A gas dissolution system

Abstract

The present invention discloses a gas dissolution system. At the liquid surface, a bubble collision intensive area 2 is formed by a counter-gas-liquid flow 4 generated by an array-distributed aeration device 1, or by an additional bubble restraining component 3, so that bubbles collide with each other in the intensive area to accelerate dissolution; below the liquid surface, a bubble cutting device 11 is provided to cut the bubbles at multiple levels to further improve the dissolution efficiency.

Description

Technical Field

[0001] The invention relates to a gas dissolution system. Background Art

[0002] A gas dissolving device is a type of device that dissolves gas into a liquid. Its main mechanism is generally to inject gas into the liquid to increase the amount of gas dissolved in the liquid. One of the larger application categories is the oxygen aerator - dissolving air into water or other liquids. In addition, there are some devices in biochemistry or chemical engineering that need to dissolve certain specific gases into specific solutions.

[0003] The air lift aerator is a relatively efficient aeration device, such as the "Air lift plug flow circulation aerator" disclosed in Chinese patent CN208762256U, which releases gas from below the liquid surface to generate bubbles. The density of the gas-liquid mixed liquid is less than that of the liquid without bubbles, so an upward gas-liquid flow can be automatically generated. This is the main principle of the air lift device, but the gas dissolution efficiency of this type of device is not high, which may be because the generated bubbles are not further processed.

[0004] The treatment of bubbles can be divided into two situations: on the liquid surface and below the liquid surface. According to the traditional double-membrane theory of gas-liquid mass transfer, there are gas film and liquid film at the gas-liquid interface. The double-membrane layer is the part with the greatest resistance in the process of gas dissolving into liquid. In the bubbles, there is also a similar double-membrane structure between the gas and the liquid in the bubble wall. Therefore, as long as the bubble is stable in shape, whether it is on the liquid surface or below the liquid surface, the process of the gas inside it dissolving into the surrounding liquid must be slow and weak.

[0005] Regarding bubbles under the liquid surface, Chinese patent CN206901853U discloses "A layered aeration device", which can cut more and smaller bubbles by setting up multiple layers of "fine gauze grids"; although the concept of "multi-layer" cutting of bubbles is mentioned, in fact they are a layer of aeration device with a layer of fine gauze grid on top, so it cannot be regarded as multi-layer cutting in the true sense, especially for the upper layer, the cutting effect may not be complete and ideal. Summary of the invention

[0006] We believe that to accelerate the dissolution of gas in liquid, the double membrane structure between gas and liquid must be in an unstable state. The more unstable it is, the easier it is for bubbles to burst. However, in the natural state, the double membrane structure of bubbles is quite stable, whether on or below the liquid surface.

[0007] Therefore, one of the main technical measures we have to take is to force the bubbles to gather, squeeze, collide and burst at high density on the liquid surface, instantly destroying their double membrane structure, allowing the gas and liquid to blend with each other, so that the amount of gas dissolved in this area will increase rapidly. At the same time, the gas-liquid two-phase flow generated by the gas lift effect will continuously flush, renew, replenish and replace this part of the surface liquid from bottom to top, ultimately improving the overall dissolution efficiency.

[0008] For bubbles in the liquid, a true multi-layer cutting method is adopted to continuously destroy their double membrane structure, making it difficult for them to form stable bubbles during the floating process and accelerating their dissolution.

[0009] In order to achieve the above object, the present invention is achieved as follows:

[0010] The gas dissolution system comprises a multi-layer gas dissolution device, wherein the gas dissolution device comprises a plurality of microbubble generators 1, wherein the microbubble generators can emit a large number of small bubbles below the liquid surface, and drive a large number of liquids to form a gas-liquid two-phase flow to flow upward due to the gas lift effect. The plurality of microbubble generators are distributed in a dense array, so that when the gas-liquid flow reaches the liquid surface, the gas-liquid flows will collide with each other in the horizontal direction, forming a bubble collision intensive area 2 between them, and a large number of bubbles will be violently squeezed, collided and burst here.

[0011] The present invention can also be implemented in this way: a bubble restraining component 3 is provided at the outer liquid surface of the collision intensive zone 2, and the bubble restraining component is a closed annular structure, which is used to prevent bubbles from diffusing outward along the liquid surface, thereby increasing the density of bubbles in the area and increasing the probability of mutual squeezing, collision and bursting; especially in the extreme case where the number of microbubble generators is small, or even only one microbubble generator, the bubbles can be restrained from gathering to form the collision intensive zone.

[0012] The present invention can also be implemented in this way. The microbubble generator is a vertically arranged air lift tube, and at least one bubble outlet 10 is opened on its tube wall. The upper outer edge of the air lift tube is sealed and fixedly connected to the upper panel of the gas bin 30, and the gas bin is connected to the gas delivery pipe 5; the pressurized gas enters the gas bin from the gas delivery pipe, and then enters the air lift tube through the micro pores, generating an air lift effect in the air lift tube, and the bubbles drive the gas-liquid flow to gush upward along the air lift tube, and the liquid is replenished from the lower pipe opening.

[0013] The present invention can also be implemented in that the micropores have a diameter of 0.2-1 mm, the number of micropores is 4-30, a single layer is evenly distributed on the same horizontal plane, or multiple layers are horizontally adjacently distributed, and the center distance between the air lift pipes is 1.5-3 times the pipe diameter.

[0014] The present invention can also be implemented in this way: a gas dissolution system is used to improve the effective utilization of a limited liquid surface; the gas bin of the latter device is covered directly above the former device to completely collect the undissolved gas of the former device as the gas source of the latter device; gaps are left between the gas bins of each layer of the device as channels for liquid renewal and replacement; the gas lift pipes of each layer should be installed in a staggered manner to prevent the gas and liquid flow of the lower layer of the gas lift pipe from directly entering the upper layer of the gas lift pipe.

[0015] The present invention can also be implemented in this way: a gas collecting hood 31 is set between the multi-layer devices, and its function is also to completely collect the undissolved gas in the lower device. The inter-stage gas supply pipe 50 is inserted into the gas collecting hood, and the pipe mouth can be set horizontally downward, and the other end is connected to the gas warehouse 30 of the next stage as the gas source. In this way, the next stage device is set directly above the previous stage device, or is set in an offset position next to it.

[0016] The present invention can also be implemented in this way: the gas delivery pipe 5 is an air extraction pipe, the bottom of the gas bin 30 is closed and the whole is located above the ambient liquid level 0, the upper outer edge of the air lift pipe is sealed and fixedly connected to the bottom plate of the gas bin, and the lower part is connected to the ambient liquid level to replenish liquid, the micropores are located above the ambient liquid level, and air is taken in from the air. The lower part of the gas bin is also provided with a return pipe 6 connected to the ambient liquid level; after the air extraction pipe draws the gas bin into negative pressure, the liquid below is drawn into the gas bin from the air lift pipe and the return pipe, and at the same time, the gas also enters the air lift pipe from the micropores, producing an air lift effect, and the gas-liquid mixture in the air lift pipe flows upward due to its relatively small specific gravity, and the liquid in the return pipe has a relatively large specific gravity and flows downward. Under the set negative pressure, the inflow and outflow of the liquid will reach a dynamic balance, that is, a working liquid level 00 is formed in the gas bin, and the bubbles form the collision intensive area 2 here to accelerate dissolution.

[0017] The present invention can also be implemented in this way: in the gas dissolution system, the gas lift pipes of each layer should be installed in a staggered manner to prevent the gas and liquid flow of the lower gas lift pipe from directly entering the upper gas lift pipe; only the exhaust pipe 5 is retained on the top layer, and the reflux pipe 6 can only be retained on the top layer.

