Ultrafiltration membrane assembly for treating offshore thickened oil produced water

Abstract

In order to solve the problems that an ultrafiltration membrane assembly is easy to be polluted and blocked and is poor in cleaning effect in the reinjection water treatment process of an existing offshore platform, the utility model provides an ultrafiltration membrane assembly for treating offshore thickened oil produced water, which comprises a membrane element and an assembly shell sleeved outside the membrane element, the membrane element comprises a central tube, a plurality of hollow fiber membrane filaments and a cementing end; the hollow fiber membrane filaments surround the external array of the central tube, the first ends of the hollow fiber membrane filaments are glued in the gluing end heads, and the second ends are packaged by monofilaments; the first end of the central tube is packaged in the cementing end, and a plurality of flow distribution holes are formed in the side wall; the second end of the assembly shell is provided with a water inlet, an air inlet and an aeration hose, and the first end is provided with a water production port; the water inlet communicates with the second end of the central pipe; the water producing port is communicated with the first ends of the hollow fiber membrane filaments; the aeration hose is arranged above the water inlet and is communicated with the air inlet. The structure and the linkage effect of the structure can effectively prevent the membrane filaments from being polluted and blocked, and the membrane filament cleaning effect is remarkably improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to ultrafiltration equipment technical field especially relates to a kind of ultrafiltration membrane assemblies for offshore heavy oil produced water treatment. BACKGROUND

[0002] Ultrafiltration membrane assembly has been widely applied in the field of water treatment, its core principle is to utilize the microporous retention function of ultrafiltration membrane, to filter liquid, remove suspended solids, colloids, macromolecular substances etc., to obtain relatively pure water. Ultrafiltration membrane has been widely applied in the field of purified water, sewage treatment, concentration separation etc. However, oil and fat have serious pollution and damage to ordinary ultrafiltration membrane, which can cause membrane surface pollution, cleaning difficulty and membrane cracking risk. Therefore, how to improve the structure of ultrafiltration membrane assembly of offshore heavy oil produced water, to improve its easy pollution and significantly improve its cleaning effect has become an urgent problem to be solved.

[0003] For example, a kind of hollow fiber ultrafiltration membrane assembly disclosed in Chinese patent literature, its announcement number CN208727190U, including filter cartridge, upper part of filter cartridge is fixedly provided with upper end cover, lower part of filter cartridge is fixedly provided with lower end cover, filter cartridge is provided with ultrafiltration membrane silk, lower end cover bottom center is provided with air inlet, lower end cover lower part side is provided with liquid inlet, upper end cover top center is provided with liquid outlet, the ultrafiltration membrane silk adopts hollow fiber ultrafiltration membrane silk, the hollow fiber ultrafiltration membrane silk is fixed in the one end close to upper end cover, and the other end is free to swing in filter cartridge. This scheme only relies on membrane silk water distribution, water flow directly impacts membrane silk to uneven distribution, impurities are easy to accumulate below membrane silk, and there is no auxiliary water flow uniform distribution structure, and easy to produce pollution;At the same time, only a single air inlet is provided, and the air flow is difficult to evenly cover each part of membrane silk when diffusing, lacks auxiliary air flow uniform diffusion design, leading to uneven air distribution, cannot fully clean membrane silk, and further affect cleaning effect. SUMMARY

[0004] The utility model mainly solves the problem of existing ultrafiltration membrane assembly easy pollution and poor cleaning effect.

[0005] To solve the above technical problems, the utility model provides a kind of ultrafiltration membrane module for offshore heavy oil produced water treatment, it includes: membrane element and the component shell of being set in membrane element outer, the membrane element includes center tube, several hollow fiber membrane filaments and glue end head, the several hollow fiber membrane filaments are arrayed around the outside of the center tube, the first end of the several hollow fiber membrane filaments is glued in the glue end head, second end monofilament package, the first end of the center tube is packaged in the glue end head, the side wall of the center tube is provided with several flow distribution holes, the second end of the component shell is provided with water inlet, air inlet and aeration hose, and its first end is provided with water outlet, the water inlet is communicated with the second end of the center tube, the water outlet is communicated with the first end of the several hollow fiber membrane filaments, the aeration hose is arranged above the water inlet, and the aeration hose is communicated with the air inlet, wherein, water inlet enters the center tube from the water inlet, and is distributed to the several hollow fiber membrane filaments by the flow distribution hole and is filtered as water production, and water production flows to the water outlet along the first end of the several hollow fiber membrane filaments, and air inlet enters the aeration hose from the air inlet, and aeration is carried out to the membrane element direction from the aeration hose.

