JP5544791B2 - Sintering machine - Google Patents

Description

  The present invention relates to a sintering machine that produces a high-strength, high-quality sintered ore using a downward suction type Dwytroid (DL) sintering machine.

  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 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 201 on a conveyor at a predetermined ratio. The cut out raw material is mixed with a suitable amount of water by using a drum mixer 202, a rotary kiln 203 or the like, mixed and granulated to obtain a sintered raw material which is pseudo particles 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 204 to form a floor layer on the great of the sintering machine pallet 208.

  The sintering raw material is charged from the surge hopper 205 arranged on the sintering machine through the drum feeder 206 and the cutting chute 207 onto the floor layer on the endless moving type sintering machine pallet 208 and sintered. A charge layer 209 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 209 ignites the carbon material in the surface layer of the charging layer 209 and air through a wind box 211 disposed under the pallet 208. 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 charge layer surface layer is ignited by the ignition furnace 210. The carbon material in the ignited charging layer continues to be burned by the air sucked from the upper layer portion of the charging layer to the lower layer portion by the windbox, and the combustion zone gradually moves to the lower layer and forward as the pallet 208 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. 13 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. 14 shows the temperature distribution in the charging layer at the time of 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.

  FIG. 15A shows the progress of sintering in the charging layer on the sintering machine pallet, FIG. 15B 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. 15B, 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. Therefore, 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, sufficient cold strength improvement and yield improvement effects cannot be enjoyed. Furthermore, the obtained sintered ore is also 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.

  Therefore, 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, a high-strength, high-quality sintered ore can be produced with high yield and safety. The object is to provide a sintering machine.

In order to achieve the above object, a sintering machine according to the present invention includes a raw material supply device for forming a charging layer by charging a sintered raw material containing fine ore and carbonaceous material onto a circulating pallet; An ignition furnace for igniting the charcoal of the charging layer; a wind box disposed below the pallet; and gaseous fuel disposed on the downstream side of the ignition furnace with an atmosphere above the charging layer A plurality of gaseous fuel supply devices that are jetted into and mixed with air to form a diluted gaseous fuel having a concentration lower than the lower limit of combustion, each gaseous fuel supply device comprising the gaseous fuel disposed in a gaseous supply hood. A plurality of gaseous fuel supply pipes to be supplied, and a shut-off valve for shutting off the supply of gaseous fuel to each gaseous fuel supply pipe, an abnormality detection unit for individually detecting an abnormality in the plurality of gaseous fuel supply apparatuses, Abnormality detection unit detects abnormalities in the gaseous fuel supply device When the, the shut-off valve of the corresponding gas fuel supply apparatus possess a gas fuel cutoff control unit that controls the closed state, the abnormality detecting unit measures a diluted gaseous fuel concentration of at least said gas supply hood At least one of a densitometer and an exhaust system abnormality detector that detects an abnormality of the exhaust system connected to the wind box, and the apparatus is configured to detect leakage of the gaseous fuel to the outside and an increase in the concentration of the gaseous fuel. It is characterized by preventing at least one of combustion above the bed .

Further, sintering machine according to claim 2 is the invention according to claim 1, wherein the abnormality detection unit, before Symbol flame detector for detecting a flame of the gas supply in the hood, detects the pressure of the gas supply hood the pressure detector, and it is characterized in that further comprising at least one of the gaseous fuel supply abnormality detector for detecting an abnormal pressure of the supply system of the gaseous fuel supplied to the gas fuel supply piping.

  The sintering machine according to claim 3 is the invention according to claim 1 or 2, wherein each of the gaseous fuel supply devices includes a gaseous fuel supply branch pipe connected to a gaseous fuel supply main pipe of a gaseous fuel supply source. A gas fuel branch section connected to the gas fuel supply branch pipe and connected to the gas fuel supply pipes in parallel, and the shut-off valve is interposed in the gas fuel supply branch pipe. It is said.

According to a fourth aspect of the present invention, there is provided the sintering machine according to any one of the first to third aspects, wherein each gaseous fuel supply pipe of each gaseous fuel supply device has a flow meter and a flow control valve individually. It is characterized by being inserted.
According to a fifth aspect of the present invention, in the invention according to the third aspect, the gas fuel supply device is characterized in that a flow meter and a flow rate control valve are inserted in the gas fuel main pipe. Yes.

  According to the present invention, in the downward suction type sintering machine, gaseous fuel is injected above the charging layer on the downstream side of the ignition furnace and mixed with air to form diluted gaseous fuel, and this diluted gaseous fuel is charged. A plurality of gaseous fuel supply devices to be introduced into the layer are arranged in series, and each gaseous fuel supply device includes a plurality of gaseous fuel supply pipes that supply the gaseous fuel disposed in a gaseous supply hood, and each gaseous fuel supply. A shutoff valve that shuts off the gaseous fuel supplied to the pipe, and when the abnormality detection unit detects an abnormality such as an abnormality in the gaseous fuel supply system of the gaseous fuel supply device or an abnormality in the exhaust wind system, Since the shutoff valve is controlled to be in the closed state, the supply of the gaseous fuel in the corresponding gaseous fuel supply apparatus can be stopped immediately when an abnormality occurs, and the effect of ensuring safe operation can be obtained.

  Moreover, each gaseous fuel supply apparatus controls the flow volume of the gaseous fuel supplied through each gaseous fuel supply piping appropriately by providing the flow rate control part comprised with a flow meter and a flow control valve at least in gaseous fuel supply piping. And a uniform diluted gas fuel can be produced in the gas supply hood.

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 graph which shows the influence which the discharge speed of gaseous fuel and the nozzle diameter exert on the concentration distribution of diluted gaseous fuel. 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 which shows the sealing mechanism of the sintering machine pallet conveyance direction of a gas supply hood. It is a figure which shows the supply system of the gaseous fuel to a heat retention furnace and a gaseous fuel supply apparatus. It is a figure which shows the gaseous fuel supply system of a gaseous fuel supply source. It is a block diagram which shows a control apparatus. It is a flowchart which shows an example of the abnormality control processing procedure performed with a control apparatus. 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.

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, in which a sintering material is generated in a sintering material generating unit 1. In this sintering raw material production | generation part 1, the anthracite or course cut out from the two anthracite hopper 1a and the coke hopper 1b is supplied to the rod mill 1c by the belt conveyor CV1 and pulverized to a predetermined particle size, and then becomes a blending tank. It is stored in the coke hopper 1d and the anthracite hopper 1e. On the other hand, iron ore powder conveyed from a betting yard (not shown) by a belt conveyor CV2 is stored in a plurality of iron ore powder hoppers 1f as a mixing tank, and lime and quick lime are similarly conveyed from the betting yard by a belt conveyor CV2. Is stored in the lime hopper 1g and the quick lime hopper 1h as the mixing tank, and further, for example, sintered ore having a size of less than 5 mm, which is sieved by the granulating unit 17 described later, is stored in the return hopper 1i as the mixing tank as a return ore. The

The hoppers 1d to 1i are quantitatively cut out and blended in a preset cut amount, mixed and granulated by the drum mixers 2a and 2b on the belt conveyor CV3, and adjusted to pseudo particles. The sintered raw material adjusted to the pseudo-particle shape and the sintered ore of 8 mm to 15 mm, for example, sieved by the granulating unit 17 described later, are sent to the sintering unit 3 as a bedstone.
In this sintering part 3, while storing the sintering raw material produced | generated by the sintering raw material production | generation part 1 in the surge hopper 4, the sinter of 8 mm-15 mm screened by the sizing part 17 mentioned later is bedded, for example. Stored in the floor hopper 5 as bedding.

