JPH0932098A - Prerotation tank for submerged pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prerotation tank for a submerged pump, by which even if an installation space is narrow, a pair of prerotation tanks can be disposed without being especially limited by the layout, and the rotation amount enough for causing a rotary flow required for discharging suspended matter and deposit can be secured. SOLUTION: A pair of prerotation tanks 10, 10' are formed by fiber reinforced plastic in such a manner as to have a weir part 16 of a designated height. The paired prerotation tanks 10, 10' are communicated with each other by communicating holes 15, 15' bored in the tangential direction in the peripheral wall in the vicinity of the bottom wall. Inflow grooves 20, 20' inclined toward the peripheral wall in the vicinity of the bottom wall of the respective prerotation tanks 10, 10' are extended from the vicinity of the top of the weir part 12, and the inflow grooves 20, 20' are also connected thereto. A submerged pump is installed in each of the prerotation tanks 10, 10'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-swivel tank provided with submersible pumps and arranged in proximity to each other, and particularly suitable for submersible pumps installed in a manhole for sewage. The present invention relates to a pre-swirl tank for a car.

[0002]

2. Description of the Related Art Liquid containing suspended matter, sediment, etc., such as sewage, is once stored in a manhole. Then, when a predetermined amount is accumulated, it is sent to the sewage treatment plant by the submersible pump installed in the manhole. A liquid discharge device using such a submersible pump is disclosed in Japanese Patent Application Laid-Open No. 3-84136 by the present applicant.
No. proposed. This discharge device includes a pre-swirl tank installed in the liquid. The pre-swirl tank has an overflow weir of a predetermined height, and an inflow groove that is inclined downward from the overflow weir toward the bottom of the pre-swirl tank is formed. Therefore, when the submersible pump installed in the pre-swirl tank is started, the liquid is sucked from the suction pipe of the submersible pump. At this time, while the amount of the liquid is large, the pressure is applied by the water head, so that the liquid flows into the pre-swirl tank through the opening above the pre-swirl tank, and the liquid does not swirl in the pre-swirl tank. When the discharge progresses and the liquid level drops to the overflow weir, the liquid enters the pre-swirling tank as a swirling flow from the inlet passage and is sucked while swirling. As a result, suspended matters, precipitates and the like are sucked and discharged at the same time as the liquid.

In the above-mentioned discharge device proposed by the applicant of the present invention, the amount of liquid entering the pre-swirl tank from the inflow groove of the overflow weir is sufficiently secured. Therefore, it does not hinder the discharge of suspended solids and sediments. However, if the amount of liquid entering the pre-swirl tank from the inflow groove is small, a sufficient swirl flow may not be obtained, and suspended matters, precipitates, etc. may not be discharged. Therefore, a pump system for sewage has been proposed in which the flow rate entering from the inflow groove is increased as much as possible. In this pump system, as shown in FIG. 3, a manhole 50 is provided with an overflow weir 51 at a position eccentric from the center in the radial direction, one of which serves as a wastewater storage portion 52, and the other of which has a pair of preliminary reservoirs. Swirl tanks 53 and 53 'are provided. From the overflow weir 51, as shown in FIG. 3B, inflow grooves 54, 54 'extending downward to the bottom peripheral wall of the pre-turning tanks 53, 53' are provided. The submersible pump 6 is provided in these pre-swirl tanks 53, 53 '.
0 and 60 'are provided respectively. Note that other reference numerals 65 and 65 in FIG. 3 denote guide rods of the submersible pump 60, and 66 denotes a detachable fitting of the submersible pump 60.

Therefore, when one of the submersible pumps 60 is started, when the liquid level of the sewage is at the upper position A, the sewage enters the pre-swirl tank 53 mainly through the opening of the pre-swirl tank 53 and then enters the suction pipe 61. It is sucked in and discharged from the discharge pipe 63 through the discharge pipe 62 to a predetermined position. When the discharge progresses and the liquid level reaches the position B at the top of the overflow weir 51, the sewage in the reservoir 52 will flow into the pre-swirl tank 53 from the inflow groove 54. Since the inflow groove 54 extends to the peripheral wall of the bottom of the pre-turning tank 53, that is, it is provided in the tangential direction of the pre-turning tank 53, the waste water is sucked into the suction pipe 61 while turning in the pre-turning tank 53. . Because the sewage swirls, floating matter,
Sediments are also sucked in at the same time as sewage.

