Oil-water separation and liquid-solid separation system and method

Abstract

The present invention discloses an oil-water separation and liquid-solid separation system and method, including a pre-emulsification oil removal and liquid-solid separator and an emulsified oil fine separator. The beneficial effects of the present invention are: providing a horizontal liquid-solid pre-separator for pre-removal of insoluble matter, a liquid-solid fine filter membrane assembly for fine removal of insoluble matter, a liquid-solid circulation and oleophilic and hydrophobic filler fluidized bed coupling pre-emulsification separation part, a hydrophilic and oleophobic filler barrier for removal of floating oil and dispersed oil, and an emulsified oil demulsification membrane assembly for fine removal of emulsified oil, a multi-zone synergistic enhanced treatment process, which achieves the simultaneous and efficient removal of insoluble matter and oil phase, solves the problem of easy clogging of oil removal materials and insoluble matter removal materials when the oil phase and insoluble matter are removed simultaneously, greatly extends the equipment operation cycle, and reduces the cost of oil-water separation and liquid-solid separation.

Description

Technical Field

[0001] The present invention relates to a separation system, in particular to an oil-water separation and liquid-solid separation system and method, belonging to the technical field of industrial water treatment. Background Art

[0002] Currently, most industrial processes, including petrochemicals, coal chemical industry, coking, and metallurgy, involve oil-water separation. While floating and dispersed oil in oily wastewater is relatively easy to treat, emulsified oil in wastewater is difficult to achieve the desired effect through conventional physical methods such as cyclone separation, inclined plate polymerization separation, and agglomeration material separation, often requiring the addition of chemical agents.

[0003] If wastewater contains insoluble impurities such as suspended matter and solids, there is generally a dilemma: should the oil or the insoluble impurities be treated first? If the insoluble impurities are treated first, the oil will quickly clog the materials used to separate the insolubles, affecting the lifespan and performance of the insoluble separation materials. If the oil is treated first, only floating oil and some dispersed oil can be removed, further improving oil removal efficiency. However, the insoluble impurities will clog the oil removal materials, or chemical treatment will be required, which can easily introduce new pollution and increase treatment costs, hindering cost reduction and efficiency improvement, environmental protection, and oil recycling. Summary of the Invention

[0004] The purpose of the present invention is to provide an oil-water separation and liquid-solid separation system and method in order to solve at least one of the above technical problems.

[0005] The present invention achieves the above-mentioned object through the following technical solutions: an oil-water separation and liquid-solid separation system and method, comprising a pre-emulsification deoiling and liquid-solid separator and an emulsified oil-essence separator, wherein the pre-emulsification deoiling and liquid-solid separator is connected to the emulsified oil-essence separator through a pipeline;

[0006] The pre-emulsification deoiling and liquid-solid separator includes a feed pipe, a horizontal liquid-solid pre-separator, an oil-water pre-emulsifier, a liquid-solid fine filter, a backwash gas inlet, a pretreatment liquid outlet and a slag discharge port. The feed pipe is opened in the middle of the cylinder of the pre-emulsification deoiling and liquid-solid separator. The feed end of the feed pipe is connected to the oily wastewater raw liquid inlet. A plurality of upward and downward inclined spray holes are provided in the horizontal section of the feed pipe. Part of the liquid is sprayed upward and downward at a certain speed through the upper and lower spray holes. The diameter of the spray hole is 1-10 mm, and the angle between the spray hole and the axis of the horizontal section of the feed pipe is 5-55 degrees.

[0007] The oil-water pre-emulsifier, horizontal liquid-solid pre-separator, and liquid-solid fine filter are all located inside the pre-emulsifier oil removal and liquid-solid separator cylinder, and the liquid-solid fine filter is located above the oil-water pre-emulsifier, and the oil-water pre-emulsifier is located above the horizontal liquid-solid pre-separator;

[0008] The slag discharge port is opened at the bottom of the pre-emulsification deoiling and liquid-solid separator cylinder.

[0009] As a further solution of the present invention: the oil-water pre-emulsifier is a filler circulating fluidized bed for strengthening the pre-emulsification of the emulsified oil.

[0010] As a further embodiment of the present invention, the oil-water pre-emulsifier includes a draft tube, a circulator bottom screen, an oleophilic material, and a support frame. The draft tube is fixedly connected to the support frame, and the support frame is connected to the inner wall of the pre-emulsification and oil removal and liquid-solid separator cylinder. The oleophilic material is placed in the draft tube. The circulator bottom screen connected to the inner wall of the pre-emulsification and oil removal and liquid-solid separator cylinder is provided below the support frame.

[0011] The ratio of the effective diversion area of the diversion tube to the effective cross-sectional area of the pre-emulsification deoiling and liquid-solid separator cylinder is 0.2-0.8:1.

[0012] As a further solution of the present invention: the horizontal liquid-solid pre-separators are symmetrically arranged on both sides of the center line of the pre-emulsification and oil removal and liquid-solid separator cylinders, and the two horizontal liquid-solid pre-separators are separated by a partition. The horizontal liquid-solid pre-separator includes a horizontal liquid-solid pre-separator shell, a central pipe, a liquid outlet trough, a solid phase external outlet trough, a downward liquid-solid vertical inlet, and a solid phase discharge barrel;

[0013] The downward liquid-solid vertical inlet is arranged in the upper middle part of the horizontal liquid-solid pre-separator, the center tube is axially arranged in the center of the separator shell, the center tube is provided with a solid phase outer outlet groove on a circular arc of 180 to 270 degrees downstream, the separator shell is provided with a liquid outlet groove on a circular arc of 270 to 350 degrees downstream, a solid phase discharge barrel is provided below the solid phase outer outlet groove, a group of cone-plate-shaped inner ring baffles and cone-disk-shaped outer ring baffles are provided in the solid phase discharge barrel, and the inner ring baffle is fixedly connected to the inner wall of the solid phase discharge barrel of the solid phase discharge barrel, the outer ring baffle is fixedly connected to the outer wall of the solid phase discharge barrel of the solid phase discharge barrel, and a liquid return port is provided on the outer wall of the solid phase discharge barrel.

