JP4344183B2 - Joint structure of fireproof double-layer pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a joining structure of a fireproof double-layered tube composed of an inner tube and an outer tube .
[0002]
[Prior art]
FIG. 4 shows a cross section of a conventional joining structure of this type of refractory double-layer pipe. The joint structure of the fireproof double-layer pipe includes a pipe joint 5 having a fireproof double-layer structure disposed between the pair of fireproof double-layer pipes 1. Each refractory bilayer tube 1, the inner tube 2, that Do from the outer tube 4 provided coaxially through the space portion 3 of the annular outer periphery thereof. On the other hand, also the pipe joint 5 consists of an inner tube 6 and outer tube 8 which is disposed coaxially through the annular space portion 7 on the outer periphery thereof. Each of the inner pipes 2 and 6 is made of a resin such as hard vinyl chloride, and each of the outer pipes 4 and 8 is made of a fiber reinforced mortar. The inner surface of the inner tube 6 of the pipe joint 5, the open end face 2b of the inner tube 2 a pair of refractory bilayer tube 1 is formed in contact with the annular protrusion 6b respectively. Between the pipe joint 5 and the outer pipe 4 of each refractory double-layer pipe 1, an annular packing 9 of ceramic fiber that functions as a joint treatment material is interposed.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional fire-resistant double-layer pipe joining structure, the annular packing 9 is made of ceramic fiber. Therefore, in the event of a fire, the fire- resistant double-layer pipe 1 and the pipe joint 5 expand and contract, There was a problem that a gap of a predetermined amount or more was generated between the fireproof double-layer pipe 1 or the pipe joint 5 and smoke leaked from the gap.
[0004]
Accordingly, the present invention has been made in view of the above-described problems in the conventional fire-resistant double-layer pipe joint structure, and provides a fire-resistant double-layer pipe joint structure that can reliably prevent smoke leakage in the event of a fire. For the purpose.
[0005]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a joint structure of the refractory bilayer tube composed of the inner and outer tubes, among which each inner tube of a pair of refractory bilayer tube for bonding is inserted from both sides A pipe joint with a fireproof two-layer structure consisting of a pipe and an outer pipe whose end faces are pressed against both end faces, and the end face of the outer pipe of each fireproof double-layer pipe hits the end face of the outer pipe of the pipe joint A sheet provided so as to cover the portion that is formed, and the sheet is an elastic adhesive sheet, in a deployed state before winding, a thickness of 0.5 to 2 mm, a width of 20 mm or more, The outer diameter of the winding part when wound in a state has a length that is 1 mm to 10 mm larger than the outer diameter of the outer pipe having the larger outer diameter among the outer pipe of the fireproof double-layer pipe and the outer pipe of the pipe joint. Features.
[0006]
The elastic pressure-sensitive adhesive sheet is preferably made of butyl rubber, and the elastic pressure-sensitive adhesive sheet is made of a synthetic rubber-based support such as butyl rubber, styrene-butadiene rubber, or polychloroprene rubber, and a pressure-sensitive adhesive such as synthetic rubber-based, silicone-based, or acrylic-based. It is desirable that it is composed of an agent.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, FIG. 1 shows a joint structure obtained by developing a joint structure of a conventional refractory double-layer tube . The joining structure 21 of the fireproof double-layered pipe composed of the inner pipe and the outer pipe includes a pair of fireproof double-layered pipes 23 and 23 for joining , and a fireproof double-layered pipe joint 25 disposed therebetween. And an annular packing 27 that functions as a joint treatment material. Each refractory bilayer pipe 23, a resin tube 29 as inner tube, Tona Ru and mortar cladding 31 as the outer tube is provided coaxially on the outer periphery thereof. On the other hand, also the pipe joint 25, the resin tube 33 as inner tube, Ru and mortar cladding 35 as an external tube provided coaxially on the outer periphery Tona. In addition, in such a form, since the vinyl chloride pipe | tube is specifically used as an example of the resin pipe | tube, it calls the vinyl chloride pipe | tubes 29 and 33 below. The vinyl chloride pipe 29 in each refractory double-layer pipe 23 extends longer than the mortar cladding pipe 31, and the end of the vinyl chloride pipe 29 is exposed on the outside in the longitudinal direction of the corresponding mortar cladding pipe 31. The vinyl chloride pipe 29, which is the inner pipe of the refractory double-layer pipe 23 , is inserted into the inner pipe of the pipe joint 25 from both sides thereof, so that the pipe joint 25 connects the exposed ends of these adjacent vinyl chloride pipes 29 to each other. Cover. An annular protrusion 37 is formed on the inner surface of the vinyl chloride pipe 33 of the pipe joint 25 so as to protrude radially inward. Therefore, when the end portion of the vinyl chloride tube 29 of a pair of refractory bilayer tube 23 is inserted into the vinyl chloride pipe 33 of the pipe joint 25 are each an end surface 23a which faces the vinyl chloride pipe 29 is annular projection 37 equivalents Ru is spaced apart from each other with contact.