[0018] The present invention can also be implemented in this way: the microbubble generator is a horizontally arranged microporous aeration tube, a plurality of microporous aeration holes or microporous aeration heads are arranged on the tube wall, and baffles are vertically arranged on both sides of the microporous aeration tube as bubble restraining components; when there are multiple microporous aeration tubes, they can be arranged in parallel in the horizontal direction.

[0019] The present invention can also be implemented in this way: multiple layers of the gas dissolution devices are stacked and combined into a multi-stage system, and a gas collecting hood 31 is provided between the multiple layers of devices, and its function is also to completely collect the undissolved gas in the lower device, and then lead it from the inter-stage gas pipeline 50 directly as the gas source for the next stage device, so that the next stage device is arranged directly above the previous stage device, or is offset and arranged next to it.

[0020] The present invention can also be implemented in this way: two baffles are arranged between the two microporous aeration tubes to form a reflux channel 6, a bottom plate 33 is arranged below the microporous aeration tube, and a U-shaped groove is formed with the baffles on both sides thereof, and front and rear baffles are also arranged at the front and rear of the device to form a box body, the upper edge of the box body is higher than the ambient liquid level 0 and higher than other baffles in the box body, the front and rear baffles have openings in the U-shaped groove part to communicate with the surrounding liquid, and the reflux channel extends downward to a specified depth in the liquid by connecting to the telescopic extension tube 60, so that the liquid in which a large amount of gas is fully dissolved in the top layer can be transported to the deep layer below, which is conducive to the replacement and circulation of the upper and lower liquid layers and improves the overall dissolution efficiency.

[0021] The present invention can also be implemented in this way: a telescopic extension tube 60 is provided at the liquid inlet opening at the bottom of the device to adjust the liquid inlet depth, and the deep liquid is used to replace the top layer liquid, thereby promoting overall circulation and improving dissolution efficiency.

[0022] The present invention can also be implemented in this way: at least one bubble cutting device 11 is arranged above the bubble outlet 10 of the microbubble generator, and the bubble cutting device is composed of a multi-layer bubble cutter 111 fixed on a substrate or a base frame 12, and the bubble cutter can be arranged in staggered layers to improve the cutting efficiency; the bubble cutter is the longitude and latitude of a grid of various materials, or a monofilament arranged in parallel, a blade with a downward blade or other thin sheet; the bubbles emitted from the bubble outlet are continuously split and cut by the bubble cutter multiple times during the floating process, and are broken into more and smaller unstable bubbles, thereby improving the dissolution efficiency; when there are multiple bubble cutting devices, they can be stacked in the vertical direction.

[0023] The present invention can also be implemented as follows: it includes at least one substrate 12, and the bubble cutter is an elastic monofilament arranged in parallel, one end of which is fixed on the substrate and the other end is suspended, so they need to have a certain rigidity, and a guide sleeve 13 is arranged on their periphery, and a flushing air port 51 is also arranged below them; when multiple substrates are included, they are arranged in pairs, or share a guide sleeve; the monofilament with debris attached will bend upward under the flushing of the gas-liquid flow, and the arrangement of the flushing air port and the guide sleeve can increase the flow rate and flow of the gas-liquid flow, thereby increasing the flushing force on the monofilament, and finally flushing away the debris; A plurality of bubble cutting devices 11 can be stacked in the vertical direction, and a gap should be left between the guide sleeves of each section of the device to facilitate the replenishment of liquid. A circle of guide cover or guide baffle 14 can be set at the lower end of the guide sleeve to prevent bubbles from escaping, or a guide baffle 14 is set inward at the upper edge outlet of the guide sleeve to guide the liquid in the tube to the outside of the opposite tube. Liquid can be replenished from above the guide baffle. After passing over the end of the guide baffle, the bubbles will continue to float up, and will basically not escape under the guidance of the guide baffle at the lower edge of the upper guide tube. Each pipe section is either arranged vertically in alignment up and down, or arranged in staggered layers according to the flow direction of the guide baffle.

[0024] The present invention can also be implemented in that the elastic monofilament has a line diameter of no more than 1.5 mm, a spacing of 4-10 mm, more than 3 layers, and a layer spacing of 4-30 mm.

[0025] The present invention can also be implemented in this way: the elastic monofilament can be tilted upward, and the angle α between it and the horizontal line does not exceed 60 degrees; this increases the difficulty of attaching debris, and even if it is attached, under the flushing of the normal working gas-liquid flow of the microbubble generator, the elastic monofilament bends slightly upward again, and the debris will be flushed away; at this time, the flushing air port 51 can also be cancelled, making the structure and operation simpler.

[0026] The present invention can significantly improve the gas dissolution efficiency. Taking water oxygenation as an example, a typical embodiment of the liquid surface collision dense area technical solution is adopted, and the oxygenation power efficiency obtained by actual measurement can reach 16.9kg / kwh; while the oxygenation power efficiency of the bubble cutting technical solution alone reaches 32.379kg / kwh; it is not only far higher than the 1.3kg / kwh of the surface aeration aerator and the 2kg / kwh of the ordinary bottom aeration aerator, but also several times higher than the nearly 5kg / kwh of the most efficient magnetic levitation + Jaeger bottom aeration plate in the CASS pool as we know. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the bubble collision intensive area formed by the gas-liquid flow distributed in the array at the liquid surface

[0028] Figure 2Schematic diagram of the embodiment of the microbubble generator being a gas lift tube (first type)

[0029] Figure 3 Schematic diagram of negative pressure application of gas lift tube embodiment (second type of embodiment)

[0030] Figure 4 Schematic diagram of an embodiment of a multi-layer negative pressure air lift tube

[0031] Figure 5 Schematic diagram of the embodiment of the microbubble generator being a microporous aeration tube (third type)

[0032] Figure 6 Schematic diagram of an embodiment of a multi-layer microporous aeration tube

[0033] Figure 7 An oblique view of an aeration pipe with a reflux function

[0034] Figure 8 Schematic diagram of the reflux channel and the retractable extension tube of the aeration pipe with reflux function embodiment

[0035] Fig. 9 Schematic diagram of the first and third embodiments of the lower part of the externally connected telescopic extension tube

[0036] Fig.10 Schematic diagram of bubble generators distributed in an equilateral triangle array

[0037] Fig.11 Schematic diagram of the bubble cutting device of the fourth embodiment

[0038] Fig.12 Schematic diagram of cutter offset setting

[0039] Fig.13 Top view of bubble cutting device

[0040] Fig.14 Schematic diagram of the upward tilt setting of elastic monofilament

[0041] Fig.15 Schematic diagram of multi-layer bubble cutting device superposition

[0042] Fig.16 Schematic diagram of vertical stacking of multi-layer gas lift pipe device

[0043] Fig.17 Schematic diagram of the side dislocation layer stacking of the multi-layer gas lift tube device

[0044] In the figure:

[0045] 0-environmental liquid level; 00-internal working liquid level; 1-micro bubble generator;

[0046] 10- Bubble outlet, including air holes, micro air holes, micro aeration holes or microporous aeration heads, jet pump outlet, etc.;

[0047] 11-bubble cutting device; 111-bubble cutter; 12-substrate or base frame;

[0048] 13- flow guide sleeve; 14- flow guide cover or flow guide baffle; 2- bubble collision intensive area;

[0049] 3-bubble restraining parts, baffles, annular frames, etc.; 30-gas chamber or box; 31-gas collecting hood;

[0050] 32-floating tank; 33-U-shaped trough bottom plate; 4-liquid flow direction;

[0051] 5-gas transmission pipe; 50-multi-stage gas transmission pipe; 51-flushing gas port;

[0052] 6- reflux pipe or reflux channel; 60- retractable extension pipe DETAILED DESCRIPTION

[0053] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings:

[0054] The gas dissolution system comprises a multi-layer gas dissolution device, wherein the gas dissolution device comprises a plurality of microbubble generators 1, wherein the microbubble generators can emit a large number of small bubbles below the liquid surface, and drive a large number of liquids to form a gas-liquid two-phase flow to flow upward due to the gas lift effect. The plurality of microbubble generators are distributed in a dense array, so that when the gas-liquid flow reaches the liquid surface, the gas-liquid flows will collide with each other in the horizontal direction, forming a bubble collision intensive area 2 between them, and a large number of bubbles will be violently squeezed, collided and burst here.

