JPH09279675A - Suction port for pump in prewhirl tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the remaining of a suspended matter such as sewage, scum, etc., in a preswirl tank and settling and deposition on a bottom wall of settled sand while obtaining capacity, in which a swirling flow generated in the preswirl tank is sucked positively. SOLUTION: 90 deg. bends 1A are installed at the lower end sections of each suction port 1 of pumps P1, P2. The lower ends of the 90 deg. bends 1A are abutted against the top faces of the bottom walls 2B, 3B of a first preswirl tank 2 and a second preswirltank 3 while the inlets of the 90 deg. bends 1A are counter- flowed to swirling flows S generated in the first preswirl tank 2 and the second preswirl tank 3, and accommodated to the swirling end sections of the swirling flows S.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction port of a pump in a pre-swirl tank, and is mainly provided in a suction water tank of a pump installed at an appropriate position of a sewage flow down piping system connecting a sewage source to a sewage treatment plant. The present invention relates to a suction port of a pump in a pre-swivel tank, which can prevent floating matters such as sewage and scum from remaining in the pre-swirl tank, and solid matters such as sand from being settled and accumulated on the bottom.

[0002]

2. Description of the Related Art Conventionally, pumps shown in FIGS. 6 and 7 have been known as suction water tanks of pumps installed at appropriate places in a sewage drainage piping system connecting a sewage generation source and a sewage treatment plant. The suction water tank includes a pair of pre-swirl tanks 2 and 3 into which the suction ports 1 of the two pumps P1 and P2 are separately inserted, that is, a first pre-swirl tank 2 having an open upper end of the peripheral wall 2A, and a peripheral wall 3A. A second pre-swirling tank 3 having an open upper end is provided with a predetermined width interval W at one side eccentric position of the bottom 5 in the suction water tank 4.
The first pre-swirl tub 2 and the second pre-swirl tub 3 are provided on the other side with a first partition 6 extending in the width direction (XX direction) and protruding from the bottom surface 10. Pre-swirling tank formation area 7
And a pre-swirl tub non-forming area 8 adjacent to the other side of the first partition wall 6. The first pre-swirl tub forming area 7 side extends in the YY direction orthogonal to the first partition wall 6. A second partition wall 9 that separately divides the swirl tank 2 and the second pre-swirl tank 3 protrudes from the bottom surface 10. The upper ends of the first partition wall 6 and the second partition wall 9 are set at the same height as the boundary 11 between the bottom surface 10 of the pre-swirling tank non-forming area 8 and the peripheral wall 4A of the suction water tank 4.

An inflow passage 12 for connecting the pre-swirling tank non-forming area 8 and the first pre-swirling tank 2 to each other is provided by a first pump P1.
Is formed in a tangential direction along the rotation direction R of the first pump P2, and is formed to be inclined downward toward the bottom. Are formed in a tangential direction along the rotation direction R of the pumps P1 and P2 and inclined downward toward the bottom.
Is installed on a pedestal 15 via a discharge bend 14, and the suction ports 1 of the respective pumps P1 and P2 are connected to the peripheral walls 2A, 3A and the bottom walls 2B, 3B of the first pre-swirl tank 2 and the second pre-swirl tank 3.
The first pre-swirl tank 2 and the second pre-swirl tank 3
It is inserted downwardly and opened.

In the suction water tank of a pump having such a structure,
The two pumps P1 and P2 are operated alternately. For example, when the first pump P1 is operated, the sewage in the suction water tank 4 is drawn from the downward suction port 1 of the first pump P1. In this state, no swirling flow is generated inside the pre-swirling tank 2. When the water level of the sewage falls below WL1, the sewage flows into the first pre-swirl tank 2 through the inflow path 12, so that the scum and other suspended matters and sediment are swirled in the first pre-swirl tank 2. Is sucked into the suction port 1 and sucked up by the first pump P1. Also,
By operating the second pump P2, the suction water tank 4
The sewage inside is pumped up from the suction port 1 of the second pump P1, and when the water level of the sewage falls below WL1, the sewage flows into the second pre-swirling tank 3 through the inflow passage 13. Then, while swirling in the second pre-swirl tank 3, suspended matter such as scum or sediment is drawn into the suction port 1 and sucked by the second pump P <b> 2.

However, the suction ports 1 of the pumps P1 and P2 respectively have a peripheral wall 2 of the first pre-swirl tank 2 and the second pre-swirl tank 3.
A, 3A and the bottom walls 2B, 3B are spaced apart from each other and are inserted into the first pre-swirl tank 2 and the second pre-swirl tank 3, and have a structure that opens downward. Therefore, the wastewater level is WL
When it is reduced to 2, even if the pumps P1 and P2 are operated, the dirty water cannot be sucked in. Generally, in the suction water tank 4 of this type, when the water level drops to WL2, the pumps P1 and P2 are controlled to stop operating after a lapse of a predetermined time. Therefore, the first pre-turning tank 2 and the second pre-turning tank 3 are controlled. The amount of sewage corresponding to the water level WL2 and suspended matters such as scum will remain inside, and the solid matter such as sand mixed in this residual sewage will settle and deposit on the bottom walls 2B, 3B. It has the drawback of depositing.

