JP2662666B2 - Operating method of vertical pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a vertical shaft pump, and more particularly to a method for operating a plurality of vertical shaft pumps installed in a suction well of a drainage station installed in a waterway or a rainwater pump facility. Related to driving method.

[0002]

2. Description of the Related Art Water flowing into a suction well of a drainage plant is
Water is often drained by the operation of a plurality of vertical shaft pumps arranged in the water intake well. In this case, a plurality of vertical shaft pumps are generally of the same type, and all the impellers of the pumps are all set at the same height and installed in a suction well to unify the drainage operable water level. Driving in the state. The drainable water level is a water level at which the drainage operation can be performed at a predetermined discharge rate (100% Q).

As described above, in the operation method in which a plurality of vertical pumps are installed with the same type and all the impeller positions are unified at the same height, the compatibility between the vertical pumps can be ensured. Or, in the event that a failure occurs, management of replacement parts to be replenished becomes easy. However, when the water level of the water intake well is lower than the water level at which the drainage operation is possible and the water level rises and reaches the water level at which the drainage operation is possible while all the vertical pumps are in the air operation (preceding standby operation), for example. At this point, the simultaneous drainage operation of all the vertical shaft pumps is started. In this case, if the total drainage amount of all the vertical shaft pumps is sufficiently larger than the amount of water flowing into the water intake well, the water level drops rapidly, and the operation is switched to the in-air operation again. That is, the in-air operation and the drainage operation may be repeated in a short cycle, which causes a problem of shortening the life of the pump.

As means for avoiding such a problem, there is a method in which a plurality of vertical shaft pumps having different height positions of the impellers are used, and the vertical operable pumps are operated with a difference in elevation in the operable water level. Conceivable. According to this operation method, a steep drop in the water level can be prevented by giving a time difference to the start timings of the drainage operation of the plurality of vertical pumps, so that the repetition cycle of the air operation and the drainage operation can be extended. However, in such an operation method, the compatibility between the vertical shaft pumps is lost, so that it is difficult to manage the replacement parts, and since the operation order is fixed, the operation time varies, and the vertical shaft pump having a higher order is used. There is a drawback in that a large difference occurs in the frequency of use of a low-rank vertical pump, which may hinder the life of a specific vertical pump.

[0005]

The problem to be solved is that a level difference is given to the operable water level of each vertical shaft pump so that there is a time difference in the start timing of the drainage operation. By extending the cycle,
The interchangeability between the vertical pumps is lost, making it difficult to manage replacement parts, and the operation order is fixed, increasing the frequency of use of specific vertical pumps, preventing their life from prolonging. If compatibility is ensured and replacement part management is facilitated, the water level in the water intake well drops rapidly, shortening the repetition cycle of aerial operation and drainage operation and shortening the life of the pump.

[0006]

According to the present invention, an opening / closing means is provided in a discharge system on the downstream side of an impeller of each of a plurality of vertical shaft pumps, and the positions of the impellers are set at the same height. Vertical shaft pumps are installed in the water intake wells, and air vent pipes provided with an open / close valve are provided in the discharge system on the upstream side of the open / close means of each vertical shaft pump. When the open / close means is closed, the vertical shaft pump is opened at the opening timing of the open / close valve. Each time difference is provided, and based on this time difference, the air pressure of the discharge system upstream of the opening / closing means and the suction system upstream of the impeller is applied to the water surface of the suction system, and the water surface rises to the water level at which the drainage operation is possible. In order to extend the life of the vertical pump by extending the repetition cycle of the air operation and the drainage operation, and to ensure the compatibility between the vertical pumps, replacement parts Tube Together with ease, achieving uniform uptime by changing the operating order, to achieve a purpose of avoiding the shortened life of a particular vertical shaft pump.

