Gas-solution mixing system with self-shunting and opposite-flushing functions and application of gas-solution mixing system

Abstract

The invention provides a self-shunting opposite-flushing gas-solution mixing system and application thereof, which comprises a gas-solution feeding unit, a mixing unit and a processing unit which are sequentially communicated along the flowing direction of fluid, and is characterized in that the mixing unit comprises a concentric-square-shaped shunting opposite-flushing pipe; the split-flow hedging pipe comprises an inlet section communicated with the gas solution supply unit, a split-flow section used for dividing a gas solution flowing in from the inlet section into two branches, a parallel-flow section used for combining the two branches and forming hedging, and an outlet section communicated with the treatment unit, the pipe diameter of the inlet section is equal to that of the outlet section, and the pipe diameter of the split-flow hedging pipe is equal to that of the outlet section. According to the system, a plurality of sections of concentric-square-shaped diversion pipelines are matched with pumping pressure, so that air solutions form hedging in the pipelines to cause bubble self-cutting, the air solution mixing time is short, the efficiency is high, the microbubble amount of mixed products is high, meanwhile, equipment of the system is easy to lay, the occupied space is small, the follow-up maintenance cost is low, and the market prospect is good.

Description

Technical Field

[0001] The invention relates to the field of gas-liquid mixing equipment, and in particular to a self-dividing and counteracting gas-liquid mixing system and applications thereof. Background Art

[0002] At present, dissolved air flotation (DAF) has been widely used in sewage treatment for more than a century. The dissolved air flotation process produces fine bubbles. Hydrophobic particles leave the liquid, and the adsorbed bubbles concentrate or filter waste (molecules, colloids or large particles). Waste is selectively absorbed on the surface of the bubbles. The separation efficiency depends largely on the number and volume of bubbles, and another part depends on the difference in surface activity. The traditional sewage treatment system has the following obvious disadvantages: First, the device occupies a huge space, which greatly increases the production cost and operating cost; second, the output (bubble density and flow rate) cannot respond immediately to the input parameters (air supply and pump speed), lacking production flexibility.

[0003] Based on the above technical problems, the inventor applied for a patent [CN106115834B] on June 27, 2016, disclosing a multi-stage aeration generator and a sewage treatment method, including a generator body, a pressure monitoring device installed on the generator body, a Venturi nozzle, a capillary tube and a concentric tube, one end of the capillary tube is connected to the Venturi nozzle, and the other end is connected to the concentric tube.

[0004] This patent uses a combination of a multi-stage aeration generator, a Venturi nozzle and a concentric tube to provide continuous and stable very fine foam, and can immediately make output changes for changes in input operating parameters; it is used to regulate air feed and pump speed to produce appropriate foam density and size for subsequent processing, but it still has the following defects in actual application: the capillary tube structure will cause certain obstructions to the gas solution due to its small pore size and high density during use, affecting the stability of the flow pressure. After a period of use, the capillary pores may also be blocked to cause further obstruction. At the same time, the subsequent maintenance of the capillary tube will still require a large cost. The Venturi nozzle will also cause unstable flow pressure after air intake, requiring a long distance of pipeline to stabilize the pressure, which will also take up a large space and is relatively limited for long-term use. Summary of the invention

[0005] The purpose of the present invention is to provide a self-diverting and hedging gas-solution mixing system and its application in view of the defects and shortcomings of the prior art. The system realizes the hedging of gas and solution in the pipeline through multi-section shunt pipelines in conjunction with pump pressure, resulting in self-cutting of bubbles. The gas-solution mixing time is short and the efficiency is high. The amount of microbubbles in the mixed product is high. At the same time, the system itself has simple equipment installation, small space occupation, low subsequent maintenance cost, and has good market prospects.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a self-dividing and counteracting gas-solution mixing system, comprising a gas-solution feeding unit, a mixing unit and a processing unit which are connected in sequence along the fluid flow direction, the mixing unit comprising a meandering diversion and counteracting pipe, the diversion and counteracting pipe comprising an inlet section connected to the gas-solution supply unit, a diversion section for dividing the gas-solution flowing in from the inlet section into two tributaries, a parallel flow section for paralleling the two tributaries and forming a counter-flow, and an outlet section connected to the processing unit, the pipe diameters of the inlet section and the outlet section being equal.

