CN114873684B - Membrane distillation assembly, mixed membrane distilled water treatment system and method - Google Patents

Abstract

The invention provides a membrane distillation assembly, a mixed membrane distilled water treatment system and a method, which relate to the field of water treatment and comprise a shell with a channel and a microporous membrane positioned in the channel, wherein the microporous membrane divides the channel into a first channel and a second channel which are parallel, one side, far away from the microporous membrane, of the first channel and one side, far away from the microporous membrane, of the second channel are respectively provided with a plurality of protruding parts, and the protruding parts are sequentially arranged along the axial direction of the channel to form a disturbance structure acting on a water body in the channel; to the poor, energy consumption height of present membrane distillation subassembly stability and the poor problem of water treatment effect, arrange the microporous membrane in the shell structure that has the passageway and carry out the membrane distillation of water, the casing consolidates the microporous membrane structure, is provided with the bellying on the shell structure inner wall, utilizes the bellying to carry out the water disturbance respectively to low temperature side and high temperature side to improve the efficiency that the water vapor that the water carried passes the microporous membrane and gets into low temperature side, guarantee the evaporation filter effect of microporous membrane to the water.

Description

Membrane distillation assembly, mixed membrane distilled water treatment system and method

Technical Field

The invention relates to the field of water treatment, in particular to a membrane distillation assembly, a mixed membrane distilled water treatment system and a method.

Background

The membrane distillation is a membrane separation process which adopts a hydrophobic microporous membrane and takes the steam pressure difference at two sides of the membrane as a mass transfer driving force, and can be used for the distillation desalination of water and the removal of volatile substances from aqueous solution. For example, when aqueous solutions at different temperatures are separated by a hydrophobic microporous membrane, solutes on both sides cannot pass through the membrane pores to enter the other side due to the hydrophobicity of the membrane, but because the water vapor pressure at the interface of the aqueous solution on the hot side and the membrane is higher than that on the cold side, the water vapor can pass through the membrane pores to enter the cold side from the warm side and condense, thereby achieving the distillation desalination of water.

The membrane distillation can process extremely high-concentration brine, however, in the membrane module and the system which are currently matched with the membrane distillation of hot spring geothermal brackish water, as the hot spring water and the brackish water have complex chemical components, the mixed salt solution of impurities such as colloid particles and the like causes certain pollution to the membrane module, thereby causing poor mass and heat transfer of the membrane module, lower purification rate and larger power consumption of the system; in addition, current membrane modules often enhance mass and heat transfer through gaskets, however gaskets, while increasing support strength, are less robust and have a greater potential for membrane module use.

Disclosure of Invention

The invention aims at overcoming the defects of the prior art, and provides a membrane distillation assembly, a mixed membrane distilled water treatment system and a method, wherein a microporous membrane is arranged in a shell structure with a channel to carry out membrane distillation of water, a bulge part is arranged on the inner wall of the shell structure, and the bulge part is used for respectively carrying out water disturbance on a low-temperature side and a high-temperature side, so that the efficiency of water vapor carried by the water body penetrating the microporous membrane to enter the low-temperature side is improved, and the evaporation and filtration effects of the microporous membrane on the water body are ensured.

The first object of the invention is to provide a membrane distillation assembly, which adopts the following scheme:

the device comprises a shell with a channel and a microporous membrane located in the channel, wherein the microporous membrane divides the channel into a first channel and a second channel which are parallel, one side, away from the microporous membrane, in the first channel and one side, away from the microporous membrane, in the second channel are respectively provided with a convex part, and the convex parts are sequentially arranged along the axial direction of the channel to form a disturbance structure acting on water in the channel.

Further, the protruding parts on the same side of the microporous membrane are sequentially staggered along the axial direction of the channel, one end of each protruding part is positioned on the side wall of the channel, the other end of each protruding part extends along the direction perpendicular to the axial direction of the channel, and the adjacent protruding parts are connected with different side walls of the channel.

Further, a plurality of rows of protruding parts are respectively arranged in the first channel and the second channel, protruding parts positioned in adjacent rows on the same side of the microporous membrane are symmetrically arranged relative to the axis of the channel, and the cross sections of the protruding parts are parallelograms.

