JP6857081B2 - Pump monitoring device and pump monitoring method - Google Patents

Description

The present invention relates to a pump monitoring device and a pump monitoring method.

At the drainage pump station, air suction vortices and underwater vortices are generated as the liquid level in the suction water tank becomes lower due to the operation of the pump. The air suction vortex is a water flow generated from the liquid surface to the suction port. An underwater vortex is a water flow generated from the bottom of a suction tank to a suction port. These vortices are one of the causes of pump vibration and also cause deterioration of the installation floor.

Patent Document 1 discloses a pump facility in which an ultrasonic sensor including a transmitter and a receiver is arranged in a suction water tank so that an air suction vortex and an underwater vortex generated in the suction water tank can be detected. Further, Patent Document 1 also discloses that a fluid injection unit is arranged in a suction water tank and water is injected to destroy an air suction vortex and an underwater vortex.

Japanese Unexamined Patent Publication No. 2017-31948

In the pump equipment of Patent Document 1, a sensor for detecting a vortex is arranged in a suction water tank, and the liquid in the suction water tank contains a foreign substance. Therefore, the sensor may detect foreign matter, and the detection accuracy is low.

An object of the present invention is to provide a pump monitoring device capable of detecting a vortex generated in a suction water tank with high accuracy, and a pump monitoring method.

When the rotating shaft is driven to discharge the liquid in the suction water tank, a thrust load in the direction opposite to the liquid discharging direction acts on the rotating shaft. In the steady state where the air suction vortex and / or the underwater vortex is not generated, the total head of the pump is higher and the discharge amount is larger than in the vortex generation state where the air suction vortex and / or the underwater vortex is generated. Further, the fluctuation of the thrust load is small (generally constant) in the steady state and larger than that in the steady state in the vortex generation state. The present invention has been made based on such new findings.

The present invention is a pump monitoring device including a pump casing that penetrates from the installation floor to the suction water tank under the installation floor, and a rotary shaft that penetrates the pump casing and is arranged from the installation floor to the suction water tank side. A thrust sensor, which is arranged on a portion of the rotating shaft located on the installation floor and for detecting a thrust load acting on the rotating shaft, and a thrust sensor based on the detection result of the thrust sensor in the suction water tank. Provided is a pump monitoring device including a controller for determining whether or not a vortex is generated.

In the pump monitoring device of this aspect, since the thrust sensor directly detects the thrust load of the rotating shaft, the generation of a vortex that affects the thrust load of the rotating shaft can be detected with high accuracy. In addition, the controller can accurately determine whether or not a vortex is generated based on the detection result of the thrust sensor. Further, since the thrust sensor is arranged not in the suction water tank but on the installation floor, it will not be damaged by dirty liquid or mixed foreign matter.

In the first aspect, the first position is arranged on the outer peripheral portion of the pump casing located in the suction water tank and is closer to the pump casing, and the second position is farther from the pump casing than the first position. A movable vortex suppressing member and an operating member for moving the vortex suppressing member to the first position and the second position are provided, and the controller determines that a vortex has been generated in the suction water tank. The vortex suppressing member is moved by the operating member so that the fluctuation of the thrust load acting on the rotating shaft is small. According to this aspect, by moving the vortex suppressing member by the operating member to a position where the fluctuation of the thrust load acting on the rotating shaft becomes small, the vortex suppressing member can eliminate the vortex in the suction water tank or suppress the generation of the vortex. .. Therefore, the vibration of the pump and the deterioration of the installation floor can be effectively suppressed.

In the second aspect, a radial sensor for detecting a radial load acting on the rotating shaft is arranged in the pump casing, and the controller is based on the detection results of the thrust sensor and the radial sensor. , It is determined whether or not a vortex is generated in the suction water tank. According to this aspect, it is possible to accurately determine whether or not a vortex is generated in the suction water tank.

The controller determines whether or not a vortex is generated based on the fluctuation of the thrust load input from the thrust sensor.

A substrate arranged on a portion of the pump casing located on the installation floor so as to be located around the rotary shaft, and a bearing fixed to the substrate and rotatably supporting the rotary shaft are provided. The thrust sensor is arranged between the substrate and the pump casing. The thrust sensor is a load cell. According to this aspect, the thrust sensor can reliably receive the thrust load acting on the rotating shaft and detect it with high accuracy.

The pump includes an impeller fixed to the end of the rotating shaft on the suction water tank side, and the pump casing detects a pressure on the downstream side of the impeller in a liquid discharge direction by the impeller. A pressure sensor for the purpose is arranged, and the controller determines whether or not a vortex is generated in the suction water tank based on the detection results of each of the thrust sensor and the pressure sensor. Alternatively, the controller determines whether or not a vortex is generated in the suction water tank based on the detection results of the thrust sensor, the radial sensor, and the pressure sensor. According to this aspect, it is possible to accurately determine whether or not a vortex is generated in the suction water tank.

