Installation system and methods for the mineralization of drinking water

Abstract

Installation system with a cartridge for mineralizing drinking water, wherein the cartridge comprises a housing with an inlet and an outlet, which is filled with calcium and / or magnesium oxide and / or calcium and / or magnesium carbonate, wherein the cartridge is also filled with a peroxide and wherein the calcium and / or magnesium oxide and / or calcium and / or magnesium carbonate is in granular form and is mixed with the peroxide.

Description

Field of invention

[0001] The invention relates to an installation system and a method for mineralizing drinking water with calcium and / or magnesium. In particular, the invention relates to an installation system with a cartridge designed as a filter candle, which is used in households, catering establishments, and the beverage industry. Background of the invention

[0002] Magnesium and calcium are important trace elements for the human body. When dissolved in water, they are also called minerals.

[0003] In areas with mineral-poor water, especially in mountainous regions, the water contains little calcium and magnesium.

[0004] It is therefore known to pass the water through a filter cartridge with a filter bed containing magnesium and calcium, thus mineralizing the water.

[0005] Filter cartridges containing magnesium carbonate, magnesium oxide, calcium oxide and calcium carbonate are particularly well-known.

[0006] In addition to the minerals magnesium and calcium, acid-neutralizing bicarbonate is also added to the water.

[0007] Besides mineralizing water that is naturally low in minerals, it is also common practice to demineralize the water first. In particular, the water can be passed through an ion exchanger to produce almost completely demineralized water.

[0008] For use as drinking water, the water can be remineralized in the next step, as described above.

[0009] This approach has the advantage that, regardless of the composition of the input water, an almost constant composition of the output water is always achieved.

[0010] This approach is therefore particularly suitable for machines for preparing hot drinks, such as fully automatic coffee machines, but also in the beverage industry.

[0011] Filter cartridges, especially filter candles, must be replaced at regular intervals.

[0012] Firstly, the calcium and magnesium-containing materials present in the cartridge are consumed depending on the amount of water treated.

[0013] Secondly, even if the cartridge is only used occasionally, it should be replaced at regular intervals.

[0014] Otherwise, there is a risk that microorganisms will multiply in the cartridge and contaminate the water.

[0015] Such microorganisms can be flushed from the incoming water into the cartridge.

[0016] Furthermore, especially during longer periods of stagnation, i.e., periods of non-use, there is a risk of backflow contamination. Microorganisms migrate against the flow of water, particularly as biofilm along pipe walls.

[0017] Document US 2013 / 0022686A1 describes a water treatment process that specifically removes heavy metals. Documents DE 19821609A1 and DE 19851345A1 describe the treatment of wastewater and lake / pond water, respectively. Document US 2016 / 0214877A1 describes the addition of a water treatment agent containing calcium oxide, calcium carbonate, or magnesium oxide. Object of the invention

[0018] In contrast, the invention is based on the objective of reducing the aforementioned disadvantages of the prior art. Summary of the invention

[0019] The object of the invention is already achieved by an installation system with a cartridge for mineralizing drinking water with the features of claim 1 and by a method for mineralizing drinking water with the features of claim 7.

[0020] Preferred embodiments and further developments of the invention can be found in the subject matter of the dependent claims and in the drawing.

[0021] The cartridge is designed for the mineralization of drinking water and includes a housing with an inlet and an outlet.

[0022] The cartridge can be, in particular, a filter candle which can be connected to a filter head that is connected to a building's water pipe.

[0023] However, the cartridge can also be designed as a cartridge for a gravity-driven water management filter.

[0024] The casing is filled with calcium and / or magnesium oxide and / or calcium and / or magnesium carbonate.

[0025] In particular, the filter bed contains both carbonates and oxides.

[0026] According to the invention, the cartridge is also filled with a peroxide.

[0027] It has been found that during stagnation phases, i.e. when no water is drawn and no water flows through the cartridge, the addition of a peroxide produces a harmless amount of hydrogen peroxide, which kills microorganisms in the filter bed without deteriorating the quality of the treated water.

[0028] The reaction rate when dissolving calcium peroxide or magnesium peroxide granules in particular is so slow that a measurable amount of hydrogen peroxide is only formed during stagnation phases.

