Device to produce a descaling composition

Abstract

A device that can be interfaced with the equipment to be cleaned, this device being capable of dispensing a descaling composition when connected with or inserted into the hydraulic circuit of the equipment to be cleaned, and a method for carrying out the process. The invention finds use for cleaning and / or descaling surfaces.

Description

TECHNICAL FIELD The present invention belongs to the technical field of descaling agents and relates in particular to a descaling composition and application thereof. The invention provides a device, which is used to obtain a descaling composition after contact with water, and a method for carrying out the process. The invention finds use for cleaning and / or descaling surfaces. BACKGROUND Known boiling I chilled water dispensing units comprise a heating water tank and a cooling water tank, both connected to mains water supply. A filter is generally interposed between the mains water supply and the heating and cooling water tanks to remove any substances or particulate matter or the like from the mains water supply, according to the filter specification. Filtration technology is used to deliver pure tasting water and deliver health benefits and contaminant reduction. Aesthetic improvements achievable with the filter include bacteriostatic effects, reduction of chemical contents (taste, odour, chlorine), and mechanical filtration to remove suspended particles; health effects can also be claimed, when the filter is able to remove heavy metals (e.g., lead) or bacteria. Some filters are even designed to reduce water hardness. Hard water is water that has a high mineral content (as opposed to “soft water”). Hard drinking water has moderate health benefits, but can pose critical problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling towers, and other water handling equipment. In domestic environments, hard water is often indicated by the lack of foam formation when soap is stirred into the water, and by the formation of limescale in kettles and water heaters. Wherever water hardness is a concern, water softening is commonly used to reduce hard water’s adverse effects. Water hardness is determined by the concentration of multivalent cations in the water. Common cations found in hard water include calcium (Ca2+) and magnesium (Mg2+). These ions enter a water supply by leaching from minerals within an aquifer. Common calcium-containing minerals are calcite and gypsum, while a common magnesium mineral is WO 2024 / 207076                                                 PCT / AU2024 / 050330 dolomite (which also contains calcium). Rainwater and distilled water are soft, because they contain few ions. The following equilibrium reaction describes the dissolution and formation of calcium carbonate (on the left) and calcium bicarbonate (on the right): CaCO3 (s) + CO2 (aq) + H2O (I) # Ca2+ (aq) + 2 HCO3’ (aq) The reaction can go in either direction. Rain containing dissolved carbon dioxide can react with calcium carbonate and carry calcium ions away with it. Then, the calcium carbonate may be re-deposited as calcite as the carbon dioxide is lost to atmosphere. The presence of dissolved bicarbonate minerals (calcium bicarbonate and magnesium bicarbonate) is generally referred to as “temporary hardness”. When dissolved, these types of minerals yield calcium and magnesium cations (Ca2+, Mg2+) and carbonate and bicarbonate anions (COs2- and HCO3’). The presence of the metal cations makes the water hard. However, unlike the permanent hardness caused by sulphate and chloride compounds, this "temporary" hardness can be reduced either by boiling the water, or by adding lime (calcium hydroxide) via the lime softening process. Boiling promotes the formation of carbonate from the bicarbonate and precipitates calcium carbonate out of solution, leaving softer water on cooling. Sulphate and chloride salts of calcium and magnesium do not precipitate out as the temperature increases. This mineral content is responsible for what is generally referred to as “permanent hardness”. The ions that cause permanent water hardness can be removed using a water softener (i.e., an ion exchange resin). Hard water can form deposits that clog plumbing. These deposits, called “scale”, are mainly composed of calcium carbonate (CaCOs), magnesium hydroxide (Mg(OH)2), and calcium sulphate (CaSO4). Calcium and magnesium carbonates tend to be deposited as whitish solids on the internal surfaces of pipes and heat exchangers. This precipitation (formation of an insoluble solid) is mainly caused by the thermal decomposition of bicarbonate ions but also occurs in cases where the carbonate ion is at saturation concentration. The resulting scale build-up restricts the flow of water in pipes; in boilers, the deposits impair the flow of heat to the water, reducing the thermal efficiency and allowing the metal components of the boiler to overheat. In a pressurized system, this overheating can lead to boiler failure. The presence of ions in an electrolyte (in this case, hard water) can also lead to galvanic corrosion, where one metal will preferentially corrode when in contact with another type of metal, when both are in contact with the electrolyte. As mentioned, hard water reduces the efficiency of water heaters: due to the thermal conversion of calcium and magnesium