Super-small-diameter tunneling machine pneumatic slag removal system and tunneling machine with same

Abstract

The application discloses a pneumatic slagging system for a super-small-diameter tunneling machine and a tunneling machine with the same, which comprises a heat exchanger, an air tank, a flow amplifier, an air conveying pipe, a pneumatic conveying pipe and a plurality of groups of pneumatic relays. The air conveying pipe is connected in series along an air conveying direction to the heat exchanger, the air tank and the flow amplifier, the input end of the air conveying pipe is connected to a liquefied compressed air supply source, and the output end is connected to a pneumatic conveying nozzle of a slag receiving mixer. The air tank supplies compressed air to a jet fan for air blowing and to pneumatic control elements. The input end of the pneumatic conveying pipe is connected to the slag receiving mixer, the plurality of groups of pneumatic relays are arranged in series along the extension direction of the pneumatic conveying pipe, and each pneumatic relay is connected to the air conveying pipe for air supply. The system can effectively reduce the occupation of the tunnel cross-sectional area, facilitate the transportation of personnel and materials in the tunnel, reduce the number of pipelines required for extension, facilitate the extension operation, and save cooling circulating water.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel boring equipment, and in particular to a pneumatic slag discharge system for an ultra-small diameter tunnel boring machine. Furthermore, the present invention also relates to a tunnel boring machine comprising the pneumatic slag discharge system for an ultra-small diameter tunnel boring machine. Background Art

[0002] In the design and actual application of ultra-small diameter full-section tunnel boring machines, due to space limitations, screw conveyors and belt conveyors can only be used on equipment with an excavation diameter of 3 meters or more. If the excavation diameter is smaller, there is insufficient space to allow for convenient transfer of pipe segments while retaining sufficient personnel maintenance channels and space for pipe and wiring layout. Therefore, in the design of 2-meter-level tunnel boring machines, the slag discharge solution is basically based on mud circulation slag discharge.

[0003] However, the slurry circulation system still requires additional trolley space to arrange the slurry pump and bypass and circulation pipelines, and space is also required in the tunnel to equip relay feed and discharge pumps. The ground separation station is also an additional cost compared to the slag discharge of the earth pressure shield. Pneumatic conveying technology is a relatively new tunnel slag discharge technology that has gradually begun to be applied in recent years. Therefore, it can be considered to be applied to ultra-small diameter full-section tunnel boring machines. The goal is to achieve slag discharge effects similar to those of the slurry circulation system while occupying as little trolley space and tunnel cross-sectional area as possible, and to minimize hardware costs to facilitate its acceptance and promotion by customers. At the same time, it can be combined with some emerging tunneling methods and technologies for system integration.

[0004] In previous designs, vacuum slag pumps were used as the primary pneumatic slag removal technology in ultra-small-diameter shield machines with a diameter of two meters. However, due to the limitations of their operating principle, the pressure differential in the suction pipe section in suction mode was only one atmosphere, and the suction range was long, resulting in low suction efficiency and an inability to match the tunneling speed. Therefore, this slag removal method was abandoned after approximately 200 meters of trial excavation. Similarly, the existing method of first using a screw machine to remove and crush the slag, followed by a vacuum slag pump for suction and discharge, also faced the problem of too small a shield space for the screw machine and crusher in ultra-small-diameter shield machines. Therefore, a more optimized design is still needed to achieve smooth slag removal for ultra-small-diameter tunnel boring machines at the two-meter level. Summary of the Invention

[0005] The present invention provides a pneumatic slag discharge system for an ultra-small diameter tunnel boring machine and a tunnel boring machine equipped with the same, so as to solve the technical problems that the pressure difference of the suction pipe section of the existing vacuum slag suction pump is only one atmosphere and the suction range is long, resulting in low suction efficiency and inability to match the tunneling speed, and the existing screw machine for slag discharge and crushing has an excessively small shield space that is not suitable for arranging the screw machine and crusher.

[0006] The technical solution adopted in the present invention is as follows:

[0007] A pneumatic slag removal system for an ultra-small diameter roadheader comprises: a heat exchanger connected to the roadheader's internal circulating water circuit and the fan's ventilation and cooling water circuit respectively, an air tank for storing air at a constant pressure, a flow amplifier for amplifying the airflow, a telescopic air delivery pipe for delivering liquefied compressed air or gasified compressed air, a telescopic air delivery pipe for pneumatically delivering mud, and multiple sets of pneumatic repeaters; the air delivery pipe is extended along the direction of excavation to connect the heat exchanger, the air tank and the flow amplifier in series in the direction of air delivery, and the input end of the air delivery pipe is connected to the air tank. It is connected to a liquefied compressed air supply source for supplying liquefied compressed air, and the output end of the air conveying pipe is connected to the pneumatic conveying nozzle of the slag mixer arranged at the head of the tunnel boring machine; the air tank also supplies compressed air to the jet fan for blowing air supply through the first air supply branch pipe, and supplies compressed air to the pneumatic control components in the tunnel boring machine that require compressed air through the second air supply branch pipe; the pneumatic conveying pipe is extended along the tunneling direction, and the input end of the pneumatic conveying pipe is connected to the slag mixer, and multiple groups of pneumatic repeaters are arranged in sequence along the extension direction of the pneumatic conveying pipe, and each pneumatic repeater is connected to the air conveying pipe for air intake.

