Removable scale collector and inhibitor filter

Abstract

The present invention provides a device (1000) with steam function, wherein the device (1000) comprises a water supply port (101), a scale inhibitor dosing element (200), a flow control device (300), a heating unit (400), a scale collector element (500) and a water treatment unit (600), wherein (i) the flow control device (300) is configured to provide a fluid (19) comprising water (10) to flow from the water supply port (101) via the heating unit (400) to the water treatment unit (600); (ii) the scale inhibitor dosing element (200) is configured to A scale inhibitor (250) is provided to the water (10) in the heating unit (400) and / or at a position upstream of the heating unit (400); (iii) the heating unit (400) is configured to heat the water (10) in a heating mode and to convert the water (10) into steam (11) in a steam generation mode; and (iv) a scale collector element (500) is arranged downstream of the heating unit (400) and upstream of the flow restriction (650), wherein the scale collector element (500) is configured to collect scale particles (21) from a fluid (19) flowing through the scale collector element (500).

Description

Technical Field

[0001] The present invention relates to the field of scale in steam devices, and more particularly to devices with steam functionality, where scale can be collected to reduce uncontrolled scale deposition in the device. The invention also relates to a scale disposal unit and a method of collecting scale in a device with steam functionality. Background Art

[0002] The problem of scale formation in devices in which water is heated is known in the art. For example, WO2005 / 108311 describes a method for reducing limestone scale deposits on surfaces and in heating elements, particularly for drinking water in food service vending and dispensing machines without affecting the water quality. The method comprises passing water through metal particles and polyphosphates to remove minerals therefrom and thereby reduce scale deposits on water contacting parts of such machines. Summary of the invention

[0003] Many household appliances treat (drinking) water. The process usually involves a heating step, in which the water is heated to a high temperature or even to boiling. During this thermal treatment, Ca and Mg ions will begin to precipitate from the water by forming sparingly soluble salts such as carbonates, sulfates, hydroxides, etc. This irreversible precipitation can settle on the inside of pipes, valves, venturis, orifices and other components or parts present in the water flow path.

[0004] Scaling or calcification can cause fluid lines to become blocked and / or heating elements to become insulated. This in turn can lead to longer processing times, reduced functional performance and ultimately even failure of the device. It can also cause visual pollution. For example, in a steam iron, scaling can cause brownish water to splash onto clothes.

[0005] In order to avoid such reduced functionality and / or malfunctions, regular cleaning is required, for example rinsing with (acid) solutions. Such cleaning, also known as descaling, decalcification or decalcification, is considered by most users to be inconvenient and troublesome.

[0006] Scale formation and / or deposition can be reduced by using ion exchange resins (IEX). Contacting water with these resins can soften the water by removing calcium and magnesium ions from the water and exchanging these ions with sodium and / or potassium ions.

[0007] WO2016 / 180647 discloses a device in which a small amount of scale inhibitor is added to water to prevent the formation of large scale particles. The device also includes a scale inhibitor absorbent for absorbing the inhibitor before the inhibitor leaves the outlet to prevent the (unwanted) outflow of scale inhibitor in the water. The absorbent can absorb the inhibitor based on, for example, physical adsorption, capillary condensation and / or chemical adsorption.

[0008] The use of a scale inhibitor does not completely prevent scale formation, but helps prevent its growth so that the resulting scale particles remain very small ("scale microcrystals"). These scale microcrystals can be easily transported to the outlet of the device, carried by or suspended in the water. However, in devices with steam function, most of the water in liquid form may carry scale particles and crystals through the device, evaporating in the steam mode. As a result, the transport of at least some of the scale crystals may be hindered and these crystals may settle on the internal surface of the heater or at a location further downstream of the heater. Over time, the scale deposits may grow and may begin to block the flow of water or steam. In addition, during this period, scale fragments may fall off again and may eventually block valves and / or other downstream flow restrictions.

[0009] In devices in which the temperature fluctuates, the process of scale formation and release of (small) pieces of deposited scale may be faster. During heating, scale may form and accumulate as a layer, for example at the inner surface of the heater. During cooling and reheating, thermal stresses may impact this layer, which may lead to the release of small pieces or fragments of scale ("scale particles"). The process of scale formation and release may be accelerated in particular in systems or devices for alternately providing hot water and steam, such as in espresso machines, where steam may be used to froth milk for cappuccino or the like, and hot water may be used to brew coffee. It has been found that, in particular in such systems, if scale is deposited in the system during steaming, the scale fragments may be released due to thermal stresses when the water is heated, resulting in scale particles of relatively large sizes. These particles will be carried by the water and may settle in the first flow restriction they encounter.

