CN120838178A

CN120838178A - A direct contact pervaporation membrane distillation separation device

Info

Publication number: CN120838178A
Application number: CN202511141030.9A
Authority: CN
Inventors: 贾元东; 贺高红; 姜晓滨; 赵光明; 刁计波; 李长�; 孙冰; 刘佳; 丁研
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2025-08-15
Filing date: 2025-08-15
Publication date: 2025-10-28

Abstract

The invention discloses a direct contact type pervaporation membrane distillation separation device which comprises a membrane pool, a membrane assembly, a vibrating membrane frame, a reciprocating driving mechanism, a bubbling unit, a flow dividing module, a converging module, a liquid collecting tank and an industrial personal computer, wherein the vibrating membrane frame is longitudinally arranged in the membrane pool in a sliding manner and realizes back-and-forth reciprocating motion. Each layer of membrane component in the vibrating membrane frame is sequentially stacked from bottom to top, and the bubbling unit comprises a bubbling machine, a first high-pressure air pipe and a second high-pressure air pipe, wherein an aeration disc is arranged on the first high-pressure air pipe, and a micro-nano aeration head is arranged on the second high-pressure air pipe. The inside of the membrane component is provided with a cavity, all the membrane components at the same level are vertically and sequentially connected in series, and a low-temperature fluid medium sequentially passes through the flow distribution module, the cavities of all the membrane components and the flow distribution module to reach the liquid collection tank. The invention combines vibration and bubbling, thus not only realizing the reduction of energy consumption, but also leading to the formation of turbulence and shear flow on the surface of the membrane to reduce the pollution on the surface of the membrane and prolonging the service life of the membrane.

Description

Direct contact type pervaporation membrane distillation separation device

Technical Field

The invention relates to the technical field of pervaporation membrane distillation, in particular to a direct contact type pervaporation membrane distillation separation device.

Background

The separation process in petrochemical industry is one of the links with the most concentrated energy consumption, wherein the energy consumption of separation equipment accounts for about 70% of the total petrochemical energy consumption, and the energy consumption in the process is huge. The membrane separation technology has unique advantages of high efficiency and low energy consumption compared with other separation technologies, so that new equipment is urgently required to be created based on the membrane separation technology so as to be suitable for difficult treatment and extreme separation requirements in petrochemical industry. Such as the existing high-salt wastewater and organic solvent dehydration and organic solvent separation membrane separation equipment in petrochemical industry, it is difficult to realize high packing density and high temperature resistance, and most of the membrane separation equipment at present basically improves the membrane life by controlling the liquid flow rate passively. Therefore, there is an urgent need to design a novel membrane separation device for high-salt wastewater, organic solvent dehydration and organic solvent separation in petrochemical industry, which has high packing density, can be infinitely expanded, can withstand higher temperature, and has an active multiple system to cooperatively improve the service life of the membrane. In summary, the above factors are key influencing factors for realizing industrialization of petrochemical industry.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a direct contact type pervaporation membrane distillation separation device, which solves the problems of difficult-to-treat high-salt wastewater, organic solvent dehydration and membrane separation of organic solvent and organic solvent in petrochemical industry, low membrane area packing density, easy pollution of membrane, incapability of active control and long service life.

In order to solve the technical problems, the invention adopts the following technical scheme:

A direct contact type pervaporation membrane distillation separation device comprises a membrane tank, a membrane assembly, a vibrating membrane frame, a reciprocating driving mechanism, a bubbling unit, a flow distribution module, a flow converging module, a liquid collecting tank, a cleaning system and an industrial personal computer, wherein the vibrating membrane frame is longitudinally arranged in the membrane tank in a sliding manner, and the reciprocating driving mechanism is arranged above the membrane tank and drives the vibrating membrane frame to reciprocate back and forth.

At least 1 layer of membrane assemblies are arranged on the vibrating membrane frame, each layer of membrane assembly comprises a plurality of membrane assemblies which are sequentially arranged at intervals from left to right, when the number of layers of membrane assemblies is more than 1, each layer of membrane assembly is sequentially stacked from bottom to top, each membrane assembly is vertically arranged, the upper end and the lower end of each membrane assembly are fixedly connected with the vibrating membrane frame, and each membrane assembly on the upper layer is vertically opposite to each membrane assembly on the adjacent lower layer one by one.

The membrane assembly is characterized in that a cavity is formed in the membrane assembly, an inlet end and an outlet end are respectively arranged at the bottom and the top of the membrane assembly, and the membrane assemblies at the same level are vertically and sequentially connected in series.

The split flow module is arranged at the lower part of the membrane pool, the inlet of the split flow module is connected with a third pipe body, and low-temperature fluid medium is supplied into the split flow module through the third pipe body under the working state.

The flow converging module is arranged above the membrane pool, the flow dividing module is connected and communicated with the flow converging module pipeline through all the membrane assemblies, an outlet of the flow converging module is connected with the top of the liquid collecting tank through a fourth pipe body, a conveying pump is arranged on the third pipe body, and a signal end of the conveying pump is communicated with the industrial personal computer.

The bubbling unit comprises a bubbling machine and a first high-pressure air pipe and a second high-pressure air pipe which are positioned below the membrane component, the bubbling machine is provided with a first servo motor which is in signal connection with the industrial personal computer, the first high-pressure air pipe and the second high-pressure air pipe are respectively provided with at least two high-pressure air pipes, the bubbling machine is fixedly arranged at the bottom of the membrane pool, the exhaust end of the bubbling machine is respectively and independently supplied with air for the first high-pressure air pipe and the second high-pressure air pipe through a three-way valve, the first high-pressure air pipe is provided with a plurality of aeration discs, and the second high-pressure air pipe is provided with a plurality of micro-nano aeration heads. The bubbling amount and the bubbling size are cooperatively regulated and controlled from micro-nanometer to micro-millimeter by controlling the blast amount and the aeration assembly (the aeration disc and the micro-nanometer aeration head).

The lower part of the membrane tank is provided with an on-line liquid concentration monitor I, and a signal end of the on-line liquid concentration monitor I is communicated with the industrial personal computer.

Further, the membrane assembly comprises a membrane body and square rigid frame bodies, wherein the rigid frame bodies are vertically arranged and are communicated on the left side and the right side, two membrane bodies are respectively provided with a flat membrane, the two membrane bodies are symmetrically arranged on the two sides of the rigid frame bodies in a bilateral symmetry mode, and the edges of the two membrane bodies are fixedly and hermetically connected with the corresponding sides of the rigid frame bodies to form an internal cavity of the membrane assembly.

The inlet end of the membrane component is positioned at the bottom of the rigid frame body, the outlet end of the membrane component is positioned at the top of the rigid frame body, and the inlet ends and the outlet ends of the two vertically adjacent rigid frame bodies are connected through pipelines.

Further, the membrane component comprises an upper box body, a lower box body and a membrane body, wherein the upper box body and the lower box body are longitudinal long-strip-shaped shells, and are arranged on the vibrating membrane frame in a parallel mode, and the upper box body and the lower box body are respectively and detachably and fixedly connected with the vibrating membrane frame.