[0008] Furthermore, the air conveying pipe includes a plurality of sections of air conveying main pipes that are arranged in sequence and are not retractable along the air conveying direction, and an air conveying telescopic sleeve that is connected between two adjacent sections of the air conveying main pipes and is retractable; the pneumatic conveying pipe includes a plurality of sections of pneumatic conveying main pipes that are arranged in sequence and are not retractable along the pneumatic conveying direction, and a pneumatic conveying telescopic sleeve that is connected between two adjacent sections of the pneumatic conveying main pipes and is retractable.

[0009] Furthermore, the pneumatic slag discharge system for the ultra-small diameter tunnel boring machine also includes a pressure-stabilizing accumulator for stabilizing pressure and storing energy. The pressure-stabilizing accumulator is connected to the pipeline of the air conveying pipe and is located upstream of the heat exchanger.

[0010] Furthermore, the internal circulation water circuit and the ventilation and cooling water circuit are each connected to a heat exchanger. The air delivery pipe connects to the heat exchange copper tubes within the heat exchanger, exchanging heat with the internal circulation water circuit and the ventilation and cooling water circuit through the heat exchange copper tubes. This allows the liquefied compressed air to absorb heat, reduce pressure, and vaporize into compressed air. The ventilation and cooling water circuit is also equipped with an air supply cooling water pump to guide the water flow.

[0011] Furthermore, the air tank includes a tank body for storing compressed air, an air pressure sensor connected to the tank body, and a proportional pressure reducing valve connected to the air delivery pipe upstream of the heat exchanger; the air pressure sensor is used to measure the pressure inside the tank body, so that the control system of the tunneling machine adjusts the opening of the proportional pressure reducing valve accordingly, thereby maintaining the pressure inside the tank body at a preset pressure; a breathing filter for filtering compressed air is also provided in the first air delivery branch connecting the tank body and the jet fan.

[0012] Furthermore, the flow amplifier includes an amplifier body, and an intake chamber sensor and an intake proportional valve respectively connected to the amplifier body; the amplifier body is provided with an amplifier intake chamber and a mixing and diffusion chamber arranged in sequence along the air flow conveying direction, and an amplifier ejector nozzle arranged in the amplifier intake chamber; the air delivery pipe connects the amplifier ejector nozzle and the mixing and diffusion chamber, so that compressed air is sprayed into the amplifier intake chamber through the amplifier ejector nozzle, and enters the mixing and diffusion chamber together with the external air introduced into the amplifier intake chamber; the intake chamber sensor is used to measure the pressure in the amplifier intake chamber, so that the control system of the tunnel boring machine adjusts the opening of the intake proportional valve accordingly, thereby keeping the pressure in the amplifier intake chamber at the set value.

[0013] Furthermore, a slag hopper front gate for connecting to an external excavation chamber is provided on the top of the slag receiving mixer; the pneumatic slag discharge system for ultra-small diameter tunnel boring machines also includes a third air supply branch pipe for connecting the air supply pipe and the excavation chamber air intake, an air intake proportional valve connected to the third air supply branch pipe, and an excavation chamber pressure sensor connected to the excavation chamber; the excavation chamber pressure sensor is used to detect the pressure of the excavation chamber, so that the control system of the tunnel boring machine can adjust the opening of the air intake proportional valve accordingly, thereby keeping the pressure in the excavation chamber at the set value.

[0014] Furthermore, the pneumatic repeater includes a repeater body connected to the pneumatic conveying pipe, a mixing gasifier connected to the air conveying pipe, a liquefied air supply valve connecting the air conveying pipe and the mixing gasifier, an expansion nozzle and an air supply proportional valve connected between the mixing gasifier and the repeater body, and a suction pressure transmitter connected to the repeater body; the suction pressure transmitter is used to measure the pressure at the inlet end of the repeater body, so that the control system of the tunnel boring machine can adjust the opening of the liquefied air supply valve and the expansion nozzle accordingly, thereby reducing the pressure in the pneumatic conveying pipe upstream of the pneumatic repeater.

[0015] Furthermore, the repeater body includes a hollow tubular main body tube, a jet pipeline connected to the main body tube at an angle, and a jet nozzle connected to the injection end of the jet pipeline; the jet pipeline is connected to the expansion nozzle; the main body tube includes a repeater inlet, a first-stage choke, a repeater suction chamber, a repeater mixing chamber, a repeater diffuser section, and a repeater outlet arranged in sequence along the pneumatic conveying direction, and the jet pipeline is connected between the first-stage choke and the repeater suction chamber.

[0016] According to another aspect of the present invention, a roadheader is provided, comprising any of the pneumatic slag discharge systems for ultra-small diameter roadheaders described above.

