Pneumatic deslagging system for ultra-small-diameter heading machine and heading machine with pneumatic deslagging system

Abstract

The invention discloses a pneumatic deslagging system for an ultra-small-diameter heading machine and the heading machine with the pneumatic deslagging system. The pneumatic deslagging system comprises a heat exchanger, an air tank, a flow amplifier, an air conveying pipe, a pneumatic conveying pipe and a plurality of sets of pneumatic repeaters. The heat exchanger, the air tank and the flow amplifier are sequentially communicated in series through the air conveying pipe in the air conveying direction, the input end of the air conveying pipe is connected with the liquefied compressed air supply source, and the output end is connected with the pneumatic conveying nozzle of the slag receiving mixer. And the air tank supplies compressed air to the jet fan for blowing and supplying air and the pneumatic control element. The input end of the pneumatic conveying pipe is connected with the slag receiving mixer, the multiple sets of pneumatic repeaters are sequentially arranged in the extending direction of the pneumatic conveying pipe, and all the pneumatic repeaters are connected with the air conveying pipe for air entraining. According to the system, the occupied area of the cross section of the tunnel can be effectively reduced, transportation of personnel and materials in the tunnel is facilitated, the number of pipelines needed by corresponding pipeline extension is reduced, extension operation is facilitated, and cooling circulating water is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel boring equipment, and in particular, to a pneumatic slag removal system for an ultra-small diameter tunnel boring machine. In addition, the present invention also relates to a tunnel boring machine comprising the above-mentioned pneumatic slag removal 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 machines and belt conveyors can only be used on equipment with an excavation diameter of 3 meters or more. If the excavation diameter is lower, there is not enough space to allow convenient transportation of pipe segments while retaining sufficient personnel maintenance channels and pipe and wiring space. Therefore, in the design of 2-meter-level tunnel boring machines, the slag discharge plan is basically based on mud circulation slag discharge.

[0003] However, the mud circulation system still requires additional trolley space to arrange the slurry pump and bypass and circulation pipelines, and the tunnel also requires space to be equipped with relay inlet and outlet pumps, and 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, in the hope of occupying the trolley space and the tunnel cross-sectional area as small as possible to obtain a slag discharge effect similar to the mud circulation system, and to compress the hardware cost as much as possible to facilitate its acceptance by customers and promotion and application. At the same time, it can be combined with some emerging excavation methods and technologies for system integration.

[0004] In the past designs, vacuum slag suction pumps were used as the main technical device for pneumatic slag removal in ultra-small diameter shield machines with a diameter of two meters. However, due to the limitations of its working principle, the pressure difference of the suction pipe section in the suction mode is only one atmosphere, and the suction distance is long, resulting in low suction efficiency and inability to match the excavation speed. Therefore, this slag removal method was abandoned after about 200 meters of trial excavation. The existing method of first using a screw machine to remove slag and crush it, and then using a vacuum slag suction pump for suction / slag removal operations, also faces the problem of too small shield space in ultra-small diameter shield machines, which is not suitable for arranging screw machines and crushers. Therefore, in general, a more optimized design is still needed to achieve smooth slag removal of ultra-small diameter tunnel boring machines at the 2-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 having 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 by the present invention is as follows:

[0007] A pneumatic slag removal system for an ultra-small diameter tunnel boring machine comprises: a heat exchanger respectively connected to a circulating water circuit in the tunnel boring machine and a ventilation and cooling water circuit of a 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 pneumatic delivery of mud, and a plurality of pneumatic repeaters; the air delivery pipe is extended and arranged along the tunneling direction so as to connect the heat exchanger, the air tank and the flow amplifier in series in sequence along the air delivery direction, and the input end of the air delivery pipe is connected to the input end of the air delivery pipe. 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 need to use compressed air through the second air supply branch pipe; the pneumatic conveying pipe is extended along the tunneling direction, 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 which are arranged in sequence at intervals along the air conveying direction and are not retractable, and an air conveying telescopic sleeve which 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 which are arranged in sequence at intervals along the pneumatic conveying direction and are not retractable, and a pneumatic conveying telescopic sleeve which is connected between two adjacent sections of the pneumatic conveying main pipes and is retractable.

[0009] Furthermore, the pneumatic slag removal system for an ultra-small diameter tunneling machine also includes a pressure-stabilizing accumulator for pressure-stabilizing energy storage, which is connected to the pipeline of the air delivery pipe and is located upstream of the heat exchanger.