[0010] Therefore, one aspect of the present invention is to provide an alternative device, in particular an alternative household appliance, which preferably further at least partially obviates one or more of the above-mentioned disadvantages. However, another aspect of the present invention is to provide an alternative method for collecting scale in a device, in particular a household appliance, which preferably further at least partially obviates one or more of the above-mentioned disadvantages.

[0011] According to the invention, a device is provided with a steam function ("device" or "steam device"). The device comprises a water supply, a scale inhibitor dosing element, a heating unit, a scale collector element and a water treatment unit.

[0012] The device may be configured to alternately generate hot water and steam. More specifically, the heating unit may be configured to heat water in a heating mode (particularly to a temperature below boiling temperature, wherein substantially no water is evaporated) and to convert water into steam in a steam forming mode (wherein at least part of the water is evaporated). The heating unit may comprise any kind of heating element capable of heating water and converting it into steam. The heating unit may, for example, comprise one or more heating elements selected from the group of a flow-through heater, a thermoblock, a heating plate and a boiler.

[0013] The device also includes or can be connected to a flow control device. The flow control device can be arranged upstream of the heating unit. The flow control device is configured to provide a fluid to flow from the water supply port to the water treatment unit via the heating unit (during operation). The fluid includes water in a liquid state and / or a vapor state or a gaseous state ("steam"). The flow control device can, for example, include a pump and / or a valve. The device can also include a flow restriction, for example, in the water treatment unit and / or upstream thereof.

[0014] The scale inhibitor dosing element is configured for providing a scale inhibitor to the fluid, in particular to water, at a location upstream of the heating unit and / or at a location in the heating unit.

[0015] The scale collector element is configured for collecting scale particles from a fluid (in liquid or gaseous state) flowing through or over the scale collector element. Thus, the scale collector unit prevents at least part of the scale particles from accumulating in a flow restriction downstream of the heating unit, in particular in a scale-sensitive flow restriction. Preferably, the scale collector element is arranged upstream of all scale-sensitive flow restrictions downstream of the heating unit. As will be explained in more detail further below, a flow restriction may be considered to be scale-sensitive when a narrow dimension of the flow restriction and / or the presence of other flow restriction elements promotes scale deposition.

[0016] With such an apparatus, scale formation in the apparatus can be controlled. In addition, uncontrolled accumulation or deposition of scale particles along the fluid or water flow path (or in the "hydraulic circuit", see below) in the apparatus can be prevented. In addition, the size of the scale particles that may form can be controlled. Thus, the transport of scale particles in the apparatus can also be controlled. Blockages of fluid flow can be reduced or prevented. The functional performance of the apparatus (e.g. in terms of litres of water treated before failure or operating hours) can be greatly increased compared to known systems. Substantially all large scale particles (e.g., with a maximum size of 1 mm or more, see further below) that may form in the apparatus can be captured in the apparatus and removed from the fluid upstream of any scale-sensitive flow restriction (such as valves, joints, (T-shaped) joints, (sharp) bends, rough inner walls and orifices), upstream of the water treatment unit or in the water treatment unit (and downstream of the heating unit, as indicated by "additional" in "additional (scale-sensitive) flow restriction"). In this way, the formation or deposition of scale in the water treatment unit is prevented. Furthermore, the products leaving the water treatment unit may be free of scale. For example, in a steam iron, possible brownish splashes on clothes can be avoided; in a coffee machine, the taste of the produced coffee can be improved.

[0017] Additionally, in embodiments of the device, scale may be physically removed (when desired) from the device to further facilitate preventing blockage of flow paths and to increase device performance and optionally life.

[0018] The device may be connectable to a water supply network or a water main, e.g. via a tap, or may be a stand-alone device, such as e.g. a stand-alone steam generating device, a water cooker etc. In particular, the device is one in which a heating step of water is applied, even more particularly comprising a heating step in which water is converted into steam, since, as explained above, in particular subsequent scaling and scaling particle formation may be a problem.

