Rotational flow air flotation oil removal device and oil-water separation process

Abstract

The invention relates to the technical field of air flotation oil removal, and discloses a rotational flow air flotation oil removal device and an oil-water separation process. The rotational flow air flotation oil removal device comprises a tank body; the cyclone assembly is arranged in the tank body and comprises a cylinder body fixedly mounted in the tank body; the gas distribution assembly is coaxially arranged at the bottom of the mixing cavity; the gas distribution assembly comprises a gas distribution disc rotationally arranged at the bottom of the mixing cavity, a gas inlet pipe connected with the center of the bottom of the gas distribution disc in a penetrating mode, a plurality of sets of cylindrical gas holes formed in the radial direction of the gas distribution disc in an array mode, a plurality of sets of spiral cover plates covering the gas distribution disc and conical gas holes formed in the spiral cover plates and corresponding to the cylindrical gas holes. According to the rotational flow air flotation oil removal device, the air distribution disc is driven to rotate intermittently, so that the cylindrical air holes correspond to the conical air holes of the spiral cover plate alternately, tiny bubbles and large bubbles matched with oil drops with different particle sizes are generated, and effective capture of tiny oil drops and rapid separation of medium and large oil drops are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air flotation oil removal, and particularly relates to a cyclone air flotation oil removal device and an oil-water separation process. BACKGROUND

[0002] The cyclone air flotation oil removal device is a high-efficiency oil-water separation device integrating cyclone separation technology and air flotation separation technology, and is widely applied to oil-containing wastewater treatment scenes in the fields of petroleum chemical industry, steel metallurgy, and oil-containing wastewater of ships. In the specific working process, the oil-containing wastewater forms a rotating flow field in the cyclone cavity, and oil droplets are gathered to the center of the cavity and water phase migrates to the cavity wall under the action of centrifugal force by using the density difference between oil phase and water phase, so that preliminary oil-water layering is completed. At the same time, the oil-containing wastewater is introduced into the air flotation tank, and air bubbles are introduced. The air bubbles adhere to the oil droplets and impurity floc in the wastewater by surface tension, form composite flocs with a density much smaller than water, and float to the surface of the wastewater under the action of Archimedes buoyancy.

[0003] The existing patent with the publication number CN115124104A discloses a cyclone air flotation oil removal system for oil-containing wastewater, which comprises a storage tank, a cyclone, a pressure gas dissolving tank, a bubble generator, an air compressor, and an air flotation oil removal tank. The storage tank is connected to the inlet of the cyclone through a first lifting pump, the outlet of the cyclone is connected to the inlet one of the pressure gas dissolving tank, the bubble generator is connected to the inlet two of the pressure gas dissolving tank through a second lifting pump, the air compressor is connected to the inlet three of the pressure gas dissolving tank, and the outlet of the pressure gas dissolving tank is connected to the air flotation oil removal tank through a third lifting pump. The top of the air flotation oil removal tank is provided with a through hole and a liquid collecting groove, and the liquid collecting groove is arranged around the peripheral wall of the air flotation oil removal tank and below the through hole. Although the above technical solution can remove oil by the cooperation of the cyclone and the air flotation oil removal tank, it has the advantage of reducing the corrosion of the treatment equipment.

[0004] In the prior art, the generation of air bubbles in the air flotation tank is mainly through the release of pressurized gas dissolved by the gas dissolving pump or directly into the wastewater through the gas hole structure of the aeration disc. However, the generated air bubbles are generally of a single size, or are micro-bubbles or large bubbles, which are difficult to adapt to the separation requirements of oil droplets of different particle sizes in oil-containing wastewater. If only micro-bubbles are used, although they can form effective adhesion with micro oil droplets in the wastewater, the slow rising speed of micro-bubbles and the weak disturbance of the wastewater result in the difficulty of fully mixing the demulsifier and flocculant in the wastewater with the oil-water emulsion, and part of the medium and large oil droplets are difficult to coalesce due to insufficient contact with air bubbles. If only large bubbles are used, although they can quickly carry medium and large oil droplets to the surface by large buoyancy, the specific surface area of the medium and large bubbles is significantly reduced, the collision contact probability with micro oil droplets is greatly reduced, and the problem of insufficient capture efficiency of micro oil droplets is caused. SUMMARY

[0005] The oil-water separation process and the oil removal device by cyclone air floatation provided by the application solve the problem of single bubble size in the existing air floatation tank, which cannot meet the separation requirements of oil droplets with different particle sizes in oily sewage.