Further, the protrusions in the first channel and the protrusions in the second channel are symmetrically arranged with respect to the microporous membrane.

The second object of the invention is to provide a mixed membrane distilled water treatment system, which adopts the following scheme:

the device comprises a filtering component, a membrane distillation component and a post-treatment component, wherein a concentrated solution outlet of the membrane distillation component is connected with an inlet of the membrane distillation component through a return pipe; the post-treatment component comprises a crystallizer and a purifier, wherein a concentrated solution outlet of the filtering component is connected with the crystallizer through a first membrane distillation component, a penetrating solution outlet of the filtering component is connected with the purifier through a second membrane distillation component, and a penetrating solution outlet of the first membrane distillation component is communicated with an inlet of the second membrane distillation component through an output pipe.

Further, the filter assembly comprises a particle filter and a colloid filter, wherein one end of the colloid filter is communicated with the particle filter, and the other end of the colloid filter is communicated with the membrane distillation assembly.

Further, the colloid filter comprises a reverse osmosis structure and/or a nanofiltration structure, a first outlet of the colloid filter is a concentrated solution outlet, and the first outlet is communicated with the first membrane distillation assembly; the second outlet of the colloid filter is a permeate outlet which is communicated with the second membrane distillation assembly.

Further, the first membrane distillation assembly is a first membrane distillation assembly, and the concentrated solution outlet of the first membrane distillation assembly is also communicated with the crystallizer.

Further, the second membrane distillation assembly is a second membrane distillation assembly, a concentrated solution outlet of the second membrane distillation assembly is communicated with the crystallizer, and a penetrating fluid outlet of the second membrane distillation assembly is communicated with the purifier.

Further, a valve is arranged on the return pipe, and a valve is arranged on a pipeline between the membrane distillation assembly and the post-treatment assembly.

A third object of the present invention is to provide a method for operating the above-described hybrid membrane distilled water treatment system, comprising the steps of:

the filter component is used for primarily filtering the water to be treated to remove particles and colloid;

the first membrane distillation assembly carries out membrane distillation treatment on concentrated solution generated during colloid removal, the concentrated solution is input into a crystallizer, and permeate is input into an inlet of the second membrane distillation assembly;

the second membrane distillation assembly carries out membrane distillation treatment on the permeate liquid output during colloid removal and the permeate liquid of the first membrane distillation assembly, the concentrated solution is input into a crystallizer, and the permeate liquid is input into a purifier;

the concentrated solution is crystallized by the purifier, and the permeate solution is purified by the purifier.

Further, the concentrated solution generated by the first membrane distillation assembly is input into the inlet of the first membrane distillation assembly through a return pipe; the concentrate from the second membrane distillation module is fed to its inlet via a return line.

Compared with the prior art, the invention has the advantages and positive effects that:

(1) To the poor, energy consumption height of present membrane distillation subassembly stability and the poor problem of water treatment effect, arrange the microporous membrane in the shell structure that has the passageway and carry out the membrane distillation of water, the casing consolidates the microporous membrane structure, is provided with the bellying on the shell structure inner wall, utilizes the bellying to carry out the water disturbance respectively to low temperature side and high temperature side to improve the efficiency that the water vapor that the water carried passes the microporous membrane and gets into low temperature side, guarantee the evaporation filter effect of microporous membrane to the water.

(2) The multi-stage geothermal driven mixed membrane distilled water treatment system is used for treating hot spring and brackish water, and the hot spring geothermal (which can be coupled with a heat pump) drives the reverse osmosis or nanofiltration and membrane distillation system of a membrane module, so that the purposes of reducing the pollution of the membrane module, improving the mass and heat transfer efficiency of the system, purifying and treating the hot spring and the brackish water into drinking water in an economic, energy-saving and high-recovery-ratio way are achieved.

(3) The water body to be treated is filtered, membrane distilled, crystallized and purified through the composite system, so that extremely high-concentration salt-containing water can be treated, and the purification rate of the brackish water is further improved through concentration of the brackish water through the membrane distillation system.

(4) Different membrane distillation assemblies are respectively configured for the first membrane distillation assembly and the second membrane distillation assembly, the first membrane distillation assembly adopts a fish scale imitation structure formed by a staggered structure, the second membrane distillation assembly adopts a leaf vein imitation structure formed by a multi-row structure, and according to the respective advantages of the two assemblies, the effects of enhancing mass and heat transfer and reducing energy consumption are achieved, the energy utilization rate can be effectively improved, and the cost is saved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.