On the other hand, the suction port 1 of each of the pumps P1 and P2 is provided with a peripheral wall 2A of the first pre-swirl tank 2 and the second pre-swirl tank 3,
3A and the bottom walls 2B, 3B are inserted into the first pre-swivel tank 2 and the second pre-swirl tank 3 with a space therebetween, and since they are simply opened downward, the entire circumference of the suction port 1 It can be said that the swirl flow S generated in the first pre-swirl tank 2 and the second pre-swirl tank 3 is not positively sucked, but the suction port 1 There is also a problem that the suction capacity of is slightly lower.

[0007]

That is, at the suction port of a pump in a conventional pre-swivel tank, sewage and scum and other suspended matter remain in the pre-swirl tank, and solid matter such as sand precipitates. It has the drawback of depositing on the bottom. In addition, there is a problem that the ability to positively absorb the swirling flow generated in the pre-swirl tank is lacking. Therefore, the present invention prevents the floating matters such as sewage and scum from remaining in the pre-turning tank, and prevents the solid matters such as sand from being deposited and deposited on the bottom.
It is an object of the present invention to provide a suction port of a pump in a pre-swirl tank which has a capability of positively sucking a swirling flow generated in the pre-swirl tank.

[0008]

In order to achieve the above object, the present invention comprises a peripheral wall having an open upper end and a bottom wall closing the lower end of the peripheral wall, the peripheral wall extending along the rotational direction of the pump. In a pre-swirl tank provided with at least one inflow passage having a directivity capable of generating a swirl flow in the pre-swirl tank, the suction port of the pump has a space from the peripheral wall and has a lower end. Is inserted into the pre-swirl tank in a state of being in contact with the upper surface of the bottom wall, and is opened countercurrent to the swirl flow. According to the present invention, since the lower end of the suction port is brought into contact with the bottom wall of the pre-swirl tank, sewage in the pre-swirl tank, suspended matters such as scum, and solid matter such as sand mixed in the sewage are removed. Can inhale efficiently. In particular, since the suction port is brought into contact with the upper surface of the bottom wall, it is possible to efficiently suck up water near the bottom having a high sand content rate, so that sand recovery efficiency can be improved. Moreover, since the suction port opens countercurrently to the swirl flow, the swirl flow generated in the pre-swirl tank can be positively sucked in, so that the scum and sand can be efficiently sucked.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view, and FIG. 2 is a cross section taken along the line AA in FIG. The same or corresponding parts as in the conventional example of FIGS. 6 and 7 are denoted by the same reference numerals, and detailed description of the structure is omitted. In FIGS. 1 and 2, a 90 ° curved pipe 1A is attached to the lower end portion of the suction port 1 of each of the pumps P1 and P2, and a peripheral wall 2A of the first pre-swirl tank 2 and a peripheral wall 3A of the second pre-swirl tank 3 are attached. Is inserted with the lower end of the 90 ° bent tube 1A abutting the upper surfaces of the bottom walls 2B and 3B.

Further, as shown in FIG. 3, the inlet of the 90 ° curved pipe 1A is opened countercurrent to the swirling flow S generated in the first pre-swirl tank 2 and the second pre-swirl tank 2. In addition, the vertical axis C of the suction pipe is eccentric from the center O of each of the first pre-swirling tank 2 and the second pre-swirling tank 3 toward the inflow passages 12 and 13. Furthermore, the swirling flow S
It corresponds to the vicinity of the winding end part s.

In the above structure, the two pumps P1 and P
2 are operated alternately. For example, by operating the first pump P1, the dirty water in the suction water tank 4 is sucked up from the inlet of the 90 ° curved pipe 1A in the suction port 1 of the first pump P1. In this state, no swirling flow is generated inside the pre-swirling tank 2. When the water level of the sewage falls below WL1, the sewage flows into the first pre-swivel tank 2 through the inflow passage 12, so that floating matters such as scum and sand while swirling in the first pre-swirl tank 2 90 including solid matter such as
° Suction from the inlet of curved pipe 1A.

By operating the second pump P2, the dirty water in the suction water tank 4 is sucked up from the inlet of the 90 ° curved pipe 1A in the suction port 1 of the second pump P2. In this state, no swirl flow is generated inside the pre-swirl tank 3. When the water level of the sewage falls below WL1, the sewage flows into the second pre-swivel tank 3 through the inflow passage 13, so that floating matters such as scum and sand while swirling in the second pre-swirl tank 3 Incorporate solid substances such as the above and suck in from the inlet of the 90 ° bent tube 1A.