The membrane body is a plurality of hollow fiber membranes of regular distribution, and each hollow fiber membrane is all vertical to be arranged, and its upper end links to each other with last box body fixed seal through last mount pad, and the lower extreme links to each other with lower box body fixed seal through lower mount pad, the inside of going up the box body communicates with each other with lower box body inside through the inner chamber of hollow fiber membrane.

The inlet end of the membrane component is positioned at the bottom of the lower box body, the outlet end of the membrane component is positioned at the top of the upper box body, and pipelines between the upper box bodies and the lower box bodies of two vertically adjacent membrane components are connected.

Further, the vibrating diaphragm frame is of a square three-dimensional frame structure, and positioning mechanisms which are equal to the diaphragm assemblies in number and correspond to the positions one by one are arranged on the inner side of the vibrating diaphragm frame.

The positioning mechanism comprises two pairs of mounting plates which are arranged up and down correspondingly, the two pairs of mounting plates are fixed on the vibrating diaphragm frame, and a U-shaped groove capable of placing the diaphragm assembly is formed between each pair of mounting plates.

The inner side of each U-shaped groove is provided with a strip-shaped locating plate, and the locating plate is connected with the mounting plates on the adjacent side of the locating plate through a group of locking bolts which are longitudinally arranged at intervals, so that the upper end and the lower end of the membrane assembly are fixed between the two pairs of mounting plates.

Further, the top of membrane pond is provided with the lid, and the bottom edge of lid can dismantle fixed seal with the membrane pond top and link to each other, and the vibrating diaphragm frame is located the below of lid.

The left and right sides symmetry of vibrating diaphragm frame is equipped with two link, and the top of membrane pond has two guide rails of parallel interval arrangement, and the upper end of two link respectively with two guide rails longitudinal sliding fit, the lower extreme passes the lid and links firmly with vibrating diaphragm frame upper end, link and lid movable seal fit.

The reciprocating driving mechanism comprises a second servo motor, a crank, a connecting rod and a slide block bearing seat, wherein one end of the crank is fixedly connected with an output shaft of the second servo motor, the slide block bearing seat is sleeved outside the crank and is in linear sliding fit with the crank, a plurality of bolt holes distributed along the length direction of the side wall of the crank are formed in the side wall of the crank, positioning bolts are arranged on the slide block bearing seat, one end of the connecting rod is hinged with the slide block bearing seat, and the other end of the connecting rod is hinged with one connecting frame.

Further, all the first high-pressure air pipes are arranged at intervals in parallel, the aeration discs on the same first high-pressure air pipe are sequentially arranged at intervals along the length direction of the aeration discs, all the second high-pressure air pipes are also arranged at intervals in parallel, and all the micro-nano aeration heads on the same second high-pressure air pipe are sequentially arranged at intervals along the length direction of the aeration discs.

The exhaust end of the bubbling machine is connected with the air inlet end of the three-way valve through a first pipe body, the three-way valve is provided with two air outlet ends, each first high-pressure air pipe is connected with one air outlet end of the three-way valve through a second pipe body, each second high-pressure air pipe is connected with the other air outlet end of the three-way valve through the same second pipe body, and the second pipe body is provided with a first stop valve.

An electromagnetic flowmeter is arranged on the first pipe body, and a signal end of the electromagnetic flowmeter is communicated with the industrial personal computer.

Further, the flow distribution module and the flow converging module are respectively arranged at the bottom and the top of the vibrating membrane frame, the top of the flow distribution module is provided with outlet ends which are equal to each layer of membrane assemblies in number and correspond to each other in position, and each outlet end of the flow distribution module is connected and communicated with the inlet end of the sub-membrane assembly at the lowest layer corresponding position through a fifth pipe body.

The bottom of the converging module is provided with inlet ends which are equal to each layer of membrane assemblies in number and correspond to each other in position one by one, each inlet end of the converging module is connected and communicated with the outlet end of the corresponding secondary membrane assembly on the uppermost layer through a sixth pipe body, an online liquid concentration monitor II is arranged in the converging module, and a signal end of the online liquid concentration monitor II is communicated and connected with an industrial personal computer.

Further, the cold water circulation system also comprises a heat exchanger and a low-temperature cold source, wherein the low-temperature cold source is connected with a shell side inlet and an outlet pipeline of the heat exchanger to form a cold water circulation loop.

The inside of liquid collection jar is equipped with the electron liquid level gauge, and its bottom is connected with the fluid-discharge tube, install first stop valve on the fluid-discharge tube, the signal end of electron liquid level gauge and first stop valve links to each other with industrial computer communication, and lower part one side of liquid collection jar links to each other with the tube side entry of heat exchanger through seventh body, and the tube side entry of heat exchanger links to each other with the one end that the flow distribution module was kept away from to the third body.

Further, the device also comprises an evaporation crystallizer provided with a stirring mechanism, the evaporation crystallizer is arranged outside the membrane tank, a sealing shell with a heating function at the bottom is adopted, an inlet of the evaporation crystallizer is connected with an outlet at the lower part of the membrane tank through an eighth pipe body, a second stop valve is arranged on the eighth pipe body, and a pressure release valve is arranged at the top of the evaporation crystallizer.

The stirring mechanism comprises stirring blades, a transmission shaft and a third servo motor, the third servo motor is arranged above the evaporation crystallizer, the stirring blades are arranged at the lower part of the inner side of the evaporation crystallizer, and the stirring blades are fixedly connected with an output shaft of the third servo motor through the transmission shaft.

Further, the cleaning system comprises a water pump and a cleaning main pipe, the water pump is arranged at one end of the cleaning main pipe, cleaning branch pipes which are equal in number and correspond to the membrane assemblies in position are arranged on the cleaning main pipe, the lower ends of the cleaning branch pipes are located on the adjacent sides of the corresponding membrane assemblies, and the upper ends of the cleaning branch pipes are connected with the cleaning main pipe.

The cleaning main pipe is provided with an electromagnetic gate valve, and the signal end of the electromagnetic gate valve is communicated with the industrial personal computer.

By adopting the technical scheme, the membrane assembly has the beneficial technical effects that the horizontal reciprocating vibration and a large number of micro-bubble bubbling modes are combined, and the increase of the water vapor flux is realized by improving the flow velocity of the surface of the membrane, so that the separation performance of the membrane is improved, and the accelerated collection of pure water is ensured. In addition, the vertical movement of the bubbles and the horizontal movement of the membrane are beneficial to forming turbulence and shear flow on the surface of the membrane, so that the enrichment of pollutants on the surface of the membrane can be effectively reduced, and further the membrane pollution is reduced.

Drawings

FIG. 1 is a schematic diagram of a first implementation of a direct contact pervaporation membrane distillation separation device according to the present invention.

Fig. 2 is a schematic view showing a combined structure of a diaphragm frame and a reciprocating drive mechanism of the present invention.

Fig. 3 is a partial enlarged view of a portion a in fig. 2.

Fig. 4 is a partial enlarged view of a portion B in fig. 2.

FIG. 5 is a schematic diagram of a second implementation of a direct contact pervaporation membrane distillation separation device according to the present invention.

