A method and apparatus for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system.

Abstract

A method and apparatus for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system includes: a water collection device installed at the bottom of the vertical pump outlet connecting pipe, a field solenoid valve control device, and a PLC programmable logic controller. When the vertical pump is running normally, the inlet solenoid valve of the water collection tank is demagnetized and closed, while the drain solenoid valve is energized and opened, allowing water in the collection tank to be discharged into a water pool. When the vertical pump stops, the inlet solenoid valve of the water collection tank is energized and opened, while the drain solenoid valve is demagnetized and closed. The normally open contact signal of the level switch is sent to the PLC programmable logic controller, which logically controls the functions of the lubricating water solenoid valve and the inlet and outlet solenoid valves of the water collection tank. When the water level exceeds the level switch in the water collection tank, the field solenoid valve control device is activated, demagnetizing and opening the lubricating water solenoid valve to deliver lubricating water to the bearing of the vertical pump, thus protecting the shaft from damage in the event of reverse rotation.

Description

Technical Field

[0001] This invention relates to a circulating water system, and more particularly, to a method and apparatus for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system. More specifically, this invention relates to a method and apparatus for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system used in the metallurgical field. Background Technology

[0002] Various circulating water systems are used in the metallurgical industry. For example, Baosteel's heavy plate circulating water system is equipped with 119 pumps, including 30 vertical pumps, which are composed of 9 pump sets. Each pump set is redundantly configured to facilitate the rotation and maintenance of each pump.

[0003] Because the maximum water supply pressure of various circulating water systems in the metallurgical industry typically needs to reach 1.2 MPa, while the general water pressure is between 0.4 and 0.6 MPa, various vertical pump sets need to deliver production water at different pressures to each user, or transfer it to various internal water treatment process systems.

[0004] Typically, in addition to the manual shut-off valve at the outlet, each vertical pump is also equipped with an electric outlet valve and a check valve to prevent backflow into the main water supply pipe when the pump stops. The composition and configuration of each vertical pump unit in the various circulating water systems are described below. Figure 1 As shown.

[0005] Under normal circumstances, the manual shut-off valves at the outlet of each vertical pump are open, while the electric valves at the outlet of the stopped vertical pumps are closed, and the check valves are automatically closed.

[0006] When the vertical pump is started, the outlet electric valve opens slowly according to the set program under the control of the PLC. Under the action of the water pressure at the outlet of the vertical pump, it overcomes the gravity of the check valve plate, and the check valve also opens automatically. The vertical pump delivers pressure and water to the water supply header, and the water supply header supplies water to the user.

[0007] When the vertical pump stops, the outlet pressure decreases. When the outlet pressure cannot overcome the weight of the check valve plate, the check valve closes, disconnecting the vertical pump from the main water supply pipe. Simultaneously, under the pressure of the main water supply pipe, the check valve is tightly closed, and the electric valve closes under the control of the PLC program. At the same time, after the vertical pump stops and the electric valve closes, the remaining water in its outlet flows back to the water tank through the suction pipe.

[0008] The structure of the vertical pump is as follows: Figure 2 As shown.

[0009] However, in the water treatment system of the thick plate, the valves at the outlet of each vertical pump are usually electric single eccentric butterfly valves, swing check valves, and single eccentric manual butterfly valves. When the check valve fails to close completely due to jamming or sealing leakage, and the electric butterfly valve has a certain leakage, water in the main pipe will backflow into the vertical pump. At the same time, under the action of water pressure, the rotor of the vertical pump will reverse.

[0010] For high-pressure vertical pumps, the higher water pressure in the main pipe results in a greater thrust on the pump rotor, leading to a higher rotational speed when reverse rotation occurs. Without effective monitoring techniques and preventative measures, reverse rotation of a vertical pump is difficult to detect, especially at night when lighting is dim, making it hard to detect in time.

[0011] On the other hand, when a vertical pump is stopped, the lubricating water is not flowing. When the pump reverses, the shaft will wear. When the pump needs to be started, the motor will be under a large load, causing it to trip. At this time, the strong torque often causes the pump shaft to be damaged or even broken due to vibration. In more serious cases, it can also damage the pump impeller. Summary of the Invention

[0012] To overcome the above problems, the object of the present invention is:

[0013] A method and apparatus for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system are provided. The method and apparatus employ a vertical pump reverse rotation detection and alarm system, and prevent wear and breakage of the vertical pump rotor shaft by adopting measures to protect the vertical pump during startup.

