RU2708856C1 - Gravity filter for purification and softening or mineralization of drinking water - Google Patents

Abstract

FIELD: water treatment.

SUBSTANCE: invention is intended for purification and softening or mineralization of drinking water and can be used for improvement of drinking water purification quality in jug type domestic filters. Gravity filter for purification and softening or mineralization of drinking water comprises a container for treated water, a funnel for receiving purified water, located in its upper part, filtering device arranged inside the funnel of the filter, including a system for fixing the filtering device in the filter funnel and a filter element made of porous block material in the form of a hollow vertical vessel with a softening or mineralizing material located in its inner space. Filtration device locking system is connected to filtering element by means of gluing or mechanical fastening. Porous block material is obtained by compression of a mixture of initial components containing particles of activated carbon and polymer binder.

EFFECT: simplification of design and assembly technology, provision of efficient water treatment by toxic pollutants up to (91–98) % and its softening during the whole resource making at least 40 %, as well as uniform mineralization of water of different rigidity under condition of using mineralizing substances in the proposed device.

10 cl, 1 tbl, 3 ex

Description

The invention relates to a gravity filter for purification and softening or mineralization of drinking water and can be used to improve the quality of drinking water purification in household jug type filters.

Currently, household filters for drinking water treatment, which are an alternative to bottled drinking water, are widely used among the population. Among them, the most popular are gravity filters, which are jug type filters, which are distinguished by their simplicity of construction, low price and do not require connection to pressure water supply systems.

Most pitcher type filters are known in the art (e.g., patent DE 000002919901, 1980, patent WO 1998017582, 1998, patent RU 2236279, 2004, patent WO 2005118481, 2005, WO 2005118104, 2005, WO 2005118482, 2005 , RU 2252062, 2005, patent RU 2437703, 2011), consist of a tank, in the upper part of which there is a receiving funnel, into which purified water is poured, and a filter device (cartridge), hermetically connected to the lower part of the receiving funnel and located in tanks in the zone of purified water.

Pitcher type gravity filters provide purification of drinking water from the most common toxic pollutants - chlorine and its compounds, organic impurities, in particular organochlorine compounds, and heavy metals, and its softening, removing calcium and magnesium cations and their bicarbonate ions from water, or water purification and its enrichment with minerals useful to the human body.

To clean and soften or purify and mineralize water by gravity filters, sorbent and / or mineralizing substances are placed in their filter device, which is a filter element in the form of a plastic housing, to which a fixation device is connected, which is used to tightly connect the filter device to the receiving funnel of the filter. In most filter devices of the pitcher-type filters, a mixture of activated carbon that removes chlorine, organic, including organochlorine contaminants, and cation exchanger in granular form (for example, patent DE 000002919901, 1980, patent WO 1998017582, 1998, is used as sorbing substances). year, patent RU 2236279, 2004, patent WO 2005118481, 2005) or a fiber form (for example, patent RU 2162010, 2001, patent RU 2429067, 2011) that removes heavy metals from water. When using weakly or strongly acidic cation exchange resins as cation exchanger (for example, patent WO 2005118482, 2005, patent RU 2236279, 2004), such a filter element additionally softens the water. For the enrichment of water with some mineral substances (mineralization), for example, fluorine, calcium, magnesium, zinc, either cation exchangers with cations of magnesium or zinc (for example, US 20180002197, 2018), or poorly soluble salts of these substances in the form of finely divided substances are used (RU patent 2092451, 1997, CN 107551645, 2018), or in the form of compressed tablets (e.g., patent RU 2533715, 2014, patent US 20190175456, 2019). A common drawback of the operation of gravity filters, in which the filter element with sorbing, softening and mineralizing substances is located in the lower part of the filter tank in the zone of purified water, is either their hyper-softening of water, that is, the transfer of water from the category of "medium hardness" (2-10 ° W) according to GOST 31865-2012 "Water. Unit of hardness" or 2-10 mEq / l) or "hard" (> 10 ° G according to GOST 31865-2012 "Water. Unit of stiffness" or more than 10 mEq / l) in the category of “excessively soft” (less than 2 ° F according to GOST 31865-2012 “Water. Unit of hardness” or less than 2 mEq / l), or the appearance of peak concentrations of mineralizing substances in purified water. Hyper softening of water and its result - excessive softness of water or its increased mineralization make water tasteless and harmful to the human body. The main reason for hyper softening and increased (peak) mineralization of water is the significant contact time of softening or mineralizing substances in the filter element body immersed in purified water with water and, as a result, additional sorption and mineralization processes occur.

