CN1660480A - Method of membrane separating property of variable pitch, membrane module apparatus and usage - Google Patents

Abstract

A membrane module based on the secondary dean eddy reinforced mass transfer features that a helical pitch varying method is used for generating a stronge and stable dean eddy for inlet to outlet, so fully playing its strong mass transfer and separation role. The helical pitch at the inlet of membrane pipe is greater than that at its outlet. It is suitable for millipore filter, ultrafilter and nano-filter.

Description

The method of varying pitch membrane separating property and film component device and purposes

Technical field

The present invention relates to a kind of physical separation method, belong to the film separation field, refer in particular to the method and apparatus of curved channel type (comprising screw type and Weaving type) hollow fiber film assembly and curved channel PP, PE tubular type and match formula membrane module, and uses thereof.

Background technology

Membrane separation technique is the ideal carrier of cleaner production; the technological progress of membrane technology improve just fast we the innovation ability aspect many engineerings as the innovation production technology, preserve the ecological environment and innovate new technology etc. with health of masses, for sustainable economic development; membrane technology is playing a part to become more and more important aspect resource recovery, environmental protection, production of energy and environmental monitoring and the quality control as unit operations, also is the key technology of fuel cell and biological separation application simultaneously.The economy of membrane process is estimated by permeation flux, unit permeation flux energy consumption and the film of film service life, and efficient is weighed by selectivity and osmotic resistance.Concentration polarization and film pollution can reduce the film permeation flux significantly, and shortened the service life of film, and economic benefit and efficient reduce, and are the application of restriction membrane process and the principal element of development.

The design of most of pressure-driven membrane process, as counter-infiltration, nanofiltration, ultrafiltration and micro-filtration, the membrane area maximization and the membrane module that are based on unit volume are easy to operate.Reduce at present many methods that concentration polarization and film pollute, comprise that the chemical modification on film surface and physical method are as flushing.Well-known hydraulic method is a kind of physical method, mainly be to rely on the eddy current or the inducing fluid unstability that produce in the turbulent flow to produce membrane process, this fluid instability can embed barrier and form in runner, also can be used for reducing the accumulation of solute-membrane interface solute by the non-stationary flow on film surface.At present, the dissimilar fluid instability that has adopted comprises the fluid instability that eddy current and rough textured film surface, fluid pulse and diaphragm face cause.In addition, except that rough surface, also can adopt the rotating filter disc system to produce the fluid instability.Successful method is the Taylor vortex that produces in the rotating ring form filter assemblies in the concentration polarization method for going of having adopted, and the major limitation of this design is to be difficult to amplify membrane area and high energy consumption.In straight line film runner, wavy barrier is set, also can produce eddy current (referring to Stairmand by periodic oppositely turbulent flow (8Hz), J.W.and Bellhouse, B.J., " Mass transfer in a pulsating turbulent flow with deposition into furrowedwalls. " Int.Heat Mass Transfer, 27,1405 (1985)).The pressure-driven fluid flows through and half-cylindrical helical duct is set on the flat sheet membrane also can produces eddy current (referring to PCT patent application WO 90/09229of Aug.23,1990 to Winzeler).All these methods all show the performance that can increase film when having eddy current, but every kind all exist the difficulty that can't overcome, and amplify and sealing problem as treating capacity.Adopt escapement extensively to be recommended and adopt at spiral wound form membrane module, can be concerning most of spiral wound form membrane modules, what adopt when hanging down axial Reynolds number is typical Poiseuille stream (referring to Toray Industries Inc.disclosed in their spiral flow filters brochure entitled Romembra Toray ReverseOsmosis Elements).

The effective utilization such as the eddy current of fluid instability, the synthetic film of concentration polarization and automatically cleaning is used and is extensively confirmed for numerous documents (referring to See Winzeler in reducing the pressure drive membrane system, H.B.and Belfort, G. (1993), Enhanced performance for pressure-driven membrane processes:Theargument for fluid instabilities, J.Membrane Sci., in 80,35-47).

