CN103979637B - A kind of refining plant of oily(waste)water and separation method - Google Patents

Abstract

A purification device and separation method for oily sewage, the device includes: a water inlet distribution device, a column separator, a floating oil collection device, an inflatable cyclone separator, at least one self-priming microbubble generator, and at least one dissolved air precipitation microbubble generator. Bubble generator, the upper part of the column is a column separator, the lower part is a built-in inflatable cyclone separator, the two are connected up and down; The inflation point is at the lower part of the cylinder. Using negative pressure self-suction jet flow to generate microbubbles and high pressure dissolved air to decompress and precipitate to generate microbubbles, two ways to inflate, cyclone separation and air flotation separation coupling, can effectively separate fine-grained oil in oily sewage, and effectively flotation particle size The lower limit is small, the separation time is short, and the operation cost is low, which solves the problem of difficult separation of emulsified oil in oily sewage.

Description

Purification device and separation method for oily sewage

technical field

The invention relates to an oil-water separation and purification device and a separation method, in particular to a purification device and a separation method for oily sewage containing emulsified oil.

technical background

Oily sewage is a wide-ranging and large-scale pollution source produced in petroleum development and utilization activities. Effective treatment of oily sewage, discharge of sewage up to standard, and recovery of oil products not only protect the environment, but also generate economic benefits, realizing the unity of environmental and economic benefits.

The oil in oily sewage mainly exists in the water body in the form of slick oil, dispersed oil, emulsified oil, dissolved oil and oil-solid matter. The difficulty of oil-water separation depends on the form of oil in the water. The finely dispersed oil and emulsified oil in the colloidal state in the sewage have a small particle size, and often adhere to some impurities and surface active substances in the water, resulting in an electric double layer. Phenomenon, maintain a stable state and are difficult to remove. Conventional oil-water separation technologies include gravity settling, filtration, cyclone separation, chemical separation, biological technology and combinations of the above technologies. The particle size of slick oil is generally greater than 100 μm, the particle size of dispersed oil is 100 μm to 25 μm, the particle size of emulsified oil is generally 25 μm to 0.1 μm, and the particle size of dissolved oil is below 0.1 μm. For example, the slick oil with a particle size of 60 μm to 150 μm in oily sewage is mainly removed by gravity sedimentation, the dispersed oil with a particle size greater than 20 μm is removed by coalescence technology, and the dispersed oil and emulsified oil with a particle size greater than 10 μm are removed by cyclone separation, filtration, and flotation Technical removal, while dissolved oil generally needs to be removed by biological technology. Due to the limitation of chemical methods, physical or physicochemical deoiling technology has become a research hotspot in recent years. The existing physical deoiling methods are basically achieved by gravity sedimentation separation, but for heavy oil with high stability For wastewater containing aggregates, since crude oil particles are difficult to collide and aggregate, simple natural gravity sedimentation alone cannot achieve satisfactory treatment results. Therefore, it is necessary to find new high-efficiency separation methods and equipment to improve the oil-water separation effect.

Contents of the invention

The purpose of the present invention is to provide a separation of fine-grained emulsified oil, oily sewage purification device and separation method with high separation efficiency, to solve the problem that the existing separation method is limited in practical application due to economic or technological invention.

The technical solution adopted by the present invention to solve its technical problems is:

The oily sewage purification device includes: column separator, water inlet distribution device, floating oil collection device, at least one inflatable cyclone separator, at least one self-priming microbubble generator and at least one dissolved air precipitation microbubble generator; In the column body of the purification device, the upper part is a column separator, and the lower part is an inflatable cyclone separator; the gas filling point S of the dissolved air precipitation microbubble generator is at the top of the column body, and the gas filling point Q of the self-priming microbubble generator is at the column body. lower body.

The water inlet distribution device is located at the upper center of the column separator and is connected with the feeding pipe.

One section of the self-priming microbubble generator is connected to a circulation pump through a pipeline, and one section enters a column separator through a pipeline and is connected to a tangential inlet Q of an inflatable cyclone.

The dissolved air precipitation microbubble generator is on the outside of the column; one section of the dissolved air precipitation microbubble generator introduces saturated air dissolved water from a pressure dissolved air tank through a pipeline, and the other section passes through the pipeline to generate dissolved air precipitation microbubbles. After depressurization, energy dissipation, mass transfer, and degassing, the degassed water containing a large number of tiny bubbles is introduced into the column separator at the aeration point S.

