Multi-channel closed gas lift reverse circulation one-way mixer

Abstract

The invention discloses a multi-channel closed type gas lift reverse circulation one-way mixer, and particularly relates to the technical field of drilling tool equipment, the multi-channel closed type gas lift reverse circulation one-way mixer comprises an inner pipe assembly and an outer pipe connector, the inner pipe assembly comprises a core pipe and a sleeve, and the sleeve is fixedly arranged outside the core pipe in a sleeving mode; a center through hole of the core pipe is a first channel, is communicated with the bottom of a drill hole and is used for discharging drilling fluid and rock debris in the drill hole, a gap between the sleeve and the core pipe is a second channel and is communicated with an air inlet channel of the air down-the-hole hammer, and the inner pipe assembly is fixedly sleeved with the outer pipe connector. A gap between the outer pipe joint and the sleeve is a third channel communicated with an air outlet channel of the air down-the-hole hammer, and air in the second channel can enter the first channel through a one-way valve arranged on the side wall of the core pipe in the circumferential direction. Independent air inlet, exhaust and deslagging channels are provided for the air down-the-hole hammer, the working back pressure of the down-the-hole hammer is reduced, the drilling efficiency is improved, meanwhile, gas-liquid-solid mixed fluid of the deslagging channel is prevented from entering an air channel in the air down-the-hole hammer, and stable and clean gas is provided for the air down-the-hole hammer.

Description

Technical Field

[0001] This invention relates to the field of drilling tools and equipment technology, and in particular to a multi-channel closed-loop gas lift reverse circulation unidirectional mixer. Background Technology

[0002] Air down-the-hole hammer drilling technology uses compressed air provided by an air compressor as power and circulating fluid to drive the piston inside the down-the-hole hammer to reciprocate and strike the drill bit. It mainly achieves efficient drilling by causing volumetric fracturing of the rock at the bottom of the well through impact. It is currently widely used in the construction of large-diameter boreholes such as water wells, geothermal wells, coal mine gas drainage wells, and ultra-long pile foundations.

[0003] Air-lift reverse circulation is considered one of the most advanced drilling technologies today. Its working principle is as follows: Compressed air is injected into the annulus between the inner and outer tubes of a double-walled drill string through an air-water tap or other air injection connector (air box). The gas flows to the bottom of the double-walled drill pipe, is injected into the inner tube through a mixer, forming numerous small bubbles. These bubbles rise rapidly along the inner tube and expand dramatically, converting the expansion work into the potential energy of the water, propelling the liquid flow. Compressed air continuously enters the inner tube, forming a low-density gas-liquid mixture in the upper part of the mixer, while the drill pipe and the lower part of the mixer contain the high-density drilling fluid. The drilling fluid in the annulus enters the waterhole of the drill string, forming a reverse circulation flow and continuously bringing rock cuttings from the bottom of the well to the surface, where they are discharged into the settling basin. The settled drilling fluid is then injected back into the wellbore, thus continuously circulating to form a continuous drilling process.

[0004] The application of air down-the-hole hammers in air-lift reverse circulation drilling is not mature. The existing mixer structure is not suitable for down-the-hole hammer reverse circulation drilling and there are still many problems. For example, the exhaust channel is connected to the central slag discharge channel and the annular drilling fluid channel. When exhausting, rock cuttings and drilling fluid are carried out, which can easily cause the back pressure of the down-the-hole hammer to be too high, affecting drilling efficiency.