[0055] In the first embodiment (Appendix Figure 1 , Attachment Figure 2 ) and the second embodiment (Appendix Figure 3 , Attachment Figure 4 ), the "microbubble generator" is the air lift tube 1. In the third embodiment (attached Figure 5 , Attachment Figure 6 , Attachment Figure 7 , Attachment Figure 8 ) is a microporous aeration tube 1; in addition, it can also be various blowers, air compressors, various types of bottled compressed gases or any other devices that can produce pressurized gas to release a large number of tiny bubbles below the liquid surface through various micro holes or aeration heads at the pipe terminal; it can also be a jet aerator or a liquid-gas energy aerator and other special aeration equipment that does not have pores but can produce gas-liquid two-phase flow below the liquid surface. They can also produce a large number of tiny bubbles under the condition of controlling a certain flow rate and air intake; therefore, we summarize it as a general superordinate concept of "microbubble generator".

[0056] The so-called "gas lift effect" means that when a large number of bubbles float up in a liquid, mechanical friction can drive part of the liquid upward. More importantly, the liquid containing a large number of bubbles has a much smaller specific gravity than pure liquid, which naturally produces an upward gas-liquid two-phase flow. When the gas-liquid flow reaches the liquid surface, it can only turn to flow horizontally along the liquid surface (see Appendix Figure 2 , Attachment Figure 3 The liquid flow direction with a turning point 4) is shown in the figure. The adjacent gas-liquid flows will collide with each other. If the flow rate and flow rate of the gas-liquid flow generated by each gas lift pipe are roughly the same, the bubbles will be swept towards the counter-intersection balance zone 2 between them (see the attached figure). Figure 1 ), and are violently squeezed, collided and exploded here, which we call the "bubble collision intensive area" for short.

[0057] The so-called "distribution in dense arrays" means arranging them into various arrays at a certain density and at a certain interval, such as a square matrix (see Appendix Figure 1 , the distance between the two lift pipes in the vertical and horizontal directions is the same - 1.5-3 times the diameter of the lift pipe) or an equilateral triangle array (see Appendix Fig.10 , the distance between each adjacent air lift pipe is the same, which is also 1.5-3 times), etc. Correspondingly, the bubble collision intensive area formed by them is a regular grid or honeycomb shape; of course, there is no strict limit on their spacing to be consistent, as long as they are gathered together at a certain density, they can also produce this hedging intersection equilibrium zone among them, but the shape will not be so regular, symmetrical and stable, which will have a certain impact on the overall dissolution efficiency.

[0058] At the outer liquid surface of the collision intensive zone 2, a bubble restraining component 3 is arranged. The bubble restraining component can be a closed annular structure, which is used to prevent bubbles from diffusing outward along the liquid surface, increase the density of bubbles in the area, and increase the probability of mutual squeezing, collision and bursting; especially in the extreme case where the number of microbubble generators is small, or even only one microbubble generator, it can also restrain the aggregated bubbles to form the collision intensive zone.

[0059] The bubble restraining component is mainly used as an auxiliary technical means to prevent bubbles from diffusing outward along the liquid surface and improve the bubble aggregation degree in the extreme case where there are few bubble generators, especially only one. Therefore, it is usually a closed annular frame above the liquid surface: for example, in the first embodiment, it is a closed rectangular frame 3 (see the attached figure) mounted on the gas tank box 30. Figure 1 , Attachment Figure 2 ), in the second embodiment, the side wall of the closed gas storage box 30 constitutes this closed annular interception frame (see attached Figure 3 ), so there is no need to set it separately. In the third embodiment, the bubble restraining component is a vertically set baffle (see attached Figure 5 ), in general, together with the front and rear baffles, form a closed box 30 (see attached Figure 7 ); Special case is: when this embodiment is applied to the production line of the oxidation ditch of sewage treatment, the aeration pipe and the baffle should be arranged along the direction of water flow, and the front and rear baffles should not be arranged to avoid increasing the flow resistance. At this time, the bubble restraint component cannot be fully enclosed; Of course, when the number of bubble generators is large, the bubble restraint component may or may not be arranged (see attached Figure 6 or attached Fig.16 The liquid surface is at 0), which is conducive to the convergence of bubbles, but not conducive to the diffusion and renewal of the surface liquid; or it can be set to be semi-closed.

[0060] The annular frame may be in a square, rectangular, circular or any other shape, which has no substantial impact on the implementation of the technical solution.

[0061] The size of the annular frame can be adjusted according to the density of the bubbles in the domain. If there are gaps between the bubbles in the domain and the domain is not fully covered, its range can be appropriately reduced, or the amount of bubble generation can be appropriately increased (assuming that the microbubble generator has a surplus). If the bubbles in the domain are not only fully covered but also multi-layered, the bubbles in the upper layer will have limited help in gas dissolution, but will waste the energy consumption and other resources of the microbubble generator. Therefore, its range can be appropriately increased, or the amount of bubbles generated by the microbubble generator can be appropriately reduced.

[0062] The bubble restraining component is a hollow tubular structure that naturally floats on the liquid surface, or is mounted on the box of the main device through a bracket or other connecting parts (see attached Figure 2 ) or its accessories, or it is part of the main part of the device, such as a baffle (see Appendix Figure 5 ), the inner wall of the box (see attached Figure 3 ) etc., and the connection and fixing methods thereof can be adopted by technicians in this industry in various conventional settings, which will not be described in detail.

[0063] Similarly, the whole set of equipment is fixed in the liquid environment by connecting parts such as brackets; or the whole set of equipment is suspended in the liquid environment by floating bodies such as buoys, see Appendix Fig. 9 The gas dissolution device can be mounted on at least one buoyancy tank 32, with an inlet and outlet valve installed on the upper part of the buoyancy tank, and the bottom connected to the liquid. The liquid level in the buoyancy tank is controlled by the inlet and outlet of compressed air to adjust the overall buoyancy of the equipment; even a power mechanism that can drive the entire device to move in a liquid environment can be added, and so on. Conventional connection and fixing methods between various components, as well as additional floating traction and movement methods, as long as they are customary settings of technical personnel in this industry and do not change the basic principles and design ideas of the main technical scheme of the device, should belong to the protection scope of the present technical scheme, so no further restrictions are made and they will not be repeated below.

[0064] The following describes the first embodiment one by one:

[0065] As attached Figure 2 As shown, the microbubble generator is a vertically arranged air lift tube 1, on the wall of which at least one micropore is provided, the upper outer edge of the air lift tube is sealed and fixedly connected to the upper panel of the gas bin 30, and the gas bin is connected to the gas delivery pipe 5; the pressurized gas enters the gas bin from the gas delivery pipe, and then enters the air lift tube through the micropores, generating an air lift effect in the air lift tube, and the bubbles drive the gas-liquid flow to gush upward along the air lift tube, and the liquid is replenished from the lower pipe opening.

[0066] Here, the gas delivery pipe 5 is connected to the gas bin from the middle of the gas bin upper panel (see attached Figure 1 ), it can also be accessed from the side wall of the gas chamber (see Appendix Fig.17 )

[0067] The micropores have a diameter of 0.2-1 mm, and the number of micropores is 4-30. A single layer is evenly distributed on the same horizontal plane, or multiple layers are horizontally adjacently distributed. The center distance between the air lift pipes is 1.5-3 times of their pipe diameters.