Further, in the present invention, the thrust load acting on the rotating shaft is detected by the thrust sensor arranged on the portion of the rotating shaft located on the installation floor, and the controller is under the installed floor based on the detection result of the thrust sensor. the occurrence of vortex in a suction water tank judgment, if it is determined that the vortex in said suction water tank occurs, the controller, as fluctuations in the thrust load is reduced which acts on the rotary shaft, the pump casing Provided is a pump monitoring method in which a vortex suppressing member movably arranged on the outer peripheral portion of the vortex suppressor is moved by an operating member.
Further, the thrust sensor arranged on the portion of the rotating shaft located on the installation floor detects the thrust load acting on the rotating shaft, and the radial sensor arranged in the pump casing detects the radial load acting on the rotating shaft. Provided is a pump monitoring method in which a controller determines whether or not a vortex is generated in a suction water tank under the installation floor based on the detection result of the thrust sensor and the detection result of the radial sensor.

In the present invention, since the thrust load of the rotating shaft is directly detected by the thrust sensor, the presence or absence of the generation of vortices in the suction water tank can be detected with high accuracy, and the controller can accurately determine. Further, since the thrust sensor is arranged not in the suction water tank but on the installation floor, it will not be damaged by dirty liquid or mixed foreign matter.

The cross-sectional view which shows the pump monitoring apparatus of 1st Embodiment of this invention. An enlarged cross-sectional view showing a part of FIG. FIG. 5 is a cross-sectional view showing the vortex suppression mechanism of FIG. The graph which shows the fluctuation of the thrust load in a steady state. A graph showing fluctuations in radial load in a steady state. The graph which shows the fluctuation of the pressure on the outlet side of the impeller in the steady state. The graph which shows the fluctuation of the thrust load in the vortex generation state. The graph which shows the fluctuation of the radial load in the vortex generation state. The graph which shows the fluctuation of the pressure on the outlet side of the impeller in the vortex generation state. The graph which analyzed the thrust load of FIG. 5A by FFT. The graph which FFT analyzed the radial load of FIG. 5B. The graph which FFT analyzed the outlet side pressure of the impeller of FIG. 5C. The cross-sectional view which shows the pump monitoring apparatus of 2nd Embodiment. An enlarged cross-sectional view showing a part of FIG. An enlarged cross-sectional view showing a part of FIG. 5A. The cross-sectional view which shows the pump monitoring apparatus of 3rd Embodiment. The cross-sectional view which shows the pump monitoring apparatus of 4th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment)
1 to 3 show a vertical shaft pump 10 equipped with a pump monitoring device 30 according to the first embodiment of the present invention. The vertical shaft pump 10 discharges a liquid such as rainwater that has flowed into the suction water tank 1 of the drainage pump station to the downstream side, and is installed on the installation floor 2 that covers the upper part of the suction water tank 1. The vertical shaft pump 10 includes a pump casing 12, a rotating shaft 22, and an impeller 25. The pump monitoring device 30 includes a thrust sensor 32 that detects the thrust load of the rotating shaft 22, and based on the detection result of the thrust sensor 32, an air suction vortex A and / or an underwater vortex B is generated in the suction water tank 1. Judge the presence or absence of.

(Overview of vertical pump)
As shown in FIG. 1, the pump casing 12 is arranged in the suction water tank 1 from above the installation floor 2 through the circular mounting hole 2a formed in the installation floor 2. The pump casing 12 includes a pumping pipe 13 arranged in the suction water tank 1 and a discharge pipe 19 fixed on the installation floor 2.

The pumping pipe 13 includes a straight pipe 14, a vane case 15, and a suction bell mouth 17. The straight pipe 14 is a pipe having a uniform diameter and extends downward from the inside of the mounting hole 2a. The vane case 15 is a substantially elliptical tubular pipe that bulges outward in the radial direction, and is connected to the lower end of the straight pipe 14. The suction bell mouth 17 is a substantially conical tubular pipe whose diameter is gradually increased downward, and is connected to the lower end of the vane case 15. The lower end opening of the suction bell mouth 17 is a suction port 18 for sucking the liquid in the suction water tank 1, and is arranged at a predetermined interval with respect to the bottom wall 1a of the suction water tank 1.

The discharge pipe 19 includes a discharge elbow 20 connected to the upper end of the pumping pipe 13 and a water pipe (not shown) arranged on the installation floor 2. The discharge elbow 20 is a bent pipe whose axis is curved by 90 degrees. The water pipe is a straight pipe having a straight axis. A flexible pipe (not shown) that can be deformed in the axial direction and the radial direction is interposed between the discharge elbow 20 and the water pipe.

The rotating shaft 22 penetrates the discharge elbow 20 and is arranged along the axis of the pumping pipe 13. The upper end of the rotating shaft 22 projects outward from the discharge elbow 20. Referring to FIG. 2, the portion of the discharge elbow 20 through which the rotating shaft 22 penetrates is liquidtightly sealed by the shaft sealing device 23.

The impeller 25 is fixed to the lower end of the rotating shaft 22 located inside the vane case 15 (on the suction water tank 1 side). A bearing casing 16 is arranged inside the vane case 15, and an impeller 25 is rotatably arranged under the bearing casing 16.