FIG. 6 is a schematic diagram of a third implementation of a direct contact pervaporation membrane distillation separation device according to the present invention.

FIG. 7 is a schematic diagram of a fourth implementation of a direct contact pervaporation membrane distillation separation device according to the present invention.

Detailed Description

The invention is described in detail below with reference to the attached drawing figures:

embodiment 1, combining fig. 1 to fig. 4, is a direct contact type pervaporation membrane distillation separation device, which is mainly used in the technical fields of high-salt wastewater treatment, organic solvent dehydration, separation between organic solvent and organic solvent, and the like, and is especially suitable for a pervaporation membrane and a membrane distillation membrane, wherein the driving force of the pervaporation membrane and the distillation membrane is mainly driven by a temperature difference, and the temperature difference at two sides of the membrane body is different, so that the vapor pressure of a raw material liquid group is different from the vapor pressure at the inner side of the membrane body, and the material with strong interaction force with the membrane preferentially reaches the other side of the membrane, thereby achieving the purposes of separation, purification and concentration.

The direct contact type pervaporation membrane distillation separation device comprises a membrane tank 1, a membrane assembly 2, a vibrating membrane frame 3, a reciprocating driving mechanism 4, a bubbling unit, a flow dividing module 61, a converging module 62, a liquid collecting tank 7, a cleaning system and an industrial personal computer, wherein a cover body is arranged at the top of the membrane tank 1, raw material liquid is injected into the membrane tank 1 through a pipeline, and the processed raw material liquid can be discharged to the outside of the membrane tank through an outlet at the bottom of the membrane tank 1.

The vibrating diaphragm frame 3 is of a square three-dimensional or cuboid frame structure, the vibrating diaphragm frame 3 is longitudinally arranged in the diaphragm pool 1 in a sliding mode, and the reciprocating driving mechanism 4 is arranged above the diaphragm pool 1 and drives the vibrating diaphragm frame 3 to reciprocate back and forth. The top of membrane pond 1 is provided with the lid, and the bottom edge of lid is dismantled fixed seal with the top of membrane pond 1 and is linked together, and vibrating diaphragm frame 3 is located the below of lid.

Two connecting frames 33 are symmetrically arranged on the left side and the right side of the vibrating diaphragm frame 3, two guide rails 34 are arranged above the diaphragm pool at intervals in parallel, the upper ends of the two connecting frames 33 are respectively in longitudinal sliding fit with the two guide rails 34, the lower ends of the two connecting frames 33 penetrate through the cover body to be fixedly connected with the upper end of the vibrating diaphragm frame 3, and the connecting frames 33 are in movable sealing fit with the cover body.

Specifically, link 33 includes two pole settings of vertical interval arrangement, has seted up on the lid and has equal and position one-to-one rectangular hole with the pole setting quantity, and every pole setting is all vertically worn to establish in the rectangular hole inboard that corresponds, each the outside of pole setting all overlaps and is equipped with the rubber seal cover of a horn mouth form, and the binding off end of rubber seal cover links to each other with the outer wall fixed seal of pole setting, and the flaring end of rubber seal cover covers the rectangular hole that corresponds to link to each other with lid upper surface fixed seal, link 33 is in-process for lid back and forth movement, guarantees the inside partial gas tightness of membrane pond 1.

The reciprocating driving mechanism 4 comprises a second servo motor 41, a crank 42, a connecting rod 43 and a slide block bearing seat 44, one end of the crank 42 is fixedly connected with an output shaft of the second servo motor 41, the slide block bearing seat 44 is sleeved outside the crank 42 and is in linear sliding fit with the crank 42, a plurality of bolt holes 45 distributed along the length direction of the side wall of the crank 42 are formed in the side wall of the crank 42, a positioning bolt 46 is arranged on the slide block bearing seat 42, one end of the connecting rod 43 is hinged with the slide block bearing seat 44, and the other end of the connecting rod 43 is hinged with one connecting frame 33. After the positioning bolts 46 unlock the slide block bearing seat 44, the slide block bearing seat 44 can slide along the length direction of the crank 42, and the position of the slide block bearing seat 44 on the crank 42 is changed, so that the amplitude of the vibrating membrane frame 3 is adjusted, and the requirements of different processes are met. The signal end of the second servo motor 41 is in communication connection with an industrial personal computer, the industrial personal computer controls the rotating speed of the second servo motor 41 through instructions to control and adjust the front and back reciprocating vibration frequency of the vibrating membrane frame 3, corresponding vibration frequency and amplitude are selected according to the processed raw material liquid, and the vibration frequency of the vibrating membrane frame 3 is 0.5-150 Hz. The vibration amplitude of the vibrating membrane frame 3 is adjusted by adjusting the position of the sliding block bearing seat 42 on the crank 42, and the adjusting range of the vibration amplitude is 0.2 cm-100 cm.

When a layer of membrane assemblies 2 is arranged in the vibrating membrane frame 3, the layer of membrane assemblies 2 are arranged in a tiled mode as a whole, and each layer of membrane assemblies 2 comprises a plurality of membrane assemblies 2 which are sequentially arranged at intervals left to right. When at least two layers of membrane assemblies 2 are arranged in the vibrating membrane frame 3, the membrane assemblies 2 of each layer are sequentially arranged in a stacked mode at intervals from bottom to top, each membrane assembly 2 of each layer is vertically arranged, the upper end and the lower end of each membrane assembly 2 are fixedly connected with the vibrating membrane frame 3, and each membrane assembly 2 of the upper layer is vertically opposite to each membrane assembly 2 of the adjacent lower layer one by one.

The inside of the membrane component 2 is provided with a cavity, the bottom and the top of the membrane component 2 are respectively provided with an inlet end and an outlet end, and all the membrane components at the same level are vertically and sequentially connected in series. The split module 61 is arranged at the lower part of the membrane tank 1, the inlet of the split module 61 is connected with a third pipe body 63, the split module 61 is connected with a low-temperature fluid medium through the third pipe body 63, the third pipe body 63 is provided with a conveying pump 631, and the signal end of the conveying pump 631 is communicated with the industrial personal computer. The converging module 62 is arranged above the membrane tank 1, the flow dividing module 61 is connected and communicated with the converging module 62 through the inner cavities of all the membrane assemblies 2, and the outlet of the converging module is connected with the top of the liquid collecting tank 7 through the fourth pipe 64.

Specifically, the membrane assembly 2 includes a membrane body 22 and a square rigid frame 21, where the rigid frame 21 is vertically disposed and has two through sides, and the membrane body 22 is two and adopts a flat membrane, such as a microfiltration membrane, a nanofiltration membrane, a dense membrane or a Janus structural membrane, and the type of the flat membrane is determined according to the processed raw material liquid and the process requirement. The two film bodies 22 are symmetrically arranged on two sides of the rigid frame body 21, and edges of the two film bodies 22 are fixedly and hermetically connected with corresponding sides of the rigid frame body 21 to form an internal cavity of the film assembly 2. The inlet ends of the membrane assemblies 2 are positioned at the bottom of the rigid frame body 21, the outlet ends of the membrane assemblies 2 are positioned at the top of the rigid frame body 21, and the inlet ends and the outlet ends of the two vertically adjacent rigid frame bodies 21 are connected through pipelines, so that the cavities of the membrane assemblies 2 in the same vertical order are communicated.