American documentation literature (US6709598, US6399031) and other list of references have all proved a fact, and the Dien eddy current in the crooked pipeline can significantly improve the separating property of membrane module, and Weaving type doughnut film properties is better than the screw type hollow-fibre membrane.To the screw type hollow-fibre membrane, be wrapped on the hollow pipe (minimum diameter 3mm) with single or several fibers, though in screw type hollow-fibre membrane patent documentation, mention various canoes, do not consider that all the change in flow and the Dien number that cause owing to osmosis in the film pipe runner change system's seepage discharge performance and energy consumption influence than rapid.Because need to support hollow pipe on the structure, so the film filling area of unit volume is less, industrialization prospect is not good.For the Weaving type hollow-fibre membrane, not patent documentation record as yet at present, have only one piece of article to relate to abroad, and only propose import Dien number than numerical value moderate (Di 〉=5), outlet Dien number than must greater than 1 optimization operation conclusion, do not further consider in the film pipe runner yet since change in flow that osmosis causes and Dien number than sharply changing to system's seepage discharge performance and energy consumption influence.

Summary of the invention

One of purpose of the present invention is the deficiency according to existing curved channel type membrane separating method, a kind of new curved channel type membrane separating method is provided, this method is at existing curved channel type (comprising screw type and Weaving type) hollow fiber film assembly and has on the basis of spiral inner flow passage candle core pattern micro-filtration membrane module Dien whirlpool secondary stream reinforcement mass transfer, full runner Dien number is proposed than balanced control method, single film is in full runner much at one in the intensity Dien vortex operation environment, thereby improves the performance of membrane module greatly.

Two of purpose of the present invention is the membrane separation assemblies that provide a kind of new Dien whirlpool secondary stream to strengthen according to said method.

Three of purpose of the present invention provides the purposes of said method and device.

According to implementer's case that purpose of the present invention proposed be: at first find during secondary stream that the fluid motion that the Dien flow phenomenon is W.R.Dean in the research crooked pipeline produces.By the analysis to curved channel Dien eddy current, under normal operation, when fluid was crossed rectilinear duct to surpass critical flow velocity stream (laminar flow and turbulent transfer point), the pressure loss can experience unexpected increase process.Dr.Dean studies show that, the unstable and secondary stream of the mobile appearance in the crooked pipeline.Even but flow velocity is far above critical flow velocity in the crooked pipeline, the pressure loss can not increase suddenly yet.This phenomenon explanation, under same speed condition, the pressure loss in the crooked pipeline is than much lower in the rectilinear duct.This flowing in the crooked pipeline has the vortex pair feature.Current Dien number (De) in helix tube is defined as:

$\mathrm{De}=\mathrm{Re}\sqrt{\frac{d_i}{d_c}}---\left(1\right)$

Re is a Reynolds number (-); d _iBe interior diameter (m); d _cBe bung flange diameter (m).

In helix tube, the Dien that what is called has been optimized is counted De ' and is used to consider pitch (b) effect:

${\mathrm{De}}^{\′}=\mathrm{Re}\sqrt{\frac{d_i}{{d^{\′}}_c}}---\left(2\right)$

d _c' the effective bung flange diameter of expression, can learn that by mathematical reasoning this diameter changes along with the variation of pitch (b):

${d_c}^{\′}{=d}_c[1+{\left(\frac{b}{\mathrm{\π}{d}_c}\right)}^2]---\left(3\right)$

