JP5381666B2 - Gas shielding method and gas shielding device upstream of blast furnace dust remover - Google Patents

Description

  The present invention relates to a pipe gas used to shield the high-temperature CO gas generated in the blast furnace at the upstream part of the dust remover when entering the repair work of the downstream equipment of the dust remover when the blast furnace is closed. The present invention relates to a shielding method and an apparatus for carrying out this gas shielding method.

  When the blast furnace is closed, various facilities are repaired. One of them is the downstream equipment of the dust remover for blast furnace gas discharged from the top of the blast furnace furnace.

  As shown in FIG. 14, the blast furnace A includes a dust remover (dust catcher) B, a gas cleaning facility (ring slit washer) C, and the like. High-temperature blast furnace exhaust gas containing CO gas is led to the gas cleaning equipment C through the riser D, downcomer E, and dust remover B, and after primary dust removal and secondary cleaning, it is introduced into the hot stove. The hot air is blown from the tuyere F into the blast furnace.

On the blast furnace off-air day, the CO gas generated from the high-temperature coke remaining in the furnace is burned by the in-furnace ignition device G and made harmless to CO ₂ gas, and then the bleeder valve H attached to the riser pipe D is opened. Repair work such as gas cleaning equipment C is carried out in the state of being released into the atmosphere.

However, in such a state, CO ₂ gas or CO gas may travel down the downcomer E to the repair work site. In such a case, it is necessary to stop the repair work or perform a repair work with an air mask or the like.

In the case of a small blast furnace, there is an example in which a large gas seal gate valve called a goggle valve is provided at the inlet of the dust remover and the gate valve is closed on a non-winding day. However, during normal operation, this gate valve is opened and is generated from the blast furnace and exposed to a gas containing a dust amount of about 10 g / Nm ³ at a high temperature of about 150 to 200 ° C. As a result, the gas seal function does not function and maintenance is difficult to use as a gas shield when the wind is off. Especially in recent large-scale blast furnaces, the pipe diameter at the inlet of the dust remover exceeds 3 m, so such a gate valve is hardly installed.

On the other hand, a device for inflating an air bag to shut off a pipe in repair work such as a gas pipe or a water pipe has been proposed (see, for example, Patent Document 1). However, in a blast furnace, for example, in the case of abnormal combustion, the high-temperature CO ₂ gas generated in the furnace (150 to 300 ° C. at the top of the furnace) may reach the downcomer, so there is a risk of deterioration and damage due to the high-temperature gas. There is no normal airbag that can be used.

  Therefore, as shown in FIG. 15, while injecting gas into a balloon-shaped airtight ball bag I and purging the inhaled gas from a plurality of gas ejection valves installed on one side of the ball bag I that open above a certain pressure. An apparatus for blocking the downcomer pipe E has been proposed (see Patent Document 2).

  However, the device disclosed in Patent Document 2 requires a great amount of labor and time for transporting and installing a ball bag having a size of 3 m or more in the folded state to the installation location and inflating the ball bag. Cost. In addition, it takes a lot of labor and time to evacuate the gas in the ball bag after the wind-breaking work and to fold and pull it out of the downcomer.

  In addition to the time required for repair work that is performed by entering the downstream equipment of the dust remover when the blast furnace is shut down, as described above, it requires a lot of labor and time for the setup work and the subsequent trace work. When shielding, it leads to the extension of the resting time and causes a decrease in production of the blast furnace.

Japanese Unexamined Patent Publication No. 63-130991 Japanese Utility Model Publication No. 3-46094

  The problem to be solved by the present invention is that the conventional gas shut-off technique requires a great deal of labor and time for the setup work and the subsequent trace finishing work.

The gas shielding method in the upstream part of the blast furnace dust remover of the present invention is
In order not to require a lot of effort and time for the setup work and subsequent trace work,
After installing a plurality of scaffolding pipes in a penetrating manner so as to be horizontal in the expansion pipe in the upstream part of the dust remover connected to the descending pipe of the blast furnace, the insulator is inserted from the direction perpendicular to the scaffolding pipes. Deployed on a pipe for scaffolding, forming a cocoon floor,
Next, a gas shield having a sealing film provided on the floor surface of the donut portion is inserted on the formed insulator floor and then expanded. The most important feature is the close contact with the inner wall.

The gas shielding apparatus in the upstream portion of the blast furnace dust remover of the present invention for carrying out the gas shielding method in the upstream portion of the blast furnace dust remover of the present invention is
A gas shielding device installed in an expansion pipe of a dust remover connected to a downflow pipe of a blast furnace,
A plurality of scaffolding pipes installed in a penetrating manner in the spreading pipe;
The insulators supported by these scaffolding pipes,
A gas shield provided with a seal film on the floor surface of the donut part, which is placed on the insulator floor formed by spreading the insulator on the scaffold pipe;
The main feature is to have

  According to the present invention, the high-temperature CO gas descending from the top of the blast furnace to the inside of the downcomer can be easily shielded in a short time at the upstream portion of the dust remover.

