JP3203554B2 - Sewage of vacuum type sewer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum drain pipe connecting a sewage generation source to a vacuum station, particularly when there is an obstacle such as a waterway or a river in the middle thereof.
The present invention relates to the protection of a vacuum sewer in which it is possible to prevent a decrease in the degree of vacuum that occurs when passing through the obstacle, to smoothly transport sewage, and to naturally remove foreign substances that accumulate in a pipe portion passing through the obstacle. It is.

[0002]

2. Description of the Related Art Vacuum-type sewage collection systems allow sewage discharged from homes and factories to flow into a vacuum valve unit buried underground by a natural flow-down inflow pipe, and the sewage flows into the vacuum valve unit. When a predetermined amount of water is collected, the vacuum valve is opened, the sewage is sucked into a vacuum sewer pipe, collected in a water collection tank of a vacuum station, and then sent to a sewage treatment plant or the like.

On the other hand, in this vacuum-type wastewater collection system, when there is an obstacle such as a waterway or a river in the middle of the vacuum sewer pipe, it is necessary to make the vacuum sewer pipe protrude deeply under the obstacle and prone. However, doing so consumes the degree of vacuum generated at the vacuum station in the lift on the uphill slope after passing through the obstacle.

For this reason, as shown in FIG. 5, an upstream vacuum sewer pipe 71 and a downstream vacuum sewer pipe 73 are connected to an obstacle 7 such as a river.
5, a vacuum sewer has a structure that is connected by a water pipe 77 passing under the lower side of the block 5 and connected by a ventilation pipe 79 straddling the upper side of the obstacle 75, and has been developed and used.

With this configuration, the sewage flowing in the upstream vacuum sewer pipe 71 passes through the water pipe 77 based on the siphon principle and flows to the downstream vacuum sewer pipe 73. On the other hand, the vacuum in the downstream vacuum sewer pipe 73 is directly transmitted to the upstream vacuum sewer pipe 71 via the ventilation pipe 79, so that the degree of vacuum does not decrease.

[0006]

However, the above-mentioned prior art has the following problems. The height of the portion 72 connected to the water pipe 77 of the upstream vacuum sewer pipe 71 is adjusted to the height of the water pipe 77 of the downstream vacuum sewer pipe 73.
Is set higher by the HA than the height of the portion 74 connected to the sewage, the sewage flowing into the water pipe 77 from the upstream vacuum sewer pipe 71 naturally flows to the downstream vacuum sewer pipe 73 by the principle of the reverse siphon. Flow out. And this is seemingly efficient when looking only at the protruding part of the vacuum sewer. However, when viewed from the entire vacuum type sewage collection system, it means that the head is lost by the difference HA between the heights of the upstream vacuum sewer pipe 71 and the downstream vacuum sewer pipe 73.

That is, in the case of this conventional example, the sewage can flow through the water pipe 77 by the head HA, but the burial depth of the downstream vacuum sewage pipe 73 is smaller than the burial depth of the upstream vacuum sewage pipe 71. It becomes deeper by the water head HA. Then, the labor for embedding the downstream-side vacuum sewer pipe 73 in the ground increases by the increased depth, resulting in an increase in cost. In order to solve this problem, the height of any one of the lift portions of the downstream side vacuum sewer pipe 73 that repeats a gentle and long downward slope portion and a steep and short upward slope lift portion is increased by the head HA. By doing so, the burial depth of the entire downstream vacuum sewer pipe 73 needs to be the same as the burial depth of the upstream vacuum sewer pipe 71. However, in this case, the loss corresponding to the head HA increases in the lift portion having the increased height.

Meanwhile, among other conventional examples, the connection height of the upstream vacuum drain pipe 71 and the downstream vacuum drain pipe 73 to the water pipe 77 is the same, as shown in FIG. Although the connection height of the downstream vacuum drain pipe 73 to the water pipe 77 is slightly higher than the upstream vacuum drain pipe 71, the vacuum drain pipe downstream of the highest position a of the inner diameter of the upstream vacuum drain pipe 71 is located. In some cases, the lowest position b of the inner diameter of tube 73 is lower. Also in these conventional examples, the sewage flows naturally in the water pipe 77.

However, in the case of these conventional examples, the water surface c of the sewage in the upstream-side vacuum sewer 71 is substantially the same as the lowest position b of the inner diameter of the downstream-side vacuum sewer 73. In other words, the sewage d in the upstream vacuum sewer 71 does not reach a full state up to the highest position a of the inner diameter of the upstream vacuum sewer 71.

