CN101983756B - Spiral coil type diffusion dialysis membrane assembly and preparation method thereof - Google Patents

Abstract

The invention discloses a spiral-wound diffusion dialysis membrane module and a preparation method thereof, which is characterized in that an ion exchange membrane and flow channel partitions on both sides are sandwiched between two central tubes, and they are closely attached to each other around the center The tubes are rolled together in the same direction and bonded and sealed at the axial edge to form a cylinder; the end of the ion exchange membrane is on the outer edge of the cylinder to form two radially symmetrical flow channel openings in the tangential direction, which are respectively bonded and sealed to fix one The side flow tube, and then the whole cylinder including the side flow tube is tightly sealed and fixed with a plastic film to form a membrane core, and the membrane core is put into a cylindrical shell, and the two ends are cast and fixed with an adhesive. It constitutes a spiral-wound diffusion dialysis membrane module with four inlet and outlet nozzles. The equipment is compact and has a high packing density, which can be assembled in a three-dimensional manner and occupies a small area; it can realize the radial spiral countercurrent flow of the diffusion liquid and the dialysate fluid, with a large degree of turbulence, high mass transfer efficiency, and a large amount of material and liquid per unit membrane area. , easy to integrate with other reaction or separation equipment.

Description

A spiral-wound diffusion dialysis membrane module and its preparation method

technical field

The invention belongs to the technical field of membrane separation equipment, and in particular relates to an anion exchange membrane or a cation exchange membrane and a channel spacer which are rolled together around a central tube and are used for separating and recovering industrial waste acid or waste lye by using the principle of diffusion dialysis. Spiral separation membrane module for acid or alkali and its preparation method.

Background technique

Diffusion dialysis uses the concentration difference as the driving force to achieve the purpose of separation by selective permeation of ions through the membrane. In theory, it does not consume energy. It is divided into positive membrane diffusion dialysis (such as for alkali recovery) and negative membrane diffusion dialysis ( Such as for acid recovery). Among them, the anion membrane diffusion dialysis technology utilizes the different selective permeability of the anion exchange membrane for hydrogen ions and metal ions to realize the separation of acid and salt. It is a relatively advanced recovery and treatment technology for industrial waste acid and has been widely used in the metallurgical industry and environmental protection fields. . In the existing technology, the diffusion dialyzer equipment proposed in US Patent US5264123 and US5217612, as well as the diffusion dialyzer produced by Shandong Tianwei Membrane Technology Co., Ltd., Japan Astorm Company and American Mech-Chem Company, are all plate and frame type Components (also known as flat plate), this type of diffusion dialyzer is composed of anion exchange membrane or cation exchange membrane, flow channel spacer, flow channel frame, flow channel switching plate, fixed splint and at least four flow channel pipe joints, its main body The structure is composed of "membrane, net and frame" stacked in sequence, and two fluid channels on the opposite side of the membrane in the diffusion dialyzer are formed by connecting the channels around the frame, that is, the diffusion fluid flow channel and the dialysate flow channel. However, due to the low packing density of the above-mentioned equipment, both ends need to be clamped with steel plates, which makes the equipment bulky, occupies a large area, and the clamping plate is easily corroded; due to the multi-layer sheet structure, it is not easy to seal between layers, and it needs The boundary line of the seal is long. In order to ensure the seal on both sides of the membrane, the processing accuracy of the plate frame and the sealing parts is high; due to the use of multi-layer partitions, the loss of flow resistance is large, and the flow distribution is uneven, so it is not easy to strengthen Mass transfer and reduce concentration polarization; due to its structure, the flow of the feed liquid on each plate is short, and the relative amount of permeate passing through the plate surface is small; in order to make the feed liquid reach a certain degree of concentration, it needs to pass through the plate Surface multiple times, or the feed liquid needs to be circulated multiple times; the fluid flow velocity is low, and the flow type is mostly laminar flow, so the degree of turbulence is small, making the mass transfer efficiency of the whole device low.

Contents of the invention

The purpose of the present invention is to provide a spiral-wound diffusion dialysis membrane module and its preparation method, so as to solve the problems of bulky equipment and low mass transfer efficiency of existing diffusion dialysis devices.

