Flue sealing balloon and flue sealing method

Abstract

To provide a simple and easy flue seal balloon which can perform repair work in a flue or the like by blocking the flow-in of a gas to a repair zone, and a flue seal method.SOLUTION: There are used two pieces of elastomer-made flue seal balloons each having a cylinder part, side faces for blocking both end parts of the cylinder part in an axial direction, an air sending port arranged at one of the side faces, and grips which are arranged in a position which is separated in the axial direction at one point of an external peripheral face of the cylinder part in a peripheral direction. The two pieces of sulfuric acid flue seal balloons are transported up to both-side positions of a zone including a manhole and a repair target of the flue via the manhole, and installed thereat, and the balloons are expanded until the external peripheral face of the cylinder part contacts with an inner wall face of the flue, thus sealing the flue.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flue sealing balloon and a flue sealing method using the flue sealing balloon, which are applied to flue gas ducts in the flue gas recovery process of copper smelting, more specifically, to ducts located near a conversion process in which sulfurous acid (SO2) gas generated in the copper smelting is converted into sulfuric acid gas (SO3). [Background technology]

[0002] Sulfurous acid (SO2) gas, an exhaust gas generated during copper smelting, is purified in an exhaust gas purification process consisting of a humidifier, a scrubber, a mist cotter, and a drying tower, and then introduced into the converter via the flue and main blower. In the converter, the sulfurous acid gas is converted into sulfuric acid (SO3) gas by a vanadium pentoxide catalyst, and then in the absorption tower, the sulfuric acid gas is brought into gas-liquid contact with circulating sulfuric acid, and the sulfurous acid gas is absorbed, and the sulfurous acid gas is finally recovered as sulfuric acid.

[0003] The flue around the converter may develop holes caused by corrosion from the sulfuric acid mist flowing from the converter, or cracks caused by expansion and contraction due to temperature changes when the equipment is shut down. If such holes, cracks, or other damage exist, there is a possibility that sulfur dioxide gas may leak from the flue, so it is necessary to shut down the equipment as soon as possible and repair the damaged area. Most such damaged areas can be repaired from the outside of the flue, but there are cases where it is better to repair from the inside of the flue.

[0004] Furthermore, if sulfuric acid mist adheres to the impeller of a blower installed in the flue passage near the converter for a long period of time, the blower may malfunction, making it necessary to urgently maintain the blower, such as by replacing the impeller.

[0005] In these cases, workers will carry out repair work from inside the facility (inside the flue) to repair damaged areas in the flue or malfunctions in the blower, but even if the blower is stopped to carry out these repair work from inside the facility, white sulfuric acid gas will flow back from the converter into the flue, filling it up. This makes it difficult to see inside the flue, and makes it extremely difficult for workers to carry out repair work while wearing a gas mask with a respirator.

[0006] For this reason, when repair work is carried out inside the equipment near the converter, it is necessary to carry out a gas purge to remove the sulfuric acid gas inside the flue. However, in this case, a long-term shutdown of about one week is required, including the heating process after the repair work, resulting in a significant loss in terms of operation and energy.

[0007] Incidentally, Japanese Patent Application Laid-Open No. 2006-226372 discloses an example of a fluid blocking device for blocking the flow of a fluid in a pipeline, which uses a bag-shaped balloon that can be inflated until it comes into contact with the inner wall surface of the pipeline. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2006-226372 A Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to provide a simple flue sealing balloon and a flue sealing method using the flue sealing balloon, which makes it possible to carry out repair work on damaged parts of a flue or malfunctions of equipment such as a blower impeller inside the equipment while blocking out sulfuric acid gas, without requiring long-term shutdowns for gas purging or the like. [Means for solving the problem]

[0010] A flue sealing balloon in one embodiment of the present invention is made of an elastomer and comprises a cylindrical portion, side surfaces sealing both axial ends of the cylindrical portion, an air supply port provided on one of the side surfaces, and a handle provided at one circumferential location on the outer circumferential surface of the cylindrical portion at a position spaced apart in the axial direction, and is capable of being carried into a flue and being inflated until the outer circumferential surface of the cylindrical portion comes into contact with the inner wall surface of the flue.