[0014] As a further solution of the present invention: the liquid-solid fine filter comprises an oleophobic material filled tank cylinder, oleophobic material, an oleophobic material filled tank, a liquid-solid separation membrane, a backwash gas inlet, and a pretreatment liquid outlet;

[0015] The oleophobic material filling tank cylinder includes an inner head, a liquid-solid fine filter housing and an oleophobic material filling tank which are sequentially connected from top to bottom. The membrane assembly is located inside the liquid-solid fine filter housing, and the pore size of the membrane is 25mm to 1000mm.

[0016] The oleophobic material is built into the oleophobic material filling tank, a liquid-solid fine filter membrane partition is horizontally connected to the liquid-solid fine filter housing, the upper end of the oleophobic material filling tank is connected to the upper end cover of the oleophobic material filling tank, a liquid-solid separation membrane is connected between the liquid-solid fine filter membrane partition and the upper end cover of the oleophobic material filling tank, the upper end cover of the oleophobic material filling tank is a circular perforated sieve plate with a pore size of 30% to 70% and a pore diameter of 0.01 cm to 0.09 cm, the bottom surface of the oleophobic material filling tank is connected to the upper end cover of the oleophobic material filling tank by a spring, and the number of springs is 3 to 10, which are evenly distributed in the filling tank;

[0017] The backwash gas inlet passes through the oil collecting chamber of the outer head and is connected to the upper end of the inner head. The outer head is connected to the top of the cylinder of the pre-emulsification deoiling and liquid-solid separator.

[0018] The lower part of the oleophobic material filling tank is provided with an inlet for the liquid to be treated, an outlet for insoluble impurities is provided, and the outlet for the pre-treated liquid is connected to the upper part of the liquid-solid fine filter housing.

[0019] As a further solution of the present invention: the emulsified oil separator includes a separator housing, a pre-treated liquid inlet, a first-stage emulsified oil demulsification and separation filter element, a second-stage emulsified oil demulsification and separation filter element, an oil collection bag, an oil phase outlet, and a purified water outlet;

[0020] The separator shell is divided into a shell front cavity, a first-stage separation cavity and a second-stage separation cavity by a first-stage emulsified oil demulsification separation filter element partition and a second-stage emulsified oil demulsification separation filter element partition arranged in parallel;

[0021] The first-stage emulsified oil demulsification and separation filter elements are arranged side by side in the first-stage separation cavity of the separator housing, the second-stage emulsified oil demulsification and separation filter elements are arranged side by side in the second-stage separation cavity of the separator housing, and the second-stage emulsified oil demulsification and separation filter elements are arranged in the second-stage emulsified oil demulsification and separation filter element housing;

[0022] The pretreatment liquid inlet is opened at the upper part of the front cavity of the separator shell, and the oil collecting bag includes a secondary separation chamber oil phase oil collecting bag and a primary separation chamber oil phase oil collecting bag. The secondary separation chamber oil phase oil collecting bag is connected to the upper part of the secondary separation chamber, and the primary separation chamber oil phase oil collecting bag is connected to the upper part of the primary separation chamber.

[0023] The purified water outlet is located at the lower part of the separator shell.

[0024] An oil-water separation and liquid-solid separation method, comprising an oil-water separation and liquid-solid separation system, the separation method comprising the following steps:

[0025] Step 1: The oily wastewater enters the horizontal liquid-solid pre-separator to achieve pre-separation of some solid insoluble matter;

[0026] Step 2: Pre-separation of solid insolubles in the oily wastewater is carried out through the coupled pre-emulsification effect of the circulator and the lipophilic and hydrophobic filler fluidized bed, so that part of the emulsion droplets are converted into free oil phase and water phase;

[0027] Step 3: The free oil phase floats to the lower end of the oleophobic material filling tank, is blocked by the oleophobic material, and then floats to the oil collecting chamber. Part of the oily wastewater enters the circulator for circulation, and part of the oily wastewater passes through the oleophobic material and enters the liquid-solid fine filter cylinder.

[0028] Step 4. After the insoluble matter is removed by the liquid-solid fine filter in the liquid-solid membrane separator, the oily wastewater enters the first separation chamber and the second separation chamber of the emulsified oil separator, and the emulsion is demulsified by the first and second emulsion separation filter elements. After demulsification, the free oil phase is collected in the oil phase collecting bag of the first separation chamber and the oil phase collecting bag of the second separation chamber, and the purified water is discharged from the purified water outlet.

[0029] As a further solution of the present invention: when the oily wastewater enters the horizontal liquid-solid pre-separator, the downward liquid-solid vertical inlet flow rate is 8m / s-17m / s.

