Storage tank flushing water treatment system

Abstract

The utility model provides a storage tank washing water treatment system. The storage tank washing water treatment system comprises a combined separation device, a hydrophilic and hydrophobic fiber coalescence demulsification separation device and an activated carbon adsorption device which are connected in sequence, the combined separation device comprises a first vertical tank body, and an axial-flow type oil-water pre-separator and a heterogeneous particle coalescence filter which are arranged in the first vertical tank body up and down; the hydrophilic and hydrophobic fiber coalescing demulsification separation device comprises a horizontal tank body and a hydrophilic and hydrophobic fiber coalescer arranged in the horizontal tank body; the activated carbon adsorption device comprises a second vertical tank body and an activated carbon adsorption module arranged in the second vertical tank body. The utility model constructs a three-stage coupled storage tank flushing water treatment system, can adapt to intermittent water inflow working conditions, avoids the generation of a large amount of hazardous wastes such as VOCs, scum, oil sludge and biochemical sludge, is short in process and high in efficiency, can realize deep treatment, and is particularly suitable for the field of deep treatment of oily wastewater.

Description

TECHNICAL FIELD

[0001] The utility model belongs to oil-containing wastewater separation equipment field, concretely relates to a kind of storage tank flushing water treatment system. BACKGROUND

[0002] Affected by global economic and regional situation changes, the volatility of oil price is high, and increasing oil reserves is an effective strategic measure to respond to major political and economic crises. In recent years, the construction of China's oil reserve facilities has grown rapidly, but the tank bottom and tank wall of oil storage tank are prone to form a layer of colloidal material composed of hydrocarbons, resins, asphaltenes and oil sludge, etc. When the storage tank is flushed, these substances enter the flushing water, resulting in high oil content, complex composition of flushing sewage, and high treatment difficulty. The mainstream process for treating storage tank flushing water is to introduce flushing sewage into a conditioning tank of refinery sewage, and to perform oil removal pretreatment through oil separation and air flotation; then, combined with biochemical deep treatment, sewage purification is realized. The traditional treatment process has problems such as high energy consumption, high drug consumption, high oil sludge and waste gas production. Chinese patent CN111533358A provides a treatment method for oil-water storage tank flushing water, which combines lifting, heating, air flotation, coagulation, sedimentation, electric adsorption, filtration and electric cation removal treatment devices together, and the process flow is complex, which increases energy consumption and cost. In addition, the traditional treatment method is generally only applicable to continuous water feeding conditions, and has low flexibility, and is not suitable for separate treatment of flushing water. However, flushing water treatment has the characteristics of intermittency.

[0003] Chinese patent CN114538639A discloses a pretreatment system for oil-containing sewage before biochemical treatment, which includes a power delivery device, a self-adaptive cyclonic air flotation separation device and a multi-medium coalescence oil removal device connected in sequence. The power delivery device is used to increase the energy of incoming oil-containing sewage. The self-adaptive cyclonic air flotation separation device includes a cyclonic air flotation separator and a rapid sedimentation module, which are used to sequentially perform cyclonic separation and sedimentation separation on the oil-containing sewage with increased energy. The multi-medium coalescence oil removal device includes one or more coalescence oil removal devices connected in series, which are used to deeply separate the water phase separated by the self-adaptive cyclonic air flotation separation device, realize the demulsification and collection of emulsified oil, and make the water phase treated by the multi-medium coalescence oil removal device enter the biochemical system. However, in the process of preliminary water-oil separation by the cyclonic air flotation separator in the self-adaptive cyclonic air flotation separation device, there are problems such as high energy consumption, high drug consumption, high oil sludge and waste gas emission. In addition, the oil content in oil-containing sewage fluctuates greatly and has a high concentration of oily suspended matter, which makes many oil-containing sewage treatment systems unsuitable.

[0004] Therefore, it is an urgent problem for those skilled in the art to develop a storage tank flushing water treatment system with high flexibility, simple process flow, small land occupation, small hazardous waste production and low treatment cost per ton of water. UTILITY MODEL CONTENT

[0005] The utility model discloses a kind of storage tank flushing water treatment systems, including sequentially connected combination separation device, hydrophobic hydrophilic fiber coalescence demulsification separation device and activated carbon adsorption device;The combination separation device includes first vertical tank body and is arranged in the first vertical tank body and is respectively upper and lower arrangement's axial flow type oil-water pre-separator and heterogeneous particle coalescence filter;The hydrophobic hydrophilic fiber coalescence demulsification separation device includes horizontal tank body and is arranged in the horizontal tank body hydrophobic hydrophilic fiber coalescer;The activated carbon adsorption device includes second vertical tank body and is arranged in the vertical tank body activated carbon adsorption module;

[0006] Wherein, the bottom of the axial flow type oil-water pre-separator is connected with the oil-containing sewage inlet pipeline.

[0007] In a preferred embodiment of the utility model,

[0008] The axial flow type oil-water pre-separator includes an oil collection pipe and a conical sleeve and a cyclone cylinder arranged above and below and communicated with each other, the cyclone cylinder is a cylindrical structure, a cyclone blade is arranged at the inner bottom of the cyclone cylinder, the lower part of the oil collection pipe is inserted from the top of the conical sleeve, and the bottom end is placed in the upper part of the cyclone cylinder; the bottom of the cyclone cylinder is connected with the oil-containing sewage inlet pipeline; wherein, the inner diameter of the top of the conical sleeve is smaller than the inner diameter of the bottom of the conical sleeve, and a plurality of water phase outlet holes are arranged on the side wall of the conical sleeve.

[0009] Preferably, the inner diameter of the cyclone cylinder is the same as the inner diameter of the bottom of the conical sleeve, and the top end of the cyclone cylinder is detachably connected with the bottom end of the conical sleeve; and / or, the outer diameter of the oil collection pipe is the same as the inner diameter of the top of the conical sleeve, and the oil collection pipe is detachably connected with the top end of the conical sleeve.

[0010] More preferably, the axial flow type oil-water pre-separator further includes a water collection sleeve arranged outside the conical sleeve, which is connected with the conical sleeve; a separation water phase outlet is arranged on the side of the water collection sleeve.

[0011] In a preferred embodiment of the utility model,

[0012] The height of the oil collection pipe is 150-230 mm; and / or,

[0013] The diameter of the oil collection pipe is 20-25 mm; and / or,

[0014] The height of the conical sleeve is 160-180 mm; and / or,

[0015] The taper of the conical sleeve is 70-80°; and / or,

[0016] The height of the cyclone cylinder is 400-600 mm; and / or,

[0017] The diameter of the cyclone cylinder is 50-70 mm.

[0018] In a preferred embodiment of the utility model,

[0019] The cyclone vane is composed of 6-8 vanes arranged uniformly; and / or,

[0020] The spiral angle of the cyclone vane is 30-60°; and / or,

[0021] The height of the cyclone vane is 30-50 mm; and / or,

[0022] The diameter of the cyclone vane is equal to the inner diameter of the cyclone cylinder; and / or,

[0023] The number of water phase outlet holes of the conical sleeve is 12-24; and / or,

[0024] The inner diameter of the water phase outlet hole of the conical sleeve is 10-15 mm; and / or,

[0025] The plurality of water phase outlet holes of the conical sleeve are arranged uniformly.

[0026] In a preferred embodiment of the utility model,

[0027] The distance between the heterogeneous particle coalescence filter and the inlet end of the first vertical tank body is 1 / 3-2 / 3 of the length of the first vertical tank body; the height of the heterogeneous particle coalescence filter is 1 / 3-1 / 2 of the height of the first vertical tank body;

[0028] Preferably,

[0029] The heterogeneous particle coalescence filter comprises an upper particle bed layer, a middle particle bed layer and a lower particle bed layer;

[0030] More preferably,

[0031] The bed layer thickness of the upper particle bed layer is 0.8-1 m; and / or,

[0032] The bed layer thickness of the middle particle bed layer is 0.6-3 m; and / or,

[0033] The lower particle bed layer comprises a bed layer thickness of 0.3-0.5 m;

[0034] Most preferably,

[0035] The particle size of the upper particle bed layer is 0.2-2 mm, and the particle density is 1.1-2.0 g / cm 3 ; and / or,

[0036] The intermediate particle bed has a particle size of 0.8–3 mm and a particle density of 1.3–4 g / cm³. 3 ; and / or,

[0037] The lower particle bed has a particle size of 4–8 mm and a particle density of 2.6–5.2 g / cm³. 3 .

