Normal pressure replacement method of knife barrel gate of normal pressure knife changing device of slurry balance shield machine

Abstract

The invention discloses a normal pressure replacement method for a knife barrel gate of a normal pressure knife changing device of a slurry balance shield machine, wherein the knife barrel gate is located on the back of a knife disc at the front end of a shield body, and the tail of the shield body is connected to a connecting section of a pipe segment, and the shield body is located on the front side of the pipe segment, and the knife barrel gate comprises the following steps: a. adjusting the knife barrel gate to the middle section position in the height direction of the cutter disc of the shield machine; b. arranging a plurality of construction hoops on the shield body at the front side of the connecting section and the pipe segment at the rear side of the connecting section, and the inner side surface of each construction hoop is in contact with the outer side wall of the shield body or the pipe segment, and the outer side surface of each construction hoop is in contact with the soil body; c. reducing the water pressure of the incision mud water bin to normal pressure, using a pump to discharge the mud water in the incision mud water bin, and connecting the incision mud water bin to the atmosphere through a pipeline; d. entering the central bin to replace the knife barrel gate. The invention is simple to operate, has low risk, high speed, good effect and low cost.

Description

Technical Field

[0001] The invention belongs to the field of shield machine equipment, and in particular relates to a normal-pressure replacement method for a knife barrel gate of a normal-pressure knife changing device of a slurry balance shield machine. Background Art

[0002] Due to the formation, the cutter is severely worn and replaced frequently during the excavation process. The knife barrel gate is also used frequently. During the frequent opening and closing process, it is easy to cause slag inclusion in the knife barrel gate seal, resulting in damage and extrusion of the knife barrel gate seal, and even leakage and water gushing. Due to the high pressure of the mud and water tank, in order to ensure the replacement of the knife barrel gate in a waterless environment under normal pressure, the mud and water tank liquid level needs to be lowered to the lowest point. However, during the construction period, it is unavoidable to replenish the mud and water tank with seepage from the rock fissures. The knife disc is rotated to the horizontal direction at 3 o'clock to ensure safe and convenient operation. The original cutter disc is designed to be replaced vertically at the 6 o'clock position. After horizontal replacement, the original work tooling needs to be modified for lifting and replacement. If it is not possible to operate under normal pressure, the knife barrel gate will be replaced under pressure, but it will be risky and expensive to enter the warehouse under pressure, and it will delay the construction period. Summary of the invention

[0003] The purpose of the present invention is to provide a normal-pressure replacement method for a knife barrel gate of a normal-pressure knife changing device of a slurry balance shield machine, which can realize the replacement of the transportation channel and working space of the knife barrel gate in a waterless normal-pressure environment.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a method for replacing a knife barrel gate of a normal pressure knife changing device of a slurry shield machine at normal pressure, wherein the knife barrel gate is located on the back of the knife disc at the front end of the shield body, the tail of the shield body is a connecting section of the pipe segment, and the shield body is located on the front side of the pipe segment, which comprises the following steps:

[0005] a. Adjust the cutter gate to the middle position in the height direction of the shield machine cutter head;

[0006] b. Set up construction hoop

[0007] A plurality of construction hoops are arranged on the shield body at the front side of the combined section and the pipe segment at the rear side of the combined section, and the inner side surface of each construction hoop is in contact with the outer side wall of the shield body or the pipe segment, and the outer side surface of each construction hoop is in contact with the soil;

[0008] c. Reduce the water pressure in the cut mud tank to normal pressure

[0009] Use a pump to discharge the mud and water in the incision mud and water bin, and connect the incision mud and water bin to the atmosphere through a pipeline;

[0010] d. Enter the central warehouse to replace the knife barrel gate

[0011] Preferably, at least two of the construction hoops are respectively located at the front side and the rear side of the combining section.