[0019] In this context, the device may be a household appliance ("appliance") having a steam function or a part thereof. The appliance may be selected, for example, from the group consisting of a steam cleaner, a food steamer, a kettle, a coffee maker, an espresso machine, a tea maker, a hot chocolate maker, a beverage dispenser, a soup cooker, a water cooker, a steam generating device, a steam iron and an air humidifier.

[0020] A household appliance may be an electronic household appliance, which comprises, for example, an electronic heating unit and optionally other functional parts. A household appliance may be defined as a piece of (electrical) equipment used in a home, in particular in a kitchen. However, a household appliance may also be used in an office. Generally, a household appliance is not an industrial appliance, but may comprise a relatively small unit, including, for example, a portable unit. Therefore, the term "household appliance" also relates to a coffee maker as an embodiment of a coffee maker, a soup maker as an embodiment of a soup maker, etc. In addition, the household appliance may be a wireless household appliance such as comprising a (rechargeable) battery and / or may be a wired household appliance.

[0021] In this document, the term "water" may be used to refer to liquid water, gaseous water (also referred to as "steam" or "vaporized water"), or a mixture of liquid and gaseous water. The term "fluid" may also be used to refer to (liquid and / or gaseous) water. Depending on the context, it will be clear to the skilled person whether water or fluid refers to liquid water, gaseous water, or a mixture of liquid and gaseous water.

[0022] In particular, due to the heating of water, minerals (such as calcium and magnesium) can crystallize to form scale (particles) that may eventually deposit. During the crystallization process, small crystals can gradually grow into larger crystals and form scale (particles). Such deposits can (gradually) at least partially block the fluid path through the device. When present in the heating unit, scale can further reduce any heat transfer to the fluid (water) to be heated. In order to minimize crystal growth, scale inhibitors can be provided to the water. Scale inhibitors can reduce the formation of scale. Specifically, scale inhibitors can limit scale nucleation and growth. Therefore, scale inhibitors are sometimes also expressed as "descalers" or "descalers" or "inhibitors". Scale inhibitors such as polyphosphates and phosphonates are well known for their scale inhibition properties. They are widely used in the food processing and drinking water industries. There are many different types of scale inhibitors. The most common types contain inorganic phosphates or organic phosphates. Organic phosphates, a synthetic inhibitor, are usually expressed as phosphonates and show excellent anti-scaling properties over a wide range of temperatures and water qualities. A typical example is hydroxy-ethylidene-1,1-diphosphonic acid or its corresponding salt. The phosphonate inhibitor is stable and effective at temperatures (even) above 100°C.

[0023] In a specific embodiment, the scale inhibitor comprises one or more of HEDP (1-hydroxy(ethane-diphosphonic acid)), NTMP (nitrilotri(methylene-phosphonic acid)), DTPMP (diethylenetriaminepenta(methylene-phosphonic acid)), and salts of one or more of the foregoing substances. The term "scale inhibitor" may also refer to a plurality of different scale inhibitors. In particular, at least HEDP is applied. In yet another embodiment, alternatively or additionally, the scale inhibitor comprises aminotri(methylenephosphonic acid) (ATMP).

[0024] The scale inhibitor may be a food grade (food approved) scale inhibitor, in particular comprising a polyphosphate compound.This is particularly advantageous if the device is intended for use in preparing food or beverages, such as for example an espresso machine, soup maker or food steamer.

[0025] The scale inhibitor dosing element may for example be configured to accommodate tablets, pellets or any other scale inhibitor type, including solids, such as granules, etc. Alternatively, the scale inhibitor dosing element may be configured to accommodate a liquid comprising a scale inhibitor. Thus, in particular at least during use of the device, the scale inhibitor dosing element accommodates the scale inhibitor. In some embodiments, the scale inhibitor may be provided in the dosing element during production of the device.

[0026] The scale inhibitor dosing element may be configured as a flow-through element. Generally, there are two options for introducing the scale inhibitor: a separate element may provide the scale inhibitor to the water substantially independently of the flow rate (or speed) of the water through the device, in particular in a constant amount or flux; alternatively, the scale inhibitor dosing element may provide (the amount of) scale inhibitor based on the flow rate of water through the device (see below).

