Method and device for preventing vertical pump from rotating reversely and damaging shaft for circulating water system

Abstract

The invention discloses a method and a device for preventing a vertical pump from reversing and damaging a shaft for a circulating water system. The device comprises a water collecting device arranged at the bottom of an outlet connecting pipe of the vertical pump, a field electromagnetic valve control device and a PLC (Programmable Logic Controller). When the vertical pump operates normally, the inlet electromagnetic valve of the water collecting tank is demagnetized and closed, the drainage electromagnetic valve is excited and opened, and if accumulated water exists in the water collecting tank, the accumulated water is drained into a water pool; when the vertical pump stops pumping, the water collecting tank inlet electromagnetic valve is opened through excitation, and the drainage electromagnetic valve is closed through demagnetization. A normally-open contact signal of the liquid level switch is sent to the PLC, and the PLC logically controls the function of the lubricating water electromagnetic valve and the control function of the electromagnetic valves at the inlet and the outlet of the water collecting tank. When the height of accumulated water exceeds a liquid level switch in the water collecting tank, the field electromagnetic valve control device is started, the lubricating water electromagnetic valve is opened through demagnetization, and lubricating water is fed into a bearing of the vertical pump so as to prevent a shaft from being damaged when the vertical pump rotates reversely.

Description

Technical field:

[0001] The present invention relates to a circulating water system, in particular, the present invention relates to a method and a device for preventing a vertical pump from reversing and damaging its shaft in a circulating water system, and more specifically, the present invention relates to a method and a device for preventing a vertical pump from reversing and damaging its shaft in a circulating water system in the metallurgical field. Background technology:

[0002] The metallurgical field is equipped with various circulating water systems. For example, Baosteel's wide and thick plate circulating water system is equipped with 119 various water pumps, including 30 vertical pumps, consisting of 9 pump groups, each of which is redundant to facilitate the rotation and maintenance of each pump.

[0003] Since the highest water supply pressure of various circulating water systems in the metallurgical field is usually 1.2MPa, and the general water pressure is 0.4-0.6MPa, various vertical pump groups need to deliver production water of different water pressures to each user, or transfer it to various internal water treatment process systems.

[0004] Usually, in addition to the outlet manual stop valve, each vertical pump is also equipped with an outlet electric valve and a check valve to prevent backflow of the water supply main pipe when the pump is stopped. Figure 1 shown.

[0005] Under normal circumstances, the outlet manual stop valves of each vertical pump are in the open state, while the outlet electric valves of the shut-down vertical pumps are in the closed state, and the check valves are in the automatically closed state.

[0006] When the vertical pump is started, the outlet electric valve opens slowly according to the set program under the control of PLC, and the gravity of the check valve plate is overcome by the water pressure at the outlet of the vertical pump, and the check valve also opens automatically. The vertical pump sends pressure and water to the water supply main pipe, and the water is supplied to users through the water supply main pipe.

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

[0008] Among them, the structure of the vertical pump is as follows Figure 2 shown.

[0009] However, in the wide and thick plate water treatment system, 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 is stuck or the seal leaks and cannot be completely closed, the electric butterfly valve has a certain amount of leakage. At this time, the water in the main pipe will flow back 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, due to the high water pressure in the main pipe, the thrust on the vertical pump rotor is greater, and the speed will be higher when reverse rotation occurs. If there is no effective monitoring technology and prevention method, the reverse rotation of the vertical pump is not easy to be discovered, especially at night when the lighting is dim, the reverse rotation of the vertical pump is difficult to be discovered in time.

[0011] On the other hand, when the vertical pump is stopped, the lubricating water is in a stopped state. When the vertical pump is reversed, the shaft of the vertical pump will wear. When the vertical pump needs to be started, the motor will bear a large load, causing the motor to trip. At this time, the strong torque often causes the shaft of the vertical pump to be damaged or even broken due to jumping. In more serious cases, the impeller of the vertical pump will also be damaged. Summary of the invention

[0012] To overcome the above problems, the present invention aims to:

[0013] Provided are a method and device for preventing a vertical pump from reverse rotation and damaging its shaft in a circulating water system. The method and device adopt a vertical pump reverse rotation detection and alarm system, and prevent wear and breakage of the vertical pump rotor shaft by starting vertical pump protection measures.

