JP2519128Y2 - Blast furnace in-furnace gas discharge device when there is no wind - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for discharging gas in a blast furnace when there is no wind.

[0002]

2. Description of the Related Art Generally, as shown in FIGS. 4 and 5, a plurality of rising pipes 18 and inspection manholes 3 are alternately arranged on the outer periphery of a furnace top shell 2 of a blast furnace 1. (A) In order to remove the gas 8 in the blast furnace 1 when the blast furnace is in a blast, the manhole 3 for inspecting the furnace provided in the furnace top shell 2 of the blast furnace 1 is opened, and the bellows 4 for degassing is connected thereto. However, a method of sucking the gas 8 in the furnace by the exhaust fan 5 connected to the bellows 4 and discharging the gas 8 to the outside of the work deck 7 is adopted, and the inspection manhole 3 is opened and the bellows 4 is connected manually. Has been done. In such a case, when the in-furnace gas is discharged to the outside by a part of the inspection manhole 3 and the exhaust fan 5, the in-furnace gas may go out of the other inspection manhole 3 depending on the strength and direction of the external wind. Since it leaks, there is a danger of gas poisoning when inspecting the furnace.

(B) In Japanese Patent Laid-Open No. 53-29209, in order to reliably prevent a small amount of blast furnace gas generated when the blast furnace is blown off from entering the dust remover through the blast furnace ascending pipe and descending pipe, Nozzles were attached to all of the plurality of ascending pipes connected to the furnace top of the blast furnace, and fans were connected to the nozzles via ducts so that the gas in the furnace could be sucked by the fan and discharged to the outside of the furnace. A blast furnace gas discharge device is disclosed.

According to this technique, as shown in FIG. 6, four rising pipes 33 connected to a gas collecting mantel 32 of a blast furnace body 31 are provided.
A blind plate is detachably attached to all of the nozzles, and nozzles 34 are attached so as to be blocked during the operation of the blast furnace, and an intake duct 36 is connected to each nozzle 34 through a bellows 35. Each 36 is connected to a discharge duct 38 via a fan 37. In addition, 39 is the inside of the furnace, 40 is a furnace top bleeder valve that is opened when there is no wind, and 41 is a downcomer pipe.

During the blast furnace blast, after the gas purging, the furnace top bleeder valve 40 is opened, and the blind plate that has blocked the nozzles 34 during the operation of the blast furnace is removed, and the fans 37 connected to the nozzles 34 through the suction ducts 36 are removed. drive. By the operation of the fan 37, as shown in FIG. 6, the air is sucked from the furnace top bleeder valve 40 which is open during a break of the air as shown by the broken line arrow, and the rising pipe
While descending 33, a small amount of gas generated in the furnace 39 is also sucked by the fan 37 and rises in the ascending pipe 33. fan
The air sucked by the air 37 and a small amount of gas are mixed in the vicinity of the nozzle 34, pass through the bellows 35 and the suction duct 36, and then the fan 37.
Is sucked into the atmosphere and discharged from the discharge duct 38 into the atmosphere.

(C) As a method for safely replacing the gas in the blast furnace when the blast furnace is blown off with air, a pipe is welded between the bottom of the ascending gas pipe and the gathering part of the ascending gas pipe. Japanese Patent Application Laid-Open No. 2-57624 discloses a method for replacing air in a furnace gas with an exhaust fan installed at the tip of a pipe. As shown in Fig. 7, this technique is used when the rising gas pipe 58
A part of the space between the bottom part 67 and the collecting part 68 of the rising gas pipe 58 is cut out, and a pipe 64 is welded to the part, and the shutoff valve 65 and the exhaust fan 66 (300 m ³ / min × 2 Stand).

Before entering the breeze of the blast furnace 51, a bleeder valve 59
And the shutoff valve 65 is closed. Then, for example, when the blast furnace 51 is in a resting state, the furnace wall 52 and the charging bell (large bell 55, small bell
56) and the like are repaired at the same time, the amount of raw material charged from the charging chute 57 is reduced. The coke ratio during the charging of the raw material is set to be 200 to 300 kg / t-molten iron, which is higher than the standard, depending on the rest time. Then, the amount of air blown from the tuyere 54 and the pressure of the air blow are gradually reduced. The charge level 53 of the raw material is lowered to the repaired portion of the furnace wall 52, and the air blowing is stopped. At this time, the raw material is not charged from the charging chute 57 at the furnace top.

