JP4728165B2 - Skirt seal structure in converter exhaust gas treatment equipment - Google Patents

Description

  The present invention is installed between the hood for exhaust gas recovery above the converter furnace port and the converter furnace port, and prevents the exhaust gas from flowing out into the atmosphere (air) and the entrainment of the atmosphere into the exhaust gas during refining. More particularly, the present invention relates to a seal structure for a skirt that is superior in durability and that can stably move up and down without being affected by dust, slag, metal, etc. Is.

  In hot metal decarburization refining (also referred to as “oxygen blowing”) in a converter where oxygen gas is blown into the hot metal or oxygen gas is blown into it, high temperature and high dust content mainly composed of carbon monoxide gas (CO gas) A large amount of exhaust gas is generated. This exhaust gas is recovered after cooling and dust removal and used as fuel, etc. In order to recover a higher concentration of carbon monoxide gas, there is no vertical contact between the converter furnace port and the hood of the converter exhaust gas treatment facility. A movable skirt is installed.

  The structure of this skirt is shown in FIG. The skirt 3 is installed between the furnace port 2 of the converter 1 and the hood 4. The skirt 3 is integrated with the skirt 3 in order to prevent air suction and exhaust gas emission between the skirt 3 and the hood 4. The partition tube 16 installed on the seal floor 5 integrally formed with the hood 4 is immersed in the seal water 18 stored in the seal jacket 17 configured as described above, and the gap between the skirt 3 and the hood 4 is sealed. It has a structure.

  In this case, the skirt 3 is provided with a driving device (not shown) such as an electric motor or a hydraulic cylinder so that the converter 1 can be tilted and the gap between the furnace port 2 and the hood 4 is minimized during oxygen blowing. 2), the hood 4 can be moved up and down along the outer periphery of the hood 4, and the water seal between the partition cylinder 16 and the sealing water 18 is maintained even when the skirt 3 moves up and down. . In FIG. 2, reference numeral 7 is a cooling water drain header for cooling the skirt 3, reference numeral 8 is a cooling water feed header for cooling the skirt 3, and reference numeral 13 is a cooling water feed header for cooling the hood 4. Reference numeral 14 is a cooling water supply pipe for cooling the skirt 3, reference numeral 14A is a cooling water drain pipe for cooling the skirt 3, reference numeral 15 is a cooling water supply pipe for cooling the skirt 3, and reference numeral 19 is This is a drainage groove for draining the seal water 18 overflowing from the seal jacket 17.

  However, in this seal structure, dust generated from the inside of the furnace during oxyblowing, scattered slag and metal can enter the seal jacket 17 and accumulate on the bottom thereof, and the skirt 3 can be raised to the upper limit position. The problem of becoming impossible occurs. In the worst case, there is a problem that the skirt 3 cannot be raised and the converter 1 containing molten steel cannot be tilted.

  Accordingly, various proposals have been made for the purpose of discharging and preventing solidification of dust, slag and metal that have entered the seal jacket 17. For example, Patent Document 1 proposes a method for preventing these accumulations by blowing gas into the seal water in the seal jacket and stirring, and washing away dust and slag. A method has been proposed in which a seal water jet nozzle is provided at the bottom of the seal jacket, and a swirl flow is formed in the seal water to promote dust discharge. However, neither of the methods disclosed in Patent Document 1 and Patent Document 2 is effective enough, and it is necessary to periodically stop the operation of the converter and clean the seal jacket, leading to a decrease in productivity. Yes.

Moreover, methods other than the seal by a water seal system are also proposed. Patent Document 3 proposes a method of connecting a skirt and a hood with a sealing cloth and sealing between the skirt and the hood with the sealing cloth. Patent Document 4 seals the skirt and the hood with a sealing cloth. Furthermore, a method of sealing between the skirt and the converter with a second sealing cloth is proposed. Also, in Patent Document 5, the skirt and the hood are connected with an expansion joint, and the skirt is connected with the expansion joint. A method of sealing between the hood has been proposed. However, none of the methods of Patent Documents 3 to 5 has problems such as the skirt being unable to move up and down due to adhesion / deposition of dust, slag and metal, and inferior durability, and is not suitable for practical use. It is.
JP 2004-162127 A JP 11-43713 A JP-A-57-181316 JP 58-22316 A JP 59-126709 A

  As described above, the water-sealed sealing method cannot prevent the accumulation of dust and the like in the seal jacket, and is forced to reduce productivity due to the cleaning of the seal jacket. However, it is not yet put into practical use due to problems such as durability.

  The present invention has been made in view of the above circumstances, and is intended to be installed between a converter furnace port and a hood above the furnace port, and exhaust gas to the atmosphere during decarburization refining. In order to seal the gap between the hood and the hood installed to prevent entrainment in the exhaust gas of the atmosphere, the skirt has excellent durability and is stable without being affected by dust, slag, metal, etc. It is an object to provide a seal structure that can move up and down, and that can replace the water seal method, which can save maintenance and improve productivity.

