Electroosmosis viscosity reduction device for muck conveying of shield spiral conveyor

Abstract

The invention discloses an electroosmosis viscosity reduction device for muck conveying of a shield spiral conveyor, and belongs to the technical field of muck conveying. The electroosmosis viscosity reduction device for muck conveying of the shield spiral conveyor comprises an anode part and a cathode part, the anode part comprises an insulating lining plate and a conductive net, the insulating lining plate is arranged on the inner wall of a machine barrel, and the conductive net is of a barrel-shaped structure and is arranged on the inner wall of the insulating lining plate; the cathode part comprises a mounting plate and a conductive slip ring, the mounting plate is connected with a rack of the conveyor, a stator of the conductive slip ring is connected with the mounting plate, and a rotor of the conductive slip ring is connected with a main shaft of the conveyor; the positive pole of the power supply device is electrically connected with the conductive net, the negative pole of the power supply device is electrically connected with the spindle through the conductive slip ring conductive part, and the power supply device is used for providing current for the conductive net. According to the electroosmosis viscosity reduction device for muck conveying of the shield spiral conveyor, the viscous force between muck and the inner wall of the machine barrel of the shield spiral conveyor can be reduced, and the muck conveying efficiency of the spiral conveyor is improved.

Description

Technical Field

[0001] This invention relates to the field of slag and soil transportation technology, and specifically to an electro-osmotic viscosity-reducing device for slag and soil transportation in tunnel boring machine screw conveyors. Background Technology

[0002] Against the backdrop of rapid development in fields such as resource development and underground engineering, the problem of strong adhesion between slag and metal interfaces is becoming increasingly prominent. This not only increases equipment wear and reduces engineering efficiency but may also pose safety hazards. Electro-osmosis technology, with its advantages of being environmentally friendly, free of chemical pollution, and relatively simple to operate, has become a research hotspot for reducing the adhesion force at this interface. Currently, there are still key problems with screw conveyors for transporting slag: during the process of conveying slag, especially high-viscosity slag and muddy slag, the slag easily adheres to the metal interface of the screw blades and the main drive shaft of the screw conveyor, and may cause adhesion and blockage on the inner wall of the cylinder, reducing the efficiency of slag transport and affecting the progress of the project.

[0003] To prevent the excavated soil from the cutterhead from adhering to the metal interface of the screw conveyor blades, the drive shaft, and the inner wall of the cylinder during transport, thus avoiding problems such as conveying blockage, increased energy consumption, and decreased efficiency, several technologies have been applied to avoid these issues. Currently, the most effective technology for addressing these problems is excavated soil amendment technology. This involves injecting polymers, foaming agents, and anti-adhesion agents into the earth pressure balance hood to improve the soil. While excavated soil amendment technology is a key solution to the blockage problem in shield tunnel screw conveyors, its success largely depends on the geological conditions at the construction site. Its application in actual construction is quite demanding, making large-scale application difficult. Furthermore, chemical soil amendments can cause soil pollution. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems in the prior art and provide an electro-osmotic viscosity reduction device for conveying excavated soil in a tunnel boring machine screw conveyor. This device can reduce the adhesive force between the excavated soil and the inner wall of the tunnel boring machine screw conveyor, thereby reducing the resistance during excavated soil conveying and improving the efficiency of the screw conveyor in conveying excavated soil.

[0005] This invention provides an electro-osmotic viscosity reduction device for transporting excavated soil in a tunnel boring machine screw conveyor, comprising: The anode section includes an insulating liner and a conductive mesh. The insulating liner has a cylindrical structure and is coaxially arranged with the conveyor barrel. The insulating liner is located on the inner wall of the barrel. The conductive mesh also has a cylindrical structure and is located on the inner wall of the insulating liner. The cathode section includes a mounting plate and a conductive slip ring. The mounting plate is connected to the frame of the conveyor, the stator of the conductive slip ring is connected to the mounting plate, and the mover of the conductive slip ring is connected to the main shaft of the conveyor. The power supply device has its positive terminal electrically connected to the conductive grid, and its negative terminal electrically connected to the main shaft through a conductive slip ring. The power supply device is used to provide current to the conductive grid.

