抵抗を検出し、細粒原料の配合量に
フィードバックすると共に、ベルレス装入パターンを最
適化することにより鉱石層の通気性を改善することが可
能になるのである。Thus, it becomes possible to strictly control the air permeability of the charge required when using an inexpensive fine grain raw material for increasing the tap ratio and reducing the hot metal cost. That is, by applying the present invention, the charge, particularly the change in the permeability of the ore is detected quickly, the charge distribution is controlled quickly without causing fluctuations in the operation of the blast furnace, or the amount of the fine-grain raw material is adjusted. It can be changed. The distribution control of the charged material can be easily achieved by using a bellless charging device as the furnace top charging device. That is, if the bellless charging device is used, the fine-grain raw material can be charged at any position in the radial direction and the circumferential direction. Therefore, the ventilation resistance of the charge at the furnace top is detected, and the fine-grain raw material is detected. It is possible to improve the air permeability of the ore layer by feeding back the blending amount and optimizing the bellless charging pattern.
【００２６】[0026]
【実施例】この発明を、内容積：4000m3、日産：8000t/
d の生産量を有する高炉に適用した場合を、従来の場合
と比較した。なお、この高炉は、炉頂装入装置として並
列ホッパー型のベルレス装入装置を有する大型高炉であ
る。高炉の炉半径は5.0mであり、従来は、シャフト圧力
計を装入面から9.5mの位置（Ｌ＝1.9 Ｒ）に設置し、図
２に示したように圧力の絶対値を測定して炉頂近傍の圧
力損失を算出していた。この従来法によれば、長期間
（１月）の平均値的には、装入物の粒径の変化などの装
入原料の通気性の変化に対応する変化を示したが、各デ
ータ間でのバラツキが大きく、日毎や週単位で操業管理
を行うことはできなかった。[Examples] The present invention has an internal volume of 4000 m 3 and a daily production of 8000 t /
The case of application to a blast furnace with a production amount of d is compared with the conventional case. This blast furnace is a large blast furnace having a parallel hopper type bellless charging device as a furnace top charging device. The furnace radius of the blast furnace is 5.0 m. Conventionally, a shaft pressure gauge was installed at a position 9.5 m from the charging surface (L = 1.9 R), and the absolute pressure value was measured as shown in FIG. The pressure loss near the furnace top was calculated. According to this conventional method, the average value for a long period (January) showed changes corresponding to changes in the air permeability of the charging raw material such as changes in the particle size of the charging. There was a large variation in the plant, and it was not possible to manage the operation on a daily or weekly basis.
【００２７】これに対し、この発明では、シャフト上部
装入面から５m の位置（Ｌ＝1.0 Ｒ）で、円周方向の４
箇所に微差圧計を設置し、炉頂圧力との差圧の直接測定
を実施した。なお、この実施例の期間中、コークス比、
出銑比等の他の操業条件は従来法とほぼ同一とした。図
５に、得られた結果を示す。従来法では、細粒原料使用
量を６％から12％に増大させると操業の安定度を示す通
気抵抗変動が増大し、それ以上の使用量増大が困難にな
ったが、８月からこの発明法に切り換えたところ、通気
抵抗の変動が減少し、９月までに細粒原料使用量を18％
まで増大させることができた。さらに、10月からは円周
方向４箇所に設けられた微差圧計を用いて円周方向の通
気性の変化を検出、ベルレス装入装置の装入開始位置を
制御することにより、円周方向の不均一性を解消したと
ころ、最終的にては20％まで細粒原料の使用量を増大す
ることができた。On the other hand, in the present invention, at a position 5 m (L = 1.0 R) from the upper loading surface of the shaft, 4 in the circumferential direction.
