JP5593607B2 - Method for producing sintered ore and sintering machine - Google Patents

Description

  The present invention relates to a method for producing a high-strength, high-quality sintered ore by using a downward suction type dweroid (DL) sintering machine, and a sintering machine used for the production.

  Sinter ore, which is the main raw material for the blast furnace ironmaking method, is generally manufactured through a process as shown in FIG. The raw materials are iron ore powder, iron mill recovered powder, sintered ore sieve 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 hoppers 1. The cut out raw material is added with an appropriate amount of water using a drum mixer 2 and the like, 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 carbon material in the charging layer continues to be burned by the air sucked from the upper layer portion to the lower layer portion of the charging layer by the windbox, and the combustion zone gradually moves to the lower layer and forward as the pallet 8 moves. Proceed (downstream). As the combustion progresses, the moisture contained in the sintering raw material particles in the charging layer is vaporized by the heat generated by the combustion of the carbonaceous material, sucked downward, and the lower layer where the temperature has not yet risen. Concentrate in the sintering 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. 15 shows the inside of the charging layer when the combustion (flame) front moving through the charging layer having a thickness of 600 mm is at a position of about 400 mm (200 mm from the surface of the charging layer) on the pallet of the charging layer. 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. 16 shows the temperature distribution in the charging layer during high production and low production of sintered ore. 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. In the case of high production, in order to increase the moving speed of the pallet, the high temperature region holding time t ₂ becomes shorter than t _{1 in the} case of low production. When the high temperature region holding time is shortened, firing becomes insufficient, resulting in a decrease in the cold strength of the sintered ore and a decrease in yield. Therefore, in order to increase the production amount of high-strength sintered ore, the yield strength is maintained and improved by increasing the strength of the sintered cake, that is, the cold strength of the sintered ore, even in the short-time sintering. It is necessary to take some measures that can be done. In general, SI (shutter index) and TI (tumbler index) are used as indices representing the cold strength of sintered ore.

  17A shows the progress of sintering in the charging layer on the sintering machine pallet, FIG. 17B 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. 17B, 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 is lowered, 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 imparting high temperature retention to the upper portion of the charging layer has been conventionally 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, so that it has not been put into practical use.

Further, even in this technique, the amount of carbon material is not reduced when the combustible gas is blown, so that the inside of the sintered layer becomes a high temperature exceeding 1380 ° C. Therefore, it is not possible to enjoy a sufficient improvement in cold strength and a yield improvement effect. Furthermore, even if the obtained sintered ore is a sintered ore with poor reducibility.
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 sintering zone cannot be made sufficiently thick (approximately (Less than 15 mm), 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, none of the conventional techniques proposed so far has been put into practical use, and the 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 present applicant, in Patent Document 5, disclosed various gaseous fuels diluted below the lower combustion limit concentration from above the charging layer of the sintering raw material that was valued on the pallet of the sintering machine. A method is proposed in which either one or both of the maximum attained temperature and the high temperature region holding time in the charging layer are adjusted by supplying, introducing into the charging layer, and burning.
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. In particular, when a gaseous fuel containing impurities such as tar and scale that easily adhere to the discharge nozzle, for example, coke oven gas, is blown onto the charging layer, nozzle cleaning and inspection in a short period of time are necessary, and the sintering operation is required. This will greatly affect the production of sintered ore.

  Accordingly, the present invention has been made paying attention to the problems of the above-described conventional example, and in a downward suction type sintering machine, discharge gas containing a pipe clogging material containing tar or scale that easily adheres to the nozzle is discharged. It aims at providing the manufacturing method and sintering machine of the sintered ore which can suppress adhesion of the piping obstruction | occlusion substance in an exit, and can lengthen a cleaning and inspection cycle.

In order to achieve the above object, a method for producing sintered ore according to the present invention comprises charging a sintered raw material containing fine ore and carbonaceous material onto a circulating pallet, and mounting the sintered raw material on the pallet. A charging step of forming an inlet layer, an ignition step of igniting the charcoal material on the surface of the charging layer using an ignition furnace, and a coke oven gas containing a pipe plugging substance in the air is ejected above the charging layer A gaseous fuel supply step for making the diluted gaseous fuel below the lower combustion limit concentration, and the diluted gas and air are sucked in a wind box disposed under the pallet and introduced into the charging layer. A sintering step of burning a diluted gaseous fuel and a carbonaceous material in the bed to produce a sintered cake, wherein the gaseous fuel supply step suppresses blockage of the coke oven gas by the piping plugging material. and either 15mm or less jets in opening diameter is more than 6mm It is ejected, and the pre-heating to Rukoto wherein between the coke oven gas to the spout.

In addition, the method for producing a sintered ore according to claim 2 is characterized in that, in the invention according to claim 1, the opening diameter of the ejection port for ejecting the coke oven gas is set to 10 mm or more and 15 mm or less. .