[0006] According to the above structure, in the water production process of ultrafiltration membrane module, water is uniformly distributed to ultrafiltration membrane module by pipe, and clean water is converged to the first end by hollow fiber membrane filament, and is discharged to the next process through water outlet. After water production is completed and the ultrafiltration membrane module is cleaned, the water inlet and the water outlet are closed, the air inlet is opened, and aeration is carried out to the membrane element direction through the aeration hose connected thereto, so that the second end of the monofilament packaged hollow fiber membrane filament is shaken, and the cleaning effect is optimized.

[0007] Preferably, the aeration hose is arranged in the second end of the component shell, and the air inlet is arranged in the side wall of the second end of the component shell.

[0008] Preferably, the aeration holes are uniformly arranged on one side surface of the aeration hose, the aeration holes are round holes with a diameter ranging from 0.5 to 2 mm, or the aeration holes are triangular holes with an area ranging from 0.3 to 5.2 square millimeters, or the aeration holes are quadrilateral holes with an area ranging from 0.125 to 2 square millimeters.

[0009] Preferably, the center tube is reversely provided with a first section, a second section and a third section along the water flow direction, each section is provided with flow distribution holes, and the diameter of the flow distribution holes of the first section, the second section and the third section ranges from 0.3 to 0.5 cm, 0.5 to 1.0 cm and 1.0 to 1.5 cm, respectively.

[0010] As preferred, the interior of the second end of the assembly shell forms a sewage chamber, which is arranged below the aeration hose, and the sidewall of the second end of the assembly shell is provided with a second discharge port, which communicates the sewage chamber with the outside space for discharging the sewage in the sewage chamber. The sewage chamber is arranged for collecting the sewage collected in all cleaning processes, and in the emptying stage, the air inlet is closed and the second discharge port is opened to discharge the sewage in the sewage chamber. The sewage chamber arranged below the membrane element collects the pollutants obtained in backwashing and cleaning, and the ultrafiltration membrane assembly is discharged by timed sewage discharge, which guarantees the clean environment inside the ultrafiltration membrane assembly and maintains the good filtering performance thereof.

[0011] As preferred, the material of the hollow fiber membrane filament is PTFE, PES, PVDF or PP. PTFE has high strength, strong chemical corrosion resistance, good pollution resistance, long service life, high flux and can be stored in dry state; PES has good heat resistance, hydrolysis resistance, modulus temperature stability and creep resistance, and good chemical stability; PVDF has high corrosion resistance, high thermal stability, high mechanical strength, easy cleaning and high separation efficiency; PP has small density, good heat resistance, high mechanical strength and good chemical stability. The membrane elements of the four materials each have their own characteristics, and different membrane materials can be selected according to different working conditions.

[0012] As preferred, the assembly shell comprises a first end cover, a membrane shell and a second end cover which are sequentially and sealingly connected, the first end cover forms the first end of the assembly shell, and the second end cover forms the second end of the assembly shell; the water inlet is coaxially arranged with the second end cover, penetrates through the second end cover and extends 5-10 cm outside the second end cover, the membrane element is attached to the inner wall of the membrane shell, the water outlet is arranged on the first end cover, and a backwashing air inlet is arranged on the water outlet.

[0013] As preferred, the membrane shell is provided with a first clamp and a second clamp corresponding to the first end cover and the second end cover, the first end cover is tightly connected with the membrane shell through the first clamp, and the second end cover is tightly connected with the membrane shell through the second clamp. The ultrafiltration membrane assembly is detachable, and when the membrane element needs to be replaced, only the old membrane element is removed and a new membrane element of the same specification is installed, the utilization rate of the membrane shell is greatly increased, the corresponding operating cost is reduced, and solid waste is also reduced.

[0014] As preferred, a first discharge port is further arranged on the first end cover, the first discharge port penetrates the first end cover and the glue joint end head in sequence and is in communication with the first end of the central pipe, and the first discharge port penetrates out of the first end cover by 5-10 cm. According to the above structure, during the air backwashing process of the ultrafiltration membrane assembly, only the first discharge port and the backwashing inlet are opened, the remaining ports are closed, air is started from the backwashing inlet, the membrane element is air backwashed at an air inlet pressure of 1 bar, and finally the air is discharged from the first discharge port. In addition, during the forward washing process of the ultrafiltration membrane assembly, except that the first lower discharge port, the water production port and the water inlet are opened, the remaining ports are closed, and the water inlet is washed through the central pipe to realize further cleaning of the ultrafiltration membrane assembly. The backwashing air inlet arranged at the water production end can increase the shaking amplitude of the hollow fiber membrane wire during the backwashing process of the ultrafiltration membrane assembly, and enhance the cleaning strength.

[0015] As preferred, the glue joint end head and the inner side of the first end cover form a water production cavity, the water production cavity is in communication with the first end of the plurality of hollow fiber membrane wires, and is used for converging produced water.

