JP6966388B2 - pump - Google Patents

Description

The present invention relates to a pump.

The pump disclosed in Patent Document 1 includes a protective pipe arranged in a pump casing so as to surround the rotating shaft, and an external water injection mechanism for supplying fresh water (clean water) to a bearing supporting the rotating shaft through the protective pipe. Be prepared. In the case of a general vertical shaft pump, since fresh water is supplied to the bearing as a lubricating liquid, the bearing can be protected from foreign matter contained in the pumped water. In the case of the preceding standby type pump, it is possible to prevent the bearing from overheating in the aerial operation in which there is no pumping water in the pump casing, so that the operation can be continued without stopping the pump.

Japanese Patent No. 4709878

In Patent Document 1, water leakage from the lubricating liquid flow path using a protective tube is prevented by arranging mechanical seals on the outside of bearings located at both ends in the axial direction of the rotating shaft. However, since water leakage from the mechanical seal that deteriorates (wears) due to operation is inevitable, the running cost of the pump of Patent Document 1 is high.

An object of the present invention is to provide a pump capable of suppressing wasteful consumption of fresh water as a lubricating liquid.

One aspect of the present invention includes a tubular pump casing that extends in the vertical direction and has a plurality of bearings inside, and a rotating shaft that is partially disposed in the pump casing and rotatably supported by the bearings. A tubular protective tube arranged between the bearings adjacent to each other in the axial direction of the rotating shaft and surrounding the rotating shaft, and a pair of mechanical seals arranged outside the bearings at both ends in the axial direction of the rotating shaft. External water injection having a lubricating liquid flow path for supplying the lubricating liquid to the bearing through the protective pipe and a first pipe connected to the lubricating liquid flow path, and supplying fresh water as the lubricating liquid. The mechanism, the second pipe connected to the pumping channel between the pump casing and the protective pipe at one end and the other end connected to the lubricating liquid flow path, and a part of the pumped water in the pumping channel are filtered. It has a filter that discharges purified water, and connects the self-injection mechanism that supplies the purified water as the lubricating liquid and the external water injection mechanism to the lubricating liquid flow path to connect the self-injection mechanism. A pair of a switching mechanism having a valve for switching between a first connection state in which the connection is cut off and a second connection state in which the self-water injection mechanism is connected to the lubricant flow path and the connection of the external water injection mechanism is cut off. A water supply mechanism having a third pipe connected to at least one of the mechanical seals and supplying the lubricating liquid to the at least one of the mechanical seals, and a flow meter for measuring the flow rate of the lubricating liquid supplied through the third pipe. When the measurement result by the flow meter is less than the defined first threshold value, the switching mechanism makes the first connection state, and when the measurement result becomes the first threshold value or more, the switching mechanism makes the first connection. Provided is a pump including a control unit for switching from a state to the second connection state.

According to this pump, since fresh water by the external water injection mechanism and purified water by the self-injection mechanism can be supplied to the bearing as lubricating liquid, the pump can be continuously operated while preventing the bearing from overheating. When the measurement result by the flow meter becomes equal to or higher than the first threshold value, the control unit changes from the first connection state in which the external water injection mechanism and the lubricating liquid flow path are connected to the second connection in which the self-water injection mechanism and the lubricating liquid flow path are connected. Switch to state. That is, when the water leakage from the mechanical seal is small, fresh water is injected into the bearing, and when the water leakage from the mechanical seal is large, purified water obtained by filtering the pumped water is injected into the bearing. Therefore, wasteful consumption of fresh water can be suppressed, and the running cost of the pump can be suppressed. Further, since the purified water by the self-water injection mechanism contains fine foreign substances that cannot be filtered completely, when there is little water leakage, the fresh water by the external water injection mechanism is circulated and supplied to the bearing to prevent the bearing from being worn.

The third pipe of the water supply mechanism has a first branch pipe connected to the first pipe of the external water injection mechanism and a second branch pipe connected to the second pipe of the self-water injection mechanism. The switching mechanism has a third connection state in which the first branch pipe is connected to the at least one mechanical seal to cut off the connection of the second branch pipe, and the switching mechanism is said to the at least one mechanical seal. It has a valve that connects a second branch pipe and switches to a fourth connection state in which the connection of the first branch pipe is cut off. According to this aspect, since the fresh water by the external water injection mechanism and the purified water by the self-injection mechanism can be supplied to the mechanical seal, wasteful consumption of the fresh water can be effectively suppressed.

When the measurement result by the flow meter becomes the second threshold value larger than the first threshold value or more, the control unit is configured to switch from the third connection state to the fourth connection state by the switching mechanism. According to this aspect, when the water leakage is small, fresh water is injected into the mechanical seal, and when the water leakage is large, the purified water obtained by filtering the pumped water is injected into the mechanical seal, so that the mechanical seal can be prevented from being worn.

The self-injection mechanism has a water storage tank for storing the purified water and a detection unit for detecting the amount of water in the water storage tank. , The switching mechanism is configured to switch from the second connection state to the first connection state. Further, when the pump casing has a state detection unit for detecting the execution state of the aerial operation without pumping and the state detection unit indicates that the aerial operation is performed, the control unit is the switching mechanism. It is configured to switch from the second connection state to the first connection state. According to these aspects, the pump can be reliably continuously operated while preventing the bearing from overheating.

The filter is a cyclone separator that separates the poured water into the purified water and the sewage, the purified water outlet of the cyclone separator is connected to the lubricating liquid flow path, and the sewage outlet of the cyclone separator is the sewage outlet. It is connected to the pumping channel. According to this aspect, the separated sewage can be discharged through the pump without leaving in the cyclone separator.

In the pump of the present invention, fresh water is replenished when the water leakage from the mechanical seal is small, and purified water is replenished when the water leakage from the mechanical seal is large. Therefore, it is possible to suppress the wasteful consumption of fresh water while preventing the elastic wear of the bearing, so that the running cost of the pump can be suppressed.

The cross-sectional view which shows the pump which concerns on 1st Embodiment of this invention. The system diagram which shows the piping composition of FIG. Sectional view of the mechanical seal. Sectional view of other mechanical seals. Sectional drawing which shows an example of a filter. Block diagram of the pump. A chart showing the open / closed state of the solenoid valve. A flowchart showing the control of the pump. FIG. 7A is a continuation of the flowchart. The system diagram which shows the piping composition of the pump of 2nd Embodiment.

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

(First Embodiment)
FIG. 1 shows a pump 10 according to the first embodiment of the present invention. The pump 10 is a pre-standby type in which the operation is started in advance before water is accumulated in the water absorption tank 1 and the operation is switched to the aerial operation, the air-water mixing operation, and the all-water operation depending on the water level in the water absorption tank 1.

