CN107381701B

CN107381701B - Ozone air flotation device and method for supplying air by using constant-pressure microbubble generator

Info

Publication number: CN107381701B
Application number: CN201710725959.5A
Authority: CN
Inventors: 金鑫; 金鹏康; 王锐; 王丹; 蒋丹丹
Original assignee: Xian University of Architecture and Technology
Current assignee: SHAANXI URSTAR ENVIRONMENTAL SCIENCE AND TECHNOLOGY Co.,Ltd.
Priority date: 2017-08-22
Filing date: 2017-08-22
Publication date: 2020-09-01
Anticipated expiration: 2037-08-22
Also published as: CN107381701A

Abstract

The invention provides an ozone air flotation device and a method for supplying air by using a constant-pressure microbubble generator, the device consists of an ozone air flotation region I, a diaphragm type constant-pressure dissolved ozone microbubble generating device II and an ozone generating system III, wherein the ozone air flotation region I is used for feeding water and purifying sewage through coagulation, ozone oxidation and air flotation synergistic action, the microbubble generating device II is used for generating microbubbles of constant-pressure dissolved ozone into the ozone air flotation region I in an internal circulation mode, the ozone generating system III is used for generating ozone from pure oxygen, and the production of pressure dissolved ozone air water is finished through the diaphragm type constant-pressure pump action. Constant-pressure micro bubbles are provided for an ozone air floatation system through the device, and the best effect of advanced wastewater treatment is obtained.

Description

Ozone air flotation device and method for supplying air by using constant-pressure microbubble generator

Technical Field

The invention belongs to the technical field of water treatment, relates to ozone floatation, in particular to pressurized dissolution of ozone air in water, and provides an ozone floatation device and method for supplying air by using a constant-pressure microbubble generator.

Background

Dissolved air floatation is a traditional water treatment technology and is widely applied to the fields of micro-polluted surface water purification and sewage advanced treatment. Through the cutting action of pressurization or high-speed rotation, air is dissolved into water, and then the dissolved air is released into the water environment under normal pressure, so that a large number of micro bubbles can be generated. The microbubbles are combined with the flocculating constituent which traps pollutant particles, and the flocculating constituent and the water are separated, so that the purpose of removing pollutants is achieved.

Compared with the bubbles (the diameter of the bubbles is in millimeter level) released by the conventional aeration device, the diameter of the micro-bubbles released by the dissolved air releaser is less than 100 microns, and the micro-bubbles have a plurality of unique advantages. Such as having a very large specific surface area, a high internal pressure, a fast dissolution rate and a slow rate of rise. This also makes the active substance in the micro bubbles easy to combine with the pollutant in the sewage and the pollutant removing efficiency of the active substance is greatly improved.

The oxidation capacity of ozone is very strong, and the oxidation-reduction potential of ozone is 2.07mv, which is second to F₂Meanwhile, the product after the ozone reaction is oxygen, so the ozone is an efficient oxidant without secondary pollution. However, the conventional ozone treatment techniques are not sufficiently high in gas-liquid mass transfer rate and utilization efficiency. Because the dissolved air floatation technology has the advantages, the ozone oxidation and the air floatation are combined, and the ozone utilization efficiency and the oxidation capacity can be effectively improved. At present, ozone-dissolving air flotation devices are ZL2004100735004, ZL201110122083.8 and the like. The key component of these devices is the microbubble generator and releaser.

The micro-bubble generating device is divided into a pressure dissolved air tank micro-bubble generator, a jet flow micro-bubble generator, a pressure convolution micro-bubble generator and the like. The air source ozone generator supplies air through the air compressor, the air compressor changes from 0.4-0.7MPa, and the pressure stability of the tail end of the dissolved air releaser of the ozone air flotation device is poor due to the periodic change of the air compressor. The direct result of unstable pressure is that the diameter of the ozone microbubbles fluctuates with the pressure, the time is large and the time is small, and the ozone air flotation water treatment effect is seriously influenced. In addition, ozone is often supplied to a plurality of aeration heads simultaneously, and double imbalance of flow and pressure exists, so that the ozone floatation efficiency is not uniformly distributed in the reactor.