[0005]

According to the pump system described above, since the storage portion 52 is made relatively large, a swirling flow can be generated. Further, since the submersible pumps 60 and 60 ′ are provided in the pair of pre-swirl tanks 53 and 53 ′, respectively, these submersible pumps 60 and 60 ′ are provided.
The advantages of extending the pump life and alternating one of the submersible pumps 60 or 60 'are recognized by alternately operating. However, there are problems to be improved. For example, a manhole 5 of a fixed size
Since two pre-swirl tanks 53 and 53 'must be provided in 0, there is a limit to enlarge the storage section 52,
It is not always possible to secure a sufficient amount to cause a swirling flow to suck in suspended matter, sediment, and the like. Especially the diameter is 1800
When installing two submersible pumps with a diameter of 150 mm in the No. 4 manhole with a size of 50 mm, the storage unit 52 of the required size
Is difficult to secure. In addition, in order to enlarge the storage portion 52, the pre-swirl tanks 53 and 53 ′ are installed in the manhole 50.
Since it must be provided eccentrically from the center of the pre-swirl tank 53, 53 ', there is also a problem in the installation layout. Furthermore, when one of the submersible pumps 60 is activated, floating matter from the pre-turning tank 53 in which the submersible pump 60 is installed,
Even if it is possible to discharge the precipitates, etc., since the suspended matter, the precipitates, etc. remain in the other pre-swirl tank 53 ', they decompose and give off a bad odor, which pollutes the environment. It is also possible. The present invention is intended to provide a pre-swirl tank for a submersible pump that solves the above-mentioned problems. Specifically, even if the installation space is small, a pair of pre-swirl tanks are particularly limited in layout. A submersible pump that can be installed without the need to secure a sufficient amount of swirling flow necessary to discharge suspended solids, sediments, etc., and has little problem of spoilage of suspended solids, sediments, etc. The purpose of the present invention is to provide a pre-swirl tank.

[0006]

In order to achieve the above object, the present invention is a pre-swirl tank provided with submersible pumps and arranged in close proximity to each other,
In the pre-swirling tank, a communication hole is opened tangentially in the tank wall near the bottom, and when the pre-swirl tanks are installed close to each other, the pre-swirling tanks are communicated with each other through the communication hole. It is configured. The invention according to claim 2 is a pre-swirl tank provided with a submersible pump and arranged so as to be adjacent to each other, wherein the pre-swirl tank is tangential to a tank wall near a bottom portion. The communication hole is opened, and an inflow groove inclined from the vicinity of the upper edge of the tank wall of the pre-swirl tank toward the peripheral wall near the bottom of the pre-swirl tank is provided to bring the pre-swirl tank close to each other. Then, the pre-swirl tank is configured to communicate with each other through the communication hole and the inflow groove. In the invention according to claim 3, the vicinity of the upper edge portion of the tank wall according to claim 2 is a weir portion having a predetermined height higher than other portions, and the invention according to claim 4 is the invention according to claims 1 to 3. The pre-swirl tank according to any one of claims 1 to 4 is molded from fiber reinforced plastic so that they are installed back-to-back symmetrically, and the invention according to claim 5 is the invention according to any one of claims 1 to 4. The pre-swivel tank described in the paragraph
It is installed in a manhole for sewage.

[0007]

