JP2673735B2 - Method for detecting operating condition of pump and method for supplying lubricating water to bearing of pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pump operating condition detection method and a pump bearing which are installed in, for example, a drainage station installed in a water channel and used for draining rainwater and the like. The present invention relates to a method of supplying lubricating water.

[Prior Art] For example, as a bearing for a vertical shaft pump, a ceramic bearing that is lubricated and cooled by self-lifting water and can continue stable operation is employed.

In this type of bearing, the dry operation is performed for a very short time immediately after the start of the pump, and after this short time elapses, lubrication and cooling are immediately performed by the self-lifting water, and stable operation is started. That is, in the ceramic bearing, the dry operation is limited to a short time.

On the other hand, with the rapid progress of urbanization, the inflow of rainwater to pumping stations installed in waterways is becoming large and rapid. In such a situation, even if the water level of the suction well at the drainage pump station drops below the pumping cutoff water level of the vertical shaft pump, the dry operation is continued, and the pre-standby operation and the air management operation that precede the operation state of the pump are performed. It is handled by doing.

In the vertical shaft pump used for the preceding standby operation and the air management operation, the dry operation will be continued for a long time,
During this time, lubrication water is not supplied to the bearing. Therefore, a ceramic bearing whose dry operation time is limited to a short time cannot be adopted for the vertical shaft pump that performs the preceding standby operation and the air management operation.

In order to solve such a problem, it is possible to supply lubricating water to the bearing from the outside, but in this case,
It is meaningless to continue supplying the lubricating water from the outside even though the pumping operation is in progress. Therefore, a method of supplying lubricating water to the bearing is adopted by measuring the water level of the water absorption well, and when the water level falls to a predetermined water level, that is, a water level lower than the pumping start water level of the vertical shaft pump. It had been.

[Problems to be Solved by the Invention] However, as described above, in the method of supplying lubricating water to the bearing based only on the water level lower than the pumping start water level of the suction well, the case where the water surface of the suction well is calm Since it is necessary to consider the case of undulation, it is usually necessary to set the supply stop water level of the lubricating water to a high value with a margin in consideration of the case of undulation.

However, according to such a control method, when the water surface is relatively calm, the lubricating water is supplied even during the pumping operation. In other words, it is not possible to accurately know the operating status of the pump, so that useless supply of lubricating water is continued for a long time, and useless water injection to the bearing cannot be omitted.

The present invention has been made in view of the above circumstances,
By effectively utilizing the fact that an air layer is formed between the pump impeller inlet and the pumping cutoff water level during air operation, a pump operating condition detection method capable of accurately detecting the operating condition of the pump, Another object of the present invention is to provide a method of supplying lubricating water to the bearing of the pump, which can accurately supply the lubricating water from the outside to the bearing and can suppress the supplied amount to the minimum necessary limit.

[Means for Solving the Problems] In order to achieve the above object, a first invention is that a pump during pumping operation is installed at a first detection position intermediate between a pumping cutoff water level specific to the pump and a pump impeller. The first terminal portion of the detection power supply circuit that uses pumped water as the current-carrying medium is arranged, and the second terminal portion is arranged at the second detection position in the pumping pipe higher than the pump impeller so that the self-pumped water during pumping operation can be obtained. Closing of the detection power supply circuit due to electrical conduction between the first terminal portion and the second terminal portion, which are electrically conducting media, and electrical conduction between the first terminal portion and the second terminal portion during air operation It is characterized in that the operating status of the pump is detected by opening the detection power supply circuit upon release.

A second aspect of the invention is to provide a bearing for a pump main shaft that is lubricated and cooled by self-pumping of a pump during pumping operation, and a lubricating water supply system that externally supplies lubricating noise and cooling water to the bearing. In a pump provided with, a first terminal portion of a detection power supply circuit, which uses the self-pumping water of the pump during pumping operation as an energizing medium, is arranged at a first detection position intermediate between the pumping cutoff water level unique to the pump and the pump impeller. In addition, by arranging the second terminal portion at a second detection position in the pumping pipe above the pump impeller, the self-pumping during the pumping operation is used as the current-carrying medium for the first terminal portion and the second terminal portion. When the detection power supply circuit is closed due to electrical continuity, the supply of lubricating water from the lubricating water supply system to the bearing is stopped, and the first operation is performed in the air.
It is characterized in that control is performed such that lubricating water is supplied from the lubricating water supply system to the bearing by opening the detection power supply circuit associated with the release of electrical connection between the terminal portion and the second terminal portion. .

[Operation] According to the first aspect of the present invention, during pumping operation, the self-pumped water of the pump is used as an energizing medium to electrically connect the first terminal portion and the second terminal portion of the detection power supply circuit to close the detection power supply circuit. On the other hand, during the air operation in which the water level has dropped to near the pumping cutoff water level, an air layer is formed between the pump impeller inlet and the pumping cutoff water level, and the detection power source uses the self-pumped water as a current-carrying medium. The electrical connection between the first terminal portion and the second terminal portion of the circuit is released and the detection power supply circuit is opened. By knowing such opening and closing of the detection power supply circuit, pumping operation and air It is possible to accurately detect the operation status of the pump such as medium operation regardless of the water surface status of the intake well.