Moreover, the manufacturing method of the sintered ore which concerns on Claim 3 uses the coke oven gas supplied to the said ignition furnace as the said coke oven gas.
In addition, a sintering machine according to claim 4 includes a pallet that circulates and moves, a raw material supply device that forms a charging layer by charging a sintered raw material containing fine ore and carbonaceous material on the pallet, An ignition furnace for igniting the carbon material in the bed, a wind box disposed below the pallet, and a coke oven gas including a pipe closing substance disposed downstream of the ignition furnace. erupted upper atmospheric layers, have a fuel injection nozzle which is and set to 15mm or less in more than 6mm as the opening diameter to be mixed with air to inhibit clogging due to the pipe clogging substance to said fuel injection nozzle And a gaseous fuel supply device provided with a preheating mechanism for preheating the coke oven gas .

Further, the sintering machine according to claim 5 is characterized in that, in the invention according to claim 4 , the opening diameter of the fuel injection nozzle is set to 10 mm or more and 15 mm or less .
Also, sintering machine according to Claim 6 is the invention according to claim 4 or 5, wherein the coke oven gas is characterized in that the use of coke oven gas is supplied to the ignition furnace.

A sintering machine according to a seventh aspect is the invention according to any one of the fourth to sixth aspects, wherein the fuel discharge nozzle promotes dilution mixing at a high speed on an outer peripheral side of a nozzle portion for ejecting coke oven gas. It is characterized in that a gas blowing portion for blowing the working gas is formed.
According to an eighth aspect of the present invention, there is provided the sintering machine according to any one of the fourth to seventh aspects, wherein the fuel discharge nozzle is configured so that a coke oven gas is formed above the charging layer while forming a vortex flow. It is characterized by being comprised so that it may discharge.

  According to the present invention, in the operation of the lower suction type sintering machine, the gas fuel containing the plugging substance is discharged into the atmosphere above the charging layer, and the diluted gaseous fuel diluted to a predetermined concentration is charged into the charging layer. It can be supplied (introduced) and burned at a target position in the charging layer. Moreover, in this case, by setting the opening diameter of the discharge port for discharging the pipe plugging substance-containing gaseous fuel to 6 mm or more, preferably 10 mm or more, the adhesion of the pipe plugging substance to the discharge port is suppressed, and cleaning and The inspection cycle can be extended and the production volume of the sintering operation can be improved.

  Here, if the opening diameter of the discharge port that discharges the gas fuel containing the pipe plugging substance is set to less than 6 mm, at least the amount of pipe plugging substances such as tar, scale, etc. attached to the discharge port will increase, and the cleaning and inspection cycle will be increased. It is necessary to shorten it, and the sintering operation must be stopped at the time of cleaning and inspection, so that the production amount of the sintering operation is reduced. However, by setting the opening diameter of the discharge port for discharging the gas fuel containing the pipe plugging substance as in the present invention to be 6 mm or more, the amount of pipe plugging substance attached can be suppressed, and it can withstand long-term use. become.

  The manufacturing method of the sintered ore which concerns on this invention is comprised including the charging process, the ignition process, the diluted gas fuel production | generation process, and the combustion process. In this manufacturing method, the charging step is a step of charging a sintered raw material containing fine ore and carbonaceous material onto 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 carbonaceous material on the surface of the charging layer using an ignition furnace. In addition, the diluted gas fuel generation step is a step of supplying and diluting the pipe plugging substance-containing gas fuel containing the pipe plugging substance into the air above the charging layer to obtain a diluted gas fuel having a combustion lower limit concentration or less, In the combustion step, the diluted gaseous fuel and air are sucked into the charging layer by the suction force of the wind box arranged under the pallet, and the diluted gaseous fuel is burned in the charging layer, and at the same time, This is a process of burning the carbonaceous material in the charging layer with the air sucked into the layer, and sintering the sintered raw material with the generated combustion heat to produce a sintered cake. The process and the combustion process are features in the present invention.

  In the dilution gas fuel generation step, the gas fuel containing the pipe plugging substance on the downstream side in the pallet traveling direction of the ignition furnace is opened to the atmosphere above the charging layer from the jet port having an opening diameter of 6 mm or more, preferably 10 mm or more. The diluted gas fuel is injected into the inside and mixed with air to obtain a diluted gas fuel having a concentration lower than the lower limit of combustion, and this is introduced into the charging layer. It is characterized by having a gaseous fuel supply device for obtaining.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a sintering machine of the present invention. As described in the above-described conventional example, CaO-containing CaO such as iron ore powder, iron mill recovered powder, sintered ore sieving powder, limestone and dolomite System auxiliary materials, granulation aids such as quick lime, raw materials such as coke powder and anthracite are cut out from individual hoppers, mixed with an appropriate amount of water with a drum mixer, granulated, and 3.0 to 6.0 mm A sintered raw material that is a pseudo particle having an average diameter is stored in the surge hopper 5, and a fine-grained sintered ore is stored in the floor hopper 4.

  Along with the movement of the endless moving sinter pallet 8, fine sinter ore is cut out from the floor hopper 4 to form a floor layer on the great of the sinter pallet 8, and the floor layer Sintering raw material is charged from the surge hopper 5 through the drum feeder 6 and the cutting chute 7 to form a charging layer 9 having a thickness (height) of about 400 to 800 mm, also called a sintering bed. .

