CN100552046C

CN100552046C - The method for operating blast furnace of blast furnace reductive agent device for blowing and this device of use

Info

Publication number: CN100552046C
Application number: CNB2005800261119A
Authority: CN
Inventors: 筑地秀明; 山口富; 佐藤道贵; 长谷川伸二; 下村昭夫
Original assignee: NKK Corp
Current assignee: JFE Steel Corp; JFE Engineering Corp
Priority date: 2004-09-30
Filing date: 2005-09-27
Publication date: 2009-10-21
Anticipated expiration: 2025-09-27
Also published as: CN1993483A

Abstract

Even provide when being blown into from the air port, also can not produce crushing and reduce coke ratio, and can suppress blast furnace reductive agent device for blowing that the blast furnace furnace wall temperature rises and the method for operating blast furnace that uses this device as the Sweet natural gas of gaseous reducing agent etc.Particularly, it is the reductive agent device for blowing that is blown into gaseous reducing agent from blast-furnace tuyere 1, have the gaseous reducing agent that is blown into gaseous reducing agent and be blown into pipe 5, be positioned at the gaseous reducing agent that this gaseous reducing agent is blown into pipe 5 front ends and be blown near the stove medial end 1a that mouthful 5a is arranged on blast-furnace tuyere 1.And, have solid reductant and be blown into pipe 7, be positioned at solid reductant that this solid reductant is blown into pipe 7 front ends and be blown into mouthful 7a and be configured in the air supply direction upstream side that gaseous reducing agent is blown into pipe 5 gas vent.And having from blast furnace inner-wall surface 2 side-prominent length setting in stove is the air port of 350～600mm.

Description

The method for operating blast furnace of blast furnace reductive agent device for blowing and this device of use

Technical field

The present invention relates to be blown into gaseous reducing agent separately or be blown into the reduction device for blowing of gaseous reducing agent and the method for operating blast furnace of this device of use together with other reductive agent from blast-furnace tuyere portion (tuyere).

Background technology

In blast furnace operation, substitute as the coke (coke) of costliness, usually be blown into the good fuel of cheapness and incendivity (combustibility) (micro mist carbon, oil, petroleum naphtha) from the air port, particularly be blown into fuel gas (fuel gas) such as Sweet natural gas, with regard to the known following method of these situations from the air port.

(1) a kind of method for operating blast furnace, its purpose is, even when being blown into micro mist carbon more than with 170kg/t, also guarantee its incendivity, the rate of displacement (replacementratio) that keeps itself and coke than the highland, and keep turnout, fuel ratio (fuel rate), it is characterized in that the outside (near operator's one side) that is blown into the position at micro mist carbon is blown into fuel gas (opening flat 4-268003 communique with reference to the spy).

(2) a kind of method for operating blast furnace, its purpose is, realize being blown in a large number synthetic resins (plastics), it is characterized in that, be blown into nozzle and be blown into the combustion-supporting material of Fill such as Sweet natural gas from being arranged on the air port portion combustion-supporting material of blowpipe Shang De Fill, simultaneously, be blown into the nozzle (nozzle) that the position also is positioned at the upstream side of air-supply Bi the combustion-supporting material of Gai Fill and be blown into synthetic resins grain (opening the 2000-178614 communique) from being arranged on reference to the spy.

And, be blown into operation about micro mist carbon, proposed to set the best method that is blown into the pipe position, in this position,, the thermal load of State of Blast Furnace bottom furnace wall portion is increased even be blown into micro mist carbon in a large number, and, can prevent that micro mist carbon is blown into the pipe melting loss.

This is blown into the pipe position determination method is that micro mist carbon is blown into the pipe position determination method, in the method, make micro mist carbon be blown into pipe and run through the wall that the hot blast that is connected with blast-furnace tuyere is blown into usefulness blowpipe (blowpipe), make this front end that is blown into pipe outstanding in this blowpipe, be blown into simultaneously from above-mentioned from blast-furnace tuyere and be blown into micro mist carbon that pipe is blown into and mobile hot blast in above-mentioned blowpipe.Setting the above-mentioned principle that is blown into the allocation position of pipe is, makes from the boundary position of blast-furnace tuyere and blowpipe to the above-mentioned distance that is blown into the pipe front end (below be sometimes referred to as be blown into the pipe position) L (mm) satisfy following (1) formula (opening flat 8-134518 communique with reference to the spy).

0.22×[PCR]+48.2≤L≤1017.3-1.33×[PCR]-14.7×[VM]…(1)

Wherein, [PCR]: the micro mist carbon amount of being blown into (kg/ pig iron t)

[VM]: volatile component containing ratio (%) in the micro mist carbon

Open in the flat 4-268003 communique in the disclosed method for operating blast furnace the spy, mainly be conceived to make the micro mist carbon amount of being blown into to increase, the purpose that is blown into fuel gas is to promote the thermolysis of micro mist carbon.

Thereby the application's fuel gas etc. are used as reductive agent equally with micro mist carbon, and this is different in itself.

And the main purpose that the spy opens the method for putting down in writing in the 2000-178614 communique is to realize being blown into synthetic resins in a large number, in order to achieve this end, has stipulated that synthetic resins blows the relativeness that implantation site and the combustion-supporting material of Fill are blown into the position.

Like this, open flat 4-268003 communique the spy, the spy opens in the 2000-178614 communique, though disclose the technology that is blown into Sweet natural gas etc. from the air port, but do not mention its prerequisite and be with Sweet natural gas etc. as and same reductive agent such as micro mist carbon, and technical problem at this moment and its solution are proposed, not to disclose the prior art of pointing out this technical problem and solution thereof.

The invention discloses technical problem and solution thereof concrete when being blown into Sweet natural gas as gaseous reducing agent etc. from blast-furnace tuyere.

Because incendivity height such as Sweet natural gas, when when blast-furnace tuyere is blown into, when being blown in the centre of blowpipe, violent burning such as the Sweet natural gas that is blown into, gas volume increases, and consequently, produces crushing (pressure drop) in blowpipe.When producing crushing, the air output in blast furnace has to reduce, and produces degradation major issue under the productivity.For fear of this problem, must make draft capacity become big, can increase running cost (running cost) but increase draft capacity, and, also produce the problem of fan (ventilator) scarce capacity because of crushing degree difference.

And when Sweet natural gas etc. during in the blowpipe internal combustion, the refrigerating unit (cooling system) that its heat is cooled around air port and the blowpipe is captured, thus, heat waste.And the cooling efficiency of refrigerating unit is step-down also.

When being blown into gaseous reducing agents such as Sweet natural gas from the air port, deflagrate from being blown into the domestic gas (city gas) that pipe is blown into.Therefore, the top temperature position in the district (raceway) of circling round in the blast furnace (following only be called " top temperature position in the stove ") also will be to the furnace wall side shifting when ratio only is blown into micro mist carbon, and the blast furnace furnace wall temperature raises, and has the problem that increases from the heat waste of furnace wall.

Usually, when furnace wall temperature raises, strengthen the furnace wall cooling, thermo-efficiency will reduce when such.Though be blown into the operation that the domestic gas purpose is the low-reductant ratio, short of solution blast furnace furnace wall temperature rising problem just is difficult to realize that low-reductant compares operation.

In this respect, open flat 4-268003 communique the spy, the spy opens in the 2000-178614 communique, though be blown into gaseous reducing agents such as Sweet natural gas, but only stipulated that micro mist carbon is blown into pipe or synthetic resins and is blown into pipe and is blown into the relative position of pipe with gaseous reducing agent, for top temperature position in the stove also without any relating to.

On the other hand, open in the flat 8-134518 communique,, open in the flat 8-134518 communique, terminate in the consideration that only is blown into micro mist carbon, for being blown into of gaseous reducing agent without any relating to the spy though considered top temperature position in the stove the spy.

As above, owing to be blown into gaseous reducing agent from the air port, thus the mobile problem that causes the blast furnace furnace wall temperature to rise of top temperature position in the stove, in the prior art also without any solution.

Summary of the invention

The object of the invention is, even provide when blast-furnace tuyere is blown into Sweet natural gas as gaseous reducing agent etc., also can not produce crushing and can reduce the blast furnace reductive agent device for blowing of coke ratio (coke rate) and use the method for operating blast furnace of this device.

And the object of the invention is, provides when when the air port is blown into gaseous reducing agent, can suppress reductive agent device for blowing and method for operating blast furnace that the blast furnace furnace wall temperature rises.

(1) blast furnace reductive agent device for blowing of the present invention is the reductive agent device for blowing that is blown into gaseous reducing agent from blast-furnace tuyere, it is characterized in that near being blown into the inboard leading section of stove that mouth is arranged on above-mentioned blast-furnace tuyere of gaseous reducing agent.

In addition, be meant near the inboard leading section of the stove of so-called blast-furnace tuyere, can not produce the position that increases caused crushing because of gas volume, described gas gas increase be by from gaseous reducing agent be blown into gaseous reducing agent that mouth is blown in the air port or the blowpipe internal combustion caused.