[0068] The aperture of the micropores cannot be set too large to avoid bubbles with too large diameters. When the aperture is too small, the gas resistance will increase significantly, limiting the flow rate and velocity of the gas input, and not enough bubbles will be generated. At the same time, the micropores are more easily clogged by debris. The aperture of a typical embodiment is 0.5 mm.

[0069] If the spacing between the gas lift tubes is too small, the liquid in the gas-liquid flow may not be fully replenished; if the spacing is too large, the strength and effect of the bubble collision will be affected. In a typical embodiment, the center distance between the tubes is twice the diameter of the tubes.

[0070] The upper end of the gas lift pipe can be located below the liquid level 0 or 00; it can also be slightly above the liquid level (no more than 50mm, see the attached Fig.17 ), at this time, the gas-liquid flow overflows from the upper end of the gas lift pipe and also flows along the horizontal plane. Bubbles can also form on the liquid surface between the gas-liquid pipe. Figure 1 The grid-like collision intensive area 2 shown in the figure, therefore, the upper end of the air lift pipe is suitable for the present technical solution whether it is on the liquid surface or below the liquid surface. If it is set above the liquid surface, the bubbles will increase the collision with the tube wall, and if it is set below the liquid surface, it may be more advantageous for the renewal and replacement of the surface liquid.

[0071] The above selection of the data ranges of the size, position relationship, etc. of the air lift tube and its micropores is also applicable to the various air lift tube embodiments mentioned later.

[0072] In practical applications, a horizontal partition can be added at the bottom of the gas chamber, above the lower port of the gas lift pipe (below the micropores) (see Appendix Figure 2 The dotted line in the middle can prevent the debris in the lower liquid from entering the air chamber in a complex environment and blocking the micropores.

[0073] The actual power efficiency of a typical embodiment is shown below based on measured data: that is, the total amount of gas (kg) that can actually be dissolved into the liquid by the device for every kilowatt-hour (kwh) of power (i.e., 1 kWh of electricity) consumed:

[0074] The measured gas is air with a flow rate of 1.06667 cubic meters per hour. The measured liquid is water with a volume of 11.0926 cubic meters. The upper end of the gas lift pipe is 20 mm below the water surface. The pressure of the pressurized gas input by the gas transmission pipe 5 is 254 mm of water column. The inner diameter of the gas lift pipe is 40 mm, the number is 36, and the center distance between the pipes is 80 mm. The diameter of the micropores is 0.5 mm, and the number of micropores is 10, which are evenly distributed along the water surface. The calculation is as follows:

[0075] Gas flow meter reading: V1 = 1.06667m3 / h

[0076] Inlet pipe pressure: P1 = 0.254m water column

[0077] =ρgh+P 0=1000kg / m 3×9.8m / s 2×0.254m+101325Pa

[0078] =2489.2+101325=103814.2kg / ms 2

[0079] Gas power: N = P 1V 1ln (P 1 / P 0)

[0080] =103814.2kg / ms 2×(1.06667m 3 / 3600s)×ln(103814.2÷101325)

[0081] =30.76×ln(1.02457)kgm 2 / s 3=0.02427=0.7465w

[0082] Experimental water temperature: T = 32.5°C

[0083] Water volume: V = 11.0926m 3

[0084] The saturated dissolved oxygen value at the experimental temperature was found to be: CS = 7.24 mg / L

[0085] The saturated dissolved oxygen value at 20°C is: CS20 = 9.09 mg / L

[0086] The measured initial value of dissolved oxygen is C1 = 0.25 mg / L, and the final value is C2 = 0.69 mg / L

[0087] Experimental time t2-t1=19.25min=19.25÷60h

[0088] Oxygen transfer coefficient: K La (T) = ln [ (C SC 1) / (C SC 2)] ÷ (t 2-t 1)

[0089] =ln[(7.24-0.25) / (7.24-0.69)]÷19.25×60 / h

[0090] =0.188 / h

[0091] Oxygen transfer coefficient at 20°C: K La (20) = K La (T) ÷ 1.024 (T-20) = 0.188 ÷ 1.345 = 0.139 / h

[0092] Oxygenation capacity: QS = K La (20) × V × C S20

[0093] =0.139 / h×11.0926m 3×9.09mg / L×1000L / m 3

[0094] =14.0156g / h

[0095] Power efficiency (ideal state): ES = QS / N = 14.0156g / h ÷ 0.7465w = 18.775kg / kwh

[0096] Fan efficiency: η = 90% (magnetic levitation fan), head and pipeline losses are ignored: k ≈ 0

[0097] Actual power efficiency: EP = E Sη (1-k) = 18.775 × 90% = 16.9 kg / kwh

[0098] To achieve a certain scale of gas dissolution capacity, high efficiency is only one aspect. On the basis of high efficiency, sufficient quantity is also required, which requires the use of a large number of the above-mentioned devices, which is bound to occupy a large amount of liquid surface. In some cases, the area of ​​the liquid surface is limited after all, so a multi-layer design is needed:

[0099] As attached Fig.16 As shown, it is a multi-layer superposition embodiment of the first type of device: a plurality of sets of the gas dissolution devices are superimposed and combined into a multi-stage system to improve the effective utilization of the limited liquid surface; the gas bin of the latter stage device is covered directly above the former stage device to completely collect the undissolved gas of the former stage as the gas source of the latter stage device; gaps are left between the gas bins of each layer of the device as channels for liquid renewal and replacement; the gas lift pipes of each layer should be installed in a staggered manner to prevent the gas and liquid flow of the lower layer gas lift pipe from directly entering the upper layer gas lift pipe.

[0100] Straight stacking is the simplest stacking method. The gas enters the gas bin 30 of the bottom layer from the gas transmission pipe 5, and enters the gas lift pipe 1 through the pores. The undissolved gas enters the gas bin 30 of the upper layer device and is completely collected. The liquid level inside it is gradually pressed down. When the liquid level is lower than the pores, the gas begins to enter the gas lift pipe of this layer from the pores, and finally reaches a dynamic balance, which is the internal working liquid level 00. The bubbles gather, collide and dissolve here; and so on, stacking layer by layer; it should be noted that the gas lift pipes of each layer cannot be installed directly opposite each other, but must be staggered so that the bubbles form a collision intensive area at the liquid level 00 outside the upper gas lift pipe, and cannot directly enter the pipe of the upper gas lift pipe.

[0101] The working liquid level of the top layer may be the environmental liquid level 0, and the bubble restraining component may or may not be provided.

[0102] There is another way to superimpose. Fig.17 As shown, an embodiment of a multi-layer side-staggered stacking is shown: a gas collecting hood 31 is arranged between the above-mentioned multi-layer devices, and its function is also to completely collect the undissolved gas in the lower device. The inter-stage gas supply pipe 50 is inserted into the gas collecting hood, and the pipe mouth can be arranged horizontally downward, and the other end is connected to the gas bin 30 of the next stage as the gas source, so that the next stage device is arranged directly above the previous stage device, or is arranged offset next to it.

[0103] The gas enters the gas bin 30 at the bottom layer from the gas pipe 5, and enters the gas lift pipe 1 through the air hole. The undissolved gas is completely collected by the gas collecting hood 31, and the liquid level inside it is gradually pressed down. When the liquid level is lower than any part of the pipe mouth of the inter-stage gas pipe 50, the gas begins to enter the gas pipe. When the pipe mouth is set horizontally downward, a stable internal working liquid level 00 is formed near the position slightly below the pipe mouth, and the bubbles gather, collide and dissolve here; the setting of the gas pipe mouth in other directions will not have a substantial impact on the implementation of the present technical solution, but the internal working liquid level 00 is not easy to stably control, so this technical feature should not be used as a limitation on the present technical solution; the gas enters the gas bin 30 of the next stage as a gas source through the inter-stage gas pipe 50; and so on, multiple layers can be stacked step by step; the working liquid level of the top layer can be set at the ambient liquid level 0, here, the gas collecting hood may or may not be set, or it can be used only as a protective cover.

