JP4651017B2 - Sewer Fushietsu structure - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a sewer subsidence structure, and more particularly, to a sewer subsidence structure in which the structures of a downstream part of a subsidence pipe and a downstream subsidence chamber are improved.

  Generally, when it is necessary to lay an underground waterway across an obstacle such as a river, a railway, or an underground burial that is difficult to relocate, the sewerage is installed in the section where the obstacle exists (reverse siphon type communication passage). ) (See, for example, Patent Documents 1 and 2). Among the examples of the structure of the Fushigoe adopted in the field of combined sewerage systems, those that incorporate an air cushion siphon system are known (for example, see Non-Patent Documents 1 and 2). Explained. FIG. 5 shows an example of a structure in which an air cushion chamber is formed by two gates.

  In this structure, as shown in FIG. 5A, an upstream sewage channel 101 and a downstream sewage channel 102 are provided on the upstream side and the downstream side with the obstacle 103 interposed therebetween, and are communicated with the sewage channels 101 and 102. Thus, an upstream side cover room 111 and a downstream side cover room 112 are vertically provided on both sides of the obstacle 103. Then, the lower ends of both the overpass chambers 111 and 112 provided vertically are connected by an overpass tube 113 that passes under the obstacle 103.

  Further, the inflow ports 115 and the outflow ports 116 at both ends of each of the overpass chambers 111 and 112 and the overpass tube 113 are provided with gates 117 and 118 for closing the inflow port 115 and the outflow port 116 from above so as to be movable up and down. It has been. The gates 117 and 118 can be opened and closed by a driving mechanism (not shown). When the two gates 117 and 118 are closed to a certain extent as shown in FIG. 5B, an air reservoir (hereinafter also referred to as an air cushion chamber) P can be formed in the upper part of the overpass pipe 113, and this is externally provided here. By introducing and containing air, the cross-sectional area of the flow path through which the sewage flows in the overpass 113 can be reduced, and the flow of sewage can be accelerated.

  When operating this gate type air cushion siphon system, as shown in FIG. 5 (A), normally, the gates 117 and 118 are fully opened, and the flow passage cross-sectional area of the overpass pipe 113 is used to sewer. Shed. When the flow path cross-sectional area is large, the flow becomes loose, and there is a possibility that the deposit T will accumulate in the overpass 113. Therefore, the deposit removal operation as shown in FIG. 5B is performed at an appropriate timing. During this deposit removal operation, the gates 117 and 118 are closed to some extent. Then, air is introduced from the outside into the air cushion chamber P formed in the upper part of the overpass pipe 113, and by holding this, the flow passage cross-sectional area through which the sewage in the overpass pipe 113 flows is reduced, and the sewage The flow of water is made faster and the deposit T is washed away. In this way, deposits in the depression tube 113 can be removed.

JP 2002-348948 A JP 2003-253739 A “Combined Sewerage and Fushikoshi” written by Hiroshi Suzuki, Public Investment Journal, Inc. December 25, 2002 Tokyo Metropolitan Sewerage Bureau Internet <URL: http://www.gesui.metro.tokyo.jp/odekake/syorijyo/03_13.htm>

  However, since the outflow amount of the sewage flowing out from the outlet 116 of the depression tube 113 is determined by the opening degree of the outlet 116 by the gate 118, the sewage that could not flow out from the outlet 116 collides with the gate 118. The sewage may stagnate or reversely flow and collide with the sewage flowing from the upstream side of the overpass 113, and the water level of the sewage may rise in the downstream area within the overpass 113. Due to the rise in the water level, the flow rate of the sewage in the downstream area of the depression pipe 113 is lowered, and it may be difficult to push the deposit into the downstream depression chamber 112.

  The rise in the water level in the downstream region of the overpass pipe 113 can be eliminated by increasing the opening degree of the outlet 116 of the overpass pipe 113 by the gate 118, but in this case, an air trap in the overpass pipe 113 When P is insufficient, the cross-sectional area of the sewage flowing through the overpass pipe 113 increases, and a flow velocity that can push the sediment in the overpass pipe 113 is given to the sewage flowing through the overpass pipe 113. There is a risk that it will not be possible.