[0017] The present invention has the following beneficial effects:

[0018] In the pneumatic slag discharge system of the present invention, 1. The use of liquefied compressed air can reduce the number of tunnel extension pipelines, that is, the secondary air supply pipe can be eliminated (part of the compressed air is introduced into the jet fan 8 after multi-stage filtration through the first air supply branch to serve as both air supply and cooling), the tunnel inlet and return water pipes can be eliminated (the slag is discharged through the pneumatic conveying pipe, and there is no need to set up the inlet and return water pipes), and the compressed air delivery pipe is eliminated (part of the compressed air is led outward through the second air supply branch). In particular, the tunnel supply and return water pipes and secondary air pipes will occupy a large percentage of the cross-section in the tunnel of an ultra-small diameter roadheader due to their large pipe diameter during long-distance excavation, which is not conducive to improving tunnel transportation. The locomotive's transportation of personnel, pipe segments, and mortar, as well as pneumatic conveying and pneumatic relaying, also require a large amount of compressed air. It is difficult to arrange a high-power air compressor on an ultra-small diameter shield machine, and the use of tunnel extension pipelines to directly convey compressed air also faces the problem of excessive pipe diameter and loss along the way. When liquefied compressed air is used as a universal medium, its physical properties of increased density and reduced volume after liquefaction are utilized to reduce the conveying diameter required for the tunnel extension pipeline. At the same time, the secondary air supply pipe, water supply and return pipe, and compressed air conveying pipe can be eliminated, thereby effectively reducing the occupation of the tunnel cross-sectional area, facilitating the transportation of personnel and materials in the tunnel, and reducing the number of pipelines required for the corresponding pipeline extension. , which is convenient for extension operation and saves cooling circulation water; 2. The heat absorbed by the liquefied compressed air during gasification and expansion is used to cool the internal circulation water, so as to save two large-diameter external circulation cooling water pipelines, and the compressed gas after heat absorption and gasification is used as the industrial gas source, air supply refrigeration and electrical component cooling, and it is also used as fresh air in the tunnel after filtering. The liquefied compressed air will be quickly gasified after decompression. When extending the pipeline, there is no need to equip a sewage tank and a sewage pump like the mud loop extension, which further reduces the hardware and operation costs; 3. Compared with the mud circulation, pneumatic conveying has a higher utilization rate of the trolley space, and there is no need to arrange complex bypass, small circulation, and reverse Flushing pipelines and a large mud pump are arranged on the trolley, thereby reducing the power distribution power required by the trolley, while saving the hardware and operating costs of the ground mud separation station. The pneumatic conveying has no negative pressure suction section, and directly relies on positive pressure blowing for pneumatic conveying to discharge slag, and directly transports the slag generated by excavation to the outside of the tunnel through the pneumatic conveying pipe; 4. The tunnel repeater is easy to arrange. Since pneumatic conveying only requires the arrangement of slag pipes and pneumatic repeaters in the slag discharge section, it saves hardware and operating costs while saving the proportion of tunnel cross-sectional area. The pneumatic repeater directly takes air from the liquefied compressed air pipeline as a power source, and can cool the local air in the tunnel while performing relaying.

[0019] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 Schematic diagram of a pneumatic slag discharge system for an ultra-small diameter roadheader according to a preferred embodiment of the present invention;

[0022] Figure 2 yes Figure 1 A partial enlarged schematic diagram;

[0023] Figure 3 yes Figure 1 Schematic diagram of a medium-mix gasifier;

[0024] Figure 4 yes Figure 1 Schematic diagram of the cross-sectional main structure of the repeater body.

[0025] Legend:

[0026] 1. Excavation chamber pressure sensor; 2. Intake proportional valve; 3. Amplifier body; 4. Suction chamber sensor; 5. Amplifier suction chamber; 6. Intake proportional valve; 7. Breathing filter; 8. Jet fan; 9. Pneumatic conveying telescopic sleeve; 10. Pneumatic conveying main pipe;

[0027] 11. Suction pressure transmitter; 12. Repeater body; 13. Mixer gasifier; 14. Air supply proportional valve;

[0028] 15. Air delivery pipe; 16. Ball valve; 17. Air delivery telescopic sleeve; 18. Heat exchanger; 19. Heat exchange copper tube; 20. Pressure stabilizing accumulator; 21. Proportional pressure reducing valve; 22. Ventilation and cooling water circuit; 23. Air supply and cooling water pump; 24. Air tank body; 25. Amplifier and ejector nozzle; 26. Mixing and diffusion chamber; 27. Gas storage pressure sensor; 28. Slag mixer; 29. ​​Slag hopper front gate; 30. Pneumatic delivery nozzle;

[0029] 31. Pneumatic motor; 32. Fan blades; 33. Expansion nozzle; 34. Vaporization chamber; 35. Heat exchange coiled tube; 36. Heat exchange air duct; 37. Throttle constant pressure reducing valve; 38. Liquefied air supply valve;

[0030] 39. Repeater inlet; 40. First-stage choke; 41. Jet pipeline; 42. Jet nozzle; 43. Repeater suction chamber; 44. Repeater mixing chamber; 45. Repeater diffuser section; 46. Repeater outlet. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0032] Reference Figure 1 A preferred embodiment of the present invention provides a pneumatic slag removal system for an ultra-small diameter roadheader, comprising: a heat exchanger 18 connected to the roadheader's internal circulating water circuit and the fan's ventilation and cooling water circuit 22; an air tank for storing air at a constant pressure; a flow amplifier for amplifying airflow; a telescopic air delivery pipe for conveying liquefied or vaporized compressed air; a telescopic pneumatic delivery pipe for pneumatically conveying slurry; and multiple sets of pneumatic relays. The air delivery pipe extends along the tunneling direction, connecting the heat exchanger 18, the air tank, and the flow amplifier in series along the air delivery direction. The air delivery pipe's input end is connected to a liquefied compressed air supply source, and its output end is connected to a pneumatic delivery nozzle 30 of a slag mixer 28 located at the head of the roadheader. The air tank also supplies compressed air to a jet blower 8 for blowing air through a first air delivery branch pipe, and to pneumatic control components within the roadheader that require compressed air through a second air delivery branch pipe. The pneumatic conveying pipe is extended along the excavation direction, the input end of the pneumatic conveying pipe is connected to the slag mixer 28, and multiple groups of pneumatic repeaters are arranged in sequence along the extension direction of the pneumatic conveying pipe, and each pneumatic repeater is connected to the air conveying pipe for air intake.

