JPS649474B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a submersible pump device in which a plurality of submersible pump units are connected in series through lifting pipes, and each submersible pump unit is operated and stopped according to the water level.

In general, the water level in a water intake pond constantly changes depending on the amount of rainfall, etc., and may fluctuate significantly depending on the season.

Therefore, when installing pump equipment, it is necessary to set the pump's pumping capacity according to the minimum water level, but if the water level is high, the pump will have more capacity than necessary, which is extremely uneconomical. . In other words, as shown in Figures 1 and 2, the lowest water level L,
The pump head at W and L is Hs (max), and in order to obtain the water amount Q _D , a pump with curved characteristics is required. On the other hand, the head at the highest water level HWL is Hs
(min), and in order to obtain the same amount of water Q _D , a pump with curved characteristics is sufficient. Therefore, from the viewpoint of energy saving, it is necessary to change the characteristics of the pump from curve to curve in accordance with the fluctuations in the water level.

Conventionally, one method for this purpose is to change the rotational speed of a motor, which is the drive source of the pump, to continuously change the rotational speed from curve 'to' as shown in FIG. However, in this type of device, the equipment cost required to control the speed of the motor is extremely high, and in particular, speed control of an underwater motor has the disadvantage that the initial cost is high.

The present invention has been made in view of the above circumstances, and consists of connecting a plurality of submersible pump units in series at a predetermined interval in the vertical direction using lift pipes, and each submersible pump unit has a water intake port. In addition, check valves are installed at least at the water intake ports of submersible pump units other than the lowest tier to prevent water from being discharged to the outside from the lower tier submersible pump units, and the operation of each of the above submersible pump units is obtained from a water level detector. By stopping from the lower stage in response to the high water level detection signal generated by An object of the present invention is to provide a submersible pump device that can operate only a minimum number of submersible pump units and can significantly reduce power consumption.

Hereinafter, one embodiment of the present invention will be specifically described with reference to FIGS. 4 and 5.

In the figure, 1, 2, and 3 are submersible pump units.
The submersible pump units 1, 2 and 2, 3 are serially connected via lift pipes 4 and 5 of the required length, and the discharge port of the top submersible pump unit 1 is connected via a lift pipe 6. leading to the surface of the water. The lowermost submersible pump unit 3 has a submersible motor 3a and a pump main body 3b arranged on the same axis and integrally joined to each other, as shown in FIG.
A water intake port 3c is provided in the lower part of the pump main body 3b,
A strainer 3d is attached to this water intake port 3c.

The pump main body 3b has two consecutive pump casings 3e, 3f, and impellers 3g, 3h are provided in each pump casing 3e, 3f. Further, a valve case 3i having substantially the same shape as the pump casing 3e is joined to the upper part of the pump casing 3e, and a check valve 3k containing a valve plate 3j is provided in the valve case 3i.

On the other hand, the top and middle submersible pump units 1
and 2 accommodates submersible motors 1a and 2a in cylindrical motor cases 1b and 2b having inner diameters larger than the outer diameters of submersible motors 1a and 2a, respectively, and pump main bodies 1c and 2c in motor cases 1b. , 2b and protrudes from the upper part of them while maintaining liquid tightness. The pump body parts 1c and 2c are the same as the pump body part 3b of the submersible pump 3.

Further, the water pumping pipes 4 and 5 are connected to the bottoms of the motor cases 1b and 2b, so that the water sucked up through the water pumping pipes 4 and 5 is made to flow through the motor cases 1b and 2b.

In addition, water intake ports 1d and 2d are provided on the upper outer peripheral surfaces of the motor cases 1b and 2b. This water intake 1
d, 2d are formed by a plurality of intake pipes 1e..., 2e..., which are connected in series through the motor cases 1b, 2b, and a lower submersible pump unit 3, Check valves 1f..., 2f... are provided to prevent the water pumped from water pumping pipes 5, 4 from being discharged to the outside from water intake ports 2d, 1d, and openings on the tip side of each water intake pipe 1e..., 2e... Strainers 1g..., 2g... are attached to the parts.

Further, 7, 8, and 9 are water level detectors, which are submerged at water depth positions corresponding to the vicinity of the upper ends of each of the submersible pump units 1, 2, and 3, respectively.