[0027] In a particular embodiment, the device is configured such that the scale inhibitor dosing element (and / or the ion exchange element, see below) only needs to be filled or provided once during the life of the device or appliance. The life of a household appliance may for example be in the range of 5 to 7 years. Thus, the present invention may contribute to a maintenance-free household appliance (at least in terms of scale formation reduction and / or inhibition), wherein the scale inhibitor dosing element (and / or the ion exchange element) may not have to be refilled, or may alternatively only be refilled a few times, such as 2 to 10 times, during the life of the appliance.

[0028] The scale inhibitor dosing element may be removably arranged in the device. Thus, the scale inhibitor dosing element may be easily replaced by another (fresh) scale inhibitor dosing element. In such a case, the scale inhibitor dosing element may be a disposable scale inhibitor dosing element. In other embodiments, the scale inhibitor dosing element or a part thereof may be integrated in the device. In such a case, the scale inhibitor dosing element may be (re)fillable, for example, with new or additional scale inhibitor.

[0029] The scale inhibitor dosing element may be configured, for example, as a flow-through element having an inlet for introducing water and an outlet in fluid communication with the heating unit. The scale inhibitor dosing element may also be configured to release the scale inhibitor upon contact with the water. In a particular embodiment, the scale inhibitor dosing element may thus be configured to provide the scale inhibitor to the water at a location in the heating unit. In other words, the scale inhibitor may be provided inside the heating unit.

[0030] The scale inhibitor dosing element may comprise a (fixed) slow-release element comprising the scale inhibitor and configured to release the scale inhibitor upon contact with water. For example, slow-release tablets or pellets may be used. However, polymers in which the scale inhibitor is releasably embedded may also be applied. Embodiments may comprise essentially any porous or non-porous material (inorganic or organic) which comprises, for example, a void volume to accommodate the inhibitor or which may be mixed with any other material to provide a controlled release of the inhibitor. Thus, for example, porous ceramics, porous plastics, porous metals are also possible in this regard, but also materials in which the inhibitor is incorporated as an additive. Combinations of two or more dosage forms of scale inhibitors may also be used, such as a liquid comprising the scale inhibitor and fine particles comprising the scale inhibitor.

[0031] The scale inhibitor may be present in the scale inhibitor dosing element as a coarse-grained powder, optionally in a fine mesh envelope. The fine mesh envelope allows on the one hand a satisfactory interaction between water and powder and on the other hand prevents that the powder itself may block the flow path. Preferably, however, the inhibitor is provided in the inhibitor dosing element in the form of compressed pellets. In a particular embodiment, such pellets may be housed in an envelope consisting partly or completely of a fine mesh material. This is particularly relevant in the case of a flow-through inhibitor dosing element.

[0032] Alternatively or additionally, the scale inhibitor dosing element comprises a metering unit configured to provide a controlled amount of scale inhibitor or a descaling liquid comprising such scale inhibitor to the water.Such an embodiment may be particularly relevant when applying a liquid scale inhibitor.

[0033] In particular, the scale inhibitor dosing element may be configured to maintain a predetermined minimum and / or maximum concentration of scale inhibitor in the water (downstream of the scale inhibitor dosing unit), for example in the range of 0.1 ppm to 10 ppm (in particular for liquid in a heating unit).

[0034] The device may further comprise a control unit or controller configured to control one or more of a flow control device (e.g. a pump and / or a valve), a heating unit, a scale inhibitor dosing element, etc. The control unit may for example be configured to provide a predetermined minimum concentration and / or a predetermined maximum concentration of the scale inhibitor in the water, for example in the range of 0.1 ppm - 10 ppm (upstream of the liquid and / or in the heating unit). To this end, the control unit may control the output of the scale inhibitor from the scale inhibitor dosing element. This may for example comprise controlling a metering system and / or controlling the inflow and output of water (in the case of a flow-through scale inhibitor dosing element), etc. The device may for example comprise a (controllable) diverter or bypass configured to control the inflow and output of water, and in particular to control the concentration of the inhibitor in the water.

[0035] As indicated above, the scale inhibitor may be provided as a liquid comprising the scale inhibitor or as a solid material (including tablets) comprising the scale inhibitor for slow release thereof. In a particular embodiment, such tablets may be arranged in the heating unit.

[0036] It seems that a significant descaling can already be achieved using only a few ppm of scale inhibitor. For example, with the present invention a coffee maker can be provided with a tablet comprising 5 to 30 grams, more particularly 5 to 10 grams of scale inhibitor, which is active throughout the life of the appliance.