[0033] When the pneumatic slag discharge system of the present invention is used for shield slag discharge, the liquefied compressed air used is compressed, dehydrated, filtered, and cooled to below the critical temperature (about 132k) by the air compressor station on the ground, and then further compressed to the advanced pressure (37.8Mpa) to liquefy it; after the liquefied compressed air enters the tunnel boring machine through the air delivery pipe, it first passes through the heat exchanger 18 and the shield machine's internal circulating water circuit and the fan's ventilation and cooling water circuit 22 for heat exchange, and then absorbs heat and vaporizes, achieving the purpose of cooling the shield equipment components. The high-pressure compressed air after absorbing heat and reducing pressure vaporizes The gas then enters the air tank for constant pressure and temporary storage; the compressed air in the air tank is divided into three outputs, one of which is decompressed and output through the second gas transmission branch as industrial gas, which is the gas source for the gas-consuming equipment on the shield; one of which is decompressed and filtered through multiple stages as fresh air and then enters the jet fan 8 and is sent out and mixed with the tunnel air to serve as part-time air supply for cooling; the last one is further decompressed and amplified by the flow amplifier, and then enters the slag mixer 28 for pneumatic conveying; the slag entering the slag mixer 28 is pneumatically conveyed through the pneumatic conveying pipe for external output.

[0034] In the pneumatic slag discharge system of the present invention, 1. The use of liquefied compressed air can reduce the number of tunnel extension pipelines, that is, the secondary air supply pipe can be eliminated (part of the compressed air is introduced into the jet fan 8 after multi-stage filtration through the first air supply branch to serve as both air supply and cooling), the tunnel inlet and return water pipes can be eliminated (the slag is discharged through the pneumatic conveying pipe, and there is no need to set up the inlet and return water pipes), and the compressed air delivery pipe is eliminated (part of the compressed air is led outward through the second air supply branch). In particular, the tunnel supply and return water pipes and secondary air pipes will occupy a large percentage of the cross-section in the tunnel of an ultra-small diameter roadheader due to their large pipe diameter during long-distance excavation, which is not conducive to improving tunnel transportation. The locomotive's transportation of personnel, pipe segments, and mortar, as well as pneumatic conveying and pneumatic relaying, also require a large amount of compressed air. It is difficult to arrange a high-power air compressor on an ultra-small diameter shield machine, and the use of tunnel extension pipelines to directly convey compressed air also faces the problem of excessive pipe diameter and loss along the way. When liquefied compressed air is used as a universal medium, its physical properties of increased density and reduced volume after liquefaction are utilized to reduce the conveying diameter required for the tunnel extension pipeline. At the same time, the secondary air supply pipe, water supply and return pipe, and compressed air conveying pipe can be eliminated, thereby effectively reducing the occupation of the tunnel cross-sectional area, facilitating the transportation of personnel and materials in the tunnel, and reducing the number of pipelines required for the corresponding pipeline extension. , which is convenient for extension operation and saves cooling circulation water; 2. The heat absorbed by the liquefied compressed air during gasification and expansion is used to cool the internal circulation water, so as to save two large-diameter external circulation cooling water pipelines, and the compressed gas after heat absorption and gasification is used as the industrial gas source, air supply refrigeration and electrical component cooling, and it is also used as fresh air in the tunnel after filtering. The liquefied compressed air will be quickly gasified after decompression. When extending the pipeline, there is no need to equip a sewage tank and a sewage pump like the mud loop extension, which further reduces the hardware and operation costs; 3. Compared with the mud circulation, pneumatic conveying has a higher utilization rate of the trolley space, and there is no need to arrange complex bypass, small circulation, and reverse Flushing pipelines and a large mud pump are arranged on the trolley, thereby reducing the power distribution power required by the trolley, while saving the hardware and operating costs of the ground mud separation station. The pneumatic conveying has no negative pressure suction section, and directly relies on positive pressure blowing for pneumatic conveying to discharge slag, and directly transports the slag generated by excavation to the outside of the tunnel through the pneumatic conveying pipe; 4. The tunnel repeater is easy to arrange. Since pneumatic conveying only requires the arrangement of slag pipes and pneumatic repeaters in the slag discharge section, it saves hardware and operating costs while saving the proportion of tunnel cross-sectional area. The pneumatic repeater directly takes air from the liquefied compressed air pipeline as a power source, and can cool the local air in the tunnel while performing relaying.

