JPH04148098A - Method of operating horizontal shaft pump - Google Patents

Abstract

PURPOSE:To prevent the timing of start of water pump-up operation from being delayed, by standby-operating a pump driving prime-mover in a clutch turn-off condition until the water level of a pump-up water well comes to a water pump-up start level, and by fulling water in a pump through the operation of a water level raising means. CONSTITUTION:A pump driving prime-mover 14 is started and is standby-operated in a clutch 13 turn-off condition until the water level of a pump-up water well 1 comes to a water pump-up start level HWL from a lowest level LWL, and a vacuum pump 20 in a water level raising means 11 is started so that the prime-mover 14 performs a full speed standby operation in such a condition that the water level is raised up to a full water level HWL1 within the pump. Further, when the water level of the pump-up water level comes to the water pump-up start level, the clutch 13 is turned on so that a pump main shaft 12 and an impeller 3 are rotated so as to start discharging. With this arrangement, even in an emergency operation in which a large volume of water abruptly flows into the pump-up water well 1, it is possible to prevent the timing of start of water pump-up operation, thereby it is possible to prevent occurrence of a flood caused by abnormal rise of the water level of the pump-up water well 1.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a method of operating a horizontal shaft pump.

[Prior Art] Conventionally, in the suction type horizontal shaft pump installed in the pump suction well 1 of the drainage pump station shown in Fig. 2, when the water level in the suction well 1 reaches the pumping start water level HWL, This water level HWL is detected by the pressure switch 23 of the vacuum system 2 or a water level detection means (not shown), and the vacuum pump 20 is started based on this detection signal, and the suction pipe 4 disposed upstream of the impeller 3 The water inside the suction pipe 4 is sucked up to the level that reaches the impeller 3 in the pump casing 5, that is, the full water level HWL1, and after this state is detected by the full water detector 6, the full water detection is performed. Based on the signal, a pump driving prime mover (for example, a diesel engine) (not shown) is started to operate the pump (
An operating method is adopted in which the impeller 3 is rotated, and then the discharge valve 7 is fully opened to perform drainage operation (pumping operation).

[Problems to be Solved by the Invention] However, in the conventional operating method, after the water level in the water suction well l reaches the pumping start water level HWL, the vacuum pump 20 is started to create a high negative pressure inside the suction pipe 4. In addition, it takes time to fill the inside of the pump casing 5 with water, and it also takes time and effort to start the pump driving motor. Therefore, a relatively long waiting time (approximately 10 minutes) is required from the time the water level reaches the pumping start water level HWL until the water is actually drained. If trouble occurs, it will be extended further.

On the other hand, in recent years, the water retention function of geological formations has been declining due to an increase in paving ratio and a decrease in green areas due to the progress of urbanization. Moreover, since the amount of water flowing into the water absorption well 1 tends to increase, a situation in which a large amount of water suddenly flows into the water absorption well 1, such as a so-called flash flood, is likely to occur.

However, in the conventional horizontal shaft pump operation method, water intake well 1
Since a relatively long waiting time is required between the time when the water level reaches the pumping start water level HWL and the pumping operation starts, in an emergency when a large amount of water suddenly flows into the water intake well 1, There may be a delay in the start timing of pumping operation.

As described above, if the start timing of the pumping operation is delayed, the water level in the water intake well 1 may rise abnormally, leading to the occurrence of a flood.

Furthermore, even if a failure occurs in the pump driving prime mover, the pump body, the vacuum system 2, the discharge valve 7, etc.,
Pumping water when the water level of water absorption well 1 has reached the pumping start water level HWL (
The above-mentioned failure cannot be confirmed until a predetermined period of time has elapsed from the point at which drainage is required, and therefore, it may not be possible to properly drain water in an emergency.

The present invention was made in view of the above circumstances, and aims to provide a method for operating a horizontal shaft pump that can prevent flooding due to an abnormal rise in the water level of a water intake well, and can also confirm failures in advance. It is said that

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a horizontal shaft pump in which a clutch is interposed in a power transmission system that transmits the output of a pump driving prime mover to the horizontal shaft pump. Before the water level in the water suction well where the horizontal shaft pump is installed reaches the pumping start water level, the pump driving prime mover is put into standby operation with the clutch OFF, and the pump is filled with water by operating the water level leg raising means. Then, when the water level reaches the pumping start water level, the clutch is turned on to perform pumping operation.

[Operation] According to the present invention, until the water level of the water intake well reaches the pumping start water level from the lowest water level, the pump driving prime mover is put into standby operation with the clutch OFF, and the water level leg raising means is activated. Since the inside of the pump is kept full of water, pumping operation (drainage operation) can be started immediately by turning on the clutch when the water level in the water suction well reaches the pumping start water level.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, and the same or corresponding parts as in the conventional example shown in FIG. 2 are given the same reference numerals, and detailed explanation thereof will be omitted.

In FIG. 1, a pump main shaft 12 with an impeller 3 fixed to its tip is connected to an output shaft 14A of a pump driving prime mover (for example, a diesel engine) 14 via a clutch 13, and is located downstream of the discharge valve 7. The outlet of the discharge pipe 8 faces the water of a drainage channel (for example, a river) 9.