[0007] Furthermore, the diversion section and the parallel flow section are symmetrical three-way structures, the diversion section includes a first diversion trunk, a first diversion branch and a second diversion branch, one end of the first diversion trunk is connected to the gas-solution feeding unit, and the other end is respectively connected to the first diversion branch and the second diversion branch;

[0008] The parallel flow section includes a first parallel flow main line, a first parallel flow branch and a second parallel flow branch. The first diversion branch is connected to the first parallel flow branch, and the second diversion branch is connected to the second parallel flow branch. The first parallel flow branch and the second parallel flow branch are connected to one end of the first parallel flow main line at one end away from the diversion section, and the other end of the first parallel flow main line is connected to the processing unit.

[0009] Furthermore, the diameters of the first shunt branch and the second shunt branch satisfy:

[0010] The sum of the flow rates of the first branch flow path and the second branch flow path is equal to the flow rate of the inlet section;

[0011] The flow rate represents the amount of gas and solution passing through the pipeline within a designed time period.

[0012] Furthermore, the gas-solution feeding unit includes a gas input pipe, a liquid input pipe, and a pressurizing device; the gas input pipe and the liquid input pipe are both connected to the input end of the pressurizing device, and the output end of the pressurizing device is connected to the mixing unit.

[0013] Furthermore, the pressurizing device is a centrifugal air-dissolving pump, a gear air-dissolving pump or a screw air-dissolving pump. The centrifugal air-dissolving pump is suitable for situations where the gas solution processing volume is small. When the gas solution processing volume is large, the centrifugal air-dissolving pump may experience cavitation and flow interruption due to structural limitations, resulting in unstable pressure and affecting the mixing effect. The gear air-dissolving pump is suitable for situations where the liquid has fewer impurities and fewer particles in the liquid. When the liquid has more impurities and more particles in the liquid, the gear air-dissolving pump will experience obvious hysteresis or even jamming. Therefore, according to on-site design requirements, it can be replaced with a screw air-dissolving pump that will not experience cavitation and flow interruption, hysteresis or jamming but has a higher cost.

[0014] Furthermore, a pressure monitoring module is provided between the pressurizing device and the mixing unit, and the pressure monitoring module includes a pressure sensor and a pressure display device. The pressure sensor is used to detect the output pressure of the pressurizing device. The pressure sensor is electrically connected to the pressure display device. The pressure sensor can sense the pressure data formed by the fluid in the device and feed it back to the pressure display device to alert the operator.

[0015] Another object of the present invention is to provide a sewage treatment method using the above-mentioned gas-liquid mixing system, comprising the following steps:

[0016] S1. Air and wastewater are pressurized through a gas-solution feeding unit to form a gas-solution and input into a mixing unit;

[0017] S2. The gas solution is first split into two branches under the action of the diversion and hedging pipe of the mixing unit, and then the two branches are paralleled to hedge each other, cutting and breaking the bubbles in the gas solution and then inputting it into the processing unit;

[0018] The S3 gas solution is filtered and treated with sewage through the gas flotation cylinder of the treatment unit.

[0019] Furthermore, the diversion hedging pipe provided in the mixing unit in step S2 is connected front and back in the mixing unit, and the gas solution enters the inlet section of the diversion hedging pipe. When the gas solution passes through the diversion section at a set flow rate under the pressure of the pressurizing device in S1, the three-way structure of the diversion section will cause the spiral flow formed by the gas solution in the first diversion main channel to be disrupted, so that the spiral flow is evenly diverted into the first diversion branch and the second diversion branch respectively, and it is ensured that the sum of the flow rates in the first diversion branch and the second diversion branch is equal to the flow rate of the inlet section. The flow rate is interpreted as a unit. The amount of gas-solution passing through the pipeline under the action of a specified pressure within a specified time; when the gas-solution of the first diversion branch and the second diversion branch respectively merge into the first parallel flow branch and the second parallel flow branch through the first parallel flow branch, the gas-solution of the parallel flow section will form two gas-solution hedges. During the hedge process, the bubbles in the two gas-solutions are cut by the bubbles themselves and the impurity particles carried by the gas-solutions to form microbubbles, and then enter the next group of diversion hedge pipes to form a second cut, and so on until the outlet section of the last group of diversion hedge pipes outputs the fully mixed gas-solution.

