JPH0340900Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention regulates the flow rate of rivers and lakes, and is used for gate bodies of water gates installed across channels for water intake and flood control, especially for upstream mouths and ceilings. This is a novel idea regarding a door body with a siphon on which a siphon conduit connects the end and the downstream discharge port.

[Conventional technology]

Regarding the gate body with a siphon, there are several inventions and ideas proposed by the applicant himself (for example, "water gate with siphon" (Japanese Patent Laid-Open No. 155412/1983) and (Japanese Patent Laid-Open No. 106008/1989). ).

Conventionally, the amount of water discharged was adjusted by raising and lowering the water gate electrically, but there were problems with staffing and mechanical maintenance, and natural overflow alone, with no moving parts, could not cope with the rapid increase in water level on the upstream side. However, these problems were solved by the development of a water gate with a siphon.

In other words, when the water level on the upstream side rises and the mouth of the siphon pipe is submerged under water due to natural overflow, the air inside the pipe is engulfed by the water flow, rapidly depressurizes, and becomes a siphon flow (transition flow), which rapidly increases the flow rate and generates a large amount of water. Allows for water discharge. Even if the water level rises further, expelling all the air in the siphon pipe and entering the pipe flow completely filled with water, the flow rate will still increase (experimentally, compared to natural overflow, the same overflow width, (With the same overflow water depth, approximately 8 times the discharge capacity can be obtained.) It has the advantage of being able to increase or decrease the amount of water discharged by adapting most sensitively to fluctuations in the upstream water level, making it effective in adjusting the water level. ing.

[Problem that the invention attempts to solve]

Flowing water reaching a sluice from upstream usually contains floating objects, and it is desirable that these floating objects are dammed by a sluice gate and do not flow downstream, except in emergencies such as flooding. This is because it may have a negative impact on water usage downstream.

Conventionally, when constructing water gates across large and medium-sized rivers, there is a method of installing a net field on the upstream side to prevent floating objects from flowing in, but this method prevents the net field from flowing when large or small floods occur due to heavy rainfall. If it is not removed separately, it may impede flood communication or cause damage, which is not desirable.

Gate bodies with siphons are usually lowered to the bottom of the river, and water is discharged from upstream to downstream through a siphon pipe suspended above the gate body, so the mouth is relatively narrow. When foreign objects get caught in the inflow area of the upstream water from the spout, changes in flow conditions have a greater effect than on door bodies other than those with a siphon. As mentioned earlier, the siphon pipe takes on one of the three flow states: natural overflow, siphon flow (transition flow), and pipe flow depending on changes in the upstream water level, and the flow rate varies significantly depending on the flow state. The function of the dam is to greatly adjust the discharge amount by increasing or decreasing it, so if the inlet is partially or completely blocked and an abnormality occurs in the amount of air mixed in with the inflow water, it will no longer function properly, and this will cause problems in the installation of the dam. This could seriously impede the purpose.

Doors with siphons, whose opening area to the upstream side is an important factor in forming the flow regime, are particularly sensitive to the effects of floating objects, so when installing a screen over the spout to prevent floating objects from entering. Floating objects that are stuck there must be constantly removed, and there is no way that they can endure such complicated management.

In order to solve the above problems, the present invention provides a dust prevention device to prevent floating objects from flowing down from the upstream side under normal conditions, and also prevents the flow rate adjustment function of the door body with a siphon due to the provision of the device. It is an object of the present invention to provide a new dustproof device for a door body with a siphon, which can remove accumulated floating matter without deterioration and can also remove accumulated floating matter by using natural forces at the appropriate time.

[Means for solving problems]

The dustproof device for a door with a siphon according to the present invention has a rotating shaft pivoted on the upstream front wall of the door, a screen frame with a screen attached to the rotating shaft, and a float near the tip of the screen. Since the screen is attached, the screen rotates according to the water level on the upstream side, which solves the above problem.

[Effect]

Since the present application has the above-mentioned configuration, under normal conditions (when the bottom of the door body is closed in contact with the riverbed), it is restrained to the door body via the rotation shaft pivoted on the front wall of the door body. The screen is lifted toward the water surface by the buoyancy of a float attached near its tip, and as a result is positioned obliquely at various angles corresponding to the upstream water level. By setting the height of the rotating shaft above the door body appropriately in advance, the screen in normal conditions will have an appropriate inclination to provide a dustproof function between the door body and the water surface on the upstream side. Floating objects from the side are blocked by this screen and cannot reach the spout. In addition, because it has an appropriate slope, even if the water near the upstream side is covered with floating objects and the inflow of water is affected, the water will sneak under the floating objects and freely flow in from the bottom of the screen and reach the spout. It has no effect whatsoever on the water flowing into the siphon line.