A transmission 27 having a clutch mechanism is connected to the upper end of the rotating shaft 22, and a drive motor 28 is connected to the transmission 27. When the rotary shaft 22 is rotated by the drive of the drive motor 28, the impeller 25 rotates integrally with the rotary shaft 22, and the liquid in the suction water tank 1 is discharged to the downstream side through the inside of the pump casing 12. ..

(State during pump operation)
When the liquid level in the suction water tank 1 is higher than that of the vane case 15, the flow of the liquid in the suction water tank 1 is slow, so that the air suction vortex A and / or the underwater vortex B as shown in FIG. 1 does not occur. When the liquid level in the suction water tank 1 is lower than the upper part of the vane case 15 due to the discharge, the flow of the liquid in the suction water tank 1 becomes high speed, so that an air suction vortex A and / or an underwater vortex B is generated.

4A to 4C show a thrust load acting on the rotating shaft 22 (FIG. 4A), a radial load acting on the rotating shaft 22 (FIG. 4B), and an impeller 25 in a steady state in which vortices A and B are not generated. The pressure acting on the outlet side of the (FIG. 4C) is shown. 5A to 5C show a thrust load acting on the rotating shaft 22 (FIG. 5A), a radial load acting on the rotating shaft 22 (FIG. 5B), and an impeller in a vortex-generating state in which the vortices A and B are generated. The pressure acting on the outlet side of 25 (FIG. 5C) is shown. In FIGS. 4A, 4B, 5A, and 5B, the vertical axis is the load and the horizontal axis is the time. In FIGS. 4C and 5C, the vertical axis is pressure and the horizontal axis is time. The thrust load is a load that acts on the rotating shaft 22 in the axial direction of the rotating shaft 22. The radial load is a load that acts on the rotating shaft 22 in the radial direction of the rotating shaft 22.

As shown in FIGS. 4A to 4C, in the steady state, only the liquid flows in the pump casing 12, so that the thrust load and the radial load acting on the rotating shaft 22 have a small fluctuation range (generally constant) and are stable. ing. Further, the pressure on the outlet side of the impeller 25 also has a small fluctuation range and is stable.

As shown in FIGS. 5A to 5C, in the vortex generation state, the vortices A and B create a two-phase flow of gas and liquid in the pump casing 12, so that the thrust load and the radial load acting on the rotating shaft 22 are large. fluctuate. The pressure on the outlet side of the impeller 25 also fluctuates greatly depending on the vortices A and B. Since the rotation frequency of the rotation shaft 22 is superposed with fluctuations having a period different from the rotation frequency, the thrust load, the radial load, and the outlet side pressure have large and complicated waveforms in the vortex generation state.

Specifically, in the vortex generation state, the thrust load, the radial load, and the displacement (increase / decrease) of the outlet side pressure per fixed time are larger than in the steady state. In particular, the thrust load in the vortex generation state fluctuates more than in the steady state even if the displacement is smoothed per fixed time. Then, in this vortex generation state, the total head of the vertical pump 10 is lower than in the steady state, and the discharge amount is smaller. Further, since the vibration of the vertical shaft pump 10 becomes large, the installation floor 2 also deteriorates.

6A and 6B are graphs obtained by FFT analysis (fast Fourier transform) of the thrust load and the radial load in the vortex generation state. Further, FIG. 6C is a graph obtained by FFT analysis of the axial vibration of the rotating shaft 22 in the vortex generation state. The vertical axis of FIGS. 6A to 6C is the load, and the horizontal axis is the frequency. The low cycle fluctuation component of FIGS. 6A to 6C is the thrust load acting on the rotating shaft 22. The 2n component of FIGS. 6A to 6C is a vibration component that is twice the rotation speed n generated by the generation of two continuous air suction vortices A and passing through the two vortices for each rotation of the impeller 25. Is. The component generated by the coupling of the drive motor 28 and the rotating shaft 22 as noise is very small as compared with the component caused by the vortices A and B. The nZ component of FIGS. 6A to 6C is a vibration component that is an integral multiple of the rotation speed n of the rotation shaft 22. The pipe vibration component of FIG. 6C is a vibration component transmitted from the pump casing 12.

As the liquid level in the suction water tank 1 decreases, a 2n component appears in the thrust load and grows. Further, when the liquid level drops, two continuous air suction vortices A are generated on the downstream side of the pump casing 12 in the liquid inflow direction. It is known that the growth of the 2n component of the thrust load is caused by the generation of two continuous air suction vortices A due to the decrease in water level and the passage through the two vortices A for each rotation of the impeller 25. To.

With reference to FIGS. 6A and 6B together with FIGS. 5A and 5B, the thrust load has a clearer state of generation of vortices A and B than the radial load. Radial loads are inferior to thrust loads in terms of detecting load components due to vortex generation. This is because noise such as vibration of the drive motor 28 is added to the radial vibration. Referring to FIG. 5C, the pressure on the outlet side of the impeller 25 also fluctuates greatly depending on the vortices A and B, but unlike the thrust load, the 2n component is small.

