RU2472567C1 - Household filter cell for tap water purification - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to filtration of tap water and that of natural flesh water sources and may be used in plug-in filtration cartridge of household filters. Filtration cartridge consists of raw water feed assembly composed of shell with radial cutouts and threaded attachment fittings to fit cartridge in filter. Also it comprises filtration assembly composed of hollow cylinder with screen at top base and membrane filtration assembly at bottom base. Membrane assembly consists of face unit and bundle of U-like hollow fibers with mean diameter of pores making at least 0.001 mcm, OD and ID making 250-350 and 80-130 mcm, respectively, that occupy 10-70% of hollow cylinder volume. Note here that ends of fibers are passed through face unit while fiber volume does not exceed 10% of membrane filtration unit volume. It comprises also layer of adsorbent arranged between screen and membrane filtration unit, purified water discharge assembly made up of funnel with obtuse angle and central hole.

EFFECT: efficient purification and removal of microorganisms.

6 cl, 1 dwg, 2 ex

Description

The invention is intended to produce benign drinking water and can be used as part of a replaceable filter cartridge of a household filter for purifying water from a water supply system and natural freshwater sources.

The technical result is the provision of economical and effective water purification from metal salts and organic compounds with its accompanying disinfection.

Known filter material of the filtration unit of the filter cartridge to reduce the number, destruction or removal of bacteria and viruses [US 2009008323]. The material of said filter is at least partially formed from a mixture of mesoporous and microporous activated carbon particles, some of which are silver plated.

The composition of the material allows to reduce the resistance to flow, however, the filtering properties of such a material do not provide the proper degree of purification of water from heavy metals due to the low total exchange capacity of activated carbons. In addition, taking into account the significant contact time required to remove bacteria using silver compounds, the material has a bacteriostatic rather than a disinfecting effect.

The prior art method of ultrafiltration to obtain environmentally friendly drinking water, in particular, using membrane devices based on hollow fiber membranes. The use of membranes in the form of hollow fibers provides the largest filtering surface in the volume of the apparatus. Typically, the type of filtration is “outside to inside fibers”.

Thus, a hollow fiber membrane apparatus is known [RU 2060804], which includes a cylindrical body with covers, in one of which openings are made for the inlet of the separated liquid and the output of the concentrate, and in the other openings for the output of the filtrate, a membrane element is placed in the housing, consisting of an axial perforated one end of the tube, two end blocks mounted on the axial tube, and hollow fibers, the ends of which are embedded in the end blocks, the block on the outlet side of the filtrate is sealed in the housing, and the other on the outlet side yes concentrate - has a gap with the body of the apparatus, and the bundle of hollow fibers is provided with a casing impervious to the liquid to be separated, opening it from the side opposite to the perforated edge of the axial tube.

As hollow fibers, laid parallel to the axis of the apparatus, it contains cellulose acetate hollow fibers with an average pore size of more than 0.001 μm, outer and inner diameters of 280 ÷ 320 and 90 ÷ 120 μm, respectively, and the volume of the interfiber (free) space in the membrane element does not exceed 10 %

The disadvantage of the invention is the lack of cleaning efficiency, due to the fact that contaminated water is supplied under a pressure of 1 ÷ 1.5 MPa, while no more than 75% of the washing fluid penetrates through the walls of the hollow fiber membrane and is discharged through its channels through the filtrate output unit. This means that at least 25% of the treated water is discharged from the apparatus along with pollutants, i.e. irretrievably lost.

The second disadvantage is that the removal of the mother liquor in the conditions of a household gravity filter is not possible.

Another disadvantage is the insufficiently high manufacturability of the apparatus, due to the fact that the ends of the hollow fibers must be sealed in both end blocks to ensure packing density.

To ensure the packing density of hollow fibers in the known module for ultrafiltration or microfiltration of water [US 6911147], the fibers are assembled in ∩-shaped bundles, the ends of which are interconnected at the bottom of the module with respect to the filtration mode by resin filling.

The disadvantage of this filtration module is the need to remove the mother liquor through a separate channel, which is unacceptable for a household gravity filter.

The closest in technical essence and combination of features is a filter cartridge [RU 74822] (prototype) containing a purified water supply unit connected to a fastening unit in a filter connected to a filtration unit connected to a purified water outlet unit, the filtration unit is made in the form of a shell filled with a mixture of adsorbent components, the purified water supply unit is made in the form of a cone-shaped shell with radial slots, the mount in the filter is made in the form of a cylindrical shell with a thread on the outer The surface, the outlet for treated water is made in the form of a funnel with an obtuse angle and the hole in the middle, a mesh is installed above the filtration unit, and an additional filtration unit is installed between the filtration unit and the outlet for treated water, made in the form of a mesh with layers of a non-woven filter cloth made of ion-exchange fiber , the additional filtration unit is connected to the outlet unit for purified water.