The spiral-wound diffusion dialysis membrane module of the present invention includes flow channel partitions distributed on both sides of the ion exchange membrane, one side of which constitutes a diffusion liquid flow channel and communicates with a pair of diffusion liquid inlet and outlet connections, and the other side constitutes a dialysate The flow channel is connected with a pair of dialysate inlet and outlet pipes; its characteristic is that the center tube is centered on a pair of spliced central tubes, and the ion exchange membrane and the flow channel spacer are tightly wound into a cylinder in a spiral manner. At the end of the ion exchange membrane, the two radially symmetrical flow channel openings in the tangential direction on the outer edge of the cylinder are respectively bonded and sealed to fix the side flow tube, which is close to the inner wall of the cylindrical shell and parallel to the central tube. Arrangement; the space supported by the flow channel partition constitutes the fluid channel and is always located on both sides of the ion exchange membrane, one side is the diffusion liquid flow channel, and the other side is the dialysate flow channel; the diffusion liquid is formed by one side The flow tube flows in, enters the flow channel partition through the liquid collection holes distributed on the peripheral wall of the ion exchange membrane, flows spirally from the outside to the inside on the side of the ion exchange membrane, and finally enters one of the center tubes from the liquid collection holes distributed on the peripheral wall of the central tube. Dialysate flows in from another central tube, enters the flow channel partition through the liquid collection hole, flows spirally from the inside to the outside on the other side of the ion exchange membrane, and finally enters another side flow pipe through the liquid collection hole and flow out.

The preparation method of the spiral-wound diffusion dialysis membrane module of the present invention is characterized in that: an ion exchange membrane and two flow channel partitions are sandwiched between two central tubes, so that the two flow channel partitions are respectively arranged on the sides of the ion exchange membrane On both sides, keep the center tube as the boundary, and the length of the ion exchange membrane at both ends is equal, and the ion exchange membrane, the flow channel spacer and the center tube are bonded and fixed; the ion exchange membrane and the flow channel spacer are closely attached to each other and surround the center tube Roll together in the same direction, apply adhesive to the axial edges of the ion exchange membrane and flow channel partition while rolling, and roll into a cylinder; roll to the end of the ion exchange membrane, outside the cylinder Two radially symmetrical flow channel openings in the tangential direction are formed on the edge, and the side flow tubes are respectively bonded and sealed at the two openings, and the side flow tubes are arranged in parallel with the central tube; The entire cylindrical body inside is tightly sealed and fixed to form a membrane core, and the membrane core is put into a cylindrical shell, so that the side flow tube is close to the inner wall of the shell, and an adhesive is used between the two ends of the membrane core and the shell It is cast and fixed to form a spiral-wound diffusion dialysis membrane module with four inlet and outlet nozzles; liquid collection holes are distributed on the peripheral walls of the center pipe and side flow pipe; two sets of "central pipe-flow The channels of channel separation net-side flow pipe respectively constitute the spiral diffusion fluid flow channel and the dialysate flow channel.

The ion-exchange membrane is a flat-plate membrane; the anion-exchange membrane requires acid resistance, and is usually made of polymer materials with quaternary ammonium groups; and the cation-exchange membrane requires alkali resistance, and is usually made of polymer materials with sulfonic acid groups or carboxylic acid groups. made of polymer materials.

The flow channel spacer can be woven from polypropylene, polyethylene, polyvinyl chloride, polyester (for acid recovery), or polyamide (for alkali recovery), and the length of a single flow channel spacer is the length of the used single 0.5-1 times the size of the ion exchange membrane, single or multi-layer can be used. In order to reduce the flow resistance, the thickness of the spacer in the radial direction of the module can be gradually increased from the outside to the inside.

The central pipe can be a pipe with a circular cross section, a pipe with a semicircular cross section, or the main part of the pipe, that is, the part of the pipe that is wrapped by the ion exchange membrane and the flow channel partition. The cross section of the pipe is semicircular and the cross section of the pipe interface end is Circular pipeline; as a preference, the main part of the pipeline, that is, the section of the pipeline wrapped by the ion exchange membrane and the flow channel partition is semicircular, and the cross section of the pipeline interface is circular, so that a pair of central tubes After being put together, the overall cross-section is circular to ensure that the components are rolled into a cylindrical shape and the cross-section of the interface end of the central pipe is circular to facilitate connection.

The side flow pipe can be a pipe with a circular cross section, a semicircular pipe with a cross section, a crescent-shaped pipe with a cross-section, or a semi-circular or crescent-shaped cross-section for the main part of the pipe, that is, the part of the pipe that is in contact with the ion exchange membrane. And the cross-section of the pipe interface end is a circular pipe; as preferably, the pipe main part that is in contact with the ion exchange membrane is crescent-shaped and the cross-section of the pipe interface end is a circular pipe; the crescent-shaped cross-section part of the side flow pipe It can be closely attached to the periphery of the cylinder body to facilitate sealing and fixing with the ion exchange membrane, and the cross section of the side flow tube interface is circular to facilitate connection.

Both the center pipe and the side flow pipe can be made of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride or polytetrafluoroethylene.

The cross-section of the shell can be circular, elliptical or rectangular, preferably circular; it can be made of polyvinyl chloride, polypropylene, or fiberglass.

