JP2014084502A - Method for feeding gas fuel to sintering machine, and gas fuel feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for feeding gas fuel, in the case gas fuel is fed and a sintering operation is performed in a downward suction type sintering machine, capable of detecting the abnormal burning of the gas fuel at high precision, and a device therefor.SOLUTION: A sintering raw material charging layer comprising fine ore and a carbonaceous material is formed on a circularly moving pallet, the carbonaceous material in the surface of the charging layer is ignited, thereafter, air including gas fuel fed from plurally gas fuel feeders installed in the downstream of the ignition furnace in the machine length direction to the inside of the hoods thereof is sucked with a wind box disposed at the lower part of the pallet and is introduced into the charging layer, and the gas fuel and the carbonaceous material are burnt in the charging layer to produce sintered ore. At this time, a thermometer for measuring the surface temperature of the charging layer is disposed in the inside of the hood of each gas fuel feeder, it is decided that the abnormal burning of the gas fuel has been caused when the measured value of the thermometer reaches a prescribed threshold or higher, and the feed of the gas fuel to the gas fuel feeding piping is stopped.

Description

  The present invention is a downward suction type dwytroid sintering machine, which is a gas suitable for use in a sintering machine that supplies gaseous fuel as part of a heat source required for sintering and produces high-quality sintered ore. The present invention relates to a fuel supply method and a gaseous fuel supply apparatus.

  Sinter ore, which is the main raw material of the blast furnace ironmaking method, is generally manufactured through a process as shown in FIG. The raw materials for sintered ore are iron ore powder, sintered ore sieving powder, recovered powder generated in steelworks, CaO-containing auxiliary materials such as limestone and dolomite, granulation aids such as quick lime, coke powder and anthracite Yes, these raw materials are cut out from each of the hoppers 1. The cut out raw material is added with an appropriate amount of water by the drum mixers 2 and 3 and the like, mixed and granulated to obtain a sintered raw material which is pseudo particles having an average diameter of 3 to 6 mm. This sintered raw material is then transferred to 400 to 800 mm on an endless moving type sintering machine pallet 8 from the surge hoppers 4 and 5 arranged on the sintering machine through the drum feeder 6 and the cutting chute 7. The charge layer 9 is charged with a thickness and is also referred to as a sintered bed. Thereafter, the carbon material on the surface of the charging layer is ignited by an ignition furnace 10 installed above the charging layer 9, and the air above the charging layer is passed through a wind box 11 disposed immediately below the pallet 8. By sucking downward, the carbonaceous material in the charging layer is sequentially burned, and the sintered raw material is melted by the combustion heat generated at this time to obtain a sintered cake. The sintered cake obtained in this way is then crushed and sized, and agglomerates of 5 mm or more are supplied to the blast furnace as a product sintered ore, and those smaller than that are reused as sintered raw materials as return ore. Is done.

  In the above manufacturing process, the carbonaceous material in the charging layer ignited by the ignition furnace 10 is continuously burned by the air sucked from the upper layer toward the lower layer in the charging layer, and has a width in the thickness direction. A combustion / melting zone (hereinafter also simply referred to as “combustion zone”) is formed. This combustion zone gradually moves from the upper layer to the lower layer as the pallet 8 moves downstream, and after passing through the combustion zone, the sintered cake layer (sintered) in which the sintering reaction has been completed. Layer) is generated.