FIG. 1 is a schematic illustration of a water treatment system in one or more embodiments of the invention;

FIG. 2 is a schematic diagram of a first membrane distillation assembly according to one or more embodiments of the present invention;

FIG. 3 is a schematic front view of a first membrane distillation assembly according to one or more embodiments of the present invention;

FIG. 4 is a schematic side view of a first membrane distillation assembly according to one or more embodiments of the present invention;

FIG. 5 is a schematic top view of a first membrane distillation assembly according to one or more embodiments of the present invention;

FIG. 6 is a schematic diagram of a second membrane distillation assembly according to one or more embodiments of the present invention;

FIG. 7 is a schematic front view of a second membrane distillation assembly according to one or more embodiments of the present invention;

FIG. 8 is a schematic side view of a second membrane distillation assembly according to one or more embodiments of the present invention;

FIG. 9 is a schematic top view of a second membrane distillation assembly in one or more embodiments of the invention.

Wherein, 1, a particle filter, 2, a colloid filter, 3, a second membrane distillation component, 4, a purifier, 5, a first membrane distillation component, 6, crystallizer, 7, valve a,8, valve b,9, valve c,10, valve d,11, first channel, 12, second channel, 13, protruding portion.

Detailed Description

Example 1

In an exemplary embodiment of the present invention, a membrane distillation assembly is provided, as shown in fig. 2-9.

The membrane distillation assembly shown in fig. 2 and 6 is used for treating membrane distilled water, especially for treating hot spring water and brackish water, microporous membranes are arranged in a shell structure with a channel to perform membrane distillation of water, protruding parts 13 are arranged on the inner wall of the shell structure, and the protruding parts 13 are used for respectively disturbing water on the low-temperature side and the high-temperature side, so that the efficiency of water vapor carried by the water entering the low-temperature side through the microporous membranes is improved, and the evaporation and filtration effects of the microporous membranes on the water are ensured.

In this embodiment, two membrane distillation assembly forms are provided, one is a fish scale simulating structure with staggered protruding portions 13, the other is a vein simulating structure with array of protruding portions 13, and the other is a second membrane distillation assembly 3.

The first membrane distillation assembly 5 shown in fig. 2-5 comprises a shell with a channel and a microporous membrane positioned in the channel, wherein the microporous membrane divides the channel into a first channel 11 and a second channel 12 which are parallel, a side, far away from the microporous membrane, of the first channel 11 and a side, far away from the microporous membrane, of the second channel 12 are respectively provided with a bulge 13, and the bulge 13 is sequentially provided with a plurality of bulges along the axial direction of the channel to form a disturbance structure acting on a water body in the channel.

Meanwhile, as shown in fig. 2, the microporous membrane components are combined with the shell to form a bionic membrane component, the protruding parts 13 on the same side of the microporous membrane are sequentially staggered along the axial direction of the channel, one end of each protruding part 13 is positioned on the side wall of the channel, the other end extends along the direction vertical to the axial direction of the channel, and the adjacent protruding parts 13 are connected with different side walls of the channel.

As shown in fig. 3-5, the shell of the first membrane distillation assembly 5 is combined with the microporous membrane to form two channels, as shown in fig. 2, the cross sections of the two channels are rectangular, the first channel 11 on one side of the microporous membrane is taken as an example, the shell is recessed from the outside to the channel direction, a protruding part 13 is formed in the channel, as shown in fig. 3, the height of the protruding part 13 penetrating into the first channel 11 is 4mm, the interval between adjacent protruding parts 13 is 5mm along the axial direction of the channel, the staggered interval between adjacent protruding parts 13 on the opposite side is 5mm, and the width of the protruding part 13 is 5mm; taking the orientation in fig. 2 as an example, the length of the boss 13 in the Y-axis direction is 12.5mm.

It can be understood that, in the above-mentioned structural parameters of the set of protruding portions 13 provided for the present embodiment, in other embodiments, the length, width, height data of the corresponding channels of the shell, the size data of the protruding portions 13, and the arrangement parameters of the protruding portions 13 may be adjusted accordingly according to the ratio of the first membrane distillation assembly 5 and the requirements of mass and heat transfer. Also, the first membrane distillation assembly 5 in the present embodiment may be used in other different systems.

