JP5248304B2 - duct - Google Patents

Description

  The present invention relates to a duct with a heat insulating material excellent in heat insulation and heat insulation used in air conditioning equipment.

Patent Document 1 relates to a non-combustible heat insulating duct pipe, and paragraph 0002 thereof describes the following explanation regarding a conventional duct with a heat insulating material. “Non-combustible heat insulation duct pipes used for heating and cooling air ducts installed in buildings have traditionally been U-shaped at one end in the width direction of thin steel strips such as galvanized steel plates and stainless steel plates. Bend, bend the other side end into an inverted L shape, wind the strip in a spiral, and fit the other inverted K (L) -shaped protruding side into the adjacent U-shaped opening, this state Then, press and hold both the upper and lower caulking rolls to wind the non-flammable heat insulating material such as glass fiber around the outer peripheral surface of the spiral tube that connects the strips in a spiral shape to form a cylindrical body. It is made by forming a waterproof and moisture-proof layer such as asphalt roofing and aluminum-deposited plastic film on the surface. "
Thus, as a conventional duct with a heat insulating material, a rigid tube such as a spiral steel pipe is used as a base tube, and a heat insulating material such as glass wool is wound around the outer peripheral surface using an adhesive, and further, the outer peripheral surface is wound around the outer peripheral surface. An aluminum film wound with an adhesive is generally known and is distributed in the market.

Japanese Patent No. 3503333

However, the conventional duct with a heat insulating material has a layer structure in which a heat insulating material such as glass wool is wound around a spiral steel pipe and the outer surface is protected by winding an aluminum film, so that it is transported, stored, and constructed. The outermost aluminum film may be torn due to impacts from the outside, or the insulating film including the heat insulating layer may be dented, deformed, or the outermost layer may be broken and the glass wool, which is a heat insulating material, may scatter. . Further, when the glass wool is exposed, there is a problem that the function of the heat insulating material is deteriorated due to water or condensation, and the life is shortened. Furthermore, since the innermost layer is a metal pipe such as a spiral steel pipe, the sound easily reverberates in the duct and is easy to propagate.
In addition, because the innermost layer in the duct has irregularities due to spiral formation, dust tends to accumulate in this part, which becomes a hotbed for the generation of bacteria, so it was necessary to clean it, but this is a difficult task to maintain Management was troublesome.
The present invention has been made in consideration of the above circumstances, is excellent in strength against external impact, can prevent deterioration of the function of the heat insulating material, hardly resonates, and has a small diameter of the duct. It is an object to provide a duct that can realize high pressure, low pressure loss, and high heat insulation.

The present invention, insulation layer of a thermosetting resin foam is formed on the inner peripheral surface of the metal spiral tube, met duct formed by further thermal insulation material layer synthetic resin film layer on the inner peripheral surface of the formation And
The synthetic resin film layer forms the innermost peripheral surface of the duct, and the innermost peripheral surface has no inner surface reinforcing band or other band-like material wound spirally, and
The metal spiral tube and the heat insulating material layer, and the heat insulating material layer and the synthetic resin film layer, respectively, are formed between the spiral tube and the synthetic resin film layer to form the heat insulating material layer. The duct is characterized by being bonded without using an adhesive due to the self-adhesiveness of a thermosetting resin injected therebetween .

