Ultrafiltration membrane module of composite construction

Abstract

The application provides a composite structure ultrafiltration membrane assembly, which comprises a shell, a water outlet is arranged at the top of the shell, a liquid inlet is arranged at the bottom of the shell, the shell is divided into a filtering area and a gas floating area which are in communication from top to bottom by a first resin sealing layer, the filtering area is divided into a liquid production area and a membrane area from top to bottom by a second resin sealing layer, membrane filaments are arranged in the membrane area, one end of the membrane filaments is embedded in the second resin sealing layer, and the membrane filament holes are in communication with the liquid production area, a waste liquid outlet is arranged below the second resin sealing layer, the gas floating area is provided with fiber fillers, and a dissolved gas releaser is arranged at one end of the liquid inlet close to the inside of the shell. The ultrafiltration membrane assembly of the application efficiently combines the gas floating structure and the ultrafiltration structure, the series connection between the two parts can be directly realized in the membrane cavity, the liquid level balance, pressure increase and decrease and other control links of other process modes are reduced, and the ultrafiltration membrane assembly has the advantages of high water production efficiency and small energy consumption.

Description

Technical Field

[0001] This invention relates to the field of ultrafiltration membrane technology, and in particular to an ultrafiltration membrane module with a composite structure. Background Technology

[0002] Dissolved air flotation for oil and algae removal and ultrafiltration microfiltration is a mature combined process in water treatment. The existing combination forms are generally divided into two types: one is an independent dissolved air flotation device + an independent ultrafiltration device, such as the integrated ultrafiltration and air flotation device disclosed in patent number CN110078175A; the other is an integrated device that separates the ultrafiltration membrane tank area within the dissolved air flotation device and uses submerged ultrafiltration negative pressure operation, such as the air flotation membrane filtration purification system in patent number CN103663820A.

[0003] Independent combined processes require separate intermediate water tanks and booster pumps, resulting in large footprints and complex equipment manufacturing and control. Furthermore, the power supplied by pressurized dissolved air flotation (DAF) is unloaded and released after losses, requiring further pressurization before entering the ultrafiltration unit, leading to significant energy consumption. Integrated processes, employing a combined design of DAF and ultrafiltration, reduce the need for intermediate water tanks, but the addition of a membrane tank and DAF increases the overall size, resulting in a still large footprint. They also require special submerged modules, leading to lower water production efficiency, and their manufacturing and control are more complex than independent processes. Similarly, the power supplied by pressurized dissolved air flotation (DAF) is unloaded and released after losses in the ultrafiltration membrane tank, requiring further self-priming pump power to operate the ultrafiltration unit, resulting in significant energy consumption. Therefore, a composite ultrafiltration membrane module with high water production efficiency and low energy consumption needs to be designed. Summary of the Invention

[0004] In view of this, the present invention proposes an ultrafiltration membrane module with a composite structure that has high water production efficiency and low energy consumption.

[0005] The technical solution of this invention is implemented as follows: On one hand, this invention provides a composite structure ultrafiltration membrane module, including a shell, an outlet at the top of the shell, an inlet at the bottom of the shell, and the shell is divided from top to bottom by a first resin sealing layer into an interconnected filtration zone and a flotation zone; the filtration zone is divided from top to bottom by a second resin sealing layer into a product zone and a membrane zone, the membrane zone is provided with membrane fibers, one end of the membrane fibers is embedded in the second resin sealing layer, and the membrane fiber pores are connected to the product zone; the shell below the second resin sealing layer is provided with a waste liquid outlet; the flotation zone is provided with fiber packing, and the inlet is provided with a dissolved gas release device at one end near the inside of the shell.

[0006] Based on the above technical solution, preferably, a water passage hole is opened at the center of the first resin sealing layer, a water passage pipe is provided on the side of the water passage hole near the air flotation zone, an oil decanting cap is sleeved on the outside of the water passage pipe, and a water passage cavity is formed between the oil decanting cap and the water passage pipe.

[0007] Based on the above technical solutions, preferably, multiple through holes are opened on the side wall of the water pipe.

[0008] Based on the above technical solutions, preferably, the decanting cap includes a connecting pipe and a filter screen. One end of the connecting pipe is embedded in the second resin sealing layer and sleeved on the outside of the water pipe. The opposite end is provided with a filter screen, which protrudes towards the bottom of the shell and has an arc-shaped cross-section.

[0009] Based on the above technical solutions, preferably, it also includes a decanting plate, which is annular and has an inverted conical cross-section. The decanting plate is disposed between the connecting pipe and the inner wall of the shell and is connected to the connecting pipe and the inner wall of the shell. The shell below the decanting plate is provided with a drain port.