The flow dividing module 61 and the converging module 62 are respectively and fixedly arranged at the bottom and the top of the vibrating membrane frame 3, the top of the flow dividing module 61 is provided with outlet ends which are equal to the number of the membrane assemblies 2 at each layer and correspond to the positions of the membrane assemblies, and each outlet end of the flow dividing module 61 is connected and communicated with the inlet end of the sub-membrane assembly 2 at the lowest layer corresponding position through a fifth pipe body 65. The bottom of the converging module 62 is provided with inlet ends which are equal to each layer of membrane assemblies 2 in number and correspond to each other in position one by one, each inlet end of the converging module 62 is connected and communicated with the outlet end of the sub-membrane assembly 2 at the corresponding position of the uppermost layer through a sixth pipe body 66, and the third pipe body 63 and the fourth pipe body 64 are respectively provided with flexible sections.

The converging module 62 is located above the cover body, the sixth pipe body 66 is a two-section flexible pipe body, two parts of the sixth pipe body 66 are connected and communicated through a rigid joint, the rigid joint is fixed on the cover body in an embedded manner and is in sealing fit with the cover body, one part of the sixth pipe body 66 is located below the cover body, and the other part of the sixth pipe body 66 is located above the cover body. The cover body seals the inside of the membrane tank 1, under the working condition, raw material liquid in the membrane tank 1 is in a state of set pressure, and the raw material liquid can improve membrane flux and separation efficiency under the action of certain pressure.

The interior of the confluence module 62 is provided with a second online liquid concentration monitor, the signal end of the second online liquid concentration monitor is communicated with the industrial personal computer, the second online liquid concentration monitor monitors the concentration value of the liquid in the confluence module 62 in real time, and the concentration value is sent to the industrial personal computer and used as one of important indexes for analyzing the running state of the whole separation device.

In the operating state, the low-temperature fluid medium is supplied to the inside of the split module 61 through the third pipe 63, enters the cavity of the lowest membrane module 2 from the split module 61, passes through the cavities of the membrane modules 2 connected in series with the split module in sequence upwards, is collected in the collecting module 62, and reaches the inside of the liquid collecting tank 7 through the fourth pipe 64 for collection. When the low-temperature fluid medium passes through the cavity of the membrane assembly 2, the pressure of the internal cavity of the membrane assembly 2 is smaller than the pressure of the external cavity, water vapor in the high-salt wastewater can quickly pass through the membrane body 22 to enter the internal cavity of the membrane assembly 2 under the action of pressure difference, the water vapor entering the membrane assembly 2 exchanges heat with the low-temperature fluid medium flowing through the membrane assembly 2 to become condensed water, the condensed water and the low-temperature fluid medium are mixed together to enter the liquid collecting tank 7, and the low-temperature fluid medium is low-temperature purified water when the high-salt wastewater in the membrane pool 1 is separated and the organic solvent is dehydrated, and the low-temperature fluid medium is the same low-temperature organic solvent as the organic solvent to be separated when the organic solvent in the membrane pool 1 is separated, namely the low-temperature fluid medium and the organic solvent to be separated are the same substance.

The inside of the vibrating membrane frame 3 is provided with positioning mechanisms which are equal to the membrane assemblies 2 in number and in one-to-one correspondence to the positions, all the positioning mechanisms are sequentially arranged at intervals from left to right, specifically, the positioning mechanisms comprise two pairs of mounting plates 31 which are vertically and correspondingly arranged, the two pairs of mounting plates 31 are fixedly mounted on the vibrating membrane frame 3, and U-shaped grooves capable of placing the membrane assemblies 2 are formed between each pair of mounting plates 31.

Each U-shaped groove is internally provided with a strip-shaped positioning plate 32, the positioning plate 32 is connected with the mounting plates 31 on the adjacent side of the positioning plate 32 through a group of locking bolts 321 which are longitudinally arranged at intervals, each group of locking bolts 321 comprises a plurality of locking bolts 321 which are longitudinally arranged at intervals and screwed on the mounting plates 31, and the positioning plate 32 fixes the upper end and the lower end of the membrane assembly 2 between the two pairs of mounting plates 31. The upper end and the lower end of the rigid frame body 21 of the membrane assembly 2 are respectively arranged between the two pairs of mounting plates 31, the locking bolts 321 are screwed to enable the positioning plates 32 to fix the upper end and the lower end of the rigid frame body 21 in the vibrating membrane frame 3, the vibrating membrane frame 3 drives all the membrane assemblies 2 to longitudinally and horizontally vibrate, the surfaces of all the planar membranes and the raw material liquid reciprocate back and forth, the flow velocity of the surfaces of the membranes can be increased, vapor pressure of the surfaces of the membranes is increased, vapor pressure difference between the inner side and the outer side of the membranes is increased, the vapor flux is increased, the separation performance of the membranes is improved, and the back and forth vibration of the surfaces of the membranes is interacted with rising bubbles to be beneficial to forming turbulence on the surfaces of the membranes, so that concentration of pollutants on the surfaces of the membranes can be effectively reduced, and membrane pollution is further reduced.

The bubbling unit comprises a bubbling machine 51, a first high-pressure air pipe 58 and a second high-pressure air pipe 52 which are arranged below the membrane component 2, wherein the bubbling machine 51 is provided with a first servo motor which is in signal connection with the industrial personal computer, and the bubbling machine 51 is used for generating high-pressure air. The first high-pressure air pipe 58 and the second high-pressure air pipe 52 are respectively provided with two high-pressure air pipes, and the two high-pressure air pipes 52 are fixedly arranged at the bottom of the membrane tank 1 at parallel intervals. The two high-pressure air pipes 58 are fixedly arranged at the bottom of the membrane tank 1 at intervals in parallel, and are positioned between the two high-pressure air pipes 52, the aeration plates 581 positioned on the same high-pressure air pipe 58 are sequentially and equally spaced along the length direction of the aeration plates 581, the aeration plates 581 are positioned at the top of the high-pressure air pipe 58, the air inlet end of the bottom of the aeration plates 581 is connected with the high-pressure air pipe 58, and a one-way valve is arranged at the joint of the aeration plates 581 and the high-pressure air pipe 58.

Specifically, the second high-pressure air pipe 52 is provided with micro-nano aeration heads 57 which are arranged at equal intervals along the length direction of the second high-pressure air pipe, each micro-nano aeration head 57 is provided with a water pump, the second high-pressure air pipe 52 is connected with the air inlet end of the micro-nano aeration head 57 and the water outlets of the micro-nano aeration heads 57 respectively positioned on the second high-pressure air pipe 52 are oppositely arranged. The exhaust end of the bubbling machine is respectively a first high-pressure air pipe 58 and a second high-pressure air pipe 52 which independently control air supply through a three-way valve 54, the first high-pressure air pipe 58 and the second high-pressure air pipe 52 respectively and independently operate, specifically, the exhaust end of the bubbling machine 51 is connected with the air inlet end of the three-way valve 54 through a first pipe body 53, the three-way valve 54 is provided with two air outlet ends, each first high-pressure air pipe 58 is connected with one air outlet end of the three-way valve 54 through a second pipe body 55, each second high-pressure air pipe 52 is connected with the other air outlet end of the three-way valve 54 through the same second pipe body 55, and a first stop valve 59 is arranged on the second pipe body 55.