[0030] The beneficial effects of the present invention are as follows: the present application provides a multi-zone collaborative enhanced treatment process of a horizontal liquid-solid pre-separator for pre-removal of insoluble matter, a liquid-solid fine filter membrane assembly for fine removal of insoluble matter, a liquid-solid circulation and oleophilic and hydrophobic filler fluidized bed coupling pre-emulsification separation part, a hydrophilic and oleophobic filler barrier for removal of floating oil and dispersed oil, and an emulsified oil demulsification membrane assembly for fine removal of emulsified oil, which realizes the simultaneous and efficient removal of insoluble matter and oil phase, solves the problem that the oil removal material and the insoluble matter removal material are easily blocked when the oil phase and insoluble matter are removed simultaneously, greatly extends the equipment operation cycle, and reduces the cost of oil-water separation and liquid-solid separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 This is a schematic cross-sectional structure diagram of the pre-emulsification, oil removal and liquid-solid separator of the present invention;

[0033] Figure 3 It is a schematic diagram of the cross-sectional structure of the emulsified oil separator of the present invention.

[0034] In the figure: 1. Pre-emulsification deoiling and liquid-solid separator, 101. Oily wastewater raw liquid inlet, 102. Feed pipe, 103. Oil-repellent material filling tank cylinder, 104. Oil-repellent material filling tank upper end cover, 105. Pre-emulsification deoiling and liquid-solid separator cylinder, 106. External head, 107. Backwash gas inlet, 108. Oil collecting chamber, 109. Internal head, 110. Liquid-solid fine filter membrane partition, 111. Pretreatment liquid outlet, 112. Liquid-solid fine filter housing, 113. Liquid-solid separation membrane, 114. Oil-repellent material, 115. Spring, 116. Oil-repellent material filling tank, 117. Guide tube, 118. Downward liquid-solid vertical inlet, 119. Liquid return port, 120. Solid phase external outlet tank, 121. Outer wall of solid phase discharge cylinder, 122. Inner wall of solid phase discharge cylinder, 1 23. Slag discharge port, 124. Inner ring baffle, 125. Horizontal liquid-solid pre-separator shell, 126. Outer ring baffle, 127. Center pipe, 128. Liquid outlet trough, 129. Circulator bottom screen, 130. Oleophilic material, 131. Support frame, 132. Injection hole, 2. Emulsified oil separator, 201. Pretreatment liquid inlet, 202. First-stage emulsified oil demulsification and separation filter element partition, 203. First-stage emulsified oil demulsification and separation filter element, 204. First-stage separation chamber, 205. Second-stage emulsified oil demulsification and separation filter element partition, 206. Second-stage emulsified oil demulsification and separation filter element, 207. Second-stage separation chamber, 208. Purified water discharge port, 209. Second-stage separation chamber oil phase oil collecting bag, 210. Second-stage emulsified oil demulsification and separation filter element shell, 211. First-stage separation chamber oil phase oil collecting bag. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] Example 1

[0037] like Figures 1 to 3 As shown, an oil-water separation and liquid-solid separation system is composed of a pre-emulsification deoiling and liquid-solid separator 1 and an emulsified oil-essence separator 2, and the pre-emulsification deoiling and liquid-solid separator 1 is connected to the emulsified oil-essence separator 2 through a pipeline;

[0038] The pre-emulsification deoiling and liquid-solid separator 1 includes a feed pipe 102, a horizontal liquid-solid pre-separator, an oil-water pre-emulsifier, a liquid-solid fine filter, a backwash gas inlet 107, a pretreatment liquid outlet 111 and a slag discharge port 123. The feed pipe 102 is opened in the middle of the pre-emulsification deoiling and liquid-solid separator cylinder 105. The feed end of the feed pipe 102 is connected to the oily wastewater raw liquid inlet 101. A plurality of upward and downward oblique spray holes 132 are provided in the horizontal section of the feed pipe 102. Part of the liquid is sprayed obliquely upward and downward at a certain speed through the upper spray hole 132 and the lower spray hole 132. The diameter of the spray hole 132 is 1-10 mm, and the angle between the spray hole 132 and the axis of the horizontal section of the feed pipe 102 is 5-55°.

[0039] The oil-water pre-emulsifier, the horizontal liquid-solid pre-separator, and the liquid-solid fine filter are all located inside the pre-emulsifier oil removal and liquid-solid separator cylinder 105, and the liquid-solid fine filter is located above the oil-water pre-emulsifier, and the oil-water pre-emulsifier is located above the horizontal liquid-solid pre-separator;

[0040] The slag discharge port 123 is provided at the bottom of the pre-emulsification deoiling and liquid-solid separator cylinder 105 .

[0041] Example 2

[0042] In addition to all the technical features of the first embodiment, this embodiment also includes:

[0043] The oil-water pre-emulsifier is a packed circulating fluidized bed used to enhance the pre-emulsification of emulsified oil.

[0044] The oil-water pre-emulsifier includes a guide tube 117, a circulator bottom screen 129, an oleophilic material 130 and a support frame 131. The guide tube 117 is fixedly connected to the support frame 131, and the support frame 131 is connected to the inner wall of the pre-emulsification deoiling and liquid-solid separator cylinder 105. The oleophilic material 130 is placed in the guide tube 117. The circulator bottom screen 129 connected to the inner wall of the pre-emulsification deoiling and liquid-solid separator cylinder 105 is provided below the support frame 131.