  The seal structure of the skirt in the converter exhaust gas treatment facility according to the first aspect of the present invention for solving the above-mentioned problem is that the upper end is fixed to a seal floor integrally formed with the hood above the converter furnace port, and the seal A water-cooled structure or a fire-resistant / heat-resistant cylindrical wall that is suspended from the floor, and a water-cooled structure that is installed between the cylindrical wall and the furnace port and that can move up and down the gap between the cylindrical wall and the hood. A skirt, a cylindrical seal plate installed on the upper portion of the cooling water header at the upper end of the skirt, with a gap slidable with the cylindrical wall, and installed on the hood side of the cylindrical seal plate A skirt seal in a converter exhaust gas treatment facility comprising a refractory construction body of a refractory / heat insulating material formed by an inclined surface having an angle greater than an angle of repose of dust generated in the furnace and a flying object from the furnace A structure, said cylindrical wall and front It is characterized in that sealing between the skirt and hood with cylindrical sealing plate.

  The seal structure of the skirt in the converter exhaust gas treatment facility according to the second invention further comprises pressure detecting means for measuring the atmospheric pressure in the gap between the hood and the cylindrical wall in the first invention. It is characterized by.

  The seal structure of the skirt in the converter exhaust gas treatment facility according to the third aspect of the present invention is the first or second aspect of the present invention, wherein the inert gas is blown into the gap between the hood and the cylindrical wall. Means are provided.

  The seal structure of the skirt in the converter exhaust gas treatment facility according to the fourth aspect of the present invention is the skirt seal structure according to the third aspect of the present invention, at least at the start of the supply of oxygen gas to the converter, at the end of the supply of oxygen gas, An inert gas blowing control means for supplying and stopping the inert gas automatically or manually at three times is provided.

  According to the present invention, instead of the conventional water sealing method, the cylindrical wall and the cylindrical sealing plate on which the refractory construction body of the fireproof and heat insulating material is laid, the seal between the skirt and the hood, Dust, slag, metal, etc. generated in the converter do not accumulate and solidify, and the skirt can move up and down stably. As a result, there is no need to stop the operation and clean the water seal part during the converter operation, and the productivity in the converter is improved. Further, by replacing the space between the skirt and the hood with an inert gas at the start of oxygen blowing and at the end of oxygen blowing, accidents such as an explosion of carbon monoxide gas can be prevented.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing an embodiment of the present invention, and is a schematic view of a seal structure of a skirt according to the present invention in a converter exhaust gas treatment facility.

  As shown in FIG. 1, a converter for recovering exhaust gas generated from the converter 1 by decarburization and refining is provided above the furnace port 2 of the converter 1 that supplies oxygen gas and performs decarburization and refining of hot metal. A hood 4 of a furnace exhaust gas treatment facility is installed. The hood 4 has a water cooling structure and is internally cooled by cooling water supplied from a cooling water supply header 13. The cooling water drain header of the hood 4 is installed in the upper part of the hood 4 but is omitted in FIG. In the converter exhaust gas treatment facility, a flue, a primary dust collector, a secondary dust collector, an induction blower, a three-way valve, a gas holder, and the like are installed on the downstream side of the hood 4. In FIG. Omitted.

  The seal floor 5 is attached to the cooling water supply header 13 integrally with the cooling water supply header 13 over the entire circumferential direction of the cooling water supply header 13. That is, the seal floor 5 and the cooling water supply header 13 are connected in an airtight state. A cylindrical wall 6 having a cylindrical shape is fixed to the seal floor 5 so that the upper end of the cylindrical wall 6 is fixed to the seal floor 5 and is suspended from the seal floor 5 over the entire circumferential direction of the hood 4. The cylindrical wall 6 is connected to the seal floor 5 in an airtight state. The cylindrical wall 6 has a water-cooling structure or a fireproof / heat-insulating structure, and FIG. 1 shows the cylindrical wall 6 having a water-cooling structure. What is necessary is just to comprise the cylindrical wall 6 by heat-resistant steel, when setting it as a fireproof and heat insulation structure. The wall surface of the cylindrical wall 6 facing the hood 4 is substantially parallel to the vertical direction and smooth.

