Outer pipe for forming flow passage for fluid to be separated, and separation device using the same

Abstract

To provide an outer pipe for forming a flow passage for a fluid to be separated that can reduce the amount of damage received by an inorganic film when assembling a separation film module by combining the outer pipe and a film separation material on which the inorganic film is formed.SOLUTION: There is provided an outer pipe 31, which is for forming a flow passage for a fluid to be separated and into which a film separation material 30 having an inorganic film formed on a surface of a tubular support is inserted, has a smooth surface obtained by smoothening an inner surface of the outer pipe.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an outer tube for forming a passage through which a fluid to be separated flows, and a separation device using the outer tube, into which a membrane separation material having an inorganic membrane formed on the surface of a tubular support is inserted. Inorganic membranes include zeolite membranes and silicalite membranes. [Background technology]

[0002] For example, zeolite crystals have molecular-sized pores in the crystals, and have molecular sieve properties that allow molecules to selectively pass through depending on the size and shape of the zeolite molecules. Utilizing this molecular sieve property, zeolites are applied in fields such as gas separation membranes, reverse permeation separation, reverse osmosis separation, and gas sensors. In particular, the use of zeolite membranes as separation membranes for separating organic solvents from mixed liquids containing water and organic solvents has attracted attention.

[0003] A known separation membrane module for separating organic solvents using a separation membrane using the above-mentioned zeolite is described in Patent Document 1, which includes a vertical tubular separation membrane, a vertical cylindrical upper end piece connected to the upper end of the separation membrane, and a vertical rod-shaped lower end piece connected to the lower end of the separation membrane.

[0004] The separation membrane described in Patent Document 1 has a zeolite membrane formed on the surface of a tubular support such as alumina, and the fluid to be separated is separated into a fluid of components that permeate the zeolite membrane and a fluid of components that do not permeate the membrane, thereby separating the fluid into its components.

[0005] The fluid to be separated passes between the outer tube and the cylindrical separation membrane, and of the fluid to be separated that comes into contact with the separation membrane, the fluid that passes through the crystalline pores of the zeolite membrane flows out through the hollow holes inside the separation module, while the fluid components that cannot pass through the crystalline pores of the zeolite membrane flow out through the gap between the separation membrane and the outer tube. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-212509 Summary of the Invention [Problem to be solved by the invention]

[0007] In order for a zeolite membrane to exhibit stable performance, it is necessary to maintain the state in which the crystalline coating is formed on the support surface as it was at the time of manufacture. For example, if the zeolite membrane comes into contact with the outer tube during module assembly and the surface of the zeolite membrane is scratched, the scratch will cause changes to the crystalline pores, leading to a decrease in performance. When the fluid to be separated is gas, the driving force used for separation is pressure, and because resin materials have problems with pressure resistance, it is necessary to use a metal material for the outer tube. In this case, the inner surface of the metal outer tube has a certain degree of surface roughness, and if the zeolite membrane comes into contact with this surface, the crystal pores of the zeolite membrane will be damaged, reducing separation performance.

[0008] The present invention has been made in view of the above points, and its object is to provide an outer tube that minimizes damage to the inorganic membrane when assembling a separation membrane module by combining a membrane separation material having an inorganic membrane such as a zeolite membrane or a silicalite membrane with an outer tube that forms a passage through which a fluid to be separated flows. [Means for solving the problem]

[0009] The present invention (1), which has been made to solve the above problems, is an outer pipe for forming a passage through which a fluid to be separated flows, into which a membrane separation material having an inorganic membrane formed on the surface of a tubular support is inserted, and which is characterized in that the inner surface of the outer pipe has a smooth surface.

[0010] Since a smooth, flat surface is formed on the inner surface of the outer tube, the possibility of damaging the inorganic membrane is reduced even if the membrane separation material comes into contact with the inner surface of the outer tube when inserting the membrane separation material into the outer tube, making it easier to assemble the separation membrane module.

[0011] The present invention (2) is the outer pipe for forming a passage according to the present invention (1), wherein the smooth surface is a polished surface or a surface of a resin coating layer. According to this invention, the smooth surface can be broadly divided into a polished surface and a resin coating layer surface. When polished, it is easy to form a smooth surface, and when a resin coating layer is used, the surface is covered with a soft resin, so the inorganic film is not damaged.

[0012] There are various methods that can be used to form a polished surface, including chemical polishing, electrolytic polishing, and mechanical polishing. Chemical polishing is a polishing method that uses the power of acid or alkali to corrode the metal surface through a chemical reaction, and is characterized by the ease of controlling the thickness of the polishing. Electrolytic polishing is a method in which the metal is immersed in an electrolytic polishing solution and an electric current is passed through the solution, with the metal being positive. In the case of stainless steel outer tubes, this has the advantage of forming a chromium passive film on the surface, transforming the metal into one with a highly corrosion-resistant surface. Mechanical polishing is a method in which the metal is worn down by mechanically rubbing it against an abrasive; a typical method is buffing, which is highly efficient.