As shown in FIG. 1, the pump 10 includes a pump casing 12, a rotary shaft 20, and an impeller 22, which have the same basic structure as a general vertical shaft pump. Further, the pump 10 includes a protective pipe 31 for the purpose of protecting the bearings 24A and 24B of the rotary shaft 20, and an external water injection mechanism 50 that supplies fresh water as a lubricating liquid into the protective pipe 31. The pump 10 of the present embodiment is further provided with a self-injection mechanism 60 using a part of the pumped water to be discharged, a switching mechanism 80 for switching the connection state of the water injection mechanisms 50 and 60 to the protection pipe 31, and a control device 90. In that respect, it differs from general vertical shaft pumps and leading standby pumps.

(Basic structure of pump)
As shown in FIG. 1, the pump casing 12 is fixed to the installation floor 2 that covers the upper part of the water absorption tank 1. The pump casing 12 includes a pumping pipe 13 arranged in the water absorption tank 1 so as to extend in the vertical direction, and a discharge pipe 17 arranged on the installation floor 2. The pumping pipe 13 includes a straight pipe 14, a vane casing 15, and a bell mouth 16, and is connected from top to bottom in this order. The discharge pipe 17 includes a discharge elbow 18 curved by 90 degrees and is connected to the upper end of the straight pipe 14. A water pipe (not shown) for draining water to the downstream side is connected to the outlet of the discharge elbow 18.

The rotating shaft 20 is arranged so as to extend in the vertical direction along the axis of the pumping pipe 13. Most (part) of the rotating shaft 20 is arranged in the pumping pipe 13, and the upper end side penetrates the discharge elbow 18 and protrudes outward.

The impeller 22 is arranged below the bearing casing 15a provided in the vane casing 15, and is attached to the lower end of the rotary shaft 20 protruding from the bearing casing 15a. The upper end of the impeller 22 is located at a predetermined drainage start water level (minimum water level).

The discharge elbow 18 is provided with a sleeve 18a at a portion through which the rotating shaft 20 penetrates, and a bearing 24A is arranged in the sleeve 18a. The bearing casing 15a is provided with a sleeve 15b at a portion through which the rotating shaft 20 penetrates, and the bearing 24B is arranged in the sleeve 15b. These bearings 24A and 24B include a sliding body made of ceramic or a resin having a low thermal conductivity. The rotary shaft 20 is rotatably supported in the pump casing 12 by the bearings 24A and 24B.

A driving means 26 (see FIG. 5) is mechanically connected to the upper end of the rotating shaft 20. As the drive means 26, an electric motor or a diesel engine, which is one of the internal combustion engines, is used. By driving the driving means 26, the impeller 22 is rotated integrally with the rotating shaft 20.

The pump 10 of the present embodiment includes an intake pipe (not shown) which is a basic structure of a general preceding standby type pump. For example, the upper end of the intake pipe is arranged above the installation floor 2, and the lower end of the intake pipe is connected to a predetermined position of the bell mouth.

The pump 10 is started by the operator based on the weather information, and at the beginning of the start, the pump 10 is operated in the air without water in the pump casing 12. When the water level in the water suction tank 1 becomes higher than the defined pumping cutoff water level (lower end of the intake pipe), the system shifts to the air-water mixing operation in which the water sucked from the suction port 16a and the air are discharged together. When the impeller 22 becomes higher than the minimum water level at which the impeller 22 is completely submerged, the operation shifts to full water operation in which only water is discharged.

When the water level drops below the minimum water level due to drainage, air is sucked together with water from the suction port 16a of the pump casing 12, and the operation shifts to the air-water mixing operation again. After that, when the pumping cutoff water level is reached, a certain amount of air is sucked from the intake pipe, so that the operation shifts to the airlock operation in which the water column is held in the pumping pipe 13. Normally, this airlock operation is maintained, and when the amount of water in the water absorption tank 1 increases, the system shifts to the all-water operation through the air-water mixing operation again. However, if a large amount of air is sucked in during the airlock operation for some reason, the water column in the pumping pipe 13 may fall off, and the operation may shift to the aerial operation.

During full-water operation, the bearings 24A and 24B may be damaged (abrasive wear) by foreign matter contained in the pumped storage. Further, since there is no pumped water in the pump casing 12 during the aerial operation, the bearings 24A and 24B may overheat due to the sliding contact with the rotating shaft 20, and these may seize. In order to prevent these problems and continue operation (rotation of the rotating shaft 20), a lubricating liquid flow path 30 for protecting the bearings 24A and 24B is provided in the pump casing 12. Further, the pump casing 12 is provided with an external water injection mechanism 50 for supplying fresh water (clean water) and a self-water injection mechanism 60 for supplying purified water as the lubricating liquid to be replenished in the lubricating liquid flow path 30.

(Overview of the lubricating fluid flow path)
Subsequently, referring to FIG. 1, the lubricating liquid flow path 30 includes a cylindrical protective tube 31 surrounding the rotating shaft 20 and mechanical seals 32A and 32B arranged outside the bearings 24A and 24B in the axial direction of the rotating shaft 20. And. Further, circulation pipes 38 are connected to both ends of the lubricating liquid flow path 30.

The protective tube 31 is arranged between the bearings 24A and 24B adjacent to each other with a vertical interval. The upper end of the protective tube 31 is liquid-tightly fitted to the lower end of the sleeve 18a of the discharge elbow 18, and the lower end of the protective tube 31 is liquid-tightly fitted to the upper end of the sleeve 15b of the bearing casing 15a. It is preferable that the protective tube 31 and the sleeves 18a and 15a are sealed by the instep packing that is not deformed and twisted by the vibration of the pump casing 12. The internal space between the protective tube 31 and the rotating shaft 20 constitutes a flow path for circulating the lubricating liquid. The internal space between the pump casing 12 and the protective pipe 31 constitutes a pumping channel 28 for discharging the water in the water absorption tank 1.

The mechanical seal 32A is arranged above the bearing 24A at the upper end, and the mechanical seal 32B is arranged below the bearing 24B at the lower end. More specifically, the discharge elbow 18 is provided with a cylindrical enclosure 33 that projects outward, and a mechanical seal 32A is arranged on the lid 34 of the enclosure 33. Further, a mechanical seal 32B is arranged at the lower end of the sleeve 15b of the bearing casing 15a.

The enclosure 33 has a cylindrical shape that surrounds the sleeve 18a. The lower end of the enclosure 33 is closed by the outer upper surface of the discharge elbow 18, and the upper end is closed by a separate lid 34. A through hole is formed in the center of the lid 34, and the rotation shaft 20 extends upward through the through hole. A lubricating liquid tank 35 is mounted on the lid 34 via a pedestal. The lubricating liquid tank 35 is a hollow annular body having a large-area opening in the center, and a ball bearing 36, which is a thrust bearing of the rotating shaft 20, is fixed to the opening. A full water detector 37 for detecting the liquid level of the lubricating liquid is arranged in the lubricating liquid tank 35.