[0020] Furthermore, the mixing unit in step S2 is connected to the processing unit in step S3 at the outlet section of the last group of diversion and hedging pipes, and the processing unit includes a spraying device and an air flotation cylinder. The gas solution after passing through the mixing unit flows to the air flotation cylinder through the spraying device.

[0021] Furthermore, in step S3, the spraying device is provided with a valve to eliminate excessive turbulent water flow, a separation chamber is provided in the middle of the spraying device, and a vent pipe is provided on the top of the separation chamber to discharge excess suspended gas and undissolved bubbles to avoid affecting the interception quality.

[0022] The beneficial effects of the present invention are as follows: the system replaces the aeration device in the form of a capillary tube by a self-dividing and hedging pipeline, which ensures the mixing effect of the gas and solution while preventing blockage problems on the one hand and reducing the operating cost and maintenance cost on the other hand. At the same time, the improvement of the flotation tank structure effectively reduces the gaps between bubbles and prevents the adhesion from falling off. The system has a good application effect in sewage treatment, effectively reduces the subsequent drug administration cost and improves the decontamination effect, and also has good application prospects in other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application, but do not constitute a limitation of the present invention.

[0024] Figure 1 Schematic diagram of the gas-solution mixing system.

[0025] Figure 2 It is a schematic diagram of the treatment unit of the gas-liquid mixing system in the sewage treatment method.

[0026] Among them: 11 is a gas inlet, 12 is a liquid inlet, 13 is a pressurizing device, 14 is a pressure monitoring module, 2 is a mixing unit, 21 is a diversion and hedging pipe, 3 is a processing unit, 31 is a flotation tank, and 32 is a spraying device. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be noted that the terms "vertical", "up", "down", "horizontal", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] like Figure 1-2 As shown, a gas-solution mixing system with self-diverting and hedging includes a gas-solution feeding unit, a mixing unit 2 and a processing unit 3 which are sequentially connected along the fluid flow direction, the mixing unit 2 includes a meandering diverting and hedging pipe 21, the diverting and hedging pipe 21 includes an inlet section connected to the gas-solution supply unit, a diverting section for dividing the gas-solution flowing in from the inlet section into two tributaries, a parallel flow section for paralleling the two tributaries and forming a hedging, and an outlet section connected to the processing unit 3, the inlet section and the outlet section have the same pipe diameter.

[0031] Furthermore, the diversion section and the parallel flow section are symmetrical three-way structures, the diversion section includes a first diversion trunk, a first diversion branch and a second diversion branch, one end of the first diversion trunk is connected to the gas-solution feeding unit, and the other end is respectively connected to the first diversion branch and the second diversion branch;

[0032] The parallel flow section includes a first parallel flow main line, a first parallel flow branch and a second parallel flow branch. The first diversion branch is connected to the first parallel flow branch, and the second diversion branch is connected to the second parallel flow branch. The first parallel flow branch and the second parallel flow branch are connected to one end of the first parallel flow main line at one end away from the diversion section, and the other end of the first parallel flow main line is connected to the processing unit 3.

[0033] When the gas-solution of the first diversion branch and the second diversion branch respectively merge into the first parallel flow main path through the first parallel flow branch and the second parallel flow branch, the gas-solution of the parallel flow section will form two gas-solution hedges. During the hedge process, the bubbles in the two gas-solutions are cut by the bubbles themselves and the impurity particles carried by the gas-solutions to form microbubbles, which then enter the next group of diversion hedge tubes 21 to form a second cutting, and so on until the outlet section of the last group of diversion hedge tubes 21 outputs the fully mixed gas-solution.

[0034] In a specific implementation, the diameters of the first shunt branch and the second shunt branch satisfy:

[0035] The sum of the flow rates of the first branch flow path and the second branch flow path is equal to the flow rate of the inlet section;

[0036] The flow rate represents the amount of gas and solution passing through the pipeline within a designed time period.