As an alternative to installing side flow tubes in the membrane module, the end of the membrane can be axially sealed to the inner wall of the shell at the two radially symmetrical tangential flow channel openings on the outer edge of the cylinder, or with The sealing strip is sealed between the outer surface of the end of the membrane and the inner wall of the shell, so that the two flow channel openings are completely separated, and then holes are opened in the corresponding positions of the shell, and two flow channel interfaces are set to replace the role of the side flow tube.

When the spiral-wound diffusion dialysis membrane module of the present invention is used as the recovery of industrial waste acid, the ion-exchange membrane in the spiral-wound diffusion dialysis membrane module is a flat anion-exchange membrane, and the waste acid feed liquid goes through the dialysate flow channel, from the inside to the The outer spiral flow, the water goes through the diffusion liquid flow channel, and flows spirally from the outside to the inside, and the flow mode of the two fluids adopts a spiral countercurrent. Using the principle of diffusion dialysis, with the concentration difference as the driving force, since the concentration of acid and its salt on the waste liquid side is much higher than that on the water side, there is a concentration gradient on both sides of the membrane, and the waste acid and salt have the tendency to permeate into the diffusion liquid flow channel. trend, but the anion exchange membrane has selective permeability and does not allow each ion to pass through with an equal opportunity; first, the anion membrane skeleton itself is positively charged, and has the ability to attract negatively charged hydration ions in the solution and repel positively charged water Therefore, under the action of the concentration difference, the anions on the waste acid side are attracted and smoothly pass through the membrane pores and enter the water side; at the same time, according to the requirements of electrical neutrality, ions with positive charges will also be entrained. , but because the hydration radius of the hydrogen ion is relatively small and the charge is small, while the hydration ion radius of the metal salt is large and has a high valence charge, so the hydrogen ions will pass through the membrane preferentially, so the acid in the waste liquid will be absorbed Separated, into the diffusion liquid flow channel. The spiral-wound diffusion dialysis membrane module of the present invention adopts spiral countercurrent flow, which increases the average concentration difference and improves the mass transfer driving force; at the same time, due to the long flow path and fast flow speed of the fluid, the mass transfer coefficient is increased, making the module performance is optimized. Multiple spiral-wound diffusion dialysis membrane modules of the present invention can also be used in series and parallel as required. Similar to the principle of recovering industrial waste acid, when the spiral-wound diffusion dialysis membrane module of the present invention is used as the recovery of industrial waste alkali, the ion-exchange membrane in the spiral-wound diffusion dialysis membrane module is a flat cation exchange membrane, because the cation membrane skeleton It is negatively charged, and has the characteristics of attracting positively charged hydration ions and repelling negatively charged hydration ions in the solution. Therefore, under the action of concentration difference, the cations on the spent alkali side are attracted and smoothly pass through the membrane pores. The side that enters the water; at the same time, according to the requirements of electrical neutrality, ions with negative charges will also be entrained, but because the hydration radius of the hydroxide ion is relatively small, the charge is less, while the hydration ion radius of other anions is smaller Large and highly charged, hydroxide ions will pass through the membrane preferentially, so that the alkali in the waste liquid will be separated.

Since the present invention adopts the structure of the spiral-wound diffusion dialysis membrane module, the arrangement is compact, the packing density is high, the volume is small, the weight is light, it can be assembled three-dimensionally, the floor area is small, and no clamping device is needed; the diffusion liquid and the dialysate can be realized The two fluids flow radially and spirally countercurrently, which increases the average concentration difference, improves the mass transfer driving force, and has a large degree of turbulence and high mass transfer efficiency, which is conducive to strengthening mass transfer and reducing concentration polarization. The liquid processing capacity is large, and it is easy to integrate with other reaction or separation equipment. The fluid flow has no branches in the radial direction, the flow path is long, and the flow speed is fast. Compared with the existing diffusion dialyzer with plate and frame structure, the present invention overcomes the bulky and bulky equipment in the prior art, which is easy to leak and be corroded, and has low mass transfer efficiency, small material and liquid treatment capacity per unit membrane area, and is not easy to be strung together. They are used in parallel, and the manufacturing cost of the device is relatively high.

Among the existing coiled membrane modules, the representative ones are the coiled reverse osmosis membrane module and the coiled nanofiltration membrane module. There is a big difference with them, so there is also a big difference in its preparation method. For example: the center pipe of the spiral-wound diffusion dialysis membrane module of the present invention is composed of two semicircular pipes with a main body cross-section, while the center pipe of the roll-type reverse osmosis and roll-type nanofiltration membrane modules is composed of a circular pipe; The invented spiral-wound diffusion dialysis membrane module is rolled by a whole membrane, while the spiral-wound reverse osmosis and rolled nanofiltration membrane modules are usually wound by multiple membrane bag leaves in parallel; the spiral-wound diffusion dialysis membrane module of the present invention The two fluids flow in spiral countercurrent or cocurrent flow, while in the roll reverse osmosis and roll nanofiltration membrane modules, one fluid flows in a spiral flow, and the other fluid flows in an axial direction. The two fluids form a staggered flow. flow; compared with the roll-type reverse osmosis and roll-type nanofiltration membrane modules, the spiral-wound diffusion dialysis membrane module of the present invention has a simpler rolling process, easier rolling operation, and lower requirements for automation in the production process.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the spiral-wound diffusion dialysis membrane assembly of the present invention;

