JPH11229484A - Retrofit pre-swirling tank - Google Patents

Abstract

(57) [Summary] [Problem] Even in flooded manholes where groundwater etc. seeps out,
Pre-swirling tank can be easily installed without being affected by flooding,
Improve installation workability. In addition, the gantry is securely fixed with mortar or concrete to suppress vibration during pump operation. SOLUTION: A mounting recess 25A, 25B of a gantry is recessed downward between pre-rotating portions 3A, 3B and a first partition wall 8A,
The first space 24A below the sewage storage unit 7 and the pre-swirl unit 3A,
The first space 2 is formed on the lower side of the pre-swirl portion forming area 12 including the periphery of the mounting recesses 3A and the mounting recesses 25A and 25B of the gantry.
The second space 24B communicating with the bottom wall 2A is connected to the upright wall 26A and the bottom 2A.
A hollow closed section structure surrounded by 6B is adopted. Mounting recess 2
After installing the gantry 10A, 10B in 5A, 25B, mortar or concrete 18 is cast, and the hollow portion 26 of the hollow closed cross section structure is filled with a high specific gravity material 27 such as sand from a filling port 28 to be preliminarily filled. The swirl tank 2 is installed at the bottom of the manhole 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retrofitting pre-swirl tank installed at the bottom of a manhole or the bottom of a suction water tank of a pump constructed at an appropriate place in a sewage drainage piping system connecting a sewage generation source and a sewage treatment plant. About.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 3 to 5, fibers such as FRP are provided at the bottom of a concrete manhole 1 constructed at an appropriate place in a sewage downflow piping system connecting a sewage generation source and a sewage treatment plant. Retrofitting pre-swirl tank 2 made of a substantially disk-shaped disk-shaped body made of reinforced plastic
Techniques for installing a pre-swirl tank are well known. The pre-swirl tank 2 includes a pair of pre-swirl units 3A and 3B.
And a pair of mounting seats 6A and 6B, a sewage storage section 7 and a partition wall section 8, and extend in the width direction at the center of the pre-swirling tank 2 in the longitudinal direction L. The first turning wall 8A of the partition wall portion 8 protruding upwardly divides the pre-swirling portion forming area 12 on one side in the longitudinal direction and the sewage storage section 7 on the other side in the longitudinal direction.

The pre-swirl units 3A, 3B are provided with pumps P1, P2
For inserting the air inlet 13 of the first partition wall 8A.
The pre-swirl portions 3A and 3B are sectioned in the width direction W and are recessed downward by a second partition wall 8B provided so as to extend to the pre-swirl portion forming area 12 side orthogonally to.

The sewage in the sewage storage unit 7 is guided to the pre-swirling unit 3A from the inflow path 4 in a tangential direction or a direction close thereto,
A pre-swirl flow is generated in the pre-swirl section 3A, which swirls in the same direction R1 as the rotation direction R of the impeller (not shown) of the pump P1. Further, the sewage in the sewage storage unit 7 is guided to the pre-swirling unit 3B from the inflow path 5 in a tangential direction or a direction close to the sewage. A pre-swirling flow that turns in the same direction R1 as the rotation direction R is generated.

The pair of mounting seats 6A and 6B are
A, 3B and the first partition wall 8A. The discharge curved pipe 9A is mounted on the mounting seat 6A, and the discharge curved pipe 9B is mounted on the mounting seat 6B. The discharge curved tube 9A mounted on the mounting seat 6A is fixed to the upper end of the gantry 10A via the mounting seat 6A, and the discharge curved tube 9B mounted on the mounting seat 6B is connected to the mounting seat 6B. And is fixed to the upper end of the gantry 10B. The discharge port of the pump P1 is connected to one end of the discharge curved pipe 9A, the lower end of the discharge pipe 11A is connected to the other end of the discharge curved pipe 9A, and the discharge pipe 9B is connected to one end of the discharge curved pipe 9B. The discharge port of the pump P2 is connected, and the lower end inlet of the discharge pipe 11B is connected to the other end of the curved discharge pipe 9B. Stand 10
The lower member 10b of each of A and 10B is fixed by anchor bolts 17 and 17 and a nut 17A erected on the bottom member 1A of the manhole 1.

