KR101311609B1 - Process for producing sintered ore and sintering apparatus - Google Patents

Abstract

A downward suction type sintering machine WHEREIN: The manufacturing method and sintering machine of the sintered ore which can manufacture high strength high quality sintered ore with high yield safely. Charged sintered raw materials including spectroscopy and carbonaceous material were formed on the pallet 8 to be circulated to form a charging layer 9, and the ignition furnace was ignited to the carbonaceous material of the formed charging layer and disposed below the pallet. A method of manufacturing a sintered ore for producing sintered ore by sucking air in a wind box, and after igniting the charging layer 9 with an ignition furnace, the liquid fuel is atomized to a particle diameter of 100 μm or less and the charged layer 9 It was supplied to the upper side of the, and it was made to supply in the state diluted from below the said charging layer 9 in the charging layer 9 below the lower limit of combustion concentration at normal temperature. The sintering machine has a liquid fuel injector for injecting liquid fuel onto the charging layer downstream of the ignition furnace.

Description

Process for producing sintered ore and sintering machine {PROCESS FOR PRODUCING SINTERED ORE AND SINTERING APPARATUS}

The present invention relates to a method for producing a sintered ore and a sintering machine for producing a sintered ore.

The sintered ore, which is the main raw material of the blast furnace making method, is generally produced via a process as shown in FIG. 15. Raw materials for sintered ore include iron ore powder, recovered in steel mills, sintered ore dust (returned ore), CaO-containing sub-raw materials such as limestone and dolomite, agglomeration preparations such as quick lime, coke powder and Anthracite, etc. These raw materials are cut out from the plurality of hoppers 1 on a conveyor at a predetermined ratio, and the raw materials are cut out by a drum mixer 2, a rotary kiln 3, or the like. Water is added, mixed and granulated to form a sintered raw material, which is a pseudo particle having an average diameter of 3.0 to 6.0 mm .. On the other hand, the granulated ore is cut out from the bottom hopper 4. A bottom layer is formed on the grate of the sinterer pallet 8.

The raw material for sintering is from the surge hopper 5 disposed on the sintering machine, through the drum feeder 6 and the charging chute 7, on the bottom layer on the endless movable sintering machine pallet 8. It charges in and forms the charging layer 9 of the sintering raw material also called a sintering bed. The thickness (height) of a charge layer is about 400-800 mm normally. Thereafter, in the ignition furnace 10 provided above the charging layer 9, a wind box (wind box) which is ignited in the carbonaceous material in the surface layer of the charging layer 9 and is arranged under the pallet 8 By sucking the air downward through 11), the carbonaceous material in the charging layer is sequentially burned, and the sintered raw material is burned and melted by the heat of combustion generated at this time to obtain a sintered cake. The sintered cake thus obtained is then crushed and grained and recovered as a sintered ore consisting of a compact of 5.0 mm or more.

In the manufacturing process, first, the ignition furnace 10 ignites the charged layer surface layer. The carbonaceous material in the ignited charge bed continues to burn with the width drawn by the air drawn from the upper layer to the lower layer by the windbox, and the combustion zone is gradually moved forward to the lower layer as the pallet 8 moves. Downstream). As the combustion progresses, the water contained in the sintered raw material particles of the charging layer is vaporized by heat generated by the combustion of the carbonaceous material, sucked downward, and concentrated in the lower sintered raw material, which has not yet risen in temperature, Form a wet zone. When the moisture concentration is above a certain level, the water fills the voids between the raw material particles that are the flow paths of the suction gas, thereby increasing the airflow resistance. In addition, the molten portion required for the sintering reaction occurring in the combustion zone also becomes a factor for increasing the airflow resistance.

The production amount (t / hr) of the sintering machine is generally determined by the sintering production rate (t / hr · m 2) × sintering machine area (m 2). That is, the production amount of the sintering machine varies depending on the size and length of the sintering machine, the thickness (loading layer thickness) of the raw material deposition layer, the bulk density of the sintering raw material, the sintering (burning) time, the yield, and the like. In order to increase the yield of sintered ore, it is considered that it is effective to improve the air permeability (pressure loss) of the charged layer to shorten the sintering time, or to increase the cold strength of the sintered cake before crushing to improve the yield. It is becoming.

FIG. 16 shows that when the front line of the combustion table moving in the charging layer having a thickness of 600 mm is located about 400 mm above (200 mm below the surface of the loading layer) the pallet of the charging layer. Shows the pressure loss and temperature distribution in the charged bed. The pressure loss distribution at this time is about 60% in the wet zone and about 40% in the combustion / melt zone.

Fig. 17 shows the temperature distribution in the charging layer at the time of high production and low production of sintered ore, that is, when the pallet moving speed is fast and late. The time for which the raw material particles are kept at a temperature of 1200 ° C. or more (hereinafter referred to as the “high temperature holding time”) is represented by t ₁ for low production and t ₂ for high production that emphasizes productivity. have. When high production, since the moving speed of the pallet high, the high temperature station holding time t ₂ is shorter than the time t ₁ of the low production. When the high temperature zone holding time is shortened, it is likely to become insufficient in sintering, the cold strength of the sintered ore decreases, and the yield decreases. Therefore, in order to increase the productivity of the high-strength sintered ore, it is necessary to take some means to increase the strength of the sintered cake, that is, the cold strength of the sintered ore, and to maintain and improve the yield even in a short time of sintering. In addition, as an index indicating the cold strength of the sintered ore, SI (shutter index) and TI (tumbler index) are generally used.

FIG. 18A shows the progress of sintering in the charging layer on the sintering machine pallet, and FIG. 18B shows the temperature distribution (heat pattern) in the sintering process in the charging layer. ) Shows the yield distribution of the sintered cake. As can be seen from FIG. 18B, the upper portion of the charged layer is less likely to rise in temperature than the lower layer portion, and the high temperature zone holding time is also shortened. Therefore, combustion melting reaction (sintering reaction) becomes inadequate and the intensity | strength of a sintered cake becomes low in this loading layer upper part, As shown in FIG.18 (c), a yield is low and a factor which causes the fall of productivity It is becoming.

In view of such a problem, a method for keeping the charge layer upper layer part at a high temperature for a long time has been conventionally proposed. For example, Patent Document 1 discloses a technique of injecting a gaseous fuel onto a charging layer after ignition in the charging layer. However, although the type of gaseous fuel (combustible gas) is unknown, the above technique uses a high concentration of gas even as propane gas (LPG) or natural gas (LNG). In addition, since the amount of coal ash is not reduced at the time of spraying combustible gas, the inside of a sintered layer becomes high temperature exceeding 1380 degreeC. Therefore, in this technique, sufficient cold strength improvement and yield improvement effect cannot be enjoyed. In addition, when combustible gas is injected immediately after the ignition furnace, there is a high risk of causing a fire in the upper space of the sintered bed due to the combustion of the combustible gas, and it is not practical.

Moreover, patent document 2 also discloses the technique which adds a flammable gas to the air attracted to a charging layer after ignition to a charging layer. After the ignition, the supply is preferably about 1 to 10 minutes. However, the surface layer immediately after the ignition in the ignition furnace has a sintered ore in the red state remaining, and depending on the supply method, a fire may be caused by the combustion of combustible gas. Although the risk is high and the specific technique is small, even if combustible gas is combusted in the sintering zone of completion of sintering, there is no effect. Combustion in the sintering zone deteriorates air permeability due to temperature rise and thermal expansion caused by the combustion gas. There is a tendency to reduce, and since the amount of carbonaceous material is not reduced at the time of blowing in combustible gas, the inside of a sintered layer becomes high temperature exceeding 1380 degreeC. Therefore, in this technique, since sufficient cold strength improvement and the yield improvement effect are not enjoyed, it has not reached practical use until now.

Moreover, patent document 3 arrange | positions a hood on the charging layer in order to make the inside of the charging layer of a sintering raw material high temperature, and starts blowing in the position immediately after an ignition furnace with the mixture gas with air or coke oven gas through the hood. Doing. However, this technique also has a high temperature at which the combustion molten zone in the sintered bed is higher than 1380 ° C, so that the effect of gas injection into the coke oven cannot be enjoyed, and at the same time, a flammable mixed gas is ignited in the upper space of the sinter bed, causing a fire. There is a risk and it is not put to practical use.

