CN215975376U

CN215975376U - Ultrasonic air floatation method and photooxidation fracturing flow-back liquid integrated treatment equipment

Info

Publication number: CN215975376U
Application number: CN202121614895.XU
Authority: CN
Inventors: 王富华; 孙泽壮; 时贤; 张卫东
Original assignee: China University of Petroleum East China
Current assignee: China University of Petroleum East China
Priority date: 2021-07-15
Filing date: 2021-07-15
Publication date: 2022-03-08
Anticipated expiration: 2031-07-15

Abstract

The utility model provides an integrated treatment device for ultrasonic air flotation and photooxidation fracturing backflow liquid, which comprises a shell and is characterized in that an inclined baffle is arranged in the shell, the inclined baffle divides the shell into a cavitation air flotation area and a photooxidation area, the lower part of the cavitation air flotation area is provided with a sludge area and a sludge discharge pipe, the side part of the cavitation air flotation area is connected with a water inlet pipe, the water inlet pipe is provided with an ozone air inlet and a hydraulic cavitation device, an ultrasonic transducer is arranged in the cavitation air flotation area, the top of the shell is provided with a slag scraping plate, a slag discharge groove and a slag discharge pipe, and the lower part of the photooxidation area is provided with a water outlet pipe and a sludge discharge pipe. And a photocatalytic clapboard and an ultraviolet lamp light tube are arranged in the photocatalytic oxidation zone. The utility model has the advantages that the hydrodynamic cavitation device and the ultrasonic cavitation device are integrated, thereby solving the problem that the air floatation device generates unstable micro bubbles; and the treatment equipment combines hydrodynamic cavitation, ultrasonic wave, ozone catalysis and photocatalysis, so that the degradation rate of organic matters is improved.

Description

Ultrasonic air floatation method and photooxidation fracturing flow-back liquid integrated treatment equipment

Technical Field

The utility model belongs to the technical field of harmless treatment equipment for fracturing flow-back fluid, and particularly relates to treatment equipment integrating an ultrasonic air floatation method and photooxidation fracturing flow-back fluid.

Background

Since the success of hydraulic fracturing technology in the united states trials in 1947, which has progressed from a simple low-emission fracturing stimulation mode to a mature stimulation technology, a research by the american oil company has shown that without hydraulic fracturing, the gas production in the united states will drop by 57% and the oil production will drop by 23% in the future 10 years. Comprehensive data based on multiple databases indicates that from 2012 to 2014, the united states produced shale gas by hydraulic fracturing techniques with water volumes as high as 1.16 million cubic meters per year and produced similar quantities of frac flowback fluid.

The fracturing flow-back fluid contains various chemical additives, salt, heavy metal, radionuclide, crude oil, natural gas compound, natural organic matter and the like extracted from a reservoir stratum, so that the fracturing flow-back fluid has the characteristics of complex pollutant components, high stability, high toxicity and the like. And the fracturing flow-back fluid also has the characteristics of large flow-back volume, high viscosity, poor water quality color, long flow-back time and the like, so that the fracturing flow-back fluid has higher harmless treatment difficulty.

In the field treatment of the fracturing flow-back fluid, the air floatation technology is most widely applied as a pretreatment method. Compared with a centrifugal machine, a hydrocyclone and a flat separator, the air floatation technology can better separate fine particles and grease, and has the advantages of small occupied area of equipment and devices, low requirement on oil density and the like. The basic principle is that gas is introduced into the fracturing flow-back fluid and floats upwards in the form of tiny bubbles under the influence of gravity, and as the surface of hydrophobic pollutants in the fracturing flow-back fluid is easy to be attached with bubbles, the pollutants such as grease, suspended particles and the like in the fracturing flow-back fluid are attached to the bubbles and float upwards to the water surface along with the bubbles to form foam-gas, water and particle (oil) three-phase mixture scum, and the scum is scraped by a scum board to achieve the purpose of separating the pollutants.

The power ultrasound refers to the ultrasound with the ultrasonic frequency of 20 kHz-100 kHz, and a series of physiological and biochemical effects can be generated when the power ultrasound acts on water. The main effect in the application of ultrasonic treatment of fracturing flow-back fluid is cavitation, and the basic principle is that micro bubbles existing in liquid vibrate under the action of a sound field, when sound pressure reaches a certain value, the bubbles rapidly expand and then close, shock waves are generated when the bubbles close, and finally collapse. The local high temperature formed by cavitation reaches 5000K, the pressure reaches 50MPa, so that water vapor is subjected to split and chain reaction to generate hydroxyl free radicals, and the hydroxyl free radicals are subjected to oxidation reaction with organic matters which are difficult to volatilize and are degraded into water and micromolecular substances.