As shown in FIG. 6C, the axial vibration of the rotating shaft 22 is noisy because the 2n component, the piping vibration component, and the vibration of another machine (drive motor 28) are added. Therefore, the configuration for detecting the axial vibration of the rotating shaft 22 in order to determine whether or not the vortices A and B are generated in the suction water tank 1 is not optimal.

As described above, the thrust load has a clear difference (fluctuation) between the detected values of the steady state and the vortex generation state as compared with the radial load, the pressure on the outlet side of the impeller 25, and the axial vibration of the rotating shaft 22. Occurs. Therefore, by directly measuring the thrust load of the rotating shaft 22, data with little error can be obtained regarding the presence or absence of the occurrence of vortices A and B. Further, it is possible to easily determine whether or not the vortices A and B are generated from the fluctuation (magnitude of displacement) of the thrust load of the rotating shaft 22. The present invention has been made based on such new findings.

Specifically, the vertical pump 10 of the present embodiment is equipped with a pump monitoring device 30 in order to detect the generation of vortices A and B. Further, a vortex suppression mechanism 40 is mounted in order to eliminate the generated vortices A and B or suppress the generation of the vortices A and B.

(Overview of pump monitoring device)
As shown in FIGS. 1 and 2, the pump monitoring device 30 has a thrust sensor 32 arranged on a portion of the rotating shaft 22 located on the installation floor 2, and vortices A and B based on the detection results of the thrust sensor 32. A controller 38 for determining the presence or absence of the occurrence of

The discharge elbow 20 is provided with an annular pedestal 33 having the same axis as the axis of the rotating shaft 22. Above the pedestal 33, an annular substrate 34 is bolted so as to surround the rotation shaft 22. A gap at a predetermined interval is formed between the pedestal 33 and the substrate 34. A ball bearing 35 that rotatably supports the rotating shaft 22 via a sleeve 36 is arranged on the inner peripheral portion of the substrate 34. The ball bearing 35 and the rotating shaft 22 are attached so as not to move relatively along the axial direction of the rotating shaft 22.

The thrust sensor 32 is arranged in the gap between the substrate 34 and the pedestal 33. One end of the thrust sensor 32 is fixed to the pedestal 33, and the other end of the thrust sensor 32 is fixed to the substrate 34. As a result, the thrust sensor 32 is arranged so as to be relatively rotatable with respect to the rotating shaft 22 and immovable in the axial direction of the rotating shaft 22. A load cell having a pair of strain gauges is used for the thrust sensor 32. When a load in the direction along the rotating shaft 22 is applied to the thrust sensor 32, the strain gauge is deformed, and the resistance value of the strain gauge changes according to the amount of the deformation. As a result, the load cell outputs a voltage according to the amount of change in the resistance value.

The controller 38 is electrically connected to the drive motor 28 and the thrust sensor 32. A personal computer can be used for the controller 38. The controller 38 controls the drive motor 28 to execute the discharge process of the liquid in the suction water tank 1. Further, the controller 38 controls the thrust sensor 32 and determines whether or not the vortices A and B are generated based on the fluctuation of the input voltage (detection result) from the thrust sensor 32.

Specifically, the controller 38 includes a storage unit (not shown) for storing a control program and data. Further, in this storage unit, a program (function) for analyzing the frequency of the thrust load acting on the rotating shaft 22 and monitoring the nZ component and the 2n component of the rotation speed of the rotating shaft 22 is stored. Further, the storage unit stores an upper limit value Lu and a lower limit value Ll for determining whether or not the vortices A and B are generated. The upper limit value Lu is larger than the upper limit value of the input voltage in the steady state, and the lower limit value Ll is smaller than the lower limit value of the input voltage in the steady state.

When the controller 38 executes the discharge process, a thrust load acts on the rotating shaft 22 in the direction opposite to the liquid discharge direction (upward in the pumping pipe 13) (downward in FIG. 1). This thrust load is transmitted to the substrate 34 via the ball bearing 35. Therefore, a downward load corresponding to the thrust load of the rotating shaft 22 is applied to the thrust sensor 32.

As described above, in the steady state in which the vortices A and B are not generated, only the liquid flows in the pump casing 12, so that the load applied to the thrust sensor 32 is substantially constant (see FIG. 4A). On the other hand, in the vortex generation state, since gas and liquid flow in the pump casing 12, the load applied to the thrust sensor 32 fluctuates (see FIG. 5A).

If the voltage input from the thrust sensor 32 is within the range of the upper limit value Lu and the lower limit value Ll, the controller 38 determines that the vortices A and B are not generated. Further, the controller 38 determines that the vortices A and B have been generated when the voltage input from the thrust sensor 32 exceeds the range of the upper limit value Lu and the lower limit value Ll. That is, if the fluctuation of the thrust load is small, it is determined that the vortices A and B are not generated, and if the fluctuation of the thrust load is large, it is determined that the vortices A and B are generated.

The pump monitoring device 30 as described above is configured to directly detect the thrust load acting on the rotating shaft 22 by the thrust sensor 32. Therefore, the generation states of the vortices A and B that affect the rotation of the rotating shaft 22 can be detected with high accuracy. Further, the controller 38 can accurately determine whether or not the vortices A and B are generated based on the detection result of the thrust sensor 32.