(2) and, blast furnace reductive agent device for blowing of the present invention, it is the reductive agent device for blowing that is blown into gaseous reducing agent from blast-furnace tuyere, it is characterized in that, have the gaseous reducing agent that is blown into gaseous reducing agent and be blown into pipe, the mouth that is blown into that this gaseous reducing agent is blown into pipe is configured near the stove medial end of above-mentioned blast-furnace tuyere.

(3) and, blast furnace reductive agent device for blowing of the present invention is characterized in that, gaseous reducing agent be blown into position configuration from the stove of above-mentioned blast-furnace tuyere inboard leading section in the scope of the stove outside 0～50mm.

(4) and, in the blast furnace reductive agent device for blowing of in above-mentioned (1)～(3), putting down in writing, it is characterized in that having solid reductant and be blown into pipe, the mouth that is blown into that this solid reductant is blown into pipe is configured in the air supply direction upstream side that is blown into mouth that is blown into pipe with respect to gaseous reducing agent.

(5) and, above-mentioned (4) record blast furnace reductive agent device for blowing in, it is characterized in that, the air-supply path in, solid reductant be blown into the pipe and gaseous reducing agent be blown into the pipe cross-over configuration.

(6) and, in the blast furnace reductive agent device for blowing of above-mentioned (4) or (5) record, it is characterized in that the mouth that is blown into that solid reductant is blown into pipe is configured in from the inboard leading section of the stove of blast-furnace tuyere in the scope of the stove outside 50～200mm.

(7) and, in above-mentioned (2)～(6) record blast furnace reductive agent device for blowing in, it is characterized in that gaseous reducing agent is blown into pipe and has kink or bend.

(8) and, blast furnace reductive agent device for blowing of the present invention, it is the reductive agent device for blowing that is blown into gaseous reducing agent from blast-furnace tuyere at least, it is characterized in that, has air port and gaseous reducing agent inlet, described air port is set to from blast furnace inner-wall surface side-prominent length (distancebetween tuyere tip and furnace wall) 350～600mm in stove, and described gaseous reducing agent is blown near the inboard leading section of mouthful stove that is arranged on this air port.

(9) and, it is the reductive agent device for blowing that is blown into gaseous reducing agent from blast-furnace tuyere at least, it is characterized in that, has air port and gaseous reducing agent inlet, described air port is set to from blast furnace inner-wall surface side-prominent length 350～400mm in stove, and described gaseous reducing agent is blown near the inboard leading section of mouthful stove that is arranged on this air port.

By being arranged on from blast furnace inner-wall surface side-prominent length 350～400mm in stove, even when being blown into gaseous reducing agents such as domestic gas from the air port, by preventing that the top temperature position is to the stove medial movement in the stove, the temperature that can suppress blast furnace furnace wall rises, simultaneously, can prevent the damaged of inlet front end as much as possible.

(10) and, it is the reductive agent device for blowing that is blown into gaseous reducing agent from blast-furnace tuyere at least, it is characterized in that, have the air port and be blown into pipe with the gaseous reducing agent that is blown into gaseous reducing agent, described air port is set to from blast furnace inner-wall surface side-prominent length 350～600mm in stove, and described gaseous reducing agent is blown near being blown into the inboard leading section of mouthful stove that is arranged on above-mentioned air port of pipe.

(11) and, it is the reductive agent device for blowing that is blown into gaseous reducing agent from blast-furnace tuyere at least, it is characterized in that, have the air port and be blown into pipe with the gaseous reducing agent that is blown into gaseous reducing agent, described air port is set to from blast furnace inner-wall surface side-prominent length 350～400mm in stove, and described gaseous reducing agent is blown near being blown into the inboard leading section of mouthful stove that is arranged on above-mentioned air port of pipe.

(12) and, in the reductive agent device for blowing of above-mentioned (10) or (11), it is characterized in that the mouth that is blown into that gaseous reducing agent is blown into pipe is configured in from inlet front end in the scope of the stove outside 0～25mm.

(13) and, method for operating blast furnace of the present invention is characterised in that, uses the reductive agent device for blowing of each record in above-mentioned (1)～(12), and is blown into gaseous reducing agent from this gaseous reducing agent device for blowing.

Description of drawings

Fig. 1: the explanatory view of the reductive agent device for blowing of an embodiment of the present invention.

Fig. 2: the explanatory view that is used for the test furnace of the embodiment of the invention.

The graphic representation of the experimental result of comparative example among Fig. 3: the embodiment 1.

The graphic representation of the experimental result of comparative example among Fig. 4: the embodiment 1.

Fig. 5: crushing velocity of variation and domestic gas are blown into the graphic representation of the relation of position among the expression embodiment 1.

Fig. 6: dust arrestment amount and micro mist carbon are blown into the graphic representation of the relation of position among the expression embodiment 6.

Fig. 7: crushing and micro mist carbon are blown into the graphic representation of the relation of position among the expression embodiment 6.

Fig. 8: the explanatory view of the reductive agent device for blowing of an embodiment of the present invention.

Fig. 9: the graphic representation of the assay of expression an embodiment of the present invention.

Figure 10: the graphic representation of top temperature position in stove when expression is not blown into domestic gas.

Figure 11: the graphic representation of top temperature position in the stove when being blown into domestic gas in the existing example of expression.

Figure 12: the explanatory view of the outstanding length L of air port in stove.

Figure 13: the explanatory view that the air port is damaged.

Figure 14: the graphic representation of the relation of the outstanding length L in expression air port and air port defect length La, Lb.

Figure 15: the gaseous reducing agent device for blowing of other embodiment of the present invention.

Figure 16: the solid reductant device for blowing of other embodiment of the present invention.

(label declaration)

1: air port, 1a: air port stove medial end, 3: blowpipe, 5: gaseous reducing agent is blown into pipe, 5a: gaseous reducing agent is blown into mouthful, 7: solid reductant is blown into pipe, 7a, solid reductant and is blown into mouth.

Embodiment

(embodiment 1)

Fig. 1 is the explanatory view of major portion of the blast furnace reductive agent device for blowing of present embodiment.

The reductive agent device for blowing of present embodiment is, with blowpipe 3 that blast-furnace tuyere 1 is connected in, setting is blown into that gaseous reducing agent as the domestic gas of gaseous reducing agent is blown into pipe 5 and the solid reductant that is blown into as the micro mist carbon of solid reductant is blown into pipe 7, makes both arranged in a crossed manner.

In addition, domestic gas mainly is a natural gas liquids, and has added to increase and use liquid propane gas, and the thermal value of the gas of use is adjusted into 11000 ± 100kcal/m ³

Gaseous reducing agent is blown into the pipe 5 circumferential walls from blowpipe 3 and inserts sideling towards the center of blowpipe 3, is bent into the direction parallel with the axis of blowpipe 3 near the center of blowpipe 3.And, be positioned at gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends and be blown into mouthful 5a and be configured in the position that retreats 25mm from the inboard leading section 1a of air port stove to the stove outside.

Solid reductant is set to be blown into pipe 7 and gaseous reducing agent and to be blown into pipe 5 and similarly to insert sideling towards the center of blowpipe 3 from the circumferential wall of blowpipe 3.And, be positioned at solid reductant that solid reductant is blown into pipe 7 front ends and be blown into mouthful 7a and extend to stove is inboard, and be configured in than being positioned at gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends and be blown into outside the stove of mouthful 5a than being blown into pipe 5 positions that intersect with gaseous reducing agent.

The rear end side that gaseous reducing agent is blown into pipe 5 is connected with the domestic gas supply-pipe of supplying with domestic gas, and never illustrated domestic gas feedway provides the domestic gas of specified pressure, specified amount to the domestic gas supply-pipe.

And solid reductant is blown into pipe 7 rear end side and the micro mist carbon gas delivery pipe coupling of gas delivery by the micro mist carbon of not shown micro mist carbon manufacturing unit manufacturing.

In the reductive agent device for blowing of above-mentioned formation, be blown into the domestic gas that pipe 5 is blown into specified amount by gaseous reducing agent, and, be blown into the micro mist carbon that pipe 7 is blown into specified amount by solid reductant.Domestic gas that is blown into and micro mist carbon play a role as the reductive agent coke for replacing.

And, in the present embodiment, because being positioned at gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends is blown into a mouthful 5a and is configured near the inboard front end of air port stove, specifically in the position that retreats 25mm from the 1a of inlet front end portion to the stove outside, thereby be blown into pipe 5 domestic gases that are blown into from gaseous reducing agent and in blowpipe 3 and air port, can not burn, supplying with in the stove and in the stove internal combustion becomes reducing gas.

In addition, in the above-described embodiment, be positioned at position configuration that gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends is blown into mouthful 5a at the example that retreats 25mm from the inboard front end 1a of air port stove to the stove outside though show, but the invention is not restricted to this, be positioned at the gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends and be blown into the position of mouthful 5a so long as the position of crushing can not take place get final product, described crushing by be blown into from gaseous reducing agent gas volume that pipe 5 domestic gases that are blown into cause in blowpipe 3 or air port 1 internal combustion increase cause.Particularly, preferred disposition is in the scope of inboard front end 1a 0～50mm outside stove from the air port stove.And, be more preferably and be configured in from the inlet front end position in the scope of the stove outside 0～25mm.

