JP4911164B2 - Sintering machine and method for producing sintered ore - Google Patents

Description

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

  Sinter ore, which is the main raw material of the blast furnace ironmaking method, is generally manufactured through a process as shown in FIG. The raw materials for sintered ore include iron ore powder, iron mill recovered powder, sintered ore sieving powder (returning), CaO-containing auxiliary raw materials such as limestone and dolomite, granulation aids such as quick lime, coke powder and anthracite These raw materials are cut out from each of the plurality of hoppers 1 at a predetermined ratio on a conveyor. The cut out raw material is added with an appropriate amount of water by the drum mixer 2, the rotary kiln 3, etc., mixed and granulated to obtain 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 sized coarse ore is cut out from the floor hopper 4 to form a floor layer on the great of the sintering machine pallet 8.

  The sintering raw material is charged on the floor layer on the endless moving type sintering machine pallet 8 through the drum feeder 6 and the cutting chute 7 from the surge hopper 5 arranged on the sintering machine, and sintered. A charge layer 9 of a sintering raw material, also called a binding bed, is formed. The thickness (height) of the charging layer is usually around 400 to 800 mm. Thereafter, the ignition furnace 10 installed above the charging layer 9 ignites the carbonaceous material in the surface layer of the charging layer 9 and air through a wind box 11 disposed under the pallet 8. Is sucked downward to sequentially burn the carbonaceous material in the charging layer, and the sintered raw material is burned and melted by the combustion heat generated at this time to obtain a sintered cake. The sintered cake thus obtained is then crushed and sized, and recovered as a product sintered ore comprising agglomerates of 5.0 mm or more.

  In the manufacturing process, first, the ignition layer 10 is ignited by the ignition furnace 10. The ignited charcoal in the charging layer continues to burn with a width by the air sucked from the upper layer part of the charging layer toward the lower layer part by the windbox, and the combustion zone gradually becomes lower as the pallet 8 moves. And forward (downstream). As the combustion progresses, the moisture contained in the sintering raw material particles of the charging layer is vaporized by the heat generated by the combustion of the carbonaceous material, sucked downward, and the lower layer that has not yet risen in temperature is burned. Concentrate in the raw material to form a wet zone. If the moisture concentration exceeds a certain level, moisture fills the gaps between the raw material particles, which are the flow paths of the suction gas, and the ventilation resistance is increased. Note that the melted portion necessary for the sintering reaction that occurs in the combustion zone is also a factor that increases the ventilation 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 volume of the sintering machine includes the machine width and length of the sintering machine, the thickness of the raw material deposition layer (charge layer thickness), the bulk density of the sintering raw material, the sintering (combustion) time, the yield, etc. It depends on. In order to increase the production of sintered ore, the air permeability (pressure loss) of the charging layer is improved to shorten the sintering time, or the cold strength of the sintered cake before crushing is increased. It is considered effective to improve the retention.

FIG. 14 shows the charging layer when the front of the combustion zone moving in the charging layer having a thickness of 600 mm is located approximately 400 mm above the pallet of the charging layer (200 mm below the charging layer surface). This shows the pressure loss and temperature distribution. The pressure loss distribution at this time is about 60% in the wet zone and about 40% in the combustion / melt zone.
FIG. 15 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 slow. The time during which the raw material particles begin to melt at a temperature of 1200 ° C. or higher (hereinafter referred to as “high temperature region holding time”) is t _{1 in} the case of low production, and in the case of high production with an emphasis on productivity. It is represented by t _2. Since the pallet moving speed is high during high production, the high temperature region holding time t ₂ is shorter than t ₁ during low production. When the high temperature region holding time is shortened, firing is likely to be insufficient, the cold strength of the sintered ore is lowered, and the yield is lowered. Therefore, in order to increase the productivity of high-strength sinter, increase the strength of the sintered cake, that is, the cold strength of the sinter, to maintain and improve the yield even during short-time sintering. It is necessary to take some measures to be able to. In general, SI (shutter index) and TI (tumbler index) are used as indices representing the cold strength of sintered ore.

  FIG. 16A shows the progress of sintering in the charging layer on the sintering machine pallet, FIG. 16B shows the temperature distribution (heat pattern) in the sintering process in the charging layer, and FIG. ) Shows the yield distribution of the sintered cake. As can be seen from FIG. 16B, the temperature of the upper portion of the charging layer is less likely to rise than the lower layer portion, and the high temperature region holding time is also shortened. Therefore, in the upper part of the charging layer, the combustion melting reaction (sintering reaction) becomes insufficient and the strength of the sintered cake becomes low, so that the yield is low and the productivity is low as shown in FIG. It is a factor that causes a decline in

  In view of these problems, a method for maintaining the charge layer upper layer portion at a high temperature for a long time has been proposed. For example, Patent Document 1 discloses a technique for injecting gaseous fuel onto a charging layer after ignition of the charging layer. However, although the kind of gaseous fuel (flammable gas) is unknown in the above technique, even if it is propane gas (LPG) or natural gas (LNG), a high concentration gas is used. Moreover, since the amount of the carbon material is not reduced when the combustible gas is blown, the inside of the sintered layer becomes a high temperature exceeding 1380 ° C. For this reason, this technique has not been able to enjoy sufficient cold strength improvement and yield improvement effects. Moreover, when inflammable gas is injected immediately after the ignition furnace, there is a high risk of fire in the upper space of the sintering bed due to combustion of the combustible gas, and this is a technology that is not realistic and has not yet been put into practical use. .

  Patent Document 2 also discloses a technique of adding a combustible gas to the air sucked into the charging layer after the charging layer is ignited. It is said that about 1 to 10 minutes of supply after ignition is preferable, but the surface layer portion immediately after ignition in the ignition furnace has red-hot sintered ore remaining, and depending on the supply method, combustible gas There is a high risk of fire due to combustion, and there are few specific descriptions, but there is no effect even if combustible gas is burned in a sintered sintered zone. Since the air permeability is deteriorated due to thermal expansion, the productivity tends to be reduced, and the amount of carbon material is not reduced when the combustible gas is blown. High temperature exceeding. For this reason, this technique has not been sufficiently put into practical use since it has not been able to enjoy a sufficient improvement in cold strength and yield improvement.

  In Patent Document 3, a hood is disposed on the charging layer in order to make the inside of the charging layer of the sintering raw material high temperature, and a mixed gas with air and coke oven gas is passed through the hood immediately after the ignition furnace. It is disclosed to blow in position. However, this technique also has a high temperature exceeding 1380 ° C. in the combustion melting zone in the sintered layer, so that the effect of coke oven gas blowing cannot be enjoyed, and the combustible mixed gas is ignited in the upper space of the sintering bed. There is a risk of fire and is not put into practical use.