bicarbonates (soluble salts) into carbonates (insoluble salts), limescale creates a barrier between the heating elements and the water in the tank. This forces the water heater to work harder and longer to heat the water, which can significantly increase operating costs and shorten the heater’s operating life. Water hardness can create problems not only when it is high, but also when it is too low: in this case, in fact, the water can be corrosive to metal pipes, fixtures, and appliances. The US National Academy of Sciences states that drinking hard water contributes to the dietary needs for calcium and magnesium. Recommendations have been made for maximum and minimum levels of calcium (40-80 ppm) and magnesium (20-30 ppm) in drinking water, and for a total hardness expressed as the sum of calcium and magnesium concentrations of 2-4 mmol / L (F. Kozisek, Health significance of drinking water calcium and magnesium, 2003). To remedy the problems caused by hardness on the heating elements, it is common practice to use cleaning products designed to remove limescale. These are acidic products, mainly based on citric, lactic, tartaric, glycolic, phosphoric or sulfamic acid, or a combination thereof. There are both powder formulations (which therefore need to be dissolved at the time of use) and liquid ones, and their use is relatively easy when it is possible to easily access the hydraulic circuit to be treated. If this is the case for coffee machines or water kettles, access to boiling I chilled water dispensing units designed to be installed in confined spaces (e.g., under the sink in the kitchen) is not so easy and generally requires the intervention of technical personnel, able to disassemble (at least partially) the equipment, to access the tanks and carry out the cleaning operation. The products currently available on the market are in solid or liquid form and must first be dissolved or mixed with water. Products in solid form are not easy to use as the user must establish how much product to dissolve in which volume of water, identify a suitable container for the operation, carry out the operation taking care not to come into contact with the solution (due to its irritating or corrosive characteristics), and finally identify the way to add the solution to the equipment to be cleaned. Using a product that comes in liquid form simplifies the process somewhat, as the product mixes more easily with water, but does not eliminate the other complications mentioned. It is an object of the present invention, in one embodiment, to provide a device that can be interfaced with the equipment to be cleaned, this device being capable of dispensing a descaling composition when connected with or inserted into the hydraulic circuit of the equipment to be cleaned. WO 2024 / 207076                                                 PCT / AU2024 / 050330 The device of the present invention, in certain embodiments, eliminates the problems associated with the use of products currently available on the market and, perhaps the main aspect, eliminates the risk of a possible contact with the solution by the user. A further problem with descaling products currently available on the market (and this applies in particular to those in liquid form) is that their marketing requires careful labelling work, in order to comply with the legislation governing the marketing of “dangerous” (irritants, or corrosive) products. It is a further object of the present invention, in certain embodiments, to provide a non-hazardous product which therefore does not require any special labelling. SUMMARY OF THE INVENTION The present invention, in one embodiment, relates to a device that can be interfaced with the equipment to be cleaned (e.g., a boiling I chilled water dispensing unit), this device being capable of dispensing a descaling composition when connected with or inserted into the hydraulic circuit of the equipment to be cleaned. The invention further relates to a method for descaling the heating water storage tank and the heating elements of a boiling I chilled water dispensing unit, using the acid solution (descaling formulation) produced by the device of the present invention. In a first aspect, the invention provides a device that allows obtaining an aqueous solution containing salts. In a second aspect, the invention provides a device for placing an ion exchange resin in acid form in contact with the aqueous solution containing salts, in order to obtain an acid solution (descaling formulation). In another aspect, the invention provides a device that allows to flush the equipment to be cleaned with the produced acid solution (descaling formulation). Also disclosed herein is a method for treating an equipment that contains scale, using the acid solution (descaling formulation) produced by the device. In some embodiments, the aqueous solution containing salts is obtained by flowing mains (drinking) water through the device and dissolving a water-soluble salt present inside the device. The nature of this water-soluble salt is chosen according to the descaling WO 2024 / 207076                                                 PCT / AU2024 / 050330 formulation to be obtained. For example, the use of sodium chloride or sodium citrate allows obtaining a descaling solution based respectively on hydrochloric acid or citric acid. The device also