CN111204835B

CN111204835B - Shallow-bin centrifugal air flotation process and device

Info

Publication number: CN111204835B
Application number: CN202010104261.3A
Authority: CN
Inventors: 高根树
Original assignee: Guangxi Guangyu Water Resources Technology Development Co ltd
Current assignee: Guangxi Guangyu Water Resources Technology Development Co ltd
Priority date: 2020-02-18
Filing date: 2020-02-18
Publication date: 2021-05-04
Anticipated expiration: 2040-02-18
Also published as: CN111204835A

Abstract

The invention provides a shallow-bin centrifugal air floatation process and a shallow-bin centrifugal air floatation device, belongs to the field of oil-water separation of petroleum, chemical industry and water supply and drainage, and mainly solves the problems of low air floatation efficiency, high energy consumption and large occupied area of the existing air floatation process technology. The method adopts a metal microporous filter plate for aeration, cuts a gas column by high-speed rotational flow to form a gas-water blending state, and accelerates the gas phase precipitation speed by means of the pressure of a centrifugal field so as to accumulate separated floating oil on a concave liquid surface; an outlet is arranged at the lower position of the center of the swirling flow field, so that the concave liquid level of the swirling flow field is ensured to be stabilized at a high position; the discharge flow is regulated at regular time, the concave liquid level of the rotational flow field is raised to intensively and organically overflow the concentrated oil water and produce high-cleanliness water, so that the oil-water separation is efficient, exquisite and automatic, and the treatment time of the oil-containing wastewater is greatly shortened; the oil stain is not open to the outside, and the appearance of the operation site is changed. The invention is used for oil-water separation or sand, water and oil three-phase separation.

Description

Shallow-bin centrifugal air flotation process and device

Technical Field

The invention relates to the field of petroleum and chemical sewage treatment, in particular to an oil-water separation and gas centrifugal separation device.

Background

Various kinds of waste water contain oil which is a common problem, and the air floatation process is commonly used for oil-water separation. Shallow pool air flotation and dissolved air flotation are typical methods for removing emulsified oil. And also adopts rotational flow air flotation. Such as the Chinese patent of cyclone air-float oil-water separator (publication No. CN 102153165B). The problem of sand in oil-water is solved by a centrifugal mode. For example, the centrifugal oil purification device (publication number CN102974165A) in chinese patent is used to extensively spin-dehydrate lubricating oil, and the dehydrated oil is still rich in emulsified oil.

The air floatation oil-water separation process technology has three general defects:

1) the air floatation tanks are deep, and the shallowest air floatation tank is 800mm deep. The equipment must be configured to produce compressed gas to overcome the resistance caused by the depth of the water body.

2) The secondary collection size of bubbles formed in the air floatation process is too large, the relative contact area is small, and the bubbles and water cannot reach the expected blending degree, so the efficiency of treating emulsified oil is not high enough, the occupied area of the pool in the air floatation project is large, and the requirement can be met only by lasting a long air floatation time.

3) The superficial area of the air floatation tank is large, and oil floating on the surface is mixed with some light substances and is not easy to be skimmed.

4) The pond surface is open, and the secondary microbial film is easy to generate.

The air floatation oil-water separation has been an open process with low efficiency, high energy consumption and large floor area.

Disclosure of Invention

The invention aims to systematically solve the problems of deep tank, overlong air floatation time, high energy consumption, difficult skimming of floating oil and the like in the existing air floatation oil-water separation technology.

In order to realize the aim, the invention provides a shallow bin centrifugal air flotation process for oil-water separation. The method is characterized in that:

first, the slurry enters a circular cavity and is rotated by an inner rotor.

And thirdly, inputting gas under pressure. The microporous columnar airflow is supplied to the slurry which uniformly rotates at a certain speed from bottom to top through the microporous plate, the airflow column is broken under the cutting of the rotating slurry to form microbubbles and gas-water mixed bodies, and the bubbles drive the emulsified oil to float upwards and centripetally concentrate to be gathered on the concave liquid surface. The gas overflowing after pressure relief is discharged from the upper part.