[0045] Furthermore, the oleophilic material 130 is filled in the annular gap channel of the circulator and the guide tube 117. The oleophilic material 130 is a nearly spherical filler formed by oleophilic and hydrophobic modification, with a diameter of 1 cm to 3 cm. The base material is at least two materials selected from polytetrafluoroethylene fiber, polyetheretherketone fiber, graphene nanoaerogel, polyphenylene sulfide foam, polyurethane foam, etc. The density of the composite material is 1.01 to 1.55 g / cm 3The modified coating is a fluorinated acrylate. The oleophilic material 130 is fluidized by the impact and propulsion of the liquid ejected from the horizontal liquid-solid pre-separator outlet, flowing upward along the annular space outside the guide tube 117. Sprayed from the downward-facing spray holes at the lower horizontal section of the feed pipe 102, the oleophilic material 130 on the upper portion of the guide tube 117 flows toward the inside of the guide tube, thereby achieving a circulating flow of the oleophilic material 130 and achieving adsorption, aggregation, and demulsification of the emulsified oil.

[0046] Furthermore, the pore size of the sieve 129 at the bottom of the circulator is smaller than that of the oleophilic material 130, with a pore size of 0.1-0.9 cm. The filter covers all cross-sectional spaces other than the bottom feed pipe of the circulator and the horizontal liquid-solid pre-separator of the same cross-section, so that the oleophilic material 130 circulates in the circulator and does not leak out from the pores of the filter.

[0047] The guide tube 117 is provided with at least one stage in the circulator, and an annular gap channel is formed between the outer wall of the guide tube 117 and the inner wall of the circulator. The guide tube 117 is fixed to the wall of the separator cylinder through a supporting frame. Both ends of the guide tube 117 are open. The height of each stage of the guide tube is 350 to 1800 mm, and the ratio of the effective area of the guide tube to the effective cross-sectional area of the separator cylinder is 0.25 to 0.8.

[0048] Example 3

[0049] In addition to all the technical features of the first embodiment, this embodiment also includes:

[0050] The horizontal liquid-solid pre-separator is symmetrically arranged on both sides of the center line of the pre-emulsification and oil removal and liquid-solid separator cylinder 105, and the two horizontal liquid-solid pre-separators are separated by a partition. The horizontal liquid-solid pre-separator includes a horizontal liquid-solid pre-separator shell 125, a central pipe 127, a liquid outlet trough 128, a solid phase external outlet trough 120, a downward liquid-solid vertical inlet 118, and a solid phase discharge barrel;

[0051] The downward liquid-solid vertical inlet 118 is arranged in the upper middle part of the horizontal liquid-solid pre-separator, the central pipe 127 is axially arranged in the center of the separator shell, the central pipe 127 is provided with a solid phase outer outlet groove 120 on a 180-270° arc downstream, and the separator shell is provided with a liquid outlet groove 128 on a 270-350° arc downstream. Taking into account the separation efficiency, pressure drop and structural strength, the width of the outlet groove 128 is 20-600 mm, the width of the liquid outlet groove 128 is 30-700 mm, and the solid phase outer outlet groove 128 is 20-600 mm. 0 is provided below, and 2-6 groups of cone-shaped inner ring baffles 124 and cone-disk shaped outer ring baffles 126 are provided in the solid phase discharge barrel. The baffles prolong the residence time of the liquid and solid phase, which is beneficial to the floating of the oil phase and the sinking of the solid phase. The inner ring baffle 124 is fixedly connected to the inner wall 122 of the solid phase discharge barrel of the solid phase discharge barrel, and the outer ring baffle 126 is fixedly connected to the outer wall 121 of the solid phase discharge barrel of the solid phase discharge barrel, and a liquid return port 119 is opened on the outer wall 121 of the solid phase discharge barrel.

[0052] Example 4

[0053] In addition to all the technical features of the first embodiment, this embodiment also includes:

[0054] The liquid-solid fine filter includes an oleophobic material-filled tank cylinder 103, oleophobic material 114, an oleophobic material-filled tank 116, a liquid-solid separation membrane 113, a backwash gas inlet 107, and a pre-treatment liquid outlet 111;

[0055] The oleophobic material filling tank cylinder 103 includes an inner head 109, a liquid-solid fine filter housing 112 and an oleophobic material filling tank 116 which are sequentially connected from top to bottom. The membrane assembly is located inside the liquid-solid fine filter housing 112, and the pore size of the membrane is 25 nanometers to 1000 nanometers.

[0056] Furthermore, the liquid-solid membrane separator is equipped with a precision filter element to remove insoluble matter from the aqueous phase. The filtration method is terminal filtration. The filter element is an inorganic membrane such as metal sintering, silicon carbide ceramics, or a corrosion-resistant and swelling-resistant organic membrane such as polyarylethernitrile. The membrane pore accuracy is 35 to 1000 nanometers, the process pressure drop is 0.02 to 0.25 MPa, and the backflushing medium is nitrogen.

[0057] The oleophobic material 114 is built into the oleophobic material filling tank 116. The liquid-solid fine filter membrane partition 110 is horizontally connected to the liquid-solid fine filter housing 112. The upper end of the oleophobic material filling tank 116 is connected to the oleophobic material filling tank upper end cover 104. A liquid-solid separation membrane 113 is connected between the liquid-solid fine filter membrane partition 110 and the oleophobic material filling tank upper end cover 104. The oleophobic material filling tank upper end cover 104 is a circular perforated sieve plate with an opening rate of 30% to 70% and a pore diameter of 0.01 cm to 0.09 cm. The bottom surface of the oleophobic material filling tank 116 is connected to the oleophobic material filling tank upper end cover 104 through a spring 115. The number of springs 115 is 3 to 10 and is evenly distributed in the filling tank.