[0014] That is, the present invention employs a monitoring and control system that enables the previously unpredictable reverse rotation of the vertical pump to be detected in a timely manner, and at the same time activates protective measures to ensure the safety of the vertical pump body by effectively protecting the vertical pump that has already reversed.

[0015] To achieve the above objectives, the technical solution of the present invention is as follows:

[0016] A method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system, characterized in that,

[0017] A water collection device and a field solenoid valve control device are installed at the bottom of the vertical pump outlet connection pipe.

[0018] The water collection device includes a water collection tank, inlet and outlet solenoid valves of the water collection tank, and a liquid level switch in the water collection tank. When the vertical pump is running normally, the inlet solenoid valve of the water collection tank is demagnetized and closed, and the drain solenoid valve is energized and opened. If there is water accumulation in the water collection tank, it will be discharged into the water pool.

[0019] When the vertical pump stops, the inlet solenoid valve of the water collection tank is energized and opened, and the drain solenoid valve is de-energized and closed.

[0020] At this time, since the electric valve and check valve on the vertical pump outlet pipe are closed, the water in the suction pipe flows back into the water tank. Under normal circumstances, there may be a small amount of water in the collection tank.

[0021] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0022] The level switch is equipped with a normally open contact. The normally open contact signal of the level switch is sent to the DI digital signal input module of the PLC programmable logic controller in the central control cabinet via a cable. The PLC programmable logic controller is equipped with a water level detection contact for the water collection tank based on the original lubricating water control logic circuit diagram of the vertical pump. The water level detection contact signal of the water collection tank controls the function of the lubricating water solenoid valve and the control function of the water collection tank inlet and outlet solenoid valves.

[0023] When the water level exceeds the level switch in the water collection tank, the on-site solenoid valve control device is activated based on the signal received from the water collection tank level switch. The solenoid valve is demagnetized and opened to send lubricating water into the bearing of the vertical pump, thus protecting the vertical pump from shaft damage in the event of reverse rotation.

[0024] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0025] As the on-site solenoid valve control device opens the lubricating water solenoid valve and sends lubricating water into the bearing of the vertical pump, the PLC programmable logic controller issues an audible and visual alarm. The faulty vertical pump flashes on the computer operation screen, and the buzzer sounds an alarm.

[0026] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0027] The circulating water system is a metallurgical thick plate water treatment system.

[0028] This invention improves the equipment as follows: Figure 3 As shown.

[0029] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0030] When the water level exceeds the level switch in the water collection tank, the on-site solenoid valve control device opens the lubricating water solenoid valve to send lubricating water into the bearing of the vertical pump. At the same time, the PLC programmable logic controller issues an audible and visual alarm, the faulty vertical pump flashes on the computer operation screen, and the buzzer sounds an alarm.

[0031] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0032] The circulating water system is a metallurgical thick plate water treatment system.

[0033] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0034] When the vertical pump stops, the inlet solenoid valve of the water collection tank is energized and opened, and the drain solenoid valve is de-energized and closed.

[0035] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0036] When the water level exceeds the level switch, the normally open contact of the level switch closes, and the signal is transmitted via cable to the DI module of the PLC in the central control cabinet. Based on the signal from the level switch in the water tank, the control system added to the PLC immediately starts, demagnetizing and opening the lubricating water solenoid valve to deliver lubricating water to the bearings of the vertical pump, protecting the shaft from damage in the event of reverse rotation. Simultaneously, the control system issues an audible and visual alarm on the operating screen, alerting operators to the abnormality of the vertical pump.

[0037] When the vertical pump stops, the inlet solenoid valve of the water collection tank is energized and opened, and the drain solenoid valve is de-energized and closed.

[0038] At this time, since the electric valve and check valve on the vertical pump outlet pipe are closed, the water in the suction pipe flows back into the water tank. Under normal circumstances, there may be a small amount of water in the collection tank.

[0039] In addition, if the check valve leaks, the pressure of the water supply main pipe will cause backflow into the vertical pump suction pipe. Since the inlet of the water collection tank is at the bottom of the outlet pipe, water will accumulate in the water collection tank. As the amount of accumulated water increases, the liquid level in the water collection tank will rise.