In addition, the limit position that why gaseous reducing agent is blown into the stove outside of pipe is set at apart from the inboard front end 50mm of air port stove place, be because, be blown into the position from the inboard front end of air port stove side shifting outside stove little by little by the domestic gas that gaseous reducing agent is blown into pipe, experimental measurement crushing velocity of variation (crushing velocity of variation=domestic gas is blown into back crushing/domestic gas and is blown into preceding crushing), its result shows that in the position of the inboard front end 50mm of distance air port stove, the crushing velocity of variation sharply rises.In embodiment described later, can describe particular case in detail.

In the above-described embodiment, be blown into means, show the gaseous reducing agent that inserts from the perisporium of blowpipe 3 and be blown into pipe 5, but the invention is not restricted to this, as shown in figure 15, also can venting channels be set and be blown into gaseous reducing agent in the air port as gaseous reducing agent.

And, when being blown into multiple solid reductant, also can make solid reductant be blown into pipe and be double wall tube or three layers of multilayered tube that pipe is above as shown in figure 16, be blown into solid reductant a, b more than 2 kinds from a position.Like this, can improve the efficient that is blown into of solid reductant.

(embodiment 2)

In above-mentioned embodiment 1, be blown into pipe 7 configuration about solid reductant, be blown into mouthful 5a than gaseous reducing agent and also be positioned at the stove outside though solid reductant is blown into mouthful 7a, concrete scope is not shown.

In this embodiment 2, be discussed below the best configuration position that solid reductant is blown into mouthful 7a, show its concrete scope simultaneously.

Because the specific heat ratio gaseous reducing agent height of solid reductant, heat-up rate is slow.Therefore, solid reductant is blown into mouth and is configured in than gaseous reducing agent and is blown into mouthful the stove outside further from inlet front end, and this makes solid reductant elongated the warm up time in blowpipe, and the incendivity in blast furnace improves.

On the other hand, when warm up time in short-term, incendivity in blast furnace reduces, and than when not descending, the unburnt solids reductive agent is stopped up at reductive agent in the coke packing layer, then can produce the problem of air permeability variation.

On the other hand, when the position that makes solid reductant be blown into mouth retreated outside stove, warm up time was elongated, and when the slow astern set a distance was above, solid reductant will burn in blowpipe or air port.When solid reductant during in blowpipe or air port internal combustion, produce crushing, the air output in blast furnace reduces, and can produce major issues such as reduction efficiency is low.

Like this, though the position that solid reductant is blown into mouthful for abundant preheating retreats into the stove outside more from the inboard front end of air port stove, but then, owing to can produce the crushing problem when excessively retreating, it is very important therefore being good at obtaining this balance.

But, in the past, it is very difficult to obtain this balance, produces this prior problem of crushing for fear of solid reductant at blowpipe or air port internal combustion, allow to produce some problems of not firing, solid reductant is blown into mouth and is configured in from inlet front end in the scope of the stove outside 50～150mm.

Therefore, in present embodiment 2, being blown into mouth with the gaseous reducing agent shown in the embodiment 1, to be configured in from inlet front end be prerequisite to the new design structure of the stove outside 0～50mm, and the optimum position scope that solid reductant is blown into mouthful is discussed.

Consequently, if being blown into mouth with gaseous reducing agent, to be configured in from inlet front end be prerequisite to the stove outside 0～50mm, the position configuration that is blown into mouthful when solid reductant is in distance inlet front end 200mm scope the time, can keep the high combustion of solid reductant in stove, also can't see simultaneously and can produce the crushing problem that is caused in blowpipe or air port internal combustion by solid reductant.

Thereby, the reductive agent device for blowing of present embodiment 2 is, gaseous reducing agent shown in Figure 1 is blown into mouthful 5a and is configured in from inlet front end in the scope of the stove outside 0～50mm, and solid reductant is blown into mouthful 7a and is configured in from inlet front end in the scope of stove outside 200mm.

And, being more preferably, solid reductant is blown into mouthful 7a and is configured in from inlet front end in the scope of the stove outside 75～200mm.

Above-mentioned scope is the reasons are as follows of optimum range.

Owing to be blown into gaseous reducing agent near inlet front end, by the combustion-supporting effect of gaseous reducing agent, the unburned part of solid reductant in stove tails off.Just, even the position that solid reductant is blown into mouthful 7a from inlet front end to stove outside 50mm degree, because near the combustion-supporting effect of the gaseous reducing agent that is blown into inlet front end can not produce unburned part in a large number yet, can not produce the problem of air permeability (permeability) variation.

And, when position that solid reductant is blown into mouthful 7a from inlet front end during to stove outside 200mm, though the abundant preheating of solid reductant, the incendivity in stove further improves, probably the crushing problem that is caused in blowpipe or air port internal combustion just like above-mentioned solid reductant.

But, owing near inlet front end, be blown into gaseous reducing agent, near gaseous reducing agent is blown into mouthful 5a, burning by means of near the burning of the gaseous reducing agent the air port in stove and near the gaseous reducing agent that does not produce the crushing degree inlet front end, even the oxygen in the consumption hot blast and fully the solid reductant of preheating can on solid reductant, not cause the burning that produces crushing by near the inlet front end yet.

In addition, be blown into mouthful 7a about solid reductant and be configured in concrete effect when inlet front end is in the 200mm scope of the stove outside, will confirm among the embodiment 6 below.

(embodiment 3)

And, move the problem that the blast furnace furnace wall temperature that caused rises in order to solve top temperature position in the stove, the contriver uses the coke filled-type test burn stove of analog blast furnace, when just being blown into domestic gas in the stove top temperature position move degree and investigate.

As shown in Figure 2, coke filled-type test burn stove (experimental combustionfurnace equipped with coke packed bed) the 10th, the stove inner height is 1000mm, depth is the rectangle stove of 600mm in the stove, and an air port 11 is arranged on the 10a of furnace wall.Hot blast is blown into blowpipe 13 and is connected with air port 11, and blowpipe 13 is provided with the inlet side pressure warning unit 15 of measuring the blowpipe internal pressure.And, being provided with coke loading port 17 and venting port 19 on stove top, venting port is provided with the outlet side pressure warning unit 21 of measuring exhaust pressure.

And, blowpipe 13 be provided with gaseous reducing agent be blown into the pipe and micro mist carbon be blown into pipe.In coke filled-type test burn stove 10, can suitably change gaseous reducing agent be blown into the pipe and solid reductant be blown into the pipe position that position and air port are set separately.

In the coke filled-type test burn stove 10 of said structure and blast furnace similarly be blown into hot blast from the air port, be blown into micro mist carbon simultaneously and, make the coke burning in the stove as the domestic gas of gaseous reducing agent.

At first, only be blown into micro mist carbon, measure furnace gas temperature this moment.It the results are shown among Figure 10.In Figure 10, transverse axis is that the longitudinal axis is represented gas composition and gas temperature from the distance of inlet front end to the stove inboard.

As shown in figure 10 as can be known, when not being blown into domestic gas, the top temperature position is the position apart from the about 500mm of inlet front end place in the stove.

Then, the situation that is blown into domestic gas is carried out same test.It the results are shown among Figure 11.In addition, the incendivity height of domestic gas is blown into directly burning of back.Therefore, when domestic gas is blown into the position in blowpipe the time, the gas volume that is caused by the domestic gas burning increases, and can produce crushing.Therefore, domestic gas is blown into the position and is formed near the inlet front end.In addition, so-called herein crushing is meant the inlet side pressure measured with inlet side pressure warning unit 15 and poor with the outlet side pressure of outlet side pressure warning unit 21 measurements.In addition, consisting of of the domestic gas that uses in experiment: methane gas 88.5 volume %, ethane gas 4.6 volume %, propane flammable gas 5.4 volume %, butagas 1.5 volume %, calorie is 11800kcal/kg.

As shown in figure 11 as can be known, when being blown into domestic gas, the top temperature position is the position apart from the about 400mm of inlet front end place in the stove.

Compare Figure 10 and Figure 11 as can be known, by being blown into domestic gas, side shifting outside stove about 100mm in top temperature position in the stove.Because domestic gas has been blown into determining positions top temperature position in the stove, be blown into the situation of domestic gas, for top temperature position in the stove being returned to and same position when not being blown into domestic gas, the position that is blown into of domestic gas is got final product to stove medial movement 100mm.

But when only making domestic gas be blown into pipe to cross inlet front end and extend in stove, pipe can fall by direct melting loss.

In order to prevent this situation, the contriver makes the air port increase to the outstanding length of stove inboard, if pipe is arranged on wherein, can prevent that then the melting loss of pipe also can be to the front end of stove medial movement pipe.

As above, be blown under the situation of domestic gas, in order to solve the problem that the blast furnace furnace wall temperature that top temperature position in the stove caused to the stove medial movement rises, the position that is blown into of domestic gas get final product to stove medial movement 100mm, promptly mobilely be blown into the above-mentioned amount of movement that domestic gas causes.

