TWI426136B - Sintering method and sintering machine - Google Patents

Description

Sintering method and sintering machine

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

The sinter of the main raw material of the blast furnace iron making process is generally manufactured through the steps shown in FIG. The raw materials of the sinter are as follows: iron powder ore, iron powder in the iron ore, sinter ore (recycled ore), limestone and dolomite and other CaO-based auxiliary materials; or granulation aids such as quicklime; or coke powder Or smokeless charcoal. These raw materials are each cut from the plurality of hoppers 1 on a conveyor belt in a predetermined ratio. The cut raw material is conveniently mixed with an appropriate amount of water by a tumbler mixer 2, a rotary kiln 3, etc., and mixed and granulated to form a sintered raw material having quasi-particles having an average particle diameter of 3.0 to 6.0 mm. On the other hand, the sieved ore pieces are cut out from the bottoming hopper 4, and a layup layer is formed on the stringer screen of the sintering machine tray 8.

The sintering raw material is formed from the receiving tank 5 disposed on the sintering machine, through the barrel feeder 6 and the cutting chute 7 , and is placed on the layup layer on the ring-shaped movable sintering machine pallet 8 to form a sintering. The sintered raw material of the bed is loaded into the layer 9. The thickness (height) of the loading layer is usually about 400 to 800 mm. Then, the carbon material in the surface layer of the loading layer 9 is ignited by the ignition furnace 10 provided above the loading layer 9, and the air is sucked downward via the bellows 11 disposed under the pallet 8. The carbon 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 obtained thereby is crushed and sieved to form an agglomerate of 5.0 mm or more. The finished product is sintered and recovered.

In the above manufacturing process, first, the surface layer of the layer to be charged is ignited by the ignition furnace 10. The ignited carbon material in the charging layer will continue to burn with a certain amount of air sucked from the upper layer of the loading layer toward the lower layer by the bellows, and the burning belt will rapidly move downward and forward with the movement of the pallet 8. (downstream side). As the combustion proceeds, the moisture contained in the sintered raw material particles charged in the layer is vaporized by the heat generated by the combustion of the carbon material, and is sucked downward, and concentrated in the lower sintering raw material whose temperature has not risen. And form a wet belt. If the water concentration is more than a certain level, the gap between the raw material particles belonging to the suction gas flow path is buried by the water, resulting in an increase in ventilation resistance. In addition, the molten portion necessary for the sintering reaction in the combustion zone also causes an increase in the ventilation resistance.

The sintering machine throughput (t/hr) is generally determined by the sintering productivity (t/hr.m ² ) x the sintering machine area (m ² ). That is, the sintering machine throughput varies depending on, for example, the machine width and length of the sintering machine, the thickness of the raw material accumulation layer (loading layer thickness), the overall density of the sintered raw material, the sintering (combustion) time, the yield, and the like. Therefore, in order to increase the production amount of the sintered ore, it is considered to be effective, for example, to improve the air permeability (pressure loss) of the packed bed, to shorten the sintering time, or to increase the cold rolling strength and the yield of the sintered cake before the crushing.

Figure 16 is a front view of a burning belt moving in a loading layer having a thickness of 600 mm. When the pallet of the loading layer is about 400 mm (200 mm below the surface of the loading layer), the pressure loss in the layer is Temperature Distribution. At this point the pressure loss distribution will be about 60% in the wet zone, burning. The molten zone is about 40%.

Figure 17 shows the temperature distribution in the loading layer during high production of sinter and low production (i.e., when the pallet moves faster and slower). Retention time starting material particles begin to melt above a temperature of 1200 deg.] C (hereinafter referred to as "high-temperature holding time domain"), represented by t _1, production of high importance to productivity is represented by t ₂ when the low production. In high production, because the moving speed of the pallet is relatively fast, the high temperature domain holding time t _{2 is} shorter than the low production t ₁ . If the holding time in the high temperature region is shortened, it is liable to become insufficiently burnt, resulting in a decrease in the cold rolling strength of the sintered ore and a decrease in the yield. Therefore, in order to improve the productivity of high-strength sinter, not only short-time sintering, but also any means to increase the strength of the sintered cake (ie, the strength of the sinter cold rolling), and to improve and maintain the yield are necessary. In addition, the index indicating the cold rolling strength of the sintered ore is generally SI (fragmentation index) and TI (drum index).

Figure 18 (a) shows the sintering process in the loading layer on the sintering machine pallet, and Figure 18 (b) shows the temperature distribution (heating mode) during the sintering process in the layer, Figure 18 ( c) Yield distribution of the sintered cake shown. It is known from Fig. 18(b) that the upper portion of the charging layer is harder to rise than the lower portion, and the holding time in the high temperature region is also shorter. Therefore, the combustion-melting reaction (sintering reaction) in the upper portion of the charging layer is insufficient, and the strength of the sintered cake is lowered. Therefore, as shown in Fig. 18(c), the yield is lowered and the productivity is lowered.

In view of such a problem, there is a proposal for self-study to maintain the upper layer of the loading layer for a long time and at a high temperature. For example, Patent Document 1 discloses a technique of injecting a gaseous fuel onto a charging layer after ignition of the charging layer. Surgery. However, the above-mentioned techniques are not clear on the types of gaseous fuels (flammable gases), and even high-concentration gases can be used even for barreled gas (LPG) or natural gas (LNG). Moreover, when the flammable gas is blown in, since the amount of the carbon material is not reduced, the sintered layer will have a high temperature exceeding 1380 °C. Therefore, this technology does not enjoy the effect of improving the full cold rolling strength and yield. Moreover, when a flammable gas is ejected immediately after the ignition furnace, the risk of fire in the sintering bed space is increased due to the combustion of the combustible gas, which is a technique that lacks reality and has not yet been put into practical use.

Further, Patent Document 2 discloses a technique of adding a combustible gas to the air sucked into the charging layer after the charging layer is ignited. After ignition, it is preferably supplied for about 1 to 10 minutes. However, there is still a red hot state sinter in the surface layer immediately after ignition of the ignition furnace. According to the supply method, there is a risk of fire caused by combustion of flammable gas. Although the specific description is small, the sintered belt after sintering has no effect even if the combustible gas is burned. If the sintering belt is burned, the temperature rises due to the combustion gas and the air permeability deteriorates due to thermal expansion. Therefore, there is a tendency to cause a decrease in productivity, and when the combustible gas is blown in, the amount of the carbon material is not reduced, so that the sintered layer will have a high temperature exceeding 1380 °C. Therefore, this technology does not enjoy the effect of improving the full cold rolling strength and yield improvement, so it has not been put into practical use so far.

Further, Patent Document 3 discloses that in order to form a high temperature in the charging layer of the sintered raw material, a cover body is disposed on the loading layer, and the cover body is passed through the air or The mixed gas of the coke oven gas is blown in at a position immediately after the ignition furnace. However, this technique is also because the temperature of the combustion melting zone in the sintered layer will become a high temperature exceeding 1380 ° C, so that the effect of blowing the coke oven gas will not be obtained, and the combustible mixed gas will ignite in the space of the sintering bed, and There is no danger of causing fire and there is no practical use.

Further, Patent Document 4 discloses a method of simultaneously blowing a low melting point solvent, a carbon material or a combustible gas at a position immediately after the ignition furnace. However, this method is also because the flammable gas is blown in a state where the flame remains on the surface, so that the risk of causing a fire in the space of the sintering bed is high, and the width of the sintering belt cannot be sufficiently thickened (about 15 mm or less). As a result, the effect of blowing a combustible gas cannot be sufficiently exhibited. Moreover, since there are a lot of low-melting-point solvents, excessive melting occurs in the upper layer, and the pores that will become air flow paths are blocked, resulting in deterioration of the air permeability and a decrease in productivity. Not yet practical.

As described above, the conventional techniques proposed so far have potential problems of practical use, and development of flammable gas blowing technology that can be implemented is expected.

In order to solve the above problems, the applicant has proposed in Patent Document 5 that a sintering raw material deposited on a pallet of a sintering machine is placed on a layer, and various gaseous fuels diluted to a lower concentration of a lower combustion limit are supplied and introduced into the gas. A method of loading into a layer and, after burning, adjusting one or both of the highest reached temperature and the high temperature domain holding time within the layer.