  An object of the present invention is made in consideration of the above-mentioned circumstances, and is to provide a sewer overpass structure for a sewer that can well discharge sediments such as earth and sand accumulated in the overpass pipe. .

The invention according to claim 1 is connected to an upstream sewerage channel and a downstream sewerage channel that are arranged with an obstacle interposed therebetween, and is connected to upstream and downstream chambers on both sides of the obstacle. Air for introducing air into the overpass in the overpass structure of a sewer having an overpass and an overpass pipe connecting the upstream and downstream overpass rooms under the obstacle. Introducing means and air pool forming means arranged on the inlet and outlet sides of the overpass pipe and forming an air pool above the inside of the overpass pipe by the air introduced by the air introduction means. The air reservoir forming means includes an upstream gate that closes an upper portion of the inflow port of the overpass tube, and a case body that covers the outflow port of the overpass tube and includes a lower opening below. is configured to have the side opening is formed on the side of the case body, the opening of the side openings Downstream gate for adjusting the area is characterized in that provided in the case body.

According to a second aspect of the present invention, in the first aspect of the present invention, the intake port is positioned in the vicinity of the lower opening of the case body, and the inside of the downstream side overpass chamber or along the downstream side overpass chamber. A guide duct is installed, and air in the overpass pipe is introduced into the guide duct.

The invention according to claim 3 is the invention according to claim 2 , wherein the free water surface is disposed between the discharge port at the upper end of the guide duct and the free water surface of the sewage in the downstream passover chamber. It is characterized in that a weir that is higher than the discharge port is provided.

According to a fourth aspect of the present invention, in the invention according to the second or third aspect , the sediment such as earth and sand discharged into the downstream side overpass chamber is taken into the downstream side overpass chamber. A guiding means for guiding to the mouth is installed.

  According to the first aspect of the present invention, the air introduced into the overpass pipe by the air introduction means is located above the inside of the overturn pipe and the case body by the upstream gate and the case body of the air reservoir forming means. An air pocket is formed along the longitudinal direction of the overflow tube. For this reason, the flow-path cross-sectional area which a sewage flows over the full length in a subsidence pipe can be decreased, and the flow rate of a sewage can be raised. In addition, the sewage in the subsidence pipe flows out smoothly from the lower opening of the case body into the downstream side subsidence chamber through the outlet and without resistance. From these things, since the flow rate of the sewage which flows through the inside of the overpass pipe is maintained appropriately also in the downstream area of the overpass pipe, sediments such as sediment deposited in the overpass pipe can be discharged well.

Furthermore, by adjusting the opening area of the side opening of the case body with the downstream gate, the height of the air pocket formed in the upper part of the inside of the bush and the case body can be adjusted. In addition, by fully opening the side opening of the case body with the downstream gate, or by raising the downstream gate to the surface of the sewage in the case body, suspended matter in the sewage flowing in the subsidence pipe is removed. , It can be discharged into the downstream passover chamber without staying in the case body. In particular, in the latter case, it is possible to maintain and secure an air reservoir above the inside of the bush and the case body.

According to the invention described in claim 2 , the intake of the guide duct installed in the downstream side cover room or along the downstream side cover room is positioned near the lower opening of the case body, Since the air in the overpass pipe is introduced into the guide duct, the air that is introduced into the guide duct and rises functions as an air lift pump, and passes from the overpass pipe through the case body to the downstream side overpass chamber. The discharged sewage and sediment can be guided into the guide duct and transferred upward.

According to the invention described in claim 3 , a weir is provided between the discharge port at the upper end of the guide duct and the free water surface of the sewage in the downstream passover chamber so that the free water surface is higher than the discharge port of the guide duct. As a result, an upward flow of sewage is generated in the guide pipe due to the difference in water level between the free surface of the sewage in the downstream passover chamber and the discharge port at the upper end of the guide duct. The sewage and deposits that have flowed out into the downstream passover chamber can also be transferred upward through the guide duct by the upward flow of sewage in the guide pipe.