[0011] The elastomer is preferably an acid-resistant rubber.

[0012] One embodiment of the present invention relates to a flue sealing method for sealing a flue having at least one manhole that allows access to the inside, when repairing an object to be repaired within the flue.

[0013] In particular, a flue sealing method according to one aspect of the present invention comprises the steps of: Using two flue sealing balloons of the present invention, Transporting and installing the two flue sealing balloons through the manhole to both sides of the section of the flue that includes the manhole and the repair target, and An inflation fluid is supplied to each of the two flue-sealing balloons through the air supply port to inflate the balloons until the outer circumferential surface of the cylindrical portion comes into contact with the inner wall surface of the flue, thereby sealing the flue. This includes:

[0014] After sealing the flue, gas present in the section can be removed via the manhole.

[0015] It is preferable that the manholes are provided at at least two locations in the path of the flue.

[0016] It is preferable that the repair target is equipment such as a blower provided in the path of the flue, and that the two locations are located on either side of the flue.

[0017] In one embodiment of the present invention, the exhaust gas and the gas present in the section are sulfuric acid gas and / or sulfur dioxide gas. In this case, the flue gas is referred to as a sulfuric acid flue gas. Effect of the Invention

[0018] By applying the flue sealing balloon of one embodiment of the present invention and the flue sealing method using this balloon, the flue can be easily sealed in a short time before sulfuric acid gas flows back into the flue from a converter or the like. It is also possible to quickly remove small amounts of sulfuric acid gas that flow into the seal and remain. This makes it possible to repair damaged areas of the flue and defects in equipment such as blowers inside the equipment without long-term operation shutdowns. For this reason, the industrial value of the present invention is extremely great. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of a flue sealing balloon according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram for explaining the placement of a flue sealing balloon according to one embodiment of the present invention when repairing a damaged portion of a flue using the balloon. [Diagram 3] FIG. 3 is a schematic diagram illustrating the installation of a flue sealing balloon according to one embodiment of the present invention when repairing a malfunction of a blower impeller of a blower located in the flue path. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] [Flue sealing balloons] 1 shows a flue sealing balloon 1 according to one embodiment of the present invention. The flue sealing balloon 1 of this example is made of elastomer and has a cylindrical shape as a whole.

[0022] The balloon 1 comprises a cylindrical portion 2, side surfaces 3 closing both axial ends of the cylindrical portion 2, an air supply port 4 provided in one of the side surfaces 3, and a handle 5 provided at one circumferential location on the outer circumferential surface of the cylindrical portion 2 at a position spaced apart in the axial direction.

[0023] The material of the balloon 1 is an elastomer containing rubber, and an appropriate elastomer can be selected from the viewpoints of elasticity and expandability. However, the elastomer is preferably an acid-resistant rubber, taking into consideration use in a flue 6 (see Figs. 2 and 3) in which sulfuric acid gas and / or sulfurous acid gas is present, and contact with the inner wall surface of the flue 6. Examples of acid-resistant rubber include chlorosulfonated polyethylene, butyl rubber, fluororubber, ethylene propylene rubber, chloroprene rubber, and nitrile rubber.

[0024] The balloon 1 has a cylindrical shape as a whole in an expanded state. Usually, the flue 6 of the exhaust gas in the exhaust gas recovery process of copper smelting has a cylindrical shape with a circular cross section, and the balloon 1 expands into a cylindrical shape, so that its outer circumferential surface can come into close contact with the inner wall surface (inner circumferential surface) of the flue 6. However, by adjusting the thickness of the balloon 1, it is possible to apply the balloon 1 to flue other than the flue having a cylindrical cross section. In addition, unlike a bag-shaped balloon, the balloon 1 has a cylindrical shape, so that it can expand in the circumferential direction while suppressing excessive expansion in the axial direction in the flue 6, and does not require a reinforcing member such as a holding plate. Therefore, it is possible to appropriately expand the balloon 1 at a predetermined location in the flue 6.