ZL2004100735004 discloses an ozone air flotation device with a pressure dissolved air tank microbubble generation system, and the air flotation effect is good. However, because the pressure source of the pressure dissolved air tank is an air compressor, the pressure of the pressure dissolved air tank is frequently changed back and forth between 0.4 and 0.7MPa, so that the pressure change in the whole system is large. The releaser pressure change is big, and inhomogeneous pressure change makes the aperture change in the bubble, also can reduce system availability factor, and consequently, it is very important that dissolved ozone air supporting system has stable pressure. In order to maintain the stability of the system, the invention patent ZL201110122083.8 discloses an ozone gas supply pressure stabilizing device and an air floatation reactor using the same, wherein the purpose of pressure stabilization is achieved by adopting a special structure of top pressure relief, bottom gas inlet and side gas outlet, but the equipment structure is complex and the effect is general.

An ozone microbubble generator developed by Beijing Benzhou nanometer technology Limited adopts a jet mode, and a gas-liquid mixture enters the bottom of a reactor through a jet device to generate ozone-air mixed gas microbubbles, wherein the average diameter of the bubbles is 51 microns. The large water head provided by the jet flow mode is derived from a lift pump with large power, micro bubbles are expected to slowly rise to react with pollutants in the ozone floatation process, and the high-speed gas-water mixed flow which is jetted out does not meet the requirement. Thus, the jet mode application is limited.

The pressurizing and whirling micro-bubble generator dissolves ozone air into water through the high-speed cutting action of the pump impeller. A pressurizing rotary micro-bubble generator developed by Kyowa engineering company in Japan adopts a self-absorption air supply mode, backflow water is in a rotating state in a rotary accelerator after being pressurized, sucked gas and the pressurizing backflow water are mixed and dissolved in the rotary accelerator, and a gas-liquid mixture is discharged by jet flow of a disperser at a high speed to form micron-sized bubbles. As with the jet mode, there is a disadvantage of high energy consumption.

Generally, the existing equipment and system comprise a series of equipment such as an air source, a pressure regulating device, an air compressor, a booster pump, a dissolved air tank, a releaser and the like, and the structure is very complex and the flow is long. From these technical backgrounds, it can be seen that research into a generating device that has stable pressure release characteristics, low energy consumption and high microbubble generation efficiency has very important meaning to improve the dissolved ozone air flotation effect of the device.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide an ozone air flotation device and method for supplying air by using a constant-pressure micro-bubble generator, in particular to a device and method for supplying air by using a diaphragm type ozone dissolving micro-bubble generator, dissolving ozone air in water to form a gas-dissolved water mixture through the pumping action of a two-stroke two-suction stroke diaphragm type hydraulic pump, releasing the gas-dissolved water mixture to an ozone air flotation area through a pressure release pipeline, and generating a large amount of micro-bubbles under the pressure reduction action; the pressure is adjusted by adjusting the stroke of a pump rod of the diaphragm type hydraulic pump, and the larger the pressure is, the smaller the average diameter of the released micro-bubbles is; under the condition of setting the stroke of the pump rod, the constant-pressure gas-dissolving water can be obtained; the larger the reciprocating frequency of the pump rod is, the larger the amount of the generated dissolved air water is. The method has the advantages of constant dissolved air pressure, good dissolved air release effect, simple operation and operation, short treatment flow and the like. The invention has the advantages of uniform distribution of dissolved ozone microbubbles, constant dissolved air pressure, good dissolved air release effect, narrow size distribution cover of microbubbles, adjustable size, simple operation and operation, short treatment process and the like, and provides constant-pressure microbubbles for an ozone air floatation system so as to obtain the optimal treatment effect of the device.