[0012] Optimized, the middle and tail connection of the shield body is distributed with a plurality of radial front injection holes, and the front injection hole valves are respectively arranged on the front injection holes. The radial front injection holes at the same axial position are evenly distributed on the peripheral surface of the middle and tail of the shield body. Before injecting polyurethane, the front injection hole valve needs to be opened to see if there is liquid spraying out. If there is spraying out, it means that the front injection hole is unobstructed. If it is not unobstructed, an electric drill needs to be used to drill into the front injection hole by no less than 35 cm. If water sprays out, the valve is quickly closed; then the pump suction pipe is placed in the diesel barrel Inhale diesel, moisten the grouting pipe with diesel and then connect the grouting pipe to the front injection hole. Inhale diesel first and open the front injection hole valve at the same time. Then quickly put the pump straw into the polyurethane barrel and start injecting polyurethane. The injection pressure shall not exceed 1Mpa. If it can be injected, the injection volume of each front injection hole shall not exceed 150L. If it cannot be injected, the front injection hole shall not be injected. Inject polyurethane into each front injection hole in the order of injecting the bottom first, then the middle and finally the top, and fill the gap between the shield and the surrounding rock mass with polyurethane to the greatest extent.

[0013] Optimally, all the segments are, from the front to the back, the first segment, the second segment, the third segment, the fourth segment, the fifth segment ... the Nth segment, and the construction hoop on the back side of the joint section is formed by first injecting mortar into a primary grouting hole and then injecting filler.

[0014] Optimized, after the mortar injection is completed, two or all of the third segment or the fourth segment or the fifth segment are opened on the corresponding segments, and polyurethane is injected respectively. The injection sequence, injection method, and injection control pressure are the same as those of the shield body injection of polyurethane. In order to avoid excessive injection pressure damaging the shield tail brush, the pressure of polyurethane injection in the secondary grouting holes on the segment does not exceed 1Mpa. If the pressure exceeds 1Mpa, the injection is stopped. If the pressure never exceeds 1Mpa, the injection amount of each grouting hole on the segment does not exceed 200L.

[0015] Optimized, secondary grouting holes are opened in several segments behind the segment injected with polyurethane, and cement-water-glass double grout is injected respectively. The injection order is to inject the bottom first, then the middle and finally the top. The grouting pressure does not exceed 1Mpa, and the grouting volume per hole does not exceed 1.2m 3 The grouting operation of the corresponding segments should be carried out ring by ring at least 1 hour after the polyurethane injection of the last segment is completed.

[0016] Optimized, in step c, after the pressure in the mud and water tank drops, adjust the mud discharge speed so that the liquid level in the air cushion tank drops to 1 meter below the center line, then stop discharging mud, observe for a period of time, adjust the pressure again, and cycle in sequence until the incision pressure is 0. During the process of decreasing the incision pressure, monitor the change in the liquid level in the bubble tank in real time.

[0017] Optimized, after the incision pressure drops to 0, the mud and water bin liquid level begins to decrease, the circulation system switches to bypass mode, and the slurry discharge flow rate is kept greater than the slurry inlet flow rate by 6~10m3. The height of the mud and water bin liquid level drop is judged by the sensor data set at the bottom. In order to prevent the mud and water bin from absorbing negative pressure during the liquid level drop, the mud and water bin is connected to the atmospheric environment during the liquid level drop. The pressure is monitored by the pressure sensor set at the incision position. After the mud and water bin liquid level drops to 1m below the center, the pipeline is opened for flushing, and the mud in the mud and water bin is discharged to the outside of the shield by gravity.

[0018] For optimization, observe the changes in the liquid level in the central warehouse, open the central hatch for ventilation for at least 20 minutes after the liquid level stabilizes, open the drain hole at the bottom of the central warehouse after the gas detection is qualified, open the pressure relief and sewage outlet on the side of the knife barrel after the personnel enter the warehouse, and install the sealing plate. After the installation is completed, close the pressure relief and sewage outlet. After the sealing plate is installed, clean the central warehouse, and weld the knife barrel gate lifting point according to the knife barrel position.

[0019] Optimized, when there are personnel working in the warehouse, it is fully open for emergency drainage, and closed after all personnel have left the warehouse. During the operation, the gravity water hole is fully open to observe the changes in water flow and the pressure sensor at the bottom of the mud discharge pipe. If there is no obvious change, replace the knife barrel gate at normal pressure. Connect the knife barrel gate oil pipe, remove the sealing plate, observe again to confirm that there is no leakage, then open the knife barrel gate by jogging, and observe the condition of the face; after confirming that the face is stable, close the knife barrel gate, remove and install the knife barrel gate, and pay attention to the installation of the positioning pin during the installation process; during the operation, open the gravity water hole, observe the changes in water flow and the pressure sensor at the bottom of the mud discharge pipe; if there is any abnormality, immediately evacuate personnel, close the knife barrel gate, and close the bottom drainage hole; after the replacement is completed, clean the central warehouse.