Moreover, patent document 4 is disclosing the method of blowing a low melting point solvent, a carbon | charcoal material, or a flammable gas simultaneously in the position immediately after an ignition furnace. However, since this method also blows inflammable gas in a state where flame remains on the surface, there is a high risk of fire in the upper space of the sintered bed, and since the width of the sintering stand cannot be sufficiently thick (less than about 15 mm), The effects of flammable gas blowing cannot be sufficiently expressed. In addition, since there are many low melting point solvents, it causes excessive melt phenomenon in the upper layer part, closes the pores used as an air flow path, worsens air permeability, and lowers productivity. Moreover, it is not put to practical use to date.

As described above, all of the conventional techniques proposed so far have great problems for practical use, and development of a flammable gas blowing technique that can be implemented is hopeless.

As a technique for solving the above-mentioned problems, the applicant of Patent Document 5 supplies various gaseous fuels diluted below the lower combustion lower concentration from the charging layer of the sintering raw material deposited on the pallet of the sintering machine and introduced into the charging layer. By combusting, the method of adjusting one or both of the highest achieved temperature and high temperature area | region holding time in a charge bed is proposed.

Patent Document 1: Japanese Patent Application Laid-Open No. 48-18102 Patent Document 2: Japanese Patent Application No. 46-27126 Patent Document 3: Japanese Patent Application Laid-Open No. 55-18585 Patent Document 4: Japanese Patent Application Laid-Open No. 5-311257 Patent Document 5: WO2007-052776 Publication

The technique of the said patent document 5 supplies (introduces) the gaseous fuel diluted to predetermined density | concentration in a downward suction type sintering machine, and performs the gaseous fuel supply which combusts in the target position in a charging layer. In addition, it is possible to appropriately control the maximum attained temperature or the high temperature zone holding time at the time of combustion of the sintered raw material, and furthermore, not only the upper layer of the charge layer which tends to lower the cold strength of the sintered ore due to lack of calories, Operation such as raising the sintered ore strength in the portion can be performed.

However, when the gaseous fuel supply and sintering operation is performed, there is a possibility that high temperature parts such as cracks of the sintered bed or the sintered cake become embers and backfire into gaseous fuel, resulting in combustion (ignition) of the gaseous fuel. If the sintering operation is continued in such a flammable state (aside from the problem of explosion), not only can the gaseous fuel be not supplied into the charging bed, but also the oxygen-deficient atmosphere in which oxygen is consumed by the combustion of the gaseous fuel It is supplied (introduced). As a result, it is not only possible to control the maximum attained temperature and the high temperature zone holding time at the time of combustion, but also cause a lack of combustion, which leads to a decrease in the strength of the sintered ore, and lower the yield and productivity. do.

Therefore, the present invention has been carried out by paying attention to the problems of the above-described prior art, and an object of the present invention is to provide a method for producing a sintered ore and a sintering machine capable of producing a high-strength high-quality sintered ore safely and safely in a downward suction type sintering machine. Doing.

In order to achieve the above object, the present invention provides a method for producing a sintered ore having a charging step for forming a charging layer, an ignition step, a liquid fuel supplying step for supplying the charging layer and a sintering step.

The charging process consists of charging a sintered raw material including spectroscopy and carbonaceous material on a pallet that is circulating to form a charging layer. The ignition process consists of igniting the carbonaceous material of the charged layer formed in the ignition furnace. The liquid fuel supplying process consists of supplying, after ignition, the liquid fuel atomized to a particle size of 100 µm or less on the charging layer. The sintering process consists of sucking air in a wind box disposed below the pallet to produce a sintered ore.

The atomized liquid fuel preferably has a particle size of 50 μm or less and a particle size of 20 μm or more. It is preferable that the atomized liquid fuel has a concentration below the lower combustion limit. It is further more preferable that the said concentration is 75% or less and 1% or more of a combustion lower limit concentration. It is most preferable that the said concentration is 25% or less and 4% or more of the lower limit of a combustion concentration.

It is preferable that the said liquid fuel supply process is the following.

(A) The granulated liquid fuel with a particle size of 100 micrometers or less is supplied on a charge layer, and it supplies to a charge layer in the state diluted to the combustion lower limit concentration at normal temperature.

(B) The atomized liquid fuel with a particle diameter of 100 micrometers or less is injected to the upper side of a charge layer.

(C) The liquid fuel is mixed with the compressed gas, atomized, and injected onto the charging layer. The compressed gas is a gas containing at least one of anti-flammable nitrogen, carbon dioxide, and water vapor as a main component.

The liquid fuel is preferably at least one selected from the group consisting of petroleum liquid fuel, alcohol liquid fuel, ether liquid fuel and other hydrocarbon compound liquid fuel. The petroleum-based liquid fuel is preferably at least one selected from the group consisting of kerosene, light oil and heavy oil. Preferably, the alcohol liquid fuel is at least one selected from the group consisting of methyl alcohol, ethyl alcohol and diethyl alcohol. The other hydrocarbon compound liquid fuel is preferably at least one selected from the group consisting of pentane, hexane, heptane, octane, nonane, decane, benzene and acetone.

It is preferable to supply the liquid fuel at any of the following positions.

(a) The atomized liquid fuel is supplied from the surface layer portion of the charging layer until the sintering cake is produced and sintering is completed.

(b) Atomized liquid fuel is supplied in the area | region where the thickness of a combustion / melting zone becomes 15 mm or more.

(c) The atomized liquid fuel is supplied after the position where the precombustion line reaches 100 mm below the surface layer.

In addition, the present invention is a circular feed pallet, a raw material supply device for charging the sintered raw material including spectroscopy and carbon material on the pallet to form a charging layer, and the ignition furnace to ignite the carbon material in the sintered raw material on the pallet And a liquid fuel injector for atomizing the liquid fuel provided on the downstream side of the ignition furnace to a particle diameter of 100 μm or less and injecting it above the charging layer, and a sintering machine having a wind box for sucking air below the pallet.

The liquid fuel injector is atomized by mixing a compressed gas supply source, a liquid fuel supply source, a compressed gas from the compressed gas supply source, and a liquid fuel from the liquid fuel supply source to inject horizontally onto the charging layer. It is desirable to have a spray mechanism. It is preferable that the said compressed gas is gas which has at least one of an anti-flammable nitrogen, a carbon dioxide gas, and water vapor as a main component. The spray mechanism horizontally conveys a conveying pipe having a downward gradient toward a downstream side for conveying a mixed fluid of the compressed gas and liquid fuel, a communication pipe connected to a lower surface side of the conveying pipe, and a liquid fuel formed on the lower surface of the communication pipe. It is preferable to have the injection nozzle of the downward gradient toward the discharge port sprayed in the direction. The liquid fuel injector preferably has a preheating mechanism for preheating the liquid fuel so as to have an optimum viscosity for atomization when the liquid fuel has a high viscosity.

The liquid fuel is preferably at least one selected from the group of petroleum liquid fuel, alcohol liquid fuel, ether liquid fuel, and other hydrocarbon compound liquid fuel in a liquid state at or near room temperature.

According to the manufacturing method of the sintered ore of this invention, in the downstream of an ignition furnace, a liquid fuel is atomized and supplied to the upper part of a charging layer below 100 micrometers of particle diameters, and below the lower combustion limit concentration at normal temperature from a charging layer to a charging layer. Since it is supplied in a diluted state, the suction of air by the windbox prevents the liquid fuel from burning on the charging layer, vaporizes in the upper layer of the charging layer, and reaches the combustion / melting zone of the lower layer, Similar to the case of using gaseous fuel as a fuel, the charging layer tends to lower the cold strength of the sintered ore due to the lack of combustion by controlling the supply position of the atomized liquid fuel, the maximum attained temperature during combustion, and the high temperature zone holding time. It is possible to carry out operations such as increasing the sintered ore intensity not only in the upper portion but also in any portion below the charged layer middle layer. All. Here, when the particle diameter of the liquid fuel exceeds 100 µm, a portion remaining in the surface layer portion of the charging layer is generated, combustion starts at the surface layer portion, wasteful, and the effect of extending the high temperature zone holding time is weakened. If it is 100 micrometers or less, combustion in the upper part and the surface layer part of a charge layer is suppressed, and once it enters a charge layer and vaporizes, it is attracted to the lower layer part, reaches a combustion / melting zone, and can burn as gaseous fuel.