[0010] Based on the above technical solutions, preferably, the fiber filler includes multiple fiber balls, which are connected in series to form multiple strings, and the two ends of each string of fiber balls are fixed to the decanting inclined plate and the bottom of the shell, respectively.

[0011] Based on the above technical solutions, preferably, the filtration zone and the air flotation zone are separately arranged, and a clamp is fitted on the outside of the shell at the connection between the filtration zone and the air flotation zone.

[0012] Based on the above technical solutions, preferably, the membrane fiber has an open end and a sealed end structure, with the open end of the membrane fiber embedded in the second resin sealing layer and the sealed end of the membrane fiber close to the air flotation zone.

[0013] Based on the above technical solutions, preferably, a lower drain port is provided on the side wall at the bottom of the housing.

[0014] Based on the above technical solutions, preferably, a support frame is also included, which is located outside the housing and connected to the bottom of the housing.

[0015] The composite structure ultrafiltration membrane module of the present invention has the following advantages over the prior art:

[0016] (1) In this invention, the pressurized dissolved air water flows through the flotation zone and the filtration zone. The pressurized dissolved air can be directly and continuously transferred, which can meet the requirements of the flotation and membrane separation processes without the need for additional power devices. After passing through the lower flotation zone, the concentration of suspended solids in the wastewater can be effectively reduced, which can reduce the load on the ultrafiltration section, enhance the antifouling ability of the ultrafiltration membrane, and has the advantages of high water production efficiency and low energy consumption.

[0017] (2) By setting up a decanting cap and a decanting inclined plate, the oil in the sewage is collected at the sewage outlet under the action of the decanting cap and the decanting inclined plate, and discharged from the sewage outlet, which has a good effect on the treatment of oily sewage.

[0018] (3) The ultrafiltration membrane module of the present invention efficiently combines the air flotation structure and the ultrafiltration structure, and the two parts can be directly connected in series within the membrane cavity, reducing many control links such as liquid level balance and pressure increase and decrease in other processes, thus reducing many control links.

[0019] (4) The ultrafiltration membrane module of the present invention does not require the configuration of an intermediate water tank, a booster pump and other auxiliary configurations, and has high integration characteristics, small footprint and simple equipment control. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is an internal structural diagram of the ultrafiltration membrane module of the present invention;

[0022] Figure 2 for Figure 1 Enlarged view of section A;

[0023] Figure 3 This is a structural diagram of the decanting cap of the ultrafiltration membrane module of the present invention.

[0024] In the diagram, 1-shell, 2-outlet, 3-inlet, 4-first resin sealing layer, 11-filtration zone, 12-flotation zone, 5-second resin sealing layer, 111-product zone, 112-membrane zone, 6-membrane fiber, 7-waste outlet, 8-fiber packing, 9-dissolved gas release device, 41-water passage hole, 10-water passage pipe, 13-decanting cap, 14-water passage cavity, 15-through hole, 131-connecting pipe, 132-filter screen, 16-decanting inclined plate, 17-drain outlet, 81-fiber ball, 18-clamp, 19-lower outlet, 20-support frame. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] like Figure 1As shown, the composite structure ultrafiltration membrane module of the present invention includes a housing 1, which is a hollow cavity closed at both ends. A water outlet 2 is located at the center of the top of the housing 1, and a liquid inlet 3 is located at the center of the bottom of the housing 1. The housing 1 is divided from top to bottom by a first resin sealing layer 4 into an interconnected filtration zone 11 and a flotation zone 12; the filtration zone 11 is further divided from top to bottom by a second resin sealing layer 5 into a product liquid zone 111 and a membrane zone 112.

[0027] Membrane filaments 6 are installed within membrane zone 112. These filaments are high-strength, rigid filaments that are not easily disturbed by water flow. Membrane filaments 6 are vertically arranged within membrane zone 112, with their length direction aligned with that of the shell 1. Membrane filaments 6 have an open end and a sealed end. The open end of membrane filament 6 is embedded in the second resin sealing layer 5, and the membrane filament opening communicates with the product liquid zone 111. The sealed end of membrane filament 6 is located near the flotation zone 12.

[0028] The shell 1 below the second resin sealing layer 5 is provided with a waste liquid outlet 7; the air flotation zone 12 is provided with fiber packing 8, the bottom side wall of the shell 1 is provided with a lower outlet 19, and the inlet 3 is provided with a dissolved air flotation dissolved air release device 9 at one end near the inside of the shell 1.