  Further, Patent Document 4 discloses a method in which a low-melting-point solvent, a carbon material, and a combustible gas are simultaneously blown at a position immediately after the ignition furnace. However, this method also has a high risk of fire in the upper space of the sintering bed because the flammable gas is blown in a state where a flame remains on the surface, and the width of the sintered band cannot be made sufficiently thick (about 15 mm). Therefore, the effect of inflammable gas blowing cannot be fully exhibited. In addition, since there are many low-melting solvents, excessive melting phenomenon is caused in the upper layer portion, and the pores that become air flow paths are blocked, resulting in deterioration of air permeability and reduction of productivity. This technology has not been put into practical use until now.

As described above, any of the conventional techniques proposed so far has a serious problem in practical use, and development of a combustible gas blowing technique that can be implemented has been eagerly desired.
As a technique for solving the above-mentioned problems, the applicant supplies various gaseous fuels diluted below the lower combustion limit concentration from above the charging layer of the sintered raw material deposited on the pallet of the sintering machine in Patent Document 5. Then, it has been proposed to adjust either one or both of the maximum attained temperature and the high temperature region holding time in the charging layer by introducing it into the charging layer and burning it.
Japanese Patent Laid-Open No. 48-18102 Japanese Patent Publication No.46-27126 JP-A-55-18585 Japanese Patent Laid-Open No. 5-311257 WO2007-052776

  The technique of the above-mentioned patent document 5 is a downward suction type sintering machine that supplies (introduces) gaseous fuel diluted to a predetermined concentration into the charging layer and burns it at a target position in the charging layer. By supplying it, it is possible to appropriately control the maximum temperature reached during combustion of the sintered raw material and the holding time in the high temperature range, and as a result, the cold layer strength of the sintered ore tends to be low due to insufficient heat. Operation which raises the sinter intensity | strength not only in a part but in the arbitrary parts below a charging layer middle layer part can be performed.

  However, when performing the above gas fuel supply sintering operation, there is a risk that the high temperature portion such as the cracked portion of the sintering bed or the sintered cake will become a fire, and the gas fuel may be backfired and the gas fuel may burn (ignition). . If the sintering operation is continued in such a flammable state (aside from the explosion problem), not only the gaseous fuel cannot be supplied into the charging layer, but also the oxygen-deficient atmosphere in which oxygen is consumed by the combustion of the gaseous fuel. Is supplied (introduced) into the charging layer. As a result, not only can the maximum temperature and high temperature range holding time during combustion not be controlled, but also a lack of combustion, resulting in a decrease in strength of the sintered ore and a decrease in yield and productivity. It will have a serious adverse effect.

  Therefore, the present invention has been made paying attention to the problems of the above conventional example, and in a downward suction type sintering machine, high strength and high quality sintered ore can be produced with high yield and safety. It aims at providing the manufacturing method of a sintering machine and sintered ore which can be performed.

In order to achieve the above object, a sintering machine according to the present invention includes a pallet that circulates and a raw material supply that forms a charging layer by charging a sintered raw material containing fine ore and carbonaceous material onto the pallet. A sintering machine comprising an apparatus, an ignition furnace for igniting the carbonaceous material in the sintering raw material on the pallet, and a wind box for sucking air below the pallet, on the downstream side of the ignition furnace, A liquid fuel injection device for atomizing the liquid fuel to a particle size of 100 μm or less and injecting it in the horizontal direction above the charging layer is provided.

In the sintering machine according to the present invention, the liquid fuel injection device includes 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 a spray mechanism that sprays in a horizontal direction on the charging layer.
Further, in the sintering machine according to the present invention, the spray mechanism is connected to a transport pipe having a downward slope toward the downstream side for transporting the mixed fluid of the compressed gas and the liquid fuel, and a lower surface side of the transport pipe. It is characterized by comprising a communication pipe and an injection nozzle having a downward slope toward the discharge port for injecting the liquid fuel formed on the lower surface of the communication pipe in the horizontal direction.

Further, in the sintering machine according to the present invention, the liquid fuel supply source is a liquid liquid of petroleum-based liquid, alcohol liquid fuel, ether liquid fuel, or other hydrocarbon-based compound liquid fuel that is in a liquid state near normal temperature. At least one is supplied to the spray mechanism as the liquid fuel .
Further, in the sintering machine according to the present invention, the compressed gas supply source supplies the spray mechanism with a compressed gas mainly composed of at least one of nitrogen, carbon dioxide gas, and water vapor having flame resistance. Yes.

Further, the sintering machine according to the present invention includes a preheating mechanism for preheating the liquid fuel so that the liquid fuel injection device and the viscosity of the liquid fuel have an optimum viscosity for atomization when the viscosity of the liquid fuel is high. It is characterized by.
Further, in the method for producing sintered ore according to the present invention, a sintered raw material containing fine ore and carbonaceous material is charged by a raw material supply device onto a circulating and moving pallet to form a charging layer to an ignition furnace. A method for producing a sintered ore that conveys and ignites the carbonaceous material in the charging layer, and sucks air by a wind box disposed below the pallet, the downstream of the ignition furnace The liquid fuel is atomized to a particle size of 100 μm or less on the upper side of the charging layer on the side and is injected in the horizontal direction.

According to the present invention, the liquid fuel injection device is provided on the downstream side of the ignition furnace, the liquid fuel injection device for atomizing the liquid fuel to a particle size of 100 μm or less and injecting it in the horizontal direction above the charging layer. The atomized liquid fuel injected in step 1 is uniformly dispersed on the charging layer, and this uniformly dispersed atomized liquid fuel is sucked into the charging layer by the wind box. As with the use of gaseous fuel that has been volatilized, the cold strength of the sintered ore can be reduced from insufficient combustion by controlling the supply position of the atomized liquid fuel, the maximum temperature reached during combustion, and the high temperature holding time. Therefore, not only the upper part of the charging layer, which is likely to be lowered, but also the operation of increasing the strength of the sintered ore in any part below the middle layer of the charging layer can be performed. In addition, by atomizing the liquid fuel and injecting it in the horizontal direction, there is no concern about ignition or the like as in the case of using the liquid fuel as it is, and the atomized liquid fuel enters the raw material charging layer. Introduction can be performed safely and stably.

  Further, by using any one of nitrogen, carbon dioxide gas, and water vapor having flame extinguishing properties as the compressed gas for atomizing the liquid fuel, combustion on the charging layer can be suppressed.

