Pumping device and pumping system

Abstract

The present invention provides a pump system that can appropriately detect bearing wear and protect the pump system, sensors, and other components from corrosion. [Solution] The pump device 3 includes a corrosion-resistant motor casing 5 and a sensor 9 installed near the bearing 8 inside the motor casing 5. The motor cable 12 and sensor cable 13 are covered by a corrosion-resistant motor cable protection tube 14 and sensor cable protection tube 15, respectively. The purge gas piping 17 through which the purge gas supplied from the purge gas supply unit 16 flows is connected to the motor cable protection tube 14 and the sensor cable protection tube 15, and the purge gas is configured to circulate inside the pump device 3.

Description

Technical Field

[0004] , , , , ,

[0001] The present invention relates to a pump device and a pump system for pumping a corrosive liquid fuel material such as liquid ammonia.

Background Art

[0002] Conventionally, a submerged motor pump has been used as a pump device for pumping a liquid fuel material (see, for example, Patent Document 1). In a conventional submerged motor pump, an electrical detection means (sensor) for detecting the wear condition of a bearing of a rotary shaft of a motor that generates a rotational driving force of an impeller is provided. Further, the sensor is installed on the outer surface of the motor frame near the bearing. A conventional submerged motor pump is used for pumping an insulating liquid such as liquefied natural gas (LNG, LPG).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, liquid ammonia, which does not emit carbon dioxide when burned, has attracted attention as a liquid fuel material. Unlike liquefied natural gas (LNG, LPG), liquid ammonia is corrosive, but conventional pumping systems do not take into account the pumping of corrosive liquid fuel materials such as liquid ammonia. To pump corrosive liquid fuel materials such as liquid ammonia in the same way as conventional liquid fuel materials such as liquefied natural gas (LNG, LPG), it is conceivable to change the motor of the pumping system to a canned motor pump (see, for example, Patent Document 2 or Patent Document 3), which uses a motor in which the stator and rotor of the motor are sealed like cans.

[0005] Incidentally, conventional canned motor pumps employ liquid-lubricated sliding bearings, and as a means of detecting wear on the sliding bearings, a bearing wear detector (sensor) is installed in the motor winding chamber, and the amount of wear on the sliding bearings is calculated from the displacement (see, for example, Patent Document 3).

[0006] However, in a sliding bearing, the outer surface of a cylindrical rotating shaft and the inner surface of a cylindrical stator facing that outer surface are provided with a certain clearance. When the rotating shaft rotates, it is lubricated and supported by a fluid film that fills this clearance. As a result, the opportunity for direct contact between the inner surface of the stator and the outer surface of the rotating shaft is suppressed, and a good rotational state can be maintained.

[0007] However, because liquid ammonia easily vaporizes with even a slight increase in temperature, and because the inner circumferential surface of the stator slides against surface, frictional heat is easily generated on the sliding surface due to sliding friction. As a result, the liquid film that should be formed in the clearance vaporizes due to the sliding heat during lubrication of the sliding bearing, causing the sliding bearing to slide dry, leading to a rapid increase in vibration and wear, and a risk of failure, i.e., a condition in which it becomes difficult to continue stable operation.

[0008] Therefore, as a measure to avoid the above risks, it is conceivable to adopt ball bearings, which are used in submerged pumps that pump conventional liquid fuel materials such as liquefied natural gas (LNG, LPG). Such submerged pumps employ ball bearings, which have a smaller sliding surface than sliding bearings. It is necessary to monitor the wear condition of ball bearings, and in conventional submerged pumps that pump liquid fuel materials, a sensor for detecting bearing wear is installed on the outer surface of the motor casing of the submerged pump.

[0009] However, there is no track record of using ball bearings in pumps designed for liquid ammonia. Furthermore, when considering the adoption of canned motor pumps, it is necessary to protect the electrical components and sensors of the canned motor from corrosion caused by liquid ammonia, as the canned motor pump will be installed in a liquid such as liquid ammonia. In addition, the motor cable that supplies power to the canned motor and the sensor cable that transmits output signals from the sensor also need to be protected from corrosion caused by liquid ammonia.