[0006] The oil-water separation process and the oil removal device by cyclone air floatation provided by the application solve the problem of single bubble size in the existing air floatation tank, which cannot meet the separation requirements of oil droplets with different particle sizes in oily sewage. The oil removal device by cyclone air floatation comprises a tank body, an air injection pipe, a cyclone assembly, a liquid inlet pipe, a gas distribution assembly, a driving mechanism, a first oil outlet pipe, a liquid outlet pipe, a gas supplement pipe, a second oil outlet pipe and a water outlet pipe. The tank body is provided with an air injection pipe coaxially arranged on the inner wall of the bottom of the tank body. The air injection pipe is coaxially arranged on the inner wall of the bottom of the tank body. The cyclone assembly is arranged in the tank body and comprises a cylinder body fixedly installed in the tank body. The liquid inlet pipe is arranged on one side of the tank body and extends into the mixing cavity. The gas distribution assembly is coaxially arranged on the bottom of the mixing cavity. The driving mechanism is arranged on the bottom of the inner wall of the tank body and is used to drive the intermittent rotation of the gas distribution disc. The first oil outlet pipe is arranged on the top of the tank body and extends into the sludge collection cavity. The liquid outlet pipe is arranged in the sludge collection cavity close to the lower position. The gas supplement pipe is arranged on one side of the tank body. The second oil outlet pipe is arranged above one side of the tank body. The water outlet pipe is arranged below one side of the tank body.

[0007] Further, a plurality of guide vanes are arranged in the circumferential direction on the inner wall of the pre-rotation cavity.

[0008] Further, the driving mechanism comprises a motor installed on the bottom of the inner wall of the tank body, an incomplete gear fixedly connected with the output end of the motor and a driven gear engaged with the incomplete gear.

[0009] Further, the driving mechanism further comprises turbulence rods equidistantly distributed along the circumferential direction of the air distribution disc, the top of the turbulence rod is symmetrically provided with two groups of turbulence vanes, the bottom of the turbulence rod is fixedly connected with a pinion, and the circumferential edge of the upper surface of the air distribution disc is fixedly connected with a gear ring, the inner ring gear of the gear ring is engaged with the pinion. The inner wall of the mixing cavity is fixedly connected with a support frame corresponding to the turbulence rod, and the turbulence rod is rotationally connected with the support frame through a bearing.

[0010] Further, the inner diameter of the bottom of the conical air hole is equal to the inner diameter of the cylindrical air hole, and the inner diameter of the top of the conical air hole is smaller than the inner diameter of the cylindrical air hole.

[0011] Further, a plurality of groups of the cylindrical air holes are distributed in the form of multiple equidistant spiral lines along the radial direction of the air distribution disc.

[0012] Further, the guide vanes, the cyclone vanes and the steady flow vanes are arranged in an interval staggered manner.

[0013] Further, the guide vanes comprise an integrally formed arc segment and a vertical segment, and the vertical segment extends vertically downward to the junction of the pre-rotation cavity and the mixing cavity.

[0014] Further, the steady flow vanes comprise an integrally formed spiral segment and a radial segment, and the radial segment extends to the inside of the steady flow cavity.

[0015] A cyclone air flotation oil-water separation process adopts the cyclone air flotation oil removal device, and comprises the following steps. Step one: pretreating the oily sewage by coarse filtration or shallow sedimentation process to remove suspended particles and block impurities with large particle size in the water; Step two: adding a demulsifier and a flocculant to the pretreated oily sewage, and preliminarily stirring through a static mixer; Step three: sending the dosed oily sewage into a cylindrical cyclone, using the centrifugal force generated by the high-speed rotation of the cyclone tube to realize uniform mixing of the medicament and the oil-water emulsion, high-efficiency demulsification, and to push the micro oil droplets to coalesce to form large oil droplets, and preliminarily separate part of the floating oil, and the separated water phase is introduced into the tank; Step four: introducing the pressurized gas into the tank through the gas injection pipe to make the gas fully dissolve in the above-mentioned water phase to form high-concentration dissolved gas water; Step five: the pressure in the tank is suddenly reduced to promote the dissolved gas to precipitate to form bubbles, and the bubbles are closely adhered to the residual oil droplets and impurity floc particles in the water under the action of surface tension to form composite flocs with a density less than water; Step six: using the cyclone assembly in the tank to make the mixed liquid form a cyclone to prolong the contact time and migration path of the composite flocs and the bubbles; Step seven: the composite flocculation under the action of Archimedes buoyancy floats to the top of the tank body and forms a floating oil layer, which is discharged through the first oil outlet pipe; Step eight: the residual water phase in the cyclone assembly enters the annular area between the tank body and the cyclone assembly through the liquid outlet pipe, and the secondary gas floatation environment is formed by continuously injecting gas through the air supplement pipe, so that the residual oil droplets are further captured; Step nine: the oil dirt generated by the secondary gas floatation is discharged through the second oil outlet pipe, and the treated clean water is discharged through the water outlet pipe.