The contriver further investigates and notices, from the viewpoint that prevents that the blast furnace furnace wall temperature from rising, wishes to make that the top temperature position also will be to the stove medial movement than the situation that only is blown into micro mist carbon in the stove.

But, in order to make in the stove top temperature position and then to the stove medial movement, what must make domestic gas is blown into the position to the stove medial movement, in this case, will make the air port further protrude in the stove inboard.When the air port further in stove when side-prominent, think that the influence of thing can cause the loss in air port in the stoves such as coke and slag.Therefore, can not make the air port at random side-prominent in stove.

At this, the viewpoint that how to change for damaged situation from the air port, investigation makes air port influence when side-prominent in stove, and the contriver has carried out following operation experiment.

1) test method

(1) air port of outstanding length in the different stoves shown in the following table 1 of bar number shown in the preparation table 1, and be arranged on the blast furnace.In addition, as shown in figure 12, outstanding length L is meant in the so-called stove, air port 30 is arranged under the state on the blast furnace distance of inboard front end 30a from State of Blast Furnace inner-wall surface 31 to the air port stove.

Table 1

Outstanding length (mm) in the stove	Air port bar number (bar)
Outstanding length (mm) in the stove	Air port bar number (bar)	300	4
350	8	300	4
350	8	400	8
450	4	400	8
450	4	500	4
600	4	500	4
600	4	700	4
800	2	700	4

(2) after being provided with 3 months, take off the air port, as shown in figure 13, measure top, the air port defect length La and bottom, the air port defect length Lb of inlet front end.

2) test-results

Figure 14 is the graphic representation of the relation of the outstanding length L in expression air port and air port defect length La, Lb, and transverse axis is represented outstanding length L in the stove, and the longitudinal axis is represented the inlet front end defect length.

As shown in figure 14 as can be known, when giving prominence to length L in increasing stove, bottom, air port defect length Lb does not almost change, and is relative therewith, and top, air port defect length La sharply increases when outstanding length L surpasses 600mm in stove.

When the air port was given prominence to length L above 600mm in stove, the reason that top, air port defect length La sharply increases was considered as follows.

Think that the damaged of inlet front end caused by two kinds of reasons, a kind of is the wearing and tearing that the coke of district portion circles round and cause of circling round, and a kind of be the melting loss that is caused by the molten iron that drips in the stove.When the outstanding length L in stove more in short-term because the wearing and tearing that cause of circling round of coke account for major part, the defect length of top and the bottom, air port does not have big variation.But, think when outstanding length L surpasses 600mm, be subjected to the dripping influence of molten iron of top, air port, the defect length that is caused by melting loss sharply increases.

As shown in Figure 12 and Figure 13, be provided with cooling tube 33 in the inside in air port, water coolant is flowing in the pipe.Therefore, when damaged arrival cooling tube 33, cooling tube 33 damages, and water will immerse in the stove, and therefore, this air port 30 can not have been used.Thereby, can think that up to the time of damaged arrival cooling tube 33 be the air port life-span.

When such consideration, the outstanding length L in air port surpasses 600mm can make the air port life-span obviously shorten, and simultaneously, takes place in the operation that cooling tube 33 damages and water is immersed in the danger of the fault in the stove and uprises.

Thereby, from air port life-span and the viewpoint that prevents to damage the stove internal fault that causes, we can say and the outstanding length L in air port should be set at below the 600mm by cooling tube.

And, being blown into micro mist carbon separately compares, in order to make in the stove top temperature position further to the stove medial movement, and further reduce the thermosteresis of furnace wall, to realize low-reductant than operation, also can be in the outstanding length L that in the scope of blast furnace inner-wall surface 2 below the inboard 600mm of stove, further increases the air port.If the outstanding length L in air port is in the following scope of 600mm, as previously mentioned, the air port life-span can not become extremely short, therefore can supply in practicality.

According to following reason, be more preferably and be made as 350～400mm.

In following embodiment, show use is made as the air port of 400mm to the outstanding length L of stove inboard from blast furnace inner-wall surface 2 example.Because being blown into pipe 5, gaseous reducing agent is used to be configured in the stove inboard, in the air port from blast furnace inner-wall surface 2 to the outstanding length L of stove inboard 400mm not necessarily, as long as it is just passable to increase the outstanding length that is blown into the amount of movement of top temperature position in the stove that domestic gas causes.According to contriver's investigation, be 50～100mm owing to be blown into the amount of movement of top temperature position in the stove that domestic gas causes, so the outstanding length in air port is just more passable in 350～400mm scope than usually long 50～100mm.

Fig. 8 is the explanatory view of major portion of the blast furnace reductive agent device for blowing of embodiment of the present invention.

The gaseous reducing agent device for blowing of present embodiment is the reductive agent device for blowing that is blown into micro mist carbon and gaseous reducing agent from blast-furnace tuyere, has the air port 1 that is set at 400mm from blast furnace inner-wall surface 2 to the outstanding length L of stove inboard, with blowpipe 3 that air port 1 is connected in, be blown into gaseous reducing agent as the domestic gas of gaseous reducing agent and be blown into pipe 5 and be blown into solid reductant as the micro mist carbon of solid reductant and be blown into pipe 7 both are arranged in a crossed manner.

The air port be set at 400mm from the outstanding length L of blast furnace inner-wall surface 2 to the stove inboard, this be because, usually the air port is about 300mm from the outstanding length L of blast furnace inner-wall surface 2 to the stove inboard, therefore, by making air port 1 to the outstanding length of the stove inboard only 100mm that extends, promptly lengthening is blown into the amount of movement of the top temperature position that domestic gas causes, and domestic gas is blown into the position can be to stove medial movement 100mm.

Gaseous reducing agent is blown into pipe 5 and inserts towards the center of blowpipe 3 sideling from the circumferential walls of blowpipe 3, and is bent into the direction parallel with the axis of blowpipe 3 near the center of blowpipe 3.And the leading section 5a that gaseous reducing agent is blown into pipe 5 is configured in the identical position with the inboard leading section 1a of air port stove.

Be blown into pipe 5 similarly with gaseous reducing agent, insert towards the center of blowpipe 3 sideling from the circumferential wall of blowpipe and solid reductant is set is blown into pipe 7.And, be positioned at solid reductant that solid reductant is blown into pipe 7 front ends be blown into mouthful 7a than and gaseous reducing agent be blown into positions that pipe 5 intersects and also extend to stove is inboard, and be configured in and be positioned at the gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends and be blown into outside the stove of mouthful 5a.

In the reductive agent device for blowing of above-mentioned formation, be blown into the domestic gas that pipe 5 is blown into specified amount by gaseous reducing agent, and, be blown into the micro mist carbon that pipe 7 is blown into specified amount by solid reductant.Domestic gas that is blown into and micro mist carbon can work by coke for replacing as reductive agent.

And, in present embodiment 3, owing to be equipped with the air port 1 that is set at 400mm from blast furnace inner-wall surface 2 to the outstanding length L of stove inboard, and being positioned at gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends is blown into a mouthful 5a and is configured near the inboard front end of air port stove, therefore, be positioned at gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends and be blown into mouthful 5a and can be configured in than normal conditions and also be positioned at the inboard about 100mm of stove place, top temperature position in the stove is formed on and common position same when only being blown into micro mist carbon.

Like this, in present embodiment 3, use is set for than the normal conditions air port 1 of the 400mm of long 100mm also to the outstanding length L of stove inboard from blast furnace inner-wall surface 2, simultaneously, being positioned at gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends is blown into a mouthful 5a and is configured near the inboard front end of air port stove, thus, be positioned at gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends and be blown into mouthful 5a and can be configured in than normal conditions and also be positioned at the inboard about 100mm of stove place, can avoid by being blown into the mobile of top temperature position in the stove that domestic gas causes.

In above-mentioned the 3rd embodiment, though show be positioned at position configuration that gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends is blown into mouthful 5a with the example of the inboard front end 1a of air port stove same position, but owing to be to make to be positioned at position that gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends is blown into mouthful 5a in essence to the inboard amount of movement that is blown into the stove top temperature position that domestic gas causes that extends of stove, therefore, when the inboard development length of the stove in air port is also longer than above-mentioned amount of movement, not necessarily need consistent with the inboard front end 1a of air port stove.

; must be set in the position that can not produce crushing; described crushing is to increase caused by be blown into pipe 5 domestic gases that are blown into from gaseous reducing agent at the gas volume that blowpipe 3 or air port 1 internal combustion are caused; this means; better be to be configured in from the inboard front end 1a of air port stove in the 0～50mm scope of the stove outside, be more preferably and be configured in 0～25mm scope.

And, in above-mentioned

embodiment

1,2 and 3, because being positioned at gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends is blown into mouthful 5a and all is configured near the inboard front end of air port stove, therefore, the domestic gas of supplying with can be in the air port or the blowpipe internal combustion, thereby the gas volume that produces not in the air port and during the blowpipe internal combustion increases caused crushing problem.And, because domestic gas is in the stove internal combustion, excessive thermal load can be applied on cooling air port 1 and blowpipe 3 refrigerating unit on every side yet, and, heat waste also reduced.