[0010] The present invention has been made in view of the above problems, and aims to provide a pump device that can maintain stable operation when pumping corrosive liquid fuel materials such as liquid ammonia, can appropriately detect bearing wear, and can protect the pump device and sensors from corrosion. [Means for solving the problem]

[0011] The pump device of the present invention is a pump device for pumping liquid fuel material from inside a tank in which corrosive liquid fuel material is stored, wherein the pump device is made of a material that is corrosion-resistant to the liquid fuel material, and comprises a motor that generates the driving force of the pump device inside the tank, a motor casing that covers the motor, a rotating shaft installed inside the motor casing and rotated by the driving force of the motor, a bearing installed inside the motor casing that rotatably supports the rotating shaft, a sensor installed inside the motor casing near the bearing and measuring the vibration of the bearing, and a unit installed outside the tank. The tank comprises a motor cable connected to a power supply unit and supplying power from the power supply unit to the motor; a sensor cable connected to a measuring device installed outside the tank and transmitting output signals from the sensor to the measuring device; a motor cable protection tube made of a material resistant to corrosion with respect to the liquid fuel material and covering the motor cable inside the tank; a sensor cable protection tube made of a material resistant to corrosion with respect to the liquid fuel material and covering the sensor cable inside the tank; and a purge gas piping connected to a purge gas supply unit installed outside the tank and through which purge gas supplied from the purge gas supply unit flows.

[0012] In this configuration, the pump device is installed inside a tank that stores corrosive liquid fuel material (e.g., liquid ammonia), but the motor of the pump device is covered by a motor casing made of a material that is resistant to corrosion from the liquid fuel material (e.g., stainless steel), thus adequately protecting the pump device from corrosion. Furthermore, by measuring vibrations with a sensor (e.g., an acceleration sensor) installed near the bearing, wear of the bearing can be appropriately detected. In this case, the motor cable that supplies power to the motor of the pump device and the sensor cable that transmits output signals from the sensor are also installed inside the tank that stores the corrosive liquid fuel material, but the motor cable and sensor cable are covered by motor cable protection tubes and sensor cable protection tubes made of materials that are resistant to corrosion from the liquid fuel material, thus adequately protecting the motor cable and sensor cable from corrosion.

[0013] Furthermore, in the pump device of the present invention, the motor may include a rotor, and the sensor may be provided on the rotor side wall surface within a motor casing that covers the motor stator.

[0014] Furthermore, in the pump device of the present invention, the motor may include a rotor, and the sensor may be located in the motor casing that covers the motor stator, at a position closest to the bearing.

[0015] Furthermore, in the pump device of the present invention, the rotating shaft may be equipped with a bearing, and the sensor may be located in the motor casing covering the motor stator, at the position closest to the surface that mechanically contacts the bearing body in which the bearing is housed.

[0016] Furthermore, in the pump device of the present invention, the purge gas piping may be connected to the motor cable protection tube and the sensor cable protection tube, and the purge gas supplied from the purge gas supply unit may be supplied from the purge gas piping through either the motor cable protection tube or the sensor cable protection tube into the motor casing, and returned from the motor casing through the other of the motor cable protection tube or the sensor cable protection tube to the purge gas piping.

[0017] This configuration makes it possible to prevent corrosion from the liquid material and condensation in low-temperature environments within the motor (stator), motor cable, sensor, and sensor cable.

[0018] Furthermore, the pump device of the present invention may be installed in the purge gas piping and may include a fuel detector that detects whether or not fuel gas vaporized from the liquid fuel material is mixed inside the purge gas piping.

[0019] Furthermore, the pump device of the present invention may also include a pressure adjustment unit installed in the purge gas piping to maintain a constant pressure inside the purge gas piping, and a pressure sensor installed in the purge gas piping to detect changes in the pressure of the purge gas inside the purge gas piping.

[0020] With this configuration, if the pressure rises above the set level, it can be determined that the invading liquid fuel material has vaporized and increased the pressure. If the pressure falls below the set level, it can be determined that the purge gas has leaked and reduced the pressure.

[0021] Furthermore, the pump device of the present invention may also include a flow rate adjustment unit installed in the purge gas piping to maintain a constant flow rate inside the purge gas piping, and a flow rate sensor installed in the purge gas piping to detect changes in the flow rate of the purge gas inside the purge gas piping.

[0022] According to this configuration, if it becomes higher than the set flow rate, it can be determined that the infiltrated liquid fuel material has vaporized and the flow rate has increased, and if it becomes lower than the set flow rate, it can be determined that the purge gas has leaked and the flow rate has decreased.