According to the second aspect of the invention, the supply and stop of the lubricating water from the external lubricating water supply system to the bearing are controlled based on the accurate detection results of the pumping operation and the air operation as described above. In any of these operations, it is possible to maintain stable lubrication and cooling effects on the bearings and to continue stable pump operation, and it is possible to minimize the amount of lubricating water supplied from the outside.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a vertical shaft pump to which the present invention is applied. In the drawing, a main shaft 2 of the vertical shaft pump 1 is a bearing 4 fixed to a base portion of a guide vane 3A above an impeller 3 and a suction well 6 in a pumping pipe 5. Is rotatably supported by a bearing 8 fixed at substantially the same height level as the floor surface 7, and is rotationally driven by a prime mover (not shown).

The bearings 4 and 8 are each made of ceramics such as silicon carbide, and each has a lubricating water supply system 9
Is supplied with lubricating water for lubrication and cooling.

The lubrication water supply system 9 includes a lubrication water supply source 9A, a pipe 9B for communicating the lubrication water supply source 9A with the bearings 4 and 8, and a valve such as a solenoid valve or an electric ball valve provided in the pipe 9B. It is composed of 9C. Therefore, when the valve 9C is opened, the lubricating water is supplied from the lubricating water supply source 9A to the bearings 4 and 8, and when the valve 9C is closed, the supply of the lubricating water to the bearings 4 and 8 is stopped.

The first detection position 10 (for example, the pumping start water level HW) between the pumping cutoff water level LWL unique to the vertical shaft pump 1 and the inlet 3a of the impeller 3
The first terminal portion 12 faces the inside of the suction side casing 11 of (L), and the second terminal portion 14 faces the inside of the pumping pipe 5 at the upper second detection position 13 of the impeller 3. Then, the detection power supply circuit 1 in which the first and second terminal portions 12 and 14 use self-pumping water as a current-carrying medium
Connected to 5.

The output signal c from the detection power supply circuit 15 is input to the display 16 for display, and the detection power supply circuit 15 outputs the closing signal Sh for closing the valve 9C during the pumping operation in which the detection power supply circuit 15 is closed, The valve opening signal Op for opening the valve 9C is output during the air operation in which the circuit 15 is opened.

In addition, in this vertical pump 1, the minimum water level LWL peculiar to the pump that sucks air when the depth of the water intake port is less than this
The impeller 3 is arranged above the
An intake pipe 18 is provided below the inlet 3a, that is, in the impeller chamber, and an air-water switching intake valve 17 is interposed in the middle thereof. Therefore, when the water level drops to the minimum water level (pumping cutoff water level) LWL peculiar to the pump when the water level drops, the intake valve 17 is opened and air is sent to the inlet 3a of the impeller 3 to change from pumping operation to air operation. When switching and raising the water level, when the water level of the suction well 6 reaches the inlet 3a level HWL of the impeller 3,
The intake valve 17 is closed to switch from air operation to pumping operation while sucking up residual air.

The intake valve 17 is opened / closed by a water level gauge (not shown) that detects the pumping start water level HWL or the pumping cutoff water level LWL specific to the vertical pump and is based on a signal output from the intake valve 17 to the intake valve 17. .

Next, a method of detecting the operating state of the vertical shaft pump and a method of supplying lubricating water to the bearings 4 and 8 will be described.

In the operating condition of the vertical pump 1 in which the main shaft 2 is rotationally driven, if the water level of the suction well 6 is equal to or higher than the pumping start water level HWL, the intake valve 17 of the intake pipe 18 is closed and the impeller 3
The pumping operation is performed because the water is sucked up.
In this case, the first terminal portion 12 and the second terminal portion 14 are electrically conducted by using the self-pumping water as a current-carrying medium to close the detection power supply circuit 15. Therefore, the signal c output from here is input to the display 16. Then, by displaying the information, it is possible to know that the vertical shaft pump 1 is in the pumping operation.

On the other hand, the detection power supply circuit 15 outputs the valve closing signal Sh and the valve 9C
Is closed, so that the bearings 4 and 8 are lubricated and cooled by the self-lifted water sucked up by the impeller 3.

Even if the water level drops below the pumping start water level HWL by continuing the pumping operation, the closed state of the intake valve 17 is maintained until the pumping cutoff water level LWL drops, and the bearing 4, which is self-pumped, 8 is lubricated and cooled.

When the water level falls near the pumping cutoff water level LWL, the intake valve 17
Is opened and air is sent to the inlet 3a of the impeller 3 to switch from pumping operation to air operation. During this air driving,
Since the electrical connection between the first terminal portion 12 and the second terminal portion 14 using the self-pumped water as the current-carrying medium is released, the detection power supply circuit 15 is opened. As a result, the signal c input from the detection power supply circuit 15 to the display 16 is converted and displayed, and it can be known that the vertical pump 1 is operating in the air.