When the aeration plate 581 provides aeration for the membrane tank 1, compressed air generated by the bubbling machine 51 enters the high-pressure air pipe I58 through the three-way valve 54 and is discharged through the upper surface of the aeration plate 581, uniform large bubbles are continuously formed in the membrane tank 1 and quickly move to the surface of the raw material liquid from bottom to top, and shearing flow in an inclined direction is formed with the front-back movement of the flat membrane, and important points are that the large bubbles are referred to as relative nano bubbles.

In addition, when the micro-nano aeration head 57 provides aeration for the membrane tank 1, high-pressure air entering the high-pressure air pipe II 52 is discharged through the micro-nano aeration head 57, uniform nano bubbles are continuously formed in the membrane tank 1 and quickly move to the surface of the raw material liquid from bottom to top, and shearing flow in an inclined direction is formed with the front-back movement of the flat membrane. The first pipe body 53 is provided with an electromagnetic flowmeter 56, a signal end of the electromagnetic flowmeter 56 is in communication connection with the industrial personal computer, the electromagnetic flowmeter 56 monitors high-pressure air flow entering the high-pressure air pipe II 52, aeration is adjusted, and bubbling amount per unit time and area can be quantized into a ratio of 4-50:1. The device provides the membrane tank 1 with the two aeration modes, and reasonable aeration modes are selected according to the raw material liquid and the process requirements.

According to the embodiment, the size and the bubble quantity of bubbles are controlled, the inorganic salt and organic pollution resistance of the membrane is improved through cooperation with a vibration system, meanwhile, the flow speed of the surface of the membrane is increased through vibration and bubbling, so that the water vapor flux can be improved, in addition, the concentration polarization of the surface of the membrane is controlled through cooperation of intelligent control of the vacuum degree and bubbling and vibration, the organic pollution resistance or the inorganic salt scaling resistance of the membrane is further improved, finally, the service life of the membrane can be greatly improved through cooperation control of the three, the operation energy consumption is reduced, and therefore the quality and the efficiency of membrane permeation gasification are improved in the process of guaranteeing high-efficiency permeation gasification.

The direct contact type pervaporation membrane distillation separation device also comprises a heat exchanger 67 and a low-temperature cold source, wherein the low-temperature cold source is connected with a shell side inlet and an outlet pipeline of the heat exchanger 67 to form a cold water circulation loop. The inside of liquid collection jar 7 is equipped with the electron liquid level gauge, and its bottom is connected with the fluid-discharge tube 71, install first stop valve 72 on the fluid-discharge tube, the signal end of electron liquid level gauge and first stop valve 72 links to each other with industrial computer communication, and lower part one side of liquid collection jar 7 links to each other with the tube side entry of heat exchanger 67 through seventh body 73, and the tube side entry of heat exchanger 67 links to each other with the one end that the flow distribution module 61 was kept away from to third body 63.

When the high-salt wastewater or the organic solvent is dehydrated, the low-temperature fluid medium adopts low-temperature purified water, the purified water is collected in the liquid collection tank 7, the temperature of the purified water is higher than that of the purified water in the flow distribution module 61, and when the organic solvent and the organic solvent are separated, the low-temperature fluid medium adopts the same low-temperature organic solvent as the organic solvent to be separated, the organic solvent separated from the inside of the membrane tank 1 is called target organic solvent, and the temperature of the organic solvent collected in the liquid collection tank 7 is higher. When the liquid (distilled water or target organic solvent) in the liquid collecting tank 7 is required to be used as a fluid medium, part of the organic solvent in the liquid collecting tank 7 needs to be cooled, specifically, part of the liquid in the liquid collecting tank 7 enters the heat exchanger 67 through the seventh pipe 73 to be cooled to obtain a low-temperature fluid medium, and then is pumped into the split module 61 through the third pipe 63 to return to the inside of the liquid collecting tank 7 in the same way, so that the continuous supply of the low-temperature fluid medium to the inside of all the membrane assemblies 2 is ensured, the liquid level of the liquid collecting tank 7 is monitored in real time by the electronic liquid level meter, and redundant liquid in the liquid collecting tank 7 is discharged periodically.

The lower part of the membrane tank 1 is provided with an on-line liquid concentration monitor I11, and a signal end of the on-line liquid concentration monitor I11 is communicated with an industrial personal computer. The linear liquid concentration monitor 11 monitors the concentration value of the raw material liquid in the membrane tank 1 in real time, under the working state, the concentration value of the raw material liquid in the membrane tank 1 increases along with the evaporation, when the concentration value of the raw material liquid reaches a set threshold value, new raw material liquid is added into the membrane tank 1, the concentration of the raw material liquid in the membrane tank 1 is reduced after the raw material liquid is mixed with the newly added raw material liquid, and the separation is continued through the membrane component 2.

When the invention is used for separating high-salt wastewater or dehydrating a solvent, the high-salt wastewater is filtered by the membrane assembly, enters the inside of the membrane assembly in the form of water vapor and exchanges heat, the water vapor is cooled in the cooling cavity 201 of the membrane assembly to form condensed water, and the condensed water is converged into the liquid collecting tank 7 through the liquid discharge pipe 73 to finally produce the high-salt wastewater in the form of liquid pure water. Taking the membrane body 22 as an example of the application of nanofiltration membrane to distillation separation of magnesium-lithium salt solution, the molecular weight cut-off is between reverse osmosis membrane and ultrafiltration membrane, about 100-2000 Da, and thus the possible pore diameter of nanofiltration membrane is estimated to be about 1-5 nm. The method is applied to magnesium-lithium salt solution separation, organic matter and chromaticity removal of surface water, hardness removal of groundwater, partial removal of soluble salt, concentration of fruit juice, separation of useful substances in medicines and the like. The main separation mechanism is the synergistic effect of pore size sieving and the rejection of the southwest, wherein the rejection of the electric charges in the membrane of the southwest dominates the mechanism.

The cleaning system comprises a water pump 81 and a cleaning main pipe 82, the water pump 81 is arranged at one end of the cleaning main pipe 82, cleaning branch pipes 83 which are equal in number and correspond to the membrane assemblies 2 in position are arranged on the cleaning main pipe 82, the lower ends of the cleaning branch pipes 83 can be connected with the upper ends of the air guide pipes 72 at the corresponding positions, and the upper ends of the cleaning branch pipes are connected with the cleaning main pipe 82. The cleaning main pipe 82 is provided with an electromagnetic gate valve 84, and a signal end of the electromagnetic gate valve 84 is communicated with the industrial personal computer. In the working state, the electromagnetic gate valve 84 is in a closed state, after a certain period of operation, dirt on the surface of the membrane is required to be cleaned, and the cleaning system uses a special cleaning agent to reversely flush the flat membranes on two sides of the cooling cavity 202 of each membrane module 2 through the cleaning branch pipe 83, so that the dirt and impurities on the surface of the membrane are removed.

