JP2000038764A - Vortex type fall work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the ingress of air with a simple constitution and to stabilize an outflow from an outlet for preventing abrasion. SOLUTION: This vortex type fall-forming work 14 is provided with a tubular drop shaft 3 having a collecting pipe connected to the upper part and an outlet 5 formed on the lower part, and a vortex 23 is formed in the drop shaft 3. In this case, a resistance plate 26 is provided near the outlet 5 inside the lower end of the drop shaft 3, so as to apply resistance to the vortex 23 moving in the drop shaft 3 and flowing toward the outlet 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swirl type head, and more particularly to a swirl type head, which suppresses the inflow of air with a simple structure and stabilizes the outflow from an outflow port to cause wear. The present invention relates to a swirling flow type head work which is prevented from being performed.

[0002]

2. Description of the Related Art In order to eliminate inundation damage caused by rainwater in urban areas, a part of rainwater during heavy rain is temporarily stored in a large-scale storage pipe provided underground, and when the water level of a river drops, An inundation countermeasure facility that pumps the water stored in the storage pipe and discharges it to the river is currently being planned.

[0003] In the above-mentioned inundation countermeasure facility, a 100-meter pipe is provided between a collecting pipe for collecting rainwater and a storage pipe provided deep underground.
Pipe facilities connecting high heads of up to 200 m are called head works, and as the head works, swirling flow head works as shown in FIGS. 8 and 9 are being studied.

FIGS. 8 and 9 show an example of a swirling flow type head provided with a spiral guide plate. A water collecting pipe 2 for sending water 1 such as rainwater separated by a water diversion facility (not shown) is provided. A vertical tubular drop shaft 3 connected to an upper portion is provided, a lower end of the drop shaft 3 is closed by a bottom plate 4, and an outlet 5 opening laterally is formed on a side surface of the drop shaft 3 above the bottom plate 4. The outlet 5 is connected to a storage part such as an underground storage pipe 7 via an outflow pipe 6 extending in the lateral direction.

[0005] An upper spiral guide path 10 is formed by disposing an upper spiral plate 8 and an upper central cylinder 9 having upper and lower ends opened at an upper portion in the drop shaft 3, and an intermediate portion in the drop shaft 3. The middle opening part 1 without a spiral plate
1 and further, a lower spiral plate 12 is provided at a lower portion in the drop shaft 3 to form a lower spiral guide path 13,
A swirling flow type drop construction 14 that forms a swirling flow inside the drop shaft 3 is configured. Further, in addition to the above-described configuration in which the intermediate opening portion 11 having no spiral plate is formed in the intermediate portion inside the drop shaft 3, a configuration in which a spiral plate is formed over the entire length in the drop shaft 3 is also considered. I have.

In FIG. 8, 15 is air, 16 is a water surface when the inflow of water 1 is small, 17 is a free water surface when the inflow of water 1 is large, and 18 is a center formed at the axial position of the drop shaft 3. The air vortex 19 is an air suction vortex formed on the free water surface 17 or the water surface 16.

As shown in FIG. 9, a vertical communication path 20 is formed in the center of the lower spiral plate 12 so as to allow the generation of the central air vortex 18.

Further, an orifice plate 21 for reducing the cross-sectional area of the flow path of the outflow pipe 6 is provided in the upper part of the middle of the outflow pipe 6 shown in FIG.

In the above-mentioned swirling flow type head construction 14, when water 1 such as rainwater separated by a diversion facility (not shown) enters the drop shaft 3 through the water collecting pipe 2, first, the water flows through the upper spiral guide path 10. The swirling flow is given by the upper spiral plate 8, subsequently released from the spiral plate at the intermediate opening 11 and freely swirled and dropped, and then adjusted to the swirling flow by the lower spiral plate 12 in the lower spiral guide path 13. After the surplus energy is reduced, it is sent from the outlet 5 below the drop shaft 3 to the underground storage pipe 7 via the outflow pipe 6 and stored. At this time, the upper end of the drop shaft 3 and the upper end of the upper central cylinder 9 are opened to communicate with the atmosphere,
The inside is prevented from becoming negative pressure.