[0023] Moreover, the pump device of the present invention may include a pressure adjustment unit installed in the purge gas pipe for keeping the pressure inside the purge gas pipe constant, a pressure sensor installed in the purge gas pipe for detecting a change in the pressure of the purge gas inside the purge gas pipe, and a flow rate sensor installed in the purge gas pipe for detecting a change in the flow rate of the purge gas inside the purge gas pipe.

[0024] According to this configuration, if it becomes higher than the set pressure, it can be determined that the infiltrated liquid fuel material has vaporized and the pressure has increased, and if it becomes lower than the set flow rate, it can be determined that the purge gas has leaked and the flow rate has decreased. Along with this, the flow rate also changes, so it becomes possible to improve the detection accuracy.

[0025] Moreover, the pump device of the present invention may include a decontamination device connected to the purge gas pipe for decontaminating fuel gas vaporized from the liquid fuel material mixed inside the purge gas pipe.

[0026] When a situation occurs where the liquid fuel material enters the inside of the motor casing, the motor cable protection pipe, or the sensor cable protection pipe, the decontamination device can decontaminate and detoxify fuel gas (for example, ammonia gas, etc.) vaporized from the liquid fuel material mixed inside the purge gas pipe.

[0027] Moreover, in the pump device of the present invention, the decontamination device includes a water supply pipe for supplying a first liquid used for decontaminating the fuel gas vaporized from the liquid fuel material, a drain pipe for discharging a second liquid generated by the decontamination of the fuel gas, and an exhaust pipe for discharging the gas from which the fuel gas has been excluded. A water supply pump for sending the first liquid to the decontamination device may be provided in the water supply pipe.

[0028] The pump system of the present invention comprises a tank for storing a corrosive liquid fuel material, and a pump device for pumping the liquid fuel material from inside the tank, wherein the pump device is made of a material that is corrosion-resistant to the liquid fuel material, and includes a motor that generates a driving force for the pump device inside the tank, a motor casing that covers the motor, a rotating shaft that is rotated by the driving force of the motor, a bearing installed in the motor casing that rotatably supports the rotating shaft, a sensor installed near the bearing inside the motor casing for measuring the vibration of the bearing, and a sensor installed outside the tank. The tank comprises a motor cable connected to a power supply unit and supplying power from the power supply unit to the motor; a sensor cable connected to a measuring device installed outside the tank and transmitting output signals from the sensor to the measuring device; a motor cable protection tube made of a material resistant to corrosion with respect to the liquid fuel material and covering the motor cable inside the tank; a sensor cable protection tube made of a material resistant to corrosion with respect to the liquid fuel material and covering the sensor cable inside the tank; and a purge gas pipe connected to a purge gas supply unit installed outside the tank and through which the purge gas supplied from the purge gas supply unit flows.

[0029] In this pump system, as with the pump device described above, the pump device is installed inside a tank that stores corrosive liquid fuel material (e.g., liquid ammonia). However, the motor of the pump device is covered by a motor casing made of a material that is resistant to corrosion against the liquid fuel material (e.g., stainless steel), thus adequately protecting the pump device from corrosion. Furthermore, by measuring vibrations with a sensor (e.g., an acceleration sensor) installed near the bearing, wear of the bearing can be appropriately detected. In this case, the motor cable that supplies power to the pump device's motor and the sensor cable that transmits output signals from the sensor are also installed inside the tank that stores corrosive liquid fuel material. However, the motor cable and sensor cable are covered by motor cable protection tubes and sensor cable protection tubes made of materials that are resistant to corrosion against the liquid fuel material, thus adequately protecting the motor cable and sensor cable from corrosion.