[0020] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: the normal pressure replacement technology is to construct a hoop on the outside of the shield and the pipe segment to isolate the water from the rear, so that the liquid level of the mud and water tank drops and the knife barrel gate replacement position is turned to the 3 o'clock position of the cutter disc, which can ensure that the operator can perform normal pressure replacement operations in a waterless environment, and solve the problem of knife barrel gate leakage by replacing the knife barrel gate at normal pressure. Due to the application of the above technical solution, the present invention has the following advantages compared with the existing pressure operation technology: simple operation, low risk, fast speed, good effect and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A schematic diagram of the position of the construction hoop of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0023] As shown in the figure, the normal pressure replacement method of the knife barrel gate of the normal pressure knife changing device of the slurry balance shield machine, the knife barrel gate 0 is located on the back of the knife disc at the front end of the shield body 1, the tail of the shield body and the connecting section 9 of the pipe segment sleeve, the shield body 1 is located on the front side of the pipe segment, and it includes the following steps:

[0024] a. Adjust the cutter gate 0 to the middle position in the height direction of the shield machine cutter head;

[0025] b. Set up construction hoop 2

[0026] A plurality of construction hoops 2 are arranged on the shield body 1 at the front side of the combination section 9 and the pipe segment at the rear side of the combination section 9, and the inner side surface of each of the construction hoops 2 is in contact with the outer side wall of the shield body 1 or the pipe segment, and the outer side surface of each of the construction hoops 2 is in contact with the soil, wherein at least two of the construction hoops 2 are respectively located at the front side and the rear side of the combination section 9; a plurality of radial front injection holes 3 are distributed at the connection between the middle and the tail of the shield body 1, and front injection hole 3 valves are respectively arranged on the front injection holes 3, and the radial front injection holes 3 at the same axial position are evenly distributed on the peripheral surface of the middle and the tail of the shield body 1;

[0027] A construction hoop 2 is provided on the shield body 1 at the front side of the joint:

[0028] Before injecting polyurethane, you need to open the valve of the front injection hole 3 to see if there is liquid spraying out. If there is liquid spraying out, it means that the front injection hole 3 is unobstructed. If it is blocked, you need to use an electric drill to drill into the front injection hole 3 by no less than 35 cm. If water sprays out, quickly close the valve; then put the pump suction pipe into the diesel barrel to suck in the diesel, wet the grouting pipe with diesel, and connect the grouting pipe to the front injection hole 3. First suck in the diesel, and at the same time open the valve of the front injection hole 3, and then quickly put the pump suction pipe into the polyurethane barrel to start injecting polyurethane. The injection pressure does not exceed 1Mpa. If it can be injected, the injection amount of each front injection hole 3 shall not exceed 150L. If it cannot be injected, the front injection hole 3 will not be injected; inject polyurethane into each front injection hole 3 in the order of first injecting the bottom, then the middle, and finally the top, and fill the gap between the shield body 1 and the surrounding rock mass with polyurethane to the greatest extent;

[0029] Set the construction hoop 2 at the rear side of the joint:

[0030] All the segments are, from the front side to the rear side, the first segment 1103, the second segment 1102, the third segment 1101, the fourth segment 1100, the fifth segment 1099, the sixth segment 1098, the seventh segment 1097, the eighth segment 1096, ... the Nth segment. The construction hoop 2 at the rear side of the joint section 9 is formed by first injecting mortar into the primary grouting hole 4 and then injecting filler. The mortar is injected synchronously during the tunneling process of the shield machine.

[0031] After the mortar is injected into the third pipe segment 1101 and the fourth pipe segment 1100, secondary grouting holes 5 are opened on the corresponding pipe segments to inject polyurethane respectively. The injection sequence, injection method and injection control pressure are the same as those when the polyurethane is injected into the shield body 1 on the front side of the joint. In order to avoid excessive injection pressure to damage the shield tail brush, the pressure of polyurethane injection into the secondary grouting holes 5 on the pipe segment does not exceed 1Mpa. If the pressure exceeds 1Mpa, the injection is stopped. If the pressure never exceeds 1Mpa, the injection amount of each grouting hole on the pipe segment does not exceed 200L.