[0016] The beneficial effects of the utility model are as follows:

[0017] First, the first end of the hollow fiber membrane wire is glued, and the second end is single-wire packaged, which not only ensures the stability of the overall structure, but also makes the solid pollutants intercepted by the hollow fiber membrane wire easy to fall off, thereby reducing the probability of generating pollution blockage and expanding the ultrafiltration water treatment range.

[0018] Second, the air inlet is arranged on the water inlet side, the second end of the hollow fiber membrane wire is suspended, and the air hose is arranged below, the air blowing makes the hollow fiber membrane wire have a larger shaking amplitude, so that the pollutants cannot accumulate on the surface of the hollow fiber membrane wire, and the cleaning effect is optimized.

[0019] Third, the flow distribution hole is arranged on the wall of the central pipe, so that the water inlet is uniformly distributed from the central pipe to the hollow fiber membrane wire along the flow distribution hole, the precise control of the water inlet distribution is realized, the uneven water flow distribution is prevented, the filtering effect of the hollow fiber membrane wire is prevented, and the probability of pollution blockage is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the structure diagram of the ultrafiltration membrane assembly of an embodiment of the utility model.

[0021] Figure 2 is the disassembly schematic view of the ultrafiltration membrane assembly of an embodiment of the utility model.

[0022] Figure 3 is the connection schematic view of the air hose and the air inlet of the ultrafiltration membrane assembly of an embodiment of the utility model.

[0023] Reference signs: 1. first end cover, 1-1. first row of ports, 1-2. water production cavity, 1-3. water production port, 1-4. backwash air inlet;

[0024] 2. membrane element, 2-1. center tube, 2-2. hollow fiber membrane filament, 2-3. glued end head;

[0025] 3. membrane shell, 3-1. first clamp, 3-2. second clamp;

[0026] 4. second end cover, 4-1. water inlet, 4-2. blowdown cavity, 4-3. second row of ports, 4-4. air inlet, 4-5. aeration hose. DETAILED DESCRIPTION

[0027] The application will be described in more detail below with reference to the drawings. It should be noted that the description of the application below with reference to the drawings is merely illustrative and not restrictive.

[0028] In the case possible, each different embodiment described below can be recombined with each other to constitute other embodiments not shown in the description below; each different technical feature described below can also be recombined with each other to constitute other embodiments not shown in the description below.

[0029] Example 1:

[0030] Please refer to Figure 1 , Figure 2 .

[0031] To solve the problem of easy fouling and poor cleaning effect of the existing ultrafiltration membrane assembly, the embodiment provides an ultrafiltration membrane assembly for offshore heavy oil produced water treatment, which is committed to reducing the water quality requirement of the ultrafiltration membrane assembly, enhancing the cleaning effect, and improving the utilization rate of the ultrafiltration membrane shell.

[0032] The main structure for filtering the inlet water includes an improved membrane element 2 and an assembly shell containing the membrane element. Specifically, the improvement of the ultrafiltration membrane assembly in the embodiment lies in that the membrane element includes a center tube 2-1, a plurality of hollow fiber membrane filaments 2-2, and a glued end head 2-3, wherein the plurality of hollow fiber membrane filaments are arrayed around the outside of the center tube, and the first end of the plurality of hollow fiber membrane filaments is glued into the glued end head, and the second end is single filament encapsulated, and the first end of the center tube 2-1 is encapsulated in the glued end head. In the above structure, the array of the plurality of hollow fiber membrane filaments and the single filament encapsulation of the second end can prevent the mutual adhesion between the hollow fiber membrane filaments, and form a basis for subsequent water distribution work.

[0033] The second end of the assembly shell is provided with a water inlet 4-1, and the first end is provided with a water outlet 1-3. The water inlet is in communication with the second end of the central pipe, and the water outlet is in communication with the first end of the hollow fiber membrane wire. When the water enters the central pipe from the water inlet, it is distributed to the hollow fiber membrane wire through the flow distribution hole for filtration to obtain the product water. The product water flows out along the first end of the hollow fiber membrane wire and converges to the water outlet.

[0034] In the ultrafiltration membrane assembly formed by the above structure, the membrane element is the core component, wherein the central pipe is located at the geometric center position of the membrane element and plays a supporting and flow guiding role. A plurality of hollow fiber membrane wires are arranged in a straight state around the central pipe and regularly arranged in an array form outside the central pipe. The first end of the hollow fiber membrane wire and the central pipe are integrally packaged in the glue end head, and the single wire of the hollow fiber membrane wire is packaged, which ensures the tight connection and good sealing between the components, so that the structure integrity of the components can be maintained and the stable ultrafiltration work can be ensured when the components are subjected to external forces such as water flow pressure and aeration impact force under different working conditions.