Further, the lower ends of the 90 ° curved pipes 1A at the suction ports 1 of the first pump P1 and the second pump P2 are brought into contact with the bottom wall 2B of the pre-swirl tank 2 and the bottom wall 3B of the pre-swirl tank 3. Since it is made possible, almost all the sewage in the pre-swirl tanks 2 and 3, suspended matters such as scum, and solid matter such as sand mixed in the sewage can be sucked. Moreover, since the inlet of the 90 ° curved pipe 1A is opened countercurrently to the swirl flow S generated in the first pre-swirl tank 2 and the second pre-swirl tank 2, the swirl flow S is more positively sucked. Will be possible. Therefore, sewage and suspended matters such as scum hardly remain in the first pre-turning tank 2 and the second pre-turning tank 3. Moreover, solid matter such as sand does not settle and deposit on the bottom walls 2B and 3B.
The strong swirl flow contains sand scraped up from the bottom by the scum separated by the shear mixing action, and is effectively sucked from the countercurrent suction port 1.

In the above embodiment, the lower end of the 90 ° curved pipe 1A at the suction port 1 of each of the first pump P1 and the second pump P2 is connected to the bottom wall 2B of the pre-swirl tank 2 and the pre-swirl tank 3. Although the description has been made with the configuration in which it is brought into contact with the bottom wall 3B,
The lower end of the 90 ° curved pipe 1A may be brought close to the bottom walls 2B and 3B. Also, two pumps P1, P2 and 2
Although the suction water tank 4 provided with two pre-swirl tanks 2 and 3 is explained, the suction water tank 4 provided with one pump and one pre-swirl tank, or three or more pumps and three or more pre-swirl tanks. It can also be applied to the suction water tank 4 equipped with.

On the other hand, a 90 ° bent pipe 1A having a special shape is attached to the lower end portion of the suction port 1 of the pump for explanation, but a general 90 ° bent pipe may be used. Further, as shown in FIG. 4, a 45 ° bent pipe 1B is attached to the lower end portion of the suction port 1 of the pump, or as shown in FIG.
The lower end of the suction port 1 of the pump is cut out diagonally and opened,
A configuration in which this opening is countercurrent to the swirling flow S may be used.
Further, the inlet of the suction port 1, that is, 90 according to the embodiment.
Although the inlet of the curved pipe 1A is described as corresponding to the winding end portion s of the swirling flow S generated in the first pre-swirl tank 2 and the second pre-swirl tank 2, the winding end is not necessarily finished. It is not necessary to correspond to the portion s, and the swirl flow S may be countercurrently opened at any portion.

[0016]

As described above, according to the present invention, the lower end of the suction port of the pump is inserted into the pre-swirl tank with the lower end of the pump abutting the upper surface of the bottom wall of the pre-swirl tank, and it is directed to the swirl flow. Since it is opened by flowing it, by continuing the operation of the pump to the level of the bottom wall of the pre-swirl tank, sewage in the pre-swivel tank, suspended matters such as scum, and solid matter such as sand mixed in the waste water Since almost all of the water can be positively sucked in, sewage and floating substances such as scum do not remain in the suction water tank. Moreover, solid matter such as sand does not settle and deposit on the bottom wall.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged plan view of a main part.

FIG. 4 is a view corresponding to FIG. 2 showing another embodiment of the suction port of the pump.

FIG. 5 is a view corresponding to FIG. 2 showing still another embodiment of the suction port of the pump.

FIG. 6 is a plan view showing a conventional example.

7 is a cross-sectional view taken along the line BB of FIG.

[Explanation of symbols]

 1 Pump suction port 1A 90 ° curved pipe (lower end component of the suction port) 1B 45 ° curved pipe (lower end component of the suction port) 2 1st pre-swirl tank 2A 1st pre-swirl tank peripheral wall 2B 1 Bottom wall of pre-swirl tank 3 Second pre-swirl tank 3A Peripheral wall of second pre-swirl tank 3B Bottom wall of second pre-swirl tank 4 Suction water tank 12 Inflow path 13 Inflow path 16 Communication path (inflow path) P1 pump P2 pump R Pump rotation direction S Swirling flow

Claims (1)

[Claims] 1. A direction in which a peripheral wall having an open upper end and a bottom wall closing the lower end of the peripheral wall are connected to the peripheral wall along the rotational direction of the pump and a swirl flow can be generated in the pre-swirl tank. In a pre-swirling tank provided with at least one inflow passage having a property, the suction port of the pump being spaced from the peripheral wall, and the lower end being in contact with the upper surface of the bottom wall. A suction port of a pump in a pre-swirl tank, which is inserted into the pre-swirl tank and opens countercurrently to the swirl flow.