JP2002286191A - Raised covering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide raised covering which can reduce fluid resistance by being applied to piping, ducts, etc., whose general inner-face is smooth. SOLUTION: A covering is attached at least partially to an inner face of a cylindrical member for conveying fluid, wherein a raising portion 13 is provided on the surface to be in contact with the fluid, and micro projecting villi 12 for reducing fluid resistance are provided on the surface of this raising portion 13. The micro villi 12 affect micro vertical vortex formed by fluid and as a result, the fluid resistance can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raised coating used to reduce the flow resistance of a fluid flowing in a cylindrical member.

[0002]

2. Description of the Related Art As a method for reducing the flow resistance of a fluid and increasing the flow efficiency, there has been proposed a method in which a spiral rib or a spiral groove is provided on the inner surface of a tubular member such as a pipe or a duct (for example, Japanese Patent Application Laid-Open No. HEI 9-110572). 6-249370). In this known method, a spiral rib (or spiral groove) is provided on the inner surface of the drain pipe, and the spiral rib (or spiral groove) forms a core of air in the center of the drain pipe at the time of drainage. By doing so, the flow rate of drainage is increased, and the flow efficiency is increased.

As another method, there has been proposed a method of providing a large number of grooves or dimples parallel to the flow direction on the inner surface of a cylindrical member for transporting a fluid (for example, Japanese Patent Application Laid-Open No. HEI 9-103572). 11-190471). In this known method, a large number of small depressions are provided on the inner surface of a cylindrical member at intervals in its circumferential direction and axial direction.
When the liquid flows through the cylindrical member, a small vortex is generated inside each depression of the liquid contact part, and the liquid contact part on the inner surface of the cylindrical member is entirely covered by a large number of small vortices, and a stable liquid film is formed. It is formed so as to stick to the inner surface of the tubular member. The liquid film formed so as to stick is formed in the same liquid layer, and the direction of rotation of the vortex flows in the direction of movement of the fluid, so that the fluid flows as if it were lubricated particles (rollers). Works. As a result, the friction between the inner surface of the tubular member and the inner surface of the tubular member is reduced, and the resistance of the flowing fluid is reduced.
Is obtained.

[0004]

However, the above-mentioned conventional method has the following problems. That is,
In the method of providing a spiral groove on the inner surface of the tubular member or the method of providing a small depression on the inner surface of the tubular member, in the process of manufacturing a board that forms such a pipe as a tubular member, duct, or the like. , Spiral grooves, it is necessary to provide a small depression on the surface, as a method, for example, by cutting a portion of a flat pipe or a flat plate surface of the pipe inner surface, spiral grooves, A small depression can be provided,
The manufacturing process for providing these becomes complicated, and the manufacturing cost also increases. In addition, it is difficult to reduce flow resistance by providing ordinary pipes already installed in various facilities with smooth inner surfaces, spiral grooves in ducts, and small depressions.To reduce flow resistance, pipes, The duct must be replaced with one with low flow resistance (having a spiral groove and a small depression), and existing pipes and ducts cannot be used.

An object of the present invention is to provide a brushed coating which can be easily applied to a general-purpose pipe, duct or the like having a smooth inner surface to reduce its flow resistance.

[0006]

According to the present invention, there is provided a coating applied to at least a part of an inner surface of a tubular member for conveying a fluid, wherein a raised portion is provided on a surface side in contact with the fluid, and the raised portion is provided. The surface of the portion is provided with fine projections or soft hairs for reducing flow resistance. Generally, the flow resistance due to the inner surface of the pipe wall is mainly determined by the state of a wall boundary layer (also referred to as a “turbulent boundary layer”) formed along the wall surface. Many minute vertical vortices are generated in the wall boundary layer, and these are considered to be factors of flow resistance. Therefore, those acting on these longitudinal vortices,
For example, if grooves, dents, projections, etc. can be effectively provided, friction between the flowing fluid and the inner surface of a tubular member such as a pipe or duct is reduced, the flow frictional resistance of the fluid is reduced, and the flow resistance is reduced. An extremely small cylindrical member is obtained.