[0005] Currently, in most multi-circulation flow channel junctions, the central slag discharge channel is connected to the inlet flow channel via a mixing hole. When the pressure inside the central slag discharge channel is greater than the pressure inside the inlet flow channel, some of the gas-liquid-solid mixture in the central slag discharge channel will flow into the inlet flow channel from the mixing hole, causing blockage of the internal air passages of the air down-the-hole hammer and preventing the air down-the-hole hammer from functioning properly. For reverse circulation drilling conditions using air down-the-hole hammers, how to improve the gas-liquid mixing effect and slag discharge capacity of the mixer while stably providing clean high-pressure air to the down-the-hole hammer has become an urgent problem for engineers in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-channel closed-loop air-lift reverse circulation unidirectional mixer to solve the problems existing in the prior art. It provides independent air intake, exhaust and slag discharge channels for the air down-the-hole hammer, reduces the working back pressure of the down-the-hole hammer, improves drilling efficiency, and at the same time prevents the gas-liquid-solid mixed fluid in the slag discharge channel from entering the internal air passage of the air down-the-hole hammer, thus providing stable and clean gas for the air down-the-hole hammer.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] This invention provides a multi-channel closed-loop gas lift reverse circulation one-way mixer, including an inner tube assembly and an outer tube connector. The inner tube assembly includes a core tube and a casing. The casing is fixedly sleeved outside the core tube. The central through hole of the core tube is a first channel, which communicates with the bottom of the borehole to discharge drilling fluid and cuttings from the borehole. The gap between the inner wall of the casing and the outer wall of the core tube is a second channel, which communicates with the air inlet channel of an air down-the-hole hammer. The outer tube connector is fixedly sleeved outside the inner tube assembly. The gap between the inner wall of the outer tube connector and the outer wall of the casing is a third channel, which communicates with the air outlet channel of the air down-the-hole hammer. Multiple one-way valves are circumferentially arranged on the side wall of the core tube, allowing gas from the second channel to enter the first channel through the one-way valves.

[0009] Preferably, the core tube includes an upper core tube, a middle core tube, and a lower core tube that are fixedly connected in sequence, and the sleeve includes an upper sleeve, a middle sleeve, and a lower sleeve that are fixedly connected in sequence. The outer side wall of the upper core tube is fixedly connected to the inner side wall of the upper sleeve by a connecting block. The outer side wall of the upper sleeve is provided with a shoulder in the circumferential direction. The outer tube joint has a limiting boss inside. One side of the shoulder contacts the limiting boss, and the other side of the shoulder is fixedly connected to the outer tube joint by an elastic retaining ring. A shoulder channel is opened in the shoulder, and the shoulder channel is connected to the third channel.

[0010] Preferably, the upper core tube, the upper sleeve, and the shoulder are integrally formed.

[0011] Preferably, a first sealing groove is provided on the outer wall of the end of the upper sleeve away from the middle sleeve, and a sealing ring is provided in the first sealing groove.

[0012] Preferably, a second sealing groove is provided on the outer wall of the lower core tube away from the middle core tube, and a sealing ring is provided in the second sealing groove.

[0013] Preferably, the sidewall of the core tube is provided with a plurality of threaded holes, and each one-way valve is threadedly installed in each of the threaded holes. The axis of the threaded hole forms a certain angle with the axis of the core tube, and the threaded hole is inclined towards the upper core tube from the outside to the inside.

[0014] Preferably, the one-way valve includes a valve body, a valve seat, and a valve core. The valve body has a flow hole. The valve seat is fixedly installed at one end of the flow hole near the first channel. The valve core is installed at one end of the flow hole near the second channel. One end of the valve core is inserted into the valve seat and is movable relative to the valve seat. The valve core has an air inlet and a blocking protrusion protruding from the valve core. The blocking protrusion is closer to the valve seat than the air inlet. A spring is disposed between the valve seat and the blocking protrusion. One end of the spring abuts against the end face of the valve seat, and the other end abuts against the blocking protrusion. When the pressure in the second channel is less than the pressure in the first channel, the valve core is not subjected to an external force toward the valve seat. The end of the valve core away from the valve seat can block one side of the flow hole, thus disconnecting the second channel from the first channel. When the pressure in the second channel is greater than the pressure in the first channel, the valve core is subjected to an external force toward the valve seat and moves toward the valve seat. The spring is compressed, and the end of the valve core away from the valve seat is away from the flow hole, thus connecting the second channel with the first channel.

[0015] Preferably, the one-way valve further includes a foaming plate, which is installed in the flow hole. One end of the foaming plate is attached to the end face of the valve seat away from the valve core, and the other end is fixedly connected to the valve body through an elastic retaining ring. The foaming plate has multiple small holes.

[0016] Preferably, the plurality of the fine pores are evenly distributed on the foamed board.

[0017] Preferably, a third sealing groove is provided at the end of the valve core away from the valve seat, and a sealing ring for sealing the valve core and the valve body is provided in the third sealing groove.