An ignition furnace 10 is disposed on the downstream side of the cut chute 7 above the charging layer 9, and the carbon material in the surface layer of the charging layer 9 is ignited by the ignition furnace 10. The ignition furnace 10 is supplied with a coke oven gas called a so-called C gas generated in a coke oven in the ironworks. By burning this coke oven gas, the charcoal in the surface layer of the charging layer 9 is supplied. Ignite the material.
A gaseous fuel supply device 15 is disposed on the downstream side of the ignition furnace 10.

  As shown in FIG. 2, one or more gas fuel supply 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. It is preferable that the gaseous fuel mist is supplied into the charging layer 9 at a position after ignition of the carbonaceous material in the charging layer 9. One or more gaseous fuel injection devices 15 are disposed downstream of the ignition furnace 10 at an arbitrary position after the combustion front has traveled below the surface layer. From the viewpoint of adjusting the cold strength and the reducibility, the size, position, and number of arrangements are determined as described later.

  As shown in FIGS. 2 and 3, the gaseous fuel supply device 15 is surrounded by a hood 16 having an open upper end that surrounds the upper portion of the sintering machine pallet 8 so that gaseous fuel does not leak outside the hood 16. A baffle plate 19 having a cross-section with a cross-sectional shape extending between the front and rear walls 17 constituting the hood 16 along the conveying direction of the sintering machine pallet 8 and having the apex upward is perpendicular to the conveying direction of the sintering machine pallet 8. A baffle plate array 20 having a configuration in which a predetermined number p is arranged in parallel while maintaining a predetermined pitch p is arranged, and the atmosphere passing through the sucked baffle plate arrays 20 is supplied from the gaseous fuel supply device 15. It can be mixed with gaseous fuel and diluted with gaseous fuel. In the present embodiment, three baffle plate rows 20 are arranged in the vertical direction, and the baffle plate rows 20 adjacent to each other in the vertical direction are between the baffle plates 19 of one baffle plate row 20. It arrange | positions so that the board 19 may be located. Further, for example, seven gaseous fuels are supplied between the baffle plates 19 on the lower side of the lowermost baffle plate row 20 in the conveying direction of the sintering machine pallet 8 and maintaining a predetermined interval in the width direction orthogonal to the conveying direction. A pipe 21 is provided. As shown in FIG. 2, each of these gaseous fuel supply pipes 21 is connected to the gaseous fuel supply source pipes 22 at both ends in the conveying direction of the sintering machine pallet 8. A coke oven gas (C gas) is supplied as a gas fuel containing a pipe closing material chamber containing a pipe closing substance such as tar or scale supplied to the furnace 10.

  Among the gaseous fuel supply pipes 21, the gaseous fuel injection nozzles 23 are disposed inwardly with respect to the gaseous fuel supply pipes 21 at both ends in the width direction, and the adjacent gaseous fuel supply pipes 21 are disposed adjacent to each other. Discharged gas fuel ejection nozzles 23 are disposed as symmetrically opposite to the discharge port for ejecting a predetermined number of gaseous fuels horizontally at a predetermined pitch in the conveying direction of the sintering machine pallet 8.

  Here, between the adjacent gaseous fuel supply pipes 21, as shown in FIG. 4, the gaseous fuel injection nozzle 23 of one gaseous fuel supply pipe 21 is in the middle between the gaseous fuel injection nozzles 23 of the other gaseous fuel supply pipe 21. The gas fuel injection nozzles 23 are arranged in a staggered manner in the horizontal direction between the adjacent gas fuel supply pipes 21 so as to be arranged at positions. For this reason, the gaseous fuels injected in the horizontal direction in the adjacent gaseous fuel supply pipes 21 are uniformly dispersed and injected onto the charging layer 9 without interfering with each other, mixed with the air, and the diluted gaseous fuel 24. Become. 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 Reference numeral 18 denotes a wall that surrounds the sintering machine pallet 8 in the traveling direction.

  Moreover, it is preferable that the gaseous fuel supply device 15 can control the supply amount of the gaseous fuel in the pallet width direction, for example, by providing a flow rate control means in the gaseous fuel supply pipe 21 or the nozzle. In particular, in the vicinity of the side wall 18 in the pallet width direction, the supplied gaseous fuel may flow toward the machine side or leak out of the machine due to the influence of the cross wind, and the gaseous fuel concentration may be diluted. Therefore, it is preferable that a large amount of gaseous fuel can be supplied in the vicinity of the sidewall 18.