[0006] Preferably, a current sensor is provided between the conductive slip ring and the negative terminal of the power supply device. The current sensor is used to detect the real-time current value passing through it. The power supply device is electrically connected to a controller. The controller has a preset current value. When the real-time current value is lower than the preset current value, the controller controls the power supply device to increase the power supply voltage.

[0007] Preferably, the outer wall of the barrel is provided with a vibrator, the vibrator is electrically connected to a self-starting sensor, the self-starting sensor is electrically connected to the current sensor, and the power supply device is electrically connected to the conductive part of the conductive slip ring through the current sensor. When the real-time current value detected by the current sensor is higher than the preset current value, the self-starting sensor controls the vibrator to vibrate.

[0008] Preferably, the side wall of the barrel is provided with multiple gas nozzles, which are arranged circumferentially around the barrel. Each gas nozzle is connected to the inner cavity of the barrel, and the orientation of each gas nozzle is tangential to the circumferential direction of the inner wall of the barrel and biased towards the discharge port side of the barrel. Each gas nozzle is connected to a solenoid valve, which is connected to a high-pressure air pump. The solenoid valve is electrically connected to the self-starting sensor. When the real-time current value detected by the current sensor is higher than the preset current value, the self-starting sensor controls the solenoid valve to open.

[0009] Preferably, the gas nozzle is unidirectionally connected from the solenoid valve to the inner cavity of the barrel.

[0010] Preferably, the main shaft of the conveyor is connected to an insulated coupling, and the main shaft of the conveyor is connected to the drive motor through the insulated coupling.

[0011] Preferably, an insulating nut is fixedly connected to the insulating liner, and an insulating bolt is threaded onto the insulating nut. The insulating bolt is used to fix the conductive mesh to the insulating liner.

[0012] Preferably, the conductive mesh is an arc-shaped titanium mesh coated with a mixed metal oxide.

[0013] Preferably, the insulating bolts press the conductive mesh onto the insulating liner using insulating washers and metal washers.

[0014] Preferably, the moving part of the conductive slip ring is connected to the main shaft through a bushing, the bushing is provided with a conductive interface, and the conductive part of the conductive slip ring is electrically connected to the bushing through the conductive interface.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides an electro-osmotic viscosity reduction device for conveying slag in a tunnel boring machine screw conveyor. By forming an electric field inside the conveyor drum, negatively charged ions in the slag migrate directionally towards the cathode, i.e., the screw blades, under the action of the electric field. During this process, water migrates synchronously, forming a continuous water film on the slag and the outer wall of the drum, and on the surface of the slag and the screw blades, thereby achieving lubrication and viscosity reduction, and reducing the adhesion and conveying resistance of the slag.

[0016] Current monitoring predicts adhesion risk. A current sensor is connected in series in the cathode circuit to detect the circuit current in real time. When the slag adheres to the outer wall of the drum, it will change the resistance between the electrodes, causing the circuit current to exceed the preset current value, thus providing a trigger signal for subsequent auxiliary deadhesion. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the structure of the mounting plate of the present invention; Figure 3 This is a schematic diagram of the control circuit of the present invention; Figure 4 This is a schematic diagram of the structure of the conductive mesh in this invention; Figure 5 This is a schematic diagram of the structure of the conductive slip ring of the present invention; Figure 6 For the present invention Figure 5 A schematic diagram of the cross-sectional structure of surface 1-1; Figure 7 For the present invention Figure 5 Schematic diagram of the cross-sectional structure of surface 2-2.