The jug type gravity filters are known from the prior art, in which the filter element of the filter device is made either in the form of two (patent RU 2526377, 08.20.2014, RU 2538746, 01/10/2015, RU 2666419, 09/07/2018), or in the form three (patent RU 2540159, 02/10/2015 year), or in the form of more than three (patent CN 107551645, 2018) work areas that perform the functions of cleaning, softening or mineralizing water. In such filtering devices, the main working area in the form of a plastic vessel with sorbent components, which performs the function of sorption water purification, is located in the main body of the filtering element of the filtering device and is located in the bottom of the tank in the zone of purified water. The second working area in the form of an additional body with sorbing or softening components, which performs the function of either additional water purification or softening, is located inside the funnel and is connected to the main body of the working area. This arrangement of the second working area allows its softening components to contact with water only during its filtration, which reduces the effect of water softening. The third working area in the form of a plastic casing with mineralizing substances, which performs the function of mineralizing water, is located below the main working area and is located in the treated water zone.

The prototype of the claimed gravity filter is a gravity filter designed for purification, softening and mineralization of water, with a filter device, the filter element of which contains three working areas (patent RU 2540159 C1, 02/10/2015), one of which is located inside the funnel in the zone of water to be purified , and the other two are in the zone of purified water. The purified water passing from the filter funnel into the second working zone, made in the form of a plastic casing with holes in the side walls and the lid located in the filter funnel and filled with weakly acid cation exchanger, softens, and then passing through the main working zone, made in the form of a plastic casing with inlet and outlet openings located in a jug in the zone of purified water and filled with sorbing substances - a mixture of activated carbon, granular and fiber cation exchange resin - it is purified from chlorine, it is heavy of metals, organic, including organochlorine compounds, and, then, passing into the third working zone, made in the form of a single or multi-sector plastic housing, located in the filter in the zone of purified water and filled with mineralizing substances, it is saturated with mineral compounds .

The disadvantages of the gravity filter prototype are the complexity of the design of its filter device due to the presence of three working zones, each of which has its own plastic housing consisting of several parts, the complexity of the assembly of the filter device, due to the sequential three-stage filling of the filter element of the filter device with softening, sorbing and mineralizing substances in three work areas, and a multi-stage assembly of the device itself.

An object of the present invention is to provide a gravitational filter for purifying and softening or mineralizing drinking water, having a simple construction and assembly technology and providing highly efficient purification and softening or purification and mineralization of drinking water.

The technical task is achieved by the proposed gravity filter for cleaning and softening or mineralizing drinking water, containing a container for purified water, a funnel for receiving purified water located in its upper part, a filter device located inside the filter funnel, including a fixation system for the filter device in the filter funnel and a filter element made of porous block material in the form of a hollow vertical vessel with emollients located in its inner space m or mineralizing material, and the fixation system of the filter device is connected to the filter element by gluing or mechanical fastening, and the porous block material is obtained by compressing when heated a mixture of the starting components containing activated carbon particles and a polymer binder. The walls of the filter element are made in the form of a hollow vertical body with a section in the form of a circle (hollow cylinder), a square, oval or complex profile, or a hollow pyramid, or a truncated hollow cone, and are hermetically connected to the lid and bottom or glued with polymer melt or other adhesive materials or by mechanical connection. The height of the filter element is (30-100) mm, the thickness of the walls, lid and bottom is (5-25) mm. The pore size of the porous block material of the walls, bottom and cover of the filter element is smaller than the particle size of the softening and mineralizing material. The porous block material of the filter element is obtained by extrusion or hot pressing of a mixture of activated carbon particles with an iodine number of more than 1000 mg / g and a polymer binder from the classes of polyesters and / or polyolefins and / or their copolymers with a melt index (2-20) g / 10 min according to ASTM D 1238 at 190 ° C and a load of 25 Kg and with a particle size of activated carbon and a polymer binder (0.05-0.5) mm, preferably (0.07-0.15) mm and with an activated carbon ratio: polymer binder (75-95) :( 25: 5) wt. % with a compression ratio during molding (12-25)% at a temperature of (10-40) ° C higher than the softening temperature of the polymer binder. The walls of the filter element of the porous block material can be made either by extrusion or hot pressing. The walls, lid and bottom of the filter element of porous block material can be manufactured separately by hot pressing. Also, the details of the filter element from porous block material: the cover and the bottom, or the walls and the bottom, or the body and the cover, made as a whole, can be made by hot pressing.

