Water filter assembly and water purifier

Abstract

We provide a water purification filter assembly that can remove PFAS from tap water. [Solution] In a water purification filter assembly F that generates purified water V from tap water W, the water purification filter assembly F comprises a hollow cylindrical filter housing 100 having an inlet 130 into which tap water W is supplied and an outlet 331 into which purified water V is discharged to the outside, and a filter module 200 built into the filter housing 100, the filter module 200 having a hollow cylindrical pre-filter 210, a hollow cylindrical antivirus filter 220 disposed inside the pre-filter 210, and a post-filter 230 disposed inside the pre-filter 220, the pre-filter 210 or the post-filter 230 being a PFAS removal filter.

Description

Technical Field

[0001] The present invention relates to a filter assembly and a water purifier. More specifically, it relates to a water purification filter assembly capable of removing PFAS from tap water and a water purifier having this water purification filter assembly.

Background Art

[0002] Various water purifiers are used as means for filtering impurities contained in tap water to obtain purified water. Such water purifiers are equipped with a number of filters for filtering tap water.

[0003] The PFAS contamination of tap water is becoming a social issue. PFAS is a general term for more than 4,730 organic fluorine compounds, which are difficult to decompose in nature and accumulate in water and the like. PFAS has also been pointed out to be toxic to humans, and its abolition and use restrictions have been imposed in international treaties. Among PFAS, PFOS and PFOA have properties of repelling water and oil and being stable to heat, and thus have been used in fire extinguishing agents, coating agents for frying pans, and the like. In Japan, the manufacture and import of PFOS and PFOA have been basically prohibited by law until 2021. In the surveys of rivers and groundwater conducted in 2021, high concentrations of PFAS (PFOS, PFOA) exceeding the target values were detected at 81 locations in 13 prefectures.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The water treatment apparatus of Patent Document 1 removes PFAS from the drinking water stored in the storage tank and purifies it. However, the water treatment device described in Patent Document 1 is a large-scale device mounted on a transport vehicle, making it difficult to apply to water purifiers. Furthermore, as a method for removing PFAS from tap water using water purifiers, there is a demand for a system in which filter assemblies are delivered to users, and users replace the filter assemblies of the water purifiers themselves.

[0006] The present invention aims to provide a water purification filter assembly capable of removing PFAS from tap water and a water purifier having this water purification filter assembly in order to solve the above-mentioned problems. [Means for solving the problem]

[0007] The present invention relates to a water purification filter assembly for generating purified water from tap water, wherein the water purification filter assembly comprises a hollow cylindrical filter housing having an inlet for supplying tap water and an outlet for discharging purified water to the outside, and a filter module built into the filter housing, wherein the filter module comprises a hollow cylindrical pre-filter, a hollow cylindrical antivirus filter disposed inside the pre-filter, and a hollow cylindrical post-filter disposed inside the antivirus filter, and either the pre-filter or the post-filter is a PFAS removal filter.

[0008] The PFAS removal filter is characterized in that it consists of a filter material that has a different specific surface area or average pore diameter from the pre-filter and the remaining post-filter. The PFAS removal filter has a specific surface area of ​​1500 m². 2 It is characterized by being made of activated carbon of / g or more. The PFAS removal filter is characterized by being made of activated carbon having a ratio of 95% or more of micropores with a pore diameter of 2 nm or less. The PFAS removal filter is characterized in that it is formed in a hollow cylindrical shape, and the hollow portion of the PFAS removal filter functions as an outflow channel communicating with the outflow portion.

[0009] The present invention is characterized in that, in a water purifier equipped with a water purification filter assembly, the above-mentioned water purification filter assembly is used as the water purification filter assembly. [Effects of the Invention]

[0010] According to the water purification filter assembly of the present invention and the water purifier having this water purification filter assembly, PFAS can be reliably removed from tap water. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows the water purification filter assembly F of this embodiment. [Figure 2] This is an exploded view of the water purification filter assembly F. [Figure 3] This is a longitudinal cross-sectional view of the water purification filter assembly F. [Figure 4] This is a partially enlarged cross-sectional view of the water purification filter assembly F. [Figure 5] This is a cross-sectional view (section AA) of the water purification filter assembly F. [Figure 6] This is a diagram showing filter module 200. [Figure 7] This is a longitudinal cross-sectional view of the filter module 200. [Modes for carrying out the invention]

[0012] Hereinafter, a water filter and water purifier according to a preferred embodiment of the present invention will be described in detail with reference to the drawings.

