Cartridge or filter candle for softening drinking water, swimming pool and bathing pool water

Abstract

Cartridge (14) or filter candle (20) for a table water filter (10), a water softening system (1) and / or a system for softening swimming and bathing pool water, wherein the cartridge (14) or filter candle (20) is filled with a zeolite granulate (17) designed as a molecular sieve, characterized in that more than 10 wt% water is added to the zeolite granulate (17) in the delivery state, based on the solids content.

Description

Field of invention

[0001] The invention relates to a method for softening drinking water, swimming pool and bathing water, and / or process water. The invention further relates to a device used for this purpose and to a cartridge or filter candle for water softening. Background of the invention

[0002] Water contains calcium and magnesium ions, the so-called hardness-causing minerals. These minerals tend to precipitate when the temperature and / or pH level rises. This process forms limescale (limescale or magnesium limescale). Approx 2+ + 2 HCO3 - → CaCO3 + CO2 + H2O Mg 2+ + 2 HCO3 - → MgCO3 + CO2 + H2O

[0003] This leads to the formation of unsightly limescale deposits that must be removed using cleaning agents. This is particularly relevant for swimming pools.

[0004] Limescale buildup can damage technical equipment (e.g., heat exchangers, water heaters, heating systems). Furthermore, increasing limescale formation impairs heat transfer and thus reduces energy efficiency. Hard water also leads to increased consumption of soaps and detergents, as insoluble calcium and magnesium salts form before the soaps or detergents can take effect.

[0005] For this reason, many waters are softened. In practice, organic ion exchangers are most commonly used for this purpose. The ion exchanger exchanges the calcium and magnesium ions in the water for the sodium ions on the ion exchanger. 2 R Org Na + Ca 2+ → R Org 2 Ca + 2 Na +

[0006] The ion exchangers currently in use have an organic matrix (e.g., cross-linked polystyrene). The disadvantage of this organic matrix is ​​that organic matter can migrate into the water, leading to contamination. Furthermore, the mechanical stress on the ion exchanger material as water flows through it can cause the formation of microplastics, which are harmful to the environment and human health. In addition, microorganisms readily colonize these materials and metabolize the organic matter. This can lead to bacterial contamination of the treated water.

[0007] To disinfect ion exchangers, oxidative disinfectants are used (for example, sodium hypochlorite, hypochlorous acid, active chlorine, e.g., produced from sodium chloride by electrolysis). However, some of the chlorine reacts with the organic matrix of the ion exchanger, is thus degraded, and is no longer available for disinfection. Furthermore, disinfection byproducts (bound chlorine) are formed, which can contaminate the wastewater and can also adsorb onto the ion exchanger. Later, when the ion exchanger is in operation, these byproducts can desorb and contaminate the treated water.

[0008] In some parts of the world, it is common practice to chlorinate drinking water for disinfection purposes (e.g., in the USA, Italy, France, and also in some regions of Germany). When organic ion exchangers are used in chlorinated drinking water, the chlorine reacts with the organic matrix of the ion exchanger, is broken down, and is no longer available to maintain disinfection capacity. The resulting disinfection byproducts, which can be harmful to health, directly contaminate the drinking water.

[0009] Furthermore, there are kettles with integrated filter cartridges filled with organic ion exchangers to soften the water supplied to the kettle. During the boiling process, the organic ion exchanger comes into contact with the rising steam, causing it to partially decompose. The decomposition products pass into the condensate, and any dripping condensate contaminates the hot water. Object of the invention

[0010] In contrast, the invention is based on the objective of at least reducing the aforementioned disadvantages of the prior art.

[0011] In particular, an object of the invention is to provide a method for softening drinking water, swimming pool water, bathing water, or process water, in which organic ion exchangers can be dispensed with and / or in which chlorine that is not used or only used to a small extent is degraded. Summary of the invention

[0012] The object of the invention is already solved by a method for softening drinking water, swimming pool and bathing water or process water, by a device for softening and by a cartridge or filter candle according to one of the independent claims.

[0013] Preferred embodiments and further developments of the invention can be found in the subject matter of the dependent claims, the description and the drawings.

[0014] The invention relates to a method for softening drinking water, swimming pool and bathing pool water and / or process water.

[0015] For this purpose, a table water filter, a filter cartridge, a water softener and / or a system for softening swimming and bathing pool water is used.

[0016] Tabletop water filters consist of a pitcher with a funnel containing a filter cartridge filled with an ion exchange material.

