RU2398619C2 - Membrane ultra-micro-filtration roll element - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to membrane ultra-micro-filtration elements (MFRE) intended for cleaning process and natural fluids of suspended particles, colloids and bacteria. MFRE consists of filtrate outlet perforated tube with membrane packs wound above separating turbulator net and comprising drain multilayer element wound by semi-permeable membrane and reflecting membrane. Additionally, MFRE is wrapped in outer turbulator net. Separating turbulator net consists of three superimposed net materials, two identical outer adjacent membrane packs adjoining work surfaces and one inerr net material arranged between the latter.

EFFECT: perfected MFRE structure.

2 tbl, 2 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to the design of an ultra-microfiltration membrane web element that works on the principle of “dead-end filtration” and is intended for the purification of technical and natural liquids from suspended solids, colloids and bacteria, in particular for the purification of saline-containing natural waters before they desalination using reverse osmosis, to obtain drinking water from contaminated technical sources, for the purification of used oils during their disposal, for the treatment and concentration of liquid media e in biotechnology and pharmaceuticals.

The semipermeable membranes used in the membrane ultra-microfiltration roll element (MFRE), on which the process of purification (separation) of the filtered liquid from particles suspended in it is carried out, have through holes with an average diameter of about 0.005 μm to 5.0 μm. Thanks to these openings, all particles that are in the filtered fluid in the form of emulsions, dispersions, colloids and solutions and having a size (average diameter) larger than the above are filtered out and precipitated as a precipitate or as a concentrate. Based on this, two principles of membrane ultra-microfiltration of liquid media are distinguished: the principle of "flow" and the principle of "dead-end" filtration. "Dead end membrane filtration" provides for separation of the filtered fluid in two elements into a precipitate and a filtrate. "Flow membrane filtration" divides the filtered fluid into two liquid streams - a concentrate stream and a filtrate stream.

The "dead end" principle of membrane filtration in a roll element was first implemented in our inventions according to the patent of the Russian Federation No. 2262978 dated 02.12.2003 and on the application for a patent of the Russian Federation No. 2004138505/15 dated 29.12.2004.

At the same time, the practical implementation of the “dead end” principle of filtration in a rolled membrane element met its difficulties, overcoming of which would increase the practical competitiveness of MFRE in the membrane technology market.

BACKGROUND

The "dead end" principle of membrane filtration of liquids, to which the claimed MFRE belongs, is presented today in the literature and on the market by two basic designs of membrane devices (elements):

- cartridge membrane ultra-microfiltration elements and

- previously declared by us roll-type membrane ultra-microfiltration elements (RF patent No. 226978 and application for a RF patent for invention No. 2004138505).

The disadvantages of the cartridge ultra-microfiltration element of the designs known to us in comparison with the roll elements of the MPRE type are the relatively low specific productivity (based on the total geometric volume), the inability to restore performance and a relatively short service life (no more than 1 year).

The design of the MFRE declared earlier by us (according to the above-mentioned security documents) is the closest modern technical solution. At the same time, as long-term pilot studies have shown, these well-known designs are not optimal on the part of the technology for restoring their performance, they require a soft washing regimen, can withstand no more than 50-100 washes and have insufficient reproducibility after a series of washes.

SUMMARY OF THE INVENTION

The objective of the invention is the creation of the design MFRE, which, improving the previously declared roll element according to the specified documents of the Russian Federation, would not have technical limitations for the use of high-speed mode and multiple recovery, made it possible to use a two-stage washing mode at high flow rates (feeds) of the washing medium (1 , 5-2.5 m ³ / h · m ² or more) and a short processing time (no more than 2-10 seconds).

At the same time, the advanced design of MFRE should not lose the high performance on the roll element achieved earlier.