Operation: A pair of pre-swirl tanks, for example, with a diameter of 1800 mm
It will be installed near the bottom of No. 4 manhole. Then, the pair of pre-turning tanks are communicated with each other through the communication hole. Each of these pre-swirl tanks has, for example, a diameter of 150
Install a mm submersible pump. When a predetermined amount of liquid, that is, dirty water is accumulated in the manhole, for example, the level switch of the control device is activated to activate one of the submersible pumps. Sewage is drawn in through the suction pipe of the submersible pump and drained through the discharge pipe. When the drainage progresses and the water level drops to a predetermined position, the dirty water in the other pre-swirl tank comes into the swirl flow from the communication hole. In the invention described in claims 2 and 3, when the water level drops to a predetermined position, the water flows in through the inflow groove and the communication hole. As a result, a strong swirling flow is generated in the pre-swirl tank, and the suspended matter, sediment, etc. are sucked in simultaneously with the wastewater in the other swirl tank
Is discharged. When a swirling flow is generated and, for example, the timer measures a predetermined time, or when the water level drops to the off level, the submersible pump is stopped by a signal from the control device. Once again, when a predetermined amount of dirty water is collected in the manhole, the other submersible pump is activated this time, and similarly, dirty water, suspended matters, sediments and the like are simultaneously sucked and discharged. Thereafter, the above operation is repeated to drain the water. In the invention according to claim 4, the pre-turning tanks symmetrically installed back to back and in the invention according to claim 5 operate as described above in the manhole for sewage.

[0008]

EXAMPLE An example in which the example of the present invention is applied to a manhole for sewage will be described below. Manhole 1 is shown in Figure 1.
As shown in, the manhole inner wall portion 2 and the bottom wall portion 3
It is configured in a tubular shape from and. Level switches Us and Ls are provided at appropriate positions above and below the inner wall portion 2 of the manhole. Also, through the manhole inner wall portion 2,
As shown in FIG. 2A, an inflow pipe 36 and a common discharge pipe 37 connected to the discharge pipe 35 of the submersible pump 30, 30 ′ are provided. Further, well-known ladders 4, 4, ... Are provided on the inner wall portion 2 of the manhole.

Since the pair of pre-swirl tanks 10 and 10 'installed on the bottom wall portion 3 of the manhole 1 are symmetrical,
Hereinafter, one pre-turning tank 10 will be described, and the other pre-turning tank 10 'will not be described redundantly by adding a dash "'" to the same reference numeral. The pre-swirl tank 10 is shown in FIG.
As shown in the perspective view of FIG. The tank portion 11 includes a peripheral wall 12 and a bottom wall 13.
Although it is formed so that the whole looks like a container,
The diameter of the upper opening is larger than the diameter of the bottom wall 13 and expands in a tapered shape. Therefore, as will be described later, the weir portion 16
Sewage flowing into the pre-swirl tank 10 from the inflow groove is swirled, gathers in the central portion, and is effectively sucked from the suction pipe of the submersible pump. Further, a protrusion 14 protruding upward is provided at the center of the bottom wall 13.

A peripheral wall 12 near the bottom wall 13 of the pre-swirl tank 10.
As shown in FIG. 2B, a communication hole 15 penetrating the peripheral wall 12 and opening to the outside is formed in the peripheral wall 1.
It is open in the tangential direction of 2. That is, the direction of the communication hole 15 is an angle θ formed by the tangent line S at the point where the communication hole 15 of the peripheral wall 12 is opened and the axis J of the communication hole 15 when the blade of the submersible pump described later rotates in the clockwise direction. Is 90
° Selected smaller than. Therefore, when the submersible pump is driven and the dirty water is sucked from the communication hole 15, the liquid flows into the pre-swirling tank 10 as a clockwise rotating flow or swirling flow.

The weir portion 16 is a horizontal flange portion 1 at the upper end of the tank portion 11.
It is higher than 7 by a predetermined amount H. And this weir 1
An inflow groove 20 having a downward slope from 6 toward the bottom wall 13 is provided. The inflow groove 20 is formed by inner and outer walls 18 and 19 which form a part of the peripheral wall 12 of the tank 11, and the bottom of the inflow groove 20 is substantially the same height as the flange 17 in the dam 16. Then, it surrounds the tank portion 11 so as to make about 1/2 turn and reaches the bottom wall 13. In addition, the inflow groove 20 in the weir portion 16 opens toward the back side of the paper surface in the figure. Therefore, as will be described later, the pair of pre-turning tanks 1
If 0 and 10 'are installed back to back, the inflow grooves 20, 2
0'comrades will communicate.