According to the fourth aspect of the present invention, sediments such as earth and sand discharged from the outflow port of the passover pipe through the lower opening of the case body into the downstream passover chamber are introduced into the intake port of the guide duct by the guiding means. Therefore, most of the deposits in the downstream passover chamber can be transported upward through the guide duct and discharged.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is an overall cross-sectional view showing an embodiment of a sewer cover structure according to the present invention. FIG. 2 is an enlarged cross-sectional view of the downstream passover chamber of FIG.

  The target sewer is a combined sewer that discharges sewage and rainwater through the same pipe, and as shown in FIG. 1, the upstream sewer is located upstream and downstream across an obstacle 100 such as a river. A water channel 1 and a downstream sewer channel 2 are provided, and an overpass 10 is provided to connect the two sewer channels 1 and 2 while avoiding the obstacle 100. As means for constituting the overturning portion 10, first, vertical shafts 4 and 5 that are communicated with the respective sewers 1 and 2 and are perpendicular to both sides of the obstacle 100 are provided.

  The lower part of each vertical shaft 4, 5 is an upstream passover chamber 11 and a downstream passover chamber 12, and the passway between the lower ends of both the passover chambers 11, 12 passes below the obstacle 100. Connected by a tube 13. The upstream part 10, the downstream part 12 and the pipe 13 constitute an overpass part 10.

  The bush 10 further includes a compressor 14 as air introduction means, an upstream gate 15 as an air reservoir formation means, a case body 16 and a downstream gate 17, and a guide duct 18 that functions as a sandpipe. .

  The compressor 14 introduces air, an inert gas, or the like (hereinafter simply referred to as air) into the depression tube 13. The upstream gate 15 is installed on the inflow port 19 side of the overpass pipe 13 so as to be movable up and down, closes the upper portion of the inflow port 19 and determines the opening degree of the inflow port 19. The upstream gate 15 moves up and down along a guide rail (not shown) and is driven up and down by a driving mechanism (not shown).

  As shown in FIGS. 2 to 4, the case body 16 is, for example, a box that is fixedly installed on the outflow port 20 side of the overpass part 13 and covers the outflow port 20, and has a lower opening 21 below. Is provided. Since the case body 16 is disposed in the downstream side depression chamber 12, the lower opening communicates with the downstream side depression chamber 12. Further, a side opening 22 is formed on the side of the case body 16, and the downstream gate 17 adjusts the opening area of the side opening 22. The downstream gate 17 is installed on the case body 16 so as to be movable up and down along a guide rail 24 (FIG. 3) provided on the case body 16, and is driven up and down by a drive mechanism (not shown) to And the opening of the side opening 22 is determined. The side opening 22 is formed continuously with the lower opening 21.

  The upstream gate 15 closes the upper part of the inlet 19 of the overpass pipe 13, and the downstream gate 17 closes the upper part of the side opening 22 of the case body 16, and the compressor 14 supplies the air into the overpass pipe 13. Is introduced, an air reservoir P is formed along the longitudinal direction of the overpass tube 13 at the upper portion of the overpass tube 13 and the upper portion of the case body 16. As a result, the cross-sectional area of the flow path through which the sewage W flows is reduced, the flow velocity of the sewage W is increased, and the sediment T such as earth and sand accumulated in the overpass pipe 13 is swept away. It is. The sewage W in the depression pipe 13 reaches the case body 16 through the outlet 20, and flows from the lower opening 21 and the opened side opening 22 of the case body 16 into the downstream depression chamber 12. Smoothly flows out without resistance.

  Here, the volume of the air reservoir P in the overpass pipe 13 is the flow rate necessary for the cross-sectional area of the sewage W flowing in the overpass pipe 13 to push away the sediment T accumulated in the overpass pipe 13. Set to ensure. The setting of the volume of the air reservoir P in the overpass pipe 13, that is, the setting of the holding height M of the air reservoir P is determined by the raising / lowering positions of the upstream side gate 15 and the downstream side gate 17.

  As shown in FIG. 2, the guide duct 18 is erected in a state where a storage space for the sewage W is secured around the downstream passway chamber 12, a discharge port 25 at the upper end, and an intake port at the lower end. 26 respectively. Note that the guide duct 18 may be provided along the downstream side cover chamber 12 outside the downstream side cover chamber 12.