  In the present invention, a gas shield provided with a sealing film on the floor surface of a donut part is folded and inserted into an expansion pipe of a dust remover, and the expansion pipe is shielded by simply performing an expansion operation after deployment (about 15 minutes). Setup work is completed. Further, the subsequent trace finishing work only needs to be performed in reverse to the setup work (about 10 minutes), so that the worker can easily and safely attach and detach without entering the CO gas atmosphere.

  For this reason, it is possible to shield the high-temperature blast furnace exhaust gas containing CO gas descending from the blast furnace body from the gas cleaning section upstream of the dust remover, so that the gas cleaning section downstream of the dust removal apparatus when the blast furnace is closed It is possible to safely perform repair work that goes into the construction site.

  In addition, the gas shielding technology of the present invention is simple, lightweight and easy to install and remove, and can save labor and time compared to the prior art, leading to a reduction in blast furnace downtime, Contributes to improved production.

It is a schematic sectional drawing which shows the implementation condition at the time of installing the gas shielding apparatus of this invention in the expansion pipe of a dust remover. FIG. 2 is an enlarged view of a part in FIG. 1. FIG. 3 is an easy view of FIG. It is the perspective view which showed the structure of the insulator. It is the perspective view which showed the state which rolled the insulator small. It is the perspective view which showed the taking-in state in the expansion pipe of an insulator. It is the perspective view which showed the state which expand | deployed the insulator. It is the perspective view which showed the taking-in state in the expansion pipe of a gas shield. It is the perspective view which showed the state which expanded the gas shield and expanded in the pipe | tube. It is the top view which showed the state which expand | deployed the gas shield. It is Wu sectional drawing of FIG. FIG. 12 is an enlarged view of a portion D in FIG. 11. It is the O section enlarged view of FIG. It is the schematic which shows the blast furnace at the time of the conventional repair. It is the schematic which shows the Example of patent document 2. FIG.

  In the present invention, a gas shield having a sealing film provided on the floor surface of a donut portion is used for a dust remover in a folded state so as not to require much labor and time for setup work and trace finishing work. This was realized by insertion and expansion into the expansion tube and subsequent expansion operation (or vice versa).

Hereinafter, exemplary embodiments for carrying out the present invention will be described with reference to FIGS.
The present invention implements a method for shielding high-temperature CO gas generated in a blast furnace at the upstream portion of the dust remover when entering the repair work for the downstream equipment of the dust remover when the blast furnace is closed. Device.

  As shown in FIGS. 1 to 3, the present invention shields the inside of the expansion pipe 1 located in the deck portion 2 attached to the expansion pipe 1 of the dust remover B connected to the downcomer pipe E. This is done using a gas shielding device of the construction.

  Reference numeral 3 denotes a gas shield 3 that shields the inside of the expansion pipe 1 and is composed of a donut portion 3a and a seal film 3b provided on the floor of the donut portion 3a.

  Reference numeral 4 denotes, for example, three scaffold pipes, which are installed in a penetrating manner so as to be horizontal at a portion of the spreading pipe 1 located upstream of the dust remover B.

  Although it is possible to support the gas shield 3 with this scaffolding pipe 4, the inner diameter of the portion of the expansion tube 1 is about 4 m, so that the gas shield 3 is stably supported so as not to fall. To make the floor surface, 20 or more scaffolding pipes 4 are required. In this case, since 40 or more through holes are provided in the portion of the expansion tube 1, there is a problem in terms of the structure and strength of the expansion tube 1.

  Therefore, in the present invention, the minimum required three scaffolding pipes 4 are installed, and the insulator 5 is inserted into a portion located upstream of the dust remover B from a direction orthogonal to the scaffolding pipes 4. A horizontal insulator floor is formed on the pipe 4 for use. The insulator 5 should have the following three conditions.

(1) Hold the gas shield 3 horizontally on the scaffolding pipe 4.
(2) A horizontal insulator bed can be formed in the portion of the expansion pipe 1.
(3) It can be rounded to a small extent and can be deployed inside the expansion tube 1 so that it can be easily inserted into the expansion tube 1 from the small manholes 6 a to 6 d provided in the portion of the expansion tube 1.