contains an ion exchange resin in acid form; in some embodiments, the resin is a strong acid cation (SAC) exchange resin; most SAC resins are composed of a polymer matrix (e.g., a styrene and divinylbenzene polymer) to which anionic functional groups, such as sulphonate (-SO3”), are bound. SAC resins are regenerated with either a sodium salt solution (Na+)for softening applications, or with an acid (IT) for demineralization applications. Weak acid cation (WAC) exchange resins are used to remove cations associated with alkalinity; they typically employ carboxylic acid functional groups (-RCOO-) and are regenerated with sulphuric or hydrochloric acid. Finally, in some embodiments, the device is equipped with means for interfacing with the equipment to be cleaned (e.g., a filter key for removable connection to the filter head manifold, in lieu of the filter unit), so as to allow effective hydraulic connection, without leaks, and a simple and clean user experience. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of a boiling I chilled water dispensing unit. Figure 2 is a schematic diagram of the boiling I chilled water dispensing unit of Figure 1, with the device of the present invention temporarily installed in lieu of the filter unit. DETAILED DESCRIPTION Figure 1 schematically depicts an exemplary boiling I chilled water dispensing system 100 for dispensing boiling I chilled water through a fluid pathway 102 into a water dispensing assembly 104. In this example, the dispensing assembly 104 represents a water dispenser for dispensing boiling I chilled water. Assembly 104 has a number of components fluidly connected to each other to define the fluid pathway 102. The component may include a valve assembly 106 having a pressure limiting valve (PLV) 108 and a multiport valve 110, a filter assembly 112 having a filter head manifold 114, a water storage tank 116, a heating means 118, a pump 120, and a dispensing tube 122. Valve assembly 106 includes an inlet 124 for receiving a supply of water under pressure, typically from a mains water supply. The pressure at the inlet 124 is regulated by the PLV 5 108 to ensure that the pressure within the fluid pathway 102 remains below a pre-set value (e.g., 500 kPa). Water from the inlet 124 is conveyed to the filter head manifold 114 through the multiport valve 110. Detachably removable from the filter head manifold 114 is a filter unit 134 for purifying the water supplied from the inlet 124. Attached to (or included in) the filter unit 134 is a filter key 136 that allows the filter unit 134 to be connected to the filter head manifold 114. Purified water leaving the filter unit is conveyed back through the filter head manifold 114 and returned to the valve assembly 106 via the multiport valve 110. From here, the purified water is conveyed downstream of the multiport valve 110 to a pressure-compensated flow regulator or restrictor 127 which is configured to maintain a constant flow rate of purified water through the fluid pathway 102 at varying static pressures (e.g., between 100 and 500 kPa). The flow of water through the valve assembly 106 to the heating and cooling water tanks is controlled or regulated by a series of solenoid-actuated valves 126. Preferably, the constant flow rate of purified water is between 1.0 litres / min and 3.0 litres / min. In many domestic or commercial purified drinking water dispensing systems, the flow rate is maintained at approximately 2.5 litres / min. Note that, in Figure 1, only the water heating tank 116 is shown. Downstream of the flow restrictor 127 is the heating water storage tank 116 for receiving the purified water through a tank inlet 128. The heating means 118 is located inside the heating water storage tank 116 and is in the form of a heating coil 130 which is immersed in the water in the heating water storage tank 116 during use. The heating means 118 is powered by a heating power source (not shown) and is adapted to heat the water in the heating water storage tank 116 upon activation. A tank outlet 132 conveys the heated purified water from the heating water storage tank 116 to the pump 120. The pump 120 is configured to deliver the purified water to a tap (not shown) via the dispensing tube 122. The system 100 may also include a smart firmware protocol (not shown) to allow the user to set various process parameters (e.g., maximum and minimum temperatures for the dispensed heated I chilled water, etc.) or to guide the user through several processes. The firmware may be available during the product commissioning phase or made available in a later phase of the maintenance service. A system 200 according to a first embodiment of the present invention is represented in Figure 2. The system 200 has an identical configuration to the system 100 of Figure 1, apart WO 2024 / 207076                                                 PCT / AU2024 / 050330 from the presence of the device 234 for obtaining a descaling composition, which is temporarily installed in lieu of the filter unit 134. According to Figure 2, water from the inlet 124 is conveyed to the filter head manifold 114 through the multiport valve 110. Detachably removable from the filter head manifold 114 is the device 234 for obtaining a descaling composition. Attached to (or included in) the device 234 is a filter key 236 that allows the device 234 to be connected