JPH08219371A - Heat insulating duct - Google Patents

Abstract

PURPOSE: To improve heat insulating performance, reduce interior pollution and reduce loss resistance during air flow by forming a resin wind-preventing layer on the inner peripheral surface of a cylinder body formed of fibrous heat- insulating material. CONSTITUTION: A resin wind-preventing layer 12 of 0.2-10mm is formed at the inner peripheral surface of a cylinder body formed of fibrous heat insulating material. This resin wind-preventing layer 12 is a wind-preventing moisture- permeable heat-compressed sheet and formed of polyvinyl chloride, polystyrene, polyolefine or the like. In addition it is desirable that the resin wind-preventing layer 12 is formed of resin of the self-deforming temperature being 80 deg.C or higher such as α-methylstyrene, urethane resin or polyethylene terephthalate. Heat insulating performance is thereby made desirable, interior pollution is reduced, and loss resistance during air flow can be reduced.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a duct having excellent heat insulating properties. More specifically, the present invention relates to a heat-insulating duct particularly suitable for circulating heated air, such as a ventilation duct in a solar system.

[0002]

BACKGROUND OF THE INVENTION In recent years, it has become possible to form a more comfortable living space by surrounding a building with a heat insulating material to control the heat energy balance. A solar system house is a typical example of a building whose heat energy balance is controlled. In this solar system house, as shown in FIG. 5, a heat insulating material 51 is arranged on the wall surface and the attic of the building 50, and the living space and the indoor space are insulated by the heat insulating material 51. Such a building 5
An air collector 52 is provided on the roof or the like of No. 1, and the warmed air in the air collector 52 is transferred to a control box 54 provided at the back of the hut or the like. And
For example, in winter, the warm air collected in the control box 54 is sent to the underfloor space 56 through the duct 55. A heat storage tank 57 is formed in this underfloor space 56, and the thermal energy of the warm air sent from the duct 55 to the underfloor space 56 is stored in this heat storage tank 57, and is taken out as necessary to heat the interior of the thermally insulated room. Used to do.

In such a solar system house 50, as the duct 55, as shown in FIG.
A tubular body 61 is used, which is formed by impregnating a resin (for example, phenol resin) into a fiber-based heat insulating material such as glass wool having heat insulating properties.

Such a tubular body 61 has a fibrous heat insulating material provided in a predetermined shape by an impregnated resin, and has a heat insulating property and is easy to process. However, when the present inventor examined the heat insulation performance in detail, it became clear that the heat insulation performance was lower than the thickness of the heat insulation material. That is, the inner peripheral surface 6 of such a tubular body 61.
It has been found that when the thickness is 1/3 from 2 to the outside, almost no heat insulation performance is exhibited. Therefore, the heat insulation performance of the duct formed from such a fiber heat insulation material is about 2/3 of the heat insulation performance calculated from the thickness of the fiber heat insulation material forming the duct wall. The temperature of the warm air due to the movement of the warm air is significantly reduced.

Further, the duct formed of such a fiber type heat insulating material has a considerable unevenness on the surface thereof, and there is a problem that the loss resistance when air flows is large. Further, such a duct is joined by diagonally cutting the fibrous heat insulating material cured by the impregnating resin, joining the diagonally cut ends, and sealing the joined portion with a tape or the like.

However, in the fiber type heat insulating material thus cured with the resin, the heat insulating material fibers scatter when cut.
Such scattered heat insulating material fibers may be carried into the room by the circulating air, and there is a problem that the scattered heat insulating material is easily contaminated in the room.

The duct formed of the above-mentioned fiber type heat insulating material is used for other than the solar system house, and has the same problem as above in other applications.

[0008]

An object of the present invention is to provide a duct having excellent heat insulating properties. Another object of the present invention is to provide a duct that has excellent heat insulation properties and is less susceptible to contamination of indoor air by the fiber-based heat insulating material. further,
It is an object of the present invention to provide a duct having excellent heat insulating properties, less indoor pollution, and low loss resistance during air circulation.

[0009]

SUMMARY OF THE INVENTION The heat insulating duct of the present invention comprises a tubular body made of a fiber type heat insulating material and a resin windproof layer formed on the inner peripheral surface of the tubular body.