The flow of sewage in the vacuum sewage pipes 71 and 73 is intermittent. When the vacuum valve 81 attached to the upstream side of the vacuum sewage pipe 71 is closed, the flow of sewage is small. The state is as shown in FIG. On the other hand, when the vacuum valve 81 is opened, the sewage in the water pipe 77 together with the sewage d accumulated in the upstream vacuum sewage pipe 71 shown in FIG.

However, as described above, the amount of the sewage d accumulated in the upstream vacuum sewer pipe 71 depends on the amount of the upstream vacuum sewer pipe 71.
It is not so large because it does not accumulate enough to fill the water,
Therefore, when the vacuum valve 81 is opened, the amount of sewage flowing through the water pipe 77 is small and the flow rate thereof is not fast.
The flow velocity and the continuation of the flow required to reliably discharge foreign matter that easily accumulates in the lowest part of the flow cannot be obtained.

Sewage flowing from the upstream vacuum sewer pipe 71 shown in FIG. 5 is separated into gas by the air pipe 79 at the connection with the air pipe 79. Sewage also invades. Normally, the sewage that has entered once returns to the upstream vacuum sewer pipe 71 again due to its gravity. However, when the flow rate of the sewage is high, the amount of the sewage flowing into the ventilation pipe 79 increases, and in some cases, the sewage jumps up. The lump of waste water becomes large enough to block the ventilation pipe 79, which may hinder the movement of gas in the ventilation pipe 79.

In order to prevent this, a gas-liquid separation tank may be installed at the connection between the upstream vacuum sewer pipe 71 and the ventilation pipe 79, but then the gas-liquid separation tank is specially manufactured and It must be installed, which increases costs.

In the conventional water pipe 77, the angle of the uphill portion is not made smaller than the angle of repose. For this reason, when the flow rate of the sewage becomes slow, the foreign matter that has risen halfway along the uphill portion of the water pipe 77 may slide down to the bottom again.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object a structure in which useless head loss can be prevented, and gas can be separated into the ventilation pipe and foreign substances in the water pipe can be easily discharged. Another object of the present invention is to provide a shelter of a vacuum sewer system that can be effectively carried out in a vacuum.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an upstream vacuum sewer pipe and a downstream vacuum sewer pipe provided on both sides of an obstacle, respectively, with a water pipe passing under the obstacle. At the same time, the lowest position of the inner diameter of the part connected to the water pipe of the downstream vacuum sewer is set to the water pipe of the upstream vacuum sewer in the overhang of the vacuum sewer connected by the ventilation pipe. The connecting portion was configured to be at the same position as the highest position of the inner diameter of the pipe or at a position slightly higher than the highest position. Further, according to the present invention, the inner diameter of the pipe around the connection portion connecting the upstream vacuum sewer pipe and the ventilation pipe is made larger than the inner diameter of the pipe in the other part. Further, according to the present invention, the inner diameter of the pipe at the bottom where the water pipe is lowest and the upward slope where the slope is ascending is made smaller than the inner diameter of the pipe at the other part of the water pipe. Further, in the present invention, the inclination angle of the uphill portion of the water pipe is set to be equal to or less than the repose angle of the foreign matter mixed in the sewage.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention. As shown in the figure, in the present embodiment, an upstream vacuum sewer pipe 2 and a downstream vacuum sewer pipe 3 provided on both sides of a water channel (obstacle) 1 are connected by a water pipe 4 passing under the water channel 1. In addition, they are connected by a ventilation pipe 5 straddling the upper side of the water channel 1.

In the case of this embodiment, the highest position of the inner diameter of the portion 21 connected to the water pipe 4 of the upstream vacuum sewer pipe 2 is connected to the water pipe 4 of the downstream vacuum sewer pipe 3. The portion 31 is made to be the same as the lowest position of the inner diameter of the tube. That is, HA = 0 in FIG.

On the other hand, the inner diameter of the upstream vacuum sewer pipe 2 and the vent pipe 5 around the connecting part 6 connecting them are larger than the inner diameters of the other parts of the upstream vacuum sewer pipe 2 and the vent pipe 5 respectively. Has formed.

Also, the lowest bottom 4 of the water pipe 4
The pipe inner diameter of the ascending portion 43 having an ascending gradient of 1
The water pipe 4 is formed smaller than the inside diameter of the other part of the pipe.

The uphill portion 43 of the water pipe 4 is formed linearly, and at the same time, the angle of inclination θ of the uphill portion 43 is set to be smaller than the angle of repose of sand.