The heavy liquid phase outlet is arranged at the center of the smooth rotating area and is lower than the concave liquid surface formed by centrifugal rotation for a certain distance, so that the light liquid phase floating oil can not flow out from the heavy liquid phase outlet at the lower part and can only be continuously accumulated on the concave liquid surface at the upper part.

When the oil content of the water-based emulsion is very small, once the floating oil and the light substances on the concave liquid surface are accumulated to a certain degree, the flow of an outlet valve is reduced through pulse regulation by a self-control program, so that the concave liquid surface of the slurry rises, overflows from a set upper outlet, and is conveyed by another way; after the pulse, the slurry concave liquid level automatically falls back to the low position for running, and floating oil or light objects are accumulated again; this cycle is continuously completed at certain intervals to achieve stable oil removal.

And for the conditions that the oil content of the water-based emulsion is large or the water content of the oil-based emulsion is large, the overflow of the outlet valve is repeatedly finely adjusted through a self-control program, and after a flow dividing point which enables the outlet water not to contain oil or the outlet water not to contain water is found, the overflow of the valve is stabilized, and the continuous operation is carried out.

For general oily wastewater, the separated heavy liquid phase can reach sufficient purity degree by controlling the flow rate in the process. The overflowing light phase is only concentrated oil water containing scum occasionally.

A shallow-bin centrifugal air flotation device according to the process, which is used for oil-water separation. The method is characterized in that:

it comprises a set of transmission device, a shell, an internal rotor pinwheel, a sleeve, a tray, a collecting hopper or a blocking plate flange and an adjustable valve arranged at a heavy liquid phase outlet.

The transmission device is upright in shaft and is used for hanging the inner rotary sub pinwheel.

The upper part of the shell is provided with two spigots and at least 2 bolt holes for fixing the transmission device; the middle part of the shell is divided into a pocket-shaped area, the inner opening surface is communicated with the rotational flow area, and the outer wall of the shell is provided with a light liquid phase outlet joint D for outputting light liquid phase floating oil or floating slag; a slurry inlet joint A and an air inlet joint B are connected to the straight cylinder at the waist part of the shell; an outlet joint C is connected to the straight cylinder at the bottom of the shell; the lower end of the shell is provided with a flange. The lower part of the shell is provided with an inward extending lug which is used for fixing the sleeve and the tray.

A large flange is arranged on the aggregate bin, and a small flange is arranged below the aggregate bin. The shell is connected with the upper part, and the valve is connected with the lower part. For the case of slurries without suspended particles, the collection hopper may be replaced by a blind flange.

The sleeve is arranged between the shell and the pinwheel, and a certain gap is kept between the sleeve and the pinwheel; the sleeve is provided with a through hole, and the inner wall of the sleeve is coaxial with the pinwheel.

The needle wheel consists of a plurality of spoke needles, a spring retainer ring, a pressing plate, at least 2 seedling hanging rings, at least 1 spacing ring, a base plate, a hub and a plurality of key bars, wherein the spoke needles are U-shaped, the rings are circumferentially hung on the seedling hanging rings and then sleeved on the hub in layers, and each layer is separated by the spacing rings at a certain interval. The lower part of the pinwheel hub is in a dome shape and is coaxial and hollow, and preferably, the hollow is in a frustum shape.

The tray is arranged near the lower part of the pinwheel, at least 2 tooth-shaped lugs extend out of the periphery of the tray, the lug bosses are connected with the shell through bolts, and a gap for heavy solid phase sedimentation between the shell and the sleeve is communicated with the collecting hopper. The tray is used for setting up a tower platform in the center, a hole in the center of the tower platform is a heavy liquid phase overflow outlet, and the hole penetrates downwards to be communicated with a heavy liquid phase output interface on the shell or the collecting hopper. The tray is distributed with sintered metal microporous filter discs in an area inside a certain radius outside the tower, a connecting channel is arranged below the filter discs, the connecting channel is connected with an outlet joint B-1 and is communicated with an air inlet joint B on the shell through a hose joint for air transmission.

The tower of the tray coaxially extends into the hollow space of the hub of the pinwheel, the orifice surface of the tower is at least higher than the spoke needles of the first layer, and a certain gap is formed between the outer wall surface of the tower and the hollow space of the hub to serve as a passage for upward overflow of heavy liquid phase.