[0018] 101. Insulating liner; 102. Conductive mesh; 103. Barrel; 104. Mounting plate; 105. Conductive slip ring; 106. Main shaft; 107. Frame; 201. Vibrator; 202. Current sensor; 203. Self-starting sensor; 204. Gas nozzle; 206. Solenoid valve; 205. High-pressure air pump; 3. Insulating coupling; 401. Insulating nut; 402. Insulating bolt; 501. Insulating gasket; 502. Metal gasket; 6. Bushing; 7. Spiral blade; 8. Power supply device; 9. Drive motor. Detailed Implementation

[0019] The following is in conjunction with the appendix Figures 1-7 The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] like Figures 1-7 As shown, the present invention provides an electro-osmotic viscosity reduction device for conveying excavated soil in a tunnel boring machine screw conveyor, comprising: an anode section, a cathode section, and a power supply device 8. The anode section includes an insulating liner 101 and a conductive mesh 102. The insulating liner 101 has a cylindrical structure and is coaxially arranged with the conveyor's cylinder 103, and is disposed on the inner wall of the cylinder 103. The conductive mesh 102 also has a cylindrical structure and is disposed on the inner wall of the insulating liner 101. The cathode section includes a mounting plate 104 and a conductive slip ring 105. The mounting plate 104 is connected to the conveyor's frame 107. The stator of the conductive slip ring 105 is connected to the mounting plate 104, and the mover of the conductive slip ring 105 is connected to the conveyor's main shaft 106. The positive terminal of the power supply device 8 is electrically connected to the conductive mesh 102, and the negative terminal of the power supply mesh is electrically connected to the main shaft 106 through the conductive part of the conductive slip ring 105. The power supply device 8 is used to provide current to the power supply mesh 102.

[0021] The working principle of the above embodiments is briefly described below: When this device is in operation, the entire device is first connected, and the power supply device 8 provides power. The positive terminal of the power supply device 8 is connected to the conductive mesh 102 via an external wire, and the negative terminal is electrically connected to the spiral blades 7 via the conductive slip ring 105 and the drive shaft 106, thereby forming a stable electric field within the spiral conveyor cylinder 103. The mesh structure of the conductive mesh 102 can uniformly cover the inner wall of the spiral conveyor cylinder 103, helping to build an axisymmetric and uniform electric field and avoiding local uneven electroosmosis. It can also increase the contact area with the slag and soil without hindering the normal flow and discharge of the slag.

[0022] After the electric field is formed, the conductive mesh 102 comes into contact with the slag and undergoes electro-osmosis. The core function of electro-osmosis for viscosity reduction is that negatively charged ions in the slag inside the cylinder 103 migrate directionally towards the cathode (main shaft 106 and spiral blades 7) under the action of the electric field, driving water to migrate synchronously in the process. A continuous water film is formed on the slag and the outer wall of the spiral conveyor cylinder 103, and on the surface of the slag and the spiral blades 7, thereby achieving lubrication and viscosity reduction, and reducing the adhesion and conveying resistance of the slag.

[0023] Meanwhile, the drive motor 9 of the screw conveyor drives the transmission shaft 106 and the screw blades 7 to rotate through the insulated coupling 3. The rotating screw blades 7 push the slag that has been devised by electro-osmosis from the feed port to the discharge port to complete the slag conveying.

[0024] The electro-osmotic viscosity reduction device of the present invention for transporting excavated soil in a tunnel boring machine screw conveyor utilizes an electric field to change the properties of the excavated soil and reduce viscosity, thereby reducing the adhesive force between the excavated soil and the inner wall of the tunnel boring machine screw conveyor cylinder 103, thus reducing the resistance during excavated soil transport and improving the efficiency of the screw conveyor in transporting excavated soil.

[0025] Based on the above embodiments, in order to ensure the stability of the current in the entire circuit, thereby ensuring the viscosity reduction effect of the entire device.

[0026] like Figure 3 As shown, the electro-osmotic viscosity-reducing device for conveying excavated soil in a tunnel boring machine as described in claim 1 is characterized in that a current sensor 202 is provided between the conductive slip ring 105 and the negative terminal of the power supply device 8. The current sensor 202 is used to detect the real-time current value passing through it. The power supply device 8 is electrically connected to a controller, which has a preset current value. When the real-time current value is lower than the preset current value, the controller controls the power supply device 8 to increase the power supply voltage. The current sensor 202 is connected in series in the circuit to detect the current value of the circuit in real time. When the moisture content of the excavated soil is low, the resistance of the entire circuit will increase and the current will decrease. At this time, the current sensor 202 detects the real-time current value passing through it. If the real-time current value of the circuit is lower than the preset current value, the controller controls the power supply device 8 to increase the power supply voltage, thereby increasing the current of the entire circuit to ensure the current stability of the entire circuit, thereby ensuring the viscosity-reducing effect of the entire device.