[0035] Alternatively, as Figure 1As shown, the air conveying pipe comprises multiple, non-retractable sections of air conveying pipes 15 spaced sequentially along the air conveying direction, and telescopic air conveying sleeves 17 connecting adjacent sections of air conveying pipes 15 and arranged to be telescopic. The pneumatic conveying pipe comprises multiple, non-retractable sections of air conveying pipes 10 spaced sequentially along the air conveying direction, and telescopic air conveying sleeves 9 connecting adjacent sections of pneumatic conveying pipes 10 and arranged to be telescopic. In this optional solution, the excavation distance is compensated by the extension of the telescopic air conveying sleeves 17 and 9 during excavation, and the pipe extension operation is performed during assembly.

[0036] Alternatively, as Figure 1 As shown, the pneumatic slag discharge system for ultra-small diameter tunnel boring machines also includes a pressure stabilizing accumulator 20 for stabilizing pressure and storing energy. The pressure stabilizing accumulator 20 is connected to the air delivery pipe and is located upstream of the heat exchanger 18. During operation, liquefied compressed air enters the pressure stabilizing accumulator 20 through the air delivery pipe 15 and the air delivery telescopic sleeve 17 for temporary storage. The pressure stabilizing accumulator 20 is conventionally configured and equipped with a heat preservation mechanism, a discharge cooling device and a safety protection device. When the temperature rises, the liquefied compressed air can be discharged to expand and absorb heat to reduce its own temperature. The safety device is used for emergency discharge when the pressure is out of control. Preferably, as Figure 1 As shown, a plurality of ball valves 16 for controlling the on-off of the air delivery pipe 15 upstream of the pressure-stabilizing accumulator 20 are further provided in the air delivery pipe 15 .

[0037] Alternatively, as Figure 1 As shown, the internal circulation water circuit and the ventilation and cooling water circuit 22 are each connected to the heat exchanger 18. The air delivery pipe connects to the heat exchange copper tube 19 within the heat exchanger 18, exchanging heat with the internal circulation water circuit and the ventilation and cooling water circuit 22 through the heat exchange copper tube 19, thereby causing the liquefied compressed air to absorb heat, reduce pressure, and vaporize into compressed air. The ventilation and cooling water circuit 22 is also equipped with an air supply cooling water pump 23 for guiding the flow of water. During operation, the water-filled heat exchanger 18 and ventilation and cooling water circuit 22 allow the decompressed liquefied compressed air to exchange heat with the internal circulation water and the ventilation and cooling water. The liquefied compressed air, after absorbing heat, further reduces pressure and expands before entering and being stored in the gas tank body 24.

[0038] Alternatively, as Figure 1As shown, the air tank includes a tank body 24 for storing compressed air, a gas pressure sensor 27 connected to the tank body 24, and a proportional pressure reducing valve 21 connected to the air delivery pipe upstream of the heat exchanger 18. The gas pressure sensor 27 measures the pressure within the tank body 24, enabling the roadheader's control system to adjust the opening of the proportional pressure reducing valve 21 accordingly, thereby maintaining the pressure within the tank body 24 at a preset level. A breathing filter 7 is also installed in the first air delivery branch connecting the tank body 24 and the jet blower 8 to filter the compressed air. During operation, the liquefied compressed air stored in the pressure-stabilizing accumulator 20 is controlled according to the supply demand. After being reduced in pressure by the proportional pressure-reducing valve 21, it is further reduced in pressure and absorbs heat and expands through the heat exchanger 18, the heat exchange copper tube 19, and the ventilation and refrigeration water circuit 22 to reach the gas tank body 24. The supply demand control position controls the constant pressure of the gas tank body 24. If the pressure of the gas tank body 24 measured by the gas storage pressure sensor 27 decreases, the opening of the proportional pressure-reducing valve 21 is increased. If the pressure of the gas tank body 24 measured by the gas storage pressure sensor 27 increases, the opening of the proportional pressure-reducing valve 21 is reduced. After reaching the set constant pressure value, the proportional pressure-reducing valve 21 is closed.

[0039] Alternatively, as Figure 1 As shown, the flow amplifier includes an amplifier body 3, and a suction chamber sensor 4 and an air intake proportional valve 6 respectively connected to the amplifier body 3. The amplifier body 3 is provided with an amplifier suction chamber 5 and a mixing and diffusion chamber 26 arranged in sequence along the air flow conveying direction, and an amplifier introduction nozzle 25 arranged in the amplifier suction chamber 5. The air delivery pipe connects the amplifier introduction nozzle 25 and the mixing and diffusion chamber 26, so that compressed air can be sprayed into the amplifier suction chamber 5 through the amplifier introduction nozzle 25, and enter the mixing and diffusion chamber 26 together with the external air introduced into the amplifier suction chamber 5. The suction chamber sensor 4 is used to measure the pressure in the amplifier suction chamber 5, so that the control system of the tunnel boring machine can adjust the opening of the air intake proportional valve 6 accordingly, thereby maintaining the pressure in the amplifier suction chamber 5 at the set value. During operation, the compressed air stored in the gas tank body 24 is divided into three paths. The first path is decompressed and then goes to the air supply network on the trolley through the second gas branch pipe to be used as industrial gas to supply other gas-consuming equipment on the shield; the second path is decompressed and filtered and then enters the jet fan 8, which provides fresh air to the trolley area while drawing the air from the rear tunnel area to the trolley area to create local convection; the third path goes directly to the flow amplifier, and after generating a jet at the amplifier's injection nozzle 25, a negative pressure is generated in the amplifier's suction chamber 5 to inhale the atmosphere in the shield area, which is mixed in the mixing and diffusion chamber 26 and then re-pressurized to the pressure required for pneumatic conveying and sent to the pneumatic conveying nozzle 30, so as to achieve the purpose of increasing the mass flow rate while reducing pressure; at the same time, the intake proportional valve 6 is controlled by the pressure of the suction chamber sensor 4 to keep the pressure difference of the amplifier body 3 constant and the working condition stable.