In the brushed coating of the present invention, a raised portion is provided on the surface side in contact with the fluid, and fine projections or fur are provided on the surface of the raised portion. This influences the minute vertical vortex formed by the fluid, and as a result, the flow resistance can be reduced. Such fine protrusions or furs greatly affect the minute vertical vortex formed in the fluid flowing near the inner surface of the cylindrical member, and the friction reduction effect obtained by the influence is such that the fluid is a liquid, a slurry and It is expressed even in gas.

[0008] Such a brushed coating is applied to the inner surface of a tubular member such as a pipe or duct having a smooth inner surface. For example, the brushed coating is applied to substantially the entire inner surface of the tubular member to form a tubular member. Can be covered with minute projections or soft hairs. This brushed coating may be simply attached to the inner surface of the tubular member, and can be easily applied to existing pipes, ducts, and the like.

Further, in the present invention, the fluid flowing through the cylindrical member is a gas. The brushed coating of the present invention can be applied even when the fluid flowing through the tubular member is a gas, and can significantly reduce the flow resistance when transporting the gas.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a brushed covering according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing the whole of the brushed covering according to the embodiment of the present invention, FIG. 2 is a partially enlarged cross-sectional view showing the brushed covering of FIG. 1, and FIG. FIG. 4 is a partially cutaway perspective view showing an example in which the coating is applied to the inner surface of the pipe, and FIG. 4 is a perspective view showing an example in which the raised coating of FIG. 1 is applied to the inner surface of the duct; FIG. 2 is an explanatory diagram for explaining the action of the micro-bristle of the brushed covering of FIG.

In FIG. 1 and FIG. 2, the brushed covering 10 shown in the drawing is composed of a base portion 11 and a raised portion 13 provided on the surface side of the base portion 11. Base part 1
Numeral 1 is affixed to the inner surface of a tubular member such as a pipe or a duct, as described later, and the raised portion 13 acts on a fluid flowing through the tubular member. As shown in FIG. 2, a large number of micro fluffs 12 are provided at minute intervals on the surface of the raised portion 13, and these micro fluffs 12 are provided integrally with the raised portion 13. These minute fluffs 12 are configured to elastically deform when a relatively small force acts.

The material of the base portion 11 is not particularly limited to the following materials, but may be made of a cloth formed of natural fibers such as cotton, hemp, silk, etc., or a synthetic fiber such as nylon, acrylic or the like. A cloth or a film or a film made of a synthetic resin such as vinyl or polyethylene, a metal foil made of a metal such as copper or iron, or the like is used. Further, the material of the raised portion 13 is not particularly limited to the following, but may be the same material as a tubular member described later, a metal material such as copper or iron, or a resin material such as polyethylene or polyacryl. Natural fibers such as cotton, hemp and silk, and synthetic fibers such as nylon and acrylic are used.

Further, the length of the micro fur 12 may be any length as long as it affects the micro longitudinal vortex 15 generated on the wall surface when the fluid flows. The effect on the micro-vertical vortices becomes small and the effect is small. Conversely, if they are too long, they themselves become resistance and hinder the flow of the fluid. It is preferably from 1 μm to 5 mm, and more preferably from 10 μm to 1 mm.

The thickness (diameter) of the fine fur 12 is not particularly limited. However, if the thickness is too small or too large, the effect on the minute vertical vortex of the fluid becomes small and the effect is small. Therefore, the thickness (diameter) is 0.1 μm to 5 m
m, more preferably 10 μm to 1 mm. Regarding the pitch of these minute furs 12,
The distance between them is not particularly limited, but if it is too large, the probability of acting on the microvertical vortex 15 of the fluid is reduced and the effect is reduced. It is difficult for the hairs 12 to act on the minute vertical vortex 15 of the fluid, and the effect thereof is reduced. Therefore, the pitch is preferably 0.01 μm to 5 mm, and more preferably 10 μm to 1 mm. More preferred.