The surge hopper 4 and the floor hopper 5 are arranged above the endless moving sinter pallet 6 so that the floor hopper 5 is located upstream of the surge hopper 4.
Then, a flooring layer cut out from the flooring hopper 5 is formed on the grate of the sintering machine pallet 6 and a flooring layer is formed on the flooring layer, and the sintering raw material is quantitatively cut out from the surge hopper 4 by the drum feeder 7. As shown in FIG. 2, a charging layer 8 having a thickness (height) of about 400 to 800 mm, which is also called a sintering bed, is formed. Here, the surge hopper 4, the floor hopper 5, and the drum feeder 7 constitute a raw material supply device.

  Then, the formed charging layer 8 is ignited on the carbon material in the surface layer portion in the ignition furnace 10, and the combustion / melting zone is lowered downward along with the conveyance of the sintering machine pallet 6, and is burned on the combustion / melting zone. A cake is formed. A heat-retaining furnace 11 and a plurality of, for example, three gas fuel supply devices 12a to 12c are disposed on the downstream side of the ignition furnace 10, and the combustion / melting zone is widened by the gas fuel supply devices 12a to 12c. The zone holding time is lengthened, and good sintered ore can be fired. Here, the heat retention furnace 11 is provided to preheat the charging layer 8 that is injected with the high-temperature exhaust gas from the sinter cooler and ignited in the ignition furnace 10. It also has the function as

The sintered cake fired in the sintering unit 3 is discharged from the sintering machine pallet 6, cooled by the cooler 16, and delivered to the sizing unit 17.
In the sizing unit 17, the cooled sintered cake is sieved with a sieve 18 having an opening of about 50 mm, and the sintered ore on the sieve is crushed to, for example, 40 mm or less by a crusher 19, and the crushed sintered ore and The sinter of less than 50 mm under the sieve is sieved, for example, with a sieve 20 having an opening of 15 mm, and the sinter of 15 mm or more is supplied as a product sinter to a blast furnace (not shown). The sinter of less than 15 mm under the sieve is sieved with a sieve 21 having an opening of about 8 mm, and a part of the sintered ore of 8 mm or more is returned to the bedding hopper 5 as bedding ore.

Further, below the sintering machine pallet 6 on which the charging layer 8 is formed, a plurality of wind boxes (wind boxes) 25 are arranged along the conveying direction of the sintering machine pallet 6. Is connected to a dry-type electrostatic precipitator 27 via a main exhaust duct 26, and a main wind exhaust device 28 is connected to the outlet side of the electrostatic precipitator 27.
Exhaust gas discharged from the outlet side of the main exhaust device 28 includes heat exchangers 29 and 30, an absorption tower 31 that performs a desulfurization process for removing sulfur compounds including SOx, a wet dust collector 32, boosters 33 and 34, heating An exhaust gas treatment unit 37 having a furnace 35, a reactor 36, and the like is subjected to exhaust gas treatment and discharged to a chimney 38.

A coke oven gas called so-called C gas generated in a coke oven in an iron works is supplied to an ignition furnace 10 disposed on the upper portion of the charging layer 8 of the sintering machine pallet 6. By burning the gas, the carbonaceous material in the surface layer of the charging layer 8 is ignited.
Gaseous fuel is supplied from a gaseous fuel supply source 60 (described later) to the heat retaining furnace 11 and the gaseous fuel supply devices 12a to 12c disposed on the downstream side of the ignition furnace 10.

As shown in FIG. 2, each of the gaseous fuel supply devices 12 a to 12 c is located downstream of the ignition furnace 10 and at any position in the pallet traveling direction in the process in which the combustion / melting zone travels in the charging layer 8. One or more are provided, and the gaseous fuel is preferably supplied into the charging layer 8 at a position after ignition of the carbonaceous material in the charging layer 8.
The gaseous fuel supply devices 12a to 12c are arranged on the downstream side of the ignition furnace 10 at one or a plurality of arbitrary positions after the combustion front advances below the surface layer. From the viewpoint of adjusting the cold strength and reducibility of the ore, the size, position, and number of arrangement are determined as described later.

  As shown in FIGS. 2 and 3, the gaseous fuel supply devices 12 a to 12 c are surrounded by a gas supply hood 41 that covers the upper portion of the sintering machine pallet 6 so that the gaseous fuel does not leak out of the gas supply hood 41. ing. The gas supply hood 41 is composed of front and rear walls 41a extending perpendicular to the conveying direction of the sintering machine pallet 6, and left and right walls 41b extending along the conveying direction of the sintering machine pallet 6, and an opening 41c is formed in the upper part. Has been.

  In the gas supply hood 41, as shown in FIG. 3, a baffle plate 42 having a cross-sectional shape extending in the conveying direction of the sintering machine pallet 6 between its front and rear walls 41 a and having a vertex upward is baked. A baffle plate array 43 having a configuration in which a predetermined number p is arranged in parallel with a predetermined pitch p in the width direction orthogonal to the transport direction of the machine pallet 6, and air that is sucked and passes through the baffle plate arrays 43; The gas fuel can be diluted by mixing with the gas fuel supplied from the gas fuel injection nozzle 46 described later. In this example, the baffle plate rows 43 are arranged in three rows in the vertical direction, and between the baffle plate rows 43 adjacent in the vertical direction, the baffle plates of the other baffle plate row 43 between the baffle plates 42 of the one baffle plate row 43. 42 is disposed.

Further, the baffle plate 42 below the lowermost baffle plate row 43 is extended between the baffle plates 42 in the conveying direction of the sintering machine pallet 6, maintains a predetermined interval in the width direction orthogonal to the conveying direction, and extends from the surface of the charging layer 8. For example, seven gaseous fuel supply pipes 45 are disposed at a height of 500 mm, for example.
The gaseous fuel supplied to the gaseous fuel supply pipe 45 includes propane gas, hydrogen gas, methane gas, carbon monoxide gas (CO), coke oven gas (C gas), liquefied natural gas, blast furnace gas (B gas), blast furnace Coke oven mixed gas (M gas), city gas, or any of these mixed gases can be applied.

Each of these gaseous fuels contains a combustion component. Any one of these gaseous fuels is discharged into the air at a high speed and mixed with air to dilute, and the diluted gas has a combustion lower limit concentration of about 75% or less. The fuel is supplied (introduced) into the charging layer 8 as fuel.
Here, the properties of propane gas, hydrogen gas, methane gas, carbon dioxide gas, coke oven gas, LNG, and blast furnace gas in the gaseous fuel are shown in Table 1 below.

In this embodiment, LNG is applied as the gaseous fuel.
Among the gaseous fuel supply pipes 45, the gaseous fuel injection nozzles 46 are arranged inwardly with respect to the gaseous fuel supply pipes 45 at both ends in the width direction, and the remaining gaseous fuel supply pipes 45 are adjacent to each other. A gas fuel injection nozzle 46 serving as an outlet for ejecting a predetermined number of gaseous fuel in the horizontal direction at a predetermined pitch in the conveying direction of the sintering machine pallet 6 is disposed at a symmetrical position opposite to the nozzle.

Here, between the adjacent gas fuel supply pipes 45, as shown in FIG. 4, the gas fuel injection nozzle 46 of one gas fuel supply pipe 45 is the center between the gas fuel injection nozzles 46 of the other gas fuel supply pipe 45. Gaseous fuel injection nozzles 46 are arranged in a staggered manner in the conveying direction of the sintering machine pallet 6 between adjacent gaseous fuel supply pipes 45 so as to be arranged at positions.
For this reason, the gaseous fuels injected in the horizontal direction in the adjacent gaseous fuel supply pipe 45 are uniformly dispersed and injected onto the charging layer 8 without interfering with each other, and mixed with the air to be diluted with the diluted gaseous fuel 47. Become.