[0030] Furthermore, the pump device of the present invention is a pump device for pumping up a liquid fuel material from inside a tank in which a corrosive liquid fuel material is stored, wherein the pump device comprises a vertical rotating shaft, a canned motor in which both the stator and rotor of the motor are covered with a can made of a material that is corrosion-resistant to the liquid fuel material, and a ball bearing that rotatably supports the rotating shaft, wherein both the stator and rotor of the motor are arranged so that the outer surface of the can is immersed in the liquid fuel material. [Effects of the Invention]

[0031] According to the present invention, bearing wear can be appropriately detected, and pump devices, sensors, and other components can be protected from corrosion. [Brief explanation of the drawing]

[0032] [Figure 1] This is an explanatory diagram showing the configuration of a pump system in an embodiment of the present invention. [Figure 2]This is a cross-sectional view of a pump device according to an embodiment of the present invention. [Figure 3] This is an explanatory diagram showing the flow of nitrogen gas in an embodiment of the present invention (when the ammonia concentration is below a threshold). [Figure 4] This is an explanatory diagram showing the flow of nitrogen gas in an embodiment of the present invention (when the ammonia concentration is above a threshold). [Modes for carrying out the invention]

[0033] Hereinafter, a pump device according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an example of a pump device used as a canned motor pump for liquid ammonia will be shown.

[0034] The configuration of the pump device according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 is an explanatory diagram showing the configuration of the pump system according to this embodiment, and Figure 2 is a cross-sectional view of the canned motor portion of the pump device according to this embodiment. The rotation axis of the canned motor is a vertical axis, and although not shown, the lower part of the rotation axis of the canned motor is connected to the vertical axis of the pump rotation axis, which is connected to the pump impeller, and these are surrounded by the pump casing.

[0035] As shown in Figures 1 and 2, the pump system 1 comprises a tank 2 in which liquid ammonia (a corrosive liquid fuel material) is stored, and a pump device 3 installed inside the tank 2 to pump up the liquid ammonia. When the canned motor is operated, the impeller of the pump below it rotates, drawing in liquid ammonia from below the pump device 3, and the liquid ammonia passes through the canned motor section and is pumped upward. The tank 2 is equipped with a tank casing 4 made of a material resistant to corrosion from liquid ammonia (e.g., stainless steel), and the pump device 3 is equipped with a motor casing 5 made of a material resistant to corrosion from liquid ammonia (e.g., stainless steel).

[0036] As shown in Figure 2, the canned motor section contains, inside the motor casing 5, a motor (stator) 6 that generates the driving force for the pump device 3, a motor (rotor) 6', a rotating shaft 7 that extends in the direction of the rotation axis (vertical direction) of the motor (rotor) 6' and is rotated by the driving force of the motor (rotor) 6', and bearings 8 that rotatably support the rotating shaft 7, located at the upper and lower positions in the direction of the rotation axis of the motor (rotor) 6'. The bearings 8 are liquid-lubricated ball bearings made of ceramic or stainless steel with corrosion resistance in mind.

[0037] Furthermore, the liquid ammonia pumped up from below the canned motor passes between the motor (stator) 6 and the motor (rotor) 6' and is pumped further upward. The motor (stator) 6 and the motor (rotor) 6' must be sealed to prevent contact with the liquid, otherwise they will be damaged by corrosion. Therefore, the motor (stator) 6 and the motor (rotor) 6' are sealed with a can made of corrosion-resistant material (stainless steel) to prevent contact with the liquid being handled, resulting in a canned motor structure. In addition, inside the motor casing 5 that covers the motor (stator) 6, acceleration sensors 9 are installed near the bearings 8 located at the closest positions above and below the rotation axis of the motor (rotor) 6', respectively, to measure the high-frequency vibration of the bearings 8.

[0038] The "proximity" refers to the upper and lower ends of the can that seals the motor (stator) 6, as shown in Figure 2, or more preferably, the wall surface inside the motor casing 5 facing the motor (rotor) 6' side, which is as close as possible to the surface that mechanically contacts the bearing body 80 that houses the bearings 8 located at the upper and lower positions in the rotation axis direction of the motor (rotor) 6'. By doing so, the sensor sensitivity to the vibration state of the nearest upper and lower bearings 8 from the motor (rotor) 6' becomes more sensitive, enabling highly accurate vibration measurement and allowing for appropriate detection of bearing wear.