And, in above-mentioned

embodiment

1,2 and 3, because being blown into pipe 7, solid reductant all is blown into pipe 5 cross-over configuration, therefore with gaseous reducing agent, the micro mist carbon that are blown into pipe 7 ejections from solid reductant can directly not blow at gaseous reducing agent and be blown on the pipe 5, can prevent that gaseous reducing agent is blown into pipe 5 loss.

And, in above-mentioned

embodiment

1,2 and 3, gaseous reducing agent all bend or bending near being blown into pipe 5 leading section, to become the direction parallel with the axis of blowpipe 3, and make domestic gas blow out the position and be in the central position, air port, therefore, domestic gas can not be blown in the stove on the bias, can stably carry out operation.In order stably to carry out operation, when air port when being circular, domestic gas be blown into the position preferably the radius that begins from the air port central shaft be the sixth of tuyere diameter with interior circle in.

If deflection is blown into domestic gas, the reduction reaction generation deflection in the stove then, the thing that causes packing into the unusual job state that waits that descends worsens, consequently the reduction efficiency variation.

In addition and since be gas stream cross gaseous reducing agent be blown into the pipe 5 in, even the bending or crooked gaseous reducing agent be blown into pipe, do not worry the obstruction and the loss of pipe yet.

In addition, in above-mentioned

embodiment

1,2 and 3, as the example of gaseous reducing agent, though exemplified domestic gas, other also can use natural gas liquids (LNG), liquefied petroleum gas (LPG) (LPG), coke gas (COG) etc.

In addition, in above-mentioned

embodiment

1,2 and 3,,, also can use other micronized synthetic resins, wood chip etc. though exemplified micro mist carbon as the example of solid reductant.

And, in above-mentioned

embodiment

1,2 and 3,,, also be same even in the situation that only is blown into gaseous reducing agent though show the example that is blown into gaseous reducing agent and solid reductant.

Embodiment 1

In order to confirm effect of the present invention, use the coke filled-type test burn stove of analog blast furnace to verify that domestic gas is blown into the relation with crushing.

Coke filled-type test burn stove 10 uses coke filled-type test burn stove shown in Figure 2.

In the coke filled-type test burn stove 10 of above-mentioned formation and blast furnace similarly 11 be blown into hot blast from the air port, be blown into simultaneously as the micro mist carbon of solid reductant with as the domestic gas of gaseous reducing agent, make the coke burning in the stove.

Implement two kinds of situations in the present embodiment, a kind of is to be blown into micro mist carbon and domestic gas (comparative example) in the 200mm position that begins from the inboard front end of air port stove, another kind is to be blown into domestic gas in the inboard front position of air port stove, is blown into micro mist carbon (example of the present invention) from its rear in the 200mm position that begins from the inboard front end of air port stove.In addition, consisting of of the domestic gas of Shi Yonging in the present embodiment: methane gas: 88.5 volume %, ethane gas: 4.6 volume %, propane flammable gas: 5.4 volume %, butagas: 1.5 volume % calorie are 11800kcal/kg.And about the micro mist carbon that uses in the present embodiment, the particulate by 74 μ m meshes sieve at interval is 80%, and kind is the blackwater charcoal.

Fig. 3, Fig. 4 make graphic representation with the test-results of the coke filled-type test burn stove 10 of above-mentioned two kinds of situations, and the longitudinal axis of Fig. 3, Fig. 4 is all represented crushing (kPa), and transverse axis is all represented the time (min).Fig. 3 is a comparative example, and Fig. 4 is embodiments of the invention.In addition, herein, so-called crushing is meant the inlet side pressure measured with inlet side pressure warning unit 15 and poor with the outlet side pressure of outlet side pressure warning unit 21 measurements.

As shown in Figure 3, in comparative example, rise to about 6kPa from about 4kPa at the time point that begins to be blown into domestic gas (beginning about 40 minutes time point) crushing from experiment.This thinks that domestic gas increases because of gas volume increases flow passage resistance force of waterproof in the air port internal combustion owing to be blown into domestic gas, and crushing rises.

On the other hand, in embodiments of the present invention, begin to be blown into domestic gas after crushing do not have big variation yet.

Like this, even embodiments of the invention have been verified the domestic gas that is blown into as gaseous reducing agent, crushing does not take place yet.

Secondly,, make domestic gas be blown into the position and gently move to the stove outside, obtain the crushing velocity of variation from the inboard front end of air port stove in order to investigate the relation that domestic gas is blown into position and crushing.As previously mentioned, so-called crushing velocity of variation is that crushing removal domestic gas is blown into the value that the back crushing obtains before being blown into domestic gas.

Fig. 5 is the graphic representation that expression crushing velocity of variation and domestic gas are blown into the relation of position, and the longitudinal axis represents that crushing changes, and transverse axis is represented the distance that begins from the inboard front end of air port stove.

As shown in Figure 5, begin to 50mm from the inboard front end of air port stove, the crushing velocity of variation is 1.0, roughly maintains an equal level, and from surpassing the 50mm beginning, the crushing velocity of variation sharply rises.

Therefore, think that the position that can be blown into domestic gas is to begin in the scope of stove outside 50mm from the inboard front end of air port stove with not producing crushing.

In addition, consider to prevent reliably that crushing from taking place, wish that more domestic gas is blown into the position for beginning in the scope of stove outside 25mm from the inboard front end of air port stove.

According to the checking result of above-mentioned test furnace as can be known, when the mode that adopts example of the present invention is blown into gaseous reducing agent, the crushing problem can not take place.At this, verify with regard to this influence to the blast furnace actual job.Checking the results are shown in the table 2.

Table 2

	Elemental operation	Comparative example	Example of the present invention
	Elemental operation	Comparative example	Example of the present invention	Go out pig iron amount (T/D)	11500	11000	11700
Air output (Nm ³/min)	8005	7930	7770	Go out pig iron amount (T/D)	11500	11000	11700
Air output (Nm ³/min)	8005	7930	7770	RAR(kg/T)	500	520	490
CR(kg/T)	400	370	340	RAR(kg/T)	500	520	490
CR(kg/T)	400	370	340	PC(kg/T)	100	100	100
Domestic gas (kg/T)	0	50	50	PC(kg/T)	100	100	100
Domestic gas (kg/T)	0	50	50	Coke rate of displacement (-)	0	0.60	1.20

In table 2, only be blown into the situation (hereinafter referred to as " elemental operation ") that micro mist carbon is not blown into domestic gas and be documented in the left hurdle; Be blown in the position of the inboard front end 200mm of distance air port stove micro mist carbon (PC (Pulverized Coal): 100kg/T) and the situation of domestic gas (50kg/T) (hereinafter referred to as " comparative example ") be documented in the middle column; With example of the present invention shown in Figure 1 be blown into pipe and comparative example be blown in the same manner micro mist carbon (PC (Pulverized Coal): 100kg/T) and the situation of domestic gas (50kg/T) (be blown into domestic gas in air port stove inboard front position, be blown into the situation of micro mist carbon in the inboard front end 200mm of distance air port stove position from its rear, hereinafter referred to as " example of the present invention ") be documented in the right hurdle.

Seeing Table 2 air output hurdle, is 8005 (Nm in the elemental operation ³/ min), be 7930 (Nm in the comparative example ³/ min), become 7770 (Nm in the example of the present invention ³/ min).This expression, owing to used the domestic gas of example of the present invention to be blown into structure, air-supply that also can be same when being blown into domestic gas with elemental operation.Even this is also not produce crushing because be blown into domestic gas.

See reductive agent than (RAR (Reducing Agent rate)) hurdle as can be known, the reductive agent ratio is 500 (kg/T) in elemental operation, is reduced to 490 (kg/T) in example of the present invention, and reduction efficiency has improved.This expression can effectively utilize the high domestic gas of reduction efficiency as reductive agent.On the other hand, in comparative example, though be blown into and the same domestic gas of measuring of the present invention's example, the reductive agent ratio is 520 (kg/T), and is taller when the reductive agent ratio becomes than elemental operation.This expression though be blown into the good domestic gas of reduction efficiency, has encouraged air output reduction and operation instabilityization because crushing rises, and can not be effective as the reductive agent utilization.

And, see coke ratio (CR) hurdle, coke ratio is 400 (kg/T) in elemental operation, becomes 340 (kg/T) in the example of the present invention, as can be known coke ratio 60 (kg/T) that descended.Owing to be blown into 50 (kg/T) domestic gas, coke ratio 60 (kg/T) that descended, this expression, domestic gas that is blown into and coke have carried out replacing (coke rate of displacement: 60/50=1.20) effectively.On the other hand, in comparative example, though be blown into and the domestic gas of the same amount of the present invention example, coke ratio is 370 (kg/T), but is to have reduced by 30 (kg/T) during than elemental operation.This expression though be blown into the good domestic gas of reduction efficiency, has encouraged air output reduction and operation instabilityization because crushing rises, and can not replace (coke rate of displacement: 30/50=0.60) with coke effectively.Consequently, in the coke rate of displacement numerical value being shown, is 0.60 in comparative example, corresponding therewith, increases to 1.20 among the present invention, and the reduction effect of coke is bigger.In addition, try to achieve the rate of displacement of coke than the reduction of removing coke ratio with domestic gas.