According to the duct according to the present invention, since the heat insulating material layer of the thermosetting resin foam is formed on the inner peripheral surface of the metal spiral tube, it is excellent in the strength against the impact from the outside. Glass wool, which is a heat insulating material, when the outermost aluminum film is torn, recessed or deformed, including the heat insulation layer, due to impact from outside during transportation, storage, construction, etc. Will not scatter. For this reason, the fall of the function of a heat insulating material, etc. can be prevented.
Moreover, since the synthetic resin film layer is formed in the innermost layer through the heat insulating material layer of the thermosetting resin foam, it is difficult for sound to reverberate and propagate in the duct. Even if a spiral tube with a goby part is used on the inner surface, there is no heat-insulating material layer and a synthetic resin film layer on the inner side, so the goze part does not protrude from the innermost peripheral surface of the duct. Turbulence can be reduced. There is no accumulation of dust in the innermost layer of the duct, and a clean state can be maintained.
In addition, the self-adhesiveness of the thermosetting resin injected between the spiral tube and the synthetic resin film layer to form the heat insulating material layer makes it possible to use the metal spiral tube and the heat insulating material layer without using an adhesive. However, the heat insulating material layer and the synthetic resin film layer are bonded to each other, and there are few processes and productivity is good. Since no adhesive is used, there is no generation of formaldehyde due to the use of the adhesive.
In addition, the thermosetting resin foam has a low thermal conductivity by using phenol urethane foam, compared with a duct using conventional glass wool, etc., so that the duct has a small diameter, low pressure loss, high Thermal insulation can be realized. Since it can be manufactured by non-fluorocarbon foaming, it is also environmentally beneficial.
Further, the density of the phenol urethane foam is 20 to 80 kg / m ³ , and the thermal conductivity (0 ° C.) is 0.020 to 0.024 W / (m · K). Loss and high heat insulation can be realized significantly.
Moreover, the synthetic resin film layer has a configuration in which riblet processing is performed in the axial direction of the duct, thereby reducing the turbulent flow of air passing through the inside and reducing pressure loss.

  Examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and additions are possible within the scope of the present invention.

  1A and 1B show a duct 1 according to an embodiment, in which FIG. 1A is a side view, FIG. 2B is a front (cross-sectional) view, FIG. It is explanatory drawing of a manufacturing method.

<Overall structure>
The duct 1 includes a cylindrical spiral tube 10 that forms an outermost layer, a heat insulating material layer 20 that forms an intermediate layer, and a synthetic resin film layer 30 that forms an innermost layer in order from the outer peripheral side to the inner peripheral side. Has been.

<Spiral tube>
The spiral tube 10 constituting the base tube of the duct 1 is made of metal and has rigidity. It is formed in a cylindrical shape by winding a belt-like plate in a spiral and fitting the overlapping portions with gouge fitting. The strip plate is composed of a galvanized steel plate, a stainless steel plate, a highly corrosion-resistant hot-dip galvanized steel plate, a vinyl chloride resin-coated steel plate, aluminum, and other metal plates, and the plate thickness is usually about 0.3 to 2.0 mm. .
The goby fitting part 11 of the spiral tube 10 is formed, for example, as shown in FIG. 2 by the gouge fitting of the outer gouge part 13 and the inner gouge part 15. In the illustrated example, the goby fitting portion 11 is formed so as to protrude on the inner peripheral surface of the spiral tube 10, does not protrude on the outer peripheral surface, and the outer peripheral surface is flat.
The outer goby portion 13 is located on one side edge of the belt-like plate and has an outer side edge portion 13a that forms a part of the outer surface of the spiral tube 10, and a U-shaped cross section that continues to the outer side edge portion 13a. It consists of a folded portion 13b that is folded back in a goby shape.
The inner goby portion 15 is located on the other side edge of the belt-like plate, and forms an inner side edge portion 15a (which wraps inside the folded portion 13b) that forms a part of the inner surface of the spiral tube 10. It consists of a folded portion 15b which is folded outwardly in a goby shape so as to be U-shaped in cross-section and connected to the side edge portion 15a.
The folded-back portion 13b of the outer goby portion 13 and the folded-back portion 15b of the inner goped portion 15 are fitted into a gap having a U-shaped cross section of the other goby portion, so that the outer gouge portion 13 and the inner gozel portion 15 are It is joined by goby fitting.
Although it is possible to form the goby fitting portion 11 on the outer peripheral surface of the spiral tube, there is a gouge fitting portion on the outer peripheral surface by using the spiral tube 10 in which the gouge fitting portion 11 is formed on the inner peripheral surface. There are no catches that occur during construction, and it is easy to work, and since there are a heat insulating material layer and a synthetic resin film layer on the inside, the goby part does not protrude on the innermost peripheral surface of the duct, so it passes through the inside Air turbulence can be reduced.
In addition, elbow pipes used for duct connection parts and spiral pipes used as curved ducts are made of relatively thin materials such as aluminum foil and iron foil with a thickness of about 0.05 to 0.15 mm. It is desirable to use it. As a spiral tube obtained by spirally winding such a thin metal plate, for example, as described in Japanese Utility Model Publication No. 3-17105 (see FIG. 4), an intermediate position between the adjacent goby fitting portions 11 is used. In addition, there may be mentioned a structure in which several corrugated ribs 12 are configured such that 12 are in close contact with each other so as to be stretchable. FIG. 4A is a partially enlarged view showing the goby fitting portion 11 and the corrugated rib 12, and FIG. 4B is a side view showing an extended state of the spiral tube 10.

