RU2349372C2 - Membrane filter element (versions), unit for micro- and ultrafiltration of liquid mixtures and liquids by reverse osmosis method (bulyzhev's filter), method of unit production - Google Patents

Abstract

FIELD: water supply.

SUBSTANCE: invention can be used for water demineralisation and effluents treatment in water treatment systems. A membrane filter element is a multilayer plane comprising a drainage frame plate combined with an ultrafiltration membrane. The plane outer surfaces are fitted with a sealed relief including a rand along the outline perimeter and a rand at the through holes designed for the supply of the water being treated and for withdrawal of the treated liquid which are placed close to the outline rand and equally-spaced from each other. The ultrafiltration unit comprises a set of membrane filter elements that are mounted closely and with mirror symmetry in respect of the pressure surface. Channels in the set are formed by matching the through holes and divided by their sealing rands. Frame sealed plates are mounted at the unit end faces. The unit is located in a sealed housing. The unit production method implies matching the calculated number of filtering sections formed by matching membrane filter elements with mirror symmetry in respect of the pressure surface, packing the set by face end plates and filling the unit with a sealing material.

EFFECT: invention allows for increasing ultrafiltration efficiency without treatment quality loss, reducing energy demand and providing for the filter operation under gravity or respectively low pressure conditions.

17 cl, 15 dwg

Description

The invention is intended for micro- and ultrafiltration, as well as for the purification of liquids by the reverse osmosis method and can be used for demineralization of water, wastewater treatment in water treatment systems in the biomedical, chemical-pharmaceutical and food industries.

Known membrane module according to the patent of the Russian Federation 2050956, publ. 12/27/1995, which contains a package of tubular membrane elements in the form of porous tubes with a membrane deposited on the outer surface, fixed in tube sheets and enclosed in a housing equipped with nozzles for supplying the fluid to be cleaned, concentrate outlet and permeate outlet nozzles made on the covers. Spherical protrusions are made on the walls of the housing, the first of which is located on the side opposite to the nozzle for supplying the liquid to be cleaned. The protrusions can be made in the form of segments fixed on the inner surface of the housing. Porous tubes have flattened sections deployed relative to each other. Membrane elements are fixed in the tube sheet with union nuts with a tapered thread or threaded conical bushings.

The known membrane module is technologically sophisticated, has a large mass and dimensions, low ultrafiltration performance, operates at high pressures.

Known membrane apparatus according to the patent of the Russian Federation 2038139, publ. 06/27/1995. The membrane apparatus contains upper and lower manifold plates with fittings and holes for introducing the initial mixture and withdrawing the concentrate and permeate. The upper plate is equipped with a turbulizing device located on the inner surface in the form of protrusions placed perpendicular to the flow of the initial mixture. The bottom plate is made with channels on the inner surface connected to the channels of the membrane elements. Each membrane element in the bag has a frame plate with holes with a turbulizing device placed on one surface and a channel-shaped drainage device on the other and a semi-permeable membrane located on the drainage device. Plates and frame plates are made with grooves for contour sealing gaskets around the holes and equipped with washers located under the gaskets.

The disadvantages of the apparatus include a small total working section and the associated low productivity per unit volume, structural complexity, and metal consumption.

The closest in purpose and technical essence is the membrane apparatus according to the patent of the Russian Federation 2083269, publ. 07/10/1997. The membrane apparatus is designed for micro, ultrafiltration and concentration of liquid media and contains semipermeable membranes and drainage plates with slots assembled in a bag. These channels are connected with through holes in which sealing rings are installed with holes on the side surface for fluid flow. Drainage plates are made of metal, the yield strength of which is less than the yield strength of the membrane material. Rings for fluid flow are made of a material whose yield strength is greater than the yield strength of the material of the drainage plate, and the ends of the rings are covered with a layer of material from which the drainage plate is made. This design ensures the tightness of the seal of thin film membranes, for example, track.

As follows from the description of the apparatus according to patent 2083269, during its manufacture, the package is sealed, for which the package is compressed between the base plates 3 and 4 with a force leading to elastic deformation of the material of the drain plates and the material covering the washers. The control of the required compression force is determined empirically by the absence of fluid leaks outside the apparatus and by the tightness test of the seal. The tightness of the seal is determined by the test "bubble". The material of the ring 17 is selected in the fluid flow channel. The material must have a high yield strength so that its side hole does not deform during compaction. High pressure polyethylene with a yield strength of 12–16 MPa is used as the material of the drainage plates. The rings are made of polypropylene, coated from two ends with layers of high-pressure polyethylene.