The inner space of the filter element is filled by (70-90)% with either a softening material or a selectively mineralizing water material in the form of particles with a size of (0.1-2.0) mm, and synthetic cation exchange materials from the class of weakly or strongly acidic cation exchangers with a sorption exchange capacity (0.5-5) mEq / ml in H + or Na + form and / or inorganic cation exchange materials from the classes of natural or synthetic zeolites, aluminosilicates, silica gels and sulfonates, and as mineralizing The materials used are either slightly soluble calcium and / or magnesium compounds: calcium oxide, calcium hydroxide, calcium fluoride, calcium sulfate, calcium sulfite, calcium carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesium sulfite, magnesium silicate, magnesium chloride, or mixtures thereof or natural minerals based on them, or synthetic ion-exchange materials either from the class of weakly acid cation exchangers with cations of magnesium or zinc, or from the class of strongly basic anion exchangers with silicate anions. The fixation system of the filter device in the filter funnel is made in a form that allows the filter device to be sealed tightly in the filter funnel and is either a threaded assembly connected to the threaded funnel assembly or a rim with tight fit elements to the funnel opening that is attached to the filter element or by gluing either with polymer melt or any other adhesive material, or by mechanical connection with the inner or outer, or with the inner and outer walls pouring element.

A distinctive feature of the claimed invention is a fundamentally new, simpler compared to the prototype, design of a gravity filter for cleaning and softening or mineralizing water, in which the filter element is made in the form of a single vessel carrying out the processes of cleaning (sorption of toxic impurities) and softening or mineralization of water without the use of additional containers (housings), while the filter element performs two functions at once: the function of filter and sorbent material and the function of ca (walls, lid and bottom) of the filter element. This design of the filter element significantly simplifies the assembly technology of the filter device of the gravitational filter, because instead of a three-stage filling of the filter device with sorbing, softening and mineralizing materials, as is the case in the prototype, a one-stage filling is required in the claimed gravity filter. The location of the filter element inside the filter funnel of the jug type ensures that the softening or mineralizing materials located inside it contact the water only during its treatment, which contributes to uniform softening and mineralization of the water in combination with high efficiency of its purification. The invention is illustrated by drawings, in which:

1 - Filter jug type

2 - Intake funnel

3 - Locking system of the filter device

4 - Filtering device

5 - Filter element

6 - Walls of the filter element

7 - the cover of the filter element

8 - The bottom of the filter device

9 - Glue connection

10 - Softening or mineralizing material

11 - Mechanical connection

FIG. 1. A general view of a jug filter (1) with a funnel (2) and a filter device (4) placed in it with a filter element in the form of a hollow cylinder (5) with walls (6), a cover (7) and a bottom (8) is shown. bonded to the body by gluing (9). The fixation system (3) of the filter device to the filter funnel, made in the form of a threaded assembly, is glued to the side wall of the device housing. A softening or mineralizing material (10) is placed inside the filter element housing. Arrows indicate the direction of water movement during filtration.

FIG. 2. A filter device with a filter element in the form of a hollow cylinder with walls (6), a cover (7) mechanically connected to the walls (6) and a bottom made in the form of one element with walls is depicted. The fixation system (3) of the filter device to the filter funnel, made in the form of a rim with elements of a snug fit to the hole of the funnel, is mechanically connected (11) to the outer side wall of the device. A mixture of softening or mineralizing material (10) is placed inside the housing of the filter element.

FIG. 3. The filtering device of FIG. 3 (vertical section, and section A-A) with a filter element in the form of a vertical hollow vessel with an oval section with walls (6), a cover (7) and a bottom (8) connected to the body by gluing (9). The fixing system (3) of the filter device to the filter funnel, made in the form of a rim with elements of tight fit to the hole of the funnel, is mechanically connected (11) with the outer side wall of the filter element housing. A mixture of softening or mineralizing material (10) is placed inside the housing of the filter element.

The above images of the inventive filtering device give an idea of its design, but are not exhaustive.

The selected shape of the filter element either provides a given rate of water filtration by the filter element, which is proportional to the filtration area and is minimum for a filter element in the form of a disk and a hollow cylinder with a hermetically sealed plug bottom, and is maximum for a filter element with a porous bottom and a cross section of complex shape, or due to its manufacturing technology: filter elements in the form of a hollow cylinder with a plug are made by extrusion; filter elements in the form of a hollow cylinder with a porous bottom, a hollow vertical vessel with a cross section in the form of an oval or complex profile, as well as in the form of a cone or a pyramid with a porous bottom or without a porous bottom, and also in the form of a disk, are made by hot pressing.