This shows that the Dien number in the crooked pipeline is all related with caliber and pitch, experimental result has also proved this point.Fig. 1 is Weaving type, screw type critical Reynolds number and pitch b graph of relation, as can be seen from the figure, and the growth that is directly proportional with pitch b of Weaving type, screw type critical Reynolds number; Fig. 2 is different center-pole diameter critical Reynolds numbers of screw type hollow fiber film assembly and pitch graph of relation, also as can be seen, also is the growth that is directly proportional at identical center-pole diameter lower critical Reynolds number with pitch from chart; Fig. 3 is an internal diameter---(di=0.3～2mm), this experimental diagrams has more clearly demonstrated internal diameter and the pitch variation influences critical Reynolds number to the critical Reynolds number influence in the pitch variation.Practical operation at membrane module is in service, and film pipe inducer infiltration capacity is less relatively, and the Dien number is than maximum in the pipe, and the reinforcement effect of mass transmitting of Dien eddy current is the most obvious; Increase with flow process, the penetrating fluid total amount increases, it is more and more littler to hold back liquid measure in the pipe, be thereby that flow velocity minimizing causing Dien number is than reducing, and solute or suspension concentration are multiplied, Dien vortex strength degree has but weakened when high solute concentration needs stronger reinforcement effect of mass transmitting, the subject matter of existing membrane separation process existence that Here it is.Know-why of the present invention is exactly: having curved channel type (comprising screw type and Weaving type) hollow fiber film assembly now or having on the basis of spiral inner flow passage candle core pattern micro-filtration membrane module Dien whirlpool secondary stream reinforcement mass transfer, by adopting the varying pitch method to change the critical Reynolds number of film pipe back segment, make the omnidistance Dien number of film pipe than not increasing and significantly reduce with flow process.Be that membrane module of the present invention is that film tube inlet section pitch ratio film pipe outlet pitch is big, the principle of design is that the pitch ratio of film tube inlet section and outlet section is 1.1-5, film tube inlet section critical Reynolds number is 1.5～2 times of the outlet of film pipe, to guarantee under the suitable operating condition of film pipe inlet outlet pressure differential, it is 5～7 that film pipe import Dien is counted ratio, and it is 2～3 that the outlet Dien is counted ratio.The present invention makes full use of the characteristic of the Dien rheologyization in the crooked pipeline, propose to adopt the varying pitch method to make to be filtered liquid to produce the Dien number than changing less strong Dien eddy current, so just given full play to omnidistance Dien whirlpool secondary stream reinforcement mass transfer, the centrifugation of membrane module from import to the outlet of membrane module.The membrane process that this method was suitable for comprises micro-filtration (MF), ultrafiltration (UF) and nanofiltration (NF).This method can be used to eliminate salt, big molecule and suspension concentration polarization and film pollution in high pressure counter-infiltration (RO), ultrafiltration (UF), micro-filtration (MF) or nanofiltration (NF) membrane process.The used film device of this method comprises that secondary stream in Dien whirlpool strengthens screw type, Weaving type hollow fiber film assembly and PP, PE tubular type and the wax core filter membrane component that declines.

Adopt the varying pitch mode can improve the method that Dien whirlpool secondary stream reinforced film is separated, this method makes separated liquid very littler than changing to exporting omnidistance Dien number from the import of membrane module, shown in Fig. 4 analyzes, thereby guarantee that Dien vortex strength degree is constant in the whole film length of tube pipe, improve the permeability and separation performance of membrane module greatly.Varying pitch Weaving type/screw type the hollow-fibre membrane that adopts optimal design to make proves that with equidistantly Weaving type/the screw type hollow-fibre membrane carries out the permeance property comparative experimental research Dien whirlpool secondary stream that obtains varying pitch Weaving type/screw type hollow-fibre membrane can strengthen Weaving type hollow-fibre membrane pure water permeability energy, the remarkable infiltration energy consumption that reduces; Concentration polarization and film when the Dien whirlpool secondary stream that produces in the Weaving type hollow-fibre membrane significantly reduces various contaminated liquid and filters pollutes, permeate recovery increases by 5～6 times, and energy consumption reduces by 40%, significantly reduces the rate of decay of membrane filtration processes.

Accompanying drawing and explanation

Fig. 1 is Weaving type/screw type critical Reynolds number and pitch b relation curve;

Fig. 2 is different center-pole diameter critical Reynolds numbers of screw type hollow fiber film assembly and pitch relation curve;

Fig. 3 is that internal diameter-pitch changes critical Reynolds number influence (di=0.3～2mm);

Fig. 4 is that the omnidistance Dien number of varying pitch film pipe is than control analysis schematic diagram;

Fig. 5 is a structural principle schematic diagram of the present invention;

Fig. 6 is the Dien volute eddy flow deferent filter membrane structural representation that declines;

Fig. 7 is a triangular section variable-pitch auger runner schematic diagram;

Fig. 8 is a Weaving type hollow fiber conduit thread connection tubular type membrane module structure schematic diagram;

Fig. 9 is a Weaving type hollow fiber conduit thread connection tubular type membrane module section structure schematic diagram.