[0014] That is, the present invention adopts a monitoring and control system, so that the previously unpredictable reversal of the vertical pump can be discovered in time, and at the same time, protective measures are activated so that the vertical pump that has reversed can be effectively protected to ensure the safety of the vertical pump body.

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

[0016] A method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system, characterized in that:

[0017] A water collection device and an on-site solenoid valve control device are installed at the bottom of the vertical pump outlet connecting pipe.

[0018] The water collection device includes a water collection tank, an inlet and outlet electromagnetic valve of the water collection tank, and a liquid level switch in the water collection tank. When the vertical pump operates normally, the inlet electromagnetic valve of the water collection tank is demagnetized and closed, and the drainage electromagnetic valve is excited and opened. If there is water in the water collection tank, it will be discharged into the pool.

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

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

[0021] According to the present invention, a method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

[0022] The liquid level switch is provided with a normally open contact, and the normally open contact signal of the liquid level switch is sent to the DI digital signal input module of the PLC programmable logic controller of the central control cabinet through a cable. The PLC programmable logic controller is provided with a water collecting tank water inlet level detection contact on the basis of the original lubricating water control logic circuit diagram of the vertical pump. The water collecting tank water inlet level detection contact signal controls the function of the lubricating water solenoid valve and the control function of the inlet and outlet solenoid valves of the water collecting tank;

[0023] When the accumulated water height exceeds the liquid level switch in the water collecting tank, the on-site solenoid valve control device is started according to the signal received from the liquid level switch of the water collecting tank, the lubricating water solenoid valve is demagnetized and opened to send lubricating water to the bearings of the vertical pump to protect the vertical pump from shaft damage when reversal occurs.

[0024] According to the present invention, a method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

[0025] When the on-site solenoid valve control device opens the lubricating water solenoid valve and sends the lubricating water into the bearings of the vertical pump, the PLC programmable logic controller sends out 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 a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

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

[0028] The present invention improves the equipment as follows Figure 3 shown.

[0029] According to the present invention, a method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

[0030] When the accumulated water height exceeds the liquid level switch in the water collection tank, the on-site solenoid valve control device opens the lubricating water solenoid valve to send the lubricating water into the bearings of the vertical pump. At the same time, the PLC programmable logic controller sends out 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 a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

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

[0033] According to the present invention, a method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

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

[0035] According to the present invention, a method for preventing a vertical pump from reversing and damaging its shaft 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 is closed, and the contact signal is sent to the DI module of the central control cabinet PLC through the cable. According to the signal of the level switch in the water collection tank, the control system added in the PLC is immediately started, so that the lubricating water solenoid valve is demagnetized and opened, and the lubricating water is sent to the bearing of the vertical pump to protect the vertical pump from shaft damage when the vertical pump is reversed. At the same time, the control system sends an audible and visual alarm on the operation screen to remind the operator to pay attention to the abnormal phenomenon of the vertical pump.

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

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

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

[0040] According to the present invention, a method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

[0041] In the PLC programmable logic controller, based on the original lubricating water control logic circuit diagram of the vertical pump, a water collecting tank water inlet level detection contact signal is set to control the lubricating water solenoid valve function and the water collecting tank inlet and outlet solenoid valve control function.

[0042] New features such as Figure 4 As shown, the dotted frame is the newly added part of the present 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 a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

[0044] Reference the normally closed contact of the vertical pump start and stop signal #PUMP6_RUN and the normally closed contact of the water collection tank level switch #PUMP6_LEVEL_SWITCH, and combine the two signals into a logical combination.

[0045] According to the present invention, a method for preventing a vertical pump from reversing and damaging its shaft 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 disconnected, the lubricating water solenoid valve #RVALVE6_OPEN is demagnetized and closed, and the lubricating water is delivered to the vertical pump bearings.