According to the invention, the problem is solved in that in the known design MFRE, which consists of:

a) from a perforated permeate tube, with membrane packets spiral-wound through a separating turbulizer grid and containing multilayer drainage wrapped in a semi-permeable membrane, the cell sizes of the drainage layers increasing in the direction from the membrane to the inner drainage layer, and

b) which (the roll element) contains a reflective cuff located on the opposite end of the roll element relative to the supply of the filtered fluid, and

c) which (the roll element) has a free exit of the separating turbulent grid and is wrapped by an external turbulent grid and

- the separating turbulent mesh is made of three mesh materials superimposed on each other, two identical outer adjacent to the working surfaces of adjacent membrane packets having mesh sizes from 0.1 × 0.1 mm to 2.0 × 2.0 mm, and one an inner mesh material located between said outer mesh materials and having mesh sizes between 0.3 × 3.0 mm and 6.0 × 6.0 mm.

For the industrial implementation of the invention, according to the invention, at present, it is proposed to use three superimposed mesh materials as a multilayer separating turbulator mesh, two of which have the same cell size and act as outer layers adjacent to the working surfaces of adjacent membrane bags and having mesh sizes from 0.1 × 0.1 mm to 2.0 × 2.0 mm, and one of which (mesh material) acts as an inner layer located between the outer mesh materials and having o cell sizes from 3.0 × 3.0 mm to 6.0 × 6.0 mm.

Practically all available on the market, or self-made, perforated tubes with an outer diameter of 20 to 100 mm, a wall thickness of 3 to 10 mm and a diameter of holes (perforations) of 2 to 8 mm can be used as a filtrate discharge tube in the claimed design of MFRE. placed on this tube evenly over the entire surface in increments of 5 mm to 30 mm. Perforated tubes are made of rigid structural materials, including polymers - polyvinyl chloride, polyethylene, polypropylene, amino plastic, ABC polycarbonate and their copolymers, including filled plastics, as well as inorganic materials such as ceramics and metals.

The main requirements for a filtrate discharge tube are sufficient strength and resistance to substances in the filtered fluid, as well as its own chemical resistance and environmental safety (no emission of harmful substances). All these requirements are known to specialists and the present invention does not make any changes or additions to them.

The ultra- and microfiltration semipermeable membranes used in the present invention, from which the membrane bags are made, are also well known to those skilled in the art and can be made and used from all suitable polymers such as polyamides, polysulfones, esters, regenerated cellulose, polyarylates, fluoroplastics. The limitation here, as is known, is the mechanical strength of the membranes, which should ensure the manufacture of membrane bags, i.e. have the ability to undergo a bend of 180 ° C without any deformation and destruction, as well as withstand the excess pressure that accompanies the processes of filtration and recovery.

As the drainage in the claimed MFRE, a multilayer structure is used, which we found in accordance with the invention on the application for RF patent No. 2004138505 of December 29, 2004. The drainage is made of mesh material having at least three layers - two identical outer and one inner, dimensions cells of which grow in the direction from the membrane (from the outer layer) to the center of the drainage (to the inner layer).

Moreover, the preferred use of the specified multilayer drainage in the claimed design MFRE is a drainage made of a drainage fabric based on warp knitted polyethylene-terephthalate material impregnated with a cured epoxy resin. This is for the outer layer of drainage. For the inner layer of drainage and for the outer turbulence grid, a meshless mesh material with an appropriate mesh size is the preferred option (see Table 1).

Reflective cuff, which is used in the claimed design MFRE, also already disclosed by us earlier in the above application for invention No. 2004138505.

The cuff is made of a chemically resistant elastomeric material such as rubbers, thermoplastic polyurethane, flexible polyvinyl chloride and various copolymers. The cuff must withstand, without deforming, and at the same time not pass the filtered fluid and the flushing system when the working pressure reaches up to 4.0 kg / cm and up to 2.0 kg / cm, respectively.

