JP2002130193A - Capacity increasing system of drainage pump station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for increasing displacement of an existing pump by internally storing an increasing pump in a vortex flow preventive plate in the device for increasing capacity of existing pump equipment. SOLUTION: In an existing pump station for arranging a vertical shaft pump 1 in a water absorbing tank 2, when increasing capacity of the vertical shaft pump 1 according to a sudden increase in an inflow quantity, two equipment for installing the increasing pump and the vortex flow preventive plate C is required, the two equipment are compounded by internally storing a columnar high speed submergible pump 3 in this vortex flow preventive plate C, and the capacity of the existing vertical shaft pump 1 is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for enhancing the capacity of existing pump equipment, and is particularly suitable for an urgent pump station remodeling.

[0002]

2. Description of the Related Art As means for increasing the capacity of existing pump equipment, there are a method of increasing the number of revolutions of the pump to increase the discharge amount, and a method of adding a sub-pump in a water channel upstream of the existing main pump. . The former method of increasing the number of revolutions of the pump and increasing the discharge amount is disclosed in JP-A-5-870
There is an invention described in Japanese Patent Publication No. 85. In addition, the latter method of adding a sub-pump in a water channel is generally performed, and there are many known examples.

[0003]

In recent years, with the progress of urbanization, urbanization and residential development have led to a decrease in green spaces and vacant spaces, or an increase in the spread of pavement such as roads, resulting in a decrease in the water retention function and a decrease in rainfall. Most of them started flowing into the pumping station. Especially in urban areas in summer, 50 per hour
This is a so-called urban type, in which concentrated torrential rains exceeding mm frequently occur, and this large amount of rainwater suddenly flows into the pumping station, flooding the pumping station, making it inoperable and damaging lowlands and depressions. There is a problem that frequent floods occur.

[0004] For this reason, there is no problem in the newly constructed pumping station if the design drainage amount is determined based on recent rainfall data. However, it is urgently necessary to increase the pumping capacity of existing pumping stations where the design drainage volume has not been determined based on recent rainfall data.

In order to increase the capacity of the existing pump, the invention disclosed in Japanese Patent Laid-Open Publication No. Hei 5-87085 discloses a method of increasing the discharge amount of a pump by increasing the number of revolutions to the maximum output of a motor. The above method is a good means to increase the pump capacity without having to replace the prime mover and without increasing the installation space. However, if the prime mover is operated at the maximum output for a long time, problems such as heat generation and burnout of the prime mover occur. In addition, even in operation at the planned displacement, the above method cannot be used in a pump facility designed with a small allowance for the prime mover.

[0006] Next, a method of increasing the capacity of the pump equipment by additionally installing a sub-pump separately in the water absorption tank without modifying the existing pump is generally performed. However, in order to increase the main pump capacity of the existing pumping station with the increase of inflow, if a separate sub-pump is installed in the same suction water tank, by installing a sub-pump upstream of the main pump, There is a problem that the auxiliary pump hinders the flow and adversely affects the suction of the downstream main pump. For this reason, as a means to prevent the flow of the sub-pump from being interrupted, there is a method of notching a partition wall of a water channel and installing an additional pump therein. However, there is a problem that the strength of the steel is reduced. In addition, since an air suction vortex and an underwater vortex are generated in the main pump with an increase in the amount of water flowing into the water channel, it is necessary to install a vortex generation prevention plate in the water channel as a means for preventing the generation of the vortex.

[0007]