[0047] According to the present invention, a method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

[0048] Since the normally closed contact of the vertical pump start and stop signal #PUMP6_RUN is disconnected, the water collection tank inlet solenoid valve #INIT6_OPEN is demagnetized and closed, and at the same time, the water collection tank discharge solenoid valve #DRAIN_CLOSE 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 is closed, the lubrication water solenoid valve #RVALVE6_OPEN is de-energized, and at the same time, the discharge solenoid valve #DRAIN_CLOSE of the water collection tank is de-energized and closed through the NOT logic, and the lubrication water is shut off.

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

[0051] The present invention further provides a device for preventing a vertical pump from reversing and damaging its shaft in a circulating water system, which is characterized in that:

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

[0053] The water collecting device includes a water collecting tank, an inlet and outlet electromagnetic valve of the water collecting tank, and a liquid level switch in the water collecting tank.

[0054] The PLC programmable logic controller sets the water collection tank water level detection contact on the basis of the original lubricating water control logic circuit diagram of the vertical pump. The water collection tank water level detection contact signal controls the function of the lubricating water solenoid valve and the control function of the water collection tank inlet and outlet solenoid valves.

[0055] The liquid level switch is set with a normally open contact, and the normally open contact signal of the liquid level switch is sent to the DI digital signal input module of the PLC programmable logic controller of the central control cabinet through a cable;

[0056] When the vertical pump is operating normally, the inlet solenoid valve of the water collection tank is demagnetized and closed, and the drainage solenoid valve is excited and opened. If there is any accumulated water in the water collection tank, it will be discharged into the pool.

[0057] When the vertical pump stops, the solenoid valve at the inlet of the water collection tank is excited and opened, and the drainage solenoid valve is demagnetized and closed;

[0058] When the accumulated water height exceeds the liquid level switch in the water collecting tank, the on-site solenoid valve control device is started according to the signal received from the liquid level switch of the water collecting tank, the lubricating water solenoid valve is demagnetized and opened to send lubricating water to the bearings of the vertical pump to protect the vertical pump from shaft damage when reversal occurs.

[0059] According to the present invention, a device for preventing a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

[0060] In the PLC programmable logic controller, the normally closed contact of the vertical pump start and stop signal #PUMP6_RUN and the normally closed contact of the water collection tank level switch #PUMP6_LEVEL_SWITCH are referenced, and the signals of the two are composed and logical.

[0061] According to the present invention, a device for preventing a vertical pump from reversing and damaging its shaft 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 disconnected, the water collection tank inlet solenoid valve #INIT6_OPEN is demagnetized and closed, and at the same time, the water collection tank discharge solenoid valve #DRAIN_CLOSE is energized and opened through non-logic.

[0063] According to the present invention, a device for preventing a vertical pump from reversing and damaging its shaft in a circulating water system is characterized in that:

[0064] If the vertical pump outlet valve leaks abnormally, the backflow of water enters the water collecting tank, causing the water level in the water collecting tank to rise, and the normally closed contact of the liquid level switch #PUMP6_LEVEL_SWITCH is disconnected, causing the lubricating water solenoid valve #RVALVE6_OPEN to be demagnetized and closed, and the lubricating water is sent to the vertical pump bearing. If the vertical pump shaft reverses, it is protected by the lubricating water. At the same time, the contact signal of the liquid level switch #PUMP6_LEVEL_SWITCH is sent to the PLC alarm circuit.

[0065] According to the present invention, if the vertical pump outlet valve leaks abnormally, the backflowing water enters the water collection tank, causing the water level in the water collection tank to rise, and the normally closed contact of the liquid level switch #PUMP6_LEVEL_SWITCH is disconnected, causing the lubricating water solenoid valve #RVALVE6_OPEN to be demagnetized and closed, and the lubricating water is sent to the vertical pump bearing. If the vertical pump shaft reverses, it is protected by the lubricating water. At the same time, the contact signal of the liquid level switch #PUMP6_LEVEL_SWITCH is sent to the PLC alarm circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 Shown is a schematic diagram of the composition and configuration of the vertical pump group in the circulating water system.

[0067] Figure 2 Shown is a schematic diagram of the vertical pump structure of the circulating water system.

[0068] Figure 3 The figure shows a schematic structural diagram of a vertical pump for preventing the vertical pump from reversing and damaging the shaft in a circulating water system according to the present invention.