[0037] The closer the angle between the first parallel flow main channel and the first parallel flow branch and the second parallel flow branch of the parallel flow section is to 90°, the greater the impact force formed by the relative collision of the gas solution in the first parallel flow branch and the second parallel flow branch, and the better the cutting effect formed.

[0038] In a specific implementation, the gas-solution feeding unit includes a gas input pipe, a liquid input pipe, and a pressurizing device; the gas input pipe and the liquid input pipe are both connected to the input end of the pressurizing device, and the output end of the pressurizing device is connected to the mixing unit.

[0039] In specific implementation, the pressurizing device 13 is a centrifugal air-dissolving pump, a gear air-dissolving pump, or a screw air-dissolving pump. The centrifugal air-dissolving pump is suitable for situations where the gas solution processing volume is small. When the gas solution processing volume is large, the centrifugal air-dissolving pump may experience cavitation and flow interruption due to structural limitations, resulting in unstable pressure and affecting the mixing effect. The gear air-dissolving pump is suitable for situations where the liquid has fewer impurities and fewer particles in the liquid. When the liquid has more impurities and more particles in the liquid, the gear air-dissolving pump will experience obvious hysteresis or even jamming. Therefore, according to on-site design requirements, it can be replaced with a screw air-dissolving pump that will not experience cavitation and flow interruption, hysteresis or jamming but has a higher cost.

[0040] In specific implementation, a pressure monitoring module 14 is provided between the pressurizing device 13 and the mixing unit 2. The pressure monitoring module 14 includes a pressure sensor and a pressure display device. The pressure sensor is used to detect the output pressure of the pressurizing device 13. The pressure sensor is electrically connected to the pressure display device. The pressure sensor can sense the pressure data formed by the fluid in the device and feed it back to the pressure display device to remind the operator to pay attention.

[0041] Another object of the present invention is to provide a sewage treatment method using the above-mentioned gas-liquid mixing system, comprising the following steps:

[0042] S1. Air and wastewater are pressurized by the gas solution feeding unit to form a gas solution and input into the mixing unit 2;

[0043] S2. The gas solution is first split into two branches under the action of the diversion counter-flow pipe 21 of the mixing unit, and then the two branches are paralleled to counter-flow, and the bubbles in the gas solution are cut and broken and then input into the processing unit 3;

[0044] In actual operation, the diversion hedging pipe 21 set in the mixing unit in step S2 is connected front and back in the mixing unit 2, and the gas solution enters the inlet section of the diversion hedging pipe 21. When the gas solution passes through the diversion section at a set flow rate under the pressure of the pressurizing device 13 in S1, the three-way structure of the diversion section will cause the spiral flow formed by the gas solution in the first diversion main channel to be disrupted, so that it is evenly diverted into the first diversion branch and the second diversion branch respectively, and it is ensured that the sum of the flow rates in the first diversion branch and the second diversion branch is equal to the flow rate of the inlet section. The flow rate is interpreted as the flow through the pipeline under the action of a specified pressure in a unit time. When the gas solution of the first branch branch and the second branch branch respectively merge into the first parallel branch and the second parallel branch and enter the first parallel main path, the gas solution of the parallel section will form two gas solutions to hedge. During the hedge process, the bubbles in the two gas solutions are cut by the bubbles themselves and the impurity particles carried by the gas solutions to form micro bubbles, and then enter the next group of branch hedge pipes 21 to form a second cut, and so on until the outlet section of the last group of branch hedge pipes 21 outputs the fully mixed gas solution; since the mixing unit 2 is composed of conventional pipelines and has no complex components, a higher pump pressure can be set. According to Henry's law ( pB＝kx,BxB ) in equilibrium with the liquid surface pressure pB Under certain conditions, the higher the pump pressure, the greater the constant kx,B The higher the gas solubility xB The higher the pump pressure, the higher the gas solubility. xB The higher the value, the higher the gas solubility limit.

[0045] S3. The gas solution is filtered and treated with sewage through the gas flotation cylinder 31 of the processing unit 3.