[0029] In a specific embodiment, both the first resin sealing layer 4 and the second resin sealing layer 5 are epoxy resin sealing layers.

[0030] In a specific embodiment, a water passage hole 41 is opened at the center of the first resin sealing layer 4. The filtration zone 11 and the flotation zone 12 are connected through the water passage hole 41. A water passage pipe 10 is provided on the side of the water passage hole 41 near the flotation zone 12. An oil decanting cap 13 is sleeved on the outside of the water passage pipe 10. A water passage cavity 14 is formed between the oil decanting cap 13 and the water passage pipe 10. The function of the oil decanting cap 13 is to remove oil from the sewage.

[0031] In a specific embodiment, multiple through holes 15 are opened on the side wall of the water pipe 10, and sewage can flow through the through holes 15 or the end of the water pipe 10.

[0032] In a specific embodiment, the decanting cap 13 includes a connecting pipe 131 and a filter screen 132. The length of the connecting pipe 131 is greater than the length of the water pipe 10. One end of the connecting pipe 131 is embedded in the second resin sealing layer 5 and sleeved on the outside of the water pipe 10. The opposite end is provided with a filter screen 132. There is a gap between the connecting pipe 131 and the water pipe 10. The filter screen 132 protrudes towards the bottom of the housing 1, and the cross-section of the filter screen 132 is arc-shaped.

[0033] In a specific embodiment, a decanting plate 16 is also included. The decanting plate 16 is annular and has an inverted conical cross-section. The decanting plate 16 is disposed between the connecting pipe 131 and the inner wall of the housing 1 and is connected to the connecting pipe 131 and the inner wall of the housing 1. The housing 1 below the decanting plate 16 is provided with a drain outlet 17.

[0034] In a specific embodiment, the fiber filler 8 includes multiple fiber balls 81, which have a multi-layer radial structure. Multiple fiber balls 81 are connected in series to form multiple strings, and the two ends of each string of fiber balls 81 are fixed to the decanting inclined plate 16 and the bottom of the shell 1, respectively. Adjacent strings of fiber balls are staggered.

[0035] In a specific embodiment, the filtration zone 11 and the flotation zone 12 are set separately, and the clamp 18 is sleeved on the outside of the housing 1 at the connection between the filtration zone 11 and the flotation zone 12, which facilitates later maintenance and repair.

[0036] In a specific embodiment, the outer side of the housing 1 at the connection between the filtration zone 11 and the flotation zone 12 is provided with a connecting groove, and the sealing connection between the filtration zone 11 and the flotation zone 12 is achieved by the clamp 18.

[0037] In a specific embodiment, a support frame 20 is also included. The support frame 20 is located outside the housing 1 and is connected to the bottom of the housing 1.

[0038] The present invention describes a method for treating wastewater using a composite ultrafiltration membrane module. Wastewater with a dissolved air pressure of 0.3-0.4 MPa, generated by a dissolved air tank, is introduced into the inlet 3 via a conduit and released through a dissolved air release device 10. Air dissolved in the water is released, forming a large number of microbubble clusters. These microbubble clusters adhere to suspended solids in the wastewater, forming a low-density bubble suspension. Under buoyancy, the suspension flows through the fiber packing 8, adsorbing onto the surface of the fiber packing 8. Under the action of the decanting cap 13 and the decanting inclined plate 16, air and suspended solids collect at the drain outlet 19 and are discharged outside the housing 1. Wastewater with some suspended solids removed enters the upper filtration zone 11 through the water pipe 10 at the upper end of the decanting cap 13. Water, driven by pressure, collects in the product water zone through the micropores on the surface of the membrane fibers 6 and is discharged through the outlet 2. Suspended solids retained on the surface of the membrane fibers 6 are discharged with the water flow through the drain outlet 19.

[0039] The composite structure ultrafiltration membrane module of the present invention can remove pollutants trapped in the membrane cavity through hydraulic backwashing, thereby restoring the membrane performance.

[0040] The composite structure ultrafiltration membrane module of the present invention supports forward flushing, reverse flushing, and backwashing discharge processes.

[0041] Forward flushing: A large flow of flushing water enters through the inlet 3, and the water flows in the forward direction to scrub the surface of the membrane fibers 6, while carrying pollutants out of the waste outlet 7 and discharged from the membrane area 112.

[0042] Reverse flushing: During forward flushing, a large flow of flushing water enters through the waste liquid port 7, and the water flows in the opposite direction to scrub the surface of the membrane fibers 6, and carries the pollutants out of the membrane area 112 through the lower discharge port 19.