  A skirt 3 that can move up and down in the gap between the hood 4 and the cylindrical wall 6 is installed between the furnace port 2 and the cylindrical wall 6 over the entire outer periphery of the hood 4. A cooling water supply header 8 is installed at the end of the skirt 3 on the lower side in the vertical direction, and a cooling water drain header 7 is installed at the end of the skirt 3 on the upper side in the vertical direction. The cooling water supply header 8 is connected to a cooling water supply pipe 14, and the cooling water supply pipe 14 is connected to a cooling water supply / drain pipe 15. Similarly, the cooling water drain header 7 is connected to a cooling water drain pipe (not shown), and this cooling water drain pipe is connected to the cooling water supply / drain pipe 15. That is, the skirt 3 is internally cooled by the cooling water supplied through the cooling water supply / drainage pipe 15, and the cooling water after cooling the skirt 3 is drained through the cooling water supply / drainage pipe 15. The skirt 3, the cooling water supply pipe 14, the cooling water drain pipe, and the cooling water supply / drain pipe 15 are integrally configured, and all of the skirt 3, the cooling water supply pipe 14, the cooling water drain pipe, and the cooling water supply / drain pipe 15 are provided. The upper side of the skirt 3 is inserted into the gap between the hood 4 and the cylindrical wall 6 by a driving device (not shown) such as an electric motor or a hydraulic cylinder, and moves up and down above the furnace port 2. .

  A metallic cylindrical sealing plate 9 is installed over the entire circumferential direction of the skirt 3 at the upper end of the cooling water drainage header 7 at the upper end of the skirt 3 while maintaining a slidable gap with the cylindrical wall 6. Has been. The cylindrical seal plate 9 has a substantially vertical direction, the surface facing the cylindrical wall 6 of the cylindrical seal plate 9 is smooth, and the surface facing the cylindrical wall 6 of the cylindrical seal plate 9 is cooling water. It is installed so as to protrude in the direction of the cylindrical wall 6 from the same plane as the projection surface of the drainage header 7 or from the coolant drainage header 7.

  In the present invention, the space between the skirt 3 and the hood 4 is sealed by the cylindrical wall 6 and the cylindrical seal plate 9, and therefore, the gap between the cylindrical wall 6 and the cylindrical seal plate 9 is preferably as small as possible. By making the cylindrical wall 6 and the cylindrical seal plate 9 have the above-described structure, the cylindrical wall 6 and the cylindrical seal plate 9 can be slid while being in close contact with each other. Further, the longer the contact surface between the cylindrical wall 6 and the cylindrical seal plate 9, the better the sealing effect. Therefore, the contact surface between the cylindrical wall 6 and the cylindrical seal plate 9 can be secured at least 200 mm. preferable.

  On the side opposite to the cylindrical wall side of the cylindrical seal plate 9, that is, on the hood 4 side of the cylindrical seal plate 9, a refractory construction body 10 of fireproof and heat insulating material is formed. The side wall surface on the hood side of the refractory construction body 10 is formed of an inclined surface having an angle greater than the repose angle of dust generated in the furnace and flying objects from the furnace. Adhering / depositing dust generated in the furnace and flying objects from the furnace at the upper part of the cooling water drain header 7 is prevented. The refractory construction body 10 can be formed, for example, by pouring construction of an alumina-based amorphous refractory or a magnesia-based amorphous refractory.

  The seal floor 5 is provided with a pressure detection end 11 for measuring the atmospheric pressure in the gap between the hood 4 and the cylindrical wall 6 and for injecting an inert gas into the gap between the hood 4 and the cylindrical wall 6. An inert gas inlet 12 is provided. The pressure detection end 11 is connected to a pressure measuring device (not shown), and the pressure measurement value is input to a control device (not shown) of the converter exhaust gas treatment facility and displayed in the converter operation room. It has become so. The inert gas inlet 12 is connected to an inert gas supply pipe (not shown) provided with a flow rate adjusting valve (not shown) and a flow rate control device (not shown). A signal from a computer for controlling the operation of the furnace is inputted, and the blowing time, blowing amount, and blowing time of the inert gas are automatically performed. That is, an inert gas can be blown at an arbitrary timing for an arbitrary time by setting the blowing conditions in advance in a computer that controls the operation of the converter. Of course, the inert gas blowing control is also possible by manual operation. As the inert gas, nitrogen gas, Ar gas, or the like can be used. A plurality of the pressure detection ends 11 and the inert gas blowing ports 12 may be arranged in the circumferential direction of the hood 4. In particular, the inert gas blowing ports 12 are used from the viewpoint of quickly and reliably performing gas replacement and dust removal. It is preferable to arrange a plurality.

  By using the seal structure of the skirt 3 according to the present invention configured as described above, exhaust gas having a high temperature and high dust content mainly composed of carbon monoxide gas generated by decarburization refining of hot metal as follows. Recover.

  That is, at the start of oxygen blowing, an explosion caused by a reaction between the air existing in the gap between the skirt 3 and the hood 4 and the generated exhaust gas is performed with the skirt 3 in the upper limit position (position indicated by a broken line in FIG. 1). In order to prevent this, after blowing an inert gas from the inert gas blowing port 12 to replace the atmosphere in the gap between the skirt 3 and the hood 4 with an inert gas atmosphere, oxygen blowing is started in this state. When 0.5 to 1.5 minutes have elapsed since the start of blowing, in which the decarburization reaction in the furnace has sufficiently progressed, the skirt 3 is lowered to the lower limit position (the position indicated by the solid line in FIG. 1). When the skirt 3 is lowered to the lower limit position, the blowing of the inert gas from the inert gas blowing port 12 is stopped.