Here, the particle size of the atomized liquid fuel is preferably 50 μm or less and 20 μm or more, and by selecting the particle size of 50 μm or less, the atomized liquid fuel is reliably used for combustion / melting of the charging layer. Can be introduced. The smaller the particle size of the atomized liquid fuel is, the smaller it is. However, the smaller the particle diameter is, the smaller the generation amount is. Therefore, it is preferable to select a particle size of 20 µm or more in consideration of the generation amount necessary for extending the high temperature zone holding time.

According to the sintering machine of the present invention, since the liquid fuel injector for atomizing the liquid fuel in the horizontal direction and atomizing the liquid fuel is provided downstream of the ignition furnace, the atomized liquid fuel injected from the liquid fuel injector Uniformly dispersed on the charge layer, this uniformly dispersed atomized liquid fuel is drawn into the charge layer through the windbox. Therefore, the liquid fuel is volatilized in the charging bed, and as in the case of using gaseous fuel, the supply position of the atomized liquid fuel, the maximum attained temperature during combustion, and the high temperature zone holding time are controlled to prevent the sintered ore from being burned. Operations such as increasing the strength of the sintered ore in any portion below the charged layer middle layer as well as the top of the charged layer where the cold strength tends to be lowered can be performed. In addition, by atomizing the liquid fuel and injecting it onto the charging layer, ignition and the like do not occur as in the case where the liquid fuel is used as it is, and the introduction into the atomized liquid fuel raw material charging layer can be performed safely and stably. have.

Moreover, the combustion on a charge layer can be suppressed by using any one of anti-flammable nitrogen, carbon dioxide, and water vapor as a compressed gas which atomizes a liquid fuel.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows one Embodiment of the sintering machine which concerns on this invention.
FIG. 2 is a schematic sectional view taken along the line AA of FIG. 1.
3 is a front view illustrating the spray mechanism.
4 is a schematic perspective view showing a liquid fuel injector spray device arrangement.
5 is an explanatory view showing a liquid fuel mist injection state of the liquid fuel injection device.
6 is a system diagram showing a system for supplying a liquid fuel and a compressed gas of a liquid fuel injector.
7 is a cross-sectional view taken along the line AA of FIG. 1 showing a specific configuration of the liquid fuel injection device.
It is explanatory drawing which shows the seal mechanism of the front-back direction of a liquid fuel injector.
FIG. 9 is a diagram showing a change and heat pattern of the combustion / melting band in the test port by liquid fuel injection.
Fig. 10 is a diagram (photo) showing the change of combustion / melting band in the test port by liquid fuel injection.
Fig. 11 is a schematic diagram showing the principle at the time of blowing the liquid fuel of the present invention, Fig. 11 (a) is a view showing the situation of the port test, and Fig. 11 (b) is a diagram illustrating the phenomenon of the port test. It is a figure, FIG.11 (c) is a figure which shows the point of combustion, and FIG.11 (d) is a figure which shows in-layer temperature.
12 is a view showing a combustion situation at the time of blowing the liquid fuel of the present invention.
Fig. 13 is a diagram showing the ignition situation at the time of blowing the liquid fuel of the present invention.
It is sectional drawing along the AA line of FIG. 1 which shows another embodiment of this invention.
15 is a view for explaining a conventional sintering process.
It is a figure explaining the pressure loss and temperature distribution in a sintered layer.
It is explanatory drawing comparing the temperature distribution at the time of high production and low production.
FIG. 18 is a graph of temperature distribution and yield distribution in a sintering machine, FIG. 18A shows the progress of sintering, FIG. 18B shows the temperature distribution, and FIG. 18C shows the yield distribution. Indicates.

The manufacturing method of the sintered ore using the sintering machine of this invention consists of a charging process, an ignition process, a liquid fuel supply process, and a sintering process. In this manufacturing method, the charging step is a step of charging a sintered raw material containing spectroscopy and carbonaceous material on a pallet which is circulating and forming a charging layer of the sintered raw material on the pallet. It is a process of igniting the carbon material of the surface of a charge layer using. In addition, the liquid fuel supplying step is a step of injecting the atomized liquid fuel to 100㎛ or less from the liquid fuel injector above the charging layer, the sintering step is the atomized liquid by the suction force of the wind box disposed under the pallet The fuel and air are sucked into the charging layer, the atomized liquid gas fuel is combusted in the charging layer, and the air sucked into the charging layer combusts the carbonaceous material in the charging layer, and the heat generated by the combustion This is a step of sintering the sintered raw material and producing a sintered cake.

In the present invention, on the downstream side of the ignition furnace, the atomized liquid fuel is injected into the atmosphere by blowing the atomized liquid fuel above the charging layer as described above, and the atomized liquid fuel is charged by air suction of the windbox while suppressing ignition. It can be volatilized in the layer.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows one Embodiment of the sintering machine which concerns on this invention. In FIG. 1, as in the conventional example described above, a plurality of sintering raw materials such as iron ore powder, recovery in steel mill, sintered ore powder, CaO-containing sub-raw materials such as limestone and dolomite, coarse lime and coking powder, anthracite coal, etc. The raw material cut out from the hopper 1 at a predetermined ratio on the conveyor, mixed with the appropriate amount of water by a drum mixer (2), a rotary kiln (3) or the like, is assembled, and the average diameter of 3.0 to 6.0 mm It becomes the sintering raw material which is a pseudo particle which has, and is stored by the surge hopper 5. On the other hand, the lump ore grains having a predetermined particle diameter are cut out from the bottom hopper 4 to form a bottom layer on the grate of the sintering machine pallet 8.

Then, the sintering raw material is charged from the surge hopper 5 through the drum feeder 6 and the charging chute 7 onto the bottom layer on the stepless movable sintering machine pallet 8, and the charging layer 9 also referred to as a sintering bed. To form. The thickness (height) of a charge layer is about 400-800 mm normally. Then, in the ignition furnace 10 provided above the charging layer 9, the wind box 11 which ignites the carbonaceous material in the surface layer of this charging layer 9, and arrange | positions under the pallet 8 is carried out. The carbonaceous material in the charged layer is sequentially burned by sucking the air downward through the air.

On the downstream side of the ignition furnace 10, a liquid fuel injector 15 for atomizing the liquid fuel in the upper side of the charging layer 9 and injecting the liquid fuel in a substantially horizontal direction is disposed.

One or more of the liquid fuel injectors 15 are disposed at any one position in the pallet traveling direction in the downstream of the ignition furnace 10 or in the process of the combustion / melting zone moving in the charging layer 9. The supply of the liquid fuel mist in the layer 9 is preferably performed at the position after ignition to the carbonaceous material in the charging layer 9. One or more of the liquid fuel injectors 15 are arranged downstream of the ignition furnace 10 at arbitrary positions after the combustion wire has advanced below the surface layer. From the standpoint of adjusting the size, the size, position, and number of arrangements are determined as described later.

This liquid fuel injector 15 has a hood 16 covering the upper part of the sintering machine pallet 8 as shown in FIG. 2, and the opening 17 of a comparatively large area is formed in the upper part of this hood 16. As shown in FIG. It is installed.

2 and 4, the compressed air supply pipe 21 and the liquid fuel supply pipe 22 in the hood 16 along the conveying direction of the sintering machine pallet 8 above the charging layer 9. ) Are arranged in plural, for example, nine pairs in parallel, while maintaining a predetermined interval in the width direction orthogonal to the conveying direction of the sintering machine pallet 8. On the lower surface side of each of the compressed air supply pipes 21 and the liquid fuel supply pipes 22, a spray mechanism 23 is arranged while maintaining a predetermined distance in the conveying direction of the sintering machine pallet 8. These spray mechanisms 23 have a staggered shape in which the spray mechanisms 23 are staggered in the conveying direction of the sintering pellets 8 so that the spraying mechanisms 23 adjacent to the width direction of the sintering pellets 8 do not face each other. Are arranged. In addition, the number of tanks of the compressed air supply pipe 21 and the liquid fuel supply pipe 22 is not limited to 9 sets, and it is preferable to arrange a plurality of sets and 3 to 15 sets.