[0038] In a preferred embodiment of this utility model,

[0039] The heterogeneous particle agglomeration filter is provided with a first filter cap and a support plate below it, which are connected to the inner wall of the first vertical tank.

[0040] Preferably, the lower side wall of the first vertical tank is provided with a primary backwash air inlet and a primary backwash water inlet, which are respectively connected to the primary backwash air inlet pipeline and the primary backwash water inlet pipeline; the top of the first vertical tank is provided with a primary backwash outlet.

[0041] More preferably, the first vertical tank is also provided with a water distribution plate, which is connected to the primary backwash water inlet pipeline and is located below the heterogeneous particle coalescence filter.

[0042] Most preferably, the water distribution plate is a sieve-hole disc spray shape; the diameter of the water distribution plate is 1 / 2 to 3 / 4 of the diameter of the first vertical tank; and / or, the vertical distance between the water distribution plate and the upper tangent of the first vertical tank is 0.2 to 1 m.

[0043] In a preferred embodiment of this utility model,

[0044] The hydrophilic and hydrophobic fiber coalescer is coaxially arranged in the middle section of the horizontal tank, and its outer wall is connected to the inner wall of the horizontal tank.

[0045] Preferred,

[0046] The distance between the hydrophilic / hydrophobic fiber coalescer and the inlet end of the horizontal tank is 1 / 4 to 1 / 3 of the length of the horizontal tank; and / or

[0047] The length of the hydrophilic / hydrophobic fiber coalescer is 1 / 4 to 1 / 2 of the length of the horizontal tank; and / or

[0048] The hydrophilic and hydrophobic fiber coalescer includes a fiber bed formed by a combination of hydrophilic and oleophilic fibers, wherein the fiber bed is block-shaped or columnar.

[0049] More preferably,

[0050] The diameter of the hydrophilic fiber and / or the oleophilic fiber is 20-50 μm;

[0051] The best option,

[0052] The weight of the lipophilic fiber is 70-80 wt% of the weight of the fiber bed.

[0053] In a preferred embodiment of the utility model,

[0054] The bottom of the horizontal tank body is provided with a secondary backwashing air inlet and a secondary backwashing water inlet, and the top of the horizontal tank body is provided with a backwashing outlet.

[0055] In a preferred embodiment of the utility model,

[0056] The activated carbon adsorption module is an activated carbon particle bed composed of activated carbon particles;

[0057] Preferably,

[0058] The particle size of the activated carbon particles in the activated carbon adsorption module is 60-100 mesh; and / or,

[0059] The height of the activated carbon particle bed in the activated carbon adsorption module is 0.6-2 m.

[0060] In a preferred embodiment of the utility model,

[0061] The lower part of the activated carbon adsorption module is provided with a second water filter cap and a support plate, which are connected with the inner side wall of the second vertical tank body;

[0062] Preferably, the distance between the second water filter cap and the support plate and the lower tangent line of the second vertical tank body is 0.5-1.5 m;

[0063] More preferably,

[0064] The lower side wall of the second vertical tank body is provided with a tertiary backwashing water inlet, and the top of the second vertical tank body is provided with a tertiary backwashing outlet.

[0065] Compared with the prior art, the utility model has the beneficial effects that:

[0066] 1. The storage tank flushing water treatment system of the utility model breaks through the traditional oil separation-air flotation-biochemical oil-containing wastewater treatment mode, constructs a three-stage coupled storage tank flushing water treatment system (physical method treatment technology combination), avoids the generation of a large amount of VOCs, dregs, oil sludge, biochemical sludge and other hazardous wastes, has a short process, high efficiency, low ton water treatment cost, can realize deep treatment, and is especially suitable for the field of oil-containing wastewater deep treatment.

[0067] 2. The storage tank flushing water treatment system of the utility model is suitable for intermittent water inlet conditions, and solves the problem of low flexibility and inability to treat flushing water alone in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0068] Figure 1 It is the structure schematic view of the storage tank flushing water treatment system of the utility model;

[0069] Figure 2 It is the structure schematic view of the combined separation device in the storage tank flushing water treatment system of the utility model;

[0070] Figure 3 It is the structure schematic view of the axial flow type oil-water pre-separator of the utility model;

[0071] Figure 4 It is the structure schematic view of the hydrophilic-hydrophobic fiber coalescence demulsification separation device in the storage tank flushing water treatment system of the utility model;

[0072] Figure 5 It is the structure schematic view of the activated carbon adsorption device in the storage tank flushing water treatment system of the utility model;

[0073] In the drawing, 1-1 is a first water inlet, 1-2 is an axial flow type oil-water pre-separator, 1-3 is a first liquid level indicator, 1-4 is a first upper pressure gauge, 1-5 is a heterogeneous particle coalescence filter, 1-6 is a pressure transmitter, 1-7 is a first lower pressure gauge, 1-8 is a first filter cap and support plate, 1-9 is a water distribution plate, 1-10 is a first water outlet, 1-11 is a first upper head pressure gauge, 1-12 is a first backwashing water inlet, 1-13 is a first backwashing air inlet, 1-14 is a first oil outlet, and 1-15 is a first backwashing outlet.

[0074] 1-2-1 is an oil collecting pipe, 1-2-2 is a conical sleeve, 1-2-3 is a cyclone cylinder, and 1-2-4 is a cyclone vane.

[0075] 2-1 is a second water inlet, 2-2 is a hydrophilic-hydrophobic fiber coalescer, 2-3 is a pressure gauge, 2-4 is a second water outlet, 2-5 is a second oil outlet, 2-6 is an oil bag, 2-7 is a second liquid level indicator, 2-8 is a second backwashing air inlet, 2-9 is a second backwashing water inlet, and 2-10 is a second backwashing outlet.

[0076] 3-1 is a third water inlet, 3-2 is a third upper head pressure gauge, 3-3 is a third upper pressure gauge, 3-4 is an activated carbon adsorption module, 3-5 is a second filter cap and support plate, 3-6 is a third lower pressure gauge, 3-7 is a third liquid level indicator, 3-8 is a pressure transmitter, 3-9 is a third water outlet, 3-10 is a third backwashing water inlet, and 3-11 is a third backwashing outlet. DETAILED DESCRIPTION

[0077] In the utility model, COD refers to the dissolved organic matter in sewage, including dissolved oil.

[0078] In the utility model, 10% v / v refers to the volume fraction of oil in sewage.

[0079] The utility model is further described in detail below with reference to the drawings:

[0080] As Figure 1 shown, the utility model provides a kind of storage tank flushing water treatment system, including combination separation device, hydrophilic-hydrophobic fiber coalescence demulsification separation device and activated carbon adsorption device connected in turn;Wherein, combination separation device is used to carry out cyclone preseparation to oily sewage and adjust flow fluctuation, realize the removal of suspended solids, also have coalescence separation effect to part of petroleum hydrocarbon droplet;Hydrophilic-hydrophobic fiber coalescence demulsification separation device is used to carry out demulsification, depth separation treatment to oily sewage after being handled by combination separation device, realize the depth separation of microfine petroleum hydrocarbon droplet, emulsified oil;Activated carbon adsorption device is used to remove COD to oily sewage after being handled by hydrophilic-hydrophobic fiber coalescence demulsification separation device.The following will be respectively combination separation device, hydrophilic-hydrophobic fiber coalescence demulsification separation device and activated carbon adsorption device are elaborated and explained.

[0081] Figure 2 The structure diagram of combination separation device is shown, by Figure 2 Known, it includes axial flow type oil-water preseperator 1-2, heterogeneous particle coalescence filter 1-5 and first vertical tank body, for removing oil droplet and suspended solids, realize the pretreatment to storage tank flushing water.Specifically, the combination separation device includes first vertical tank body and the axial flow type oil-water preseperator 1-2 and heterogeneous particle coalescence filter 1-5 arranged in the first vertical tank body.The axial flow type oil-water preseperator 1-2 and the heterogeneous particle coalescence filter 1-5 are arranged on, below.The axial flow type oil-water preseperator 1-2 is connected with oily sewage inlet pipeline, both connection first aspect can make oily sewage enter axial flow type oil-water preseperator 1-2 and carry out the preliminary separation of water and oil, second aspect can realize the fixing of axial flow type oil-water preseperator 1-2 in primary vertical tank body.Specific to the embodiment, the side wall of the first vertical tank body is provided with primary water inlet 1-1, and the oily sewage inlet pipeline passes through the primary water inlet 1-1 to be connected with the bottom in the axial flow type oil-water preseperator 1-2, so that the entry of oily sewage and the fixing of the axial flow type oil-water preseperator 1-2 in the primary vertical tank body are realized.Exemplarily, the axial flow type oil-water preseperator 1-2 is connected with oily sewage inlet pipeline by flange.The heterogeneous particle coalescence filter 1-5 is connected with the inner side wall of the first vertical tank body.