to the filter head manifold 114. The device 234 contains at least one water-soluble salt and at least one ion exchange resin in acid form. The water-soluble salt is chosen according to the descaling formulation to be obtained. For example, the use of sodium chloride or sodium citrate allows obtaining a descaling solution based respectively on hydrochloric acid or citric acid. Other suitable salts include the alkali metal salts of inorganic and organic acids (e.g., sodium sulphate, potassium nitrate, sodium sulfamate, etc.). The person skilled in the art will appreciate that the use of any water-soluble salt can lead to the synthesis of the corresponding acid of the anion considered. For example, sodium chloride, sodium citrate, sodium sulphate, and sodium sulfamate can lead to respectively obtaining hydrochloric acid, citric acid, sulphuric acid, and sulfamic acid. The person skilled in the art will also appreciate that the solubility of the salt depends on the nature of the salt itself; for example, the solubility of potassium nitrate in water is 383 g / L at 25°C, while that of sodium nitrate is 912 g / L (“Physical Constants of Inorganic Compounds”, in CRC Handbook of Chemistry and Physics, David R. Lide, ed., CRC Press, Boca Raton, FL, 2005). Consequently, if a descaling formulation based on nitric acid is desired, it appears more appropriate to use sodium nitrate instead of potassium nitrate, since the latter is less soluble. If a citric acid-based descaling formulation is desired, it is advisable to use trisodium citrate pentahydrate (solubility of 920 g / L, molar mass of 348.06 g / mol) instead of tripotassium citrate monohydrate (solubility of 640 g / L, molar mass of 324.40 g / mol). Similarly, for a sulfamic acid-based descaling formulation, sodium sulfamate (solubility of 1652 g / L) appears more appropriate than potassium sulfamate (777.5 g / L). The device also contains at least one ion exchange resin in acid form; in a preferred embodiment, the resin is a strong acid cation exchange resin, in which anionic functional groups, such as sulphonates (-SO3”), are bound to a polymer matrix. A resin in acid form has protons bound to the anionic functional groups (e.g., the functional groups are sulfonic acid moieties, -SO3H). In a less preferred embodiment, a weak acid cation exchange resin typically employing carboxylic acid moieties (-RCOOH) may also be employed. WO 2024 / 207076                                                 PCT / AU2024 / 050330 The device 234 may also contain means for forcing the water to follow a certain path or for preventing the ion exchange resin beads from being entrained by the water flow. The means for forcing the water to follow a certain path can consist of a series of walls, having the purpose of increasing the length of the path between the inlet and the outlet from the device. In one embodiment, said means may consist of a series of concentric cylindrical walls, organized in such a way as to force the water to move from top to bottom, and vice versa, inside the container, and from the outside to the inside, until it reaches a conduit towards the outlet. Alternatively, the water can be directed towards the bottom of the device through a conduit, and then allowed to permeate through the active bed (represented by the resin and the salt) until it comes out of an outlet conduit located at the top. As regards the means for preventing the ion exchange resin beads from being entrained by the water flow, these can be represented by one or more mesh filters or perforated sheets, which have openings smaller than those of the ion exchange resin beads. At least one of them must be located near the outlet conduit. According to an embodiment of the present invention, when water from the inlet 124 is conveyed into the device 234, the dissolution of the water-soluble salt supplies the water with cations which can then be exchanged for the protons of the ion exchange resin. As a result, the water inside the device 234 is converted into an acid solution, which can then be used for the descaling of various components installed downstream of the device 234. Since temperature can improve the rate of most chemical reactions, the descaling properties of the acid solution can be greatly enhanced by heating the solution. Those skilled in the art will therefore recognise that the effectiveness of the acid solution will greatly increase as the solution is conveyed to the heating water storage tank 116 and the heating means 118 powered on. As mentioned above, this operation can be managed through dedicated instructions within the smart firmware protocol. The latter may also contain instructions for activating / pausing the solenoid-actuated valves 126 and regulating the contact time of the water inside the device 234, so as to allow the proper dissolution of the salt and the subsequent release of protons by the ion exchange resin. Since the heating water storage tank 116 may have a larger volume than that of the device 234, the filling of the heating water storage tank 116 with the acid solution produced by the device 234 can take place in several steps. In some embodiments, multiple aliquots of acid solution are conveyed to the heating water storage tank 116 and the heating process is started once the tank is full. Considering that the water-soluble salt and the ion exchange resin