JP3370830B2 - Vacuum sewer lift loss prevention device - 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 sewer lift loss prevention device capable of preventing lift loss even in a place where a lift is required due to an obstacle or the like.

[0002]

2. Description of the Related Art FIG. 3 is a schematic view showing an example of a vacuum type waste water collecting system. As shown in the figure, the sewage discharged from each home 50 or factory, etc.
Through to the vacuum valve unit 53 buried underground. When a predetermined amount of the dirty water is accumulated in the vacuum valve unit 53, the vacuum valve 55 opens and is sucked into the vacuum sewer pipe 57,
The water is collected in the water collection tank 61 of the vacuum pumping station 59, and is further sent to a wastewater treatment plant or the like by the pressure pump 63.

The vacuum pump 65 is operated so that the degree of vacuum in the water collection tank 61 is usually in the range of -6 mAq to -7 mAq.

On the other hand, since the degree of vacuum required to open and close the vacuum valve 55 is -2.5 mAq, the vacuum valve 55 at the end is opened and closed even when the vacuum degree at the vacuum pump station 59 is the lowest, that is, -6 mAq. In order to do so, it is necessary that the loss in the pipeline along the way is within 3.5 mAq.

The loss of the pipeline constituted by the vacuum sewer pipe 57 includes a loss in a static state (a state in which there is no flow) and a dynamic state (a state in which the design wastewater is flowing). When considering the loss of the entire pipeline, it is necessary that the loss in both states be within the allowable loss (that is, 3.5 mAq).

That is, the sum of the losses in the static state = the sum of the static lift losses ≦ 3.5
mAq sum of losses in dynamic state = sum of dynamic lift losses + sum of friction losses ≦ 3.5 mAq.

Here, the static lift loss is the head loss when the lift is full without the flow of dirty water and is calculated by [lift height-pipe inner diameter]. On the other hand, the dynamic lift loss is the lift loss head when the design wastewater flows, and is calculated by [lift height x 0.5].

When the vacuum sewer pipe 57 crosses an obstacle such as a water channel, the vacuum sewer pipe 57 needs to straddle the obstacle or to lie below the obstacle. In the part of the slope, a large lift loss occurs because the sewage is lifted by the vacuum force using the lift. Specifically, the lift height is 1.2m to 1.5m.
Becomes

Therefore, when such an obstacle crosses at a plurality of locations, the water head is largely consumed at that location, and the sewage collection range of the entire vacuum sewage collection system becomes narrow.

In order to prevent this drawback, the following method has been conventionally proposed. As shown in Japanese Patent Laid-Open No. 4-258424, the vacuum sewage pipes provided on the upstream side and the downstream side of the obstacle are connected by a water pipe that passes under the obstacle, and also over the upper side of the obstacle. How to connect with the trachea. As a result, the sewage passes through the water pipe by the siphon principle, and the vacuum degree is transferred from the upstream side to the vacuum sewage pipe on the downstream side by the vent pipe without loss.

As shown in JP-A-5-202556, the end of the vacuum waste water pipe on the upstream side of the obstacle is connected to the inflow tank, and the end of the vacuum waste water pipe on the downstream side is connected to the outflow tank. A method of connecting these tanks with a siphon pipe for passing sewage over the obstacle and a ventilation pipe for passing gas.
As a result, the sewage passes through the siphon pipe by the siphon principle, and the degree of vacuum is transferred by the ventilation pipe from the upstream side to the vacuum sewage pipe on the downstream side without loss.

As disclosed in Japanese Patent Laid-Open No. 4-258427, a pump and a water pipe installed in a manhole provided at the end of an upstream vacuum wastewater pipe are used to position the vacuum wastewater pipe higher than the upstream vacuum wastewater pipe. A method in which sewage is pumped to a certain downstream vacuum sewage pipe and both vacuum sewage pipes are connected by a ventilation pipe.

[0013]

However, the above-mentioned conventional example has the following problems. (1) In the case of the above-mentioned conventional example, since the water pipe is overlaid, this portion must be constructed by the non-open cutting method using the propulsion method or the like, resulting in a large construction cost.

(2) In the case of the above conventional example, the highest position of the siphon tube is due to when the siphon tube is filled with water in the initial state and when gas enters the siphon tube for some reason during use. It is necessary to attach a vacuum pump to the, which increases the construction cost.

(3) In the case of the above-mentioned conventional example, since the dirty water in a vacuum state is pumped up, the suction performance (N
High performance is required as PSH), and applicable pumps are limited. Therefore, not only is the cost high,
It requires maintenance of the pump and becomes complicated. Moreover, since the pump is driven, the operating cost becomes high.

The present invention has been made in view of the above-mentioned points, and an object thereof is to provide a lift loss prevention device for a vacuum sewer system which requires low construction cost, requires a small amount of power, and is easy to maintain. To do.