To ensure the surface of the sorbents of the material of the housing, cover and bottom of the filter element that is most accessible for sorption, the manufacturing process of the filter block is carried out at a temperature of (10-40) ° C above the softening temperature of the polymer binder. At a temperature lower than 10 ° C the softening temperature of the polymer binder, the formation of a mechanically strong block material of the filter element does not occur, and at a temperature higher than 40 ° C the softening temperature of the polymer binder, a significant surface of the sorbent is blocked as a result of leakage of the polymer binder.

The choice of the range of compression ratio of the initial mixture of components of the granular material (12-25)% is due to the fact that in this range the production of mechanically strong porous material is ensured. When the compression ratio is less than 12%, the resulting material does not have the necessary mechanical strength. With a compression ratio of more than 25%, the resulting material contains small pores, which makes it difficult for water to pass through them.

The choice of a polymer binder from the class of polyolefins (for example, low-pressure polyethylene, high-pressure polyethylene, polypropylene) and polyesters (polyethylene terephthalate) or their copolymers (for example, a polyethylene-vinyl acetate copolymer) is caused, on the one hand, by their chemical inertness and insolubility in water, s on the other hand, sufficiently low softening temperatures, allowing to intensify the manufacturing process of the housing, cover and bottom of the filter element of the inventive filter device in the form of porosity wow block material. The wall thickness range of the porous block material of the housing, the cover and the bottom of the filter element, which is (5-25) mm, provides, on the one hand, an optimal filtration rate - with a wall thickness of more than 25 mm, due to the high hydrodynamic resistance, the filtration rate becomes unsatisfactory for practical use on the other hand, since the walls of the housing, the cover and the bottom of the filter element perform the function of sorption water purification, when their thickness is less than 5 mm, their volume becomes insufficient to accommodate I have in them a sufficient amount of sorbent - activated carbon.

Varying the height of the filter element housing in the range (30-100) mm is due to the fact that, with a housing height of less than 30 mm, the area and volume of the side walls become insufficient for effective sorption cleaning, just as the layer thickness becomes insufficient for effective softening and mineralization of water, through which passes water in the filter element. The height of the filter element housing of more than 100 mm makes it difficult to place the filter element inside the funnel of most existing jug type filters due to their size.

To ensure effective purification of water from chlorine, organic and organochlorine compounds, the porous block material of the housing, lid and bottom of the filter element is made using activated carbons with an iodine number of more than 1000 mg / l, since such carbons provide effective sorption and, therefore, water purification over a significant resource from these pollutants, and all the components used (sorbent and polymer binder) are used in powder form with a particle size of (0.05-0.5) mm, preferably (0.07 -0.15) mm. The particle size of the activated carbon and the polymer binder of less than 0.05 mm leads to an increase in the hydrodynamic resistance of the porous block material, and, as a result, to a decrease in the filtration rate. When the particle size of activated carbon and polymer binder is more than 0.5 mm, the efficiency of water purification decreases due to a decrease in the real surface of the filtration (sorption) of the sorbent particles.

The selected range of sorption capacity of ion-exchange material (0.5-5) mEq / l is due to the fact that when using materials with an exchange capacity of less than 0.5 mEq / l to achieve sufficient water softening efficiency for their acceptable resource for consumers would need to be used in an amount incompatible with the volume of the filter element; materials with an exchange capacity of more than 5 mEq / l are expensive and therefore cannot be used in mass-produced filters.

Filling the inner space of the filter element with either softening material and / or mineralizing material by (70-90)% of its internal volume is due to the need for the presence of these materials in the filter element in an amount that ensures effective softening and mineralization of water. When filling the inner space of the filter element with these materials less than 70% of its internal volume, the effectiveness of softening and mineralization becomes insufficient from a consumer point of view; when filling the inner space of the filter element with these materials more than 90% of its volume, pressure on the walls of the housing, the cover and the bottom of the filter element is possible due to an increase in the volume of cation exchange or anion exchange materials as a result of their swelling when they replace the counterion during water treatment, which can lead to to the destruction of the housing of the filter element. The particle size of the softening and mineralizing materials (0.1-2.0) mm is selected in order to ensure the maximum contact area of the particles of these materials with the treated water and the optimal hydrodynamic resistance, providing a satisfactory filtration rate. When the particle size of these materials is less than 0.1 mm, the water filtration rate of the filtering element is significantly reduced, when the particle size is more than 2 mm, the contact area of the softening and mineralizing particles with the treated water is reduced, which leads to unsatisfactory effectiveness of water softening and mineralization.