Embodiment 2, with reference to fig. 2 to 5, is a direct contact type pervaporation membrane distillation separation device, which is mainly used in the technical fields of high-salt wastewater treatment, organic solvent dehydration, separation between organic solvents, and the like, and is particularly suitable for a pervaporation membrane and a membrane distillation membrane.

The reciprocating driving mechanism 4 comprises a second servo motor 41, a crank 42, a connecting rod 43 and a slide block bearing seat 44, one end of the crank 42 is fixedly connected with an output shaft of the second servo motor 41, the slide block bearing seat 44 is sleeved outside the crank 42 and is in linear sliding fit with the crank 42, a plurality of bolt holes 45 distributed along the length direction of the side wall of the crank 42 are formed in the side wall of the crank 42, a positioning bolt 46 is arranged on the slide block bearing seat 42, one end of the connecting rod 43 is hinged with the slide block bearing seat 44, and the other end of the connecting rod 43 is hinged with one connecting frame 33. After the positioning bolts 46 unlock the slide block bearing seat 44, the slide block bearing seat 44 can slide along the length direction of the crank 42, and the position of the slide block bearing seat 44 on the crank 42 is changed, so that the amplitude of the vibrating membrane frame 3 is adjusted, and the requirements of different processes are met.

The signal end of the second servo motor 41 is in communication connection with an industrial personal computer, the industrial personal computer controls the rotating speed of the second servo motor 41 through instructions to control and adjust the front and back reciprocating vibration frequency of the vibrating membrane frame 3, corresponding vibration frequency and amplitude are selected according to the processed raw material liquid, and the vibration frequency of the vibrating membrane frame 3 is 0.5-150 Hz. The vibration amplitude of the vibrating membrane frame 3 is adjusted by adjusting the position of the sliding block bearing seat 42 on the crank 42, and the adjusting range of the vibration amplitude is 0.2 cm-100 cm.

When a layer of membrane assemblies 2 is arranged in the vibrating membrane frame 3, the layer of membrane assemblies 2 are arranged in a tiled mode as a whole, and each layer of membrane assemblies 2 comprises a plurality of membrane assemblies 2 which are sequentially arranged at intervals left to right. When being equipped with two-layer membrane module 2 in the vibrating diaphragm frame 3 at least, each layer membrane module 2 is from bottom to top interval range upon range of arrangement in proper order, and each membrane module 2 of every layer all vertically sets up, and its upper and lower both ends all link to each other with vibrating diaphragm frame 3 is fixed, and each membrane module 2 of upper strata is vertically just right with each membrane module 2 of adjacent lower floor respectively one by one.

Specifically, the membrane assembly 2 includes an upper box 23, a lower box 24, and a membrane body 22, where the upper box 23 and the lower box 24 are elongated shells arranged longitudinally, and are arranged on the vibrating membrane frame 3 in parallel relatively one above the other, and the upper box 23 and the lower box 24 are detachably and fixedly connected with the vibrating membrane frame 3 respectively.

The membrane body 22 is a plurality of hollow fiber membranes which are distributed regularly, the types of the hollow fiber membranes adopt hydrophobic microfiltration membranes, nanofiltration membranes, compact membranes or Janus structure membranes, and the type of the hollow fiber membranes is determined according to the processed raw material liquid and the process requirements. The hollow fiber membranes are vertically arranged, the upper ends of the hollow fiber membranes are fixedly and hermetically connected with the upper box body 23 through an upper mounting seat, the lower ends of the hollow fiber membranes are fixedly and hermetically connected with the lower box body 24 through a lower mounting seat, and the inner parts of the upper box body 23 are communicated with the inner parts of the lower box body 24 through inner cavities of the hollow fiber membranes. Specifically, the upper mounting seat is fixedly embedded on the bottom plate of the upper box body 23, the outer side wall of the upper mounting seat is fixedly and hermetically matched with the bottom plate of the upper box body 23, the lower mounting seat is fixedly embedded on the top plate of the lower box body 24, and the outer side wall of the lower mounting seat is fixedly and hermetically matched with the top plate of the lower box body 24

The inlet end of each membrane module 2 is positioned at the bottom of the lower box body 24, the outlet end of each membrane module 2 is positioned at the top of the upper box body 23, the upper box bodies 23 of the two vertically adjacent membrane modules 2 are connected with and communicated with each other through pipelines, namely, the bottom of the lower box body 24 of the membrane module positioned above, and the tops of the upper box bodies 23 of the other membrane modules 2 adjacent to the lower side are connected together through a section of connecting pipe 25 to form a structure of vertically and sequentially connecting the membrane modules in series in the same order.

Each U-shaped groove is internally provided with a strip-shaped positioning plate 32, the positioning plate 32 is connected with the mounting plates 31 on the adjacent side of the positioning plate 32 through a group of locking bolts 321 which are longitudinally arranged at intervals, each group of locking bolts 321 comprises a plurality of locking bolts 321 which are longitudinally arranged at intervals and screwed on the mounting plates 31, and the positioning plate 32 fixes the upper end and the lower end of the membrane assembly 2 between the two pairs of mounting plates 31. The upper case 23 and the lower case 24 of the diaphragm assembly 2 are respectively placed between the two pairs of mounting plates 31, and the positioning plate 32 is fixed in the diaphragm frame 3 by tightening the locking bolts 321.

The vibration film frame 3 drives all the film components 2 to vibrate longitudinally and horizontally, and the surfaces of all the hollow fiber films and the raw material liquid do reciprocal motion, firstly, the flow velocity of the surfaces of the hollow fiber films can be increased, so that the water vapor pressure difference of the surfaces of the hollow fiber films is increased, further, the water vapor flux of the hollow fiber films is increased, further, the separation performance of the hollow fiber films is improved, secondly, the reciprocal back and forth vibration of the hollow fiber films and the rising interaction of bubbles are easy to form turbulence on the surfaces of the hollow fiber films, and the turbulence can greatly lighten the enrichment of large-particle pollutants on the surfaces of the hollow fiber films, further lighten the film pollution.

In addition, when the micro-nano aeration head 57 provides aeration for the membrane tank 1, high-pressure air entering the high-pressure air pipe II 52 is discharged through the micro-nano aeration head 57, uniform nano bubbles are continuously formed in the membrane tank 1 and quickly move to the surface of the raw material liquid from bottom to top, and shearing flow in an inclined direction is formed with the front-back movement of the fiber membrane. Specifically, the staggered water flow is formed on the surface of the membrane by means of stirring of bubbles, so that disturbing force and shearing force are generated, pollutants on the surface of the membrane fall off under the action of force, and the contact between the surface of the membrane and the pollutants is reduced along with the arrival of the steam drum on the surface of raw material liquid, so that the organic pollution, inorganic scaling and adhesion of microorganisms on the membrane can be greatly reduced, and the service life of the membrane is prolonged.