The second membrane distillation assembly 3 shown in fig. 6-9 comprises a shell with a channel and a microporous membrane positioned in the channel, wherein the microporous membrane divides the channel into a second channel 12 and a second channel 12 which are parallel, a side, far away from the microporous membrane, of the second channel 12 and a side, far away from the microporous membrane, of the second channel 12 are respectively provided with a bulge 13, and a plurality of bulge 13 are sequentially arranged along the axial direction of the channel to form a disturbance structure acting on a water body in the channel.

Meanwhile, as shown in fig. 6, the microporous membrane components are combined with the shell to form a bionic membrane component, a plurality of rows of protruding parts 13 are respectively arranged in the first channel 11 and the second channel 12, the protruding parts 13 positioned in adjacent rows on the same side of the microporous membrane are symmetrically arranged relative to the axis of the channel, and the cross section of the protruding parts 13 is in a parallelogram.

As shown in fig. 7-9, the shell of the second membrane distillation assembly 3 is combined with the microporous membrane to form two channels, as shown in fig. 7, the cross sections of the two channels are rectangular, the first channel 11 on one side of the microporous membrane is taken as an example, the shell is recessed from the outside to the channel direction, a protruding part 13 is formed in the channel, as shown in fig. 3, the protruding part 13 is a parallelogram baffle, the height of the parallelogram baffle penetrating into the first channel 11 is 4mm, and the included angle between the parallelogram baffle on the same side and the side face of the shell is set to be 45 degrees, and the short side of the parallelogram baffle is 5mm. The short sides of the two-side parallelogram baffle plates are 2.5mm away from the shell, and the horizontal spacing distance of the X-axis direction of the same-side parallelogram baffle plates is 5mm, and the horizontal spacing distance of the short sides of the two-side parallelogram baffle plates is 5mm.

It can be understood that, in the above-mentioned structural parameters of the set of protruding portions 13 provided for the present embodiment, in other embodiments, the length, width, height data of the corresponding channels of the shell, the size data of the protruding portions 13, and the arrangement parameters of the protruding portions 13 may be adjusted accordingly according to the proportion of the second membrane distillation assembly 3 and the requirements of mass and heat transfer. Also, the second membrane distillation assembly 3 in the present embodiment may be used in other different systems.

It should be noted that the structure of the protruding portion 13 may be formed by recessing the housing inward, or may be formed by disposing a protruding portion in the passage, so that processing can be performed easily.

Meanwhile, the fact that the protruding portion 13 of the second membrane distillation assembly 3 is a parallelogram baffle means that the projection of the protruding portion 13 on the plane where the microporous membrane is located is a parallelogram, and the protruding portion 13 is in a prism shape as a whole. The protruding portion 13 of the first membrane distillation assembly 5 can also be a cuboid structure, a cube structure or other prismatic structures and cylindrical structures, and can achieve the disturbance effect on the water body in the channel.

The protruding parts 13 in the first channel 11 and the protruding parts 13 in the second channel 12 are symmetrically arranged relative to the microporous membrane, so that bilateral disturbance is realized, the efficiency of water vapor carried by the water body passing through the microporous membrane to enter the low-temperature side is improved, and the evaporation and filtration effects of the microporous membrane on the water body are ensured.

As shown in table 1 below, the second membrane distillation module 3 has a larger flux improvement and enhanced mass and heat transfer effect compared to the conventional air-through module, and at the same time, the second membrane distillation module 3 can exhibit a larger permeation flux and heat flux in numerical simulation compared to the first membrane distillation module 5.

As shown in the following table 1, compared with the conventional air-through component, the first membrane distillation component 5 has larger flux improvement, enhanced mass and heat transfer effect, and simultaneously has better consumption reduction performance in numerical simulation, and the power loss factor and friction factor of the feed liquid side, namely the hot side, are smaller than those of the second membrane distillation component 3.

TABLE 1 comparison of Membrane distillation Performance parameters of first Membrane distillation Assembly, second Membrane distillation Assembly and empty channel Membrane Assembly

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Example 2

In another exemplary embodiment of the present invention, as shown in fig. 1-9, a hybrid membrane distilled water treatment system is provided.