[0040] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0041] The PLC programmable logic controller is configured with functions for controlling the lubricating water solenoid valve by detecting the water level at the inlet of the water collection tank and controlling the inlet and outlet solenoid valves of the water collection tank, based on the original lubricating water control logic circuit diagram of the vertical pump.

[0042] New features such as Figure 4 As shown, the dashed box represents the new part of this invention based on the original lubricating water control logic circuit diagram of the vertical pump.

[0043] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0044] The normally closed contacts of the vertical pump start / stop signal #PUMP6_RUN and the normally closed contacts of the water tank level switch #PUMP6_LEVEL_SWITCH are used to form an AND logic.

[0045] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0046] When the vertical pump is running, the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is opened, the lubricating water solenoid valve #RVALVE6_OPEN is demagnetized and closed, and lubricating water is delivered to the vertical pump bearing.

[0047] According to the present invention, a method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0048] Because the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is opened, the inlet solenoid valve #INIT6_OPEN of the water collection tank is demagnetized and closed, and at the same time, the discharge solenoid valve #DRAIN_CLOSE of the water collection tank is energized and opened through the NOT logic.

[0049] That is, when the vertical pump stops, the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN closes, the lubricating water solenoid valve #RVALVE6_OPEN is de-energized and disconnected, and at the same time, the discharge solenoid valve #DRAIN_CLOSE of the water collection tank is de-energized and closed through NOT logic, and the lubricating water is shut off.

[0050] According to the present invention, if the outlet valve of the vertical pump is in good condition, there will be no water accumulation in the water collection tank, the normally closed contact of the level switch #PUMP6_LEVEL_SWITCH will be closed, and the entire system will be in good condition.

[0051] This invention also provides a device for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system, characterized in that...

[0052] A water collection device, a field solenoid valve control device, and a PLC programmable logic controller are installed at the bottom of the vertical pump outlet connection pipe.

[0053] The water collection device includes a water collection tank, inlet and outlet solenoid valves for the water collection tank, and a level switch in the water collection tank.

[0054] The PLC programmable logic controller is set up with a water level detection contact for the water collection tank based on the original lubricating water control logic circuit diagram of the vertical pump. The signal from the water level detection contact controls the lubricating water solenoid valve and the inlet and outlet solenoid valves of the water collection tank.

[0055] The level switch is equipped with normally open contacts, and the signal from the normally open contacts of the level switch is sent to the DI digital signal input module of the PLC programmable logic controller in the central control cabinet via a cable.

[0056] When the vertical pump is running normally, the inlet solenoid valve of the water collection tank is demagnetized and closed, and the drain solenoid valve is energized and opened, so that any water accumulated in the water collection tank is discharged into the water pool.

[0057] When the vertical pump stops, the inlet solenoid valve of the water collection tank is energized and opened, and the drain solenoid valve is demagnetized and closed.

[0058] When the water level exceeds the level switch in the water collection tank, the on-site solenoid valve control device is activated based on the signal received from the water collection tank level switch. The solenoid valve is demagnetized and opened to send lubricating water into the bearing of the vertical pump, thus protecting the vertical pump from shaft damage in the event of reverse rotation.

[0059] According to the present invention, a device for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0060] The PLC programmable logic controller uses the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN and the normally closed contact of the water tank level switch #PUMP6_LEVEL_SWITCH, and the signals of the two are combined into AND logic.

[0061] According to the present invention, a device for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0062] When the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is opened, the inlet solenoid valve #INIT6_OPEN of the water collection tank is demagnetized and closed, and at the same time, the discharge solenoid valve #DRAIN_CLOSE of the water collection tank is energized and opened through a NOT logic.

[0063] According to the present invention, a device for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system is characterized in that,

[0064] If the vertical pump outlet valve leaks abnormally, backflowing water enters the collection tank, causing the water level in the collection tank to rise. The normally closed contact of the level switch #PUMP6_LEVEL_SWITCH is opened, causing the lubricating water solenoid valve #RVALVE6_OPEN to close and demagnetize. Lubricating water is then supplied to the vertical pump bearing. If the vertical pump shaft reverses, it is protected by the lubricating water. At the same time, the signal from the level switch #PUMP6_LEVEL_SWITCH contact is sent to the PLC alarm circuit.