This diluted gas fuel 47 uses the suction force of the wind box 25 under the sintering machine pallet 6 and passes through the sintered cake formed on the surface layer of the charging layer 8 to the deep part (lower layer) of the charging layer. be introduced.
In addition, each of the gaseous fuel supply devices 12a to 12c discharges the gaseous fuel at high speed into the atmosphere above the charging layer 8, thereby mixing with the surrounding air in a short time, It is necessary to dilute to a concentration below the lower combustion limit concentration and then introduce the diluted gaseous fuel into the charge bed.

  In the present invention, the gaseous fuel supply devices 12a to 12c allow the gaseous fuel to be discharged into the atmosphere at a high speed above the charging layer 8, thereby mixing with the surrounding air in a short time, and the gas. The reason why it is necessary to dilute the fuel to a concentration below the lower combustion limit concentration and then introduce the diluted gaseous fuel 47 into the charging 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. 2 and Table 3. 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.

  In addition, it is preferable to perform discharge of gaseous fuel in the said gaseous fuel supply apparatus 12a-12c at the height of 300 mm or more above the charging layer surface. Fig. 6 shows the expansion of methane gas when methane gas (concentration: 100%) is discharged from two types of nozzles with a nozzle diameter of 2 mmφ and 1 mmφ in a flow rate range of 20 to 300 m / s and discharged vertically downward. This shows the spread at positions 0.2 m, 0.4 m, 0.6 m and 0.8 m from the nozzle tip. From these figures, the smaller the nozzle diameter and the higher the speed of the gaseous fuel to be discharged, the easier the mixing with the surrounding air occurs, and the dilution is promoted. It can be seen that the distance from the nozzle tip increases at 0.4 m. Therefore, the present invention considers this result and the rebound of the discharged gaseous fuel on the charged layer surface, and the gaseous fuel is supplied to the atmosphere at a height of 300 mm or more above the charged layer surface. To do.

  Next, in this invention, the discharge speed of the gaseous fuel from the gaseous fuel injection nozzle 46 provided in the gaseous fuel supply piping 45 of the gaseous fuel supply apparatus 12a-12c is discharged at high speed from a viewpoint of preventing backfire. Specifically, it is desirable to discharge at a rate that is at least twice the burning rate of the gaseous fuel, more preferably at a rate that is at least twice the turbulent burning rate of the gaseous fuel. That is, in the sintering operation of the present invention, there is a sintered layer that forms or is forming a combustion / melting zone in the sintering machine pallet, and there is always a fire type. Thus, the discharge operation of the gaseous fuel is performed. The gaseous fuel is diluted by the stage of being sucked / introduced into the surface layer of the charging layer to be below the lower combustion limit concentration in the atmosphere, but the possibility of flashback always follows. Therefore, in order to prevent backfire even when the gas fuel is ignited, the discharge speed of the gas fuel is at least twice the combustion speed of the gas fuel, more preferably twice the turbulent combustion speed. It is desirable to discharge at the above speed.

In order to obtain the discharge speed of the gaseous fuel, the discharge pressure of the gaseous fuel from the gaseous fuel injection nozzle 46 is preferably set to 300 mmAq or more and less than 40000 mmAq with respect to the atmospheric pressure.
In addition, when the piping for discharging the gaseous fuel and the opening have the same shape, generally, the closer the fuel is to the supply source header, the easier the fuel comes out, and the farther the fuel becomes, the more difficult it is to go 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.

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 41 that covers the upper portion of the sintering machine pallet 6 is provided. The hood 41 suppresses the influence of the crosswind on the concentration distribution of the diluted gas fuel. That is, as a result of various studies, the present inventors have found that the installation of the hood 41 is more effective than a screen as a measure against cross wind. However, as described above, the hood 41 has an opening 41c above or has an appropriate transmittance (void ratio), and needs to have a structure capable of taking in air from this portion.

Thereby, the coke oven gas injected from the gaseous fuel injection nozzle 46 and the atmosphere are mixed inside the hood 41.
Further, as shown in FIG. 3, a cross wind attenuating fence 41e made of punch metal having a transmittance of about 30% is provided at the upper ends of the left and right sidewalls 17b along the conveying direction of the sintering machine pallet 6 of the hood 41. It is preferable.

  In addition, a gap is inevitably generated between the lower side of the hood 41 and the surface of the sintered bed (the surface of the charging layer). 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 introduced into the hood 41 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 41.

  Therefore, between the lower ends of the left and right walls 41b along the conveying direction of the sintering machine pallet 6 of the hood 41 and the pallet sidewall 6a, as schematically shown in FIG. A wiper seal 48 with a seal sheet interposed between the extending wire brushes is installed, and a cover 49 is provided outside the wiper seal 48 to cover the wiper seal 48 from the outside. The seal material is not limited to the wiper seal 48, 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 8.

On the other hand, between the lower ends of the front and rear walls 41a and left and right walls 41b of the hood 41 and the surface of the charging layer 8 on the upstream side and the downstream side in the conveying direction of the sintering machine pallet 6, as shown in FIG. It is preferable to form an air curtain 172 by disposing an air passage 171 along the front and rear walls 41a and ejecting air from below the air passage 171.
Moreover, the installation position, size, and number of arrangements of the gaseous fuel supply devices 12a to 12c are set as follows.

That is, after the carbon material in the charging layer 8 is ignited, the diluted gas fuel 47 is supplied (introduced) onto the charging layer 8. The reason for this is that even if the diluted gas fuel 47 is supplied at a position immediately after ignition, it only burns on the surface layer of the charging layer 8, and the diluted gas fuel 47 does not affect the combustion layer at all. is there. Therefore, it is necessary to supply the diluted gas fuel 47 to the charging layer 8 after the sintering raw material above the charging layer 8 is baked to form a sintered cake layer. The diluted gas fuel 47 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 8. The reasons other than the above for supplying the diluted gas fuel 47 after the sintered cake layer is formed are as follows.
(A) If the diluted gaseous fuel 47 is supplied in a state where no sintered cake (sintered layer) is formed on the top of the charge layer 8, there is a possibility that combustion will occur on the charge layer 8. .
(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 above the charging layer 8 of the diluted gas fuel 47, after the surface layer portion of the charging layer 8 is ignited by the ignition furnace 10, after ignition and a sintered cake is generated on the surface, The surface layer portion of the charging layer 8 has no fire type and the probability of backfire (ignition) is low. As shown in FIG. 15A, the sintered cake has a thickness that increases as the sintering machine pallet 6 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 12a is provided. In the case where a plurality of gaseous fuel supply devices 12a to 12c are provided, since there is no fire on the surface of the charging layer 8 at the downstream side of the first gaseous fuel supply device 12a, the gaseous fuel is at an arbitrary position. Supply devices 12 b and 12 c can be provided, and in this embodiment, three gaseous fuel supply devices 12 a to 12 c are arranged in series along the conveying direction of the sintering machine pallet 6.

  Further, in order to adjust either or both of the maximum cylinder temperature and the high temperature region holding time of the charging layer 8, 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 state, the diluted gas fuel 47 is preferably supplied. When the thickness of the combustion / melting zone is less than 15 mm, the cooling effect of the air sucked through the sintered cake (sintered layer) and the diluted gas fuel 47 causes the effect to be insufficient even if the diluted gas fuel 47 is burned, This is because the thickness of the combustion / melting zone cannot be increased.

On the other hand, when the diluted gas fuel 47 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 increased, and the high temperature region holding time is increased. Thus, a sintered ore with high cold strength can be obtained.
The introduction of the diluted gas fuel 47 into the charging layer 8 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 8. -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 47 is supplied in the vicinity of the sidewalls of the pallet width direction both coal portions where the yield reduction is large.

The gaseous fuel supply device 12a 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 present invention, the introduction of the diluted gas fuel 47 into the charging layer also means that the reheating of the produced sintered cake is promoted. That is, this diluted gaseous fuel is originally supplied with a highly reactive gaseous fuel compared to the solid fuel to the portion where the cold strength of the sintered ore 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.

