JP2001219132A - Self-preventing/automatic removing structure for adhesion of scale to tube wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new self-preventing/automatic removing structure for adhesion of scale to tube wall without depending upon a scale adhesion preventing process using chemical agent. SOLUTION: This self-preventing/automatic removing structure for the adhesion of scale (filth) to the tube wall is structured of a network flow path part 10A consisting of a first parallel flow path element group 12A and a second parallel flow path element group 12B which are made to each other on the same plane with a continuous state of confluence and diversion, formed on the inner peripheral face of the tube wall 18 using a plurality of projecting parts (a pillar part) 16A. A fluid flows through a duct at a specified or higher velocity, generating a flipflop current to automatically remove the adhering scale.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing self-adhesion of scale (dirt) to a pipe wall by the flow of an internal fluid.
Regarding a new structure to be automatically removed. In particular, air ducts,
The present invention is suitable for automatically removing scale (dirt) adhering to a pipe wall such as a chimney, a water pipe, and a tunnel.

Here, a rectangular / circular cylindrical body having a full opening cross section will be described as an example. However, the present invention can also be applied to a tube wall having an annular opening cross section such as a double tube heat exchanger. The fluid may be a gas or a liquid.

[0003]

2. Description of the Related Art Conventionally, prevention of adhesion of a pipe wall scale is as follows.
The treatment was performed by a scale adhesion preventing treatment of applying a chemical so that the scale was hardly adhered.

However, in the surface treatment with a chemical, there is a problem of a working environment due to a solvent or the like at the time of applying the chemical, and it is necessary to apply the chemical periodically. This is because the effect of preventing the adhesion of scale by the drug usually decreases with time.

[0005] In view of the above, an object of the present invention is to provide a novel self-prevention / automatic removal structure of tube wall scale adhesion, which is not based on a scale adhesion prevention treatment by a chemical.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have proposed a vibration-generating flow path body (flip-flop flow in a fluid) having the following structure proposed in Japanese Patent No. 2841173 and having the following structure. ).

[0007] A group of parallel flow paths (first parallel flow path element group)
And a group of parallel flow paths (second parallel flow path element group) intersecting on the same plane to form a network flow path in which merging and branching are continuous. Vibration generating flow path body in the ejection direction. And, as a result of diligent efforts, I came up with a self-prevention / automatic removal structure of the tube wall scale adhesion having the following configuration.

[0008] A structure for self-prevention / automatic removal of scale (dirt) adhered to a tube wall, wherein the inner peripheral surface of the tube wall and / or
Alternatively, on the outer peripheral surface, a network flow path section in which the first parallel flow path element group and the second parallel flow path element group intersect on the same plane and the merge and the branch flow are continuous is formed by a number of convex portions (columns). Part).

[0009]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

The configuration and operation of the above-described network flow path 10 will be specifically described with reference to FIG.

The network flow path 10 basically has a configuration in which a first parallel flow path element group 12 and a second parallel flow path element group 14 intersect on the same plane, so that a merge and a branch flow are continuous. . The network pipe 10 is formed by being surrounded by a pipe wall 18 of a flat pipe.

Specifically, the network flow path 10 has four
A group of parallel flow paths (dashed-dotted lines) 12 composed of at least four (six in the figure) flow paths and another group of parallel flow paths (two-dot-dashed line) 14 also composed of four or more flow paths are roughly formed. 15-90 °
(Preferably 20-60 °, more preferably 25 °-
40 °), and the entire arrangement of the channel groups is substantially symmetrical. With this configuration, a so-called pendulum flow (flip-flop flow) can be generated in the flow, which can alternately change the ejection direction of the fluid periodically. If the included angle α is too small or too large, it is difficult to obtain the Coanda effect (phenomenon of attaching a flow pulse to a wall), and it is difficult to generate a pendulum motion (flip-flop flow) in the fluid.

The width (diameter) w of the convex portion (diamond in the example) 16
And the ratio (w / s) of the clearance s between the projections 16 is usually 1
/ 2 to 2/1, desirably substantially the same.

If the width w of the convex portion 16 is too small, the gap s becomes relatively large, so that it is difficult to obtain the Coanda effect (phenomenon of attaching a flow vein to a wall), and it is difficult to generate a pendulum flow (flip-flop). Conversely, if the width w of the convex portion 16 is too large, the clearance s becomes relatively small, and it becomes difficult to secure a large flow rate.

Here, the flip-flop flow refers to a flow accompanied by fluid oscillation to the left and right similar to the switching phenomenon seen in a flip-flop circuit in electronics.

In this flip-flop flow, rhombuses (FIG. 1), circles (FIG. 3), ellipses (FIG. 5), and polygonal projections (columns) 16, 16A and 16B are arranged. The present inventors have confirmed by flow visualization experiments that expression is caused in the network pipelines 10, 10A, and 10B.