The hub has an upwardly open hole or slot therein to remove gas phase constituents trapped at the dome at the heavy liquid phase overflow outlet.

Further preferably, a cambered spigot coaxial with the rotor is arranged on the lug boss of the shell and presses the sleeve in a matching manner.

Preferably, the device comprises an output pipe head, one end of the output pipe head is connected with the heavy liquid phase overflow outlet of the tray through pipe threads or a conical opening, the middle of the output pipe head is movably connected with an outlet joint C of the shell through pipe threads or section sealing, and the other end of the output pipe head is connected with the adjustable valve through a joint or a flange.

And a certain area at the center of the upper part of the shell is provided with a hole for exhausting.

Drawings

FIG. 1 is a schematic diagram of the general structure of a shallow-bin centrifugal air-flotation device according to an embodiment of the invention;

FIG. 2 is a schematic diagram of a partial transmission of a shallow-bin centrifugal air-flotation device according to an embodiment of the invention;

FIG. 3 is a main schematic view of a partial shell structure of a shallow-bin centrifugal air-flotation device according to an embodiment of the invention;

FIG. 4 is a schematic partial sectional view of a housing of a shallow-chamber centrifugal air-flotation device according to an embodiment of the invention;

FIG. 5 is a schematic view of a partial pinwheel configuration of a shallow-bin centrifugal air flotation device according to an embodiment of the invention;

FIG. 6 is a schematic view of a partial tray structure of a shallow-bin centrifugal air-flotation device according to an embodiment of the invention;

description of the reference numerals

The transmission device 100:

a motor reducer 101, a baffle plate 102, a choke seat 103, a reaction plate 104, an upper bearing seat assembly 105, a shaft 106, an oil seal 107, an upper bearing cover 108, a bearing 109, a lower bearing seat 110, a lower bearing cover 111, a key bar 112, a gasket 113, a stop gasket 114 and a round nut 115;

the housing 200:

a top end seat plate 201, an eye tube 202, a notch cylinder 203, an upper cover 204, a cone cylinder 205, a straight cylinder 206, a pulp inlet A207, a lug plate 208, an air inlet joint B209, a lower flange 210, a transition joint C211 and a light liquid phase outlet joint D212;

the pin wheel 300:

hub 301, spring collar 302, pressure plate 303, seedling hanging ring 304, spacing ring 305, spoke needle 306, backing plate 307 and key bar 308;

a sleeve 400;

the tray 500:

a tower tube 501, a disk seat 502, a microporous filter 503, a gas pipe joint 504, an elbow joint 505 and a notch ring 506;

a collection hopper 600;

a butterfly valve 700;

an output cartridge 800;

a regulating valve 900;

a bracket 950.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are exemplary and intended to be illustrative of the present invention and are not to be construed as limiting the present invention.

Example one

The shallow-bin centrifugal air flotation device according to an embodiment of the invention is described below with reference to the accompanying drawings. As shown in fig. 1-6.

Referring to fig. 1, the shallow-bin centrifugal air flotation device comprises a set of transmission device 100, a housing 200, a pin wheel 300, a sleeve 400, a tray 500, a collecting hopper 600, a gate valve 700, an output pipe head 800, a regulating valve 900 and a set of brackets 950. The transmission 100 is vertically fixed to the housing 200 via a spigot and a bolt. The housing 200 is flanged to the lower collection hopper 600. The collection hopper 600 is then engaged with adjacent equipment via a knife gate valve 700. The outlet stub 800 is horizontally fixed to the housing 200 by means of a screw thread and is then flanged to the regulating valve 900. The tray 500 holds the sleeve 400 coaxially with the pinwheel 300. The upper part of the tower of the tray 500 coaxially extends into the pinwheel 30, and the lower part is communicated with the output pipe head 800.

A control cabinet is matched, and the size of a valve opening of the regulating valve is controlled by a program.

As shown in fig. 2, the transmission 100 includes a motor reducer 101, a baffle plate 102, a nozzle base 103, a reaction plate 104, an upper bearing base assembly 105, a shaft 106, and/or at least 2 oil seals 107, an upper bearing cap 108, at least one bearing 109, a lower bearing base 110, a lower bearing cap 111, a spline 112, a washer 113, a stop washer 114, and 2 round nuts 115.