[0029] In addition to killing microorganisms in the filter bed, back-contamination in the installation system is also reduced or even completely prevented.

[0030] The carbonates and oxides are present as granules, as is preferably the peroxide.

[0031] Peroxides that are particularly suitable are peroxides of metals, especially alkali metals and alkaline earth metals.

[0032] Sodium peroxide, potassium peroxide, magnesium peroxide, calcium peroxide and zinc peroxide, as well as mixtures of at least two of the peroxides mentioned, are particularly suitable.

[0033] Agglomerated materials, in particular, are easy to handle, as dust formation is largely prevented.

[0034] In particular, the peroxide material may be in the form of at least some alkali metal peroxide granules and / or alkaline earth metal peroxide granules and / or metal peroxide granules, especially calcium or magnesium peroxide.

[0035] Adding one of these materials can raise the pH value of the water in the filter during stagnation phases, especially to 10-13. This can kill microorganisms.

[0036] Furthermore, hydrogen peroxide can form, which also kills microorganisms.

[0037] It is therefore an alkalizing and / or oxidizing material.

[0038] A peroxide material is preferred which has particles whose particle size is less than 5 mm, preferably less than 3 mm, particularly preferably in the range between 0.2 and 10 mm, preferably between 0.5 and 2.5 mm.

[0039] These granulated peroxide materials dissolve in water so slowly that hydrogen peroxide is only formed in the water in the water treatment plant during the stagnation phase in a measurable quantity, in particular more than 1 mg / l, maximum 50 mg / l, which has the desired biocidal effect.

[0040] This reduces or even almost completely prevents biofilm formation and the associated recontamination of the installation system and / or the growth of microorganisms into the cartridge, as well as the release of microorganisms into the water taken after the stagnation phase.

[0041] In particular, the growth of germs or biofilm through the cartridge is prevented.

[0042] As soon as water is drawn off, the hydrogen peroxide formed during the preceding stagnation phase is flushed into the drawn water and is therefore present in low concentration in relation to the total amount of water drawn off.

[0043] Calcium peroxide granules and magnesium peroxide granules, produced by pressing peroxide powder into a molded body and then breaking it up, are particularly suitable for use in the invention. Such materials are described, for example, in DE 102 48 652 A1. Compared to the corresponding non-agglomerated peroxides, these are less prone to clumping or dusting and are therefore easier to dose.

[0044] According to one embodiment of the invention, the cartridge also contains cross-linked silica, in particular polysilicic acid.

[0045] Drinking water typically contains only small amounts of silicon. Silicon is a so-called trace element that the human body needs and which, in many cases, is beneficial to health. Silicon deficiency can cause health problems such as hair loss, brittle nails, impaired collagen production, and decreased elasticity of the skin and blood vessels, as well as osteoporosis. A number of diseases, such as diabetes, atopic dermatitis, arteriosclerosis, kidney stones, and goiter, are also associated with silicon deficiency. With increasing age, the silicon content in some tissues, such as blood vessels, bones, and skin, can decrease.

[0046] It is therefore important to provide the body with a sufficient amount of silicon.

[0047] The addition of silicon can also improve the taste of the water.

[0048] The amorphous silicon dioxide can be present in particular in an amount of at least 5%, but preferably less than 40% (percentages always refer to the dry weight of the filter bed in weight percent).

[0049] The cross-linked silicic acid releases silicon when it passes through water.

[0050] Preferably, cross-linked silica is used in the form of a silica gel in the form of an aqueous, porous, amorphous modification of silicon dioxide (SiO2).

[0051] Instead of cross-linked silicic acid and silica gel, the terms "amorphous silicon dioxide", "polysilicic acid" and "silicic acid dioxide" are often used.

[0052] At least when selecting a material with high moisture content and / or a high proportion of silanol groups, such a high solubility can be achieved that sufficient silicon release is obtained.

[0053] A hydrolysis reaction appears to be necessary for dissolving cross-linked silica. The dissolution rate therefore depends on the hydrolysis rate, which in turn depends on the modification of the silicon dioxide. For modifications, especially those of highly heated silicon dioxide with a framework structure containing many Si-O-Si bonds, the energy requirement is higher, as these bonds must first be cleaved. Therefore, modifications with a high water content and / or a high loss on ignition are preferred.