In the heat insulating duct of the present invention, since the resin windproof layer is formed on the inner peripheral surface of the tubular body formed of the fiber type heat insulating material, the air flowing in the duct enters the fiber type heat insulating material. Therefore, the duct of the present invention has excellent heat insulation. Further, by forming the resin windproof layer in this manner, the inner peripheral surface of the duct becomes smooth, so that the loss resistance of the duct becomes small. For example, when the heat insulating duct of the present invention is used as a blower duct of a solar system house, the blower blows air. The blower system such as a fan can be downsized. Further, since the heat insulating duct of the present invention has the resin windproof layer formed on the inner peripheral surface thereof, when the duct is cut, it is difficult for the section of the fiber type heat insulating material to be mixed into the circulating air from the joint portion. The air is not easily contaminated with fiber insulation.

[0011]

DETAILED DESCRIPTION OF THE INVENTION Next, the heat insulating duct of the present invention will be specifically described with reference to the drawings. FIG. 1 is a vertical sectional view showing an embodiment of the heat insulating duct of the present invention, and FIG.
FIG. 2 is a sectional view taken along the line AA in FIG. 1.

The heat insulating duct 10 of the present invention is shown in FIGS.
As shown in, a tubular body 11 made of a fiber-based heat insulating material,
It has a resin windbreak layer 12 formed on the inner peripheral surface of the cylindrical body 11.

Inside the cylindrical body 11, there is formed a ventilation hole 13 opening in the longitudinal direction. In the heat insulating duct of the present invention, the tubular body 11 has a ventilation hole 13 in the center of which is a fiber-based heat insulating material.
Is formed by winding a fibrous heat insulating material. The fiber-based heat insulating material used here may be an aggregate of fibers usually used as a heat insulating material, and examples thereof include glass wool, rock wool, and synthetic resin fiber nonwoven fabric. In the present invention, glass wool is particularly preferable. Such a fiber-based heat insulating material has a structure in which fibers are intertwined with each other, and a considerable amount of air is contained between the fibers, and the air contained between the fibers is stagnant without moving. By forming an air layer by means of this, adiabatic action is exhibited.

A cylindrical body 11 made of such a fiber type heat insulating material.
May be formed by shaping the fibrous heat insulating material into a tubular shape, or may be formed by impregnating the fibrous heat insulating material with a resin and shaping it into a desired shape and fixing the shape. Good.
The resin used here may be one that is not softened or deteriorated by the heated air flowing through the duct, and therefore, a thermosetting resin such as a phenol resin is preferably used.

A cylindrical body 11 made of such a fiber type heat insulating material.
The thickness W ₁ of the wall surface depends on the temperature of the circulating air and the type of fiber-based heat insulating material used. A resin windproof layer 12 is formed on the inner peripheral surface of the tubular body 11 made of this fiber-based heat insulating material.

The resin windbreak layer 12 prevents the heated air flowing through the ventilation holes 13 from entering the fiber type heat insulating material. That is, conventionally, the duct in which the fibrous heat insulating material is formed into a cylindrical shape with a thermosetting resin such as a phenol resin has been used as described above. It was found that in the duct made of the heat insulating material, a part of the heated air flowing through the ventilation hole enters the inside of the fiber heat insulating material from the inner peripheral surface of the duct. For example,
When the temperature on the wall surface of the duct made of the fibrous heat insulating material is measured, it is as shown by the broken line in FIG.

In FIG. 3, the temperature of the air flowing in the ventilation hole is T ₀ . In a duct made of a conventional fiber-based heat insulating material, the air circulating in the ventilation holes penetrates into the duct wall from the surface of the inner wall of the duct, and the wall thickness made of the fiber-based heat insulating material is 1
With a duct of 2.5 mm, the temperature T ₂ at a depth of about 1/3 from the inner peripheral surface of the duct to the outside as shown in FIG.
It is almost the same as the temperature T _{0 of the} circulating air in the ventilation hole. That is,
In this duct, it means that the circulating air in the ventilation hole has penetrated to the outside from the inner peripheral surface of the duct to a depth of about 1/3.

Therefore, in the duct formed of the conventional fiber type heat insulating material, about 2/3 of the heat insulating material used merely functions as the heat insulating material. Further, in the duct formed of such a conventional fiber-based heat insulating material, the surface of the duct is formed because the air flowing in the ventilation holes enters the fiber-based heat insulating material and the fibrous heat insulating material is exposed on the inner peripheral surface of the duct. Since it is not smooth, the loss resistance of the duct increases.

On the other hand, in the heat insulating duct of the present invention, as shown in FIGS. 1 and 2, the resin windproof layer 12 is formed on the inner peripheral surface of the cylindrical body made of the fiber type heat insulating material 11. The resin windproof layer 12 can be formed of, for example, polyolefin (eg, polyethylene, polypropylene), polyvinyl chloride, polystyrene, poly α-methylstyrene, polyethylene terephthalate, polyurethane, epoxy resin, or various resins.