In particular, as shown in FIG. 1, an arrangement in which the angle (intersection intersection angle) formed by the intersection line connecting the centers between the convex portions (column portions) 16, 16 is 30 °, a group of parallel Channel (dashed-dotted line) 12 and another group of parallel channels (dashed-dotted line)
In the network pipeline (flow path) 10 in which 14 is 30 °, a flip-flop flow appears remarkably.

[0018] In the "diamond-shaped convex portion", the connected vibration of the vortex appears remarkably around the diamond-shaped convex portion as the cross-section of the flow path behind the rhombic convex portion changes. However, the oscillation state of the flip-flop flow in the conduit of the “circular convex part” does not appear until the vortex coupling vibration as in the “diamond convex part”, and the remarkable occurrence of the flip-flop flow (level ) Are different.

Further, in the open channel (open channel) having the arrangement intersection angle of 30 ° in “the channel at least where the ceiling wall does not exist”, the flat channel (of a flat section where the ceiling wall exists) is formed. In comparison, although the flip-flop flow is less remarkable, a clear flip-flop flow can be expected when the flow velocity (Reynolds number: Re) is large, or in the case of an air duct or chimney.

As described above, the present inventors experimentally confirmed the flow of flip-flops (vibration of flow veins) in the pillars (convex portions) of various shapes forming the cross flow path. In addition, it has been confirmed that a flip-flop flow also occurs in an open channel (open channel).

FIGS. 2 and 3 and FIGS. 4 and 5 show embodiments of the present invention in which the cross section of the tube is rectangular and circular, respectively. FIG.
5 is a developed view cut in the flow direction in FIG. 2 and FIG. 5 is a developed view cut in the flow direction in FIG.

The first parallel flow path element groups 12A and 12B and the second parallel flow path element group 14
A and 14B intersect on the same plane, and the network flow paths 10A and 10B in which the merge and the branch are continuous are formed by a large number of convex portions 16A and 16B.

At this time, as shown in FIGS. 2 and 4, the shapes of the convex portions (column portions) 16A and 16B are rounded hemispherical or arched in cross section from the viewpoint of the manufacture of the tube wall and the maintenance. Things are desirable. Naturally, the shape of the projection is cylindrical,
The shape may be a prism, a cone, a pyramid, or the like.

The arrangement pitch of the projections 16A and 16B, the clearance, and the distance of the flow path tube are determined by the size (diameter and diameter) of the projections (columns) 16A and 16B having the arrangement intersection angle according to the description of FIG.
Height).

The height of the projections 16A and 16B is preferably 3 to 10% with respect to the diameter (diameter) of the cylindrical body in a rectangular or circular cylindrical air duct or chimney as shown in FIGS. Is about several percent.

If the protruding heights of the projections (columns) 16A and 16B are too high, the overall resistance of the in-pipe flow path is undesirably increased.

Further, in the case of a tunnel T having a road width of several meters as shown in FIG. 6 (it is of course applicable to the case of an air duct or a chimney), the height of the projection 16C in the network flow path 10C is high. It is desirable that the height of the fire detector or the alarm is about 20 or more.

Network flow paths 10A, 10B, 10C
Is provided in principle over the entire length of the pipe, but is particularly provided on one or more of only the flow path starting point side, the flow path end point side, and the area immediately before the bent pipe, where dirt is easily attached. Is also good.

In each of the above configurations, particularly in the case of a road tunnel T, as shown in FIGS. 7 and 8, a network flow path section is provided between the tops of the projections 16C and / or between the projections 16C. It is desirable that the scale sweeping members 22, 22A, 22B extending in the flow direction of 10C be disposed rotatably. It can be expected that the self-prevention / automatic removal effect of the adhesion of automatic stains will be increased.

That is, the scale sweeping members 22, 22
A and 22B are usually formed of strip-shaped rubber straps or straps with brushes on the lower surface, and the tops and protrusions of the projections (columns) 16C forming the network flow path 10C via the monkey ring 24 and the hinge pins 25. 16C, attached between 16C.

Since the scale sweeping member 22 is attached via the monkey ring 24 or the hinge pin 25, the scale sweeping member 22 is moved in the flow direction by the flip-flop flow (pulsation flow: pendulum motion) generated around the convex portions 16C, 16C. A pendulum motion occurs on the left and right, sweeping the wall. For this reason, the dust (dirt) to be attached or adhered floats in the air, and the attachment of the dirt is prevented or automatically removed.

Further, since ventilation is necessary in the road tunnel T, a ventilation wall 19 is formed on the back side by floating the pipe wall 18C, and ventilation holes 27 are formed at predetermined intervals in the pipe wall 18C.
The recess 27 for ventilation holes provided with a is formed.

Next, the usage of the above embodiment will be described with reference to FIGS.
The description will be made mainly by taking 9 as an example.