[Patent Document 1] Japanese Patent Laid-Open No. 48-18102

[Patent Document 2] Japanese Patent Publication No. Sho 46-27126

[Patent Document 3] Japanese Patent Laid-Open No. 55-18585

[Patent Document 4] Japanese Patent Laid-Open No. Hei 5-311257

[Patent Document 5] WO2007-052776

The technique of the above-mentioned Patent Document 5 is to supply (import) a gaseous fuel diluted to a predetermined concentration into a charging layer in a lower suction belt sintering machine, and to carry it at a target position in the loading layer. The combustion of the gaseous fuel supply can properly control the maximum temperature of arrival of the sintering raw material for combustion and the holding time of the high temperature range, even in the upper layer of the loading layer which is likely to cause the cold rolling strength of the sintered ore to be reduced due to insufficient heat. Any part below the layer in the loading layer can be operated to increase the strength of the sintered ore.

However, when the gas fuel supply sintering operation is performed, a high temperature portion such as a crack portion of the sintered bed or the sintered cake may become a fire, and the gas fuel may be backfired, and there is a possibility that the gaseous fuel is burned (fired). If the sintering operation is continued in such a igniting state (the explosion problem is another level problem), it is not only impossible to supply the gaseous fuel to the charging layer, but also the oxygen-deficient atmosphere due to the consumption of oxygen due to the combustion of the gaseous fuel. Is supplied (imported) into the load layer. As a result, not only the highest temperature reached during combustion and the holding time of the high temperature region cannot be controlled, but also the combustion is insufficient, resulting in a decrease in the strength of the sintered ore, which reduces the yield and productivity, and thus has a significant adverse effect on the sintering operation.

The present invention has been made in view of the problems of the above-described conventional examples, and an object of the invention is to provide a method for producing a sintered ore which can produce high-strength and high-quality sintered ore in a low-yield and safe manner in a lower suction belt sintering machine. And sintering machine.

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

In the loading step, a sintered raw material containing fine ore and carbonaceous material is placed on a circulating moving pallet to form a packed layer. The ignition step ignites the carbon material in which the packed layer has been formed by means of an ignition furnace. The liquid fuel supply step is performed after the ignition, and the liquid fuel micronized to a particle diameter of 100 μm or less is supplied to the packed bed. The sintering step is performed by air suction using a bellows disposed below the pallet to produce a sintered ore.

The finely divided liquid fuel preferably has a particle diameter of 50 μm or less and 20 μm or more. Preferably, the microparticulated liquid fuel has a concentration below a lower concentration of combustion. The above concentration is preferably 75% or less and 1% or more of the lower limit of the combustion concentration. The above concentration is preferably 25% or less and 4% or more of the lower limit of the combustion concentration.

The above liquid fuel supply step is preferably as follows:

(A) The liquid fuel which has been microparticulated to a particle diameter of 100 μm or less is supplied to the packed bed, and is supplied to the packed bed in a state where it is diluted to a lower limit of the lower limit of combustion at normal temperature.

(B) The liquid fuel atomized to a particle diameter of 100 μm or less is sprayed toward the upper side of the packed bed.

(C) The liquid fuel is mixed in a compressed gas and atomized, and then sprayed onto the packed bed. The compressed gas system is a gas containing at least one of nitrogen, carbon dioxide, and water vapor having a flame-retardant property as a main component.

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

Liquid fuel is preferably supplied in one of the following locations:

(a) The micronized liquid fuel is supplied from the surface of the surface layer of the charging layer to the surface of the sintered layer.

(b) burning. The micronized liquid fuel is supplied in a region where the thickness of the molten belt is 15 mm or more.

(c) After the combustion front reaches the 100 mm position below the surface layer, the micronized liquid fuel is supplied.

Furthermore, the sintering machine according to the present invention includes: a pallet, a material supply device, an ignition furnace, a liquid fuel injection device, and a bellows; and the pallet is cyclically moved; the raw material supply device is Filling the plate with powder ore Forming a charging layer with the sintering material of the carbon material; the ignition furnace igniting the carbon material in the sintering raw material on the pallet; the liquid fuel injection device is disposed on the downstream side of the ignition furnace, and is liquid The fuel is atomized to a particle diameter of 100 μm or less and sprayed toward the upper side of the loading layer; the bellows is air-sucked toward the lower side of the tray.

Preferably, the liquid fuel injection device is provided with: a compressed gas supply source, a liquid fuel supply source, and a spray mechanism for performing a compressed gas from the compressed gas supply source and a liquid fuel from the liquid fuel supply source. After mixing, it is micronized, and then sprayed in the horizontal direction on the above-mentioned loading layer. The compressed gas is preferably a gas containing at least one of nitrogen, carbon dioxide, and water vapor having a flame-retardant property as a main component. Preferably, the spray mechanism includes a transfer pipe, a communication pipe, and a spray nozzle; and the transfer pipe transports the mixed fluid of the compressed gas and the liquid fuel to a downstream side and has a downward slope; the communication pipe is connected to The lower side of the transfer pipe; the injection nozzle is inclined downward toward a discharge port that can eject the liquid fuel formed under the communication pipe in the horizontal direction. Preferably, the liquid fuel injection device has a preheating mechanism that preheats the liquid fuel in a manner that the microparticles are optimally viscous when the viscosity of the liquid fuel is high.

The liquid fuel is preferably at least one selected from the group consisting of petroleum-based liquid fuels, alcohol-based liquid fuels, ether-based liquid fuels, and other hydrocarbon-based compound-based liquid fuels which are in a liquid state at a normal temperature.

According to the manufacturing method of the sintered ore according to the present invention, since the liquid fuel is atomized to a particle diameter of 100 μm or less and supplied to the upper side of the charging layer on the downstream side of the ignition furnace, it is then subjected to normal temperature from the loading layer toward the loading layer. The product is supplied in a state of being diluted below the lower limit of combustion concentration, so that the liquid fuel is not burned on the packed bed by the air suction by the bellows, and is reached after the upper layer of the packed layer is vaporized. The burning of the lower layer. Melting the belt and burning it according to the gaseous fuel, as in the case of using a gaseous fuel, by controlling the supply position of the micronized liquid fuel, the highest reaching temperature at the time of combustion, and the holding time in the high temperature range, sintering due to insufficient combustion The strength of the cold cold rolling is reduced, and not only the upper portion of the layer but also any portion below the middle layer of the layer can be subjected to an operation of increasing the strength of the sintered ore. Here, if the liquid fuel particle diameter exceeds 100 μm, a residual portion will occur in the surface layer portion of the layer, and combustion will start in the surface portion, resulting in a lot of waste, and the effect of prolonging the holding time in the high temperature region is weakened. If it is below 100 μm, it will inhibit the combustion at the upper part and the surface layer of the loading layer, and once it is introduced into the loading layer, it will be vaporized and sucked to the lower layer and reach the combustion. The molten zone can be burned according to the gaseous fuel.

Here, the particle size of the micronized liquid fuel is preferably 50 μm or less and 20 μm or more, and the particle size is selected to be 50 μm or less, so that the atomized liquid fuel can be surely introduced into the layer to be burned. In the melting zone. The particle size of the microparticulated liquid fuel is preferably as small as possible, but the finer the particle size, the more the amount of production is reduced. Therefore, it is preferable to select the particle diameter by considering the amount of production necessary for prolonging the holding time in the high temperature range. 20 μm or more.

According to the sintering machine of the present invention, since the liquid fuel injection device that atomizes the liquid fuel and sprays in the horizontal direction is provided above the charging layer on the downstream side of the ignition furnace, the liquid fuel injection device ejects the fine particles. The liquid fuel is uniformly dispersed on the loading layer, and the uniformly dispersed micronized liquid fuel will pass through the bellows and be drawn into the charging layer. Therefore, as the liquid fuel is volatilized in the charging layer and used according to the gaseous fuel, the supply position of the micronized liquid fuel, the highest temperature at the time of combustion, and the holding time in the high temperature range are controlled, resulting in sintering due to insufficient combustion. The strength of the cold cold rolling is reduced, and not only the upper portion of the layer but also any portion below the middle layer of the layer can be operated to increase the strength of the sintered ore. Moreover, by atomizing the liquid fuel and spraying it onto the charging layer, there is no concern that, for example, when the liquid fuel is directly used, a liquid fuel such as a igniting can be safely and stably performed. Import the raw material into the layer.

Further, as the compressed gas for atomizing the liquid fuel, combustion on the packed bed can be suppressed by using any of nitrogen, carbon dioxide, and water vapor having a flame-retardant property.