<Insulation layer>
The heat insulating material layer 20 is disposed in close contact with the inner peripheral surface of the spiral tube 10. The heat insulating material constituting the heat insulating material layer 20 is made of a thermosetting resin foam.
The thermosetting resin foam has a closed cell structure and is formed of polyurethane foam, phenol foam, phenol urethane foam, or the like. Preferably, phenol urethane foam is used.
A phenol urethane foam is a foam obtained by mixing a phenol resin with a polyol and an isocyanate which are main components constituting a urethane foam.
Combines the advantages of phenolic foam with excellent heat resistance and heat insulation, and the advantages of urethane foam with excellent cost performance and workability. Excellent self-curing and self-adhesive properties, and as a major feature, foaming with CFCs and CFCs to achieve high thermal insulation (thermal conductivity of about 0.026), which was a major problem with polyurethane foam, is foaming with CFCs instead. it can. This makes it possible to achieve high thermal insulation (0.024 or less) while realizing environmental measures.
It can be obtained by mixing a foaming agent, a curing agent, a foam stabilizer and the like with the main constituent components, foaming and curing. For example, a foaming ratio of 15 to 25 times can be used.
The density of the phenol urethane foam is preferably 20 to 80 kg / m ³ , and the thermal conductivity (0 ° C.) is 0.020 to 0.024 W / (m · K).
Although the thickness of the heat insulating material layer 20 depends on the size of the duct and the like, it is usually 10 to 25 mm.

<Synthetic resin film layer>
The synthetic resin film layer 30 is formed in close contact with the inner surface of the heat insulating material layer 20. By providing the synthetic resin film layer 30 on the inner surface of the heat insulating material layer 20, a cylindrical internal space having no projecting portion and forming a smooth surface as a whole is formed, and turbulent flow of air passing through the inside hardly occurs.
For the synthetic resin film of the synthetic resin film layer 30, a thermoplastic resin having good adhesion to the heat insulating material layer 20, gas barrier properties, and heat resistance is used. For example, a PET (polyethylene terephthalate) film is used. The thickness of the synthetic resin film layer 30 is, for example, 30 to 100 μm. It is also possible to use a composite film having a plurality of layers in addition to a single layer.
The synthetic resin film layer 30 preferably has a riblet process on its inner surface in the axial direction of the duct. By applying the riblet processing, the turbulent flow of air passing through the inside can be reduced and the pressure loss can be reduced. An example of the riblet is one in which fine linear protrusions are provided in the axial direction of the duct at an interval of 10 to 100 μm, for example.

<Manufacturing method>
Although the manufacturing method of the duct based on this invention is not limited at all, an example is shown below.
(1) As shown to Fig.3 (a), the mold 40 which wound the synthetic resin film 30 is inserted in the center of the spiral pipe 10 of the metal required length made into the cylinder. As this mold, one having a diameter that can be enlarged or reduced (not shown) is used.
(2) Next, in the state where both ends of the gap are closed in the gap 25 formed between the spiral tube 10 and the mold 40 (form 40 wound with the synthetic resin film 30), the above-mentioned thermosetting is performed. A required amount of a thermosetting resin (composition) having self-adhesive properties for forming a foamable resin foam is injected together with a foaming agent, a curing agent, and a catalyst as necessary.
(3) After the injected thermosetting resin is foamed and cured, only the mold 40 is drawn out with the mold diameter reduced. Thereby, as shown in FIG. 3B, the heat insulating material layer 20 of the thermosetting resin foam is formed on the inner peripheral surface of the metal spiral tube 10, and further on the inner peripheral surface of the heat insulating material layer 20. The duct 1 in which the synthetic resin film layer 30 is formed is obtained.
Due to the self-adhesiveness of the thermosetting resin, the metal spiral tube 10 and the heat insulating material layer 20 and the heat insulating material layer 20 and the synthetic resin film layer 30 are firmly bonded simultaneously without using an adhesive. There are few steps and productivity is good. Since no adhesive is used, there is no generation of formaldehyde due to the use of the adhesive.
In addition to the above, it is possible to use a method of filling the resin material in the middle of foaming in a foam shape by air pressure, or any other appropriate method.