[0104] In practical applications, a transverse partition as described above is sometimes added to the lower part of each gas chamber (see Appendix Figure 2 In this case, the middle part of the gas delivery pipe 50 may also be provided with an inverted U-shaped pipe (see the attached figure). Fig.17 ) to prevent debris from following the liquid from the previous stage's gas collecting hood through the gas pipe and directly entering the gas warehouse when the gas is shut off, causing blockage of the micro-pores on the gas-liquid pipe.

[0105] The second embodiment (see attached Figure 3 ), which is actually the application of the first embodiment in the negative pressure system: the gas delivery pipe 5 is an air extraction pipe, the bottom of the gas bin 30 is closed and the whole is located above the ambient liquid level 0, the upper outer edge of the air lift pipe is sealed and fixedly connected to the bottom plate of the gas bin, and the lower part is connected to the ambient liquid level to replenish the liquid, the micropores are located above the ambient liquid level, and air is taken in from the air, and the lower part of the gas bin is also provided with a return pipe 6 connected to the ambient liquid level; after the air extraction pipe draws the gas bin into a negative pressure, the liquid below is drawn into the gas bin from the air lift pipe and the return pipe, and at the same time, the gas also enters the air lift pipe from the micropores, generating an air lift effect, the gas-liquid mixture in the air lift pipe flows upward due to its relatively small specific gravity, and the liquid in the return pipe has a relatively large specific gravity and flows downward, under the set negative pressure, the inflow and outflow of the liquid will reach a dynamic balance, that is, a working liquid level 00 is formed in the gas bin, and the bubbles form the collision intensive area 2 here to accelerate the dissolution.

[0106] Further, as attached Figure 4 What is shown is a multi-layer stacking embodiment of the negative pressure system described above: a multi-stage system is formed by vertically stacking multiple layers of the gas dissolving device; the gas lift pipes of each layer should be installed in a staggered manner to prevent the gas and liquid flow of the lower layer gas lift pipe from directly entering the upper layer gas lift pipe; only the exhaust pipe is retained on the top layer, and the reflux pipe 6 can only be retained on the top layer.

[0107] The vacuum pipe 5 evacuates the gas bin on the highest layer, and the liquid is pumped into the gas bin from the reflux pipe 6; at this time, there is no liquid in the gas bins on the lower layers, and there are gas lift pipes connecting the gas bins. Therefore, all the gas bins are in a negative pressure state. At the bottom layer, liquid is also pumped in from the gas lift pipe, and at the same time, gas also enters the gas lift pipe from the external environment through the micro-pores on the bottom layer. When the liquid level inside the gas bin on the bottom layer is pumped to the vicinity of the micro-pores, the liquid level will no longer rise (because if the liquid level floods the pores, the upper part is a closed space and no negative pressure is generated). This is the internal working liquid level 00, and bubbles gather here to form the collision intensive area; when the gas bin on this layer is provided with a reflux pipe, the working liquid level 00 It will be slightly lower. Canceling the reflux pipe has no effect on the workflow, but can make the overall structure simpler and more compact; by analogy, the liquid is pumped into each layer of the gas warehouse layer by layer from bottom to top, and the vacuum degree of each layer of the gas warehouse is higher than that of the lower layer; until the highest layer, the gas-liquid flow pumped up from the multi-layer gas lift pipes reaches a dynamic balance with the reflux in the reflux pipe 6, forming the working liquid level 00 of the highest layer; for each upper device, it can be regarded as a single-layer negative pressure device as described above, and the upper enclosed space of the lower gas warehouse can be regarded as the environmental space, and the internal working liquid level 00 of the lower layer can be regarded as the environmental liquid level 0; similar to the positive pressure system, the gas lift pipes of each layer cannot be set directly opposite each other.

[0108] The third embodiment (see attached Figure 5) is an aeration tube embodiment: the microbubble generator is a horizontally arranged microporous aeration tube, a plurality of microporous aeration holes or microporous aeration heads are arranged on the tube wall, baffles are vertically arranged on both sides of the microporous aeration tube as bubble restraining components; when there are multiple microporous aeration tubes, they can be arranged in parallel along the horizontal direction.

[0109] The baffle can be arranged in a variety of situations:

[0110] One is that each aeration pipe has a baffle on both sides, see the attached Figure 5 The first aeration pipe on the left;

[0111] One is that multiple aeration pipes share a pair of baffles, see attached Figure 5 There are three aeration pipes on the right;

[0112] One is that there is a baffle between the two aeration pipes, see the attached Figure 5 The two aeration pipes, left 2 and left 3;

[0113] There is also a type where there are two baffles between the two aeration pipes. Figure 5 Between the two aeration pipes, left 1 and left 2.

[0114] The portion of the upper end of the baffle plate that is above the liquid surface is the bubble restraining component 3, and the portion below the liquid surface constitutes a gas lift channel or a reflux channel.

[0115] The bubbles emitted from the multiple aeration holes on each aeration pipe form multiple upward gas-liquid flows along the air lift channel formed by the baffle, forming the collision intensive area 2 at the liquid surface; when multiple aeration pipes are arranged adjacent to each other, the gas-liquid flows are distributed in an array, and a similar attachment area 2 can also be formed at the liquid surface. Figure 1 The grid-like bubble collision dense area.

[0116] When multiple aeration pipes are arranged in parallel in the horizontal direction, a main air pipe 5 is branched to supply air (see attached Figure 7 ), at the other end of the aeration pipe or connected to each other to balance the pressure between the pipes.

[0117] Further, as attached Figure 6 As shown, it is an embodiment of a multi-layer aeration pipe: a multi-stage system is formed by stacking multiple layers of the gas dissolving devices. A gas collecting hood 31 is provided between the multiple layers of devices, and its function is also to completely collect the undissolved gas in the lower device, and then directly draw it out from the inter-stage gas transmission pipe 50 as the gas source of the next stage device, so that the next stage device is arranged directly above the previous stage device, or is arranged offset next to it.

[0118] The multilayer stacking device of the first embodiment (see attached Fig.17) is similar, the gas pipe 5 supplies gas to the aeration pipe at the bottom layer, and the undissolved gas is completely collected by the gas collecting hood 31, and the liquid level inside it is gradually pressed down. When the liquid level is lower than any part of the pipe mouth of the inter-stage gas pipe 50, the gas begins to enter the gas pipe. When the pipe mouth is set horizontally downward, a stable internal working liquid level 00 is formed near the position slightly below the pipe mouth, and the bubbles gather, collide and dissolve here; then the gas enters the gas main of the next level through the inter-stage gas pipe 50 as a gas source; and so on, multiple layers can be stacked step by step; the working liquid level of the top layer can be set at the ambient liquid level 0.

[0119] As attached Figure 7 , Attachment Figure 8 The figure shows an embodiment of an aeration tube with a reflux function: two baffles are arranged between the two microporous aeration tubes to form a reflux channel 6, a bottom plate 33 is arranged below the microporous aeration tube to form a U-shaped groove with the baffles on both sides thereof, and front and rear baffles are also arranged at the front and rear of the device to form a box body 30, the upper edge of the box body is higher than the ambient liquid level 0 and also higher than other baffles in the box body, the front and rear baffles have openings in the U-shaped groove part to communicate with the surrounding liquid, and the reflux channel extends downward to a specified depth in the liquid by connecting to a telescopic extension tube 60, so that the liquid in which a large amount of gas is fully dissolved in the top layer can be transported to the deep layer below, which is helpful for the replacement and circulation of the upper and lower liquid layers and improves the overall dissolution efficiency.