[0058] Furthermore, oleophobic material 114 is embedded within the oleophobic material filling tank cylinder. The upper end cap of the filling tank is fixed to the liquid-solid membrane separator cylinder. The upper end cap of the filling tank is a circular perforated sieve plate with an opening ratio of 30% to 70% and a pore diameter of 0.01 cm to 0.09 cm. The lower end cap of the filling tank is connected to the upper end cap via springs. The number of springs is 3 to 10 and is evenly distributed within the filling tank. Oleophobic material 114 is a nearly spherical filler modified to be hydrophilic and oleophobic, with a diameter of 0.1 cm to 0.8 cm. The base material is at least one of sand, silicon carbide powder, and aluminum oxide powder, and the modified coating is a fluorine-containing epoxy resin.

[0059] The backwash gas inlet 107 passes through the oil collecting chamber 108 of the outer head 106 and is connected to the upper end of the inner head 109. The outer head 106 is connected to the top of the pre-emulsification deoiling and liquid-solid separator cylinder 105.

[0060] The lower part of the oleophobic material filling tank 116 is provided with an inlet for the liquid to be treated, and the lower part of the oleophobic material filling tank 116 is provided with an outlet for insoluble impurities. The pre-treated liquid outlet 111 is connected to the upper part of the liquid-solid fine filter housing 112 .

[0061] Example 5

[0062] In addition to all the technical features of the first embodiment, this embodiment also includes:

[0063] The emulsified oil separator includes a separator housing, a pre-treatment liquid inlet 201, a first-stage emulsified oil demulsification and separation filter element 203, a second-stage emulsified oil demulsification and separation filter element 206, an oil collecting bag, an oil phase outlet, and a purified water outlet 208.

[0064] The separator housing is divided into a housing front cavity, a primary separation cavity 204 and a secondary separation cavity 207 by a primary emulsified oil demulsification separation filter element partition 202 and a secondary emulsified oil demulsification separation filter element partition 205 arranged in parallel;

[0065] The first-stage emulsified oil demulsification and separation filter element 203 is arranged side by side in the first-stage separation cavity 204 of the separator housing, and the second-stage emulsified oil demulsification and separation filter element 206 is arranged side by side in the second-stage separation cavity 207 of the separator housing, and the second-stage emulsified oil demulsification and separation filter element 206 is arranged in the second-stage emulsified oil demulsification and separation filter element housing 210;

[0066] The pre-treatment liquid inlet 201 is opened in the upper part of the front cavity of the separator shell. The oil collecting bag includes a secondary separation chamber oil phase oil collecting bag 209 and a primary separation chamber oil phase oil collecting bag 211. The secondary separation chamber oil phase oil collecting bag 209 is connected to the upper part of the secondary separation chamber 207, and the primary separation chamber oil phase oil collecting bag 211 is connected to the upper part of the primary separation chamber 204.

[0067] The purified water outlet 208 is located at the lower portion of the separator housing.

[0068] Furthermore, the process pressure drop of the emulsified oil separator is 0.001~0.005MPa, the emulsified oil demulsification separation filter element can separate water-in-oil emulsions, and the base materials of the first-stage emulsified oil demulsification separation filter element and the second-stage emulsified oil demulsification separation filter element are composite materials of at least two materials selected from polyimide, polytetrafluoroethylene, polyphenylene sulfide, polyarylether nitrile, graphene nanoaerogel, etc.; the first-stage emulsified oil demulsification separation filter element can demulsify and coalesce emulsion droplets of 5~15 microns, and the second-stage emulsified oil demulsification separation filter element can demulsify and coalesce emulsion droplets of 0.05~5 microns.

[0069] Furthermore, the internal components such as the guide tube in this application can be fixed in the tank body using various common parts and methods. All internal components can be made of various common metal materials. To prevent corrosion and wear, anti-corrosion and wear-resistant coatings can be sprayed on their surfaces.

[0070] It can be seen that the proposed processes of coupling the draft tube and oleophilic and hydrophobic filler to the fluidized bed pre-emulsification, the hydrophilic and oleophobic material barrier and oil removal, the horizontal liquid-solid pre-separator pre-insoluble matter removal, and the liquid-solid fine filter membrane fine insoluble matter removal are not independent, simple superpositions, but rather an organic coupling that integrates many factors. For example, the liquid velocity in the horizontal liquid-solid pre-separator outlet trough, the draft tube height, the ratio of the effective area to the effective cross-sectional area of the circulation mixer, the circulation velocity of the circulator, and the packing density of the oleophilic and hydrophobic filler all vary according to different process conditions, the oil content, insoluble matter content, and emulsification degree of the oily wastewater.

[0071] Example 6

[0072] An oil-water separation and liquid-solid separation system and method, comprising an oil-water separation and liquid-solid separation system, and the separation method comprising the following steps:

[0073] 1) Oily wastewater with a certain flow rate enters the feed pipe 102 through the oily wastewater raw liquid inlet 101. Part of the liquid is sprayed out obliquely upward and downward at a certain speed through the upper and lower spray holes 132 of the horizontal feed pipe. The upper spray hole pushes the liquid to flow to the upper right, pushing the oil phase blocked by the oleophobic filler to separate from the filler. The lower nozzle pushes the liquid to flow inside the guide tube. The remaining liquid is divided into two paths at the lower end of the vertical feed pipe and enters the horizontal liquid-solid pre-separator tangentially at a certain speed.