[0010] Furthermore, the inner circulation water circuit and the ventilation and refrigeration water circuit are respectively connected to the heat exchanger; the air delivery pipe is connected to the heat exchange copper pipe in the heat exchanger to exchange heat with the inner circulation water circuit and the ventilation and refrigeration water circuit through the heat exchange copper pipe, so that the liquefied compressed air absorbs heat, reduces pressure and gasifies into compressed air. The ventilation and refrigeration water circuit is also provided with an air supply cooling water pump for guiding the flow of water.

[0011] Furthermore, the air tank includes a tank body for storing compressed air, an air storage 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 storage pressure sensor is used to measure the pressure inside the tank body, so that the control system of the tunnel boring machine can adjust 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 pipe connecting the tank body and the jet fan.

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

[0013] Furthermore, a slag hopper front gate for connecting to an external excavation chamber is also 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, there is also provided a roadheader, comprising any of the pneumatic slag removal 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 cancelled (part of the compressed air is introduced into the jet of the jet fan 8 after multi-stage filtration through the first air supply branch pipe to serve as both air supply and cooling), the tunnel water inlet and return pipes can be cancelled (the slag is output by the pneumatic conveying pipe, and there is no need to set up the water inlet pipe and the water return pipe), and the compressed air conveying pipe can be cancelled (part of the compressed air is led out through the second air supply branch pipe). In particular, the tunnel water supply and return pipe and the secondary air pipe will occupy a large percentage of the cross-section in the tunnel of the 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, 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, the 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 inlet and return pipe and compressed air delivery 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 air after heat absorption and gasification is used as the industrial gas source, air supply refrigeration and electrical component cooling. After filtering, it is also used as fresh air in the tunnel. 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 suction pump like the mud loop extension, which further reduces the hardware and operation costs; 3. Compared with 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 discharge 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 relaying.

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

[0020] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the 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 front view structure of the repeater body.

[0025] Legend:

[0026] 1. Excavation chamber pressure sensor; 2. Air intake proportional valve; 3. Amplifier body; 4. Suction chamber sensor; 5. Amplifier suction chamber; 6. Suction 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. Mixing 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 refrigeration water circuit; 23. Air supply cooling water pump; 24. Air tank body; 25. Amplifier 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. Gasification chamber; 35. Heat exchange coiled tube; 36. Heat exchange air duct; 37. Throttling constant pressure reducing valve; 38. Liquefied air supply valve;

[0030] 39. Repeater inlet; 40. First-stage throat contraction; 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 The preferred embodiment of the present invention provides a pneumatic slag removal system for an ultra-small diameter tunnel boring machine, comprising: 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 the air flow, an air delivery pipe telescopically arranged for delivering liquefied compressed air or gasified compressed air, a pneumatic delivery pipe telescopically arranged for pneumatic delivery of mud, and a plurality of pneumatic relays. The air delivery pipe is extended and arranged along the tunneling 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 receiving mixer 28 arranged at the head of the tunnel boring machine. The air tank also supplies compressed air to a jet fan 8 for blowing air supply through a first air delivery branch pipe, and supplies compressed air to a pneumatic control element in the tunnel boring machine that needs 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, and the high-pressure compressed air after absorbing heat and reducing pressure vaporizes The compressed air 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 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 refrigeration; the last one is further decompressed and amplified by a 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 output to the outside.

[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 cancelled (part of the compressed air is introduced into the jet of the jet fan 8 after multi-stage filtration through the first air supply branch pipe to serve as both air supply and cooling), the tunnel water inlet and return pipes can be cancelled (the slag is output by the pneumatic conveying pipe, and there is no need to set up the water inlet pipe and the water return pipe), and the compressed air conveying pipe can be cancelled (part of the compressed air is led out through the second air supply branch pipe). In particular, the tunnel water supply and return pipe and the secondary air pipe will occupy a large percentage of the cross-section in the tunnel of the 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, 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, the 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 inlet and return pipe and compressed air delivery 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 air after heat absorption and gasification is used as the industrial gas source, air supply refrigeration and electrical component cooling. After filtering, it is also used as fresh air in the tunnel. 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 suction pump like the mud loop extension, which further reduces the hardware and operation costs; 3. Compared with 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 discharge 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 relaying.