The disadvantages of the apparatus are as follows: the surface of the filtration is small in relation to the size of the drainage plate and, as a result, the productivity of the apparatus is small; Technologically imperfect is the reception of membrane compaction in the ring region by compression to metal deformation.

The technical task of the invention is to increase the total working section per unit of the working volume of the apparatus and productivity without compromising the quality of cleaning; reduce the cost of the ultrafilter by creating a more technological module, reduce energy consumption due to the refusal to create high pressures and ensure pressure-free operation of the ultrafilter or at a relatively low pressure in the range of 2-4 kg / sq. cm.

The tasks are solved by the claimed invention.

Membrane filter element (option 1) characterized in that it is a multilayer board including a drainage frame plate (hereinafter referred to as a frame plate); combined with an ultrafiltration membrane, an arbitrary uniform relief is made on the outer surfaces of the board to ensure membrane hardening, including contouring, edging of the through hole for supplying the liquid to be cleaned from the frame plate side; and the edging of at least two through holes for draining the purified liquid (concentrate) from the side of the membrane; through holes of the board are located near the contour border and are equidistant from each other; while these edging is made airtight.

Membrane filter element (option 2) characterized in that it is a multilayer board, including at least two drainage frame plates; a membrane for ultrafiltration is placed between the plates, an arbitrary relief is made on the outer sides of the plates, including edging along the contour of the plates, on one side is the edging of at least two through holes for draining the cleaned liquid (concentrate), and on the other side is the edging of the through hole for supplying fluid to be cleaned; through holes are located near the contour border and are equidistant from each other; while these edging is made airtight.

The membrane filter element according to the 1st and 2nd options is characterized in that the ultrafiltration membranes are made of a thin polymer film, for example, lavsan or others. Depending on the chosen technology, the filter element can be manufactured using an ultrafiltration membrane from the range of purchased products, and can also be applied to the drainage frame plate by spraying.

The membrane filter element according to both options is characterized in that the frame plate is made of porous materials: textolite, or porous polymeric materials, or in the form of a porous metal plate obtained by powder metallurgy.

The relief, including the edging, is made of a sealing material that is applied to the surface of the membrane and plate by screen printing or by spraying using materials, for example, capron or others, and the same with fillers, for example, dispersed metal, etc.

The module is declared as a combination of membrane filter elements.

Module for micro- and ultrafiltration and separation and purification of liquid mixtures and liquids by the reverse osmosis method (hereinafter referred to as the ultrafiltration module) in the form of a package containing a combination of membranes and drainage frame plates, through holes and channels, means for separating the supply and discharge channels at the place of execution holes, sealing the package end plates, means of hermetically sealing the package, characterized in that the package consists of an arbitrary number of membrane filter elements according to any claimed variant, ION tightly with mirror symmetry with respect to the pressing surface, wherein the channels in the package are formed by combining the through holes and separated by sealing edgings respective openings, and the ends sealed module mounted frame plate overlapping the holes with an airtight edging and having at least one through hole; means are provided for sealing the module in the form of studs on the end plates, and it is also envisaged to place the module in the housing of sealed material to avoid leaks, for example, of polyurethane.

A method for manufacturing a module for micro- and ultrafiltration and separation and purification of liquid mixtures and liquids by the reverse osmosis method is claimed, wherein the bag is sealed, characterized in that the outer surfaces of the membrane filter element are in the form of a multilayer plate including one or more drainage frame plates combined with a membrane for ultrafiltration, an arbitrary relief of the sealing material is applied by spraying or screen printing, including edging along the contour of both surfaces her, the edging, at least on one side of the board of two through holes of the membrane, combined with the channel for removal of the purified liquid (concentrate) and the edging on the other side of the board of the through hole of the frame plate, compatible with the channel for supplying the cleaned liquid; make unified separate filter sections of unit productivity by combining membrane filter elements according to any claimed embodiment with mirror symmetry with respect to the pressing surface; make a module in the form of a package of filter sections by combining the required estimated number of sections; they seal the bag with end plates by means of, for example, studs, and place the bag in the housing by filling the surface of the module, mainly the peripheral faces of the filter elements, with hermetic material.