Further, the gaseous fuel supply device 15 causes the gaseous fuel to be discharged into the atmosphere at a high speed above the charging layer 9, thereby mixing with the surrounding air in a short time, and below the lower combustion limit concentration of the gaseous fuel. It is necessary to introduce the diluted gaseous fuel 24 into the charging layer.
As described above, the reason why the gaseous fuel is diluted to a concentration lower than the lower combustion limit concentration is as follows.
Table 1 shows the lower combustion limit concentration, supply concentration, and the like of typical gaseous fuels that can be used in the present invention. In order to prevent the occurrence of fire, the gas concentration when supplying gaseous fuel into the sintered raw material is safer as it is lower than the lower combustion limit concentration. That is, it is necessary for safety to supply the fuel so that it does not burn (cannot) at room temperature. In this respect, city gas has a lower combustion limit concentration that is similar to that of C gas (coke oven gas), but since the amount of heat is higher than that of C gas, the supply concentration can be lowered. Therefore, from the viewpoint of ensuring safety, city gas that can reduce the supply concentration is superior to C gas, but C gas can be procured from a coke oven in the steelworks, so running costs are reduced to city gas. Significantly lower compared.

  Table 2 shows the combustion components (hydrogen, CO, methane) contained in the gaseous fuel, the lower and upper combustion concentrations of these components, laminar flow, combustion speed during turbulent flow, and the like. In order to prevent the occurrence of fire during sintering, that is, to prevent the occurrence of fire due to gaseous fuel supplied during sintering, it is necessary to prevent backfire, but for that purpose, at least laminar combustion The gaseous fuel may be discharged at a speed higher than the speed, preferably higher than the turbulent combustion speed. For example, when methane, which is a main combustion component of city gas, is used as a gaseous fuel, there is no fear of backfire if it is discharged at a speed exceeding 3.7 m / s. On the other hand, since hydrogen gas has a higher turbulent combustion speed than CO and methane, it is necessary to discharge hydrogen gas at a higher speed in order to ensure safety. From this point, when comparing the gaseous fuel shown in Table 1, the city gas that does not contain the hydrogen component can slow down the discharge speed compared to the C gas containing 59 vol% of the hydrogen component. Is advantageous. Moreover, since city gas does not contain a CO component, it is safe without causing gas poisoning. Therefore, from the viewpoint of ensuring safety, it can be said that city gas has favorable characteristics when used as gaseous fuel. C gas can also be used as a gaseous fuel, but has the above-mentioned problems and is difficult. In the present invention, these points are also solved.

  Table 3 shows the results of evaluating the advantages and disadvantages of the type of supplying the gaseous fuel. In the table, direct top blowing means that gas fuel such as city gas or C gas is supplied (discharged) as it is, and is diluted to a predetermined concentration by entraining the surrounding atmosphere and sucked into the charging layer (introduced) The premixed blowing is a so-called pre-mixing method in which air and gaseous fuel are mixed in advance and diluted to a predetermined concentration and supplied to the charging layer and sucked (introduced) into the charging layer. Refers to the mix format. In the direct injection type, it is easy to prevent backfire if gaseous fuel is discharged at a speed higher than the turbulent combustion rate described above, but in the premixed injection type, when a concentration deviation occurs, backfire is caused. there is a possibility. On the other hand, in the direct-injection type, when gaseous fuel is mixed with the surrounding atmosphere and diluted, uneven concentration tends to occur, so there is a possibility of causing uneven combustion in the charged layer compared to the premixed injection type. large. However, in the case of comprehensive evaluation including equipment costs without considering running costs, direct injection of city gas is the most dominant, but in consideration of running costs, direct injection of C gas is most advantageous. is there.

  In the present invention, the gaseous fuel supply device 15 causes the gaseous fuel to be discharged into the atmosphere at a high speed above the charging layer 9, thereby mixing with the surrounding air in a short time, and the gaseous fuel is The reason why it is necessary to dilute to a concentration below the lower combustion limit concentration and then introduce the diluted gaseous fuel into the charge layer is as follows.

  As shown in FIG. 5 (a), a sintered pan having an inner diameter of 300 mmφ × a height of 400 mm is filled with a sintered cake, and a nozzle is embedded at a depth of 90 mm from the center of the sintered cake, Table 4 shows the results of measuring the methane gas concentration in the circumferential direction and the depth direction in the sintered cake by blowing 100% methane gas to 1 vol% against air. On the other hand, as shown in FIG. 5 (b), the distribution of the methane gas concentration was measured in the same manner as described above for the case where methane gas was supplied from a position 350 mm above the sintered cake using the same nozzle. This is shown in FIG. From these results, when methane gas was directly introduced into the sintered cake, the lateral diffusion of methane gas was insufficient, whereas when methane gas was supplied above the sintered cake, It can be seen that the methane gas concentration in the cake is almost uniform and diffuses sufficiently in the lateral direction. From the above results, it is understood that the gaseous fuel is preferably diluted uniformly before being introduced into the charging layer by supplying it into the air above the sintered cake.

  Next, a problem in using C gas is that it contains tar and scale which are piping plugging substances. Therefore, in a so-called thin tube having an injection nozzle diameter of 1 to 3 mmΦ, the sinter ore manufacturing method itself in which the C gas is supplied is difficult to continue after waiting for several days. Therefore, in the present invention, the opening diameter of the gaseous fuel injection nozzle 23 for discharging the gaseous fuel from the gaseous fuel supply pipe 21 is preferably set to 6 mm or more because it is a coke oven gas containing tar and scale as the gaseous fuel. . The reason for this is that if the opening area of the discharge part is small, a pipe clogging material made of a mixture of tar and scale adheres to the injection nozzle 23, and the injection nozzle 23 is cleaned and inspected every few days or every two to three weeks. In the meantime, the production amount is reduced because the sintering operation needs to be stopped.