[0008]
The annular packing 27 is the outer periphery of the end portion of the vinyl chloride tube 29 of the fireproof double-layer tube 23, and is between the end surface of the mortar cladding tube 31 of the fireproof double-layer tube 23 and the end surface of the mortar cladding tube 35 of the pipe joint 25. Placed in position. The annular packing 27 is made of a resin foam. Specific examples of the resin foam include a material mainly composed of polyolefin foam, foamed polyethylene or foamed polypropylene, and an elastic material such as polystyrene foam, urethane foam, polyethylene foam, and EPDM foam. Further, the annular packing 27 has a thickness of 5 to 20 mm (more preferably 5 to 10 mm) and an inner diameter of 0 to 5 mm (more preferably) than the outer diameter of the vinyl chloride tube 29 of the fireproof double-layer tube 23. the 2 to 5 mm) rather small, its outer diameter to the large value (more preferably than the outer diameter of the mortar cladding tube 31 of a refractory bilayer tube 23 is set to 12~50mm). The reason for setting these dimensions is that if the thickness is less than 5 mm, the restoration may be insufficient and the change in joint width may not be tracked. This is because improvement cannot be expected. Also, if the inner diameter is 5 mm or more smaller than the outer diameter of the vinyl chloride pipe 29, there is a risk of damage during mounting. Conversely, if the inner diameter is larger than the outer diameter of the vinyl chloride pipe 29, the packing will slip off the sliding fire-resistant double-layer pipe when compressed. Because there is a fear. Furthermore, when the outer diameter is not 12 mm or more larger than the outer diameter of the mortar cladding tube 31, the outer diameter is smaller than the mortar cladding tube 31 of the refractory double-layer tube 23, and the joint portion may not be completely covered. On the other hand, if the diameter is increased by 50 mm or more, the improvement of the leakage prevention effect cannot be expected with respect to the increase of the diameter, and in addition, it becomes easy to peel off due to an external force, and the appearance of the finish is impaired because it protrudes excessively from the piping. Problems can arise.
[0009]
An adhesive layer is provided on both sides of the annular packing 27. Thereby, even if the mortar cladding tubes 31 and 35 move, the joint portion does not leave. The annular packing 27 is attached to the pipe joint 25 in advance. Thereby, a pair of fireproof two-layer pipe 23 can be inserted and assembled in the pipe joint 25 to which the annular packing 27 is affixed, and workability | operativity becomes favorable.
[0010]
Next, regarding the joint structure of the fireproof double-layered tube having the above-described configuration, the test results for the leakage prevention performance are shown below. FIG. 2 schematically shows a test facility for leakage prevention performance. In the test container 41, the fire-resistant double-layer tube joint structure 21 according to the present invention and the fire-resistant double-layer tube joint structure as a comparative example are accommodated. An air supply source 45 is connected to the test container 41 via a supply pipe 43. The outflow end 43a of the supply pipe 43 is arranged inside the joint structure of the fireproof two-layer pipe, and air is supplied only to the inside of the joint structure of the fireproof two-layer pipe. Furthermore, an opening pipe 47 and a communication pipe 49 are connected to the test container 41. An inflow end 47 a of the opening pipe 47 is disposed inside the test vessel 41 and outside the fire-resistant two-layer pipe joining structure, and an opening valve 51 is provided on the downstream side of the opening pipe 47. Yes. The inflow end 49 a of the communication pipe 49 is disposed inside the fireproof two-layer pipe joint structure, and a manometer 53 for measuring pressure is provided on the downstream side of the communication pipe 49.