  In the present invention, the diluted gas fuel 47 is supplied from the upper part of the charged layer after ignition so that at least a part of the introduced diluted gas fuel 47 in the charged layer remains unburned in the combustion / melting zone. It is preferable that combustion is performed at a target position where it is desired to compensate for combustion heat. 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 47 is performed in the upper layer part of the charging layer that is likely to be insufficient in heat (insufficient holding time in the high temperature region), sufficient combustion heat is provided, and this part is sintered. The quality of the cake can be improved, and further, if the supply operation of the diluted gas fuel 47 extends to the zone below the middle layer, the recycle by the diluted gas fuel 47 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 8 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 47 into the charging layer 8, 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 charge layer 8 after ignition, the combustion (flame) front gradually expands downward and forward (downstream) as the sintering machine pallet 6 moves, so that the position of the combustion / melting zone Changes as shown in FIG. And as shown in FIG.15 (b), the heat 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 according to position in the pallet 6 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 diluted gas fuel 47 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 47, the shape of the combustion / melting zone, that is, the thickness in the height direction of the combustion / melting zone and / or the width in the pallet traveling direction 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 be said that the supply (introduction) of the diluted gas fuel 47 into the charging layer 8 is for controlling the cold strength of the entire product sintered ore. In other words, the original purpose of supplying the diluted gas fuel 47 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 47 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 the present invention in consideration of the concentration of the diluted gas fuel 47, 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 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 present invention, the introduction position of the diluted gas fuel 47 into the charging layer 8 in the pallet traveling direction is a sintered ore in an arbitrary zone between the sintered cake formed in the charging layer 8 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), 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 8 is controlled.

Table 4 below shows the lower limit concentration of combustion of various gaseous fuels and the upper limit concentration of injecting the gaseous fuel (75%, 60%, 25% of the lower limit concentration of combustion).
For example, since propane gas has a lower combustion limit concentration of 2.2 vol%, the gas concentration upper limit diluted to 75% is 1.7 vol%, and the gas concentration upper limit diluted to 60% is 1.3 vol%, diluted to 25%. The gas concentration used is 0.6 vol%. Accordingly, the preferred range is as follows. Note that the lower limit of the diluted gas concentration, that is, the lower limit concentration at which the effect of supplying gaseous fuel is manifested is 0.05 vol% in the case of propane gas.
Preferred range (1): 2.2 vol% to 0.05 vol%
Preferred range (2): 1.7 vol% to 0.05 vol%
Preferred range (3): 1.3 vol% to 0.05 vol%
Preferred range (4): 0.6 vol% to 0.05 vol%

In addition, since the lower limit concentration of combustion for C gas is 5.0 vol%, 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%, diluted to 25%. The gas concentration used is 1.3 vol%. 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%

LNG gas has a combustion lower limit concentration of 4.8 vol%, so the upper limit of gas concentration diluted to 75% is 3.6 vol%, and the upper limit of gas concentration diluted to 60% is 2.9 vol%, diluted to 25%. The gas concentration is 1.2 vol%. Accordingly, the preferred range is as follows. The lower limit concentration at which the effect of supplying the gaseous fuel of LNG gas is 0.1 vol%.
Preferred range (1): 4.8 vol% to 0.1 vol%
Preferred range (2): 3.6 vol% to 0.1 vol%
Preferred range (3): 2.9 vol% to 0.1 vol%
Preferred range (4): 1.2 vol% to 0.1 vol%

In addition, since the lower limit concentration of blast furnace gas is 40.0 vol%, the upper limit of gas concentration diluted to 75% is 30.0 vol%, and the upper limit of gas concentration diluted to 60% is 24.0 vol%, diluted to 25%. The gas concentration used is 10.0 vol%. Accordingly, the preferred range is as follows. Note that the lower limit concentration at which the effect of supplying the gaseous fuel of the blast furnace gas is 0.24 vol%.
Preferred range (1): 40.0 vol% to 1.25 vol%
Preferred range (2): 30.0 vol% to 1.25 vol%
Preferred range (3): 24.0 vol% to 1.25 vol%
Preferred range (4): 10.0 vol% to 1.25 vol%

About the heat insulation furnace 11, as shown in FIG. 8, it is the same as that of gaseous fuel supply apparatus 12a-12c except that the gaseous fuel supply piping 11b arrange | positioned in the gas supply hood 11a is set to four. It has the composition of.
Then, the four corners of the heat insulating furnace 11 and the gas supply hood 11a and 41 of the gas fuel supply apparatus 12a~12c, as shown in FIG. 8, for example a gas analyzer 51 for detecting methane CH ₄ concentration gas fuel supply The ignition detector 52 is disposed below the gas analyzer 51, and the gas supply hood 11a is disposed at an intermediate position between the gas analyzer 51 and the ignition detector 52. And a pressure transmitter 53 for detecting the pressure in 41 is provided via a manual valve 54. The gas analyzer 51, the ignition detector 52, and the pressure transmitter 53 constitute an abnormality detection unit. And the gaseous fuel supply system | strain to the heat retention furnace 11 and the gaseous fuel supply apparatuses 12a-12c is comprised as shown in FIG. 8 and FIG.

That is, the gaseous fuel supply system includes a thermal fuel supply source 60 that supplies gaseous fuel to the thermal insulation furnace 11 and the gaseous fuel supply devices 12a to 12c, and the thermal insulation furnace 11 that is supplied with the gaseous fuel from the gaseous fuel supply source 60 and the respective components. It is comprised with the separate gaseous fuel supply control part 61 and 62a-62c provided in the vicinity of the gaseous fuel supply apparatus 12a-12c.
As shown in FIGS. 8 and 9, the gaseous fuel supply source 60 includes a gaseous fuel input unit 71 to which LNG or city gas is supplied, and a nitrogen gas input unit 72 to which nitrogen gas for purging the inside of the pipe is supplied. A miscellaneous air input unit 73 is provided for supplying miscellaneous air to be used as an automatic valve to be described later and purge air for each nozzle.

  As shown in FIG. 9, a gaseous fuel supply main pipe 74 is connected to the gaseous fuel input portion 71. The gas fuel supply main pipe 74 is provided with a pressure release portion 76 including three manual valves 75 in the vicinity of the gas fuel input portion 71. Further, a pressure transmitter 77, a thermometer 78, and an electromagnetic flow meter 79 are provided on the downstream side of the depressurization portion 76 of the gaseous fuel supply main pipe 74, and thereby the pressure, temperature and flow rate of the gaseous fuel supply main pipe 74 are provided. Measure.

  In addition, the gaseous fuel supply main pipe 74 includes a flow rate adjustment valve 82 in which manual valves 80 and 81 are provided on the downstream side of the electromagnetic flow meter 79, and a shutoff valve 83, a check valve 84, a shutoff valve 85, and A flame arrester 86 that prevents the flame from entering the gaseous fuel supply source is arranged in that order, and the flow regulating valve 82 is used to keep the thermal insulation furnace 11 and the individual gaseous fuel supply control units 61 of the gaseous fuel supply devices 12a to 12c and The gaseous fuel flow rate of the entire gaseous fuel supply system is controlled based on the integrated value of the gaseous fuel supply amount detected by 62a to 62c. A nitrogen purge line 98 is connected between the check valve 85 and the frame arrester 86.

  Further, a nitrogen gas pipe 90 is connected to the nitrogen gas input section 72 as shown in FIG. The nitrogen gas pipe 89 is provided with a pressure relief portion 92 including three manual valves 91 in the vicinity of the nitrogen gas input portion 72. A nitrogen purge line 98 is connected to the nitrogen gas pipe 90 via a pressure gauge 93, a shutoff valve 94, a manual valve 95, a check valve 96 and a shutoff valve 97. The nitrogen purge line 98 is connected to the manual valve 99. To the gaseous fuel supply main pipe 74. Further, two nitrogen purge lines 101 and 102 are connected between the gas vent 92 and the pressure gauge 93 via manual valves 99 and 100.