[0013] The method for applying the resin coating layer is to degrease and bake the inner surface of the outer tube, then apply a primer (adhesive) undercoat, then apply a top coat (resin) overcoat, and bake the coating. If the resin is a fluororesin, it has self-adhesive properties, so there is no need to apply a primer undercoat.

[0014] The present invention (3) is a separation device for separating a fluid to be separated, comprising: a tube plate dividing the interior of a tank into two spaces, a first space and a second space; a tank body having a raw fluid inlet and a first fluid outlet communicating with the first space; a lid body which, when combined with the tank body, forms the tank; a membrane separation material having an inorganic membrane formed on the surface of a tubular support, the membrane separation material having one end communicating with the second space and the other end sealed within the first space; and an outer pipe into which the membrane separation material is inserted and which forms a passage through which the fluid to be separated flows, the outer pipe having both ends communicating with the first space. A plurality of the outer pipes into which the membrane separation material is inserted are arranged within the tank, the inner surface of the outer pipe being smoothed, the fluid to be separated that has permeated the inorganic membrane flows out from the second fluid outlet, and the fluid to be separated that has not permeated the inorganic membrane flows out from the first fluid outlet.

[0015] In the present invention (3), the inner surface of the outer tube is smoothed to form a flat surface, which reduces the possibility of damaging the inorganic membrane during the assembly process of the membrane separation material and the outer tube, resulting in a separation device of the present invention (3) with highly uniform separation performance.

[0016] The present invention (4) is a separation device according to the present invention (3), characterized in that the outer tube has an inner tube material inside the outer tube, the smooth surface is formed on the inner surface of the inner tube material, and after the membrane separation material is attached to the outer tube, a wire and a locking portion for removing the inner tube material from the main body of the tank are formed at the end of the inner tube material.

[0017] In the present invention (4), an inner tube material is provided inside the outer tube, and a smooth surface is formed on the inner surface of the inner tube material, so that when the membrane separation material is installed inside the outer tube, the membrane separation material is not damaged by the inner surface of the outer tube. After the membrane separation material is attached to the outer pipe, the inner pipe can be easily removed from the tank body because a wire and a locking portion are formed at the end of the inner pipe for removing the inner pipe. This allows the membrane separation material to be easily attached coaxially to the outer pipe and allows the flow paths for the fluid to be separated to be spaced equally apart in the direction perpendicular to the axis.

[0018] The present invention (5) is a separation device according to the present invention (3), characterized in that the outer pipe has an inner tube material inside the outer pipe, the smooth surface is formed on the inner surface of the inner tube material, and the inner tube material has an excess length that allows it to be removed from the main body of the tank after the membrane separation material is attached to the outer pipe.

[0019] In the present invention (5), an inner tube material is provided inside the outer tube, and a smooth surface is formed on the inner surface of the inner tube material, so that when the membrane separation material is installed inside the outer tube, the membrane separation material is not damaged by the inner surface of the outer tube. The inner cylinder has an excess length that allows it to be removed from the tank body after the membrane separation material is attached to the outer pipe, making it easy to remove the inner cylinder, which allows the membrane separation material to be easily attached coaxially to the outer pipe and makes the flow paths for the fluids to be separated evenly spaced in the direction perpendicular to the axis. [Effects of the Invention]

[0020] According to the present invention, when a separation membrane module is assembled by combining a membrane separation material having an inorganic membrane such as a zeolite membrane or a silicalite membrane with an outer tube for forming a passage through which a fluid to be separated flows, an outer tube can be provided that minimizes damage to the inorganic membrane. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view showing a separation device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing the membrane separation material and outer pipe in the separation device of FIG. 1 in a combined state. [Figure 3] FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a separation device according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view showing an embodiment of the present invention (4). [Figure 6] FIG. 10 is a cross-sectional view showing a modified example of the embodiment of the present invention (4). DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses.

[0023] Fig. 1 shows a cross-sectional view of a separation device according to a first embodiment of the present invention, in which an outer pipe is provided. As shown in Fig. 1(A), the separation device 1 has a tank 10 as a housing, which is made up of a main body 11 and a lid 12. The space inside the tank 10 is divided into a first space 14 and a second space 15 by a tube plate 13, as shown in Fig. 1(B).

[0024] The first space 14 is divided into smaller spaces by an upper horizontal partition plate 19, a lower horizontal partition plate 20, an upper vertical partition plate 23, and a lower vertical partition plate 22. The smaller spaces formed by these partition plates are intended to control the flow of the fluid to be separated.