The separating turbulent mesh, as described above and in claim 1 of the claims, can be made of three mesh knot-free materials, superimposing them on top of each other directly in the manufacture of a roll element. However, the separating turbulent mesh can be prepared in advance as a single mesh material, for example, laying on top of each other and then welding (heat or other welding) mesh-sized mesh materials corresponding to the cell size. In this case, it is preferable to use polymeric materials as initial mesh materials, in which the lower and upper superimposed elements (cords, threads, jumpers) are fastened together by welding at an angle from 60 to 90 with the formation of cells from 0.1 to 6 in size , 0 mm. An external single-layer turbulent mesh is also manufactured as meshless mesh material.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the basic design of the inventive MFRE (in longitudinal section), placed in the housing of the membrane module in which the MFRE is operated, where

d is the diameter of the filtrate outlet pipe,

D _m - the outer diameter of the cuff,

D is the outer diameter of the roll element.

On figa shows on an enlarged scale 3-layer drainage, which is used according to the invention in the optimal embodiment MFRE; the location of the outer layer, its grooves and the location of the inner layer are given.

Figure 2 shows the claimed basic design of a separating turbulent mesh (RTS) made of 3 mesh meshless materials superimposed on one another, two identical outer (19), with which the RTS is adjacent to the working surfaces of adjacent membrane bags, and one inner mesh material (20) located between the outer materials.

1 - a perforated perforated tube that has through holes (11) in its wall in the area of their contact with the drainage (5) of the membrane bags (2), and also has a plug for one-sided on one of its ends (Fig. 1 on the left) the output of the filtrate (Fig.1 output of the filtrate to the right).

2 - membrane bags, with the help of which this fluid is filtered and which consist of multilayer drainage (5) wrapped (packed) with a semipermeable membrane (4) during the production of MFRE.

3 - a separating turbulatory grid that separates the membrane packets (2) and serves as a channel for supplying the filtered medium to the outer surfaces of the membrane packets (2), and in the process of restoring the performance of MFRE, it serves as a channel for supplying a water-air mixture to the surfaces to be cleaned (2) ) and the conclusion of the cleaning wash filtrate.

4 - semipermeable ultrafiltration or microfiltration membrane.

5 - drainage, which is located inside the membrane bags (2) and which is connected to the filtrate outlet pipe (1), with its through holes (11).

6 - external turbulizer mesh MFRE, which wrapped the roll element and which is spatially connected to the turbulizer grid (3), separating the membrane packets (2).

7 is a reflective cuff that closes the free passage of the filtered fluid and the wash filtrate passing through the external free channel (12), which is located above the external turbulence grid, to the drain line (10) of the wash filtrate and the water-air wash mixture, and which is completely reflective for water-air mixture.

8 - the cover of the membrane module housing (13), in which the MFRE is operated and processed (to restore operability). This cover is connected to a flush line.

9 - shut-off valve on the branch line (10). Closed during the filtering period. Opened during the flushing of MFRE.

10 - line for removal of the washing filtrate and air-water mixture

11 - through holes in the filtrate outlet perforated tube, used to drain the filtrate and supply the washing filtrate.

12 - free zone (annular gap) for the passage of the filtered liquid and the flushing air-air mixture to the surface of the external turbulator (6) and then radially along the separating turbulators that separate the membrane packets to the surfaces of the semipermeable membrane.

13 - the membrane module housing in which the MFRE is operated and flushed.

14 - inner (outlet - for filtrate and inlet - for washing filtrate) layer of multilayer drainage, consisting of at least two external drainage layers (made in the best case of a drainage web (5), having grooves with walls (15) and transverse fastening ties (16), and the inner layer (optimally made in the form of a conventional external turbulent grid).

15 - walls of the grooves of the drainage web.

16 - transverse fastening ties of the drainage web.

17 - monofilament, of which the inner layer of drainage consists in the optimal embodiment.

18 - strips of the membrane web (4), which at the first stage of gluing the membrane package are impregnated with glue.

19 - the outer layer of the separating turbulent mesh (figure 2, pos. "B").

20 - the inner layer of the separating turbulatory grid (figure 2, pos. "C").

DETAILED DESCRIPTION OF THE INVENTION

In addition to the above regarding the industrial implementation of the invention, we note that the applicant has manufactured and tested 25 prototypes of the claimed design MFRE, the performance of which in comparison with the improved design MFRE (by application No. 2004138505) are shown in tables 1 and 2.