[0039] As shown in Figures 1 and 2, outside the tank 2 are a power supply unit 10 that supplies power to the pump device 3, and two measuring devices 11 (upper measuring device 11 and lower measuring device 11) that receive output signals from a pair of upper and lower acceleration sensors 9. A motor cable 12 that supplies power from the power supply unit 10 is connected to the motor (stator) 6, and sensor cables 13 that transmit output signals to the measuring devices 11 (upper measuring device 11 and lower measuring device 11) are connected to the pair of upper and lower acceleration sensors 9, respectively. The motor cable 12 and sensor cables 13 are covered by motor cable protection tubes 14 and sensor cable protection tubes 15, respectively, which are made of a material that is corrosion-resistant to liquid ammonia (for example, stainless steel). Since the motor (stator) 6 is a canned motor structure sealed with a corrosion-resistant material can to prevent contact with the liquid being handled, the motor cable 12 and the acceleration sensors 9 and their sensor cables 13 can be connected to the power supply unit 10 and measuring devices 11 (upper measuring device 11 and lower measuring device 11) outside the tank 2 without coming into contact with the liquid ammonia inside the tank. The sensor cable protection tube 15 can also be called the internal tank piping.

[0040] As shown in Figure 1, outside the tank 2, there is a nitrogen tank 16 for supplying nitrogen gas as a purge gas, and a nitrogen gas piping 17 through which the nitrogen gas supplied from the nitrogen tank 16 flows. Here, the nitrogen tank 16 corresponds to the purge gas supply unit of the present invention, and the nitrogen gas piping 17 corresponds to the purge gas piping of the present invention. The nitrogen gas piping 17 is connected to the motor cable protection tube 14 and the sensor cable protection tube 15, and the nitrogen gas supplied from the nitrogen tank 16 is supplied from the nitrogen gas piping 17 through the sensor cable protection tube 15 into the motor casing 5, and then returned from the inside of the motor casing 5 through the motor cable protection tube 14 to the nitrogen gas piping 17. For example, liquefied ammonia has a boiling point of -33.4°C, but this configuration makes it possible to prevent condensation in the motor (stator) 6, motor cable 12, acceleration sensor 9, and sensor cable 13 in a low-temperature environment. Alternatively, the nitrogen gas supplied from the nitrogen tank 16 may be supplied from the nitrogen gas piping 17 through the motor cable protection tube 14 into the motor casing 5, and then returned from the inside of the motor casing 5 through the sensor cable protection tube 15 to the nitrogen gas piping 17.

[0041] Furthermore, as shown in Figure 1, the nitrogen gas piping 17 is equipped with a pressure adjustment unit 18 that maintains a constant internal pressure, and a pressure sensor 19 that detects changes in the nitrogen gas pressure inside the nitrogen gas piping 17. By providing the pressure sensor 19 installed in the nitrogen gas piping 17 to detect changes in the nitrogen gas pressure inside the piping 17, it is possible to determine that if the pressure rises above a set level, it is determined that the invading liquid fuel material has vaporized and increased the pressure, and if the pressure falls below a set level, it is determined that the purged nitrogen gas has leaked and reduced the pressure.

[0042] Furthermore, the nitrogen gas piping 17 is equipped with a flow sensor 20 that detects changes in the flow rate of nitrogen gas inside the nitrogen gas piping 17, and a flow adjustment unit that maintains a constant flow rate inside the nitrogen gas piping 17. By providing the flow sensor 20 that detects changes in the flow rate of nitrogen gas inside the nitrogen gas piping 17, it is possible to determine that the flow rate has increased because the liquid fuel material that has entered has vaporized if the flow rate is higher than the set rate, and that the flow rate has decreased because nitrogen gas has leaked if the flow rate is lower than the set rate.

[0043] Furthermore, by providing a pressure adjustment unit 18 installed in the nitrogen gas piping 17 to maintain a constant internal pressure, a pressure sensor 19 installed in the nitrogen gas piping 17 to detect changes in gas pressure inside the nitrogen gas piping, and a flow sensor 20 installed in the nitrogen gas piping 17 to detect changes in gas flow rate inside the nitrogen gas piping 17, it becomes possible to more accurately determine that if the pressure rises above a set level, it is due to the vaporization of the invading liquid fuel material causing an increase in pressure, and if the flow rate falls below a set level, it is due to a leak of purge gas causing a decrease in flow rate.

[0044] The pressure adjustment unit 18 can be configured, for example, with a pressure reducing valve. The nitrogen gas piping 17 is also equipped with an ammonia detector 21 that detects whether or not ammonia gas vaporized from liquid ammonia is mixed inside the nitrogen gas piping 17. The ammonia detector 21 can detect, for example, the presence of ammonia gas inside the nitrogen gas piping 17 when the concentration of ammonia contained in the nitrogen gas inside the nitrogen gas piping 17 exceeds a predetermined threshold.