As described above, by making the water 1 flow in a swirling flow, the energy of the drop is reduced, and the drop landing portion at the lower end of the drop shaft 3 does not generate vibration or damage due to impact or the like. Thus, a large amount of water 1 can flow smoothly in a short time.

Further, since the outflow pipe 6 is provided with the orifice plate 21, the pressure loss of the outflow pipe 6 can be increased. Outflow to the storage pipe 7 can be suppressed.

That is, as shown in FIG. 7, the relationship between the flow rate of the water 1 flowing through the outflow pipe 6 and the air entrapment ratio is shown, and when no orifice plate is provided, as shown by the line A in FIG. Since the aeration rate increases and the water 1 containing air is sent to the storage pipe 7, it is necessary to newly install piping equipment or the like for the air release in the outflow pipe 6 or the storage pipe 7. This causes a problem that the equipment cost increases, and also causes a problem that an unpleasant odor may be generated at a portion where the extracted air is opened to the ground.

On the other hand, when the orifice plate 21 as described above is installed in the outflow pipe 6, the air entrapment rate can be greatly reduced as shown by the line B in FIG. Can be prevented.

As shown in FIG. 8 and FIG. 9, in addition to the swirl-flow type drop construction 14 having spiral plates 8 and 12 inside the drop shaft 3 to generate a swirl flow, the water collection pipe 2 A swirling flow type drop construction in which the vortex flow is generated inside the drop shaft 3 by connecting the tangential direction to the drop shaft 3 is also considered. By providing an orifice plate in the tube to increase the pressure loss in the outflow tube,
It is possible to prevent the air from being mixed into the water and flowing out to the storage pipe.

[0015]

However, the above-mentioned conventional swirling flow type head has the following problems.

FIGS. 10 and 11 are a perspective view and a plan view, respectively, of the lower end of the drop shaft 3 shown in FIG. In FIGS. 10 and 11, a center tube 22 is provided at the center of the drop shaft 3, which is different from the configuration of FIG. 8 in this point. Since this does not affect the general operation, description will be made with reference to FIGS.

The swirling flow 23 formed by the lower spiral plate 12 flows toward the outlet 5 while the swirling force is applied, so that the water flow violently collides with the inner surface of the outflow pipe 6. Therefore, there is a problem that the inner surface of the outflow pipe 6 is significantly worn by rainwater or the like in which solid matter is mixed in the water.

Further, as described above, since the swirling flow 23 flows toward the outlet 5 while the swirling force is applied, the swirling flow 23 flows to the corner portion 24 on the side toward the outlet 5 due to the swirling air. The pool 25 is formed,
Since a contraction flow is formed in the outflow pipe 6, the substantial cross-sectional area of the flow path of the outflow pipe 6 is reduced. Therefore, there is a problem that the structure of the outflow pipe 6 becomes large due to the necessity of performing the cleaning.

Further, as described above, since the orifice plate 21 is provided in the outflow pipe 6, a contraction occurs in the outflow pipe 6 as shown in FIG. There is a problem that the flow rate of the water flowing in the lower part is further increased, and the installation of the orifice plate 21 narrows the flow path in the outflow pipe 6.
As shown in (1), the cross-sectional area of the outflow pipe 6 becomes large in order to form a flow path having a required cross-sectional area below the orifice plate 21, and the equipment such as the outflow pipe 6 becomes large. Had the problem of getting lost.

The present invention has been made in view of the above-mentioned circumstances, and a swirl-flow type head structure capable of suppressing the inflow of air with a simple structure and stabilizing the outflow from an outflow port so as not to cause abrasion. The purpose is to provide.

[0021]

According to the present invention, there is provided a tubular drop shaft having a water collecting pipe connected to an upper portion and an outlet formed at a lower portion, and a swirling flow is formed inside the drop shaft. A swirling flow type dropping machine, comprising a resistance plate at a position near the outlet inside the lower end of the drop shaft, the resistance plate turning the inside of the drop shaft and resisting the swirling flow toward the outlet. It relates to a flow-type head.