[0069] Figure 4 The figure shows the electrical control logic circuit diagram of the monitoring and control system for preventing the vertical pump from reverse rotation and shaft damage according to the present invention, wherein the hardware contact part has been modified.

[0070] Figure 5 Shown is a schematic diagram of the connection of the water collecting tank of the present invention. DETAILED DESCRIPTION

[0071] Example

[0072] A device for preventing vertical pumps from reversing and damaging shafts in Baosteel's wide and thick plate circulating water system in the metallurgical field. Since the maximum water pressure of the vertical pump is no more than 0.6MPa, the water collection tank of the present invention is made of seamless steel pipes and the water collection tank is calculated and made with a pressure level of 1.0MPa. The water collection tank structure and configuration accessories are as follows: Figure 5 A water collection device is added at the bottom of the vertical pump outlet connecting pipe, which is composed of the water collection tank inlet and outlet solenoid valves, the water collection tank body and the liquid level switch.

[0073] The inlet pipe of the water inlet solenoid valve is connected to the bottom of the water outlet pipe of the vertical pump, and the outlet pipe of the discharge solenoid valve is inserted into the pool. The accumulated water in the water collection tank is discharged into the pool. All connecting pipes are galvanized pipes with a diameter of 15mm. The liquid level switch uses an inserted float. The floating ball movement position is positioned by the rod clamp. The specific position can be positioned as needed. The output contact signal is transmitted to the PLC cabinet in the central control room through a cable. The diameter of the water collection tank is 200mm and the height is 250mm. The tank body is welded and the cover is connected by bolts. At the same time, there is a bracket to fix the water collection tank.

[0074] When the vertical pump operates normally, the solenoid valve at the inlet of the water collection tank is demagnetized and closed, and the drainage solenoid valve is energized and opened. Any accumulated water in the water collection tank will be discharged into the pool.

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

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

[0077] If the check valve leaks, water will flow back into the vertical pump suction pipe under the pressure of the water supply main pipe. Since the water inlet of the water collecting tank is at the bottom of the outlet pipe, water will accumulate in the water collecting tank. As the amount of accumulated water increases, the liquid level in the water collecting tank will rise.

[0078] When the water level exceeds the level switch, the normally open contact of the level switch is closed, and the contact signal is sent to the DI module of the central control cabinet PLC through the cable. According to the signal of the level switch in the water collection tank, the control system added in the PLC is immediately started, so that the lubricating water solenoid valve is demagnetized and opened, and the lubricating water is sent to the bearing of the vertical pump to protect the vertical pump from damage to the shaft when the vertical pump is reversed. At the same time, the control system sends an audible and visual alarm on the operation screen to remind the operator to pay attention to the abnormal phenomenon of the vertical pump.

[0079] Based on the original lubricating water control logic diagram of the vertical pump, a water collecting tank water level detection contact is added. The water collecting tank water level detection contact signal controls the lubricating water solenoid valve function and adds the water collecting tank inlet and outlet solenoid valve control function. New functions such as Figure 4 As shown, the dotted box is the newly added part.

[0080] Reference the normally closed contact of the vertical pump start and stop signal #PUMP6_RUN and the normally closed contact of the water collection tank level switch #PUMP6_LEVEL_SWITCH, and combine the two signals into a logical combination.

[0081] When the vertical pump is running, the normally closed contact of the vertical pump start and stop signal #PUMP6_RUN is disconnected, the lubricating water solenoid valve #RVALVE6_OPEN is demagnetized and closed, and the lubricating water is delivered to the vertical pump bearing. Since the normally closed contact of the vertical pump start and stop signal #PUMP6_RUN is disconnected, the water collection tank inlet solenoid valve #INIT6_OPEN is demagnetized and closed, and the water collection tank discharge solenoid valve #DRAIN_CLOSE is excited and opened through the NOT logic.

[0082] like Figure 4As shown in the figure, when the vertical pump stops, the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is closed, the lubricating water solenoid valve #RVALVE6_OPEN is de-energized, and the lubricating water is shut off. At the same time, the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is closed, so that the water collection tank inlet solenoid valve #INIT6_OPEN is energized and opened, and the water collection tank discharge solenoid valve #DRAIN_CLOSE is de-energized and closed through the NOT logic.