Therefore, the preferable conditions of the insulator 5 are the following two.
(A) Since it is better that the gap between the insulators 5 is small so that a horizontal insulator floor on which the gas shield 3 is installed can be formed, a lightweight pipe 5a such as an aluminum tube is packed together as shown in FIG. Then, they are connected by a wire rope 5b and formed into a circular bowl shape that matches the inner surface shape of the expansion tube 1. At this time, if the interval between the pipes is too large, it is difficult to form a bowl shape, and smoothness is not achieved when the pipes are rounded. In addition, as long as it is easy to be rolled into a bowl shape and bundled, and is light and strong in bending strength, not only aluminum pipes but also aluminum bars may be used.

(B) Lightweight, rounded as shown in FIG. 5 to facilitate the work of taking in from the manhole 6a. For example, it is divided into two semicircular shapes and deployed together in the expansion pipe 1, It is desirable to form.

  The gas shielding method of the present invention is carried out as follows using the gas shielding apparatus of the present invention provided with the gas shield 3, the scaffolding pipe 4, and the insulator 5 having the above-described configuration.

  First, three pairs are provided in three pairs (six) of through-holes 1a provided at, for example, equally spaced positions in the horizontal position of the expansion section 1 of the deck section 2 attached to the expansion pipe 1 of the dust remover B. The scaffolding pipe 4 is installed in a penetrating manner.

  Thereafter, from one of the paired manholes 6a, 6b provided in a direction orthogonal to the scaffolding pipe 4, as shown in FIG. 6, semi-circular insulators 5a, 5b Are sequentially inserted in a bundled state. This insertion operation is performed using a hanging rope (not shown) between the other manholes 6b provided at the facing positions from the one manhole 6a side.

  At this time, one insulator 5a is inserted at the position a in FIG. 6 and the other insulator 5b is inserted at the position b in FIG. After the insertion, the pair of manholes 6c and 6d provided in a direction orthogonal to the manholes 6a and 6b are sequentially deployed on the scaffolding pipe 4 so as to unwind the bundles rounded using a hand (not shown). As shown in FIG. 7, the insulators 5 a and 5 b are combined in the expansion pipe 1 to form a circular insulator floor.

  Next, as shown in FIG. 8, the gas shield 3, which is small and folded in a state where the donut 3 a is deflated, is inserted on the formed insulator floor through the one manhole 6 a.

  Here, the gas shield 3 has a weight (for example, 30 kg) that is small enough to be folded and carried by one person. Also, if the material has a heat resistance of 79 ° C. or less, such as polyvinyl chloride normally used for airbags, it may be deteriorated or damaged by high-temperature gas. ° C), strength and flexibility (for example, nylon chloroprene).

  After the insertion, the gas shield 3 is developed on the insulator floor so as to be positioned in the center of the expanded pipe 1 using a hand maneuver (not shown) from the four-direction manholes 6a to 6d. After the deployment, as shown in FIG. 9, for example, gas is introduced into the donut portion 3 a through the compressor 7, the pressure regulator 8, and the air supply / exhaust hose 9 installed outside the manhole 6 a.

FIG. 10 is a developed plan view of the gas shield 3, and FIG. 11 is a Wu cross-sectional view of FIG.
The donut portion 3a of the gas shield 3 is provided with a supply / exhaust port 3aa and a pressure detection port 3ab, and the supply air from the compressor 7 is supplied from the supply / exhaust port 3aa via the supply / exhaust hose 9. The donut portion 3a is expanded into a donut shape.

  As a result, the sealing film 3 b forms a circular surface, and the outer peripheral side surface of the donut portion 3 a expands and comes into close contact with the inner wall of the tube 1. 9 to 11, for example, a seal belt 11 is attached to the outer periphery of the donut portion 3 a, and the seal belt 11 is in close contact with the inner wall surface of the spread tube 1.

  FIG. 12 is an enlarged view of the portion D of FIG. 11, in which the seal belt 11 is in close contact with the inner wall surface of the expansion tube 1 in a state where the donut portion 3 a is expanded. In this state, the gas is shielded from the gas cleaning equipment C side.

  In FIG. 13 showing an enlarged view of the O portion of FIG. 12 as the seal belt 11, two rows of concave and convex grooves 11a such as rubber tires are arranged on the surface that is in close contact with (in contact with) the inner wall of the expansion tube 1. Shows what you did. When such a seat belt 11 is adopted, the outer peripheral surface of the donut portion 3a does not directly hit the inner wall surface of the spread pipe 1 with a surface of a refractory or the like having a certain high temperature (about 100 ° C. or less). The risk of deterioration due to hot gas, catching, and tearing can be prevented.