The gas-filled cyclone separator includes a tangential inlet, a cylindrical vortex section, a large cone section, a small cone section and a straight pipe section; the tangential inlet is located on the upper side of the cylindrical vortex section, and the cylindrical vortex section Downwards are the large cone section, small cone section and straight pipe section; flange connection and direct welding are used between each cone section; the large cone angle α of the large cone section is 18-20°, and the small cone angle θ of the small cone section is 6~10°.

The dissolved air separation microbubble generator comprises a nozzle, a static mixing element group and a conduit; the nozzle is connected to the static mixing element group by a screw, and the static mixing element group is connected to the conduit by a thread; the static mixing element group consists of several twisted 180 ° or 270° spiral plates, two adjacent plates are vertically assembled in the casing, in a left-handed or right-handed shape; the diameter D of the nozzle and the number n of the spiral plates in the static mixing element group can be selected according to the The size of the bubble size needs to be adjusted.

The method of separating oily sewage, the oily sewage F enters the column separator from the water distribution device, flows downward, and the oil droplets in the oily sewage collide with the bubbles generated by the self-priming microbubble generator and the dissolved air precipitation microbubble generator , adhesion, rise to the oil slick collection device, the downward fluid is then pressurized and circulated to the self-priming microbubble generator through the inverted cone, and enters the inflatable cyclone tangentially for cyclone separation, while the bottom flow passes through the diversion Tube T is discharged as treated water.

Beneficial effects, due to the adoption of the above scheme, the two-stage inflatable flotation column is composed of a column separator, an inflatable cyclone separator, a self-priming bubble generator and a dissolved air precipitation microbubble generator; the main body of the device is a circular For the cross section of the cylinder, clear water (or circulating water) is pressurized and dissolved in the pressure dissolved air tank to form saturated dissolved air water. The saturated dissolved air water passes through the dissolved air precipitation microbubble generator at a certain pressure, and the pressure is reduced instantaneously. After energy dissipation, mass transfer, and gas release, a large number of dense microbubbles are formed and flow out from the dissolved air precipitation microbubble generator; the dissolved air precipitation microbubble generator is composed of a nozzle, a static mixing element, and a conical conduit. Saturated dissolved air water passes through the nozzle, depressurizes, dissipates energy, transfers mass, and releases gas once, and then passes through the static mixing element. The dissolved air water is the working medium, which flows in the pipeline and impacts the built-in plate element to increase the laminar flow movement of the fluid. Velocity gradient or form turbulent flow. In laminar flow, it is "segmentation-position movement-reconvergence". In turbulent flow, in addition to the above three situations, the fluid will also generate severe eddy flow in the direction of the cross section, which has a strong shear force. In the working medium, secondary depressurization, energy dissipation, mass transfer, gas release, and further division of the microbubbles, finally forming a large number of dense microbubbles and flowing out through the conical conduit; the released degassed water with a large number of microbubbles When entering the flotation column, due to its greatly reduced kinetic energy, low flow rate, and close to static, the ideal state of "static separation" for flotation column separation is approximately realized; The inverted cone at the lower end of the separator, after being pressurized by the circulating pump, passes through the self-priming micro-bubble generator to complete the whole process of injecting gas and dispersing the gas into micro-bubbles; oily sewage containing a large number of micro-bubbles , tangentially enters the gas-filled cyclone separator, due to the limitation of the wall, it changes from linear motion to high-speed rotary motion, and expands along the wall to form a swirl layer, forming a stable centrifugal force field in the cyclone, and at the same time, the oil droplets in the water and Bubbles collide and adhere to each other. Under the action of centrifugal force, they enter the oil phase in the center of the hydrocyclone, and then vertically upward to form an overflow, and the water phase near the wall of the cyclone moves downward to form an underflow, thereby realizing the separation of oil and water; the oily sewage is separated by flotation The feed port in the upper part of the column is fed; the oily sewage flows downward, and the air bubbles flow upward, forming a gas-liquid countercurrent state; during the countercurrent process, the air bubbles collide with and adhere to the oil beads, forming a bubble-oil bead complex that floats up to the column together The foam layer formed on the top of the body is discharged through the collection tank.