And, see Table 2 go out pig iron amount hurdle, going out pig iron amount in elemental operation is 11500 (T/D), is increased to 11700 (T/D) in the example of the present invention, the effect that is blown into the good domestic gas of reduction efficiency is reflected in out pig iron amount aspect.On the other hand, in comparative example, going out pig iron amount is 11000 (T/D), also lacks during than elemental operation.This be because, though be blown into the good domestic gas of reduction efficiency,, rise by crushing and to have encouraged air output and reduce and the operation instabilityization because to be blown into mode improper, can not be effective as the reductive agent utilization.

Like this, improper even be blown into the high gaseous reducing agent of reduction efficiency as domestic gas if it is blown into mode, can not carry out effective blast furnace operation.

In this respect, according to the present invention, realized effective blast furnace operation, its effect is very big.

(embodiment 2) (gaseous reducing agent: LNG)

With the domestic gas of liquefaction natural (LNG) gas replacement embodiment 1, just verify with the checking of test furnace with to the influence of blast furnace actual job.In addition, except that replace domestic gas with LNG gas, test conditions is carried out the method identical with embodiment 1.In addition, consisting of of the LNG gas that uses in the present embodiment: methane gas: 88.8 volume %, ethane gas: 5.6 volume %, propane flammable gas: 3.7 volume %, butagas: 1.8 volume %, calorie is 11800kcal/kg.And about the micro mist carbon that uses in the present embodiment, the particulate by 74 μ m meshes sieve at interval is 80%, and kind is the blackwater charcoal.

Consequently, within the scope of the present invention, be blown into gaseous reducing agent and can not produce the crushing problem.And, just the influence of blast furnace actual job is verified that its effect is shown in Table 3.

Table 3

	Elemental operation	Comparative example	Example of the present invention
	Elemental operation	Comparative example	Example of the present invention	Go out pig iron amount (T/D)	11500	11200	11600
Air output (Nm ³/min)	8005	7930	7770	Go out pig iron amount (T/D)	11500	11200	11600
Air output (Nm ³/min)	8005	7930	7770	RAR(kg/T)	500	522	495
CR(kg/T)	400	372	345	RAR(kg/T)	500	522	495
CR(kg/T)	400	372	345	PC(kg/T)	100	100	100
LNG gas (kg/T)	0	50	50	PC(kg/T)	100	100	100
LNG gas (kg/T)	0	50	50	Coke rate of displacement (-)	0	0.56	1.10

In table 3, the situation (hereinafter referred to as " elemental operation ") that is not blown into LNG gas is documented in the left hurdle; The situation (hereinafter referred to as " comparative example ") that is blown into micro mist carbon and LNG gas (50kg/T) in the position of the inboard front end 200mm of distance air port stove is documented in the middle column; The situation that pipe and comparative example be blown into LNG gas (50kg/T) in the same manner that is blown into example of the present invention shown in Figure 1 (is blown into LNG gas in air port stove inboard front position, be blown into the situation of micro mist carbon in the inboard front end 200mm of distance air port stove position from its rear, hereinafter referred to as " example of the present invention ") be documented in the right hurdle.

Seeing Table 3 air output hurdle, is 8005 (Nm in the elemental operation ³/ min), be 7930 (Nm in the comparative example ³/ min), become 7770 (Nm in the example of the present invention ³/ min).This expression, owing to used the LNG air-blowing of example of the present invention to go into structure, air-supply that also can be same when being blown into LNG gas with elemental operation.Even this is also not produce crushing because be blown into LNG gas.

See reductive agent than the hurdle as can be known, the reductive agent ratio is 500 (kg/T) in elemental operation, is reduced to 495 (kg/T) in example of the present invention, and reduction efficiency has improved.This expression can effectively utilize the high LNG gas of reduction efficiency as reductive agent.On the other hand, in comparative example, though be blown into and the same LNG gas of measuring of the present invention's example, the reductive agent ratio is 522 (kg/T), and is taller when the reductive agent ratio becomes than elemental operation.This expression though be blown into the good LNG gas of reduction efficiency, has encouraged air output reduction and operation instabilityization because crushing rises, and can not be effective as the reductive agent utilization.

And, see the coke ratio hurdle, coke ratio is 400 (kg/T) in elemental operation, becomes 345 (kg/T) in the example of the present invention, as can be known coke ratio 55 (kg/T) that descended.Owing to press 50(kg/T) be blown into LNG gas, coke ratio 55 (kg/T) that descended, this expression, LNG gas that is blown into and coke have carried out replacing (coke rate of displacement: 55/50=1.10) effectively.On the other hand, in comparative example, though be blown into and the LNG gas of the same amount of the present invention example, coke ratio is 372 (kg/T), but is to have reduced by 28 (kg/T) during than elemental operation.This expression though be blown into the good LNG gas of reduction efficiency, has encouraged air output reduction and operation instabilityization because crushing rises, and can not replace (coke rate of displacement: 28/50=0.56) with coke effectively.Same with embodiment 1, consequently, the coke rate of displacement is 0.58 in comparative example, relative therewith, increases to 1.10 among the present invention.

And, see Table 3 go out pig iron amount hurdle, going out pig iron amount in elemental operation is 11500 (T/D), is increased to 11600 (T/D) in the example of the present invention, the effect that is blown into the good LNG gas of reduction efficiency is reflected in out pig iron amount aspect.On the other hand, in comparative example, going out pig iron amount is 11200 (T/D), also lacks during than elemental operation.This be because, though be blown into the good LNG gas of reduction efficiency,, rise by crushing and to have encouraged air output and reduce and the operation instabilityization because to be blown into mode improper, can not be effective as the reductive agent utilization.

Like this, improper even be blown into the high gaseous reducing agent of reduction efficiency as LNG gas if it is blown into mode, can not carry out effective blast furnace operation.

(embodiment 3) (gaseous reducing agent: LPG)

Replace the domestic gas of embodiment 1 with propane flammable gas (LPG), just with the checking of test furnace with the blast furnace reality is pretended influence already verify.In addition, except that replace domestic gas with LPG gas, test conditions is carried out the method identical with embodiment 1.In addition, consisting of of the LPG gas that uses in the present embodiment: propane flammable gas: 95 volume %, butagas: 5 volume %, calorie is 11100kcal/kg.And about the micro mist carbon that uses in the present embodiment, the particulate by 74 μ m meshes sieve at interval is 80%, and kind is the blackwater charcoal.

Consequently, within the scope of the present invention, be blown into gaseous reducing agent and can not produce the crushing problem.And, just the influence of blast furnace actual job is verified that its effect is shown in Table 4.

Table 4

	Elemental operation	Comparative example	Example of the present invention
	Elemental operation	Comparative example	Example of the present invention	Go out pig iron amount (T/D)	11500	11400	11900
Air output (Nm ³/min)	8005	7900	7890	Go out pig iron amount (T/D)	11500	11400	11900
Air output (Nm ³/min)	8005	7900	7890	RAR(kg/T)	500	517	488
CR(kg/T)	400	367	338	RAR(kg/T)	500	517	488
CR(kg/T)	400	367	338	PC(kg/T)	100	100	100
LPG(kg/T)	0	50	50	PC(kg/T)	100	100	100
LPG(kg/T)	0	50	50	Coke rate of displacement (-)	0	0.66	1.24

In table 4, the situation (hereinafter referred to as " elemental operation ") that is not blown into LPG gas is documented in the left hurdle; The situation (hereinafter referred to as " comparative example ") that is blown into micro mist carbon and LPG gas (50kg/T) in the position of the inboard front end 200mm of distance air port stove is documented in the middle column; The situation that pipe and comparative example be blown into LPG gas (50kg/T) in the same manner that is blown into example of the present invention shown in Figure 1 (is blown into LPG gas in air port stove inboard front position, be blown into the situation of micro mist carbon in the inboard front end 200mm of distance air port stove position from its rear, hereinafter referred to as " example of the present invention ") be documented in the right hurdle.

Seeing Table 4 air output hurdle, is 8005 (Nm in the elemental operation ³/ min), be 7900 (Nm in the comparative example ³/ min), become 7890 (Nm in the example of the present invention ³/ min).This expression, owing to used the LPG air-blowing of example of the present invention to go into structure, air-supply that also can be same when being blown into LPG gas with elemental operation.Even this is also not produce crushing because be blown into LPG gas.

See reductive agent than the hurdle as can be known, the reductive agent ratio is 500 (kg/T) in elemental operation, is reduced to 488 (kg/T) in example of the present invention, and reduction efficiency has improved.This expression can effectively utilize the high LPG gas of reduction efficiency as reductive agent.On the other hand, in comparative example, though be blown into and the same LPG gas of measuring of the present invention's example, the reductive agent ratio is 517 (kg/T), and is taller when the reductive agent ratio becomes than elemental operation.This expression though be blown into the good LPG gas of reduction efficiency, has encouraged air output reduction and operation instabilityization because crushing rises, and can not be effective as the reductive agent utilization.