A fine differential pressure gauge was installed at the location, and the differential pressure from the furnace top pressure was directly measured. During the period of this example, the coke ratio,
Other operating conditions such as tap ratio are almost the same as the conventional method. The results obtained are shown in FIG. In the conventional method, when the amount of the fine grain raw material used was increased from 6% to 12%, the fluctuation of the ventilation resistance, which indicates the stability of the operation, increased, and it became difficult to further increase the amount used. After switching to the law, fluctuations in ventilation resistance decreased, and the amount of fine-grain raw material used was 18% by September.
Could be increased to. In addition, from October, changes in air permeability in the circumferential direction will be detected using fine differential pressure gauges installed at four locations in the circumferential direction, and the charging start position of the bellless charging device will be controlled to enable the circumferential direction to be measured. After eliminating the non-uniformity, the amount of fine-grain raw material used could be increased to 20%.
【００２８】[0028]
【発明の効果】かくして、この発明によれば、高出銑比
操業における装入原料の通気性を厳密に管理することが
できるので、安定した高炉操業ひいては安定した生産量
の増大を実現できる。また、高出銑比操業が可能になる
ことにより、高炉稼働基数の削減、労働生産性の向上、
固定費の削減が可能になる。さらに、同一の生産性を維
持したままで、細粒原料の使用量の増大が可能になり、
この細粒原料の使用量増大により、焼結工場で粉原料に
コークスを添加して再焼成を行うなどの必要がなくなる
ので、顕著な経済的なメリットを享受することができ
る。As described above, according to the present invention, it is possible to strictly control the air permeability of the charging raw material in the operation of high output ratio, so that the stable operation of the blast furnace and the stable increase of the production amount can be realized. In addition, by enabling the operation of high output ratio, it is possible to reduce the number of operating blast furnaces, improve labor productivity,
Fixed costs can be reduced. Furthermore, it is possible to increase the amount of fine grain raw material used while maintaining the same productivity.
Due to the increase in the amount of the fine-grain raw material used, it is not necessary to add coke to the powder raw material and perform re-baking at the sintering plant, so that remarkable economic merit can be enjoyed.
【図１】この発明に従う、炉頂微差圧測定方法と装入通
気抵抗指数算出要領の説明図である。FIG. 1 is an explanatory view of a method for measuring a furnace top fine differential pressure and a procedure for calculating a charging ventilation resistance index according to the present invention.
【図２】従来法に従う、シャフト圧力計を用いた装入物
通気抵抗指数算出要領の説明図である。FIG. 2 is an explanatory diagram of a procedure for calculating a charging airflow resistance index using a shaft pressure gauge according to a conventional method.
【図３】炉の高さ方向の圧力損失および圧力勾配を示し
た図である。FIG. 3 is a diagram showing a pressure loss and a pressure gradient in a height direction of a furnace.
【図４】高炉操業に伴う、炉頂温度、Ｌs 、炉頂微差圧
および装入物通気抵抗指数の変動状態を示した図であ
る。FIG. 4 is a diagram showing a variation state of a furnace top temperature, Ls, a furnace top slight differential pressure, and a charge air permeability resistance index associated with a blast furnace operation.
【図５】高炉操業に伴う、細粒原料の使用量および装入
物通気抵抗指数の推移を従来法と発明法とで比較して示
した図である。FIG. 5 is a graph showing changes in the amount of fine-grain raw material used and changes in the charge air permeability resistance index in the conventional method and the invented method in association with blast furnace operation.