  The manufacturing method of the sintered ore using the sintering machine of this invention is comprised from the charging process, the ignition process, the liquid fuel supply process, and the sintering process. In this manufacturing method, the charging step is a step of charging a sintered raw material containing fine ore and carbonaceous material on a circulating pallet and forming a charging layer of the sintered raw material on the pallet, The ignition step is a step of igniting the carbon material on the upper surface of the charging layer using an ignition furnace. The liquid fuel supply step is a step of injecting the liquid fuel atomized from the liquid fuel injection device into the air above the charging layer in the horizontal direction, and the sintering step is disposed under the pallet. The atomized liquid fuel and air are sucked into the charging layer by the suction force of the wind box, and the atomized liquid gaseous fuel is burned in the charging layer and simultaneously sucked into the charging layer. This is a step of burning the carbonaceous material in the charging layer with the air and sintering the sintered raw material with the heat generated by the combustion to produce a sintered cake.

In the present invention, on the downstream side of the ignition furnace, the liquid atomized above the charging layer as described above is injected into the atmosphere in the horizontal direction, thereby atomizing the liquid while suppressing ignition and the like The fuel can be uniformly dispersed on the charging layer and can be volatilized in the charging layer by air suction of the windbox.
FIG. 1 is a schematic configuration diagram showing an embodiment of a sintering machine according to the present invention. In FIG. 1, as in the conventional example described above, iron ore powder, iron mill recovered powder, sintered ore sieving powder, CaO-containing auxiliary raw materials such as limestone and dolomite, granulation aid such as quick lime, coke powder Sintered raw materials such as coal and anthracite are cut out from a plurality of hoppers 1 on a conveyor at a predetermined ratio, and the cut out raw materials are mixed and granulated by adding an appropriate amount of water using a drum mixer 2, rotary kiln 3, etc. The sintered raw material which is a pseudo particle having an average diameter of 6.0 mm is stored in the surge hopper 5. On the other hand, the lump ore adjusted to a predetermined particle size is cut out from the bedding hopper 4 to form a bedding layer on the grate of the sintering machine pallet 8.

  Then, the sintered raw material is charged from the surge hopper 5 through the drum feeder 6 and the cutting chute 7 onto the floor layer on the endless moving type sintering machine pallet 8, and the charging layer 9, also called a sintering bed, is formed. Form. The thickness (height) of the charging layer is usually around 400 to 800 mm. Thereafter, the ignition furnace 10 installed above the charging layer 9 ignites the carbonaceous material in the surface layer of the charging layer 9 and air through a wind box 11 disposed under the pallet 8. Is sucked downward to sequentially burn the carbonaceous material in the charging layer.

A liquid fuel injection device 15 that atomizes the liquid fuel on the upper side of the charging layer 9 and injects it in a substantially horizontal direction is disposed downstream of the ignition furnace 10.
One or more liquid fuel injection devices 15 are disposed downstream of the ignition furnace 10 and at any position in the pallet traveling direction in the process in which the combustion / melting zone proceeds in the charging layer 9. The supply of the liquid fuel mist to the inside is preferably performed at a position after ignition of the carbonaceous material in the charging layer 9. One or a plurality of liquid fuel injection devices 15 are disposed downstream of the ignition furnace 10 at any position after the combustion front has traveled below the surface layer. From the viewpoint of adjusting the cold strength, the size, position, and number of arrangements are determined as described later.

As shown in FIG. 2, the liquid fuel injection device 15 includes a hood 16 that covers an upper portion of the sintering machine pallet 8, and an opening 17 having a relatively large area is provided on the upper portion of the hood 16.
As shown in FIGS. 2 and 4, in the hood 16, a compressed air supply pipe 21 and a liquid fuel supply pipe 22 along the conveying direction of the sintering machine pallet 8 are disposed above the charging layer 9. A plurality of, for example, 9 sets, for example, are arranged in parallel with a predetermined interval in the width direction perpendicular to the conveyance direction. A spray mechanism 23 is disposed on the lower surface side of each compressed air supply pipe 21 and liquid fuel supply pipe 22 while maintaining a predetermined distance in the conveying direction of the sintering machine pallet 8. The spray mechanisms 23 are arranged in a staggered manner in the transport direction of the sintering machine pallet 8 so that the spray mechanisms 23 adjacent in the width direction of the sintering machine pallet 8 do not face each other. In addition, 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 arrange a plurality of sets of 3 to 15 sets.

  As shown in an enlarged view in FIG. 3, each spray mechanism 23 includes a vertical pipe 24 connected to the lower surface of the compressed gas supply pipe 21, a mixing unit 25 formed at an intermediate portion of the vertical pipe 24, and the mixing unit. 25 and a lower surface of the liquid fuel supply pipe 22, and a branch injection section 27 that branches in a bifurcated manner in the width direction of the sintering machine pallet 8 disposed at the lower end of the vertical pipe 24. It is configured.

The branch injection unit 27 includes two symmetrical injection nozzle units 28 a and 28 b with the vertical pipe 24 interposed therebetween. From these injection nozzle portions 28a and 28b, for example, liquid fuel mist 29 atomized into fine particles of 100 μm or less is injected in a substantially horizontal direction.
Here, the reason why the particle size of the liquid fuel mist 29 is set to 100 μm or less is that when the particle size exceeds 100 μm, a portion remaining in the surface layer portion of the charging layer 9 is generated and starts to burn in the surface layer portion. In addition, it does not contribute to the extension of the high temperature region holding time of the upper layer and the middle layer, which is insufficient in combustion in the charging layer 9, and is wasted. Further, the particle size of the liquid fuel mist 29 is preferably as small as possible, but since the generation amount decreases as the particle size is decreased, the particle size of the liquid fuel mist 29 is preferably selected as 50 μm or less and 20 μm or more. When the particle size of the liquid mist 29 is 50 μm or less, the combustion above the charging layer 9 and in the surface layer portion is suppressed, and the liquid mist 29 passes through a crack portion in the sintered cake formed on the surface layer or is sintered. It vaporizes once in the cake, passes through the sintered cake in a gas state, reaches the combustion / melting zone, and burns. Further, when the particle size is less than 20 μm, the generation amount of the liquid fuel mist 29 is reduced, and by introducing the liquid fuel mist 29 into the charging layer 9, a good effect of extending the high temperature region holding time is exhibited. I can't.

  Each of the injection nozzle portions 28a and 28b has an opening angle of, for example, about 85 degrees with respect to the central axis of the vertical pipe 24, which has a slight downward slope that the center line gradually decreases from the vertical pipe 26 toward the tip. Is set to As described above, since the injection nozzle portions 28a and 28b have a slight downward slope, the liquid fuel mist remains as liquid in the injection nozzle portions 28a and 28b when the injection of the liquid fuel mist is finished. All are dripped.