The submersible motors 1a, 2a, 3a of each submersible pump unit 1, 2, 3 are connected to the water level detector 7,
The submersible pump units 1, 2, and 3 are controlled on and off by the water level detection signals 8 and 9, and even when the water level of the intake reservoir 10 reaches the lowest water level LWL, the submersible pump unit 3 at the lowest stage remains at the water level. The water level is located below the highest water level HWL.
Needless to say, in the case where the submersible pump unit 1 is lowered, the submersible pump unit 1 at the top stage is located below the water surface.

Next, the control procedure for each submersible pump unit 1, 2, and 3 will be explained.

When the water level of the water intake reservoir 10 is at the highest water level HWL and the water level detector 7 is outputting a high water level detection signal, only the submersible motor 1a is energized and only the submersible pump unit 1 is operated.

Next, when the water level of the water intake reservoir 10 drops to the intermediate water level MWL and the water level detection signal is not output from the water level detector 7 and the water level detection signal is output from the water level detector 8, the submersible motors 1a and 2a are energized. It is operated by two submersible pump units 1 and 2.

Furthermore, when the water level of the water intake pond 10 falls to the lowest water level LWL and the water level detection signals are not output from the water level detectors 7 and 8, and the water level detection signal is output from the water level detector 9, the submersible motors 1a, 2a, 3a is energized and operated by three submersible pump units 1, 2, and 3.

As is clear from the above explanation, according to the submersible pump device of the present invention, each submersible pump unit 1,
2 and 3 are stopped from the lower stage in response to the high water level detection signal obtained from the water level detectors 7 and 8, so it is difficult to use large equipment such as when controlling the speed of a submersible motor as in the past. Since no cost is required and only the minimum number of submersible pump units necessary to obtain the required head in accordance with water level fluctuations in the intake pond 10 are operated, power consumption can be significantly reduced. can.

In addition, submersible pump units 1 and 2 other than the lowest stage
Water intakes 1d and 2d are provided in each of the submersible pump units 2 and 3, respectively, so that when the submersible pump units 2 and 3 or the submersible pump unit 3 are stopped, water can be taken directly through the water intakes 1d or 2d. It is possible to avoid the resistance loss that occurs when suctioning through the inside.

Furthermore, a check valve 1 is provided at each of the water intake ports 1d and 2d.
Since the submersible pump systems 1 and 2 are provided with the submersible pump systems 1 and 2, there is no risk that the water sucked up through the submersible pump systems 1 and 2 will leak to the outside via the water intake ports 1d and 2d.

In the above embodiment, a case has been described in which three submersible pump systems 1, 2, and 3 are connected in series, but the number can be increased or decreased as appropriate depending on the water depth of the intake pond, the range of water level fluctuation, etc.

Alternatively, as shown in FIG. 6, the quay of the water intake pond 10 may be excavated and the submersible pump units 11, 12, and 13 may be installed at an angle.

Furthermore, the water level detectors 7, 8, and 9 in the above embodiments are ordinary ones that operate by detecting the presence of water.
The present invention is not particularly limited to such a device, and, for example, a water pressure detector or the like may be provided at the bottom of the intake pond to detect fluctuations in water level based on changes in water pressure.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the relationship between water level fluctuations in the intake pond and pump head, Figures 2 and 3 are characteristic diagrams showing the relationship between pump discharge volume and head, and Figure 4 is an illustration of the present invention. FIG. 5 is a sectional view of a submersible pump unit of the same embodiment, and FIG. 6 is a schematic diagram showing another embodiment of the present invention. 1, 2, 3... Submersible pump unit, 1d, 2
d, 3c... Water intake, 1f, 2f... Check valve, 4, 5
...Lifting pipe, 7, 8, 9...Water level detector.

Claims (1)

[Claims] 1. A plurality of submersible pump units are connected in series using lift pipes at predetermined intervals in the vertical direction, each of the above submersible pump units is provided with a water intake port, and at least the submersible pump units other than the lowest stage are connected in series. A check valve is provided at the water intake to prevent the water pumped from the lower submersible pump unit through the lift pipe from being discharged to the outside from the water intake, and the operation of each of the submersible pump units is controlled at the height obtained from the water level detector. A submersible pump device characterized by stopping from the lower stage side in response to a water level detection signal.