[0017]

In order to solve the above problems, the present invention provides an upstream vacuum wastewater pipe and a downstream vacuum wastewater pipe installed at a position higher than the upstream vacuum wastewater pipe. , contact between the the collection tank for temporarily storing the sewage discharged from the vacuum sewage pipe connected to the end portion of the vacuum sewage pipe of the upstream side, and said population water tank and the downstream side of the vacuum sewer pipe <br/> the outflow pipe for sewage passes to continue, the vent pipe of the gas passage that connects the vacuum sewage pipe of the water collecting tank and the downstream catchment is connected to the water collecting tank An air intake pipe that connects the tank to the atmosphere, a switching valve that switches to open one of the ventilation pipe and the air intake pipe and close the other, and a water level detection that detects the water level in the water collection tank comprising a vessel, toward the upstream side of the vacuum sewer pipe into the collection tank
If sewage or gas flows through it, open it and head in the opposite direction.
A mechanism for closing when sewage or gas is about to flow,
The water level detection that a predetermined amount of sewage has Tsu accumulated in the water collecting tank
When the intelligent device detects that the switch valve closes the ventilation pipe and opens the air intake pipe to allow outside air to flow into the water collection tank, the vacuum pressure in the vacuum waste water pipe on the downstream side and the air pressure in the water collection tank The wastewater in the water collection tank was configured to be pushed up to the vacuum wastewater pipe on the downstream side through the outflow pipe by the differential pressure.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of the present invention. As shown in the figure, the present invention comprises an upstream vacuum wastewater pipe 3, a downstream vacuum wastewater pipe 6 installed at a position higher than the vacuum wastewater pipe 3, and an upstream vacuum wastewater pipe 3. A water collecting tank 2 connected to an end portion, a sewage passage outflow pipe 5 and a gas passage vent pipe 7 connected between the water collection tank 2 and the vacuum sewage pipe 6 on the downstream side; An air intake pipe 8 for communicating the water tank 2 with the atmosphere, and a switching valve 9 attached to each of the ventilation pipe 7 and the air intake pipe 8.
-1 and 9-2.

Here, the vacuum waste water pipe 3 on the upstream side is buried to a normal burial depth, and a flap valve 12 for opening and closing the end face is attached to the end face thereof. The flap valve 12 has a mechanism that opens when sewage or gas flows from the upstream into the water collection tank 2 in the vacuum sewage pipe 3 and closes when sewage or gas tries to flow in the opposite direction. Is. A water control valve 4 is attached in the middle of the upstream vacuum dirty water pipe 3.

The water collection tank 2 is installed in a manhole 1 provided underground, and has a vacuum wastewater pipe 3, an outflow pipe 5, and a ventilation pipe 7.
Are connected respectively. A water level detector 11 is attached to the predetermined position.

The water level detector 11 has a function of detecting the water level when the waste water in the water collecting tank 2 is almost empty and the water level when a predetermined amount of waste water needs to be drained.

The vacuum sewage pipe 6 on the downstream side is installed near the surface of the earth so as to straddle the obstacle 13 such as a water channel.

The air intake pipe 8 is branched from the middle of the ventilation pipe 7, and its tip is open to the atmosphere.

The switching valves 9-1 and 9-2 operate in conjunction with each other so that when one is open, the other is closed.
The signal from the water level detector 11 is input to the switching valve 9-1,
It is controlled by control means (not shown) which outputs to 9-2.

Next, the operation of this device will be described. First, normally, the switching valve 9-1 is closed and the switching valve 9-2 is opened. Therefore, the vacuum pressure in the downstream vacuum wastewater pipe 6 is introduced into the water collection tank 2 through the ventilation pipe 7 and is transmitted to the upstream side vacuum wastewater pipe 3 in a state where the pressure is not reduced. .

As a result, the sewage enters the water collection tank 2 through the vacuum sewage pipe 3 and is temporarily stored in the water collection tank 2.

When the amount of dirty water in the water collection tank 2 increases and the water level rises to a predetermined position, the water level detector 11 detects this and opens the switching valve 9-1 and opens the switching valve 9-2. Close it.

As a result, air flows into the water collecting tank 2 through the air intake pipe 8 and the atmospheric pressure in the water collecting tank 2 becomes atmospheric pressure.

At this time, since the vacuum pressure of the downstream vacuum wastewater pipe 6 is maintained, the wastewater in the water collecting tank 2 passes through the outflow pipe 5 to the downstream vacuum wastewater pipe 6 due to this pressure difference. Pushed up.

On the other hand, at this time, the vacuum waste water pipe 3 on the upstream side is closed by the flap valve 12, so that the air does not flow backward and the vacuum is maintained.

When the water level in the water collecting tank 2 is lowered and the sewage is almost emptied, the water level detector 11 detects this and switches the open / close states of the switching valves 9-1, 9-2, and the ventilation pipe 7 Is opened, the air intake pipe 8 is closed, the state is returned to the initial state, and the above operation is repeated.