Here, the angle of repose refers to the angle of inclination of a mountain piled up when sand is dropped on water and deposited on the bottom, and the angle at which the sand does not collapse and falls below that angle. The reason why the angle of repose of the sand is set is that it is more difficult to discharge the foreign matter having fine particles such as sand from the water pipe 4 in particular.

Both the upstream vacuum sewer pipe 2 and the downstream vacuum sewer pipe 3 have a gentle downward slope.

Next, description will be given of the operation of the vacuum sewer when it is moved over. The sewage flowing through the upstream vacuum sewer pipe 2 is first subjected to gas-liquid separation at the connection part 6 of the ventilation pipe 5, and at this time, the inner diameter of the upstream vacuum sewer pipe 2 is changed to another one. Since the diameter is larger than the inner diameter of the pipe, the flow rate of the flowing sewage is reduced, and the gas and liquid are easily separated.

On the other hand, since the inside diameter of the ventilation pipe 5 at the connecting portion 6 is also larger than the inside diameter of the other parts of the ventilation pipe 5, the lump of sewage jumped up into the ventilation pipe 5 forms the ventilation pipe 5. Blockage is reduced, and it falls again into the upstream vacuum sewer pipe 2 as it is. For this reason, the pressure pulsation width can be reduced.

From the above, the gas-liquid separation at the connecting portion 6 can be performed smoothly. In addition, in the case of the present embodiment, since the inner diameter of the pipe is simply changed, there is no need to separately install a tank for gas-liquid separation, and it can be constituted only by a commercially available pipe material, so that the installation cost can be reduced. .

Next, the sewage that has passed through the connecting portion 6 is introduced into the water pipe 4 and passes from the bottom portion 41 to the upslope portion 43, and the inner diameter of the bottom portion 41 and the upslope portion 43 becomes thinner. Flow rate of the passing sewage increases. As a result, foreign substances that are to accumulate on the bottom 41 can be effectively discharged.

In the present embodiment, the inclination angle θ of the ascending portion 43 is set to be equal to or less than the angle of repose even when the foreign matter which has risen to the middle of the ascending portion 43 is about to fall again due to the decrease or stop of the flow rate of the sewage. So, the ascending part 4
The foreign matter that has fallen on the inner wall of No. 3 does not roll down on the inner wall and stops at that position. Therefore, when the flow rate of the sewage water increases again, the foreign matter is discharged from that position to the downstream vacuum drain 3.

Particularly, in this embodiment, the bottom portion 41 and the ascending slope portion 43 are formed in a straight line. However, the friction loss of the straight portion is very small. do not do.

As described above, in this embodiment, HA = 0. Therefore, when the portion 21 of the upstream vacuum sewer pipe 2 connected to the water pipe 4 is completely filled, the sewage passing through the water pipe 4 is naturally pushed up until the water surface reaches the downstream vacuum sewer pipe. When the sewage further flows in, the pushed up sewage flows down the downstream vacuum sewer pipe 3 according to the gradient of the pipe.

As described above, in this embodiment, HA =
Since it is set to 0, it is not necessary to make the installation depth of the downstream-side vacuum sewer pipe 3 deeper than the installation depth of the upstream-side vacuum sewer pipe 2, so that the installation work becomes easy and the static lift loss in the overhang portion is reduced. Can be 0.

When the flow rate of sewage is small as described above, the portion 21 of the upstream vacuum drain pipe 2 connected to the water pipe 4 is completely filled as shown in FIG. This means that the amount of sewage stored in the upstream vacuum sewer pipe 2 is large, as is apparent from comparison with FIG.

Therefore, by opening the vacuum valve 81 attached to the upstream side of the upstream vacuum sewer pipe 2, the wastewater in the water pipe 4 and the large amount of wastewater stored in the upstream vacuum sewer pipe 2 can be rapidly and simultaneously reduced. In addition, the water can be discharged to the downstream vacuum sewage pipe 3 so that the flow velocity thereof can be increased, the duration of the flow can be lengthened, and the foreign matters remaining in the water pipe 4 can be reliably discharged.

FIG. 3 is a schematic sectional view showing a second embodiment of the present invention. In the figure, the difference from the first embodiment is that the portion 3 of the downstream side vacuum sewer 3 connected to the water pipe 4
1 is that the lowest position of the inner diameter is slightly higher than the highest position of the inner diameter of the portion 21 connected to the water pipe 4 of the upstream vacuum sewer pipe 2. That is, HA> 0 in FIG.
And

As shown in FIG. 4, even if the portion 21 of the upstream vacuum sewer pipe 2 connected to the water pipe 4 is completely filled with water, sewage flows into the downstream vacuum sewer pipe 3 and does not flow. Absent. In order to suck up the sewage into the downstream vacuum sewer pipe 3, it is necessary to suck up the water head HA.