[0035] Alternatively, if Figure 1As shown, the air conveying pipe includes a plurality of sections of air conveying main pipes 15 which are arranged in sequence and are not retractable along the air conveying direction, and an air conveying telescopic sleeve 17 which is connected between two adjacent sections of the air conveying main pipes 15 and is telescopically arranged. The pneumatic conveying pipe includes a plurality of sections of pneumatic conveying main pipes 10 which are arranged in sequence and are not retractable along the pneumatic conveying direction, 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. In this optional solution, the excavation distance is compensated by the extension of the air conveying telescopic sleeve 17 and the pneumatic conveying telescopic sleeve 9 during excavation, and the pipeline extension operation is performed during assembly.

[0036] Alternatively, if Figure 1 As shown, the pneumatic slag removal system for ultra-small diameter tunnel boring machines also includes a pressure-stabilizing accumulator 20 for pressure-stabilizing energy storage. The pressure-stabilizing accumulator 20 is connected to the pipeline of 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 temperature can be lowered by discharging the liquefied compressed air to expand and absorb heat. The safety device is used for emergency discharge when the pressure is out of control. Preferably, as Figure 1 As shown, the air delivery pipe 15 upstream of the pressure-stabilizing accumulator 20 is also provided with a plurality of ball valves 16 for controlling the on-off thereof.

[0037] Alternatively, if Figure 1 As shown, the inner 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 tube 19 in the heat exchanger 18, so as to exchange heat with the inner circulation water circuit and the ventilation and refrigeration water circuit 22 through the heat exchange copper tube 19, thereby causing the liquefied compressed air to absorb heat, reduce pressure and gasify into compressed air. The ventilation and refrigeration water circuit 22 is also provided with an air supply cooling water pump 23 for guiding the flow of water. When working, the water-filled heat exchanger 18 and the ventilation and refrigeration water circuit 22 will cause the decompressed liquefied compressed air to exchange heat with the inner circulation water and the ventilation and refrigeration water, and the liquefied compressed air after absorbing heat will further reduce pressure and expand and enter and be stored in the gas tank body 24.

[0038] Alternatively, if Figure 1As shown, the air tank includes 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 in the air delivery pipe connected to the upstream of the heat exchanger 18. The gas storage pressure sensor 27 is used to measure the pressure in the 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 tank body 24 at a preset pressure. A breathing filter 7 for filtering compressed air is also provided in the first gas delivery branch connecting the tank body 24 and the jet fan 8. 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 expanded by absorbing heat 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 performs constant pressure control on 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, if 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 diffusing chamber 26 arranged in sequence along the air flow conveying direction, and an amplifier ejector nozzle 25 arranged in the amplifier suction chamber 5. The air delivery pipe connects the amplifier ejector nozzle 25 and the mixing and diffusing chamber 26, so that the compressed air is sprayed into the amplifier suction chamber 5 through the amplifier ejector nozzle 25, and enters the mixing and diffusing 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 adjusts the opening of the air intake proportional valve 6 accordingly, thereby keeping 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 routes. The first route is decompressed and then goes to the air supply network on the trolley through the second gas transmission branch pipe, and is used as industrial gas to supply other gas-consuming equipment on the shield; the second route is decompressed and filtered and then enters the jet fan 8, which provides fresh air to the trolley area while drawing the air in the rear tunnel area to the trolley area to create local convection; the third route goes directly to the flow amplifier, and after a jet is generated at the amplifier injection nozzle 25, a negative pressure is generated in the amplifier 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 suction 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, if Figure 1 and Figure 2 As shown, the top of the slag mixer 28 is also provided with a slag bucket 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 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. During operation, the gas at the air intake proportional valve 2 measures the difference between the actual air pressure at the top of the excavation chamber and the pressure set by the driver through the excavation chamber pressure sensor 1. After calculation, the air 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 slag bucket slightly lower than the air pressure at the top of the shield body 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 slag bucket, and 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. On the basis of their own pressure difference flow rate, they are accelerated through 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 falls 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, so as to avoid pipe blockage (sudden increase in pressure of the excavation chamber pressure sensor 1) or empty suction (sudden decrease in pressure of the excavation chamber pressure sensor 1).