Combined with the small and uniform size of the microbubbles produced by dissolved air precipitation and the good separation effect of the flotation column, the method of producing microbubbles produced by dissolved air precipitation is introduced into the flotation column system, making use of the two inflation methods and the cyclone separation and separation The "combined effect" of the two separation methods of air flotation separation, the two-stage inflatable flotation column broadens the size range of oil droplets in the separation of oily oily water by the flotation method, and strengthens the separation effect.

Advantages: The "combined effect" of micro-bubbles generated by self-priming ejection airflow and micro-bubbles generated by dissolved air precipitation, cyclone separation and air flotation separation can effectively separate the fine-grained oil in oily sewage, It effectively solves the problem of difficult separation of fine-grained oil, the lower limit of effective flotation particle size is small, the separation time is short, and the operation cost is low, which solves the problem of difficult separation of emulsified oil in oily sewage.

Description of drawings

Figure 1 is a schematic structural view of the two-stage inflatable flotation column of the present invention.

Fig. 2 is a structural schematic diagram of the dissolved air precipitation microbubble generator of the present invention.

Fig. 3 is a schematic structural view of the pneumatic cyclone separator of the present invention.

In the figure, 1. Column separator; 2. Feeding distribution device; 3. Slick oil collection device; 4. Inflatable cyclone separator; 5. Self-priming microbubble generator; 6. Dissolved gas precipitation microbubble generator ;7, inverted cone; 41, tangential inlet; 42, cylindrical vortex section; 43, large cone section; 44, small cone section; 45 straight pipe section; 61, nozzle; 62, static mixing element group; 63, cone shaped conduit.

detailed description

Embodiment 1: The purification device includes a column separator 1, an inflow distribution device 2, a floating oil collection device 3, at least one inflatable cyclone separator 4, at least one self-priming microbubble generator 5 and at least one dissolved air separation microbubble generator. Bubble generator 6; in the column body of described purifying device, the upper part is column separator 1, and the lower part is inflatable cyclone separator 4; The filling point Q of the formula microbubble generator 5 is at the lower part of the cylinder.

The water inlet distribution device 2 is connected to the feeding pipe at the upper center of the column separator 1 .

One section of the self-priming microbubble generator 5 is connected to a circulating pump through a pipeline, and one section enters the column separator 1 through a pipeline and is connected to the tangential inlet Q of the inflatable cyclone.

Described gas-dissolved micro-bubble generator 6 is on the outside of the column body; one section of the gas-dissolved micro-bubble generator 6 introduces saturated gas-dissolved water from a pressure dissolved gas tank through a pipeline, and the other section passes through the pipeline through the gas-dissolved micro-bubble generator. The degassed water containing a large number of tiny bubbles in the bubble generator 6 is introduced into the column separator 1 at the filling point S after decompression, energy dissipation, mass transfer and degassing.

Described dissolved gas is separated out microbubble generator 6 and comprises a nozzle 61, static mixing element group 62 and conduit 63; Nozzle 61 is connected with static mixing element group 62 by thread, and static mixing element group 62 is connected with conduit 63 by thread; The static mixing element group 62 is composed of a number of spiral plates twisted 180° or 270°, and the adjacent two plates are vertically assembled in the casing, which is left-handed or right-handed; the diameter D of the nozzle 61 is the size of the static mixing element group 62 The number n of the spiral plates can be adjusted according to the size of the required air bubbles.

The gas-filled cyclone separator 4 includes a tangential inlet 41, a cylindrical vortex section 42, a large cone section 43, a small cone section 44 and a straight pipe section 45; the tangential inlet 41 is located on the cylindrical vortex section 42 On one side, the cylindrical vortex section 42 is followed by a large cone section 43, a small cone section 44 and a straight pipe section 45; the cone sections are connected by flanges and directly welded; the large cone angle α of the large cone section is 18~ 20°, the small cone angle θ of the small cone section is 6-10°.

The method for separating the oily sewage, the oily sewage F enters the column separator 1 from the water inlet distribution device 2, and flows downward, the oil droplets in the oily sewage are mixed with the self-priming microbubble generator 5 and the dissolved air microbubble generator 6 The generated bubbles collide and adhere, and rise to the floating oil collection device 3, and the downward fluid is pressurized and circulated to the self-priming microbubble generator 5 through the inverted cone 7, and then enters the inflatable cyclone 4 tangentially for cyclone. The flow is separated, while the bottom flow is discharged through the draft tube T as treated water.