The photocatalysis method is a method which has low cost, environmental protection and mild reaction condition and can effectively remove pollutants in the fracturing flow-back fluid. The degradation mechanism is as follows: under the excitation of light, the photocatalytic material generates electrons and holes, then the holes are combined with hydroxyl radicals to generate hydroxyl radicals, the electrons are combined with oxygen to generate superoxide radicals, and the two radicals have strong oxidizability and can oxidize organic pollutants adsorbed on the surface of the photocatalytic material into inorganic micromolecules such as carbon dioxide, water and the like, so that the aim of purifying waste water is fulfilled.

However, the existing ultrasonic air flotation device also has the problems of too low bubble generation rate, large bubbles and unobvious demulsification and separation effects; and the harmless treatment of the fracturing flow-back fluid has the defects of complex process, wide occupied area of equipment, high energy consumption, high maintenance frequency and the like.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide the integrated treatment equipment combining the ultrasonic air floatation method and the photooxidation fracturing flow-back fluid, which has the advantages of simple structure, convenient use and operation, no pollution, high energy utilization rate and obvious COD and grease removal effect.

In order to achieve the purpose, the utility model provides the following technical scheme:

the utility model provides an ultrasonic air floatation method combines photooxidation fracturing to return processing apparatus of flowing back integration, includes the casing, its characterized in that be equipped with oblique baffle in the casing, oblique baffle separates the casing for cavitation air floatation district and photocatalytic oxidation district, cavitation air floatation district and photocatalytic oxidation district pass through the upper portion intercommunication, cavitation air floatation district lower part is equipped with mud district, mud pipe, cavitation air floatation district lateral part and water piping connection, the inlet tube is equipped with ozone air inlet, hydrodynamic cavitation device, the inside ultrasonic transducer that is equipped with of cavitation air floatation district, the casing top is equipped with scum board, slag groove, slag pipe, photocatalytic oxidation district lower part is equipped with outlet pipe, mud pipe. And a photocatalytic clapboard and an ultraviolet lamp tube are arranged in the photocatalytic oxidation area.

Further, the casing is cylindrical, and the material is the carbon steel, vertical installation, has stronger mobility, area is less.

Further, the hydrodynamic cavitation device is a venturi tube, the venturi tube comprises an inlet section, an outlet section and a contraction section which are 20cm in length respectively, a throat part with the length of 1mm and a diffusion section with the length of 70mm, wherein the contraction angle alpha is 15 degrees; the diffusion angle θ is 7 °.

Furthermore, the inclined angle of the inclined baffle is 60-80 degrees, so that the fracturing flow-back fluid can form a rotational flow, and the polymerization of micro bubbles and grease is promoted.

Further, the ultrasonic transducer is connected with an ultrasonic generator outside the shell through an ultrasonic terminal.

Further, the ultrasonic transducers are arranged in a ring shape and fixed in parallel in the axial direction, and 8 ultrasonic transducers are uniformly arranged along the circumference.

Furthermore, the ultrasonic frequency of the ultrasonic transducer is 20-60 kHz, and the ultrasonic power is 150-300W.

Furthermore, the scum board is driven by the scum motor to rotate, the scum groove is used for collecting scum generated by the rotation of the scum board and discharging the scum outwards through the scum pipe, the scum board is made of carbon steel, the scum speed is 0.02m/s, and the scum motor power is 0.75-2.5 kW.

Further, the photocatalytic oxidation area comprises at least one photocatalytic clapboard axially fixed in parallel to the shell, the photocatalytic clapboard comprises a substrate and photocatalytic layers arranged on the surfaces of two sides of the substrate, a flow channel is formed between every two adjacent photocatalytic clapboards, and the adjacent photocatalytic clapboardsAn ultraviolet lamp tube is arranged between the two, the power of the ultraviolet lamp tube is 150W-200W, and the fracturing flow-back fluid passes through ozone and a photocatalytic oxidant TiO₂After the co-treatment, the organic pollutants adsorbed on the surface of the photocatalytic barrier 16 are oxidized into inorganic small molecules such as carbon dioxide and water.

The utility model has the advantages and positive effects that:

1. is scientific and efficient. The hydraulic cavitation device and the ultrasonic device can simultaneously generate a large number of micro bubbles with small diameter, high air floatation efficiency and strong controllability. Meanwhile, the cavitation effect generated by the ultrasonic wave can improve the efficiency of oxidizing the organic matters in the fracturing flow-back fluid by ozone, and the COD value in the fracturing flow-back fluid is greatly reduced by combining the photocatalytic oxidation effect.

2. Is economical and environment-friendly. Ozone introduced into the treatment equipment can generate micro bubbles for air floatation treatment, and can also be coupled with ultrasonic waves and ultraviolet light to oxidize and fracture pollutants in the flowback fluid, so that the ozone utilization rate is improved, and the treatment cost is reduced.