Further, when the lower end of the drop shaft is closed by a bottom plate and an outlet is formed laterally above the bottom plate, a resistance plate protruding radially inward of the drop shaft may be provided. When the outlet formed at the lower end of the drop shaft is open to a horizontal pipe extending in the lateral direction, a resistance plate protruding in the radial direction of the drop shaft is provided. The resistance plate is fixed to the inner surface of the drop shaft, and the projecting width of the resistance plate is about 40% to 60% of the radial width of the swirling flow formed inside the drop shaft.

According to the above means, the following effects can be obtained.

[0024] A resistance plate is provided at a position near the outlet inside the lower end of the drop shaft so as to provide resistance to the swirl flowing toward the outlet by turning inside the drop shaft. Air contamination can be effectively reduced.

Further, since the swirling flow toward the outlet collides with the resistance plate and flows around the resistance plate, the flow velocity toward the outlet becomes slower and the flow becomes stable, so that the flow from the outlet becomes stable. It is possible to prevent the water from flowing out stably so that the outlet pipe is not partially worn.

Further, since the outflow pipe fills the inside of the outflow pipe and the water flows stably, the cross-sectional area of the outflow pipe can be made as small as possible.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 5 show an embodiment of the present invention corresponding to the configuration of the lower end of the drop shaft 3 shown in FIGS. At a position near the outlet 5, a resistance plate 26 is provided so as to provide resistance to the swirling flow 23 that turns inside the drop shaft 3 toward the outlet 5.

The resistance plate 26 is fixed to the lower inner surface of the drop shaft 3 and the bottom plate 4 and is provided so as to protrude radially inward of the drop shaft 3.

The position where the resistance plate 26 is installed is near the outlet 5, and as shown in FIG.
And the center portion of the drop shaft 3 from the center line of the outlet 5 to the corner portion 24.
Side and a position separated by an angle θ of about 100 °.

The protruding width of the resistance plate 26 is shown in FIGS.
The width W2 of the swirl flow 23 formed inside the drop shaft 3 is about 40% to 60% of the radial width W1.

Further, the length H of the resistance plate 26 in the vertical direction is selected based on a guide between a length approximately equal to the height of the outlet 5 and a length of approximately one pitch of the lower spiral plate 12. Good.

Next, the operation of the above embodiment will be described.

The basic operation of the swirling flow head 14 is the same as that shown in FIG.

In the embodiment shown in FIGS. 1 to 5, a swirling flow 23 swirling inside the drop shaft 3 toward the outlet 5 is provided at a position near the outlet 5 inside the lower end of the drop shaft 3.
Is provided with the resistance plate 26, so that the swirling flow 23 toward the outlet 5 collides with the resistance plate 26 and bypasses the resistance plate 26 as shown in FIGS. As a result, the flow velocity of the flow 23A from the corner portion 24 toward the outlet 5 is reduced and stabilized, and the resistance of the resistance plate 26 causes a difference between the flow 23A and the side on which the resistance plate 26 is installed. The flow 23B flowing from the opposite side to the outlet 5 is also generated stably, so that the water flows out from the outlet 5 stably, so that there is no partial wear on the outlet pipe 6, and 3 and 4
As shown in (1), since the water flows stably in the outflow pipe 6, the cross-sectional area of the outflow pipe 6 can be made as small as possible.

Further, by installing the resistance plate 26 as described above, as shown by the line C in FIG. 7, air is mixed with the line B when the orifice plate 21 of FIG. The rate could be reduced.

At this time, if the width W2 of the resistance plate 26 is too small or the length H of the resistance plate 26 is too small, the resistance given to the swirling flow 23 becomes small, and a sufficient air removal effect and the outlet 5 If the width W2 of the resistance plate 26 is too large or the length H of the resistance plate 26 is too large, the resistance given to the swirling flow 23 becomes excessive, and Problems such as turbulence in the heading flow or a decrease in the swallowing processing amount of the drop shaft 3 occur.

Therefore, the width W2 for projecting the resistance plate 26
2 and FIG. 5, the radial width W1 of the swirling flow 23 formed inside the drop shaft 3 is about 40%.
% To about 60%.
The vertical length H of 6 is preferably selected between a length substantially equal to the height of the outlet 5 and a length of about 1 pitch of the lower spiral plate 12 as a guide.

