JPH05240200A - Siphon type pump - Google Patents

Abstract

PURPOSE:To shorten the time required for siphon formation and reduce the facility cost by providing a guide plate for guiding a water flow toward the upper surface side of a discharge piping in the lower stream side pipe from the top part of the discharge piping. CONSTITUTION:When a pump rotating shaft 6 is driven by a rotating driving device, the water in a sucking water passage is sucked by the rotation of an impeller 7. The water flowing down on the lower stream side over the top part 5a of a discharge piping 5 runs toward a discharge tank 4 while entangling the air remaining in the pipe. A part of the entangled air is separated from the water flow before it reaches the discharge tank 4, and tries to rise along the upper surface side 5b of the discharge piping. However, a part of the water flow guided by a guide plate 10 flows along the upper surface side 5b of the discharge piping, and this water entangles the air again and flows out toward the discharge tank 4. Thus, the internal air can be discharged within a short time, compared with a conventional passage to form a siphon, and the arrangement of a special vacuum pump is not required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a siphon type pump used when a large amount of waste water is discharged with a low head.

[0002]

2. Description of the Related Art As is well known, in a pump having a low head with a small water level difference between suction and discharge, the middle of the discharge pipe is located at a level higher than the maximum water level (HWL) and is arranged in a siphon shape. Often used as. In this siphon type pump, it is necessary to eliminate air in the siphon type discharge pipe at the time of starting to form a siphon. In this case, conventionally, the flow velocity in the discharge pipe is constant (at least 1 m / min).
(It is said to be s or more) so that residual air in the top of the discharge pipe is made to flow out, or an intake hole is formed at the top of the discharge pipe to use the residual air with a vacuum pump or the like. The method of forced discharge was adopted.

[0003]

However, of the above-mentioned siphon forming means at the time of starting the pump, the former one is so constructed that the residual air is drawn only by making the flow velocity equal to or higher than a certain level. Therefore, it takes a considerably long time, and the start of normal operation is delayed by that much. Especially, in the case of a large-capacity pump, if the set flow rate at the time of siphon formation is slow, it will be delayed by a dozen minutes. In the latter case, a vacuum pump or the like is required, which leads to an increase in equipment cost and an increase in the number of pump station components, resulting in a decrease in reliability of the entire system.

The present invention has been made in order to solve the above problems, and it is possible to shorten the time required for siphon formation and to reduce the equipment cost by eliminating the need for a vacuum pump or the like. It is intended to provide a pump.

[0005]

In order to achieve the above object, a siphon type pump of the present invention is a pump in which a discharge pipe is arranged in a siphon type, and flows in the pipe downstream of the top of the discharge pipe. The guide plate for guiding the water flow toward the upper surface side of the discharge pipe is provided.

The siphon type pump of the present invention is a pump in which the discharge pipe is arranged in a siphon shape, and a partition plate for partitioning the pipe flow passage into an upper surface side and a lower surface side is suitable from the top in the pipe downstream from the top of the discharge piping. The configuration is such that it is provided in the flow direction from a position that is a distance lower.

[0007]

With the above-described first configuration, the water flow that flows down beyond the top of the discharge pipe to the downstream side is directed toward the discharge tank that communicates with the lower end of the discharge pipe while entraining the air remaining in the pipe into the flow. A part of the water flow, which is guided by the guide plate, flows along the upper surface of the discharge pipe.

Therefore, the air that separates from the water flow before reaching the discharge tank and rises along the upper surface of the discharge pipe is caught in the water flow flowing along the upper surface of the discharge pipe and flows out toward the discharge tank. Therefore, the siphon can be formed by discharging the internal air in a shorter time as compared with the conventional flow path.

With the above-described second structure, the water flow that flows down beyond the top of the discharge pipe to the downstream side is directed toward the discharge tank that communicates with the lower end of the discharge pipe while entraining the air remaining in the pipe into the flow. Flowing. At this time, the water flow entraining air flows down separately into the upper surface side flow path and the lower surface side flow path partitioned by the partition plate, and the water flow flowing on the lower surface side than the partition plate ensures that the air flows to the discharge tank. Discharge.
Therefore, the siphon can be formed by discharging the internal air in a shorter time as compared with the conventional flow path.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, a suction pipe 3 opening to the water suction passage 2 is connected to one end of the pump casing 1, and a discharge pipe 5 extending to the discharge tank 4 is connected to the other end. A rotary shaft 6 is provided vertically penetrating the pump casing 1, and the rotary shaft 6 is driven by an external rotary drive device (not shown). Further, an impeller 7 is attached to the lower end side of the rotating shaft 6, and the rotating shaft 6 is provided with bearings 8 and 8 ′ at a position above and below the impeller 7.
Is supported by. Further, a fixed guide blade 9 is provided above the impeller 7 so as to be fixed to the pump casing 1.