3. Simple process and small occupied area. The air flotation technology and the advanced oxidation technology are mature technologies in sewage treatment, and the technology can be applied to the treatment of fracturing flow-back liquid. Secondly, the three technologies can be coupled according to the principles of different technologies, the designed integrated treatment equipment can treat the fracturing flow-back fluid with high efficiency and low energy, and the treatment equipment has simple process and small occupied area.

Description of the drawings:

FIG. 1 is a schematic view of an integrated treatment device for flowback liquid by combining ultrasonic air floatation and photooxidation fracturing

FIG. 2 schematic diagram of hydrodynamic cavitation apparatus

The device comprises an ozone inlet 1, an ozone inlet 2, a water inlet pipe 3, a hydrodynamic cavitation device 4, a sludge area 5, a sludge discharge pipe 6, a cavitation air flotation area 7, an ultrasonic terminal 8, an ultrasonic transducer 9, a shell 10, a slag scraping plate 11, a slag scraping motor 12, a slag discharge groove 13, a slag discharge pipe 14, a photocatalytic oxidation area 15, an ultraviolet lamp tube 16, a photocatalytic partition plate 17, an inclined baffle plate 18, a water outlet pipe 19, a sludge discharge pipe 20, an inlet section 21, a contraction section 22, a throat passage 23, a diffusion section 24 and an outlet section.

The specific implementation mode is as follows:

the present invention will be described in further detail with reference to the accompanying drawings.

An integrated treatment device of ultrasonic air-float method and photooxidation fracturing flow-back liquid, as shown in figure 1, the treatment equipment comprises a shell 9, an inclined baffle 17 is arranged in the shell 9, the inclined baffle 17 divides the shell 9 into a cavitation air flotation zone 6 and a photocatalytic oxidation zone 14, specifically, the upper parts of the cavitation air flotation zone 6 and the photocatalytic oxidation zone 14 are communicated, the lower part of the cavitation air flotation zone 6 is provided with a sludge zone 4 and a sludge discharge pipe 5, the side part of the cavitation air flotation zone 6 is connected with a water inlet pipe 2, the water inlet pipe 2 comprises an ozone inlet 1 and a hydrodynamic cavitation device 3, an ultrasonic transducer 8 is arranged in the cavitation air flotation zone 6, the top of the shell 9 is provided with a slag scraping plate 10 and a slag discharging groove 12, the lower part of the photocatalytic oxidation area 14 is provided with a water outlet pipe 18 and a sludge discharging pipe 19, the photocatalytic oxidation area 14 is internally provided with a photocatalytic clapboard 16 and an ultraviolet lamp tube 15.

The shell 9 is made of carbon steel in a cylindrical shape, is vertically installed, and has high mobility and small occupied area.

The inlet tube 2 is the tangential distribution pipe, and the fracturing is returned flowing back and is followed inlet tube 2 entering cavitation air flotation district 6, at the inside hydrodynamic cavitation device 3 that is equipped with of inlet tube 2, and wherein hydrodynamic cavitation device 3 is venturi tube, hydrodynamic cavitation device 3 includes inlet section 20, contraction section 21, throat 22, diffuser 23, export section 24, inlet section 20 and export section 24 length are 20cm, the diameter is 4 mm's pipeline, return flowing back in venturi tube's entry outlet department steady flow for the fracturing, contraction section 21 length is 20mm, and throat 24 length is 1mm, and the diameter is 1mm, and diffuser 23 length is 70mm, and the contraction angle alpha is 15, and diffusion angle theta is 7. The upper portion of inlet tube 2 is equipped with ozone air inlet 1 for ozone is blown into to the casing, and wherein ozone concentration is 10 ~ 40 mg/L.

The sludge zone 4, which settles sludge under gravity separation. The sludge discharge pipe 5 is used for discharging sludge.

The inclined baffle 17 is designed to be vertical at the upper end, the inclined design at the lower end is realized, and the inclined plane is 60-80 degrees in the horizontal plane, so that the fracturing backflow liquid can form a rotational flow, and the polymerization of micro bubbles and grease is promoted.

Ultrasonic transducer 8 links to each other with the outer supersonic generator of casing through ultrasonic wave wiring end 7, and wherein 6 upper portions in cavitation air supporting district are provided with 2 sets of ultrasonic transducer 8, adopt the annular to arrange and axial direction parallel is fixed, and every group evenly arranges 12 ultrasonic transducer along the circumference of surveying in cavitation air supporting district 6, 8 ultrasonic frequency of ultrasonic transducer are 20 ~ 60kHz, and ultrasonic power is 150 ~ 300W. The cavitation air floating zone 6 can utilize an ultrasonic transducer to generate ultrasonic cavitation, and is combined with cavitation generated by a hydraulic cavitation device to generate ultramicro bubbles to convey scum such as grease, suspended particles and the like in the fracturing flow-back fluid to the scum board 10.