[0065] According to the present invention, if an abnormal leak occurs in the outlet valve of the vertical pump, backflowing water enters the water collection tank, causing the water level in the tank to rise. This opens the normally closed contact of the level switch #PUMP6_LEVEL_SWITCH, demagnetizing and closing the lubricating water solenoid valve #RVALVE6_OPEN, allowing lubricating water to be supplied to the vertical pump bearing. If the vertical pump shaft reverses direction, it is protected by the lubricating water. Simultaneously, the signal from the level switch #PUMP6_LEVEL_SWITCH is sent to the PLC alarm circuit. Attached Figure Description

[0066] Figure 1 The diagram shows the composition and configuration of a vertical pump set for a circulating water system.

[0067] Figure 2 The diagram shows the structure of a vertical pump in a circulating water system.

[0068] Figure 3 The diagram shows a vertical pump structure for preventing reverse rotation and shaft damage in a circulating water system, as described in this invention.

[0069] Figure 4 The diagram shown is the electrical control logic circuit of the monitoring and control system for preventing vertical pump shaft damage by reversing. The hardware contacts have been modified.

[0070] Figure 5 The diagram shown is a schematic diagram of the water collection tank connection of the present invention. Detailed Implementation

[0071] Example

[0072] A device for preventing reverse rotation and shaft damage of a vertical pump in the circulating water system of Baosteel's heavy plates in the metallurgical field is disclosed. Since the maximum output water pressure of the vertical pump is no greater than 0.6 MPa, the water collection tank of this invention is constructed using seamless steel pipe welding, and the tank is designed for a pressure rating of 1.0 MPa. The structure and accessories of the water collection tank are as follows... Figure 5 As shown. A water collection device is added to the bottom of the outlet connection pipe of the vertical pump, consisting of inlet and outlet solenoid valves of the water collection tank, the water collection tank body and the liquid level switch.

[0073] The inlet pipe of the inlet solenoid valve connects to the bottom of the outlet pipe of the vertical pump, and the outlet pipe of the discharge solenoid valve is inserted into the water tank. Water accumulated in the collection tank is discharged into the water tank. All connecting pipes are galvanized pipes with a diameter of 15mm. The level switch uses an insert-type float, whose movement is positioned by a rod clamp, allowing for precise positioning as needed. The output contact signal is transmitted to the PLC cabinet in the central control room via cable. The collection tank has a diameter of 200mm and a height of 250mm. The tank body is welded, and the cover is bolted on. A bracket is also provided to secure the collection tank.

[0074] When the vertical pump is running normally, the inlet solenoid valve of the water collection tank is demagnetized and closed, and the drain solenoid valve is energized and opened, so that any water accumulated in the water collection tank is discharged into the water pool.

[0075] When the vertical pump stops, the inlet solenoid valve of the water collection tank is energized and opened, and the drain solenoid valve is de-energized and closed.

[0076] At this time, since the electric valve and check valve on the vertical pump outlet pipe are closed, the water in the suction pipe flows back into the water tank. Under normal circumstances, there may be a small amount of water in the collection tank.

[0077] If the check valve leaks, the pressure from the main water supply pipe will cause backflow into the vertical pump's suction pipe. Since the inlet of the water collection tank is at the bottom of the outlet pipe, water will accumulate in the collection tank, and as the amount of accumulated water increases, the liquid level in the collection tank will rise.

[0078] When the water level exceeds the level switch, the normally open contact of the level switch closes, and the signal is transmitted via cable to the DI module of the PLC in the central control cabinet. Based on the signal from the level switch in the water tank, the control system added to the PLC immediately starts, demagnetizing and opening the lubricating water solenoid valve to deliver lubricating water to the bearings of the vertical pump, protecting the shaft from damage in the event of reverse rotation. Simultaneously, the control system issues an audible and visual alarm on the operating screen, alerting operators to the abnormality of the vertical pump.

[0079] Based on the original lubricating water control logic diagram of the vertical pump, an inlet water level detection contact for the water collection tank is added. The signal from this contact controls the lubricating water solenoid valve, and the inlet and outlet solenoid valves of the water collection tank are also added for control. New functions include... Figure 4 As shown, the part within the dashed box is the newly added part.