within the device 234 become progressively depleted during contact with multiple volumes of water, the concentration of the acid solution is expected to decrease with the number of volumes of water treated within the device 234. To take advantage of the higher acidity in the initial volumes of acid solution produced, in some embodiments, the heating process can begin once the heating coil 130 of the heating means 118 is fully submerged in the solution. Such an approach allows focusing on the heating coil 130 of the heating means 118, rather than on the walls of the heating water storage tank 116, maximizing the descaling strength of the solution. The smart firmware protocol included in the system may contain instructions on the dwell time for the descaling treatment; the heating water storage tank 116 may contain a temperature probe to monitor the temperature of the liquid and allow the smart firmware protocol to power the heating means 118 as required, thus avoiding the occurrence of overheating conditions. The smart firmware protocol may also contain instructions for flushing the heating water storage tank 116 with purified filtered water after the descaling procedure is completed; in such a case, the smart firmware protocol may guide the user through the process of removing the device 234, and reinstalling the filter unit 134, before finalising the descaling procedure. Although specific embodiments of the invention are illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternative and / or equivalent implementations exist. It should be appreciated that the exemplary embodiment or exemplary embodiments are examples only and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein. It will also be appreciated that in this document the terms “comprise”, “comprising”, “include”, “including”, “contain”, “containing”, “have”, “having”, and any variations thereof, are intended to be understood in an inclusive (i.e. non-exclusive) sense, such that the process, method, device, apparatus or system described herein is not limited to those features or parts or elements or steps recited but may include other elements, features, parts or steps not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the terms “a” and “an” used herein are intended to be understood as meaning WO 2024 / 207076                                                 PCT / AU2024 / 050330 one or more unless explicitly stated otherwise. Moreover, the terms “first”, “second”, etc. are used merely as labels, and are not intended to impose numerical requirements on or to establish a certain ranking of importance of their objects. The following examples, whose purpose is purely illustrative and not limiting the present invention, are provided to describe the use of the device and highlight some characteristics of the various descaling solutions obtainable. Example 1: Tests in batch mode. The device of the present invention contains at least one water-soluble salt and at least one ion exchange resin in acid form; the water-soluble salt is chosen according to the descaling formulation to be obtained. To test the effect of contacting the mixture with water, 250 g of resin in acid form (for example, Purofine® PFC100H) were dispersed in 3 L of RO water, and the pH measured and recorded. For clarity, RO water means tap water that has been run through a reverse osmosis system, to remove most of the dissolved ions, unwanted molecules, and larger particles potentially present prior to the treatment. The effectiveness of the reverse osmosis treatment is apparent during the execution of the tests, since the pH of the resin dispersion in osmotic water is different from that of the resin dispersion in tap water (because the latter contains ions exchangeable with the protons of the resin, dispersion in tap water has a more acidic pH). Several tests were performed, each time starting from 250 g of resin in acid form, dispersed in 3 L of RO water, and using different salts. For these tests, the salts were chosen because they were available, therefore without any preclusion or reasoning as to the nature of the descaling solution obtained. Increasing quantities of salt were added to the dispersion and the pH was measured and recorded when the measurement stability was reached, i.e. when the equilibrium of the chemical exchange reaction between the cations supplied by the salt and the protons released from the resin was reached. The obtained pH data are shown in Table 1. Table 1. pH measured for a dispersion of 250 g of resin in acid form in 3 L of RO water, after addition of increasing amounts of salts. SALT +5 g +10 g +15 g +20 g +30 g Sodium Sulphate decahydrate 2.10 1.90 1.83 1.80 1.70 Sodium Nitrate 1.85 1.60 1.49 1.40 1.30 Monosodium Phosphate 2.28 2.10 1.95 1.85 1.80 Trisodium Citrate dihydrate 2.87 2.70 2.60 2.60 2.55 Sodium Chloride 1.75 1.50 1.40 1.35 1.29 Table 1 shows that the final pH value differs according to the salt used, since the exchange reaction with the resin produces a solution of a more or less strong acid, which can also be more or less buffered. As expected from a chemical point of view, the solution obtained by using sodium chloride is clearly more acidic than that obtained by using sodium citrate; on the other hand, monosodium phosphate produces a buffer solution containing phosphoric acid and monosodium phosphate. Example 2: Tests with