[0082] It needs to be explained that, Figure 2 The number of axial flow type oil-water preseperator 1-2 in the above embodiment is two, and both are connected with oily sewage inlet pipeline.However Figure 2 The number of axial flow type oil-water preseperator 1-2 in the above embodiment does not constitute limitation to combination separation device.

[0083] Figure 3 A schematic diagram of the axial flow oil-water pre-separator 1-2 is shown, consisting of... Figure 3 It is understood that the device includes an oil collecting pipe 1-2-1 and a conical sleeve 1-2-2 and a vortex cylinder 1-2-3, which are arranged above and below and interconnected. The vortex cylinder 1-2-3 contains vortex blades 1-2-4. The lower part of the oil collecting pipe 1-2-1 is located within the conical sleeve 1-2-2 and the vortex cylinder 1-2-3. The bottom of the vortex cylinder 1-2-3 is connected to the oily wastewater inlet pipeline. The vortex blades 1-2-4 are located below the oil collecting pipe 1-2-1. The vortex cylinder 1-2-3 is a hollow cylindrical structure with openings at both the top and bottom, forming a vortex cavity within it. The bottom of the vortex cylinder 1-2-3 is connected to the oily wastewater inlet pipeline via a flange. The vortex blades 1-2-4 are located inside the vortex cylinder 1-2-3 and are connected to the inner wall of the vortex cylinder 1-2-3. Preferably, the height of the swirl tube 1-2-3 is 400-600 mm; and / or, the diameter of the swirl tube 1-2-3 is 50-70 mm. More preferably, the swirl blade 1-2-4 consists of 6-8 blades evenly arranged; and / or, the helix angle of the swirl blade 1-2-4 is 30-60°; and / or, the height of the swirl blade 1-2-4 is 30-50 mm; and / or, the diameter of the swirl blade 1-2-4 is equal to the inner diameter of the swirl tube 1-2-3.

[0084] The top of the vortex tube 1-2-3 is connected to the bottom of the conical sleeve 1-2-2. Preferably, the vortex tube 1-2-3 and the conical sleeve 1-2-2 are detachably connected, that is, the top of the vortex tube 1-2-3 and the bottom of the conical sleeve 1-2-2 are detachably connected; for example, the two can be detachably connected by a flange or bolts. More preferably, the inner diameter of the top of the vortex tube 1-2-3 is the same as the inner diameter of the bottom of the conical sleeve 1-2-2. The conical sleeve 1-2-2 is a hollow cone structure with openings at both the top and bottom, and the inner diameter of its top is smaller than the inner diameter of its bottom. The side wall of the conical sleeve 1-2-2 is provided with multiple conical sleeve water phase outlet holes, so that the water phase can be rotated out of the conical sleeve 1-2-2 through the conical sleeve water phase outlet holes. Preferably, the number of water phase outlet holes in the conical sleeve is 12 to 24; and / or, the inner diameter of the water phase outlet holes in the conical sleeve is 10 to 15 mm; and / or, the plurality of water phase outlet holes in the conical sleeve are evenly arranged. More preferably, the height of the conical sleeve 1-2-2 is 160 to 180 mm; and / or, the taper of the conical sleeve 1-2-2 is 70 to 80°. Most preferably, the plurality of water phase outlet holes in the conical sleeve are arranged in two rows.

[0085] The top of the conical sleeve 1-2-2 is connected with the outer sidewall of the oil collecting pipe 1-2-1, and the top of the conical sleeve 1-2-2 can be welded with the outer sidewall of the oil collecting pipe 1-2-1. The top of the conical sleeve 1-2-2 can also be detachably connected with the oil collecting pipe 1-2-1; for example, the two can be detachably connected through flanges or bolts. The oil collecting pipe 1-2-1 is a hollow cylindrical structure with openings at the top and bottom. The aforementioned "the lower part of the oil collecting pipe 1-2-1 is arranged in the conical sleeve 1-2-2 and the cyclone cylinder 1-2-3" means that a part of the oil collecting pipe 1-2-1 is arranged in the conical sleeve 1-2-2 and the cyclone cavity, and another part is arranged above the conical sleeve 1-2-2. In other words, the height of the top of the oil collecting pipe 1-2-1 in the vertical direction is greater than the height of the top of the conical sleeve 1-2-2 in the vertical direction, the height of the bottom of the oil collecting pipe 1-2-1 in the vertical direction is less than the height of the bottom of the conical sleeve 1-2-2 in the vertical direction, and the height of the bottom of the oil collecting pipe 1-2-1 in the vertical direction is greater than the height of the top of the cyclone vane 1-2-4 in the vertical direction. Preferably, the height of the oil collecting pipe 1-2-1 is 150-230 mm; and / or, the diameter of the oil collecting pipe 1-2-1 is 20-25 mm.

[0086] In a preferred embodiment of the utility model, the axial flow type oil-water pre-separator 1-2 is further provided with a water collecting sleeve, the water collecting sleeve is arranged outside the conical sleeve 1-2-2 and is connected with the conical sleeve 1-2-2. In this embodiment, the top of the water collecting sleeve is connected with the top of the conical sleeve 1-2-2, and the bottom of the water collecting sleeve is connected with the bottom of the conical sleeve 1-2-2. The inner diameter of the water collecting sleeve is greater than the outer diameter of the conical sleeve 1-2-2, so as to temporarily store the water phase turned out by the conical sleeve 1-2-2. In this embodiment, a separated water phase outlet is formed in the side surface of the water collecting sleeve, so as to turn out the temporarily stored water phase from the axial flow type oil-water pre-separator 1-2.

[0087] In summary, the oily sewage in the inlet pipeline enters the cyclone chamber from the bottom of the cyclone 1-2-3, and forms a rotating fluid under the action of the cyclone vane 1-2-4 and moves upward. In the rotating fluid, the outer layer is mainly water phase and the inner layer is mainly oil phase. In the process of upward movement of the rotating fluid, the oil phase in the inner layer enters the oil collection pipe 1-2-1. The water phase in the outer layer enters the conical sleeve 1-2-2, and since the conical sleeve water phase outlet hole is provided on the conical sleeve 1-2-2, the water phase in the outer layer is turned out of the conical sleeve 1-2-2 through the conical sleeve water phase outlet hole and enters the water collection sleeve. Since the water collection sleeve is provided with a separated water phase outlet, the water phase turned out of the conical sleeve water phase outlet hole is turned out of the axial flow oil-water pre-separator 1-2 through the separated water phase outlet, and under the action of gravity, falls to the heterogeneous particle coalescence filter 1-5. The conical sleeve 1-2-2 in the axial flow oil-water pre-separator 1-2 realizes the steady flow of the rotating fluid, which is more conducive to oil-water separation, and thus quickly realizes oil-water separation, especially for oily sewage with a large oil-water phase ratio (about 10% v / v), a Reynolds coefficient of the inlet fluid of 10000-30000, and an inlet flow rate of 0.1-0.8 m / s.

[0088] The heterogeneous particle coalescence filter 1-5 is connected to the inner side wall of the first vertical tank body, and a particle bed layer is arranged in the heterogeneous particle coalescence filter 1-5. The particle bed layer has the functions of filtering and separating suspended solids and coalescing and separating oil droplets. The distance between the heterogeneous particle coalescence filter 1-5 and the inlet end of the first vertical tank body is 1 / 3-2 / 3 of the length of the first vertical tank body; and the height of the heterogeneous particle coalescence filter 1-5 is 1 / 3-1 / 2 of the height of the first vertical tank body. Preferably, the cross-sectional average flow velocity of the particle bed layer is 0.003-0.1 m / s; and / or, the pressure difference between the inlet and outlet of the particle bed layer is 0.1-0.2 Mpa. Preferably, the heterogeneous particle coalescence filter 1-5 includes a plurality of particle bed layers made of different materials, and more preferably includes 3-6 particle bed layers made of different materials, so as to achieve a better filtering and separating effect of suspended solids and coalescing and separating effect of oil droplets. In the embodiment, the heterogeneous particle coalescence filter 1-5 includes three particle bed layers, which are referred to as an upper particle bed layer, a middle particle bed layer and a lower particle bed layer. The thickness of the upper particle bed layer is 0.8-1 m; and / or, the thickness of the middle particle bed layer is 0.6-3 m; and / or, the thickness of the lower particle bed layer is 0.3-0.5 m. The upper particle bed layer can be made of, but is not limited to, a polytetrafluoroethylene organic polymer material with a particle size of 0.2-2 mm and a particle density of 1.1-2.0 g / cm 3 The middle particle bed layer can be made of, but is not limited to, a polytetrafluoroethylene organic polymer material with a particle size of 0.8-3 mm and a particle density of 1.3-4 g / cm 3Walnut shell, quartz sand type inorganic granular material; the lower layer of the granular bed can specifically adopt, but is not limited to, granular size of 4-8mm, granular density of 2.6-5.2g / cm 3 Cobbles, garnet type heavy large size particles.