The mechanical seal 32A is attached to the through hole of the lid 34 through which the rotating shaft 20 is penetrated, the rotating shaft 20 is shaft-sealed, and the internal space of the enclosure 33 communicating with the inside of the protective tube 31 is sealed. The mechanical seal 32B seals the rotating shaft 20 and seals the lower end of the sleeve 18a communicating with the inside of the protective tube 31. These mechanical seals 32A and 32B include a rotating ring attached to the rotating shaft 20 and a fixed ring attached to the housing, and the lubricating liquid in the lubricating liquid flow path 30 leaks to the outside through these sliding contact surfaces. Prevent it from happening.

For example, for the upper mechanical seal 32A, a single type having one rotating ring and one fixed ring is used. For the lower mechanical seal 32B, the tandem type shown in FIG. 3A or the double type shown in FIG. 3B is used. These mechanical seals 32B include a pair of rotating rings 32a and a pair of fixed rings 32b. As shown in FIG. 3A, in the tandem mechanical seal 32B, a pair of rotating rings 32a are arranged in the same posture (orientation) with respect to a pair of fixed rings 32b fixed to the housing 32c. As shown in FIG. 3B, in the double-shaped mechanical seal 32B, a pair of rotating rings 32a are arranged in opposite directions, and fixed rings 32b are arranged on both sides of these rotating rings 32a. The housing 32c of these mechanical seals 32B is provided with an injection hole 32d for injecting a lubricating liquid (external fluid) between the pair of fixed rings 32b.

The circulation pipe 38 is arranged outside the pump casing 12. One end of the circulation pipe 38 is connected to the lubricating liquid tank 35 on the upper end side of the lubricating liquid flow path 30, and the lubricating liquid tank 35 is connected to the mechanical seal 32A by the connecting pipe 39. The other end of the circulation pipe 38 is connected to the sleeve 15b on the lower end side of the lubricating liquid flow path 30 via the connecting pipe portion 15c. The connecting pipe portion 15c extends from the outer peripheral wall of the vane casing 15 through the bearing casing 15a to the sleeve 15b. As a result, the lubricating liquid tank 35 on one end side of the lubricating liquid flow path 30 and the sleeve 15b on the other end side of the lubricating liquid flow path 30 communicate with each other via the circulation pipe 38. A flow rate adjusting valve 40 for adjusting the flow rate of the lubricating liquid is interposed in the circulation pipe 38.

A blade member 41 for circulating the lubricating liquid is attached to the rotating shaft 20 so as to be located in the enclosure 33. By rotating the blade member 41 integrally with the rotating shaft 20, the lubricating liquid inside the lubricating liquid flow path 30 and the circulation pipe 38 is circulated clockwise in FIG. 1. Specifically, the lubricating liquid in the enclosure 33 flows downward in FIG. 1 through the gap between the sleeve 18a (bearing 24A) and the rotating shaft 20, and flows into the protective pipe 31. Subsequently, the lubricating liquid flows downward in the protective pipe 31 in the figure, passes through the gap between the sleeve 15b (bearing 24B) of the bearing casing 15a and the rotating shaft 20, and further passes through the connecting pipe portion 15c to the circulation pipe 38. Inflow. Subsequently, the lubricating liquid rises up the circulation pipe 38 to reach the lubricating liquid tank 35, passes through the housing of the connecting pipe 39 and the mechanical seal 32A, and returns to the inside of the enclosure 33. The lubricating liquid circulated in this way lubricates the bearings 24A and 24B in the sleeves 18a and 15b. Further, the mechanical seals 32A and 32B prevent the lubricating liquid from leaking from the inside to the outside of the lubricating liquid flow path 30.

(Outline of external water injection mechanism)
As shown in FIGS. 1 and 2, the external water injection mechanism 50 includes a water receiving tank 52 connected to the water source facility 51 and a water supply pipe (first pipe) 56 connected to the water receiving tank 52 as a lubricating liquid. Fresh water is replenished in the lubricating liquid flow path 30.

The water receiving tank 52 is arranged at a position higher than the lubricating liquid tank 35, and is connected to the water source equipment 51 via a connecting pipe 53. A solenoid valve 54 and a ball tap valve 55 are interposed in the connection pipe 53. The control device 90 switches the solenoid valve 54 between a valve open state in which the water source equipment 51 and the water receiving tank 52 communicate with each other and a valve closed state in which the water source equipment 51 and the water receiving tank 52 communicate with each other. The ball tap valve 55 is a water stop valve that shuts off communication between the water source equipment 51 and the water receiving tank 52 when fresh water is stored up to a water level defined in the water receiving tank 52.

One end of the water supply pipe 56 is connected to the water receiving tank 52, and the other end is connected to the lubricating liquid tank 35. The water supply pipe 56 of the present embodiment is connected to the circulation pipe 38, and a part of the circulation pipe 38 is used as a common pipe to supply fresh water to the lubricating liquid tank 35.

When the lubricating liquid in the lubricating liquid flow path 30 becomes insufficient, the fresh water in the water receiving tank 52 is supplied to the lubricating liquid tank 35 via the water supply pipe 56 by the head pressure. As a result, the lubricating liquid in the lubricating liquid flow path 30 including the circulation pipe 38 is always maintained in a fixed quantity.

Due to the operation of the pump 10, the rotating ring 32a and the fixed ring 32b of the mechanical seal 32B, which are consumable parts, are worn (deteriorated), and the problem that the lubricating liquid leaks between them is inevitable. In this case, since the amount of fresh water (clean water) used as the lubricating liquid increases, the running cost of the pump 10 increases. In order to prevent this problem, in the present embodiment, a self-injection mechanism 60 using a part of pumped water and a switching mechanism 80 for switching the connection state with the lubricating liquid flow path 30 are provided. Further, in order to detect an abnormality in the mechanical seal 32B, a water supply mechanism 70 provided with a flow meter 72 is provided.

(Outline of self-water injection mechanism)
Subsequently, referring to FIGS. 1 and 2, the self-water injection mechanism 60 includes a water supply pipe (second pipe) 61 connected to the pumping passage 28 and the lubricating liquid flow path 30, and a filter 62 that filters a part of the pumped water. And, the purified water filtered as the lubricating liquid is replenished to the lubricating liquid flow path 30. Further, the self-water injection mechanism 60 includes a water storage tank 64 for storing a predetermined amount of purified water.

The water supply pipe 61 has a first portion 61a connecting the pump casing 12 and the filter 62, a second portion 61b connecting the filter 62 and the water storage tank 64, and a third portion 61b connecting the water storage tank 64 and the lubricating liquid tank 35. It comprises a portion 61c. With reference to FIG. 4, one end of the first portion 61a is connected to the discharge elbow 18 (downstream side of the impeller 22) having the highest pressure in the pump casing 12 (pumping passage 28), and the first portion 61a The other end is connected to the pumping inlet 62c of the filter 62. One end of the second portion 61b is connected to the purified water outlet 62d of the filter 62, and the other end of the second portion 61b is connected to the water storage tank 64. One end of the third portion 61c is connected to the bottom of the water storage tank 64, and the other end of the third portion 61c is connected to the lubricating liquid tank 35 via a part of the circulation pipe 38.