  FIG. 2 shows that the carbon material in the surface of the charging layer ignited in the ignition furnace is continuously burned by the sucked air to form a combustion zone, which sequentially moves from the upper layer to the lower layer of the charging layer. It is the figure which showed typically the process in which is formed. FIG. 3A shows the temperature distribution when the combustion zone is present in each of the upper layer portion, middle layer portion and lower layer portion of the charging layer shown in the thick frame shown in FIG. It is shown schematically. The strength of the sintered ore is influenced by the product of the temperature and time maintained at a temperature of 1200 ° C. or higher, and the greater the value, the higher the strength of the sintered ore. Therefore, the middle layer and lower layer in the charging layer are preheated by being transported by the air sucked by the combustion heat of the carbon material in the upper charging layer, so that it can be held at a high temperature for a long time. On the other hand, the upper portion of the charge layer is not preheated, and therefore the combustion heat is insufficient, and the combustion melting reaction (sintering reaction) necessary for sintering tends to be insufficient. As a result, the yield distribution of the sintered ore in the cross section in the width direction of the charging layer becomes lower in the upper layer portion of the charging layer as shown in FIG. Also, the pallet both width ends cannot secure sufficient holding time in the high temperature range necessary for sintering due to heat dissipation from the pallet side walls and excessive cooling due to the large amount of air passing through, and the yield is also high. Lower.

  In order to cope with these problems, conventionally, the amount of carbonaceous material (powder coke) added to the sintered raw material has been increased. However, by increasing the amount of coke added, as shown in FIG. 4, the temperature in the sintered layer can be increased and the time maintained at 1200 ° C. or higher can be extended. The highest temperature exceeds 1400 ° C. and deviates from the appropriate range, and on the contrary, the reducibility and cold strength of the sintered ore are reduced.

  In view of this, several techniques have been proposed for the purpose of maintaining the upper portion of the charging layer at a high temperature for a long time. For example, Patent Document 1 discloses a technique for injecting gaseous fuel onto a charging layer after the charging layer is ignited. Patent Document 2 discloses a technique in which air is sucked into the charging layer after the charging layer is ignited. In addition, in Patent Document 3, a hood is disposed on the charging layer so that the inside of the charging layer of the sintering raw material is heated, and air or coke is discharged from the hood. A technique for blowing a mixed gas with a furnace gas at a position immediately after the ignition furnace, and Patent Document 4 propose a technique for simultaneously blowing a low-melting-point solvent and a carbonaceous material or a combustible gas at a position immediately after the ignition furnace. .

  However, since these technologies use high-concentration gaseous fuel and do not reduce the amount of carbonaceous material when fuel gas is injected, the maximum temperature reached during sintering in the charged layer is the upper limit for operation management. When the temperature exceeds 1400 ° C, the calcium ferrite produced during the sintering process decomposes, producing a sintered ore with low reducibility and low cold strength, and the yield improvement effect cannot be obtained. Increased temperature and thermal expansion due to fuel combustion may deteriorate air permeability, reduce productivity, and use of gaseous fuel may cause a fire in the upper space of the sintering bed (charging layer). Therefore, none of them has been put into practical use.

  Thus, as a technique for solving the above problems, the present inventors have reduced the amount of carbonaceous material added in the sintering raw material, and lacked the amount of heat necessary for sintering downstream of the ignition furnace of the sintering machine. In the first half of the length of the sintering machine where the upper part of the charging layer causes a sintering reaction, various gaseous fuels diluted below the lower combustion limit concentration are introduced into the charging layer from above the pallet and burned in the charging layer. By doing so, Patent Literature 5 proposes a technique for controlling both the maximum attained temperature in the charging layer and the high temperature region holding time within an appropriate range.

  Apply technology such as Patent Document 5 above to the method of manufacturing sintered ore using a downward suction type sintering machine, reduce the amount of carbonaceous material added to the sintering raw material, and then dilute below the lower combustion limit concentration When the gaseous fuel is introduced into the charging layer and the gaseous fuel is burned in the charging layer, as shown in FIG. Because it burns in the inside (sintered layer), the width of the combustion / melting zone can be expanded in the thickness direction without exceeding the maximum temperature of the combustion / melting zone exceeding 1400 ° C. The area retention time can be extended.

  By the way, when performing a sintering operation by supplying gaseous fuel from a gaseous fuel supply device installed on the downstream side of the ignition furnace of the sintering machine, the gaseous fuel is safe because of its property to easily cause combustion and explosion. There is a top priority. In this regard, in the present invention, since the gaseous fuel is diluted and supplied to a concentration at which neither combustion nor explosion occurs at room temperature, there is no problem in safety under normal circumstances.