[0027] As a preferred option, such as Figure 1 and Figure 3 As shown, the outer wall of the barrel 103 is equipped with a vibrator 201, which is electrically connected to a self-starting sensor 203. The self-starting sensor 203 is electrically connected to a current sensor 202. The power supply device 8 is electrically connected to the conductive part of the conductive slip ring 105 through the current sensor 202. When the real-time current value detected by the current sensor 202 is greater than the preset current value, the self-starting sensor 203 controls the vibrator 201 to vibrate. When slag adheres to the inner wall of the barrel 103, the resistance of the entire circuit will decrease (the contact area between the slag and the conductive mesh (102) will increase), and the current in the circuit will increase. After the real-time current value of the circuit detected by the current sensor 202 is greater than the preset current value, it transmits the signal to the self-starting sensor 203. The self-starting sensor 203 immediately triggers the action, connects the power supply circuit of the vibrator 201, and drives the vibrator 201 to start. The vibrator 201 generates vibration from the outer side of the outer wall of the drum 103. The vibration energy is transferred to the insulating liner 101 and the conductive mesh 102. On the one hand, it shakes off the slag adhering to the inner wall of the drum 103; on the other hand, its high-frequency vibration can destroy the bonding bridges and agglomeration structures between slag particles, weaken the internal friction between particles, and further enhance the de-adhesion effect. When the circuit current returns to the normal threshold, the self-starting sensor 203 automatically cuts off the power supply circuit of the vibrator 201, realizing the on-demand start and stop of the vibrator 201. This makes the whole process form a "electric-vibration-current" composite effect. The vibration enhances de-adhesion, the screw conveyor ensures slag discharge, and the three work together to ultimately achieve efficient and low-resistance slag transportation.

[0028] As a preferred option, such as Figure 3 As shown, the side wall of the barrel 103 is provided with a plurality of gas nozzles 204, which are arranged circumferentially along the barrel 103. Each gas nozzle 204 is connected to the inner cavity of the barrel 103. The orientation of each gas nozzle 204 is tangential to the circumferential direction of the inner wall of the barrel 103 and biased towards the discharge port side of the barrel 103. The gas nozzles 204 are connected to a solenoid valve 206, which is connected to a high-pressure air pump 205. The solenoid valve 206 is electrically connected to the self-starting sensor 203. When the real-time current value detected by the current sensor 202 is higher than the preset current value, the self-starting sensor 203 controls the solenoid valve 206 to open. When the real-time current value of the circuit is higher than the preset current value, the self-starting sensor 203 immediately triggers the linkage control mechanism and simultaneously starts two cleaning actions to ensure the continuous performance of the electro-osmosis effect: First, the vibrator 201 on the outer wall of the control cylinder 103 is started, and the slag adhering to the inner wall of the control cylinder 103 and the surface of the conductive mesh 102 is loosened and detached through vibration, and the thick layer of adhering material is initially broken; Second, the solenoid valve 206 is opened, and the high-pressure air pump 205 delivers high-pressure gas to the gas nozzle 204 on the side wall of the control cylinder 103. The gas nozzles 204 are evenly distributed around the circumference of the barrel 103, with one nozzle every 90° along the circumference, for a total of four nozzles. The gas nozzles 204 are tangential to the inner wall of the barrel 103 and slightly biased towards the discharge port. After the high-pressure gas is injected through the gas nozzles 204, a uniform annular airflow (i.e., "ring cutter airflow") is formed on the inner wall of the barrel 103. This airflow can precisely sweep the conductive mesh 102 and the inner wall along the circumference of the inner wall of the barrel 103, forming a synergistic effect with the vibration of the vibrator 201, thoroughly removing residual adhering slag, restoring the conductivity and integrity of the electroosmotic field of the conductive mesh 102, and further improving the viscosity reduction effect and slag conveying efficiency.