The inventive gravity filter for purification, softening or mineralization of drinking water (1) operates as follows: the water to be purified is poured into a funnel (2), from which it passes into the filtering device (4) through the side walls (6) and the cover (7) of the filter element ( 5) made of porous block material, being purified from toxic impurities. Then the water enters the inner hollow part of the filter element, where, depending on the material located there (10), it either softens and is cleaned of heavy metals (the material is a softener), or it is mineralized and cleaned of heavy metals, after which it passes through the bottom (8 ) the filter element to the bottom of the filter, where it is stored until it is used.

Below are examples of specific designs of the filtering device, and the table shows the results of their tests on the effectiveness of cleaning, softening and mineralization of water. The above examples give an idea of the characteristics of the claimed filtering device, but are not exhaustive.

Example 1. Gravity filter with a filtering device, in which a locking system in the form of a threaded assembly is connected to the filtering element by gluing with polyethylene melt, the walls of the filtering element are made in the form of a hollow cylinder with a height of 50 mm and a thickness of 15 mm; the walls and the bottom of the filter element are made in the form of one element, the cover is mechanically connected to the walls of the filter element .. The walls, cover and bottom of the filter element are made by hot pressing at a temperature of 145 ° C and a compression ratio of 12% of the mixture of activated carbon - 85 wt. %, polymer binder - polyethylene terephthalate with a softening temperature of 115 ° C - 15% wt. %, particle size of the mixture components (0.08-0.1) mm. A softening material is placed inside the filter element - weakly acid cation exchanger in H + form with a particle size of 0.3 mm, filling the internal volume of the filter element by 80%). Tests on the effectiveness of water purification and softening were carried out when the filter element was placed in the funnel of the pitcher filter. Evaluation of the effectiveness of softening was performed by measuring the hardness of the source and softened water at an initial water hardness of 5 ° hardness. The effectiveness of water softening and purification was carried out in accordance with GOST 31952-2012 WATER TREATMENT DEVICES. General requirements for effectiveness and methods for its determination. The test results are presented in the table.

Example 2. A gravity filter with a filter device, in which a locking system in the form of a rim with elements of tight fit to the hole of the funnel is attached to the housing of the filter element by mechanical fixation. The walls of the filter element in the form of a hollow cylinder with a height of 75 mm and a thickness of 20 mm are hermetically connected to the lid and the bottom by gluing with polyethylene melt. The walls, lid and bottom of the filter element are made of porous block material obtained by hot pressing at a temperature of 145 ° C and a compression ratio of 15% from a mixture: activated carbon - 90 wt. %, polymer binder - polyethylene terephthalate with a softening temperature of 115 ° C - 10 wt. %, particle size of the components of the mixture (0.06-0.08) mm. Inside the filter element there is a mineralizing material in the form of a mixture (30:70) wt. % ”Calcite with weakly acid cation exchanger with magnesium cations in an amount filling the internal volume of the filter element by 90%. Tests on the effectiveness of purification, softening and mineralization of water were carried out when placing the filter element in the funnel of the pitcher filter. Evaluation of the effectiveness of mineralization was carried out at an initial water hardness of 2 ° hardness and 5 ° hardness. Assessment of the effectiveness of water purification was carried out in accordance with GOST 31952-2012 WATER TREATMENT DEVICES. General requirements for effectiveness and methods for its determination. The effectiveness of water mineralization was carried out by the release of magnesium and calcium cations into water. The test results are presented in the table.

Example 3. A gravity filter with a filtering device with a locking system in the form of a threaded assembly connected to the filtering element by gluing with polyethylene melt. The walls of the filter element in the form of a hollow vertical body with an oval section 30 mm high and 10 mm thick are mechanically connected to the cover of the filter element, and the bottom and walls of the filter element are made as one element. The walls, the cover and the bottom of the filter element are made by hot pressing at a temperature of 135 ° C and a compression ratio of 25% from a mixture with a particle size of (0.12-0.2) mm, consisting of activated carbon -75 wt. % and polymer binder - 25 wt. % - a mixture of polyethylene terephthalate and low pressure polyethylene (85:15) wt. % with a softening temperature of 125 ° C. A softening material, a weakly acid cation exchanger in H + form, with a particle size of 0.7 mm in an amount filling the internal volume of the filter element by 70% is placed inside the filter element housing. Tests on the effectiveness of water purification and softening were carried out when the filter element was placed in the funnel of the pitcher filter. Evaluation of the effectiveness of softening was carried out by measuring the hardness of the source and softened water at an initial water hardness of 5 ° hardness. The effectiveness of water softening and purification was carried out in accordance with GOST 31952-2012 WATER TREATMENT DEVICES. General requirements for effectiveness and methods for its determination. The test results are presented in the table.