[0013] [Water purification filter assembly F] Figure 1 shows the water purification filter assembly F of this embodiment. Figure 2 is an exploded view of the water purification filter assembly F. Figure 3 is a longitudinal sectional view of the water purification filter assembly F. Figure 4 is an enlarged partial cross-sectional view of the water purification filter assembly F.

[0014] The water purification filter assembly F is detachably attached to a water purifier (including a water server, etc.) not shown in the figure to generate purified water V from tap water W. By replacing the water purification filter assembly F, the water purification function of the water purifier can be maintained.

[0015] The water purification filter assembly F is composed of a filter housing 100 and a filter module 200 built into the filter housing 100. The filter housing 100 consists of a hollow cylindrical housing body 110 and a housing lid 120 that covers and closes the upper side of the housing body 110. A supply passage 140 for supplying drinking water such as tap water W is formed between the outer wall of the filter housing 100 and the filter module 200.

[0016] On the lower surface that closes the lower side of the housing body 110, a tubular inflow portion 130 for allowing tap water W to flow into the interior of the filter housing 100 is formed. The inflow portion 130 is formed to project downward from the center of the lower surface of the housing body 110. The inflow portion 130 has an annular step formed in the central portion, a through hole formed inside it to serve as an inflow passage for tap water, and two O-ring insertion grooves formed side by side outside it.

[0017] 〔Filter Module 200〕 Figure 6 is a view showing the filter module 200. Figure 7 is a longitudinal sectional view of the filter module 200.

[0018] The filter module 200 includes a filter lid portion 300 and a filter group. The filter cover section 300 consists of an upper cover 310 that forms the top surface and a lower cover 330 that forms the bottom surface, and the filter group is arranged between the upper cover 310 and the lower cover 330.

[0019] The upper cover 310 has a protrusion 311 that supports the filter group, which protrudes downward from the center of the lower surface. This protrusion 311 fits into the hollow section (outflow channel 250) of the carbon filter 230, which will be described later.

[0020] The lower cover 330 has an inner lower cover 320 that supports the filter group and a tubular outlet section 331 that allows purified water V to flow out to the outside. The outlet section 331 is formed by protruding downward from the center of the lower surface of the inner lower cover 320. The outlet section 331 is inserted into the inlet section 130, and its lower end is positioned at the same location as the lower end of the inlet section 130. In other words, the outlet section 331 is concentric with the inlet section 130. As a result, the outlet section 331 also functions as part of the filter housing 100.

[0021] The filter group consists of a PFAS removal filter 210, an antivirus filter 220, and a carbon filter 230, all of which are formed in a hollow cylindrical shape. An antivirus filter 220 is placed inside the PFAS removal filter 210, and a carbon filter 230 is placed inside the antivirus filter 220. A nonwoven fabric 212 is wrapped around the outer surface of the PFAS removal filter 210. The nonwoven fabric 212, the PFAS removal filter 210, the antivirus filter 220, and the carbon filter 230 are formed to have concentric circles and are assembled together to form a single cylindrical shape.

[0022] The nonwoven fabric 212 plays a role in removing relatively large particulate matter from drinking water (tap water W) and reducing turbidity. The PFAS removal filter 210 is a pre-filter that removes organic fluorine compounds contained in drinking water (tap water W). Concerns about the effects of PFAS in drinking water on the human body are widely known. The most notable are PFOA, PFOS, and other anionic (negatively charged) PFAS compounds.

[0023] The PFAS removal filter 210 has countless tiny pores and removes PFAS from drinking water (tap water W). The pores of the PFAS removal filter 210 are approximately 1 to 20 nm in diameter and are classified into micropores (2 nm or less in diameter), mesopores (2 to 50 nm), and macropores (50 nm or more). High-performance carbon filters (high-performance activated carbon, microcarbon) can be used as the PFAS removal filter 210. High-performance activated carbon has a micropore ratio of 95% or higher. In addition, high-performance activated carbon has a specific surface area (absorption area) of 1,500 m² per gram. 2 It is 1 / g or more.

[0024] The antivirus filter 220 is a filter made of a filter material having numerous fine cavities, and can use, for example, a hollow fiber membrane filter or a reverse osmosis membrane (RO membrane) filter. The antivirus filter 220 removes viral components contained in the purified water filtered by the PFAS removal filter 210.