Means for Solving the Problems To solve the above-mentioned problems, the construction of the capacity increasing device of the drainage pump station according to the present invention comprises:
In a pump station in which an impeller is provided in a pump casing and a vertical pump having a suction bell mouth for sucking fluid into the pump casing is disposed in a water absorption tank, a lower end is provided upstream of the vertical pump in the water absorption tank. Has a vortex preventing plate protruding below the lowest water level, and a pump is built in the vortex preventing plate. The pump incorporated in the eddy current prevention plate is a column-type high-speed submersible pump, and the eddy current prevention plate includes one or more column-type high-speed submersible pumps. In addition, screens are arranged on the lower end surface and the upstream side surface of the vortex prevention plate facing the suction portion of the column type high-speed submersible pump incorporated in the vortex prevention plate, so that coarse foreign substances are not sucked. . As described above, in order to cope with an increase in the amount of inflow to the existing pumping station, the two problems of installation of the vortex prevention plate and installation of the booster pump are combined, and the problem is solved by incorporating the booster pump in the vortex prevention plate You can do it.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is to enhance the pumping capacity of an existing pumping station by the above-described configuration.
The installation location and shape of the eddy current prevention plate differ depending on the type of eddy current generated in the water channel. Generally, a vortex preventing plate A provided vertically on the wall behind the main pump prevents vortices generated by suction of surface air, and a vortex preventing plate B provided on the bottom surface below the suction bell mouth of the main pump.
This is to prevent the generation of underwater vortices. In addition, a vortex prevention plate C provided in the water channel on the upstream side of the main pump prevents air suction vortices generated by suction of surface air. Of the three eddy current prevention plates A, B, and C, the eddy current prevention plate most suitable for incorporating a booster pump is optimally incorporated in the eddy current prevention plate C in consideration of installation space and maintenance space.

The type of the booster pump incorporated in the vortex prevention plate C employs a column type high-speed submersible pump in consideration of the built-in space and the ease of lifting during maintenance. And this booster pump has 1
By installing a screen or a plurality of screens, a screen is provided on the lower end portion of the swirl prevention plate C and the side surface on the upstream side of the water channel facing the suction site of the booster pump, so that the diameter of the booster pump is smaller than that of the main pump. Since the maximum passing particle size is also small, the screen removes solids having a size equal to or greater than the maximum passing particle size to prevent clogging.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a side view in which a part of an existing pump equipment in which the pump capacity is enhanced by the apparatus of the present invention is cut. Reference numeral 1 denotes a vertical shaft pump, which is an existing main pump, which sucks water such as rainwater flowing into a water absorption tank 2 from a suction bell mouth 1a and pressurizes it with an impeller 1b provided in a pump casing 1c. This pressurized water is used as guide blades 1d.
And the water is discharged from the discharge elbow 1e.

The water absorption tank 2 is provided with a vortex preventing plate for preventing a vortex generated due to an increase in the flow velocity accompanying an increase in the inflow. The function of the eddy current prevention plate will be described in detail with reference to FIGS. A vortex preventing plate A vertically provided on a wall surface behind the vertical pump 1 suppresses a swirling flow at a rear portion of the vertical pump 1 and prevents an air suction vortex generated by sucking surface air of the water absorption tank 2. It is. Next, a swirl prevention plate B is provided in a cross shape on the bottom surface immediately below the center of the suction bell mouth 1a of the vertical shaft pump 1. The swirling flow of the water flowing into the water absorption tank 2 from the upstream is suppressed by the swirl prevention plate B, and the underwater swirl generated when the water is sucked from the suction bell mouth 1a to the impeller 1b can be prevented. The lower end protrudes below the lowest water level LLWL on the upstream side of the vertical shaft pump 1, and the flow on the free surface in the water absorption tank 2 is suppressed by the vortex prevention plate C vertically provided between the side walls of the water absorption tank 2. Therefore, it is possible to prevent the generation of the air suction vortex generated by sucking the surface air.

Reference numeral 3 denotes a capacity-enhancing pump provided to cope with an increase in the amount of inflow to the pumping station, and uses a column-type high-speed submersible pump. The high-speed submersible pump 3 is incorporated in the eddy current prevention plate C for installation space and ease of maintenance. In FIG. 3, the vertical pump 1 operates between the water level of HWL and LWL. However, during a flood such as heavy rain, the inflow into the pumping station becomes larger than the drainage of the vertical pump 1 and exceeds the water level of HWL. Come. When the water level becomes equal to or higher than the HWL water level, the high-speed submersible pump 3 starts operating.