Fig. 2 is the schematic diagram of the central pipe and the side flow pipe of the spiral-wound diffusion dialysis membrane module of the present invention;

Fig. 3 is a schematic diagram of the assembly of the spiral-wound diffusion dialysis membrane module membrane, net and pipe of the present invention;

Fig. 4 is a schematic diagram of the rolling and sealing process of the spiral-wound diffusion dialysis membrane module of the present invention;

Fig. 5 is the schematic diagram of the cross-sectional structure of the spiral-wound diffusion dialysis membrane core of the present invention, that is, the flow channel;

Fig. 6 is a schematic diagram of an optional shell connection of the spiral-wound diffusion dialysis membrane module of the present invention;

Fig. 7 is a schematic diagram of the waste acid recovery performance testing device of the spiral-wound diffusion dialysis membrane module of the present invention.

Detailed ways

The spiral-wound diffusion dialysis membrane module will be described in detail below with reference to the accompanying drawings.

Example 1: Preparation process of a spiral-wound diffusion dialysis membrane module with an effective membrane area of 0.5 square meters

Fig. 1 is a schematic diagram of the overall structure of the spiral-wound diffusion dialysis membrane module of the present invention; Fig. 2 shows a schematic diagram of the center pipe and side flow pipe of the spiral-wound diffusion dialysis membrane module. Between the two central tubes 1 and 7, an ion exchange membrane 3 and two flow channel spacers 4 and 5 are sandwiched, so that the two flow channel spacers 4 and 5 are respectively arranged on both sides of the ion exchange membrane 3, and the central tube is maintained 1 and 7 as the boundary, the lengths of the ion exchange membranes at both ends are equal, and the ion exchange membrane 3, the flow channel separation net 4, 5 and the central tube 1 and 7 are bonded and fixed; the ion exchange membrane 3 and the flow channel separation net 4 and 5 close to each other around the two central tubes 1 and 7 and rolled together in the same direction, and coated with adhesive on the axial edges of the ion exchange membrane 3 and flow channel partitions 4 and 5 while rolling, and rolled into a cylinder; rolled to the end of the ion exchange membrane 3, two radially symmetrical tangential flow channel openings are formed on the outer edge of the cylinder, and the side flow tubes 6 and 6 are respectively bonded and sealed at the two openings. 8. The side flow tubes 6 and 8 are arranged in parallel with the central tubes 1 and 7; then the entire cylinder including the side flow tubes 6 and 8 is tightly wound and fixed with a plastic film to form a membrane core, and the membrane core is installed Into the cylindrical shell 2, make the side flow tubes 6 and 8 close to the inner wall of the shell 2, the two ends of the membrane core and the shell 2 are cast and fixed with adhesive, forming a spiral coil with four inlet and outlet joints Diffusion dialysis membrane module; liquid collection holes 10 and 9 are respectively distributed on the peripheral walls of the central pipe 1, 7 and side flow pipes 6, 8; The "network-side flow pipe" channel constitutes the spiral diffusion fluid flow channel 12 and the dialysate flow channel 13 respectively.

The manufactured spiral-wound diffusion dialysis membrane module includes flow channel partitions 4 and 5 distributed on both sides of the ion exchange membrane 3, one side of which constitutes a diffusion liquid flow channel 12 and is connected with a pair of diffusion liquid inlet and outlet nozzles 6 and 1 The other side constitutes the dialysate flow channel 13 and communicates with a pair of dialysate inlet and outlet connecting pipes 7 and 8; with a pair of central tubes 1 and 7 assembled as the axis, the ion exchange membrane 3 and the flow channel are separated The nets 4 and 5 are spirally rolled into a cylindrical body close to each other, and a pair of side flow pipes 6 and 8 are bonded and sealed on the outer edge of the cylinder, and are arranged parallel to the inner wall of the shell 2 and the central pipes 1 and 7; The space supported by the road partitions 4 and 5 forms a fluid channel and is always located on both sides of the ion exchange membrane 3, one side of which is the diffusion liquid flow channel 12, and the other side is the dialysate flow channel 13; the diffusion liquid is formed by one of them. The root side flow tube 6 flows in, enters the flow channel partition 4 through the liquid collecting holes 9 distributed on the peripheral wall, and flows spirally from the outside to the inside on the side of the ion exchange membrane 3, and finally flows from the collecting hole 9 distributed on the peripheral wall of the central tube 1. The liquid hole 10 enters one of the central tubes 1 and flows out; the dialysate flows in from the other central tube 7, enters the flow channel partition 5 through the liquid collection hole 10, and flows spirally from the inside to the outside on the other side of the ion exchange membrane 3 , and finally enter another side flow pipe 8 through the liquid collecting hole 9 and flow out.