[0025] The cylindrical portion 2 has a cylindrical shape with an outer diameter that is approximately constant along its axial direction when the balloon 1 is inflated. The outer diameter of the cylindrical portion 2 is larger than the inner diameter of the flue 6. The outer diameter of the cylindrical portion 2 is selected arbitrarily depending on the size of the flue 6 to which it is applied. It is sufficient that the cylindrical portion 2 has an outer diameter that allows it to expand at least until it comes into contact with the inner wall surface of the flue 6.

[0026] The axial length of the cylindrical portion 2 is basically arbitrary as long as the sealing performance of the flue 6 by the balloon 1 is ensured. Therefore, from the viewpoint of transportability, it is preferable that the axial length of the cylindrical portion 2 is as short as possible as long as the sealing performance is ensured. The axial length of the cylindrical portion 2 is preferably equal to or less than the outer diameter of the cylindrical portion 2, more preferably 0.5 to 0.9 times the outer diameter of the cylindrical portion 2, and even more preferably 0.6 to 0.8 times the outer diameter of the cylindrical portion 2.

[0027] The side surfaces 3 are generally disc-shaped and are provided so as to close both axial ends of the cylindrical portion 2. Each side surface 3 has generally the same outer diameter as the cylindrical portion 2 when the balloon 1 is inflated. By providing the side surfaces 3, the balloon 1 is able to expand into a cylindrical shape since it preferentially expands in the radial direction during the transition from the folded state to the inflated state.

[0028] The thickness of the cylindrical portion 2 and the side surface 3 is appropriately determined taking into consideration the type of elastomer, the overall size of the balloon 1, its inflatability, its foldability when deflated, ease of transport, etc. For example, the thickness is preferably 0.3 mm to 3.0 mm, and more preferably 0.5 mm to 1.5 mm.

[0029] In the balloon 1 of this embodiment, two handles 5 are provided at one circumferential location on the outer circumferential surface of the cylindrical portion 2 at positions spaced apart in the axial direction. The number of handles 5 is preferably two or more, considering the portability of the balloon 1 in the contracted state, so that the balloon 1 can be easily carried by holding both handles 5 or one of the handles 5 and the cylindrical portion 2 with both hands. The size and thickness of the handles 5 are set arbitrarily in consideration of the portability of the balloon 1, as long as they do not impede the sealing property of the balloon 1 when the balloon 1 is inflated. For example, the size of each handle 5 is preferably 200 mm x 200 mm. The thickness of each handle 5 is preferably 0.3 mm to 3.0 mm, and more preferably 0.5 mm to 1.5 mm.

[0030] In the balloon 1 of this example, one of the two side surfaces 3 is provided with an air supply port 4 and an exhaust port 7. In this example, the air supply port 4 is composed of an opening provided on the side surface 3 and an attachment connected and fixed to this opening. When the balloon 1 is inflated and during use, it is connected to an attachment provided at the tip of the air supply hose 14. This state continues while the balloon 1 is in use. As a result, during use, the internal pressure within the balloon 1 is maintained so that the balloon 1 is in close contact with the inner wall surface of the flue 6. The air supply port 4 can also be provided with a valve body that prevents the inflation fluid, air or an inert gas such as nitrogen gas, from flowing out from inside the balloon 1 to the outside.

[0031] In the balloon 1 of this example, an exhaust port 7 is provided separately on one side surface 3 at a position away from the air supply port 4. The exhaust port 7 also consists of an opening provided on the side surface 3 and an attachment connected and fixed to this opening. When the balloon 1 is in storage or in an inflated state, a closing flange 8 is attached to the attachment of the exhaust port 7. When the balloon 1 is to be deflated, the inflation fluid can be discharged from inside the balloon 1 by removing the closing flange 8.

[0032] The materials constituting the air supply port 4, the exhaust port 7, and the closing flange 8 are arbitrarily selected from known materials.

[0033] The balloon 1 of this embodiment has appropriate elasticity and expandability, and preferably also has acid resistance, so that it can be transported and applied to a flue 6 where sulfur dioxide gas and / or sulfuric acid gas is present, such as a flue 6 for exhaust gas in an exhaust gas recovery process of copper smelting. In addition, the handle 5 allows the balloon 1 in a folded state to be easily carried into the flue 6. Therefore, by applying the balloon 1 according to the inner diameter of the flue 6, it is possible to install the balloon 1 at a necessary location in the flue 6 without the need for a reinforcing member, and by expanding the balloon 1 into a cylindrical shape until it contacts the inner wall surface of the flue 6, it is possible to properly seal the flue 6.