[0054] When cross-linked silica comes into contact with water, less polymerized or unpolymerized silica is released (e.g., monosilicic acid, disilicic acid).

[0055] Silica is a weak acid. Therefore, it only slightly alters the pH value and conductivity of the treated water.

[0056] Cross-linked silica can be produced, for example, as follows.

[0057] Possible starting materials for the cross-linked silica are aqueous solutions of alkali silicate, preferably sodium silicate, from which an amorphous silica is precipitated by the addition of an acid.

[0058] The precipitated silica is filtered off, washed and dried.

[0059] Preferably, the silica is not heated above 250 °C during drying, as otherwise the silanol groups may be cleaved off. According to a preferred embodiment of the invention, the cross-linked silica has a loss on ignition at 1000 °C of more than 6%, preferably more than 7% (analogous to FGK-AV “Loss on Ignition” (2012-12)). The loss on ignition is therefore determined according to FGK-AV “Loss on Ignition”, only at a slightly lower temperature of 1000 °C. In particular, the loss on ignition is between 7% and 9%.

[0060] Loss on ignition is a measure of the proportion of silanol groups. As explained above, silicas contain a certain amount of water chemically bound in the form of silanol groups. This is determined by the loss on ignition at 1000 °C. The loss on ignition can be determined based on the original substance, but is calculated using the substance dried at 105 °C.

[0061] Preferably, the silica has a loss on drying of over 30%, preferably over 40%, particularly preferably over 50%, and especially a loss on drying of 55 to 65%. The loss on drying can be determined according to DIN EN ISO 787-2 - 1995-04.

[0062] It has been found that silica can be heated to about 130 °C and dried without a significant decrease in solubility.

[0063] According to a preferred embodiment of the invention, the silica has a specific surface area of ​​over 300 m². 2 / g, preferably over 700 m 2 / g, especially preferred above 800 m 2 / g, especially between 820 and 1000 m 2 / G.

[0064] The specific surface area can be determined according to the BET method according to DIN ISO 9277-2017-07.

[0065] Silica is preferably used, which has a solubility at 25 °C (in deionized water) of over 80 mg / l, preferably over 100 mg / l, and particularly preferably over 150 mg / l. In particular, the solubility is between 140 and 180 mg / l (calculated as SiO₂). The solubility can be determined by stirring a sufficient quantity of silica, large enough that it does not dissolve completely, in 25 °C warm water until saturation is reached.

[0066] The silica can be in the form of granules, especially with a mean grain size of 0.5 to 3.0 mm.

[0067] The internal structure of silica consists of a large network of interconnected microscopic pores with a high content of silanol groups, which can attract and retain water through physisorption and capillary action. This gives the material sufficient solubility in water. This is achieved by using silica with a high specific surface area and a high proportion of silanol groups (characterized by a high loss on ignition at 1000 °C).

[0068] Preferably, the cartridge is filled with synthetically produced silica.

[0069] Substances registered as silica, in particular under CAS numbers 112926-00-8, 7631-86-9, 1343-98-2, 7699-41-4, 63231-67-4 or 10193-36-9, may be used.

[0070] In addition to silicon enrichment of drinking water, it has been shown that this can also effectively provide corrosion protection for installations and machines.

[0071] According to one embodiment of the invention, the filter bed contains over 3%, preferably over 5%, particularly preferably over 10% peroxide.

[0072] Preferably, the filter bed contains less than 50%, more preferably less than 30% and most preferably less than 25% peroxide.

[0073] In another embodiment of the invention, a zinc peroxide is used.

[0074] The cartridge is preferably filled with at least 40% calcium and / or magnesium oxide and / or carbonate.

[0075] The invention further relates to a method wherein the cartridge described above is used in an installation system.

[0076] The water is passed over a filter bed containing calcium and / or magnesium oxide and / or carbonate to release calcium and / or magnesium into the water.

[0077] According to the invention, during a stagnation phase, the filter bed is disinfected by a dissolving peroxide with hydrogen peroxide.