  However, in the case of a gaseous fuel supply method in which high-concentration gaseous fuel is jetted at high speed into the air in the gaseous fuel supply device (hood) and instantly diluted below the lower combustion limit concentration, for example, there is some abnormality in the gaseous fuel supply system If the gas fuel jet velocity decreases or the gas fuel leaks from a place other than the normal jet outlet, the supplied gas fuel is introduced into the raw material charging layer. Before combustion, it may be ignited by the type of fire in the sintered raw material charge layer ignited in the ignition furnace above the raw material charge layer, causing abnormal combustion or explosion, leading to a serious disaster There is. Therefore, when ignition of the gaseous fuel occurs, it is necessary to detect it early and stop the supply of the gaseous fuel. In view of this, the inventors have proposed technologies for detecting ignition by installing a flame detector (ignition detector) for detecting ultraviolet rays in the hood of the gaseous fuel supply apparatus.

Japanese Patent Laid-Open No. 48-018102 Japanese Examined Patent Publication No. 46-027126 Japanese Patent Application Laid-Open No. 55-018585 JP 05-311257 A WO2007 / 052776 JP 2010-132946 A JP 2010-156036 A JP 2011-052858 A

  However, although the safety of the sintering operation has been greatly improved by the installation of the above flame detector, sunlight, illumination light inside the building, construction work, etc., which enters from the gap under the hood of the gaseous fuel supply device Misdetection and malfunction of the flame detector frequently occur due to disturbance light such as arc generated during welding, which has caused a great hindrance in stably performing the sintering operation supplied with gaseous fuel.

  The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to prevent abnormal combustion of the gaseous fuel when performing the sintering operation by supplying the gaseous fuel in the lower suction type sintering machine. An object of the present invention is to propose a gaseous fuel supply method capable of detecting gaseous fuel accurately and stably and stably supplying gaseous fuel, and to provide a gaseous fuel supply apparatus therefor.

  The inventors have intensively studied to solve the above problems. As a result, in order to prevent erroneous detection and malfunction as described above and to accurately detect abnormal combustion of gaseous fuel, the upper surface of the raw material charging layer is replaced with a flame detector that detects light such as ultraviolet rays. The method of directly detecting the temperature was found to be the simplest and most effective, and the present invention was developed.

  That is, the present invention is to form a charging layer by charging a sintered raw material containing fine ore and carbonaceous material on a circulating pallet, after igniting the carbonaceous material on the charging layer surface in an ignition furnace, Air containing gaseous fuel supplied into the hood from a plurality of gaseous fuel supply devices installed in the machine length direction downstream of the ignition furnace is sucked with a wind box disposed below the pallet and introduced into the charging layer. A method for supplying gaseous fuel to a sintering machine for producing sintered ore by burning the gaseous fuel and carbonaceous material in a charging layer, wherein the surface temperature of the charging layer is in a hood of the gaseous fuel supply device When the measured value of the thermometer reaches a temperature equal to or higher than a predetermined threshold, it is determined that abnormal combustion of the gaseous fuel has occurred, and the gaseous fuel to the gaseous fuel supply pipe is The gaseous fuel supply method is characterized in that the supply of the gas is stopped.

  The gaseous fuel supply method of the present invention is characterized in that after the supply of the gaseous fuel is stopped, an inert gas is introduced into the gaseous fuel supply pipe.

  Moreover, the gaseous fuel supply method of this invention sets the said threshold value to the temperature of 50 degreeC or more, It is characterized by the above-mentioned.

  The present invention also includes a hood that is disposed above the pallet of the sintering machine and that is open at the top and bottom and that surrounds the four sides, a baffle plate that is disposed in the hood in the horizontal and vertical directions, and the baffle plate A plurality of gaseous fuel supply pipes arranged horizontally below, a thermometer for measuring the surface temperature of the raw material charging layer on the pallet, and a control device for controlling the supply of gaseous fuel to the gaseous fuel supply pipes A gas fuel supply device for a sintering machine, wherein the control device determines that abnormal combustion of the gas fuel has occurred when the measured value of the thermometer is equal to or higher than a predetermined threshold; A gaseous fuel supply apparatus having a function of stopping supply of gaseous fuel to a gaseous fuel supply pipe.