However, by setting the opening diameter of the gaseous fuel injection nozzle 23 to 6 mm or more, the cleaning frequency of the gaseous fuel injection nozzle 23 can be extended to about six months, and the cleaning frequency to make the opening diameter 10 mm or more is 10 months or more. Can be extended to
As described above, the larger the opening diameter of the gaseous fuel injection nozzle 23, the more the adhesion of the pipe clogging material made of a mixture of tar and scale can be suppressed. Therefore, the opening diameter is desirably 15 mm or less.
Note that a preheating mechanism for preheating the gaseous fuel injection nozzle 23, the gaseous fuel supply pipe 21 and the like is arranged so that pipe clogging substances such as tar and scale are solidified in the gaseous fuel supply pipe 21 and the gaseous fuel injection nozzle 23. If suppressed, the cleaning and inspection cycle can be further extended.

When the piping for discharging these gaseous fuels and the opening have the same shape, in general, the closer the fuel is to the supply source header, the easier the fuel comes out, and the farther the fuel becomes, the less likely it is to come out. Therefore, when using long piping,
(A) Use a tapered pipe with a gradually reduced cross-sectional area in the pipe. (B) Increase the opening cross-sectional area as it is farther from the fuel supply header. (C) Opener and nozzle as it is farther from the fuel supply header. Narrow the pitch and increase the sum of openings or nozzle cross-sectional area per unit pipe length.
By applying any one of these or combining them, fuel can be supplied evenly even when the pipe length is long.

In addition, it is preferable to perform discharge of the gaseous fuel in the said gaseous fuel supply apparatus at the height of 300 mm or more above the charging layer surface.
Moreover, it is preferable that the gaseous fuel is discharged by the gaseous fuel supply device with a height of 300 mm or more above the surface of the charging layer and a discharge direction substantially horizontal.
FIG. 6 is an experiment for measuring the C gas diffusivity in the charged layer of the sintering raw material when using C gas. That is, when the C gas concentration is biased in the charging layer, the problem of non-uniform sinter quality that can cause combustion unevenness is avoided.

  FIG. 6 shows a sintered raw material packed bed a when a gas supply pipe c is arranged above the surface b of the sintered raw material packed bed a and C gas is supplied by a nozzle d provided with the gas supply pipe c. It is the C gas diffusivity measuring device which measured C gas concentration in the inside. C gas is discharged from the nozzle d of the gas supply pipe c in a state where the air above the surface b of the sintered raw material packed layer a is sucked from the lower part of the sintered raw material packed layer a and filled. The C gas diffusivity was determined by measuring the C gas concentration collected at each circle 1 to 15 in the layer a. The nozzle d of the gas supply pipe c was discharged toward the surface b of the packed bed a, but was blown down, and discharged toward the direction along the surface b of the packed bed a was horizontal horizontal blowing. Called.

FIG. 7 shows the results. The C gas concentrations detected in the upper, middle and lower layers of the packed bed a during horizontal horizontal blowing are shown in FIG. B (a), and the C gas concentrations when discharged downward are shown in FIG. This is shown in FIG.
C gas, like CH ₄ gas, is difficult to diffuse in the packed bed a, and the horizontal and horizontal blowing has a more uniform C gas concentration than the bottom blowing.
8 and 9 show the analysis results of the downward blowing gas diffusion mixing, and the results under the conditions shown in FIG. 8 (C gas blowing, nozzle diameter 10 mm, downward discharge speed 3 m / s) are shown in FIG. In FIG. 9, there is an area where gas diffusion mixing is insufficient between the nozzles in both the vertical and horizontal cross sections, and this nonuniform concentration of C gas is supplied to the charging layer of the sintering raw material, resulting in generation of combustion villages. Can be expected to be unavoidable.

FIG. 10 shows the result of analysis as horizontal horizontal blowing with the same nozzle diameter and discharge speed. It can be seen that the horizontal laterally blown C gas is sucked together with the atmosphere to the charged layer side of the sintering raw material and supplied in a uniform mixed state.
The pan test results are shown in FIG. Comparison was made based on the strength of sinter, yield, productivity, and sintering time obtained by sintering operation without gas blowing, but the horizontal horizontal blowing supply form was the best compared to the base and downward gas supply. It became the result. The horizontal horizontal blowing refers to a state parallel to the charged layer of the sintering raw material and is allowable in the range of ± 30 degrees in the horizontal direction. This is preferably in the range of ± 20 degrees in the horizontal direction.