The filter 62 is a cyclone separator that filters the poured pumped water and separates it into purified water and sewage. FIG. 4 shows an example of a cyclone separator. The cyclone separator includes a container 62a having a conical cylindrical portion at one end, and a lid portion 62b that closes the other end of the container 62a. A pumping inlet 62c to which the first portion 61a is connected is formed on the outer peripheral portion of the container 62a so as to be located on the lid portion 62b side. A purified water outlet 62d for discharging purified water from which foreign matter has been removed by centrifugation is formed in the lid portion 62b, and a second portion 61b is connected to the purified water outlet 62d. A sewage outlet 62e for discharging sewage containing separated foreign matter is formed in the container 62a so as to be located on the opposite side of the lid portion 62b, and one end of the drain pipe 63 is connected to the sewage outlet 62e. There is. Referring to FIG. 1, the other end of the drain pipe 63 is connected to the bell mouth 16 so as to communicate with the upstream side of the impeller 22 which is a lower pressure portion than the inside of the filter 62 in the pumping channel 28.

The water storage tank 64 is arranged at a position higher than that of the lubricating liquid tank 35. In order to avoid defective replenishment of the lubricating liquid to the lubricating liquid flow path 30 due to insufficient water purification, a water level sensor (detection unit) 65 for detecting the stored water amount (water level) is arranged in the water storage tank 64. When the water level sensor 65 becomes lower than the specified water level in the water storage tank 64, the water level sensor 65 outputs a specified signal to the control device 90.

The self-water injection mechanism 60 functions by the pressure in the pump casing 12 during full water operation.

Specifically, the pressure in the discharge elbow 18 (inside the first portion 61a of the water supply pipe 61) is P1, the pressure in the second portion 61b is P2, the pressure in the third portion 61c is P3, and the pressure in the drain pipe 63 is. Assuming that the pressure is P4 and the pressure in the bell mouth 16 is P5, the pressures P1, P2, P3, P4 and P5 decrease in this order (P1> P2 ≧ P3> P4> P5) during full water operation. However, there is a situation where the pressure P2 in the second portion 61b and the pressure P3 in the third portion 61c are the same.

Due to this pressure difference, a part of the pumped water in the pump casing 12 is supplied to the filter 62 through the first portion 61a. Referring to FIG. 4, the pumped storage PW flowing into the filter 62 swirls along the inner wall of the container 62a (see swirling flow RF). As a result, the pressure near the inner wall of the container 62a becomes high, and the pressure near the central axis of the container 62a becomes low. Further, in the vicinity of the central axis of the container 62a, a flow UF toward the purified water outlet 62d is generated on the lid portion 62b side, and only a swirling flow toward the sewage outlet 62e is generated on the opposite side.

The solid matter contained in the pumped storage PW is separated by centrifugal force due to the swirling flow RF, rotates toward the sewage outlet 62e side, and is discharged as sewage DW from the sewage outlet 62e to the drain pipe 63. This sewage DW is discharged into the pump casing 12 through the drain pipe 63.

The purified water CW from which the solid matter has been separated is discharged from the purified water outlet 62d to the second portion 61b. However, minute solid matter that does not cause wear on the bearings 24A and 24B may be discharged from the purified water outlet 62d while being contained in the purified water CW. As shown in FIGS. 1 and 2, the purified water CW flowing into the second portion 61b is temporarily stored in the water tank 64. Then, it is supplied to the lubricating liquid flow path 30 through the third portion 61c according to the amount of water leakage from the mechanical seal 32B.

In this way, by using the cyclone separator as the filter 62, a part of the pumped water can be filtered to generate purified water without using an extra power source (pump) or the like. Further, since the sewage outlet 62e is connected to the pumping channel 28, the separated sewage can be discharged through the pump 10 without leaving it in the cyclone separator.

(Overview of water supply mechanism)
As shown in FIGS. 1 and 2, the water supply mechanism 70 includes a water supply pipe (third pipe) 71 for supplying the lubricating liquid to the mechanical seal 32B. As the lubricating liquid, a dedicated external fluid may be used, but it is preferable to use both fresh water by the external water injection mechanism 50 and clean water by the self-injection mechanism 60. In the present embodiment, in order to use both fresh water and purified water, the water supply pipe 71 includes a first branch pipe 71a connected to the water supply pipe 56 and a second branch pipe 71b connected to the water supply pipe 61 (third portion 61c). And are provided.

The water supply pipe 71 is connected to the injection hole 32d of the mechanical seal 32B shown in FIG. 4A or FIG. 4B, and supplies the lubricating liquid to the sliding surfaces of the rotary ring 32a and the fixed ring 32b. The first branch pipe 71a is connected to the upstream side of the connection portion of the water supply pipe 56 with the circulation pipe 38. The second branch pipe 71b is connected to the upstream side of the connection portion with the circulation pipe 38 in the third portion 61c of the water supply pipe 61.

A flow meter 72 for measuring the flow rate of the lubricating liquid supplied to the mechanical seal 32B is interposed in the water supply pipe 71. The liquid leaking from the sliding surface includes the lubricating liquid of the lubricating liquid flow path 30 and the lubricating liquid of the mechanical seal 32B. Therefore, when the leakage increases, the measurement result (flow rate) by the flow meter 72 becomes large.

(Overview of switching mechanism)
Subsequently, referring to FIGS. 1 and 2, the switching mechanism 80 switches the connection state of the external water injection mechanism 50 and the self-water injection mechanism 60 to the lubricating liquid flow path 30, and the external water injection mechanism 50 and the self-water injection mechanism 60 to the mechanical seal 32B. It is provided for switching the connection state of. The switching mechanism 80 includes solenoid valves 81 to 86 interposed in the individual pipes.

The solenoid valve 81 for replenishing fresh water and the solenoid valve 82 for replenishing clean water are provided for switching the connection state of the water injection mechanisms 50 and 60 with respect to the lubricating liquid flow path 30. The solenoid valve 81 is interposed in the water supply pipe 56, and the solenoid valve 82 is interposed in the third portion 61c of the water supply pipe 61. Further, check valves 87A and 87B are interposed in the water supply pipe 56 and the third portion 61c, respectively. The solenoid valve 81 is opened by the control device 90 and the solenoid valve 82 is closed, so that the external water injection mechanism 50 is connected to the lubricating liquid flow path 30 and the connection of the self-water injection mechanism 60 is cut off. It can be in one connected state. The solenoid valve 81 is closed by the control device 90 and the solenoid valve 82 is opened, so that the self-water injection mechanism 60 is connected to the lubricating liquid flow path 30 and the connection of the external water injection mechanism 50 is cut off. It can be in a two-connected state.