Among the figure: 1, diffusion barrier; 2, helical flow path guider; 3, film shell; 4, helical flow path; 5, feed(raw material)inlet; 6, penetrating fluid outlet; 7, concentrate row mouth; 8, tubular membrane underseal cap; 9, the helical flow path annular feed pipe that enters the mouth; 10, tubular membrane closedtop cap; 11, top cover; 12, feed(raw material)inlet; 13, film shell; 14, diffusion barrier; 15, penetrating fluid outlet; 16, concentrated solution outlet; 17, film outer casing screw; 18, Weaving type hollow-fibre membrane; 19, division board; 20, feed(raw material)inlet; 21, penetrating fluid outlet; 22, concentrate row mouth; 23, film shell; 24, Weaving type boss ratio; 25, center-pole 3mm screw type boss ratio; 26, Weaving type critical Reynolds number; 27, center-pole 3mm screw type critical Reynolds number; 28, center-pole 3mm boss ratio; 29, center-pole 3.5mm boss ratio; 30, center-pole 3mm critical Reynolds number; 31, center-pole 3.5mm critical Reynolds number; 32, the uniform pitch Dien is counted ratio; 33, the varying pitch Dien is counted ratio; 34, uniform pitch critical Reynolds number; 35, varying pitch critical Reynolds number; 36, bore (di=0.3～2mm).

The specific embodiment

The invention will be further described below in conjunction with accompanying drawing, accompanying drawing 5 is a structural principle schematic diagram of the present invention, from accompanying drawing as can be seen, the present invention is a kind of membrane separation assemblies, comprise feed(raw material)inlet 12, film shell 13, diffusion barrier 14, penetrating fluid outlet 15, concentrated solution outlet more than 16 parts, wherein diffusion barrier 14 is curved channel type (comprising screw type and Weaving type) hollow fiber film assemblies or has spiral inner flow passage candle core pattern micro-filtration membrane module, diffusion barrier 14 is installed in the film shell 13, parting liquid 12 enters diffusion barrier 14 and separates from the feed(raw material)inlet, isolated penetrating fluid flows into the cavity of film shell 13, discharge through penetrating fluid outlet 15, the concentrate that parting liquid has separated is discharged through concentrated solution outlet 16 again.Its characteristics are that the pitch of diffusion barrier 14 membrane modules is varying pitch, the film tube inlet section pitch ratio film pipe outlet pitch that is membrane module is big, the principle of design is that the pitch ratio of film tube inlet section and outlet section is 1.1-5, film tube inlet section critical Reynolds number is 1.5～2 times of the outlet of film pipe, to guarantee under the suitable operating condition of film pipe inlet outlet pressure differential, it is 5～7 that film pipe import Dien is counted ratio, and it is 2～3 that the outlet Dien is counted ratio.The membrane module working method of this method is a cross-flow filtration, and the membrane process that is suitable for comprises micro-filtration (MF), ultrafiltration (UF), nanofiltration (NF) and counter-infiltration (RO).The used film device of this method comprises that secondary stream in Dien whirlpool strengthens screw type, Weaving type hollow fiber film assembly and PP, PE tubular type and the wax core filter membrane component that declines.Materials such as membrane module package, feed pipe adopt health grade stainless steel or opaque engineering plastics (transparent Guan Yi brings out biological pollution).Hollow-fibre membrane can be micro-filtration (MF), ultrafiltration (UF), nanofiltration (NF) and counter-infiltration (RO).Tubular membrane is generally micro-filtration (MF), the ultrafiltration (UF) of different bore size.