In order to achieve the purpose, the invention adopts the technical scheme that:

an ozone air-floating device using constant pressure microbubble generator to supply air comprises:

the ozone air flotation area I is a water treatment area and is used for realizing an ozone air flotation process, a water inlet pipe 1, a dissolved air pipe 2, a slag discharge pipe 5, a return pipe 6 and a water outlet pipe 3 with a water outlet electric valve 4 are connected, and the intermittent operation of slag discharge and operation is realized by opening and closing the water outlet electric valve 4;

the ozone generating system III is used for generating ozone air mixed gas and supplying the ozone air mixed gas to the diaphragm type constant-pressure dissolved ozone microbubble generating device II;

a diaphragm type constant-pressure dissolved ozone microbubble generator II mainly comprises a water inlet electromagnetic valve 7, a water inlet electromagnetic valve 8, a water outlet electromagnetic valve 9, a diaphragm type constant-pressure pump 10 and a motor 11, wherein deep treatment water discharged from a return pipe 6 enters a cavity of the diaphragm type constant-pressure pump 10 through the water inlet electromagnetic valve 7, ozone-air mixed gas enters the cavity of the diaphragm type constant-pressure pump 10 through the water inlet electromagnetic valve 8, the motor 11 drives a pump rod 103 of the diaphragm type constant-pressure pump 10 to make stroke motion, under a pressurization condition, the ozone-air mixed gas is dissolved into water, and pressure dissolved gas water enters an ozone gas floating area I through the water outlet electromagnetic valve 9 and a dissolved gas pipe 2 to be decompressed and released.

And the ozone generating system III is used for generating ozone air mixed gas and supplying the ozone air mixed gas to the diaphragm type constant-pressure dissolved ozone microbubble generating device II.

In ozone air supporting district I, including outer barrel and interior barrel, interior barrel is total with outer barrel at the bottom, and the highly being less than outer barrel of interior barrel, and inlet tube 1 and dissolved air pipe 2 are connected in the bottom of interior barrel, and outlet pipe 3 sets up between outer barrel and interior barrel, wears out outer barrel, and back flow 6 sets up at outer barrel lateral wall, is located the top of outlet pipe 3, and scum pipe 5 sets up the top at ozone air supporting district I. In an ozone floating area I, decomposing organic matters into small molecules through the oxidation of ozone and the catalytic ozonation of aluminum; under the action of coagulant, the suspended matter and hydrophobic easy-to-coagulate matter are trapped and separated under the action of air floating.

The ozone generation area III mainly comprises a flow regulating valve 12, an ozone generator 13 and an oxygen tank 14, wherein an air source of the ozone generator 13 is an oxygen source provided by the oxygen tank 14, and under the condition of reducing air supply quantity, the ozone concentration is improved to meet the required ozone consumption quantity. The ozone air mixed gas generated by the ozone generator 13 enters the cavity of the diaphragm type constant pressure pump 10 through the flow regulating valve 12 and the air inlet electromagnetic valve 8.

The ozone generator 13 is provided with a cooling water circulation system.

In the diaphragm type constant-pressure dissolved ozone microbubble generation system II, when dissolved gas water enters the ozone air floatation area I through the dissolved gas pipe 2 under the action of high pressure and is released, stable pressure is instantaneously released, and the gas dissolved in the water forms a large number of microbubbles with the diameter of 30-50 microns. The flocs are carried to a separation area of an ozone air floatation area I in combination with the flocs and discharged out of the ozone air floatation device in the form of scum, so that the water purification is realized.

The cavity of the diaphragm type constant pressure pump 10 is divided by a diaphragm 101, wherein the space on the same side with a pump rod 103 is a hydraulic chamber 102, the space on the other side is a water-gas mixing chamber 104, the hydraulic chamber 102 is filled with a hydraulic agent, the pressure of the pump rod 103 is transmitted to the diaphragm 101 through the hydraulic agent, and the diaphragm 101 transmits the pressure to gas and liquid in the water-gas mixing chamber 104, so that the ozone-air mixed gas is dissolved in return water to generate constant-pressure dissolved water. The diaphragm 101 is made of a pressure-resistant and ozone-resistant tetrafluoroethylene material, chloroprene rubber, fluororubber, or polyvinylidene fluoride.