  Thus, since the spray mechanisms 23 are arranged in a staggered manner in the conveying direction of the sintering machine pallet 8, the liquid fuel mist 29 injected from the injection nozzle portions 28a and 28b of each spray mechanism 23 is shown in FIG. As shown, the particles are uniformly dispersed and injected onto the charging layer 9 without interfering with each other. Then, using the suction force of a wind box (not shown) under the sintering machine pallet 8, the sintered cake generated on the surface layer of the charging layer 9 is introduced to the deep part (lower layer) of the charging layer. The

  As shown in detail in FIG. 6, each compressed gas supply pipe 21 is connected to a compressed gas supply pipe 31 via a flow meter FC and a control valve VC on the upstream side of the sintering machine pallet 8. A gas supply source pipe 31 is connected to a compressed gas supply source 32. The compressed gas supply source 32 has a storage tank 33 for storing a gas mainly containing any one of nitrogen, carbon dioxide gas and water vapor having flame extinguishing properties, and the gas stored in the storage tank 33 is a compressor. The compressed gas is compressed into a compressed gas at 34, stored in the receiver tank 35, and supplied to each control valve VC from the receiver tank 35 via the compressed gas supply pipe 31. Here, between the receiver tank 35 and the flow meter FC, a main flow path LM in which a control valve VC is inserted, and a bypass flow path that bypasses the control valve VC and supplies a relatively small flow rate of compressed air. LB. The bypass channel LB is in a state in which the liquid fuel mist 29 is not injected from the spray mechanism 23, and a small amount of compressed gas from the receiver tank 35 passes through the bypass channel LB and the flow meter FC to the spray mechanism 23. The nozzles 28a and 28b of the spray mechanism 23 are prevented from being clogged.

  Similarly, each liquid fuel supply pipe 22 is connected to the liquid fuel supply source pipe 36 via the flowmeter FF and further via the control valve VF on the upstream side of the sintering machine pallet 8. It is connected via a fuel supply pump 37 to a liquid fuel storage tank 38 as a liquid fuel supply source. Here, each of the liquid fuel supply pipe 22 and the liquid fuel supply source pipe 36 is arranged to be inclined in a descending gradient in which the arrangement height on the downstream side is lower than that on the upstream side, and the injection of the liquid fuel mist 29 is finished. It is preferable that the liquid fuel is not left in the liquid fuel supply pipe 22 and the liquid fuel supply pipe 36 when the liquid fuel is supplied.

As the liquid fuel, at least one of petroleum liquid fuels such as kerosene, light oil and heavy oil that are liquid at room temperature, alcohol liquid fuels such as ethyl alcohol and methyl alcohol, ether liquid fuels, and other hydrogen oxide liquid fuels Using the above, these are stored in the liquid fuel storage tank 38.
Here, the liquid fuel that can be used in the present invention and its characteristics are shown in Table 1 below.

  The liquid fuel mist 29 for atomizing and injecting such liquid fuel has an ignition temperature of blast furnace gas, coke oven gas, blast furnace / coke oven mixed gas, city gas, natural gas or methane gas, ethane gas, propane gas, butane gas, or Since the ignition temperature is higher than any of the gaseous fuels of these mixed gases, the combustion temperature is higher than the temperature of the charging layer 9, that is, the surface layer of the sintering bed, and the combustion is performed inside the charging layer 9, so that It is effective for expanding the temperature of the burning / melting zone. In particular, the effect is large when the ignition temperature is close to 500 ° C.

In addition, it is desirable that a large amount of liquid fuel mist 29 can be supplied to the position of the low yield portion in the vicinity of the left and right sidewalls 18 of the hood 16.
In addition, since waste oil etc. may contain the component which is easy to ignite, and the component with low ignition temperature, it is unpreferable for using by this invention. When 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, the sintering material bed, it reaches the vicinity of the combustion zone in the charging layer 9. Since it burns in the upper space of the surface layer of the previous charge layer 9 or in the vicinity of the surface layer of the charge layer 9, it is burned in the vicinity of the combustion zone of the charge layer 9 intended by the present invention to extend the high temperature holding time. This is because the effect cannot be obtained.

  Moreover, in the said embodiment, the spray mechanism 23 which injects the liquid fuel mist 29 demonstrated the case where liquid fuel was mixed with compressed gas by the mixing part 25, atomized, and injected on the charging layer 9 in the horizontal direction. However, the present invention is not limited to this, and the liquid fuel mist obtained by mixing the compressed gas and the liquid fuel supplied from the compressed gas supply source 32 and the fuel supply pump 37 with a mixer is supplied to each spray mechanism via the mist supply pipe. You may make it supply to 23 branch injection parts 27. In this case, it is preferable to maintain the liquid fuel mist at a temperature not lower than the ignition temperature and lower than the ignition temperature so that the liquid fuel mist does not re-liquefy.

  And in this invention, as mentioned above, the food | hood 16 which covers the upper part of the sintering machine pallet 8 is provided. The hood 16 suppresses the influence of the cross wind on the concentration distribution of the liquid fuel mist 29. That is, as a result of various studies by the inventors, it has been found that the installation of the hood 16 is more effective than a screen as a measure against cross wind. However, as described above, the hood 16 has an opening 17 in the upper central portion or has an appropriate transmittance (void ratio), and it is necessary to have a structure capable of taking in air from this portion. .

  Thereby, the liquid fuel mist 29 ejected from the spray mechanism 23 and the atmosphere are mixed inside the hood 16. When the opening 17 is a sintering machine having a width of 5 m of the sintering machine pallet 8 and is about 1 m, the pressure loss of the hood 16 can be almost ignored. In addition, it was found that when the gap is provided in the opening 17, the pressure loss can be suppressed to about several mmAq if the transmittance is about 80%. Furthermore, by installing the baffle plate 40 in the hood 16, there is an effect of suppressing the vortex flow in the hood 16, and the porosity of the partition provided on the top (periphery) of the hood 16 is in the range of 30 to 40%. Was found to be the most effective from the analysis results. Further, as shown in FIG. 7, a cross wind attenuating fence 16c composed of punch metal having a transmittance of about 30% is provided at the upper ends of the left and right sidewalls 18 along the conveying direction of the sinter pallet 8 of the hood 16. It is preferable.

  In addition, a gap is inevitably generated between the lower side of the hood 16 and the surface of the sintered bed (the surface of the charging layer), but if the gap is not sufficiently sealed, for example, the transmittance is 20 to 20%. When it was 30%, it was found that air was engulfed from this portion into the hood 16 and the concentration distribution of the liquid fuel mist was increased. Therefore, it is important to prevent air from entering from the lower end of the hood 16.