The method for producing a sintered ore using the sintering machine of the present invention comprises the following steps: a charging step, an ignition step, a liquid fuel supply step, and a sintering step. In the manufacturing method, the charging step is a step of performing a cyclically moving pallet, a sintering raw material containing fine ore and a carbon material, and a step of forming a sintering raw material charging layer on the pallet; the ignition step is used Ignition furnace, on the loading layer The step of igniting the carbon material of the surface. Further, the liquid fuel supply step is a step of spraying the liquid fuel atomized to 100 μm or less from the liquid fuel injection device toward the loading layer; the sintering step is performed by pumping the bellows disposed under the pallet Suction, pumping the above-mentioned micronized liquid fuel and air into the charging layer, and burning the micronized liquid fuel in the charging layer while utilizing the air sucked into the loading layer The step of producing a sintered cake by burning the carbon material in the charged layer and sintering the sintered raw material by the heat generated by the combustion.

In the present invention, by spraying the liquid fuel which is atomized above the charging layer to the atmosphere on the downstream side of the ignition furnace, the atomized liquid fuel is used to utilize the air of the bellows while suppressing the ignition or the like. Pumping and volatilizing in the loading layer.

Fig. 1 is a schematic structural view showing an embodiment of a sintering machine of the present invention. In Fig. 1, as in the conventional example described above, for example, iron powder ore, iron powder in the ironmaking, sinter sieve, limestone, dolomite, and the like, a CaO-based auxiliary material; a granulation aid such as quicklime; Sintering raw materials such as coke powder or smokeless carbon are cut out from the plurality of hoppers 1 on the conveyor belt according to a predetermined ratio, and the cut raw materials are added with appropriate amount of water such as a tumble mixer 2, a rotary kiln 3, and mixed and granulated. A sintered raw material having quasiparticles having an average particle diameter of 3.0 to 6.0 mm is formed and stored in the receiving tank 5. On the other hand, the ore block having a predetermined particle size is cut out from the bottoming hopper 4, and a layup layer is formed on the stringer screen of the sintering machine tray 8.

Then, the sintering raw material is fed from the receiving tank 5 through the drum feeder 6 and the cutting chute 7 to the layup layer on the ring-shaped movable sintering machine pallet 8, thereby forming a charging layer, also called a sintering bed. 9. The thickness (height) of the loading layer is usually about 400 to 800 mm. Then, the carbon material in the surface layer of the loading layer 9 is ignited by the ignition furnace 10 provided above the loading layer 9, while the air is sucked to the lower side via the bellows 11 disposed below the pallet 8, Thereby, the carbon material in the charging layer is sequentially burned.

Then, a liquid fuel injection device 15 is disposed on the downstream side of the ignition furnace 10, and the liquid fuel is atomized on the upper side of the charging layer 9, and is ejected in a horizontal direction.

The liquid fuel injection device 15 is on the downstream side of the ignition furnace 10 and burns. During the process of loading the molten belt in the loading layer 9, more than one position is provided at any position in the direction in which the pallet is carried, and the liquid fuel mist supplied into the layer 9 is supplied, preferably in the carbon material loaded into the layer 9. The position after ignition is implemented. The liquid fuel injection device 15 is disposed on the downstream side of the ignition furnace 10, and is disposed at any position after the combustion front line travels to the surface layer, and is disposed at any position from the viewpoint of the sinter ore cold rolling strength of the product to be adjusted, size, and position. The number of configurations is determined as described later.

As shown in FIG. 2, the liquid fuel injection device 15 has a cover 16 covering the upper portion of the sintering machine holder 8, and a large opening 17 is provided in the upper portion of the cover 16.

In the cover body 16, as shown in FIG. 2 and FIG. 4, a compressed air supply pipe 21 and a liquid are disposed above the loading layer 9 in the conveying direction of the sintering machine tray 8. Fuel supply piping 22. Further, the compressed air supply pipe 21 and the liquid fuel supply pipe 22 are held at a predetermined interval in the width direction orthogonal to the direction in which the sintering machine pallet 8 is conveyed, and a plurality of arrays (for example, nine groups) are arranged in parallel. On the lower surface side of each of the compressed air supply piping 21 and the liquid fuel supply piping 22, a spray mechanism 23 is disposed at a predetermined distance in the conveying direction of the sintering machine pallet 8. In the spray mechanism 23, the spray mechanism 23 is arranged in a staggered manner in the transport direction of the sintering machine pallet 8 so that the spray mechanisms 23 adjacent to each other in the width direction of the sintering machine pallet 8 are not opposed to each other. Further, the number of sets of the compressed air supply pipe 21 and the liquid fuel supply pipe 22 is not limited to nine sets, and it is preferable to provide a plurality of sets (for example, 3 to 15 sets).

Each of the spray mechanisms 23 is an enlarged view of FIG. 3 and includes a vertical pipe 24, a mixing portion 25, a connecting pipe 26, and a branching spray portion 27. The vertical pipe 24 is connected to the lower surface of the compressed gas supply pipe 21. The mixing portion 25 is formed at an intermediate portion of the vertical pipe 24. The connecting pipe 26 connects the mixing portion 25 to the lower surface of the liquid fuel supply pipe 22. The branch injection portion 27 is disposed at the lower end of the vertical pipe 24, and branches into a double shape in the width direction of the sintering machine tray 8.

The branch injection portion 27 has two injection nozzle portions 28a and 28b that are symmetrical with respect to the vertical pipe 24. The liquid fuel mists 29 atomized to the fine particles of, for example, 100 μm or less are ejected in the horizontal direction from the ejection nozzle portions 28a and 28b.

Here, the reason why the particle diameter of the liquid fuel mist 29 is set to 100 μm or less is If the particle diameter exceeds 100 μm, the portion remaining in the surface layer portion of the layer 9 will be generated, and the combustion will start in the surface layer portion, resulting in insufficient heat in the upper layer and the middle portion due to insufficient combustion in the layer 9 . The domain retention time is extended and contributes to waste. Further, although the particle diameter of the liquid fuel mist 29 is preferably as small as possible, the amount of generation of the liquid fuel mist 29 is preferably reduced by 50 μm or less and 20 μm or more. When the particle diameter of the liquid fuel mist 29 is 50 μm or less, the burning of the upper layer and the surface layer portion of the charging layer 9 is suppressed, and the cracked portion in the sintered cake formed by the surface layer is used, or the sintered cake is first vaporized, and then depending on the gas state. By sintering the cake and reaching the burning. The zone is melted and burned. Further, when the particle diameter is less than 20 μm, the amount of generation of the liquid fuel mist 29 is reduced, and the introduction of the liquid fuel mist 29 into the charging layer 9 cannot be exhibited, and the effect of maintaining the holding time in the high temperature region is prolonged.

Each of the jet nozzle portions 28a and 28b is set to be slightly inclined downward from the vertical pipe 24 toward the tip end as the center line thereof is gradually lowered, and is opened at an angle of, for example, about 85 degrees with respect to the central axis of the vertical pipe 24. Accordingly, the injection nozzle portions 28a and 28b are set such that the tip end is slightly inclined downward, and when the injection of the liquid fuel mist is completed, the liquid fuel mist does not form liquid remaining in the injection nozzle portions 28a and 28b, but will be all dropping. The above opening angle is preferably from 20 degrees to 90 degrees. More preferably 45 degrees to 85 degrees.

Accordingly, since the spray mechanism 23 is arranged in a staggered manner in the conveyance direction of the sintering machine pallet 8, the liquid fuel mist 29 ejected from the injection nozzle portions 28a and 28b of the respective spray mechanisms 23 will be as shown in FIG. Show, not mutual Interference, but evenly spreads onto the loading layer 9. Then, the sintered cake formed in the surface layer of the loading layer 9 is introduced into the deep portion (lower layer) of the charging layer by the suction force of the bellows (not shown) under the sintering machine tray 8.