[0016] The beneficial effects of the present application are as follows: By setting the cyclone assembly, the air distribution assembly and the driving mechanism, the cylindrical air holes and the conical air holes of the spiral cover plate are alternately corresponding by driving the air distribution disc to rotate intermittently, so that the micro bubbles and the large bubbles suitable for different particle size oil droplets are generated, the effective capture of the micro oil droplets and the rapid separation of the medium and large oil droplets are realized, the adaptation range of the device to different oil-containing sewage is effectively improved, the problems of insufficient mixing and low capture efficiency caused by single bubble size are avoided, and the mixing chamber edge dead water area is eliminated by the synchronous rotation of the spoiler rod with the air distribution disc, the bubble agglomeration is dispersed, and the uniform mixing of the gas-liquid-oil three phases is further improved.

[0017] By setting the guide vane, the cyclone vane and the steady flow vane, the mixed liquid in the mixing chamber can be smoothly introduced into the pre-rotation cavity through the cooperation of the arc segment and the vertical segment of the guide vane, and a stable cyclone is formed, the reverse setting of the cyclone vane and the steady flow vane can gradually weaken the cyclone intensity of the mixed liquid, avoid the dispersed oil droplets caused by too strong cyclone, and at the same time, the migration path and time of the oil droplets and impurity flocculation in the mixed liquid are prolonged, the adhesion probability of the oil droplets and impurity flocculation and bubbles is increased, and the separation efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a three-dimensional structure schematic diagram of the present application; Figure 2 It is a front view structure cross section schematic diagram of the present application; Figure 3 It is a cylinder body three-dimensional structure cross section schematic diagram of the present application; Figure 4 It is a gas injection pipe and air distribution assembly three-dimensional structure cross section schematic diagram of the present application; Figure 5 It is an air distribution disc and spiral cover plate three-dimensional structure explosion schematic diagram of the present application; Figure 6 It is a spiral cover plate local three-dimensional structure cross section schematic diagram of the present application; Figure 7 It is an air distribution disc, air inlet pipe, spiral cover plate, conical air hole and driving mechanism three-dimensional structure schematic diagram of the present application; Figure 8This is a three-dimensional structural diagram of the air distribution plate, air inlet pipe, cylindrical air hole and drive mechanism of the present invention. Figure 9 This is a three-dimensional cross-sectional view of the drive mechanism of the present invention; Figure 10 This is a bottom view of the three-dimensional structure of the cylindrical body of the present invention; Figure 11 This is an exploded three-dimensional structural diagram of the guide vane, swirl vane, and flow stabilizer vane of the present invention.

[0019] In the picture: 1. Tank body; 2. Air injection pipe; 3. Swirl assembly; 31. Cylinder; 32. Mixing chamber; 33. Pre-swirling chamber; 34. Swirl chamber; 35. Flow stabilizing chamber; 36. Sludge collection chamber; 4. Liquid inlet pipe; 5. Air distribution assembly; 51. Air distribution plate; 52. Air inlet pipe; 53. Cylindrical air hole; 54. Spiral cover plate; 55. Conical air hole; 56. Connecting column; 57. L-shaped bracket; 6. Drive mechanism; 61. Motor; 62. Incomplete 63. Driven gear; 64. Baffle rod; 65. Baffle blade; 66. Pinion; 67. Gear ring; 68. Support frame; 7. First oil outlet pipe; 8. Liquid outlet pipe; 9. Air supply pipe; 10. Second oil outlet pipe; 11. Water outlet pipe; 12. Guide vane; 121. Arc-shaped section; 122. Vertical section; 13. Swirl blade; 14. Flow stabilizing blade; 141. Spiral section; 142. Radial section; 15. Air outlet pipe. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] Example 1, refer to Figures 1-2 The present invention provides a cyclone flotation oil removal device, including a tank 1 and an air injection pipe 2 coaxially disposed on the inner wall of the bottom of the tank 1, and further including: The swirl assembly 3 is installed inside the tank 1.