[0025] A plurality of outer pipes 31 are disposed between the upper horizontal partition plate 19 and the lower horizontal partition plate 20, and each outer pipe is in contact with the support plate 21. The support plate 21 is mesh-like, allowing fluids to pass through. The fluid to be separated that flows in from the raw fluid inlet 16 flows through the tank 10 in the direction of the arrows shown in the figure, and the treated fluid flows out from the first fluid outlet 17 and the second fluid outlet 18.

[0026] A smooth surface 32 is formed on the inner surface of each outer tube 31. A membrane separator 30 having a zeolite membrane formed on the surface of a tubular alumina support is inserted into each outer tube 31.

[0027] The main body 11 is fitted with a raw fluid inlet 16 through which the fluid to be separated enters and a first fluid outlet 17 through which the fluid to be separated that has not permeated the zeolite membrane flows out, and the lid 12 is fitted with a second fluid outlet 18 through which the fluid to be separated that has permeated the zeolite membrane flows out.

[0028] 1, a retaining member 33 is attached to the left end of each membrane separation material 30, and the retaining member 33 is fixed to the tube sheet 13 with screws. The retaining member 33 is hollow so that the fluid that has permeated the zeolite membrane flows out into the second space 15. Note that while FIG. 1 shows an embodiment in which four outer tubes 31 are arranged, the number of outer tubes is not limited to four and may be changed in various ways. The number of lower vertical partition plates 22 and upper partition plates 23 may also be changed in various ways.

[0029] Figure 2 is a cross-sectional view showing the membrane separation material 30 and outer tube 31 assembled in the separation device of Figure 1. The membrane separation material 30 penetrates the space partitioned by the tube plate 13, upper horizontal partition plate 19, and lower horizontal partition plate 20, and is fixed at the top to the tube plate 13 with male threads 35 and female threads 24. To maintain airtightness, an O-ring 39, a spacer 40 and a ring receiver 41 are provided.

[0030] Below the female thread 24 is a hollow upper end piece 34, which is connected to the membrane separation material 30 with a glass seal ring 36, and the lower part is connected to a solid lower end piece 37 with a glass seal ring 36, and the lower end piece 37 is supported by the support plate 21. The surface of the membrane separation material 30 is a zeolite membrane.

[0031] An outer tube 31 is attached between the upper horizontal partition plate 19 and the lower horizontal partition plate 20. A smooth surface 32 is formed on the inner surface of the outer tube 31. In this embodiment, the smooth surface 32 is the surface of a resin coating layer (fluororesin layer). Resin coating resins include various types, such as fluororesin, epoxy resin, urethane resin, acrylic resin, and silicone resin. A protrusion 38 is disposed at the lower end of the outer tube 31 for positioning a lower end piece 37. The gap between the zeolite membrane of the membrane separation material 30 and the smooth surface 32 is narrow, typically about 2 to 4 mm, and the length of the membrane separation material 30 is about 200 to 1200 mm. Therefore, it is difficult to prevent contact between the membrane separation material 30 and the outer tube 31 when inserting the membrane separation material 30 into the outer tube 31. However, the presence of the smooth surface 32 reduces damage to the zeolite membrane even if the membrane separation material 30 and the outer tube 31 come into contact.

[0032] FIG. 3 is a partial cross-sectional view showing the outer tube, and the inner surface of the outer tube 31 is coated with a fluororesin, and the surface is made smooth 32.

[0033] Fluororesin coatings have many advantages in preventing damage to the zeolite membrane, including good properties such as slipperiness, low adhesion, heat resistance, chemical resistance, corrosion resistance, water repellency, oil repellency, and abrasion resistance.

[0034] Fluororesin has a low coefficient of friction and is slippery, making the zeolite membrane less susceptible to damage. Its anti-adhesion properties make it difficult for foreign matter contained in the fluid to be separated to adhere to the fluororesin layer. Its heat, chemical, and corrosion resistance, as well as its water and oil repellency, make the fluororesin layer less susceptible to damage even when the fluid to be separated is high temperature and pressure, or contains corrosive gases. Its high abrasion resistance extends the life of the fluororesin layer.

[0035] Figure 4 is a cross-sectional view showing a separation device according to embodiment 2 of the present invention. The separation device 100 shown in Figure 4 has a structure in which two separation devices according to embodiment 1 shown in Figure 1 are connected facing each other. The reference numerals shown in Figure 4 are the reference numerals shown in Figure 1 plus one hundred, and the names of the respective members shown in Figure 4 are the same as those of the respective members in Figure 1, so description of the respective members will be omitted.