  Therefore, between the lower ends of the left and right sidewalls 18 along the conveying direction of the sintering machine pallet 8 of the hood 16 and the pallet sidewalls 8a, the lower surface of the branch injection portion 27 of the spray mechanism 23, and the upper surface of the charging layer 9 As shown schematically in FIG. 7, a wiper seal 41 having a seal sheet interposed between wire brushes extending in the conveying direction of the sintering machine pallet 8 is installed, and the wiper seal 41 is covered on the outside from the outside. A cover 42 is provided. The seal material is not limited to the wiper seal 41, and seal materials such as a chain curtain, a seal brush, and a close seal can be applied. Moreover, it is preferable that the sealing material is heat resistant, flexible or has a high 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 rear plate portions 16b of the hood 16 and the surface of the charging layer 9 on the upstream side and the downstream side in the conveying direction of the sintering machine pallet 8, the front and rear walls of the hood 16 as shown in FIG. It is preferable to form an air curtain 44 by disposing an air passage 43 along 19 and ejecting air from below the air passage 43.
Further, the installation position, size, and number of arrangements of the liquid fuel injection device 15 are set as follows.

  That is, after the carbon material in the charging layer 9 is ignited, the liquid fuel mist 29 is supplied (introduced) onto the charging layer 9. The reason for this is that even if the liquid fuel mist 29 is supplied at a 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, it is necessary to supply the liquid fuel mist to the charging layer 9 after the sintering raw material on the upper part of the charging layer 9 is fired to form a sintered complete band which is a layer of a sintered cake.

  The principle of using the liquid fuel mist of the present invention will be described with reference to FIG. FIG. 10A is a photograph when ethanol is used in a pan test with a particle size of about 50 μm. It can be seen that the combustion melting zone greatly expands with ethanol blowing. FIG. 10B schematically illustrates this phenomenon, and the left side in the figure indicates the sintering reaction when the gaseous fuel is diluted and blown. The coke, which is a coagulant, is ignited in an ignition furnace, and the sintering reaction of the powder coke progresses downward while descending the charging layer of the sintering raw material. A sintered zone is formed in a sintered zone, and when a gaseous fuel is diluted and injected between the sintered zone and the powder coke combustion zone, a gas combustion zone of diluted gas is generated. It is responsible for extending the high temperature range holding time without increasing the maximum temperature. The right side shows the sintering reaction when the liquid fuel mist according to the present invention is used. Gasification of the liquid fuel mist occurs in the sintering completed zone. Therefore, in the present invention, as described above, the particle size of the liquid fuel mist is set to 100 μm or less, preferably 50 μm or less. If the particle size exceeds 100 μm, the heat in the sintering complete zone is used to leave droplets, which may cause combustion at the surface layer. When the particle size of the liquid fuel mist is 100 μm or less, the liquid fuel mist (liquid fuel particles) is gasified including the agglomerated particles to become liquid fuel vapor, and between the sintering completed zone and the powder coke combustion zone. When a liquid fuel is blown in as a liquid fuel mist, a gas combustion zone of liquid fuel gas is generated, where the high temperature region holding time is expanded and extended without increasing the maximum temperature, and the same phenomenon as the use of gaseous fuel is exhibited.

When injecting liquid fuel, the gasification (liquid fuel vapor) region of liquid fuel particles shown in FIG. 10B is important.
That is, in the liquid fuel gasification region of FIG. 10B, it is important to first 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 combustion limit concentration of Table 1. . When blowing, it is necessary to make it 75% or less of the lower combustion limit concentration so as not to burn in the surface layer part of the sintering completed zone, and the lower limit is at least 1% of the lower combustion limit concentration in order to utilize fuel heat. To do. Preferably, it is 25% or less and 4% or more of the lower limit concentration of combustion. The upper limit is determined from the safety of fire and the lower limit is determined from the effective heat. Moreover, it is necessary to be below the ignition temperature.

  As shown in FIG. 10 (c), the point of combustion is that the maximum temperature in the sintering reaction is controlled on the powder coke side A, and the high temperature region retention time is the liquid fuel side B that maintains the combustion zone temperature below the maximum temperature. Is burning. An example is shown in FIG. The temperature curve shown as C is an in-layer temperature history during sintering production in a sintering reaction when only powder coke is used as a coagulant. The maximum temperature is controlled by the amount of powder coke, and the high temperature range holding time E is determined by this temperature pattern. When extending the high temperature range holding time with this C temperature pattern, it is necessary to increase the amount of powder coke added to expand the base of the high temperature range of 1200 ° C or higher, but at the same time, it is necessary to increase the maximum temperature. was there. The temperature pattern when using liquid fuel is shown as D. As shown in FIG. 10 (c), the combustion of the liquid fuel is the combustion on the liquid fuel side B in FIG. 10 (c) that maintains the combustion zone temperature below the maximum temperature. The combination of the two results in the temperature pattern D in FIG. 10D in which the temperature in the base region is increased without changing the maximum temperature. With this temperature pattern D, the base of the region of 1200 ° C. or higher is expanded, and the high temperature region holding time F is secured.

FIG. 11 is a photograph of a pan test of a conventional sintering method and a sintering method using a liquid fuel mist. In conventional sintering, the powder coke ratio is high due to the utilization of combustion heat of powder coke. In addition, the combustion / melting zone that appears white even when the height is high is approximately 65 mm in this experiment.
In the liquid fuel gasification zone (sintering completion zone), the temperature of the zone is higher than the boiling point of the liquid fuel and lower than the ignition temperature (can be controlled by lowering the concentration below the lower combustion limit concentration). Examples of heavy oil and ethanol are shown, but the amount of powder coke used was reduced in order to keep the maximum temperature at 1380 ° C. In both cases, the burning / melting zone that looks white was expanded, and the obtained sintered ore strength was higher than that of the conventional sintering method using only powdered coke.

Further, in the gasification region (sintering completion zone) of the liquid fuel in FIG. 10B, the temperature of the region needs to be not less than the boiling point of the liquid fuel and not more than the ignition temperature. By doing so, the phenomenon shown in FIG. 11 is obtained.
When the temperature of the gasification region (sintering completion zone) is equal to or higher than the ignition temperature (high concentration close to the lower combustion limit concentration), the surface of the sintering completion zone before entering the powder coke combustion zone as shown in FIG. In this case, the liquid fuel vapor is burned, the effect is lost, and oxygen is insufficient. This adversely affects the sintering operation.