Embodiment one

Accompanying drawing 6 is the Dien volute eddy flow deferent filter membrane component structural representation that declines, as can be seen from the figure, the Dien volute eddy flow deferent filter membrane construction package that declines comprises diffusion barrier 1, film shell 3, feed(raw material)inlet 5, penetrating fluid outlet 6, concentrate row mouthfuls 7, a few part, wherein: the entrance point that membrane module feed(raw material)inlet 5 and concentrate row mouthfuls 7 is in tubular membrane component respectively and relative importer to the end of pipe, for parting liquid separates cavity, film shell 3 lower ends are provided with concentrate row mouth 7 in the film shell 3; Diffusion barrier 1 is a tubular membrane, place in the film shell 3, micro-filtration (MF) for different bore size, ultrafiltration (UF) structure of hollow shape filter membrane body, there is tubular membrane underseal cap 8 to seal below the diffusion barrier 1, there is tubular membrane closedtop cap 10 to cover above, tubular membrane closedtop cap 10 is middle perforate shape, middle perforate exports 6 with penetrating fluid on the tubular membrane closedtop cap 10 and communicates, on tubular membrane closedtop cap 10, be connected with top cover 11, be equipped with penetrating fluid outlet 6 on the top cover 11, between diffusion barrier 1 and film shell 3, also be provided with helical flow path 4, helical flow path 4 is made of helical flow path guider 2, the spirality circulation channel section configuration of helical flow path guider 2 is rectangles, and be the variable-pitch auger runner, the pitch ratio of entrance and outlet section is 2-4, the last spiral port and the helical flow path of the film shell 3 annular feed pipe 9 that enters the mouth communicates, the helical flow path annular feed pipe 9 that enters the mouth links to each other with feed(raw material)inlet 5 again, parting liquid 5 enters the helical flow path annular feed pipe 9 that enters the mouth from the feed(raw material)inlet, flow into film shell 3 lower ends by helical flow path 4 again, through concentrate row mouthful 7 discharges.This device can be used to eliminate salt, big molecule and suspension concentration polarization and film pollution in high pressure counter-infiltration (RO), ultrafiltration (UF), micro-filtration (MF) or nanofiltration (NF) membrane process.

Embodiment two

Accompanying drawing 6 is Dien volute eddy flow deferent another example structure schematic diagram of filter membrane component that declines, these embodiment other parts are all the same with embodiment, different places be, the spirality circulation channel section configuration of helical flow path guider 2 is triangles, and be the variable-pitch auger runner, the pitch ratio of entrance and outlet section is 8-15.Can know by inference according to embodiment one and two, the spirality circulation channel section configuration of helical flow path guider 2 can also be a square or semicircular.

Embodiment three

Accompanying drawing 7-9 is a kind of Weaving type hollow fiber conduit thread connection tubular type membrane module structure schematic diagram, as can be seen from the figure, the Weaving type hollow fiber film assembly comprises Weaving type hollow-fibre membrane 18, film outer casing screw 17, division board 19, feed(raw material)inlet 20, penetrating fluid outlet 21, concentrate row mouth 22 and film shell more than 23 parts.Wherein: parting liquid 20 enters from the feed(raw material)inlet, after Weaving type hollow-fibre membrane 18 separates, penetrating fluid is discharged in the shell 23, discharge by penetrating fluid outlet 21 again, concentrate after the separation is by outside concentrate row mouthful 22 discharge pipes, be characterized in that the braiding pitch of Weaving type hollow-fibre membrane 18 is the variable-pitch auger runner, the pitch ratio of entrance and outlet section is 3-4.

Claims (9)

1, a kind of method of varying pitch membrane separating property, it is characterized in that: this method is at existing curved channel type hollow fiber film assembly and has on the basis of spiral inner flow passage candle core pattern micro-filtration membrane module Dien whirlpool secondary stream reinforcement mass transfer, utilize the characteristic of the Dien rheologyization in the crooked pipeline, change the critical Reynolds number of film pipe back segment by the varying pitch method, make the omnidistance Dien number of film pipe and be filtered liquid to produce the Dien number from import to the outlet of membrane module more less than changing than not increasing and significantly reduce, making with flow process.