Further, since the thrust sensor 32 is arranged not in the suction water tank 1 but on the installation floor 2, it will not be damaged by a dirty liquid or a mixed foreign matter. Of course, the thrust sensor 32 does not erroneously detect due to the influence of foreign matter. Then, when the controller 38 determines that the vortices A and B have been generated in the suction water tank 1, the vortices A and B generated by the vortex suppressing mechanism 40 can be extinguished or the generation of the vortices can be suppressed.

(Outline of vortex suppression mechanism)
As shown in FIGS. 1 and 3, the vortex suppressing mechanism 40 includes a vortex suppressing member 42 arranged on the lower outer peripheral portion of the pumping pipe 13, a mounting frame 44 for movably mounting the vortex suppressing member 42, and a mounting frame 44. It is provided with an operating member 49 for moving the vortex suppressing member 42.

The vortex suppressing member 42 is a member having a circular shape in a plan view extending vertically along the axis of the pumping pipe 13 from the lower part of the suction bell mouth 17 to the upper part of the vane case 15. The vortex suppressing member 42 may be hollow or solid. Four vortex suppressing members 42 are arranged with respect to the mounting frame 44 at intervals in the circumferential direction. Referring to FIG. 3, the vortex suppressing member 42 has a first position (two on the left side in FIG. 3) closer to the outer peripheral portion of the pumping pipe 13 and a second position separated from the outer peripheral portion of the pumping pipe 13 than the first position. It is movably held by the operating member 49 at two positions (two on the right side in FIG. 3).

Similar to the vortex suppressing member 42, the mounting frame 44 is provided from the lower part of the suction bell mouth 17 to the upper part of the vane case 15. The mounting frame 44 includes a horizontal frame member 45, a vertical frame member 46, and a connecting member 47.

The horizontal frame member 45 is an annular pipe centered on the axis of the pumping pipe 13, and is fixed to the upper outer peripheral portion of the suction port 18 of the suction bell mouth 17.

The vertical frame member 46 is a straight pipe having a lower end joined to the horizontal frame member 45 and arranged along the axis of the pumping pipe 13 toward the upper part of the vane case 15. The vertical frame member 46 is made of a rigid body (metal) that is not deformed by a load due to the inflow of liquid into the suction water tank 1 and a load from the movable vortex suppressing member 42. The vertical frame members 46 are arranged in the same number as the vortex suppressing members 42 (four in the present embodiment) at intervals in the circumferential direction with respect to the horizontal frame members 45. A predetermined portion of the vertical frame member 46 may be fixed to the vane case 15 or the suction bell mouth 17.

The connecting member 47 connects the vortex suppressing member 42 to the vertical frame member 46 so as to be rotatable, that is, to connect the vortex suppressing member 42 to the pumping pipe 13 so as to be able to rotate in the horizontal direction. It is placed in a place. The connecting member 47 includes a tubular member 47a rotatably attached to the vertical frame member 46, and an arm 47b protruding radially outward from the tubular member 47a. A vortex suppressing member 42 is joined to the tip of the arm 47b. The total length of the arm 47b is set to a dimension arranged at the second position set by the vortex suppressing member 42.

As shown in FIG. 3, the operating member 49 individually moves the vortex suppressing member 42 to the first position and the second position. The operating member 49 of the present embodiment is composed of a hydraulic or atmospheric pressure type cylinder. The cylinder body 50 is rotatably connected to a bracket 52 fixed to the vertical frame member 46. The rod 51 is rotatably connected to a bracket 53 fixed to the vortex suppressing member 42. One end of a flexible and pressure resistant tube (not shown) is connected to the cylinder body 50. The other end of this tube is connected to a drive unit (pump) 55 arranged on the installation floor 2.

A controller 38 is electrically connected to the drive unit 55. The drive unit 55 is controlled by the controller 38 to drive the operating member 49 and move the vortex suppressing member 42 to a predetermined position between the first position and the second position. Specifically, the vortex suppressing member 42 is pressed by advancing the rod 51, the vortex suppressing member 42 is rotated with respect to the vertical frame member 46, and the vortex suppressing member 42 is moved toward the first position. Further, the vortex suppressing member 42 is pulled by retracting the rod 51, the vortex suppressing member 42 is rotated with respect to the vertical frame member 46, and the vortex suppressing member 42 is moved toward the second position. The vortex suppressing member 42 is held at the position moved by the operating member 49.

The controller 38 drives the drive unit 55 to move the vortex suppressing member 42 to the region where the air suction vortex A is generated. Specifically, the controller 38 vortexes so that the fluctuation of the thrust load acting on the rotating shaft 22 becomes small, that is, the input voltage from the thrust sensor 32 is within the range of the upper limit value Lu and the lower limit value Ll. The restraining member 42 is moved.