During oxygen blowing, dust, slag, and bullion are spouted along with the decarburization reaction in the furnace, and some of them penetrate between the skirt 3 and the hood 4, but the fireproof inside the cylindrical seal plate 9. Since the object construction body 10 is formed of an inclined surface having an angle greater than the angle of repose of dust generated in the furnace and flying objects from the furnace, the slag and the metal having a relatively large particle size are the upper part of the skirt 3. It falls into the furnace without adhering or depositing on it. Further, after the skirt 3 is lowered to the lower limit position, the pressure measured through the pressure detection end 11 is adjusted to the atmospheric pressure by adjusting the rotational speed of the secondary dust collector damper or the induction fan of the converter exhaust gas treatment equipment. Te 0mmH ₂ O~ + 5mmH by controlling the range of ₂ O, may be combustion exhaust gas generated and ejecting becomes minimum, to maximize recovery of high concentrations of carbon monoxide gas.

  At the end of the oxygen blowing, an inert gas inlet 12 is used to prevent a risk that the carbon monoxide gas filled between the skirt 3 and the hood 4 reacts with the air sucked from the furnace outlet 2 to explode. Then, an inert gas is blown in, and after the space is replaced with the inert gas, the skirt 3 is raised to the upper limit position.

  When the blowing is completed, the inert gas is blown again from the inert gas blowing port 12 with the skirt 3 at the upper limit position at any time before the start of the next blowing, Dust and the like that have entered and adhered to the hood 4 are removed.

  As described above, the inert gas blowing from these inert gas blowing ports 12 is automatically performed by obtaining a signal from a computer that controls the operation of the converter. Of course, the blowing of the inert gas can also be controlled by manual operation without being automatically performed.

  As described above, according to the present invention, instead of the conventional water sealing method, the cylindrical wall 6 and the cylindrical sealing plate 9 on which the refractory construction body 10 is laid, the skirt 3 and the hood 4 Since the gap is sealed, dust, slag, metal, etc. generated in the converter 1 do not accumulate and solidify at the sealing part, and the skirt 3 can be moved up and down stably. As a result, during the converter operation There is no need to stop the operation and clean the water seal, and productivity in the converter is improved.

It is the schematic of the seal structure of the skirt which concerns on this invention. It is the schematic of the sealing structure of the conventional skirt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Converter 2 Furnace opening 3 Skirt 4 Hood 5 Seal floor 6 Cylindrical wall 7 Cooling water drainage header 8 Cooling water supply header 9 Cylindrical seal board 10 Refractory construction object 11 Pressure detection end 12 Inert gas injection port 13 Cooling water supply water Header 14 Cooling water supply pipe 15 Cooling water supply / drain pipe 16 Partition cylinder 17 Seal jacket 18 Seal water 19 Drainage groove

Claims (4)

A cylindrical wall of a water-cooled structure or a fire-resistant / heat-resistant structure, the upper end of which is fixed to a seal floor integrally formed with the hood above the converter furnace opening, and is suspended from the seal floor;
A water-cooled skirt installed between the cylindrical wall and the furnace port and capable of moving up and down the gap between the cylindrical wall and the hood;
A cylindrical sealing plate installed on the upper portion of the cooling water header at the upper end of the skirt, with a gap slidable with the cylindrical wall;
A refractory construction body of fireproof and heat insulating material, which is installed on the hood side of the cylindrical seal plate and formed with an inclined surface having an angle greater than an angle of repose of dust generated in the furnace and flying objects from the furnace; A skirt seal structure in a converter exhaust gas treatment facility comprising:
A sealing structure for a skirt in a converter exhaust gas treatment facility, wherein the space between the skirt and the hood is sealed by the cylindrical wall and the cylindrical sealing plate.   2. The skirt seal structure in a converter exhaust gas treatment facility according to claim 1, further comprising pressure detection means for measuring an atmospheric pressure in a gap between the hood and the cylindrical wall.   The skirt in a converter exhaust gas treatment facility according to claim 1 or 2, further comprising an inert gas blowing means for blowing an inert gas into a gap between the hood and the cylindrical wall. Seal structure.   An inert gas which is supplied and stopped automatically or manually by the operation of oxygen gas at the start of oxygen gas supply to the converter, at the end of oxygen gas supply and at least three times after the oxygen gas supply is completed. 4. A skirt seal structure in a converter exhaust gas treatment facility according to claim 3, further comprising gas blowing control means.

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