[0034] [Fue sealing method] FIG. 2 is a schematic diagram of a flue sealing method according to one embodiment of the present invention, and FIG. 3 is a schematic diagram of a flue sealing method according to another embodiment of the present invention.

[0035] The flue sealing method of this example makes it possible to seal a flue 6 that has at least one manhole 9 that allows access to the inside when repairing an object to be repaired within the flue 6 (such as a damaged area 10 in the flue 6 or the impeller of a blower 11).

[0036] In particular, the flue sealing method of this example uses two of the above-mentioned flue sealing balloons 1 of the present invention. Then, the two sulfuric acid flue sealing balloons 1 are transported through the manhole 9 to both sides of the section of the flue 6 that includes the manhole 9 and the repair target (repair section 12), and are installed.

[0037] As shown in Figure 2, manholes 9 that allow workers to enter and exit are installed at specified intervals in the flue gas flue 6 in the flue gas recovery process of copper smelting. For example, if a damaged area 10 occurs in the flue 6 and it is necessary to repair the damaged area 10 from the inside of the flue 6, the manhole 9 closest to the damaged area 10 is used.

[0038] For example, if the flue 6 is located near the upstream side of a converter (not shown) that converts sulfurous acid (SO2) gas into sulfuric acid gas (SO3), it takes about one hour for the white sulfuric acid gas to flow back into the flue and fill it after the converter and equipment such as a blower for transporting exhaust gas in the flue are stopped. Therefore, immediately after stopping the equipment, a worker wearing a gas mask with a respirator opens the cover of the manhole 9, passes through the manhole 9, and carries the folded balloon 1 by using the handle 5 to two places in the flue 6, one before and one after the damaged area 10 and the repair section 12 including the manhole 9.

[0039] After the balloon 1 is carried to the installation site and the worker exits the flue 6, the balloon 1 is inflated by supplying air or an inert gas such as nitrogen gas into the balloon 1 in advance or at the installation site through an air supply hose connected to the air supply port 4. The inflation fluid for the balloon 1 is selected according to the application and the conditions of the installation site. In this example, air can be used as the inflation fluid.

[0040] When the inflation fluid is supplied to the balloon 1, the balloon 1 expands into a cylindrical shape as shown in Fig. 1, and its outer periphery comes into contact with the inner wall surface of the flue 6 as a whole, and the outer periphery of the balloon 1 and the inner wall surface of the flue 6 are tightly attached, sealing the flue 6 at two points in the installation location. This prevents gases 13 such as sulfur dioxide and sulfuric acid gas from flowing into the repair section 12, which includes the manhole 9 and the damaged area 10, from both sides.

[0041] In this example, the small amount of gas remaining in the repair section 12, specifically, the residual gas such as sulfur dioxide gas present in the flue 6 and sulfuric acid gas that flowed in before the balloon 1 was installed, is removed from the repair section 12 by sucking and processing through the manhole 9. This makes it possible to carry out repair work on the damaged area 10 in the repair section 12. Note that in this example, after the repair work is completed, the closing flange 8 fitted into the exhaust port 7 of the balloon 1 is removed to remove the air from the balloon 1, and the worker uses the handle 5 to carry the balloon 1 from the flue 6 to the outside through the manhole 9, completing the work.

[0042] figure 2As shown in FIG. 1, when at least one manhole 9 is installed in the flue 6, two balloons 1 are installed so as to sandwich both the manhole 9 and the damaged area 10 from both sides, thereby sealing the flue 6 and enabling repair of the damaged area 10. However, from the viewpoint of shortening the repair section 12 sandwiched between the two balloons 1, or considering a case where a balloon 1 can be installed on one side of the manhole 9 but there is not enough space to install a balloon 1 on the other side of the manhole 9, it is preferable that at least two manholes 9 are installed in the flue 6.