Further, the detection power supply circuit 15 outputs the valve opening signal Op, and the valve 9C
Is opened, the lubricating water is supplied from the lubricating water supply system 9 to the bearings 4, 8 to lubricate and cool the bearings 4, 8. Therefore, even if the vertical pump is switched to air operation and the bearings 4 and 8 are no longer lubricated due to self-pumping,
Lubrication is supplied by the lubricating water supplied from the lubricating water supply system 9, so that stable operation can be continued.

When the water level of the suction well 6 rises to reach the pumping start water level HWL by continuing the air operation, the pumping operation is switched to the above-described pumping operation as described above, and the bearings 4 and 8 are lubricated by the self-pumping.

As described above, since the bearings 5 and 8 are lubricated and cooled by the lubricating water supplied from the lubricating water supply system 9 during the air operation of the vertical shaft pump 1, the preparatory standby operation in which the dry operation is continued for a long time is performed. The ceramic bearings 5 and 8 can also be used for the vertical pump 1 that performs the air management operation.

Needless to say, the present invention can be applied not only to the vertical shaft pump 1 described in the above embodiment, but also to other pumps that can perform air operation.

The second detection position 13 may be higher than the outlet 3b of the impeller 3.

[Advantages of the Invention] Since the present invention is configured as described above, it has the effects described below.

According to the pump operating condition detection method of claim 1, during pumping operation, the first terminal portion and the second terminal portion of the detection power supply circuit are electrically conducted using the self-pumped water of the pump as a current-carrying medium. Then, the detection power supply circuit is closed, and the water level drops near the pumping cutoff water level to form an air layer between the pump impeller inlet and the pumping cutoff water level. The pumping operation is performed by knowing the open / closed state of the detection power supply circuit, such as the detection power supply circuit being closed by releasing the electrical continuity between the first terminal portion and the second terminal portion of the detection power supply circuit used as the energizing medium. This has the effect of being able to accurately detect the operating status of the pump, such as whether it is in operation or in the air, regardless of the water surface status of the intake well.

According to the method for supplying lubricating water to the bearing of the pump described in claim (2), it is possible to know whether the pump is in the pumping operation or in the air operation by opening and closing the detection power supply circuit. When pumping operation that can lubricate the bearing by pumping water, open the lubrication water supply system, and when operating in the air that cannot lubricate the bearing by self-pumping, open the lubrication water supply system and supply it from here. The lubricating water can lubricate and cool the bearing to continue stable operation. Therefore, the ceramic bearing can be adopted for the pump that performs the preceding standby operation and the air management operation, which has been impossible in the past, and the versatility can be improved. In addition, since the amount of lubricating water supplied to the bearing can be suppressed to a necessary minimum, it is possible to save the lubricating water and the power for supplying the lubricating water.

[Brief description of the drawings]

The drawings are schematic diagrams showing an embodiment of a vertical shaft pump to which the present invention is applied. 1 …… Pump (vertical shaft pump) 2 …… Main shaft 3 …… Impeller 3a …… Impeller inlet 3b …… Impeller outlet 4 …… Impeller inlet 4, 8 …… Bearing 9 …… Lubricating water supply System 10 …… First detection position 12 …… First terminal 13 …… Second detection position 14 …… Second terminal HWL …… Pump start water level LWL …… Pump cutoff water level

Claims (2)

(57) [Claims] 1. A first terminal portion of a detection power supply circuit, which uses the self-pumping water of the pump during pumping operation as an energizing medium, is arranged at a first detection position intermediate between the pumping cutoff water level specific to the pump and the pump impeller. , The second terminal portion is arranged at a second detection position in the pumping pipe above the pump impeller, and the self-pumping during the pumping operation is used as an electric medium to electrically connect the first terminal portion and the second terminal portion. The operating state of the pump is detected by closing the detection power supply circuit due to the continuous conduction and opening the detection power supply circuit due to the release of electrical continuity between the first terminal portion and the second terminal portion during air operation. A method for detecting the operating status of a pump, characterized in that 2. A bearing for a pump main shaft, which is lubricated and cooled by the pump itself during pumping operation, and a lubricating water supply system for externally supplying lubricating water for lubrication and cooling to the bearing. In the pump, at the first detection position intermediate between the pumping water cutoff level specific to the pump and the pump impeller, the first terminal portion of the detection power supply circuit using the self-pumping water of the pump during the pumping operation as an energizing medium is arranged. The two terminal portions are arranged at a second detection position in the pumping pipe above the pump impeller to electrically connect the first terminal portion and the second terminal portion using the self-pumping water during the pumping operation as a current-carrying medium. The supply of lubricating water from the lubricating water supply system to the bearing is stopped by closing the detection power supply circuit associated with the above, and the electrical continuity between the first terminal portion and the second terminal portion is released during air operation. By opening the detection power supply circuit Method of supplying lubricating water with respect to the bearing of the pump, which comprises carrying out the bearing from the water supply system to control so as to supply lubricating water.