[0032] Secondary grouting holes 5 are opened in the fifth segment 1099, the sixth segment 1098 and the seventh segment 1097, and 1:1 cement-water-glass double slurry is injected respectively. The injection order is to inject the bottom first, then the middle and finally the top. The grouting pressure does not exceed 1Mpa, and the grouting volume per hole does not exceed 1.2m 3 The grouting operation of the corresponding segments should be carried out ring by ring at least 1 hour after the polyurethane injection of the last segment is completed;

[0033] After the construction hoop 2 is set, the original primary grouting hole 4 of the pipe segment that has been grouted and the secondary grouting hole 5 opened later and the valve installed on the front grouting hole on the shield body 1 are opened to check the leakage amount to determine whether the hoop meets the requirements; if the water flow is small, the next step can be carried out, and if there is water spraying, continue to add polyurethane until all the secondary grouting holes 5 between the tail shield and the 1097 ring that have been grouted no longer spray water;

[0034] c. Reduce the water pressure in the cut mud tank to normal pressure

[0035] After the mud and water system bypass mode cycles, adjust the SAMSON pressure according to the pressure reduction gradient shown in Table 1. After the mud and water tank pressure drops, open the hydraulic ball valve of the slurry discharge pipeline to adjust the mud discharge speed so that the air cushion tank liquid level drops to 1 meter below the center line. Then close the hydraulic ball valve of the slurry discharge pipeline. After observing the specified time, adjust the pressure again and cycle in sequence until the incision pressure is 0. During the process of incision pressure drop, monitor the change of the bubble tank liquid level in real time, and judge the water gushing amount in the formation according to the change of the liquid level shown in Table 1.

[0036]

[0037] Table 1 Incision water pressure drop gradient table

[0038] After the incision pressure drops to 0, the mud and water bin liquid level begins to decrease, the circulation system switches to bypass mode, and the hydraulic ball valve of the slurry discharge pipeline is opened at the same time to keep the slurry discharge flow rate greater than the slurry inlet flow rate by 6~10m3. The height of the mud and water bin liquid level drop is judged by the sensor data set at the bottom. To prevent the mud and water bin from absorbing negative pressure during the process of liquid level drop, the valve on the B6.1.1 pipeline is opened during the process of liquid level drop to connect the mud and water bin to the atmospheric environment. Pressure monitoring is performed through the pressure sensor set at the incision position.

[0039] After the liquid level in the mud and water tank drops to 1m below the center, open the pipeline MV03R / MV03L (DN150), flush 1 and 2 (DN100), and drain the mud in the mud and water tank to the outside of shield 1 by gravity;

[0040] d. Enter the central warehouse to replace the knife barrel gate 0

[0041] Observe the changes in the liquid level in the central warehouse, open the central hatch for ventilation for 30 minutes after the liquid level stabilizes, and open the drainage hole at the bottom of the central warehouse after the gas detection is qualified. (When there are people working in the warehouse, open it throughout the process for emergency drainage, and close it after all people have left the warehouse).

[0042] After entering the warehouse, the personnel open the pressure relief and drainage outlet on the side of the knife barrel and install the sealing plate. After the installation is completed, close the pressure relief and drainage outlet. (10.3 Knife barrel sealing cover, 10.4 Pressure relief and drainage outlet)

[0043] After the sealing plate is installed, clean the central warehouse and weld the knife barrel gate 0 lifting point according to the knife barrel position. During the operation, open the gravity water hole throughout the operation, observe the changes in water flow and observe the pressure sensor at the bottom of the mud discharge pipe. If there is no obvious change, replace the knife barrel gate 0 at normal pressure. Connect the knife barrel gate 0 oil pipe, remove the sealing plate, observe again to confirm that there is no leakage, then open the knife barrel gate 0 and observe the condition of the face; after confirming that the face is stable, close the knife barrel gate 0, remove and install the knife barrel gate 0, and pay attention to the installation of the positioning pin during the installation process. During the operation, open the gravity water hole throughout the operation, observe the changes in water flow and observe the pressure sensor at the bottom of the mud discharge pipe. If there is any abnormality, evacuate personnel immediately, close the knife barrel gate 0, and close the bottom drainage hole. After the replacement is completed, clean the central warehouse.