The suction stroke of a pump rod 103 of the diaphragm type constant pressure pump 10 is divided into 2 steps, wherein in the first step, a water outlet electromagnetic valve 9 and an air inlet electromagnetic valve 8 are closed, a water inlet electromagnetic valve 7 is opened, and 80-90% of space in a water-air mixing chamber 104 is filled; and secondly, closing the water inlet electromagnetic valve 7 and the water outlet electromagnetic valve 9, opening the air inlet electromagnetic valve 8, and filling the ozone-air mixed gas into the water-air mixing chamber 104.

The stroke of a pump rod 103 of the diaphragm type constant pressure pump 10 is divided into 2 steps, in the first step, a water inlet electromagnetic valve 7, a water inlet electromagnetic valve 8 and a water outlet electromagnetic valve 9 are closed, the pump rod 103 carries to occupy 10210-20% of a hydraulic chamber, and ozone-air mixed gas is dissolved into water through pressure conduction to form a gas-water mixture of dissolved gas-water. And step two, opening the water outlet electromagnetic valve 9, closing the water inlet electromagnetic valve 7 and the air inlet electromagnetic valve 8, carrying out the pump rod 103 to extrude the air-water mixture of 80-90% of the air-water mixing chamber 104, and then performing cycle operation in sequence to obtain constant-pressure dissolved ozone microbubbles.

Clear water generated in the bottom area of the ozone floating area I provides a water source of dissolved air water for the diaphragm type constant-pressure dissolved ozone microbubble generating device II.

The invention also provides an ozone air floatation method for supplying air by utilizing the constant-pressure microbubble generator, which comprises the following arrangement:

generating ozone-air mixed gas;

based on a diaphragm type constant pressure pump 10, dissolving the ozone into the return water provided by the ozone air flotation device to obtain pressurized dissolved air water;

the obtained pressurized dissolved air water is sent to an ozone air flotation device for decompression and release.

Compared with the prior art, the invention has the beneficial effects that:

1. the diaphragm type constant pressure pump is a core dissolved gas water supply system.

The diaphragm type constant pressure pump 10 provided by the invention has a simple structure, simplifies the prior production process, can fully mix gas and water, improves the generation efficiency of dissolved gas water, and reduces energy consumption.

2. The electromagnetic valve program control realizes water inlet, air inlet, dissolved air pressing and the release of the dissolved air water.

The diaphragm type ozone dissolving microbubble generation system II provided by the invention realizes the generation and release of dissolved air water through the synergistic action of the constant pressure pump 10 and the

electromagnetic valves

7, 8 and 9, and the synergistic process is shown in the following table:

operating conditions	Electromagnetic valve 7	Solenoid valve 8	Electromagnetic valve 9	Pump rod position
					Inflow water	Opening device	Closing device	Closing device	Suction lift	1
Intake air	Closing device	Opening device	Closing device	Suction lift							2
					Pressed dissolved air water	Closing device	Closing device	Closing device	Stroke	1
Releasing dissolved air water	Closing device	Closing device	Opening device	Stroke							2

3. The ozone air flotation zone I is controlled by one key through a water discharge electromagnetic valve 4.

The ozone floating zone I completes the functions of ozone oxidation, sterilization, coagulation, air floating, decoloration, deodorization and the like in a reactor, and also has the operation processes of water inlet, dissolved gas water inlet, slag discharge, water discharge, backflow water and the like. The reflux and dissolved gas water inlet are independent internal circulation systems, and the water inlet, the water discharge and the slag discharge are independent systems. The ozone air flotation zone I controls water inlet, water discharge and slag discharge through a water discharge electromagnetic valve 4 by one key. And under the condition that the electromagnetic valve is opened, water is normally fed and drained. And under the condition that the electromagnetic valve is closed, the water inlet pump is started to realize the liquid level rising and slag discharging processes. After the slag discharge is finished, the electromagnetic valve 4 is opened, and the ozone air flotation system enters a normal operation state. The opening of the electromagnetic valve is controlled by a time relay, the running time is 0.5-3h according to the size of the system, and the deslagging time interval is set to be 50-300 s.