  The air pipe 110 is connected to the air input section 63 for chores, and the air pipe 110 is purged by the gas fuel injection nozzles 46 of the heat insulating furnace 11 and the gas fuel supply devices 12a to 12c (not shown) via the manual valve 111. In addition to being supplied as air, the air is supplied to the gas analyzer 51 disposed in the heat retaining furnace 11 and the gaseous fuel supply devices 12a to 12c via the filter 112 and the manual valve 113, and further to each air drive valve for driving the valve. Supplied as

And the gaseous fuel supply main piping 74 is extended to the vicinity of the thermal insulation furnace 11 and each gaseous fuel supply apparatus 12a-12c, and is formed in this thermal fuel supply main piping 74 in the thermal insulation furnace 11 and each gaseous fuel supply apparatus 12a-12c. The individual gaseous fuel supply control units 61 and 62a to 62c are connected.
Since these individual gas fuel supply control units 61 and 62a to 62c have the same configuration, the individual gas fuel supply control unit 62c will be described with reference to FIG.

  The individual gaseous fuel supply control unit 62c has a gaseous fuel supply branch pipe 120 connected to the gaseous fuel supply main pipe 74 of the gaseous fuel supply source 60, and a manual valve 121 and an air-driven type are connected to the gaseous fuel supply branch pipe 120. Gas fuel shut-off valve 122, check valve 123, air-driven gas fuel shut-off valve 124, flame arrester 125, pressure transmitter 126, manual valve 127, flow meter 128, automatic control valve 129 and manual valve 130 It is inserted. The terminal end of the gaseous fuel supply branch pipe 120 is connected to the branch portion 131. A bypass pipe 132 is connected between the pressure transmitter 126 and the manual valve 127 and between the upstream side of the branch portion 131, and a manual valve 133 is inserted in the bypass pipe 132. Here, the flow rate of the gaseous fuel supplied to the gaseous fuel supply device 12c is adjusted to a predetermined value by the flow meter 68 and the automatic adjustment valve 69.

  In the branch portion 131, the gaseous fuel input from the gaseous fuel supply branch pipe 120 is equally divided into a plurality of, for example, seven gaseous fuel supply pipes 45 disposed in the gas supply hood 41 of the gaseous fuel supply apparatus 12c. To distribute. A manual valve 134, a flow meter 135, a check valve 136, a manual adjustment valve 137, a pressure gauge 138 and a pressure transmitter 139 are inserted in each gaseous fuel supply pipe 45, and the flow rate measured by the flow meter 135 is measured. The manual adjustment valve 137 is adjusted so that the set flow rate is obtained. Note that the branching section 131 is connected to a diffusion pipe 141 through which a manual valve 140 is inserted and a sampling pipe 143 through which a manual valve 142 is inserted.

  Further, in the individual gaseous fuel supply control unit 62c, the nitrogen purge line 102 of the gaseous fuel supply source 60 includes a pressure gauge 145, an air driven nitrogen gas shut-off valve 146, a manual valve 147, a check valve 148, an air driven type. Is connected between the flame arrester 125 and the pressure transmitter 126 of the gaseous fuel supply branch pipe 120 through a nitrogen gas shut-off valve 149. Further, the nitrogen purge line 101 of the gaseous fuel supply source 60 is connected to the downstream side of the manual valve 133 in the bypass pipe 132 via the manual valve 151, a coupling 152 connectable at the time of abnormality, and the manual valve 153.

  The other gaseous fuel supply devices 12a and 12b have the same gaseous fuel supply system as described above. As for the heat insulating furnace 11, four gaseous fuel supply pipes 11b are provided in the gaseous supply hood 11a as shown in FIG. Except for this, a gaseous fuel supply system similar to the gaseous fuel supply devices 12a to 12c is formed, and functions as a gaseous fuel supply device similar to the gaseous fuel supply devices 12a to 12c.

  And as shown in FIG. 10, the gas analyzer 51, the ignition detector 52, and pressure which are arrange | positioned in the gas supply hood 41 of the thermal insulation furnace 11 and each gaseous fuel supply apparatus 12a-12c which comprise an abnormality detection part. The detected values of the transmitter 53, the detected values of the pressure transmitter 77, the thermometer 78 and the flow meter 79 of the gaseous fuel supply main pipe 74 of the gaseous fuel supply source 60, the individual gaseous fuel supply control units 61 and 62a to The pressure transmitter 126 of the gas fuel supply branch pipe 120 of 62c, the pressure detection value of the pressure transmitter 139 inserted in each gas fuel supply pipe 45, and the rotation state of the main exhaust device 28 and the boost boosters 33 and 34 are detected. The rotation detection signals of the rotation sensors 160a to 160c are supplied to a control device 161 as a gaseous fuel cutoff control unit constituted by, for example, a microcomputer. On the output side of the control device 161, shut-off valves 83 and 85 inserted in the gaseous fuel supply main pipe 74 and shut-off valves for driving and controlling the shut-off valves 122 and 124 inserted in the respective gaseous fuel supply branch pipes 120 are provided. A drive circuit 162 is connected.

And the control apparatus 161 performs the abnormality control process shown in FIG.
As shown in FIG. 11, the abnormality control process is performed first in step S <b> 1 with the gas concentration and ignition detector 52 detected by the gas analyzer 51 disposed in the heat retaining furnace 11 and the gaseous fuel supply devices 12 a to 12 c. Then, various detection signals of various pressure transmitters, detection values of rotation sensors 160a to 160c of the main exhaust device 28 and boost boosters 33 and 34 are read.

  Next, the process proceeds to step S2, and it is determined whether or not there is a pressure detection value exceeding the individually set pressure upper limit values P1max to Pnmax among the pressure detection values P1 to Pn of the read pressure transmitter. To do. When the determination result indicates that the pressure detection value Pi (i = 1 to n) exceeds the pressure upper limit value Pimax, the process proceeds to step S3, where the pressure transmitter where Pi> Pimax is, It is determined which of the gaseous fuel supply source 60 and the individual gaseous fuel supply control units 61 and 62a to 62c is present, and a shut-off signal for shutting off the shut-off valve 83, 85 or 122, 124 for the gas fuel existing in the corresponding region is generated. Output to the corresponding shut-off valve drive circuit 162. Next, the process proceeds to step S4, and an opening operation signal for opening the nitrogen gas shut-off valves 94, 97 or 146, 149 in the moving region for a predetermined time is output to the corresponding shut-off valve drive circuit 162. Next, the process proceeds to step S5, the abnormality alarm signal is output to the alarm device 163, and then the process returns to step S1.

  On the other hand, when the determination result of step S2 is that there is no pressure transmitter whose pressure detection value Pi exceeds the pressure upper limit value Pimax, the process proceeds to step S6. In this step S6, it is determined whether or not there is a gas analyzer 51 that detects a diluted gas fuel concentration exceeding a preset diluted gas fuel concentration threshold. If this determination result is that there is a gas analyzer 51 that has detected a diluted gas fuel concentration that exceeds the diluted gas fuel concentration threshold, the process proceeds to step S7 and the relevant warming furnace 11 or gaseous fuel supply devices 12a to 12c. A cutoff signal for controlling the gaseous fuel cutoff valves 122 and 124 of any of the individual gaseous fuel supply control units 61 and 62a to 62c to the cutoff state is output to the corresponding cutoff valve drive circuit 162. Next, the process proceeds to step S8, an opening operation signal for opening the nitrogen gas shut-off valves 146 and 149 for a predetermined time is output to the corresponding shut-off valve drive circuit 162, and then the process proceeds to step S5.