Figure 1-5 shows the structure of the membrane filter element according to the first embodiment. In Fig.6, 7 shows a package of membranes in the first embodiment. On Fig-13 shows respectively the membrane filter element and the membrane package according to the second embodiment. On Fig, 15 shows the end plates of the module.

The membrane filter element according to option 1 in FIGS. 1-5 is a multilayer board and includes a drainage frame plate 1 of porous polyurethane with a relief 2 in the form of strokes without forming closed zones, applied, for example, by spraying or screen printing. The relief 3 and 4 is also made along the contour of the plate and around the through hole 5, which in the modular package serves to supply the cleaned liquid. On one side, the plate 1 is aligned with a membrane 6 for ultrafiltration of a polymer material, for example, lavsan [for the choice of membranes or material for the manufacture of membranes, see http://www.vladipor.ru. The site presents the products of CJSC STC Vladipor and its partners NPP Tekhnofiltr. STC develops and produces polymer membranes of micro-, ultra- and nanofiltration, reverse osmosis, gas-separation, pervaporation. Polymer microfiltration elements based on: polyamide; polysulfone; cellulose acetate; lavsan, etc. Scopes of membranes: microbiological, physicochemical studies; purification, filtration, purity analysis; water softening; concentration and purification of saline solutions, biological products; obtaining pyrogen-free water; water disinfection; complete set of household membrane determinants]. An arbitrary relief 7 of polyurethane, relief 8 along the contour of the membrane and relief 9 around the holes 10, which in the modular package serve to drain the filtered liquid (concentrate), are also applied to the membrane. In the manufacturing process of the circuit board, the membrane can also be applied by spraying a polymer material onto a plate with a relief made on it (Figs. 4-7), which does not change the essence of cleaning and preserves the design characteristic, which consists in combining the membrane and the plate along the entire active surface of cleaning. Spraying along the contour and around the holes (or screen printing of the relief) is made of sealed materials, which during assembly allows the formation of supply and outlet channels for liquids isolated from each other. The height of the relief depends on the processing capabilities of the selected materials and may range from fractions of mm to several mm. Its main role, similar to the role of stiffeners, is to strengthen the membrane and plate of thin polymeric materials. At the same time, an open trace pattern of the relief 2 contributes to an even distribution of liquid in the inlet chamber. For the same purpose, holes 5 and 10 are equidistant from each other. The density of the relief may be different. If we take into account that the “live section” of the ultrafiltration membrane is approximately 1000 times smaller than that of the frame plate, then the density of the relief (and its pattern) can be changed over a wide range and is determined by the condition that the required tensile and tensile strengths of the plate are reached and membranes. Drawing - in the form of strokes, segments, dots, etc.

The membrane filter element according to option 2 (Figs. 8–11) is a multilayer board containing two drainage frame plates 1, an ultrafiltration membrane 6 is placed between the plates, an arbitrary relief 2 is made on the outer sides of the plates 1. An airtight edging 3 is made on both sides of the board along the contour of the plates. The tight edging of the holes is made: on one side - for at least two through holes 10 for draining the cleaned liquid (concentrate), and on the other side - for the through hole 5 for supplying the cleaned liquid.

The membrane materials in both cases may be different from among known materials for these purposes and new, for example, from polyethylene terephthalate, polycarbonate, polypropylene and others. Depending on the chosen technology, the filter element can be manufactured using an ultrafiltration membrane from the range of purchased products, and can also be applied to the drainage frame plate by spraying.

The frame plate for membrane filter elements is made of porous materials, for example textolite, and other materials can also be used: silicone, rubber, porous polymeric materials, for example polypropylene or polyurethane; in the form of a porous metal plate obtained by powder metallurgy.

The relief, including the edging, is made of a sealing material that is applied to the surface of the membrane and plate by screen printing or by spraying using materials of polyurethane, nylon, and the same with fillers, for example dispersed metal, etc.