The high-speed submersible pump 3 described above is shown in FIG.
Built in the eddy current prevention plate C,
Bottom surface just below suction bell 5 of submersible pump 3 and upstream side surface
The screen 4 is stretched at the lower end. Vertical axis of main pump
The diameter of the high-speed submersible pump 3 is smaller than that of the pump 1,
Since the large passing particle size is also small, this screen 4
Do not inhale large solids larger than the passing particle size
You. If the water level is higher than HWL in Fig. 3, high-speed submersible pump
3 drives the submersible motor 6 incorporated in the suction bell 5
The water sucked from the water passes through the water pipe 7 and is discharged from the discharge port 8
By draining water, the function of the vertical pump 1
This is to increase the power. As an example, an existing
The specifications of the pump are 1500 mmφ in diameter and the discharge amount (Q) = 300
m^Three/ Min, a 20% capacity increase is required
When the discharge amount (Q) = 300m ^Three/Min×0.2=
60m^Three/ Min booster pump is required,
The diameter of the submersible pump is 700 mmφ, but the high-speed pump
If a pump is used, it becomes possible with a diameter of 600 mmφ. Augment
The smaller the diameter of the pump, the thinner the vortex prevention plate C
The cost of remodeling work is reduced. Furthermore, as shown in FIG.
Discharge amount (Q) = 30m^Three/ Min small diameter high speed underwater
By incorporating two pumps 3, the vortex prevention plate C can be thinned.
Can be done. In addition, two or more intensifiers
It is a matter of course that a loop can be built in.

FIG. 4 shows a conventional installation method of the intensifying pump 10, in which a partition wall 12 of a water passage 11 to the water absorption tank 2 is cut off.
The intensifier pump 10 is installed at this location. In this conventional method, the remodeling work period is prolonged, and the strength of the partition wall 12 as the civil engineering structure may be reduced. In addition, as the inflow amount increases, it becomes necessary to install a vortex preventing plate C for preventing the generation of a vortex due to an increase in the flow velocity in the water channel 11, so that the cost of the remodeling work becomes high.

[0015]

According to the present invention, as described above, with the rapid increase in the amount of inflow to the pumping station due to the concentrated torrential rain frequently occurring in urban areas, the capacity of existing pumps is increased and the flow speed of the water channel is increased. It has become necessary to provide a vortex prevention plate for preventing eddy currents. The present invention combines these two facilities by incorporating a booster pump in the eddy current prevention plate. By combining these, it is possible to shorten the construction period for capacity expansion without modifying the existing pump equipment and reduce the construction cost. Even if a second capacity enhancement work is required in the future, it can be easily modified.

[Brief description of the drawings]

FIG. 1 is a side view in which a part of a pump equipment provided with an apparatus of the present invention is cut.

FIG. 2 is a plan view of the pump equipment taken along line YY of FIG. 1;

FIG. 3 is a side view in which a part of the capacity enhancing device of the present invention is cut.

FIG. 4 is a plan view of a pump facility provided with a conventional capacity enhancing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical pump 1a Suction bell mouth 1b Impeller 1c Pump casing 2 Water absorption tank 3 High-speed submersible pump 4 Screen C Eddy current prevention plate LLWL Minimum water level

Claims (4)

[Claims] An impeller (1) is provided on a pump casing (1c).
b) and a pump station in which a vertical shaft pump (1) having a suction bell mouth (1a) for sucking a fluid into the pump casing (1c) is disposed in a water absorption tank (2).
On the upstream side of the vertical pump (1) in the water absorption tank (2),
An apparatus for enhancing the capacity of a drainage pump station, characterized in that a vortex preventing plate (C) whose lower end protrudes below the lowest water level (LLWL) is provided vertically and a pump is built in the vortex preventing plate (C). 2. The capacity increasing device of a drainage pump station according to claim 1, wherein the pump incorporated in the vortex preventing plate (C) is a column-type high-speed submersible pump (3). 3. The capacity of the drainage pump station according to claim 1, wherein a plurality of column-type high-speed submersible pumps (3) built in the vortex preventing plate (C) are provided. Intensifier. 4. A screen (4) stretched on a vortex preventing plate (C) facing a suction portion of a column-type high-speed submersible pump (3). A capacity enhancement device for a drainage pumping station according to item 1.