In the present embodiment, the central pipes 1 and 7, the side flow pipes 6 and 8 all adopt acid and alkali resistant polyvinyl chloride plastic pipes, the cross section of its main part is semicircular, and the inner diameter is 20mm, and the length of the semicircular cross section is the same as that used. The width of the ion exchange membrane 3 is the same, and the surrounding walls are provided with liquid collecting holes 9 and 10 respectively. The cross-section of the interface end is circular. Figure 3 shows the schematic diagram of the spiral wound diffusion dialysis membrane module membrane, network, and tube assembly of the present invention: in this embodiment, a DF120 type with a size of 1500×370mm is sandwiched between the central tubes 1 and 7 The dialysis negative membrane (provided by Shandong Tianwei Membrane Technology Co., Ltd.) is used as the ion exchange membrane 3 and the two polypropylene flow channel partitions 4 and 5, so that the two polypropylene flow channel partitions 4 and 5 are respectively arranged on the ion exchange membrane 3 and the ends are aligned, the lengths of flow channel spacers 4 and 5 are equal, and are half of the total length of ion exchange membrane 3, at half of the length direction of ion exchange membrane 3, the ion exchange membrane is made of adhesive The exchange membrane 3, the flow channel spacer 4, 5 are bonded and fixed to the central tube 1, 7; Fig. 4 is a schematic diagram of the rolling and sealing process of the spiral-wound diffusion dialysis membrane module of the present invention: keeping the ion exchange membrane 3 and the flow channel spacer 4, 5 are close to each other, and epoxy resin adhesive is coated on the axial edges of the ion exchange membrane 3 and the flow channel spacers 4 and 5 to form a sealing edge 11, and the central tubes 1 and 7 that are assembled together are used as the Axial center, make the flow channel spacer 4 and 5 close to the liquid collection hole, roll together in the same direction to make a cylinder; Figure 5 is a cross-sectional structure of the spiral-wound diffusion dialysis membrane core of the present invention, that is, a schematic view of the flow channel . As shown in Figure 5, the opening edges of the two flow passages in the radially symmetrical direction of the outer edge of the cylinder are axially sealed on the pipe wall along the flow pipes 6 and 8 on both sides, and the opening end communicates with the liquid collection hole 9, and the "center The passage between pipe 1-flow channel separation net 4-side flow pipe 6" constitutes the diffusion fluid flow channel 12, and the passage between "central pipe 7-flow passage separation net 5-side flow pipe 8" constitutes the dialysate flow passage 13, The diffusion fluid flow channel 12 and the dialysate flow channel 13 are always located on both sides of the ion exchange membrane 3 , and the names of the two flow channels can be interchanged according to the type of fluid flowing through them. The entire cylindrical body including the side flow pipes 6 and 8 is tightly sealed and fixed with a polyvinyl chloride plastic film to form the membrane core of the spiral-wound diffusion dialysis membrane module. The membrane core is installed in the polyvinyl chloride cylindrical shell 2, and the end is cast and sealed with epoxy resin adhesive to form the spiral-wound diffusion dialysis membrane module 18. The effective membrane area of the whole module is 0.5m ² , and the external dimension is 380×Φ90mm. To facilitate series and parallel assembly, a rectangular or hexagonal bracket can be installed on the shell 2 .

Under the condition that other conditions remain unchanged in this embodiment, a similar spiral-wound diffusion dialysis membrane module can be produced by replacing the central pipe with a pipe with a circular cross-section or a pipe with a semi-circular cross-section; as a preference, In this embodiment, the main part of the pipeline (that is, the part wrapped by the ion exchange membrane and the flow channel separation net) is used in which the cross section of the pipeline is semicircular and the cross section of the pipeline interface end is circular, so that a pair of central tubes can be assembled together. The overall cross-section is circular to ensure that the components are rolled into a cylindrical shape, and the cross-section of the interface end of the central tube is circular to facilitate connection.

Under the condition that other conditions remain unchanged in this embodiment, the side flow pipe is replaced by a pipe with a circular cross section, a semicircular pipe with a cross section, a crescent-shaped pipe with a cross section, or the main part of the pipe (that is, with the ion exchange membrane The part in contact) the pipe section is semicircular or crescent-shaped and the pipe interface end cross-section is circular, and similar spiral-wound diffusion dialysis membrane modules can be made; as a preference, the main part of the pipe (that is, with ion exchange The part in contact with the membrane) the cross-section of the pipe is crescent-shaped and the cross-section of the pipe interface is circular. The crescent-shaped cross-section of the side flow pipe can be close to the periphery of the cylinder to facilitate sealing and fixing with the ion exchange membrane. The cross-section is circular to facilitate connection.