The solenoid valve 83 for fresh water lubrication and the solenoid valve 84 for clean water lubrication are provided for switching the connection state of the water injection mechanisms 50 and 60 with respect to the mechanical seal 32B. The solenoid valve 83 is interposed in the first branch pipe 71a, and the solenoid valve 84 is interposed in the second branch pipe 71b. The solenoid valve 83 is opened by the control device 90 and the solenoid valve 84 is closed, so that the external water injection mechanism 50 is connected to the mechanical seal 32B and the connection of the self-water injection mechanism 60 is cut off. Can be in a state. The solenoid valve 83 is closed by the control device 90 and the solenoid valve 84 is opened, so that the self-water injection mechanism 60 is connected to the mechanical seal 32B and the connection of the external water injection mechanism 50 is cut off. Can be in a state.

The switching mechanism 80 of the present embodiment includes a solenoid valve 85 for pumping pumping and a solenoid valve 86 for discharging sewage. The solenoid valve 85 is interposed in the first portion 61a of the water supply pipe 61, and the solenoid valve 86 is interposed in the drain pipe 63. When the solenoid valve 85 is opened by the control device 90, the filtration of the pumped water by the filter 62 is permitted, and when the solenoid valve 85 is closed, the filtration of the pumped water by the filter 62 is stopped. The control device 90 allows the discharge of sewage to the pump casing 12 by opening the solenoid valve 86, and stops the discharge of sewage to the pump casing 12 by closing the solenoid valve 86.

(Overview of control device)
A control device (control unit) 90 is provided on the installation floor 2 in order to switch to an appropriate connection state by the switching mechanism 80 according to the operating state of the pump 10. As shown in FIG. 5, the control device 90 is electrically connected to the drive means 26, the water level sensor 65, the flow meter 72, the solenoid valves 81 to 86, and the vibration sensor 92. The control device 90 controls the drive means 26 and the solenoid valves 81 to 86 based on the input signals (detection results) from the water level sensor 65, the flow meter 72, and the vibration sensor 92. As the control device 90, for example, a personal computer can be used. The control device 90 includes a program for controlling the pump 10 and a storage unit (memory) 91 in which a threshold value, a determination value, and the like used in the program are stored.

The vibration sensor 92 is attached to, for example, the discharge elbow 18 of the pump casing 12 and constitutes a state detection unit for detecting the operating state of the pump 10. In the preceding standby type pump 10, the magnitude of vibration acting on the pump casing 12 differs depending on the operating state, and increases in the order of aerial operation, all-water operation, airlock operation, and air-water mixing operation. The vibration sensor 92 detects the vibration acting on the pump casing 12, and outputs a signal corresponding to the magnitude of the vibration to the control device 90. The state detection unit is not limited to the vibration sensor 92, and a water level sensor that detects the water level in the water absorption tank 1 may be used, or both the vibration sensor 92 and the water level sensor may be used.

The storage unit 91 has a determination value for determining whether the pump 10 is in the air operation, the airlock operation, the gas-liquid mixing operation, or the all-water operation based on the detection result of the vibration sensor 92. V1 to V3 are stored. These increase in the order of the first judgment value V1, the second judgment value V2, and the third judgment value V3. When the detection result is less than the first judgment value V1, the control device 90 determines that it is in the aerial operation state, and when the detection result is the first judgment value V1 or more and less than the second judgment value V2, the control device 90 operates all water. If it is judged to be a state and the detection result is the second judgment value V2 or more and less than the third judgment value V3, it is judged to be an airlock operation state, and if the detection result is the third judgment value V3 or more, air-water mixing is performed. Judge as operating condition.

Referring to FIG. 6, in the case of a state other than the total water operation, the control device 90 has an external water injection mechanism 50 with respect to the lubricating liquid flow path 30 regardless of the state of the mechanical seal 32B and the amount of water stored in the water storage tank 64. Is set to the first connection state, and the external water injection mechanism 50 is connected to the mechanical seal 32B to be the third connection state, and the water supply pipe 61 of the self-water injection mechanism 60 is switched to the cutoff state. Specifically, the solenoid valve 81 for replenishing fresh water is opened, the solenoid valve 82 for replenishing purified water is closed to make the first connection state, and the solenoid valve 83 for lubricating fresh water is opened to lubricate the purified water. By closing the solenoid valve 84 for, the third connection state is set, the solenoid valve 85 for pumping water is closed, and the solenoid valve 86 for discharging sewage is closed (first aspect of FIG. 6).

In the case of the all-water operation state, the control device 90 determines the connection state of the water injection mechanisms 50 and 60 to the lubricating liquid flow path 30 and the mechanical seal 32B, and the connection state of the water injection mechanisms 50 and 60 to the lubricating liquid flow path 30 and the mechanical seal 32B, based on the state of the mechanical seal 32B and the amount of water stored in the water storage tank 64. The communication state of the water supply pipe 61 of the self-water injection mechanism 60 is switched.

The storage unit 91 stores the states of the mechanical seal 32B, that is, the threshold values T1 to T3 for determining the presence / absence of abnormality and the abnormality level based on the measurement result of the flow meter 72. These increase in the order of the first threshold value T1, the second threshold value T2, and the third threshold value T3. The control device 90 determines that the measurement result is a normal state when the measurement result is less than the first threshold value T1, and determines that the measurement result is an abnormal state of the level 1 when the measurement result is equal to or more than the first threshold value T1 and less than the second threshold value T2. When the result is the second threshold value T2 or more and less than the third threshold value T3, it is determined to be a level 2 abnormal state, and when the measurement result is the third threshold value T1 or more, it is determined to be a level 3 abnormal state.

Referring to FIG. 6, when the mechanical seal 32B is normal, the control device 90 is in the first connection state in which the external water injection mechanism 50 is connected to the lubricating liquid flow path 30, and the external water injection mechanism 50 is connected to the mechanical seal 32B. Is set to the third connection state, and the communication state of the water supply pipe 61 of the self-water injection mechanism 60 is switched according to the amount of water stored in the water storage tank 64. Specifically, when the amount of water stored is appropriate, the solenoid valve 81 for replenishing fresh water is opened and the solenoid valve 82 for replenishing purified water is closed to make the first connection state, and the solenoid valve 83 for lubricating fresh water is set. Is opened, and the solenoid valve 84 for purifying water lubrication is closed to make the third connection state, the solenoid valve 85 for pumping water is closed, and the solenoid valve 86 for discharging sewage is closed (FIG. 6 second aspect). When the amount of water stored is insufficient, the solenoid valve 85 for pumping out and the solenoid valve 86 for discharging sewage are opened, which is different from the case where the amount of water stored is appropriate (the third aspect of FIG. 6). ..