  The inlet 26 of the guide duct 18 is provided in the vicinity of the lower opening 21 of the case body 16 and is provided in communication with the side opening 22 of the case body 16. Air is continuously introduced from the compressor 14 into the overpass tube 13 and an air reservoir P is formed in the overpass tube 13. The air introduced into the overpass tube 13 becomes bubbles K. Then, it passes through the lower opening 21 and the opened side opening 22 of the case body 16 to reach the guide duct 18 and ascends in the guide duct 18 and is released into the atmosphere. The air functions as an air lift pump by rising in the guide duct 18 as bubbles K, and guides the sewage W including earth and sand that has flowed into the downstream side overpassage chamber 12 from the lower opening 21 of the case body 16. It is guided into the duct 18 and moved upward in the guide duct 18.

  In addition, a weir 27 is provided between the discharge port 25 at the upper end of the guide duct 18 and the free water surface of the sewage W of the downstream passway chamber 12 so that the free water surface is higher than the discharge port 25 of the guide duct 18. Yes. Due to the difference in water level H between the free water surface of the sewage W in the downstream passway chamber 12 and the discharge port 25 of the guide duct 18 blocked by the weir 27, an upward flow of the sewage W is generated in the guide duct 18, Also by this upward flow, the sediment T such as earth and sand contained in the sewage W is lifted upward in the guide duct 18 and transferred. Here, the height of the weir 27 is set to a level that causes an upward flow of the sewage W in the guide duct 18 due to the water level difference H in consideration of the flow path loss of the guide duct 18.

  Further, a guide slope 28 as guide means is formed at the bottom of the downstream passover chamber 12. This guiding slope 28 passes through the lower opening 21 and the opened side opening 22 of the case body 16 and deposits T such as earth and sand in the overpass pipe 13 discharged into the downstream side overpass chamber 12 together with the sewage W. Are guided and collected near the vicinity of the intake 26 of the guide duct 18. As a result, most of the deposit T discharged into the downstream pass-through chamber 12 is taken in from the intake 26 of the guide duct 18 and transferred to the upper side of the guide duct 18.

Next, the operation will be described.
When operating the sewer, normally, the upstream gate 15 opens the inflow port 19 of the overpass pipe 13, the downstream gate 17 opens the side opening 22 of the case body 16, and the overflow pipe 13 flows. The road cross-sectional area is set large and sewage W is allowed to flow. If the flow path cross-sectional area is set large, the sewage W will flow slowly in the overpass pipe 13, and sediment T such as earth and sand may gradually accumulate in the overpass pipe 13. Therefore, the deposit removal operation, that is, the cleaning operation is performed at an appropriate timing.

  During the cleaning operation, the upstream gate 15 closes the inlet 19 of the cover tube 13 and the downstream gate 17 closes the side opening 22 of the case body 16 to an appropriate opening degree. In this state, the compressor 14 is driven to pressure-feed air into the overpass tube 13, and an air reservoir P is formed in the upper portion of the overpass tube 13 and the upper portion of the case body 16. By maintaining this state, the flow path cross-sectional area of the sewage W flowing through the inside of the overpass pipe 13 is reduced, the flow velocity of the sewage W flowing through the inside of the overpass pipe 13 is increased, and the sediment in the overpass pipe 13 is increased. The object T is washed away. At this time, the sewage W in the depression pipe 13 reaches the case body 16 through the outlet 20 of the depression pipe 13 together with the deposit T, and the lower opening 21 of the case body 16 and the side opening in the open state. 22 smoothly flows out into the downstream pass-through chamber 12 without resistance.

  Further, air in the air reservoir P in the overpass pipe 13 becomes bubbles K in the sewage W and reaches the case body 16, and the lower opening 21 of the case body 16 and the opened side opening 22 (mainly, mainly). It goes up into the guide duct 18 through the open side opening 22) and acts as an air lift pump. Further, an upward flow of the sewage W is generated in the guide duct 18 due to a difference in water level H between the free water surface of the sewage W in the downstream passover chamber 12 set by the weir 27 and the discharge port 25 of the guide 28. . The sewage W and the sediment T that have flowed into the downstream side overpassage chamber 12 by the action of the upward flow of the sewage W due to these air lift pumps and the water level difference H are introduced into the guide duct 18 from the intake 26 of the guide duct 18. And is moved upward in the guide duct 18.