In conclusion, the invention changes the dissolved air flotation which is characterized by the prior air compressor and the dissolved air tank, and finishes the processes of water inlet, air inlet, generation and release of the dissolved air water and the like in a diaphragm type constant pressure pump. When the dissolved gas water is released, the pressure is in direct proportion to the stroke of the pump rod; under the condition of a certain stroke, the pressure is in a constant state, and a stable pressure slow release source is provided for the decompression and release of the gas dissolving water, so that ozone micro-bubbles with relatively consistent diameters are obtained. Compared with the conventional microbubble generation system, the ozone microbubble generation process provided by the invention reduces the air compressor, the dryer, the dissolved air pump and the pressure dissolved air tank, and has the advantages of simple flow, more simplification of the system, less energy consumption and more simplicity and convenience in operation.

Drawings

Fig. 1 is a schematic structural diagram of an ozone floatation device for supplying air to a constant-pressure microbubble generator.

Fig. 2 is a structural view of a diaphragm type constant pressure pump according to the present invention.

Detailed Description

The present invention will now be described with reference to the accompanying drawings, which are given by way of illustration and explanation only and should not be construed as limiting the scope of the present invention in any way.

As shown in fig. 1, the ozone floatation device for supplying air to the constant-pressure microbubble generator of the present invention comprises an ozone floatation area I, a diaphragm type constant-pressure dissolved ozone microbubble generator II and an ozone generation system iii. The ozone air floating area I is a water treatment area and realizes an ozone air floating process and is connected with a water inlet pipe 1, a dissolved air pipe 2, a slag discharge pipe 5, a return pipe 6 and a water outlet pipe 3 with a water outlet electric valve 4. In the hardware structure, including outer barrel and interior barrel, interior barrel is total with outer barrel at the bottom, and the highly being less than outer barrel of interior barrel, and inlet tube 1 and dissolved air pipe 2 are connected in the bottom of interior barrel, and outlet pipe 3 sets up between outer barrel and interior barrel, wears out outer barrel, and back flow 6 sets up at outer barrel lateral wall, is located the top of outlet pipe 3, and slag pipe 5 sets up the top at ozone air supporting district I.

Raw water and PAC are mixed and then enter the inner cylinder body through the water inlet pipe 1, and are fully mixed with ozone air dissolved water from the air dissolved pipe 2. At this time, the ozone oxidizes and decomposes the pollutants in the water into small molecular substances by using strong oxidizing property. Under the catalytic action of metal ions Al, ozone molecules are decomposed to generate a large number of hydroxyl radicals, and the hydroxyl radicals have strong oxidizability and no selectivity in oxidation, so that dissolved organic matters in water are further carbonized and removed. The coagulant in the raw water traps suspended particles and partial oxidation products in the water to form large flocs, the flocs move upwards under the action of micro bubbles to form scum, and the water moves downwards to obtain clarified effluent. And the intermittent operation of slag discharge and operation is realized by opening and closing the water outlet electric valve 4.

The core of the constant-pressure ozone dissolved microbubble generating device II is a diaphragm type constant-pressure pump 10. The water inlet of the diaphragm type constant pressure pump 10 is connected with a water inlet electromagnetic valve 7, and the water inlet electromagnetic valve 7 is connected with a return pipe 6. An air inlet of the diaphragm type constant pressure pump 10 is connected with an air inlet electromagnetic valve 8, and the air inlet electromagnetic valve 8 is connected with an ozone air pipe. The water outlet of the diaphragm type constant pressure pump 10 is connected with a water outlet electromagnetic valve 9, and the water outlet electromagnetic valve 9 is connected with a dissolved air pipe of the ozone air flotation device. The pump rod 103 of the diaphragm type constant pressure pump 10 is connected to the eccentric wheel of the motor 11. The return pipe 6 to the gas dissolving pipe 2 forms an independent closed loop system. The air inlet, water inlet and dissolved air water generation and discharge are realized by the combination control of a Programmable Logic Controller (PLC) on a water inlet electromagnetic valve 7, a water inlet electromagnetic valve 8 and a water outlet electromagnetic valve 9.