The resin windproof layer 12 is formed by a method of sticking a film made of the above resin, a method of preparing a solution of the above resin dissolved in an organic solvent and applying the solution to form a layer, and a ventilation hole. It can be formed by a method of pouring the above-mentioned resin powder into the inside and fusing it to the inner peripheral surface.

For example, a resin windproof layer according to the present invention can be formed by producing a sheet or film from the above resin in advance and adhering the sheet or film to the inner peripheral surface of the cylindrical body 11.

Further, for example, a nonwoven fabric made of a polyolefin fiber such as polyethylene is compressed under heating to produce a heat-compressed sheet having moisture permeability but windproof property. The heat-compressed sheet becomes the resin windproof sheet according to the present invention by arranging the heat-compressible sheet on the inner peripheral portion of the cylindrical body 11 by, for example, adhering. Although this heat-compressed sheet has the same wind-proof property as a normal polyolefin sheet, it has moisture permeability unlike a normal polyolefin sheet. By using the moist heat compression sheet, dew condensation is less likely to occur in the fibrous heat insulating material.

Particularly in the present invention, it is preferable that the resin windbreak layer is formed of a resin that does not deform even if heated air at about 80 ° C. continuously flows.
Therefore, the resin windproof layer may be formed of a thermosetting resin, but particularly in the present invention, it is preferable that the resin windbreak layer is formed of a resin having a self-deformation temperature of 80 ° C. or higher.

Examples of the resin having such a self-deformation temperature of 80 ° C. or higher and suitable for forming the resin windproof layer include poly α-methylstyrene, polyurethane and polyethylene terephthalate. These resins have excellent heat resistance and are flexible to some extent, and use of such a resin improves workability.

The thickness W ₂ of the resin windproof layer formed of the above resin is usually 0.2 to 10 mm, preferably 0.2.
Within the range of ~ 5 mm. By forming the resin windproof layer in this manner, infiltration of heated air into the fiber-based heat insulating material is eliminated, and as shown by the solid line in FIG. Corresponding heat insulation is developed,
The temperature of the outer peripheral surface of the heat insulating duct is ΔT ° C (T ₃₎ higher than the temperature of the outer peripheral surface of the heat insulating duct in which the resin windproof layer is not formed on the inner peripheral surface.
-T ₁ ) lower. That is, the thermal energy leaking from the outer peripheral surface of the heat insulating duct is reduced. Further, by providing the resin windproof layer, the surface of the ventilation hole becomes smooth, so that the loss resistance is reduced. Further, by forming the resin windproof layer in this way, the portion where the fiber-based heat insulating material directly contacts the circulating air is extremely reduced, and even when the heat insulating duct is cut, it remains in the fiber-based heat insulating material. Fiber pieces and the like are less likely to be mixed into the circulating air, so that the living space is not contaminated with the fiber heat insulating material.

The heat insulating duct 10 of the present invention has the tubular body 11 made of the fiber type heat insulating material as described above and the resin windproof layer 12 on the inner peripheral surface of the tubular body 11. In the heat insulating duct 10, it is preferable that the metal thin film layer 15 is formed on the outer peripheral surface of the cylindrical body 11 made of a fiber heat insulating material.

The metal thin film layer 15 is usually made of aluminum foil. By forming the metal thin film layer 15 on the outer peripheral surface of the cylindrical body 11 in this manner, it is possible to physically protect the fibrous heat insulating material and prevent water from entering the fibrous heat insulating material from the outside. it can. Furthermore, by providing this metal thin film layer 15, the heat insulating property of the duct is also improved.

Another heat insulating duct is joined to the end of such a heat insulating duct for use. At the time of this joining, it is preferable that the end portion of the heat insulating duct of the present invention is formed into a hollow shape so that the end portions of other ducts fit with each other. In Figure 1, 16
Is shown. The heat insulation duct of the present invention is connected by inserting one end of another duct into the end, and the airtight tape is wound from the outside on the connection thus formed. It is also possible to apply an adhesive agent to the joint portion to join them.

Further, in order to bend and join the heat insulating duct of the present invention, the two heat insulating ducts can be joined by cutting the ends diagonally and sealing the cut surfaces together with a tape or the like. . Further, the heat insulating duct of the present invention has the resin windproof layer formed on the inner peripheral surface, and since this portion can be adhered to each other by the adhesive, the cut surface is coated with the adhesive to join the heat insulating duct. Then, the tape can be sealed from the outer periphery of the heat insulating duct bonded. By thus using the adhesive together, the fibrous heat insulating material in the joint portion is prevented from coming into contact with the circulating air, and the adhesiveness in the joint portion is improved.