[0089] The top of the first vertical tank body is provided with a first oil discharge port 1-14, and the oil phase in the oil collecting pipe 1-2-1 is finally transferred out of the first vertical tank body through the top of the oil collecting pipe 1-2-1 and the first oil discharge port 1-14. The bottom of the first vertical tank body is provided with a first water outlet 1-10, so that the oil-containing sewage treated by the axial flow type oil-water pre-separator 1-2 and the heterogeneous particle coalescence filter 1-5 is transferred out of the combined separation device and can be further transferred to the next process. The side of the first vertical tank body is also provided with a first liquid level gauge 1-3 to monitor the liquid level height in the combined separation device.

[0090] In a preferred embodiment of the utility model, the side of the first vertical tank body is provided with a first upper pressure gauge 1-4 and a first lower pressure gauge 1-7. The first upper pressure gauge 1-4 is arranged above the heterogeneous particle coalescence filter 1-5 to monitor the pressure at the inlet of the granular bed. The first lower pressure gauge 1-7 is arranged below the heterogeneous particle coalescence filter 1-5 to monitor the pressure at the outlet of the granular bed, and thus the pressure difference between the two is obtained. The side of the first vertical tank body is also provided with a transformer 1-6 to obtain the real-time pressure difference at the inlet and outlet of the granular bed according to the real-time pressure of the first upper pressure gauge 1-4 and the first lower pressure gauge 1-7. The top surface of the first vertical tank body is provided with a first upper head pressure gauge 1-11 to detect the working pressure in the first vertical tank body.

[0091] In a preferred embodiment of the utility model, the lower part of the heterogeneous particle coalescence filter 1-5 is provided with a first water filter cap and support plate 1-8, which is arranged in the first vertical tank body and connected with the inner side wall of the first vertical tank body. The first water filter cap and support plate 1-8 can support the heterogeneous particle coalescence filter 1-5 and further remove the suspended solids in the oil-containing sewage.

[0092] In an optimal embodiment of the utility model, the lower side wall of the first vertical tank body is provided with a first backwashing air inlet 1-13 and a first backwashing water inlet 1-12, both of which are arranged below the heterogeneous particle coalescence filter 1-5. The first backwashing air inlet 1-13 is connected with a first backwashing air pipeline, so that the gas in the first backwashing air pipeline enters the first vertical tank body and backwashes it. The first backwashing water inlet 1-12 is connected with a first backwashing water pipeline, so that the water in the first backwashing water pipeline enters the first vertical tank body and backwashes it. The top of the first vertical tank body is provided with a first backwashing outlet 1-15, so that the first backwashing air or the first backwashing water can be discharged from the first vertical tank body. Preferably, a backwashing material running prevention component is arranged at the position of the first backwashing outlet 1-15.

[0093] In an optimal embodiment of the utility model, a water distribution plate 1-9 is further arranged in the first vertical tank body and connected with the first backwashing water pipeline, so as to fix the water distribution plate 1-9 and uniformly distribute the first backwashing water. The water distribution plate 1-9 is preferably arranged below the heterogeneous particle coalescence filter 1-5, and more preferably arranged below the first water filter cap and support plate 1-8. The type of the water filter cap can be selected according to the size of the filter material, the processing capacity, the pressure bearing strength and the like.

[0094] The structure type of the water distribution plate 1-9 includes but is not limited to a sieve hole disc shape and a sieve hole cylinder shape, and is preferably a sieve hole disc shape. When the water distribution plate 1-9 is a sieve hole disc shape, the diameter of the water distribution plate 1-9 is 1 / 2-3 / 4 of the diameter of the first vertical tank body, and the vertical distance between the water distribution plate 1-9 and the upper tangent line of the first vertical tank body is 0.2-1 m. For example, the water distribution plate 1-9 is a sieve hole disc shape, the diameter of the water distribution plate 1-9 is 3 / 4 of the diameter of the first vertical tank body, and the vertical distance between the water distribution plate 1-9 and the upper tangent line of the first vertical tank body is 0.8 m.

[0095] When the pressure difference between the first water inlet 1-1 and the first water outlet 1-10 reaches 0.3-0.4 MPa or the separation efficiency decreases to 88%, backwashing of the combined separation device is needed, and preferably, nitrogen and water are mixed for backwashing. For example, nitrogen is used for backwashing for 5-10 min, then backwashing water is introduced into the first vertical tank body, and water is used for backwashing for 5-10 min. The aforementioned nitrogen backwashing and water backwashing are repeated three times, which is regarded as one backwashing.

[0096] In summary, the oily sewage in the oily sewage inlet pipeline enters the cyclone cavity through the first water inlet 1-1 and the bottom of the cyclone cylinder 1-2-3, and forms a rotating fluid under the action of the cyclone blade 1-2-4 and moves upward. In the rotating fluid, the outer layer is mainly water phase and the inner layer is mainly oil phase. During the upward movement of the rotating fluid, the oil phase in the inner layer enters the oil collection pipe 1-2-1 and then is discharged through the first oil outlet 1-14, that is, the combined separation device. The water phase in the outer layer enters the conical sleeve 1-2-2, and since the conical sleeve 1-2-2 is provided with a conical sleeve water phase outlet hole, the water phase in the outer layer is discharged from the conical sleeve 1-2-2 through the conical sleeve water phase outlet hole and enters the water collection sleeve. Since the water collection sleeve is provided with a separated water phase outlet, the water phase discharged from the conical sleeve water phase outlet hole is discharged from the axial flow oil-water pre-separator 1-2 through the separated water phase outlet. Under the action of gravity, the water phase discharged from the axial flow oil-water pre-separator 1-2 enters the heterogeneous particle coalescence filter 1-5, and the suspended solids are removed and the petroleum hydrocarbon is preliminarily coalesced and separated through the heterogeneous particle coalescence filter 1-5. The suspended solids and part of the petroleum hydrocarbon droplets are intercepted in the heterogeneous particle coalescence filter 1-5. The water phase from which the suspended solids and part of the petroleum hydrocarbon droplets are removed continues to move downward, passes through the first water filter cap and support plate 1-8, and is finally discharged from the combined separation device through the first water outlet 1-10.

[0097] Figure 4 The structure diagram of the hydrophilic-hydrophobic fiber coalescence demulsification separation device is shown, which comprises a horizontal tank body, Figure 4 It can be seen that the horizontal tank body is provided with a second water inlet 2-1, and specifically to the embodiment, the left side of the horizontal tank body is provided with the second water inlet 2-1, which is connected with the first water outlet 1-10 in the combined separation device, so that the water phase treated by the axial flow oil-water pre-separator 1-2 and the heterogeneous particle coalescence filter 1-5 is transferred into the hydrophilic-hydrophobic fiber coalescence demulsification separation device, that is, into the horizontal tank body.

[0098] The hydrophilic-hydrophobic fiber coalescence demulsification separation device (horizontal tank) is provided with a hydrophilic-hydrophobic fiber coalescer 2-2 which is connected with the circumferential surface of the horizontal tank and is used for demulsification and deep separation treatment of the oil-containing sewage treated by the combined separation device, so as to realize deep separation of micro-fine petroleum hydrocarbon droplets and emulsified oil. Preferably, the distance between the hydrophilic-hydrophobic fiber coalescer 2-2 and the inlet end of the horizontal tank is 1 / 4-1 / 3 of the length of the horizontal tank; and / or, the length of the hydrophilic-hydrophobic fiber coalescer 2-2 is 1 / 4-1 / 2 of the length of the horizontal tank; and / or, the hydrophilic-hydrophobic fiber coalescer 2-2 is provided with a fiber bed layer formed by combination and weaving of hydrophilic fibers and oleophilic fibers, and the fiber bed layer can be in the form of blocks, columns or the like. Since the fiber bed layer has better separation performance for oil and water when flowing horizontally, the fiber bed layer is arranged in the horizontal tank. More preferably, the hydrophilic fibers can be made of glass fiber, stainless steel, hastelloy, monel alloy or the like, and the oleophilic fibers can be made of polyester, nylon, polypropylene, polytetrafluoroethylene or the like; and more preferably, the diameter of the hydrophilic fibers and / or the oleophilic fibers is 20-50 μm.