[0029] As a preferred option, such as Figure 3 As shown, the gas nozzle 204 is unidirectionally connected from the solenoid valve 206 to the inner cavity of the barrel 103. The unidirectional connection of the gas nozzle 204 effectively prevents backflow of slag and clogging of the gas nozzle 204, ensuring the normal operation of the entire device.

[0030] As a preferred option, such as Figure 1 and Figure 5 As shown, the main shaft 106 of the conveyor is connected to an insulated coupling 3, and the main shaft 106 is connected to the drive motor 9 through the insulated coupling 3. The drive motor 9 drives the main shaft 106 and the spiral blades 7 to rotate through the insulated coupling 3. On the one hand, this can strictly block the current conduction between the main shaft 106 (cathode) and the drive motor 9, avoid current leakage into the drive motor 9 and causing equipment damage, ensure the integrity of the current loop in the electroosmosis field, and ensure that the electroosmosis viscosity reduction effect is not affected by the circuit.

[0031] As a preferred option, such as Figure 1 and Figure 4 As shown, an insulating nut 401 is fixedly connected to the insulating liner 101, and an insulating bolt 402 is threaded onto the insulating nut 401. The insulating bolt 402 is used to fix the conductive mesh 102 to the insulating liner 101. The insulating nut 401 is fixed to the insulating liner 101, and the conductive mesh 102 is locked and fixed by the insulating bolt 402. The entire process uses insulating materials for the components, which can effectively avoid the formation of additional conductive circuits by the fixing parts, prevent current shunting from affecting the electroosmotic field strength, and ensure that the conductive mesh 102 (anode) can concentrate the release of current to act on the slag.

[0032] As a preferred option, such as Figure 1 and Figure 4 As shown, the conductive mesh 102 is an arc-shaped titanium mesh with a mixed metal oxide coating. By embedding the arc-shaped titanium mesh with a mixed metal oxide coating as an anode into the outer wall of the screw conveyor barrel 103, it ensures that the inner wall of the barrel is uniformly covered by the mesh anode. Furthermore, the titanium mesh with a mixed metal oxide coating has high strength and corrosion resistance, and can withstand vibration, slag erosion, and highly corrosive environments during conveyor operation. It also facilitates reliable insulation installation via the insulating liner 101 and insulating bolts 402, effectively preventing short circuits with the barrel 103 and ensuring the long-term stable operation of the electroosmosis viscosity reduction experiment.

[0033] As a preferred option, such as Figure 1 and Figure 4 As shown, the insulating bolt 402 presses the conductive mesh 102 onto the insulating liner 101 through the insulating gasket 501 and the metal gasket 502. The insulating gasket 501 is attached between the conductive mesh 102 and the insulating bolt 402, which can prevent the insulating bolt 402 from directly contacting the conductive mesh 102 and causing local insulation damage or current concentration, ensuring uniform current distribution on the surface of the conductive mesh 102 and improving the consistency of electroosmotic viscosity reduction.

[0034] As a preferred option, such as Figure 5 As shown, the movable element of the conductive slip ring 105 is connected to the main shaft 106 via a bushing 6. The bushing 6 is provided with a conductive interface, and the conductive part of the conductive slip ring 105 is electrically connected to the bushing 6 via the conductive interface. The screw conveyor drive main shaft 106 and screw blades 7 are connected to the negative terminal of the power supply via the connection port of the bushing 6 through the conductive slip ring 105, which can improve the reliability of the electrical connection, thereby ensuring the stability and continuity of the entire device's operation.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. An electro-osmotic viscosity-reducing device for conveying excavated soil in a tunnel boring machine screw conveyor, characterized in that, include: The anode section includes an insulating liner (101) and a conductive mesh (102). The insulating liner (101) has a cylindrical structure and is coaxially arranged with the conveyor barrel (103). The insulating liner (101) is located on the inner wall of the barrel (103). The conductive mesh (102) also has a cylindrical structure and is located on the inner wall of the insulating liner (101). The cathode section includes a mounting plate (104) and a conductive slip ring (105). The mounting plate (104) is connected to the frame (107) of the conveyor. The stator of the conductive slip ring (105) is connected to the mounting plate (104), and the mover of the conductive slip ring (105) is connected to the main shaft (106) of the conveyor. The power supply device (8) has its positive terminal electrically connected to the conductive mesh (102), and its negative terminal electrically connected to the main shaft (106) through the conductive part of the conductive slip ring (105). The power supply device (8) is used to provide current to the conductive mesh (102).