[0017] The water poured into the funnel typically flows through the filter cartridge by gravity alone and collects in the pitcher. Filter cartridges used in countertop water filters are generally not regenerated but disposed of once exhausted.

[0018] Water softeners are primarily used for supplying drinking water to homes. They are typically installed inline in a water supply line. The ion exchange material in the water softener is usually regenerated automatically.

[0019] Furthermore, there are water softening systems designed as under-sink water filters for a faucet or as filter cartridges for beverage production systems (e.g., water dispensers, coffee machines). Water softening systems for heating systems can also include a filter candle or cartridge with an ion exchange material, through which the water used to fill the heating system is passed.

[0020] The invention further relates to a system for softening the swimming and bathing pool water of a swimming pool.

[0021] According to the invention, the drinking water, swimming pool water, bathing pool water, or process water is passed through a molecular sieve.

[0022] Molecular sieves are porous, inorganic materials belonging to the class of aluminosilicates. According to current technology, molecular sieves are primarily used for gas processing (e.g., for drying, removal of hydrogen sulfide, carbonyl sulfides, mercaptans, carbon dioxide, nitrogen, and hydrocarbons).

[0023] It has been shown that when molecular sieves are pretreated with an aqueous salt solution, especially sodium chloride solution, they are subsequently able to absorb the dissolved calcium and magnesium ions from a water stream and exchange them for sodium ions.

[0024] The molecular sieve acts as an inorganic ion exchanger, thereby depleting the water of calcium and magnesium while simultaneously enriching it with sodium. 2 R Anorg Na + Ca 2+ → R Anorg 2Ca + 2Na +

[0025] Similarly, the calcium and magnesium ions dissolved in the water can be exchanged for other cations if the molecular sieve has been pretreated with an aqueous salt solution of the corresponding cation. For example, an exchange for potassium ions occurs with pretreatment using an aqueous potassium salt solution (e.g., potassium chloride), or an exchange for zinc ions occurs with pretreatment using an aqueous zinc salt solution (e.g., zinc chloride). Similarly, the calcium ions dissolved in the water can be exchanged for magnesium ions if the molecular sieve is pretreated with an aqueous magnesium salt solution (e.g., magnesium chloride). 2 R Anorg K + Ca 2+ → R Anorg 2Ca + 2 K + R Anorg 2Zn + Ca 2+ → R Anorg 2Ca + Zn 2+ R Anorg 2Mg + Ca 2+ → R Anorg 2Ca + Mg 2+

[0026] It has been found that molecular sieves, especially zeolites, have a sufficient capacity for water softening and, like organic ion exchangers, can also be regenerated with a saline solution.

[0027] Zeolites, however, contain no organic components and do not react with substances used for disinfection, such as chlorine.

[0028] In particular, a zeolite A and / or zeolite X can be used as a molecular sieve.

[0029] The method according to the invention is particularly suitable for water containing chlorine, especially water with a total chlorine content of at least 0.05 mg / l. The method according to the invention can therefore be used in particular for swimming pool and bathing pool water.

[0030] According to a preferred embodiment of the invention, a system for softening swimming and bathing pool water is used, wherein the swimming pool is first filled with water and this water is then pumped through the molecular sieve by a pump in recirculation mode. The required make-up water is passed directly through the molecular sieve.

[0031] Using conventional water softening systems with an organic ion exchanger makes it difficult to soften the water for a swimming pool, as these systems are very complex to dimension for the high volume flow required to fill a swimming pool in a sufficiently short time, and organic ion exchangers cannot be used in the circulation flow because, as described above, they consume the chlorine present in the water.

[0032] Since the zeolites according to the invention do not react with the commonly used chlorine, the water softening system can be operated in recirculation mode and thus soften the water gradually.

[0033] The inflow concentration of the water softener changes constantly during this operating mode. Here, c(t) = Co e (-v̇*t / v) . where c(t) is the concentration of water hardness at time t, c o The initial water hardness concentration, V the volume flow rate of the water passing over the zeolite, and V the system volume. The water softener's control system regenerates according to this formula instead of solely based on operating time and / or treated water volume. This extends the operating time of the water softener before regeneration is due, thus saving regeneration fluid, water, and wastewater.

[0034] According to a further development of the invention, the regeneration intervals of the system are thus increased with increasing water softening, particularly of swimming pool and bathing pool water. The next regeneration is therefore carried out after a volume of water, which increases with each regeneration, has passed through the molecular sieve.