The proposed design based on flexible elastic elements made of thin-film materials allows the application of technological methods traditionally used, for example, in radio engineering, and related to the technology of manufacturing printed circuit boards. So the relief on the membrane and the plate is applied by printing, for example, by screen printing or by spraying using the previously mentioned polymeric materials (polyurethane, nylon, etc.). The thickness of the board elements is the minimum attainable and is determined by the technology’s capabilities to create durable defect-free products that ensure high-quality ultrafiltration - it's a few millimeters or less. Such dimensions allow a thousandfold increase in the total cross-section of filtration by forming packages of membrane filter elements. And at the same time, the size of such packages is comparable with the known ultrafiltration apparatus. The main advantage of the claimed invention is that, using simple, well-known technologies, it is possible to create an ultrafiltration device with a productivity greater than approximately three orders of magnitude.

Module 11 for micro- and ultrafiltration and separation and purification of liquid mixtures and liquids by the reverse osmosis method is a package of an arbitrary number of membrane filter elements according to any claimed embodiment, composed tightly with mirror symmetry relative to the pressing surface. A single membrane filter element contains all the basic elements for performing the ultrafiltration function: inlet and outlet channels and isolated volumes for the liquid and concentrate being cleaned and is a unified component of the ultrafiltration module.

Using the membrane filter element according to option 1 (Fig.6-7), the channels 12 for draining the purified liquid in the bag are formed by combining the holes 10. The cavity 13 between the filter elements, formed by the membranes 6 and the relief 7, is isolated from the channel 12 by a sealing border 8 of the holes 10. This the cavity communicates with the channel 14 for supplying the liquid to be cleaned, which is formed by combining the holes 5. The cavity 15 formed by the drainage plate and the relief on it communicates with the holes 10 of the channel 12 and is isolated from the channel 14 due to the herm egg edging aligned holes 5. The filtering process takes place in parallel in all the sections of the module. The cleaning fluid enters all the cavities 13 and through the membranes 6 enters the cavities 15 and then into the channel 12 with the purified fluid.

Using the membrane filter element according to option 2 (Figs. 12-13), the channels 12 for draining the purified liquid are also formed by combining the holes 10, which are isolated from the cavity 13 and open in the cavity 15. The channel 14 for supplying the cleaned liquid is formed by combining the holes 5, which are isolated through a tight edging from the cavity 15 and communicate with the cavities 13. In the process, the fluid enters all cavities 13 through the holes 5, passes one drainage plate, is filtered using a membrane 6 and through the second drainage plate after upaet into the cavity 15 and channels 12 for discharging purified liquid.

Almost the entire module volume is a “living cross-section” of filtration, with the exception of edging over a small area of frame plates and membranes.

The end frame sealed plates 16 of the module (figures 14, 15) are made in the form of frame plates. One plate has a through hole 17 configured to align with the holes 10 for draining the cleaned liquid and with the possibility of hermetically isolating the hole 5 of the channel 14. The other end plate has a through hole 18 made with the possibility of matching with the hole 5 for supplying the cleaned liquid and tight insulation of the holes 10 of the channel 12.

The module is sealed using studs on the end plates (not shown), while checking the module for leaks on the mating surfaces is carried out by known methods, for example, immersion in liquid.

The ultrafiltration module is manufactured using printed circuit board manufacturing and assembly technology.

To manufacture a separate membrane filter element in the form of a multilayer board, an arbitrary relief of a sealing material (for example, polyurethane) is applied to the outer surfaces of the board by spraying or screen printing. The indicated relief methods are equivalent for solving the problem of high-quality filtration, and the choice of method is associated with technological feasibility (determined by the cost and reliability of the module). The relief includes edging along the contour of both surfaces and edging through the holes of the board. On one side of the board, a sealing rim of the two through holes of the board is formed, forming a channel in the bag for draining the cleaned liquid. On the other side of the board, the holes are edged, forming a channel for supplying the liquid being cleaned in the packet. Unified filter sections of unit productivity are made by combining membrane filter elements according to any claimed embodiment with mirror symmetry with respect to the pressing surface. The module is assembled in the form of a package of filter sections by combining the required estimated number of sections. In Fig.6, 7 shows a module of membrane filter elements according to 1 embodiment, and Fig.12, 13 - the same, from filter elements according to 2 embodiment. The package is sealed with end plates 16, which are pulled together with studs. In order to avoid leaks, the bag is filled with hermetic material 19 (for example, from capron, silicone, rubber, polyurethane materials) mainly along the surface of the peripheral faces of the filter elements.