[0007]

According to the present invention, with the open / close means provided in the discharge system on the downstream side of the impeller of each vertical shaft pump closed, the air vent attached to the discharge system on the upstream side of the open / close means of each vertical shaft pump is closed. By giving a time difference for each vertical shaft pump to the valve opening timing of the pipe opening / closing valve, the air pressure of the discharge system upstream of the opening / closing means and the suction system upstream of the impeller is loaded on the water surface of the suction system based on this time difference. However, it is possible to prevent the water surface from rising to the operable water level for drainage. For this reason, it is possible to provide a time difference between the drainage operable water level arrival times of the vertical shaft pumps, that is, the drainage operation start timing. Further, by controlling the valve opening timing of the on-off valve, the time difference between the drain operation start timings can be set arbitrarily, and the drain operation start order can be set arbitrarily.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a vertical shaft pump to which an embodiment of the present invention is applied.
Multiple (eg, two) vertical pumps 2A, 2 of the same type
B is installed with the positions of the impellers 2a and 2b set to the same height. Suction systems 3A and 3B formed by suction casings are mounted upstream of the impellers 2a and 2b, and discharge systems 4A and 4B formed by discharge pipes are mounted downstream of the impellers 2a and 2b. 4
B is provided with opening / closing means 5. The opening / closing means 5 includes discharge valves 6A and 6B interposed in the middle of the discharge systems 4A and 4B, and flap valves 8A and 8B attached to outlets of the discharge systems 4A and 4B that open to the discharge well 7 adjacent to the water intake well 1. Is configured. Also, the discharge systems 4A, 4A on the upstream side
B, that is, air vent pipes 10A, 10B provided with on-off valves 9A, 9B are attached to the discharge systems 4A, 4B in the region between the discharge valves 6A, 6B and the impellers 2a, 2b. On-off valve 9A,
9B is constituted by, for example, a solenoid valve or a motor-operated valve.

Next, the operation will be described. For example, with the discharge valves 6A and 6B of the vertical shaft pumps 2A and 2B closed, the open / close valve 9A on the vertical shaft pump 2A side is opened, and the vertical shaft pump 2B is opened.
Side on-off valve 9B is closed. The water level of the water absorption well 1 is the impeller 2a. 2A, the suction system 3A
Rises at the same level as the water level of the water absorption well 1. That is, the discharge system 4A upstream of the discharge valve 6A and the suction system 3A upstream of the impeller 2a.
Is an air vent pipe 10A having an open / close valve 9A.
The air level is not applied to the water surface in the suction system 3A because it is in communication with the atmosphere through the air inlet, so that the water level in the suction system 3A rises at the same level as the water level in the water absorption well 1.
On the other hand, the discharge system 4B on the upstream side of the discharge valve 6B and the impeller 2b
The upstream suction system 3B constitutes the suction system 3B in accordance with the rise in the water level of the water absorption well 1 because the on-off valve 9B provided on the air vent pipe 10B is closed and the communication with the atmosphere is shut off. A gradually higher air pressure is applied to the water surface in the suction casing, and a rise in the water level is suppressed at a balance point with the air pressure. Therefore, the water level of the water absorption well 1 is the water level H at which the vertical pumps 2A and 2B can be drained.
By rising to WL, the suction system 3A of the vertical pump 2A
The water level in the tank also rises to the same level, at which point the discharge valve 6
When the valve A is opened, the vertical pump 2A starts the drainage operation. However, the water level in the suction system 3B of the vertical shaft pump 2B is suppressed from rising at a balance point with the air pressure lower than the water level HWL at which the drainage operation is possible for the above-described reason, so that the drainage operation is not performed. Even if a predetermined time has elapsed from this point, if the water level in the suction well 1 is at the level of the operable drainage water level HWL or higher, a valve opening signal is input to the on-off valve 9B to open the discharge valve 6B. Discharge system 4B on the upstream side
The suction system 3B on the upstream side of the impeller 2b communicates with the atmosphere via an air vent pipe 10B, and the load of air pressure on the water surface in the suction system 3B is eliminated, so that the water level in the suction system 3B is set to the on-off valve 9B. The water level of the water intake well 1 at the time when the valve opening signal is input, that is, the water level at which the drainage operation can be performed, HWL, or the level thereof rises at a stretch, and the vertical pump 2B also starts the drainage operation.