2, the method for a kind of varying pitch membrane separating property according to claim 1 is characterized in that: the membrane module working method of this method is a cross-flow filtration, and the membrane process that is suitable for comprises micro-filtration, ultrafiltration and nanofiltration.

3, the device of varying pitch membrane separating property method according to claim 1, comprise feed(raw material)inlet (12), film shell (13), diffusion barrier (14), penetrating fluid outlet (15), several parts of concentrated solution outlet (16), diffusion barrier (14) is curved channel type hollow fiber film assembly or has spiral inner flow passage candle core pattern micro-filtration membrane module diffusion barrier (14), diffusion barrier (14) is installed in the film shell (13), (12) enter diffusion barrier (14) and separate parting liquid from the feed(raw material)inlet, isolated penetrating fluid flows into the cavity of film shell (13), discharge through penetrating fluid outlet (15) again, the concentrate that parting liquid has separated is discharged through concentrated solution outlet (16), it is characterized in that: the pitch of diffusion barrier (14) membrane module is varying pitch, the film tube inlet section pitch ratio film pipe outlet pitch of membrane module is big, the pitch ratio of film tube inlet section and outlet section is 1.1-5, film tube inlet section critical Reynolds number is 1.5～2 times of the outlet of film pipe, to guarantee under the suitable operating condition of film pipe inlet outlet pressure differential, it is 5～7 that film pipe import Dien is counted ratio, and it is 2～3 that the outlet Dien is counted ratio.

4, the device of varying pitch membrane separating property method according to claim 3, it is characterized in that: the entrance point that membrane module feed(raw material)inlet (5) and concentrate row mouthful (7) is in tubular membrane component respectively and relative importer to the end of pipe, for parting liquid separates cavity, film shell (3) lower end is provided with concentrate row mouthful (7) in the film shell (3); Diffusion barrier (1) is a tubular membrane, place in the putamina (3), micro-filtration (MF) for different bore size, ultrafiltration (UF) structure of hollow shape filter membrane body, there is tubular membrane underseal cap (8) to seal below the diffusion barrier (1), there is tubular membrane closedtop cap (10) to cover above, tubular membrane closedtop cap (10) is middle perforate shape, middle perforate exports (6) with penetrating fluid on the tubular membrane closedtop cap (10) and communicates, on tubular membrane closedtop cap (10), be connected with top cover (11), be equipped with penetrating fluid outlet (6) on the top cover (11), between tubular membrane (1) and putamina (3), also be provided with helical flow path (4), helical flow path (4) is made of helical flow path guider (2), and be the variable-pitch auger runner, the pitch ratio of entrance and outlet section is 2-3, the last spiral port and the helical flow path of putamina (3) the annular feed pipe (9) that enters the mouth communicates, the helical flow path annular feed pipe (9) that enters the mouth links to each other with feed(raw material)inlet (5) again, (5) enter the helical flow path annular feed pipe (9) that enters the mouth to parting liquid from the feed(raw material)inlet, (40 flow into putamina (3) lower end, discharge through concentrate row mouthful (7) by helical flow path again.

5, the device of varying pitch membrane separating property method according to claim 2 is characterized in that: described membrane module comprises that secondary stream in Dien whirlpool strengthens screw type, Weaving type hollow fiber film assembly and PP, PE tubular type and the wax core filter membrane component that declines.

6, the device of varying pitch membrane separating property method according to claim 2 is characterized in that: materials such as described membrane module package, feed pipe are health grade stainless steel or opaque engineering plastics.

7, the device of varying pitch membrane separating property method according to claim 2 is characterized in that: the spirality circulation channel section configuration of described helical flow path guider (2) is a rectangle.

8, the device of varying pitch membrane separating property method according to claim 2 is characterized in that: the spirality circulation channel section configuration of described helical flow path guider (2) is that triangle is square or semicircular.

9, according to the purposes of claim 1 or 3 described varying pitch membrane separating property methods and device, it is characterized in that: this method can be used to eliminate salt, big molecule and suspension concentration polarization and film pollution in high pressure counter-infiltration, ultrafiltration, micro-filtration or NF membrane process.

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