As shown in FIG. 3, each spray mechanism 23 includes a vertical pipe 24 connected to a lower surface of the compressor body supply pipe 21, and a mixing section 25 formed at an intermediate portion of the vertical pipe 24. And a connecting pipe 26 for connecting between the mixing section 25 and the lower surface of the liquid fuel supply pipe 22 and the width direction of the sintering machine pallet 8 disposed at the lower end of the vertical pipe 24. It consists of the branch injection part 27 which splits into a bifurcated shape.

The branch injection part 27 has two injection nozzle parts 28a and 28b which are symmetrical with the vertical piping 24 interposed. From these injection nozzle parts 28a and 28b, the liquid fuel mist 29 atomized with the microparticles | fine-particles of 100 micrometers or less, for example is injected in a substantially horizontal direction.

Here, the reason for setting the particle diameter of the liquid fuel mist 29 to 100 micrometers or less is that when a particle diameter exceeds 100 micrometers, the part which remains in the surface layer part of the charging layer 9 will generate | occur | produce, and it will start burning in a surface layer part. The waste is not contributed to the extension of the high temperature zone holding time of the upper layer and the middle layer, which is insufficient in combustion in the charging layer 9. The smaller the particle diameter of the liquid fuel mist 29 is, the more preferable it is. However, the smaller the particle diameter is, the smaller the generation amount is. Therefore, the particle diameter of the liquid fuel mist 29 is preferably 50 μm or less and more preferably 20 μm or more. . When the particle diameter of the liquid mist 29 is 50 micrometers or less, the combustion in the upper part and the surface layer part of the charging layer 9 is suppressed, and it passes through the crack part in the sintered cake formed in a surface layer, or vaporizes once in a sintered cake, The sintered cake is passed in a gaseous state to reach the combustion / melting zone and combust. If the particle diameter is less than 20 µm, the amount of generation of the liquid fuel mist 29 decreases, and the introduction of the liquid fuel mist 29 into the charging layer 9 cannot exert a favorable effect of extending the high temperature zone holding time. .

Each of the injection nozzle portions 28a, 28b is, for example, about 85 degrees with respect to the central axis of the vertical pipe 24, which is a slight forward downward gradient that gradually descends as its center line goes from the vertical pipe 24 to the tip. It is set to be the opening angle of. In this way, when the injection nozzle portions 28a and 28b have a slight forward downward gradient, when the injection of the liquid fuel mist is finished, the liquid fuel mist does not remain as liquid in the injection nozzle portions 28a and 28b. , All are dropped. It is preferable that the said opening angle is 20 degrees-90 degrees. More preferably, they are 45 degrees-85 degrees.

Thus, since the spray mechanism 23 is arranged in the zigzag shape in the conveyance direction of the sintering machine pallet 8, the liquid fuel mist 29 sprayed from the injection nozzle parts 28a and 28b of each spray mechanism 23 is carried out. 5 does not interfere with each other and is uniformly dispersed and sprayed onto the charging layer 9. Subsequently, the suction force of the windbox (not shown) below the sintering machine pallet 8 is used, and is introduced into the core portion (lower layer) of the charging layer via the sintered cake produced in the surface layer of the charging layer 9.

As shown in detail in FIG. 6, each of the compressed gas supply pipes 21 is provided through the flow meter FC on the upstream side of the sintering machine pallet 8 and through the control valve VC. Is connected to the compressor body supply main pipe (31). This compressor body source 32 has a storage tank 33 for storing a gas used as the main component of nitrogen, carbon dioxide gas and water vapor having an anti-inflammatory property, and the gas stored in the storage tank 33 It is compressed by the compressor 34 to form a compressed gas, which is stored in the receiver tank 35 and supplied to each control valve VC from the receiver tank 35 through the compressor body supply main pipe 31. Here, the main flow path LM in which the control valve VC is inserted between the receiver tank 35 and the flow meter FC is bypassed, and the control valve VC is bypassed to provide compressed air with a relatively small flow rate. The bypass flow path LB to be supplied is provided. In the bypass flow path LB, the compressed gas from the receiver tank 35 passes through the bypass flow path LB and the flowmeter FC while the liquid fuel mist 29 is not being injected from the spray mechanism 23. It is supplied to the spray mechanism 23, and the clogging of the injection nozzle parts 28a and 28b of the spray mechanism 23 is prevented.

Each liquid fuel supply pipe 22 is likewise connected to the liquid fuel supply main pipe 36 via a flow meter FF on the upstream side of the sintering machine pallet 8 and via a control valve VF, which is connected to the liquid fuel supply main pipe 36. Is connected to the liquid fuel storage tank 38 as a liquid fuel supply source through the fuel supply pump 37. Here, each of the liquid fuel supply pipe 22 and the liquid fuel supply main pipe 36 is inclined at a forward downward gradient in which the arrangement height on the downstream side is lower than the upstream side, and the injection of the liquid fuel mist 29 is terminated. In this case, the liquid fuel supply pipe 22 and the liquid fuel supply main pipe 36 are preferably configured such that no liquid fuel remains.

As the liquid fuel, at least one of petroleum liquid fuels such as kerosene, light oil and heavy oil, liquid liquid fuels such as ethyl alcohol and methyl alcohol, ether liquid fuels and other hydrocarbon liquid fuels which are liquid at room temperature may be used. And they are stored in the liquid fuel storage tank 38.

Here, the liquid fuel used for this invention and its characteristic are shown in following Table 1.

The liquid fuel mist 29 which atomizes and injects such liquid fuel has an ignition temperature of blast furnace gas, coke furnace gas, blast furnace / coke furnace mixed gas, city gas, natural gas or methane gas, ethane gas, propane gas, butane gas. Or because the ignition temperature is higher than that of any one of these gaseous fuels, the blowing layer 9 is blown to burn further in the charging layer 9, which is higher than the temperature of the surface layer of the sintered bed. It is effective for the expansion of the skirt temperature of the combustion / melt at the position of It is preferable that the ignition temperature of a liquid fuel is 180 degreeC-500 degreeC.

Moreover, it is preferable to comprise so that many liquid fuel mist 29 can be supplied in the position of the low yield part of the vicinity of the side wall 18 on the left and right sides of the hood 16. As shown in FIG.

On the other hand, since waste oil etc. may contain the component which is easy to ignite, and the component with low ignition temperature, it is not preferable to use in this invention. In the case where a liquid fuel such as waste oil containing a component having a low ignition temperature or flash point is vaporized in advance and supplied onto the charging layer 9, that is, on the sintered raw material bed, before reaching the vicinity of the combustion zone in the charging layer 9. Since it burns in the upper space of the surface layer of the charging layer 9 or in the vicinity of the surface layer of the charging layer 9, it burns in the vicinity of the combustion zone of the charging layer 9 which this invention intends, for example to 1200 degreeC or more. This is because the effect of prolonging the high temperature zone holding time to be held cannot be obtained.

The reason why the liquid hot zone holding time can be extended by injecting the liquid fuel mist 29 above the charging layer 9 is because of the experimental apparatus shown in FIG. 9, that is, a vertical tube with a transparent quartz window. A test port (diameter: 150 mm Φ, height: 400 mm H) of a shape was prepared, and the same sintering raw material as that used in the sintering plant of the present applicant, using sesame oil as the liquid fuel to be used, that is, Table 2 below The filling layer is formed of the sintered raw material shown in Fig. 2, and the height of the blowing nozzle for spraying sesame oil is 320 mm from the surface of the charging layer, and the COKE FINE ratio is 5.0% (base is 5.25%) and the like. The amount of heat equivalent, the ignition time was set to 30 seconds, the suction thickness was 1200 mmH ₂ O, the blowing amount to 5.0 ml / min, and the blowing position was set from 30 seconds to 30 minutes after the ignition. In addition, the blowing period was set between 1 to 6 minutes after ignition. Here, sesame oil as liquid fuel has a flash point of 255 ° C, a calorific value of 40.3 kJ / g, and a density of 0.92 g / cm 3.

As shown in Fig. 9, the liquid fuel injection test result shows that the width of the combustion zone after 5 min has elapsed to 65 mm in the absence of liquid fuel injection (base) is 50 mm below the surface of the charging layer. The pattern rapidly rises after 1 min after ignition and exceeds 1200 ° C., and the temperature decreases after maintaining the state above 1200 ° C. for 33 sec.