The sewage storage section 7 is provided on the other side of the first partition wall 8A in the longitudinal direction L through the vertical step surface 14 over the entire area in the width direction W. The sewage storage section 7 is inclined in a downward gradient from the other end in the longitudinal direction L to the lower end of the vertical step surface 14, and communicates with the inflow water passages 4 and 5 on both sides in the width direction W of the first partition wall 8A. ing. In addition, the gantry 10A, 1
4B, four bolts 15, 15... (Only two bolts 15, 15 are shown in the drawing) are fixed through the upper member 10a from below. Therefore, each of the lower members 10b of the gantry 10A, 10B
Are fixed to the bottom member 1A of the manhole 1 with the anchor bolts 17, 17, and bolts 15, 15,... Are provided in four mounting holes 6A, 6B, respectively. Only through holes) and four through holes (only two through holes are shown in the drawing) provided in the base portion 9C of the discharge curved pipes 9A and 9B, and are projected upward. By screwing a nut 16 onto these protruding portions, the mounting base 1 is mounted via the mounting seats 6A and 6B.
0A and 10B, the pre-swirling tank 2 and the discharge curved pipes 9A and 9
B is supported.

While the pre-swirl tank 2 is supported by the gantry 10A, 10B, the pre-swirl tank 2 and the bottom member 1A of the manhole 1 are provided.
And a space 24 surrounded by the standing wall 1B of the manhole 1;
That is, the first space 24A below the sewage storage section 7 and the second space 24 formed below the pre-swirl section forming area 12 including the periphery of the pre-swirl sections 3A and 3B and communicating with the first space 24A.
B, mortar or concrete 18 is cast from a gap between the outer circumference of the pre-swirling tank 2 and the inner circumference of the upright wall 1B of the manhole 1. The bottoms of the pre-rotation sections 3A and 3B are manhole 1 by anchor bolts 19 and nuts 19A.
Is fixed to the bottom member 1A.

As described above, the mortar or concrete 18 placed in the first space 24A and the second space 24B is used.
After curing and curing, the pumps P1 and P2 are lowered along the guide wires 20 and 20 from the upper end opening of the manhole 1 and the discharge port of the pump P1 is connected to one end of the discharge curved pipe 9A, and the discharge port of the pump P2 is formed. Is connected to one end of the discharge curved pipe 9B. As a result, the suction port 13 of the pump P1 is inserted into the pre-rotation section 3A, and the suction port 13 of the pump P2 is inserted into the pre-rotation section 3A.
B is inserted. The lower end of the discharge pipe 11A is connected to the other end of the curved discharge pipe 9A, and the lower end of the discharge pipe 11B is connected to the other end of the discharge curved pipe 9B. The outlet at the upper end of the discharge pipes 11A and 11B is the header pipe 2
1 is connected to a drain pipe 22 outside the manhole 1.

As described above, in the manhole 1 in which the pre-swirling tank 2 made of fiber-reinforced plastic is installed, the sewage inflow pipe 23 is provided.
Sewage flows into the manhole 1 from the
When the water level rises to the operation start water level HWL of P1 and P2, the water level HWL is detected by water level detection means (not shown), and an operation start signal is output to the pump P1 or P2 based on the water level detection. By operating the pumps P1 or P2 alternately, the water level becomes the upper end level L of the pre-swirling tank 2.
After dropping to WL1, the sewage in the sewage storage section 7 flows into the pre-swirl section 3A or 3B through the inflow path 4 or the inflow path 5, and the rotation direction R1 of the pump impeller in the pre-swirl sections 3A and 3B. Pre-turn in the same direction R2. Therefore, the pump can be efficiently and smoothly sucked from the entire circumference of the suction port 13 of the pump. In addition, since solid matter such as sand mixed in the water can be collected directly below the suction port 13 of the pump, the solid matter such as sand set in the pre-swirl 3A or 3B can be easily discharged together with the water. Objects can be prevented from remaining and accumulating.

[0010]

However, in the conventional pre-rotation tank 2, the outer circumference of the pre-rotation tank 2 and the upright wall 1 of the manhole 1 are not provided.
The space 2 formed by the first space 24A and the second space 24B communicating with the first space 24A from the gap between the inner circumferences of the first space B and the second space 24B.
Since the mortar or concrete 18 is configured to be poured into the mortar 4 or the concrete 4, the mortar or concrete 1 is used in the flooded manhole 1 in which groundwater or the like leaks out.
8 is difficult to cast, and it takes a long time to cure after the casting. Therefore, the installation workability of the pre-rotation tank 2 is inferior. On the other hand, since it is difficult to cast mortar or concrete 18 over the entire area of the space 24 without gaps, the mortar or concrete 18 is used to mount the gantry 10A, 10A.
B is difficult to fix without a gap, and a gap is easily generated between the gantry 10A, 10B and the mortar or concrete 18.
When such a gap is generated, the fixing strength of the gantry 10A, 10B by the mortar or the concrete 18 is reduced, and large vibration is generated during the operation of the pumps P1, P2. Therefore, the present invention can easily install a pre-swirling tank without being affected by water discharge, even in a flood water manhole where a groundwater or the like oozes or a suction water tank of a pump, and can improve installation workability. In addition, the present invention provides a retrofitting pre-swirl tank that can easily and securely fix the gantry with mortar or concrete without gaps, increase the fixing strength of the gantry with mortar or concrete, and suppress vibration during pump operation. It is intended to be.