Then, the bleeder valve 59 installed at the top of the ascending gas pipe 58 is opened, and the B gas in the blast furnace 51 is bleeder pipe.
Emitted from 62. Then, the shutoff valve 65 in the pipe 64 between the bottom portion 67 of the rising gas pipe 58 and the collecting portion 68 of the rising gas pipe 58 is opened, and at the same time, the exhaust fan 66 is also started. Then, the gas in the furnace is forcibly sucked into the exhaust fan 66. Also, since the atmosphere near the charging bell will be sucked into the furnace,
There is no concern about gas poisoning, the atmosphere near the charging bell is at room temperature, and the charging bell can be safely repaired.

[0009]

The conventional method (A) described above has the following problems. (1) Although it is necessary to quickly perform the degassing work at the top of the blast furnace when the blast furnace is in a blast, the manhole opening and duct connection are done manually, so there is a risk of carbon monoxide gas poisoning due to the gas inside the furnace take time.

(2) When the manhole is opened or the duct is connected, the gas in the furnace may be ignited and a gas explosion may occur, which is extremely dangerous for the work. (3) On the work deck around the furnace top iron shell, various work is performed when there is no wind, and the bellows for degassing occupy a large work deck space, which hinders the work.

In the technique disclosed in JP-A-53-29209 (B) (see FIG. 6), a blind plate is attached to the nozzles 34 attached to all the ascending pipes 33 during operation, and the wind is blown off. At this time, the blind plate is removed and the bellows 35 connects the nozzle 34 and the suction duct 36 to discharge the blast furnace top gas.Therefore, it takes time to attach and remove the blind plate and the bellows, and carbon monoxide gas poisoning There is a risk of falling due to work at high altitudes.

Further, in the method disclosed in Japanese Patent Application Laid-Open No. 2-57624 (C) (see FIG. 7), it does not take time to open the manhole or attach or detach the blind plate, but Repair of bells (large bell 55, small bell 56) and furnace wall
When repairing 52, etc. at the same time, the atmosphere near the charging bell and the air outside the furnace from the inspection port 60 opened for repairing the furnace wall are sucked in at the same time, so the intake air volume becomes enormous and The capacity of the wind turbine 66 needs to be very large. If the capacity of the exhaust fan 66 is insufficient, the pressure inside the furnace will increase toward the bottom of the blast furnace, and depending on the wind direction and wind speed, the harmful gas inside the furnace will leak out of the furnace, and Etc. will bring danger.

On the other hand, during the operation of the blast furnace, the shutoff valve 65 is closed to operate.
Since high pressure operation of 2.5 kg / cm ² is common, if the shut-off valve 65 is not completely sealed due to adhesion and accumulation of dust in the blast furnace exhaust gas, the shut-off valve 65 leaks the blast furnace top gas. , Will result in energy loss and risk of gas poisoning.

An object of the present invention is to provide a device for discharging the gas in the furnace when the blast furnace is blown off, which solves the drawbacks of the prior art.

[0015]

Means for Solving the Problems The present invention for achieving the above-mentioned object is a blast furnace in-furnace gas discharge device at the time of a blast having a manhole for in-furnace inspection in a blast furnace top iron shell. A gas discharge pipe seat provided on the furnace top iron shell, a double seal type cutoff valve device connected to the gas discharge pipe seat, and an exhaust gas connected to the secondary side of the double seal type cutoff valve device. A blast furnace in-furnace gas discharge device when there is no wind, characterized by comprising an air blower.

The double seal type shut-off valve device is as follows.
An inert gas for airtight sealing, which is connected in the middle of the circular case and has a pair of valve bodies that rotate in a circular case that connects between two valve seats arranged in series to open and close the valve seat. Inert for airtight seal, which is equipped with a sealing means and a pressure detecting means, or has two shut-off valves arranged in series through a short pipe and is connected in the middle of the short pipe. It may be provided with a gas enclosing means and a pressure detecting means. Furthermore, it is preferable to dispose the manhole for inspecting the furnace immediately below the gas exhaust pipe seat.