[0035] The flow distribution hole is provided on the side wall of the central pipe and communicates the inside of the central pipe with the outside space of the hollow fiber membrane wire, so as to ensure that the water can be uniformly dispersed along the flow distribution hole and uniformly distributed in the space of the hollow fiber membrane wire array, thereby forming a better water distribution effect and preventing the adhesion or blockage of the membrane wire.

[0036] These flow distribution holes are arranged in an orderly layout from top to bottom along the pipe wall of the central pipe. When the liquid flows in the central pipe, the liquid can be gradually penetrated and diffused from the inside of the central pipe to the outside space of the central pipe in a uniform and orderly manner by means of the arrangement of the flow distribution hole. The distribution of the liquid in the entire internal space of the ultrafiltration membrane assembly is finely controlled, so that the liquid can form a uniform and stable flow field environment around the hollow fiber membrane wire.

[0037] For the improved membrane element, the central pipe is in communication with the water inlet of the assembly shell for receiving water. After the water flows into the central pipe from the water inlet, it is uniformly distributed to the hollow fiber membrane wire along the flow distribution hole arranged on the side wall of the central pipe. The hollow fiber membrane wire quickly filters the water to generate product water, which converges at the first end of the hollow fiber membrane wire. The first end of the hollow fiber membrane wire is in communication with the water outlet, and the product water is output.

[0038] The uniform water inlet flow field formed by the membrane element and the assembly shell can ensure that each hollow fiber membrane can participate in the filtration work under suitable water flow conditions, avoid the situation that some membrane filaments cannot fully exert the filtration efficiency due to too fast local water flow, and further avoid the situation that the filtration is insufficient. At the same time, the problem of excessive or insufficient local pressure caused by uneven water flow distribution is also prevented, the stability and efficiency of the entire ultrafiltration process are effectively maintained, the interception and filtration effect of the hollow fiber membrane on various impurities are maximized, and the stability and reliability of the output water quality of the ultrafiltration membrane assembly are ensured.

[0039] Based on the above structure, the water production process is as follows: the water inlet is uniformly distributed to the ultrafiltration membrane assembly through the center pipe, sequentially flows through the hollow fiber membrane to complete the filtration to form clean water, i.e. water production, and the clean water is gathered along the membrane to the first end and then flows out of the water outlet to provide high-quality water source for the subsequent process.

[0040] The oil content of the water inlet before being filtered by the above ultrafiltration membrane assembly is ≤5 mg / L, the suspended solids are ≤5 mg / L, and the temperature is 60-100℃, and the oil content of the water production after being filtered by the membrane assembly is ≤3 mg / L, and the suspended solids of the water production are ≤1 mg / L, which has a significant filtration effect. Through comparative analysis of the oil content, suspended solids content and other key water quality indicators of the water inlet and the water production, the filtration efficiency of the ultrafiltration membrane assembly is clearly and intuitively displayed, the oil substances and suspended solids and other impurities contained in the water can be precisely and efficiently intercepted and removed, and the water quality of the treated water production is ensured to better meet the strict requirements of subsequent water use links for high-quality water sources.

[0041] At the same time, the second end of the assembly shell is internally provided with an aeration hose 4-5, and a gap is reserved in the middle for the water inlet 4-1 to pass through, so that the overall structure will not be horizontally displaced, and the stability of the structure is enhanced. The second end of the assembly shell is also provided with an air inlet 4-4, and one end of the aeration hose is in communication with the air inlet, and the other end is sealed, and only the aeration holes are used for aeration to ensure that the external air source can be smoothly input into the aeration hose.

[0042] In the aeration process after cleaning the ultrafiltration membrane assembly: the water inlet and the water outlet are closed, the first drain port 1-1 and the air inlet are opened, the aeration hose produces micro air flow from bottom to top, promotes the hollow fiber membrane to shake, and makes the attached dirt fall off to the drain chamber 4-2, thereby improving the self-cleaning ability and service life.

[0043] The second end of the single-wire packaged hollow fiber membrane wire is shaken by aeration and the first end is fixed, effectively removing the surface contaminants of the membrane wire, and the cleaning efficiency is higher than that of the existing two-end packaging form; the array of hollow fiber membrane wires is outside the center tube 2-1, the gap can prevent adhesion, and the single wires are shaken respectively during aeration, which improves the filtration and cleaning efficiency and ensures smooth ultrafiltration; the flow distribution holes on the side wall of the center tube allow water to flow uniformly to the membrane wire, improve the uniformity of water flow distribution, and optimize the filtration effect and the treatment efficiency of the liquid. After the aeration process, the accumulated pollutants during the air backwashing and forward washing processes are discharged through the emptying process.