When the air suction vortex A disappears or the generation of the air suction vortex A is suppressed, the inside of the suction water tank 1 is restored to a steady state, so that the fluctuation of the thrust load acting on the rotating shaft 22 becomes small and stable. Therefore, by moving the vortex suppressing member 42 so that the fluctuation of the input voltage from the thrust sensor 32 becomes small, the air suction vortex A can be effectively extinguished and the generation of the air suction vortex A can be effectively suppressed. it can. As a result, the vibration of the vertical shaft pump 10 and the deterioration of the installation floor 2 can be effectively suppressed.

The vortex suppressing member 42 does not float following the water level in the suction water tank 1, but is rotatably attached to the pumping pipe 13 in the horizontal direction and is held in a predetermined position by the operating member 49. Therefore, since the position of the vortex suppressing member 42 is not affected by the liquid level in the suction water tank 1, the generation of the air suction vortex A at a position radially outward from the pumping pipe 13 is effectively suppressed by the vortex suppressing member 42. it can.

(Second Embodiment)
7 to 8B show a vertical shaft pump 10 equipped with the pump monitoring device 30 of the second embodiment. The pump monitoring device 30 of the second embodiment is different from the first embodiment in that a radial sensor 60 for detecting a radial load acting on the rotating shaft 22 is arranged in a vane case 15 of the vertical shaft pump 10. ..

As shown in FIGS. 8A and 8B, the radial sensor 60 is arranged in the sensor case 62, and is arranged in the lower part of the bearing casing 16 via the sensor case 62. The sensor case 62 includes a case main body 63 having an opening at the lower end and a cover 64 covering the opening of the case main body 63. The sensor case 62 is fixed by bolts in the recess 58 formed in the bearing casing 16. Inside the sensor case 62, an underwater bearing 65 that rotatably supports the rotating shaft 22 and an annular support member 66 are arranged.

The support member 66 is arranged on the radial outer side of the underwater bearing 65. The inner diameter of the support member 66 is larger than the outer diameter of the underwater bearing 65, and the outer diameter of the support member 66 is smaller than the inner diameter of the case body 63. Bolts 67 are attached to the support member 66 so as to penetrate from the inside to the outside in the radial direction. The support member 66 is positioned in the case body 63 by bringing the tip of the bolt 67 into contact with the inner peripheral surface of the case body 63.

Two radial sensors 60 are arranged in the gap between the underwater bearing 65 and the support member 66. Referring to FIG. 8B, the pair of radial sensors 60, 60 are arranged at intervals of 90 degrees in the circumferential direction about the axis of the rotating shaft 22. One end of the radial sensor 60 is fixed to the underwater bearing 65, and the other end of the radial sensor 60 is fixed to the support member 66. Like the thrust sensor 32, the radial sensor 60 is composed of a load cell having a pair of strain gauges. The radial sensor 60 may be configured by a piezo type (piezoelectric type) load cell.

A radial sensor 60 is electrically connected to the controller 38. The storage unit of the controller 38 stores a second upper limit value and a second lower limit value for determining whether or not the vortices A and B are generated. The second upper limit value is larger than the upper limit value of the radial sensor 60 in the steady state, and the second lower limit value is smaller than the lower limit value of the radial sensor 60 in the steady state. The controller 38 determines whether or not vortices A and B are generated in the suction water tank 1 based on the detection results of the thrust sensor 32 and the radial sensor 60.

Specifically, in the controller 38, the input voltage from the thrust sensor 32 is within the range of the first upper limit value and the first lower limit value, and the input voltage from the radial sensor 60 is within the range of the second upper limit value and the second lower limit value. If so, it is determined that the vortices A and B have not been generated. Further, in the controller 38, the input voltage from the thrust sensor 32 exceeds the range of the first upper limit value and the first lower limit value, or the input voltage from the radial sensor 60 exceeds the range of the second upper limit value and the second lower limit value. Then, it is determined that the vortices A and B have been generated. Of course, when both the input voltage from the thrust sensor 32 and the input voltage from the radial sensor 60 exceed the range of the upper limit value and the lower limit value, it may be determined that the vortices A and B have been generated.

In the pump monitoring device 30 of the second embodiment as described above, the thrust sensor 32 directly detects the thrust load acting on the rotating shaft 22, and the radial sensor 60 directly detects the radial load acting on the rotating shaft 22. Therefore, the generation states of the vortices A and B that affect the rotation of the rotating shaft 22 can be detected with higher accuracy. Further, the controller 38 can accurately determine whether or not vortices A and B are generated based on the detection results of the thrust sensor 32 and the radial sensor 60.

(Third Embodiment)
FIG. 9 shows a vertical shaft pump 10 equipped with the pump monitoring device 30 of the third embodiment. The pump monitoring device 30 of the third embodiment is different from the first embodiment in that a pressure sensor 70 for detecting the outlet pressure of the impeller 25 is arranged in the vane case 15 of the vertical shaft pump 10.

The pressure sensor 70 is fixed so as to penetrate the vane case 15 so that the detection unit is located in the pump casing 12. The detection unit of the pressure sensor 70 is located at the upper end of the impeller 25 in the axial direction of the pumping pipe 13. The pressure sensor 70 can be any of a resistance wire type, a capacitance type, a mechanical type, and the like as long as it can detect the pressure on the outlet side of the impeller 25. The pressure sensor 70 may be fixed so as to penetrate the straight pipe 14, and its arrangement position may be on the downstream side of the impeller 25 in the liquid discharge direction.