[0099] For example, the preparation method of the fiber bed layer is as follows: first, 5-11 oleophilic fibers and 3-6 hydrophilic fibers are combined to form a bundle-shaped fiber; then the bundle-shaped fiber is woven into an Ω shape with a diameter of 3-5 mm to form a single-layer fiber net; and finally, the single-layer fiber net is stacked to form the fiber bed layer. Therefore, the hydrophilic-hydrophobic fiber coalescer 2-2 is provided with a fiber bed layer with high filling density which is formed by combination and weaving of hydrophilic fibers and oleophilic fibers. The fiber bed layer is used for capturing and coalescing separation of oil droplets by coalescence and interception. The oil droplets coalesced and grown on the fiber bed layer will migrate along the Ω shape of the fiber bed layer and gather at the top of the Ω shape. Preferably, the weight of the oleophilic fibers is 70-80 wt% of the weight of the fiber bed layer, and in this case, the separation efficiency of oil and water is optimal.

[0100] The bottom of the hydrophilic-hydrophobic fiber coalescence demulsification separation device (horizontal tank) is provided with a secondary water outlet 2-4, and in this embodiment, the right bottom of the horizontal tank is provided with the secondary water outlet 2-4 which is connected with the activated carbon adsorption device, so as to make the water phase treated by the hydrophilic-hydrophobic fiber coalescence demulsification separation device enter the activated carbon adsorption device. The top of the hydrophilic-hydrophobic fiber coalescence demulsification separation device (horizontal tank) is provided with a secondary oil discharge port 2-5, and in this embodiment, the right top of the horizontal tank is provided with the secondary oil discharge port 2-5, so as to make the oil phase treated by the hydrophilic-hydrophobic fiber coalescence demulsification separation device discharge. Preferably, the secondary oil discharge port 2-5 is provided with an oil bag 2-6 and a second liquid level meter 2-7. The oil bag 2-6 is used for storing the oil separated by the hydrophilic-hydrophobic fiber coalescer 2-2, and the second liquid level meter 2-7 is used for observing the interface of oil and water.

[0101] The bottom of the hydrophilic-hydrophobic fiber coalescence demulsification separation device (horizontal tank) is provided with a secondary backwashing air inlet 2-8 and a secondary backwashing water inlet 2-9, and the top of the hydrophilic-hydrophobic fiber coalescence demulsification separation device (horizontal tank) is provided with a backwashing outlet 2-10. Preferably, the backwashing outlet 2-10 is arranged on the left side of the hydrophilic-hydrophobic fiber coalescer 2-2, the secondary backwashing water inlet 2-9 is arranged on the right side of the hydrophilic-hydrophobic fiber coalescer 2-2, and the secondary backwashing air inlet 2-8 is arranged on the lower side of the hydrophilic-hydrophobic fiber coalescer 2-2. The use methods of the secondary backwashing air inlet 2-8, the secondary backwashing water inlet 2-9 and the backwashing outlet 2-10 are basically the same as those of the aforementioned primary backwashing water inlet 1-12, the primary backwashing air inlet 1-13 and the primary backwashing outlet 1-15, which will not be described here. The hydrophilic-hydrophobic fiber coalescence demulsification separation device is also provided with a pressure gauge 2-3 arranged on the right side of the hydrophilic-hydrophobic fiber coalescer 2-2 to monitor the pressure during backwashing.

[0102] When the pressure difference between the secondary water inlet 2-1 and the secondary water outlet 2-4 of the hydrophilic-hydrophobic fiber coalescence demulsification separation device reaches 0.2-0.4 MPa or the separation efficiency decreases to 90%, backwashing of the hydrophilic-hydrophobic fiber coalescence demulsification separation device is required, preferably using nitrogen and water for mixed backwashing. For example, nitrogen backwashing can be used for 5-10 min, and then backwashing water is introduced into the horizontal tank for 5-10 min of water backwashing. The aforementioned nitrogen backwashing and water backwashing are repeated three times, which is regarded as one backwashing.

[0103] Figure 5 The structure of the activated carbon adsorption device is shown in the structural schematic diagram, which comprises a second vertical tank, Figure 5 It can be seen that the activated carbon adsorption device (second vertical tank) is provided with a tertiary water inlet 3-1, and in this embodiment, the upper left side of the second vertical tank is provided with a tertiary water inlet 3-1, which is connected with the secondary water outlet 2-4 in the hydrophilic-hydrophobic fiber coalescence demulsification separation device, so that the water phase treated by the hydrophilic-hydrophobic fiber coalescence demulsification separation device is transferred into the activated carbon adsorption device, i.e. into the second vertical tank thereof. The activated carbon adsorption device (second vertical tank) is provided with a tertiary water outlet 3-9, and in this embodiment, the lower part of the second vertical tank is provided with a tertiary water outlet 3-9, so that the purified water from which COD is removed is transferred out of the activated carbon adsorption device, i.e. out of the storage tank for washing water treatment system.

[0104] The active carbon adsorption device (second vertical tank body) is internally provided with an active carbon adsorption module 3-4, which is connected with the circumferential surface of the second vertical tank body, and is used for deep treatment of COD and adsorption of fine oil droplets. The active carbon adsorption module 3-4 is an active carbon particle bed layer composed of active carbon particles. Preferably, the particle size of the active carbon particles in the active carbon adsorption module 3-4 is 60-100 mesh; and / or the height of the active carbon particle bed layer in the active carbon adsorption module 3-4 is 0.6-2 m.

[0105] In a preferred embodiment of the utility model, the side surface of the second vertical tank body is provided with a third upper pressure gauge 3-3 and a third lower pressure gauge 3-6 to monitor the pressure at the inlet and outlet of the active carbon adsorption module 3-4 respectively. The side surface of the second vertical tank body is also provided with a pressure transmitter 3-8 to obtain the real-time pressure difference at the inlet and outlet of the active carbon adsorption module 3-4 according to the real-time pressure of the third upper pressure gauge 3-3 and the third lower pressure gauge 3-6. More preferably, the side surface of the second vertical tank body is also provided with a third liquid leveler 3-7 to monitor the liquid level height in the active carbon adsorption device. The top surface of the second vertical tank body is provided with a third upper head pressure gauge 3-2 to detect the working pressure in the second vertical tank body.

[0106] In a preferred embodiment of the utility model, the lower part of the active carbon adsorption module 3-4 is provided with a second water filter cap and support plate 3-5, which is connected with the inner side wall of the second vertical tank body. The second water filter cap and support plate 3-5 can support the active carbon adsorption module 3-4 and further remove the suspended solids in the oily sewage. The model of the water filter cap can be selected according to the filter size, treatment capacity, pressure bearing strength, etc. Preferably, the distance between the second water filter cap and support plate 3-5 and the lower tangent of the second vertical tank body is 0.5-1.5 m.

[0107] The lower side wall of the active carbon adsorption device (second vertical tank body) is provided with a third backwashing water inlet 3-10, which is preferably arranged below the active carbon adsorption module 3-4. The top of the active carbon adsorption device (second vertical tank body) is provided with a third backwashing outlet 3-11. The use method of the third backwashing water inlet 3-10 and the third backwashing outlet 3-11 is basically the same as that of the first backwashing water inlet 1-12 and the first backwashing outlet 1-15, which will not be repeated here. When the adsorption efficiency of the active carbon adsorption device decreases to 85%, the active carbon adsorption device needs to be backwashed or the active carbon module needs to be replaced. Water is used for backwashing, and the backwashing time is 30 min, which is regarded as one backwashing.