Testing of the samples was carried out on city (Vladimir) tap water, which served as a filtered liquid.

Productivity (initial, contaminated and regenerated MFRE) was measured by the amount of filtrate (purified water) discharged per unit time (liter / hour) by the filtrate discharge tube with the valve 9 closed (Fig. 1). Tap water was supplied from the pressure end side of the MFRE (in Fig. 1, the water supply for filtration is indicated by an arrow). In this case, a standard case was used having an inner diameter (D _m ) of 65 mm (examples 1-4) and 100 mm (examples 5-8). Examples 2-8 relate to MFRE, which used the inventive multilayer separating turbulator. In all examples, multilayer drainage was used. Example 1 - control, with a single-layer separating turbulator.

The recovery (regeneration) of the contaminated MPE (the pollution level of which is given in Section 1.6 of Table 2 - see the drop in productivity compared to the initial one) was carried out in two stages at a relatively high level, as was achieved thanks to the invention of a multilayer separating turbulator (separating turbulent grid), feeding the filtrate from 0.8 to 2.5 m ³ / h · m ² , and a water-air mixture (from 1.0 to 3.0 m ³ / h) and the feeding time from 2 to 10 seconds, respectively.

At the first washing stage the washing liquid (purified tap water) supplied through filtratotvodyaschuyu tube countercurrently to the direction of filtration, the filtrate through an output line by controlling the flow (m ³ / h · m ²⁾ and the washing time (sec). The end of the first washing stage was set at a predetermined time for the supply of washing liquid.

At the second stage of washing, a water-air mixture was used, which was supplied directly through the supply line of the filtered liquid, controlling and setting the flow of the mixture (m ³ / h) and the flow time (sec). The end of the second washing stage was set at a predetermined time of supply of the water-air mixture.

After the completion of the 2-stage process of restoring the performance of the MFRE, the restored productivity was measured (Section 3, Table 2) and the maximum possible number of restoration of the performance of the MFRE was recorded (Section 4, Table 2).

As can be seen from the experimental data, the claimed design MFRE retained the advantages of the previous design and at the same time acquired a new significant quality - the ability to use the intensive washing mode and increase the service life (the possible number of rinses).

Table 1 Examples of the proposed method for the manufacture of membrane ultrafiltration and microfiltration roll element №№ The name of the stages and techniques of the method of manufacturing MFRE The data in examples 1-8 one 2 3 four 5 6 7 8 one. Production of multilayer separating turbulatory nets, drainage and membrane bags 1.1 Material of two outer layers, drainage, mm / unit / mm 0.16 0.32 0.25 0.20 0.16 0.20 0.16 0.32 24 12 twenty 16 twenty 16 24 12 0.16 0.32 0.20 0.25 0.16 0.16 0.20 0.32 1.2 Material of the inner layer of drainage, angle of scraps / cell size / angle of installation, mm 0 ° 90 ° 90 ° 90 ° 60 ° 75 ° 75 ° 90 ° 3 four 3 2 3 3,5 3 2 45 ° 45 ° 45 ° 45 ° 45 ° 45 ° 45 ° 30 ° 1.3 Membrane Bag Material 430 × 300 400 × 400 400 × 400 400 × 300 450 × 400 450 × 400 450 × 400 450 × 300 - ultrafilter, size, mm × mm - microfilter, size, mm × mm 1.4 The material of the outer layers separating the turbulent mesh, mesh size mm × mm - 0.1 × 0.1 1.0 × 1.0 1.0 × 1.0 1.5 × 1.5 1.0 × 1.0 2.0 × 2.0 1.5 × 1.5 1.5 Material of the inner layer separating the turbulent mesh, mesh size mm × mm - 3.0 × 3.0 4.0 × 4.0 4.0 × 4.0 4.0 × 4.0 4.0 × 4.0 4.0 × 4.0 5.5 × 5.5 1.6 Bonding membrane bags - impregnation, glue / concentr.,% ^** PU / 30 E / 30 PU / 40 E / 40 E / 50 PU / 50 PU / 60 PU / 60 2. Filtration pipe, material / d PVC *** / 20 pvc / 20 pvc / 20 pvc / 20 pvc / 20 pvc / 20 pvc / 20 pvc / 20 3. Winding membrane bags, amount 3 3 3 3 four four four four - bonding, glue / temperature, ° С PU / 20 E / 20 PU / 20 E / 20 E / 20 PU / 20 PU / 25 PU / 25 four. Wrapping with a turbulence mesh, SKR angle / cell size / mouth angle. 90/4/45 90/4/45 90/4/45 90/3/45 90/4/45 90/4/45 90/4/45 60/4/30 5. Reflective sleeve installation, D _m / D 65 / 58.5 65 / 58.5 65 / 58.5 65 / 58.5 95 / 88.5 95 / 88.5 95 / 88.5 95 / 88.5 * groove size / number of grooves / mesh cell size; ** PU - polyurethane adhesive, E - epoxy adhesive; *** PVC - hard polyvinyl chloride.