And, see the coke ratio hurdle, coke ratio is 400 (kg/T) in elemental operation, becomes 338 (kg/T) in the example of the present invention, as can be known coke ratio 62 (kg/T) that descended.Owing to press 50(kg/T) be blown into LPG gas, coke ratio 62 (kg/T) that descended, this expression, LPG gas that is blown into and coke have carried out replacing (coke rate of displacement: 62/50=1.24) effectively.On the other hand, in comparative example, though be blown into and the LPG gas of the same amount of the present invention example, coke ratio is 367 (kg/T), but is to have reduced by 33 (kg/T) during than elemental operation.This expression though be blown into the good LPG gas of reduction efficiency, has encouraged air output reduction and operation instabilityization because crushing rises, and can not replace (coke rate of displacement: 33/50=0.66) with coke effectively.

And, see Table 4 go out pig iron amount hurdle, going out pig iron amount in elemental operation is 11500 (T/D), is increased to 11900 (T/D) in the example of the present invention, the effect that is blown into the good LPG gas of reduction efficiency is reflected in out pig iron amount aspect.On the other hand, in comparative example, going out pig iron amount is 11400 (T/D), reduces during than elemental operation.This be because, though be blown into the good LPG gas of reduction efficiency,, rise by crushing and to have encouraged air output and reduce and the operation instabilityization because to be blown into mode improper, can not be effective as the reductive agent utilization.

Like this, improper even be blown into the high gaseous reducing agent of reduction efficiency as LPG gas if it is blown into mode, can not carry out effective blast furnace operation.

(embodiment 4) (gaseous reducing agent: COG)

Replace the domestic gas of embodiment 1 with coke gas (COG), just with the checking of test furnace with the blast furnace reality is pretended influence already verify.In addition, except that replace domestic gas with COG gas, test conditions is carried out the method identical with embodiment 1.In addition, consisting of of the COG gas that uses in the present embodiment: hydrogen: 58.5 volume %, CO gas: 6.4 volume %, CO ₂Gas: 2.0 volume %, methane gas: 27.4 volume %, ethane gas: 2.6 volume %, N ₂Gas: 2 volume %, in addition, calorie is 4580kcal/Nm ³And about the micro mist carbon that uses in the present embodiment, the particulate by 74 μ m meshes sieve at interval is 80%, and kind is the blackwater charcoal.

Consequently, within the scope of the present invention, be blown into gaseous reducing agent and can not produce the crushing problem.And, just the influence of blast furnace actual job is verified that its effect is shown in Table 5.

Table 5

	Elemental operation	Comparative example	Example of the present invention
	Elemental operation	Comparative example	Example of the present invention	Go out pig iron amount (T/D)	11500	11300	11900
Air output (Nm ³/min)	8005	7780	7760	Go out pig iron amount (T/D)	11500	11300	11900
Air output (Nm ³/min)	8005	7780	7760	RAR(kg/T)	500	529	500
CR(kg/T)	400	379	350	RAR(kg/T)	500	529	500
CR(kg/T)	400	379	350	PC(kg/T)	100	100	100
COG gas (kg/T)	0	50	50	PC(kg/T)	100	100	100
COG gas (kg/T)	0	50	50	Coke rate of displacement (-)	0	0.42	1.00

In table 5, the situation (hereinafter referred to as " elemental operation ") that is not blown into COG gas is documented in the left hurdle; The situation (hereinafter referred to as " comparative example ") that is blown into micro mist carbon and COG gas (50kg/T) in the position of the inboard front end 200mm of distance air port stove is documented in the middle column; The situation that pipe and comparative example be blown into COG gas (50kg/T) in the same manner that is blown into example of the present invention shown in Figure 1 (is blown into COG gas in air port stove inboard front position, be blown into the situation of micro mist carbon in the inboard front end 200mm of distance air port stove position from its rear, hereinafter referred to as " example of the present invention ") be documented in the right hurdle.

Seeing Table 5 air output hurdle, is 8005 (Nm in the elemental operation ³/ min), be 7780 (Nm in the comparative example ³/ min), become 7760 (Nm in the example of the present invention ³/ min).This expression, owing to used the COG air-blowing of example of the present invention to go into structure, air-supply that also can be same when being blown into COG gas with elemental operation.Even this is also not produce crushing because be blown into COG gas.

See reductive agent than the hurdle as can be known, the reductive agent ratio is 500 (kg/T) in elemental operation, be that 500 (kg/T) do not change in example of the present invention, but in comparative example, be blown into the LPG gas of same amount, but the reductive agent ratio rises to 529 (kg/T).

And, see the coke ratio hurdle, coke ratio is 400 (kg/T) in elemental operation, is reduced to 350 (kg/T) in the example of the present invention, can reduce high price coke 50 (kg/T) (coke rate of displacement: 50/50=1.00) as can be known.On the other hand, in comparative example, though be blown into and the COG gas of the same amount of the present invention example, coke ratio is 379 (kg/T), but is to have reduced by 21 (kg/T) during than elemental operation.This expression though be blown into the good COG gas of reduction efficiency, has encouraged air output reduction and operation instabilityization because crushing rises, and can not replace (coke rate of displacement: 21/50=0.42) with coke effectively.

And, see Table 5 go out pig iron amount hurdle, going out pig iron amount in elemental operation is 11300 (T/D), is increased to 11900 (T/D) in the example of the present invention, the effect that is blown into the good COG gas of reduction efficiency is reflected in out pig iron amount aspect.On the other hand, in comparative example, going out pig iron amount is 11300 (T/D), also lacks during than elemental operation.This be because, though be blown into the good COG gas of reduction efficiency,, rise by crushing and to have encouraged air output and reduce and the operation instabilityization because to be blown into mode improper, can not be effective as the reductive agent utilization.

Like this, improper even be blown into the high gaseous reducing agent of reduction efficiency as COG gas if it is blown into mode, can not carry out effective blast furnace operation.

(embodiment 5) (solid reductant: synthetic resins)

Replace the micro mist carbon of embodiment 1 with synthetic resins (ash content 3.0 quality % (db), C:85.0 quality % (daf), H:15 quality % (daf)), just with the checking of test furnace with the blast furnace reality is pretended influence already verify.In addition, except that replacing the micro mist carbon with being combined in resin, test conditions is carried out the method identical with embodiment 1.In addition, the median size of the synthetic resins that uses in the present embodiment is 6.5mm, and the resin kind is a polyethylene.

Consequently, within the scope of the present invention, be blown into gaseous reducing agent and can not produce the crushing problem.And, just the influence of blast furnace actual job is verified that its effect is shown in Table 6.

Table 6

	Elemental operation	Comparative example	Example of the present invention
	Elemental operation	Comparative example	Example of the present invention	Go out pig iron amount (T/D)	11500	11400	11700
Air output (Nm ³/min)	7870	7950	7800	Go out pig iron amount (T/D)	11500	11400	11700
Air output (Nm ³/min)	7870	7950	7800	RAR(kg/T)	503	520	493
CR(kg/T)	403	370	343	RAR(kg/T)	503	520	493
CR(kg/T)	403	370	343	Synthetic resins (kg/T)	100	100	100
Domestic gas (kg/T)	0	50	50	Synthetic resins (kg/T)	100	100	100
Domestic gas (kg/T)	0	50	50	Coke rate of displacement (-)	0	0.66	1.20

In table 6, the situation (hereinafter referred to as " elemental operation ") that is not blown into domestic gas is documented in the left hurdle; The situation (hereinafter referred to as " comparative example ") that is blown into synthetic resins and domestic gas (50kg/T) in the position of the inboard front end 200mm of distance air port stove is documented in the middle column; Be blown into pipe and comparative example with example of the present invention shown in Figure 1 (are blown into domestic gas in air port stove inboard front position by the situation that 50 (kg/T) are blown into domestic gas in the same manner, be blown into the situation of synthetic resins in the inboard front end 200mm of distance air port stove position from its rear, hereinafter referred to as " example of the present invention ") be documented in the right hurdle.

Seeing Table 6 air output hurdle, is 7870 (Nm in the elemental operation ³/ min), be 7950 (Nm in the comparative example ³/ min), become 7800 (Nm in the example of the present invention ³/ min).This expression, owing to used the domestic gas of example of the present invention to be blown into structure, air-supply that also can be same when being blown into domestic gas with elemental operation.Even this is also not produce crushing because be blown into domestic gas.

See reductive agent than the hurdle as can be known, the reductive agent ratio is 503 (kg/T) in elemental operation, is reduced to 493 (kg/T) in example of the present invention, and reduction efficiency has improved.This expression can effectively utilize the high domestic gas of reduction efficiency as reductive agent.On the other hand, in comparative example, though be blown into and the same domestic gas of measuring of the present invention's example, the reductive agent ratio is 520 (kg/T), and is taller when the reductive agent ratio becomes than elemental operation.This expression though be blown into the good domestic gas of reduction efficiency, has encouraged air output reduction and operation instabilityization because crushing rises, and can not be effective as the reductive agent utilization.