[0025] The carbon filter 230 is a post-filter that removes chlorine, organic matter, pesticides, moldy odors, and limescale odors from drinking water (tap water W). The carbon filter 230 also removes volatile organic compounds (VOCs), lead (Pb), and heavy metals. Furthermore, the hollow portion (inner space) of the carbon filter 230 functions as an outflow channel 250 that communicates with the outflow section 331.

[0026] Both the PFAS removal filter 210 and the carbon filter 230 are made from activated carbon or activated carbon fibers (ACF), but they differ in their ability to remove impurities and other substances. As mentioned above, the activated carbon (high-performance activated carbon) in the PFAS removal filter 210 has a micropore ratio of 95% or more and a specific surface area (absorption area) of 1,500 m² per gram. 2 It is 1 / g or more. On the other hand, the activated carbon in the carbon filter 230 has a micropore ratio of approximately 90% and a specific surface area of ​​1,000 m² per gram. 2 It is approximately / g In other words, the PFAS removal filter 210 (either one) differs from the carbon filter 230 (the other one) in either its specific surface area or average pore diameter. The PFAS removal filter 210 consists of a filter material with a larger specific surface area and a smaller average pore diameter compared to the carbon filter 230.

[0027] A phosphate bead 240 is placed in the hollow section (outflow channel 250) of the carbon filter 230. The phosphate bead 240 is placed downstream of the outflow channel 250 in a packaged pack (nonwoven fabric bag). The phosphate bead 240 is filled so as to fill at least the downstream side of the outflow channel 250.

[0028] Phosphate Bead 240 controls scale formation caused by hardness substances and calcareous deposits in purified water V. Phosphate Bead 240 consists of small spheres (particulate matter) made of polyphosphate. Phosphate Bead 240 has a size of 1 / 16 inch to 1 / 4 inch. Because polyphosphate beads have slow dissolution properties, they are very useful for sustained and stable phosphate (PO4) water treatment. Phosphate Bead 240 can maintain water clarity through its mineral sequestration function and scale control, and can suppress and reduce corrosion throughout the entire drainage piping system. The polyphosphate bead is not limited to being molded into granular form, but may also be in the form of pellets or powders cut to a predetermined size by extrusion. The phosphate bead 240 may not be contained in a packaging pack, but may also be placed directly in the outflow channel 250.

[0029] [Water purification process] Next, we will describe the water purification process of tap water using the water purification filter assembly F. Tap water W supplied from an external source flows into the filter housing 100 through the space between the inlet 130 and the outlet 331. Tap water W is guided by the lower cover 330 of the filter module 200 into the supply passage 140 on the outer circumference of the filter housing 100. The supply passage 140 of the filter housing 100 is then filled with tap water W, and the filter module 200 is immersed in the tap water W.

[0030] First, tap water W passes through nonwoven fabric 212. By passing through nonwoven fabric 212, relatively large particulate matter is removed from the tap water W. Next, tap water W flows into the PFAS removal filter 210. By passing through the PFAS removal filter 210, PFAS such as PFOA and PFOS are completely removed from the tap water W (it becomes purified water V). Furthermore, purified water V flows into the antivirus filter 220. By passing through the antivirus filter 220, purified water V removes various bacteria and substances harmful to the human body that remain in the tap water W. Finally, the tap water W flows into the carbon filter 230. By passing through the carbon filter 230, the chlorine, organic substances, and odors contained in the tap water W are removed.

[0031] The purified water V, from which PFAS has been removed, then flows into the outflow channel 250 (the hollow section of the carbon filter 230). Purified water V (tap water W) flows from the outflow channel 250 towards the outflow section 331. At this time, the purified water V immerses the phosphate bead 240 which is packed into the outflow channel 250. By passing through the phosphate bead 240, the formation of scale caused by hardness substances and calcareous materials is controlled. Finally, the purified water V is discharged to the outside via the outlet 331.

[0032] The present invention is not limited to the embodiments described above, and includes various modifications to the embodiments described above, without departing from the spirit of the invention. In other words, the specific shapes and configurations given in the embodiments are merely examples and can be modified as appropriate.

[0033] The filter group (nonwoven fabric 212, PFAS removal filter 210, antivirus filter 220, carbon filter 230) in the filter module 200 is just one example. In other words, the configuration (materials) and arrangement of the filter group in the filter module 200 can be arbitrarily set. Filters of the form of wound filters or pleated filters may also be used.