The heat insulating duct of the present invention has the above-mentioned structure, but the present invention is not limited to this and can be variously modified within the scope of the present invention. The heat insulating duct of the present invention does not need to have a circular cross-sectional shape as shown in FIG. 1, and may have various cross-sectional shapes such as a square shape and an elliptical shape. FIG. 4 shows a heat insulating duct of the present invention having a quadrangular cross section structure. In FIG. 4, the heat insulating duct is shown by 10 and the resin windbreak layer is shown by 12. Further, the fiber type heat insulating material is indicated by 11, and the metal thin film layer is indicated by 15.

The heat insulating duct of the present invention as described above can be used similarly to the conventional duct. For example, as shown in FIG. 5, in a solar house, to be used as a duct for transferring heated air from an air collector 52 provided on a roof to an underfloor space via a control box 54 provided at the back of a house. You can

Further, it can be effectively used not only as a duct in such a solar house but also as a duct for moving air having a temperature difference from the outside air.

[0033]

In the heat insulating duct of the present invention, since the resin windproof layer is formed on the inner peripheral surface of the tubular body made of the fiber type heat insulating material, the circulating air does not enter the fiber type heat insulating material. Therefore, the duct of the present invention has excellent heat insulation. Further, by forming the resin windproof layer in this manner, the inner peripheral surface of the duct becomes smooth, so that the loss resistance of the duct becomes small and the blower system can be made compact. Further, the heat insulating duct of the present invention, since the resin windproof layer is formed on the inner peripheral surface thereof, it is difficult for the pieces of the fiber type heat insulating material to be mixed into the circulating air from the joint when the duct is cut, Indoor air is less likely to be contaminated with fiber insulation.

By forming the resin windproof layer from a sheet formed by compressing a nonwoven fabric of polyolefin fiber under heating, the resin windproof layer has both windproof property and moisture permeability. No condensation occurs in the fiber-based heat insulating material.

Further, by forming the resin windproof layer using a specific resin having a self-deformation temperature of 80 ° C. or higher, the heat insulating duct exhibits good heat resistance and is heated by, for example, an air collector in a solar house. It can be effectively used as a duct for transferring air.

Furthermore, by attaching a metal thin film layer made of, for example, aluminum foil to the outer peripheral surface of the tubular body made of a fiber type heat insulating material, the strength of this heat insulating duct is increased and the heat insulating performance is also improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a heat insulating duct of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a graph schematically showing the temperature measured in the thickness direction of the fiber-based heat insulating material forming the heat insulating duct.

FIG. 4 is a cross-sectional view showing another example of the heat insulating duct of the present invention.

FIG. 5 is a diagram showing an example in which a heat insulating duct is used in a solar house.

FIG. 6 is a vertical cross-sectional view showing a conventional heat insulating duct.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Thermal insulation duct 11 ... Cylindrical body which consists of fiber type thermal insulation material 12 ... Resin windproof layer 13 ... Ventilation hole 15 ... Metal thin film layer

Claims (8)

[Claims] 1. A heat insulating duct comprising a tubular body made of a fiber type heat insulating material and a resin windproof layer formed on the inner peripheral surface of the tubular body. 2. The heat insulating duct according to claim 1, wherein the tubular body made of a fiber-based heat insulating material is formed into a predetermined cross-sectional shape by impregnating resin. 3. The heat insulating duct according to claim 1, wherein the thickness of the resin windbreak layer is in the range of 0.2 to 10 mm. 4. The heat insulating duct according to any one of claims 1 to 3, wherein the resin windproof layer is a windproof, moisture-permeable, heat-compressed sheet of a polyolefin nonwoven fabric. 5. The resin windproof layer is formed of at least one kind of resin selected from the group consisting of polyvinyl chloride, polystyrene and polyolefin, according to any one of claims 1 to 3. Insulation duct described in that section. 6. The resin windbreak layer has a self-deformation temperature of 80.
The heat insulation duct according to any one of claims 1 to 3, which is formed of a resin having a temperature of not less than ° C. 7. The resin having a self-deformation temperature of 80 ° C. or higher is at least one kind of resin selected from the group consisting of α-methylstyrene, urethane resin and polyethylene terephthalate. Insulated duct described. 8. The heat insulation duct according to claim 1, wherein a metal thin film layer is formed on an outer peripheral surface of the cylindrical body.