[0046] In actual operation, the mixing unit in step S2 is connected to the processing unit in step S3 at the outlet section of the last group of diversion and hedging pipes. The processing unit includes a spraying device and an air flotation cylinder. The gas solution after passing through the mixing unit flows to the air flotation cylinder through the spraying device. An inclined plate is arranged on the top of the air flotation cylinder. The inclined plate acts to gradually reduce the horizontal surface area of ​​the top of the air flotation cylinder, squeeze the microbubbles released by the spraying device, and reduce the gaps between the bubbles that appear during the rising process of the microbubbles. Large-scale microbubbles will form electric charges due to the high-speed movement of water molecules and air molecules in the gas solution in different directions. The integrated charged bubbles change the surface tension of the water to help adsorb colored groups and some hydrophilic colloids. Reducing the gaps between bubbles helps prevent adherents (suspended matter SS, organic pollutants COD, etc.) from falling off, while reducing the cost of putting in medicinal materials (polyaluminum chloride PAC, polyacrylamide PAM, etc.) in subsequent processing links.

[0047] In actual operation, the spraying device 32 in step S3 is provided with a valve to eliminate excessive turbulent water flow. A separation chamber is provided in the middle of the spraying device 32, and a vent pipe is provided on the top of the separation chamber to discharge excess suspended gas and undissolved bubbles to avoid affecting the interception quality. When ensuring that the gas solubility is sufficient, the valve can be removed to ensure the release flow rate of the gas solution.

[0048] In one embodiment, a dyeing and bleaching factory uses the old-style dissolved air flotation (i.e., using a pressure dissolved air tank for gas-liquid mixing) as mentioned in the background technology to treat sewage, removes non-hydrophilic pollutants (such as surfactants, detergents, etc.) from the bleaching and dyeing sewage, and finally achieves the effect that the size of the foam can be reduced to 1 to 10 microns, the air solubility reaches 10 to 15% molar fraction, and static flotation is performed using a solid-liquid separation cylinder. The chemical oxygen demand COD of the treated product is reduced from 3000 mg / L to less than 800 mg / L. Due to factors such as fewer bubbles, taking the treatment of 1 cubic meter of sewage per hour as an example, a solid-liquid separation cylinder with a capacity of 1.5 cubic meters is required for static flotation, which occupies a large space.

[0049] In another embodiment, a dyeing and bleaching factory uses a multi-stage aeration generator and a sewage treatment method as shown in the patent [CN106115834B] mentioned in the background technology to remove non-hydrophilic pollutants (such as surfactants, detergents, etc.) from the bleaching and dyeing sewage. The design pressure of the pump is set to 10 bar, and the operating liquid temperature is 25-30°C. The final effect is that the size of the foam can be reduced to 1-10 microns, the air solubility can be increased to 15-25% molar fraction, and the chemical oxygen demand COD of the treated product is reduced from 3000 mg / L to less than 500 mg / L. However, there is a clogging problem. During the long-term operation period of nearly 4 months, dirt accumulation gradually forms in the gap between the capillary pores and the capillary ducts, resulting in obvious clogging and reduced efficiency. The capillary ducts need to be replaced, resulting in certain downtime costs and maintenance costs.

[0050] In another embodiment, a dyeing factory adopts the sewage treatment method using the gas-liquid mixing system with self-dividing and hedging shown in the present invention to remove non-hydrophilic pollutants (such as surfactants, detergents, etc.) from the bleaching and dyeing sewage. The design pressure of the pump is set to 10 bar, and the operating liquid temperature is 25-30°C. The final effect is that the size of the foam can be reduced to 1-10 microns, the air solubility can be increased to 15-25% molar fraction, the chemical oxygen demand COD of the treated product is reduced from 3000 mg / L to less than 500 mg / L, and no blockage or other problems requiring shutdown maintenance are observed during the long-term operation period of more than 6 months. At the same time, the startup equipment cost is reduced by 40%, the operating cost of the flotation equipment such as the pump and electricity cost in the operating cost is reduced by 30%, and the subsequent treatment cost such as the subsequent AAO dosing cost is reduced by 50%, and the shedding rate of the adhesion of the microbubbles (bleaching and dyeing sewage pollution particles, etc.) in the flotation tank is greatly reduced, and the separation effect is effectively improved in combination with the scraper.