[0018] The present invention achieves the following technical effects compared to the prior art:

[0019] This invention provides a multi-channel closed-loop air-lift reverse circulation unidirectional mixer. The first, second, and third channels are independent of each other. The first channel is connected to the bottom of the borehole to discharge drilling fluid and cuttings. The second channel can unidirectionally fill the air-driven down-the-hole hammer with gas, and the third channel can unidirectionally exhaust the air-driven down-the-hole hammer. They do not affect each other, enabling closed-loop circulation of the air-driven down-the-hole hammer, greatly reducing the working back pressure of the air-driven down-the-hole hammer, and effectively protecting the stability of the borehole wall. The high-pressure gas in the second channel can enter the first channel through a one-way valve, forming a gas-liquid-solid mixture in the first channel and discharging it. At the same time, the one-way valve can prevent the gas-liquid-solid mixture in the first channel from entering the second channel, avoiding blockage of the internal air passages of the air-driven down-the-hole hammer, providing stable and clean gas for the down-the-hole hammer, and ensuring the normal operation of the air-driven down-the-hole hammer. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram showing the connection between a multi-channel closed-loop air lift reverse circulation unidirectional mixer and a drill pipe and an air down-the-hole hammer.

[0022] Figure 2 A schematic diagram of a multi-channel closed-loop air lift reverse circulation unidirectional mixer;

[0023] Figure 3 A schematic diagram of the upper core tube, upper sleeve, and shoulder;

[0024] Figure 4 for Figure 3 Top view;

[0025] Figure 5 This is a schematic diagram of the core tube structure;

[0026] Figure 6 This is a schematic diagram of the lower core tube structure;

[0027] Figure 7 for Figure 6 Top view;

[0028] Figure 8 for Figure 2 Enlarged view of section A;

[0029] Figure 9 This is a schematic diagram of a one-way valve.

[0030] Figure 10 This is a schematic diagram of the valve core structure;

[0031] Figure 11 This is a schematic diagram of the structure of a foam board.

[0032] In the diagram: 1-Drill pipe; 2-Multi-channel closed-loop air-lift reverse circulation one-way mixer; 21-Outer pipe connector; 22-Upper casing; 221-First sealing groove; 23-Middle casing; 24-Lower casing; 25-Upper core tube; 26-Middle core tube; 261-Threaded hole; 27-One-way valve; 271-Valve body; 272-Valve seat; 273-Valve core; 274-Air inlet; 275-Foaming plate; 276-Small hole; 277-Valve seat unscrewing hole; 278-Spring; 279-Valve body unscrewing hole; 2710-Third sealing groove; 28-Elastic retaining ring; 29-Lower core tube; 291-Second sealing groove; 292-Straightening block; 210-Shoulder; 3-Air down-the-hole hammer; 4-First channel; 5-Second channel; 6-Third channel; 7-Fourth channel. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The purpose of this invention is to provide a multi-channel closed-loop air-lift reverse circulation unidirectional mixer to solve the problems existing in the prior art. It provides independent air intake, exhaust and slag discharge channels for the air down-the-hole hammer, reduces the working back pressure of the down-the-hole hammer, improves drilling efficiency, and at the same time prevents the gas-liquid-solid mixed fluid in the slag discharge channel from entering the internal air passage of the air down-the-hole hammer, thus providing stable and clean gas for the air down-the-hole hammer.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] This invention provides a multi-channel closed-loop air-lift reverse circulation unidirectional mixer, such as... Figure 1-2As shown, the assembly includes an inner tube assembly and an outer tube connector 21. The inner tube assembly includes a core tube and a casing. The casing is fixedly fitted outside the core tube. The central through hole of the core tube is a first channel 4, which is connected to the bottom of the borehole to discharge drilling fluid and cuttings. The gap between the inner wall of the casing and the outer wall of the core tube is a second channel 5, which is connected to the air intake channel of the air down-the-hole hammer 3. The outer tube connector 21 is fixedly fitted outside the inner tube assembly, and the gap between the inner wall of the outer tube connector 21 and the outer wall of the casing is a third channel 6. The second channel 5 is connected to the air outlet channel of the air down-the-hole hammer 3. Multiple one-way valves 27 are arranged circumferentially on the side wall of the core tube, and the gas in the second channel 5 can enter the first channel 4 through the one-way valves 27. During normal drilling, the upper end of the multi-channel closed-loop air-lift reverse circulation unidirectional mixer 2 is connected to the active drill pipe 1 and the drilling rig swivel. The drill pipe 1 has a three-channel structure, and its lower end is connected to the air down-the-hole hammer 3. After the wellbore design depth, air compressor, and multi-channel drilling tools are selected, the submersion depth of the multi-channel closed-loop air-lift reverse circulation unidirectional mixer 2 is set within the optimal submersion depth range. The first channel 4, the second channel 5, and the third channel 6 are independent of each other and are connected to the three channels of the drill pipe 1 and the three channels of the air down-the-hole hammer 3, respectively. The first channel 4 is the central slag discharge channel, and the fourth channel 7 is the gap between the inner wall of the borehole and the outer wall of the outer pipe joint 21. The first channel 4 and the fourth channel 7 are connected at the bottom of the borehole and are used to discharge drilling fluid and cuttings from the borehole. During normal drilling, due to the difference in fluid density between the first channel 4 and the fourth channel 7, the pressure difference between the liquid column of the first channel 4 and the fourth channel 7 is the power source for reverse circulation slag discharge. The second channel 5 can unidirectionally inflate the air down-the-hole hammer 3, and the third channel 6 can unidirectionally exhaust the air down-the-hole hammer 3. They do not interfere with each other and can realize the closed circulation of the air down-the-hole hammer 3, which greatly reduces the working back pressure of the air down-the-hole hammer 3 and effectively protects the stability of the hole wall. The high-pressure gas in the second channel 5 can enter the first channel 4 through the one-way valve 27, so that a gas-liquid-solid mixture is formed in the first channel 4 and discharged. At the same time, the one-way valve 27 can prevent the gas-liquid-solid mixture in the first channel 4 from entering the second channel 5, so as to avoid blockage of the internal air passage of the air down-the-hole hammer 3, provide stable and clean gas for the down-the-hole hammer, and ensure the normal operation of the air down-the-hole hammer 3.