[0044] In another preferred embodiment, the aeration holes are carefully arranged on the side surface of the aeration hose facing the membrane element 2, and the aeration holes are arranged in a uniformly distributed state on the surface of the aeration hose, aeration towards the membrane element. The purpose is to provide stable and uniform aeration effect for the membrane element of the ultrafiltration membrane assembly during subsequent operation by the efficient gas conduction of the aeration hose and the uniform gas distribution function of the aeration holes. The aeration drives the single wire shaking of the hollow fiber membrane wire 2-2, which makes the pollutants separate from the surface of the hollow fiber membrane wire.

[0045] In a further preferred embodiment, the aeration holes can be circular holes with a diameter range of 0.5-2 mm. The circular hole shape can achieve uniform gas release, and the circumferential symmetry structure makes the gas diffusion resistance consistent in all directions, which can form a uniform gas-liquid mixing environment near the membrane element, ensure that the hollow fiber membrane wire is impacted by balanced gas flow, and improve the stability and filtration performance of the assembly.

[0046] The lower limit of the hole diameter is 0.5 mm, which makes the aeration holes produce stable and controllable bubbles, the gas flow rate is moderate, the bubbles can fully mix with the liquid and the membrane element, and a soft micro-gas flow is formed to gently shake the membrane wire to remove pollutants without damaging the membrane wire.

[0047] The upper limit of the hole diameter is 2 mm, which can meet the higher requirements of complex working conditions for aeration intensity, can handle larger sticky local attachments, achieve thorough cleaning, and maintain the stability of gas-liquid mixing and the balance of fluid dynamics in the assembly.

[0048] In another further preferred embodiment, the aeration holes are triangular holes with an area range of 0.3-5.2 square millimeters. The triangular hole shape can make the ejected gas flow form a concentrated jet, produce local strong disturbance, effectively break the oil film and other aggregates in offshore heavy oil produced water, improve the aeration cleaning effect, and ensure complete removal of pollutants. The lower limit of 0.3 square millimeters: fine concentrated jet is produced, which is suitable for precise cleaning scenarios and can target local pollutants to ensure the stability and integrity of the membrane wire. The upper limit of 5.2 square millimeters: meets the high-intensity aeration needs when handling large amounts of complex produced water, can overcome high viscosity and tightly adhered pollutants, and maintain good filtration performance.

[0049] In another further preferred embodiment, the aeration holes are arranged as quadrilateral holes, and the area of the quadrilateral holes is 0.125-2 square millimeters. The quadrilateral holes can make the ejected gas form a relatively orderly flow state, help to create a more stable gas-liquid mixing environment around the membrane element, and ensure that the hollow fiber membrane filaments can be uniformly aerated, thereby improving the operation stability and filtration effect of the ultrafiltration membrane module.

[0050] The lower limit of 0.125 square millimeters: generates a relatively mild and fine gas flow, which is suitable for scenarios that require fine aeration or do not require high aeration intensity, can effectively clean without excessively disturbing the membrane filaments, and maintain the good state of the membrane filaments. The upper limit of 2 square millimeters: meets the needs of high aeration intensity in the treatment of complex water quality (such as offshore heavy oil produced water), can strongly disturb the liquid and break the viscous resistance, and ensure thorough cleaning to maintain the high filtration performance of the module.

[0051] The above size setting of the aeration holes, if the aeration holes are too small, the aeration effect will be affected, and the dislodged dirt is easy to block the aeration holes. If the aeration holes are too large, the gas flow will be too large, which will disperse the hollow fiber membrane filaments or cause the entanglement and damage of the hollow fiber membrane filaments.

[0052] In addition, the appropriate area range and shape can not only reduce the risk of aeration hole blockage by impurities in the water, but also ensure sufficient aeration intensity and good gas distribution. Therefore, in order to better adapt to complex and variable working conditions and ensure the long-term stable operation of the ultrafiltration membrane module, other shapes of aeration holes with strictly calculated sizes can also be selected.

[0053] In a further preferred embodiment, the material of the hollow fiber membrane filaments can be selected from one or more of PTFE, PES, PVDF, and PP. PTFE has high strength, strong resistance to chemical corrosion, good anti-pollution performance, long service life, high flux, and can be stored in a dry state; PES has good heat resistance, hydrolysis resistance, modulus temperature stability, and anti-cracking performance, and also has good chemical stability; PVDF has high corrosion resistance, high thermal stability, large mechanical strength, easy cleaning, and high separation efficiency; and PP has small density, good heat resistance, large mechanical strength, and good chemical stability. These material properties can meet the needs of different working conditions and improve the performance of the ultrafiltration membrane module.

[0054] In another preferred embodiment, the design of the flow distribution holes is improved. The central tube is divided into a first section, a second section, and a third section according to the reverse direction of the water flow, wherein the flow distribution holes arranged in the first section have a hole diameter range of 0.3-0.5 cm; the flow distribution holes arranged in the second section have a hole diameter range of 0.5-1.0 cm; and the flow distribution holes arranged in the third section have a hole diameter range of 1.0-1.5 cm. The above three sections can be divided into the same length, or the lengths can be divided according to actual needs.

