Degassing membrane assembly

Abstract

The present invention aims to provide a degassing membrane assembly to improve degassing efficiency. To achieve this, the degassing membrane assembly comprises an outer tube, an inner tube embedded within the outer tube, and a membrane filament assembly comprising hollow degassing membrane filaments disposed between the outer and inner tubes. The assembly also includes a turbulence enhancement zone disposed between the outer and inner tubes, wherein a turbulence enhancement structure is disposed within the turbulence enhancement zone.

Description

Technical Field

[0001] The present invention relates to a degassing membrane module. Background Art

[0002] The degassing membrane assembly includes a liquid flow path and a gas flow path. A hollow fiber membrane group is arranged in the liquid flow path. A vacuum is drawn at one end of the gas flow path, and the liquid passes between the numerous hollow fibers. Liquid molecules cannot pass through the fiber walls, but gas molecules can. During operation, the liquid flows through the hollow fibers under a certain pressure. The inside of the hollow fibers is continuously evacuated by vacuum or by using a gas purge combined with vacuum, creating a certain negative pressure. In this way, the gas in the liquid continuously overflows from the liquid through the hollow fibers, thereby achieving the purpose of removing the gas from the liquid. The large number of hollow fibers in the degassing membrane assembly can expand the area of the gas-liquid interface, thereby accelerating the degassing rate.

[0003] The Chinese invention patent application with publication number CN104209006A discloses such a degassing membrane assembly, which includes a degassing membrane assembly consisting of a hollow fiber membrane bundle, a tube shell, a left end cover, a right end cover, a liquid inlet and a vacuum port on the left end cover, a liquid outlet and an air inlet on the right end cover, a vacuum chamber formed between the left end cover and the tube shell, an air inlet chamber formed between the right end cover and the tube shell, a spiral baffle, a guide pipe, a circular baffle, etc. The guide pipe consists of a water distribution pipe, a solid connector, and a collecting pipe. The solid connector combines the water distribution pipe and the collecting pipe into a complete guide pipe.

[0004] However, the industry has been looking forward to obtaining a degassing membrane component with higher degassing efficiency to meet application requirements, such as the need for increased feed liquid flow rate. Summary of the Invention

[0005] The object of the present invention is to provide a degassing membrane assembly to improve degassing efficiency.

[0006] In order to achieve the above-mentioned purpose, a degassing membrane assembly includes an outer tube, an inner tube embedded in the outer tube, and a membrane filament group of hollow degassing membrane filaments arranged between the outer tube and the inner tube. It also includes a turbulence enhancement zone arranged between the outer tube and the inner tube, and a turbulence enhancement structure is arranged in the turbulence enhancement zone.

[0007] In one or more embodiments of the degassing membrane assembly, the membrane filament group of the degassing membrane is connected by binding wires, and the turbulence enhancement structure includes additional binding wires, and the additional binding wires make the binding wire density in the turbulence enhancement area greater than the binding wire density in other areas between the outer tube and the inner tube.

[0008] In one or more embodiments of the degassing membrane assembly, the binding wire density in the turbulence enhanced region is at least twice as high as that in the other regions.

[0009] In one or more embodiments of the degassing membrane assembly, the wire spacing in the turbulence enhanced zone is 1 / 2 or less of the wire spacing in other zones.

[0010] In one or more embodiments of the degassing membrane module, the inner tube includes a closed section, and the turbulence enhanced zone surrounds the closed section.

[0011] In one or more embodiments of the degassing membrane assembly, the turbulence enhancement zone and the closed section are configured to be of equal length and aligned in the axial direction.

[0012] In one or more embodiments of the degassing membrane assembly, the turbulence enhancement zone surrounds a portion of the closed section and is partially staggered in the axial direction.

[0013] In one or more embodiments of the degassing membrane assembly, the turbulence enhanced zone is adjacent to or spaced apart from the closed section in the axial direction.

[0014] In one or more embodiments of the degassing membrane assembly, the inner tube includes a closed section, and the length of the closed section is more than twice the radial width between the outer tube and the inner tube.

[0015] In one or more embodiments of the degassing membrane assembly, the degassing membrane assembly further includes a liquid inlet joint, a liquid outlet joint, and a vacuum joint. The inner tube includes a liquid distribution section, a closed section, and a liquid collection section distributed along the axial direction. The closed section is arranged between the liquid distribution section and the liquid collection section. The liquid distribution section and the liquid collection section are respectively communicated with the outer tube. The liquid inlet joint is connected to the liquid distribution section of the inner tube, and the liquid outlet joint is connected to the liquid collection section of the inner tube; the vacuum joint is communicated with the interior of the degassing membrane filament.