[0034] In this embodiment, a high-performance carbon filter (high-performance activated carbon) was used as the PFAS removal filter 210, but this is just one example. For example, a plant-derived adsorbent consisting of β-cyclodextrin may be used as the PFAS removal filter 210. Alternatively, a filter made by mixing powdered or granular β-cyclodextrin with carbon or the like may be used. β-cyclodextrin has uniform nanoscale cyclodextrin cavities and can reliably remove PFAS from drinking water (tap water W) through hydrophobic interactions with PFAS. For example, DEXSORB adsorbent from Cyclopure can be used as the PFAS removal filter 210.

[0035] In this embodiment, the pre-filter is a PFAS removal filter 210 and the post-filter is a carbon filter 230, but this is just one example. The pre-filter may be a carbon filter and the post-filter a PFAS removal filter. In other words, either the pre-filter or the post-filter can be a PFAS removal filter.

[0036] In this embodiment, activated carbon was used as the filter material for the pre-filter and post-filter, but this is just one example. Various filter materials can be used for the pre-filter and post-filter. Granular materials such as charcoal powder, clay, and diatomaceous earth may be used as the filter material. Porous materials such as porous ceramics, sintered metals, ceramics, and plastics may also be used as the filter material. Furthermore, mixtures of these materials may also be used. The pre-filter and post-filter may use the same filter media or different filter media.

[0037] In this embodiment, the carbon filter 230 is formed in a hollow cylindrical shape, but this is just one example. For example, the hollow portion (outflow channel 250) of the carbon filter 230 may be formed only on the lower side (not penetrating vertically). Alternatively, high-performance activated carbon may be used as the carbon filter 230, either in granular or powder form.

[0038] In this embodiment, the phosphate bead 240 is placed downstream of the outflow channel 250 in a packaging pack (nonwoven fabric bag), but this is just one example. Instead of the packaging pack, nonwoven fabric or the like may be placed at the lower end of the outflow channel 250 or at the outflow section 331. In this embodiment, the phosphate bead 240 was arranged to fill the downstream side of the outflow channel 250, but this is just one example. The phosphate bead 240 may also be arranged to fill the outflow channel 250 without any gaps.

[0039] In this embodiment, the outlet section 331 and the inlet section 130 are arranged concentrically, but this is just one example. The outlet section 331 and the inlet section 130 may be arranged in different locations. [Explanation of symbols]

[0040] F Water filter assembly 100 filter housing 110 Housing body 120 Housing Cover 130 Inlet 140 Supply passage 200 filter modules 210 PFAS Removal Filter (Pre-filter) 212 Nonwoven fabric 220 Antivirus Filter 230 Carbon Filter (Post-filter) 240 Phosphate Bead 250 Outlet channel 300 Filter cover 310 Upper lid 311 Protrusion 320 Internal lower lid 330 Lower lid 331 Outlet W Tap water (drinking water) V Water purification

Claims

1. In a water purification filter assembly that generates purified water from tap water, The aforementioned water purification filter assembly is A hollow cylindrical filter housing having an inlet for supplying tap water and an outlet for discharging purified water to the outside, The filter module built into the aforementioned filter housing, Prepare, The aforementioned filter module A hollow cylindrical pre-filter, A hollow cylindrical antivirus filter is placed inside the aforementioned pre-filter, A post-filter is placed inside the aforementioned antivirus filter, It has, A water purification filter assembly characterized in that either the pre-filter or the post-filter is a PFAS removal filter.

2. The water purification filter assembly according to claim 1, characterized in that the PFAS removal filter is made of a filter material that has a specific surface area or average pore diameter different from the pre-filter and the remaining one of the post-filter.

3. The water purification filter assembly according to claim 1, characterized in that the PFAS removal filter is made of activated carbon with a specific surface area of ​​1500 m² / g or more.

4. The water purification filter assembly according to claim 1, characterized in that the PFAS removal filter is made of activated carbon having a pore diameter of 2 nm or less at a ratio of 95% or more.

5. The water purification filter assembly according to claim 1, characterized in that the PFAS removal filter is formed in a hollow cylindrical shape, and the hollow portion of the PFAS removal filter functions as an outflow channel communicating with the outflow portion.

6. In a water purifier equipped with a water filter assembly, A water purifier characterized in that the water filter assembly is the water filter assembly described in any one of claims 1 to 5.

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