[0055] The third section of the flow distribution hole has a larger aperture. Given that a certain pressure and flow accumulation has been formed at the second end of the central tube in the initial stage of water flow, the large aperture can efficiently and uniformly disperse a large amount of water flow to the internal area of the ultrafiltration membrane assembly, effectively avoiding the occurrence of water flow dead angles or local water flow weakness at the second end, and ensuring that the hollow fiber membranes can carry out efficient filtration under good water flow conditions, thereby laying a good foundation for the overall filtration.

[0056] The second section of the flow distribution hole has a moderately reduced aperture. As the water flow continues to advance and the flow changes, the aperture can maintain the balance of liquid exchange inside and outside the central tube, ensuring that the water flow passing through this place can be uniformly distributed around the hollow fiber membranes at an appropriate speed and flow rate, thereby preventing the filtration efficiency from being reduced due to slow water flow and avoiding insufficient filtration caused by fast water flow, and further optimizing the filtration efficiency of the middle area.

[0057] The first section of the flow distribution hole has a smaller aperture. When the water flow approaches the first end of the central tube, the smaller aperture can make the liquid flow out at a slower speed, which is helpful for fine and uniform dispersion of the water flow in this area, avoids the local pressure imbalance or excessive disturbance of the membranes caused by the water flow impacting the hollow fiber membranes too fast, and thus ensures that the membranes can work in a relatively stable water flow environment in the final filtration stage, thereby improving the final precision and stability of the filtration.

[0058] Based on the above arrangement of the flow distribution hole, if the aperture of the flow distribution hole is smaller than the minimum aperture, the water flow resistance increases greatly, the water inflow slows down in the central tube, and the water distribution efficiency is affected. The water outflow of each section of the flow distribution hole is uneven, which destroys the fine water distribution effect, the water supply to the membranes is difficult to be uniform, and the membranes are easily blocked by impurities, which affects the operation of the assembly. The fine water distribution effect achieved by reasonably setting flow distribution holes with different apertures is destroyed, the membranes cannot be supplied with uniform water, and thus the filtration effect is affected. If the aperture of the flow distribution hole is larger than the maximum aperture, the water flow is too fast and strong at the corresponding section of the flow distribution hole, which causes serious uneven water distribution in the local area. The large water flow impacts the membranes, causing damage to the membranes, reducing the filtration performance, and shortening the service life. Fine water distribution cannot be achieved, which is not conducive to the best filtration effect of the assembly.

[0059] In another preferred embodiment, the glued end head leaves a space with the first end of the assembly shell to form a water production cavity 1-2, which communicates with the first end of the hollow fiber membranes for water outflow, receives and converges the produced water, and makes the produced water flow out of the water outlet. The glued end head can block the water inflow into the water production cavity from entering the hollow fiber membrane array space, preventing the water inflow from mixing with the produced water. Thus, during the production of the produced water, the water inflow can only enter the central tube through the water inlet, be dispersed to the hollow fiber membrane array space through the flow distribution hole, be converged to the water production cavity through the first end of the hollow fiber membranes, and then flow out of the water outlet.

[0060] Example 2:

[0061] Please refer to Figure 1 andFigure 2 .

[0062] The embodiment provides a kind of ultrafiltration membrane module for offshore heavy oil produced water treatment, it is on the basis of the existing architecture of embodiment 1, more in-depth detailed description is carried out to the specific structure of module shell.This embodiment, module shell includes first end cap 1, membrane shell 3 and second end cap 4 sealed connection in sequence, wherein the water inlet 4-1 mentioned in embodiment 1 is arranged through the low end of second end cap, and water outlet 1-3 is arranged on first end cap, membrane shell covers outside membrane element 2, first end cap, membrane shell and second end cap form a closed space for accommodating membrane element, carry out a series of operations such as water production.And first end cap and membrane element form water production cavity 1-2, for accommodating water production;Second end cap and membrane shell, membrane element form a closed space for accommodating water or cleaning water.

[0063] Wherein, the side wall of membrane shell covers the surface of membrane element, and hollow fiber membrane wire 2-2 is stably limited between center tube 2-1 and membrane shell, to provide physical protection for membrane element, avoid mechanical damage such as collision and extrusion from outside during transportation, installation or operation, ensure the integrity of membrane element structure, so as to ensure that ultrafiltration membrane module can continuously and stably play its filtering function.

[0064] The first end of membrane shell is provided with first clamp 3-1, and the second end is provided with second clamp 3-2, the first end cap is tightly connected with the membrane shell through the first clamp, and the membrane shell and the second end cap are tightly connected through the second clamp, so as to form a closed space.