The liquid fuel mist can be supplied at an arbitrary position until the sintering is completed as long as a sintered cake layer is formed on the surface of the charging layer 9. The reasons other than the above, in which the liquid fuel mist is supplied after the sintered cake layer is formed, are as follows.
(A) If the liquid fuel mist is supplied in the state immediately after ignition in which no sintered cake is formed on the top of the charge layer 9, there is a possibility of burning on the charge layer 9.
(B) It is preferable to supply the liquid fuel mist to a portion where it is necessary to improve the yield of the sintered ore, that is, to supply combustion at a portion where it is desired to increase the strength of the sintered ore.

  In order to adjust either the charging layer maximum cylinder temperature or the high temperature region holding time or both, the thickness of the combustion / melting zone is at least 15 mm or more, preferably 20 mm or more, more preferably 30 mm or more, It is preferable to supply liquid fuel mist. When the thickness of the combustion / melting zone is less than 15 mm, the cooling effect by the air sucked through the sintered layer (sintered cake) and the liquid fuel mist causes the effect to be insufficient even if the liquid fuel mist is burned. This is because the thickness of the melting zone cannot be increased. On the other hand, when the liquid fuel mist is supplied at a stage where 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 expanded, and the high temperature region holding time is increased. It can be extended, and as a result, a sintered ore with high cold strength can be obtained.

  The liquid fuel mist is introduced into the charging layer 9 at a position where the combustion front is lowered below the surface layer and the combustion / melting zone is lowered from the surface layer by 100 mm or more, preferably 200 mm or more, that is, in the charging layer 9 It is preferable that the sintered cake region (sintered layer) generated in the lower layer passes through without burning, and is supplied so as to burn when the combustion front moves 100 mm or more from the surface layer. The reason is that if the combustion front is at a position lower than the surface layer by 100 mm or more, the adverse effect of cooling by the air sucked through the sintered layer is reduced, and the thickness of the combustion / melting zone can be increased. . Furthermore, if the combustion / melting zone is at a position 200 mm or more lower than the surface layer, the influence of cooling by air is substantially eliminated, and the thickness of the combustion / melting zone can be increased to 30 mm or more. The supply of the liquid fuel mist is more preferably performed in the vicinity of the sidewalls of the both pallet width direction coal portions where the yield reduction is large.

The liquid fuel injection device 15 differs depending on the size of the sintering machine. For example, in a sintering machine having a production amount of about 15,000 t / day and a length of 90 m, the ignition furnace 10 It is preferable to arrange at a position about 5 m or less downstream.
In the sintering machine according to the present invention, the liquid fuel mist supply position (introduction position to the charging layer) is the ignition furnace exit side in the pallet traveling direction, and the so-called combustion front after the formation of the sintered cake is below the surface layer. It is preferable to carry out at one or more arbitrary positions from the position advanced to (for example, the position where the combustion of the liquid fuel mist occurs below the surface layer to 100 mm or more, preferably about 200 mm or less) until the sintering is completed. This means that, as described above, the introduction of the liquid fuel mist is started when the combustion front moves below the surface of the charging layer, and as a result, the combustion of the liquid fuel mist is started. This means that there is no risk of explosion and a safe sintering operation is possible.

  In the method for producing a sintered ore according to the present invention, the introduction of the liquid fuel mist into the charging layer also means that the reheating of the produced sintered cake is promoted. That is, this liquid fuel mist is originally supplied with a liquid fuel mist that is more reactive than solid fuel to a portion where the cold strength of the sinter is low and the cold strength of the sintered ore is likely to be short of heat. This is because the heat of combustion in this portion that is likely to be deficient is compensated for, and the regeneration / expansion of the combustion / melting zone is assumed.

  Further, in the method for producing sintered ore according to the present invention, the supply of the liquid fuel mist from the upper part of the charged layer after ignition is such that at least a part of the introduced liquid fuel mist in the charged layer remains unburned. It is preferable to reach the combustion / melting zone and burn at a target position where combustion heat is to be compensated. It is thought that it is more effective to spread the liquid fuel mist supply, that is, the introduction effect into the charging layer not only to the upper part of the charging layer but also to the combustion / melting zone which is the central part in the thickness direction. Because. In other words, if the supply of liquid fuel mist is performed in the upper layer of the charging layer, which is prone to heat shortage (insufficient holding time in the high temperature range), sufficient combustion heat is provided, and this portion of the sintered cake In addition, if the liquid fuel mist supply action extends to the zone below the middle layer, recombustion / melting with liquid fuel mist on top of the combustion / melting zone with the original carbon material This results in the same result as forming a band, leading to a widening of the combustion / melting zone in the vertical direction, so it is possible to extend the holding time of the high temperature range without increasing the maximum temperature, so the moving speed of the pallet This is because sufficient sintering can be realized without dropping the thickness. As a result, the quality of the sintered cake of the entire charged layer is improved (improving the cold strength), and consequently the quality (cold strength) and productivity of the product sintered ore are improved.

Further, in the present invention, when the liquid fuel mist is introduced (supplied) into the charging layer, not only the supply position thereof is adjusted, but also the form of the combustion / melting zone itself is controlled. It is preferable to control the maximum temperature reached in the melting zone and / or the high temperature region holding time.
In general, in the charged layer after ignition, the combustion (flame) front gradually expands downward and forward (downstream) with the movement of the pallet, and the position of the combustion / melting zone is as described above with reference to FIG. It changes as shown in (a). And as shown in FIG.16 (b), the thermal history received in the sintering process in a sintered layer differs in an upper layer, a middle layer, and a lower layer, and it is high temperature range holding time (about 1200 degreeC or more with an upper layer-lower layer). Time) is very different. As a result, the yield of the sintered ore by position in the pallet shows a distribution as shown in FIG. That is, the yield of the surface layer portion (upper layer portion) is low, and the yield distribution is high in the middle layer and the lower layer portion. Therefore, when the liquid fuel mist is supplied according to the method of the present invention, the combustion / melting zone expands in the vertical thickness, the width in the pallet traveling direction, and the like, which is reflected in the quality improvement of the product sintered ore. . And since the intermediate | middle layer part and lower layer part which become high yield distribution can control high temperature range holding time, it can raise a yield more.

  By adjusting the supply (introduction) position of the liquid fuel mist, the form 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 can be controlled, and the maximum Achieving temperature and high temperature range holding time can be controlled. These controls make the effects of the present invention stand out more and are always sufficient through expansion of the vertical thickness of the combustion / melting zone and the width of the pallet traveling direction, and control of the maximum temperature reached and the high temperature range holding time. Performs firing and contributes effectively to improving the cold strength of the sintered product ore.