The central pipe and the side flow pipe can be made of polyethylene, polypropylene, polyvinylidene fluoride, or polytetrafluoroethylene besides polyvinyl chloride.

Under the condition that other conditions remain unchanged, the DF120 dialysis anion membrane used in this example is replaced by other flat-type acid-resistant anion-exchange membrane or alkali-resistant cation-exchange membrane, and a spiral coil with similar shape and structure can be produced. Type diffusion dialysis membrane module. Among them, the anion exchange membrane is usually made of polymer materials with quaternary ammonium groups, and the membrane module made of anion exchange membranes is used for the separation and recovery of waste acid; while the cation exchange membrane is usually made of The membrane modules made of cation-exchange membranes are used for the separation and recovery of spent caustic soda.

In addition to being woven from polypropylene, the flow channel separator can also be woven from polyethylene, polyvinyl chloride, polyester (for acid recovery), or polyamide (for alkali recovery) , the length of the single flow channel spacer can be 0.5-1 times that of the single ion exchange membrane used, and can be single-layer or multi-layer. In order to reduce the flow resistance, the thickness of the spacer can gradually increase from the outside to the inside in the radial direction of the module. .

The cross-section of the shell can be circular, elliptical or rectangular, preferably circular; it can be made of polyvinyl chloride, polypropylene, or fiberglass; considering the cost, it is preferably polyvinyl chloride.

Fig. 6 is a schematic diagram of an optional shell connection of the spiral-wound diffusion dialysis membrane module of the present invention. As shown in Figure 6, as an alternative to installing side flow pipes in the membrane module, the end of the membrane can be axially sealed at the two radially symmetrical tangential flow channel openings on the outer edge of the cylinder. Paste on the inner wall of the shell, or use a sealing strip to seal between the outer surface of the end of the membrane and the inner wall of the shell, so that the two flow channel openings are completely separated, and then open holes at the corresponding positions of the shell, and set two flow channel interfaces 14 and 15, To replace the role of the side stream tube.

Fig. 7 is a schematic diagram of the waste acid recovery performance testing device of the spiral-wound diffusion dialysis membrane module of the present invention. As shown in Figure 7, use the spiral-wound diffusion dialysis membrane module 18 to recover waste acid, inject equal volumes of waste acid and tap water into the waste acid head tank 17 and water head tank 16, and take over from the dialysate inlet respectively. 7 and the diffusion liquid inlet connecting pipe 6 flow into the spiral-wound diffusion dialysis membrane module 18, adjust the flow rate of acid and water, maintain the flow ratio of waste acid and tap water within a certain range, maintain the liquid level, and flow out the residual acid from the dialyzing liquid outlet connecting pipe 8 , and take over 1 from the outlet of the diffusion liquid to flow out the recovered acid. In order to increase the flow rate, facilitate metering and facilitate exhaust, a constant flow pump or a vacuum pump can be respectively connected to the dialysate outlet connection pipe 8 and the diffusion liquid outlet connection pipe 1.

The spiral-wound diffusion dialysis membrane module produced in this example with an effective membrane area of ^0.5m2 is suitable for laboratory research, and its packing density is ^206.9m2 / ^m3 ; while the existing membrane module with the same effective area The packing density of the small plate and frame diffusion dialysis device is only 92.6m ² /m ³ .

Example 2: The preparation process of the spiral-wound diffusion dialysis membrane module with an effective membrane area of 10 square meters

The rolling method adopted in this example is the same as that in Example 1, adopting the DF120 type dialysis negative membrane with a size of 14000×800mm, the central tube and the side flow tube are all polyvinyl chloride plastic tubes with a semicircular cross-section, and the inner diameter The diameter is Φ25mm, and the end is bonded with polyvinyl chloride pipe fittings to convert it into a circular section. The flow channel partition is made of polyethylene material. The effective membrane area of the spiral-wound diffusion dialysis membrane module is 10m ² , and the overall size is 1000× Φ200mm.

If the spiral-wound diffusion dialysis membrane module produced in this example is connected in series and parallel, it can be more suitable for the recovery and production process of industrial waste acid. Its packing density is 356.7m ² /m ³ and its weight is 17.8Kg. Currently produced by Shandong Tianwei Membrane Technology Co., Ltd., the HKY-025 plate and frame diffusion dialyzer filled with 32m ² membrane has a packing density of only 173.2m ² /m ³ and a weight of 280Kg.