[0017]

[Operation] According to the present invention, a gas seal pipe seat is provided on the blast furnace top iron shell, and a double seal shutoff valve device connected to the gas discharge pipe seat and a double seal shutoff valve device are provided. Since the exhaust duct connected to the secondary side and the exhaust fan connected to this exhaust duct were permanently installed, the double-seal shutoff valve device completely prevented the high-pressure top gas from leaking outside the furnace during blast furnace operation. It can prevent energy loss and danger due to leakage of toxic gas.

Further, when the blast furnace is off, it is not necessary for an operator to open the inspection manhole to attach or detach the exhaust bellows or attach or detach the blind plate of the exhaust nozzle, and to open or close the double seal shutoff valve. It is possible to discharge and stop the gas in the furnace in a short time by just doing so, and to shorten the downtime, and there is almost no danger of gas poisoning or other work because the manual work by the worker as described above is not necessary.

According to the present invention, since the manhole for inspecting the furnace is arranged immediately below the gas exhaust pipe seat, when the manhole is opened, the atmosphere outside the furnace is easily sucked into the furnace from the manhole and the gas inside the furnace is easily sucked. Are rarely leaked from manholes and the risk of gas poisoning is significantly reduced. Further, the double-seal type shutoff valve device of the present invention is equipped with a sealing tube and pressure gauge filled with an inert gas for airtight sealing which is connected in the middle of a circular case or a short tube. If the pressure is set higher than the pressure of the top gas by filling it with an inert gas such as nitrogen gas, not only will there be no leakage through the shutoff valve of the top gas, but two valve bodies When one or both seals in the valve seat are insufficient, the gas for airtight sealing leaks into the furnace or duct and the pressure drops,
Since the pressure drop can be detected by the pressure gauge, it is possible to easily know the leakage due to the sealing failure of the shut-off valve, the maintainability is improved, and the risk due to the gas leakage in the furnace can be remarkably reduced.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1 is a partially cutaway elevational view showing a first embodiment of the present invention. A gas discharge pipe seat 9 is provided exclusively above the furnace top iron shell 2 of the blast furnace 1, and a double seal type shutoff valve 10 is installed in this pipe seat 9. An expansion joint 15 and an exhaust duct 16 are connected to the double seal shutoff valve 10, and the exhaust fan 5 is connected to the exhaust duct 16.
And the gas discharge pipe 6 is connected.

The double seal type shutoff valve 10 has a circular case 10a for connecting between two valve seats 11a and 12a arranged in series.
It has a pair of primary side valve body 11 and secondary side valve body 12 which rotate inside to open and close the valve seats 11a and 12a. And circular case 10a
At the same time that a gas sealing pipe 14 is connected as a gas sealing means and a pressure detector 13 is installed as a pressure detecting means, the pressure inside the case 10a of the double seal shutoff valve 10 is detected, In order to maintain the airtightness inside the valve, the adjusting valve 14a is adjusted from the gas sealing pipe 14 to supply the inert gas.

During operation of the blast furnace 1, the pair of primary side valve element 11 and secondary side valve element 12 provided in the circular case 10a of the double seal type shutoff valve device 10 are located at the valve seats 11a and 12a, respectively. The shutoff valve device 10 has a double seal structure to shut off the gas in the furnace of the blast furnace. Then, the pressure inside the shutoff valve device 10 is constantly detected by the pressure detector 13 to monitor the seal state, and if a leak is detected, the primary valve body 11
And the adjustment valve to increase the tightening pressure of the secondary valve body 12.
14a is opened and an inert gas such as N ₂ gas is supplied from the gas sealing pipe 14 into the circular case 10a to be sealed therein, and the pressure increase in the shutoff valve device 10 causes the valve seats 11a and 12 of the valve seats 11a and 12a to be closed. The seal pressure is increased to ensure the seal and completely prevent the gas in the furnace from leaking to the outside.

When the blast furnace 1 is in a blast, the gas pressure in the double-seal shutoff valve device 10 is lowered, and then the pair of valve bodies 11 and 12 are rotated to open the valve seats 11a and 12a and the exhaust fan 5
To operate the blast furnace gas for gas exhaust pipe seat 9 and shut-off valve device 1
It is discharged into the atmosphere from 0, the exhaust duct 16, the exhaust fan 5, and the gas discharge pipe 6. In the present invention, unlike the conventional blast furnace gas discharge work using a manhole, a series of devices via a dedicated gas discharge pipe seat 9 is installed, so the work can be performed quickly and reliably. Not only that, remote operation without human power is possible.