[0044] Observe the changes in the liquid level in the central warehouse, open the central hatch for ventilation for 30 minutes after the liquid level stabilizes, and open the drainage hole at the bottom of the central warehouse after the gas detection is qualified. (When there are people working in the warehouse, open it throughout the process for emergency drainage, and close it after all people have left the warehouse).

[0045] After entering the warehouse, the personnel open the pressure relief and drainage outlet on the side of the knife barrel and install the sealing plate. After the installation is completed, close the pressure relief and drainage outlet. (10.3 Knife barrel sealing cover, 10.4 Pressure relief and drainage outlet)

[0046] After the sealing plate is installed, clean the central warehouse and weld the knife barrel gate 0 lifting point according to the knife barrel position. During the operation, open the gravity water hole throughout the operation, observe the changes in water flow and observe the pressure sensor at the bottom of the mud discharge pipe. If there is no obvious change, replace the knife barrel gate 0 at normal pressure. Connect the knife barrel gate 0 oil pipe, remove the sealing plate, observe again to confirm that there is no leakage, then open the knife barrel gate 0 and observe the condition of the face; after confirming that the face is stable, close the knife barrel gate 0, remove the knife barrel gate 0 and install a new knife barrel gate 0. Pay attention to the installation of the positioning pin during the installation process. During the operation, open the gravity water hole throughout the operation, observe the changes in water flow and observe the pressure sensor at the bottom of the mud discharge pipe. If there is any abnormality, evacuate the personnel immediately, close the new knife barrel gate 0, and close the bottom drainage hole. After the replacement is completed, clean the central warehouse.

[0047] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for replacing a knife barrel gate of a normal pressure knife changing device of a slurry shield machine at normal pressure, wherein the knife barrel gate is located on the back of the knife disc at the front end of the shield body, the tail of the shield body is a connecting section of the pipe segment, and the shield body is located at the front side of the pipe segment, characterized in that: It includes the following steps: a. Adjust the cutter gate to the middle position in the height direction of the shield machine cutter head; b. Set up construction hoop A plurality of construction hoops are arranged on the shield body at the front side of the combined section and the pipe segment at the rear side of the combined section, and the inner side surface of each construction hoop is in contact with the outer side wall of the shield body or the pipe segment, and the outer side surface of each construction hoop is in contact with the soil; c. Reduce the water pressure in the cut mud tank to normal pressure Use a pump to discharge the mud and water in the incision mud and water bin, and connect the incision mud and water bin to the atmosphere through a pipeline; d. Enter the central warehouse to replace the knife barrel gate; All the segments are sequentially the first segment, the second segment, the third segment, the fourth segment, the fifth segment ... the Nth segment from the front side to the rear side, and the construction hoop on the rear side of the joint section is formed by first injecting mortar into the primary grouting hole and then injecting a filler; A plurality of radial front injection holes are distributed at the connection between the middle and the tail of the shield body, and front injection hole valves are respectively arranged on the front injection holes. The radial front injection holes at the same axial position are evenly distributed on the peripheral surface of the middle and the tail of the shield body. Before injecting polyurethane, the front injection hole valve needs to be opened to see if there is liquid spraying out. If it sprays out, it means that the front injection hole is unobstructed. If it is blocked, an electric drill needs to be used to drill into the front injection hole by no less than 35 cm. If water sprays out, the valve is quickly closed; then the pump suction pipe is placed in the diesel barrel to suck in diesel, and the grouting pipe is wetted with diesel and connected to the front injection hole. Diesel is sucked in first, and the front injection hole valve is opened at the same time. Then the pump suction pipe is quickly placed in the polyurethane barrel to start injecting polyurethane. The injection pressure does not exceed 1Mpa. If it can be injected, the injection amount of each front injection hole does not exceed 150L. If it cannot be injected, the front injection hole is not injected; polyurethane is injected into each front injection hole in the order of first injecting the bottom, then the middle, and finally the top, so as to fill the gap between the shield body and the surrounding rock mass with polyurethane to the greatest extent; After the mortar is injected into two or all of the third segment, the fourth segment or the fifth segment, secondary grouting holes are opened on the corresponding segments to inject polyurethane respectively. The injection sequence, injection method and injection control pressure are the same as those of the shield body injection of polyurethane. Secondary grouting holes are opened in several segments behind the segments injected with polyurethane, and cement-water-glass double liquid slurry is injected respectively. The injection order is to inject the bottom first, then the middle and finally the top.