The specific implementation method is as follows: the two-stage inflatable flotation column is composed of a column separator, an inflatable cyclone separator, a self-priming bubble generator and a dissolved air precipitation microbubble generator; Feed in; oily sewage flows downward, and air bubbles flow upward, forming a gas-liquid countercurrent state; in the process of countercurrent, air bubbles collide with and adhere to oil droplets to form a bubble-oil bead complex that floats up to the top of the column to form a foam layer. The collection tank is discharged; the clear water (or circulating water) is pressurized and dissolved in the pressure dissolved air tank to form saturated dissolved air water, and the saturated dissolved air water passes through the dissolved air precipitation microbubble generator at a certain pressure, releasing a large number of microbubbles The degassed water enters the flotation column; at the same time, the oily sewage in the column passes through the inverted cone at the lower end of the built-in cyclone separator of the flotation column, pressurized by the circulating pump, and passes through the self-priming microbubble generator. It enters the gas-filled cyclone separator tangentially. Under the action of centrifugal force, the oil phase enters the center of the cyclone and then vertically upwards to form an overflow, and the water phase close to the wall moves downwards to form an underflow, thereby realizing oil-water separation.

Embodiment 2: In Fig. 1, along the direction of the column separator 1 from top to bottom, there are successively the filling point S of the water inlet distribution device 2, the dissolved air precipitation microbubble generator 6, and the filling point Q of the self-priming microbubble generator and gas-filled cyclone separator 4. The water inlet is at the middle and upper part of the cylinder, and is connected with the water inlet distribution device. The dissolved air precipitation microbubble generator 6 is placed outside the column, and a tube is connected with the dissolved air precipitation microbubble generator 6 and inserted into the column body, and the insertion position is in the middle of the column body. Further down is the gas-filled cyclone separator 4, and the lower segment of the gas-charged cyclone is an inverted cone 7. The self-priming microbubble generator 5 is placed outside the column, one section of which is connected to the outlet of the circulation pump through a pipeline, and the other section is connected to a pipe and introduced into the column, and connected to the tangential inlet Q of the inflatable cyclone 4. Connect a pipe from the lower section of the inverted cone 7 to extend out of the column from the bottom of the column, and connect with the inlet of the circulation pump.

In FIG. 2 , the dissolved gas evolution microbubble generator 6 includes a nozzle 61 , a set of static mixing elements 62 , and a tapered conduit 63 . The nozzle 61 is connected with the static mixing element group 62 through a thread, and the static mixing element group 62 is connected with the tapered conduit 63 through a thread. The static mixing element group 62 is composed of a number of spiral plates twisted 180° or 270°, and two adjacent plates are vertically assembled in the casing in a left-handed or right-handed shape. The diameter D of the nozzle 61 and the number n of spiral plates in the static mixing element group 62 can be adjusted according to the size of the required bubble size. When the bubble size needs to be reduced, the diameter D can be reduced or n can be increased; A larger bubble size increases the diameter D or decreases n. After the saturated dissolved air water W from the pressurized air-dissolving tank passes through the dissolved-air precipitation microbubble generator 6, it forms degassed water containing a large number of fine bubbles, and then enters the column separator.

In FIG. 3 , the gas cyclone 4 includes a tangential inlet 41 , a cylindrical vortex section 42 , a large cone section 43 , a small cone section 44 and a straight pipe section 45 . The oily sewage enters the cylindrical vortex section 42 from the tangential inlet 41 of the inflatable cyclone 4, causing the liquid to vortex; the large cone section 43 uses the shrinkage of the cone section to increase the liquid flow rate and form a spiral rotation speed, which is large The cone section 43 is short and has a large taper, which can increase the swirl acceleration to facilitate the separation of oil and water; the small cone section 44 is the main separation section, and the small taper can reduce the upper limit of the particle size of the separated oil, and can also maintain a higher rotation speed to overcome Frictional loss of kinetic energy; the liquid flow rate in the straight pipe section 45 is basically stable and there is a certain backflow, which is convenient for further separation of oil and water.