As follows from the table of the results of the resource tests for purification, softening and mineralization of water, the claimed gravity filter provides for an effective cleaning over a long life, sufficient softening from the consumer point of view and uniform additional mineralization of water with different hardness.

Effect: a gravity filter for purification and softening or mineralization of drinking water with a simplified design and assembly technology is proposed, while ensuring effective purification of water by toxic pollutants up to (91-98)%, and its softening throughout the life of at least 40 %, which is sufficient from a consumer point of view, as well as uniform mineralization of water of various hardness, provided that mineralizing substances are used in the proposed device, achieved by short-term contact mineralizing substance with purified water.

Claims (10)

1. Gravity filter for cleaning and softening or mineralizing drinking water, containing a container for purified water, a funnel for receiving purified water, located in its upper part, a filter device located inside the filter funnel, including a fixation system for the filter device in the filter funnel and a filter element made of a porous block material in the form of a hollow vertical vessel with a softening or mineralizing material located in its inner space, and the filter fixing system The device is connected to the filter element by gluing or mechanical fastening, and the porous block material is obtained by compressing when heated a mixture of the starting components containing activated carbon particles and a polymer binder. 2. The gravity filter for purification and softening or mineralization of drinking water according to claim 1, characterized in that the fixation system of the filter device is made in a form that allows the filter device to be sealed in the filter funnel and represents a threaded assembly connected to the threaded funnel assembly, or a rim with elements of tight fit to the opening of the funnel, which are attached to the housing of the filter element by gluing with polymer melt, or any other adhesive material, or by mechanical connection eniya with the inner or the outer or the inner and outer walls of the filter element. 3. Gravity filter for cleaning and softening or mineralization of drinking water according to claim 1, characterized in that the height of the filter element is (30-100) mm. 4. Gravity filter for cleaning and softening or mineralization of drinking water according to claim 1, characterized in that the filter element is made in the form of a hollow vertical vessel with porous walls, a bottom and a lid. 5. Gravity filter for purification and softening or mineralization of drinking water according to claim 1, characterized in that the porous block material of the filter element contains pores whose size is smaller than the particle size of the softening or mineralizing material. 6. Gravity filter for cleaning and softening or mineralization of drinking water according to claim 1, characterized in that the thickness of the porous block material of the filter element is (5-25) mm. 7. Gravity filter for purification and softening or mineralization of drinking water according to claim 1, characterized in that as a porous block material of the filter element using a heat-treated mixture of powdered materials from activated carbon with an iodine number of more than 1000 mg / g and a polymer binder with a size particles of activated carbon and a polymer binder (0.05-0.5) mm, preferably (0.07-0.15) mm and with a ratio of activated carbon: polymer binder (75-95) :( 5-25) wt.% . 8. The gravity filter for cleaning and softening or mineralizing drinking water according to claim 1, characterized in that the porous block material of the filter element is made by extrusion or hot pressing at a temperature of (10-40) ° C higher than the softening temperature of the polymer binder, and with a compression ratio during molding (12-25)%, and polymers from the classes of polyolefins and / or polyesters and / or their copolymers with a melt index (2 -20) g / 10 min according to ASTM D 1238 are used as a polymer binder 190 ° C and a load of 25 kgf. 9. The gravity filter for purification and softening or mineralization of drinking water according to claim 1, characterized in that the inner space of the filter element is filled with (70-90)% softening material with a particle size of (0.1-2.0) mm from class weakly or strongly acidic cation exchangers with a sorption exchange capacity of (0.5-5) mEq / ml in H + or Na + form and / or from classes of synthetic or natural zeolites, aluminosilicates, silica gels and sulfonates, or a mixture thereof. 10. The gravity filter for cleaning and softening or mineralizing drinking water according to claim 1, characterized in that the inner space of the filter element is filled with (70-90)% water-mineralizing material with a particle size of (0.1-2.0) mm from sparingly soluble compounds of calcium and / or magnesium, or natural minerals based on them, or synthetic ion-exchange materials, or from the class of weakly acid cation exchangers with cations of magnesium or zinc, or from the class of strongly basic anion exchangers with silicate anions.

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