[0022] Specifically, refer to Figures 2-3 The swirl assembly 3 includes a cylindrical body 31 fixedly installed inside the tank 1. The cylindrical body 31 has a mixing chamber 32, a pre-swirl chamber 33, a swirl chamber 34, a flow stabilizing chamber 35, and a sludge collection chamber 36 that are sequentially opened from bottom to top. An annular area is formed between the inner wall of the tank 1 and the outer wall of the cylindrical body 31. The annular area is used to form a secondary air flotation environment, which can perform secondary treatment on the residual water phase and further improve the oil removal efficiency.

[0023] The inlet pipe 4 is located on one side of the tank body 1 and extends into the mixing chamber 32. The outlet end of the inlet pipe 4 faces the tangential direction of the inner wall of the mixing chamber 32, which is used to realize the tangential inlet of oily wastewater.

[0024] The air distribution assembly 5 is coaxially arranged at the bottom of the mixing chamber 32.

[0025] Specifically, referring to Figure 2 , Figures 4-6 and Figure 10 , the air distribution assembly 5 includes an air distribution disc 51 rotatably arranged at the bottom of the mixing chamber 32, an air inlet pipe 52 connected through the center of the bottom of the air distribution disc 51, a plurality of groups of cylindrical air holes 53 arranged in an array along the radial direction of the air distribution disc 51, a plurality of groups of spiral cover plates 54 covering the air distribution disc 51, and a plurality of groups of conical air holes 55 corresponding to the cylindrical air holes 53 and arranged on the spiral cover plates 54. Elastic diaphragms are arranged in the cylindrical air holes 53 and the conical air holes 55 to allow only airflow to pass through, thereby achieving a one-way sealing function. The inner diameter of the bottom of the conical air hole 55 is equal to the inner diameter of the cylindrical air hole 53, and the inner diameter of the top of the conical air hole 55 is smaller than the inner diameter of the cylindrical air hole 53. The plurality of groups of spiral cover plates 54 are fixedly connected through a connecting column 56, and the outer peripheral end of each group of spiral cover plates 54 is fixedly connected to the inner wall of the mixing chamber 32 through an L-shaped support 57. The air inlet pipe 52 extends into the gas injection pipe 2 and is rotatably connected to the bottom of the tank body 1 through a sealing bearing, allowing the air inlet pipe 52 to rotate in the gas injection pipe 2 while ensuring sealed delivery of the gas. Similarly, the air distribution disc 51 is rotatably connected to the bottom of the mixing chamber 32 through a sealing bearing, effectively sealing the bottom of the mixing chamber 32 and preventing leakage of the medium in the mixing chamber 32.

[0026] It should be noted that the plurality of groups of cylindrical air holes 53 are distributed in multiple circles of equidistant spiral lines along the radial direction of the air distribution disc 51. The cylindrical air holes 53 arranged in spiral lines can guide the gas to be discharged along a spiral path, thereby enhancing the shearing contact between the gas and the oil-contaminated water in the mixing chamber 32, promoting more uniform dispersion of the gas bubbles into the liquid, and avoiding local bubble concentration.

[0027] During use, when the air distribution disc 51 is intermittently rotated to make the cylindrical air holes 53 correspond to the conical air holes 55, the high-pressure gas delivered by the air inlet pipe 52 enters the inside of the air distribution disc 51 and then flows upwards along the cylindrical air holes 53 and subsequently enters the corresponding conical air holes 55. Since the inner diameter of the bottom of the conical air holes 55 is equal to the inner diameter of the cylindrical air holes 53, and the inner diameter of the top of the conical air holes 55 is smaller than the inner diameter of the cylindrical air holes 53, the gas flow is squeezed and accelerated in the conical air holes 55, and finally released in the form of high-speed jet from the top of the conical air holes 55, and broken into tiny bubbles. When the air distribution disc 51 is intermittently rotated to make the cylindrical air holes 53 misaligned with the conical air holes 55, the gas flow is directly discharged upwards from the cylindrical air holes 53, and at this time, large bubbles are formed and released. The tiny bubbles can fully contact the tiny oil droplets suspended in the water body, forming a stable composite flocculation structure, which is not easy to break due to flow field disturbance during the rising process, avoiding the re-dispersion of oil droplets into the water. The large bubbles can quickly carry medium and large oil droplets to float, and by using the alternating generation of the two kinds of bubbles, the problems of insufficient mixing and low trapping efficiency caused by single bubble size are avoided.

[0028] The driving mechanism 6 is arranged at the bottom of the inner wall of the tank body 1 and is used to drive the intermittent rotation of the air distribution disc 51.

[0029] Specifically, referring to Figures 7-8 , the driving mechanism 6 includes a motor 61 installed at the bottom of the inner wall of the tank body 1, an incomplete gear 62 fixedly connected with the output end of the motor 61, and a driven gear 63 engaged with the incomplete gear 62. The driven gear 63 is fixedly connected to the outer surface of the air inlet pipe 52. When the incomplete gear 62 drives the driven gear 63 to complete one rotation, the air distribution disc 51 rotates by a corresponding angle with the driven gear 63, and the cylindrical air holes 53 move between the two adjacent spiral cover plates 54, and the gas is directly discharged from the cylindrical air holes 53 without passing through the conical air holes 55, forming large bubbles. When the incomplete gear 62 drives the driven gear 63 to rotate by the same angle again, the air distribution disc 51 rotates by a corresponding angle with the driven gear 63 again, and the cylindrical air holes 53 correspond to the conical air holes 55 on the corresponding spiral cover plate 54, thereby realizing the alternating generation of tiny bubbles and large bubbles.

[0030] Further, referring to Figures 9-10The driving mechanism 6 further comprises turbulence rods 64 equidistantly distributed along the circumferential direction of the air distribution disc 51, the top of the turbulence rod 64 is symmetrically provided with two groups of turbulence vanes 65, the bottom of the turbulence rod 64 is fixedly connected with a pinion 66, the circumferential edge of the upper surface of the air distribution disc 51 is fixedly connected with a gear ring 67, the inner ring gear of the gear ring 67 is engaged with the pinion 66, and a gap exists between the gear ring 67 and the L-shaped support 57, so that when the air distribution disc 51 rotates, the gear ring 67 will not be in contact with the L-shaped support 57, and when the air distribution disc 51 rotates, the gear ring 67 will rotate together, and the engagement between the gear ring 67 and the pinion 66 enables the turbulence rod 64 and the turbulence vane 65 to rotate synchronously, wherein the turbulence vane 65 is inclined, and can disturb the mixed liquid in the edge region of the mixing chamber 32 during rotation, thereby avoiding the formation of a dead water region in the edge region, and also dispersing the bubbles gathered in the edge region, so that the gas, liquid and oil in the edge region and the central region of the mixing chamber 32 can be efficiently mixed.

[0031] The inner wall of the mixing chamber 32 is fixedly connected with a support frame 68 corresponding to the turbulence rod 64, and the turbulence rod 64 is rotatably connected with the support frame 68 through a bearing, and the support frame 68 provides support for the turbulence rod 64.

[0032] Wherein, referring to Figures 1-2 The top of the tank body 1 is provided with a first oil outlet pipe 7, the first oil outlet pipe 7 extends into the sewage collecting chamber 36, the inlet end of the first oil outlet pipe 7 is close to the top of the sewage collecting chamber 36, and is used for discharging the accumulated floating oil in the sewage collecting chamber 36.

[0033] The lower part of the sewage collecting chamber 36 is provided with a liquid outlet pipe 8, the liquid outlet pipe 8 is arrayed along the circumferential direction of the sewage collecting chamber 36, and the outlet end of the liquid outlet pipe 8 is located in the annular region formed between the tank body 1 and the cylinder body 31, and is used for guiding the residual water phase in the sewage collecting chamber 36 after treatment to be discharged for secondary flotation.

[0034] One side of the tank body 1 is provided with a gas supplement pipe 9, the gas outlet end of the gas supplement pipe 9 penetrates into the annular region formed between the tank body 1 and the cylinder body 31, and the gas supplement pipe 9 is provided with a one-way valve, which is used for supplementing high-pressure gas into the annular region.

[0035] The top of one side of the tank body 1 is provided with a second oil outlet pipe 10, the second oil outlet pipe 10 penetrates through the side wall of the tank body 1 and communicates with the annular region, and is used for discharging the secondary floating oil floating in the annular region.

[0036] The lower part of one side of the tank body 1 is provided with a water outlet pipe 11, the water outlet pipe 11 penetrates through the side wall of the tank body 1 and communicates with the annular region, and the water outlet pipe 11 is provided with a flow control valve, which is used for discharging the finally treated clean water.

[0037] The top of the tank body 1 is further provided with a gas outlet pipe 15, which is used for discharging the accumulated gas in the tank body 1.

[0038] Further, with reference to Figure 2 and Figure 11 The inner wall of the pre-rotation cavity 33 is provided with a plurality of groups of guide vanes 12 in the circumferential direction. Specifically, the guide vanes 12 include an arc-shaped section 121 and a vertical section 122. The vertical section 122 extends vertically downward to the junction of the pre-rotation cavity 33 and the mixing cavity 32. The curvature of the arc-shaped section 121 is adapted to the inner wall of the pre-rotation cavity 33, so as to guide the mixed liquid along an arc-shaped path. The vertical section 122 can directly guide the mixed liquid discharged from the mixing cavity 32, so as to smoothly transition the mixed liquid from the mixing cavity 32 into the pre-rotation cavity 33.

[0039] The inner wall of the pre-rotation cavity 33 is provided with a plurality of groups of guide vanes 12 in the circumferential direction. Specifically, the guide vanes 12 include an arc-shaped section 121 and a vertical section 122. The vertical section 122 extends vertically downward to the junction of the pre-rotation cavity 33 and the mixing cavity 32. The curvature of the arc-shaped section 121 is adapted to the inner wall of the pre-rotation cavity 33, so as to guide the mixed liquid along an arc-shaped path. The vertical section 122 can directly guide the mixed liquid discharged from the mixing cavity 32, so as to smoothly transition the mixed liquid from the mixing cavity 32 into the pre-rotation cavity 33.

[0040] Specifically, the stable flow vane 14 includes a spiral section 141 and a radial section 142. The radial section 142 extends to the inside of the stable flow cavity 35. The spiral section 141 gradually reduces the rotational speed of the mixed liquid through spiral guidance. When the mixed liquid flows to the radial section 142, the mixed liquid entering the stable flow cavity 35 is in a stable laminar flow state, so as to promote the gathered oil droplets to stably float to the sludge collection cavity 36 under the action of buoyancy, avoid the oil droplets from rolling up and down due to the rotation flow, and further improve the efficiency and stability of oil-water separation.

[0041] The guide vanes 12, the cyclone vanes 13, and the stable flow vanes 14 are arranged in a staggered manner, so that the mixed liquid smoothly transitions between the cavities. When the mixed liquid enters the pre-rotation cavity 33 from the mixing cavity 32, it first contacts the guide force of the guide vane 12 to form a preliminary rotation flow. Then, the mixed liquid enters the lower part of the cyclone cavity 34 and contacts the cyclone vane 13. When the mixed liquid continues to flow upward through the upper part of the cyclone cavity 34, it contacts the stable flow vane 14, so that the mixed liquid smoothly transitions from the rotation flow state of the cyclone vane 13 to the stable flow state of the stable flow vane 14.

[0042] The application provides a working principle of the oil removal device of the cyclone air flotation, and the oil-containing sewage is transported into a mixing cavity 32 of a cyclone assembly 3 through a liquid inlet pipe 4, and meanwhile, a motor 61 is started to drive an incomplete gear 62 to rotate, and through intermittent meshing with a driven gear 63, the air inlet pipe 52 and the air distribution disc 51 are driven to rotate intermittently. In the rotating process of the air distribution disc 51, the air inlet pipe 52 at the bottom of the air distribution disc 51 guides the high-pressure gas in the air injection pipe 2 into the air distribution disc 51. When the cylindrical air hole 53 on the air distribution disc 51 corresponds to the conical air hole 55 on the spiral cover plate 54, the gas enters the conical air hole 55 through the cylindrical air hole 53, and under the extrusion and acceleration of the conical flow channel, the micro bubbles are formed. The micro bubbles and the micro oil droplets in the mixing cavity 32 fully contact to form stable composite flocs. When the cylindrical air hole 53 and the conical air hole 55 are disengaged due to the continuous rotation of the air distribution disc 51, the gas is directly discharged from the cylindrical air hole 53 to form large bubbles. The large bubbles quickly carry the medium and large oil droplets to float up. Meanwhile, in the rotating process of the air distribution disc 51, the tooth ring 67 at the edge of the air distribution disc 51 drives the pinion 66 to rotate, so that the turbulence rod 64 and the turbulence blade 65 rotate synchronously, the mixed liquid at the edge region of the mixing cavity 32 is disturbed, the dead water region is avoided, and the bubble agglomeration is dispersed, so that the three phases of gas, liquid and oil are uniformly mixed.

[0043] The mixed gas-liquid-oil mixture enters the pre-rotation cavity 33, is preliminarily guided by the vertical section 122 of the guide blade 12 and is arc-guided by the arc-shaped section 121 of the guide blade 12, so that the oil droplets are preliminarily gathered. Then, the mixture enters the cyclone cavity 34, the lower turbulence blade 13 makes the mixture continue to form a cyclone, and the upper steady flow blade 14 reduces the rotation speed through the spiral section 141, and then converts the cyclone into vertical laminar flow through the radial section 142 and guides the vertical laminar flow into the steady flow cavity 35.

[0044] Under the laminar flow state in the steady flow cavity 35, the composite flocs and the oil droplets stably float up to the sludge collection cavity 36 under the action of buoyancy, the floating oil is discharged through the first oil outlet pipe 7, the residual water phase in the sludge collection cavity 36 is guided into the annular region formed by the tank body 1 and the cylinder body 31 through the liquid outlet pipe 8, the air supplement pipe 9 supplements the high-pressure gas to the annular region for secondary air flotation, further captures the residual oil droplets, the secondary floating oil is discharged through the second oil outlet pipe 10, and finally the treated water is discharged after being regulated by the flow control valve on the water outlet pipe 11, so that the whole cyclone air flotation oil removal process is completed.

[0045] In the second embodiment, the application further provides a cyclone air flotation oil-water separation process, which adopts the cyclone air flotation oil removal device and includes the following steps. Step one: the oil-containing sewage is pretreated by a coarse filtration or shallow sedimentation process to remove the suspended particles and block-shaped impurities with large particle sizes in the water; Step two: the demulsifier and the flocculant are added into the pretreated oil-containing sewage, and the mixture is preliminarily stirred through a static mixer; Step three: the oil-containing sewage with the added medicine is sent into the cylindrical cyclone, and the centrifugal force generated by the high-speed rotation of the cyclone tube is used to realize the uniform mixing of the medicine and the oil-water emulsion, high-efficiency demulsification, and the aggregation of the micro oil droplets to form large oil clusters, so as to preliminarily separate part of the floating oil, and the water phase after the separation is introduced into the tank 1; Step four: the pressurized gas is introduced into the tank 1 through the gas injection pipe 2, so that the gas is fully dissolved in the above-mentioned water phase to form high-concentration dissolved gas water; Step five: the pressure in the tank 1 is suddenly reduced, so that the dissolved gas is precipitated to form bubbles, and the bubbles are closely adhered to the residual oil droplets and impurity flocs in the water under the action of surface tension to form composite flocs with a density less than water; Step six: the cyclone assembly 3 in the tank 1 is used to make the mixed liquid form a cyclone, so as to prolong the contact time and migration path of the composite flocs and the bubbles; Step seven: the composite flocs float to the top of the tank 1 under the action of the Archimedes buoyancy to form a floating oil layer, and are discharged through the first oil outlet pipe 7; Step eight: the residual water phase in the cyclone assembly 3 is introduced into the annular area between the tank 1 and the cyclone assembly 3 through the liquid outlet pipe 8, and the gas is continuously injected through the air supplement pipe 9 to form a secondary air flotation environment, so as to further capture the residual oil droplets; Step nine: the oil and dirt generated by the secondary air flotation is discharged through the second oil outlet pipe 10, and the treated clean water is discharged through the water outlet pipe 11.

[0046] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A cyclone flotation oil removal device, comprising: Tank body; The gas injection pipe, coaxially arranged on the inner wall of the bottom of the tank, is characterized by further comprising: A swirl assembly is disposed inside the tank. The swirl assembly includes a cylindrical body fixedly installed inside the tank. The cylindrical body is provided with a mixing chamber, a pre-swirl chamber, a swirl chamber, a flow stabilizing chamber, and a sludge collection chamber, which are sequentially opened from bottom to top. The inlet pipe is located on one side of the tank and extends into the mixing chamber; A gas distribution assembly is coaxially disposed at the bottom of the mixing chamber. The gas distribution assembly includes a gas distribution plate rotatably disposed at the bottom of the mixing chamber, an air inlet pipe that is connected through the center of the bottom of the gas distribution plate, multiple sets of cylindrical air holes arranged radially along the gas distribution plate, multiple sets of spiral cover plates covering the gas distribution plate, and conical air holes corresponding to the cylindrical air holes on the spiral cover plates. The multiple sets of spiral cover plates are fixedly connected to each other by connecting columns. The outer periphery of each set of spiral cover plates is fixedly connected to the inner wall of the mixing chamber by an L-shaped bracket. The air inlet pipe extends into the gas injection pipe and is rotatably connected to the bottom of the tank by a sealed bearing. The drive mechanism, located at the bottom of the inner wall of the tank, is used to drive the air distribution plate to rotate intermittently. The first oil outlet pipe is located at the top of the tank and extends into the sludge collection chamber; The liquid outlet pipe is located in the sludge collection chamber near the bottom, and the outlet end of the liquid outlet pipe is located in the annular area between the cylinder and the tank. The gas supply pipe is located on one side of the tank. The second oil outlet pipe is located on the upper side of one side of the tank. The water outlet pipe is located on the lower side of the tank.

2. The cyclone flotation oil removal device according to claim 1, characterized in that: The inner wall of the pre-swirl chamber is arranged with multiple sets of guide blades in a circumferential direction, and the inner wall of the swirling chamber is arranged with multiple sets of swirling blades and multiple sets of stabilizing blades in a circumferential direction. The swirling blades are located below the stabilizing blades, and the swirling blades and stabilizing blades are in opposite directions.

3. The cyclone flotation oil removal device according to claim 1, characterized in that: The drive mechanism includes a motor installed at the bottom of the inner wall of the tank, an incomplete gear fixedly connected to the output end of the motor, and a driven gear meshing with the incomplete gear. The driven gear is fixedly connected to the outer surface of the air inlet pipe.

4. The cyclone flotation oil removal device according to claim 3, characterized in that: The drive mechanism also includes eccentrically distributed baffle rods along the circumference of the air distribution plate. Two sets of baffle blades are symmetrically arranged at the top of the baffle rods. A small gear is fixedly connected to the bottom of the baffle rods. A toothed ring is fixedly connected to the circumferential edge of the upper surface of the air distribution plate. The inner toothed ring of the toothed ring meshes with the small gear. The inner wall of the mixing chamber is fixedly connected to a support frame that corresponds to a baffle rod. The baffle rod is rotatably connected to the support frame through a bearing.

5. The cyclone flotation oil removal device according to claim 1, characterized in that: The inner diameter of the bottom of the conical vent is equal to the inner diameter of the cylindrical vent, while the inner diameter of the top of the conical vent is smaller than the inner diameter of the cylindrical vent.

6. The cyclone flotation oil removal device according to claim 1, characterized in that: The multiple sets of cylindrical air holes are distributed in a spiral pattern with equal spacing along the radial direction of the air distribution plate.

7. The cyclone flotation oil removal device according to claim 2, characterized in that: The guide vanes, swirl vanes, and flow stabilizers are arranged alternately at intervals.

8. The cyclone flotation oil removal device according to claim 2, characterized in that: The guide blade includes an integrally formed arc-shaped section and a vertical section, with the vertical section extending vertically downward to the junction of the pre-swirl chamber and the mixing chamber.

9. The cyclone flotation oil removal device according to claim 2, characterized in that: The flow-stabilizing blade includes an integrally formed helical section and a radial section, with the radial section extending into the flow-stabilizing cavity.

10. A cyclone flotation oil-water separation process, employing the cyclone flotation oil removal device as described in claim 1, characterized in that, Includes the following steps: Step 1: Pre-treat oily wastewater by removing large suspended particles and lumpy impurities from the water through coarse filtration or shallow sedimentation processes. Step 2: Add demulsifier and flocculant to the pretreated oily wastewater and stir it initially using a static mixer; Step 3: The oily wastewater after dosing is sent into a column hydrocyclone. With the help of the centrifugal force generated by the high-speed swirling of the hydrocyclone tube, the agent and the oil-water emulsion are mixed evenly and the emulsion is broken efficiently. At the same time, the tiny oil droplets are pushed to aggregate and form large oil clumps, and some floating oil is initially separated. The separated aqueous phase is then introduced into the tank. Step 4: Introduce pressurized gas into the tank through the gas injection pipe to fully dissolve the gas in the aqueous phase above, forming high-concentration dissolved gas water; Step 5: The pressure inside the tank drops sharply, causing dissolved gas to precipitate and form bubbles. The bubbles adhere tightly to residual oil droplets and impurity flocs in the water under the action of surface tension, forming a composite floc with a density less than that of water. Step Six: Use the swirling assembly inside the tank to create a swirling flow in the mixture, extending the contact time and migration path between the composite flocs and the bubbles; Step 7: The composite flocs float to the top of the tank's sludge collection chamber under the action of Archimedes buoyancy, forming a floating oil layer, which is then discharged through the first oil outlet pipe; Step 8: The residual aqueous phase in the cyclone assembly enters the annular area between the tank and the cyclone assembly through the liquid outlet pipe, and is continuously injected with air through the air supply pipe to form a secondary air flotation environment to further capture residual oil droplets. Step 9: The oil sludge generated by the secondary air flotation is discharged through the second oil outlet pipe, and the treated clean water is discharged through the water outlet pipe.

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