A pressure sensor 70 is electrically connected to the controller 38. The storage unit of the controller 38 stores a third upper limit value and a third lower limit value for determining whether or not vortices A and B are generated. The third upper limit value is larger than the upper limit value of the pressure sensor 70 in the steady state, and the third lower limit value is smaller than the lower limit value of the pressure sensor 70 in the steady state. The controller 38 determines whether or not vortices A and B are generated in the suction water tank 1 based on the detection results of the thrust sensor 32 and the pressure sensor 70.

Specifically, in the controller 38, the input voltage from the thrust sensor 32 is within the range of the first upper limit value and the first lower limit value, and the input voltage from the pressure sensor 70 is within the range of the third upper limit value and the third lower limit value. If so, it is determined that the vortices A and B have not been generated. Further, in the controller 38, the input voltage from the thrust sensor 32 exceeds the range of the first upper limit value and the first lower limit value, or the input voltage from the pressure sensor 70 exceeds the range of the third upper limit value and the third lower limit value. Then, it is determined that the vortices A and B have been generated. Of course, when both the input voltage from the thrust sensor 32 and the input voltage from the pressure sensor 70 exceed the range of the upper limit value and the lower limit value, it may be determined that the vortices A and B have been generated.

In the pump monitoring device 30 of the third embodiment as described above, the thrust sensor 32 directly detects the thrust load acting on the rotating shaft 22, and the pressure sensor 70 detects the pressure on the outlet side of the impeller 25. Therefore, the generation states of the vortices A and B that affect the rotation of the rotating shaft 22 can be detected with higher accuracy. Further, the controller 38 can accurately determine whether or not the vortices A and B are generated based on the detection results of the thrust sensor 32 and the pressure sensor 70.

(Fourth Embodiment)
FIG. 10 shows a vertical shaft pump 10 equipped with the pump monitoring device 30 of the fourth embodiment. In the pump monitoring device 30 of the third embodiment, both the radial sensor 60 of the second embodiment and the pressure sensor 70 of the third embodiment are arranged in the pump casing 12 in the vane case 15 of the vertical shaft pump 10. In that respect, it differs from the first embodiment.

The controller 38 determines whether or not vortices A and B are generated in the suction water tank 1 based on the detection results of the thrust sensor 32, the radial sensor 60, and the pressure sensor 70. Specifically, in the controller 38, the input voltage from the thrust sensor 32 is within the range of the first upper limit value and the first lower limit value, and the input voltage from the radial sensor 60 is within the range of the second upper limit value and the second lower limit value. If the input voltage from the pressure sensor 70 is within the range of the third upper limit value and the third lower limit value, it is determined that the vortices A and B are not generated. Further, in the controller 38, the input voltage from the thrust sensor 32 exceeds the range of the first upper limit value and the first lower limit value, or the input voltage from the radial sensor 60 exceeds the range of the second upper limit value and the second lower limit value. Or, when the input voltage from the pressure sensor 70 exceeds the range of the third upper limit value and the third lower limit value, it is determined that the vortices A and B have been generated. Of course, when the input voltage from the thrust sensor 32, the input voltage from the radial sensor 60, and the input voltage from the pressure sensor 70 all exceed the range of the upper limit value and the lower limit value, the vortices A and B are said to have occurred. You may judge.

In the pump monitoring device 30 of the fourth embodiment as described above, the thrust sensor 32 directly detects the thrust load acting on the rotating shaft 22, and the radial sensor 60 directly detects the thrust load acting on the rotating shaft 22, and the pressure. The pressure on the outlet side of the impeller 25 is detected by the sensor 70. Therefore, the generation states of the vortices A and B that affect the rotation of the rotating shaft 22 can be detected with higher accuracy. Further, the controller 38 can accurately determine whether or not vortices A and B are generated based on the detection results of the thrust sensor 32, the radial sensor 60, and the pressure sensor 70.

The pump monitoring device 30 and the pump monitoring method of the present invention are not limited to the configuration of the above embodiment, and various changes can be made.

For example, the rotating shaft 22 may be rotatably supported by a thrust pad bearing or a tilting pad bearing instead of the ball bearing 35. In this case, the thrust sensor 32 may be arranged between the annular substrate of the thrust pad bearing or the tilting pad bearing and the pump casing.

The mechanism for moving the vortex suppressing member 42 to the first position and the second position can be changed as needed. Further, the operating member 49 and the driving unit 55 can also be changed according to the mechanism for moving the vortex suppressing member 42.

The pump in which the pump monitoring device 30 is arranged is not limited to the vertical axis pump 10, and may be a horizontal axis pump in which the rotating shafts are arranged sideways.