The simplicity of the design of the filter cartridge as a whole allows to increase the reliability and convenience of its operation and to ensure effective purification of water from metal salts and organic compounds, but it does not allow the removal of microorganisms, including microbes and bacteria, the presence of which is characteristic of water from a water supply system and natural freshwater sources, not pre-trained for drinking purposes.

On the other hand, the design of the prototype with an additional filtration unit fundamentally allows you to modify the filter cartridge for various technical tasks.

The inventive filter cartridge of a household filter for drinking water purification is aimed at obtaining environmentally friendly drinking water, in particular at improving the characteristics of water purification from microorganisms, through the use of hollow fiber membranes as part of an additional filtration unit.

The technical result is achieved by the fact that a filter cartridge for a household filter for drinking water purification is proposed, consisting of sequentially located downstream of the water: the purified water supply unit, which is a shell with radial slots and equipped with a cartridge holder in the filter, made in the form of a cylindrical shell with thread on the outer surface; filtration unit, made in the form of a hollow cylinder, in the upper base of which a mesh is installed, and in the lower base, an additional membrane filtration unit, consisting of an end block and a bundle of ∩-shaped hollow fibers with an average pore size of at least 0.001 μm, outer and inner diameters 250–350 and 80–130 μm, respectively, occupying 10–70 vol% of a hollow cylinder, while the ends of the fibers are passed through the end block, and the interfiber space does not exceed 10% of the volume of the membrane filtration unit; a layer of an absorbent component located between the grid and the membrane filtration unit; node output purified water, made in the form of a funnel with an obtuse angle and a hole in the middle.

It is advisable that a polymer selected from the range of polypropylene, polyethylene, polysulfone, polyalkylsulfone, polyvinylidene fluoride, polyacrylonitrile is used as the material of the hollow fibers.

It is also advisable that 10 ÷ 20 wt.% Hollow fibers are pre-treated with a hydrophilizing agent, which is used non-ionic surfactants based on polyethylene glycol.

It is important that the end block of the membrane filtration unit made of polymerized resin or of vitreous polymer has a tight connection with the shell of the hollow cylinder of the filtration unit.

The technical result is also achieved by the fact that a mixture of granular sorbents consisting of silver-containing activated carbon with an Ag concentration from 0.05 to 5.0 wt.% And with a grain size of 0.6 ÷ 1.7 mm, activated carbon with a grain size of 0.3 ÷ 0.6 mm and is used as an adsorbing component carboxyl-containing cation exchangers in the following ratio of components, vol.%:

silver activated carbon with granule size 0.6 ÷ 1.7 mm 20 ÷ 50 Activated carbon with granule size 0.3 ÷ 0.6 mm 20 ÷ 50 carboxyl-containing cation exchangers 5 ÷ 40.

It is possible that the mount of the filter cartridge in the filter is additionally sealed with a polymer O-ring.

The essence of the proposed technical solution lies in the fact that the purification of drinking water is carried out by an additional membrane filtration unit, which includes a bundle of ∩-shaped hollow fibers, and the components of the mother liquor, which cannot be removed under the conditions of a household gravity filter, are sorbed by a layer of an absorbent component. The use of hollow fibers also leads to an additional disinfecting effect.

The use of ∩-shaped hollow fibers directed by their apex towards the flow of treated water allows one to ensure the packing density of hollow fibers, which means to increase the effective filtration surface.

The selection of the characteristics of the hollow fibers and the preliminary treatment of a certain part of the hollow fibers with a hydrophilizing agent can improve the hydrodynamic separation conditions in the additional membrane filtration unit and, in general, carry out pressure-free filtration.

The membrane filtration unit is manufactured as follows. Hollow fibers are collected in ∩-shaped bundles, the ends of which are placed in a hollow cylinder of the filtration unit. Then, about a fifth of the hollow cylinder is filled with resin or liquid monomer and their polymerization is carried out to obtain a solid or glassy material of the end block. The resulting billet of the end block is cut about half the thickness by a guillotine knife to release the ends of the hollow fibers.

The invention is illustrated in FIG.

In FIG. presents a schematic diagram of a filter cartridge for a household filter for drinking water treatment, on which: 1 - means for attaching a cartridge to the filter; 2 - node supply of purified water; 3 - polymer ring seal; 4 - mesh; 5 - filtration unit; 6 - layer of an absorbent component; 7 - ∩-shaped hollow fibers; 8 - end block of an additional membrane filtration unit; 9 - node output purified water.