2. The electro-osmotic viscosity reducing device for conveying excavated soil in a tunnel boring machine as described in claim 1, characterized in that, A current sensor (202) is provided between the conductive slip ring (105) and the negative terminal of the power supply device (8). The current sensor (202) is used to detect the real-time current value passing through it. The power supply device (8) is electrically connected to a controller. The controller has a preset current value. When the real-time current value is lower than the preset current value, the controller controls the power supply device (8) to increase the power supply voltage.

3. The electro-osmotic viscosity reducing device for conveying excavated soil in a tunnel boring machine as described in claim 2, characterized in that, The outer wall of the barrel (103) is provided with a vibrator (201), the vibrator (201) is electrically connected to a self-starting sensor (203), the self-starting sensor (203) is electrically connected to the current sensor (202), and the power supply device (8) is electrically connected to the conductive part of the conductive slip ring (105) through the current sensor (202). When the real-time current value detected by the current sensor (202) is greater than the preset current value, the self-starting sensor (203) controls the vibrator (201) to vibrate.

4. The electro-osmotic viscosity reducing device for conveying excavated soil in a tunnel boring machine as described in claim 3, characterized in that, The side wall of the barrel (103) is provided with a plurality of gas nozzles (204). The plurality of gas nozzles (204) are arranged around the barrel (103). Each gas nozzle (204) is connected to the inner cavity of the barrel (103). The orientation of each gas nozzle (204) is tangent to the circumference of the inner wall of the barrel (103) and biased toward the discharge port side of the barrel (103). The gas nozzles (204) are connected to a solenoid valve (206). The solenoid valve (206) is connected to a high-pressure air pump (205). The solenoid valve (206) is electrically connected to the self-starting sensor (203). When the real-time current value detected by the current sensor (202) is greater than the preset current value, the self-starting sensor (203) controls the solenoid valve (206) to open.

5. The electro-osmotic viscosity reducing device for conveying excavated soil in a tunnel boring machine as described in claim 4, characterized in that, The gas nozzle (204) is unidirectionally connected from the solenoid valve (206) to the inner cavity of the barrel (103).

6. The electro-osmotic viscosity reducing device for conveying excavated soil in a tunnel boring machine as described in claim 1, characterized in that, The main shaft (106) of the conveyor is connected to an insulating coupling (3), and the main shaft (106) of the conveyor is connected to the drive motor (8) through the insulating coupling (3).

7. The electro-osmotic viscosity reducing device for conveying excavated soil in a tunnel boring machine as described in claim 1, characterized in that, An insulating nut (401) is fixedly connected to the insulating liner (101), and an insulating bolt (402) is threaded onto the insulating nut (401). The insulating bolt (402) is used to fix the conductive mesh (102) onto the insulating liner (101).

8. The electro-osmotic viscosity reducing device for conveying excavated soil in a tunnel boring machine as described in claim 1, characterized in that, The conductive mesh (102) is an arc-shaped titanium mesh with a mixed metal oxide coating.

9. The electro-osmotic viscosity reducing device for conveying excavated soil in a tunnel boring machine as described in claim 7, characterized in that, The insulating bolt (402) presses the conductive mesh (102) onto the insulating liner (101) through the insulating gasket (501) and the metal gasket (502).

10. The electro-osmotic viscosity reducing device for conveying excavated soil in a tunnel boring machine as described in claim 1, characterized in that, The mover of the conductive slip ring (105) is connected to the main shaft (106) through the bushing (6). The bushing (6) is provided with a conductive interface, and the conductive part of the conductive slip ring (105) is electrically connected to the bushing (6) through the conductive interface.

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