[0035] This can be done, for example, based on a calculated data set stored in the system's control unit. The initial water hardness and the volume of water to be softened are included in the data set.

[0036] Preferably a molecular sieve with a mean pore size of over 2 angstroms, preferably over 3 angstroms and / or under 15 angstroms, preferably under 8 angstroms, is used.

[0037] In particular, a granulate is used as the molecular sieve. The granulate preferably has a mean particle size between 0.2 mm and 5 mm.

[0038] It has been found that a high capacity for a zeolite can be achieved when using such materials.

[0039] Preferably, a table water filter, a filter cartridge, a water softening system and / or a system for softening swimming and bathing pool water is used, which does not include an organic ion exchanger.

[0040] The inventive method allows the total hardness of drinking and / or bathing water to be reduced by at least 2 °dH, preferably by at least 10 °dH, simply by passing it over the molecular sieve.

[0041] In a preferred embodiment of the invention, the table water filter, the filter cartridge, the water softening system and / or the system for softening swimming and bathing pool water is supplied with a zeolite granulate to which, based on the solids content, at least 10% by weight of water has been added.

[0042] Therefore, at least 10 g of water are added to 100 g of zeolite granules. Adding such a small amount of water reduces the heat generated by hydration energy during the initial use of the granules to such an extent that no disruptive heat buildup occurs.

[0043] Preferably, less than 25% by weight, preferably less than 20% by weight, water is added to the zeolite granules.

[0044] This means the granules are not yet so wet that water leaks out during transport.

[0045] The granules can, for example, be sprinkled with water and optionally dried to the desired residual moisture content.

[0046] However, according to another embodiment of the invention, the residual moisture of the zeolite material can also be specifically adjusted to such a low water content that, upon initial contact with water in the table water filter, in the filter cartridge, the water softening system and / or the system for softening swimming and bathing pool water, a heat generation, in particular up to 100 °C, occurs which can be used for disinfection.

[0047] The invention further relates to a device for carrying out the method described above. This device is particularly designed as a table water filter, filter cartridge, or under-sink filter with a cartridge or filter candle. Furthermore, the device can be designed as a water softening system in which the molecular sieve is automatically regenerated by passing a salt solution, in particular a sodium chloride solution, through it.

[0048] According to a further development of the invention, the device, in particular if it is designed as a water softening system, can include a pressure relief valve through which gas formed due to heat development in the molecular sieve can escape.

[0049] The invention further relates to a cartridge or filter candle filled with zeolite granules and designed for use in a device described above, in particular a countertop water filter or an under-counter water softener. Preferably, the cartridge or filter candle is filled with the zeolite granules to at least 30%, preferably at least 60% of its volume.

[0050] To reduce heat generation during initial use, at least 10% by weight of water, but preferably less than 20% by weight, can be added to the zeolite granules in the delivered state, based on the solids content.

[0051] The cartridge or filter candle may be packaged in a tear-open pouch upon delivery. However, the amount of water added to the zeolite granules is so small that no water escapes after removal from the pouch.

[0052] Preferably, the cartridge or filter candle has an internal volume between 50 and 2000 ml.

[0053] The cartridge or filter candle is preferably free of organic ion exchangers; in particular, the zeolite granules are not mixed with any other solid.

[0054] This can result in a pure, single-material product that is well suited for recycling.

[0055] An ion exchanger made of an inorganic matrix would therefore be advantageous. This would prevent the water from being contaminated with organic matter and would simplify disinfection.

[0056] It has now been discovered that so-called molecular sieves can also be used for water softening and function as ion exchangers.

[0057] The method according to the invention is suitable for softening virtually any type of water. It can be used particularly for drinking water. Description of exemplary embodiments: Example embodiment 1:

[0058] A molecular sieve (zeolite A) is regenerated with an aqueous sodium chloride solution, thereby converting it to the sodium form. The molecular sieve is rinsed with water and is then ready for operation. In operating mode, water is passed over the molecular sieve, resulting in water that is depleted of calcium and magnesium (softened) and enriched with sodium. After a certain operating time, the exchange capacity of the molecular sieve is exhausted. It can then be regenerated with an aqueous sodium chloride solution and is subsequently ready for operation again.