The discharge pipe 5 is formed in a siphon shape with the top portion 5a in the middle thereof located at a level higher than the maximum water level (HWL) in the discharge tank 4, and a plurality of pipes are provided downstream of the top portion 5a. The guide plates 10 are arranged along the flow direction. Further, the guide plate 10 guides the water flow flowing in the pipe toward the upper surface side 5b of the discharge pipe 5,
It is inclined at an appropriate angle with respect to the pipe axis of the discharge pipe 5.
Further, a valve 11 for vacuum breaking is provided on the top portion 5a of the discharge pipe 5.
Is provided, and the valve 11 is operated to open when the pump is stopped to destroy the siphon.

The operation of the above structure will be described below. When the rotary shaft 6 is driven by the rotary drive device, the water in the water suction passage 2 is sucked up by the rotation of the impeller 7.
Then, the water flow that flows down to the downstream side beyond the top portion 5a of the discharge pipe 5 flows toward the discharge tank 4 that communicates with the lower end of the discharge pipe 5 while entraining the air remaining in the pipe into the flow. At this time, a part of the entrained air separates from the water stream before reaching the discharge tank 4, and tries to rise along the upper surface side 5b of the discharge pipe 5. However, a part of the water flow guided by the guide plate 10 flows along the upper surface side 5b of the discharge pipe 5, and this water flow re-engages the air and flows out toward the discharge tank 4. Therefore, the siphon can be formed by discharging the internal air in a shorter time as compared with the conventional flow path.

FIG. 3 shows another embodiment of the present invention. Members having the same functions as those of the previous embodiment are designated by the same reference numerals and the description thereof will be omitted. In FIG. 3, a partition plate 21 is provided in the pipe on the downstream side of the top portion 5a of the discharge pipe 5. This partition plate 21 has a flow path inside the pipe and a flow path 21 on the upper surface side.
It is divided into a and the lower surface side 21b, and is provided up to the vicinity of the opening in the direction of flow from a position a proper distance below the top 5a.

According to this structure, the top portion 5a of the discharge pipe 5 is
The water flow that passes over and flows down to the downstream side flows toward the discharge tank 4 that communicates with the lower end of the discharge pipe 5 while entraining the air remaining in the pipe into the flow. At this time, the water flow entrained with the air flows into the upper surface side flow passage 21 which is partitioned by the partition plate 21.
a and the lower surface side flow path 21b are separately flowed down, and the water flow flowing on the lower surface side from the partition plate discharges air by the high flow velocity.
Surely discharge up to. Therefore, the siphon can be formed by discharging the internal air in a shorter time as compared with the conventional flow path.

[0015]

As described above, according to the present invention, by providing the guide plate in the pipe, the air that is going to rise along the upper surface of the discharge pipe is caught in the water flow flowing along the upper surface of the discharge pipe and discharged. can do.

Further, by dividing the water flow entrained with air into the upper surface side flow path and the lower surface side flow path by the partition plate, the air can be reliably discharged to the discharge tank by the high flow velocity of the water flow flowing on the lower surface side. ..

Therefore, the siphon can be formed by discharging the internal air in a shorter time than the conventional flow path.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a pump according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of main parts in the same embodiment.

FIG. 3 is a cross-sectional view of essential parts in the same embodiment.

[Explanation of symbols]

 5 Discharge pipe 5a Top part 10 Guide plate 21 Partition plate

Claims (2)

[Claims] 1. A pump having a discharge pipe arranged in a siphon shape, wherein a guide plate for guiding a water flow flowing in the pipe toward the upper surface side of the discharge pipe is provided in the pipe downstream from the top of the discharge pipe. Siphon pump. 2. In a pump in which the discharge pipe is arranged in a siphon shape, a partition plate that divides the pipe flow passage into an upper surface side and a lower surface side is flowed into the pipe on the downstream side from the top portion of the discharge pipe from a position a proper distance below the top portion. A siphon pump characterized by being installed in the direction.