[0016] The aforementioned degassing membrane assembly adds a turbulence enhancement zone, and sets a turbulence structure in the turbulence enhancement zone to reduce the concentration polarization of the feed liquid, thereby increasing the degassing efficiency of the feed liquid, increasing the contact time between the feed liquid and the membrane filament, and further improving the degassing efficiency.

[0017] In addition, since the closed section is provided in the inner tube, the length of the liquid flow channel between the liquid inlet joint and the liquid outlet joint is lengthened through the closed section, thereby changing the flow length of the liquid.

[0018] The higher degassing efficiency allows for increased flow rates, thus meeting the requirements of high flow rate applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0020] Figure 1 It is a half-section view of the degassing membrane assembly.

[0021] Figure 2 is a half-section view of an alternative embodiment.

[0022] Figure 3 is a half-section view of another alternative embodiment.

[0023] Figure 4 is a half-section view of yet another alternative embodiment. DETAILED DESCRIPTION

[0024] The following discloses a variety of different implementation methods or examples of the subject technical solutions. To simplify the disclosure, specific examples of the various elements and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of protection of the present invention. For example, a first feature described later in the specification is formed above or on a second feature, which may include an implementation method in which the first and second features are formed in a directly connected manner, or an implementation method in which an additional feature is formed between the first and second features, so that the first and second features may not be directly connected. In addition, the disclosures may repeat the figure marks and / or letters in different examples. This repetition is for brevity and clarity and does not in itself represent the relationship between the various implementation methods and / or structures to be discussed. Further, when a first element is described in a manner connected to or combined with a second element, the description includes an implementation method in which the first and second elements are directly connected or combined with each other, and also includes an implementation method in which one or more other intervening elements are added to indirectly connect or combine the first and second elements.

[0025] like Figure 1 As shown, the degassing membrane assembly includes an inner tube 1, an outer tube 2, a liquid inlet joint 3, a liquid outlet joint 4, and a vacuum joint 5.

[0026] The inner tube 1 includes a liquid distribution section 11 , a closed section 12 and a liquid collection section 13 . The closed section 12 is arranged between the liquid distribution section 11 and the liquid collection section 13 .

[0027] Water distribution holes or slits are distributed on the pipe body of the liquid distribution section 11 , and the liquid enters the area between the inner pipe 1 and the outer pipe 2 from the liquid distribution section 11 through the water distribution holes or slits.

[0028] The closed section 12 is a solid area into which the liquid cannot enter. The closed section 12 forces the liquid to enter the area between the inner tube 1 and the outer tube 2 through the water distribution holes or slits. In an alternative embodiment, both ends and the tube wall of the closed section 12 are closed, and the interior is hollow.

[0029] The pipe body of the liquid collecting section 13 is also provided with water collecting holes or slits, and the liquid between the inner pipe 1 and the outer pipe 2 enters the liquid collecting section 13 through the water collecting holes or slits.

[0030] The area between the outer tube 2 and the inner tube 2 is closed at both ends, and the feed liquid will not flow out from both ends.

[0031] The liquid inlet connector 3 is used to connect to an external pipeline or connector. It has a flange structure. The liquid to be degassed enters the liquid distribution section 11 of the inner tube 1 through the liquid inlet connector 3. The liquid inlet connector 3 has a neck section 31 that is inserted into the liquid distribution section 11 of the inner tube 1. The outer wall of the neck section 31 and the inner wall of the liquid distribution section 11 are sealed by a sealing element such as an O-ring. In an alternative embodiment, the liquid inlet connector 3 is integrally formed with the inner tube 1.

[0032] The liquid outlet connector 4 is connected to an external pipe or connector and has a flange structure, which facilitates quick connection with an external pipe or connector. The degassed liquid enters the liquid collecting section 13 from the area between the inner tube 1 and the outer tube 2, then enters the liquid outlet connector 4, and is finally discharged from the liquid outlet connector 4. The liquid outlet connector 4 has a tube neck 41, which is inserted into the liquid collecting section 13 of the inner tube 1. The outer wall surface of the tube neck 41 and the inner wall surface of the liquid collecting section 13 are sealed by a sealing element such as an O-ring. In an alternative embodiment, the liquid outlet connector 4 is also constructed as an integral part of the inner tube 1.