table 2 Examples of the implementation of the proposed method for restoring the health of the prototypes of the membrane ultra-microfiltration roll element (MFRE). №№ Name indicators MFRE and modes of implementation of the method of recovery The data in examples 1-8 one 2 3 four 5 6 7 8 one. The parameters of the tested samples MFRE 1.1 outer diameter, D, mm 60 60 60 60 90 90 90 90 1.2 length mm 300 400 400 300 400 400 400 300 1.3 filtration surface area, m ² 0.5 0.5 0.5 0.4 1,0 1,0 1,0 0.8 1.4 type of used semiconductors. membranes - cellulose acetate ultrafilter + - - - + - - - - phenylone based ultrafilter - + - - - + - - - cellulose acetate microfilter - - + - - - + - - microfilter based on hydrophilized. fluoroplastic - - - + - - - + 1.5 initial performance MFRE purified water, l / h 40 40 90 85 80 90 200 200 1.6 the performance of MFRE (according to the system of clause 1.5) before twenty thirty 60 60 fifty 60 130 130 washing (contaminated MFRE), l / h 2. Recovery of performance of MFRE 2.1 The first stage of flushing. The filtrate obtained from the system of Claim 1.5 was used. the flow rate of the filtrate for washing, m ³ / h · m ² 0.5 0.8 1,2 1,2 2.0 2.0 2.5 2.0 - time of washing with filtrate, s 5 5 2 2 10 10 5 5 2.2 The second stage of flushing. The composition of the water-air mixture: - water, volumetric part one one one one one one one one - air, volumetric part 10 10 twenty twenty 10 10 twenty twenty Air-water supply mode: - flow rate of the mixture, m ³ / h 1,0 1,2 1,2 1,2 3.0 3.0 3.0 3.0 - the time of washing with a water-air mixture, s 2 2 3 3 2 2 3 3 3. MFRE performance (according to the system of clause 1.5) after recovery performance, l / h 35 40 85 70 80 90 180 170 four. The maximum number of recoveries, units one hundred 500 400 450 500 700 500 400

Claims (1)

Membrane ultra-microfiltration roll element, consisting of a perforated permeate tube with membrane bags spiral-wound through a separating turbulator mesh and containing multilayer drainage wrapped in a semi-permeable membrane, and the cell sizes of the drainage layers increase in the direction from the membrane to the inner reflection layer of the drainage located on the opposite to the filing of the filtered fluid end of the roll element, and the roll element taken by an external turbulizer mesh, characterized in that the separating turbulizer mesh is made of three superimposed mesh materials, two identical outer ones adjacent to the working surfaces of adjacent membrane bags and having mesh sizes from 0.1 × 0.1 to 2.0 × 2.0 mm, and one internal mesh material located between these external mesh materials and having mesh sizes of 3.0 × 3.0 and 6.0 × 6.0 mm.

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