The flow velocity is above a certain level (Re number: 2000 or more)
Then, a flip-flop flow (a pendulum flow) is generated, and the wall surface is swept by the fluid. Dust (dirt) to be attached or adhered floats in the air to prevent or remove dirt. In this embodiment, since the scale sweeping member is rotatably attached to the top and periphery of the convex portion 16C and further rotatably between the convex portions 16C, 16C, the scale sweeping members 22, 22A,
The sweeping phenomenon of the wall surface is increased by 2B.

Therefore, the dust (dirt) to be attached or adhered floats in the air due to the sweeping phenomenon of the fluid flow and / or the sweeping phenomenon of the scale sweeping member. Prevention or removal of dirt is prevented.

In the case where the flow velocity of the steady flow is slow (below a predetermined Re number) so as not to generate a flip-flop flow, a fixed interval (one hour to several hours depending on the degree of dirt (scale) and the type of dirt). (Every other day), if the flow velocity is increased by a fluid transporter (blower, pump, etc.) to generate a flip-flop flow, the adhered dirt can be automatically removed.

[0037]

The self-prevention / automatic removal structure of the tube wall scale according to the present invention comprises a first parallel flow path element group and a second parallel flow path element on the inner peripheral surface and / or outer peripheral surface of the tube wall. The following operations and effects are exhibited by the configuration in which the network flow path section in which the groups intersect on the same plane and the merge and the branch are continuous is formed by a large number of projections (columns).

When the flow velocity exceeds a certain level, a flip-flop flow (a pendulum flow) is generated, and the wall surface is swept by the fluid. For this reason, the dust (dirt) to be attached or adhered floats in the air, and the attachment of the dirt is prevented or removed.

Further, the scale sweeping member is rotatable,
In the case where the protrusion is rotatably attached to the top and periphery of the protrusion and further to the protrusion ring, the sweeping phenomenon of the wall surface is further increased by the scale sweeping member. For this reason, the dust (dirt: scale) to be attached or adhered floats in the air, and the attachment of dirt is prevented or removed.

Therefore, according to the present invention, the treatment for preventing the scale from being adhered by the chemical becomes unnecessary.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view for explaining a network channel section to which the present invention is applied.

FIG. 2 is a vertical end view and a front view of a pipeline when the present invention is applied to a rectangular pipeline.

FIG. 3 is a developed plan view when cut in a vertical direction in FIG. 2;

FIG. 4 is a vertical sectional view and a front view of a pipeline when the same is applied to a circular pipeline.

FIG. 5 is a developed plan view when cut in the vertical direction in FIG. 4;

FIG. 6 is a schematic front view when the same is applied to a road tunnel.

FIG. 7 is a plan view showing an embodiment in which a scale sweeping member is provided in the network flow path portion.

FIG. 8 is an end view of a part of the rear part, which is taken along line 8-8 in FIG. 7;

[Explanation of symbols]

10, 10A, 10B, 10C Network flow path 12, 12A, 12B First parallel flow path element group 14, 14A, 14B Second parallel flow path element group 16, 16A, 16B, 16C Convex part forming network flow path 18 , 18A, 18B, 18C Pipe wall 22, 22A, 22B Scale sweeping member 24 Monkey ring 25 Hinge pin

Continued on the front page (72) Inventor Takashi Kudo 2-7-11, Shirokane, Showa-ku, Nagoya City, Aichi Prefecture Inside Maruyasu Kogyo Co., Ltd. (72) Inventor Shinsaburo Umeda 2-230 Meiodai, Fukuyama-shi, Hiroshima F-term ( Reference) 2D061 AE05 AE10 2D063 FA01 FA08 3B116 AA13 AA38 AB53 BB01 BB90

Claims (4)

[Claims] 1. A structure for self-prevention / automatic removal of scale (dirt) attached to a pipe wall, wherein a first parallel flow path element group and a second parallel flow path element are provided on an inner peripheral surface and / or an outer peripheral surface of the tube wall. A self-adhesion of pipe wall scale, characterized in that a network flow path section is formed by a large number of projections (columns) where a flow path element group intersects on the same plane and a merge and a branch flow are continuous. Prevention / automatic removal structure. 2. A group of first parallel flow path elements, each of which includes four or more flow path elements, and another group of second parallel flow paths, each of which includes four or more flow paths. The element groups are crossed at an included angle of about 20 to 60 °, and the overall arrangement of the first parallel flow path element group and the second parallel flow path element group is substantially symmetrical. The self-prevention / automatic removal structure of tube wall scale adhesion according to claim 1. 3. A scale sweeping member extending in a flow direction of a network flow path portion is rotatably provided between a top portion of the convex portion and / or the convex portion. 2. The self-prevention / automatic removal structure of tube wall scale adhesion described in 2. 4. The scale sweeping member has a strap shape perpendicular to a wall surface.
Self-prevention / automatic removal structure of tube wall scale adhesion as described.