Each of the compressed gas supply pipes 21 is connected to the compressed gas supply source pipe 31 via the control valve VC via the flow meter FC on the upstream side of the sintering machine tray 8, which is connected to the compressed gas supply source pipe 31. It is coupled to a compressed gas supply source 32. The compressed gas supply source 32 has a storage tank 33 for storing a gas which is used as a main component of nitrogen, carbon dioxide, and water vapor having a flame-retardant property, and the gas stored in the storage tank 33 uses a compressor. The compressed gas is compressed to form a compressed gas, and is stored in the receiving groove 35, and is supplied from the receiving groove 35 to the respective control valves VC via the compressed gas supply source pipe 31. Here, between the receiving groove 35 and the flow meter FC, a main flow path LM through which the control valve VC is inserted, and a bypass flow path LB that bypasses the control valve VC to supply a small flow of compressed air are provided. The bypass flow path LB causes the compressed gas from the receiving groove 35 to flow through the bypass flow path LB and the flow meter FC in a state where the liquid fuel mist 29 is not ejected from the spray mechanism 23, and supplies a small amount of compressed gas to the spray. The mechanism 23 prevents the ejection nozzle portions 28a and 28b of the spray mechanism 23 from being clogged.

Similarly, the liquid fuel supply pipe 22 is connected to the liquid fuel supply source pipe 36 via the control valve VF via the flow meter FF on the upstream side of the sintering machine tray 8, and the liquid fuel supply source pipe 36 is via the fuel supply pump. 37 is connected to a liquid fuel storage tank 38 belonging to a liquid fuel supply source. in In this case, the liquid fuel supply pipe 22 and the liquid fuel supply source pipe 36 are preferably disposed obliquely with respect to the upstream side, respectively, at a lower arrangement height on the downstream side and inclined downward, and the injection of the liquid fuel mist 29 ends. At this time, a state in which liquid fuel does not remain in the liquid fuel supply pipe 22 and the liquid fuel supply source pipe 36 is formed.

The liquid fuel is a petroleum liquid fuel such as kerosene, light oil or heavy oil which is liquid at normal temperature; or an alcohol liquid fuel such as ethanol or methanol; or an ether liquid fuel; at least one of other hydrocarbon liquid fuels. Above, these are stored in the liquid fuel storage tank 38.

Here, the liquid fuel and its characteristics which can be used in the present invention are shown in Table 1 below.

This liquid fuel is subjected to micronization and injection of a liquid fuel mist 29 because the ignition temperature is higher than, for example, blast furnace gas, coke oven gas, blast furnace. Coke oven mixed gas, city gas, natural gas, or methane gas, ethane gas, The ignition temperature of any gaseous fuel such as propane gas, butane gas, or a mixed gas thereof is therefore higher in temperature than the loading layer 9 (i.e., the surface layer of the sintering bed) and further inside the loading layer 9 Burning, burning at the blowing point. The temperature expansion in the flat region at the bottom of the melting zone curve has an effect. The liquid fuel is preferably used at a temperature of 180 ° C to 500 ° C.

Further, it is preferable to provide a state in which a large amount of the liquid fuel mist 29 is supplied to the position of the low-yield portion in the vicinity of the left and right side walls 18 of the cover 16.

Further, since waste oil or the like contains a component which is easy to ignite or has a low ignition temperature, the present invention is preferably not used. The reason is that when a liquid fuel such as waste oil containing a component having a lower ignition temperature or a lower ignition point is preliminarily gasified and supplied to the charging layer 9 (i.e., a bed of a sintered raw material), it is in the loading layer 9 Before the vicinity of the combustion zone, combustion occurs in the upper space of the surface layer of the loading layer 9 or even in the vicinity of the surface layer of the layer 9. Therefore, it is not possible to obtain the intention of burning in the vicinity of the combustion zone of the loading layer 9 The effect of maintaining the temperature in the high temperature region maintained at, for example, 1200 ° C or higher is prolonged.

Accordingly, the reason why the liquid high temperature region holding time can be prolonged by spraying the liquid fuel mist 29 above the loading layer 9 is to prepare the experimental device shown in Fig. 9 (i.e., the vertical tubular window with the transparent quartz window). Test pot) (diameter: 150 mm Φ, height: 400 mmH), the liquid fuel used is sesame oil, and the same sintered raw material used by the applicant in the sintering plant, that is, the sintered raw material shown in Table 2 below is used to form the loading layer. And the height of the blowing nozzle for spraying the sesame oil is set to be 320 mm from the surface of the charging layer, and the powder coke ratio is set to be equivalent to 5.0% (reference 5.25%), and the ignition time is set to 30 seconds, and the pumping time is set. The suction force was set to 1200 mmH ₂ O, the blowing amount was set to 5.0 ml/min, and the blowing position was set to 30 seconds after ignition to 1/2 portion of the upper layer. Further, the blowing period is set to be 1 to 6 minutes after ignition. Here, the sesane oil property of the liquid fuel is 255 ° C, a calorific value of 40.3 kJ / g, and a density of 0.92 g / cm ³ .

The result of the liquid fuel injection test is as shown in Fig. 9. In the state where the liquid fuel is not blown (reference), the width of the combustion zone after the ignition for 5 minutes is 65 mm, and the heating is 50 mm downward from the surface of the loading layer. The mode is rapidly increased after 1 minute after ignition and exceeds 1200 ° C. The state exceeding 1200 ° C is maintained for 33 sec, and then the temperature is lowered.

In contrast, when sesame oil is blown for 1 to 6 minutes after ignition, the width of the combustion zone after expansion for 5 minutes will be expanded to 114 mm, and the heating mode 50 mm from the surface of the loading layer is from the ignition. After 1 min, it rises sharply and exceeds 1200 ° C. After maintaining it for more than 1200 ° C for 82 sec, The temperature is slower and the slope is lowered.

Therefore, by blowing the sesame oil, the width of the combustion zone can be enlarged, and the holding time of the heating mode exceeding 1200 ° C (ie, the holding time in the high temperature range) can be set to 82 sec, compared to the case where no liquid fuel is blown. The width of the burning zone can be expanded by about 1.75 times, and the holding time of the high temperature zone can be extended by about 2.5 times.

Further, in the same test apparatus, in comparison with the above-described blowing conditions, the combustion belts were compared in three states: a state in which no liquid fuel was blown, a state in which sesame oil was blown, and a state in which heavy oil was blown. As a result, as shown in FIG. 10, the width of the combustion zone can be enlarged when the state of the sesame oil is blown, and the width of the combustion zone can be further enlarged even when the heavy oil is blown, compared to the state in which the liquid fuel is not blown. . The properties of each liquid fuel are as described in Table 3. It is assumed that the calorific value (kJ/g) of rapeseed oil and sesame oil is equivalent to soybean oil, and the rapeseed oil density (g/cm ³ ) is also equivalent to soybean oil. value. Although these rapeseed oils and soybean oils are not shown, it has been confirmed that the width of the burning zone and the holding time of the high temperature zone are prolonged as in the case of sesame oil. Even if the kerosene is confirmed, the width of the burning zone corresponding to the heavy oil is enlarged and the high temperature domain is maintained. Prolonged.

Further, in the above embodiment, the liquid fuel is mixed into the pressure by the mixing unit 25 by the spray mechanism 23 that sprays the liquid fuel mist 29. In the case where the condensed gas is atomized and then sprayed toward the loading layer 9 in the horizontal direction, the present invention is not limited thereto, and the compressed gas supplied from the compressed gas supply source 32 and the fuel supply pump 37 may be used. The liquid fuel is mixed with a liquid mixer to form a liquid fuel mist, which is supplied to the branch injection portion 27 of each of the spray mechanisms 23 via a mist supply pipe. In this case, in order to prevent the liquid fuel mist from being reliquefied, it is preferred to maintain the temperature above the boiling point of the liquid fuel and not above the ignition temperature.

Then, in the present invention, as described above, the cover 16 for covering the upper portion of the sintering machine tray 8 is provided. The cover 16 can suppress the influence of the cross wind on the concentration distribution of the liquid fuel mist 29. In other words, the present inventors have conducted various reviews, and as a result, it has been found that the installation of the cover 16 has an effect of achieving a screen or more in terms of cross wind countermeasures. However, as described above, the cover 16 must have a structure in which the upper center portion has the opening 17, or has an appropriate transmittance (void ratio), and the atmosphere can be taken in from the portion.

Thereby, inside the cover 16, the liquid fuel mist 29 discharged from the spray mechanism 23 is mixed with the atmosphere. The opening 17 is a sintering machine having a width of 5 m of the sintering machine holder 8, and if it is about 1 m, the pressure loss of the cover 16 is almost negligible. Further, it has been found that when a gap is provided in the opening 17, when the transmittance is set to about 80%, the pressure loss to the extent of several mmAq can be suppressed. Further, by providing the rectifying plate 40 in the cover body 16, the eddy current in the cover body 16 is suppressed, and the air gap of the screen provided in the upper portion (around) of the cover body 16 is in the range of 30 to 40%. The most effective inside, this department It is known from the analysis results. Further, as shown in Fig. 7, the upper end of the left and right side walls 18 of the cover body 16 in the conveying direction of the sintering machine pallet 8 is preferably provided with a cross wind attenuation fence 16c made of punched metal or the like having a transmittance of about 30%.