Comprising the following steps:

a primary water purification and particulate pretreatment system configured to filter large particle size particulates through a powder box filter or screen and primary treat the hot spring or brackish water in a reverse osmosis or nanofiltration module, again filtering the colloidal particulates;

a concentrated solution treatment system configured to treat the concentrated salt solution flowing out of the primary water treatment system through the bionic membrane module MD1 and to crystallize the concentrated salt solution which cannot be reused through the crystallizer 6;

a secondary water treatment system configured to treat permeate flowing out of the primary water treatment system and MD1 via the biomimetic membrane module MD 2;

a post-treatment system configured to treat the final permeate as potable water by the purification device.

In this embodiment, as shown in fig. 1, the primary water purifying and particulate pretreatment system is a filtration module, the concentrate treatment system and the secondary water treatment system are membrane distillation modules, a concentrate outlet of the filtration module is connected with a crystallizer 6 of the post-treatment module through a first membrane distillation module, a permeate outlet of the filtration module is connected with a purifier 4 of the post-treatment module through a second membrane distillation module, and a permeate outlet of the first membrane distillation module is communicated with an inlet of the second membrane distillation module through an output pipe.

As shown in fig. 1, the filter assembly includes a particulate filter 1 and a colloid filter 2, one end of the colloid filter 2 is connected to the particulate filter 1, and the other end is connected to the membrane distillation assembly. The particle filter 1 adopts a powder box filter or a filter screen, the colloid filter 2 adopts a reverse osmosis or nanofiltration component, the powder box filter or the filter screen is used as the particle filter 1 to be connected with the reverse osmosis component or the nanofiltration component corresponding to the colloid filter 2, the colloid filter 2 comprises a reverse osmosis structure and/or a nanofiltration structure, a first outlet of the colloid filter 2 is a concentrated solution outlet, and the concentrated solution outlet is communicated with the first membrane distillation component 5; the second outlet of the colloid filter 2 is a permeate outlet and is communicated with a second membrane distillation assembly.

The powder box filter or the filter screen and the reverse osmosis or nanofiltration device are selected according to the specific hot spring system performance and the characteristics of brackish water, and the commercial products mature in the prior art can be selected to meet the requirements.

It is understood that the first membrane distillation assembly is a first membrane distillation assembly 5, and the concentrated solution outlet thereof is also communicated with the crystallizer 6; the second membrane distillation component is a second membrane distillation component 3, the concentrated solution outlet of which is communicated with a crystallizer 6, and the permeate outlet of which is communicated with a purifier 4.

In this embodiment, as shown in fig. 1, the membrane distillation assembly corresponds to a bionic membrane assembly, the first membrane distillation assembly 5 corresponds to a first bionic membrane assembly MD1, the second membrane distillation assembly 3 corresponds to a second bionic membrane assembly MD2, and meanwhile, the first membrane distillation assembly 5 and the second membrane distillation assembly 3 in embodiment 1 may be adopted.

The membrane distillation assembly is communicated with the crystallizer 6 or the purifier 4 through a pipeline, the first bionic membrane assembly MD1 and the second bionic membrane assembly MD2 have the benefits of enhancing mass transfer and heat transfer and increasing flux, the bionic modified membrane assembly of the first bionic membrane assembly MD1 is arranged in a concentration branch and has smaller power loss, the energy consumption is better reduced, and the bionic modified membrane assembly of the second bionic membrane assembly MD2 is arranged in a permeation serial branch and has better mass transfer and heat transfer effect, the flux can be increased more, and the water yield is improved.

Through the shell micro-channel design of the simulated veins and the fish scales in the embodiment 1, the first bionic membrane module MD1 and the second bionic membrane module MD2 achieve the effects of enhancing mass and heat transfer and reducing energy consumption, thereby effectively improving the energy utilization rate and saving the cost.