FIG. 2 is a partially cutaway elevational view showing a second embodiment of the present invention. The difference from the above-mentioned embodiment of FIG. 1 is that a manhole for inspection is provided immediately below the gas exhaust pipe seat 9. It is where 3 is arranged. With this configuration, when the inspection manhole 3 is opened to inspect the inside of the furnace,
The outside air 19 is sucked from the inspection manhole 3 to eliminate the risk of gas poisoning when inspecting the furnace.

FIG. 3 is a partially cutaway elevational view showing a third embodiment of the present invention. Instead of the double seal type shutoff valve device 10 in the embodiment of FIG. Since a pair of upper and lower shutoff valves 21 and 22 are provided with the short pipe 20 interposed therebetween, and the short pipe 20 is provided with a pressure sensor 13 in the short pipe 20 and a gas sealing pipe 14 for hermetically sealing the valve interior, the operational effects and the like are In addition to being similar to the first embodiment, the shut-off valve structure is simpler and the maintainability is superior to that of the first embodiment.

[0026]

According to the present invention, the following effects can be obtained. (1) It is possible to perform the gas discharge work in the furnace when the blast furnace is blown off by remote control without the need for manpower, and it is possible to shorten the blown down time and improve the safety. (2) During operation of the blast furnace, it is possible to reliably prevent high-pressure in-furnace gas from leaking out of the furnace through the exhaust device, and if the shut-off valve seal is incomplete, fill gas in the double-seal shut-off valve device. It is possible to easily take measures to prevent gas leakage in the furnace by tightening the shut-off valve or increasing the pressure of the enclosed gas by detecting the pressure. (3) When the furnace top inspection manhole is opened and the inside of the furnace is inspected, it is possible to reliably expect intake of outside air from the manhole, and it is possible to prevent the risk of gas poisoning due to gas leakage in the furnace.

[Brief description of drawings]

FIG. 1 is an elevational view showing a first embodiment of the present invention in a partial cross section.

FIG. 2 is an elevational view showing a second embodiment of the present invention in a partial cross section.

FIG. 3 is an elevational view showing a partial cross-section of a third embodiment of the present invention.

FIG. 4 is an elevation view showing a conventional example in a partial cross section.

5 is a plan view showing an arrow AA of FIG. 4. FIG.

FIG. 6 is a perspective view showing another conventional example.

FIG. 7 is a sectional view showing still another conventional example.

[Explanation of symbols]

1 Blast furnace 2 Top iron shell 3 Inspection manhole 4 Bellows 5 Exhaust fan 6 Gas discharge pipe 7 Working deck 8 Blast furnace gas 9 Gas exhaust pipe seat 10 Double seal structure shutoff valve 11 Primary valve body 12 Secondary valve body 13 Pressure detector 14 Gas filling pipe 15 Expansion joint 16 Exhaust duct 17 Filling gas (N ₂ gas) 18 Ascending pipe 19 Outside air 20 Short pipe 21 Lower shutoff valve 22 Upper shutoff valve

Claims (4)

(57) [Scope of utility model registration request] 1. A blast furnace in-furnace gas exhausting device having a manhole for in-furnace inspection in the blast furnace top iron shell, the gas exhaust pipe seat being provided in the furnace top iron shell, A blast furnace furnace at the time of blast, comprising a double-seal shutoff valve device connected to the gas exhaust pipe seat, and an exhaust fan connected to the secondary side of the double-seal shutoff valve device. Internal gas discharge device. 2. A circular seal having a double-seal shutoff valve device that rotates in a circular case connecting between two valve seats arranged in series to open and close the valve seat. 2. The blast furnace gas discharge device during blast furnace according to claim 1, further comprising an airtight sealing inert gas enclosing means and a pressure detecting means, which are connected in the middle of the case. 3. A double-seal shutoff valve device has two shutoff valves arranged in series via a short pipe, and an inert gas sealing means for airtight seal connected in the middle of said short pipe. The blast-furnace in-furnace gas discharge device at the time of a blast, according to claim 1, further comprising a pressure detecting means. 4. The blast furnace in-furnace gas discharging device at the time of a blast, according to claim 1, 2 or 3, wherein the in-furnace inspection manhole is arranged immediately below the gas discharging pipe seat.