[0074] 2) The horizontal liquid-solid pre-separator with a slit shell separates by the synergistic effect of inertial separation and centrifugal separation. The oily wastewater mixture passes through the inlet section of the horizontal liquid-solid pre-separator and enters the separator cavity vertically downward. Since the inertia of the solid particle phase in the liquid-solid two-phase flow is much greater than that of the liquid phase, the solid particles turn along the separator wall at a large tangential velocity, thereby achieving liquid-solid separation under the action of inertia. The area from the separator inlet to the collision of the oily wastewater and the separator is called the inertial separation zone. The subsequent area is mainly where centrifugal separation plays a major role, which is called the centrifugal separation zone. Under the action of centrifugation, the particles after the collision move in a circular motion along the arc section of the arch-shaped shell and are discharged from the solid phase outer outlet slot 120 in a tangential direction. The remaining majority of the oily wastewater is discharged from the liquid outlet slot 128. A solid phase discharge pipe is arranged below the solid phase outlet groove 120 of the horizontal liquid-solid pre-separator. An inner ring baffle and an outer ring baffle are arranged inside the discharge pipe, which stabilizes the pressure distribution from the solid phase outlet of the horizontal liquid-solid pre-separator to the discharge pipe, avoids the liquid phase from being brought into the discharge pipe, improves the liquid-solid separation efficiency, and realizes the pre-separation of insoluble matter such as solids in oily wastewater.

[0075] 3) The oily wastewater is ejected from the horizontal liquid-solid pre-separator outlet trough 128 and enters the circulator from the lower annular gap channel of the circulator. The oleophilic filler is fluidized under the impact and push of the liquid ejected from the horizontal liquid-solid pre-separator outlet trough 128, flows upward along the annular gap channel outside the guide tube, and the oleophilic hydrophobic filler flowing to the upper part of the guide tube is ejected and pushed by the downward-sloping injection hole at the lower part of the horizontal section of the feed pipe 102 and the density difference within the circulator. It flows toward the inside of the guide tube and flows from top to bottom within the guide tube, thereby achieving a regular circulation of the oleophilic hydrophobic filler and liquid. The circulation of the oleophilic hydrophobic filler and the oily wastewater enhances the collision probability and contact efficiency of the oleophilic hydrophobic filler and the emulsified oil droplets. The oil droplets are continuously adsorbed and aggregated by the oleophilic hydrophobic material, and then continuously separated from the oil-in-water emulsified oil droplets. The pre-emulsification and oil-water pre-separation of the emulsified oil are achieved during the circulation flow. After the oily wastewater passes through the pre-emulsification effect of the circulator and the oleophilic and hydrophobic filler coupling, part of the emulsion is transformed into free oil phase and water phase.

[0076] 4) The free oil phase in the oily wastewater floats to the lower end of the oleophobic material filling tank 116 and is blocked by the hydrophilic oleophobic filler. The blocked oil phase is pushed away from the hydrophilic oleophobic filler by the upward jet from the injection hole at the upper end of the horizontal section of the feed pipe 102, and floats to the oil collecting chamber 108 of the pre-emulsification deoiling and liquid-solid separator 1. The water phase passes through the filler and enters the cylinder of the liquid-solid precision separator.

[0077] 5) The oily wastewater that has passed through the hydrophilic and oleophobic filler enters the liquid-solid fine filter and enters from the outside of the cylindrical liquid-solid separation membrane 113 vertically suspended in the membrane separator. Most of the insoluble matter such as solids and suspended matter is intercepted on the outside of the membrane, and the clear liquid flows out from the inner cavity of the liquid-solid separation membrane 113. After being collected, it is discharged from the pretreatment liquid outlet 111. When it runs for a certain period of time, the automatic control system outputs an instruction, and backwash nitrogen enters the liquid-solid fine filter from the backwash gas inlet 107. The pressure pulse enters the cavity formed by the liquid-solid fine filter partition 110 and the inner head 109. Under the action of the pressure pulse, the insoluble matter on the outside of the liquid-solid fine filter separation membrane detaches from the liquid-solid separation membrane and falls to the upper end of the oleophobic material filling tank 116.

[0078] 6) The upper end cap of the oleophobic material filling tank 116 is fixed to the liquid-solid fine filter cylinder, and the lower end cap of the oleophobic material filling tank 116 is connected to the upper end cap via a spring. When backflushing nitrogen enters the liquid-solid fine filter, the oily wastewater feed is cut off, the valve of the slag discharge port 123 is opened, and the water inlet pressure acting on the lower end cap of the oleophobic material filling tank 116 disappears. The lower end cap of the oleophobic material filling tank 116 falls due to gravity, driving the spring to undergo elastic deformation, increasing the volume of the oleophobic material filling tank 116 and the gaps between the hydrophilic and oleophobic materials. The solids, suspended matter, and other insoluble matter at the upper end cap of the oleophobic material filling tank 116 fall through the gaps between the hydrophilic and oleophobic materials into the circulator, and then settle to the bottom of the system through the filter screen at the bottom of the circulator.