[0051] In summary, the present invention ensures the mixing effect of gas and liquid, prevents clogging problems on the one hand, and reduces operating costs on the other hand. At the same time, the improvement of the structure of the flotation tank effectively reduces the gaps between bubbles, prevents adherends from falling off, reduces the equipment footprint and maintenance costs, and has a good application effect in sewage treatment, effectively reduces the subsequent drug administration costs and improves the decontamination effect. At the same time, it also has good application prospects in other fields, such as gas-gas mixing, gas-liquid mixing, and liquid-liquid mixing.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gas-solution mixing system with self-dividing and counteracting flow, comprising a gas-solution feeding unit, a mixing unit and a processing unit which are sequentially connected along the fluid flow direction, characterized in that: The mixing unit includes a meander-shaped diversion and hedging pipe, which includes an inlet section connected to the gas-solution supply unit, a diversion section for dividing the gas-solution flowing in from the inlet section into two branches, a parallel flow section for paralleling the two branches and forming a hedging, and an outlet section connected to the processing unit, and the pipe diameters of the inlet section and the outlet section are equal.

2. The gas-liquid mixing system with self-dividing and counteracting according to claim 1, characterized in that: The diversion section and the parallel flow section are three-way structures symmetrical to each other, the diversion section includes a first diversion trunk, a first diversion branch, and a second diversion branch, one end of the first diversion trunk is connected to the gas-solution feeding unit, and the other end is respectively connected to the first diversion branch and the second diversion branch; The parallel flow section includes a first parallel flow main line, a first parallel flow branch and a second parallel flow branch. The first diversion branch is connected to the first parallel flow branch, and the second diversion branch is connected to the second parallel flow branch. The first parallel flow branch and the second parallel flow branch are connected to one end of the first parallel flow main line at one end away from the diversion section, and the other end of the first parallel flow main line is connected to the processing unit.

3. The gas-liquid mixing system with self-dividing and counteracting according to claim 2 is characterized in that: The diameters of the first shunt branch and the second shunt branch satisfy: The sum of the flow rates of the first branch flow path and the second branch flow path is equal to the flow rate of the inlet section; The flow rate represents the amount of gas and solution passing through the pipeline within a designed time period.

4. The gas-liquid mixing system with self-dividing and counteracting according to claim 1 is characterized in that: The gas-solution feeding unit comprises a gas input pipe, a liquid input pipe and a pressurizing device; the gas input pipe and the liquid input pipe are both connected to the input end of the pressurizing device, and the output end of the pressurizing device is connected to the mixing unit.

5. The gas-liquid mixing system with self-dividing and counteracting according to claim 4, characterized in that: The pressurizing device is a centrifugal air-dissolving pump, a gear air-dissolving pump or a screw air-dissolving pump.

6. The gas-liquid mixing system with self-dividing and counteracting according to claim 4, characterized in that: A pressure monitoring module is provided between the pressurizing device and the mixing unit. The pressure monitoring module comprises a pressure sensor and a pressure display device. The pressure sensor is used to detect the output pressure of the pressurizing device. The pressure sensor is electrically connected to the pressure display device.

7. The use of the gas-liquid mixing system according to any one of claims 1 to 6 in a sewage treatment method, characterized in that: Here are the steps: S1. Air and wastewater are pressurized through a gas-solution feeding unit to form a gas-solution and input into a mixing unit; S2. The gas solution is first split into two branches under the action of the diversion and hedging pipe of the mixing unit, and then the two branches are paralleled to hedge each other, cutting and breaking the bubbles in the gas solution and then inputting it into the processing unit; The S3 gas solution is filtered and treated with sewage through the gas flotation cylinder of the treatment unit.

8. A sewage treatment method according to claim 7, characterized in that: The mixing unit in step S2 is connected to the processing unit in step S3 at the outlet section of the last group of diversion and hedging pipes. The processing unit includes a spraying device and an air flotation cylinder. The gas solution after passing through the mixing unit flows to the air flotation cylinder through the spraying device.

9. A sewage treatment method according to claim 7, characterized in that: In step S3, the spraying device is provided with a valve, a separation chamber is provided in the middle of the spraying device, and an air release pipe is provided on the top of the separation chamber.

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