During use, the oily sewage F enters the column separator 1 from the feeding device 2 and flows downward. Attached, rises and floats to the floating oil collection device 3, and the downward fluid is pressurized and circulated to the self-priming microbubble generator 5 through the inverted cone 7, and enters the inflatable cyclone 4 tangentially for cyclone separation, while the bottom flow passes through The draft tube T is discharged as treated water.

Claims (4)

1. an oil-containing sewage purifying device, comprise post separator (1), floating oil collecting device (3), self-suction microbubble generator (5), described self-suction microbubble generator (5) one end is connected with recycle pump by pipeline, it is characterized in that: also comprise and go out microvesicle generators (6) into water distribution device (2), inflatable cyclone separator (4), at least one molten air elutriation; In the cylinder of described refining plant, top is post separator (1), and bottom is inflatable cyclone separator (4); The other end of self-suction microbubble generator (5) is entered in post separator (1) by pipeline and is connected with the tangential inlet Q of inflatable cyclone separator (4), molten air elutriation goes out the inflation point S of microvesicle generators (6) on cylinder top, and the inflation point Q of self-suction microbubble generator (5) is in cylinder bottom; Described water inlet distribution device (2), at the central upper portion position of post separator (1), is connected with water inlet pipe; Described molten air elutriation goes out microvesicle generators (6) outside cylinder; Molten air elutriation goes out microvesicle generators (6) sections by the saturated dissolved gas water of pipeline introducing from pressure air-dissolving tank, and another section will go out microvesicle generators (6) through molten air elutriation by pipeline and contain the outgas water of a large amount of micro-bubble in inflation point S introducing post separator (1) through step-down, energy dissipating, mass transfer, outgas.

2. according to the oil-containing sewage purifying device described in claim 1, it is characterized in that: described molten air elutriation goes out microvesicle generators (6) and comprises a nozzle (61), static mixing element group (62) and conduit (63); Nozzle (61) and static mixing element group (62) are by screwed connection, and static mixing element group (62) and conduit (63) pass through screwed connection; Static mixing element group (62) is made up of the spiral plate of some torsions 180 ° or 270 °, and adjacent two plate orthogonal sets are contained in sleeve pipe, in left-handed or dextrorotation shape; The number n of the middle spiral plate of the diameter D size of nozzle (61), static mixing element group (62) can adjust according to the size of required bubble size.

3. oil-containing sewage purifying device according to claim 1, it is characterized in that: described inflatable cyclone separator (4), comprise a tangential inlet (41), cylinder swirl section (42), large cone section (43), small cone section (44) and straight length (45); Tangential inlet (41) is positioned at the upper side of cylinder swirl section (42), and cylinder swirl section (42) is down followed successively by large cone section (43), small cone section (44) and straight length (45); Each cone is intersegmental with Flange joint and directly welding; The large cone angle of large cone section αbe 18 ~ 20 °, the small-angle of small cone section θit is 6 ~ 10 °.

4. the method using oil-containing sewage purifying device described in claim 1 to be separated oily(waste)water, it is characterized in that: oily(waste)water F enters in post separator (1) by distribution device of intaking (2), flow downward, molten air elutriation goes out microvesicle generators (6) sections by the saturated dissolved gas water of pipeline introducing from pressure air-dissolving tank, another section will go out microvesicle generators (6) through step-down through molten air elutriation by pipeline, energy dissipating, mass transfer, the outgas water that outgas contains a large amount of micro-bubble is introduced in post separator (1) at inflation point S, in oily(waste)water, oil droplet goes out with by self-suction microbubble generator (5) and molten air elutriation the bubble hit that microvesicle generators (6) produces, adhere to, rise floating to floating oil collecting device (3), downward fluid again through back taper (7) pressurized circulation to self-suction microbubble generator (5), tangentially enter inflatable cyclone separator (4), carry out cyclonic separation, because wall restriction is high speed rotary motion by translate linear motion, and launch to form eddy flow layer along wall, stable centrifuge field is formed in swirler, oil droplet simultaneously in water and bubble mutually collide and adhere to, under centrifugal action, enter the oil phase of swirler central section, and then form overflow vertically upward, aqueous phase near wall moves downward formation underflow, and underflow is discharged as process water through thrust-augmenting nozzle T.