The pre-swirl tank 10 configured as described above
Is molded from fiber reinforced plastic in the factory in this embodiment. Further, in this embodiment, the outer surface of the pre-swirl tank 10 is made of concrete C as shown in FIG.
Etc. so that the bottom surface becomes horizontal. Therefore,
Bring in a pair of pre-turning tanks 10 and 10 'into the manhole 1,
As shown in FIG. 1 and FIG. 2 (a), they can be easily installed back to back.
Once installed, the pair of pre-rotation tanks 10 and 10 'communication holes 1
5, 15 'communicate with each other. In addition, the inflow grooves 20, 2
0's are also connected to each other at the highest weir 16.
After installation, the manhole inner wall 2 and the pre-swirl tank 10, 1
Close the gap with 0'with concrete C ', etc. Further, as shown in FIG. 2A, the manhole 1 is partitioned into substantially equal parts by partition members 16 ″ and 16 ″ each having a weir 16 extending in the diameter direction.

As is well known in the art, the submersible pump 30,
30 'to the respective guide rods 33, 33, 33', 3
Carry in to manhole 1 by 3 '. Then, the discharge ports of the submersible pumps 30 and 30 'are attached to the detachable fittings 34 and 3
4'is connected to the respective discharge pipes 35, 35 '. Thereby, as shown in (a) of FIG. 1 and FIG. 2, in each of the pair of pre-turning tanks 10 and 10 ′,
Submersible pumps 30, 30 'are installed. At this time, the lower ends of the openings of the suction pipes 31 and 31 'are located directly above the projections 14 and 14 of the pre-swirl tanks 10 and 10'.

Next, the drainage action of the above embodiment will be described.
Sewage flows from the inflow pipe 36, and the upper level switch U
When s detects this, one of the submersible pumps 30 is activated by a signal from the control device. In this state, since the head of the wastewater is large, the wastewater is directly supplied into the tank portion 11 from the open portion above the pre-swirl tank 10, the wastewater is sucked up from the suction pipe 31 without swirling, and the discharge pipe 35 Is sent to, for example, a sewage treatment plant through a common discharge pipe 37.

When the drainage progresses and the liquid level reaches the level of the weir 16, and the lower level switch Ls detects this, for example, a timer for stopping the submersible pump 30 in operation is turned on. When the liquid level falls below the weir portion 16, the dirty water in the other pre-swirl tank 10 'flows into the pre-swirl tank 10 through the inflow grooves 20' and 20. Further, since the water level of the pre-swirl tank 10 is lowered and the head of the water is reduced, the water also flows in from the communication holes 15 ′, 15. The inflow groove 20 is the peripheral wall 1 of the tank portion 11.
Since the communication hole 15 is formed in the tangential direction of the peripheral wall 12 and is formed by the inner and outer walls 18 and 19 forming a part of 2, the sewage flows into the pre-swirl tank 10 as a strong swirl flow. Then, it is sucked up from the suction pipe 31 while turning. Therefore, suspended matters, precipitates and the like are also sucked and discharged at the same time. When the off level is reached, the time is up and the submersible pump 30 is stopped. When the amount of dirty water flowing into the manhole 1 from the inflow pipe 36 increases with the lapse of time and the upper level switch Us detects this, the other submersible pump 30 'operates in the same manner. Thereafter, the pair of submersible pumps 30 and 30 'are alternately operated to drain water.

The present invention can be implemented in various forms without being limited to the above embodiments. For example, in the above-mentioned embodiment, since the weir portion 16 which is higher than the horizontal flange portion 17 by a predetermined amount H is provided, a large amount of swirling water is secured, but the volumes of the pre-swirl tanks 10 and 10 'are sufficiently large. Therefore, the swirl flow can be sufficiently generated without providing the exceptionally high weir portion 16. Therefore, the present invention can be implemented without the weir portion 16. It is also clear that the same operation can be performed without the inflow groove 20. At this time, the swirling sewage has a communication hole 1
Only 5'and 15 will flow in. Furthermore, even if there is no weir 16 higher than the horizontal flange 17 by a predetermined amount H,
It is also possible to provide the inflow grooves 20, 20 'from the position of the lower horizontal collar portion 17. Also, depending on the installation layout, the pair of pre-swirl tanks 10 and 10 'can be installed separately from each other. At this time, a pipe is interposed between the communication holes 15 'and 15 and the inflow grooves 20 and 20' are also connected via an appropriate groove member. Furthermore, the pre-swirl tank 10 can be divided and molded, and can be integrated by connecting, for example, in a factory or an installation site. Although the pair of pre-swirl tanks 10 and 10 'are applied to the manhole 1 in the above embodiment, the present invention is also applicable to drainage facilities such as sewage treatment plants, chemical plants, paper mills, pig farms, and the like. Clearly, the same applies.