However, this water head HA can be offset by lowering the height of one of the lift portions of the downstream vacuum sewer pipe 3 by the water head HA. There is no static lift loss due to the drain pipe 3 being higher than the upstream vacuum drain pipe 2.

[0037]

As described in detail above, the present invention has the following excellent effects. The lowest position of the inner diameter of the part connected to the water pipe of the downstream vacuum sewer is the same as or slightly less than the highest position of the inner diameter of the part connected to the water pipe of the upstream vacuum sewer. Since it is located at a high position, not only can the useless head loss be prevented, but also it is not necessary to increase the burial depth of the downstream-side vacuum sewer pipe, so that civil engineering costs can be reduced. In addition, since the amount of sewage stored in the upstream vacuum sewer pipe is large, the drainage effect of the water pipe is large.

The lowest position of the inside diameter of the part connected to the water pipe of the downstream vacuum sewer is the same as or the same as the highest position of the inside diameter of the part connected to the water pipe of the upstream vacuum sewer. Sewage that is stored in the upstream vacuum sewer when the flow of the sewage is small and the part connected to the drain pipe of the upstream vacuum sewer is completely full. Since the amount of water can be increased, opening the vacuum valve increases the flow rate when the wastewater in the water pipe and the wastewater stored in the upstream vacuum sewer are rapidly and simultaneously discharged to the downstream vacuum wastewater pipe. Therefore, the duration of the flow can be lengthened, and the foreign matters accumulated in the water pipe can be reliably discharged.

Since the inner diameter of the pipe around the connection between the upstream vacuum sewer pipe and the ventilation pipe is larger than the inner diameter of the other parts, gas-liquid separation can be smoothly performed at this connection, and the pipe can be simply cut. The construction cost can be reduced because it is not necessary to separately install a special device such as a gas-liquid separation tank just by changing the inner diameter.

Since the inside diameter of the pipe at the lowest part of the water pipe and the uphill part at the uphill is made smaller than the inside diameter of the pipe at the other part of the water pipe, the flow velocity of the passing sewage increases, Foreign matter can be effectively discharged.

Since the angle of inclination of the upward slope of the water pipe is set to be equal to or less than the angle of repose, the foreign matter that has fallen on the inner wall of the upward slope does not roll down the inner wall and stops at that position, and the flow rate of the sewage increases again. At this time, the foreign matter is discharged from that position to the downstream vacuum sewer pipe, so that the foreign matter can be effectively discharged.

Since special equipment and special civil works are not required, and can be laid by ordinary piping and civil engineering work using only the pipe material, the lay can be performed easily and at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the first embodiment.

FIG. 3 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 4 is an operation explanatory diagram of the second embodiment.

FIG. 5 is a schematic sectional view showing a conventional example.

FIGS. 6 (a) and 6 (b) are operation explanatory diagrams of the present invention and a conventional example, respectively.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waterway (obstacle) 2 Upstream vacuum sewer pipe 3 Downstream vacuum sewer pipe 4 Water pipe 5 Ventilation pipe 6 Connection part 7 Manual valve

Claims (4)

(57) [Claims] 1. A vacuum sewer system comprising an upstream vacuum sewer pipe provided on both sides of an obstacle and a downstream vacuum sewer pipe connected by a water pipe passing under the obstacle and a vent pipe. In shoveling, the lowest position of the inside diameter of the part connected to the water pipe of the downstream vacuum sewer is the same as the highest position of the inside diameter of the part connected to the water pipe of the upstream vacuum sewer, or The overpass of the vacuum sewer, which is set higher than that. 2. The vacuum type according to claim 1, wherein the upstream vacuum sewer pipe and the ventilation pipe have a larger inside diameter at a peripheral portion of a connection portion connecting the both, than at other portions. The sewer of the sewer. 3. The water pipe according to claim 1, wherein an inner diameter of the pipe at a bottom portion at the lowest point and an inner slope at an upward slope is smaller than an inner diameter of a pipe at another portion of the water pipe. 2. The sheltering of the vacuum sewer according to claim 1. 4. The shelter of a vacuum sewer according to claim 1, wherein the angle of inclination of the uphill portion of the water pipe is equal to or less than the angle of repose of foreign matter mixed into the wastewater.