Example 3: Recovery of Industrial Titanium White Waste Acid by Spiral Wound Diffusion Dialysis Membrane Module

Using the waste acid recovery performance test device of the spiral-wound diffusion dialysis membrane module as shown in accompanying drawing 7, use the spiral-wound diffusion dialysis membrane module 18 in embodiment 1 to carry out the waste acid recovery process test, simulate industrial titanium dioxide waste Acid solution, prepare H ₂ SO ₄ /FeSO ₄ feed solution sample, the concentration is shown in Table 1:

Table 1 FeSO ₄ /H ₂ SO ₄ Concentration of Feed Liquid Sample

Inject waste acid and tap water of equal volume into waste acid head tank 17 and water head tank 16 respectively, adjust the flow rate of acid and water, maintain the flow ratio of waste acid and tap water to be about 0.9-1.2, keep the liquid level, and after being stabilized, Determination of sulfuric acid and ferrous sulfate concentration in residual acid and recovered acid, calculation of H ⁺ recovery rate, Fe ²⁺ leakage rate, etc. The concentration of H ₂ SO ₄ was determined by acid-base titration, and the concentration of Fe ²⁺ was determined by redox titration. The test results are shown in Table 2:

Table 2 Diffusion dialysis results of FeSO ₄ /H ₂ SO ₄ feed liquid samples

It can be seen from Table 2 that for the FeSO ₄ /H ₂ SO ₄ system, the recovery rate of H ₂ SO ₄ can reach more than 80%, while the leakage rate of Fe ²⁺ is less than 20%, and the average flow rate of spent acid is 0.978mL/min That is to say, the waste acid treatment capacity per unit membrane area of the spiral-wound diffusion dialysis membrane module used in this example is 1.956mL/min.m ² . The waste acid treatment capacity per unit membrane area of the diffusion dialysis device can only reach about 1.1mL/min.m ² , indicating that the mass transfer efficiency of the spiral-wound diffusion dialysis membrane module is better than that of the plate-and-frame diffusion dialysis device in the prior art.

Example 4: Recovery of steel pickling waste liquid by spiral-wound diffusion dialysis membrane module

As shown in accompanying drawing 7, use the spiral-wound diffusion dialysis membrane module 18 in embodiment 1 to carry out the process test of simulating steel pickling waste liquid recovery, prepare HCl/FeCl _Feed liquid sample, concentration is shown in Table 3:

Table 3HCl/FeCl Concentration of _feed liquid sample

Inject waste acid and tap water of equal volume into waste acid head tank 17 and water head tank 16 respectively, adjust the flow rate of acid and water, maintain the flow ratio of waste acid and tap water to be about 0.9-1.2, keep the liquid level, and after being stabilized, Measure the concentration of hydrochloric acid and ferrous chloride in residual acid and recovered acid, and calculate H ⁺ recovery rate, Fe ²⁺ leakage rate, etc. The concentration of HCl was determined by acid-base titration, and the concentration of Fe2 ⁺ was determined by redox titration. The test results are shown in Table 4:

Table 4HCl/FeCl _Diffusion dialysis results of feed liquid sample

It can be seen from Table 4 that for the HCl/FeCl ₂ system, the recovery rate of HCl can reach more than 85%, while the leakage rate of Fe ²⁺ is less than 20%, and the average flow rate of spent acid is 5.268mL/min, that is to say, the The waste acid treatment capacity per unit membrane area of the spiral-wound diffusion dialysis membrane module used in the example is 10.536mL/min.m ² , and according to the experiment, to achieve a similar treatment effect, the unit membrane of the plate and frame diffusion dialysis device used in small experiments The area waste acid treatment capacity can only reach 3.5mL/min.m ² , indicating that the mass transfer efficiency of the spiral-wound diffusion dialysis membrane module is better than that of the plate and frame diffusion dialysis device in the prior art, and compared with the FeSO ₄ /H ₂ SO ₄ system, for HCl/FeCl ₂ system, this advantage is more obvious.

From Example 1, Example 2, Example 3 and Example 4, it can be concluded that the packing density of the spiral-wound diffusion dialysis membrane module of the present invention is higher, the volume is small, and the weight is light; The countercurrent flow makes the mass transfer driving force larger, the mass transfer efficiency is higher, and the material and liquid processing capacity per unit membrane area is larger.