Further, although a gap is inevitably formed between the lower side of the cover 16 and the surface of the sintered bed (the surface of the mounting layer), it is known that if the gap portion is insufficiently sealed, for example, the penetration rate is 20 to 30%, From this portion, air is drawn into the inside of the cover 16, resulting in an increase in the concentration distribution of the liquid fuel mist. Therefore, it is preferable to prevent air from intruding from the lower end of the cover 16.

Therefore, between the lower end of the left and right side walls 18 of the cover body 16 in the conveying direction of the sintering machine pallet 8 and the side wall 8a of the pallet, and the lower surface of the branch spraying portion 27 of the spray mechanism 23 and the upper surface of the loading layer 9, as shown in Fig. 7. It is shown that the edge strip 41 in which the sealing sheet is inserted is interposed between the wire brushes extending in the conveying direction of the sintering machine pallet 8, and the lid body 42 covering the edge strip 41 from the outside is provided outside. Further, the sealing material is not limited to the edge strip 41, and a sealing material such as a chain curtain, a seal brush, or a sealing seal may be used. Further, the above-mentioned sealing material preferably has heat resistance, and has high flexibility and deformation freedom, and does not cause damage to the surface of the mounting layer 9.

On the other hand, on the upstream side and the downstream side in the conveying direction of the sintering machine pallet 8, between the lower end of the front and rear plate portion 16b of the cover 16 and the surface of the loading layer 9, as shown in Fig. 8, along the front and rear of the cover 16 The wall 19 is provided with an air passage 43, and air is blown from below the air passage 43 to form an air curtain 44.

Furthermore, the setting position, size, and number of configurations of the liquid fuel injection device 15 The amount is set as follows.

That is, after the carbon material in the charging layer 9 is ignited, the liquid fuel mist 29 is supplied (imported) onto the charging layer 9. The reason is that even if the supply of the liquid fuel mist 29 is performed at the position immediately after ignition, the combustion only occurs on the surface layer of the charging layer 9, and the liquid fuel mist does not have any influence on the combustion layer. Therefore, it is necessary to supply the molten material to the charging layer 9 after the sintered raw material charged in the upper portion of the layer 9 is fired to form a sintered finished belt belonging to the sintered cake layer.

The principle of use of the liquid fuel mist of the present invention will be described with reference to FIG. Fig. 11 (a) shows a photograph in which ethanol was formed to have a particle diameter of about 50 μm and tested in a pot. It is known that as the ethanol is blown in, the combustion melting zone will be greatly expanded. A schematic illustration of this phenomenon is shown in Fig. 11(b), and the left side in the figure refers to a sintering reaction when a liquid fuel is blown. The powder coke belonging to the condensate is ignited by the ignition furnace, and the combustion zone formed of the powder coke lowers the charging layer of the sintering raw material while causing the sintering reaction to proceed downward. The sintering belt formed by the sintering belt, when a liquid fuel is blown between the sintering completion belt and the powder coke combustion belt, a gas combustion belt of the liquid fuel gas is generated, where the maximum temperature rise is not caused. The release time in the high temperature range is extended. Shown on the right side is the sintering reaction in the use of the liquid fuel mist of the present invention. In the present invention, the particle diameter of the liquid fuel mist is set to 100 μm or less, preferably 50 μm or less, as described above. When the particle diameter exceeds 100 μm, the heat of the belt is completed by sintering, and the liquid droplets remain, and there is a possibility of burning in the surface layer portion. If the liquid fuel mist particle size is set at 100μm In the following, the liquid fuel mist (liquid fuel particles) also contains agglomerated particles, which are vaporized to form a vapor of the liquid fuel, when the liquid fuel is formed into a liquid fuel mist and blown between the sintered finish belt and the powdered coke combustion zone. In this case, a gas combustion zone of liquid fuel gas is generated, and in this case, the high temperature range holding time is extended without causing the maximum temperature to rise, and the same phenomenon as when using a gaseous fuel is exhibited.

When the liquid fuel is blown, as shown in Fig. 11 (b), the gasification (liquid fuel vapor) region of the liquid fuel particles is important.

That is, in the liquid fuel vaporization region of Fig. 11(b), first, it is preferable to spray the liquid fuel from the spray nozzle so that the vapor concentration of the liquid fuel becomes equal to or lower than the lower limit of combustion of Table 1. In order to prevent the surface layer portion of the sintered belt from being burned during the blowing, it is necessary to set it to 75% or less of the lower limit of the combustion concentration, and the lower limit is to use the fuel heat, and at least 1% or more of the lower limit of the combustion concentration. It is preferably 25% or less and 4% or more of the lower limit of the combustion concentration. The upper limit is determined by safety considerations such as fire, and the lower limit is determined by the effective heat. In addition, it must be below the ignition temperature.

As shown in Fig. 11(c), the burning time is the highest temperature in the sintering coke reaction on the powder coke side A, and the high temperature domain holding time is the combustion of the liquid fuel side B which maintains the combustion zone temperature below the maximum temperature. Figure 11 (d) shows this example. The temperature profile indicated by C is that when the powdered coke is formed into a condensed material, the in-layer temperature at the time of sintering production in the sintering reaction is experienced. The maximum temperature is controlled by the amount of powdered coke, and the high temperature range holding time E is determined by the temperature profile. when According to the C temperature type, when the holding time of the high temperature region is prolonged, the amount of powdered coke added is increased, and the flat bottom region of the curve in the region of 1200 ° C or higher in the high temperature region is expanded, but the maximum temperature must also be increased. The temperature profile of the liquid fuel used is expressed by D. As shown in Fig. 11 (c), the combustion of the liquid fuel is based on the combustion of the liquid fuel side B in Fig. 11 (c) which maintains the temperature of the combustion zone below the maximum temperature. By the combination of the two, the temperature profile D of Fig. 11(d) which raises the temperature of the flat region at the bottom of the curve can be obtained without causing the maximum temperature change. By using this temperature profile D, the flat bottom region of the curve in the region above 1200 ° C is enlarged, and the high temperature region is maintained for the time F.

Fig. 12 is a photograph showing a pot test of a conventional sintering method and a liquid fuel mist using a sintering method. In the conventional sintering, the powder coke is relatively high because of the heat of combustion of the powdered coke. And, even if it is high, it seems to burn in white. The molten zone was stopped at about 65 mm in this experiment.

In the gasification zone (sintering completion zone) of the liquid fuel, the temperature of the zone is set to be equal to or higher than the boiling point of the liquid fuel, and is below the ignition temperature (which can be controlled by making the concentration lower than the lower limit of combustion), and the liquid fuel For heavy oil and ethanol, in order to suppress the maximum temperature to 1380 ° C, the amount of powder coke used is reduced. Anyone can seem to be burning in white. The sinter strength obtained by expanding the molten bands is higher, and a higher sintering method than the conventional sintering method using only powdered coke can be obtained.

Further, in the liquid fuel vaporization region (sintering completion zone) in Fig. 11(b), the temperature of the region must be equal to or higher than the boiling point of the liquid fuel and equal to or lower than the ignition temperature. Thereby, the phenomenon shown in Fig. 12 can be obtained.

In addition, if the temperature of the gasification zone (sintering completion zone) is above the ignition temperature (high concentration close to the lower combustion limit concentration), as shown in Fig. 13, the surface of the sintering completion zone before entering the powder coke combustion zone, liquid fuel The vapor will burn, causing the effect to disappear, which will adversely affect the sintering operation caused by insufficient oxygen.

Further, the supply of the liquid fuel mist can be carried out at any position up to completion of sintering as long as a layer of the sintered cake is formed on the surface of the charging layer 9. The reason why the supply of the liquid fuel mist is carried out after forming the layer of the sintered cake is as follows in addition to the above.

(a) If the supply of the liquid fuel mist is performed in the immediately fired state in which the sintered cake is not formed on the upper portion of the loading layer 9, there is a possibility that combustion is caused on the charging layer 9.

(b) The supply of the liquid fuel mist is carried out in a part in which the yield of the sintered ore must be increased, that is, it is preferably supplied in such a manner that the portion where the strength of the sintered ore is increased is burned.