[0079] 7) After the oily wastewater passes through the pre-emulsification coupling of the guide tube and the oleophilic and hydrophobic filler circulating fluidized bed, the oil removal by the hydrophilic and oleophobic material barrier, the pre-removal of insoluble matter by the horizontal liquid-solid pre-separator, and the fine removal of insoluble matter by the liquid-solid membrane filter, it is discharged from the purified water outlet 111 and enters the emulsified oil fine separator 2. Driven by pressure, it enters the primary separation chamber 204 through the primary emulsified oil demulsification separation filter element 203. During the process, the water-in-oil emulsion droplets with an average particle size of 5 to 15 microns are demulsified and aggregated into free oil droplets with a larger diameter, which then float to the oil phase collecting bag 211 of the primary separation chamber and are separated from the water phase. After demulsification and oil removal by the primary emulsified oil demulsification and separation filter, the wastewater, driven by pressure, passes through the secondary emulsified oil demulsification and separation filter 206 and enters the secondary separation chamber 207. During this process, the oil-in-water emulsion droplets, with an average particle size of 0.05 to 5 microns, are demulsified and aggregated into larger free oil droplets. These droplets then float to the oil phase collection bag 209 in the secondary separation chamber and are separated from the water phase. The purified water after oil removal is discharged from the purified water outlet 208.

[0080] Working Principle: A horizontal liquid-solid pre-separator pre-removes insolubles, a liquid-solid separation membrane assembly finely removes insolubles, a liquid-solid circulation coupled with oleophilic material 130 pre-emulsification separation section, an oleophobic material 114 blocks and removes floating oil, and an emulsified oil demulsification membrane assembly finely removes emulsified oil. Oily wastewater first passes through the horizontal liquid-solid pre-separator for pre-insoluble removal, followed by liquid-solid circulation coupled with oleophilic material 130 for pre-emulsification separation, and oleophobic material 114 for blocking and removing floating oil. The blocked free oil phase floats to the oil collection chamber at the top of the separator. The wastewater, free of floating oil, dispersed oil, and some insolubles, is then passed through the liquid-solid separation membrane assembly for fine insoluble removal, and then through the emulsified oil demulsification assembly for deep demulsification and removal of emulsified oil. The oil phase is collected in an oil collection bag, and the purified water is discharged from the system.

[0081] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0082] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An oil-water separation and liquid-solid separation system, comprising a pre-emulsification oil removal and liquid-solid separator (1) and an emulsified oil separator (2), characterized in that: The pre-emulsification and oil removal and liquid-solid separator (1) and the emulsified oil-essence separator (2) are connected via a pipeline; The pre-emulsification deoiling and liquid-solid separator (1) comprises a feed pipe (102), a horizontal liquid-solid pre-separator, an oil-water pre-emulsifier, a liquid-solid fine filter, a backwash gas inlet (107), a pre-treatment liquid outlet (111) and a slag discharge port (123); the feed pipe (102) is opened in the middle of the pre-emulsification deoiling and liquid-solid separator cylinder (105); the feed end of the feed pipe (102) is connected to the oily wastewater raw liquid inlet (101); a plurality of upward and downward oblique injection holes (132) are provided in the horizontal section of the feed pipe (102); part of the liquid is ejected obliquely upward and downward at a certain speed through the upper injection hole (132) and the lower injection hole (132); the diameter of the injection hole (132) is 1-10 mm, and the angle between the injection hole (132) and the axis of the horizontal section of the feed pipe (102) is 5-55°; The oil-water pre-emulsifier, the horizontal liquid-solid pre-separator, and the liquid-solid fine filter are all located inside the pre-emulsifier oil removal and liquid-solid separator cylinder (105), and the liquid-solid fine filter is located above the oil-water pre-emulsifier, and the oil-water pre-emulsifier is located above the horizontal liquid-solid pre-separator; The slag discharge port (123) is provided at the bottom of the pre-emulsification deoiling and liquid-solid separator cylinder (105); The oil-water pre-emulsifier is a filler circulating fluidized bed used to enhance the pre-emulsification of the emulsified oil; The horizontal liquid-solid pre-separator is symmetrically arranged on both sides of the center line of the pre-emulsification and oil removal and liquid-solid separator cylinder (105), and the two horizontal liquid-solid pre-separators are separated by a partition. The horizontal liquid-solid pre-separator includes a horizontal liquid-solid pre-separator shell (125), a central pipe (127), a liquid outlet trough (128), a solid phase external outlet trough (120), a downward liquid-solid vertical inlet (118), and a solid phase discharge barrel; The downward liquid-solid vertical inlet (118) is arranged in the upper middle part of the horizontal liquid-solid pre-separator, the central tube (127) is axially arranged in the center of the separator shell, the central tube (127) is provided with a solid phase outer outlet groove (120) on a circular arc of 180 to 270 degrees downstream, and the separator shell is provided with a liquid outlet groove (128) on a circular arc of 270 to 350 degrees downstream, a solid phase discharge barrel is provided below the solid phase outer outlet groove (120), a group of cone-plate-shaped inner ring baffles (124) and cone-disk-shaped outer ring baffles (126) are provided in the solid phase discharge barrel, and the inner ring baffles (124) are fixedly connected to the inner wall (122) of the solid phase discharge barrel, the outer ring baffles (126) are fixedly connected to the outer wall (121) of the solid phase discharge barrel, and a liquid return port (119) is provided on the outer wall (121) of the solid phase discharge barrel.

2. The oil-water separation and liquid-solid separation system according to claim 1, characterized in that: The oil-water pre-emulsifier comprises a guide tube (117), a circulator bottom screen (129), an oleophilic material (130) and a support frame (131), wherein the guide tube (117) is fixedly connected to the support frame (131), and the support frame (131) is connected to the inner wall of the pre-emulsification deoiling and liquid-solid separator cylinder (105), and the oleophilic material (130) is placed in the guide tube (117). The circulator bottom screen (129) connected to the inner wall of the pre-emulsification deoiling and liquid-solid separator cylinder (105) is provided below the support frame (131); The ratio of the effective flow guide area of the guide cylinder (117) to the effective cross-sectional area of the pre-emulsification deoiling and liquid-solid separator cylinder (105) is 0.2-0.8:

1.