[0108] In summary, the oily sewage in the oily sewage inlet pipeline enters the rotating flow cavity through the first water inlet 1-1 and the bottom of the cyclone cylinder 1-2-3, and forms a rotating fluid under the action of the rotating vane 1-2-4 and moves upward. In the rotating fluid, the outer layer is mainly water phase and the inner layer is mainly oil phase. In the process of upward movement of the rotating fluid, the oil phase in the inner layer enters the oil collecting pipe 1-2-1, and then is discharged from the combined separation device through the first oil outlet 1-14. The water phase in the outer layer enters the conical sleeve 1-2-2, and since the conical sleeve water phase outlet hole is formed in the conical sleeve 1-2-2, the water phase in the outer layer is discharged from the conical sleeve 1-2-2 through the conical sleeve water phase outlet hole and enters the water collecting sleeve. Since the water collecting sleeve is provided with a separated water phase outlet, the water phase discharged from the conical sleeve water phase outlet hole is discharged from the axial flow oil-water pre-separator 1-2 through the separated water phase outlet. Under the action of gravity, the water phase discharged from the axial flow oil-water pre-separator 1-2 enters the heterogeneous particle coalescence filter 1-5, and the suspended solids and the preliminary coalescence separation of petroleum hydrocarbon are realized through the heterogeneous particle coalescence filter 1-5. In other words, the suspended solids and part of the petroleum hydrocarbon droplets are intercepted in the heterogeneous particle coalescence filter 1-5. The water phase from which the suspended solids and part of the petroleum hydrocarbon droplets are removed continues to move downward, passes through the first water filter cap and support plate 1-8, and finally enters the hydrophilic and hydrophobic fiber coalescence demulsification separation device through the first water outlet 1-10 and the second water inlet 2-1.

[0109] The oily sewage treated by the combined separation device moves downstream of the hydrophilic and hydrophobic fiber coalescence demulsification separation device through the second water inlet 2-1. In this process, the secondary treatment is carried out through the hydrophilic and hydrophobic fiber coalescer 2-2, the oily sewage is demulsified and deeply separated, and the fine petroleum hydrocarbon droplets and emulsified oil are deeply separated. The oil phase separated by the hydrophilic and hydrophobic fiber coalescence demulsification separation device is discharged from the second oil outlet 2-5 at the top of the horizontal tank body. The water phase treated by the hydrophilic and hydrophobic fiber coalescence demulsification separation device is finally transferred into the activated carbon adsorption device through the second water outlet 2-4 and the third water inlet 3-1.

[0110] The water phase treated by the hydrophilic and hydrophobic fiber coalescence demulsification separation device moves downward (under the action of gravity) in the activated carbon adsorption device, enters the activated carbon adsorption module 3-4, and realizes the removal of COD through the activated carbon adsorption module 3-4. The purified water from which the COD is removed continues to move downward, passes through the second water filter cap and support plate 3-5, and finally is discharged from the activated carbon adsorption device through the third water outlet 3-9, that is, is discharged from the storage tank flushing water treatment system.

[0111] The use method of the storage tank flushing water treatment system is:

[0112] S1: The oily sewage sequentially passes through the axial flow oil-water pre-separator 1-2 and the heterogeneous particle coalescence filter 1-5 in the combined separation device, and first-stage treated sewage is obtained.

[0113] S11: The oil content in the oil-containing sewage in the oil-containing sewage import pipeline is <1000 mg / L, the COD content is <2000 mg / L, and the suspended solids content is <500 mg / L. The oil-containing sewage in the oil-containing sewage import pipeline enters the combined separation device from the outlet pump of the adjusting tank, specifically, enters the axial flow oil-water pre-separator 1-2 through the first water inlet 1-1, and more specifically, enters the cyclone cavity of the axial flow oil-water pre-separator 1-2 through the bottom of the cyclone cylinder 1-2-3, and forms a rotating fluid under the action of the cyclone blade 1-2-4 and moves upward. In the rotating fluid, the outer layer is mainly water phase and the inner layer is mainly oil phase. In the process of upward movement of the rotating fluid, the oil phase in the inner layer enters the oil collection pipe 1-2-1, and then is discharged out of the combined separation device through the first oil discharge port 1-14. The water phase in the outer layer enters the conical sleeve 1-2-2, and since the conical sleeve water phase outlet hole is formed in the conical sleeve 1-2-2, the water phase in the outer layer is discharged out of the conical sleeve 1-2-2 through the conical sleeve water phase outlet hole and enters the water collection sleeve. Since the water collection sleeve is provided with a separated water phase outlet, the water phase discharged from the conical sleeve water phase outlet hole is discharged out of the axial flow oil-water pre-separator 1-2 through the separated water phase outlet.

[0114] S12: Under the action of gravity, the water phase discharged out of the axial flow oil-water pre-separator 1-2 enters the heterogeneous particle coalescence filter 1-5, and the suspended solids are removed and the petroleum hydrocarbon is preliminarily coalesced and separated through the heterogeneous particle coalescence filter 1-5, to obtain the first treated sewage. The suspended solids and part of the petroleum hydrocarbon droplets are intercepted in the heterogeneous particle coalescence filter 1-5. The water phase from which the suspended solids and part of the petroleum hydrocarbon droplets are removed continues to move downward, and after passing through the first water filter cap and support plate 1-8, the first treated sewage is finally transferred into the hydrophilic and hydrophobic fiber coalescence demulsification separation device through the first water outlet 1-10 and the second water inlet 2-1. Preferably, the petroleum content in the first treated sewage is <20 mg / L, and the suspended solids content is <20 mg / L.

[0115] S2: The first treated sewage enters the hydrophilic and hydrophobic fiber coalescence demulsification separation device to obtain the second treated sewage.

[0116] The primary treated sewage after being treated by the combined separation device enters the hydrophilic-hydrophobic fiber coalescence demulsification separation device through the secondary water inlet 2-1 and moves downstream of the hydrophilic-hydrophobic fiber coalescence demulsification separation device. In this process, secondary treatment is carried out through the hydrophilic-hydrophobic fiber coalescer 2-2 to demulsify and deeply separate the oily sewage, so as to realize deep separation of fine petroleum hydrocarbon droplets and emulsified oil. The oil phase separated by the hydrophilic-hydrophobic fiber coalescence demulsification separation device is discharged from the secondary oil discharge port 2-5 at the top of the horizontal tank. The water phase (secondary treated sewage) after being treated by the hydrophilic-hydrophobic fiber coalescence demulsification separation device is finally transferred into the activated carbon adsorption device through the secondary water outlet 2-4 and the tertiary water inlet 3-1. Preferably, the content of petroleum in the secondary treated sewage is <5 mg / L, and the content of suspended solids is <20 mg / L.

[0117] S3: The secondary treated sewage enters the activated carbon adsorption device to obtain purified water.

[0118] The water phase after being treated by the hydrophilic-hydrophobic fiber coalescence demulsification separation device moves downward (under the action of gravity) in the activated carbon adsorption device, enters the activated carbon adsorption module 3-4, and realizes removal of COD through the activated carbon adsorption module 3-4. Preferably, the adsorption time of the activated carbon adsorption module 3-4 is 0.5-2 h. The purified water after removal of COD continues to move downward, passes through the second water filter cap and the support plate 3-5, and is finally transferred out of the activated carbon adsorption device through the tertiary water outlet 3-9, i.e., out of the storage tank flushing water treatment system. More preferably, the content of petroleum in the purified water in the tertiary water outlet 3-9 is <0.5 mg / L, the content of COD is <200 mg / L, and the content of suspended solids is <20 mg / L.

[0119] Example 1

[0120] The specific conditions of the storage tank flushing water of a company are as follows: The storage tank flushing water (i.e., oily sewage) has large flow fluctuation, a large amount of difficult-to-separate emulsion and small suspended particles. The content of petroleum in the oily sewage is relatively high and is often maintained at 1700-1900 mg / L; the content of COD is often maintained at 1850-1920 mg / L; and the content of suspended solids is high and is often maintained at 420-460 mg / L. The storage tank flushing water treatment system of the present application is used to treat the oily sewage, and the specific parameters are as follows:

[0121] In the axial flow oil-water pre-separator 1-2 of the combined separation device, the height of the cyclone cylinder 1-2-3 is 500 mm, the diameter of the cyclone cylinder 1-2-3 is 60 mm, the cyclone vane 1-2-4 is composed of 8 uniformly arranged vanes, the spiral angle of the cyclone vane 1-2-4 is 30°, the vane height of the cyclone vane 1-2-4 is 40 mm, and / or the diameter of the cyclone vane 1-2-4 is the inner diameter of the cyclone cylinder 1-2-3. The height of the conical sleeve 1-2-2 is 160 mm, and the taper of the conical sleeve 1-2-2 is 70°. The number of water phase outlet holes of the conical sleeve is 24, and the inner diameter of the water phase outlet hole of the conical sleeve is 15 mm. The number of separated water phase outlets is 4, and the inner diameter of the separated water phase outlet is 20 mm. The height of the oil collecting pipe 1-2-1 is 180 mm, and the diameter of the oil collecting pipe 1-2-1 is 20 mm.