  In the present invention, it can also be said that the supply (introduction) of the liquid fuel mist into the charging layer is for controlling the cold strength of the entire product sintered ore. In other words, the original purpose of supplying the liquid fuel mist is to improve the cold strength of the sintered cake and eventually the sintered ore. The cold strength (shutter index SI) of the sintered ore is about 75 to 85%, preferably 80% or more, more preferably 90% through the control of the high temperature range holding time, which is the time spent in the belt, and the control of the maximum temperature reached. That's it.

  In the present invention, this strength level is particularly in consideration of the concentration of the liquid fuel mist, the supply amount, the supply position and the supply range, preferably considering the amount of carbonaceous material in the sintered raw material (under the condition that the input heat amount is constant). By adjusting above, it can be achieved inexpensively. On the other hand, the improvement of the cold strength of sintered ore may lead to an increase in ventilation resistance and a decrease in productivity. In the present invention, such problems are also controlled by controlling the maximum temperature and holding time in the high temperature range. In order to solve this problem, the cold strength of the sintered ore is improved. In addition, the cold strength SI value of the sintered ore manufactured by the real machine sintering machine shows a value 10-15% higher than the value obtained by a pan 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 a sintered ore in an arbitrary zone between the sintered cake formed in the charging layer and the wet zone. It is based on how to make the cold strength of. For this control, in the present invention, the scale (size), number, position (distance from the ignition furnace) and gas concentration of the liquid fuel injection device, preferably the amount of carbonaceous material (solid fuel) in the sintered raw material By adjusting according to the above, not only the size of the combustion / melting zone (the thickness in the vertical direction and the width in the pallet traveling direction) but also the high temperature reached temperature and the high temperature range holding time are controlled. Controls the strength of the sintered cake formed in the charge layer.

Next, the operation of the above embodiment will be described.
First, as shown in FIG. 1, the granulated ore from the floor hopper 4 is cut out to form a floor layer on the great of the sintering machine pallet 8, and the surge hopper 5 to the drum feeder are formed on the floor layer. The sintered raw material quantitatively cut out in 6 is charged to form a charging layer 9 of about 400 to 800 mm, which is also called a sintering bed.

Then, as the sintering machine pallet 8 is conveyed, the carbonaceous material in the surface layer of the charging layer 9 moved under the ignition furnace 10 is ignited.
In the charged layer 9 after ignition, the combustion (flame) front gradually expands downward and forward (downstream) as the sintering machine pallet 8 moves, and the position of the combustion / melting zone is as described above. It changes as shown in FIG. Then, when the position of the combustion / melting zone reaches about 200 mm from the surface layer that shifts from the upper layer to the middle layer, the sintering machine pallet 8 reaches the position of the liquid fuel injection device 15.

In this liquid fuel injection device 15, the liquid fuel mist 29 is uniformly injected 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.
That is, in the liquid fuel injection device 15, the compressed gas supply pipe 22 extending in parallel with the conveying direction of the sintering machine pallet 8 and the liquid fuel at a position away from the surface of the charging layer 9 of the liquid sintering machine pallet 8 by a predetermined distance. A predetermined number of sets of supply pipes 22 are arranged in the width direction perpendicular to the conveying direction, and compressed gas and liquid fuel are mixed into each set of compressed gas supply pipes 21 and liquid fuel supply pipes 22 and atomized to 100 μm or less. A spray mechanism 23 for injecting the liquid fuel as a liquid fuel mist in a substantially horizontal direction is disposed.

  And, as shown in FIG. 5, this spray mechanism 23 is arranged with a half-pitch shift in the conveying direction of the sintered pallet 8 so that the adjacent spray mechanisms 23 do not face each other, A uniform injection region is formed without the liquid fuel mists 29 injected from the injection nozzle portions 28a and 28b of the spray mechanism 23 in adjacent groups interfering with each other.

  The injected liquid fuel mist 29 is mixed with the air rectified by the rectifying plate 40 and diluted to below the lower combustion limit concentration at normal temperature, so that combustion above the charging layer 9 can be suppressed. At this time, at least one of nitrogen, carbon dioxide gas, and water vapor having flame extinguishing properties is used as a main component as atomizing gas for atomizing the liquid fuel, and the liquid fuel mist 29 has such flame extinguishing properties. Since compressed gas is contained, it can suppress reliably that the liquid fuel mist 29 is burned by the upper side of the charging layer 9. FIG.

Then, the liquid fuel mist 29 injected from the injection nozzle portions 28a and 28b of each spray mechanism 23 and diluted with air moves the air downward through the window box 11 disposed under the sintering machine pallet 8. By sucking, it is introduced into the charging layer 9.
The liquid fuel mist 29 introduced into the charging layer 9 passes through the sintered cake generated in the surface layer portion, reaches the combustion / melting zone 100 mm or more below the surface, and is burned in this combustion / molten layer. The For this reason, the high temperature region holding time is originally short and heat is likely to be insufficient, and the high temperature region holding time for maintaining the upper and middle layer regions where the cold strength of the sintered ore is low at a high temperature region of 1200 ° C. or higher can be increased. The cold strength of the ore can be improved. Accordingly, it is possible to improve the yield of the upper and middle layer portions with a low yield shown in FIG. 16C when the liquid fuel mist 29 is not blown.

  In this way, when the supply operation of the liquid fuel mist 29 extends to the region below the middle layer, a recombustion / melting zone by the liquid fuel mist 29 is formed on the combustion / melting zone by the original carbon material. Results in equal expansion and expansion of the combustion / melting zone in the vertical direction, so that it is possible to extend the holding time of the high temperature region without increasing the maximum temperature, so the moving speed of the sintering machine pallet 8 is reduced. Sufficient sintering can be realized without this. As a result, the quality of the sintered cake of the charging layer 9 as a whole (improvement of cold strength) is brought about, leading to improvement of the quality (cold strength) and productivity of the sintered ore.

When the supply of liquid fuel to the fuel supply pipe 21 is started and when the supply of liquid fuel is stopped, the heated gas is supplied as a purge gas to the liquid fuel supply pipe 21 to burn the liquid fuel remaining in the pipe It is preferable to remove them.
Thus, in the above-described embodiment, after the surface layer of the charging layer 9 is ignited by the ignition furnace 10, the liquid fuel mist 29 is uniformly placed on the upper side of the charging layer 9 of the sintering machine pallet 8 by the liquid fuel injection device 15. Compared to the case of using diluted gaseous fuel obtained by diluting gaseous fuel such as propane gas, LNG, M gas, etc. with air by using dispersed fuel, liquid fuel with a high ignition temperature is used. Instead of using it as it is, it is atomized with compressed gas and injected as liquid fuel mist, so that it is possible to reliably suppress the possibility of ignition on the upper side of the charging layer 9. In addition, by using a gas mainly containing at least one of nitrogen, carbon dioxide, and water vapor having flame extinguishing properties as the compressed gas, it is possible to further suppress the risk of ignition on the upper side of the charging layer 9.