  The control device in the gaseous fuel supply apparatus of the present invention has a function of stopping the supply of the gaseous fuel and introducing an inert gas into the gaseous fuel supply pipe when it is determined that abnormal combustion of the gaseous fuel has occurred. It is characterized by.

  According to the present invention, it is possible to reliably detect abnormal combustion of gaseous fuel in the gaseous fuel supply apparatus, so that it is possible to safely and stably realize a sintering operation for supplying gaseous fuel, It becomes possible to produce a high-quality sintered ore that is strong and excellent in reducibility safely and stably.

It is a schematic diagram explaining a sintering process. It is a schematic diagram explaining the change in the charging layer accompanying progress of sintering. It is a figure explaining the temperature distribution when a combustion zone exists in each position of the upper layer part of the charging layer, the middle layer part, and the lower layer part, and the yield distribution of the sintered ore in the width direction cross section of the charging layer. . It is a figure explaining the temperature change in the charging layer by the change (increase) of the amount of carbon materials. It is a schematic diagram explaining the effect which gaseous fuel supply has on high temperature range holding time. It is a figure explaining the pallet, ignition furnace, and gaseous fuel supply apparatus in the sintering machine of this invention. It is sectional drawing of the pallet width direction of the gaseous fuel supply apparatus of this invention. It is a figure explaining the example of the gaseous fuel supply apparatus which installed the flame detector. It is a figure explaining the gaseous fuel supply apparatus of this invention which installed the thermometer. It is a figure explaining the gaseous fuel supply system of the gaseous fuel supply apparatus of this invention.

Embodiments of the present invention will be described below.
FIG. 6 is an example of a side view showing a pallet, an ignition furnace, and a gaseous fuel supply device of a sintering machine according to the present invention, and an endless moving type sintering machine pallet 8 includes a plurality of pallet trucks 13 connected in a row. Are configured to move on the rail 14. Further, as shown in FIG. 7, the pallet carriage 13 is composed of a grate 13a in which a sintering raw material is charged and deposited, and side walls 13b rising from both edges in the width direction of the grate 13a.
Further, reference numeral 15 in FIG. 6 denotes a raw material charging section comprising a floor mine hopper 4, a surge hopper 5, a drum feeder 6, and a cutting chute 7 (not shown) for charging the sintered raw material onto the sintering machine pallet 8. The bedding ore (returned ore) and the sintered raw material cut and charged through these materials form the charging layer 9 on the grate 13a of the sintering machine pallet 8.

  Further, an ignition furnace 10 is installed on the downstream side of the raw material charging section 15, and a plurality of gas fuel supply devices 16 (three in FIG. 6) are installed in series on the downstream side of the ignition furnace. . Here, the gaseous fuel supply device 16 introduces the gaseous fuel into the charging layer on the sintering machine pallet 8 ignited in the ignition furnace 10 and burns it, thereby forming a combustion / sintering zone of the charging layer. A hood 17 surrounding the four sides disposed above the sintering machine pallet 8 as shown in FIG. And a plurality of baffle plates 18 arranged in the hood 17 in the horizontal and vertical directions, and a plurality of gas fuel supply pipes 19 arranged in the horizontal direction below the baffle plates 18 in the hood 17.