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

[0084] If the vertical pump outlet valve leaks abnormally, the backflow of water enters the water collection tank, causing the water level in the water collection tank to rise, and the normally closed contact of the liquid level switch #PUMP6_LEVEL_SWITCH is disconnected, causing the lubricating water solenoid valve #RVALVE6_OPEN to be demagnetized and closed, and the lubricating water is sent to the vertical pump bearing. If the vertical pump shaft reverses, it will be protected by the lubricating water. At the same time, the contact signal of the liquid level switch #PUMP6_LEVEL_SWITCH is sent to the PLC alarm circuit.

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

[0086] The device and method of the present invention are applicable to the original vertical pump operation method. The control of the electromagnetic valve is automatically controlled according to the interlocking program. Only an audible and visual alarm content is added to be displayed on the computer operation screen. After the vertical pump causing the abnormality is repaired and processed, the alarm is automatically reset and eliminated. At the same time, the device and method of the present invention do not hinder the repair of the abnormal fault vertical pump. Various operations involved in the repair process can be performed according to the previous operation procedures.

[0087] This embodiment was implemented in the ACC water supply filter 3# pump of the wide and thick plate circulating water. After multiple tests and assessments, it can meet the actual needs of preventing the vertical pump from reversing. In the actual application of more than six months since its implementation, a reversal alarm has occurred. When the vertical pump was inspected on site, the reversal phenomenon occurred. When the check valve was disassembled and inspected in time, it was found that there was scale and corrosion between the check valve shaft and the shaft seat, causing the valve plate to rotate inflexibly and not completely closed, avoiding the possible reversal and shaft damage phenomenon.

Claims

1. A method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system, characterized in that: A water collection device and an on-site solenoid valve control device are installed at the bottom of the vertical pump outlet connecting pipe. The water collection device includes a water collection tank, an inlet and outlet electromagnetic valve of the water collection tank, and a liquid level switch in the water collection tank. When the vertical pump operates normally, the inlet electromagnetic valve of the water collection tank is demagnetized and closed, and the drainage electromagnetic valve is excited and opened. If there is water in the water collection tank, it will be discharged into the pool. When the vertical pump stops, the solenoid valve on the water collection tank inlet is energized and opened, and the drain solenoid valve is deenergized and closed.

2. A method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system as claimed in claim 1, characterized in that: The liquid level switch is provided with a normally open contact, and the normally open contact signal of the liquid level switch is sent to the DI digital signal input module of the PLC programmable logic controller of the central control cabinet through a cable. The PLC programmable logic controller is provided with a water collecting tank water inlet level detection contact on the basis of the vertical pump lubricating water control logic circuit diagram, and the water collecting tank water inlet level detection contact signal controls the function of the lubricating water solenoid valve, and the control function of the water collecting tank inlet and outlet solenoid valves; When the accumulated water height exceeds the liquid level switch in the water collecting tank, the on-site solenoid valve control device is started according to the signal received from the liquid level switch of the water collecting tank, the lubricating water solenoid valve is demagnetized and opened to send lubricating water to the bearings of the vertical pump to protect the vertical pump from shaft damage when reversal occurs.

3. A method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system as claimed in claim 2, characterized in that: When the accumulated water height exceeds the liquid level switch in the water collection tank, the on-site solenoid valve control device opens the lubricating water solenoid valve to send the lubricating water into the bearings of the vertical pump. At the same time, the PLC programmable logic controller sends out an audible and visual alarm, the faulty vertical pump flashes on the computer operation screen, and the buzzer sounds an alarm.

4. A method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system as claimed in claim 1 or 2, characterized in that: The circulating water system is a metallurgical wide and thick plate water treatment system.

5. A method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system as claimed in claim 2, characterized in that: When the water level exceeds the liquid level switch, the control system in the PLC starts, demagnetizes the lubricating water solenoid valve and opens it to send lubricating water into the bearings of the vertical pump to protect the vertical pump from shaft damage when reverse rotation occurs. At the same time, the control system sends out an audible and visual alarm on the operation screen to remind the operator to pay attention to abnormal phenomena in the vertical pump.