[0120] The aeration pipe aerates in the U-shaped trough to form an air lift effect. The gas-liquid flow gushes out from the upper end of the U-shaped trough to form a bulge higher than the liquid level 0. It is restricted by the upper edge of the box and cannot flow out. It can only flow into the reflux channel 6 next to it. Here, the gas-liquid flow 4 collides to form a collision intensive area 2 (see attached Figure 8 ); liquid is replenished from the openings of the U-shaped groove portion of the front and rear baffles; the extension tube 60 can extend to a specified depth in the liquid, where the pressure inside and outside the tube is balanced, and when liquid above the liquid surface flows in from the top, there is no pressure flowing out from the bottom of the tube at any depth. Therefore, the gas-rich liquid in the upper layer can be smoothly injected into the liquid environment at a specified depth, which is suitable for overall balanced dissolution of deeper and larger liquid pools.

[0121] In fact, the extension tube can also be applied to the aforementioned embodiments, including the first and third embodiments, embodiments in which the lower part (the bottom layer when there are multiple layers) has an open liquid inlet: a retractable extension tube 60 is set at the liquid inlet opening at the bottom of the device to adjust the liquid inlet depth, and use the deep liquid to replace the top layer liquid, thereby promoting overall circulation and improving dissolution efficiency.

[0122] See attached Fig. 9After a retractable extension tube is installed at the bottom liquid inlet of the gas bin, box or cover 30 at the bottom of the device, it is extended to a specified depth. Under the gas lifting action of the upper device, the deep liquid is extracted to the upper layer to update and replace the surface liquid in which the gas has been dissolved, which is exactly the opposite of the action of injecting the top layer liquid into the deep liquid in the previous embodiment.

[0123] In order to achieve the invention purpose of cutting bubbles in liquid, we have designed a fourth embodiment, which can be applied to all the above embodiments or used alone:

[0124] At least one bubble cutting device 11 is arranged above the bubble outlet of the micro-bubble generator. The bubble cutting device is composed of a multi-layer bubble cutter 111 fixed on a substrate or a base frame 12. The bubble cutter can be arranged in staggered layers to improve cutting efficiency. It is the longitude and latitude of a grid of various materials, or a monofilament arranged in parallel, a blade with a downward edge or other thin sheet. The bubbles emitted from the bubble outlet are continuously split and cut by the bubble cutter for multiple times during the floating process, and are broken into more and smaller unstable bubbles, thereby improving the dissolution efficiency. When there are multiple bubble cutting devices, they can be stacked in the vertical direction.

[0125] The bubble cutting device (see attached Fig.11 , excluding the bubble outlets 10 and 51 below) can be used alone, as long as there is a bubble generator below. We have even tested the actual oxygenation power efficiency of the bubble cutting device alone (specific data and calculations are attached); of course, if the bubble constraint component 3 set at the liquid surface is used to form the collision intensive area 2, the overall efficiency can be further improved.

[0126] The bubble outlet 10 includes not only the air holes, micro holes, micro aeration holes or microporous aeration heads on the air lift pipe or aeration pipe in the aforementioned embodiments, but also the gas-liquid outlet of a jet aerator or a liquid-gas energy aerator, etc.; that is, at least one bubble cutting device can be arranged above each of the bubble outlets 10. For example, in the first and second embodiments, it can be arranged in each of the air lift pipes and installed at a position higher than the micro holes. In the third embodiment, it can be arranged along the aeration pipe and installed above each group of aeration holes or each aeration head. They form various arrays in their own way, and the bubbles cut by the bubble cutting device can gather in the collision intensive area on the liquid surface for further dissolution.

[0127] The bubble cutters in each layer can be arranged in staggered layers (see attached Fig.12), that is, the cutters 111 of two adjacent layers may not be completely aligned, they may deviate by a certain distance, a typical value of which may be half of the spacing, so that if a small bubble passes through the middle of the grid or wire of the lower layer, it will be cut from the middle by the grid or wire of the current layer.

[0128] The most common bubble cutter 111 is a grid, and from the experimental results, the efficiency of cutting bubbles with a grid is the highest. However, in practical applications, the grid has a fatal flaw - it is very easy to be blocked by debris, especially by fibrous debris such as hair, which is difficult to remove.

[0129] If a single wire is set in parallel, although its ability to cut bubbles is slightly worse than that of a grid, the chance of being attached to debris will be reduced by more than half (under the same wire spacing). The situation of using a blade (with the edge facing down) or other thin sheets is similar to that of a single wire.

[0130] In order to reduce the probability of debris attachment and further remove these debris, our core technical solution is: the bubble cutting device comprises at least one substrate 12, and the bubble cutter is an elastic monofilament 111 arranged in parallel, one end of which is fixed on the substrate and the other end is suspended, so they need to have a certain rigidity, and a guide sleeve 13 is arranged on their periphery, and a flushing air port 51 is also arranged below them; when multiple substrates are included, they are arranged in pairs or share a guide sleeve; the monofilament with debris attached will bend upward under the flushing of the gas-liquid flow, and the setting of the flushing air port and the guide sleeve can increase the flow rate and flow of the gas-liquid flow, thereby increasing the flushing force on the monofilament, and finally flushing away the debris; multiple bubble cutting devices 11 can be stacked in the vertical direction, and a gap should be left between the guide sleeves of each section of the device to facilitate the replenishment of liquid, and a circle of guide cover can be set at the lower end of the guide sleeve (see attached Fig.14 ) or baffle (see Appendix Fig.15 )14 prevents bubbles from escaping, or at the upper edge outlet of the guide sleeve, a guide baffle 14 is set inward to guide the liquid in the tube to the outside of the opposite tube. Liquid can be replenished from above the guide baffle. After passing over the end of the guide baffle, the bubbles will continue to float up and will basically not escape under the guidance of the guide baffle at the lower edge of the upper guide tube. The pipe sections are either arranged vertically in alignment up and down, or arranged in staggered layers according to the flow direction of the guide baffle.

[0131] The specific working principle is: multiple layers of parallel monofilaments are distributed layer by layer, and bubbles will inevitably be cut layer by layer by these monofilaments in the process of passing and floating from bottom to top. In the actual environment, fibrous debris such as hair entrained in the gas-liquid flow will be attached to these monofilaments. The monofilaments are suspended at one end and are elastic. The monofilaments with debris attached will bend upward under the scouring of the gas-liquid flow, and the bending amplitude will be greater towards the end. The debris at the end of the monofilament will be directly washed away because it is difficult to attach, and the debris not at the end will also be gradually washed to the end; the monofilaments that get rid of the debris rebound and reset; sometimes when the debris is attached more firmly or gradually accumulates more, the flushing air port can be opened to release a large amount of gas. Coupled with the restraining effect of the guide sleeve, the gas-liquid flow will rush upward at a faster rate, the flushing force will be stronger, the monofilament will bend upward to a greater extent, and the flushing effect on the debris will be better.

[0132] When multiple layers of bubble cutting devices are stacked, gaps should be left between the pipe sections. The gaps determine the amount of liquid to be replenished. If the gaps are small and the replenished amount is insufficient, the liquid mainly enters from the bottom. After being dissolved layer by layer, the amount of dissolved gas in the liquid increases layer by layer, and the higher it is, the more difficult it is for the gas to continue to dissolve, and the dissolution efficiency will be reduced. This should generally be avoided as much as possible, but there is a special application case - in the sewage treatment process, local high dissolved oxygen (DO) water can induce short-range nitrification and denitrification reactions, which have an unexpectedly special effect on removing nitrogen from sewage.

[0133] If the gap between each layer of pipe sections is increased, the gas-liquid flow can absorb more fresh liquid from the surrounding area due to the gas lift effect during the rising process, which is very helpful for improving the overall dissolution efficiency.

[0134] For further information, see Appendix Fig.15 The guide baffle 14 can be arranged in multiple pieces, and its functions are, first, to guide the liquid with dissolved gas in the tube to diffuse outward, and to add fresh liquid into the upper guide sleeve; second, to prevent bubbles from escaping outward. There are too many forms to list, so I will not repeat them here.