[0037] In a further preferred embodiment of the present invention, the core tube comprises an upper core tube 25, a middle core tube 26, and a lower core tube 29 that are fixedly connected in sequence, and the sleeve comprises an upper sleeve 22, a middle sleeve 23, and a lower sleeve 24 that are fixedly connected in sequence, as shown below. Figure 3-4As shown, the outer wall of the upper core tube 25 is fixedly connected to the inner wall of the upper sleeve 22 by a connecting block. A shoulder 210 is circumferentially provided on the outer wall of the upper sleeve 22. A limiting boss is provided inside the outer tube connector 21. One side of the shoulder 210 contacts the limiting boss, and the other side of the shoulder 210 is fixedly connected to the outer tube connector 21 by an elastic retaining ring 28. A shoulder 210 channel is provided inside the shoulder 210, and the shoulder 210 channel is connected to the third channel 6. The upper core tube 25, the middle core tube 26, and the lower core tube 29 can be connected as a whole by welding or threading. The upper sleeve 22, the middle sleeve 23, and the lower sleeve 24 can also be connected as a whole by welding or threading.

[0038] In a further preferred embodiment of the present invention, the upper core tube 25, the upper sleeve 22, and the shoulder 210 are integrally formed.

[0039] In a further preferred embodiment of the present invention, a first sealing groove 221 is provided on the outer wall of the end of the upper sleeve 22 away from the middle sleeve 23, and a second sealing groove 291 is provided on the outer wall of the end of the lower core tube 29 away from the middle core tube 26. A sealing ring is provided in both the first sealing groove 221 and the second sealing groove 291. The sealing ring of the first sealing groove 221 can effectively seal the second channel 5 and the third channel 6, and the sealing ring of the second sealing groove 291 can effectively seal the first channel 4 and the second channel 5.