[0017]

As described above, according to the present invention, the pre-swirl tank is provided with the communication hole in the tangential direction in the tank wall near the bottom, and when the pre-swirl tanks are installed close to each other, the pre-swirl tank is Since they are communicated with each other through the communication holes, one of the submersible pumps is driven to drain water, and when the water level drops to a predetermined position, the liquid in the other pre-swirl tank will flow in a strong swirl flow from the communication holes. . Since the volume of the pre-swirl tank is relatively large, the inflow amount at this time is large. Therefore, according to the present invention, even if it is installed in a narrow space such as No. 4 manhole, the amount of the liquid swirling for a sufficient time necessary for discharging the floating material floating in the liquid, the sedimented sediment, etc. The effect peculiar to the present invention that it is ensured is obtained. At this time, since the liquid in the other pre-swirl tank flows in from the communication hole, the suspended matter, the precipitate, etc. in the other pre-swirl tank are also discharged at the same time,
There are also few problems of decay such as precipitates. Further, simply installing the pre-swirling tanks close to each other ensures a sufficient amount of time for maintaining the swirling flow, so that there is an effect that the degree of freedom in the installation layout of the pre-swirl tanks can be obtained. According to the invention of claim 2, in addition to the communication hole, an inflow groove is provided from the vicinity of the top of the tank wall of the pre-swirl tank toward the peripheral wall near the bottom of the pre-swirl tank, so that the water level is at a predetermined position. When it goes down, the liquid in the other pre-swirl tank comes into the swirl flow through the inflow groove, and eventually comes into the swirl flow through the communication hole. Therefore, the same effect as the above invention can be obtained. According to the third aspect of the invention, since the tank wall is the weir portion having the predetermined height, a large amount of swirling liquid can be secured. Therefore, it is possible to obtain the effect that the suspended matter, the precipitate, and the like can be discharged more completely. According to the invention described in claim 4, since the pre-swirl tank is molded from the fiber reinforced plastic, in addition to the above effects, an effect that installation work on site can be done by placing concrete or the like is obtained. Further, since they are installed symmetrically back to back, the number of molds for forming the pre-turning tank is small, and the pre-turning tank can be obtained at low cost.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention installed in a manhole.

2 is a diagram showing an embodiment of the present invention, in which FIG.
Is a top view, and (b) is a perspective view of the pre-swirl tank.

FIG. 3 is a view showing a conventional example, in which (a) is a sectional view thereof,
(B) is a top view.

[Explanation of symbols]

 1 Manhole 10, 10 'Pre-swirl tank 15, 15' Communication hole 16, 16 'Weir 20, 20' Inflow groove 30, 30 'Submersible pump

Claims (5)

[Claims] 1. A pre-swirl tank provided with a submersible pump and arranged to be installed close to each other, wherein the pre-swirl tank has a communication hole in a tangential direction in a tank wall near a bottom portion. A pre-turning tank for a submersible pump, characterized in that, when the pre-turning tanks are installed close to each other, the pre-turning tanks are communicated with each other through the communication holes. 2. A pre-swirl tank provided with a submersible pump and arranged so as to be close to each other, wherein the pre-swirl tank has a communication hole in a tangential direction in a tank wall near a bottom portion. Along with the opening, an inflow groove inclined from the vicinity of the upper edge of the tank wall of the pre-turning tank toward the peripheral wall near the bottom of the pre-turning tank is provided, and the pre-turning tanks are installed close to each other. Then, the pre-turning tank is communicated with each other through the communication hole and the inflow groove. 3. A pre-rotating tank for a submersible pump, wherein the vicinity of the upper edge portion of the tank wall according to claim 2 is a weir portion having a predetermined height higher than other portions. 4. The pre-turning tank for a submersible pump according to claim 1, wherein the pre-turning tank is made of fiber reinforced plastic and is symmetrically installed back to back. 5. A pre-turning tank for a submersible pump, wherein the pre-turning tank according to claim 1 is installed in a sewage manhole.