FIG. 6 shows another embodiment of the present invention. In FIG. 6, an outlet 5 at the lower end of the drop shaft 3 is connected to a horizontal pipe such as an outflow pipe or a storage pipe extending in the lateral direction. 27, and a resistance plate 26 that protrudes in the radial direction is fixed inside the lower end of the drop shaft 3.

In the configuration shown in FIG. 6, the reduction of the air entrapment rate can be suppressed by the provision of the resistance plate 26, and the problem of impact and wear on the horizontal pipe 27 can be reduced by attenuating the turning force. .

It should be noted that the present invention is not limited to the above-described embodiment, and can be applied regardless of the presence or absence of the central tube. In the illustrated example, a spiral plate is provided inside the drop shaft to generate a swirling flow. The case of the swirling flow type head constructed in this way is exemplified, but the invention is also applicable to a swirling flow type head construction in which a water collecting pipe is connected to the drop shaft from a tangential direction to generate a vortex inside the drop shaft. It goes without saying that various changes can be made without departing from the spirit of the present invention.

[0042]

As described above, according to the swirling flow head of the present invention, the swirling flow swirling inside the drop shaft and heading toward the outlet is located at a position near the outlet inside the lower end of the drop shaft. Since the resistance plate that gives resistance is provided, the mixing of air can be effectively reduced due to the pressure loss caused by the resistance plate. Since the water flows by bypassing the plate, the flow velocity toward the outlet becomes slower and the flow becomes stable, so that the water flows out from the outlet stably so that the outlet pipe is partially worn. In addition, since water flows stably by filling the inside of the outflow pipe, an excellent effect that the cross-sectional area of the outflow pipe can be reduced to a necessary minimum size can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention in a see-through manner.

FIG. 2 is a plan view of FIG.

FIG. 3 is a side view of FIG. 1;

FIG. 4 is a view taken in the direction of arrow IV in FIG. 3;

FIG. 5 is a front view of a resistance plate.

FIG. 6 is a side view showing another example of the embodiment of the present invention.

FIG. 7 is a diagram showing a comparison of the relationship between the flow rate flowing through the outflow pipe and the air mixing ratio when an orifice is provided, without an orifice, and when a resistance plate is provided.

FIG. 8 is a schematic overall side sectional view of a head work currently being planned.

FIG. 9 is a schematic partial sectional side view of FIG. 8;

FIG. 10 is a perspective view showing the lower part of the drop shaft of FIG. 8 in a see-through manner.

FIG. 11 is a plan view of FIG. 10;

FIG. 12 is a side view of FIG. 10;

FIG. 13 is a view taken in the direction of the arrow XIII in FIG. 12;

[Explanation of symbols]

 2 Water collecting pipe 3 Drop shaft 4 Bottom plate 5 Outlet 14 Swirling flow type drop construction 23 Swirling flow 26 Resistance plate 27 Horizontal pipe W1 Radial width W2 Width

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Riki Yoshimoto 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawashima-Harima Heavy Industries, Ltd. F-term (reference) 2D063 AA00

Claims (4)

[Claims] 1. A swirling flow type dropping machine comprising a tubular drop shaft having a water collecting pipe connected to an upper part thereof and an outlet formed at a lower part, and forming a swirling flow inside the drop shaft. A swirling flow type dropping work provided with a resistance plate for turning the inside of the drop shaft and moving toward the outlet at a position near the outlet inside the lower end of the drop shaft. 2. A lower end of the drop shaft is closed by a bottom plate, an outlet is formed laterally above the bottom plate, and a resistance plate projecting radially inward of the drop shaft is connected to an inner surface of the drop shaft. The swirling flow type drop head according to claim 1, wherein the swiveling type head is fixed to a bottom plate. An outlet formed at a lower end of the drop shaft is open to a horizontal pipe extending in a lateral direction, and a resistance plate projecting in a radial direction of the drop shaft is fixed to an inner surface of the drop shaft. The swirling flow type head work according to claim 1, characterized in that: 4. The projecting width of the resistance plate is about 40% to 60% of the radial width of the swirling flow formed inside the drop shaft.
The swirling flow type head work according to claim 1, 2 or 3, characterized in that it is of the order of magnitude.