  The upper portion and the lower portion of the hood 17 are open, and the baffle plate 18 in the hood 17 is a member having a U-shaped cross section with the apex upward, and extends along the conveying direction of the sintering machine pallet 8. In addition, a plurality of rows are arranged in a plurality of rows and in the vertical direction with a predetermined pitch in the width direction orthogonal to the conveying direction of the sintering machine pallet 8. A plurality of gaseous fuel supply pipes 19 extend in the conveying direction of the sintering machine pallet 8 and are arranged at a predetermined interval in the pallet width direction orthogonal to the conveying direction. Gaseous fuel is supplied from a gaseous fuel supply element tube which is desired to be performed. Each gaseous fuel supply pipe 19 is provided with a gaseous fuel ejection nozzle or an opening for ejecting gaseous fuel in the horizontal direction. As this gaseous fuel, combustible gas such as blast furnace gas (B gas), coke oven gas (C gas), blast furnace / coke oven mixed gas (M gas), LNG (natural gas), city gas, methane gas, ethane gas, propane gas, etc. Sexual gas or a mixed gas thereof can be used. Further, unconventional natural gas (shale gas) collected from a shale layer and different from conventional natural gas can be used in the same manner as LNG.

  Further, the gaseous fuel contained in the air introduced into the charging layer needs to be not more than the lower combustion limit concentration of the gaseous fuel. If the concentration of the diluted gas fuel is higher than the lower combustion limit concentration, combustion may occur above the charging layer, and the effect of supplying the gaseous fuel may be lost or an explosion may occur. In addition, if the diluted gas fuel has a high concentration, it is burned in a low temperature range, so that it may not be able to effectively contribute to the extension of the high temperature range holding time. Preferably, the concentration of the diluted gaseous fuel is 3/4 or less of the lower combustion limit concentration at normal temperature in the atmosphere, more preferably 1/5 or less of the lower combustion limit concentration, and further preferably 1/10 or less of the lower combustion limit concentration. . However, if the concentration of the diluted gas fuel is less than 1/100 of the lower combustion limit concentration, the calorific value due to combustion is insufficient and the effect of improving the strength and yield of the sintered ore cannot be obtained. 1/100. As for natural gas (LNG), the lower limit concentration of LNG at room temperature is 4.8 vol%, so the concentration of diluted gas fuel is preferably in the range of 0.05 to 3.6 vol%. The range of -1.0 vol% is more preferable, and the range of 0.05-0.5 vol% is even more preferable. In addition, the method of supplying diluted gaseous fuel is a method of supplying air in which gaseous fuel is previously diluted to a lower combustion limit concentration or less, and a high concentration gaseous fuel is jetted into the air at high speed to instantaneously lower the lower combustion combustion concentration. Any method of dilution may be used.

  By the way, in the case of the method in which high-concentration gaseous fuel is jetted into the air at a high speed as described above and instantly diluted below the lower combustion limit concentration, the gas fuel lowers the original pressure or the gas fuel outlet is clogged. When the velocity of the gaseous fuel ejected due to, for example, decreases, the gaseous fuel ejected from the gaseous fuel supply pipe is ignited by the type of fire in the charging layer ignited in the ignition furnace, and abnormal combustion occurs above the raw material charging layer. There is a risk of it happening.

  As a method for detecting such abnormal combustion, conventionally, for example, as shown in FIG. 8, flame detectors (ignition detectors) 21 having a viewing angle of 90 degrees or more are installed at four corners in the hood of the gaseous fuel supply device. The method is adopted. However, since this flame detector detects the ultraviolet rays emitted by the flame when the gaseous fuel burns and detects ignition, the gap between the lower hood of the gaseous fuel supply device and the upper surface of the raw material charging layer There is a problem that erroneous detection or malfunction is likely to occur due to ambient light such as sunlight incident on the building, illumination light in the building, or arc generated during welding during construction or the like.

  Therefore, the inventors examined a method that can replace the flame detection method for detecting ultraviolet rays or the like emitted by a flame. As a result, the upper surface of the raw material charging layer on the exit side of the ignition furnace is cooled by the air flow introduced into the charging layer even though it is immediately after being ignited in the ignition furnace, and within a few minutes after ignition. When the gas fuel is cooled to a temperature of 50 ° C. or lower and abnormal combustion such as ignition occurs in the gaseous fuel introduced into the raw material charge layer, the upper surface of the raw material charge layer is kept at a temperature of 50 ° C. or higher. It has been found that rising easily and therefore abnormal combustion of gaseous fuel can be detected with high accuracy by a simple method of measuring the upper surface temperature of the raw material charging layer.