[0037] In further embodiments, the scale inhibitor dosing element may be configured to provide water (at the location of the scale inhibitor dosing element) with scale inhibitor in the range of 1 ppm to 10 ppm (at a location upstream of and / or in the heating unit).

[0038] The term "scaling inhibitor dosing element" may relate to a plurality of (different) scaling inhibitor dosing elements. For example, in an embodiment, the device may comprise a first scaling inhibitor dosing element comprising a liquid comprising scaling inhibitor and a second scaling inhibitor dosing element comprising a pellet comprising scaling inhibitor. Likewise, the term "scaling inhibitor" may relate to a plurality of (different) scaling inhibitors (comprising one or more scaling inhibitor dosing elements).

[0039] In other embodiments, the device may include an ion exchange element configured to remove calcium ions from water. The ion exchange element may be further configured to remove magnesium ions from water. Therefore, the ion exchange element can soften water and thus (further) reduce the formation of scale. The ion exchange element may include an ion exchange resin. The ion exchange resin may be configured to remove calcium (and magnesium) ions from water when in contact with water. The ion exchange resin may include an insoluble structure or matrix that essentially acts as a medium for ion exchange. The ion exchange resin may decalcify water by replacing calcium and magnesium ions with other ions such as sodium or potassium ions. The resin may retain these other ions at its active sites, and when contacted with water comprising calcium and / or magnesium ions, one or more of the ions may replace (at least a portion of) the ions at the active sites. In an embodiment, the resin may be regenerated (refilled or reactivated) by contacting it with a solution comprising high concentrations of other ions (wherein, for example, calcium and / or magnesium ions are again at least partially replaced by other ions). Resins can be divided into four main types that differ in their functional groups: strongly acidic resins, which typically include sulfonic acid groups; strongly basic resins, which typically include quaternary amino groups; weakly acidic resins, which typically include carboxylic acid groups; and weakly basic resins, which typically include primary, secondary and / or tertiary amino groups. For softening water, acidic resins may be particularly relevant.

[0040] The ion exchange resin may include a weak acid resin in particular. In further embodiments, the ion exchange resin may include a combination of different resin types. The ion exchange resin may, for example, include a weak acid resin and a strong acid resin, or, for example, the ion exchange resin may include a combination of resins with different active sites (combined, or, for example, configured in series in a fluidic manner). The terms "ion exchange element" and "ion exchange resin" may refer to a plurality of ion exchange elements and / or a plurality of ion exchange resins, respectively.

[0041] The ion exchange element may be configured as a flow-through element having a fluid inlet and a fluid outlet, wherein water exiting the outlet comprises a reduced amount of calcium (and optionally magnesium) ions relative to water entering the inlet. The ion exchange element may be arranged upstream of or in the heating unit.

[0042] The ion exchange element may be removably disposed in the device. The ion exchange element may, for example, be a disposable ion exchange element that can be replaced with a fresh element. Alternatively, the ion exchange resin may be replaced with a fresh ion exchange resin. In other embodiments, the ion exchange element may be regenerated.

[0043] The scale inhibitor dosing element may include a total inhibitor volume (Vi) of the scale inhibitor, and the ion exchange element may include an ion exchange resin, which includes a total resin volume (Vr). The resin volume may be equal to or less than 500 ml, such as equal to or less than 200 ml, such as equal to or less than 100 ml, in particular equal to or less than 50 ml, such as equal to or less than 20 ml, such as equal to or less than 10 ml. In a specific embodiment, the resin volume may be at least 5 ml. As described above, only a very small amount of scale inhibitor may be required to prevent scale crystal growth. The total inhibitor volume may be, for example, in the milliliter range, such as 0.1-10 ml, in particular 0.5-5 ml, and even more particularly 1-2 ml. In a specific embodiment, the ratio of the total resin volume (Vr) to the total inhibitor volume (Vi) can therefore be selected from the range of 500:1-50:1.

[0044] Preferably, the ion exchange element, or at least its outlet, is arranged upstream of the scale inhibitor dosing element, or at least its inlet.