The upper bearing seat assembly 105 is a square or diamond-shaped bearing with a seat. Two angular contact ball bearings 109 are disposed in the lower bearing housing 110 and are stacked in opposition, and the lubricating space is closed by an upper bearing cover 108, a lower bearing cover 111, and an oil seal 107. The lower bearing block 110 receives grease through the bore in the shaft 106 through the nozzle block 103. The oil nozzle base 103 limits the motor reducer 101 together with the baffle plate 102. The reaction plate 104 is limited by a threaded hole of the housing 200, and the motor reducer 101 is positioned.

The pinwheel 300 is arranged at the lower end of the transmission shaft 106, transmits torsional force through the key strip 112 and is fixed through the washer 113, the stop washer 114 and the 2 round nuts 115. The spigot of the upper bearing block assembly 105 fits within the inner circle of the top flange 201 of the housing 200 and serves as a first fulcrum for the actuator 100. The lower bearing seat 111 is engaged with the inner circle of the upper cover 206 of the housing 200 with a spigot as a second fulcrum of the transmission 100.

Referring to fig. 3 and 4, the housing 200 includes an upper end seat plate 201, an eye tube 202, a notched cylinder 203, an upper cover 204, a tapered cylinder 205, and/or at least 2 tabs 208, a large diameter straight cylinder 206, a lower flange 210, and a large tubular thread transition joint C211. The top seat plate 201, the engagement eye socket 202 and the top cover 204 together form a support for the transmission 100. The cone cylinder 207 is connected with a gap cylinder until the upper cover 204 and the upper part of the outer straight cylinder 206 enclose a bottleneck shoulder-shaped light liquid phase oil overflow area which is connected with a light liquid phase outlet connector D212. The outer wall of the middle part of the shell 200 is provided with a pulp inlet A207, the inner wall of the lower part is provided with a lug 208, and the outer wall is provided with an air inlet joint B209 and a transition joint C211. The bottom end is connected to the lower flange 210.

A hole or threaded hole is formed in the center of the cover 204 to receive a tube connector for venting air.

It should be noted that it is preferable to provide,

1) the transmission mode, the bearing box sealing structure composition and the shaft end locking mode can also adopt other modes known by the technical personnel in the field of the technology.

2) The shape of the light liquid phase isolation region can be regular or irregular.

Referring to fig. 5, the pinwheel 300 is composed of a hub 301, a spring collar 302, a pressure plate 303, a plurality of seedling hanging rings 304, a plurality of spacing rings 305, a plurality of spoke needles 306, a backing plate 307 and three key bars 308. The spoke needles 306 are U-shaped, are circumferentially hung on the seedling hanging ring 304 and are sleeved on the hub 301 in layers, each layer is separated by a spacing ring 305 at a certain interval, and are overlapped and clamped by a spring collar 302, a pressing plate 303 and a backing plate 307, and the spoke needles are connected with the hub 301 by a key bar 308 to transmit driving torsion force. The lower part of the hub 301 is dome-shaped coaxial hollow, preferably the hollow is frustum-shaped.

As shown in fig. 6, a tower tube 501 is centrally seated on the tray 500 and coaxially extends into the hollow space of the hub 301, the orifice surface of the tower tube 501 is higher than the spoke needles 306 of the first layer, and a certain gap is formed between the outer wall surface of the tower tube 501 and the hollow space of the hub 301 to serve as a passage for the heavy liquid phase to overflow upwards. A sintered metal microporous filter plate 503 is arranged in a certain area of the outer ring plate seat 502 of the tray 500, a cylindrical hollow area is arranged below the filter plate, an annular groove is arranged on the back of the filter plate to be communicated with the hollow area, and a notch ring 506 seals the notch and is connected with a gas pipe connector 504; a bent pipe joint 505 is connected to the center of the disk seat 502. The tray 500 has a spigot coaxial with the pinwheel 300 to press against the fixed sleeve 400.