[0011]

In order to achieve the above object, a retrofit type pre-swirl tank according to the present invention is characterized in that a plurality of pre-swirl portions into which suction ports of a plurality of pumps are individually inserted are arranged in a longitudinal direction. The first partition wall, which is recessed downward with an offset in the width direction on the side and extends upward in the width direction on the other side of the pre-swing portion, is provided on one side of the first partition wall. The pre-swirl section is formed in a longitudinal direction into a pre-swirl section forming area and a sewage storage section on the other side of the first partition wall. The plurality of pre-swirl sections are respectively extended perpendicularly to the first partition wall toward the pre-swirl section forming area side. A second partition wall is provided for partitioning in the width direction, and the sewage in the sewage storage section is guided to each of the plurality of pre-swirl sections in a tangential direction or a direction close thereto, and pump blades are provided in the pre-swirl section. A board with an inflow path that generates a pre-swirl flow that turns in the same direction as the car's rotation In a retrofitted pre-swirling tank installed at the bottom of a manhole or a suction water tank of a pump, discharge ports of a plurality of pumps having suction ports inserted in the pre-swirling part are connected to one end, and an inlet of a discharge pipe is provided. Is provided with a plurality of pedestals for mounting and supporting the discharge curved tube connected to the other end, and the installation recesses of the gantry for loading and installing these pedestals are recessed downward near the plurality of pre-rotation parts. A first space formed below the sewage storage section and a pre-swirl section forming area including a periphery of each of the plurality of pre-swirl sections and the installation recesses of the plurality of pedestals and communicating with the first space. The two spaces have a hollow closed cross section structure, and a filling port for filling a high specific gravity material is provided in the hollow portion of the hollow closed cross section structure so as to be openable and closable. ADVANTAGE OF THE INVENTION According to this invention, a filling port can be opened and the hollow part of a hollow closed cross-section structure can be filled with high specific gravity material, such as mortar, concrete, or sand, and installed.
On the other hand, after mounting and installing the gantry in each of the installation recesses of the plurality of gantry, mortar or concrete can be poured into the installation recess of each of the gantry without gaps.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. A feature of the present invention is that a structure in which installation recesses of a plurality of pedestals are recessed downward near a plurality of pre-swirl units, and a first space and a second space communicating with the first space are formed as hollow closed sections. The structure has a structure in which a filling port for filling a high specific gravity material is provided in the hollow portion of the hollow closed cross-sectional structure so as to be openable and closable. The description of the structure and operation is omitted, and the same parts as those in the conventional example are denoted by the same reference numerals.

In FIG. 1 and FIG.
Mounting recesses 25A, 2 of the gantry between 3B and first partition 8A.
5B is recessed downward. On the other hand, the first space 24A below the sewage storage section 7 and the first swirling sections 3A and 3B and the surroundings of the installation recesses 25A and 25B of the pedestal are formed below the pre-swirl section forming area 12 and include the first space. The second space 24B communicating with the space 24A has a hollow closed cross-sectional structure surrounded by an upright wall 26A and a bottom portion 26B, and the hollow portion 26 of the hollow closed cross-sectional structure is filled with a high specific gravity material 27 such as mortar, concrete or sand. A filling port 28 is provided in the sewage storage section 7, and the filling port 28 can be opened and closed by a removable lid 29. The top surface of the lid 29 is configured to be flush with the sewage storage unit 7.

[0014] Four through-holes (only two through-holes are shown in the drawings) formed through the bottom of each of the mounting recesses 25A and 25B of the gantry are provided on the bottom member 1A of the manhole 1. The inserted anchor bolts 17, 17 are inserted, and the upper ends thereof are projected above the bottoms of the installation recesses 25A, 25B of the gantry. Next, the gantry 10A is inserted into the mounting recess 25A of the gantry, and the mounting recess 25B of the gantry is mounted.
The anchor bolts 17 and 4 are inserted into four through holes (only two through holes are shown in the drawing) formed through the lower member 10b.
17 is inserted above the lower member 10b so as to protrude above the lower member 10b, and a nut 17A is screwed into the lower member 10b to fix the mounting recesses 25A and 25B of the gantry to the bottom member 1A of the manhole 1. Stands 10A, 10 on 25A, 25B
B is installed. Further, the bottom portions of the pre-rotation portions 3A and 3B are fixed to the bottom member 1A of the manhole 1 by anchor bolts 19 and nuts 19A.