From this result, considering the rebound of the discharged gaseous fuel on the surface of the charging layer, the supply of C gas to the atmosphere should be performed at a height of 300 mm or more above the charging layer surface and the supply of C gas should be The horizontal horizontal blowing is performed above the surface of the layer.
Next, the countermeasure against the cross wind of the gaseous fuel supply apparatus of the present invention will be described.
In the present invention, as described above, the hood 16 that covers the upper portion of the sintering machine pallet 8 is provided. The hood 16 suppresses the influence of the crosswind on the concentration distribution of the diluted gas fuel 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 coke oven gas injected from the gaseous fuel injection nozzle 23 and the atmosphere are mixed inside the hood 16.
Further, as shown in FIG. 3, a cross wind attenuating fence 16c made 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 entrained into the hood 16 from this portion, and the concentration distribution of the diluted gas fuel 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. 3, 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 outer side thereof. 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 ends 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 gaseous fuel injection device 15 are set as follows.

That is, the diluted gas fuel 24 is supplied (introduced) onto the charging layer 9 after a sintering completion zone is formed on the charging layer 9 after the carbon material in the charging layer 9 is ignited. The reason is that there is a risk of backfire even if the diluted gas fuel 24 is supplied at the position where the red hot part is present immediately after ignition. Therefore, it is necessary to supply the diluted gas fuel 24 to the charging layer 9 after the sintered raw material above the charging layer 9 is fired to form a sintered cake layer. The diluted gas fuel 24 can be supplied at any 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 for supplying the diluted gas fuel 24 after the sintered cake layer is formed are as follows.
(A) If the diluted gas fuel 24 is supplied in a state where no sintered cake (sintered layer) is formed on the top of the charging layer 9, there is a possibility that combustion will occur on the charging layer 9. .
(B) It is preferable to supply the diluted gas fuel to a portion where it is necessary to improve the yield of the sintered ore, that is, to supply combustion in a portion where the strength of the sintered ore is desired to be increased.

  In order not to burn on the upper side of the charging layer 9 of the diluted gas fuel 24, after the surface layer portion of the charging layer 9 is ignited by the ignition furnace 10, after ignition and the sintered cake is generated on the surface, There is no fire type in the surface layer portion of the charging layer 9, and the probability of backfire (ignition) is low. As shown in FIG. 14 (a), the sintered cake becomes thicker as the sintering machine pallet 8 moves from the ignition furnace 10 to the downstream side. When the thickness from the surface is 20 mm or more, the possibility of backfire is sufficiently low, and when the thickness of the sintered cake is 50 mm or more, backfire can be reliably prevented.

  Thus, the suitable blowing position of the diluted gas fuel in which the thickness of the sintered cake is 20 mm or more, preferably 50 mm or more is a position 5 to 6 m downstream from the ignition furnace 10, and the first gas is located at this position. A fuel supply device 15 is provided. In the case where a plurality of gaseous fuel supply devices 15 are arranged, since there is no fire on the surface of the charging layer 9 as long as it is downstream of the first gaseous fuel supply device 15, the gaseous fuel supply device is at an arbitrary position. In this embodiment, four gaseous fuel supply devices 15 are arranged in series along the conveying direction of the sintering machine pallet 8.

  In addition, in order to adjust either or both of the maximum charge layer temperature and the high temperature region holding time, 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 In this case, it is preferable to supply the diluted gas fuel 24. When the thickness of the combustion / melting zone is less than 15 mm, the cooling effect by the air sucked through the sintered cake (sintered layer) and the diluted gas fuel 24 is insufficient even if the diluted gas fuel 24 is burned, This is because the thickness of the combustion / melting zone cannot be increased.

On the other hand, when the diluted gas fuel 24 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 range holding time is increased. Thus, a sintered ore with high cold strength can be obtained.
The introduction of the diluted gas fuel 24 into the charging layer 9 is performed 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 to supply so that it may pass through the sintered cake area | region (sintered layer) produced | generated in the lower layer, without burning, and may burn in the stage which the combustion front moved 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. Further, it is more preferable that the diluted gas fuel 24 is supplied in the vicinity of the sidewalls of the both pallet width direction coal portions where the yield reduction is large.

The gaseous fuel supply 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 method for producing sintered ore according to the present invention, the introduction of the diluted gaseous fuel 24 into the charging layer also means that the reheating of the produced sintered cake is promoted. In other words, this dilute gaseous fuel is originally supplied with a gaseous fuel mist that is more reactive than solid fuel to the low-strength cold ore portion of the sintered ore that tends to be short of heat due to a short holding time in the high temperature range. 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 diluted gaseous fuel 24 from the upper part of the charged layer after ignition is such that at least a part of the introduced diluted gaseous fuel 24 in the charged layer is unburned. It is preferable that the fuel reaches the combustion / melting zone and is burned at a target position where combustion heat is to be compensated. It is considered that it is more effective to supply the diluted gas fuel, that is, to introduce the 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. That is, if the supply of the diluted gas fuel 24 is performed in the upper layer portion of the charging layer that is likely to be insufficient in heat (insufficient holding time in the high temperature range), sufficient combustion heat is provided, and this portion is sintered. The quality of the cake can be improved, and further, if the supply operation of the diluted gas fuel 24 is extended to the zone below the middle layer, the recycle by the diluted gas fuel 24 is performed on the combustion / melting zone of the original carbon material. The result is equivalent to the formation of a combustion / melting zone, 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 pallet This is because sufficient sintering can be realized without lowering the moving speed of. 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 product sintered ore.