[0045] Furthermore, as shown in Figure 1, an ammonia abatement pipe 22 is branched off from the nitrogen gas pipe 17 to abate ammonia gas. The ammonia abatement pipe 22 is connected to an ammonia abatement device 23, which abates ammonia gas vaporized from liquid ammonia mixed inside the nitrogen gas pipe 17.

[0046] The ammonia abatement device 23 is connected to a water supply pipe 24 for supplying water (washing water) used to abate ammonia gas, a drain pipe 25 for discharging the ammonia water produced by the ammonia gas abatement, and an exhaust pipe 26 for discharging nitrogen gas from which ammonia gas has been removed. The water supply pipe 24 is equipped with a water pump 27 for supplying water (washing water) used to ammonia gas abatement to the ammonia abatement device 23.

[0047] The ammonia abatement piping 22 is equipped with an automatic valve 28 that is controlled to open when ammonia gas is being treated for abatement, and a blower 29 for sending nitrogen gas mixed with ammonia gas to the ammonia abatement device 23. The automatic valve 28 of the ammonia abatement piping 22 is controlled to close when ammonia gas is not being treated for abatement. The nitrogen gas piping 17 is equipped with an automatic valve 30 that is controlled to close when ammonia gas is being treated for abatement. The automatic valve 30 of the nitrogen gas piping 17 is controlled to open when ammonia gas is not being treated for abatement.

[0048] Figures 3 and 4 are explanatory diagrams showing the flow of nitrogen gas in the pump system 1 of this embodiment. In Figures 3 and 4, the flow of nitrogen gas is indicated by arrows. As shown in Figure 3, if the ammonia detector 21 does not detect that ammonia gas is mixed inside the nitrogen gas piping 17, that is, if the concentration of ammonia contained in the nitrogen gas in the nitrogen gas piping 17 is below a predetermined threshold, the automatic valve 30 of the nitrogen gas piping 17 is opened and the automatic valve 28 of the ammonia removal piping 22 is closed.

[0049] Furthermore, as shown in Figure 4, if the ammonia detector 21 detects that ammonia gas is mixed inside the nitrogen gas piping 17, that is, if the concentration of ammonia contained in the nitrogen gas in the nitrogen gas piping 17 is above a predetermined threshold, the automatic valve 30 of the nitrogen gas piping 17 is closed and the automatic valve 28 of the ammonia removal piping 22 is opened.

[0050] In this embodiment of the pump device 3, the pump device 3 is installed inside a tank 2 that stores corrosive liquid ammonia (e.g., liquid ammonia), but the motor (stator) 6 is covered by a motor casing 5 made of a material that is resistant to corrosion against liquid ammonia (e.g., stainless steel), so the pump device 3 can be properly protected from corrosion. In addition, wear of the bearing 8 can be properly detected by measuring vibration with an acceleration sensor 9 installed near the bearing 8. In this case, the motor cable 12 that supplies power to the motor 6 of the pump device 3 and the sensor cable 13 that transmits the output signal from the acceleration sensor 9 are also installed inside the tank 2 that stores liquid ammonia, but the motor cable 12 and sensor cable 13 are covered by a motor cable protection tube 14 and a sensor cable protection tube 15 made of a material that is resistant to corrosion against liquid ammonia, so the motor cable 12 and sensor cable 13 can be properly protected from corrosion.

[0051] Furthermore, according to the pump device 3 of this embodiment, nitrogen gas supplied from the nitrogen tank 16 is supplied from the nitrogen gas piping 17 to the inside of the motor casing 5 through either the motor cable protection tube 14 or the sensor cable protection tube 15, and then returned from the inside of the motor casing 5 to the nitrogen gas piping 17 through the other of the motor cable protection tube 14 or the sensor cable protection tube 15. In this way, nitrogen gas can be circulated using the motor cable protection tube 14 and the sensor cable protection tube 15, so the inside of the motor casing 5 can be effectively purged with nitrogen gas compared to the case where nitrogen gas cannot be circulated. Therefore, even if liquid ammonia enters the inside of the motor casing 5, the motor (stator) 6 can be properly protected from corrosion by purging. Also, in this case, since nitrogen gas can be circulated, the inside of the motor cable protection tube 14 and the sensor cable protection tube 15 can also be effectively purged with nitrogen gas. Therefore, even if liquid ammonia enters the inside of the motor casing 5, the motor cable 12 and the sensor cable 13 can be properly protected from corrosion by purging.