  Furthermore, if the gas analyzer 51 that has detected the diluted gas fuel concentration exceeding the diluted gas fuel concentration threshold value does not exist in the determination result of step S6, the process moves to step S9, and the ignition detection that detects the ignition. If there is an ignition detector 52 that determines whether or not the detector 52 exists and detects the ignition, the process proceeds to step S10, and the relevant warming furnace 11 or the gaseous fuel supply devices 12a to 12c. A cutoff signal for controlling the gaseous fuel cutoff valves 122 and 124 of any of the individual gaseous fuel supply control units 61 and 62a to 62c to the cutoff state is output to the corresponding cutoff valve drive circuit 162. Next, the process proceeds to step S11, and an open operation signal for opening the nitrogen gas shutoff valves 146 and 149 of the corresponding individual gas fuel supply control units 61 and 62a to 62c for a predetermined time is output to the shutoff valve drive circuit 162. Then, the process proceeds to step S5.

  Furthermore, when the determination result of step S9 indicates that there is no ignition detector 52 that detects ignition, the process proceeds to step S12, and the detected pressure value exceeding the preset internal pressure set value is detected. It is determined whether or not the pressure transmitter 53 exists. If there is a pressure transmitter 53 that has detected a pressure detection value that has exceeded the internal pressure set value as a result of this determination, the process proceeds to step S13 and the corresponding heat retaining furnace 11 or gaseous fuel supply devices 12a to 12c. After the shut-off signal for controlling the shut-off state for the gas fuel shut-off valves 122 and 124 of any one of the individual gaseous fuel supply controllers 61 and 62a to 62c is output to the corresponding shut-off valve drive circuit 162, the process proceeds to step S5. To do. Next, the process proceeds to step S14, and an opening operation signal for opening the nitrogen gas cutoff valves 146 and 149 of the corresponding individual gaseous fuel supply control units 61 and 62a to 62c for a predetermined time is output to the cutoff valve drive circuit 162. Then, the process proceeds to step S5.

  Furthermore, if the pressure transmitter 53 having a detected pressure value that exceeds the internal pressure set value does not exist in the determination result in step S12, the process proceeds to step S15 and the rotation of the rotation sensor 160a of the main exhaust device 28 is performed. It is determined whether or not the detected speed value is less than a preset rotation speed threshold value. If the detected rotation speed value is less than the rotation speed threshold value, the process proceeds to step S16, and the gaseous fuel supply source 60 of the gaseous fuel supply source 60 A shut-off signal for shutting off the gas fuel shut-off valves 83 and 85 inserted in the pipe 74 is output to the corresponding shut-off valve drive circuit 162. Next, the process proceeds to step S17, and an opening operation signal for opening the nitrogen gas shut-off valves 94 and 97 of the gaseous fuel supply source 60 for a predetermined time is output to the corresponding shut-off valve drive circuit 162, and then the process proceeds to step S5. To do.

Furthermore, when the determination result in step S15 is that the rotation speed detection value of the main air exhaust device 28 is equal to or greater than the rotation speed threshold value, the process proceeds to step S18 and rotation speed detection of the rotation sensors 160b and 160c of the boost boosters 33 and 34 is detected. It is determined whether or not the value is less than the rotation speed threshold value. If the rotation detection value is less than the rotation speed threshold value, the process proceeds to step S16.
When the determination result in step S18 indicates that the rotation speeds of the rotation sensors 160b and 160c of the boost boosters 33 and 34 are normal, the process returns to step S1.

Next, the operation of the above embodiment will be described.
First, as shown in FIG. 1, the sized sintered ore is cut out from the floor hopper 5 to form a floor layer on the grate of the sinter pallet 6, and the drum from the surge hopper 4 on the floor layer. The sintering raw material quantitatively cut out by the feeder 7 is charged to form a charging layer 8 of about 400 to 800 mm, which is also called a sintering bed.

Then, as the sintering machine pallet 6 is conveyed, the carbonaceous material in the surface layer of the charging layer 8 moved below the ignition furnace 10 is ignited.
In the charged layer 8 after ignition, the combustion (flame) front gradually expands downward and forward (downstream) with the movement of the sintering machine pallet 6 along with the heating in the heat-retaining furnace 11. Thus, the position of the combustion / melting zone 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 6 reaches the position of the first gaseous fuel supply device 12a.

In this gaseous fuel supply device 12a, LNG is injected in the horizontal direction by the gaseous fuel injection nozzle 46 in the hood 41 covering the upper side of the sintering machine pallet 6.
At this time, as shown in FIG. 4, the gaseous fuel injection nozzle 46 is halfway in the conveying direction of the sintering machine pallet 6 between adjacent groups so that the gaseous fuel injection nozzles of the adjacent gaseous fuel supply pipes 45 do not face each other. Since they are arranged with a pitch shift, a uniform injection region is formed in the conveying direction of the sintering machine pallet 6 without the LNG injected from the gaseous fuel injection nozzles 46 in the adjacent set interfering with each other.

The injected gaseous fuel is mixed with air turbulent by the baffle plate 42 and diluted below the lower combustion limit concentration at room temperature, and combustion above the charging layer 8 can be suppressed.
The diluted gaseous fuel 47 injected from the gaseous fuel injection nozzle 46 and diluted with air is moved downward through the wind box 25 by the main exhaust device 28 disposed on the lower side of the sintering machine pallet 6. The suction layer 8 is introduced into the charging layer 8 by suction.

  The diluted gas fuel 47 introduced into the charging layer 8 passes through the sintered cake produced 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. Therefore, it is possible to improve the yield of the upper and middle layer portions with a low yield shown in FIG. 15C when the diluted gas fuel 47 is not injected.

  As described above, when the supply operation of the diluted gas fuel 47 extends to the region below the middle layer, a recombustion / melting zone by the dilution gas fuel 47 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 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 6 is reduced. Sufficient sintering can be realized without this. As a result, the quality of the sintered cake of the charging layer 8 as a whole (improvement of cold strength) is brought about, leading to improvement of the quality of the ore (cold strength) and productivity.

At this time, in a normal sintering operation state, the gaseous fuel injected from the gaseous fuel injection nozzles 46 in the gas supply hoods 11a and 41 of the heat retaining furnace 11 and the gaseous fuel supply devices 12a to 12c is obstructive. Mixing with the air supplied through the baffle plates 42 of the plate row 43, the methane CH ₄ concentration is controlled to be 1/3 or less of the lower combustion limit concentration, and the generation of the high concentration portion due to the deviation of the methane CH ₄ concentration. In addition, there is no leakage or ignition of LNG to the outside.

For this reason, when the gaseous fuel supply control process of FIG. 11 is performed by the control device 161, the pressure detection value Pi detected by each pressure transmitter does not exceed the individually set pressure upper limit value Pimax. At the same time, the methane CH ₄ concentration detected by the gas analyzer 51 disposed in the heat retaining furnace 11 and each of the gaseous fuel supply devices 12a to 12c is also less than the set value, and the ignition state is not detected by the ignition detector 52. When the internal pressure detected by the transmitter 53 is within the set range, and the main exhaust device 28 and the boost boosters 33 and 34 are normal, the alarm device 163 does not issue an alarm, and each shut-off valve The open state is maintained.

  For this reason, in the individual gaseous fuel supply control units 61 and 62a to 62c, the flow rate adjustment valve 129 is controlled so that the gaseous fuel flow rate detected by the flow meter 128 is within a preset setting range. At the same time, the gaseous fuel flow rate of the gaseous fuel supply main pipe 74 is controlled by a value obtained by integrating the pressure detection values detected by the flow meters 128 of the individual gaseous fuel supply control units 61 and 62a to 62c.

  Moreover, in each individual gaseous fuel supply control part 61 and 62a-62c, the flow volume of the gaseous fuel branched by the branch part 131 is detected with the flowmeter 135, and it adjusts manually so that the flow volume of this flowmeter 135 may become a setting flow volume. By manually adjusting the valve 137, the amount of gas fuel discharged in the horizontal direction from the gas fuel injection nozzle 46 of each gas fuel supply pipe 45 is set individually, and the diluted gas fuel in the gas supply hoods 11a and 41 is set. The density of 47 can be made uniform without being biased.