Therefore, in the present invention, as shown in FIG. 9, a thermometer 22 for measuring the temperature of the upper surface of the charged raw material layer is installed in the hood of the gaseous fuel supply apparatus, and the measured temperature of the thermometer is a predetermined threshold value. When the temperature rises to the above, it is determined that abnormal combustion of the gaseous fuel has occurred.
Here, the temperature serving as the threshold is preferably set to a temperature of 50 ° C. or higher. However, if the threshold temperature is set too high, the accuracy of detecting abnormal combustion will decrease, or the detection of abnormal combustion will be delayed by the amount of time required to increase the upper surface temperature of the raw material charging layer. The temperature is preferably 80 ° C. or lower, more preferably 60 ° C. or lower.
In addition, if the time when the temperature is equal to or higher than the threshold for determining the occurrence of abnormal combustion is too short, there is a risk of false detection due to the temperature inside the local crack generated on the surface of the sintered cake. Since detection of combustion is delayed, it is preferable to set it in the range of 2 to 5 seconds.

  The thermometer for measuring the temperature of the raw material charge layer surface is not particularly limited as long as the time required for the measurement is short. For example, if it is a thermometer using a radiation thermometer or a thermocouple, thermography, etc. It can be used suitably. The number of thermometers installed may be one or more per gas fuel supply device, and there is no particular limitation, but it is preferable that the upper surface of the raw material charging layer in the hood can be measured over the entire surface. .

  In addition, as a countermeasure when it is determined that abnormal combustion of the gaseous fuel has occurred, the supply of gaseous fuel to the gaseous fuel supply device is stopped from the viewpoint of preventing a fire or explosion caused by the high concentration gaseous fuel. It is an indispensable matter. Further, from the viewpoint of improving safety, it is preferable to completely replace the gaseous fuel by introducing an inert gas into the gaseous fuel supply system that supplies the gaseous fuel to the gaseous fuel supply pipe.

In FIG. 10, the temperature of the upper surface of the raw material charging layer is measured by a thermometer 22 installed above the raw material charging layer, and it is determined by the control device 23 whether or not the measured value is below a predetermined threshold value. This shows an example of the gaseous fuel supply device of the present invention that controls the supply of gaseous fuel (LNG) and inert gas (N ₂ gas). Specifically, FIG. 10A shows a case where the measured value is determined to be equal to or less than a threshold value (normal). In this case, a shut-off valve provided in the gaseous fuel supply main pipe 24 is shown. 25 shows a state in which the gaseous fuel is supplied to the gaseous fuel supply device 16 with the opening 25 and the shutoff valve 27 provided in the inert gas supply pipe 26 closed.
FIG. 10B shows a case where the measured value is determined to exceed the threshold (abnormal). In this case, the shutoff valve 25 provided in the main pipe 24 of the gaseous fuel supply pipe. Is closed, the supply of gaseous fuel to the gaseous fuel supply device 16 is stopped, the shutoff valve 27 provided in the inert gas supply pipe 26 is opened, and the inert gas is introduced into the gaseous fuel supply pipe 19. The state which has excluded the gaseous fuel which remained in piping is shown. As the inert gas, Ar gas, CO ₂ gas, or the like can be used in addition to the N ₂ gas.
By doing in this way, even when abnormal combustion of gaseous fuel arises, it can prevent reliably reaching a big disaster.