[0043] More specifically, as shown in FIG. 3, when equipment such as a blower 11 is present in the path of the flue 6 and the repair target is inside the equipment such as the impeller of the blower 11, it is possible to install a balloon 1 on one side of the manhole 9 farther from the blower 11 in order to enable access to the equipment on at least one side (the left side in the example of FIG. 3), but it is impossible to install a balloon 1 on the other side of the manhole 9 closer to the blower 11. In such a case, manholes 9 are installed in two positions on both sides of the equipment that may require repair, such as the blower 11, at a predetermined distance from the equipment in the flue 6. In this way, when the repair target is equipment such as the blower 11 installed in the path of the flue 6, it is preferable that at least two positions for installing manholes are located on either side of the equipment in the flue 6.

[0044] In this case, the inside of the flue 6 is entered from two manholes 9 of the flue 6 installed near the blower 11, and the balloon 1 is installed and inflated at an appropriate position on at least one side of the blower 11, on the opposite side of the flue 6 to the blower 11. In the example of FIG. 3, the blower 11 can be accessed from the left side of the blower 11, but the blower 11 cannot be accessed because the valve 15 is present on the right side of the blower 11. For this reason, in this example, the balloon 1 is installed on the left side of the blower 11, on the opposite side to the blower 11, and on the opposite side, the balloon 1 is installed on the side of the manhole 9 where the blower 11 and the valve 15 are located, and inflated. In this way, the balloon 1 is installed so that the length of the repair section 12 is as short as possible, and the flue 6 is sealed. Similarly, if necessary, after removing residual gas from the repair section 12, it is possible to repair the inside of the equipment, such as the impeller of the blower 11.

[0045] The flue sealing method of this example makes it possible to easily seal the flue 6 in a short time before gas 13, such as white sulfuric acid gas, flows back into the flue 6 from a converter or the like. Therefore, even if gas 13, such as sulfuric acid gas, flows into the repair section 12 during sealing, it is possible to quickly remove a small amount of remaining gas 13 through the manhole 9. Therefore, it is possible to shorten the equipment downtime by about one week compared to the case where the entire flue 6 is gas purged and then the repair area is repaired. [Explanation of symbols]

[0046] 1. Balloon 2 Cylindrical section 3. Aspects 4 Air outlet 5 Handle 6 Flue 7. Exhaust port 8 Blind flange 9. Manhole 10 Damage 11 Blower 12 Repair Section 13. Gas 14 Air supply hose 15 Valve

Claims

1. A flue sealing balloon comprising a cylindrical portion, side surfaces closing both axial ends of the cylindrical portion, and two or more handles each capable of being grasped, the two or more handles being provided at one circumferential location on the outer circumferential surface of the cylindrical portion at positions spaced apart in the axial direction, the cylindrical portion, the side surfaces, and the two or more handles being made of an elastomer, and one of the side surfaces being provided with an air supply port consisting of an opening provided on the one side surface and an attachment connected and fixed to the opening, the balloon having at least one manhole allowing access to the interior, capable of being transported into a flue where a worker can move through the interior, and capable of being inflated until the outer circumferential surface of the cylindrical portion comes into contact with the inner wall surface of the flue.

2. 2. The flue sealing balloon of claim 1, wherein said elastomer is an acid resistant rubber.

3. A flue sealing method for repairing a repair target in a flue having at least one manhole that allows access to the inside and in which a worker can move inside, comprising: Using two flue sealing balloons according to claim 1 or 2, Transporting and installing the two flue sealing balloons through the manhole to both sides of the section of the flue that includes the manhole and the repair target, and an inflation fluid is fed to each of the two flue-sealing balloons through the air supply port to inflate the balloons until the outer circumferential surface of the cylindrical portion comes into contact with the inner wall surface of the flue, thereby sealing the flue. A method of sealing a flue comprising:

4. 4. The method of claim 3, further comprising removing gas present in said section through said manhole after sealing said flue.

5. The flue sealing method according to claim 3 or 4, wherein the manholes are provided at at least two locations in the flue path.

6. The flue sealing method according to claim 5 , wherein the repair target is equipment provided in the path of the flue, and the two locations are located on either side of the equipment in the flue.

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