  After such a cleaning operation is completed, the upstream gate 15 fully opens the inlet 19 of the overpass pipe 13 and the downstream gate 17 fully opens the side opening 22 of the case body 16 to return to the normal state. . Since the side opening 22 of the case body 16 is fully opened, the floating matter present in the sewage W in the bushing pipe 13 and the case body 16 during the cleaning operation does not stay in the case body 16 and remains in the guide duct. 18 or into the downstream passover chamber 12. The deposit T transferred to the upper side of the guide duct 18 during the cleaning operation is transported using an appropriate transport means and discarded.

  Apart from switching between normal and cleaning operations as described above, the operation may be switched between clear and rainy weather when there is a difference in the amount of sewage. That is, since the cross-sectional area of the pass-through pipe 13 is set on the assumption of the flow rate of the sewage W in rainy weather, the flow velocity of the sewage W flowing through the pass-through pipe 13 during fine weather when the flow rate of the sewage W is small. May become too late, and there is a risk that earth and sand will accumulate in the pipe. Therefore, during fine weather, switching is performed so as to increase the flow rate of the sewage W flowing through the inside of the pipe.

  More specifically, when the amount of sewage is small, the opening 19 of the bush-over pipe 13 is opened by the upstream gate 15 and the side opening 22 of the case body 16 is opened by the downstream gate 17 so as to have an appropriate opening degree. Then, air is introduced into the overpass tube 13 by the compressor 14, and an air reservoir P is formed above the inside of the overpass tube 13 and the case body 16. Thereby, the flow-path cross-sectional area of the sewage W which flows through the inside of the depression pipe 13 is decreased, and the flow velocity of this sewage W is increased. By doing so, it is difficult for sediment T such as earth and sand to be deposited in the inside of the bypass tube 13. When the amount of sewage increases in the rain, the upstream gate 15 opens the inflow port 19 of the overpass pipe 13 and the downstream gate 17 opens the side opening 22 of the case body 16 respectively. The air pool P is eliminated so that a large amount of sewage W can flow in the overpass pipe 13.

With the configuration as described above, the following effects (1) to (5) are achieved according to the above embodiment.
(1) The air introduced into the overpass pipe 13 from the compressor 14 is introduced into the overpass pipe 13 and over the inside of the case body 16 by the upstream gate 15 and the case body 16. An air reservoir P is formed along the longitudinal direction. For this reason, the flow path cross-sectional area through which the sewage W flows can be reduced over the entire length of the overpass pipe 13, and the flow velocity of the sewage W can be increased. In addition, the sewage W in the overpass pipe 13 smoothly flows out of the lower opening 21 of the case body 16 and the open side opening 22 into the downstream side overpass chamber 12 without resistance through the outlet 20. From these things, since the flow rate of the sewage W flowing through the inside of the overpass pipe 13 is appropriately maintained even in the downstream area of the overpass pipe 13, the sediment T such as earth and sand accumulated in the overpass pipe 13 is excellent. Can be discharged.

  (2) Adjusting the opening area of the side opening 22 of the case body 16 by the downstream gate 17, thereby adjusting the height of the air pocket P formed in the upper part of the inside of the bush 13 and the case body 16. Can do. Further, when the side gate 22 of the case body 16 is fully opened by the downstream side gate 17 or the downstream side gate 17 is raised to the water surface position of the sewage W in the case body 16, Floating matter present in the sewage W flowing in the pipe 13 can be discharged into the downstream side overpassage chamber 12 without staying in the case body 16. When raising the downstream side gate 17 to the water surface position of the sewage W in the case body 16, it is preferable because the air reservoir P can be maintained and secured above the inside of the overpass pipe 13 and the case body 16.

  (3) The intake port 26 of the guide duct 18 installed in the downstream side chamber 12 is positioned near the lower opening 21 of the case body 16 and communicates with the side opening 22 of the case body 16. Provided, the air in the overpass tube 13 is introduced into the guide duct 18. The air (bubbles K) that rises when introduced into the guide duct 18 functions as an air lift pump, and the sewage W and sediment T that have flowed out of the overpass pipe 13 through the case body 16 and into the downstream side overpass chamber 12. Can be guided into the guide duct 18 and transferred above the guide duct 18.