The slag scraping plate 10 is driven to rotate by a slag scraping motor 11, the slag discharging groove 12 is used for collecting scum generated by rotation of the slag scraping plate 4 and discharging the scum outwards through a slag discharging pipe 13, the slag scraping plate 10 is made of carbon steel, the slag scraping speed is 0.02m/s, and the power of the slag scraping motor 11 is 0.75-2.5 kw. The fracturing flow-back fluid flows to the photocatalytic oxidation zone 14 after being treated by the slag scraping zone at the top of the shell 9.

The photocatalytic oxidation area 14 comprises at least one photocatalytic clapboard 16 which is axially fixed in parallel to the shell 9, the photocatalytic clapboard 16 comprises a substrate and photocatalytic layers which are arranged on the surfaces of two sides of the substrate, a flow channel is formed between every two adjacent photocatalytic clapboards 16, an ultraviolet lamp tube 15 is arranged between every two adjacent photocatalytic clapboards 16, the power of the ultraviolet lamp tube is 150-200W, and the fracturing backflow liquid passes through ozone and photocatalytic oxidant TiO₂After the co-treatment, the organic pollutants adsorbed on the surface of the photocatalytic partition plate 16 are oxidized into inorganic micromolecules such as carbon dioxide, water and the like, the treated fracturing flow-back fluid is discharged through a water outlet pipe 18, and a small amount of sludge is settled in the photocatalytic oxidation area 14 under the action of gravity and is discharged through a sludge discharge pipe 19.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides an ultrasonic air floatation method combines photooxidation fracturing to return processing apparatus of flowing back integration, includes the casing, its characterized in that be equipped with oblique baffle in the casing, oblique baffle separates the casing for cavitation air floatation district and photocatalytic oxidation district, cavitation air floatation district and photocatalytic oxidation district pass through the upper portion intercommunication, cavitation air floatation district lower part is equipped with mud district, mud pipe, cavitation air floatation district lateral part and water piping connection, the inlet tube is equipped with ozone air inlet, hydrodynamic cavitation device, inside ultrasonic transducer that is equipped with of cavitation air floatation district, the casing top is equipped with scum board, slag groove, slag pipe, photocatalytic oxidation district lower part is equipped with outlet pipe, mud pipe, inside photocatalysis baffle, the ultraviolet tube of being equipped with of photocatalytic oxidation district.

2. The integrated treatment equipment for the ultrasonic air floatation method and the photooxidation fracturing flow-back fluid as claimed in claim 1, wherein the shell is cylindrical, is made of carbon steel and is vertically installed.

3. The integrated treatment equipment for the ultrasonic air flotation method and photooxidation fracturing flow-back fluid as claimed in claim 1, wherein the hydraulic cavitation device is a venturi tube, the composition structure of the venturi tube comprises an inlet section, an outlet section and a contraction section which are 20cm in length respectively, a throat part with the length of 1mm and a diffusion section with the length of 70mm, wherein the contraction angle α is 15 °; the diffusion angle θ is 7 °.

4. The integrated treatment equipment for the ultrasonic air floatation method and the photooxidation fracturing flow-back fluid as claimed in claim 1, wherein the inclined baffle has an inclination angle of 60-80 °.

5. The integrated treatment equipment for the ultrasonic air flotation method and the photooxidation fracturing flow-back fluid as claimed in claim 1, wherein the ultrasonic transducer is connected with an ultrasonic generator outside the shell through an ultrasonic terminal, the ultrasonic transducer is fixed in an annular arrangement and an axial parallel manner, 8 ultrasonic transducers are uniformly arranged along the circumference, the ultrasonic frequency of the ultrasonic transducer is 20-60 kHz, and the ultrasonic power is 150-300W.

6. The integrated treatment equipment for the ultrasonic air-float process and photooxidation fracturing flow-back fluid as claimed in claim 1, wherein the scum board is driven to rotate by a scum motor, the scum groove is used for collecting scum from the scum board rotation and discharging the scum outwards through a scum pipe, the scum board is made of carbon steel, the scum speed is 0.02m/s, and the scum motor power is 0.75-2.5 kW.

7. The integrated treatment equipment for the ultrasonic air floatation process and the photooxidation fracturing flow-back fluid in combination as claimed in claim 1, wherein the photocatalytic oxidation zone comprises at least one photocatalytic partition board axially fixed in parallel to the housing, the photocatalytic partition board comprises a substrate and photocatalytic layers arranged on the two side surfaces of the substrate, a flow channel is formed between the adjacent photocatalytic partition boards, an ultraviolet lamp tube is arranged between the adjacent photocatalytic partition boards, and the power of the ultraviolet lamp tube is 150W-200W.