[0052] Furthermore, in this embodiment, the pressure adjustment unit 18 maintains a constant pressure inside the nitrogen gas piping 17. If liquid ammonia enters the motor casing 5, motor cable protection tube 14, or sensor cable protection tube 15, vaporized ammonia gas is generated from the liquid ammonia, causing a change in the pressure inside the nitrogen gas piping 17. In this case, the pressure sensor 19 can detect the change in nitrogen gas pressure inside the nitrogen gas piping 17, thereby detecting that liquid ammonia has entered the motor casing 5, motor cable protection tube 14, or sensor cable protection tube 15.

[0053] Furthermore, if liquid ammonia enters the motor casing 5, motor cable protection tube 14, or sensor cable protection tube 15, vaporized ammonia gas will be generated from the liquid ammonia, changing the flow rate of nitrogen gas inside the nitrogen gas piping 17. In this case, the flow sensor 20 can detect the change in the flow rate of nitrogen gas inside the nitrogen gas piping 17, thereby detecting that liquid ammonia has entered the motor casing 5, motor cable protection tube 14, or sensor cable protection tube 15.

[0054] Furthermore, in this embodiment, if liquid ammonia enters the motor casing 5, motor cable protection tube 14, or sensor cable protection tube 15, vaporized ammonia gas from the liquid ammonia will enter the nitrogen gas piping 17. In this case, the ammonia detector 21 can detect whether or not vaporized ammonia gas from the liquid ammonia has entered the nitrogen gas piping 17, thereby detecting that liquid ammonia has entered the motor casing 5, motor cable protection tube 14, or sensor cable protection tube 15.

[0055] Furthermore, in this embodiment, if liquid ammonia enters the motor casing 5, motor cable protection tube 14, or sensor cable protection tube 15, the ammonia abatement device 23 can detoxify the ammonia gas vaporized from the liquid ammonia that has entered the purge gas piping. [Industrial applicability]

[0056] As described above, the pump device according to the present invention has the effect of appropriately detecting bearing wear and protecting the pump device, sensors, etc. from corrosion, and is useful when used as a canned motor pump for liquid ammonia, etc. [Explanation of Symbols]

[0057] 1. Pump System 2 tanks 3. Pumping device 4 Tank casing 5. Motor casing 6. Motor (stator) 6' Motor (Rotor) 7 Rotating Shaft 8 bearings 80 Bearing body 9. Accelerometer (sensor) 10 Power supply 11. Measuring devices (upper measuring device, lower measuring device) 12 Motor Cables 13 Sensor Cable 14 Motor cable protection tube 15 Sensor cable protection tube 16. Nitrogen tank (purge gas supply unit) 17. Nitrogen gas piping (purge gas piping) 18 Pressure adjustment section 19. Pressure sensor 20 Flow Sensor 21 Ammonia detector (detector) 22 Ammonia removal piping 23 Ammonia abatement device (abatement device) 24 Water supply pipe 25 Drain pipe 26 Exhaust pipe 27 Water supply pump 28 Automatic valves 29 Blower 30 Automatic valves

Claims

1. In a pumping device for drawing up a liquid fuel material from inside a tank in which a corrosive liquid fuel material is stored, The pump device is, A motor casing, which is made of a material that is corrosion-resistant to the liquid fuel material, and which covers the motor stator of the pump device inside the tank, A motor installed inside the motor casing generates the driving force for the pump device, A rotating shaft that is rotated by the driving force of the motor, A bearing installed in the motor casing and rotatably supporting the rotating shaft, A sensor is installed near the bearing within the motor casing to measure the vibration of the bearing, A motor cable connected to a power supply unit installed outside the tank, which supplies power from the power supply unit to the motor, A sensor cable connected to a measuring device installed outside the tank, which transmits the output signal from the sensor to the measuring device, A motor cable protection tube, which is made of a material that is corrosion-resistant to the liquid fuel material and covers the motor cable inside the tank, A sensor cable protection tube, which is made of a material that is corrosion-resistant to the liquid fuel material and covers the sensor cable inside the tank, A purge gas pipe is connected to a purge gas supply unit installed outside the tank, and through which the purge gas supplied from the purge gas supply unit flows. A pumping device equipped with the following features.