  In this normal sintering operation state, all of the thermal insulation furnace 11 and each of the gas fuel supply devices 12a to 12c 122 and 124 and the shutoff valves 83 and 85 of the gas fuel supply main pipe 74 are controlled to be opened, and each gas fuel is supplied. LNG is injected from the gaseous fuel injection nozzles provided in the supply pipes 11 b and 46, and this is mixed with air to become the diluted gas fuel 47. The diluted gas fuel 47 is introduced into the charging layer 8 by suction from the wind box 25. It is possible to widen the sintering / combustion zone and extend the holding time of the high temperature region.

  However, normally, the diluted gas fuel 47 is formed in a state where a sintered cake is formed on the surface layer portion of the charging layer 8 and the sintering / combustion zone is 30 mm, preferably 50 mm below the surface of the charging layer 8. Since it is introduced into the charging layer 8, there is no fire on the upper surface of the charging layer 8, and the diluted gas fuel 47 does not burn, but for some reason the diluted gas fuel 47 is located above the charging layer 8. This is detected by the ignition detector 52.

  For this reason, in the abnormality control process of the control device 161, when the ignition detector 52 from which the ignition is detected is shifted to the step S10 from the step S9, for example, is the heat insulation furnace 11, the individual gaseous fuel of the heat insulation furnace 11 A shutoff signal for shutting off the gas fuel shutoff valves 122 and 124 of the supply control unit 61 is output to the shutoff valve drive circuit 162. For this reason, in this shutoff valve drive circuit 162, the valve drive air is supplied to the gas fuel shutoff valves 122 and 124 to shut off, and the supply of the gas fuel to the heat insulating furnace 11 is immediately stopped. For this reason, it is possible to reliably prevent the ignition in the heat insulation furnace 11 from spreading and to exert the explosion effect. Next, the process proceeds to step S11, and an opening operation signal for opening the nitrogen gas shutoff valves 146 and 149 of the individual gas fuel supply control unit 61 of the heat retaining furnace 11 for a predetermined time is output to the corresponding shutoff valve drive circuit 162. Then, nitrogen gas is supplied to the downstream side of the flame arrester 125 of the individual gaseous fuel supply control unit 61, and the gaseous fuel remaining in the gaseous fuel supply branch pipe 120, the branch part 131 and each gaseous fuel supply pipe 45 is discharged. To do.

  Similarly, even when ignition is detected by the ignition detector 52 disposed in any one of the gaseous fuel supply devices 12a to 12c, the individual gas of the corresponding gaseous fuel supply device 12j (j = a to c). The gas fuel shutoff valves 122 and 124 of the fuel supply controller 62j are shut off, and the supply of the gas fuel to the gas fuel supply device 12j is immediately stopped. Next, the nitrogen gas shut-off valves 146 and 149 are opened for a predetermined time, and the gaseous fuel remaining in the gaseous fuel supply branch pipe 120, the branch portion 131, and each gaseous fuel supply pipe 45 is discharged.

  As described above, when at least one of the gas fuel shutoff valves 122 and 124 of the individual gas fuel supply control units 61 and 62a to 62c of the heat retaining furnace 11 and the gas fuel supply devices 12a to 12c is shut off, the process proceeds to step S5. Then, since an alarm signal is output to the alarm device 163, an alarm is issued by the alarm device 163, and the operator can be notified that the supply of gaseous fuel has been stopped.

  In addition, the gas fuel supply pipe 45 disposed in at least one gas supply hood 11a or 41 of the heat retaining furnace 11 and the gas fuel supply devices 12a to 12c may have a broken hole, or an individual gas fuel supply control unit 61. Intake air due to a malfunction of the flow rate control unit 62a to 62c, or a drift of gaseous fuel due to blockage of some of the gaseous fuel supply pipes 45 in the gas supply hoods 11a and 41 and a decrease in the rotational speed of the main exhaust device 28 When the dilution gas concentration in the gas supply hood 11a or 41 increases due to a decrease in the amount and the gas concentration output from the gas analyzer 51 exceeds the dilution gas fuel concentration threshold, the abnormality control process in FIG. Then, the process proceeds from step S6 to step S7, and any one of the individual gas fuel supply control units 61 and 62a to 62c to which the corresponding gas analyzer 51 belongs is provided. The gaseous fuel shut-off valve 122 and 124 outputs to the blocking signal for the cut-off state to the cutoff valve driving circuit 162 to cut off the gas fuel cutoff valve 122 and 124 Te. Next, the process proceeds to step S8, and an opening operation signal for opening the nitrogen gas shutoff valves 146 and 149 of the corresponding individual gas fuel supply control unit 61 for a predetermined time is output to the corresponding shutoff valve drive circuit 162, By opening the nitrogen gas shut-off valves 146 and 149 for a predetermined time, the gaseous fuel remaining in the gaseous fuel supply branch pipe 120, the branch part 131 and the gaseous fuel supply pipe 45 is discharged. Even in this state, the process proceeds to step S5, where an alarm signal is output to the alarm device 163, and the alarm device 613 issues an alarm.

  Further, the pressure transmitters 139 and 126 disposed in the respective portions are formed by blocking the gas fuel supply pipes 11b and 45, the branch part 131, and the gas fuel supply branch pipe 120 of the heat retaining furnace 11 and the gas fuel supply devices 12a to 12c. When the detected pressure detection value Pi exceeds the pressure upper limit value Pimax, the process proceeds from step S2 to step S3 in the abnormality control process of FIG. 11 described above, and the corresponding pressure transmitters 139 and 126 are connected to the individual gaseous fuel supply control unit 61. And 62a to 62c, and outputs a shut-off signal for shutting off the shut-off valves 122 and 124 of the corresponding individual gaseous fuel supply control units 61 and 62a to 62c to the corresponding shut-off valve drive circuit 162. Then, the supply of the gaseous fuel in the corresponding individual gaseous fuel supply control unit is shut off. Thereafter, the process proceeds to step S4, where an opening operation signal for opening the nitrogen gas shut-off valves 146 and 149 of the corresponding individual gas fuel supply control unit for a predetermined time is output to the corresponding shut-off valve drive circuit 162, By opening the gas shutoff valves 146 and 149 for a predetermined time, nitrogen gas is supplied to the downstream side of the shutoff valve 124 of the gaseous fuel supply branch pipe 120 and the remaining gaseous fuel is discharged. Even in this state, the process proceeds to step S5, where an alarm signal is output to the alarm device 163, and the alarm device 613 issues an alarm.

  Furthermore, the above-mentioned figure also applies when the pressure of the gaseous fuel supply main pipe 74 of the gaseous fuel supply source 60 rises and the detected pressure value Pi detected by the pressure transmitter 77 exceeds the upper pressure limit Pimax for some reason. 11, the process proceeds from step S <b> 2 to step S <b> 3, and a shut-off signal for shutting off the shut-off valves 83 and 85 of the gaseous fuel supply source 60 is output to the corresponding shut-off valve drive circuit 162. The supply of gaseous fuel to each individual gaseous fuel supply control part 61 and 62a-62c is stopped by making the cutoff valve 83 and 84 into a cutoff state. Thereafter, an opening operation signal for opening the nitrogen gas shut-off valves 94 and 97 of the gaseous fuel supply source 60 for a predetermined time is output to the corresponding shut-off valve drive circuit 162, and the nitrogen gas shut-off valves 94 and 97 are output for a predetermined time. By setting the open state, nitrogen gas is supplied to the downstream side of the gas fuel shutoff valve 85 of the gas fuel supply main pipe 74, and all the gas fuel remaining in the individual gas fuel supply control units 61 and 62a to 62c is removed. Discharge. In this state, an alarm signal is supplied to the alarm device 163 to generate an alarm.