The outlet stub 800 is internally connected to an elbow joint 505, is centrally fixed to the internally threaded transition joint C211 of the housing 200, and is flanged at the other end to an adjustable valve 900.

The process and technical principle of the shallow-bin centrifugal air flotation device for oil-water separation are explained as follows:

the slurry enters the cavity of the housing 200, enters the gap between the housing 200 and the sleeve 400, fills the collection hopper 600, and then is dispersed circumferentially.

When the liquid level is higher than the collecting hopper 600, the pinwheel 300 contacts the slurry to form centrifugal rotational flow. Under the centrifugal action, a concave liquid surface is formed on the surface of the slurry. When particles are encountered, the particles are retained in the clearance outside the sleeve 400 and fall by gravity, and are collected in the collection hopper 600.

Gas with certain pressure is input from an air inlet joint B209 of the shell 200, enters an air pipe joint 504 of the tray 500 through a hose and emerges from the microporous filter plate 503; the air column is kneaded and crushed after contacting with the centrifugal rotational flow, rapidly moves upwards and centripetally under the action of buoyancy and centrifugal force, and carries emulsified oil and light substances to be collected on the concave liquid surface. The gas that is separated out is discharged from the holes in the upper cover 204 of the housing 200.

And after the accumulation of the light liquid phase reaches a certain amount, the opening degree of the valve is reduced, so that the liquid level in the cyclone cavity rises, and light liquid phase substances overflow from the opening to the isolation area and are output through a light liquid phase outlet D212.

Advantageous effects

Compared with the prior art, the shallow-bin centrifugal air flotation process and device have the following beneficial effects:

1) the invention utilizes high-speed centrifugal rotational flow to cut the gas column from the microporous filter plate, the pore space of the microporous filter plate can be kept stable at 1 micron, the rotational flow cutting forms a water-gas mixed state, and the centrifugal action accelerates the gas phase separation, so that the emulsified oil can be separated upwards quickly and efficiently. The air floatation time is shortened to be finished within a few seconds, and the air floatation device is more efficient than any existing air floatation technology.

2) The invention arranges the low-level heavy liquid phase collecting port in the central area of the centrifugal field, maintains enough water pressure through the ascending overflow channel, overflows the heavy liquid phase in a subsurface flow mode, provides guarantee for continuous accumulation of thin oil wastewater on the concave free liquid level, and can output the heavy liquid phase with high cleanliness.

3) The liquid level is raised by controlling the flow of the valve to overflow the light liquid phase, and the light liquid phase is separated simply, practically, cleanly and cleanly.

4) The device is small in size and convenient to install or integrate in a large system.

5) The liquid level thickness in the bin is limited to 200-300 mm, the pressure requirement on gas is greatly reduced, the duration time of the air floatation process is reduced, and the energy consumption of the rotor is obviously reduced by deducting the energy consumption of the air floatation operation.

6) It is suitable for the synchronous three-phase separation of sand, water and oil.

Claims

1. A shallow bin centrifugal air flotation process is used for oil-water separation and is characterized in that:

firstly, slurry enters a circular cavity and is rotated by an inner rotator;

thirdly, inputting gas with pressure; the microporous columnar airflow is supplied to the slurry which uniformly rotates at a certain speed from bottom to top through the microporous plate, the airflow column is broken under the cutting of the rotating slurry to form microbubbles and gas-water mixed bodies, and the bubbles drive the emulsified oil to float upwards and centralize centripetally to be gathered on the concave liquid surface; the gas overflowing after pressure relief is discharged from the upper part;

the heavy liquid phase outlet is arranged at the center of the smooth rotating area and is lower than the concave liquid surface formed by centrifugal rotation for a certain distance, so that light liquid phase floating oil cannot flow out from the heavy liquid phase outlet at the lower part and only can be continuously accumulated on the concave liquid surface at the upper part;

when the oil content of the water-based emulsion is very small, once the floating oil and the light substances on the concave liquid surface are accumulated to a certain degree, the flow of an outlet valve is reduced through pulse regulation by a self-control program, so that the concave liquid surface of the slurry rises, overflows from a set upper outlet, and is conveyed by another way; after the pulse, the slurry concave liquid level automatically falls back to the low position for running, and floating oil or light objects are accumulated again; the circulation is continuously completed at certain intervals to realize stable oil removal;