2. The motor comprises a rotor, The aforementioned sensor is The pump device according to claim 1, provided on the rotor side wall surface within the motor casing that covers the motor stator.

3. The motor comprises a rotor, The aforementioned sensor is The pump device according to claim 1, wherein the pump is located within the motor casing covering the motor stator, at a position closest to the bearing.

4. The aforementioned rotating shaft is equipped with a bearing, The aforementioned sensor is The pump device according to claim 1, wherein the bearing is located in the motor casing covering the motor stator, at the position closest to the surface that mechanically contacts the bearing body housing the bearing.

5. The pump device according to claim 1, wherein the purge gas piping is connected to the motor cable protection tube and the sensor cable protection tube, and the purge gas supplied from the purge gas supply unit is supplied from the purge gas piping through either the motor cable protection tube or the sensor cable protection tube into the motor casing, and returned from the motor casing through the other of the motor cable protection tube or the sensor cable protection tube to the purge gas piping.

6. The pump device according to claim 5, further comprising a fuel detector installed in the purge gas piping for detecting whether or not fuel gas vaporized from the liquid fuel material is mixed inside the purge gas piping.

7. A pressure adjustment unit is installed in the purge gas piping and maintains a constant pressure inside the purge gas piping, A pressure sensor installed in the purge gas piping detects changes in the pressure of the purge gas inside the purge gas piping, The pump device according to claim 6, comprising:

8. A flow rate adjustment unit is installed in the purge gas piping to maintain a constant flow rate inside the purge gas piping, A flow sensor is installed in the purge gas piping and detects changes in the flow rate of the purge gas inside the purge gas piping. The pump device according to claim 5 or claim 6, comprising:

9. A pressure adjustment unit is installed in the purge gas piping and maintains a constant pressure inside the purge gas piping, A pressure sensor installed in the purge gas piping detects changes in the pressure of the purge gas inside the purge gas piping, A flow sensor is installed in the purge gas piping and detects changes in the flow rate of the purge gas inside the purge gas piping. The pump device according to claim 6, comprising:

10. The pump device according to claim 6, further comprising a detoxification device connected to the purge gas piping for detoxifying fuel gas vaporized from the liquid fuel material mixed inside the purge gas piping.

11. The aforementioned pollution control device is A water supply pipe for supplying a first liquid used to detoxify the fuel gas vaporized from the aforementioned liquid fuel material, A drain pipe for discharging the second liquid generated by the detoxification of the fuel gas, An exhaust pipe for discharging the gas from which the aforementioned fuel gas has been removed, They are equipped, The pump device according to claim 10, wherein the water supply pipe is provided with a water supply pump for sending the first liquid to the abatement device.

12. A tank for storing corrosive liquid fuel materials, A pump device for drawing up the liquid fuel material from inside the tank, In a pump system equipped with, The pump device is, A motor casing, which is made of a material that is corrosion-resistant to the liquid fuel material and covers the motor of the pump device inside the tank, A motor installed inside the motor casing generates the driving force for the pump device, A rotating shaft that is rotated by the driving force of the motor, A bearing installed in the motor casing and rotatably supporting the rotating shaft, A sensor is installed near the bearing within the motor casing to measure the vibration of the bearing, A motor cable connected to a power supply unit installed outside the tank, which supplies power from the power supply unit to the motor, A sensor cable connected to a measuring device installed outside the tank, which transmits the output signal from the sensor to the measuring device, A motor cable protection tube, which is made of a material that is corrosion-resistant to the liquid fuel material and covers the motor cable inside the tank, A sensor cable protection tube, which is made of a material that is corrosion-resistant to the liquid fuel material and covers the sensor cable inside the tank, A purge gas pipe is connected to a purge gas supply unit installed outside the tank, and through which the purge gas supplied from the purge gas supply unit flows. A pump system equipped with the following features.

13. In a pumping device for drawing up a liquid fuel material from inside a tank in which a corrosive liquid fuel material is stored, The pump device is, A vertical axis rotating shaft, A canned motor in which both the stator and rotor of the motor are covered with a can made of a material that is corrosion-resistant to the liquid fuel material, A ball bearing that rotatably supports the aforementioned rotating shaft, Equipped with, A pump device in which the stator and rotor of the motor are both arranged such that the outer surface of the can is immersed in the liquid fuel material.

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