2. The normal pressure replacement method for the knife barrel gate of the normal pressure knife changing device of the slurry balance shield machine according to claim 1 is characterized in that: In order to avoid excessive injection pressure damaging the shield tail brush, the polyurethane injection pressure in the secondary grouting holes on the pipe segment shall not exceed 1Mpa. If the pressure exceeds 1Mpa, the injection shall be stopped. If the pressure never exceeds 1Mpa, the injection volume of each grouting hole on the pipe segment shall not exceed 200L.

3. The normal pressure replacement method for the knife barrel gate of the normal pressure knife changing device of the slurry shield machine according to claim 1 is characterized in that: The grouting pressure shall not exceed 1Mpa, and the grouting volume per hole shall not exceed 1.2m 3 The grouting operation of the corresponding segments should be carried out ring by ring at least 1 hour after the polyurethane injection of the last segment is completed.

4. The normal pressure replacement method for the knife barrel gate of the normal pressure knife changing device of the slurry shield machine according to claim 1 is characterized in that: In step c, after the pressure in the mud and water tank drops, adjust the mud discharge speed so that the liquid level in the air cushion tank drops to 1 meter below the center line, then stop discharging mud. After observing for a period of time, adjust the pressure again and repeat the cycle until the incision pressure is 0. During the process of decreasing the incision pressure, monitor the change in the liquid level in the bubble tank in real time.

5. The normal pressure replacement method for the knife barrel gate of the normal pressure knife changing device of the slurry balance shield machine according to claim 4 is characterized in that: After the incision pressure drops to 0, the mud and water bin liquid level begins to decrease, and the circulation system switches to bypass mode to keep the slurry discharge flow rate greater than the slurry inlet flow rate by 6~10m3. The height of the mud and water bin liquid level drop is judged by the sensor data set at the bottom. In order to prevent the mud and water bin from absorbing negative pressure during the liquid level drop, the mud and water bin is connected to the atmospheric environment during the liquid level drop. The pressure is monitored by the pressure sensor set at the incision position. After the mud and water bin liquid level drops to 1m below the center, the pipeline is opened for flushing, and the mud in the mud and water bin is discharged to the outside of the shield by gravity.

6. The normal pressure replacement method for the knife barrel gate of the normal pressure knife changing device of the slurry balance shield machine according to claim 5 is characterized in that: Observe the changes in the liquid level in the central warehouse. After the liquid level stabilizes, open the central hatch for ventilation for at least 20 minutes. After the gas test is qualified, open the drain hole at the bottom of the central warehouse. After the personnel enter the warehouse, open the pressure relief and sewage outlet on the side of the knife barrel, and install the sealing plate. After the installation is completed, close the pressure relief and sewage outlet. After the sealing plate is installed, clean the central warehouse and weld the knife barrel gate lifting point according to the knife barrel position.

7. The normal pressure replacement method for the knife barrel gate of the normal pressure knife changing device of the slurry balance shield machine according to claim 6 is characterized in that: When there are personnel working in the warehouse, keep it open throughout the process for emergency drainage, and close it after all personnel have left the warehouse. During the operation, keep the gravity water holes open throughout the process to observe the changes in water flow and the pressure sensor at the bottom of the mud discharge pipe. If there is no obvious change, replace the knife barrel gate at normal pressure. Connect the knife barrel gate oil pipe, remove the sealing plate, observe again to confirm that there is no leakage, then open the knife barrel gate by jogging, and observe the condition of the face. After confirming that the face is stable, close the knife barrel gate, remove and install the knife barrel gate, and pay attention to the installation of the locating pins during the installation process. During the operation, keep the gravity water holes open throughout the process to observe the changes in water flow and the pressure sensor at the bottom of the mud discharge pipe. If there is any abnormality, immediately evacuate personnel, close the knife barrel gate, and close the bottom drainage holes. After the replacement is completed, clean the center warehouse.

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