Firstly, the water outlet electromagnetic valve 9 is closed, the air inlet electromagnetic valve 8 is closed, the water inlet electromagnetic valve 7 is opened, the pump rod 103 opens the first section of the suction stroke, the circulating water enters the water-gas mixing chamber 104 through the return pipe 6, and the entering amount accounts for 80-90% of the volume of the water-gas mixing chamber 104. Secondly, the water outlet electromagnetic valve 9 is closed, the water inlet electromagnetic valve 7 is closed, the air inlet electromagnetic valve 8 is opened, the pump rod 103 opens the second section of the suction stroke, and ozone air enters the water-air mixing chamber 104 to fill the whole space. Then, the water inlet solenoid valve 7, the air inlet solenoid valve 8 and the water outlet solenoid valve 9 are closed, the pump rod 103 opens for the first section of the stroke, the pressure is transmitted to the diaphragm 101 by the hydraulic oil in the hydraulic chamber 102, and the diaphragm 101 moves towards the water-air mixing chamber 104. Under the huge pressure (0.4-0.8Mpa), the ozone air is dissolved into the circulating water to generate ozone-dissolved air water. And finally, opening the water outlet electromagnetic valve 9, closing the water inlet electromagnetic valve 7 and the air inlet electromagnetic valve 8, opening the pump rod 103 in the second section of the stroke under the action of the motor 11, and allowing 80-90% of ozone-dissolved air water to enter the ozone air floating device through the air dissolving pipe 2. In the ozone flotation device, dissolved ozone air is released into a water body due to a pressure reduction, while a large amount of fine bubbles are generated.

The micro bubbles with huge number make the gas solution of dissolved gas appear milk white in appearance and disperse uniformly into water in the form of cloud, because the floating speed of the micro bubbles in water is very slow, the bubbles can stably exist for 3-6min after stopping gas supply and disappear after stopping gas supply, when the gas flow is 1L/min, the gas content of the micro bubble system is measured to be nearly 2 times of that of the bubbling system, an underwater camera is adopted to measure the particle size of the bubbles, and the average diameter, the bubble density and the specific surface area of the bubbles are respectively 48 mu m and 3.9 × 10 after processing 1000 bubbles and calculating⁴Pieces/ml and 364/m. Because the particle size of the bubbles is small, the specific surface area and the number of the bubbles in the unit volume of the solution are very large,the mass transfer efficiency of the ozone air can be obviously improved.

The system ozone generating system III mainly comprises an ozone generator 13, an oxygen tank 14 and an ozone-air mixed gas flow regulating valve 12. The concentration of ozone in the oxygen source ozone generator is 80-100mg/L, which is nearly 4 times of that of the air ozone generator, and under the condition of the same air quantity, the oxidation removal quantity can be enhanced. The flow regulating valve 12 is adjusted to control the flow of the ozone air to the most appropriate degree, and the air quantity and the operating cost can be saved.

In the invention, the hydraulic retention time in the ozone flotation device is 40-50min, the coagulant adding amount is 50-100mg/L, the reflux ratio is 20-40%, the gas-liquid ratio is 1:9-10, the ozone concentration is 80-100mg/L, the working frequency of the diaphragm constant pressure pump is 30-90spm, and the stroke length is 20-40 mm.

Claims

1. An ozone air-floating device using constant pressure microbubble generator to supply air comprises:

the ozone air flotation area I is a water treatment area and is used for realizing an ozone air flotation process, a water inlet pipe (1), a dissolved air pipe (2), a slag discharge pipe (5), a return pipe (6) and a water outlet pipe (3) with a water outlet electric valve (4) are connected, and the intermittent operation of slag discharge and operation is realized by opening and closing the water outlet electric valve (4);

the diaphragm type constant-pressure dissolved ozone microbubble generator II mainly comprises a water inlet electromagnetic valve (7), a water inlet electromagnetic valve (8), a water outlet electromagnetic valve (9), a diaphragm type constant-pressure pump (10) and a motor (11), wherein deeply-treated water discharged from a return pipe (6) enters a cavity of the diaphragm type constant-pressure pump (10) through the water inlet electromagnetic valve (7), ozone-air mixed gas enters the cavity of the diaphragm type constant-pressure pump (10) through the water inlet electromagnetic valve (8), the motor (11) drives a pump rod (103) of the diaphragm type constant-pressure pump (10) to make stroke motion, the ozone-air mixed gas is dissolved into water under a pressurization condition, and pressure dissolved gas water enters an ozone gas floating area I through the water outlet electromagnetic valve (9) and a dissolved gas pipe (2) to be decompressed and released;