And, see the coke ratio hurdle, coke ratio is 403 (kg/T) in elemental operation, becomes 343 (kg/T) in the example of the present invention, as can be known coke ratio 60 (kg/T) that descended.Owing to be blown into 50 (kg/T) domestic gas, coke ratio 60 (kg/T) that descended, this expression, domestic gas that is blown into and coke have carried out replacing (coke rate of displacement: 60/50=1.20) effectively.On the other hand, in comparative example, though be blown into and the domestic gas of the same amount of the present invention example, coke ratio is 370 (kg/T), but is to have reduced by 33 (kg/T) during than elemental operation.This expression though be blown into the good domestic gas of reduction efficiency, has encouraged air output reduction and operation instabilityization because crushing rises, and can not replace (coke rate of displacement: 33/50=0.66) with coke effectively.

And, see Table 6 go out pig iron amount hurdle, going out pig iron amount in elemental operation is 11500 (T/D), is increased to 11700 (T/D) in the example of the present invention, the effect that is blown into the good domestic gas of reduction efficiency is reflected in out pig iron amount aspect.On the other hand, in comparative example, going out pig iron amount is 11400 (T/D), also lacks during than elemental operation.This be because, though be blown into the good domestic gas of reduction efficiency,, rise by crushing and to have encouraged air output and reduce and the operation instabilityization because to be blown into mode improper, can not be effective as the reductive agent utilization.

Embodiment 6

In order to confirm the effect of embodiment 2, use coke filled-type test burn stove shown in Figure 2 to experimentize, to being blown into and not being blown into the situation of domestic gas, investigation micro mist carbon is blown into the influence of position.In addition, domestic gas is blown into that the position is constant to be made as apart from stove Inner Front End 25mm place, air port.

Illustrated among Fig. 6 when making micro mist carbon be blown into the graphic representation that position micro mist carbon when inlet front end changes by 50mm is blown into the relation of the dust arrestment amount in position and the exhaust.In Fig. 6, the longitudinal axis is represented the dust arrestment amount, and transverse axis represents that micro mist carbon is blown into the position.

Shown in Fig. 6 graphic representation, when being blown into and be not blown into domestic gas, micro mist carbon is blown into the position and retreats to the stove outside from inlet front end more, and the dust arrestment amount in the exhaust reduces more.This explanation, the distance that begins from inlet front end is long more, and the preheating of the micro mist carbon in blowpipe is abundant more, and the incendivity of micro mist carbon in stove is high more.

And, being blown under the situation of domestic gas, the dust arrestment amount from exhaust reduces, and thinks that the incendivity of micro mist carbon has improved by the caused combustion-supporting effect of the combustion heat of domestic gas in stove.

From the graphic representation of Fig. 6 as can be known, when being blown into domestic gas near inlet front end, even micro mist carbon is blown into the position at distance inlet front end 50mm place, dust arrestment amount in the exhaust and the roughly Schwellenwert when not being blown into domestic gas are equal extent.Confirm thus,, also the air permeability problem can not take place even embodiment 2 described micro mist carbon are blown into the position at distance inlet front end 50mm place.

Fig. 7 shows when making micro mist carbon be blown into the graphic representation that position micro mist carbon when inlet front end changes by 50mm is blown into the relation of position and crushing.In Fig. 7, the longitudinal axis is represented crushing, and transverse axis represents that micro mist carbon is blown into the position.

As shown in Figure 7, when not being blown into domestic gas, when the distance of distance inlet front end surpassed 150mm, crushing sharply rose, and is corresponding therewith, when being blown into domestic gas, when the distance of distance inlet front end surpasses 200mm, confirms that just crushing rises.

When being blown into domestic gas, owing to cause the burning of domestic gas near the inlet front end in stove, oxygen from the hot blast that blowpipe is sent consumes near inlet front end, be difficult to cause burning, think that the micro mist carbon that crushing is risen is blown into the position for being offset about 50mm from inlet front end to the stove outside at the micro mist carbon of this position.

Like this, from the graphic representation of Fig. 7 as can be known, when being blown into domestic gas near inlet front end, even micro mist carbon is blown into the position at distance inlet front end 200mm place, crushing and the roughly Schwellenwert when not being blown into domestic gas are equal extent.Confirm thus,, also the crushing problem can not take place even embodiment 2 described micro mist carbon are blown into the position at distance inlet front end 200mm place.

As mentioned above, confirmed, wished that solid reductant is blown into set positions and is being blown into the scope apart from inlet front end 200mm that the position also is positioned at the stove outside than gaseous reducing agent when gaseous reducing agent being blown into set positions in inlet front end 0～50mm scope the time.

And, according to Fig. 6, Fig. 7, for make the dust arrestment amount still less and crushing littler, that more wishes solid reductant is blown into set positions in distance inlet front end 75～200mm scope.

Embodiment 7

In order to confirm effect of the present invention, use the coke filled-type test burn stove of above-mentioned analog blast furnace shown in Figure 2, measure top temperature position in the stove of embodiment shown in Figure 8.It the results are shown among Fig. 9.

As shown in Figure 9, the top temperature position is apart from the about 500mm of inlet front end place in the stove, and is identical with the above-mentioned situation that is not blown into domestic gas shown in Figure 10.

Confirm thus, use is set at the air port 1 of 400mm to the outstanding length L of stove inboard from blast furnace inner-wall surface 2, simultaneously, being positioned at gaseous reducing agent that gaseous reducing agent is blown into pipe 5 front ends is blown into a mouthful 5a and is configured near the inboard front end of air port stove, thus, can avoid being blown into moving of top temperature position in the stove that domestic gas causes.

Industrial applicibility

In the present invention, be formed near the inboard leading section of blast-furnace tuyere stove by gaseous reducing agent being blown into the position, can make gaseous reducing agent in the stove internal combustion, can not prevent that the crushing in the blowpipe from occuring in air port and blowpipe internal combustion. Consequently, can effectively utilize gaseous reducing agent and reduction efficiency is reduced, can improve the coke replacement rate. And, can alleviate the thermic load of the cooling device of cooling air port and blowpipe etc., and prevent heat waste.

And, in the present invention, near the gaseous reducing agent that has outstanding length setting from from the blast furnace internal face to the stove inboard and be the air port of 350～600mm and be arranged on the inboard leading section of this air port stove is blown into mouth, thus, even when being blown into the gaseous reducing agents such as domestic gas from the air port, also can prevent the interior maximum temperature position of stove to the furnace wall side shifting, and can make the interior maximum temperature position of stove more to the stove medial movement, can suppress the rising of blast furnace furnace wall temperature and extremely not shorten the air port life-span. Consequently, can utilize domestic gas to be blown into to carry out low-reductant and compare operation.

Claims

1. a blast furnace reductive agent device for blowing is the reductive agent device for blowing that is blown into gaseous reducing agent from blast-furnace tuyere, and wherein, the mouth that is blown into of gaseous reducing agent is arranged on from the inboard leading section of the stove of described blast-furnace tuyere in the scope of the stove outside 0～50mm,

Have solid reductant and be blown into pipe, the mouth that is blown into that this solid reductant is blown into pipe is configured in the air supply direction upstream side that is blown into mouthful with respect to gaseous reducing agent.

2. blast furnace reductive agent device for blowing, it is the reductive agent device for blowing that is blown into gaseous reducing agent from blast-furnace tuyere, wherein, have the gaseous reducing agent that is used to be blown into gaseous reducing agent and be blown into pipe, the mouth that is blown into that this gaseous reducing agent is blown into pipe is configured in from the inboard leading section of the stove of described blast-furnace tuyere in the scope of the stove outside 0～50mm

Have solid reductant and be blown into pipe, the mouth that is blown into that this solid reductant is blown into pipe is configured in the air supply direction upstream side that is blown into mouth that is blown into pipe with respect to gaseous reducing agent.

3. blast furnace reductive agent device for blowing according to claim 2, wherein, in the air-supply path, solid reductant is blown into pipe and gaseous reducing agent is blown into the pipe cross-over configuration.

4. blast furnace reductive agent device for blowing according to claim 1 and 2, wherein, the mouth that is blown into that solid reductant is blown into pipe is configured in from the inboard leading section of the stove of blast-furnace tuyere in the scope of the 200mm in the stove outside.

5. blast furnace reductive agent device for blowing according to claim 2, wherein, gaseous reducing agent is blown into pipe and has kink or bend.

6. blast furnace reductive agent device for blowing according to claim 1 and 2, wherein, it is 350mm～600mm that the air port is set for from blast furnace inner-wall surface side-prominent length in stove.

7. blast furnace reductive agent device for blowing according to claim 6, wherein, it is 350mm～400mm that the air port is set for from blast furnace inner-wall surface side-prominent length in stove.

8. blast furnace reductive agent device for blowing according to claim 6, wherein, the mouth that is blown into that gaseous reducing agent is blown into pipe is configured in from inlet front end in the scope of the stove outside 0～25mm.