  (4) A weir 27 is provided between the discharge port 25 at the upper end of the guide duct 18 and the free water surface of the sewage W in the downstream passway chamber 12 so that the free water surface is higher than the discharge port 25 of the guide duct 18. For this reason, an upward flow of the sewage W is generated in the guide pipe 18 due to the difference in water level H between the free water surface of the sewage W in the downstream passover chamber 12 and the discharge port 25 of the guide duct 18. Also by the upward flow of the sewage W in the guide pipe 18, the sewage W and the sediment T that have flowed out into the downstream side overpassage chamber 12 can be transferred upward through the guide duct 18.

  (5) Sediment T such as earth and sand discharged from the outflow port 20 of the overpass pipe 13 into the downstream side overpassage chamber 12 through the lower opening 21 and the opened side opening 22 of the case body 16 is guided. Since it is guided and collected near the inlet 26 of the guide duct 18 by the inclined surface 28, most of the deposit T in the downstream side overpassage chamber 12 can be transferred upward through the guide duct 18 and discharged. .

As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this.
For example, in the above-described embodiment, the case where the case body 16 as a box covers the outlet 20 of the overpass pipe 13 is described, but an elbow pipe that opens downward is inserted into the outlet 20 of the overpass pipe 13. The elbow pipe may be a case body having a lower opening.

1 is an overall cross-sectional view showing an embodiment of a sewer surpassing structure according to the present invention. It is sectional drawing which expands and shows the downstream passover room of FIG. It is sectional drawing which follows the III-III line of FIG. It is a disassembled perspective view which shows the case body of FIG. 2, a downstream gate, a guide duct, etc. It is a hollow part incorporating the conventional air cushion siphon system, and (A) is a schematic sectional view showing a normal time and (B) a cleaning time, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upstream sewage channel 2 Downstream sewage channel 10 Boeing part 11 Upstream side overpassing room 12 Downstream side overpassing room 13 Boeing pipe 14 Compressor (air introduction means)
15 Upstream gate (air pool formation means)
16 Case body (air reservoir forming means)
17 Downstream gate (air reservoir formation means)
18 Guide duct 19 Inflow of the overpass pipe 20 Outlet of the overpass pipe 21 Lower opening of the case body 22 Side opening of the case body 25 Outlet of the guide duct 26 Intake of the guide duct 27 Weir 28 Induction slope (induction means)
100 Obstacle H Water level difference K Bubble P Air reservoir M Air reservoir retention height T Deposit

Claims (4)

Connected to the upstream sewage channel and the downstream sewage channel sandwiched between the obstacles, the upstream side and downstream side chambers are arranged on both sides of the obstacle. In the lower part structure of the sewer having a lower pipe and a downstream pipe connecting the upper and lower rooms,
An air introduction means for introducing air into the above-mentioned depression pipe;
An air reservoir forming means which is disposed on the inlet and outlet sides of the above-described depression pipe and forms an air reservoir above the inside of the above-mentioned depression pipe by the air introduced by the air introduction means;
The air reservoir forming means has an upstream gate that closes the upper part of the inflow port of the overpass pipe, and a case body that covers the outflow port of the overpass pipe and has a lower opening below. is composed Te,
A sewer surpassing structure , wherein a side opening is formed on a side of the case body, and a downstream gate for adjusting an opening area of the side opening is provided in the case body . A intake duct is positioned near the lower opening of the case body, and a guide duct is installed in the downstream side overpass chamber or along the downstream side overpass chamber. Air in the overpass pipe is introduced into the guide duct. The sewer underground structure of the sewer according to claim 1 . 3. A weir is provided between the discharge port at the upper end of the guide duct and the free water surface of the sewage in the downstream passover chamber, and the free water surface is higher than the discharge port of the guide duct. The sewer surpass structure of the sewer described in 1. The Downstream FukuEtsu chamber, according to claim 2 or 3, characterized in that the induction means for inducing deposits gravel or the like to be discharged to the downstream side FukuEtsu chamber of the guide duct to the inlet is installed The sewer surpass structure of the sewer described in 1.

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