In order to be able to adjust either or both of the highest cylinder temperature or the high temperature domain holding time of the loading layer, it is preferably burned. The supply of the liquid fuel mist is performed in a state where the thickness of the molten belt is at least 15 mm or more (preferably 20 mm or more, more preferably 30 mm or more). The reason is if it burns. The thickness of the molten zone is less than 15 mm, and the cooling effect by the air sucked by the sintered layer (sintered cake) and the liquid fuel mist causes the effect of burning even if the liquid fuel mist is burned, and the combustion cannot be expected. The thickness of the molten zone is enlarged. on the other hand, Burning above. The thickness of the molten zone is 15mm or more (preferably 20mm or more, more preferably 30mm or more), and the liquid fuel mist is supplied and burned. The thickness of the molten zone is greatly expanded, and the holding time in the high temperature region can be prolonged, and the sintered ore having a higher cold rolling strength can be obtained.

Furthermore, the introduction of the liquid fuel mist into the loading layer 9 is preferably carried out under the surface of the combustion line and burned. The molten ribbon is lowered to a position of more than 100 mm from the surface layer, preferably more than 200 mm, that is, it is not caused to be loaded into the layer 9. The sintered cake region (sintered layer) formed in the lower layer is passed through by combustion, and is supplied in a state in which the combustion front line moves to a stage of 100 mm or more from the surface layer. The reason is that if the combustion front line is lowered to a position of more than 100 mm from the surface layer, the adverse effect of cooling caused by the suction of air through the sintered layer can be alleviated, and the crucible can be burned. The thickness of the molten zone is enlarged. In addition, if burning. The melting zone is lowered to a position 200mm or more from the surface layer, which will slightly relieve the cooling effect caused by the air and can be burned. The thickness of the molten ribbon is increased by more than 30 mm. Further, the supply of the liquid fuel mist is preferably carried out in the vicinity of the side walls of the both end portions in the width direction of the pallet where the yield is greatly lowered.

Further, the liquid fuel injection device 15 differs depending on the scale of the sintering machine. For example, a sintering machine having a production capacity of about 15,000 t/day and a machine length of 90 m is preferably disposed at a position about 5 m after the downstream side of the ignition furnace 10. .

In the sintering machine of the present invention, the supply position of the liquid fuel mist (the introduction position to the charging layer) is preferably from the exit side of the ignition direction in the direction in which the tray is formed, and the so-called combustion front line after the generation of the sintered cake proceeds to the surface layer. Position (for example, from the surface The lower one is 100 mm or more, preferably about 200 mm or less, and the position where the liquid fuel mist is burned is started, and it is performed at any position between one or more positions until the completion of sintering. This phenomenon is as described above, meaning that the introduction of the liquid fuel mist is started at the stage where the combustion front line moves under the surface of the loading layer, and as a result, the combustion of the liquid fuel mist will occur inside the loading layer, and then quickly move to the more. The lower layer, therefore means that there is no threat of explosion and a safe sintering operation.

The method for producing a sintered ore according to the present invention also means introducing a liquid fuel mist into the layer to promote reheating of the resulting sintered cake. That is, the supply of the liquid fuel mist is originally maintained in a high temperature region for a short period of time, which is liable to cause heat deficiency, resulting in a lower cold rolling strength of the sintered ore, and a higher reactivity of the liquid fuel than the solid fuel. The fog will make up for the burning heat of this part which is easy to cause deficiency, and is responsible for the burning. The meaning of the regeneration-expansion of the molten zone.

Furthermore, the method for producing a sintered ore according to the present invention is preferably supplied from a liquid fuel mist in an upper portion of the charged layer after ignition, preferably at least a part of a liquid fuel mist introduced into the packed layer, and is maintained in an unburned state. combustion. The molten zone is burned at a target position where the heat of combustion is to be compensated. The reason is the supply of liquid fuel mist, that is, the introduction effect into the loading layer is not only loaded into the upper part of the layer, but also affects the combustion in the central part of the thickness direction. Melting the belt, the judgment will be more effective. That is, if the supply of the liquid fuel mist is carried out in the upper layer of the charging layer which is likely to cause heat shortage (insufficient holding time in the high temperature region), sufficient combustion heat will be supplied to improve the quality of the sintered cake in this portion even if Liquid fuel mist The supply function is also below the middle-level zone, and it is burned with the original carbon material. On the molten zone, the liquid fuel mist is used to form re-combustion. The situation of the molten zone has the same result because it is associated with combustion. Since the molten belt is widened in the vertical direction, the effect of prolonging the holding time in the high temperature range can be achieved without increasing the maximum reaching temperature, so that sufficient sintering can be achieved without lowering the moving speed of the pallet. As a result, the quality of the sintered cake which is integrated into the entire layer is improved (the cold rolling strength is improved), and the quality (cold rolling strength) and productivity of the finished sintered ore can be obtained.

Furthermore, in the present invention, when the liquid fuel mist is introduced (supplied) into the layer, it is preferred to adjust not only the supply position but also the combustion. The shape of the molten zone itself is controlled, and it is also burning. The maximum temperature of the molten zone and/or the holding time of the high temperature zone are controlled.

Generally, in the loaded layer after ignition, with the movement of the pallet, the front line of the combustion (flame) rapidly expands downward and forward (downstream side), burning. The position of the molten ribbon is also changed as shown in Fig. 18(a) above. However, as shown in Fig. 18(b), the thermal history experienced 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 region is maintained between the upper layer and the lower layer (becoming about 1200 ° C or higher). The time) has a big difference. As a result, the sinter yield in the pallet is distributed as shown in Fig. 18(c). That is, the formation of the surface layer portion (upper layer portion) has a low yield, and the middle layer and the lower layer portion have a high yield distribution. Here, if the liquid fuel mist is supplied and burned according to the method of the present invention. The thickness of the molten belt is increased in the vertical direction and the width of the pallet. This phenomenon will be reflected in the quality improvement of the finished sinter. Then, it becomes the middle part and the lower part of the high-yield distribution, and the yield can be further improved because the high-temperature field holding time can be controlled.

By adjusting the supply (introduction) position of the above liquid fuel mist, it is possible to burn. The form of the molten zone (i.e., the thickness of the burning zone in the height direction of the molten zone and/or the width of the direction in which the pallet is oriented) is controlled, and the maximum reaching temperature and the holding time of the high temperature region can be controlled. These control systems can further highlight the effects of the present invention through the combustion of the pair. The thickness of the molten strip in the vertical direction and the width of the pallet, or the control of the maximum temperature and the holding time in the high temperature range can be sufficiently burned to contribute to the improvement of the cold rolling strength of the finished sintered ore.

Further, in the present invention, the supply (introduction) of the liquid fuel mist to the packed bed may be controlled by controlling the cold rolling strength of the entire finished sintered ore. That is, the initial purpose of supplying liquid fuel mist is to improve the cold rolling strength of the sintered cake (even the sintered ore), especially through the supply position control of the liquid fuel mist, and the sintering raw material is burning. The control of the high temperature range retention time in the molten zone and the control of the highest temperature reached, the cold rolling strength (splitting index SI) of the sintered ore is set at about 75 to 85%, preferably more than 80%, and more preferably up to 90. %the above.

The strength level is in the present invention, in particular, by considering the concentration of the liquid fuel mist, the supply amount, the supply position, and the supply range, and considering the amount of the carbon material in the preferred sintered raw material (the input heat is set to a certain condition) ), and adjustments can be made at low cost. In addition, the cold rolling strength of the sinter is increased, on the other hand There is a case where the ventilation resistance is increased and the productivity is lowered. However, in the present invention, the problem is that the maximum temperature of arrival and the holding time of the high temperature region are controlled and released, and the cold rolling strength of the sintered ore can be improved. In addition, the SI value of the sintered ore cold rolling strength produced by the actual machine sintering machine is further increased by 10-15% compared with the value obtained by the pot test.

In the manufacturing method of the present invention, in the direction in which the pallet is advanced, the introduction position of the liquid fuel mist into the charging layer is from any region between the sintered cake formed in the loading layer and the wet belt. What is the basis of the sinter cold rolling strength is set as the benchmark. In order to perform this control, in the present invention, the amount (size), the number, the position (the distance from the ignition furnace), the gas concentration of the liquid fuel injection device, and the amount of the carbon material (solid fuel) in the sintering raw material are used. Adjustment, mainly because not only burns. The size of the molten strip (the thickness in the up-and-down direction and the width of the pallet) is controlled even by the high temperature reaching temperature and the high temperature holding time, whereby the strength of the sintered cake generated in the packed layer can be controlled.