[0059] It is a reversible process: Operating mode: Water softening: 2 R Anorg Na + Ca 2+ → R Anorg 2Ca + 2Na + Regeneration: R Anorg 2Ca + 2Na + → 2 R Anorg Na + Ca 2+

[0060] Instead of regeneration with sodium chloride, potassium chloride or another salt can also be used. The ion exchange then takes place against the cation of this salt, e.g., potassium. Example 2:

[0061] 50 ml of molecular sieve are placed in a column and washed with 1000 ml of demineralized water. For regeneration, 65 ml of sodium chloride solution (c=60 g / l) are then passed over the molecular sieve and subsequently washed with 500 ml of demineralized water. Next, calcium- and magnesium-containing water (test water) is passed over the molecular sieve. This water has a calcium concentration of 155 mg / l and a magnesium concentration of 26 mg / l. This results in a total hardness of 27.6 °dH (German hardness) for the test water. The hardness is measured at the column outlet, depending on the volume of test water flowing through it. 1The molecular sieve is then regenerated with the aforementioned sodium chloride solution, and the loading process with the aforementioned test water is repeated. The total hardness is again determined in the column outlet (run). 2 ) . List of characters Fig. Figure 1 is a schematic view of a system for softening swimming and bathing pool water. Fig. Figure 2 is a perspective view of a table water filter. Fig. Figure 3 is a cross-sectional view of the filter cartridge used in the table water filter. Fig. Figure 4 shows a filter candle. Fig. Figure 5 is a diagram showing the total hardness of the effluent from the column containing the molecular sieve, according to the preceding embodiment example 2. Detailed description of the drawings

[0062] Fig. Figure 1 is a schematic view of a swimming and bathing water pool 7, which is equipped with a water softening system according to the invention. 1 is provided.

[0063] The water softener 1 includes a pump 3 as well as a container 2 , which is filled with zeolite granules (not shown).

[0064] The water softening system is connected to the water pipes via an inlet. 4 connected, via the water from swimming pool 7 by means of the pump 3 through the container 2 is being pumped.

[0065] The water softener 1 Softened water is returned to swimming pool 7 via outlet 5.

[0066] The water softener 1 It is therefore operated in recirculation mode.

[0067] This has the advantage that the swimming pool 7 can first be filled with water, with a flow rate to which the softening layer can be adjusted. 1 is not designed for this.

[0068] Then the water softening system is used. 1 The water is softened.

[0069] Due to the use of a zeolite as an ion exchanger, the chlorine used in swimming pool 7 is not broken down.

[0070] The attachment 1 The system can include a bypass 6, through which a portion of the water is not softened but returned to the swimming pool 7. This allows the water softening system to be smaller than required for the full circulation flow rate.

[0071] For the regeneration of the zeolite in the container 2 will be the feed water 9 with salt from a brine tank 8 passed over the zeolite at intervals.

[0072] The zeolite is regenerated by exchanging it for sodium ions. The salt solution used for regeneration is then drained off. 23 fed into the sewer system.

[0073] The distances between the intervals, relative to the volume of water passing through the container 2 The volume of water supplied can be increased with increasing softening of the water in the swimming pool (7).

[0074] This can be achieved, for example, by a system control unit (not shown) in which the amount of water to be softened and its initial hardness level can be stored.

[0075] Fig. Figure 2 is a schematic view of a table water filter. 10 .

[0076] The table water filter 10 includes a jug 11 , in which a funnel 12 is used.

[0077] Into the funnel 12 is in turn a cartridge 14used, which is filled with zeolite granules.

[0078] Via an enema 13 Water is poured into the funnel 12 filled.

[0079] The water flows through the cartridge by gravity. 14 and collects in the jug 11 .

[0080] Fig. Figure 3 is a sectional view of the cartridge. 14 .

[0081] The cartridge 14 includes at least one inlet; in this embodiment, there are two inlets of different heights, namely the inlets 16a and 16b , available.

[0082] The cartridge also includes 14 a sealing edge 18 , by means of which it sits sealed in the funnel.

[0083] Via the inlet 16a , 16b The water flows into the cartridge. 14 , passes through the filter medium and exits via an outlet 15 out of.

[0084] Unlike the filter cartridges most commonly used in practice, this cartridge 14 not with an organic ion exchange resin, but with zeolite granules 17 filled.

[0085] The filter bed is free of organic components. Preferably, the cartridge 14 only with zeolite granules 17 filled. However, the use of an organic ion exchange resin and / or activated carbon has been omitted.

[0086] The use of this filter cartridge 14 This has the advantage that no organic components are released into the water. Furthermore, the risk of bacterial contamination is significantly lower than with organic ion exchange resins. In particular, according to one embodiment, activated carbon can be omitted.