6. A method for preventing a vertical pump from reversing and damaging its shaft for a circulating water system as claimed in claim 1, characterized in that: In the PLC programmable logic controller, the normally closed contact of the vertical pump start and stop signal #PUMP6_RUN and the normally closed contact of the water collection tank level switch #PUMP6_LEVEL_SWITCH are referenced, and the signals of the two are composed and logical.

7. A method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system as claimed in claim 6, characterized in that: When the vertical pump is running, the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is disconnected, the lubricating water solenoid valve #RVALVE6_OPEN is demagnetized and closed, and the lubricating water is delivered to the vertical pump bearings.

8. A method for preventing a vertical pump from reversing and damaging its shaft in a circulating water system as claimed in claim 6, characterized in that: When the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is disconnected, the water collection tank inlet solenoid valve #INIT6_OPEN is demagnetized and closed, and at the same time, the water collection tank discharge solenoid valve #DRAIN_CLOSE is energized and opened through non-logic.

9. A device for preventing a vertical pump from reversing and damaging its shaft in a circulating water system, characterized in that: A water collection device, an on-site solenoid valve control device and a PLC programmable logic controller are installed at the bottom of the vertical pump outlet connecting pipe. The water collecting device includes a water collecting tank, an inlet and outlet electromagnetic valve of the water collecting tank, and a liquid level switch in the water collecting tank. The PLC programmable logic controller sets the water collection tank water level detection contact on the basis of the original lubricating water control logic circuit diagram of the vertical pump. The water collection tank water level detection contact signal controls the function of the lubricating water solenoid valve and the control function of the water collection tank inlet and outlet solenoid valves. The liquid level switch is set with a normally open contact, and the normally open contact signal of the liquid level switch is sent to the DI digital signal input module of the PLC programmable logic controller of the central control cabinet through a cable; When the vertical pump is operating normally, the inlet solenoid valve of the water collection tank is demagnetized and closed, and the drainage solenoid valve is excited and opened. If there is any accumulated water in the water collection tank, it will be discharged into the pool. When the vertical pump stops, the solenoid valve at the inlet of the water collection tank is excited and opened, and the drainage solenoid valve is demagnetized and closed; When the accumulated water height exceeds the liquid level switch in the water collecting tank, the on-site solenoid valve control device is started according to the signal received from the liquid level switch of the water collecting tank, the lubricating water solenoid valve is demagnetized and opened to send lubricating water to the bearings of the vertical pump to protect the vertical pump from shaft damage when reversal occurs.

10. A device for preventing a vertical pump from rotating reversely and damaging its shaft in a circulating water system as claimed in claim 9, characterized in that: In the PLC programmable logic controller, the normally closed contact of the vertical pump start and stop signal #PUMP6_RUN and the normally closed contact of the water collection tank level switch #PUMP6_LEVEL_SWITCH are referenced, and the signals of the two are composed and logical.

11. A device for preventing a vertical pump from reversing and damaging its shaft for use in a circulating water system as claimed in claim 9, characterized in that: When the normally closed contact of the vertical pump start / stop signal #PUMP6_RUN is disconnected, the water collection tank inlet solenoid valve #INIT6_OPEN is demagnetized and closed, and at the same time, the water collection tank discharge solenoid valve #DRAIN_CLOSE is energized and opened through non-logic.

12. A device for preventing a vertical pump from reversing and damaging its shaft for use in a circulating water system as claimed in claim 9, characterized in that: If the vertical pump outlet valve leaks abnormally, the backflow of water enters the water collecting tank, causing the water level in the water collecting tank to rise, and the normally closed contact of the liquid level switch #PUMP6_LEVEL_SWITCH is disconnected, causing the lubricating water solenoid valve #RVALVE6_OPEN to be demagnetized and closed, and the lubricating water is sent to the vertical pump bearing. If the vertical pump shaft reverses, it is protected by the lubricating water. At the same time, the contact signal of the liquid level switch #PUMP6_LEVEL_SWITCH is sent to the PLC alarm circuit.

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