When the abnormality of the mechanical seal 32B is level 1, the control device 90 switches the connection state of the water injection mechanisms 50 and 60 to the lubricating liquid flow path 30 according to the amount of water stored in the water storage tank 64, and is external to the mechanical seal 32B. The water injection mechanism 50 is connected to the third connection state, and the water supply pipe 61 of the self-water injection mechanism 60 is in the communication state. Specifically, when the amount of water stored is appropriate, the solenoid valve 81 for replenishing fresh water is closed, and the solenoid valve 82 for replenishing purified water is opened to bring the second connection state, and the solenoid valve 83 for lubricating fresh water is set. Is opened, and the solenoid valve 84 for purifying water lubrication is closed to make the third connection state, the solenoid valve 85 for pumping water is opened, and the solenoid valve 86 for discharging sewage is opened (Fig. 6). When the amount of water stored is insufficient, the solenoid valve 81 for replenishing fresh water is opened and the solenoid valve 82 for replenishing purified water is closed to make the first connection state. Different (fifth aspect of FIG. 6).

When the abnormality of the mechanical seal 32B is level 2, the control device 90 switches the connection state of the lubricating liquid flow path 30 and the water injection mechanisms 50 and 60 to the mechanical seal 32B according to the amount of water stored in the water storage tank 64, and self-injects water. The water supply pipe 61 of the mechanism 60 is in a communication state. Specifically, when the amount of water stored is appropriate, the solenoid valve 81 for replenishing fresh water is closed, and the solenoid valve 82 for replenishing purified water is opened to bring the second connection state, and the solenoid valve 83 for lubricating fresh water is set. Is closed, and the solenoid valve 84 for purifying water lubrication is opened to make the fourth connection state, the solenoid valve 85 for pumping water is opened, and the solenoid valve 86 for discharging sewage is opened (FIG. 6th aspect of 6). When the amount of water stored is insufficient, the solenoid valve 81 for replenishing fresh water is opened, and the solenoid valve 82 for replenishing purified water is closed to make the first connection state, and the solenoid valve 83 for lubricating fresh water is opened. However, it differs from the case where the amount of water stored is appropriate in that the solenoid valve 84 for lubricating water is closed to bring it into the third connection state (the seventh aspect of FIG. 6).

When the abnormality of the mechanical seal 32B is level 3, the control device 90 stops the driving means 26 and closes all the solenoid valves 81 to 86 (the eighth aspect of FIG. 6).

As described above, when the leakage of the mechanical seal 32B becomes equal to or higher than the first threshold value T1, the control device 90 changes from the first connection state in which the external water injection mechanism 50 is connected to the lubricating liquid flow path 30 to the lubricating liquid flow path 30. On the other hand, the self-water injection mechanism 60 is switched to the connected second connection state. That is, when the water leakage from the mechanical seal 32B is small, fresh water is injected into the bearings 24A and 24B, and when the water leakage from the mechanical seal 32B is large, the purified water obtained by filtering the pumped water is injected into the bearings 24A and 24B. Therefore, since wasteful consumption of fresh water can be suppressed, the running cost of the pump 10 can be suppressed. Further, since the purified water by the self-water injection mechanism 60 contains fine foreign substances that cannot be filtered completely, when the water leakage is small, the fresh water by the external water injection mechanism 50 is circulated and supplied to the bearings 24A and 24B to supply the bearings 24A and 24A. Abrasive wear of 24B can be prevented.

When the leakage of the mechanical seal 32B increases and becomes the second threshold value T2 or more, the mechanical seal 32B is switched from the third connection state in which the external water injection mechanism 50 is connected to the fourth connection state in which the self-water injection mechanism 60 is connected. .. That is, since the mechanical seal 32B can also be supplied with fresh water by the external water injection mechanism 50 and purified water by the self-water injection mechanism 60, wasteful consumption of fresh water can be effectively suppressed. Moreover, when the water leakage is small, the fresh water by the external water injection mechanism 50 is injected into the mechanical seal 32B, and when the water leakage is large, the purified water by the self-water injection mechanism 60 is injected into the mechanical seal, so that the mechanical seal 32B can be prevented from being worn.

When the amount of water stored in the water storage tank 64 falls below the specified amount of water, the system returns to the first connection state and the third connection state in which the external water injection mechanism 50 is connected to the lubricating liquid flow path 30 and the mechanical seal 32B. When the state of the pump 10 is other than the full water operation, the pump 10 is returned to the first connection state and the third connection state in which the external water injection mechanism 50 is connected to the lubricating liquid flow path 30 and the mechanical seal 32B. That is, when the lubricating liquid cannot be sufficiently replenished by the self-water injection mechanism 60, the pump 10 can be reliably continuously operated while preventing the bearings 24A and 24B from overheating in order to switch to the external water injection.

Next, the control by the control device 90 will be specifically described with reference to FIGS. 7A and 7B. In addition, referring to FIG. 6 together, the flags fa to fh in FIGS. 7A and 7B indicate the following states.
fa: Whether the pump is other than full water operation (first aspect)
fb: Whether the mechanical seal is normal and the amount of water stored is appropriate (second aspect)
fc: Whether the mechanical seal is normal and the amount of water stored is insufficient (third mode)
fd: Whether or not the mechanical seal is abnormal at level 1 and the amount of water stored is appropriate (fourth aspect).
fe: Whether the mechanical seal is abnormal at level 1 and the amount of water stored is insufficient (fifth mode).
ff: Whether or not the mechanical seal is abnormal at level 2 and the amount of water stored is appropriate (fifth mode).
fg: Whether the mechanical seal is abnormal at level 2 and the amount of water stored is insufficient (7th aspect)
fh: Whether or not the mechanical seal is a level 3 abnormality (eighth aspect)

When the driving means 26 is driven, the control device 90 determines the operating state of the pump 10 based on the detection result of the vibration sensor 92. If it is determined in step S1 that the pump 10 is not in full water operation, the flag fa is set to 1 in step S2, the other flags fb to fh are cleared (zero), the process proceeds to step S16, and the switching mechanism 80 is set to FIG. Switch to the first aspect of.

When it is determined that the pump 10 is in full water operation, the control device 90 determines whether or not there is an abnormality in the mechanical seal 32B based on the measurement result of the flow meter 72. Specifically, in step S3, it is determined whether or not the measurement result of the flow meter 72 is less than the first threshold value T1. When the measurement result is less than the first threshold value T1, that is, when there is no abnormality in the mechanical seal 32B, it is determined in step S4 whether or not the amount of water stored in the water storage tank 64 is appropriate. When the amount of water stored is appropriate, the flag fb is set to 1 in step S5, the other flags fa, fc to fh are cleared, the process proceeds to step S16, and the switching mechanism 80 is switched to the second aspect of FIG. When the amount of water stored is insufficient, the flag fc is set to 1 in step S6, the other flags fa, fb, fd to fh are cleared, the process proceeds to step S16, and the switching mechanism 80 is switched to the third aspect of FIG.