[0078] The peroxide is preferably configured such that at least 1 mg / l, preferably less than 50 mg / l, of hydrogen peroxide is formed during a stagnation phase.

[0079] Before mineralization, the water can be demineralized. This ensures a consistently uniform water composition. Detailed description of the drawing

[0080] The subject matter of the invention will below be described with reference to the exemplary embodiment according to Fig. 1 will be explained in more detail.

[0081] Fig.Figure 1 is a schematic view of a cartridge 1, which in this embodiment is designed as a filter candle 1.

[0082] The filter candle 1 includes a head with a connection which is designed for insertion into a filter candle head (not shown) already present on site and connected to a water pipe.

[0083] The head of the filter candle 1 includes an inlet 3 and an outlet 4, which is designed as a ring main extending around the inlet 3.

[0084] Entrance 3 leads into a downpipe 6.

[0085] In this embodiment, the filter candle 1 is screwed into the filter candle head (not shown) via a thread 5.

[0086] The housing 2 of the cartridge 1 comprises a filter bed 8, which is formed from magnesium carbonate, magnesium oxide, calcium oxide, calcium carbonate and / or a mixture thereof and at least one peroxide, in particular magnesium peroxide or calcium peroxide.

[0087] The water flows through the inlet 3 along the downpipe 6 to the bottom of the housing 2, where it enters the filter bed 8 via an inlet 7, which may include a filter.

[0088] The water then passes through the filter bed 8 in the opposite direction and is enriched with at least calcium and magnesium.

[0089] Preferably, the filter bed 8 also contains granular amorphous silicon dioxide.

[0090] The water to be treated passes through a further filter layer 9, which may contain activated carbon for the removal of pollutants, for example, to the outlet 4 and is forwarded to the point of consumption.

[0091] During operation, the functionality differs from that of conventional filter cartridges, except for the use of amorphous silicon dioxide. The reaction rate of the peroxide granules is so low that no measurable amount of hydrogen peroxide is released into the water being treated during operation.

[0092] During a stagnation phase, however, hydrogen peroxide is formed, which has a germicidal effect due to its oxidative properties.

[0093] This keeps the filter bed 8 germ-free.

[0094] Furthermore, cartridge 1 prevents backflow contamination towards the installation system.

Claims

[1] Installation system with a cartridge for mineralizing drinking water, wherein the cartridge comprises a housing with an inlet and an outlet, which is filled with calcium and / or magnesium oxide and / or calcium and / or magnesium carbonate, wherein the cartridge is also filled with a peroxide and wherein the calcium and / or magnesium oxide and / or calcium and / or magnesium carbonate is in granular form and is mixed with the peroxide. [2] Installation system according to the preceding claim, characterized by that the cartridge is also filled with an amorphous silicon dioxide, in particular with at least 5% and / or less than 40%. [3] Installation system according to one of the preceding claims, characterized by that the cartridge contains, relative to the filter bed, over 3%, preferably over 5%, particularly preferably over 10% and / or under 50%, preferably under 30%, particularly preferably under 25% peroxide. [4] Installation system according to one of the preceding claims, characterized by that the peroxide is a calcium peroxide, magnesium peroxide and / or zinc peroxide. [5] Installation system according to any of the preceding claims, characterized by that the cartridge is filled with at least 40% calcium and / or magnesium oxide and / or calcium and / or magnesium carbonate. [6] Installation system according to one of the preceding claims, characterized by that the cartridge is designed as a filter candle that can be connected to a connection head or as a cartridge for a gravity-driven water filter. [7] Method for mineralizing drinking water using a cartridge in an installation system according to one of the preceding claims, wherein the water is passed over a filter bed containing calcium and / or magnesium oxide and / or calcium and / or magnesium carbonate to transfer calcium and / or magnesium to the water, wherein in a stagnation phase the filter bed is disinfected by a dissolving peroxide with hydrogen peroxide and wherein the calcium and / or magnesium oxide and / or calcium and / or magnesium carbonate is in granular form and is mixed with the peroxide. [8] Method according to claim 7, characterized by that the water is demineralized before mineralization.

Images