[0065] This sealing design is very important, on the one hand, prevent foreign matter such as impurities, dust, microorganisms and other foreign matters from entering the inside of ultrafiltration membrane module, avoid pollution to membrane element and internal water flow, affect the filtering effect;On the other hand, it also effectively prevents the leakage of internal water flow, gas and other media, maintains the working pressure and fluid state inside the module, ensures the normal operation of ultrafiltration process.

[0066] In a preferred embodiment, the water inlet penetrates the surface of the second end cap by 5-10 cm, this design can ensure the stability of water flow in the initial stage of water inlet, because the protruding water inlet can let the water inlet have a distance outside to buffer and adjust the water flow direction and flow rate, avoid the impact of too large to affect the water distribution effect of center tube.In addition, when actually installing, it is convenient to butt joint with external water inlet pipeline, can better guarantee the sealing performance, operation space is large, visibility is good, reduce the connection difficulty, improve the installation efficiency.Maintenance, cleaning nearby dirt, impurities is easier to touch, check, dredge when there is blockage and other problems are more convenient.

[0067] When the protrusion of the water inlet is less than 5 cm, the initial stability of the water flow is poor, the water flow is easy to impact the central pipe and affect the water distribution effect, the operation space is small during installation, the visibility is poor, the sealing performance is difficult to guarantee, the connection is difficult, and it is more difficult to clean the dirt and check the dredging problem during maintenance; when the protrusion is greater than 10 cm, it is not easy to clean.

[0068] In another preferred embodiment, a first exhaust port 1-1 is further arranged on the first end cover, the first exhaust port sequentially penetrates the first end cover and the glue end 2-3, and the second end of the first exhaust port is in communication with the central pipe. The first exhaust port is designed to exhaust the air in the area formed by the membrane element, the membrane shell and the second end cover before filtration, so as to prevent bubbles from being formed in the hollow fiber membrane array space during water distribution, thereby affecting the filtration performance.

[0069] Therefore, based on the above structure, the exhaust process can be performed before water production: the water inlet, the first exhaust port and the water outlet are opened, water enters the central pipe and diffuses into the ultrafiltration membrane assembly through the flow distribution hole. Until water flows out of the first exhaust port, the first exhaust port is closed, the exhaust is completed, and a good fluid environment is created for subsequent operation.

[0070] In another preferred embodiment, the first exhaust port penetrates the first end cover and protrudes outward, and the distance range is set to 5-10 cm. The design of this length can first ensure that during the exhaust process, too much water is not discharged from the first exhaust port before the air is exhausted. Secondly, it is more intuitive to observe the exhaust condition, thereby ensuring that the first exhaust port is closed in time. Less than 5 cm will affect the observation effect, and more water will overflow before the air is completely exhausted, and more than 10 cm is not easy to clean.

[0071] When the ultrafiltration membrane assembly needs to be cleaned, by reasonably controlling the opening and closing state of the corresponding structures of the first end cover and the second end cover, different reverse washing operations such as air reverse washing and forward washing can be realized.

[0072] Therefore, in another preferred embodiment, a reverse washing air inlet 1-4 is further arranged on the water outlet, which can perform air reverse washing on the ultrafiltration membrane assembly after the water production process is completed. Thus, the cleanliness of the ultrafiltration membrane assembly is maintained, and the service life thereof is increased. The air reverse washing process includes: closing all ports on the housing assembly except the reverse washing air inlet and the first exhaust port, and introducing air at 1 bar pressure from the reverse washing air inlet to form a reverse air flow to flush the dirt on the surface of the hollow fiber membrane, clean the membrane and avoid damage to the membrane. In addition, forward washing can also be performed, which includes: opening the first exhaust port and the water outlet, and simultaneously opening the water inlet to form a flushing water flow through the central pipe and the flow distribution hole to comprehensively scrub the membrane element and remove the attached dirt. This design makes the forward washing and reverse washing operations more convenient and efficient, can timely restore the filtration performance of the membrane assembly, and prolong the service life thereof.

[0073] In another preferred embodiment, the corresponding structure for accumulating pollutants during the air backwash process, the forward washing process, and the aeration process mentioned in Embodiment 1 is processed. A second end cover forms a pollution discharge cavity 4-2 inside, and a second discharge port 4-3 is arranged on the side wall, which is connected to the outside space and used to discharge the pollutants in the pollution discharge cavity. Based on the above structure, the emptying process is carried out: close the air inlet 4-4 and open the second discharge port, and the pollutants and mixed water flow obtained by shaking and cleaning during the aeration, forward washing, and other processes are discharged from the ultrafiltration membrane assembly through the pollution discharge structure, the inside is cleaned, and the next operation is prepared.