1 ... Suction water tank 1a ... Bottom wall 2 ... Installation floor 2a ... Mounting hole 10 ... Vertical pump 12 ... Pump casing 13 ... Pumping pipe 14 ... Straight pipe 15 ... Vane case 16 ... Bearing casing 17 ... Suction bell mouth 18 ... Suction port 19 ... Discharge pipe 20 ... Discharge elbow 22 ... Rotating shaft 23 ... Shaft sealing device 25 ... Impeller 27 ... Transmission 28 ... Drive motor 30 ... Pump monitoring device 32 ... Thrust sensor 33 ... Pedestal 34 ... Board 35 ... Ball bearing 36 ... Sleeve 38 ... Controller 40 ... Swirl suppression mechanism 42 ... Swirl suppression member 44 ... Mounting frame 45 ... Horizontal frame member 46 ... Vertical frame member 47 ... Connecting member 47a ... Cylinder member 47b ... Arm 49 ... Acting member 50 ... Cylinder body 51 ... Rod 52 ... Bracket 53 ... Bracket 55 ... Drive 58 ... Recess 60 ... Radial sensor 62 ... Sensor case 63 ... Case body 64 ... Cover 65 ... Underwater bearing 66 ... Support member 67 ... Bolt 70 ... Pressure sensor

Claims (10)

A pump casing that penetrates from above the installation floor to the suction water tank under the installation floor,
A pump monitoring device including a rotating shaft that penetrates the pump casing and is arranged from the installation floor to the suction water tank side.
A thrust sensor, which is arranged on a portion of the rotating shaft located on the installation floor and for detecting a thrust load acting on the rotating shaft,
A controller for determining the presence or absence of the occurrence of vortex in the suction water tank based on a detection result of the thrust sensor,
Vortex suppression that is arranged on the outer peripheral portion of the pump casing located in the suction water tank and can move to a first position closer to the pump casing and a second position separated from the pump casing than the first position. Parts and
E Bei an actuating member for moving the vortex suppressing member to the first position and the second position,
When the controller determines that a vortex has been generated in the suction water tank, the pump monitoring device moves the vortex suppressing member by the operating member so that the fluctuation of the thrust load acting on the rotating shaft becomes small. The pump monitoring device according to claim 1, wherein the controller determines the presence or absence of vortex generation based on fluctuations in the thrust load input from the thrust sensor. A substrate arranged on a portion of the pump casing located on the installation floor so as to be located around the rotation axis.
A bearing that is fixed to the substrate and rotatably supports the rotating shaft is provided.
The pump monitoring device according to claim 1 or 2, wherein the thrust sensor is arranged between the substrate and the pump casing. The pump monitoring device according to any one of claims 1 to 3 , wherein the thrust sensor is a load cell. A radial sensor for detecting a radial load acting on the rotating shaft is arranged in the pump casing.
The pump monitoring device according to any one of claims 1 to 4 , wherein the controller determines whether or not a vortex is generated in the suction water tank based on the detection results of the thrust sensor and the radial sensor. A pump casing that penetrates from above the installation floor to the suction water tank under the installation floor,
With the rotating shaft arranged from the installation floor to the suction water tank side through the pump casing.
A pump monitoring device equipped with
A thrust sensor, which is arranged on a portion of the rotating shaft located on the installation floor and for detecting a thrust load acting on the rotating shaft,
A radial sensor arranged in the pump casing for detecting a radial load acting on the rotating shaft, and a radial sensor.
With a controller that determines whether or not a vortex is generated in the suction water tank based on the detection result of the thrust sensor and the detection result of the radial sensor.
A pump monitoring device. The pump includes an impeller fixed to the end of the rotating shaft on the suction tank side.
A pressure sensor for detecting the pressure on the downstream side of the impeller in the direction of discharging the liquid by the impeller is arranged in the pump casing.
The pump monitoring device according to any one of claims 1 to 4 , wherein the controller determines whether or not a vortex is generated in the suction water tank based on the detection results of each of the thrust sensor and the pressure sensor. .. The pump includes an impeller fixed to the end of the rotating shaft on the suction tank side.
A pressure sensor for detecting the pressure on the downstream side of the impeller in the liquid discharge direction by the impeller is arranged in the pump casing.
The pump monitoring device according to claim 5 or 6, wherein the controller determines whether or not a vortex is generated in the suction water tank based on the detection results of the thrust sensor, the radial sensor, and the pressure sensor. The thrust sensor placed on the installation floor of the rotating shaft detects the thrust load acting on the rotating shaft.
Based on the detection result of the thrust sensor, and judgment of the occurrence of vortex in the controller in the suction tank the installation floor,
When it is determined that a vortex has been generated in the suction water tank, the controller sets a vortex suppressing member movably arranged on the outer peripheral portion of the pump casing so that the fluctuation of the thrust load acting on the rotating shaft becomes small. Moved by the operating member ,
Pump monitoring method. The thrust sensor placed on the installation floor of the rotating shaft detects the thrust load acting on the rotating shaft and also detects the thrust load.
A radial sensor placed inside the pump casing detects the radial load acting on the rotating shaft.
Based on the detection result of the thrust sensor and the detection result of the radial sensor, the controller determines whether or not a vortex is generated in the suction water tank under the installation floor.
Pump monitoring method.

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