When the measurement result is equal to or higher than the first threshold value T1 in step S3, that is, when there is an abnormality in the mechanical seal 32B, it is determined in step S7 whether or not the measurement result of the flow meter 72 is less than the second threshold value T2. When the measurement result is less than the second threshold value T2, that is, when the abnormality of the mechanical seal 32B is level 1, it is determined in step S8 whether or not the amount of water stored in the water tank 64 is appropriate. When the amount of water stored is appropriate, the flag fd is set to 1 in step S9, the other flags fa to fc and fe to fh are cleared to proceed to step S16, and the switching mechanism 80 is switched to the fourth aspect of FIG. When the amount of water stored is insufficient, the flag fe is set to 1 in step S10, the other flags fa to fd and ff to fh are cleared, the process proceeds to step S16, and the switching mechanism 80 is switched to the fifth aspect of FIG.

When the measurement result is the second threshold value T2 or more in step S7, it is determined in step S11 whether or not the measurement result of the flow meter 72 is less than the third threshold value T3. When the measurement result is less than the third threshold value T3, that is, when the abnormality of the mechanical seal 32B is level 2, it is determined in step S12 whether or not the amount of water stored in the water tank 64 is appropriate. When the amount of water stored is appropriate, the flag ff is set to 1 in step S13, the other flags fa to fe, fg, and fh are cleared to proceed to step S16, and the switching mechanism 80 is switched to the sixth aspect of FIG. When the amount of water stored is insufficient, the flag fg is set to 1 in step S14, the other flags fa to ff, fh are cleared, the process proceeds to step S16, and the switching mechanism 80 is switched to the seventh aspect of FIG.

When the measurement result is the third threshold value T3 or more in step S11, the flag fh is set to 1 in step S15, the other flags fa to fg are cleared, the process proceeds to step S16, and the switching mechanism 80 is switched to the eighth aspect of FIG. ..

As described above, based on the operating state of the pump 10, the measurement result of the flow meter 72 corresponding to the leakage from the mechanical seal 32B, and the amount of water stored in the water storage tank 64, the solenoid valves 81 to 86 are set from the first aspect to the first aspect. Switching to any of the eight modes (step S16). Then, in step S17, it is determined whether or not the flag fh is 1 (eighth aspect). Then, when the flag fh is not 1, that is, when the abnormality of the mechanical seal 32B is level 2 or less, the process proceeds to step S1 and the operation accompanied by the switching by the switching mechanism 80 is continued.

On the other hand, when the flag fh is 1 in step S17, that is, when the abnormality of the mechanical seal 32B is level 3, the process proceeds to step S18, the drive means 26 is stopped, and the notification means outputs the pump 10. Stop the operation. The output by the notification means includes the output of a warning sound by the piezoelectric buzzer built in the control device 90, the display of the warning screen by the monitor connected to the control device 90, and the like.

As described above, according to the pump 10 of the present embodiment, when the water leakage from the mechanical seal 32B is small, the external water injection mechanism 50 replenishes the fresh water, and when the water leakage from the mechanical seal 32B increases, the self-water injection mechanism 60 purifies the water. To replenish. Further, the connection state is switched by the switching mechanism 80 based on the operating state of the pump 10, the leakage amount of the mechanical seal 32B, and the water storage amount in the water storage tank 64. Therefore, it is possible to suppress the wasteful consumption of fresh water (clean water) while preventing the elastic wear of the bearings 24A and 24B, so that the running cost of the pump 10 can be suppressed.

(Second Embodiment)
FIG. 8 shows the external water injection mechanism 50 and the self-water injection mechanism 60 of the pump 10 of the second embodiment. This second embodiment is different from the first embodiment in that two filters 62A and 62B are used for the self-water injection mechanism 60 and a water supply pump 67 is used instead of the water storage tank 64.

For the filters 62A and 62B, for example, the same cyclone separator as in the first embodiment can be used. With reference to FIG. 4, the first portion 61a of the water supply pipe 61 is connected to the pumping inlet 62c of the first filter 62A. The purified water outlet 62d of the first filter 62A is connected to the pumping inlet 62c of the second filter 62B by a connecting pipe 66. The second portion 61b of the water supply pipe 61 is connected to the purified water outlet 62d of the second filter 62B. The drain pipe 63 includes branch pipes 63a and 63b, the first branch pipe 63a is connected to the sewage outlet 62e of the first filter 62A, and the second branch pipe 63b is connected to the sewage outlet 62e of the second filter 62B. It is connected to the.

The second portion 61b of the water supply pipe 61 is connected to the suction port of the water supply pump 67, and the third portion 61c of the water supply pipe 61 is connected to the discharge port of the water supply pump 67. The water supply pump 67 secures the flow rate of purified water from the first portion 61a to the third portion 61c of the water supply pipe 61.

In the control by the control device 90 of the second embodiment, the switching of the third aspect, the fifth aspect and the seventh aspect in FIG. 6 is not performed. When the pump 10 is not in full water operation, it is switched to the first aspect in FIG. 6, when there is no abnormality in the mechanical seal 32B, it is switched to the second aspect in FIG. 6, and when a level 3 abnormality occurs in the mechanical seal 32B, FIG. Switch to the eighth aspect in 6.

When a level 1 abnormality occurs in the mechanical seal 32B, the solenoid valve 81 for replenishing fresh water is closed and the solenoid valve 82 for replenishing purified water is opened as in the fourth aspect of FIG. By setting the connected state and operating the water supply pump 67, a predetermined amount of purified water is forcibly supplied to the lubricating liquid flow path 30.

When a level 2 abnormality occurs in the mechanical seal 32B, the solenoid valve 81 for replenishing fresh water is closed and the solenoid valve 82 for replenishing clean water is opened as in the sixth aspect of FIG. In the connected state, the solenoid valve 83 for lubricating fresh water is closed, and the solenoid valve 84 for lubricating clean water is opened to make the fourth connection state, and the water supply pump 67 is operated to lubricate a predetermined amount of purified water. It is forcibly supplied to the liquid flow path 30 and the mechanical seal 32B.

In the second embodiment as described above, as in the first embodiment, it is possible to suppress the wasteful consumption of fresh water (clean water) while preventing the elastic wear of the bearings 24A and 24B, so that the running cost of the pump 10 can be reduced. Can be suppressed. Further, since the pair of filters 62A and 62B and the water supply pump 67 are provided, purified water having less fine foreign matter than in the first embodiment can be reliably supplied to the lubricating liquid flow path 30 and the mechanical seal 32B.