１ 高炉シャフト ２ シャフト圧力計 ３ データ収録・演算装置 ４ アップテイク ５ 炉頂圧力計 ６ 炉頂温度計 ７ ステーブ ８ 装入物 ９ 微差圧計 10 サウンジング 1 Blast furnace shaft 2 Shaft pressure gauge 3 Data recording / calculation device 4 Uptake 5 Furnace top pressure gauge 6 Furnace top thermometer 7 Stave 8 Charge 9 Fine differential pressure gauge 10 Sounding
Claims (3)
性を評価するに当たり、 基準装入物表面からの距離が炉口半径の 1.5倍以内の位
置における炉内圧力と炉頂部空間の圧力との差圧を直接
測定し、得られた値とサウンジングで測定した実際の装
入物表面の位置に基づいて炉内に装入された装入物層の
通気性を判断することを特徴とする竪型炉における装入
物層の通気性評価法。1. When evaluating the air permeability of a raw material charge layer charged into a vertical furnace, the pressure inside the furnace and the furnace at a position where the distance from the standard charge surface is within 1.5 times the radius of the furnace opening Directly measure the pressure difference with the pressure in the top space and judge the air permeability of the charge layer charged in the furnace based on the obtained value and the position of the actual charge surface measured by sounding A method for evaluating the permeability of a charge layer in a vertical furnace characterized by the above.
わたる複数の位置で差圧測定を行うことを特徴とする竪
型炉における装入物層の通気性評価法。2. The method for evaluating the permeability of a charge layer in a vertical furnace according to claim 1, wherein the differential pressure measurement is performed at a plurality of positions in the circumferential direction of the vertical furnace.
炉である場合に、炉頂差圧の測定を、鉄原料装入から３
分以内に行うことを特徴とする竪型炉における装入物層
の通気性評価法。3. The method according to claim 1 or 2, wherein when the vertical furnace is a blast furnace, the measurement of the differential pressure at the top of the furnace is performed from the charging of iron raw material to
A method for evaluating the permeability of a charge layer in a vertical furnace, which is characterized by being performed within minutes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16342095A JPH0913110A (en) | 1995-06-29 | 1995-06-29 | Permeability evaluation method of charging layer in vertical furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16342095A JPH0913110A (en) | 1995-06-29 | 1995-06-29 | Permeability evaluation method of charging layer in vertical furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0913110A true JPH0913110A (en) | 1997-01-14 |
Family
ID=15773568
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16342095A Pending JPH0913110A (en) | 1995-06-29 | 1995-06-29 | Permeability evaluation method of charging layer in vertical furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0913110A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101257606B1 (en) * | 2011-10-31 | 2013-04-29 | 현대제철 주식회사 | Judgment method of permeability of lower part inblast furnace |
| EP2431484A4 (en) * | 2009-05-29 | 2014-06-11 | Jfe Steel Corp | PROCESS FOR OPERATING A HIGH-FURNACE |
| JP2018044199A (en) * | 2016-09-13 | 2018-03-22 | 新日鐵住金株式会社 | Operation method of blast furnace |
| CN109186787A (en) * | 2018-10-24 | 2019-01-11 | 河南华润电力首阳山有限公司 | A kind of system for detecting temperature and method of the big packet of boiler top |
| CN116064980A (en) * | 2023-01-17 | 2023-05-05 | 马鞍山钢铁股份有限公司 | A Method of Using Pressure Gradient to Characterize Blast Furnace Gas Flow |
-
1995
- 1995-06-29 JP JP16342095A patent/JPH0913110A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2431484A4 (en) * | 2009-05-29 | 2014-06-11 | Jfe Steel Corp | PROCESS FOR OPERATING A HIGH-FURNACE |
| KR101257606B1 (en) * | 2011-10-31 | 2013-04-29 | 현대제철 주식회사 | Judgment method of permeability of lower part inblast furnace |
| JP2018044199A (en) * | 2016-09-13 | 2018-03-22 | 新日鐵住金株式会社 | Operation method of blast furnace |
| CN109186787A (en) * | 2018-10-24 | 2019-01-11 | 河南华润电力首阳山有限公司 | A kind of system for detecting temperature and method of the big packet of boiler top |
| CN116064980A (en) * | 2023-01-17 | 2023-05-05 | 马鞍山钢铁股份有限公司 | A Method of Using Pressure Gradient to Characterize Blast Furnace Gas Flow |
| CN116064980B (en) * | 2023-01-17 | 2023-12-05 | 马鞍山钢铁股份有限公司 | Method for representing blast furnace airflow by using pressure gradient |
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