[0040] Alternatively, as Figure 1 and Figure 2 As shown, the top of the slag mixer 28 is also equipped with a slag hopper front gate 29 for connecting to the external excavation chamber. The pneumatic slag removal system for ultra-small diameter roadheaders also includes a third air branch line connecting the air delivery pipe and the excavation chamber air intake, an air intake proportional valve 2 connected to the third air branch line, and an excavation chamber pressure sensor 1 connected to the excavation chamber. The excavation chamber pressure sensor 1 is used to detect the excavation chamber pressure, allowing the roadheader control system to adjust the opening of the air intake proportional valve 2 accordingly, thereby maintaining the set pressure in the excavation chamber. During operation, the gas at the intake proportional valve 2 is measured by the excavation chamber pressure sensor 1 to calculate the difference between the actual air pressure at the top of the excavation chamber and the pressure set by the driver. After calculation, the intake proportional valve 2 is proportionally controlled to keep the air pressure at the top of the excavation chamber constant; the compressed air at the pneumatic conveying nozzle 30 generates a jet through the jet nozzle, and makes the pressure below the gate 29 in front of the hopper slightly lower than the air pressure at the top of the shield and generates a flow direction. The slag cut off by the cutter head is driven by the passive stirring rod and the scraping bucket to fall above the gate 29 in front of the hopper, and is driven by the airflow. After the oversized stones are dried out by the slag drying net, they enter the pneumatic conveying nozzle 30 through the front gate 29 of the slag bucket. Based on their own pressure difference flow rate, they are accelerated by the jet nozzle, surpassing the suspension speed of the pneumatic conveying, and gradually accelerated to the conveying speed in the air. The driver controls the speed at which the slag stones fall into the pneumatic conveying nozzle 30 through the front gate 29 of the slag bucket according to the excavation speed and the pressure feedback from the excavation chamber pressure sensor 1 to avoid pipe blockage (sudden increase in the pressure of the excavation chamber pressure sensor 1) or air suction (sudden decrease in the pressure of the excavation chamber pressure sensor 1).

[0041] Alternatively, as Figure 1 and Figure 3As shown, the pneumatic repeater includes a repeater body 12 connected to the pneumatic conveying pipeline, a mixer-gasifier 13 connected to the air conveying pipeline, a liquefied air supply valve 38 connecting the air conveying pipeline and the mixer-gasifier 13, an expansion nozzle 33 and an air supply proportional valve 14 connected between the mixer-gasifier 13 and the repeater body 12, and a suction pressure transmitter 11 connected to the repeater body 12. The suction pressure transmitter 11 is used to measure the pressure at the inlet end of the repeater body 12, so that the control system of the roadheader can adjust the opening of the liquefied air supply valve 38 and the expansion nozzle 33 accordingly, thereby reducing the pressure in the pneumatic conveying pipeline upstream of the pneumatic repeater. A pneumatic automatic controller (pneumatic controller, mature technology, no longer detailed here) is conventionally installed at the pneumatic relay, which automatically controls the liquefied air supply valve 38 and the expansion nozzle 33 according to the pressure of the suction pressure transmitter 11. When the pressure at the suction pressure transmitter 11 exceeds the pressure value preset by the pneumatic controller, the liquefied air supply valve 38 will open. At this time, the liquefied compressed air in the tunnel extension pipeline is decompressed and vaporized through the heat exchange duct 36, the heat exchange winding tube 35 and the vaporization chamber 34 in the mixing vaporizer 13, and absorbs heat and expands. The expansion nozzle 33 is proportionally controlled according to the difference between the preset value and the suction pressure transmitter 11, and the pneumatic motor 31 is driven to drive the fan blades 32 to rotate, so that the hot air in the tunnel enters the heat exchange duct 36 and exchanges heat with the liquefied compressed air; when the liquefied air supply valve 38 is not open, the pneumatic control mechanism and the suction pressure transmitter 11 rely on the small pressure reducing valve of the throttling constant pressure reducing valve 37 as the air source for the weak air consumption.