the device (flow through mode). A device according to the present invention was assembled by mixing a given amount of resin in acid form and a given amount of water-soluble salt (sodium chloride, for these tests); tap water was flown through the device at different flow rates, collecting it in an initially dry and clean container. When 3 L of water passed through the device, the flow was stopped and the pH of the water in the container was measured and recorded. Several tests were carried out, starting each time with a new portion of resin in acid form and using different quantities of salt. For these tests, sodium chloride was chosen, without paying particular attention to the nature of the descaling solution obtained. The water flow rate was controlled using a flow restrictor able to limit the flow rate to 2.5 litres per minute. The pH of the obtained solutions is shown in Table 2. Table 2. pH measured for the solution obtained by passing 3 L of tap water through the device of the present invention, filled with 200 or 250 g of resin in acid form, and with different amounts of sodium chloride. Test conditions pH of the solution 200 g or resin + 20 g of NaCI, flow rate of 2.5 L / min 1.53 200 g or resin + 40 g of NaCI, flow rate of 2.5 L / min 1.35 250 g or resin + 50 g of NaCI, flow rate of 2.5 L / min 1.30 250 g or resin + 100 g of NaCI, flow rate of 2.5 L / min 1.25 An additional test was performed by replacing the 2.5 L / min flow restrictor with a 1.1 L / min one and using the same conditions shown in the first row of Table 2; the pH of the obtained solution resulted to be 1.55, suggesting that, although the conditions of higher flow rate decrease the residence time of the water in the device, the better mixing allows to better exploit the functions of the device. Certain embodiments of the present invention, as described in the above description, are: A. A device when used for obtaining a descaling composition (234) upon contact with water, containing at least one water-soluble salt and at least one ion exchange resin in acid form. B. A device according to A, wherein said device also contains means for forcing the water to follow a certain path or for preventing the ion exchange resin beads from being entrained by the water flow. C. A device according to claim B, wherein said means for forcing the water to follow a certain path consist of a series of walls, having the purpose of increasing the length of the path between the inlet and the outlet from the device. D. A device according to claim B, wherein said means for preventing the ion exchange resin beads from being entrained by the water flow consist in one or more mesh filters or perforated sheets, which have openings smaller than those of the ion exchange resin beads. E. A device according to any of A-D, wherein said device also contains a filter key (236) to allow connection to a filter head manifold (114). F. A device according to any of A-E, wherein at least one water-soluble salt is chosen according to the descaling formulation to be obtained. G. A device according to any of A-F, wherein at least one ion exchange resin is a strong acid cation exchange resin. H. A device according to G, wherein the ion exchange resin contains sulphonate functional groups bound to a polymer matrix. I. A method for descaling the heating water storage tank (116) and the heating means (118) of a boiling I chilled water dispensing unit using a device according to any of the previous claims, the method including the steps of: • temporarily installing the device for obtaining a descaling composition (234) to the filter head manifold (114) of the water dispensing unit, in lieu of the filter unit (134); • conveying water from the inlet (124) into the device for obtaining a descaling composition (234), to allow the dissolution of at least one salt, supply the water with cations that can be exchanged with the protons of at least one ion exchange resin, and finally converting the water into an acid solution; • conveying a sufficient volume of acid solution into the heating water storage tank (116) to at least completely submerge the heating coil (130) of the heating means (118); • powering the heating means (118) to heat the solution. J. The method of I, further comprising the step of keeping the heated acid solution in contact with the surfaces to be descaled for a dwell period. K. The method of K, further comprising the following steps: • removing the device for obtaining a descaling composition from the filter head manifold (114) of the water dispensing unit; • re-installing the filter unit (134) into the filter head manifold (114); • flushing the heating water storage tank (116) with purified filtered water after the dwell period for the descaling procedure is completed. WO 2024 / 207076 REFERENCE NUMERAL LIST 100 Exemplary boiling I chilled water dispensing unit 102 Fluid pathway 104 Water dispensing assembly 106 Valve assembly 108 Pressure limiting valve (PLV) 110 Multiport valve 112 Filter assembly 114 Filter head manifold 116 Water storage tank 118 Heating means 120 Pump 122 Dispensing tube 124 Inlet of valve assembly 126 Solenoid-actuated valve 127 Pressure-compensated flow restrictor 128 Tank inlet 130 Heating coil 132 Tank outlet 134 Filter unit 136 Filter key 200 System according to a first embodiment 234 Device for obtaining a descaling composition