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

First, as shown in FIG. 1, the sieved ore block is cut out from the bottoming hopper 4, and a layup layer is formed on the stringer screen of the sintering machine tray 8, and then the receiving bucket is loaded on the floor. 5 The cylindrical raw material feeder 6 is used to perform the quantitatively cut sintering raw material, and the charging layer 9 which is also called a "sintering bed" is formed to be about 400 to 800 mm.

Then, with the conveyance of the sintering machine pallet 8, the carbon material in the surface layer of the loading layer 9 which has moved to the ignition furnace 10 is ignited.

After the ignition of the loading layer 9, with the movement of the sintering machine tray 8, the combustion (flame) front line rapidly downwards and the front (downstream side) expands and burns. The position of the molten zone will vary as shown in Figure 18(a) above. Then, when burning. When the position of the molten belt is moved from the upper layer to the middle layer and reaches about 200 mm from the surface layer, the sintering machine tray 8 reaches the position of the liquid fuel injection device 15.

In the liquid fuel injection device 15, the liquid fuel mist 29 is uniformly sprayed toward the surface of the charging layer 9 by the spray mechanism 23 in the cover 16 which covers the upper portion of the sintering machine tray 8.

That is, in the liquid fuel injection device 15, at a predetermined distance from the surface of the charging layer 9 of the liquid sintering machine pallet 8, the conveying direction of the sintering machine tray 8 is extended in parallel and the width orthogonal to the conveying direction. A combination of a predetermined array of compressed gas supply piping 21 and a liquid fuel supply piping 22 is disposed in the direction, and a spray mechanism 23 is disposed in each of the compressed gas supply piping 21 and the liquid fuel supply piping 22, and the spray mechanism 23 is a compressed gas and The liquid fuel is mixed and atomized into a liquid fuel having a particle diameter of 100 μm or less, preferably a particle diameter of 50 μm or less, and a particle diameter of 20 μm or more, and after being formed into a liquid fuel mist, is sprayed in a horizontal direction.

Then, as shown in FIG. 5, the spray mechanism 23 is disposed so as to be opposed to each other in the direction in which the spray mechanism 23 of the adjacent group does not face each other, and is disposed at a half pitch between the adjacent groups in the direction in which the sintering machine tray 8 is conveyed. The liquid fuel mist 29 ejected from the injection nozzle portions 28a and 28b of the spray mechanism 23 forms a uniform injection region that does not interfere with each other.

The injected liquid fuel mist 29 is mixed with the air rectified by the rectifying plate 40, and is diluted to a lower limit of the combustion lower limit concentration at normal temperature to suppress combustion above the charging layer 9. In this case, at least one of nitrogen, carbon dioxide, and water vapor having a flame-retardant property is used as a component for atomizing the liquid fuel, and the liquid fuel mist 29 contains such a consumer. The flame compresses the gas, so that it is possible to surely suppress the combustion of the liquid fuel mist 29 on the upper side of the charging layer 9.

Then, the liquid fuel mist 29 ejected from the injection nozzle portions 28a and 28b of each of the spray mechanisms 23 is sucked to the lower side via the bellows 11 disposed on the lower side of the sintering machine tray 8, thereby The rectified air passing through the rectifying plate 40 is mixed and introduced into the loading layer 9.

The liquid fuel mist 29 introduced into the loading layer 9 passes through the sintered cake formed in the surface layer portion and reaches the burning of 100 mm or more from the lower side of the surface. Melt the band and burn in it. The molten layer is burned. Therefore, the original high temperature field has a short holding time, which is easy to cause heat shortage, and the cold rolling strength of the sintered ore can be lower. The middle layer maintains a high temperature range maintained in a high temperature region above 1200 ° C for a long time, and the crucible can improve the cold rolling strength of the sintered ore. Therefore, when the liquid fuel mist 29 is not blown, the yield shown in Fig. 18(c) is low. The yield of the middle department.

Accordingly, if the supply of the liquid fuel mist 29 affects the area below the middle portion, it forms a combustion with the original carbon material. On the molten zone, the formation of liquid fuel mist 29 constitutes re-combustion. The same result of the situation of the molten zone, Because it will lead to burning. Since the width of the molten strip in the vertical direction is enlarged, the effect of prolonging the holding time in the high temperature range can be achieved without increasing the maximum reaching temperature, so that sufficient speed can be achieved without lowering the moving speed of the sintering machine tray 8. sintering. As a result, the quality of the sintered cake which can be integrated into the entire layer 9 can be improved (the cold rolling strength is improved), and the quality (cold rolling strength) and productivity of the sintered ore can be improved.

Further, when the fuel supply pipe 21 starts to supply the liquid fuel and when the liquid fuel supply is stopped, the heated gas is supplied as a forced gas to the liquid fuel supply pipe 21 to burn the liquid fuel remaining in the pipe. And removed.

Accordingly, in the above embodiment, after the surface layer of the charging layer 9 is ignited by the ignition furnace 10, the liquid fuel injection device 15 is conveniently placed on the upper side of the charging layer 9 of the sintering machine holder 8, so that the liquid fuel mist 29 is uniformly Dispersing and spraying, thereby using a diluted gaseous fuel diluted with air, such as a gas fuel such as a barrel gas, LNG, mixed gas, etc., because a liquid fuel having a higher ignition temperature is used, and Instead of directly using the liquid fuel, the compressed gas is subjected to atomization, and after the liquid fuel mist is formed, the injection is performed, so that the possibility of ignition on the upper side of the charging layer 9 can be surely suppressed. Further, by using a gas having at least one of nitrogen, carbon dioxide, and water vapor which is a flame-retardant property as a main component of the compressed gas, it is possible to further suppress the possibility of ignition on the upper side of the charging layer 9.

Further, in the above embodiment, the liquid is disposed on the downstream side of the ignition furnace 10. In the case of the fuel injection device 15, the liquid fuel injection device 15 may be disposed on the downstream side of the holding furnace when the holding furnace is disposed on the downstream side of the holding furnace 10.

In the above embodiment, the cover body 16 of the liquid fuel injection device 15 is configured to have a structure in which the opening 17 is provided. However, the structure is not limited thereto, and the structure may be as shown in FIG. The upper end is open, and between the cover 17 and the front and rear walls 19, three rows of barrier rows 52 are arranged in the vertical direction, and the barrier rows 52 are extended in the direction in which the sintering plate 8 is conveyed. And the barrier plate 51 having a U-shaped cross section at an upper end, and the barrier plate 51 is disposed in a width direction orthogonal to the conveying direction of the sintering machine pallet 8, and maintains a predetermined pitch in a predetermined pitch p The construction of the number. Between the barrier ribs 52 adjacent to each other in the up-and-down direction, the barrier ribs 51 disposed as the other barrier ribs 52 are located between the barrier ribs 51 of one of the barrier ribs 52 and at the lowermost barrier A spray mechanism 23 is disposed between the barrier plates 51 on the lower side of the plate row 52.

In the above-described embodiment, the case where the liquid fuel is supplied from the liquid fuel storage tank 38 to the liquid fuel supply source piping 36 and the liquid fuel supply piping 22 at normal temperature will be described, but it is not limited thereto, and is related to, for example, C heavy oil. The liquid fuel having a high viscosity at room temperature and being difficult to be micronized is preheated to, for example, 130 ° C to 150 ° C by using, for example, steam, and is supplied to the liquid fuel supply pipe 22 after the viscosity is lowered, whereby the spray mechanism 23 can be utilized. It is easily micronized, and after the liquid fuel mist 29 is formed, the spraying can be performed.

(industrial availability)

The technique of the present invention can be effectively used as a manufacturing technique for a sintered ore such as iron for use, particularly for a raw material for a blast furnace, or as a technique for forming other ore blocks.