[0122] In the heterogeneous particle coalescence filter 1-5 of the combined separation device, three kinds of particle beds are included, which are referred to as upper layer particle bed, middle layer particle bed and lower layer particle bed. The bed thickness of the upper layer particle bed is 1 m, which includes polytetrafluoroethylene material with particle size of 0.2 mm and particle density of 1.8 g / cm 3 ; the bed thickness of the middle layer particle bed is 0.6 m, which includes quartz sand material with particle size of 0.8 mm and particle density of 3 g / cm 3 ; the bed thickness of the lower layer particle bed is 0.3 m, which includes garnet material with particle size of 4 mm and particle density of 3 g / cm 3 . The average cross-sectional flow velocity of the particle bed is 0.003 m / s 3 , and the pressure difference between the inlet and outlet of the particle bed is 0.12 Mpa.

[0123] In the hydrophilic and hydrophobic fiber coalescence demulsification separation device, the hydrophilic and hydrophobic fiber coalescer 2-2 is provided with a fiber bed (Ω shape) formed by combination and weaving of hydrophilic fibers and oleophilic fibers, and the fiber bed is selected in block form. The hydrophilic fiber is made of stainless steel and hastelloy alloy material, the oleophilic fiber is made of polypropylene and polytetrafluoroethylene material, the diameter of the hydrophilic fiber and the oleophilic fiber is 20 μm, and the weight of the oleophilic fiber is 75 wt% of the weight of the fiber bed.

[0124] In the activated carbon adsorption device, the particle size of the activated carbon particles in the activated carbon adsorption module 3-4 is 100 mesh, and the height of the activated carbon particle bed in the activated carbon adsorption module 3-4 is 1.5 m.

[0125] The treatment method for the oil-containing wastewater in this embodiment is as follows:

[0126] S1: The oily sewage sequentially passes through the axial flow oil-water pre-separator 1-2 and the heterogeneous particle coalescence filter 1-5 in the combined separation device to obtain the first-stage treated sewage.

[0127] S11: The oily sewage in the oily sewage inlet pipeline enters the combined separation device from the outlet pump of the adjusting tank, specifically, enters the axial flow oil-water pre-separator 1-2 through the first-stage water inlet 1-1, and more specifically, enters the cyclone cavity of the axial flow oil-water pre-separator 1-2 through the bottom of the cyclone cylinder 1-2-3, and forms a rotating fluid under the action of the cyclone vane 1-2-4 and moves upward. In the rotating fluid, the outer layer is mainly water phase and the inner layer is mainly oil phase. In the process of upward movement of the rotating fluid, the oil phase in the inner layer enters the oil collection pipe 1-2-1, and then is discharged out of the combined separation device through the first-stage oil discharge port 1-14. The water phase in the outer layer enters the conical sleeve 1-2-2, and since the conical sleeve water phase outlet hole is formed in the conical sleeve 1-2-2, the water phase in the outer layer is discharged out of the conical sleeve 1-2-2 through the conical sleeve water phase outlet hole and enters the water collection sleeve. Since the water collection sleeve is provided with a separated water phase outlet, the water phase discharged from the conical sleeve water phase outlet hole is discharged out of the axial flow oil-water pre-separator 1-2 through the separated water phase outlet.

[0128] S12: Under the action of gravity, the water phase discharged out of the axial flow oil-water pre-separator 1-2 enters the heterogeneous particle coalescence filter 1-5, and the suspended solids are removed and the petroleum hydrocarbon is preliminarily coalesced and separated through the heterogeneous particle coalescence filter 1-5 to obtain the first-stage treated sewage. The suspended solids and part of the petroleum hydrocarbon droplets are intercepted in the heterogeneous particle coalescence filter 1-5. The water phase from which the suspended solids and part of the petroleum hydrocarbon droplets are removed continues to move downward, and after passing through the first water filter cap and support plate 1-8, the first-stage treated sewage is finally discharged into the hydrophilic and hydrophobic fiber coalescence demulsification separation device through the first-stage water outlet 1-10 and the second-stage water inlet 2-1.

[0129] S2: The first-stage treated sewage enters the hydrophilic and hydrophobic fiber coalescence demulsification separation device to obtain the second-stage treated sewage.

[0130] The first-stage treated sewage treated by the combined separation device enters the hydrophilic and hydrophobic fiber coalescence demulsification separation device through the second-stage water inlet 2-1 and moves to the downstream of the hydrophilic and hydrophobic fiber coalescence demulsification separation device. In this process, the second-stage treatment is carried out through the hydrophilic and hydrophobic fiber coalescer 2-2 (bed layer of hydrophilic and hydrophobic fibers with different weaving forms) to demulsify and deeply separate the oily sewage, so as to realize the deep separation of fine petroleum hydrocarbon droplets and emulsified oil. The oil phase separated by the hydrophilic and hydrophobic fiber coalescence demulsification separation device is discharged from the second-stage oil discharge port 2-5 at the top of the horizontal tank body. The water phase (second-stage treated sewage) treated by the hydrophilic and hydrophobic fiber coalescence demulsification separation device is finally discharged into the activated carbon adsorption device through the second-stage water outlet 2-4 and the third-stage water inlet 3-1.

[0131] S3: secondary sewage water enters the activated carbon adsorption device to obtain purified water.

[0132] The water phase treated by the hydrophobic and hydrophilic fiber coalescence demulsification separation device moves downward (under the action of gravity) in the activated carbon adsorption device, enters the activated carbon adsorption module 3-4, and realizes removal of COD through the activated carbon adsorption module 3-4. The adsorption time of the activated carbon adsorption module 3-4 is 1 h. The purified water after removal of COD continues to move downward, passes through the second water filter cap and the support plate 3-5, and finally is transferred out of the activated carbon adsorption device through the third water outlet 3-9, that is, out of the storage tank flushing water treatment system.

[0133] Comparative Example 1

[0134] The specific situation of the flushing water of a certain company is as follows: the flow of the storage tank flushing water (i.e. oily sewage) fluctuates greatly, and there are a large amount of emulsions and micro-suspended particles that are difficult to separate. The oil content in the oily sewage is relatively high, and is often maintained at 1700-1900 mg / L; the COD content is often maintained at 1850-1920 mg / L; the suspended solids content is high, and is often maintained at 420-460 mg / L. The oily sewage is treated by a conventional treatment method in this comparative example, specifically: the storage tank flushing sewage is introduced into a refinery sewage adjusting tank, and then is pretreated by oil removal and air flotation, and then is subjected to biochemical deep treatment.

[0135] Before the oily sewage is treated, the oil content, COD content, and suspended solids content of the oily sewage are detected according to the national standard method. After the system of Example 1 and Comparative Example 1 is operated for two weeks, the oil content, COD content, and suspended solids content of the system inlet and the total outlet of the system (the treatment capacity is 1 m 3 / h) are detected again, and the results are shown in Table 1.

[0136] Table 1 Water quality of the inlet and outlet in Example 1

[0137]

[0138] According to the data in Table 1, before the oily sewage is treated, the average oil content of the oily sewage at the system inlet is 1826.4 mg / L, the average COD content is 1874 mg / L, and the average suspended solids content is 433 mg / L. After the system of Example 1 is operated for two weeks, the average oil content of the purified water at the position of the third water outlet 3-9 in the system of Example 1 is 0.43 mg / L, the average COD content is 166 mg / L, and the average suspended solids content is 17 mg / L. After the system of Comparative Example 1 is operated for two weeks, the average oil content of the water at the outlet of the system of Comparative Example 1 is 57.83 mg / L, the average COD content is 277 mg / L, and the average suspended solids content is 19 mg / L.

[0139] Through comparative analysis of the results of Table 1, it can be seen that the oil-containing sewage can be effectively removed from dispersed oil, emulsified oil and suspended solids, and the oil content of the treated sewage can be as low as 0.43mg / L, the COD value can be reduced to 166mg / L, and the suspended solids content can be reduced to 17mg / L, which are significantly lower than the results of the comparative example 1 treated by the traditional process. Therefore, it can be known that the treatment effect of the storage tank flushing water treatment system on the oil-containing sewage is better.