On the other hand, when sesame oil is blown in for 1 to 6 minutes after ignition, the width of the combustion zone at 5 minutes after ignition is expanded to 114 mm, and a heat pattern below 50 mm from the surface of the charging layer is 1 minute from ignition. After passing, the temperature rises rapidly and exceeds 1200 ° C, and the temperature is lowered to a relatively gentle gradient after maintaining the state above 1200 ° C for 82 sec.

Therefore, by injecting sesame oil, the width of the combustion zone can be increased, and the holding time exceeding 1200 ° C in the heat pattern, that is, the high temperature zone holding time can be set to 82 sec. Compared to the case of not, the combustion zone width was extended to about 1.75 times and the hot zone holding time was extended by about 2.5 times.

In addition, using a test apparatus equivalent to the above, when the combustion zone is compared with the three blowing states of liquid fuel blowing, sesame oil blowing and heavy oil blowing under the same blowing conditions as shown in FIG. In comparison, the width of the combustion zone could be increased in the sesame oil blowing state, and the width of the combustion zone could be further increased in the heavy oil blowing state, as compared with the state without blowing the liquid fuel. The properties of each liquid fuel are as shown in Table 3, and the calorific value (kJ / g) of rapeseed oil and sesame oil is assumed to be the same as soybean oil, and the density (g / cm 3) of rapeseed oil is also the same as soybean oil. Is assumed. Although not shown in these rapeseed oil and soybean oil, the combustion zone width and the extension of the high temperature zone maintenance time equivalent to sesame oil were confirmed, and the kerosene oil was also extended the combustion zone width and the extension of the high temperature zone maintenance time equivalent to heavy oil. .

Moreover, in the said embodiment, in the spray mechanism 23 which injects the liquid fuel mist 29, liquid fuel is mixed with compressed gas in the mixing part 25, and it atomizes and injects in the horizontal direction on the charging layer 9 Although the case was demonstrated, it is not limited to this, The liquid fuel mist which mixed the compressed gas and liquid fuel supplied from the compressor body supply source 32 and the fuel supply pump 37 by the mixer is respectively carried out through the mist supply piping. You may make it supply to the branch injection part 27 of the spray mechanism 23. FIG. In this case, it is preferable to keep the liquid fuel mist at a temperature not lower than the boiling point of the liquid fuel so as not to reliquefy.

In the present invention, as described above, the hood 16 covering the upper portion of the sintering machine pallet 8 is provided. By this hood 16, the influence on the density | concentration distribution of the liquid fuel mist 29 by a cross wind is suppressed. That is, as a result of various examinations by the present inventors, it has been found that the installation of the hood 16 has an effect more than a partition as a countermeasure against transverse wind. However, as described above, the hood 16 has an opening 17 in the upper center portion, or has an appropriate transmittance (porosity), and it is necessary to have a structure capable of accepting the atmosphere from this portion.

As a result, the liquid fuel mist 29 ejected from the spray mechanism 23 and the atmosphere are mixed in the hood 16. When the opening 17 has a width of the sintering machine pallet 8 of about 5 m in the case of a 5 m sintering machine, the pressure loss of the hood 16 can be largely ignored. Moreover, when providing a space | gap in the opening 17, when the transmittance | permeability was about 80%, it turned out that it can suppress by the pressure loss of about several mmAq. In addition, by providing a rectifying plate 40 in the hood 16, there is an effect of suppressing the vortex in the hood 16, and the partition provided on the upper part (circumference) of the hood 16. It was found from the results of the analysis that the porosity was most effective in the range of 30 to 40%. Moreover, as shown in FIG. 7 at the upper end of the left and right sidewalls 18 along the conveyance direction of the sintering machine pallet 8 of the hood 16, the transverse wind damping fence comprised from punch metal etc. of 30% of transmittance | permeability ( It is preferable to provide 16c).

Moreover, although a space | gap necessarily arises between the lower side of the hood 16 and the sintered bed surface (charge layer surface), if the sealing of this space | interval part is not enough, if the transmittance | permeability is 20-30%, It was found that air was drawn into the hood 16 from the portion to increase the bias of the concentration distribution of the liquid fuel mist. Therefore, it is desirable to prevent intrusion of air from the lower end of the hood 16.

For this reason, between the lower end of the left and right sidewalls 18 along the conveyance direction of the sintering machine pallet 8 of the hood 16, and the pallet sidewall 8a, and the branch injection part 27 of the spray mechanism 23 The wire plate seal 41 which inserted the seal sheet between the lower surface and the upper surface of the charging layer 9 between the wire brushes extended in the conveyance direction of the sintering machine pallet 8 as shown typically in FIG. This is provided, and the cover 42 which covers the wire plate seal 41 from the outer side is provided in the outer side. In addition, as a sealing material, not only the wire plate seal 41 but sealing materials, such as a chain curtain, a seal brush, and an adhesive seal, can be applied. Moreover, it is preferable that the said sealing material is heat resistant, and also has the flexibility and the degree of freedom of deformation, and does not damage the surface of the charging layer 9.

On the other hand, between the lower end of the front-and-back plate part 16b of the hood 16 in the conveyance direction of the sintering machine pallet 8 and the downstream side, and the surface of the charging layer 9, the hood 16 as shown in FIG. It is preferable to arrange the air passage 43 along the front and rear walls 19 of the), and to blow air from the lower side of the air passage 43 to form the air curtain 44.

In addition, the installation position, the size, and the arrangement number of the liquid fuel injector 15 are set as follows.

That is, after being ignited by the carbonaceous material in the charging layer 9, the liquid fuel mist 29 is supplied (introduced) on the charging layer 9. The reason is that even if the liquid fuel mist 29 is supplied at the position immediately after ignition, it only burns on the surface layer of the charging layer 9, and the liquid fuel mist does not affect the combustion layer at all. Therefore, after the sintering raw material of the upper part of the charging layer 9 is baked and the sintering completion stage which is a layer of a sintering cake is formed, it is necessary to supply a liquid fuel mist to the charging layer 9.

The principle at the time of using the liquid fuel mist of this invention is demonstrated using FIG. FIG. 11 (a) is a photograph when ethanol is used in a pot test with a particle diameter of about 50 μm. FIG. It can be seen that the combustion melting zone is greatly expanded with ethanol blowing. A diagram schematically illustrating this phenomenon is FIG. 11B, and the left side of the diagram shows a sintering reaction when a liquid fuel is blown in. FIG. The powdered coke, which is a coagulant, is ignited in the ignition furnace, and the sintering reaction proceeds downward while the combustion zone by the powdered coke descends the charging layer of the sintered raw material. The sintering stage is made of the sintering completion stage, and when the liquid fuel is blown in between the sintering completion stage and the minute coke burning zone, a gas combustion zone of liquid fuel gas is generated, whereby the high temperature zone holding time is extended without raising the maximum temperature. Doing. The right side shows the sintering reaction at the time of using the liquid fuel mist which becomes this invention. The gasification of the liquid fuel mist occurs in the sintering completion zone. Therefore, in the present invention, as described above, the particle diameter of the liquid fuel mist is 100 µm or less, preferably 50 µm or less. When the particle diameter exceeds 100 µm, the droplets remain by using heat of the sintered stage, and there is a fear of combustion in the surface layer portion. When the particle diameter of the liquid fuel mist is 100 μm or less, the liquid fuel mist (liquid fuel particles) is gasified by including the aggregated particles to form a vapor of the liquid fuel. A gas combustion zone of liquid fuel gas when blown in as a liquid fuel mist is generated, whereby the high temperature zone holding time is extended without prolonging the maximum temperature, thereby exhibiting the same phenomenon as gaseous fuel use.

When blowing the liquid fuel, the gasification (liquid fuel vapor) region of the liquid fuel particles shown in Fig. 11B is important.

That is, in the gasification region of the liquid fuel of FIG. 11B, it is preferable to spray the liquid fuel from the spray nozzle so that the vapor concentration of the liquid fuel is equal to or lower than the lower limit of combustion in Table 1 first. At the time of injection, it is necessary to be 75% or less of the lower limit of the combustion limit so as not to burn in the surface layer portion of the sintered stage, and the lower limit is at least 1% of the lower limit of the combustion limit in order to utilize fuel heat. Preferably it is 25% or less and 4% or more of a combustion lower limit. The upper limit is determined from the safety of fire, etc., and the lower limit is determined from the effective heat amount. Moreover, it needs to be below ignition temperature.