The first pipe body 53 is provided with an electromagnetic flowmeter 56, a signal end of the electromagnetic flowmeter 56 is in communication connection with the industrial personal computer, the electromagnetic flowmeter 56 monitors high-pressure air flow entering the high-pressure air pipe II 52, aeration is adjusted, and bubbling amount per unit time and area can be quantized into a ratio of 4-50:1. The device provides the membrane tank 1 with the two aeration modes, and reasonable aeration modes are selected according to the raw material liquid and the process requirements.

According to the embodiment, the size and the bubble quantity of bubbles are controlled, the inorganic salt and organic pollution resistance of the membrane are improved through cooperation with a vibration system, meanwhile, the flow speed of the surface of the membrane is increased through vibration and bubbling, so that the water vapor flux can be improved, in addition, the concentration polarization of the surface of the membrane is controlled through cooperation of intelligent control of the vacuum degree, bubbling and vibration, the organic pollution resistance and the inorganic salt scaling resistance of the membrane are further improved, finally, the service life of the membrane can be greatly improved through cooperation control of the three, the operation energy consumption is reduced, and therefore the quality and the efficiency of membrane permeation gasification are improved in the process of guaranteeing high-efficiency permeation gasification.

When the high-salt wastewater or the organic solvent is dehydrated, the low-temperature fluid medium adopts low-temperature purified water, the purified water is collected in the liquid collection tank 7, the temperature of the purified water is higher than that of the purified water in the flow distribution module 61, and when the organic solvent and the organic solvent are separated, the low-temperature fluid medium adopts the same low-temperature organic solvent as the organic solvent to be separated, the organic solvent separated from the inside of the membrane tank 1 is called target organic solvent, and the temperature of the organic solvent collected in the liquid collection tank 7 is higher.

When the liquid (distilled water or the target organic solvent) in the liquid collection tank 7 is required to be used as the fluid medium, a part of the organic solvent in the liquid collection tank 7 needs to be subjected to cooling treatment, specifically, a part of the liquid in the liquid collection tank 7 enters the heat exchanger 67 through the seventh pipe 73 to be cooled to obtain the low-temperature fluid medium, and then is pumped into the split module 61 through the third pipe 63 to return to the liquid collection tank 7 in the same way, so that the low-temperature fluid medium is continuously provided for the interiors of all the membrane assemblies 2. The low-temperature fluid medium enters the lower shell 24 of the membrane assembly 2, upwards enters the upper shell 23 of the membrane assembly 2 from the lower shell 24 through the inner cavity of the hollow fiber membrane, then enters the upper membrane assembly 2 through the connecting pipe 25, and sequentially upwards flows, enters the interior of the confluence module 62 and enters the interior of the liquid collection tank 7. When the low-temperature fluid medium passes through the inside of the hollow fiber membrane, high-temperature water vapor or high-temperature target organic solvent enters the inside of the hollow fiber membrane through the micropores on the side wall of the hollow fiber membrane, and the low-temperature fluid medium is cooled to form a liquid state, is mixed with the low-temperature fluid medium in the hollow fiber membrane and is conveyed upwards together. The electronic liquid level meter monitors the liquid level of the liquid collecting tank 7 in real time, and periodically discharges redundant liquid in the liquid collecting tank 7.

When the invention is used for separating high-salt wastewater, the high-salt wastewater enters the membrane assembly in the form of water vapor after being filtered by the membrane assembly and exchanges heat, the water vapor is cooled in the cooling cavity 201 of the membrane assembly to form condensed water, and the condensed water is converged into the liquid collecting tank 7 through the liquid discharge pipe 73 to finally produce the high-salt wastewater in the form of liquid pure water. Taking the membrane body 22 as an example of the application of nanofiltration membrane to distillation separation of magnesium-lithium salt solution, the molecular weight cut-off is between reverse osmosis membrane and ultrafiltration membrane, about 100-2000 Da, and thus the possible pore diameter of nanofiltration membrane is estimated to be about 1-5 nm. The method is applied to magnesium-lithium salt solution separation, organic matter and chromaticity removal of surface water, hardness removal of groundwater, partial removal of soluble salt, concentration of fruit juice, separation of useful substances in medicines and the like. The main separation mechanism is the synergistic effect of pore size sieving and the rejection of the southwest, wherein the rejection of the electric charges in the membrane of the southwest dominates the mechanism.

Embodiment 3, combining fig. 2, 3, 4 and 6, a direct contact type pervaporation membrane distillation separation device has the same main body part as that of embodiment 1, and is different in that the direct contact type pervaporation membrane distillation separation device further comprises an evaporation crystallizer 9 provided with a stirring mechanism, the evaporation crystallizer is arranged outside the membrane tank 1, a sealed shell with a heating function at the bottom is adopted, an inlet of the evaporation crystallizer 9 is connected with an outlet at the lower part of the membrane tank 1 through an eighth pipe 91, a second stop valve 92 and the same delivery pump are arranged on the eighth pipe 91, and a pressure relief valve is arranged at the top of the evaporation crystallizer 9.

The stirring mechanism comprises stirring blades 94, a transmission shaft and a third servo motor 95, the third servo motor 95 is arranged above the evaporation crystallizer 9, the stirring blades 94 are arranged at the lower part of the inner side of the evaporation crystallizer 9, and the stirring blades are fixedly connected with an output shaft of the third servo motor 95 through the transmission shaft.

The linear liquid concentration monitor 11 monitors the concentration value of the raw material liquid in the membrane tank 1 in real time, in the working state, the concentration value of the raw material liquid in the membrane tank 1 is increased along with the evaporation, when the concentration value of the raw material liquid reaches a set threshold value, the industrial personal computer controls the second stop valve 92 to be opened through a signal instruction, the raw material liquid in the membrane tank 1 enters the evaporation crystallizer 9 through the eighth pipe 91, then the second stop valve 92 is closed, new raw material liquid is added into the membrane tank 1, the concentration of the raw material liquid in the membrane tank 1 is reduced after the raw material liquid is mixed with the newly added raw material liquid, and the separation is continued through the membrane assembly 2. The evaporation crystallizer 9 heats and continuously stirs the high-concentration raw material liquid entering the evaporation crystallizer 9, crystals are continuously precipitated after the high-concentration raw material liquid in the evaporation crystallizer 9 reaches a saturated state, crystals are obtained in the evaporation crystallizer 9, and the eighth pipe 91 is not conducted in the heating crystallization process.

Embodiment 4, referring to fig. 2 to 5, a direct contact type pervaporation membrane distillation separation device has the same main body as that of embodiment 2, and is characterized in that the direct contact type pervaporation membrane distillation separation device further comprises an evaporation crystallizer 9 provided with a stirring mechanism, the evaporation crystallizer is arranged outside the membrane tank 1, a sealing shell with a heating function at the bottom is adopted, an inlet of the evaporation crystallizer 9 is connected with an outlet at the lower part of the membrane tank 1 through an eighth pipe 91, a second stop valve 92 and the same delivery pump are arranged on the eighth pipe 91, and a pressure release valve is arranged at the top of the evaporation crystallizer 9.