[0135] The elastic monofilament is first required to have a certain elasticity. In addition, since it can only be fixed at one end when working, it must also have a certain rigidity. The most preferred material at present is spring steel straight hard wire, which can be as thin as 0.1mm and has good elasticity and rigidity. Of course, other materials such as various metal wires, plastics or various polymer materials, ceramic materials, etc., as long as they can meet certain elasticity and rigidity requirements and can complete the main functions of this technical solution, they should belong to the protection scope of this technical solution, so no excessive restrictions will be made.

[0136] The elastic monofilament has a line diameter of no more than 1.5 mm, a spacing of 4-10 mm, more than 3 layers, and a layer spacing of 4-30 mm.

[0137] Obviously, the smaller the wire diameter of the bubble cutter, the better the cutting effect, as long as it can meet the engineering requirements for stiffness and elasticity. The wire diameter of the typical embodiment is 0.15mm; the spacing between the single wires cannot be too large, otherwise the probability of most small bubbles being cut will be reduced, and it cannot be too small. If it is too small, the bubbles will not be easy to pass through and the gas-liquid flow resistance will increase. Moreover, after the bubbles pass through, they are more likely to merge into large bubbles, affecting the cutting efficiency.

[0138] The above-mentioned selection of the data ranges such as the size and position relationship of the bubble cutter is also applicable to the bubble cutters in the various embodiments mentioned later.

[0139] Because the monofilaments have dual requirements of elasticity and rigidity, from the perspective of actual materials, their working length will be subject to certain restrictions and will generally not be too long. Therefore, in practical applications, they can be arranged opposite to each other in pairs (see Appendix Fig.13 The relative settings of the upper and lower Fig.14 If two vertical baffles are set up next to it (attached Fig.13 The dotted line portion) forms a square guide sleeve 13; if the substrate 12 is set wider, it will form a rectangle or even a long strip (without length limit); at the same time, the vertical baffles on both sides can also serve as the substrate 12 to set the bubble cutter on it.

[0140] In addition, a circular flow guide sleeve 13 (see attached Fig.13 The circular dotted line portion, and the left and right baffles of the vertical dotted line portion can be cancelled), for example, the bubble cutting device can be set in the air lift tube of the first or second embodiment, installed above the micro-pores, and the air lift tube will also play the role of a guide sleeve.

[0141] The following is the actual power efficiency measured for a single bubble cutting device:

[0142] The single wire is made of steel wire with a diameter of 0.15mm, a working length (i.e., the clearance length excluding the fixed end) of 90mm, a spacing of 5mm up and down, left and right, no misalignment, a single end is fixed in a 90*90mm square tube (guide sleeve), a pipe section height of 400mm, and a quantity of 1:

[0143] The experimental gas is air with a flow rate of 0.209162 cubic meters per hour, and the experimental liquid is water with a volume of 12.401 cubic meters. The pressure of the pressurized gas input from the air inlet pipe is 605 mm water column.

[0144] Gas flow meter reading: V1 = 0.209162m3 / h

[0145] Inlet pipe pressure: P1 = 0.605m water column

[0146] =ρgh+P 0=1000kg / m 3×9.8m / s 2×0.605m+101325Pa

[0147] =5929+101325=107254kg / ms 2

[0148] Gas power: N = P 1V 1ln (P 1 / P 0)

[0149] =107254kg / ms 2×0.209162m 3 / 3600s×ln(107254÷101325)

[0150] =6.231517×ln1.058514kgm 2 / s 3=0.3543617w

[0151] Experimental water temperature: T = 28.8°C

[0152] Water volume: V = 12.401m 3

[0153] The saturated dissolved oxygen value at the experimental temperature was found to be: CS = 7.716 mg / L

[0154] The saturated dissolved oxygen value at 20°C is: CS20 = 9.09 mg / L

[0155] The measured initial value of dissolved oxygen is C1 = 0.56 mg / L, and the final value is C2 = 0.805 mg / L

[0156] Experimental time t2-t1=15min

[0157] Oxygen transfer coefficient: K La T = ln [(C SC 1) / (C SC 2)] ÷ (t 2-t 1)

[0158] =ln[(7.716-0.56) / (7.716-0.805)]÷15×60 / h

[0159] =0.139344459 / h

[0160] Oxygen transfer coefficient at 20°C: K La 20 = K La T ÷ 1.024 (T-20)

[0161] =0.139344459÷1.23208201=0.11309674 / h

[0162] Oxygenation capacity: QS = K La 20 × V × C S20

[0163] =0.11309674 / h×12.401m 3×9.09mg / L×1000L / m 3

[0164] =12.74884g / h

[0165] Ideal power efficiency: ES = QS / N = 12.74884g / h ÷ 0.3543617w = 35.9769kg / kwh

[0166] Fan efficiency: η=90%Magnetic suspension fan, water head and pipeline loss are ignored: k≈0

[0167] Actual power efficiency: EP = E Sη (1-k) = 35.9769 × 90% = 32.379 kg / kwh

[0168] As for the flushing air port, it can be set below the bubble generator, and they can share the same air inlet pipe. During normal operation, the pressure is low, only the bubble generator generates bubbles, and the flushing air holes are closed by liquid; when flushing is required, the air inlet pressure is increased, and the gas overcomes the liquid level pressure difference and is released in large quantities from the flushing air port with a larger air outlet below.

[0169] A layer of elastic material membrane can also be provided on the flushing air port, and pores are cut on the membrane. The pores are naturally closed due to the elasticity of the material under normal conditions, and will be flushed open by the gas when the air pressure is large enough.

[0170] Furthermore, the elastic monofilament 111 can be arranged to tilt upward, and the angle α between the elastic monofilament 111 and the horizontal line does not exceed 60 degrees (see the attached figure). Fig.14 ); it makes it more difficult to attach debris. Even if it is attached, under the flushing of the normal working gas-liquid flow of the microbubble generator, the elastic monofilament will bend slightly upward and the debris will be flushed away; at this time, the flushing air port 51 can also be cancelled, making the structure and control simpler.

[0171] In a typical embodiment, a 30 degree angle is selected.

[0172] The directions such as up, down, left, right, front and back described in this article are only for the convenience of describing and illustrating the implementation details of the technical solution with reference to the drawings in the specification, and should not be regarded as limitations on this technical solution.

[0173] The above describes several implementation modes of the present invention. Due to space limitations, reasonable arrangements and combinations between the various implementation modes cannot be listed one by one. For those skilled in the art, several combinations, deformations and improvements can be made without departing from the creative concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A gas dissolution system, comprising a multi-layer gas dissolution device, characterized in that: The gas dissolving device comprises a plurality of microbubble generators (1), wherein the microbubble generators emit a large number of small bubbles below the liquid surface, and drive a large number of liquids to form a gas-liquid two-phase flow to flow upward due to the gas lift effect. The plurality of microbubble generators are distributed in a dense array, so that when the gas-liquid flow reaches the liquid surface, the gas-liquid flow will collide with each other in the horizontal direction, forming a bubble collision dense area (2) between them, where a large number of bubbles are violently squeezed, collided and burst; The micro-bubble generator is a vertically arranged air lift tube, and at least one bubble outlet (10) is provided on the tube wall thereof, and the bubble outlet comprises an air hole, or a micro-air hole, or a micro-aeration hole, or a micro-pore aeration head, or a jet pump outlet; the upper outer edge of the air lift tube is sealed and fixedly connected to the upper panel of the air bin (30), and the air bin is connected to the air delivery pipe (5); the pressurized gas enters the air bin from the air delivery pipe, and then enters the air lift tube through the micro-air hole, generating an air lift effect in the air lift tube, and the bubbles drive the gas-liquid flow to gush upward along the air lift tube, and the liquid is replenished from the lower pipe opening; The gas dissolution system is designed to improve the effective utilization of the limited liquid surface; the gas bin of the rear-stage device is covered directly above the front-stage device to completely collect the undissolved gas of the front stage as the gas source of the rear-stage device. A gap is left between the gas bins of each layer of devices as a channel for liquid renewal and replacement. The gas lift pipes of each layer should be installed in a staggered manner to prevent the gas and liquid flow of the lower layer of gas lift pipes from directly entering the upper layer of gas lift pipes.