As shown in Fig. 11C, the point of combustion controls the maximum temperature in the sintering reaction on the minute coke side A, and the high temperature zone holding time is the liquid fuel side B that maintains the combustion zone temperature below the maximum temperature. Combustion. The example is shown in FIG.11 (d). The temperature curve shown as C is the in-layer temperature history at the time of sintering manufacture in the sintering reaction at the time of making only coke as a coagulant. The maximum temperature is controlled by the amount of minute coke, and the temperature range holding time E is determined by this temperature pattern. When extending the high temperature zone holding time with this C temperature pattern, it is necessary to increase the amount of minute coke added to enlarge the skirt in the region of 1200 ° C or higher which is the high temperature zone, but at the same time, it is necessary to increase the maximum temperature. The temperature pattern at the time of using liquid fuel is shown as D. FIG. As shown in Fig. 11C, the combustion of the liquid fuel is the combustion of the liquid fuel side B of Fig. 11C which maintains the combustion zone temperature below the maximum temperature. By the combination of both, the temperature pattern D of FIG. 11 (d) obtained by raising the temperature of the skirt region without changing the maximum temperature is obtained. By this temperature pattern D, the skirt of the area | region of 1200 degreeC or more is expanded and high temperature area holding time F is ensured.

12 is a photograph of a pot test of a conventional sintering method and a liquid fuel mist use sintering method. In the conventional sintering, the minute coke ratio is high due to the use of the minute coke combustion heat. Moreover, even if it was high, the combustion / melting band which looked white remained about 65 mm in this experiment.

In the gasification region (sintering completion zone) of the liquid fuel, heavy oil as a liquid fuel in which the temperature of the region is equal to or higher than the boiling point of the liquid fuel and is equal to or lower than the ignition temperature (controllable by lowering the concentration than the lower combustion limit). Although the example of ethanol is shown, in order to suppress the maximum temperature to 1380 degreeC, the use amount of powdered coke was reduced. The combustion / melt band which all appeared white was enlarged, and the obtained sintered ore intensity was higher than the conventional sintering method which uses only powder coke.

Moreover, in the gasification area | region (sintering completion zone) of the liquid fuel of FIG. 11B, the temperature of the area | region should be more than the boiling point of liquid fuel and below ignition temperature. By doing so, it becomes the phenomenon like FIG.

If the temperature of the gasification zone (sintered zone) is equal to or higher than the ignition temperature (high concentration close to the lower combustion limit), the liquid fuel vapor is burned on the surface of the sintered zone before entering the minute coke burning zone as shown in FIG. It is rather adversely affected in the sintering operation such as disappearing and oxygen shortage.

In addition, supply of the liquid fuel mist can be performed in arbitrary positions until sintering is completed, if the layer of a sintered cake is formed in the surface of the charging layer 9. The reason other than the above which performs supply of a liquid fuel mist after the layer of a sintered cake is formed is as follows.

(a) When the liquid fuel mist is supplied in the state immediately after ignition in which the sintered cake is not formed on the charging layer 9, there is a possibility that combustion occurs on the charging layer 9.

(b) It is preferable to supply the liquid fuel mist to a portion where the yield of the sintered ore needs to be improved, that is, to supply the combustion in a portion to increase the strength of the sintered ore.

The thickness of the combustion / melting zone is at least 15 mm, preferably at least 20 mm, more preferably at least 30 mm, in order to adjust either or both of the charge-bed maximum cylinder temperature or the hot zone holding time. In this state, it is preferable to perform the supply of the liquid fuel mist. If the thickness of the combustion / melting zone is less than 15 mm, the effect of cooling the liquid fuel mist by the air sucked through the sintered layer (sintered cake) and the liquid fuel mist is insufficient. This is because it cannot be expanded. On the other hand, when the liquid fuel mist is supplied at a stage in which the thickness of the combustion / melting zone is 15 mm or more, preferably 20 mm or more, more preferably 30 mm or more, the thickness of the combustion / melting zone is greatly enlarged, and the high temperature zone is increased. The holding time can be extended, and further, a sintered ore with high cold strength can be obtained.

In addition, the introduction of the liquid fuel mist into the charging layer 9 includes a position where the combustion wire is lowered below the surface layer and the combustion / melting zone is lowered by 100 mm or more, preferably 200 mm or more, from the surface layer, that is, the charge layer 9 It is preferable that the sintered cake region (sintered layer) generated in the middle / lower layer passes without burning, and is supplied so as to burn at a stage in which the wire before combustion has moved 100 mm or more from the surface layer. The reason for this is that when the combustion wire is lowered from the surface layer by 100 mm or more, the adverse effect of the cooling by air sucked through the sintered layer is reduced, and the thickness of the combustion / melting zone can be increased. In addition, when the combustion / melting zone is 200 mm or more from the surface layer, the influence of cooling by air is substantially eliminated, and the thickness of the combustion / melting zone can be expanded to 30 mm or more. Moreover, it is more preferable to supply liquid fuel mist in the vicinity of the side walls of the pallet width direction both ends of a large yield fall.

In addition, the liquid fuel injector 15 also varies depending on the size of the sintering machine. For example, in a sintering machine having a production capacity of about 150,000 t / day and a length of 90 m, the downstream side of the ignition furnace 10 is about 5 m. It is preferable to arrange | position in a later position.

In the sintering machine according to the present invention, the supply position (introduction position into the charging layer) of the liquid fuel mist is at the exit side of the ignition furnace in the pallet advancing direction, so that the so-called combustion wire after the sintered cake is formed has moved below the surface layer. It is preferable to carry out at one or more arbitrary positions from the position (for example, the position where the combustion of the liquid fuel mist occurs at 100 mm or more below the surface layer, preferably about 200 mm or less) until the sintering is completed. Do. This means that as described above, the introduction of the liquid fuel mist starts in the stage where the wire before the combustion has moved below the surface layer of the charging layer, so that combustion of the liquid fuel mist takes place inside the charging layer, and Since it moves to a lower layer with progress, it means that there is no fear of explosion and safe sintering operation is attained.

In the manufacturing method of the sintered ore which concerns on this invention, the introduction of the liquid fuel mist in a charge layer also means that it promotes the reheating of the produced | generated sintered cake. That is, the supply of liquid fuel mist is likely to be insufficient due to supply of liquid fuel mist, which is more reactive than solid fuel, to a portion where the high temperature zone holding time is short and the heat deficiency is low, and the cold strength of the sintered ore is low. This is because it takes on the meaning of preserving the heat of combustion of this part and promoting regeneration-expansion of combustion / melting zone.

Moreover, in the manufacturing method of the sintered ore which concerns on this invention, supply of the liquid fuel mist from the charging layer upper part after ignition reaches combustion / melting zone with at least one part of the liquid fuel mist introduce | transduced in the charging layer unburned, It is desirable to burn at the target position where it is desired to preserve. This is because it is thought that it is more effective to supply the liquid fuel mist, that is, the introduction effect into the charging layer not only to the upper portion of the charging layer but also to the combustion / melting zone, which is the central portion in the thickness direction. That is, when the supply of liquid fuel mist is performed at the upper layer of the charging layer that is likely to be heat deficient (lack of high temperature holding time), sufficient heat of combustion can be provided, and the quality of the sintered cake of this part can be improved, and The effect of supplying the liquid fuel mist to the zone below the middle layer is equivalent to the formation of reburning / melting zone by the liquid fuel mist on the combustion / melting zone of the original carbonaceous material. This is because it is possible to achieve the extension of the high temperature region holding time without increasing the maximum attained temperature because it is connected with the width expansion in the vertical direction, so that sufficient sintering can be realized without lowering the pallet moving speed. As a result, the quality improvement (improvement of cold strength) of the sintered cake of the whole charging layer is brought, and also leads to the improvement of the quality (cold strength) and productivity of a characteristic sintered ore.

In the present invention, in the introduction (supply) of the liquid fuel mist into the charging bed, not only the supply position is adjusted, but also the combustion / melt itself is controlled, and further, in the combustion / melt stage, It is a preferred configuration to also control the maximum attained temperature and / or hot zone hold time.