  Pallet width is 5m, effective machine length (length from ignition furnace to waste mining section) is 82m, charging layer thickness is 700mm, gaseous fuel of 7.5m length after about 4m downstream of ignition furnace Three supply devices are arranged in series, and from the gaseous fuel supply device, the diluted gaseous fuel concentration is 0.4 vol% (in a sintered raw material charging layer containing 4.7 mass% carbonaceous material). As a comparative example, a flame detector for detecting ultraviolet rays as shown in FIG. 8 was installed in an actual sintering machine that performs sinter operation by supplying LNG to a carbon material equivalent to about 0.4 mass%). Compare the detection accuracy of abnormal combustion of gaseous fuel by applying the gaseous fuel supply device of the present invention having a thermometer (radiation thermometer) as shown in FIG. evaluated.

  As a result, abnormal combustion of the gaseous fuel could be detected without overlooking the apparatus of the invention example and the comparative example, but in the apparatus of the comparative example in which the flame detector was installed, the erroneous detection was once per month. On the other hand, in the apparatus of the present invention, false detection was 0 times / month. From the above results, it was confirmed that by applying the gaseous fuel supply device of the present invention, abnormal combustion of the gaseous fuel can be detected with high accuracy, and a high-quality sintered ore can be produced safely and stably.

  The gaseous fuel supply method of the present invention is not only useful as a method for producing sintered ore used as a raw material for iron making, particularly as a blast furnace, but can also be preferably applied to other ore agglomeration techniques.

  1: Raw material hopper, 2, 3: Drum mixer, 4: Bedlay hopper, 5: Surge hopper, 6: Drum feeder, 7: Cutting chute, 8: Pallet, 9: Charging layer, 10: Ignition furnace, 11 : Wind box (wind box), 12: Cut-off plate, 13: Pallet cart, 13a: Great, 13b: Side wall, 14: Rail, 15: Raw material charging unit, 16: Gas fuel supply device, 17: Hood, 18: baffle plate, 19: gaseous fuel supply pipe, 21: flame detector, 22: thermometer, 23: control device, 24: main pipe of gaseous fuel supply pipe, 25: gaseous fuel cutoff valve, 26: inert gas supply Piping, 27: Inert gas shutoff valve

Claims (5)

A sintering raw material containing fine ore and carbonaceous material is charged on a circulating pallet to form a charging layer, and the carbonaceous material on the charging layer surface is ignited in an ignition furnace, and then in the machine direction downstream of the ignition furnace The air containing the gaseous fuel supplied into the hood from a plurality of gaseous fuel supply devices installed in the hood is sucked with a wind box disposed below the pallet and introduced into the charging layer. A method for supplying gaseous fuel to a sintering machine for producing sintered ore by burning gaseous fuel and carbonaceous material,
A thermometer for measuring the surface temperature of the charging layer is disposed in the hood of the gaseous fuel supply device, and when the measured value of the thermometer reaches a temperature equal to or higher than a predetermined threshold, abnormal combustion of the gaseous fuel A gaseous fuel supply method characterized in that the fuel gas supply to the gaseous fuel supply pipe is stopped. 2. The gaseous fuel supply method according to claim 1, wherein after the supply of the gaseous fuel is stopped, an inert gas is introduced into the gaseous fuel supply pipe. The gaseous fuel supply method according to claim 1, wherein the threshold is set to a temperature of 50 ° C. or more. A hood that is located above the pallet of the sintering machine and that opens up and down and surrounds the four sides.
A plurality of baffle plates disposed horizontally and vertically in the hood;
A plurality of gaseous fuel supply pipes arranged horizontally below the baffle plate;
A thermometer for measuring the surface temperature of the raw material charging layer on the pallet;
A gas fuel supply device of a sintering machine having a control device for controlling the supply of gas fuel to the gas fuel supply pipe,
When the measured value of the thermometer reaches a temperature equal to or higher than a predetermined threshold, the control device determines that abnormal combustion of the gaseous fuel has occurred and stops the supply of the gaseous fuel to the gaseous fuel supply pipe. A gaseous fuel supply device having a function. 5. The control device according to claim 4, wherein the control device has a function of stopping the supply of the gaseous fuel and introducing an inert gas into the gaseous fuel supply pipe when it is determined that the abnormal combustion of the gaseous fuel has occurred. The gaseous fuel supply apparatus of description.

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