As described above, in a state where the discharge valves 6A and 6B provided in the discharge systems 4A and 4B on the downstream side of the impellers 2a and 2b of the vertical shaft pumps 2A and 2B are closed, each of the vertical shaft pumps 2A and 2B is closed.
A, 2B, discharge systems 4A upstream of the discharge valves 6A, 6B,
The vertical shaft pumps 2A, 2B are connected to the opening timings of the on-off valves 9A, 9B of the air vent pipes 10A, 10B attached to the 4B.
By providing a time difference for each B, the suction systems 3A, 3B are determined by the air pressures of the discharge systems 6A, 6B upstream of the discharge valves 6A, 6B and the suction systems 3A, 3B upstream of the impellers 2a, 2b based on the time difference. The water surface is drainable, and the operable water level HW
L can be suppressed from rising. for that reason,
Since the vertical pumps 2A and 2B, in which the positions of the impellers 2a and 2b are set at the same height, respectively, can have a time difference in the drainage operable water level arrival time, that is, the drainage operation start timing, a plurality of pumps can be drained at the same timing. Unlike the conventional operation method, which started operation, the aerial operation and drainage operation are not frequently repeated due to a sudden drop in the water level, but the repetition cycle is extended to extend the life of the pump Can be contributed to. In addition, the compatibility between pumps is ensured, and the management of replacement parts is facilitated. Further, by controlling the valve opening timing of the on-off valves 9A and 9B, the time difference between the drain operation start timings can be arbitrarily set, and the drain operation start order can be arbitrarily set, so that the operating time can be made uniform. By doing so, it is possible to avoid the disadvantage that the life of a specific vertical pump is shortened.

In the above embodiment, two vertical pumps 2A,
Although the description has been made using 2B, the present invention can be implemented even if three or more vertical shaft pumps are used, and the same operation and effect as those of the above embodiment can be obtained. Discharge valve 6
A and 6B are closed, but the flap valve 8A,
If 8B is submerged in the discharge well 7, the discharge valves 6A and 6B need not be closed. Further, a manual switching valve may be used as the opening / closing valves 9A and 9B, or a solenoid valve or an electric valve may be used similarly to the above embodiment, and a water level detecting means for detecting the water level of the water intake well 1 and a delay such as a timer may be used. The means may be used together to automatically set the time difference of the drain operation start timing and the drain operation start order.

[0012]

As described above, according to the present invention, the opening timing of the opening / closing valve of the air vent pipe has a time difference for each vertical pump, and the discharge system and the blade upstream of the opening / closing means are based on this time difference. The air pressure of the suction system on the upstream side of the vehicle is applied to the water surface of the suction system, and this water surface is suppressed from rising to the level at which the drain operation is possible. Since a time difference can be provided, the water level in the water intake well is prevented from dropping sharply, and the repetition cycle of aerial operation and drainage operation is extended to extend the life of the pumps and ensure compatibility between pumps Thus, management of replacement parts can be facilitated. Further, by controlling the valve opening timing of the on-off valve, the time difference between the drainage operation start timings can be set arbitrarily, and the drainage operation start order can be set arbitrarily. There are advantages such as the inconvenience of shortening the life of a specific vertical pump can be avoided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vertical shaft pump to which an embodiment of the present invention is applied.

[Explanation of symbols]

 Reference Signs List 1 water absorption well 2A vertical shaft pump 2B vertical shaft pump 2a impeller 2b impeller 3A suction system (suction casing) 3B suction system (suction casing) 4A discharge system 4B discharge system 9A open / close valve 9B open / close valve 10A air vent pipe 10B air vent pipe HWL drain operation Possible water level

Claims (1)

(57) [Claims] An opening / closing means is provided in a discharge system on the downstream side of an impeller of each of a plurality of vertical shaft pumps, and the positions of the impellers are set at the same height. An air vent pipe provided with an on-off valve is provided in the discharge system on the upstream side of the on-off means of each of the vertical pumps, and when the on-off means is closed, the valve opening timing of the on-off valve has a time difference for each of the vertical pumps. Based on the above, the air pressure of the discharge system on the upstream side of the opening / closing means and the suction system on the upstream side of the impeller is loaded on the water surface of the suction system so that the water surface is suppressed from rising to a drainable operable water level and operated. A method of operating a vertical shaft pump, characterized in that: