Search

CN-122010234-A - Rotational flow air floatation device for oilfield water treatment

CN122010234ACN 122010234 ACN122010234 ACN 122010234ACN-122010234-A

Abstract

The invention belongs to the technical field of oilfield produced water treatment, in particular to a rotational flow air floatation device for oilfield water treatment, which comprises a tank body, a rotational flow air floatation cover, a water distributor, an oil discharging mechanism and an air dissolving mechanism, wherein an annular cavity and a spiral injection groove are arranged in a nozzle of the water distributor, so that gas in air dissolving water can be released in a controlled manner and rotational flow is enhanced, the oil discharging mechanism comprises a component with a spiral scraping plate and a central upright rod containing oleophilic hydrophobic materials, the component is respectively used for guiding high-viscosity oil sludge to discharge and collect light oil, a shock absorber comprising a piston and a gas spring is arranged on a connecting pipe of the air dissolving mechanism so as to relieve fluid pulse, and an adjusting structure consisting of a cone and the gas spring is arranged in a purified water outlet pipe.

Inventors

  • LIU BING
  • YAN CHANGPING

Assignees

  • 上海四方全服能源装备工程有限公司
  • 上海四方锅炉集团工程成套股份有限公司

Dates

Publication Date
20260512
Application Date
20260327

Claims (10)

  1. 1. The rotational flow air floatation device for oilfield water treatment is characterized by comprising a base plate (1), a tank body (2), a rotational flow air floatation cover (6), a water distributor (11), a first oil discharge assembly, a second oil discharge assembly and an air-dissolving water mechanism; The tank body (2) is supported above the base plate (1) through the supporting legs (3), an annular partition plate (5) is fixed in the tank body (2), the rotational flow air floatation cover (6) is fixedly connected to the bottom of the annular partition plate (5) and the top opening of the rotational flow air floatation cover is aligned with the central hole of the annular partition plate (5), and the tank body (2) is provided with a sewage inlet pipe (4), a sewage discharge pipe (10) and a purified water outlet pipe (9); The water distributor (11) is arranged in the tank body (2) and is positioned in the cyclone air flotation cover (6), the water distributor (11) comprises an L-shaped pipe (12), a water distribution disc (13), a plurality of arc-shaped water distribution pipes (14) and nozzles (15), the L-shaped pipe (12) penetrates through the side wall of the tank body (2), the water distribution disc (13) is fixedly communicated with the tail end of the L-shaped pipe (12), the arc-shaped water distribution pipes (14) are distributed along the periphery of the water distribution disc (13) and are communicated with the water distribution disc, the tail end of each arc-shaped water distribution pipe (14) is provided with the nozzle (15), and the spraying direction of the nozzle (15) is tangential to the inner wall of the cyclone air flotation cover (6), so that the air-dissolved water is sprayed tangentially along the inner wall of the cyclone air flotation cover (6) to form a cyclone; The first oil discharge assembly and the second oil discharge assembly are arranged at the top of the tank body (2) and are used for respectively discharging thick oil sludge and light oil; The air-dissolving water mechanism is used for providing air-dissolving water for the water distributor (11).
  2. 2. The rotational flow air floatation device for oilfield water treatment according to claim 1, wherein an annular cavity (16) is arranged in the nozzle (15), a water outlet channel of the nozzle (15) is communicated with the annular cavity (16) through a plurality of inclined holes (17), and a side cavity wall of the annular cavity (16) far away from the arc-shaped water distribution pipe (14) is provided with a plurality of spiral injection grooves (18); When the gas-soluble water flows through the water outlet channel of the nozzle (15), the dissolved gas enters the annular cavity (16) through the inclined hole (17) for flash evaporation, and the flash evaporation gas is tangentially sprayed into the cyclone air flotation cover (6) through the spiral injection groove (18) so as to enhance the centrifugal strength of the cyclone field.
  3. 3. A cyclonic air flotation device for oilfield water treatment as claimed in claim 2, wherein the first oil extraction assembly comprises an outer sleeve (19), an oil extraction pipe I (20), a conical plate I (21), a plurality of helical flights (22) and an oil extraction pipe II (23); The outer sleeve (19) is fixedly penetrated through the top of the tank body (2), the oil drain pipe I (20) is coaxially fixed in the outer sleeve (19) and the bottom end of the oil drain pipe I extends downwards, the conical plate I (21) is connected between the inner wall of the outer sleeve (19) and the outer wall of the oil drain pipe I (20) and the outer diameter of the top is larger than the outer diameter of the bottom, and the oil drain pipe II (23) is communicated with the side wall of the outer sleeve (19) and is positioned below the conical plate I (21); A plurality of spiral scrapers (22) are circumferentially fixed on the top inner wall of the tank body (2), the spiral direction of the spiral scrapers is opposite to the rotation direction of the liquid flow, and the spiral scrapers are used for guiding the rotating thick oil sludge to an annular space between the outer sleeve (19) and the oil discharge pipe I (20).
  4. 4. A cyclonic air flotation device for oilfield water treatment according to claim 3, wherein the second oil extraction assembly comprises the oil extraction pipe I (20), a plurality of fixed bars (24) and a hollow upright (25); The fixed rods (24) are fixed on the inner wall of the oil drain pipe I (20) and are connected to the top of the hollow upright rod (25), the hollow upright rod (25) extends downwards into the cyclone air floatation cover (6) and is connected with the top of the water distribution disc (13), a plurality of holes (26) are formed in the rod wall of the hollow upright rod (25), and oleophilic and hydrophobic materials are filled in the holes (26) to absorb and guide light oil to enter the hollow upright rod (25) and drain through the oil drain pipe I (20).
  5. 5. The rotational flow air floatation device for oilfield water treatment according to claim 4, wherein the air dissolving water mechanism comprises a dissolved air pump (29), a surge tank (30), an air return pipe (32) and a connecting pipe (36); The liquid inlet end of the dissolved air pump (29) is communicated with the water purifying outlet pipe (9) and the air return pipe (32) through pipelines, the air return pipe (32) is communicated with the exhaust pipe (27) at the top of the tank body (2), the liquid outlet end of the dissolved air pump (29) is communicated with the pressure stabilizing tank (30) through a liquid injection pipe (33), and the pressure stabilizing tank (30) is communicated with the L-shaped pipe (12) of the water distributor (11) through a connecting pipe (36).
  6. 6. A rotational flow air flotation device for oilfield water treatment according to claim 5, wherein the connecting pipe (36) is provided with a shock absorber (37), the shock absorber (37) comprises a buffer tube (38), a piston (39) and a gas spring I (41); The buffer tube (38) is communicated with the connecting tube (36), the piston (39) is arranged in the buffer tube (38) in a sliding mode, a plurality of through holes (40) are formed in the piston (39), and the gas spring I (41) is connected between the top of the buffer tube (38) and the piston (39) and used for buffering pressure fluctuation in the connecting tube (36).
  7. 7. The rotational flow air floatation device for oilfield water treatment according to claim 6, wherein the air return pipe (32) is further communicated with an air inlet pipe (34) for supplementing air.
  8. 8. The rotational flow air floatation device for oilfield water treatment according to claim 7, wherein a conical plate II (47) is fixed below the spiral scraping plate (22) in the tank body (2), the top of the conical plate II (47) is connected to the inner wall of the tank body (2), the bottom is connected to the top of the annular partition plate (5), and the top inner diameter is larger than the bottom inner diameter.
  9. 9. The rotational flow air floatation device for oilfield water treatment according to claim 8, wherein a disc (7) is fixed below the rotational flow air floatation cover (6) in the tank body (2), a plurality of sieve holes (8) are formed in the disc (7), the inner cavity of the tank body (2) is partitioned by the disc (7), an inlet of the sewage draining pipe (10) is positioned above the disc (7), and an inlet of the purified water outlet pipe (9) is positioned below the disc (7).
  10. 10. The rotational flow air floatation device for oilfield water treatment according to claim 9, wherein a liquid level stabilizing mechanism is arranged in the purified water outlet pipe (9), and the liquid level stabilizing mechanism comprises a fixed ring (42), a cone (46) and a gas spring II (45); The fixed ring (42) is fixed in the purified water outlet pipe (9), conical grooves (43) are formed in the top and the bottom of the fixed ring, the conical bodies (46) and the conical grooves (43) in the bottom of the fixed ring (42) are oppositely arranged and jointly define an annular water outlet gap, and the gas spring II (45) supports the conical bodies (46) so that the area of the annular water outlet gap can be adaptively adjusted along with the pressure change at the bottom of the tank body (2) to stabilize the liquid level in the tank.