for the conditions that the oil content of the water-based emulsion is large or the water content of the oil-based emulsion is large, the overflow of the outlet valve is repeatedly finely adjusted through a self-control program, and after a flow dividing point which enables the outlet water not to contain oil or the outlet water not to contain water is found, the overflow of the valve is stabilized, and the continuous operation is carried out;

the shallow bin centrifugal air floatation device for the shallow bin centrifugal air floatation process comprises a set of transmission device, a shell, an inner rotor pinwheel, a sleeve, a tray, a material collecting hopper and an adjustable valve arranged at a heavy liquid phase outlet;

the transmission device is vertical in shaft and is used for hanging the inner rotor pinwheel;

the upper part of the shell is provided with two spigots and at least 2 bolt holes for fixing the transmission device; the middle part of the shell is divided into a pocket-shaped area, the inner opening surface is communicated with the rotational flow area, and the outer wall of the shell is provided with a light liquid phase outlet joint D for outputting light liquid phase floating oil or floating slag; a slurry inlet joint A and an air inlet joint B are connected to the straight cylinder at the waist part of the shell; an outlet joint C is connected to the straight cylinder at the bottom of the shell; the lower end of the shell is provided with a flange; the lower part of the shell is provided with an inward extending lug boss for fixing the sleeve and the tray;

the collecting hopper is provided with a large flange and a small flange below; the upper part is connected with the shell and the lower part is connected with the valve; for the case of slurry without suspended particles, the collection hopper is replaced by a blind flange;

the sleeve is arranged between the shell and the pinwheel, and a certain gap is kept between the sleeve and the pinwheel; the sleeve is provided with a through hole, and the inner wall of the sleeve is coaxial with the pinwheel;

the needle wheel consists of a plurality of spoke needles, a spring retainer ring, a pressure plate, at least 2 seedling hanging rings, at least 1 spacing ring, a base plate, a hub and a plurality of key bars, wherein the spoke needles are U-shaped, the rings are circumferentially hung on the seedling hanging rings and then sleeved on the hub in layers, and each layer is separated by the spacing rings at a certain interval; the lower part of the hub is in a dome shape and is coaxial hollow, and the hollow is in a frustum shape;

the tray is arranged near the lower part of the pinwheel, at least 2 tooth-shaped lugs extend out of the periphery of the tray, the tray is connected with lug bosses of the shell through bolts, a gap for heavy solid phase sedimentation is arranged between the shell and the sleeve, and the gap is communicated with the aggregate bin; the tray is used for setting up a tower platform in the center, a hole is formed in the center of the tower platform and is a heavy liquid phase overflow outlet, and the hole penetrates downwards to be communicated with a heavy liquid phase output interface on the shell or the collecting hopper; the tray is distributed with sintered metal microporous filter plates in an inner area with a certain radius outside the tower platform, a cylindrical hollow area is arranged below the filter plates, and a channel is connected with an outlet joint B-1 and communicated with an air inlet joint B on the shell through a hose joint for air transmission;

the tower of the tray coaxially extends into the hub hollow space, the orifice surface of the tower is at least higher than the first layer of the spoke needles at the bottom of the hub, and a certain gap is formed between the outer wall surface of the tower and the hub hollow space and is used as a passage for upward overflow of heavy liquid phase;

the hub is provided with a hole or a groove which is opened upwards to the top end and is used for discharging gas phase components which are retained at the dome top of the heavy liquid phase overflow outlet;

2. The shallow-bin centrifugal air flotation process according to claim 1, characterized in that: and an arc-surface spigot coaxial with the rotor is arranged on the lug boss of the shell to press and clamp the sleeve in a matching manner.

3. The shallow-bin centrifugal air flotation process according to claim 1, characterized in that: one end of the output pipe head is connected with the heavy liquid phase overflow outlet of the tray through pipe threads or a conical opening, the middle of the output pipe head is movably connected with an outlet joint C of the shell through pipe threads or section sealing, and the other end of the output pipe head is connected with the adjustable valve through a joint or a flange.