[0011]
In the test facility having such a configuration, first, a fire-resistant double-layer tube joining structure 21 as a reference example is disposed in a test container 41, and the test container 41 is sealed. Then, air is supplied from the air supply source 45 through the supply pipe 43 into the refractory double-layer pipe joining structure 21. In such supply, the pressure inside the joining structure 21 of the fireproof double-layered tube becomes about 980 Pa (100 mmH ₂ O), and the pressure inside and outside the joining structure 21 is balanced via the joint, and the inside of the test container 41 is fireproof. The pressure outside the joining structure 21 of the two-layered tube is also increased to about 980 Pa (100 mmH ₂ O). From this state, the release valve 51 is opened to open the inside of the test container 41. Thereby, the air inside the joining structure 21 of the refractory double-layer pipe can flow out of the joining structure 21 from the joint portion. And the pressure inside the joining structure 21 of the refractory double-layer tube during this period is measured by the manometer 53, and the pressure decrease from the initial internal pressure of about 980 Pa (100 mmH ₂ O) is detected as the degree of leakage at the joint.
[0012]
In the joint structure 21 of the fireproof double-layer pipe of this reference example, a nominal diameter (JIS K 6741) of 50 mm is used as the vinyl chloride pipe 29 of the fireproof double-layer pipe 23, and the annular packing 27 is formed from EPDM foam. A pipe having a thickness of 10 mm and an outer diameter 46 mm larger than the outer diameter of the vinyl chloride pipe 29 of the fireproof double-layer pipe 23 is used. The outer diameter of the mortar covering tube 35 of the pipe joint 25 is equal to the outer diameter of the annular packing 27. Or more at a junction structure 21 of the refractory bilayer tubes, such as the residual pressure after opening the initial pressure of about 980Pa (100mmH ₂ O) was about 578Pa (59mmH ₂ O). In order to sufficiently block smoke in actual use, it is sufficient that the residual internal pressure after opening is about 196 Pa (20 mm H ₂ O) from the initial internal pressure of about 980 Pa (100 mm H ₂ O). On the other hand, with respect to the conventional fire-resistant double-layered tube joint structure shown in FIG. 4, when the test process and conditions were carried out in the same manner, the residual internal pressure after release from the initial internal pressure of about 980 Pa (100 mmH ₂ O) was about 29. The pressure was 4 Pa (3 mmH ₂ O). Thus even at the joint structure 21 of the refractory bilayer tube as a reference example, it was found that can exhibit sufficient leakage prevention performance in joints. In addition, for each of the joining structure of the fireproof double-layer pipe as a reference example and the joining structure of the conventional fireproof double-layer pipe shown in FIG. 4, a heating test for 72 minutes in accordance with ISO 834 was also conducted. Smoke leakage was observed in the fire-resistant double-layer pipe joint structure, but no smoke leak was observed in the fire-resistant double-layer pipe joint structure as a reference example .
[0013]
Embodiment.
FIG. 3 shows a joining structure of a refractory double-layer pipe according to an embodiment of the present invention. The fireproof double-layered pipe joint structure 51 according to the embodiment of the present invention uses an elastic adhesive sheet in place of the annular packing as the joint treatment material in the above reference example . In this embodiment, the end surfaces of the mortar cladding tube 31 of each fireproof double-layer tube 23 are abutted against the corresponding end surfaces of the vinyl chloride tube 33 and the mortar cladding tube 35 of the pipe joint 25. Elastic adhesive sheet 57, so as to cover the part fraction end faces of the mortar cladding tube 31 of the pair of refractory bilayer pipe 23 is confronted to the end surface of the mortar cladding 35 of the pipe joint 25, the refractory bilayer tube 23 It is wound over the mortar cladding tube 31 and the mortar cladding tube 35 of the pipe joint 35 and is attached to both. The elastic pressure-sensitive adhesive sheet 57 is a rubber-like elastic body having a self-bonding property such as butyl rubber, or a synthetic rubber base such as butyl rubber, styrene butadiene rubber, or polychloroprene rubber, and a synthetic rubber base, a silicone base, an acrylic base, or the like. It consists of an adhesive. Moreover, about the elastic adhesive sheet 57 , the dimension of the expansion | deployment state before the winding is demonstrated, The thickness is 0.5-2 mm (preferably 0.5-1 mm), The width | variety (pipe at the time of winding to a pipe | tube) axial direction) 20mm or more, a length (circumferential direction upon wrapping to the tube), the outer winding portion than the outer diameter of the larger the winding outer tube (mortar cladding 35 of FIG. 3, the pipe joint 25) The diameter is set to be 1 mm to 10 mm larger (preferably 5 to 10 mm larger). The reason for setting these dimensions is that if the thickness is less than 0.5 mm, the shape is difficult to stabilize, and it is easy to cause a leak that causes leakage. May be insufficient. Further, if the width is less than 20 mm, the adhesive strength of the tube to be coated is insufficient, when it exceeds 100 mm, increase of leakage prevention effect against the increase in the outer diameter of can not be expected. Further, when the sheet length is wound in the unfolded state, the end face of the outer tube of the refractory double-layer tube is not less than 1 mm larger than the outer diameter of the tube to be wound with the larger outer diameter of the winding portion. There may not be completely cover the portion that is confronted to the end surface of the outer tube of the joint, it becomes greater beyond the 10mm than the outer diameter of the object to be wrapped tube, leakage increases to a pair of outer diameter of the wrapped portion This is because improvement of the prevention effect cannot be expected.