[0040] In a further preferred embodiment of the present invention, as shown in the example below... Figure 5 As shown, the side wall of the core tube 26 has multiple threaded holes 261 circumferentially formed, and each one-way valve 27 is threadedly installed in each threaded hole 261, such as... Figure 8 As shown, the axis of the threaded hole 261 forms a certain angle α with the axis of the central core tube 26, and the threaded hole 261 is inclined from the outside to the inside toward the upper core tube 25. The one-way valve 27 is threadedly connected to the threaded hole 261 through the valve body unscrewing hole 279 and a special tool, which is convenient for installation. The high-pressure air in the second channel 5 enters the first channel 4 through the one-way valve 27 and rises and expands, which reduces the fluid density in the first channel 4 and forms a pressure difference.

[0041] In a further preferred embodiment of the present invention, as shown in the example below... Figure 9As shown, the one-way valve 27 includes a valve body 271, a valve seat 272, and a valve core 273. The valve body 271 has a flow hole. The valve seat 272 is fixedly installed at one end of the flow hole near the first channel 4. The valve core 273 is installed at one end of the flow hole near the second channel 5. One end of the valve core 273 is inserted into the valve seat 272 and can move relative to the valve seat 272. The valve core 273 has an air inlet 274 and an intercepting protrusion protruding from the valve core 273. The intercepting protrusion is closer to the valve seat 272 than the air inlet 274. A spring 278 is provided between the valve seat 272 and the intercepting protrusion. One end of the spring 278 abuts against the end face of the valve seat 272. The other end abuts against the end face of the intercepting protrusion near the valve seat 272. When the pressure in the second channel 5 is less than the pressure in the first channel 4, the valve core 273 is not subjected to an external force toward the valve seat 272. The end of the valve core 273 away from the valve seat 272 can block the side of the flow hole, thus disconnecting the second channel 5 from the first channel 4. When the pressure in the second channel 5 is greater than the pressure in the first channel 4, the valve core 273 is subjected to an external force toward the valve seat 272 and moves toward the valve seat 272. The spring 278 is compressed, and the end of the valve core 273 away from the valve seat 272 and away from the flow hole connects the second channel 5 and the first channel 4. The opening pressure of the valve core 273 can be adjusted. Specifically, a special tool is inserted into the valve seat unscrewing hole 277, and the compression of the spring 278 is adjusted by the threads between the valve seat 272 and the valve body 271.

[0042] In a further preferred embodiment of the present invention, as shown in the example below... Figure 11 As shown, the one-way valve 27 also includes a foaming plate 275, which is installed inside the flow hole. One end of the foaming plate 275 is attached to the end face of the valve seat 272 away from the valve core 273, and the other end is fixedly connected to the valve body 271 through an elastic retaining ring 28. Multiple small holes 276 are evenly distributed on the foaming plate 275. Gas, under a certain pressure, passes through the air inlet 274 of the valve core 273, flows through the internal air passage of the valve core 273, and then passes through the foaming plate 275. The small holes 276 on the foaming plate 275 can disperse the gas, forming a large number of small bubbles. These small bubbles can quickly form a three-phase mixed fluid with drilling fluid and cuttings. After the foaming plate 275 is installed, the elastic retaining ring 28 is inserted to achieve axial limiting.

[0043] In a further preferred embodiment of the present invention, as shown in the example below... Figure 10 As shown, a third sealing groove 2710 is provided at the end of the valve core 273 away from the valve seat 272. A sealing ring for sealing the valve core 273 and the valve body 271 is provided in the third sealing groove 2710. The sealing ring installed in the third sealing groove 2710 can effectively prevent the gas-liquid-solid mixed fluid in the first channel 4 from flowing into the second channel 5.

[0044] In a further preferred embodiment of the present invention, as shown in the example below... Figure 6-7As shown, the lower core tube 29 is equipped with a straightening block 292. The straightening block 292 can be three or four pieces depending on the actual use requirements. The straightening block 292 works with the lower casing 24 to straighten the walls of the middle core tube 26 and the middle casing 23, thereby achieving smooth docking with the drill pipe 1.