For the manufacture of plates and membranes, other materials can be used, in addition to the example. Their choice is determined by the conditions of cost reduction, technology simplification and compatibility with the environment being cleaned. As membranes, predominantly finished products are used.

Each filter element and module as a whole have a large filtering surface, are easy to manufacture, have low weight and dimensions while increasing productivity by 2-3 orders of magnitude. The increased filtering surface eliminates the use of high pressures and ensures pressure-free operation of the ultrafilter or at low pressure in the range of 2-4 kg / sq. Cm.

Claims (17)

1. Membrane filter element, characterized in that it is a multilayer plate, including a drainage frame plate, combined with a membrane for ultrafiltration, an arbitrary uniform relief is made on the outer surfaces of the plate, including a border around the contour, a border through the hole for supplying the cleaned liquid from the frame side plates and edging of at least two through holes for the removal of purified liquid from the side of the membrane; the through holes of the board are located near the contour border and are equidistant from each other, while these borders are made airtight. 2. The membrane filter element according to claim 1, characterized in that the membrane is made of a thin polymer material, for example, lavsan. 3. The membrane filter element according to claim 1, characterized in that the membrane is made by spraying on a frame plate. 4. The membrane filter element according to claim 1, characterized in that the frame plate is made of porous textolite. 5. The membrane filter element according to claim 1, characterized in that the frame plate is made of porous metal obtained by powder metallurgy. 6. The membrane filter element according to claim 1, characterized in that the relief is made of polyurethane. 7. The membrane filter element according to claim 1, characterized in that the relief is made of polyurethane with a filler in the form of a dispersed metal. 8. Membrane filter element, characterized in that it is a multilayer plate, including at least two drainage frame plates; a membrane for ultrafiltration is placed between the plates, an arbitrary relief is made on the outer sides of the plates, including edging along the contour of the plates, on one side is the edging of at least two through holes for draining the cleaned liquid, and on the other side is the edging of the through hole for supplying the cleaned liquid; through holes are located near the contour border and are equidistant from each other, while these borders are made airtight. 9. The membrane filter element according to claim 8, characterized in that the membrane is made of a thin polymer material, for example, from lavsan. 10. The membrane filter element of claim 8, characterized in that the membrane is made by spraying on a frame plate. 11. The membrane filter element of claim 8, characterized in that the frame plate is made of porous textolite. 12. The membrane filter element of claim 8, characterized in that the frame plate is made of porous metal obtained by powder metallurgy. 13. The membrane filter element of claim 8, wherein the relief is made of polyurethane. 14. The membrane filter element of claim 8, wherein the relief is made of polyurethane with a filler in the form of a dispersed metal. 15. Module for micro- and ultrafiltration and separation and purification of liquid mixtures and liquids by the reverse osmosis method in the form of a bag containing a combination of membranes and drainage frame plates, through holes and channels, means for separating the supply and discharge channels at the location of the holes, sealing the end faces plates, means of hermetically sealed package, characterized in that the package consists of an arbitrary number of membrane filter elements according to any claimed variant, composed tightly with mirror symmetry triey pressing against the surface, the channels in the package are formed by combining the through holes and separated by sealing edgings respective openings, and the ends of the module frame mounted airtight plate overlapping the holes with an airtight edging and having at least one through hole; the module is also equipped with sealing means in the form of studs on the end plates and is housed in a housing made of sealed material. 16. The ultrafiltration module according to clause 15, wherein the housing is made of a sealed material - polyurethane. 17. A method of manufacturing a module for micro- and ultrafiltration and separation and purification of liquid mixtures or liquids by the reverse osmosis method, in which the package is sealed, characterized in that on the outer surfaces of the membrane filter element in the form of a multilayer plate including one or more drainage frame plates, combined with an ultrafiltration membrane, apply an arbitrary relief of the sealing material by spraying or screen printing, including edging along the contour of both surfaces, DCCH at least one side of the board through holes of the two membranes fay to the channel outlet and the purified liquid edging on the other side of the board frame plate through hole, aligned with the channel for supplying the cleaning liquid; make unified separate filter sections of unit productivity by combining membrane filter elements according to any claimed embodiment with mirror symmetry with respect to the pressing surface; make a module in the form of a package of filter sections by combining the required estimated number of sections; they seal the bag with end plates and place the bag in the housing by filling the surface of the module, mainly the peripheral faces of the filter elements, with hermetic material.

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