[0042] Alternatively, as Figure 1 、 Figure 3 and Figure 4 As shown, the repeater body 12 includes a hollow tubular main body tube, a jet pipeline 41 connected to the main body tube at an angle, and a jet nozzle 42 connected to the injection end of the jet pipeline 41. The jet pipeline 41 is connected to the expansion nozzle 33. The main body tube includes a repeater inlet 39, a first-stage choke 40, a repeater suction chamber 43, a repeater mixing chamber 44, a repeater diffuser section 45, and a repeater outlet 46, which are arranged in sequence along the pneumatic conveying direction, and the jet pipeline 41 is connected between the first-stage choke and the repeater suction chamber 43. During operation, the vaporized high-pressure compressed air enters the jet pipeline 41, generates a jet through the jet nozzle 42, generates a vacuum at the repeater suction chamber 43, and reduces the pressure at the repeater inlet 39, so as to achieve the purpose of reducing the exhaust back pressure of the previous stage pneumatic conveying pipeline. The slag blown from the upper conveying pipeline enters the repeater through the repeater inlet 39, is accelerated and decompressed at the first-stage throat 40, and finally enters the repeater suction chamber 43 to generate swirl flow. It exchanges momentum with the jet flow in the repeater mixing chamber 44 to further increase the speed to compensate for the loss along the way. After being decelerated and pressurized at the repeater diffuser section 45, it enters the tunnel extension pipeline from the repeater outlet 46 to continue pneumatic conveying. Preferably, if Figure 4As shown, the swirl flow at the repeater suction chamber 43 is to improve the momentum exchange efficiency and reduce the wear of the repeater cylinder wall by using the turbulent layer. The mass flow injection ratio of this structure can reach more than 1 to 5 when the jet pressure difference is 8 bar through simulation.

[0043] A preferred embodiment of the present invention provides a tunnel boring machine, including a pneumatic slag discharge system for ultra-small diameter tunnel boring machines as described above. Thus, the tunnel boring machine of the present invention can utilize the physical property of liquefied compressed air that its density increases and its volume decreases after liquefaction, thereby reducing the conveying diameter required for the tunnel extension pipeline. At the same time, the secondary air supply pipe, the water inlet and return pipe, and the compressed air delivery pipe can be eliminated, thereby effectively reducing the occupation of the tunnel cross-sectional area and facilitating locomotive transportation. The heat absorbed by the liquefied compressed air during vaporization and expansion can be utilized to cool the internal circulation water, so as to save two large-diameter external circulation cooling water pipelines, and the compressed gas after heat absorption and vaporization can be utilized as an industrial gas source, air supply refrigeration, and electrical component cooling. After filtering, it can also be used as fresh air in the tunnel. The liquefied compressed air will quickly vaporize after decompression, and there is no need to extend the pipeline like a mud loop when extending the pipeline. In that way, it is equipped with a sewage tank and a sewage suction pump, which further reduces the hardware and operating costs; the utilization rate of the trolley space is higher, and there is no need to arrange complex bypass, small circulation, backwash and other pipelines, and to arrange a large mud pump on the trolley, thereby reducing the power distribution power required for the trolley, while saving the hardware and operating costs of the ground mud separation station, and the pneumatic conveying has no negative pressure suction section, and directly relies on positive pressure blowing for pneumatic conveying and slag discharge, and directly transports the slag generated by excavation to the outside of the tunnel through the pneumatic conveying pipe; the tunnel repeater is easy to arrange, because pneumatic conveying only requires the arrangement of slag pipes and pneumatic repeaters in the slag discharge section, so it saves hardware and operating costs while saving the proportion of tunnel cross-sectional area, and the pneumatic repeater directly takes air from the liquefied compressed air pipeline as a power source, and can cool the local air in the tunnel while relaying.

[0044] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A pneumatic slag removal system for an ultra-small diameter roadheader, characterized in that: include: A heat exchanger (18) connected to the internal circulating water circuit of the tunnel boring machine and the ventilation and cooling water circuit (22) of the fan, an air tank for storing air at a constant pressure, a flow amplifier for amplifying air flow, an air delivery pipe telescopically arranged for delivering liquefied compressed air or gasified compressed air, a pneumatic delivery pipe telescopically arranged for pneumatically delivering mud, and a plurality of pneumatic relays; The air delivery pipe is extended and arranged along the excavation direction to connect the heat exchanger (18), the air tank and the flow amplifier in series in sequence along the air delivery direction; the input end of the air delivery pipe is connected to a liquefied compressed air supply source for supplying liquefied compressed air; and the output end of the air delivery pipe is connected to a pneumatic delivery nozzle (30) of a slag mixer (28) provided at the head of the excavator; The air tank also supplies compressed air to a jet blower (8) for blowing air through a first air supply branch pipe, and supplies compressed air to pneumatic control components in the tunnel boring machine that require compressed air through a second air supply branch pipe; The pneumatic conveying pipe is extended along the excavation direction, the input end of the pneumatic conveying pipe is connected to the slag mixer (28), and multiple groups of pneumatic repeaters are arranged in sequence along the extension direction of the pneumatic conveying pipe, and each pneumatic repeater is connected to the air conveying pipe for air intake.

2. The pneumatic slag removal system for an ultra-small diameter roadheader according to claim 1, characterized in that: The air delivery pipe comprises a plurality of air delivery main pipes (15) which are sequentially arranged at intervals along the air delivery direction and are non-retractable, and an air delivery telescopic sleeve (17) which is connected between two adjacent air delivery main pipes (15) and is telescopically arranged. The pneumatic conveying pipe comprises a plurality of sections of pneumatic conveying main pipes (10) which are sequentially arranged at intervals along the pneumatic conveying direction and are non-retractable, and a pneumatic conveying telescopic sleeve (9) which is connected between two adjacent sections of the pneumatic conveying main pipes (10) and is telescopically arranged.