[0140] In the description of the utility model, it is to be explained that, unless another explicit provision and limitation, the term "connects", "connects" should be broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connects, can be mechanical connection, also can be electrical connection, can be directly connected, also can pass through the indirect connection of intermediate medium. For ordinary skilled in the art, the specific meaning of the above-mentioned term in the utility model can be understood according to specific circumstances.

[0141] In the description of the utility model, unless otherwise stated, the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0142] The above technical solution is only one embodiment of the utility model, and for those skilled in the art, on the basis of the principle disclosed in the utility model, various types of improvements or deformations can be easily made, and are not limited to the technical solution described in the above embodiment of the utility model, therefore, the above description is only preferred, and does not have a limiting meaning.

Claims

1. A storage tank wash water treatment system, characterized by, The system comprises a combined separation device, a hydrophilic-hydrophobic fiber coalescence demulsification separation device and an activated carbon adsorption device connected in sequence; the combined separation device comprises a first vertical tank body and an axial flow oil-water pre-separator and a heterogeneous particle coalescence filter arranged in the first vertical tank body respectively at upper and lower positions; the hydrophilic-hydrophobic fiber coalescence demulsification separation device comprises a horizontal tank body and a hydrophilic-hydrophobic fiber coalescence device arranged in the horizontal tank body; and the activated carbon adsorption device comprises a second vertical tank body and an activated carbon adsorption module arranged in the vertical tank body. The bottom of the axial flow oil-water pre-separator is connected with an oil-containing sewage inlet pipeline.

2. The system according to claim 1, wherein The axial flow oil-water pre-separator comprises an oil collection pipe and a conical sleeve and a cyclone cylinder arranged in the conical sleeve respectively at upper and lower positions and in communication with each other, the cyclone cylinder is in a cylindrical structure, the inner bottom of the cyclone cylinder is provided with cyclone blades, the lower part of the oil collection pipe is inserted into the top of the conical sleeve, and the bottom end of the oil collection pipe is arranged in the upper part of the cyclone cylinder; the bottom of the cyclone cylinder is connected with the oil-containing sewage inlet pipeline; the inner diameter of the top of the conical sleeve is smaller than the inner diameter of the bottom of the conical sleeve, and a plurality of water phase outlet holes of the conical sleeve are arranged on the side wall of the conical sleeve.

3. The system according to claim 2, wherein The inner diameter of the cyclone cylinder is the same as the inner diameter of the bottom of the conical sleeve, and the top end of the cyclone cylinder is detachably connected with the bottom end of the conical sleeve; and / or the outer diameter of the oil collection pipe is the same as the inner diameter of the top of the conical sleeve, and the oil collection pipe is detachably connected with the top end of the conical sleeve.

4. The system according to claim 3, wherein The axial flow oil-water pre-separator further comprises a water collection sleeve arranged outside the conical sleeve and connected with the conical sleeve, and a separated water phase outlet is arranged on the side of the water collection sleeve.

5. The system according to claim 2, wherein The height of the oil collection pipe is 150-230 mm; and / or The diameter of the oil collection pipe is 20-25 mm; and / or The height of the conical sleeve is 160-180 mm; and / or The taper of the conical sleeve is 70-80°; and / or The height of the cyclone cylinder is 400-600 mm; and / or The diameter of the cyclone cylinder is 50-70 mm.

6. The system according to claim 2, wherein The cyclone blades are composed of 6-8 blades arranged uniformly; and / or The spiral angle of the cyclone blades is 30-60°; and / or The height of the cyclone blades is 30-50 mm; and / or The diameter of the cyclone blades is equal to the inner diameter of the cyclone cylinder; and / or The number of the water phase outlet holes of the conical sleeve is 12-24; and / or The inner diameter of the water phase outlet holes of the conical sleeve is 10-15 mm; and / or The water phase outlet holes of the conical sleeve are arranged uniformly.

7. The system according to claim 1, wherein The heterogeneous particle coalescence filter comprises a plurality of particle beds of different materials; the distance between the heterogeneous particle coalescence filter and the inlet end of the first vertical tank is 1 / 3-2 / 3 of the length of the first vertical tank; the height of the heterogeneous particle coalescence filter is 1 / 3-1 / 2 of the height of the first vertical tank.

8. The tank washing water treatment system according to claim 7, wherein, The heterogeneous particle coalescence filter comprises an upper particle bed, a middle particle bed and a lower particle bed.

9. The tank washing water treatment system according to claim 8, wherein, The bed thickness of the upper particle bed is 0.8-1 m; and / or, The bed thickness of the middle particle bed is 0.6-3 m; and / or, The bed thickness of the lower particle bed is 0.3-0.5 m.

10. The tank washing water treatment system according to claim 9, wherein, The upper particle bed has a particle size of 0.2-2 mm and a particle density of 1.1-2.0 g / cm 3 ; and / or, The particle size of the particles in the middle layer is 0.8-3 mm, and the particle density is 1.3-4 g / cm 3 ; and / or, The particle size of the lower particle bed is 4-8 mm, and the particle density is 2.6-5.2 g / cm 3 .

11. The tank washing water treatment system according to claim 1, wherein, A first water filter cap and a support plate are arranged below the heterogeneous particle coalescence filter and connected to the inner side wall of the first vertical tank.

12. The tank washing water treatment system according to claim 11, wherein, A first backwashing air inlet and a first backwashing water inlet are arranged on the lower side wall of the first vertical tank and connected to a first backwashing air pipeline and a first backwashing water pipeline respectively; and a first backwashing outlet is arranged on the top of the first vertical tank.

13. The tank washing water treatment system according to claim 12, wherein, A water distribution disc is further arranged in the first vertical tank and connected to the first backwashing water pipeline and arranged below the heterogeneous particle coalescence filter.

14. The tank washing water treatment system according to claim 13, wherein, The water distribution disc is a sieve disc with a circular shape; the diameter of the water distribution disc is 1 / 2-3 / 4 of the diameter of the first vertical tank; and / or the vertical distance between the water distribution disc and the upper tangent of the first vertical tank is 0.2-1 m.

15. The tank washing water treatment system according to claim 1, wherein, The hydrophilic and hydrophobic fiber coalescer is coaxially arranged in the middle section of the horizontal tank and the outer wall thereof is connected to the inner wall of the horizontal tank.

16. The tank washing water treatment system according to claim 15, wherein, The distance between the hydrophilic and hydrophobic fiber coalescer and the inlet end of the horizontal tank is 1 / 4-1 / 3 of the length of the horizontal tank; and / or The length of the hydrophilic and hydrophobic fiber coalescer is 1 / 4-1 / 2 of the length of the horizontal tank; and / or The hydrophilic and hydrophobic fiber coalescer comprises a fiber bed formed by combination of hydrophilic fibers and oleophilic fibers, and the fiber bed is in a block shape or a column shape.

17. The tank washing water treatment system according to claim 16, wherein, The diameter of the hydrophilic fibers and / or the oleophilic fibers is 20-50 μm.

18. The tank washing water treatment system according to claim 17, wherein, The weight of the lipophilic fibers is 70-80 wt% of the weight of the fiber bed.

19. The tank washing water treatment system of claim 1, wherein, The bottom of the horizontal tank body is provided with a secondary backwashing air inlet and a secondary backwashing water inlet, and the top of the horizontal tank body is provided with a backwashing outlet.

20. The tank washing water treatment system of claim 1, wherein, The activated carbon adsorption module is an activated carbon particle bed composed of activated carbon particles.

21. The tank washing water treatment system of claim 20, wherein, The particle size of the activated carbon particles in the activated carbon adsorption module is 60-100 mesh; and / or, The height of the activated carbon particle bed in the activated carbon adsorption module is 0.6-2 m.

22. The tank washing water treatment system of claim 1, wherein, The activated carbon adsorption module is provided below with a second water filter cap and a support plate, which are connected with the inner side wall of the second vertical tank body.

23. The tank washing water treatment system of claim 22, wherein, The distance between the second water filter cap and support plate and the lower tangent line of the second vertical tank body is 0.5-1.5 m.

24. The tank washing water treatment system of claim 23, wherein, The lower side wall of the second vertical tank body is provided with a tertiary backwashing water inlet, and the top of the second vertical tank body is provided with a tertiary backwashing outlet.

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