[0080] The normally closed contacts of the vertical pump start / stop signal #PUMP6_RUN and the normally closed contacts of the water tank level switch #PUMP6_LEVEL_SWITCH are used to form an AND logic.

[0081] When the vertical pump is running, the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN opens, the lubricating water solenoid valve #RVALVE6_OPEN closes to demagnetize, and lubricating water is supplied to the vertical pump bearing. Because the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN opens, the water tank inlet solenoid valve #INIT6_OPEN closes to demagnetize, and simultaneously, the water tank discharge solenoid valve #DRAIN_CLOSE is energized and opened via NOT logic.

[0082] like Figure 4As shown, when the vertical pump stops, the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN closes, the lubricating water solenoid valve #RVALVE6_OPEN is de-energized, and the lubricating water supply is shut off. Simultaneously, the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN closes, causing the water collection tank inlet solenoid valve #INIT6_OPEN to open, while the NOT logic de-energizes and closes the water collection tank discharge solenoid valve #DRAIN_CLOSE.

[0083] If the outlet valve of the vertical pump is in good condition, there will be no water accumulation in the collection tank, the normally closed contact of the level switch #PUMP6_LEVEL_SWITCH will close, and the entire system will be in good condition.

[0084] If an abnormal leak occurs at the outlet valve of the vertical pump, backflowing water will enter the collection tank, causing the water level in the tank to rise. This will open the normally closed contact of the level switch #PUMP6_LEVEL_SWITCH, demagnetizing and closing the lubricating water solenoid valve #RVALVE6_OPEN, allowing lubricating water to be supplied to the vertical pump bearing. If the pump shaft reverses direction, the lubricating water will protect it. Simultaneously, the signal from the level switch #PUMP6_LEVEL_SWITCH is sent to the PLC alarm circuit.

[0085] The newly added logic control system uses the standard modules of the PLC itself, and modifies and adds new functions to the original lubricating water solenoid valve control system to meet the needs of the new equipment.

[0086] The device and method of this invention are applicable to the original operation method of vertical pumps. The control of the solenoid valves is all automatic control according to the interlocking program. The only addition is an audible and visual alarm displayed on the computer operation screen. After the vertical pump malfunction caused by the abnormality is repaired and handled, the alarm is automatically reset and cleared. At the same time, the device and method of this invention do not hinder the repair work of the abnormal vertical pump. All operations involved in the repair process can be performed according to the previous operating procedures.

[0087] This embodiment was implemented on the No. 3 pump of the ACC filter in the wide and thick plate circulating water system. After multiple tests and evaluations, it has been found to meet the actual needs of preventing reverse rotation of the vertical pump. In the more than six months of actual application so far, one reverse rotation alarm occurred. On-site inspection of the vertical pump revealed the reverse rotation phenomenon. Upon disassembly and inspection of the check valve, scale and corrosion were found between the check valve shaft and the shaft seat, causing the valve plate to rotate inflexibly and not to close completely, thus preventing a possible reverse rotation and shaft damage.

Claims

1. A method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system, characterized in that, A water collection device and a field solenoid valve control device are installed at the bottom of the vertical pump outlet connection pipe. The water collection device includes a water collection tank, an inlet solenoid valve, an outlet solenoid valve, and a level switch in the water collection tank. When the vertical pump is running normally, the inlet solenoid valve of the water collection tank is demagnetized and closed, and the outlet solenoid valve is energized and opened. If there is water accumulation in the water collection tank, it will be discharged into the water pool. When the vertical pump stops, the inlet solenoid valve of the water collection tank is energized and opened, while the outlet solenoid valve is de-energized and closed. The level switch is equipped with a normally open contact. The normally open contact signal of the level switch is sent to the DI digital signal input module of the PLC programmable logic controller in the central control cabinet via a cable. The PLC programmable logic controller is equipped with a water level detection contact for the water collection tank based on the control logic circuit diagram of the vertical pump lubrication water. The water level detection contact signal of the water collection tank controls the function of the lubrication water solenoid valve and the control function of the water collection tank inlet and outlet solenoid valves. When the water level exceeds the level switch in the water collection tank, the on-site solenoid valve control device is activated based on the signal received from the water collection tank level switch. The solenoid valve is demagnetized and opened to send lubricating water into the bearing of the vertical pump, thus protecting the vertical pump from shaft damage in the event of reverse rotation.