[0041] Alternatively, if Figure 1 and Figure 3As shown, the pneumatic repeater includes a repeater body 12 connected to the 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 tunnel boring machine adjusts 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. A pneumatic automatic controller (pneumatic controller, mature technology, no longer described here) is conventionally installed at the pneumatic relay, and the liquefied air supply valve 38 and the expansion nozzle 33 are automatically controlled according to the pressure of the suction pressure transmitter 11. When the pressure at the suction pressure transmitter 11 exceeds the preset pressure value of 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 gasified through the heat exchange duct 36, the heat exchange winding tube 35 and the gasification chamber 34 in the mixing gasifier 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 opened, the pneumatic control mechanism and the weak air consumption of the suction pressure transmitter 11 rely on the small pressure reducing valve of the throttling constant pressure reducing valve 37 as the air source.

[0042] Alternatively, if Figure 1 , Figure 3 and Figure 4 As shown, the repeater 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 injection end of the jet pipeline 41. The jet pipeline 41 is connected to the expansion nozzle 33. The body tube includes a repeater inlet 39, a first-stage throat 40, a repeater suction chamber 43, a repeater mixing chamber 44, a repeater expansion 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 throat and the repeater suction chamber 43. During operation, the gasified 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 upper-level pneumatic conveying pipeline. The slag blown from the upper conveying pipeline enters the repeater through the repeater inlet 39, speeds up and reduces pressure at the first-stage throat 40, and finally enters the repeater suction chamber 43 to generate swirl, exchanges momentum with the jet in the repeater mixing chamber 44 to further speed up to compensate for the loss along the way, and after speeding up and increasing pressure at the repeater expansion section 45, enters the tunnel extension pipeline from the repeater outlet 46 to continue pneumatic conveying. Preferably, as 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 a super small diameter tunnel boring machine as described above, so that 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, and at the same time, can eliminate the secondary air supply pipe, the water inlet and return pipe, and the compressed air conveying pipe, thereby effectively reducing the occupation of the tunnel cross-sectional area and facilitating the transportation of locomotives; the heat absorbed by the liquefied compressed air during its 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 air after absorbing heat and vaporization can be utilized as the industrial gas source, air supply refrigeration, and electrical component cooling, and after filtering it, it can also be used as fresh air for the tunnel, and the liquefied compressed air will be rapidly vaporized after being depressurized, so when extending the pipeline, there is no need to extend the mud loop like in the mud loop. In that case, 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, backwashing 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 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 needs to arrange the slag discharge pipe and the pneumatic repeater of the slag discharge section, so it saves hardware and operating costs while saving the proportion of the 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 above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope 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 the air flow, an air delivery pipe telescopically arranged for delivering liquefied compressed air or gasified compressed air, a pneumatic delivery pipe telescopically arranged for pneumatic delivery of mud, and a plurality of pneumatic repeaters; 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 fan (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 and arranged 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 tunnel boring machine according to claim 1, characterized in that: The air delivery pipe comprises a plurality of air delivery main pipes (15) which are arranged in sequence and at intervals along the air delivery direction and are not 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 arranged in sequence and at intervals along the pneumatic conveying direction and are not retractable, and a pneumatic conveying telescopic sleeve (9) which is connected between two adjacent sections of the pneumatic conveying main pipes (10) and is retractably arranged.

3. The pneumatic slag removal system for an ultra-small diameter tunnel boring machine according to claim 1, characterized in that: The pneumatic slag removal system for an ultra-small diameter tunneling machine also includes a pressure stabilizing accumulator (20) for stabilizing pressure and storing energy. The pressure stabilizing accumulator (20) is connected to the pipeline of the air conveying pipe and is located upstream of the heat exchanger (18).

4. The pneumatic slag removal system for an ultra-small diameter tunnel boring machine 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 and reduce pressure and gasify into compressed air; The ventilation and refrigeration water circuit (22) is also provided with an air supply cooling water pump (23) for guiding the flow of water.

5. The pneumatic slag removal 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 can adjust 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 comprises an amplifier body (3), and a suction chamber sensor (4) and an air suction 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 tunnel boring machine 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 removal 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 connecting to an external excavation chamber; The pneumatic slag removal system for an ultra-small diameter roadheader 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 (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 removal 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 an 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 tunnel boring machine 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 removal system for an ultra-small diameter roadheader according to claim 8, characterized in that: The repeater body (12) comprises 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 pipe 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: It includes a pneumatic slag removal system for an ultra-small diameter tunnel boring machine as shown in any one of Figures 1-9.

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