  Furthermore, when the rotation speed detected by the rotation sensor 160a of the main exhaust device 28 becomes equal to or lower than the rotation speed threshold, and the rotation speed detected by the rotation sensors 160b and 160c of the boost boosters 33 and 34 becomes lower than the rotation speed threshold. 11, in the abnormality control process of FIG. 11, the process proceeds from step S15 or step S18 to step S16, and a shutoff signal for shutting off the gas fuel shutoff valves 83 and 85 of the gas fuel supply source 60 is applied to the corresponding shutoff valve drive circuit. 162, the gas fuel shutoff valves 83 and 85 are shut off, and the supply of the gas fuel to the individual gas fuel supply control units 61 and 62a to 62c is stopped. Next, the process proceeds to step S17, and an opening operation signal for opening the nitrogen gas shutoff valves 94 and 97 of the gaseous fuel supply source 60 for a predetermined time is output to the corresponding shutoff valve drive circuit 162 to shut off the nitrogen gas. The valves 94 and 97 are kept open for a predetermined time, and nitrogen gas is supplied to the downstream side of the gas fuel shutoff valve 85 of the gas fuel supply main pipe 74 and remains in the individual gas fuel supply control units 61 and 62a to 62c. Discharge gaseous fuel. Next, the process proceeds to step S5, where an alarm signal is output to the alarm device 163, and an alarm is issued from the alarm device 163.

  Thus, according to the present invention, the gas supply is performed by increasing the pressure in the gas supply hoods 11a and 41 of the heat retaining furnace 11 and the gas fuel supply devices 12a to 12c or increasing the concentration of the diluted gas fuel. When the gas fuel is likely to leak from the hoods 11a and 41 to the outside, the gas fuel shutoff valves 122 and 124 of the corresponding individual gas fuel supply control units 61 and 62a to 62c are put into a shut-off state. Leakage of gaseous fuel from the supply hoods 11a and 41 can be reliably prevented.

  Similarly, when the ignition detector 52 detects the ignition of the gas fuel in the gas supply hoods 11a and 41 of the heat retaining furnace 11 and the gas fuel supply devices 12a to 12c, the corresponding individual gas fuel supply control units 61 and 62a to It is possible to reliably prevent the ignition state of the gaseous fuel from the gas supply hoods 11a and 41 from continuing by shutting off the gas fuel shutoff valves 122 and 124 of 62c.

  Further, the pressure transmitters 126 and 139 detect an increase in the pressure detection value Pi due to the pipe blockage in any of the gas fuel supply branch pipe 120 and the gas fuel supply pipe 45 in each individual gas fuel supply control unit 61 and 62a to 62c. When this exceeds the pressure upper limit value Pimax, the supply of the gaseous fuel to the corresponding individual gaseous fuel supply control units 61 and 62a to 62c is stopped, and the diluted gaseous fuel in the gas supply hoods 11a and 41 due to the blockage of the pipe Can be prevented in advance.

In addition, in the said embodiment, although the case where the heat retention furnace 11 was provided was demonstrated, it is not limited to this, The heat retention furnace 11 can be abbreviate | omitted. Further, the number of the gaseous fuel supply devices 12a to 12c is not limited to the above, and can be appropriately set according to the amount of gaseous fuel blown into the combustion / melting zone.
Moreover, in the said embodiment, although the case where the gaseous fuel supplied to the heat retention furnace 11 and gaseous fuel supply apparatus 12a-12c was made into the same fuel was demonstrated, it is not limited to this, The thermal insulation furnace 11 and gaseous fuel Different gaseous fuels may be supplied individually by the supply devices 12a to 12c.

  Moreover, in the said embodiment, although the case where LNG was applied as gaseous fuel was demonstrated, it is not limited to this, Other propane gas, hydrogen gas, methane gas, carbon monoxide gas (CO), coke oven Any of gas (C gas), blast furnace gas (B gas), blast furnace / coke oven mixed gas (M gas), city gas, or a mixed gas thereof can be applied. In this case, a densitometer corresponding to the gaseous fuel to be applied may be applied.

  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.

DESCRIPTION OF SYMBOLS 1 ... Firing raw material production | generation part 2a, 2b ... Drum mixer 3 ... Sintering part 4 ... Surge hopper 5 ... Bedding hopper 6 ... Sinter pallet 7 ... Drum feeder 8 ... Charge layer 10 ... Ignition furnace 11 ... Incubation furnace 11a ... Gas supply hood 11b ... Gas fuel supply pipes 12a to 12c ... Gas fuel supply device 16 ... Sinter cooler 17 ... Rectifier 25 ... Wind box 28 ... Main exhaust fan 33, 34 ... Booster booster 37 ... Exhaust gas treatment part 41 ... gas supply hood,
42 ... baffle plate 43 ... baffle plate row 45 ... gas fuel pipe 46 ... gas fuel injection nozzle 47 ... diluted gas fuel 51 ... gas analyzer 52 ... ignition detector 53 ... pressure transmitter 60 ... gas fuel supply sources 61, 62a- 62c ... Individual gas fuel supply control units 77, 126, 139 ... Pressure transmitters 83, 85, 122, 124 ... Gas fuel shutoff valves 160a to 160c ... Rotation sensor 161 ... Control device 162 ... Shutoff valve drive circuit 163 ... Alarm device

Claims (5)

A raw material supply device for charging a sintered raw material containing fine ore and carbonaceous material on a circulating pallet to form a charging layer;
An ignition furnace for igniting the charcoal of the charging layer;
A wind box disposed below the pallet;
A plurality of gaseous fuel supply devices disposed on the downstream side of the ignition furnace, wherein gaseous fuel is injected into the atmosphere above the charging layer and mixed with air to obtain a diluted gaseous fuel having a lower combustion limit concentration or less; With
Each gaseous fuel supply device includes a plurality of gaseous fuel supply pipes that supply the gaseous fuel disposed in a gaseous supply hood, and a shutoff valve that shuts off the supply of gaseous fuel to each gaseous fuel supply pipe, An abnormality detection unit that individually detects an abnormality in the plurality of gaseous fuel supply devices, and when the abnormality detection unit detects an abnormality in the gaseous fuel supply device, the shut-off valve of the corresponding gaseous fuel supply device is closed possess a gas fuel cutoff control unit that controls to,
The abnormality detection unit includes at least one of a concentration meter that measures at least a diluted gas fuel concentration in the gas supply hood and an exhaust system abnormality detector that detects an abnormality of the exhaust system connected to the wind box. A sintering machine that prevents at least one of leakage of the gaseous fuel to the outside and combustion above the charging layer due to an increase in the concentration of the gaseous fuel . The abnormality detecting unit, before Symbol flame detector for detecting a flame of the gas supply in the hood, the pressure detector for detecting the pressure of the gas supply hood, and the supply system of the gaseous fuel supplied to the gaseous fuel supply pipe The sintering machine according to claim 1, further comprising at least one of gaseous fuel supply abnormality detectors for detecting a pressure abnormality.   Each of the gaseous fuel supply devices includes a gaseous fuel supply branch pipe connected to a gaseous fuel supply main pipe of a gaseous fuel supply source, a gaseous fuel supply branch pipe connected to the gaseous fuel supply branch pipe, and the gaseous fuel supply pipes connected in parallel. The sintering machine according to claim 1, wherein the shutoff valve is inserted into the gaseous fuel supply branch pipe.   4. The sintering machine according to claim 1, wherein a flow meter and a flow control valve are individually inserted in each gaseous fuel supply pipe of each gaseous fuel supply device. 5.   4. The sintering machine according to claim 3, wherein each of the gaseous fuel supply devices has a flow meter and a flow control valve interposed in the gaseous fuel branch pipe.

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