On the other hand, during floods, the water level cannot be adjusted by discharging water over the top of the gate body, so the gate body is raised to form a channel between it and the riverbed, and a large amount of water is discharged to balance the water level on both the upstream and downstream sides. We aim to At this time, floating objects from the upstream side due to floods, etc. increase dramatically, but all of them go straight under the door body and flow downstream. As the door body itself rises, the relative vertical relationship between the rotation axis of the screen and the upstream water level is reversed, and the slope of the screen becomes opposite to the normal slope. Floating objects that were accumulated on the screen during normal times are released from their restraints as the angle reverses.
Pushed by its own weight and flow velocity, it slips under the bottom of the door and flows downstream. In the event of an emergency (flood), floating debris can be predicted downstream and countermeasures taken.
And since this happens infrequently, taking advantage of this opportunity to wipe away the objects on the screen can be said to be an extremely rational opportunity to eliminate the troublesome and dangerous task of cleaning.

〔Example〕

An embodiment of the present application will be described based on FIGS. 1 to 3. Figures A, B, and C are schematic side cross-sectional views showing normal conditions (Figure A), under floating flow during a flood (Figure B), and during maximum discharge during a flood (Figure C).

In each figure, a siphon conduit 2 formed by connecting a spout 3, a top end 4, and a discharge port 5 is suspended above the door body 1 with a siphon. A rotary shaft 7 is rotatably supported at a suitable height on the front wall 6 on the upstream side of the door body 1, and a screen girder 9 is fixed to this rotary shaft 7.

As shown in Fig. 2 (front view seen from the upstream side) and Fig. 3 (plan view), the screen 8 is constructed by intersecting long members vertically and horizontally at regular intervals and fixed to the screen girder 9. Ru. A float 10 is fixed near the tip of this screen. Other known members such as a screen support stand 11 and a main roller 12 for raising and lowering the guide are attached as other main attachments.

As mentioned earlier, it is necessary to avoid the influence of suspended objects on the flow conditions of the siphon, so the upward tilt angle of the screen is approximately 45° under normal conditions.
The downward tilt angle of the screen during floods also
It is desirable to set it to around 45°. This setting can be easily calculated based on the average upstream water level in normal times, the position of the rotating shaft, and the position of the support stand. In addition, in order to avoid the above effects, for example, when the thickness of the siphon conduit is 150 mm, the inclination and elevation angle of the screen is empirically set to 45 degrees, and the distance L from the front wall of the door body to the center point C is 700 mm. degree,
It is desirable that the distance H from the top and bottom of the siphon conduit be approximately 500 mm.

[Effect of idea]

Since the dust-proofing device for the door body with a siphon of the present invention produces the above-mentioned effect, under normal conditions, floating objects are only anchored on the water surface on the upstream side, which is quite far away from the siphon spout, and there is no possibility of entering the spout. It has no effect on water inflow.

In the event of a flood, the door body itself is raised, the flow path moves from the top of the door body to the bottom, and the angle of the screen changes from 45° upwards to 90° with respect to the door body, and then changes to a reverse slope downward, and the screen is locked during this time. The accumulated floating matter flows downstream along with the large amount of floating matter typical of floods, leaving the screen completely cleared of foreign matter. Therefore, there is no need to remove floating objects that are stuck to the screen again.

The structure of the present application is relatively simple, and it can be easily applied to an existing door body with a siphon.

[Brief explanation of the drawing]

Figures 1A, B, and C are side sectional views showing the effect of the embodiment of the present application, Figure 2 is a front view seen from the upstream side, and Figure 3 is a front view as seen from the upstream side.
The figure is a plan view. 1... Door body with siphon, 2... Siphon conduit, 3... Spout, 4... Top, 5... Discharge port,
6... Front wall, 7... Rotating shaft, 8... Screen,
9...Screen digit, 10...Float.

Claims (1)

[Scope of utility model registration request] A rotary shaft 7 is pivotally supported on the upstream front wall 6 of the door body 1 with a siphon on which the siphon conduit 2 connecting the upstream spout 3, the top end 4, and the downstream discharge port 5 is mounted, and a screen 8 is attached to the rotary shaft. The screen girder 9 with the
A dustproof device with a door body equipped with a siphon that allows the screen to rotate upstream according to the water level.