Description

Rotational flow air floatation device for oilfield water treatment Technical Field The invention relates to the technical field of oilfield produced water treatment, in particular to a rotational flow air floatation device for oilfield water treatment. Background In the oil field exploitation process, a large amount of oil field water is generated, and the water contains pollutants such as crude oil, suspended matters, mechanical impurities and the like, so that the surrounding soil and the water environment are seriously polluted if the water is directly discharged, and the water is required to be deeply treated to remove the pollutants if the water is recycled, so that the subsequent use or discharge standard is achieved. The cyclone air-float technology is used as a high-efficiency solid-liquid separation technology, and is widely applied to the field of oilfield water treatment, and the core principle is to separate pollutants from water body by utilizing the combination of centrifugal force generated by cyclone and buoyancy generated by air-float, so as to realize water quality purification. At present, the existing oilfield water treatment rotational flow air floatation device still has a plurality of defects in practical application: 1. In the mixing link of the gas-dissolved water and the oilfield water, the gas-dissolved water often cannot form stable spiral flow, so that micro bubbles separated out from the gas-dissolved water are not fully contacted with micro oil drops and suspended matters in the oilfield water, and part of micro pollutants are difficult to be adhered and coalesced by the micro bubbles, so that the separation effect is influenced. Meanwhile, in the spraying process of the gas-dissolved water, dissolved gas is easy to flash suddenly, so that the gas explosion phenomenon is generated, the stability of a swirl field can be damaged, the internal structure of the device can be impacted, and the service life of the device is shortened; 2. Most of the existing devices adopt a single oil discharging structure, the separated thick oil sludge and light oil cannot be discharged in a grading way, the thick oil sludge is easy to block an oil discharging channel, so that the oil discharging is not smooth, and after the light oil and the oil sludge are mixed and discharged, secondary separation treatment is required additionally, so that the subsequent treatment procedures and cost are increased. In addition, although a part of the device is provided with a grading oil discharging structure, the oil discharging efficiency is lower, the inner wall of the top of the device is difficult to clean due to accumulation of oil sludge, and the separation effect is further affected after long-term use; 3. the concentration of the air-soluble water prepared by the existing air-soluble water mechanism is uneven, and pulse flow is easy to occur in the conveying process, so that the flow rate of the air-soluble water entering the device is unstable, the angular speed of a swirl field is damaged, and the separation efficiency is affected. Meanwhile, the air-dissolving mechanism lacks an effective air-supplementing mechanism, and when the air in the device is insufficient, the air cannot be supplemented in time, so that the generation amount of micro bubbles is reduced, and the separation effect is further reduced; 4. The existing device is lack of a self-adaptive adjusting structure at a water purifying outlet, when the inflow flow of oilfield water fluctuates, the liquid level in the device is easy to change drastically, the excessive liquid level can cause the discharge of pollutants which are not completely separated together with the purified water to influence the water quality of the water outlet, and the excessive liquid level can cause the damage of the air seal in the device to influence the stability of the cyclone air floatation process. In addition, in the cyclone separation process of the traditional device, impurities are easy to accumulate at the bottom of the device, are difficult to thoroughly discharge, and can block a purified water outlet after long-term accumulation, so that the normal operation of the device is affected. Disclosure of Invention Aiming at the problems that a flash evaporation gas explosion of gas dissolved water damages a cyclone field, oil discharge is not graded and is easy to block, secondary treatment is needed, the fluctuation of the fluctuation cyclone of the gas dissolved water is stable, and the liquid level fluctuation influences the quality of effluent water and the stability of the cyclone in the conventional cyclone dissolved gas floatation device, the invention develops the targeted research and development. In order to achieve the above purpose, the present invention adopts the following technical scheme: the rotational flow air floatation device for oilfield water treatment comprises a base plate, a tank body, a rotational flow air floatation cover, a wat