FIG. 2 is a schematic sectional view showing another embodiment of the present invention. The difference between this embodiment and the previous embodiment is that the blower or compressor 14 is provided in the middle of the air intake pipe 8.
Is the point where it was attached.

When the apparatus according to the present invention is installed near the vacuum pumping station 59 shown in FIG. 3, the degree of vacuum in the vacuum wastewater pipe 6 is about -6 mAq to -7 mAq. The pressure difference from the atmospheric pressure is large, so the outflow pipe 5
By this, sewage can be easily pushed up in a short time.

However, when the device according to the present invention is installed at a position farther than the vacuum pumping station 59, the degree of vacuum in the vacuum wastewater pipe 6 is lowered due to the line loss, so that the difference from the atmospheric pressure is reduced. Since the pressure becomes small, it becomes difficult to push up the sewage by the outflow pipe 5, and the sewage discharge time also becomes long.

Therefore, in the present embodiment, when the sewage is pushed up by the outflow pipe 5, the blower or the compressor 14 forcibly pushes the air into the air intake pipe 8 so that the pressure in the water collection tank 2 becomes equal to or higher than the atmospheric pressure. The pressure difference with the vacuum waste water pipe 6 on the downstream side is forcibly increased, whereby the water collection tank 2
The sewage inside was able to be pushed up easily and in a short time.

The blower or compressor 14 is used when the sewage is to be pushed up to a particularly high position or the sewage discharge time is shortened, even if the vacuum inside the vacuum sewage pipe 6 is not low. it can.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to this, and various modifications such as the following are possible. In the above-described embodiment, the switching valves 9-1 and 9-2 are attached to the ventilation pipe 7 and the air intake pipe 8, respectively.
Alternatively, a three-way valve may be attached to the branch portion of the air intake pipe 8 to switch between opening and closing of the ventilation pipe 7 and the air intake pipe 8.

In the above embodiment, the ventilation pipe 7 and the air intake pipe 8 were connected to one pipe and connected to the water collecting tank 2. However, the ventilation pipe 7 and the air intake pipe 8 are completely different pipes. You may connect to the water collection tank 2 separately.

[0039]

As described in detail above, the present invention has the following excellent effects. Even if it is necessary to provide a climbing slope in the pipeline of the vacuum wastewater pipe in order to avoid obstacles, the lift loss at that portion can be eliminated. Therefore, the sewage collection range of the vacuum sewage collection system can be widened.

Since the pipe can be installed so as to cross over the obstacle, the construction cost can be reduced.

It is not necessary to separately install expensive equipment such as a vacuum pump and a motor, and the power source required for operation is a small power source that operates the switching valve. Therefore, not only is the construction cost low, The operating cost will be cheaper,
In addition, maintenance becomes easy.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the present invention.

FIG. 3 is a schematic view showing an example of a vacuum type waste water collecting system.

[Explanation of symbols]

1 manhole 2 Water collection tank 3 Vacuum sewage pipe on the upstream side 5 Outflow pipe 6 Downstream vacuum sewage pipe 7 Ventilation pipe 8 Air intake pipe 9-1, 9-2 switching valve 14 Blower

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) E03F 3/02 E03F 5/22

Claims (2)

(57) [Claims] 1. An upstream vacuum wastewater pipe, a downstream vacuum wastewater pipe installed at a position higher than the upstream vacuum wastewater pipe, and an end portion of the upstream vacuum wastewater pipe. a collection tank for temporarily storing the sewage discharged from the vacuum sewage pipe, and outflow pipe for contact <br/> sewage passes to continue between the said population water tank and the downstream side of the vacuum sewage pipe, the a ventilation tube for gas passage which connects the collection tank and the downstream side of the vacuum sewage pipe, and the air intake pipe which connects the collection tank to the outside air is connected to the water collecting tank, and the vent tube comprising a switching valve for switching the one of the air intake pipe and opens one of the other so as to close, and a water level detector for detecting the water level in the collection tank, collecting the upstream side of the vacuum sewer pipe Sewage and
If gas flows, it opens and sewage goes in the opposite direction.
When gas is going to flow is provided to close mechanism, wherein the water level detection that a predetermined amount of sewage has Tsu reservoir into collection tank
When the intelligent device detects that the switch valve closes the ventilation pipe and opens the air intake pipe to allow outside air to flow into the water collection tank, the vacuum pressure in the vacuum waste water pipe on the downstream side and the air pressure in the water collection tank A vacuum sewer lift loss prevention device characterized in that the wastewater in the water collection tank is pushed up to the vacuum wastewater pipe on the downstream side through the outflow pipe by a differential pressure. 2. The lift loss prevention device for a vacuum sewer according to claim 1, wherein the air intake pipe is provided with a blower or a compressor for increasing the pressure of the outside air to supply it to the water collection tank.