As shown in fig. 1, the post-treatment system is a post-treatment assembly, the post-treatment assembly comprises a crystallizer 6 and a purifier 4, the purifier 4 is connected by a permeate pipeline of the second bionic membrane assembly MD2, and the crystallizer 6 is connected by a concentrate pipeline of the first bionic membrane assembly MD1 and the second bionic membrane assembly MD 2. The return pipe is provided with a valve, and a valve is arranged on a pipeline between the membrane distillation assembly and the post-treatment assembly

The membrane distillation mode can be selected from direct contact type, vacuum type, etc. The membrane distillation system provided in the prior art is mostly in a series connection mode, and the parallel connection mode obtains larger membrane flux and water making ratio in the existing experiments and simulations, and has the advantages of flexible operation, convenient operation and maintenance and the like.

A higher flux to water ratio will be obtained with the parallel approach. When the hot spring and brackish water system needs to be scaled up, the series or parallel subsystems can be overlapped on the side of the total hot inlet pipe and the total cold outlet pipe in the same way on the basis of the series system so as to scale up engineering requirements and scale.

Example 3

In still another embodiment of the present invention, as shown in fig. 1 to 9, a water treatment method is provided, using the hybrid membrane distilled water treatment system of embodiment 2.

The method comprises the following steps:

the filter component is used for primarily filtering the water to be treated to remove particles and colloid;

the first membrane distillation assembly carries out membrane distillation treatment on the concentrated solution generated during colloid removal, the concentrated solution is input into a crystallizer 6, and the permeate is input into the inlet of the second membrane distillation assembly;

the second membrane distillation assembly carries out membrane distillation treatment on the permeate liquid output during colloid removal and the permeate liquid of the first membrane distillation assembly, the concentrated solution is input into a crystallizer 6, and the permeate liquid is input into a purifier 4;

the concentrated solution generated by the first membrane distillation assembly is input into the inlet of the first membrane distillation assembly through a return pipe; the concentrated solution generated by the second membrane distillation assembly is input into the inlet of the second membrane distillation assembly through a return pipe;

the concentrated solution is crystallized by the purifier 4, and the permeate is purified by the purifier 4.

With reference to fig. 1 and fig. 2 to fig. 9, the detailed working method is as follows:

firstly, a filter component corresponding to a primary water purification and particulate matter pretreatment system is used for leading hot spring water or brackish water conveyed by a pipeline into a powder box filter or a filter screen in a membrane distillation feed liquid pretreatment system to carry out primary treatment on impurities such as large-scale particulate matters, and sending filtrate into a reverse osmosis or nanofiltration component filter device through a serial pipeline to carry out secondary treatment on impurities such as small-scale particulate matters and primary purification on the hot spring water or the brackish water.

Then, the concentrated solution after primary purification is sent into a first bionic membrane module MD1 through a pipeline by the concentrated solution treatment system, the concentrated solution is subjected to re-concentration in a membrane distillation mode, the re-concentrated lower-concentration salt solution is controlled by a valve d10 and returns to a feed liquid side inlet of the first bionic membrane module MD1, and membrane distillation is performed again in a circulating mode; and the higher concentration concentrated solution (according to the specific conditions of the system, for example, when the total dissolved solid concentration TDS of the solution is higher than 200-300 g/L) obtained from the solution outlet of the first bionic membrane module MD1 is controlled by a valve c9 and enters the crystallizer 6 through a pipe, so that the waste solution exceeding the upper limit of the recycling concentration is crystallized.

Meanwhile, the secondary water treatment system flows the permeate purified by primary purification into a second bionic membrane module MD2 through a pipeline, performs secondary purification in a membrane distillation mode on the permeate, and after secondary purification, lower-concentration salt solution is controlled by a valve a7 and returns to a feed liquid side inlet of the second bionic membrane module MD2, and membrane distillation is performed again in a circulating mode; and the higher concentration concentrated solution (according to the specific conditions of the system, for example, when the total dissolved solid concentration TDS of the feed solution is higher than 200-300 g/L) obtained from the feed solution outlet of the second bionic membrane module MD2 is controlled by a valve b8 and enters the crystallizer 6 through a pipe, so that the waste solution exceeding the upper limit of the recycling concentration is crystallized.

Finally, the post-treatment system sends the permeate flowing out from the second bionic membrane module MD2 into the purifier 4, and treats the distillate into drinking water through the process of adding minerals and the like.