Claims

1. A device (234) when used for obtaining a descaling composition upon contact with water, containing at least one water-soluble salt and at least one ion exchange resin in acid form, wherein said device contains a series of walls to increase the length of a path between an inlet and an outlet of the device, and means for preventing the ion exchange resin from being entrained by water flow through the device.

2. A device according to claim 1, wherein said means for preventing the ion exchange resin beads from being entrained by the water flow consist in one or more mesh filters or perforated sheets, which have openings smaller than those of the ion exchange resin beads.

3. A device according to any of the previous claims, wherein said device also contains a filter key (236) to allow connection to a filter head manifold (114).

4. A device according to any of the previous claims, wherein at least one water-soluble salt is chosen according to the descaling composition to be obtained.

5. A device according to any of the previous claims, wherein at least one ion exchange resin is a strong acid cation exchange resin.

6. A device according to claim 5, wherein the ion exchange resin contains sulphonate functional groups bound to a polymer matrix.

7. A method for descaling a heating water storage tank (116) and a heating means (118) of a boiling / chilled water dispensing unit using a device according to any of the previous claims, the method including the steps of:• temporarily installing the device for obtaining a descaling composition (234) to the filter head manifold (114) of the water dispensing unit, in lieu of a filter unit (134) connected to the filter head manifold (114);• conveying water from the inlet (124) into the device for obtaining a descaling composition (234), to allow the dissolution of at least one salt, supply the water with cations that can be exchanged with the protons of at least one ion exchange resin, and finally converting the water into an acid solution;• conveying a sufficient volume of acid solution into the heating water storage tank (116) to at least completely submerge a heating coil (130) of the heating means (118) in the heating water storage tank;• powering the heating means (118) to heat the acid solution.2024253427   07 Sep 20268. The method of claim 7, further comprising the step of keeping the heated acid solution in contact with the surfaces to be descaled for a dwell period.

9. The method of claim 8, further comprising the following steps:• removing the device for obtaining a descaling composition from the filter head manifold (114) of the water dispensing unit;• re-installing the filter unit (134) into the filter head manifold (114);• flushing the heating water storage tank (116) with purified filtered water after the dwell period for the descaling procedure is completed.

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