[0033] A hollow degassing membrane wire group is arranged in the area between the inner tube 1 and the outer tube 2. Figure 1 is hidden in order to facilitate the observation of other structures, and Figure 1 The points in the area between the inner tube 1 and the outer tube 2 represent the degassed liquid. Similarly, the liquid inlet joint 3, the liquid outlet joint 4, and the liquid in the inner tube 1 are not shown. This simplification makes it easier to observe the structure of the degassing assembly. The degassing membrane filaments are essentially arranged in the axial direction of the degassing membrane assembly, and the degassing membrane filaments are connected by horizontal binding wires. Figure 1 Additional tie wires 7 are shown, but the tie wires, which primarily serve as braided connections, are hidden. Additional tie wires can also connect the degassing membrane wires, but more importantly, as described later, the additional tie wires serve as turbulence enhancement structures. One way to form a turbulence enhancement structure with additional tie wires is to increase the distribution density of the tie wires, for example, the tie wire density at the turbulence enhancement structure is twice or more than the tie wire density in other areas. Another way is to reduce the gaps between the tie wires, for example, the tie wire gaps at the turbulence enhancement structure are 1 / 2 or less of the tie wire gaps in other areas. Reducing the gaps between the tie wires generally results in an increase in the tie wire density, but the gaps between the tie wires can also be reduced by increasing the thickness of the tie wires.

[0034] Combine Figure 1The degassing assembly is constructed such that the liquid flow path is as follows: the liquid enters from the liquid inlet joint 3, flows through the liquid distribution section 11, bypasses the closed section 12, enters the area between the inner tube 1 and the outer tube 2, the liquid collection section 13, and the liquid outlet joint 4. The length of the closed section 12 is more than twice the radial width d between the outer tube 2 and the inner tube 1, so as to lengthen the liquid flow path length between the liquid inlet joint 3 and the liquid outlet joint 4. Figure 1 Taking the half-section view shown in FIG as an example, the area between outer tube 2 and inner tube 1 is shown as an annular shape, and the radial width between outer tube 2 and inner tube 1 is the width of this annular area. Setting the length of the closed section to at least twice the radial width d between outer tube 2 and inner tube 1, while maintaining the liquid distribution section 11 and liquid collection section 13, increases the length of outer tube 2 accordingly, thereby increasing the flow path length of the liquid. This increase in flow path length increases the liquid residence time, ultimately improving degassing efficiency.

[0035] The feed connector 3 and the discharge connector 4 are connected to a vacuum connector 5 and a purge connector 6 respectively. The feed connector 3 and the discharge connector 4 define cavities respectively, and these cavities are communicated with the interior of the membrane filament. A hollow degassing membrane filament group is arranged in the area between the inner tube 1 and the outer tube 2. By connecting a vacuum pump to the vacuum connector 5, a vacuum is drawn inside the membrane filament, and then the air in the feed liquid outside the membrane filament is sucked into the membrane filament, and then sucked from the membrane filament into the vacuum connector 5 and discharged from the vacuum connector 5. Figure 1 The illustrated embodiment further comprises a purge connector 6 , through which purge gas is input into the membrane filaments, and the filtered gas and the purge gas are extracted together from the vacuum connector 5 .

[0036] A turbulence enhancement zone 8 is provided between the outer tube 2 and the inner tube 1, and a turbulence enhancement structure is provided in the turbulence enhancement zone 8. As mentioned above, the turbulence enhancement structure is achieved by adding an additional binding wire 7, but is not limited thereto. Any structure can be used as long as the turbulence characteristics of the turbulence enhancement zone 8 (which can be measured by the Reynolds number) are more obvious. Due to the additional binding wire 7, the binding wire density in the turbulence enhancement zone 8 is greater than the binding wire density in other areas between the outer tube 2 and the inner tube 1. Due to the provision of the turbulence enhancement structure, the self-mixing of the feed liquid is improved and the concentration polarization in the feed liquid is reduced. There are two forms of liquid flow, one is laminar flow and the other is turbulent flow (turbulent flow). The laminar flow form is prone to concentration polarization, resulting in a concentration difference between the center of the liquid and the two sides, affecting the mass transfer efficiency, while turbulence can reduce the concentration polarization phenomenon. By providing a turbulence enhancement structure along the vertical interface of the liquid flow direction, the liquid flow form is changed, tending to form a turbulent state, thereby reducing concentration polarization and further improving the degassing efficiency. In addition, by providing the closed section 12 in the inner tube 1 , the flow path length of the liquid flow is lengthened, thereby providing conditions for providing the turbulence enhancement zone 8 .

[0037] like Figure 1As shown, the closed section 12 is axially equal in length to the turbulence enhanced zone 8. In an alternative embodiment, the closed section 12 is axially longer or shorter than the turbulence enhanced zone 8 and is aligned in the axial direction.