In the above-described embodiment, the case where the liquid fuel injection device 15 is disposed on the downstream side of the ignition furnace 10 has been described. However, the present invention is not limited to this, and a heat insulation furnace is disposed on the downstream side of the ignition furnace 10. In such a case, the liquid fuel injection device 15 may be disposed on the downstream side of the heat retaining furnace.
Moreover, in the said embodiment, although the case where the food | hood 16 of the liquid fuel injection apparatus 15 was set as the structure which has the opening 17 upwards is demonstrated, it is not limited to this, As shown in FIG. , The baffle plate 51 extending in the conveying direction of the sintering machine pallet 8 between the front and rear walls 19 of the hood 16, and having the cross-shaped baffle plate 51 with the apex upward, the conveying direction of the sintering machine pallet 8. 3 baffle plate rows 52 having a configuration in which a predetermined number of baffle plates are arranged in parallel in the width direction orthogonal to the vertical direction, and one baffle is arranged between the baffle plate rows 52 adjacent in the vertical direction. The baffle plate 51 of the other baffle plate row 52 is disposed between the baffle plates 51 of the plate row 52, and the spray mechanism 23 is arranged between the baffle plates 51 below the lowermost baffle plate row 52. Can also be configured Kill.

  Furthermore, in the above-described embodiment, the case where liquid fuel is supplied from the liquid fuel tank 38 to the liquid fuel supply source pipe 36 and the liquid fuel supply pipe 22 at room temperature has been described. However, the present invention is not limited to this. For liquid fuels that have high viscosity at room temperature such as those that are difficult to atomize, preheat to, for example, 130 ° C. to 150 ° C. using steam or the like to reduce the viscosity and supply the liquid fuel to the liquid fuel supply pipe 22 Thus, it can be easily atomized by the spray mechanism 23 and injected as the liquid fuel mist 29.

  The technique of the present invention is useful as a technique for producing sintered ore used as a raw material for iron making, particularly as a blast furnace, but can also be used as another ore agglomeration technique.

It is a schematic structure figure showing one embodiment of the present invention. It is typical sectional drawing on the AA line of FIG. It is a front view which shows a spray mechanism. It is a typical perspective view which shows the spray mechanism arrangement | positioning of a liquid fuel injection apparatus. It is explanatory drawing which shows the liquid fuel mist injection state of a liquid fuel injection apparatus. It is a systematic diagram which shows the supply system of the liquid fuel and compressed gas of a liquid fuel injection apparatus. It is sectional drawing on the AA line of FIG. 1 which shows the specific structure of a liquid fuel injection apparatus. It is explanatory drawing which shows the sealing mechanism of the front-back direction of a liquid fuel injection apparatus. It is sectional drawing on the AA line of FIG. 1 which shows other embodiment of this invention. It is a schematic diagram which shows the principle at the time of liquid fuel blowing of this invention. It is a figure which shows the combustion condition at the time of liquid fuel blowing of this invention. It is a figure which shows the ignition condition at the time of liquid fuel blowing of this invention. It is a figure explaining the conventional sintering process. It is a figure explaining the pressure loss and temperature distribution in a sintered layer. It is explanatory drawing which compared the temperature distribution at the time of high production and low production. It is a graph of the temperature distribution and yield distribution in a sintering machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Raw material hopper 2 ... Drum mixer 3 ... Rotary kiln 4 ... Surge hopper 5 ... Floor hopper 6 ... Drum feeder 7 ... Cutting chute 8 ... Sinter pallet 9 ... Charging layer 10 ... Ignition furnace 11 ... Wind box 15 ... Liquid fuel Injection device 16 ... hood,
DESCRIPTION OF SYMBOLS 21 ... Compressed air supply piping 22 ... Liquid fuel supply piping 23 ... Spray mechanism 24 ... Vertical piping 25 ... Mixing part 26 ... Connection piping 27 ... Branch injection part 28a, 28b ... Injection nozzle part 29 ... Liquid fuel mist 31 ... Compressed gas supply Original pipe 32 ... compressed gas supply source 33 ... storage tank 34 ... compressor 35 ... receiver tank 36 ... liquid fuel supply source pipe 37 ... fuel supply pump 38 ... liquid fuel storage tank 51 ... baffle plate 52 ... baffle plate row

Claims (7)

A circulating pallet,
A raw material supply device for charging a sintered raw material containing fine ore and carbonaceous material onto the pallet to form a charging layer;
An ignition furnace for igniting the carbonaceous material in the sintered raw material on the pallet;
A sintering machine comprising a wind box for sucking air below the pallet,
A sintering machine comprising a liquid fuel injection device for atomizing liquid fuel to a particle size of 100 μm or less above the charging layer and injecting it horizontally in the downstream side of the ignition furnace.   The liquid fuel injection device comprises 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 is atomized to mix the charge. The sintering machine according to claim 1, further comprising a spray mechanism that sprays horizontally on the layer.   The spray mechanism is formed on a transport pipe that is inclined downward toward the downstream side that transports the fluid mixture of the compressed gas and the liquid fuel, a communication pipe that is connected to the lower surface side of the transport pipe, and a lower surface of the communication pipe. The sintering machine according to claim 2, wherein the sintering machine is composed of an injection nozzle having a downward slope toward a discharge port for injecting the liquid fuel in a horizontal direction. The liquid fuel supply source is the spray mechanism in which at least one of petroleum liquid fuel, alcohol liquid fuel, ether liquid fuel, and other hydrocarbon compounds liquid fuel that is in a liquid state near room temperature is used as the liquid fuel. The sintering machine according to claim 2, wherein the sintering machine is supplied to the sintering machine. The compressed gas supply source, a nitrogen with antiphlogistic, any one of claims 2 to 4, characterized in that for supplying carbon dioxide gas, a compressed gas composed mainly of at least one of water vapor in the spray mechanism The sintering machine described in 1.   6. The liquid fuel injection device according to claim 1, further comprising a preheating mechanism for preheating the liquid fuel so that the liquid fuel has an optimum viscosity for atomization when the viscosity of the liquid fuel is high. The sintering machine of any one of Claims 1. A sintered raw material containing fine ore and carbonaceous material is charged onto a circulating pallet by a raw material supply device to form a charging layer, transported to an ignition furnace, and the carbonaceous material in the charging layer is ignited. In addition, a method for producing sintered ore in which air is sucked by a wind box disposed below the pallet,
A method for producing sintered ore, characterized in that liquid fuel is atomized to a particle size of 100 μm or less and injected in the horizontal direction above the charging layer on the downstream side of the ignition furnace.

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