The use of a polymer O-ring in the mount of the filter cartridge in the filter does not allow a part of the water containing microorganisms to bypass the filter cartridge, therefore it is allowed to use both elastic and inelastic polymers from the series: polypropylene, polyethylene, styrene and acrylonitrile copolymer acrylonitrile butadiene styrene.

The use of a mesh in the upper base of the hollow cylinder of the filtration unit allows you to distribute the flow of purified water over the entire cross section of the filtration unit and prevent the adsorbent component from being washed out of it.

The use of a layer of an absorbent component allows you to sorb the components of the mother liquor containing metal salts and organic compounds, as well as inhibit the process of bacterial propagation inside the filter cartridge.

The use of hollow fibers allows you to separate the purified water into the filtrate and the mother liquor and additionally remove microorganisms.

The use of the end block of an additional membrane filtration unit contributes to the formation of a filtrate stream at the outlet of the filtration unit.

The filter cartridge of the household filter for drinking water purification works as follows (Fig.).

The cartridge is installed in the household filter using the fastening means 1, then water is poured into the container for supplying the filtered water to the filter. Water through the slots of the purified water supply unit 2, sealed with a polymer ring seal 3, enters the grid 4 in the upper base of the hollow cylinder of the filtration unit 5, where it is distributed over the entire cross section of the filtration unit and falls into the layer of the absorbent component 6, the composition of which is selected for the sorption of components stock solution, usually metal salts and organic compounds. Next, the water enters the bundle of ∩-shaped hollow fibers 7, in which the microorganisms are purified by separation of the purified water into the filtrate and the mother liquor. Through the ends of the hollow tubes passed through the end block of the additional membrane filtration unit 8, the formed filtrate stream enters the outlet of purified water 9 and then to the collection tank for filtered water of the household filter.

Below are examples of achieving a technical result when using the inventive filter cartridge with a capacity of 6 dm ³ / h. The examples illustrate but do not limit the use of the proposed filter cartridge.

As examples below are the data from the protocols of laboratory studies of water samples from the centralized water supply system of Moscow, artificially contaminated with the studied pollutants, before and after using the inventive filter cartridge.

The inventive filter cartridge of a household filter for drinking water purification allows economically and efficiently obtain environmentally friendly drinking water, in particular purified from microorganisms.

Claims (6)

1. A filter cartridge for a household filter for drinking water purification, consisting of sequentially arranged downstream water: a purified water supply unit, which is a shell with radial slots and equipped with a cartridge holder in the filter, made in the form of a cylindrical shell with a thread on the outer surface; a filtration unit, made in the form of a hollow cylinder, in the upper base of which a mesh is installed, and in the lower base, an additional membrane filtration unit, consisting of an end block and a bundle of ∩-shaped hollow fibers with an average pore size of at least 0.001 μm, outer and inner diameters 250–350 and 80–130 μm, respectively, occupying 10–70 vol% of a hollow cylinder, while the ends of the fibers are passed through the end block, and the interfiber space does not exceed 10% of the volume of the membrane filtration unit; a layer of an absorbent component located between the grid and the membrane filtration unit; node output purified water, made in the form of a funnel with an obtuse angle and a hole in the middle. 2. The filter cartridge according to claim 1, characterized in that a polymer selected from the series: polypropylene, polyethylene, polysulfone, polyalkylsulfone, polyvinylidene fluoride, polyacrylonitrile is used as the material of the hollow fibers. 3. The filter cartridge according to claim 1, characterized in that 10 ÷ 20 wt.% Of the hollow fibers are pre-treated with a hydrophilizing agent, which is used non-ionic surfactants based on polyethylene glycol. 4. The filter cartridge according to claim 1, characterized in that the end block of the membrane filtration unit made of polymerized resin or of glassy polymer has a tight connection with the shell of the hollow cylinder of the filtration unit. 5. The filter cartridge according to claim 1, characterized in that a mixture of granular sorbents consisting of silver-containing activated carbon with an Ag concentration from 0.05 to 5.0 wt.% And with a granule size of 0.6 ÷ 1 is used as an absorbent component. , 7 mm, activated carbon with a granule size of 0.3 ÷ 0.6 mm and carboxyl-containing cation exchangers in the following ratio of components, vol.%:
silver activated carbon with a granule size of 0.6 ÷ 1.7 mm 20 ÷ 50 Activated carbon with a granule size of 0.3 ÷ 0.6 mm 20 ÷ 50 carboxyl-containing cation exchangers 5 ÷ 40 6. The filter cartridge according to claim 1, characterized in that the mount of the filter cartridge in the filter is additionally sealed with a polymer ring seal.

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