  Here, the supply air pressure to the donut part 3a is set to an expansion pressure such that the donut part 3a does not rupture, for example, about 15 to 20 kPa. In the example of FIG. 9, the internal pressure of the donut portion 3 a is led to the pressure regulator 8 by the pressure detection hose 10 so that the air pressure from the compressor 7 is not supercharged and the expansion pressure becomes too high. It is controlled by a safety valve inside the regulator 8.

  In the example shown in FIG. 12, good gas sealing performance is confirmed when the internal pressure of the donut portion 3a is set to 18 kPa.

  In the resignation work of the gas shielding device of the present invention, in order to deflate (exhaust) the donut 3a, the pressure regulator 8 is removed, an exhaust blower (not shown) is connected, and forced exhaust is performed. A series of trace clearing operations to be taken out from the inside of the expansion pipe 1 such as the gas shield 3 and the like thereafter are performed in reverse of the setup operation.

  The present invention is not limited to the above example, and it goes without saying that the embodiments may be changed as appropriate within the scope of the technical idea described in each claim.

  For example, when the donut portion 3a of the gas shield 3 is inflated to shield the blast furnace A side and the gas cleaning equipment C side, there is a risk that the gas shielding body 3 will rise if the pressure on the gas cleaning equipment C side rises.

  In this case, in order to prevent the gas shield 3 from rising and maintain the tight shielding between the doughnut portion 3a and the inner wall surface of the expansion tube 1 and continue gas shielding, a seal on the upstream side of the donut portion 3a is used. What is necessary is just to insert and arrange sandbags and the like from the manholes 6a to 6d in the circumferential direction on the film 3b. The same effect can be obtained even if water is applied to the inside of the donut 3a like a vinyl pool instead of the sandbag, but in this case, it is necessary to drain the water at the time of clearing work.

  Moreover, in FIGS. 6-8, the manhole 6a, 6b of the direction which takes in the gas shield 3 and insulator 5a, 5b has shown what was made into the square shape in consideration of workability | operativity. Further, the manholes 6c and 6d orthogonal to the manholes 6a and 6b are generally rounded so as to facilitate a manual operation (not shown) and an expansion (expansion) operation of the gas shield 3 in the expansion pipe 1. Shows the type. However, both of them may be square or round.

  The gas shutoff technology at the upper part of the blast furnace dust remover according to the present invention is not limited to gas shielding between the descending pipe of the blast furnace and the spreader pipe of the dust remover, but can also be applied to seals of pipes that may be deteriorated or damaged by temperature.

A Blast Furnace B Dust Remover C Gas Cleaner D Draft Pipe E Descent Pipe F Tuyere G Furnace Ignition System H Breeder Valve 1 Expansion Pipe 2 Deck Part 3 Gas Shield 3a Donut Part 3aa Supply / Exhaust Port 3ab Pressure Detection Port 3b Seal Film 4 Scaffolding pipe 4a Pipe 4b Wire rope 5, 5a, 5b Insulator 6a-6d Manhole 11 Seal belt 7 Compressor 8 Pressure regulator 9 Supply / exhaust hose 10 Pressure detection hose

Claims (6)

After installing a plurality of scaffolding pipes in a penetrating manner so as to be horizontal in the spreading pipe of the dust remover connected to the descending pipe of the blast furnace, insert the insulator from the direction perpendicular to the scaffolding pipes for the scaffolding. Unfold on the pipe, form a cocoon floor,
Next, a gas shield having a sealing film provided on the floor surface of the donut portion is inserted on the formed insulator floor and then expanded. A gas shielding method in an upstream portion of a blast furnace dust remover, characterized in that the gas tightly contacts an inner wall. A gas shielding device installed in an expansion pipe of a dust remover connected to a downflow pipe of a blast furnace,
A plurality of scaffolding pipes installed in a penetrating manner in the spreading pipe;
The insulators supported by these scaffolding pipes,
A gas shield provided with a seal film on the floor surface of the donut part, which is placed on the insulator floor formed by spreading the insulator on the scaffold pipe;
The gas shielding apparatus in the upstream part of a blast furnace dust remover characterized by having.   3. The gas shielding apparatus at an upstream portion of a blast furnace dust remover according to claim 2, wherein the insulator is formed in a semi-circular shape that is divided into two pairs.   The gas shield device at the upstream portion of the blast furnace dust remover according to claim 2 or 3, wherein the insulator has a configuration in which a pipe material or a steel bar is connected with a rope.   The gas shielding apparatus in the upstream part of the blast furnace dust remover according to any one of claims 2 to 4, wherein a sealing belt for gas sealing is installed on an outer peripheral side surface of the donut part of the gas shielding body.   6. The gas shielding apparatus at an upstream portion of a blast furnace dust remover according to claim 5, wherein the seal belt is made of rubber with an uneven groove.

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