[0014]
Next, regarding the joint structure of the refractory double-layer tube according to the present embodiment having the above-described configuration, the test results regarding the leakage prevention performance are shown below. The same leakage prevention performance test equipment as in the reference example shown in FIG. 2 is used. Moreover, as the joining structure 51 of the fireproof two-layer pipe according to this embodiment, a nominal diameter (JIS K 6741) of 50 mm is used as the vinyl chloride pipe 29 of the fireproof two-layer pipe 23, and the elastic adhesive sheet 57 is supported by butyl rubber. It is composed of a body and a synthetic rubber adhesive, and in the unfolded state, it has a thickness of 1 mm, a width of 50 mm, and a length of 1000 mm . Test results, the residual pressure after opening the initial pressure of about 980Pa (100mmH ₂ O) was about 813.4Pa (83mmH ₂ O). In order to sufficiently block smoke in actual use, it is sufficient that the residual internal pressure after opening is about 196 Pa (20 mmH ₂ O). Therefore, the joint structure 51 of the refractory double-layer pipe according to the present embodiment is also included. It has been found that sufficient leakage prevention performance can be exhibited at the portion where the end face of the outer pipe of each fireproof double-layer pipe is abutted against the end face of the outer pipe of the pipe joint . In addition, when a heating test for 72 minutes in accordance with ISO834 was performed as in the case of the reference example, no smoke leakage was observed even in the joined structure of the fireproof two-layer tube of the present embodiment.
[0015]
【The invention's effect】
As described above, according to the joining structure of the fireproof double-layered pipe of the present invention, the end face of the outer pipe of each fireproof double-layered pipe becomes the end face of the outer pipe of the pipe joint by using the elastic adhesive sheet of a predetermined condition. It has become possible to more reliably prevent smoke from leaking from the part that is being struck .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a joining structure of a fireproof two-layer pipe as a reference example .
FIG. 2 is a diagram schematically showing a test facility for leakage prevention performance.
FIG. 3 is a cross-sectional view of a joint structure of a refractory double-layer tube according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view of a conventional refractory double-layer tube joining structure.
[Explanation of symbols]
21, 51... Refractory double-layer pipe joint structure, 23 refractory double-layer pipe, 25 refractory double-layer pipe joint, 27, annular packing, 29, resin (vinyl chloride) ) Tube (inner tube of refractory double-layer tube), 31 ... Mortar cladding tube (outer tube of refractory double-layer tube), 33 ... Resin (vinyl chloride) tube (inner tube of pipe joint), 35 ... -Mortar cladding tube (outer tube of pipe joint), 57 ... elastic adhesive sheet.

Claims (3)

In the joint structure of a fireproof double-layered tube consisting of an inner tube and an outer tube,
A fire-resistant double-layer structure comprising an inner tube in which ends of each inner tube of a pair of fire-resistant double-layer tubes to be joined are inserted from both sides and an outer tube in which the end surfaces of each outer tube are abutted against both end surfaces And a sheet wound so as to cover a portion where the end face of the outer pipe of each fireproof double-layer pipe is abutted against the end face of the outer pipe of the pipe joint , and the sheet is an elastic adhesive sheet. there are, in the deployed state, the thickness of 0.5 to 2 mm, 20 mm or wider, outside of which the outer tube of the outer tube and pipe fittings of the outer diameter of the refractory bilayer tube winding portion when wound in that state structure for joining refractory bilayer tube characterized by having a large 1mm~10mm larger length such than the outer diameter of the outer tube diameter. A joining structure of a fireproof two-layer pipe, wherein the elastic adhesive sheet is made of butyl rubber. The elastic adhesive sheet is composed of a synthetic rubber base such as butyl rubber, styrene butadiene rubber or polychloroprene rubber, and a synthetic rubber base, silicone base, acrylic base adhesive or the like. Layered tube joint structure.

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