Claims (9)

1. A spiral-wound diffusion dialysis membrane module, including flow channel partitions distributed on both sides of the ion exchange membrane, one side of which constitutes a diffusion liquid flow channel and communicates with a pair of diffusion liquid inlet and outlet pipes, and the other side constitutes a dialysis The liquid flow channel is connected with a pair of dialysate inlet and outlet connecting pipes; its characteristic is that the center tube is centered on a pair of spliced central tubes, and the ion exchange membrane and the flow channel spacer are tightly attached to each other and spirally wound into a cylinder , the axial edges of the ion exchange membrane and the channel spacer are bonded and sealed by adhesive, and the two radially symmetrical channel openings in the tangential direction on the outer edge of the cylinder at the end of the ion exchange membrane are respectively bonded and sealed. One side flow tube, the side flow tube is arranged parallel to the inner wall of the cylindrical shell and the central tube; the space supported by the flow channel partition constitutes the fluid channel and is always located on both sides of the ion exchange membrane, one of which is the diffusion The other side is the dialysate flow channel; the diffusion liquid flows in from one of the side flow pipes, and enters the flow channel partition through the liquid collection holes distributed on the surrounding wall, and is spirally formed on the side of the ion exchange membrane. It flows from outside to inside, and finally enters one of the central tubes from the collecting holes distributed on the peripheral wall of the central tube and flows out; the dialysate flows in from the other central tube, enters the flow channel partition through the collecting holes, and flows out on the other side of the ion exchange membrane. One side spirally flows from the inside to the outside, and finally enters the other side flow pipe through the liquid collection hole and flows out. 2. The preparation method of the spiral-wound diffusion dialysis membrane module according to claim 1, characterized in that: an ion exchange membrane and two flow channel partitions are sandwiched between the two central tubes, so that the two flow channel partitions are respectively arranged on the On both sides of the ion exchange membrane, keep the center tube as the boundary, and the length of the ion exchange membrane at both ends is equal, and the ion exchange membrane, the flow channel spacer and the center tube are bonded and fixed; the ion exchange membrane and the flow channel spacer are closely attached to each other Roll together in the same direction around the central tube, apply adhesive to the axial edges of the ion exchange membrane and the flow channel partition while rolling, and roll into a cylinder; roll to the end of the ion exchange membrane, Two radially symmetrical flow channel openings in the tangential direction are formed on the outer edge of the cylinder, and the side flow tubes are respectively bonded and sealed at the two openings, and the side flow tubes are arranged in parallel with the central tube; The entire cylindrical body including the side flow tube is tightly wound and fixed to form a membrane core, and the membrane core is put into a cylindrical shell so that the side flow tube is close to the inner wall of the shell, and the gap between the two ends of the membrane core and the shell It is cast and fixed with adhesive to form a spiral-wound diffusion dialysis membrane module with four inlet and outlet nozzles; liquid collection holes are distributed on the peripheral walls of the central tube and side flow tube; two groups of " The channels of "central tube-flow channel spacer-side flow tube" respectively constitute the spiral diffusion liquid flow channel and the dialysate flow channel. 3. the preparation method of spiral-wound diffusion dialysis membrane module as claimed in claim 2 is characterized in that described ion-exchange membrane is a flat film; Anion-exchange membrane is made of polymer material with quaternary ammonium group; Cation-exchange membrane is made of Made of polymer materials with sulfonic acid groups or carboxylic acid groups. 4. The preparation method of the spiral-wound diffusion dialysis membrane module as claimed in claim 2, characterized in that the flow channel partition is made of polypropylene, polyethylene, polyvinyl chloride, polyester or polyamide material, and the single flow channel The length of the spacer is 0.5-1 times that of the single ion exchange membrane used, and it is single-layer or multi-layer; the thickness of the spacer gradually increases from the outside to the inside in the radial direction of the module. 5. The preparation method of the spiral-wound diffusion dialysis membrane module as claimed in claim 2, characterized in that the central pipe adopts a circular pipeline in cross section, a semicircular pipeline in cross section, or the main part of the pipeline is covered by ion exchange membrane And part of the pipe section wrapped by the flow channel separation net is semicircular and the pipe interface end section is circular. 6. The preparation method of the spiral-wound diffusion dialysis membrane module as claimed in claim 2, wherein the side flow pipe adopts a pipe with a circular cross section, a semicircular pipe with a cross section, a crescent-shaped pipe with a cross section, or The main part of the pipe is the part of the pipe that is in contact with the ion exchange membrane, the cross section of the pipe is semicircular or crescent-shaped, and the cross section of the pipe interface is circular. 7. the preparation method of spiral-wound diffusion dialysis membrane module as claimed in claim 2 is characterized in that described central pipe or side flow pipe are all made of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride or polytetrafluoroethylene material. 8. The preparation method of the spiral-wound diffusion dialysis membrane module as claimed in claim 2, characterized in that the cross-section of the module housing is circular, elliptical or rectangular; it is made of polyvinyl chloride, polypropylene or fiberglass. 9. The preparation method of the spiral-wound diffusion dialysis membrane module as claimed in claim 2, characterized in that the end of the membrane is axially sealed on the circular cylinder at the two radially symmetrical tangent flow channel openings on the outer edge of the cylinder. On the inner wall of the cylinder shell, or seal between the outer surface of the end of the membrane and the inner wall of the cylinder shell with a sealing strip, so that the two flow channel openings are completely separated, and then set holes at the corresponding positions of the cylinder shell Two runner interfaces.

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