Next, by removing the lid 29, the filling port 28 is removed.
Is filled with a high specific gravity material (for example, sand) 27 into a hollow portion 26 having a hollow closed cross-sectional structure, and a filling port 28 is closed with a lid 29, thereby installing the pre-swirling tank 2 at the bottom of the manhole 1. Mortar or concrete 18 is cast into the installation recesses 25A and 25B of the gantry.

That is, even in the flooded manhole 1 in which groundwater or the like seeps out, the hollow portion 26 can be easily filled with the high specific gravity material 27 without being affected by the flooding, and the pre-rotation tank 2 can be installed. In addition, the installation workability of the pre-rotation tank 2 is improved. In addition, the mortar or concrete 18 can be easily poured into the installation recesses 25A and 25B of the gantry without any gap.
8, the fixing strength of the gantry 10A, 10B can be increased, and vibration during the operation of the pumps P1, P2 can be effectively suppressed.

In the above embodiment, sand is used as the high specific gravity material 27, but mortar or concrete 18 may be used instead of sand. In addition, although the description has been given using the single-shape pre-swirl tank 2, the present invention can also be applied to the pre-swirl tank 2 that is integrally connected so as to be able to be divided into a plurality. If the pre-swirl tank 2 is integrally connected so as to be able to be divided into a plurality of parts, the pre-swirl tank 2 is divided and carried into the manhole 1 through the small opening 1C, and the pre-swirl tank 2 is assembled inside the manhole 1. be able to. Furthermore, although the pre-swirling tank 2 installed at the bottom of the manhole 1 has been described, the present invention can also be applied to the pre-swirling tank 2 installed at the bottom of the suction water tank of the pump.

[0018]

As described above, the retrofit type pre-swirling tank according to the present invention can easily remove a high specific gravity material without being affected by the flooding even in a flooding manhole or a flooding suction tank into which groundwater or the like leaks. Since the pre-swirl tank can be installed by filling the hollow portion, the workability of installing the pre-swirl tank is improved. In addition, mortar or concrete can be easily poured into the installation recess of the gantry without gaps,
By increasing the fixing strength of the gantry with mortar or concrete, vibration during pump operation can be effectively suppressed.

[Brief description of the 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 a plan view of a conventional example.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a sectional view taken along line CC of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Manhole 2 Retrofit pre-swirling tank 3A Pre-swirling part 3B Pre-swirling part 4 Inflow path 5 Inflow path 7 Sewage storage part 8 Partition wall part 8A 1st partition wall 8B 2nd partition wall 9A Discharge curved pipe 9B Discharge curved pipe 10A Mounting stand Reference Signs List 10B Mount 11A Discharge pipe 11B Discharge pipe 12 Pre-swirling part forming area 13 Pump inlet 18 Mortar or concrete 24 Space 24A First space 24B Second space 25A Mounting recess of mounting 25B Mounting recess of mounting 26 Hollow of hollow closed section structure Part 27 Sand (high specific gravity material) 28 Filling port P1 Pump P2 Pump R1 Rotation direction of pump impeller R2 Rotation direction of pre-swirling flow

Claims (1)

[Claims] 1. A plurality of pre-swirl portions into which suction ports of a plurality of pumps are separately inserted are downwardly recessed at one side in the longitudinal direction with an interval in the width direction, and are provided with other pre-swirl portions. By the first partition wall extending in the width direction on the side and protruding upward,
The pre-swirl section forming area on one side of the first partition wall and the sewage storage section on the other side of the first partition wall are partitioned in the longitudinal direction, and extend to the pre-swirl section forming area side orthogonal to the first partition wall. A second partition wall is separately provided to partition the plurality of pre-swirling units in the width direction, and the sewage in the sewage storage unit is guided to each of the plurality of pre-swirling units in a tangential direction or a direction close thereto. A board-like body provided with an inflow passage for generating a pre-swirl flow swirling in the same direction as the rotation direction of the pump impeller in the pre-swirl section, and a retrofit installed at the bottom of a manhole or a suction water tank of the pump. In the pre-swirl tank, the discharge ports of a plurality of pumps each having a suction port inserted into the pre-swirl section are connected to one end, and a plurality of discharge pipes, each having an inlet of the discharge pipe connected to the other end, are mounted and supported. The mounting recesses of the gantry for loading and installing these gantry A pre-swirl section forming area including a first space below the sewage storage section, and a periphery of each of the plurality of pre-swirl sections and a plurality of mounting recesses of the gantry, which are recessed downward near the plurality of pre-swirl sections. And a second space communicating with the first space is formed as a hollow closed cross-sectional structure, and a filling port for filling a high specific gravity material is provided in a hollow portion of the hollow closed cross-sectional structure so as to be openable and closable. A retrofitting pre-swirl tank characterized by the following.