3. The pneumatic slag discharge system for an ultra-small diameter roadheader according to claim 1, characterized in that: The pneumatic slag discharge system for an ultra-small diameter roadheader further comprises a pressure stabilizing accumulator (20) for stabilizing pressure and storing energy. The pressure stabilizing accumulator (20) is connected to the pipeline of the air delivery pipe and is located upstream of the heat exchanger (18).

4. The pneumatic slag discharge system for an ultra-small diameter roadheader according to claim 1, characterized in that: The internal circulation water circuit and the ventilation and refrigeration water circuit (22) are respectively connected to the heat exchanger (18); The air delivery pipe is connected to the heat exchange copper pipe (19) in the heat exchanger (18) to exchange heat with the internal circulation water circuit and the ventilation and refrigeration water circuit (22) through the heat exchange copper pipe (19), thereby causing the liquefied compressed air to absorb heat, reduce pressure, and gasify into compressed air; The ventilation and cooling water circuit (22) is also provided with an air supply cooling water pump (23) for guiding the flow of water.

5. The pneumatic slag discharge system for an ultra-small diameter roadheader according to claim 1, characterized in that: The air tank comprises a tank body (24) for storing compressed air, a gas storage pressure sensor (27) connected to the tank body (24), and a proportional pressure reducing valve (21) connected to an air delivery pipe upstream of a heat exchanger (18); The gas storage pressure sensor (27) is used to measure the pressure in the gas tank body (24), so that the control system of the tunnel boring machine adjusts the opening of the proportional pressure reducing valve (21) accordingly, thereby maintaining the pressure in the gas tank body (24) at a preset pressure; A breathing filter (7) for filtering compressed air is also provided in the first air delivery branch pipe connecting the air tank body (24) and the jet blower (8).

6. The pneumatic slag removal system for an ultra-small diameter roadheader according to claim 1, characterized in that: The flow amplifier includes an amplifier body (3), and a suction chamber sensor (4) and an air intake proportional valve (6) respectively connected to the amplifier body (3); The amplifier body (3) is provided with an amplifier suction chamber (5) and a mixing and diffusing chamber (26) arranged in sequence along the airflow conveying direction, and an amplifier ejection nozzle (25) arranged in the amplifier suction chamber (5); The air delivery pipe is connected to the amplifier injection nozzle (25) and the mixing and diffusion chamber (26), so that the compressed air is sprayed into the amplifier suction chamber (5) through the amplifier injection nozzle (25) and enters the mixing and diffusion chamber (26) together with the external air introduced into the amplifier suction chamber (5); The suction chamber sensor (4) is used to measure the pressure in the amplifier suction chamber (5), so that the control system of the roadheader adjusts the opening of the suction proportional valve (6) accordingly, thereby maintaining the pressure in the amplifier suction chamber (5) at a set value.

7. The pneumatic slag discharge system for an ultra-small diameter roadheader according to claim 1, characterized in that: The top of the slag mixer (28) is also provided with a slag hopper front gate (29) for communicating with an external excavation chamber; The pneumatic slag removal system for an ultra-small diameter roadheader further includes a third air supply branch pipe for connecting the air supply pipe and the excavation chamber air intake, an air intake proportional valve (2) connected to the third air supply branch pipe, and an excavation chamber pressure sensor (1) connected to the excavation chamber; The excavation chamber pressure sensor (1) is used to detect the pressure of the excavation chamber so that the control system of the roadheader adjusts the opening of the air intake proportional valve (2) accordingly, thereby maintaining the pressure in the excavation chamber at a set value.

8. The pneumatic slag discharge system for an ultra-small diameter roadheader according to claim 1, characterized in that: The pneumatic repeater comprises a repeater body (12) connected to a pneumatic conveying pipe, a mixing gasifier (13) connected to the air conveying pipe, a liquefied air supply valve (38) connecting the air conveying pipe and the mixing gasifier (13), an expansion nozzle (33) and an air supply proportional valve (14) connected between the mixing gasifier (13) and the repeater body (12), and a suction pressure transmitter (11) connected to the repeater body (12); The suction pressure transmitter (11) is used to measure the pressure at the inlet end of the repeater body (12), so that the control system of the roadheader can adjust the opening of the liquefied air supply valve (38) and the expansion nozzle (33) accordingly, thereby reducing the pressure in the pneumatic conveying pipe upstream of the pneumatic repeater.

9. The pneumatic slag discharge system for an ultra-small diameter roadheader according to claim 8, characterized in that: The relay body (12) includes a hollow tubular body tube, a jet pipeline (41) connected to the body tube at an angle, and a jet nozzle (42) connected to the jet end of the jet pipeline (41); The jet pipeline (41) is connected to the expansion nozzle (33); The main body tube comprises a repeater inlet (39), a first-stage throat contraction, a repeater suction chamber (43), a repeater mixing chamber (44), a repeater expansion section (45), and a repeater outlet (46) which are sequentially arranged along the pneumatic conveying direction, and a jet pipeline (41) is connected between the first-stage throat contraction and the repeater suction chamber (43).

10. A tunnel boring machine, characterized in that: The pneumatic slag discharge system for an ultra-small diameter roadheader comprises the pneumatic slag discharge system for an ultra-small diameter roadheader according to any one of claims 1 to 9.

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