In general, in the charged layer after ignition, while the combustion (flame) wire gradually expands downward and forward (downstream) with the movement of the pallet, the position of the combustion / melting zone is described above with reference to FIG. 18A. As shown in FIG. As shown in FIG. 18B, the thermal history received in the sintering process in the sintered layer is different in the upper layer, the middle layer, and the lower layer, and the high temperature zone holding time (time of about 1200 ° C. or more) between the upper layer and the lower layer is It's very different. As a result, the yield of the sintered ore by the position in a pallet shows distribution as shown to FIG. 18 (c). That is, the yield of the surface layer part (upper layer part) is low, and it becomes a high yield distribution in a middle layer and a lower layer part. Therefore, according to the method of the present invention, when the liquid fuel mist is supplied, the thickness of the combustion / melting zone in the vertical direction, the width of the pallet traveling direction, and the like are expanded, which is reflected in the improvement of the quality of the sintered ore. And since the middle layer part and the lower layer part which become a high yield distribution can control more high temperature area holding time, a yield can be raised further.

By adjusting the supply (introduction) position of the liquid fuel mist, it is possible to control the shape of the combustion / melting zone, that is, the thickness in the height direction of the combustion / melting zone and / or the width in the pallet traveling direction, High temperature zone holding time can be controlled. These controls further improve the effect of the present invention, and always achieve sufficient plasticity by controlling the thickness of the combustion / melting band in the vertical direction and the width of the pallet traveling direction, or controlling the maximum attainment temperature and the high temperature zone holding time, It contributes to the improvement of the cold strength of the characteristic sintered ore efficiently.

In the present invention, the supply (introduction) of the liquid fuel mist in the charging layer may be said to control the cold strength of the whole sintered ore. That is, the first object of supplying the liquid fuel mist is to improve the cold strength of the sintered cake, and further, the sintered ore. In particular, the high temperature, which is the time for controlling the supply position of the liquid fuel mist or the time when the sintered raw material stays in the combustion / melting zone, The cold strength (shutter index SI) of the sintered ore is set to about 75 to 85%, preferably 80% or more, and more preferably 90% or more by controlling the reverse holding time and controlling the maximum attainment temperature.

In the present invention, this strength level is made inexpensively by adjusting the concentration, the supply amount, the supply position, and the supply range of the liquid fuel mist, preferably after taking into account the amount of carbonaceous material in the sintered raw material (under the condition of constant input calorific value). Can be achieved. In addition, although the improvement of the cold strength of sintered ore may raise the ventilation resistance and the fall of productivity on the one hand, in the present invention, after solving such a problem by controlling also the maximum achieved temperature or the high temperature zone holding time, Improves cold strength. In addition, the cold-strength SI value of the sintered ore manufactured by the actual sintering machine shows the value 10-15% higher than the value obtained by a pot test.

In the production method of the present invention, the introduction position of the liquid fuel mist in the charging layer in the pallet traveling direction is the cold strength of the sintered ore in any zone between the sintered cake generated in the charging layer and the wet zone. Based on what to do. For this control, in the present invention, the size (size), number, position (distance from the ignition furnace), and the gas concentration of the liquid fuel injector are preferably adjusted according to the amount of coal ash (solid fuel) in the sintered raw material. This controls not only the size of the combustion / melting zone (thickness in the vertical direction and the width in the pallet traveling direction), but also the high temperature attainment temperature and the high temperature zone holding time, thereby controlling the strength of the sintered cake produced in the charging layer. do.

Next, the operation of the above embodiment will be described.

First, as shown in FIG. 1, the lump ore established from the bottom hopper 4 is cut out, the bottom layer is formed on the great part of the sintering machine pallet 8, and the drum feeder 6 is removed from the surge hopper 5 on this bottom layer. The sintered raw material cut out in quantitatively is charged and forms a charging layer 9 of about 400 to 800 mm, also called a sintered bed.

And with the conveyance of the sintering machine pallet 8, it burns by the carbon | charcoal material in the surface layer of the charging layer 9 moved below the ignition furnace 10. As shown in FIG.

In the charging layer 9 after ignition, as the combustion (flame) wire gradually expands downward and forward (downstream) with the movement of the sintering machine pallet 8, the position of the combustion / melting zone is described in the above-mentioned figure. It changes as shown to 18 (a). Then, when the position of the combustion / melt reaches about 200 mm from the surface layer moving from the upper layer to the middle layer, the sintering machine pallet 8 reaches the position of the liquid fuel injector 15.

In the liquid fuel injector 15, the liquid fuel mist 29 is uniformly sprayed onto the surface of the charging layer 9 by the spray mechanism 23 in the hood 16 covering the upper side of the sintering machine pallet 8. do.

That is, in the liquid fuel injector 15, the compressed gas supply pipe extending in parallel in the conveying direction of the sinter pellet 8 at a position away from the surface of the charging layer 9 of the liquid sinter pellet 8 22) and the tanks of the liquid fuel supply pipe 22 are arranged in a predetermined number of tanks in the width direction orthogonal to the conveying direction, and the compressed gas and the liquid fuel supply pipe 22 in the compressor body supply pipe 21 and the liquid fuel supply pipe 22 of each tank. A spray mechanism 23 is disposed in which the liquid fuel is mixed to have a particle size of 100 µm or less, preferably 50 µm or less, and atomized to a particle diameter of 20 µm or more as a liquid fuel mist in a substantially horizontal direction.

And since this spray mechanism 23 is arrange | positioned at the conveyance direction of the sintered pallet 8 half pitch between adjacent tanks so that the spray mechanism 23 of adjacent tanks may not oppose, as shown in FIG. The liquid fuel mist 29 injected from the injection nozzle parts 28a and 28b of the spray mechanism 23 in an adjacent tank does not interfere with each other, and the uniform injection area | region is formed.

The injected liquid fuel mist 29 is mixed with the air rectified in the rectifying plate 40 to be diluted below the lower limit of combustion at normal temperature, thereby suppressing the combustion above the charging layer 9. At this time, as the atomizing gas for atomizing the liquid fuel, at least one of anti-flammable nitrogen, carbon dioxide, and water vapor is used as a main component, and these anti-flammable compressed gases are included in the liquid fuel mist 29. As a result, the liquid fuel mist 29 can be reliably suppressed from burning above the charging layer 9.

The liquid fuel mist 29 injected from the spray nozzle portions 28a and 28b of each spray mechanism 23 sucks air downward through the wind box 11 disposed below the sintering machine pallet 8. By doing so, it is mixed with the air rectified by the rectifying plate 40 and introduced into the charging layer 9.

The liquid fuel mist 29 introduced into the charging layer 9 passes through the sintered cake formed in the surface layer portion to reach a combustion / melting zone 100 mm or more below the surface and is burned in this combustion / melting layer. As a result, the high temperature zone holding time is short, and it is easy to become heat short, and the high temperature zone holding time for holding the phase / middle layer where the cold strength of the sintered ore is low at a high temperature range of 1200 ° C or more can be extended, and the cold strength of the sintered ore is increased. Can improve. Therefore, when the liquid fuel mist 29 is not blown in, the yield of the upper / middle layer portion having a low yield shown in FIG. 18C can be improved.

Thus, if the supply action of the liquid fuel mist 29 is extended to the area | region below a middle layer part, the recombustion / melting zone by the liquid fuel mist 29 will be formed on the combustion / melting zone by the original carbonaceous material. This results in an equivalent result, which leads to widening in the vertical direction of the combustion / melting zone, and thus it is possible to achieve the extension of the high temperature zone holding time without increasing the maximum attained temperature, thereby lowering the moving speed of the sintering pallet (8). Sufficient sintering can be achieved without work. As a result, the quality improvement (improvement of cold strength) of the sintered cake of the charging layer 9 whole is brought about, and also it leads to the improvement of the quality (cold strength) and productivity of sintered ore.

Further, when the liquid fuel is supplied to the fuel supply pipe 21 and the supply of the liquid fuel is stopped, the heating gas is supplied to the liquid fuel supply pipe 21 as a purge gas and the liquid remaining in the pipe is supplied. It is desirable to burn off fuel.

Thus, in the said embodiment, after igniting on the surface layer of the charging layer 9 in the ignition furnace 10, the liquid fuel injector 15 liquids above the charging layer 9 of the sintering machine pallet 8 By uniformly dispersing and injecting the fuel mist 29, a liquid fuel having a high ignition temperature is used as compared with the case of using a diluting gas fuel in which gaseous fuels such as propane gas, LNG, and M gas are diluted with air, This liquid fuel is not used as it is, but is atomized with a compressed gas and injected as a liquid fuel mist, so that the risk of ignition from above the charging layer 9 can be reliably suppressed. In addition, by using a gas containing at least one of anti-inflammatory nitrogen, carbon dioxide, and water vapor as a main component as the compressed gas, the risk of ignition on the upper side of the charging layer 9 can be further suppressed.