In the present invention, when introducing (supplying) the diluted gas fuel 24 into the charging layer 9, not only adjusting the supply position but also controlling the form of the combustion / melting zone itself, It is preferable to control the maximum temperature reached and / or the high temperature region holding time in the combustion / melting zone.
In general, in the charged layer 9 after ignition, the combustion (flame) front gradually expands downward and forward (downstream) as the sintering machine pallet 8 moves, so that the position of the combustion / melting zone Changes as shown in FIG. And as shown in FIG.17 (b), the thermal history received in the sintering process in a sintered layer differs in an upper layer, an intermediate | 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 sintered ore by position in the pallet 8 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, if the diluted gas fuel 24 is supplied according to the method of the present invention, the combustion / melting zone has an increased thickness in the vertical direction and a width in the pallet traveling direction, which is reflected in improving the quality of the product sintered ore. is there. 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 diluted gas fuel 24, 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, It is possible to control the maximum temperature and the high temperature holding time. 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 diluted gas fuel 24 into the charging layer 9 is for controlling the cold strength of the entire sintered product ore. That is, the original purpose of supplying the diluted gas fuel 24 is to improve the cold strength of the sintered cake, and consequently the sintered ore, and in particular, the supply position control of the diluted gas fuel 24 and the sintering raw material are combusted. -Through control of the high temperature region holding time, which is the time to stay in the melting zone, and control of the maximum temperature, the cold strength (shutter index SI) of the sintered ore is about 75 to 85%, preferably 80% or more, more preferably 90% or more.

  In the present invention, this strength level is particularly determined in consideration of the concentration of carbon dioxide in the sintered raw material, the supply amount, the supply position, and the supply range of the diluted gas fuel 24 (under the condition that the amount of heat input is constant). ) By adjusting the 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 diluted gas fuel 24 into the charging layer 9 in the pallet traveling direction is in an arbitrary zone between the sintered cake formed in the charging layer 9 and the wet zone. Based on how the cold strength of sintered ore is made. For this control, in the present invention, the scale (size), number, position (distance from the ignition furnace), gas concentration of the gaseous 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. The strength of the sintered cake formed in the charging layer 9 is controlled.

  When C gas is used, the lower limit concentration of combustion is 5.0 vol%, so the upper limit of gas concentration diluted to 75% is 3.8 vol%, and the upper limit of gas concentration diluted to 60% is 3.0 vol%, 25% The gas concentration diluted to 1.3 vol% is to be used. Accordingly, the preferred range is as follows. In the case of C gas, the lower limit concentration at which the effect of supplying gaseous fuel is manifested is 0.24 vol%.

Preferred range (1): 5.0 vol% to 0.24 vol%
Preferred range (2): 3.8 vol% to 0.24 vol%
Preferred range (3): 3.0 vol% to 0.24 vol%
Preferred range (4): 1.3 vol% to 0.24 vol%
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 20 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 gaseous fuel supply device 15.

In the gaseous fuel supply device 15, the gaseous fuel is injected by the gaseous fuel injection nozzle 23 in the hood 16 that covers the upper side of the sintering machine pallet 8.
At this time, as shown in FIG. 4, the gaseous fuel injection nozzle 23 is arranged with a half-pitch shift in the conveying direction of the sintering pallet 8 so that the adjacent spray mechanisms 23 do not face each other. Therefore, a uniform injection region is formed without the gaseous fuels injected from the gaseous fuel injection nozzles 23 in adjacent groups interfering with each other.

  At this time, even if it is coke oven gas (C gas) containing many piping obstruction | occlusion substances, such as a tar and a scale, the opening diameter of the gaseous fuel injection nozzle 23 is set to 6 mm or more, preferably 10 mm or more. , Can suppress the adhesion of pipe clogging substances, can extend the period of cleaning and inspection for more than half a year to 10 months, reduce the number of stops of the sintering operation for cleaning and inspection, and reduce the production volume of the sintering operation Can be improved. In this case, a preheating mechanism for preheating the gaseous fuel injection nozzle 23, the gaseous fuel supply pipe 21, and the like is arranged, and a pipe closing material such as tar or scale is solidified in the gaseous fuel supply pipe 21 or the gaseous fuel injection nozzle 23. If this is suppressed, the cleaning and inspection cycle can be further extended.

The injected gaseous fuel is mixed with air turbulently flowed by the baffle plate 19 and diluted below the lower combustion limit concentration at room temperature, and combustion above the charging layer 9 can be suppressed.
The diluted gaseous fuel 24 injected from the gaseous fuel injection nozzle 23 and diluted with air sucks the air downward through the wind box 11 disposed on the lower side of the sintering machine pallet 8, thereby mounting the diluted gaseous fuel 24. It is introduced into the entrance layer 9.