1‧‧‧Material hopper

2‧‧‧Turn mixer

3‧‧‧Rotary kiln

4‧‧‧ receiving bucket

5‧‧‧ bottom hopper

6‧‧‧Tubular feeder

7‧‧‧Cut the chute

8‧‧‧Sintering machine pallet

9‧‧‧Loading layer

10‧‧‧Ignition furnace

11‧‧‧ bellows

15‧‧‧Liquid fuel injection device

16‧‧‧ Cover

16b‧‧‧ front and rear board

16c‧‧‧ crosswind attenuation fence

17‧‧‧ openings

18‧‧‧ side wall

21‧‧‧Compressed air supply piping

22‧‧‧Liquid fuel supply piping

23‧‧‧Spray mechanism

24‧‧‧Vertical piping

25‧‧‧Mixed Department

26‧‧‧Connected piping

27‧‧‧ branch spray department

28a, 28b‧‧‧jet nozzle

29‧‧‧liquid fuel mist

31‧‧‧Compressed gas supply piping

32‧‧‧Compressed gas supply

33‧‧‧ gas storage tank

34‧‧‧Compressor

35‧‧‧ socket

36‧‧‧Liquid fuel supply piping

37‧‧‧fuel supply pump

38‧‧‧Liquid fuel storage tank

40‧‧‧Rectifier board

41‧‧‧Edge banding

42‧‧‧ cover

43‧‧‧Air passage

44‧‧‧Air curtain

51‧‧‧Resist barrier

52‧‧‧Resistance board

FC‧‧‧ flowmeter

LB‧‧‧ bypass flow path

LM‧‧ mainstream road

VC‧‧‧ control valve

Fig. 1 is a schematic structural view showing an embodiment of a sintering machine of the present invention.

Fig. 2 is a schematic cross-sectional view taken along line A-A of Fig. 1;

Figure 3 is a front elevational view of the spray mechanism.

4 is a schematic perspective view showing the configuration of a spray mechanism of a liquid fuel injection device.

Fig. 5 is an explanatory view showing a liquid fuel mist injection state of the liquid fuel injection device.

Fig. 6 is a system diagram of a supply system of liquid fuel and compressed gas in a liquid fuel injection device.

Fig. 7 is a cross-sectional view showing the specific configuration of the liquid fuel injection device taken along line A-A in Fig. 1.

Fig. 8 is an explanatory view of a front-rear direction sealing mechanism of the liquid fuel injection device.

Figure 9 shows the combustion in a test pot using a liquid fuel blown. Schematic diagram of melting zone change and heating.

Figure 10 shows the combustion in a test pot using a liquid fuel blown. Melting zone change map (photo).

Figure 11 is a schematic view showing the principle of the liquid fuel blowing in the present invention, (a) a pot test The condition map of the test, (b) a schematic diagram of the phenomenon of the pot test, (c) the time point of the combustion, and (d) the temperature map of the layer.

Fig. 12 is a view showing the state of combustion of the liquid fuel of the present invention when it is blown.

Fig. 13 is a view showing the state of ignition of the liquid fuel of the present invention when it is blown.

Figure 14 is a cross-sectional view taken along line A-A of Figure 1 according to another embodiment of the present invention.

Figure 15 is an explanatory view of a conventional sintering process.

Fig. 16 is an explanatory view showing pressure loss and temperature distribution in a sintered layer.

Fig. 17 is an explanatory diagram for comparison of temperature distribution at the time of high production and low production.

Figure 18 is a graph showing the temperature distribution and yield distribution in a sintering machine, (a) the progress of sintering, (b) the temperature distribution, and (c) the yield distribution.

1‧‧‧Material hopper

2‧‧‧Turn mixer

3‧‧‧Rotary kiln

4‧‧‧ receiving bucket

5‧‧‧ bottom hopper

6‧‧‧Tubular feeder

7‧‧‧Cut the chute

8‧‧‧Sintering machine pallet

9‧‧‧Loading layer

10‧‧‧Ignition furnace

11‧‧‧ bellows

15‧‧‧Liquid fuel injection device

Claims (21)

A method for manufacturing a sintered ore comprises: a charging step of loading a sintered raw material containing fine ore and a carbon material on a circulating moving plate to form a charging layer; and an ignition step for forming a loaded layer The carbon material is ignited by an ignition furnace; after the ignition, the liquid fuel is micronized to a liquid fuel having a particle diameter of 100 μm or less, and is supplied to the charging layer, and is diluted to a lower concentration than the lower limit of combustion at normal temperature. And supplying to the loading layer; and the sintering step, the air is sucked by the bellows disposed under the tray, and the carbon material and the micronized liquid fuel are burned in the charging layer to manufacture Sinter. The method for producing a sintered ore according to the first aspect of the invention, wherein the microparticulated liquid fuel has a particle diameter of 50 μm or less and 20 μm or more. The method for producing a sintered ore according to the first aspect of the invention, wherein the microparticulated liquid fuel has a concentration lower than a lower limit of combustion concentration. The method for producing a sintered ore according to the third aspect of the invention, wherein the concentration is 75% or less and 1% or more of a lower limit of combustion concentration. The method for producing a sintered ore according to the fourth aspect of the invention, wherein the concentration is 25% or less and 4% or more of a lower limit of combustion concentration. The method for producing a sintered ore according to the first aspect of the invention, wherein the liquid fuel supply step is micronized to a liquid having a particle diameter of 100 μm or less. The fuel is sprayed horizontally on the upper side of the loading layer. The method for producing a sintered ore according to claim 1, wherein the liquid fuel supply step is to mix the liquid fuel in the compressed gas, atomize it, and spray it onto the packed bed. The method for producing a sintered ore according to the seventh aspect of the invention, wherein the compressed gas system is a gas containing at least one of nitrogen, carbon dioxide, and water vapor having a flame-retardant property. The method for producing a sintered ore according to the first aspect of the invention, wherein the liquid fuel is selected from the group consisting of petroleum liquid fuel, alcohol liquid fuel, ether liquid fuel, and other hydrocarbon compound liquid fuel. 1 person. The method for producing a sintered ore according to claim 9, wherein the petroleum-based liquid fuel is selected from the group consisting of kerosene, light oil, and heavy oil. The method for producing a sintered ore according to claim 9, wherein the alcohol liquid fuel is at least one selected from the group consisting of methanol, ethanol, and diethanol. The method for producing a sintered ore according to claim 9, wherein the other hydrocarbon-based compound liquid fuel is a group consisting of pentane, hexane, heptane, octane, decane, decane, benzene, and acetone. Select at least one of the groups. The method for producing a sintered ore according to the first aspect of the invention, wherein the liquid fuel supply step is to form a sintered cake in a surface layer portion of the loading layer. The micronized liquid fuel is supplied during the period from the completion of the sintering. 1. The method of manufacturing a sintered ore according to claim 1, wherein the liquid fuel supply step is in combustion. The micronized liquid fuel is supplied in a region having a melting zone thickness of 15 mm or more. The method of manufacturing a sintered ore according to claim 1, wherein the liquid fuel supply step is to supply the micronized liquid fuel after the combustion front reaches a position of 100 mm below the surface layer. A sintering machine is provided with: a pallet which can be circulated and moved; a raw material supply device on which a sintering raw material containing powder ore and carbon material is charged to form a charging layer; an ignition furnace is disposed on the pallet The carbon material in the sintering raw material is ignited; the liquid fuel injection device is disposed on the downstream side of the ignition furnace, and the liquid fuel is atomized to a particle diameter of 100 μm or less and sprayed toward the loading layer; and the bellows Air suction is performed below the pallet. The sintering machine of claim 16, wherein the liquid fuel injection device is provided with: a compressed gas supply source, a liquid fuel supply source, and a spray mechanism; and the spray mechanism compresses the compressed gas supply source The gas and the liquid fuel from the liquid fuel supply source are mixed, microparticulated, and sprayed in the horizontal direction toward the loading layer. The sintering machine of claim 17, wherein the sprayer The structure includes a transfer pipe that is inclined downward toward a downstream side of the mixed fluid for transporting the compressed gas and the liquid fuel, a communication pipe connected to a lower surface side of the transfer pipe, and an injection nozzle that faces The liquid fuel formed under the communication pipe is inclined downward toward the discharge port which is sprayed in the horizontal direction. The sintering machine of claim 16, wherein the liquid fuel is a group consisting of a petroleum liquid fuel, an alcohol liquid fuel, an ether liquid fuel, and other hydrocarbon compound liquid fuels which are in a liquid state at a normal temperature. Select at least one of the groups. The sintering machine according to claim 17, wherein the compressed gas system is a gas containing at least one of nitrogen, carbon dioxide and water vapor having a flame-retardant property. The sintering machine of claim 16, wherein the liquid fuel injection device has a preheating mechanism, wherein the preheating mechanism is micronized to have an optimum viscosity when the viscosity of the liquid fuel is high. In the manner, the liquid fuel is preheated.