2. The method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system as described in claim 1, characterized in that, When the water level exceeds the level switch in the water collection tank, the on-site solenoid valve control device opens the lubricating water solenoid valve to send lubricating water into the bearing of the vertical pump. At the same time, the PLC programmable logic controller issues an audible and visual alarm, the faulty vertical pump flashes on the computer operation screen, and the buzzer sounds an alarm.

3. The method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system as described in claim 1, characterized in that, The circulating water system is a metallurgical thick plate water treatment system.

4. The method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system as described in claim 1, characterized in that, When the water level exceeds the level switch, the control system in the PLC is activated, demagnetizing and opening the lubricating water solenoid valve to send lubricating water into the bearing of the vertical pump. This protects the vertical pump from shaft damage in the event of reverse rotation. At the same time, the control system issues an audible and visual alarm on the operation screen to alert the operator that the vertical pump has malfunctioned.

5. The method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system as described in claim 1, characterized in that, The PLC programmable logic controller uses the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN and the normally closed contact of the water tank level switch #PUMP6_LEVEL_SWITCH, and the signals of the two are combined into AND logic.

6. The method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system as described in claim 5, characterized in that, When the vertical pump is running, the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is opened, the lubricating water solenoid valve #RVALVE6_OPEN is demagnetized and closed, and lubricating water is delivered to the vertical pump bearing.

7. The method for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system as described in claim 5, characterized in that, When the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is opened, the inlet solenoid valve #INIT6_OPEN of the water collection tank is demagnetized and closed, and at the same time, the outlet solenoid valve #DRAIN_CLOSE of the water collection tank is energized and opened through a NOT logic.

8. A device for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system, characterized in that, A water collection device, a field solenoid valve control device, and a PLC programmable logic controller are installed at the bottom of the vertical pump outlet connection pipe. The water collection device includes a water collection tank, inlet and outlet solenoid valves of the water collection tank, and a level switch in the water collection tank. The PLC programmable logic controller is set up with a water level detection contact for the water collection tank based on the original lubricating water control logic circuit diagram of the vertical pump. The signal from the water level detection contact controls the lubricating water solenoid valve and the inlet and outlet solenoid valves of the water collection tank. The level switch is equipped with normally open contacts, and the signal from the normally open contacts of the level switch is sent to the DI digital signal input module of the PLC programmable logic controller in the central control cabinet via a cable. When the vertical pump is running normally, the inlet solenoid valve of the water collection tank is demagnetized and closed, and the outlet solenoid valve is energized and opened, so that any water accumulated in the water collection tank is discharged into the water pool. When the vertical pump stops, the inlet solenoid valve of the water collection tank is energized and opened, and the outlet solenoid valve is demagnetized and closed. When the water level exceeds the level switch in the water collection tank, the on-site solenoid valve control device is activated based on the signal received from the water collection tank level switch. The solenoid valve is demagnetized and opened to send lubricating water into the bearing of the vertical pump, thus protecting the vertical pump from shaft damage in the event of reverse rotation.

9. The device for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system as described in claim 8, characterized in that, The PLC programmable logic controller uses the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN and the normally closed contact of the water tank level switch #PUMP6_LEVEL_SWITCH, and the signals of the two are combined into AND logic.

10. The device for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system as described in claim 8, characterized in that, When the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is opened, the inlet solenoid valve #INIT6_OPEN of the water collection tank is demagnetized and closed, and at the same time, the outlet solenoid valve #DRAIN_CLOSE of the water collection tank is energized and opened through a NOT logic.

11. The device for preventing reverse rotation and shaft damage of a vertical pump in a circulating water system as described in claim 8, characterized in that, If the vertical pump outlet valve leaks abnormally, backflowing water enters the collection tank, causing the water level in the collection tank to rise. The normally closed contact of the level switch #PUMP6_LEVEL_SWITCH is opened, causing the lubricating water solenoid valve #RVALVE6_OPEN to close after demagnetization. Lubricating water is then supplied to the vertical pump bearing. If the vertical pump shaft reverses, it is protected by the lubricating water. At the same time, the signal from the level switch #PUMP6_LEVEL_SWITCH contact is sent to the PLC alarm circuit.

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