it is characterized in that the preparation method is characterized in that,

the cavity of the diaphragm type constant pressure pump (10) is divided by a diaphragm (101), wherein the space on the same side of a pump rod (103) is a hydraulic chamber (102), the space on the other side of the pump rod is a water-gas mixing chamber (104), the hydraulic chamber (102) is filled with a hydraulic agent, the pressure of the pump rod (103) is transmitted to the diaphragm (101) through the hydraulic agent, and the diaphragm (101) transmits the pressure to gas and liquid in the water-gas mixing chamber (104), so that ozone-air mixed gas is dissolved in water to generate pressure dissolved gas water;

the suction stroke of a pump rod (103) of the diaphragm type constant pressure pump (10) is divided into 2 steps, wherein in the first step, a water outlet electromagnetic valve (9) and an air inlet electromagnetic valve (8) are closed, a water inlet electromagnetic valve (7) is opened, and 80-90% of the space in a water-air mixing chamber (104) is filled; secondly, closing the water inlet electromagnetic valve (7) and the water outlet electromagnetic valve (9), opening the air inlet electromagnetic valve (8), and filling the ozone-air mixed gas into the water-air mixing chamber (104);

the stroke of a pump rod (103) of the diaphragm type constant pressure pump (10) is divided into 2 steps, firstly, a water inlet electromagnetic valve (7), a water inlet electromagnetic valve (8) and a water outlet electromagnetic valve (9) are closed, the pump rod (103) carries to occupy 10-20% of the space of a hydraulic chamber (102), and ozone-air mixed gas is dissolved into water through pressure conduction to form a gas-water mixture of pressure dissolved gas-water; and secondly, opening a water outlet electromagnetic valve (9), closing a water inlet electromagnetic valve (7) and an air inlet electromagnetic valve (8), carrying and extruding 80-90% of gas-water mixture in a gas-water mixing chamber (104) by a pump rod (103), and then sequentially circulating to work to obtain constant-pressure dissolved ozone microbubbles.

2. The apparatus as claimed in claim 1, wherein the ozone floating device comprises an outer cylinder and an inner cylinder, the inner cylinder and the outer cylinder are at the same bottom, the inner cylinder is shorter than the outer cylinder, the water inlet pipe (1) and the dissolved air pipe (2) are connected to the bottom of the inner cylinder, the water outlet pipe (3) is arranged between the outer cylinder and the inner cylinder and penetrates out of the outer cylinder, the return pipe (6) is arranged on the side wall of the outer cylinder and is located above the water outlet pipe (3), and the slag discharge pipe (5) is arranged at the top of the ozone floating region I.

3. The ozone floatation device for supplying air by using the constant-pressure microbubble generator as claimed in claim 1, wherein the ozone generation area iii mainly comprises a flow control valve (12), an ozone generator (13) and an oxygen tank (14), and ozone-air mixed gas generated by the ozone generator (13) enters the cavity of the diaphragm type constant pressure pump (10) through the flow control valve (12) and the air inlet solenoid valve (8), so that the ozone concentration is increased to meet the required ozone consumption amount in the case of reducing the air supply amount.

4. The ozone floatation device for supplying air using a constant-pressure microbubble generator according to claim 3, characterized in that the ozone generator (13) is provided with a cooling water circulation system.

5. The ozone floatation device using constant pressure microbubble generator to supply air of claim 1, wherein in the diaphragm type constant pressure dissolved ozone microbubble generation system ii, when the pressure dissolved air water enters the ozone floatation region I through the dissolved air pipe (2) under the action of high pressure and is released, the stable pressure is instantaneously released, and the gas dissolved in the water forms a large number of microbubbles with the diameter of 30-50 μm.

6. The apparatus of claim 1, wherein the membrane type constant pressure ozone microbubble generator II is supplied with water from a pressure dissolved air water source by clean water generated in the bottom region of the ozone flotation region I.