The shape of the fine fur 12 is not particularly limited, but may be a straight one as shown in FIG.
One that is bent in a predetermined direction or an arbitrary direction, one that is bent in a predetermined direction or an arbitrary direction, or the like is used. As shown in FIG. 3, the raised coating 10 is attached to the inner peripheral surface of a pipe 14 having a circular outer shape as a cylindrical member. In this application example, the brushed coating 10 is attached to substantially the entire inner peripheral surface of the pipe 14, the base portion 11 is attached to the inner surface of the pipe 14, and the raised portion 13 contacts the fluid flowing through the pipe 14. I do. In addition, as shown in FIG. 4, the brushed covering 10 is attached to substantially the entire inner surface of the duct 16 having a rectangular external shape as a cylindrical member in the same manner as described above. As described above, the brushed coating 10 is attached to the inner surface of various tubular members, and by being attached in this manner, it can be attached to existing pipes and ducts and modified into pipes and ducts having low flow resistance. it can.

When a gas such as a fuel gas, a liquid such as tap water, a slurry or the like is conveyed in a direction indicated by an arrow 18 through the pipe 14 (duct 16), as shown in FIG. A minute vertical vortex 15 of the fluid is generated near the pipe wall of the duct 16), that is, in the wall boundary layer, and the generated minute vertical vortex 15 is generated by a large number of the brushed coatings 10 adhered to the pipe 14 (the duct 16). Is affected by the physical effect of the micro fur 12, the friction between the flowing fluid and the inner surface of the pipe 14 (duct 16) is reduced, and the flow resistance of the fluid is reduced. Thus, the flow loss can be reduced and the fluid can be transported with high efficiency. The brushed coating 10 does not need to be provided in the entire area of the pipe 14 (duct 16), and the desired effect described above can be achieved by sticking it to a certain area.

While the embodiment of the brushed covering according to the present invention has been described above, the present invention is not limited to such an embodiment, and various modifications and alterations can be made without departing from the scope of the present invention. It is. For example, in the illustrated embodiment, a large number of minute fluffs 12 are provided on the surface of the raised portion 12, but a similar effect can be achieved by providing many minute protrusions instead of such fluffs 12. The material, length, thickness, pitch, and the like of these minute projections can be configured in the same manner as the above-described fluff 12.

Further, for example, in the illustrated embodiment, the raised coating material is formed in a sheet shape, but is not limited to such a shape, and may be formed in a tube shape, for example.

[0019]

According to the brushed coating of the first aspect of the present invention, the raised portion is provided on the surface side in contact with the fluid, and the raised portion has fine projections or soft hairs.
The minute protrusions or furs affect the minute vertical vortex formed by the fluid, and as a result, the flow resistance can be reduced. This brushed coating is attached to the inner surface of a tubular member such as a pipe or duct having a smooth inner surface. For example, by applying the brushed coating to substantially the entire inner surface of the tubular member, the inner surface of the tubular member is minutely projected. Or soft fur. This brushed coating may be simply attached to the inner surface of the tubular member,
Even existing pipes, ducts, etc. can be easily constructed.

Further, according to the brushed coating of the second aspect of the present invention, the flow resistance of a gas when it is conveyed can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an entire embodiment of a raised covering according to the present invention.

FIG. 2 is a partially enlarged cross-sectional view showing the raised coating of FIG.

FIG. 3 is a partially cutaway perspective view showing an example in which the brushed covering of FIG. 1 is applied to the inner surface of a pipe.

FIG. 4 is a perspective view showing an example in which the raised coating material of FIG. 1 is applied to an inner surface of a duct.

FIG. 5 is an explanatory diagram for explaining the action of the fine fur on the brushed covering of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Brushed coating material 11 Base part 12 Fine fur 13 Brushed part 14 Piping 15 Fine vertical vortex 16 Duct

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hiroshi Higuchi 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi Inside Osaka Gas Co., Ltd. (72) Inventor Koichi Nishimura 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi No. Osaka Gas Co., Ltd. F-term (reference) 3H025 BA25

Claims (2)

[Claims] 1. A coating applied to at least a part of an inner surface of a cylindrical member for conveying a fluid, wherein a raised portion is provided on a surface side in contact with the fluid, and a flow resistance is reduced on a surface of the raised portion. A raised coating, which is provided with fine projections or soft hairs. 2. The raised coating according to claim 1, wherein the fluid flowing through the tubular member is a gas.