Different membrane distillation assemblies are respectively configured for the first membrane distillation assembly 5 and the second membrane distillation assembly 3, the first membrane distillation assembly 5 adopts a fish scale imitation structure formed by a staggered structure, the second membrane distillation assembly 3 adopts a leaf vein imitation structure formed by a multi-column structure, and according to the respective advantages of the two assemblies, the effects of strengthening mass and heat transfer and reducing energy consumption are achieved, and the energy utilization rate can be effectively improved and the cost can be saved.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. The mixed membrane distilled water treatment system is characterized by comprising a filtering component, a membrane distillation component and a post-treatment component, wherein a concentrated solution outlet of the membrane distillation component is connected with an inlet of the membrane distillation component through a return pipe; the post-treatment assembly comprises a crystallizer and a purifier, wherein a concentrated solution outlet of the filtering assembly is connected with the crystallizer through a first membrane distillation assembly, a penetrating solution outlet of the filtering assembly is connected with the purifier through a second membrane distillation assembly, and a penetrating solution outlet of the first membrane distillation assembly is communicated with an inlet of the second membrane distillation assembly through an output pipe;

the first membrane distillation component and the second membrane distillation component both comprise a shell with a channel and a microporous membrane positioned in the channel, the microporous membrane divides the channel into a first channel and a second channel which are parallel, a side, far away from the microporous membrane, of the first channel and a side, far away from the microporous membrane, of the second channel are respectively provided with a plurality of protruding parts, and the protruding parts are sequentially arranged along the axial direction of the channel to form a disturbance structure acting on water in the channel;

the first membrane distillation assembly is a first membrane distillation assembly, and a concentrated solution outlet of the first membrane distillation assembly is also communicated with the crystallizer;

the second membrane distillation assembly is a second membrane distillation assembly, a concentrated solution outlet of the second membrane distillation assembly is communicated with the crystallizer, and a penetrating fluid outlet of the second membrane distillation assembly is communicated with the purifier;

in the first membrane distillation assembly, the protruding parts on the same side of the microporous membrane are sequentially staggered along the axial direction of the channel, one end of each protruding part is positioned on the side wall of the channel, the other end of each protruding part extends along the direction vertical to the axial line of the channel, and the adjacent protruding parts are connected with different side walls of the channel;

in the second membrane distillation assembly, a plurality of rows of protruding parts are respectively arranged in the first channel and the second channel, protruding parts positioned in adjacent rows on the same side of the microporous membrane are symmetrically arranged relative to the axis of the channel, and the cross sections of the protruding parts are parallelograms.

2. The hybrid membrane distilled water treatment system of claim 1, wherein the protrusions in the first channel and the protrusions in the second channel are symmetrically arranged with respect to the microporous membrane.

3. The hybrid membrane distilled water treatment system of claim 1, wherein the filtration assembly comprises a particulate filter and a colloidal filter, the colloidal filter being in communication with the particulate filter at one end and the membrane distillation assembly at the other end;

the return pipe is provided with a valve, and a valve is arranged on a pipeline between the membrane distillation assembly and the post-treatment assembly.

4. A hybrid membrane distilled water treatment system according to claim 3, wherein the colloid filter comprises a reverse osmosis structure or a nanofiltration structure, and the first outlet of the colloid filter is a concentrate outlet and is communicated with the first membrane distillation assembly; the second outlet of the colloid filter is a permeate outlet and is communicated with the second membrane distillation assembly.

5. A method of operating a hybrid membrane distilled water treatment system according to any one of claims 1-4, comprising the steps of:

the filter component is used for primarily filtering the water to be treated to remove particles and colloid;

the first membrane distillation assembly carries out membrane distillation treatment on concentrated solution generated during colloid removal, the concentrated solution is input into a crystallizer, and permeate is input into an inlet of the second membrane distillation assembly;

the second membrane distillation assembly carries out membrane distillation treatment on the permeate liquid output during colloid removal and the permeate liquid of the first membrane distillation assembly, the concentrated solution is input into a crystallizer, and the permeate liquid is input into a purifier;

the concentrated solution is crystallized by the purifier, and the permeate solution is purified by the purifier.

6. The method of operating a hybrid membrane distillation water treatment system as claimed in claim 5, wherein the concentrate from said first membrane distillation module is fed to its inlet through a return line; the concentrate from the second membrane distillation module is fed to its inlet via a return line.

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