<Example>
The duct was manufactured based on the said manufacturing method using the cylindrical 150 mm diameter formwork which installed the turnbuckle inside. In addition, as a thermosetting resin material for forming a heat insulating material layer (phenol urethane foam), isocyanate: polyol (with phenol resin) = 1: 1 by weight ratio (specific gravity 1.15, viscosity 300 to 400 (Pa · s) and a foaming ratio of 25 to 30 times).
The obtained duct has the following configuration.
・ Spiral tube: Spiral steel tube with outer diameter of 175mm, thickness 0.5mm ・ Heat insulation layer: Density of phenol urethane foam is 40kg / m ³ , thermal conductivity (0 ℃) is 0.022W / (m ・ K)
Synthetic resin film: PET film with a thickness of 50 μm

The duct obtained in the above example and a commercially available conventional duct (the same material as in the above example, a spiral tube having the same structure as a base tube, and a glass wool heat insulating material (density: 40 kg / m ³ , Thermal conductivity: 0.045W / (m · K), thickness 25mm) is wound using an adhesive, and an aluminum film is wound around the outer peripheral surface using an adhesive) The following effects are obtained when compared to.
(1) Reducing the diameter Since the heat insulating performance of the heat insulating material is about twice that of glass wool, the duct of the embodiment having the same inner diameter as the conventional product has a thickness of about 10 mm compared to the thickness of the conventional heat insulating material of 25 mm. It can be suppressed to a degree. For this reason, while having the performance equivalent to the conventional product, the installation space in a building can be made small and work efficiency can be improved.
About 20% space saving can be realized in transportation and storage space.
(2) Low pressure loss Since the inner diameter of the duct having the same outer diameter as that of the conventional product can be increased by about 30 mm, the pressure loss of the air passing through the duct is reduced by 50 to 70% compared to the conventional product. Can do. Thereby, exceptional loss can be reduced in the same installation space.
(3) High heat insulation The duct of the embodiment having the same outer diameter and inner diameter as the conventional product can obtain heat insulation performance about twice that of conventional glass wool. Thereby, it becomes difficult to transfer the heat in the duct to the outside, and the thermal efficiency can be improved.
Non-fluorocarbon foaming using phenol urethane foam achieves a thermal conductivity of 0.022 or less, which could not be achieved with non-fluorocarbons, and is superior in terms of flame retardancy compared to general rigid polyurethane foam.
The use of non-fluorocarbon foam insulation can avoid global warming and ozone depletion problems.

The duct 1 is shown, (a) is a side view, (b) is a front (cross-sectional) view. 2 is a side cross-sectional view illustrating a goby portion 11. FIG. It is a front view of a duct and is an explanatory view of a manufacturing method. It is the elements on larger scale and the side view of spiral pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Duct 10 Spiral pipe 20 Thermal insulation layer 30 Synthetic resin film layer 40 Formwork

Claims (1)

A heat insulating material layer of a thermosetting resin foam is formed on the inner peripheral surface of a metal spiral tube, and further a synthetic resin film layer is formed on the inner peripheral surface of the heat insulating material layer ,
The synthetic resin film layer forms the innermost peripheral surface of the duct, and the innermost peripheral surface has no inner surface reinforcing band or other band-like material wound spirally, and
The metal spiral tube and the heat insulating material layer, and the heat insulating material layer and the synthetic resin film layer, respectively, are formed between the spiral tube and the synthetic resin film layer to form the heat insulating material layer. A duct characterized by being bonded without using an adhesive due to the self-adhesiveness of a thermosetting resin injected therebetween.

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