[0038] In yet another alternative embodiment, the length of the turbulence enhanced zone 8 is independent of the length of the closed section 12 and is designed solely based on the turbulence intensity to be achieved.

[0039] In yet another alternative embodiment, Figure 4 As shown, the turbulence enhancement zone 8 surrounds the partially enclosed section 12 and is partially offset in the axial direction.

[0040] In yet another alternative embodiment, Figure 2 As shown, the turbulence enhanced region 8 and the closed section 12 are completely offset in the axial direction.

[0041] In yet another alternative embodiment, Figure 3 As shown, the turbulence enhanced region 8 is adjacent to the closed section 12 in the axial direction.

[0042] In the above alternative embodiments, the turbulence enhancement zone 8 can reduce the concentration polarization of the feed liquid, thereby improving the degassing efficiency of the feed liquid, increasing the contact time between the feed liquid and the membrane filaments, and further improving the degassing efficiency.

[0043] In the above alternative embodiment, after the turbulence enhanced zone 8 is combined with the closed section 12, the turbulence enhanced zone surrounds the closed section. On the one hand, the closed section is used to lengthen the length of the liquid flow channel between the liquid inlet joint and the liquid outlet joint, thereby changing the flow length of the feed liquid. On the other hand, the feed liquid inevitably passes through the turbulence enhanced zone, thereby better reducing the concentration polarization effect. Therefore, the feed liquid degassing efficiency is higher, thereby allowing the feed liquid flow rate to increase, thereby meeting the requirements of high feed liquid flow rate applications.

[0044] exist Figure 1 In the illustrated embodiment, the feed connector 3 and the discharge connector 4 are coaxially arranged in a straight-in and straight-out manner, but their arrangement is not limited to this. In an alternative embodiment, the feed connector 3 and the discharge connector 4 are arranged in a side-to-side straight-out or straight-to-side-out manner, that is, the axis of the feed connector 3 or the discharge connector 4 is set to intersect with the axis of the inner tube 1.

[0045] In addition, although the illustrated embodiment uses a gas purge combined with a vacuum mode to continuously remove the internal gas of the degassing membrane filament, it is not limited thereto, and the gas can also be removed only under the action of vacuum.

[0046] Although the present invention is disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent variations, and modifications made to the above embodiments in accordance with the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A degassing membrane assembly comprising an outer tube, an inner tube embedded in the outer tube, and a membrane filament group of hollow degassing membrane filaments arranged between the outer tube and the inner tube, characterized in that: It also includes a turbulence enhancement zone provided between the outer tube and the inner tube, wherein a turbulence enhancement structure is provided in the turbulence enhancement zone; The membrane filament groups of the degassing membrane are braided and connected by binding wires, and the turbulence enhancement structure includes additional binding wires, and the additional binding wires make the binding wire density in the turbulence enhancement area greater than the binding wire density in other areas between the outer tube and the inner tube; The inner tube includes a closed section, and the turbulence enhanced zone surrounds the closed section.

2. The degassing membrane assembly according to claim 1, wherein The density of the binding wires in the turbulence enhanced area is at least twice that of the other areas.

3. The degassing membrane assembly according to claim 1, wherein The wire-binding spacing in the turbulence enhanced zone is 1 / 2 or less of the wire-binding spacing in the other zones.

4. The degassing membrane assembly according to claim 1, wherein The turbulence enhancement zone and the closed section are arranged to have the same length and are aligned in the axial direction.

5. The degassing membrane assembly according to claim 1, wherein The turbulence enhancement zone surrounds a portion of the closed section and is partially staggered in the axial direction.

6. The degassing membrane assembly according to claim 1, wherein The turbulence enhanced zone is adjacent to or spaced apart from the closed section in the axial direction.

7. The degassing membrane assembly according to claim 1, wherein The inner tube includes a closed section, and a length of the closed section is more than twice the radial width between the outer tube and the inner tube.

8. The degassing membrane assembly according to claim 1, wherein The degassing membrane assembly also includes a liquid inlet joint, a liquid outlet joint, and a vacuum joint. The inner tube includes a liquid distribution section, a closed section, and a liquid collection section distributed along the axial direction. The closed section is arranged between the liquid distribution section and the liquid collection section. The liquid distribution section and the liquid collection section are respectively communicated with the outer tube. The liquid inlet joint is connected to the liquid distribution section of the inner tube, and the liquid outlet joint is connected to the liquid collection section of the inner tube; the vacuum joint is communicated with the interior of the degassing membrane filament.

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