The vacuum system 2 includes a vacuum pump 20, an intake pipe 24 that communicates the intake side of the vacuum pump 20 with the impeller inlet 10 of the pump casing 5, and an intake pipe 24 that is interposed in series with the intake pipe 24 from the vacuum pump 20 side. It is composed of a valve 21 and a pressure switch 23, and the vacuum system 2 constitutes a water level raising means 11.

The water level leg raising means 11 raises the water level in the suction pipe 4 (the water level in the pump) not only when the discharge valve 7 is fully closed but also when it is fully opened, to a full water level at which the horizontal axis pump can drain water with its self-priming ability. HW
It has a function that can be raised to LI.

Specifically, when the discharge valve 7 is fully opened, a series of sealed spaces A formed from the water surface in the suction pipe 4 to the outlet of the discharge pipe 8 facing the water in the drainage channel 9 are made negative pressure, and the suction pipe 4 is
A vacuum pump 20 capable of suctioning and raising the water level in the tank up to the full water level HWL1 is assigned to the vacuum system 2. It is maintained properly by the operation control of 20.

Next, the operation of the above configuration will be explained.

(i) Until the water level of the water intake valve reaches the pumping start water level HWL from the lowest water level LWL, the pump drive prime mover 14 is started and put into standby operation with the clutch 13 in the OFF state, and the water level raising means 11 Activate. That is, the vacuum pump 20 is started. Further, the valve 21 may be left open.

(2) By the operation of the water level raising means 11 in (2) above, the water level in the suction pipe 4 is raised to the full water level HWLI. That is, the inside of the pump reaches the full water level HWLI.

■ Until the water level in the water suction well 1 reaches the pumping start water level HWL, the pump drive prime mover 14 is in full-speed standby operation while the pump is raised to the full water level HWLI by the operation of the water level raising means 11. It will be done.

(2) Turn on the clutch 13 when the water level in the water intake well 1 reaches the pumping start water level HWL. As a result, the pump main shaft 12
Then, the impeller 3 rotates and starts draining water. That is, as soon as the water level in the water suction well 1 reaches the pumping start water level HWL, pumping operation (drainage operation) is immediately performed.

In this way, as soon as the water level in the water intake well 1 reaches the pumping start water level HWL, the pumping operation is started immediately, so even in an emergency when a large amount of water suddenly flows into the water intake well 1, the pumping operation can be started immediately. Since there is no delay in the start timing, it is possible to reliably prevent flooding caused by an abnormal rise in the water level of the water intake well l.

In addition, even if a failure occurs in the pump body, the pump driving prime mover 14, the vacuum system 2, the discharge valve 7, etc., the failure will be resolved before the water level in the water intake well 1 reaches the pumping start water level HWL. Since this can be confirmed and dealt with, proper drainage is possible in an emergency, and the reliability of the drainage pump station can be improved.

It is also possible to confirm the failure at an earlier point in time by carrying out the operation (2) above at the lowest water level LWL with no swirl.

In the embodiment, the water level raising means 11 is operated by the vacuum system 2.
However, the present invention is not limited to the above-mentioned embodiment, and the water intake well l is configured to be airtight, and the pressure is set based on the pressure detection signal of the pressure switch 23. The high pressure of the value is indicated by multiple arrows P in FIG.
As shown in , the water level raising means 11 may be constituted by a compressed air supply system (not shown) that can apply a load to the water surface in the water absorption well 1.

[Effect of the invention] Since the present invention is configured as described above.

This produces the following effects.

In other words, when the water level in the water intake well reaches the pumping start water level,
Since the pump driving prime mover can immediately switch from standby operation to pumping operation (full-speed drainage operation), there is no delay in the start of pumping operation even in an emergency when a large amount of water suddenly flows into the water intake well. Therefore, it is possible to reliably prevent flooding caused by an abnormal rise in the water level of the water intake well, and
Even in the unlikely event that a failure occurs in the pump body, pump driving engine, vacuum system, discharge valve, etc., the failure will be confirmed and dealt with before the water level in the suction well reaches the pumping start water level. Therefore, proper drainage can be performed in an emergency, and the reliability of the drainage pump station can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of a conventional example. l...Water intake well 11...Water level raising means 13...Clutch 14...Pump drive prime mover HWL...Pumping start water level LWL...Lowest water level HWLl...Pump full water level

Claims (1)

[Claims] (1) In a horizontal shaft pump in which a clutch is interposed in the power transmission system that transmits the output of the pump driving prime mover to the horizontal shaft pump, the water level of the water intake well in which the horizontal shaft pump is installed reaches the pumping start water level. Before starting pumping, the pump drive prime mover is put into standby operation with the clutch OFF, and the inside of the pump is filled with water by operating the water level raising means, and when the water level reaches the pumping start water level, the clutch is turned ON to perform pumping operation. A method of operating a horizontal shaft pump characterized by the following.