Moreover, in the said embodiment, although the case where the liquid fuel injector 15 was arrange | positioned downstream of the ignition furnace 10 was demonstrated, it is not limited to this, The heat retention furnace in the downstream of the ignition furnace 10 was demonstrated. Is disposed, the liquid fuel injector 15 may be disposed downstream of the heat retention path.

Moreover, in the said embodiment, although the case where the hood 16 of the liquid fuel injector 15 was set as the structure which has the opening 17 upper was demonstrated, it is not limited to this, as shown in FIG. The upper end of the hood 16 is opened, and the cross section U shape which extends along the conveyance direction of the sintering machine pallet 8 between the front and back months 19 of the hood 17, and makes a top point upwards. The baffle plate row 52 having a configuration in which the baffle plate 51 is arranged in a predetermined number in parallel in the width direction perpendicular to the conveying direction of the sintering machine pallet 8 in a vertical direction. The baffle plate 51 of the other baffle plate row 52 is arranged in three rows, and between the baffle plate rows 52 adjacent to the vertical direction, between the baffle plates 51 of one of the baffle plate rows 52. It arrange | positioned so that it may be located, and the spray mechanism 2 between the baffle plates 51 in the lower side of the baffle row 52 of the lowest stage. 3) may be arranged.

In the above embodiment, the case where liquid fuel is supplied from the liquid fuel tank 38 to the liquid fuel supply main pipe 36 and the liquid fuel supply pipe 22 at room temperature has been described, but the present invention is not limited thereto. Liquid fuel having a high viscosity at room temperature such as C heavy oil and difficult to atomize is preheated to, for example, 130 ° C. to 150 ° C. using steam or the like, and lowered in viscosity to be supplied to the liquid fuel supply pipe 22. By this, the spray mechanism 23 can be easily atomized and can be sprayed as the liquid fuel mist 29.

Although the technique of this invention is useful as a manufacturing technique of the sintered ore used as a raw material for steelmaking, especially a blast furnace, it can be used also as another ore compaction technique.

One; Raw material hopper 2; Drum mixer
3; Rotary kiln 4; Surge hopper
5; Bottom hopper 6; Drum feeder
7; Charging chute 8; Sinterer Pallet
9; Charging layer 10; By ignition
11; Windbox 15; Liquid Fuel Injector
16; Hood 21; Compressed Air Supply Pipe
22; Liquid fuel supply line 23; Spray apparatus
24; Vertical plumbing 25; Mixing portion
26; Connecting piping 27; Branch jet
28a, 28b; Injection nozzle unit 29; Liquid fuel mist
31; Compressor body supply main pipe 32; Compressor Source
33; Gas storage tank 34; Compressor
35; Receiver tank 36; Liquid fuel supply main pipe
37; Fuel supply pump 38; Liquid Fuel Storage Tank
41; Wire plate seal 51; Disturbance plate
52; Baffle heat

Claims (22)

A charging step of charging a sintered raw material including spectroscopic stones and carbonaceous material on a pallet to be circulated to form a charging layer;
The ignition process to ignite with the ignition furnace,
A liquid fuel supplying step of supplying the atomized liquid fuel with a particle diameter of 100 µm or less on the charging layer after ignition;
It has a sintering process for sucking air in the wind box disposed below the pallet to produce a sintered ore,
The liquid fuel supplying process is a method for producing a sintered ore, characterized in that the atomized liquid fuel having a particle diameter of 100㎛ or less in the horizontal direction from the upper side of the charging layer. The method of claim 1,
The atomized liquid fuel has a particle size of 50 μm or less and a particle size of 20 μm or more. The method of claim 1,
The liquid fuel supplying step is characterized in that the production of a sintered ore characterized in that the liquid fuel atomized to a particle diameter of 100 μm or less is supplied onto the charging layer, and the liquid fuel is supplied to the charging layer in a state diluted to a lower combustion lower concentration at normal temperature. Way. The method of claim 1,
The atomized liquid fuel has a concentration of less than the lower combustion limit concentration, the manufacturing method of the sintered ore. 5. The method of claim 4,
The said concentration is 75% or less and 1% or more of the lower limit of combustion, The manufacturing method of the sintered ore characterized by the above-mentioned. The method of claim 5, wherein
The concentration is 25% or less of the lower limit of combustion and 4% or more. delete A charging step of charging a sintered raw material including spectroscopic stones and carbonaceous material on a pallet to be circulated to form a charging layer;
The ignition process to ignite with the ignition furnace,
A liquid fuel supplying step of supplying the atomized liquid fuel with a particle diameter of 100 µm or less on the charging layer after ignition;
It has a sintering process for sucking air in the wind box disposed below the pallet to produce a sintered ore,
The liquid fuel supplying step is a method for producing a sintered ore, characterized in that the liquid fuel is mixed with the compressed gas, atomized, and sprayed onto the charging layer. The method of claim 8,
The compressed gas is a gas containing, as a main component, at least one of anti-flammable nitrogen, carbon dioxide, and water vapor. The method of claim 1,
And the liquid fuel is at least one selected from the group consisting of petroleum liquid fuel, alcohol liquid fuel, ether liquid fuel and other hydrocarbon compound liquid fuel. 11. The method of claim 10,
The petroleum-based liquid fuel is at least one selected from the group consisting of kerosene, light oil and heavy oil. 11. The method of claim 10,
The alcohol-like liquid fuel is at least one member selected from the group consisting of methyl alcohol, ethyl alcohol and diethyl alcohol. 11. The method of claim 10,
The other hydrocarbon compound liquid fuel is at least one selected from the group consisting of pentane, hexane, heptane, octane, nonane, decane, benzene and acetone. The method of claim 1,
The liquid fuel supplying step is a method for producing a sintered ore, characterized in that to supply the atomized liquid fuel from the surface layer portion of the charging layer until the sintering is completed after the sintered cake is produced. The method of claim 1,
The liquid fuel supplying process is a method for producing a sintered ore, characterized in that the atomized liquid fuel is supplied in a region where the thickness of the combustion / melting zone becomes 15 mm or more. The method of claim 1,
The liquid fuel supplying process is a method for producing a sintered ore, characterized in that for supplying the atomized liquid fuel after the position where the combustion wire reaches 100 mm below the surface layer. With circular moving pallet,
A raw material supply device which charges a sintered raw material containing spectroscopic stones and carbonaceous material on the pallet to form a charging layer;
An ignition furnace for igniting carbon material in the sintered raw material on the pallet;
A liquid fuel injector which is provided on the downstream side of the ignition furnace and injects a liquid fuel into a charged layer by atomizing the liquid fuel to a particle diameter of 100 m or less;
Has a windbox that draws air under the pallet,
The liquid fuel injector is atomized by mixing a compressed gas supply source, a liquid fuel supply source, a compressed gas from the compressed gas supply source, and a liquid fuel from the liquid fuel supply source, and sprayed in the horizontal direction on the charging layer. A sintering machine comprising a spray mechanism. delete The method of claim 17,
The spray mechanism horizontally conveys a conveying pipe having a downward gradient toward a downstream side for conveying a mixed fluid of the compressed gas and liquid fuel, a communication pipe connected to a lower surface side of the conveying pipe, and a liquid fuel formed on the lower surface of the communication pipe. A sintering machine, characterized by having a spray nozzle of a downward gradient toward a discharge port sprayed in a direction. The method of claim 17,
The liquid fuel supply source supplies at least one liquid fuel selected from the group of petroleum liquid fuel, alcohol liquid liquid, ether liquid fuel, and other hydrocarbon compound liquid fuel in a liquid state at room temperature to the spray apparatus. Sintering machine characterized in that. The method of claim 17,
And said compressed gas source supplies to said spray mechanism a compressor body containing at least one of anti-flammable nitrogen, carbon dioxide, and water vapor as a main component. The method of claim 17,
And the liquid fuel injector has a preheating mechanism for preheating the liquid fuel so as to have an optimum viscosity for atomization when the liquid fuel has a high viscosity.

Images