[0036] 4, second spaces 115 are disposed on the left and right sides, and a first space 114 is disposed between these two second spaces 115. A raw fluid inlet 116 through which the fluid to be separated enters and a first fluid outlet 117 through which the fluid to be separated that has not permeated the zeolite membrane flows out are attached, and second fluid outlets 118 through which the fluid to be separated that has permeated the zeolite membrane flows out are attached to the two left and right lids 112.

[0037] By using the structure of the separation device 100 shown in FIG. 4, the membrane separation material 130 can be inserted from the left and right, so that even a long membrane separation material can be easily incorporated into the main body 111.

[0038] 5 shows an embodiment of the present invention (4), in which an inner tube member 43 is provided inside the outer tube 31. A resin tube or the like is generally used as this inner tube member 43. If the inner tube is made of resin, it can be said that the smooth surface 32 is formed on the inner surface. A locking portion 44 is formed at the end of the inner tubular member 43, and a wire 45 is attached to the locking portion 44, so that by pulling up and removing the wire 45 after placing the membrane separation material 30 inside the outer tube 31, the membrane separation material 30 can be easily attached coaxially to the outer tube 31, and the flow paths for the fluid to be separated can be arranged at equal intervals in the direction perpendicular to the axis. Figures 5(A) to 5(C) show the state in which the inner tubular member 43 is sequentially removed and the holding member 33 is set.

[0039] Figure 6 shows a modified embodiment of the present invention (4), in which the inner tubular member 43 has an excess length that allows it to be removed from the main body 11 of the tank 10 after the membrane separation material 30 has been attached to the outer pipe 31, and the end of the inner tubular member 43 protrudes above the tube sheet 13 as shown in Figure 6(A). By grasping the end of the inner tubular member 43 and pulling it upward (see Figure 6(B)), the inner tubular member 43 can be removed from the outer pipe 31. Thereafter, the holding member 33 is set as shown in Figure 6(C). [Industrial Applicability]

[0040] As described above, when assembling a separation membrane module by combining a membrane separation material having a zeolite membrane formed on the surface of a tubular support with an outer tube for forming a passage through which the fluid to be separated flows, an outer tube is provided in which the zeolite membrane is less likely to be damaged, and this outer tube can be suitably used in a separation device with highly uniform separation performance. [Explanation of symbols]

[0041] 1 Separation device 10 Tank 11 Main unit 12 Lid 13 Tube plate 14 1st space 15 Second space 16 Raw fluid inlet 17 1st fluid outlet 18 2nd fluid outlet 19 Upper horizontal partition 20 Lower horizontal partition 21 Support plate 22 Lower vertical partition 23 Upper vertical partition 24 female thread 30 Membrane separation material 31 Outer tube 32 Smooth surface 33 Retaining member 34 Upper end piece 35 Male thread 36 Seal ring 37 Lower end piece 38 Protrusion 39 O-ring 40 spacer 41 Ring holder 43 Inner cylinder material 44 Locking part 45 wire

Claims

1. An outer tube for forming a passage through which a membrane separation material having an inorganic membrane formed on the surface of a tubular support is inserted, and through which a fluid to be separated flows, An outer pipe for forming a passage, characterized in that the inner surface of the outer pipe has a smoothed, flat surface.

2. 2. The outer pipe for forming a passageway according to claim 1, wherein the smooth surface is a polished surface or a surface of a resin coating layer.

3. A separation device for separating a fluid to be separated, a tube plate that divides the interior of the tank into two spaces, a first space and a second space; a main body of the tank having a raw material fluid inlet and a first fluid outlet communicating with the first space; a lid body that includes a second fluid outlet that communicates with the second space and that combines with the main body to form the tank; a membrane separation material having an inorganic membrane formed on the surface of a tubular support, one end of which communicates with the second space and the other end of which is sealed within the first space; an outer pipe for forming a passage through which the membrane separation material is inserted and through which the fluid to be separated flows, the outer pipe having both ends communicating with the first space; a plurality of outer pipes into which the membrane separation material is inserted are disposed in the tank, and the inner surfaces of the outer pipes are smoothed to form smooth surfaces; The separation device wherein the fluid to be separated that has permeated the inorganic membrane flows out from the second fluid outlet, and the fluid to be separated that has not permeated the inorganic membrane flows out from the first fluid outlet.

4. The separation device described in claim 3, characterized in that the outer pipe has an inner tube material inside the outer pipe, the smooth surface is formed on the inner surface of the inner tube material, and a wire and a locking portion for removing the inner tube material from the main body of the tank after the membrane separation material is attached to the outer pipe are formed on the end of the inner tube material.

5. 4. The separation device according to claim 3, wherein the outer pipe includes an inner cylindrical member inside the outer pipe, the smooth surface is formed on the inner surface of the inner cylindrical member, and the inner cylindrical member has an excess length that allows it to be removed from the main body of the tank after the membrane separation material is attached to the outer pipe.

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