2. The gas dissolution system according to claim 1, characterized in that: A bubble restraining component (3) is arranged at the outer liquid surface of the collision intensive area (2). The bubble restraining component is a closed annular structure, which is used to prevent bubbles from diffusing outward along the liquid surface, increase the density of bubbles in the area, and increase the probability of mutual squeezing, collision and bursting; especially in the extreme case where the number of microbubble generators is small, or even only one microbubble generator, it can restrain the bubbles from gathering to form the collision intensive area.

3. The gas dissolution system according to claim 1, characterized in that: The micropores have a diameter of 0.2-1 mm, and the number of micropores is 4-30. A single layer is evenly distributed on the same horizontal plane, or multiple layers are horizontally adjacently distributed. The center distance between the air lift pipes is 1.5-3 times of their pipe diameters.

4. The gas dissolution system according to claim 1, characterized in that: A gas collecting hood (31) is arranged between the multi-layer gas dissolving devices, and its function is to completely collect the undissolved gas in the lower device. The inter-stage gas transmission pipe (50) is inserted into the gas collecting hood, and the pipe mouth is arranged horizontally downward, and the other end is connected to the gas bin (30) of the next stage as the gas source. In this way, the next stage device is arranged directly above the previous stage device, or is arranged offset next to it.

5. The gas dissolution system according to claim 1, characterized in that: The gas delivery pipe (5) is an air extraction pipe. The bottom of the gas bin (30) is closed and the whole is located above the ambient liquid level (0). The upper outer edge of the air lift pipe is sealed and fixedly connected to the bottom plate of the gas bin, and the lower part is connected to the ambient liquid level to replenish liquid. The micropores are located above the ambient liquid level and take in air from the air. The lower part of the gas bin is also provided with a return pipe (6) connected to the ambient liquid level. After the air extraction pipe pumps the gas bin into negative pressure, the liquid below is pumped into the gas bin from the air lift pipe and the return pipe. At the same time, the gas also enters the air lift pipe from the micropores to produce an air lift effect. The gas-liquid mixture in the air lift pipe flows upward due to its relatively small specific gravity, and the liquid in the return pipe flows downward due to its relatively large specific gravity. Under the set negative pressure, the inflow and outflow of the liquid will reach a dynamic balance, that is, a working liquid level (00) is formed in the gas bin, and the bubbles form the collision intensive area (2) here to accelerate dissolution.

6. The gas dissolution system according to claim 5, characterized in that: The gas dissolution devices at each layer have gas lift pipes that are staggered to prevent the gas and liquid flow of the lower layer gas lift pipes from directly entering the upper layer gas lift pipes; only the gas delivery pipe (5) is retained at the top layer, and only the reflux pipe (6) is retained at the top layer.

7. The gas dissolution system according to claim 1, characterized in that: The microbubble generator is a horizontally arranged microporous aeration tube, a plurality of bubble outlets (10) are arranged on the tube wall, and baffles are vertically arranged on both sides of the microporous aeration tube as bubble restraining components; when there are multiple microporous aeration tubes, they are arranged in parallel in the horizontal direction.

8. The gas dissolution system according to claim 7, characterized in that: Between the multiple layers of gas dissolving devices, a gas collecting hood (31) is provided, which is used to completely collect the undissolved gas in the lower layer device, and then lead it from the inter-stage gas transmission pipe (50) to directly serve as the gas source for the next stage device, so that the next stage device is arranged directly above the previous stage device, or is arranged offset to the side.

9. The gas dissolution system according to claim 8, characterized in that: Two baffles are arranged between the two microporous aeration tubes to form a reflux channel. A bottom plate (33) is arranged below the microporous aeration tube to form a U-shaped groove with the baffles on both sides thereof. Front and rear baffles are also arranged at the front and rear of the device to form a box body. The upper edge of the box body is higher than the ambient liquid level (0) and higher than other baffles in the box body. The front and rear baffles have openings in the U-shaped groove part to communicate with the surrounding liquid. The reflux channel extends downward to a specified depth in the liquid through a continuous telescopic extension tube (60). In this way, the liquid in which a large amount of gas is fully dissolved in the top layer is transported to the deep layer below, which is conducive to the replacement and circulation of the upper and lower liquid layers and improves the overall dissolution efficiency.

10. The gas dissolution system according to claim 8, characterized in that: A telescopic extension tube (60) is arranged at the liquid inlet opening at the bottom of the device to adjust the liquid inlet depth, and the deep layer liquid is used to replace the top layer liquid, thereby promoting overall circulation and improving the dissolution efficiency.

11. A gas dissolution system according to any one of claims 1 to 10, characterized in that: At least one bubble cutting device (11) is arranged above the bubble outlet (10) of the micro-bubble generator. The bubble cutting device is composed of a plurality of bubble cutters (111) fixed on a substrate (12). The bubble cutters are arranged in staggered layers to improve cutting efficiency. The bubble cutters are longitude and latitude lines of a grid of various materials, or parallel monofilaments, blades with downward-facing edges, or other thin sheets. The bubbles emitted from the bubble outlet are repeatedly chopped by the bubble cutters during the floating process, and are broken into more and smaller unstable bubbles, thereby improving dissolution efficiency. When there are a plurality of the bubble cutting devices, they are arranged in a stacked manner in the vertical direction.

12. The gas dissolution system according to claim 11, characterized in that: The invention comprises at least one substrate (12), wherein the bubble cutters are elastic monofilaments arranged in parallel, one end of which is fixed on the substrate and the other end is suspended in the air, so they need to have a certain rigidity, and a flow guide sleeve (13) is arranged on their periphery, and a flushing air port (51) is also arranged below them; when multiple substrates are included, they are arranged in pairs or share a flow guide sleeve; the monofilaments with debris attached will bend upwards under the flushing of the gas-liquid flow, and the arrangement of the flushing air port and the flow guide sleeve increases the flow rate and flow of the gas-liquid flow, thereby increasing the flushing force on the monofilaments, and finally flushing away the debris; multiple The bubble cutting device (11) is stacked in the vertical direction, and a gap is left between the guide sleeves of each section of the device to facilitate the replenishment of liquid. A circle of guide cover or guide baffle (14) is set at the lower end of the guide sleeve to prevent bubbles from escaping; or a guide baffle (14) is set inward at the upper edge outlet of the guide sleeve to guide the liquid in the tube to the outside of the opposite tube. The liquid is replenished from above the guide baffle. After passing the end of the guide baffle, the bubble will continue to float up and will not escape under the guidance of the guide baffle at the lower edge of the upper guide tube. Each pipe section is arranged vertically and aligned up and down, or arranged in staggered layers according to the flow direction of the guide baffle.

13. The gas dissolution system according to claim 12, characterized in that: The elastic monofilament has a line diameter of no more than 1.5 mm, a spacing of 4-10 mm, more than 3 layers, and a layer spacing of 4-30 mm.

14. The gas dissolution system according to claim 12, wherein: The elastic monofilament is tilted upward, and the angle α between the elastic monofilament and the horizontal line does not exceed 60 degrees, which increases the difficulty of attaching debris. Even if the debris is attached, the elastic monofilament will be slightly bent upward under the flushing of the normal working gas-liquid flow of the microbubble generator, and the debris will be flushed away.

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