[0043] Backwash discharge: A large flow of backwash water enters the membrane fiber product zone 111 from the outlet 2, is discharged through the interception hole of the membrane fiber 6, squeezes out the pollutants in the embedded hole and enters the membrane zone 112, and is discharged from the module from the lower outlet 19.

[0044] During component cleaning, a large flow of pressurized cleaning agent is injected into the component through the inlet 3, soaking the membrane fibers 6. The cleaning solution reacts with the contaminants on the membrane fibers, loosening or dissolving the contaminants, and is then discharged from the component through the waste outlet 7 with the cleaning water flow.

[0045] The ultrafiltration membrane module of this invention eliminates the need for an intermediate water tank, booster pump, and other auxiliary components, boasts high integration, a small footprint, and simple equipment control. The power provided by the pressurized dissolved air in the flotation zone is sufficient for both flotation and membrane separation processes, significantly reducing energy loss and eliminating the need for an additional booster pump. Through the combined action of the flotation zone packing material and decanting cap, suspended solids and oil in wastewater can be effectively removed, reducing the amount of sediment buildup in the filtration zone and enhancing its anti-fouling capabilities.

[0046] The ultrafiltration membrane module of the present invention efficiently combines the air flotation structure and the ultrafiltration structure, and the two parts can be directly connected in series within the membrane cavity, reducing many control links such as liquid level balance and pressure increase / decrease in other processes, thus reducing many control links.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite structure ultrafiltration membrane module, comprising a housing (1), wherein the top of the housing (1) is provided with an outlet (2) and the bottom of the housing (1) is provided with an inlet (3), characterized in that: The shell (1) is divided from top to bottom by a first resin sealing layer (4) into an interconnected filtration zone (11) and an air flotation zone (12); the filtration zone (11) is divided from top to bottom by a second resin sealing layer (5) into a product zone (111) and a membrane zone (112); the membrane zone (112) is provided with membrane fibers (6), one end of the membrane fibers (6) is embedded in the second resin sealing layer (5), and the membrane fiber pores are connected to the product zone (111); the shell (1) below the second resin sealing layer (5) is provided with a waste liquid outlet (7); the air flotation zone (12) is provided with fiber packing (8), and the liquid inlet (3) is provided with a dissolved gas release device (9) at one end near the inside of the shell (1); A water passage hole (41) is opened at the center of the first resin sealing layer (4). A water passage pipe (10) is provided on the side of the water passage hole (41) near the air flotation zone (12). A decanting cap (13) is sleeved on the outside of the water passage pipe (10). A water passage cavity (14) is formed between the decanting cap (13) and the water passage pipe (10). The decanting cap (13) includes a connecting pipe (131) and a filter screen (132). One end of the connecting pipe (131) is embedded in the second resin sealing layer (5) and sleeved on the outside of the water pipe (10). The opposite end is provided with a filter screen (132). The filter screen (132) protrudes towards the bottom of the shell (1) and the cross-section of the filter screen (132) is arc-shaped. The ultrafiltration membrane module with the composite structure also includes a decanting plate (16), which is annular and has an inverted conical cross-section. The decanting plate (16) is disposed between the connecting pipe (131) and the inner wall of the shell (1) and is connected to the connecting pipe (131) and the inner wall of the shell (1). The shell (1) below the decanting plate (16) is provided with a drain port (17). The fiber filler (8) includes multiple fiber balls (81), which are connected in series to form multiple strings. The two ends of each string of fiber balls (81) are fixed to the decanting inclined plate (16) and the bottom of the shell (1), respectively. Multiple through holes (15) are opened on the side wall of the water pipe (10). The membrane fiber (6) has an open end and a sealed end structure. The open end of the membrane fiber (6) is buried in the second resin sealing layer (5), and the sealed end of the membrane fiber is close to the air flotation zone (12).

2. The ultrafiltration membrane module with a composite structure as described in claim 1, characterized in that: The filtration zone (11) and the flotation zone (12) are set separately, and a clamp (18) is fitted on the outside of the shell (1) at the connection between the filtration zone (11) and the flotation zone (12).

3. The ultrafiltration membrane module with a composite structure as described in claim 1, characterized in that: The bottom side wall of the housing (1) has a lower drain port (19).

4. The ultrafiltration membrane module with a composite structure as described in claim 1, characterized in that: It also includes a support frame (20), which is located outside the housing (1) and connected to the bottom of the housing (1).

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