3. The oil-water separation and liquid-solid separation system according to claim 1, characterized in that: The liquid-solid fine filter comprises an oleophobic material-filled tank cylinder (103), oleophobic material (114), an oleophobic material-filled tank (116), a liquid-solid separation membrane (113), a backwash gas inlet (107), and a pretreatment liquid outlet (111); The oleophobic material filling tank cylinder (103) comprises an inner head (109), a liquid-solid fine filter housing (112), and an oleophobic material filling tank (116) which are sequentially connected from top to bottom. The liquid-solid fine filter membrane assembly is located inside the liquid-solid fine filter housing (112), and the pore size of the membrane is 25 nanometers to 1000 nanometers. The oleophobic material (114) is built into the oleophobic material filling groove (116), and a liquid-solid fine filter membrane partition (110) is horizontally connected to the liquid-solid fine filter housing (112). The upper end of the oleophobic material filling groove (116) is connected to the oleophobic material filling groove upper end cover (104). A liquid-solid separation membrane (113) is connected between the liquid-solid fine filter membrane partition (110) and the oleophobic material filling groove upper end cover (104). The oleophobic material filling groove upper end cover (104) is a circular perforated sieve plate with an opening rate of 30% to 70% and a pore diameter of 0.01 cm to 0.09 cm. The bottom surface of the oleophobic material filling groove (116) is connected to the oleophobic material filling groove upper end cover (104) through a spring (115). The number of springs (115) is 3 to 10 and is evenly distributed in the filling groove. The backwash gas inlet (107) passes through the oil collecting chamber (108) of the outer head (106) and is connected to the upper end of the inner head (109); the outer head (106) is connected to the top end of the pre-emulsification deoiling and liquid-solid separator cylinder (105); The lower portion of the oleophobic material filling tank (116) is provided with an inlet for the liquid to be treated, the lower portion of the oleophobic material filling tank (116) is provided with an outlet for insoluble impurities, and the pre-treated liquid outlet (111) is connected to the upper portion of the liquid-solid fine filter housing (112).

4. The oil-water separation and liquid-solid separation system according to claim 1, characterized in that: The emulsified oil separator comprises a separator housing, a pre-treated liquid inlet (201), a first-stage emulsified oil demulsification and separation filter element (203), a second-stage emulsified oil demulsification and separation filter element (206), an oil collecting bag, an oil phase outlet, and a purified water outlet (208); The separator housing is divided into a housing front cavity, a first-stage separation cavity (204), and a second-stage separation cavity (207) by a first-stage emulsified oil demulsification separation filter element partition (202) and a second-stage emulsified oil demulsification separation filter element partition (205) arranged in parallel; The first-stage emulsified oil demulsification and separation filter elements (203) are arranged side by side in the first-stage separation cavity (204) of the separator housing, the second-stage emulsified oil demulsification and separation filter elements (206) are arranged side by side in the second-stage separation cavity (207) of the separator housing, and the second-stage emulsified oil demulsification and separation filter elements (206) are arranged in the second-stage emulsified oil demulsification and separation filter element housing (210); The pre-treated liquid inlet (201) is provided at the upper portion of the front chamber of the separator housing, the oil collecting bag comprises a secondary separation chamber oil phase oil collecting bag (209) and a primary separation chamber oil phase oil collecting bag (211), the secondary separation chamber oil phase oil collecting bag (209) is connected to the upper portion of the secondary separation chamber (207), and the primary separation chamber oil phase oil collecting bag (211) is connected to the upper portion of the primary separation chamber (204); The purified water outlet (208) is located at the lower part of the separator housing.

5. A separation method based on the oil-water separation and liquid-solid separation system according to claim 1, comprising the oil-water separation and liquid-solid separation system, characterized in that: The separation method comprises the following steps: Step 1: The oily wastewater enters the horizontal liquid-solid pre-separator to achieve pre-separation of some solid insoluble matter; Step 2: Pre-separation of solid insolubles in the oily wastewater. The oily wastewater is pre-emulsified by the coupling of the circulator and the fluidized bed of the oleophilic material 130, so that part of the emulsion droplets are converted into free oil phase and water phase. Step 3: The free oil phase floats to the lower end of the oleophobic material filling tank (116), is blocked by the oleophobic material (114), and then floats to the oil collecting chamber (108). Part of the oily wastewater enters the circulator for circulation, and part of the oily wastewater enters the liquid-solid filter cylinder through the oleophobic material (114); Step 4: After the oily wastewater passes through the liquid-solid filter in the liquid-solid membrane separator to remove insoluble matter, it enters the first separation chamber (204) and the second separation chamber (207) of the emulsified oil separator, and the emulsion is demulsified by the first and second emulsion separation filter elements. After demulsification, the free oil phase is collected in the oil phase collecting bag (211) of the first separation chamber and the oil phase collecting bag (209) of the second separation chamber, and the purified water is discharged from the purified water outlet (208).

6. The method for oil-water separation and liquid-solid separation according to claim 5, characterized in that: When the oily wastewater enters the horizontal liquid-solid pre-separator, the flow rate of the descending liquid-solid vertical inlet (118) is 8m / s-17m / s.

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