The parts not described in the invention can be realized by adopting or referring to the prior art.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc., are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

It should be understood that the above description is not intended to limit the invention to the particular embodiments disclosed, but to limit the invention to the particular embodiments disclosed, and that the invention is not limited to the particular embodiments disclosed, but is intended to cover modifications, adaptations, additions and alternatives falling within the spirit and scope of the invention.

Claims

1. A direct contact pervaporation membrane distillation separation device, comprising a membrane tank, a membrane assembly, a vibrating membrane frame, a reciprocating drive mechanism, a bubbling unit, a diversion module, a confluence module, a liquid collection tank, a cleaning system, and an industrial computer. The vibrating membrane frame is disposed within the membrane tank, and the reciprocating drive mechanism drives the vibrating membrane frame to move back and forth.

At least one layer of membrane components is provided on the vibrating membrane frame. When the number of membrane components is greater than one, the membrane components are stacked in sequence from bottom to top. Each layer of membrane components includes multiple membrane components arranged in a transversely spaced manner. All membrane components are vertically fixed on the vibrating membrane frame. Each membrane component on the upper layer is vertically aligned with each membrane component on the adjacent lower layer.

The membrane module has a cavity inside, an inlet end and an outlet end, and the membrane modules at the same position are vertically connected in series;

The diversion module is located at the bottom of the membrane pool, and the inlet of the diversion module is connected to the liquid collection tank pipeline;

The confluence module is located above the membrane pool and is connected to the diversion module through the cavities of all membrane components. The outlet of the confluence module is connected to the top pipeline of the liquid collection tank. In the working state, the liquid collection tank can continuously pump low-temperature fluid medium into the diversion module.

The bubbling unit includes a bubbler, multiple aeration discs and multiple micro-nano aeration heads. The aeration discs and micro-nano aeration heads are regularly arranged at the bottom of the membrane tank. The bubbler is connected to all the aeration discs and all the aeration disc pipelines respectively.

An online liquid concentration monitor is provided at the bottom of the membrane pool.

2. A pervaporation membrane distillation separation device according to claim 1, characterized in that the membrane assembly comprises a membrane body and a square rigid frame, the rigid frame being arranged vertically, the membrane body comprising two flat membranes, the two membrane bodies being symmetrically arranged on the left and right sides of the rigid frame and fixedly and hermetically connected to the rigid frame to form the cavity of the membrane assembly;

The inlet and outlet of the membrane assembly are located at the bottom and top of the rigid frame respectively, and the inlet and outlet ends of two vertically adjacent rigid frames are connected by pipelines.

3. A pervaporation membrane distillation separation device according to claim 1, characterized in that the membrane assembly comprises an upper box body, a lower box body and a membrane body, the upper box body and the lower box body are arranged in parallel with one higher and the other lower, and are fixed on the vibrating membrane frame;

The membrane body is a plurality of hollow fiber membranes arranged vertically, the upper end of the hollow fiber membrane is connected to the interior of the upper box body, and the lower end is connected to the interior of the lower box body;

The inlet end of the membrane assembly is located at the bottom of the lower box body, and the outlet end thereof is located at the top of the upper box body. The upper box body and the lower box body that are vertically adjacent are connected by pipelines.

4. A direct contact pervaporation membrane distillation separation device according to claim 1, characterized in that the vibrating membrane frame is an open structure, and a positioning mechanism is provided inside the vibrating membrane frame, the number of which is equal to the number of membrane modules and the positions of which correspond one to one;

The positioning mechanism includes two pairs of mounting plates arranged correspondingly above and below, with a U-shaped groove formed between each pair of mounting plates, and the upper and lower ends of the membrane assembly are fixed between the two pairs of mounting plates.

5. A direct contact pervaporation membrane distillation separation device according to claim 1, characterized in that a cover is provided above the membrane pool, the edge of the cover is fixedly connected to the top of the membrane pool, and the vibrating membrane frame is located below the cover;

Two connecting frames are symmetrically arranged on the vibrating membrane frame, and two guide rails are arranged above the membrane pool. The upper ends of the two connecting frames are longitudinally slidably matched with the two guide rails respectively, and the lower ends are fixedly connected to the vibrating membrane frame. The connecting frames are movably sealed with the cover body;

The reciprocating drive mechanism includes a second servo motor, a crank, a connecting rod and a slider bearing seat. One end of the crank is fixedly connected to the output shaft of the second servo motor. A slider bearing seat sleeve is provided on the crank. One end of the connecting rod is hinged to the slider bearing seat, and the other end is hinged to one of the connecting frames.

6. A direct contact pervaporation membrane distillation separation device according to claim 1, characterized in that all aeration plates are connected to the bubbler via a high-pressure air pipe 1, the high-pressure air pipe 1 is arranged horizontally, the aeration plates are spaced apart along the length of the high-pressure air pipe 1, all micro-nano aeration heads are connected to the bubbler via a high-pressure air pipe 2, the high-pressure air pipe 2 is arranged parallel to the high-pressure air pipe 1, and the micro-nano aeration heads are spaced apart along the length of the high-pressure air pipe 2;

The bubbler is connected to the air inlet pipeline of the three-way valve, and the two air outlet ends of the three-way valve are respectively connected to the high-pressure air pipe 1 and the high-pressure air pipe 2.

7. A direct contact pervaporation membrane distillation separation device according to claim 1, characterized in that the diverter module and the confluence module are respectively mounted at the bottom and top of the vibrating membrane frame, the top of the diverter module has outlet ports equal in number to and corresponding in position to the membrane assemblies in each layer, and each outlet port of the diverter module is connected to the inlet port of the corresponding membrane assembly in the lowest layer through a fifth tube;

The bottom of the confluence module has inlet ends that are equal in number to the number of membrane components in each layer and correspond in position to each other. Each inlet end of the confluence module is connected to the outlet end of the corresponding membrane component in the top layer through a sixth tube body. An online liquid concentration monitor 2 is provided inside the confluence module.

8. The direct contact pervaporation membrane distillation separation device according to claim 1, further comprising a heat exchanger and a low-temperature cooling source, wherein the low-temperature cooling source and the shell side of the heat exchanger constitute a cold water circulation loop;

A drain pipe is provided at the bottom of the liquid collection tank, a first stop valve is installed on the drain pipe, and the lower part of the liquid collection tank is connected through the inlet pipeline of the heat exchanger diversion module.

9. A direct contact pervaporation membrane distillation separation device according to claim 1, characterized in that it also includes an evaporation crystallizer with a heating function at the bottom, a stirring mechanism is configured inside the evaporation crystallizer, the inlet of the evaporation crystallizer is connected to the lower pipeline of the membrane pool, and a pressure relief valve is provided on the top of the evaporation crystallizer.

10. A direct contact pervaporation membrane distillation separation device according to claim 1, characterized in that the cleaning system includes a water pump and a cleaning main pipe, the water pump is connected to one end of the cleaning main pipe by a pipeline, and the cleaning main pipe is provided with cleaning branches equal in number to and corresponding in position to the membrane modules, and the lower end of each cleaning branch is located on an adjacent side of the corresponding membrane module.