[0087] Fig. 4 shows a filter candle 20, as is usually the case with inline use for a water softening system connected to the mains, for example a table water filter.

[0088] The filter candle 20 includes a head with a connector 21 This can, for example, include a thread and encompasses inlet and outlet.

[0089] The case 22 the filter candle 20 According to the invention, it is also filled with zeolite granules.

[0090] Fig. Figure 5 shows a diagram in which the total hardness of the effluent is plotted according to the embodiment 2 described above.

[0091] The x-axis represents the volume passed through the molecular sieve, and the y-axis represents the total hardness (°dH) of the effluent from the column containing the molecular sieve.

[0092] It is particularly noticeable that even after regeneration with the sodium chloride solution, the capacity is almost identical to the first run. Reference symbol list 1 water softener 2 containers 3 Pump 4 Inlet 5 outlet 6 Bypass 7 swimming pools 8 brine containers for regenerating the molecular sieve 9 Feed water 10 table water filters 11 cans 12 funnels 13 Filling opening 14 cartridges 15 outlet 16a,16b Enema 17 Zeolite granules 18 Sealing edge 20 filter candles 21 connection 22 cases 23 Procedure 24 filters

Claims

[1] Method for softening drinking water, swimming pool and bathing water and / or process water, wherein a table water filter, a filter cartridge, a water softening system and / or a system for softening swimming pool and bathing water is used. characterized by that the drinking water, swimming pool water and / or process water is passed through a molecular sieve. [2] Method according to the preceding claim, characterized by that a zeolite is used as the molecular sieve, in particular a zeolite A and / or zeolite X. [3] Method according to any of the preceding claims, characterized by , that chlorine-containing water is softened, in particular water with a total chlorine content of at least 0.05 mg / l. [4] Method according to any of the preceding claims, characterized by, that a system for softening swimming and bathing pool water is used, wherein the swimming pool is first filled with water and this water is then pumped through the molecular sieve by a pump in recirculation mode. [5] Method according to any of the foregoing claims, characterized by , that regeneration intervals of the water softening system, in particular the system for softening the water of a swimming and bathing pool, are increased with increasing water softening. [6] Method according to any of the foregoing claims, characterized by that a molecular sieve with a mean pore size of over 2 Ångström, preferably over 3 Ångström and / or under 15 Ångström, preferably under 8 Ångström, is used. [7] Method according to any of the foregoing claims, characterized by , that a granulate is used as the molecular sieve, in particular with a mean grain size between 0.2 mm and 5 mm. [8] Method according to any of the foregoing claims, characterized by that a table water filter, a filter cartridge, a water softening system and / or a system for softening swimming and bathing pool water is used which does not include an organic ion exchanger. [9] Method according to any of the foregoing claims, characterized by that the total hardness of the drinking and / or swimming and bathing pool water is reduced by at least 2 °dH, preferably by at least 10 °dH, by passing it over the molecular sieve. [10] Method according to any of the preceding claims, characterized by that the molecular sieve is regenerated with a salt solution, in particular a sodium chloride solution. [11] Method according to any of the foregoing claims, characterized bythat the table water filter, the water softening system and / or the system for softening swimming and bathing pool water is supplied with zeolite granules to which, based on the solids content, at least 10% by weight of water has been added and / or that less than 25% by weight, preferably less than 20% by weight, of water has been added to the zeolite granules. [12] Method according to any of the foregoing claims, characterized by , that the zeolite is adjusted to such a low water content that upon initial contact with water in the table water filter, in the filter cartridge, the water softening system and / or the system for softening swimming and bathing pool water, a heat development, especially up to 100 °C, occurs which is used for disinfection. [13] Device designed to carry out a method according to any of the preceding claims. [14] Cartridge or filter candle for use in a device according to one of the preceding claims, wherein the cartridge is filled with zeolite granules. [15] Cartridge or filter candle according to the preceding claim, characterized by that the cartridge or filter candle is filled with the zeolite granules to at least 30%, preferably at least 60%, of its volume. [16] Cartridge or filter candle according to any of the preceding claims, characterized by , that the zeolite granules in the delivered state, in particular where the cartridge or filter candle is in a tear-open package, have more than 10% by weight of water added, based on the solids content, and / or that the cartridge and / or filter candle is free of organic ion exchangers, in particular that the zeolite granules are not mixed with any other solid.

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