The pump 10 of the present invention is not limited to the configuration of the above embodiment, and various modifications can be made.

For example, the lubricating liquid may be circulated counterclockwise with respect to the lubricating liquid flow path 30. The number of bearings is not limited to two, and three or more bearings may be arranged. In this case, the protective pipe 31 is arranged between the bearings adjacent to each other on the upper and lower sides.

Switching between the first connection state and the second connection state, and switching between the third connection state and the fourth connection state may be performed by a three-way valve. When the amount of purified water in the water storage tank 64 is appropriate, purified water may be supplied from the self-injection mechanism 60 to the lubricating liquid flow path 30 regardless of the operating state of the pump 10.

Both the pair of mechanical seals 32A and 32B may be supplied with fresh water of the external water injection mechanism 50 and purified water of the self-water injection mechanism 60 as external fluids. Further, the mechanical seals 32A and / or 32B may be supplied with a lubricating liquid different from that of fresh water and purified water.

In the second embodiment, three or more filters may be used. Even when two or more filters are used, a water tank may be used as in the first embodiment. Even when a water storage tank is used, a water supply pump may be used as in the second embodiment.

The pump of the present invention is not limited to the preceding standby type in which the operation is started in advance before the water flows into the water absorption tank 1, and may be a vertical shaft pump that starts the operation in a state where a predetermined amount of water is accumulated.

1 ... Water absorption tank 2 ... Installation floor 10 ... Pump 12 ... Pump casing 13 ... Pumping pipe 14 ... Straight pipe 15 ... Vane casing 15a ... Bearing casing 15b ... Sleeve 15c ... Connection pipe 16 ... Bellmouth 16a ... Suction port 17 ... Discharge Pipe 18 ... Discharge elbow 18a ... Sleeve 20 ... Rotating shaft 22 ... Impeller 24A, 24B ... Bearing 26 ... Driving means 28 ... Pumping channel 30 ... Lubricant flow path 31 ... Protective pipe 32A, 32B ... Mechanical seal 32a ... Rotating ring 32b ... Fixed ring 32c ... Housing 32d ... Injection hole 33 ... Enclosure 34 ... Lid 35 ... Lubricant tank 36 ... Ball bearing 37 ... Full water detector 38 ... Circulation pipe 39 ... Connection pipe 40 ... Flow control valve 41 ... Blade member 50 ... External water injection mechanism 51 ... Water source equipment 52 ... Water receiving tank 53 ... Connection pipe 54 ... Electromagnetic valve 55 ... Ball tap valve 56 ... Water supply pipe (first pipe)
60 ... Self-water injection mechanism 61 ... Water supply pipe (second pipe)
61a ... 1st part 61b ... 2nd part 61c ... 3rd part 62, 62A, 62B ... Filter 62a ... Container 62b ... Lid 62c ... Pumping inlet 62d ... Purified water outlet 62e ... Sewage outlet 63 ... Drain pipe 63a ... 1st branch pipe 63b ... 2nd branch pipe 64 ... Water tank 65 ... Water level sensor 66 ... Connection pipe 67 ... Water supply pump 70 ... Water supply mechanism 71 ... Water supply pipe (3rd pipe)
71a ... 1st branch pipe 71b ... 2nd branch pipe 72 ... Flow meter 80 ... Switching mechanism 81 ... Solenoid valve for replenishing fresh water 82 ... Solenoid valve for replenishing purified water 83 ... Solenoid valve for lubricating fresh water 84 ... For purifying water lubrication Solenoid valve 85 ... Solenoid valve for pumping water 86 ... Solenoid valve for discharging sewage 87A, 87B ... Check valve 90 ... Control device (control unit)
91 ... Storage unit 92 ... Vibration sensor

Claims (6)

A cylindrical pump casing that extends vertically and has multiple bearings inside,
A rotating shaft that is partially located in the pump casing and rotatably supported by the bearings,
A tubular protective tube arranged between the bearings adjacent to each other in the axial direction of the rotating shaft and surrounding the rotating shaft, and a pair of mechanical seals arranged outside the bearings at both ends in the axial direction of the rotating shaft. And a lubricating liquid flow path for supplying the lubricating liquid to the bearing through the protective tube,
An external water injection mechanism having a first pipe connected to the lubricating liquid flow path and supplying fresh water as the lubricating liquid.
A second pipe having one end connected to the pumping channel between the pump casing and the protective pipe and the other end connected to the lubricating liquid flow path, and a part of the pumped water in the pumping channel are filtered to purify water. A self-injection mechanism that has a filter that discharges water and supplies the purified water as the lubricating liquid.
The first connection state in which the external water injection mechanism is connected to the lubricating liquid flow path to cut off the connection of the self-water injection mechanism, and the self-water injection mechanism is connected to the lubricating liquid flow path to disconnect the self-water injection mechanism. A switching mechanism having a valve for switching to the second connection state in which the connection of the mechanism is cut off, and
A water supply mechanism having a third pipe connected to at least one of the pair of mechanical seals and supplying lubricating liquid to the at least one of the mechanical seals.
A flow meter that measures the flow rate of the lubricating liquid supplied through the third pipe,
When the measurement result by the flow meter is less than the predetermined first threshold value, the switching mechanism sets the first connection state, and when the measurement result becomes the first threshold value or more, the switching mechanism starts from the first connection state. A pump including a control unit for switching to the second connection state. The third pipe of the water supply mechanism has a first branch pipe connected to the first pipe of the external water injection mechanism and a second branch pipe connected to the second pipe of the self-water injection mechanism. ,
The switching mechanism has a third connection state in which the first branch pipe is connected to the at least one mechanical seal to cut off the connection of the second branch pipe, and the first is to the at least one mechanical seal. The pump according to claim 1, further comprising a valve for connecting two branch pipes and switching to a fourth connection state in which the connection of the first branch pipe is cut off. When the measurement result by the flow meter becomes the second threshold value larger than the first threshold value or more, the control unit is configured to switch from the third connection state to the fourth connection state by the switching mechanism. The pump according to claim 2. The self-injection mechanism has a water storage tank for storing the purified water and a detection unit for detecting the amount of water in the water storage tank.
Any of claims 1 to 3, wherein when the detection result of the detection unit falls below a predetermined amount of water, the control unit is configured to switch from the second connection state to the first connection state by the switching mechanism. The pump according to item 1. The pump casing has a state detection unit for detecting an execution state of aerial operation without pumping.
Any of claims 1 to 4, wherein when the state detection unit indicates that the operation is in the air, the control unit is configured to switch from the second connection state to the first connection state by the switching mechanism. The pump according to item 1. The filter is a cyclone separator that separates the pumped water into the purified water and the sewage.
The pump according to any one of claims 1 to 5, wherein the purified water outlet of the cyclone separator is connected to the lubricating liquid flow path, and the sewage outlet of the cyclone separator is connected to the pumping channel.

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