  The diluted gas fuel 29 introduced into the charging layer 9 passes through the sintered cake generated in the surface layer portion, reaches the combustion / melting zone 20 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. 17C when the diluted gas fuel 24 is not injected.

  In this way, when the supply operation of the diluted gas fuel 24 is extended to the region below the middle layer, the recombustion / melting zone by the dilution gas fuel 24 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.

In the above embodiment, the case where the gaseous fuel injection nozzle 23 is simply constituted by a nozzle having an opening has been described. However, the present invention is not limited to this, and as shown in FIG. Alternatively, the rotor blades 60 may be arranged to eject the gaseous fuel as a vortex, so that the mixing with the air can be performed more reliably.
Further, in the above embodiment, the case where the gaseous fuel supply 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. If it is, the gaseous fuel supply device 15 may be disposed on the downstream side of the heat retaining furnace.

Moreover, in the said embodiment, although the case where the hood 16 of the gaseous fuel injection apparatus 15 was made into the hood which opened upwards was demonstrated, it is not limited to this, An upper end is narrowed and opening of predetermined | prescribed opening ratio is made. You may make it form.
Furthermore, in the above embodiment, the case where the coke oven gas is applied as the gaseous fuel has been described. However, the present invention is not limited to this, and an M gas in which the coke oven gas and the blast furnace gas are mixed is applied. Also good.

  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 a schematic block diagram of a gaseous fuel supply apparatus. It is sectional drawing of the direction orthogonal to the conveyance direction of a gaseous fuel supply apparatus. It is explanatory drawing which shows the gaseous fuel injection state of a gaseous fuel supply apparatus. It is a figure explaining the experiment which investigates the influence of the gaseous fuel supply position to a sintering cake. It is a figure explaining the experiment which measures the C gas diffusion degree in the charging layer of a sintering raw material. It is a figure explaining the measurement result of the experiment of FIG. It is a figure which shows the conditions of lower blowing gas diffusion mixing. It is an analysis result of the experiment of FIG. It is a figure which shows the result analyzed as horizontal horizontal blowing, making the nozzle diameter and discharge speed the same. It is a graph which shows the influence which the discharge speed of gaseous fuel and the nozzle diameter have on the concentration distribution of dilution gas. It is explanatory drawing which shows the seal state before and behind the hood. It is a front view which shows the modification of a gaseous fuel injection nozzle. 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 ... Gas fuel Injection device 16 ... hood,
19 ... baffle plate 20 ... baffle plate row 21 ... gaseous fuel pipe 22 ... gaseous fuel supply source pipe 23 ... gaseous fuel injection nozzle

Claims (8)

A charging step of charging a sintered raw material including powdered ore and carbonaceous material on a circulating pallet and forming a charging layer of the sintered raw material on the pallet;
An ignition step of igniting the charcoal material on the surface of the charging layer using an ignition furnace;
A gaseous fuel supply step of ejecting a coke oven gas containing a pipe plugging substance in the air above the charging layer to make a diluted gaseous fuel having a lower combustion limit concentration or less;
The diluted gas and air are sucked in a wind box arranged under the pallet and introduced into the charging layer, and the diluted gas fuel and the carbon material are burned in the charging layer to produce a sintered cake. And a sintering process to
In the gaseous fuel supply step, the coke oven gas is ejected from a jet port having an opening diameter of 6 mm or more and 15 mm or less so as to suppress blockage by the piping plugging substance, and the coke oven gas is supplied to the jet port. in the manufacturing method of sintered ore, wherein preheating to Rukoto.   2. The method for producing a sintered ore according to claim 1, wherein an opening diameter of an ejection port for ejecting the coke oven gas is set to 10 mm or more and 15 mm or less. The method for producing a sintered ore according to claim 1 or 2 , wherein the coke oven gas is a coke oven gas supplied to the ignition furnace. A circulating pallet,
A raw material supply device for forming a charge layer by charging a sintered raw material containing fine ore and carbonaceous material on the pallet;
An ignition furnace for igniting the charcoal of the charging layer;
A wind box disposed below the pallet;
The diameter of the coke oven gas that is disposed downstream of the ignition furnace and that contains a pipe plugging substance is injected into the atmosphere above the charging layer and mixed with air suppresses blockage by the pipe plugging substance. that it has a fuel injection nozzle and set in 15mm or less more than 6mm, and a gaseous fuel supply device disposed preheating mechanism for preheating the coke oven gas until the fuel injection nozzle as A featured sintering machine. 5. The sintering machine according to claim 4 , wherein an opening diameter of the fuel injection nozzle is set to 10 mm or more and 15 mm or less. The sintering machine according to claim 4 or 5 , wherein the coke oven gas is a coke oven gas supplied to the ignition furnace. Said fuel injection nozzles, one of claims 4 to 6, characterized in that blown air blowing portion of the diluted mixture for accelerating the gas at a high speed is formed on the outer peripheral side of the nozzle portion for ejecting the coke oven gas The sintering machine according to item 1. The fuel injection nozzle, coke oven gas, according to any one of claims 4 to 7, characterized in that it is configured to discharge the upper side of the sintering bed while forming a vortex Sintering machine.

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