[0074] The pollution discharge cavity and the second discharge port play a key role in the emptying process and other operations, and can successfully discharge the pollutants and mixed water flow obtained by shaking and cleaning during the forward washing, air backwash, and other processes from the ultrafiltration membrane assembly, ensure that the inside of the assembly is always clean, avoid the negative impact of accumulated pollutants on the filtration performance, and further ensure the long-term stable operation and high filtration efficiency of the ultrafiltration membrane assembly.

[0075] In summary, such a design improves the stability, filtration efficiency, backwash and pollution discharge capacity, and maintenance convenience of the ultrafiltration membrane assembly through perfect structure layout and function setting, so that it can better meet the water purification demand and maintain a good working condition in long-term operation.

[0076] It should be understood that the embodiments are only used to illustrate the present application and not to limit the scope of the present application. In addition, it should be understood that after reading the content taught by the present application, those skilled in the art can make various changes or modifications to the present application, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Claims

1. An ultrafiltration membrane module for the treatment of offshore heavy oil produced water, characterized in that, The membrane element and the assembly shell are sleeved outside the membrane element. The membrane element comprises a center tube, a plurality of hollow fiber membrane filaments and a glued end head; the plurality of hollow fiber membrane filaments are arranged outside the center tube, the first end of the plurality of hollow fiber membrane filaments is glued in the glued end head, and the second end is single filament encapsulated; the first end of the center tube is encapsulated in the glued end head, and the side wall of the center tube is provided with a plurality of flow distribution holes; The second end of the assembly shell is provided with a water inlet, an air inlet and an aeration hose, and the first end is provided with a water production outlet; the water inlet is in communication with the second end of the center tube; the water production outlet is in communication with the first end of the plurality of hollow fiber membrane filaments; the aeration hose is arranged above the water inlet, and the aeration hose is in communication with the air inlet; Wherein, the water inlet enters the center tube through the water inlet, and is distributed to the plurality of hollow fiber membrane filaments through the flow distribution holes to be filtered into water production, and the water production flows along the first end of the plurality of hollow fiber membrane filaments to the water production outlet; And the air inlet enters the aeration hose through the air inlet, and the aeration hose aeration is arranged in the membrane element direction.

2. The ultrafiltration membrane module according to claim 1, characterized in that The aeration hose disc is arranged in the second end of the assembly shell, the air inlet is arranged in the side wall of the second end of the assembly shell; a plurality of aeration holes are arranged on the aeration hose.

3. The ultrafiltration membrane module according to claim 2, characterized in that The aeration holes are uniformly arranged on one side surface of the aeration hose; The aeration hole is a circular hole, and the diameter of the circular hole is 0.5-2mm, or The aeration hole is a triangular hole, and the area of the triangular hole is 0.3-5.2 square millimeters, or The aeration hole is a quadrilateral hole, and the area of the quadrilateral hole is 0.125-2 square millimeters.

4. The ultrafiltration membrane module according to claim 1, wherein The center tube is reversely provided with a first section, a second section and a third section along the water flow direction, each section is provided with a flow distribution hole, and the flow distribution hole diameter range of the first section, the second section and the third section is arranged as 0.3-0.5cm, 0.5-1.0cm, 1.0-1.5cm in turn.

5. The ultrafiltration membrane module according to claim 1, wherein The second end of the assembly shell forms a sewage discharge cavity inside, the sewage discharge cavity is arranged below the aeration hose, and the side wall of the second end of the assembly shell is provided with a second discharge port, the second discharge port is in communication with the sewage discharge cavity and the outside space, and is used for discharging the sewage in the sewage discharge cavity.

6. The ultrafiltration membrane module according to claim 1, wherein The material of the hollow fiber membrane filament is PTFE, PES, PVDF or PP.

7. The ultrafiltration membrane module according to any one of claims 1 to 6, characterized in that The assembly shell comprises a first end cover, a membrane shell and a second end cover which are sequentially sealed and connected, the first end cover forms the first end of the assembly shell, and the second end cover forms the second end of the assembly shell; the water inlet is coaxially arranged with the second end cover and penetrates through the second end cover and extends 5-10cm outside the second end cover, the membrane element is attached to the inner wall of the membrane shell, the water production outlet is arranged on the first end cover, and a backwashing air inlet is arranged on the water production outlet.

8. The ultrafiltration membrane module according to claim 7, characterized in that Corresponding to the first end cover and the second end cover, the first end cover is tightly connected with the membrane shell through the first clamp, and the second end cover is tightly connected with the membrane shell through the second clamp.

9. The ultrafiltration membrane module according to claim 8, characterized in that The first end cover is further provided with a first discharge port which penetrates the first end cover and the rubberized end head in sequence and is in communication with the first end of the central tube and extends out of the first end cover by 5-10 cm.

10. The ultrafiltration membrane module according to claim 9, characterized in that The rubberized end head and the inner side of the first end cover form a water production cavity which is in communication with the first end of the hollow fiber membrane filaments and is used for gathering produced water.

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