[0045] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A multi-channel closed-loop air-lift reverse circulation unidirectional mixer, characterized in that: The device includes an inner tube assembly and an outer tube connector. The inner tube assembly includes a core tube and a casing. The casing is fixedly fitted over the core tube. The central through hole of the core tube is a first channel, which communicates with the bottom of the borehole to discharge drilling fluid and cuttings. The gap between the inner wall of the casing and the outer wall of the core tube is a second channel, which communicates with the air intake channel of the air down-the-hole hammer. The outer tube connector is fixedly fitted over the inner tube assembly. The gap between the inner wall of the outer tube connector and the outer wall of the casing is a third channel, which communicates with the air outlet channel of the air down-the-hole hammer. Multiple one-way valves are circumferentially arranged on the side wall of the core tube, allowing gas from the second channel to enter the first channel through the one-way valves.

2. The multi-channel closed-loop air-lift reverse circulation unidirectional mixer according to claim 1, characterized in that: The core tube includes an upper core tube, a middle core tube, and a lower core tube that are fixedly connected in sequence. The sleeve includes an upper sleeve, a middle sleeve, and a lower sleeve that are fixedly connected in sequence. The outer side wall of the upper core tube is fixedly connected to the inner side wall of the upper sleeve by a connecting block. The outer side wall of the upper sleeve is provided with a shoulder in the circumferential direction. The outer tube joint has a limiting boss inside. One side of the shoulder contacts the limiting boss, and the other side of the shoulder is fixedly connected to the outer tube joint by an elastic retaining ring. A shoulder channel is opened in the shoulder, and the shoulder channel is connected to the third channel.

3. The multi-channel closed-loop air-lift reverse circulation unidirectional mixer according to claim 2, characterized in that: The upper core tube, the upper sleeve, and the shoulder are integrally formed.

4. The multi-channel closed-loop air-lift reverse circulation unidirectional mixer according to claim 2, characterized in that: A first sealing groove is provided on the outer wall of the end of the upper sleeve away from the middle sleeve, and a sealing ring is provided in the first sealing groove.

5. The multi-channel closed-loop air-lift reverse circulation unidirectional mixer according to claim 2, characterized in that: A second sealing groove is provided on the outer wall of the lower core tube away from the middle core tube, and a sealing ring is provided in the second sealing groove.

6. The multi-channel closed-loop air-lift reverse circulation unidirectional mixer according to claim 2, characterized in that: The sidewall of the core tube has multiple threaded holes circumferentially formed, and each one-way valve is threadedly installed in each of the threaded holes. The axis of the threaded hole forms a certain angle with the axis of the core tube, and the threaded hole is inclined towards the upper core tube from the outside to the inside.

7. The multi-channel closed-loop air-lift reverse circulation unidirectional mixer according to claim 1, characterized in that: The one-way valve includes a valve body, a valve seat, and a valve core. The valve body has a flow hole. The valve seat is fixedly installed at one end of the flow hole near the first channel. The valve core is installed at one end of the flow hole near the second channel. One end of the valve core is inserted into the valve seat and is movable relative to the valve seat. The valve core has an air inlet and an intercepting protrusion protruding from the valve core. The intercepting protrusion is closer to the valve seat than the air inlet. A spring is disposed between the valve seat and the intercepting protrusion. One end of the spring abuts against the end face of the valve seat, and the other end abuts against the intercepting protrusion. When the pressure in the second channel is less than the pressure in the first channel, the valve core is not subjected to an external force toward the valve seat. The end of the valve core away from the valve seat can block one side of the flow hole, thus disconnecting the second channel from the first channel. When the pressure in the second channel is greater than the pressure in the first channel, the valve core is subjected to an external force toward the valve seat and moves toward the valve seat. The spring is compressed, and the end of the valve core away from the valve seat is away from the flow hole, thus connecting the second channel with the first channel.

8. The multi-channel closed-loop air-lift reverse circulation unidirectional mixer according to claim 7, characterized in that: The one-way valve also includes a foaming plate, which is installed in the flow hole. One end of the foaming plate is attached to the end face of the valve seat away from the valve core, and the other end is fixedly connected to the valve body through an elastic retaining ring. The foaming plate has multiple small holes.

9. The multi-channel closed-loop air-lift reverse circulation unidirectional mixer according to claim 8, characterized in that: Multiple tiny pores are evenly distributed on the foamed board.

10. The multi-channel closed-loop air-lift reverse circulation unidirectional mixer according to claim 7, characterized in that: The valve core has a third sealing groove at the end away from the valve seat, and a sealing ring is provided in the third sealing groove to seal the valve core and the valve body.

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