[0045] The ion exchange element affects the pH of the water. More specifically, the ion exchange element imparts a fairly constant pH to the water. A more constant pH of the water can provide a more constant amount of scale inhibitor dissolved in the water, and thus can facilitate more accurate dosing of the scale inhibitor.

[0046] In further embodiments, the ion exchange element and the scale inhibitor dosing element may be arranged at substantially the same location. The ion exchange resin and the scale inhibitor dosing element may, for example, be arranged in one scale treatment unit. For example, pellets or granules comprising scale inhibitors may be mixed or combined with the ion exchange resin in the scale treatment unit. Alternatively, the ion exchange resin may be arranged upstream of the scale inhibitor dosing element within the scale treatment unit.

[0047] More generally, the scale treatment unit may be configured to include a combination of elements related to reducing scale. These elements (hereinafter also referred to as "scale reduction elements") may, for example, include a scale inhibitor dosing element, an ion exchange element, and a scale collector element. The scale treatment unit may include a combination of two or three of these scale reduction elements. To this end, the scale treatment unit may, for example, include a plurality of sections, wherein each section includes one or more of the scale reduction elements.

[0048] The use of a scale inhibitor and an ion exchange element in a household appliance in which water is heated may provide a considerable extension of the number of operating hours or litres of water heated without a fault. The term "fault" relates in particular to an undesired change in the operation of the device. In an embodiment, a fault may be defined as a complete blockage of the water flow. However, a fault may also involve a predetermined increase in the preparation time per cup of coffee (or other beverage). The efficiency / effectiveness of the scale reduction measures may in particular be related to an increase in the operating time until the fault occurs or an increase in the volume of water treated (relative to a device without scale reduction measures).

[0049] It has been found experimentally that the use of scale inhibitors and ion exchange resins can increase the amount of water that can be processed (heated) in a coffee machine until a malfunction occurs, six times or more. Scale inhibitors and / or ion exchange elements can significantly reduce scale formation / deposition in such devices. However, in devices that generate steam in addition to hot water, this effect is less significant. It has been found experimentally that during usability tests, the amount of water that can be processed in an appliance with a steam function (and alternately heating and evaporating water) (including ion exchange elements and scale inhibitors) can be six times or more lower than in an appliance without a steam function (however, it is still significantly higher compared to a reference in which no ion exchange elements and inhibitors are applied). Therefore, it was found that when tested in a hot water / steam combination, the efficiency or effectiveness of the combination of an ion exchange element and a scale inhibitor element is reduced by at least six times compared to hot water alone. Additional analysis shows that scale particles have accumulated in valves that are sensitive to calcification during steam generation. In contrast, no accumulation was found in the valve when only water was heated.

[0050] Without being bound by theory, it is assumed that during steaming, all water surrounding dissolved solids (e.g. scale particles or crystals) is removed by evaporation. Some scale solids may be transported with the steam, but most of the solids may settle on the hot surface of the heating unit and form a solid scale layer. This solid layer may only be weakly attached to the surface of the heating unit and may be very brittle. If the device is subsequently used in a heating mode, the solid layer may break into smaller scale particles due to thermal stresses. These particles may be washed away with the hot water and accumulate further downstream of the heating unit in the first flow restriction they encounter. If no evaporation / steaming occurs in the heating unit (and therefore no scale layer is present in the heating unit), the water may essentially only include small scale crystals, which may be easily entrained in the water and may flow through the device and its flow restriction without accumulating.

[0051] Therefore, the device according to the invention comprises a scale collector element (or "scale collector") to collect scale particles upstream of such a flow restriction in which particles might otherwise accumulate. The scale collector element is arranged downstream of the heating unit. The scale collector element may, for example, be arranged at the outlet of the heating unit and may, for example, physically contact the heating unit. In other embodiments, the scale collector element may be arranged further downstream of the heating unit. In particular, the scale collector element is arranged upstream of any (scale-sensitive) flow restriction.

[0052] Therefore, the present invention provides, inter alia, a combination of scale reduction measures, thereby providing an effective anti-scaling solution for devices with steam functionality, in particular household appliances.

[0053] In the present context, the term "scale-sensitive flow restriction" relates to a flow restriction in which scale particles can be decelerated relative to the fluid conveying the scale particles. The flow restriction does not necessarily restrict the flow of the fluid itself. For example, the flow restriction can restrict the flow of scale particles without substantially restricting the flow of the fluid. The particles can be at least partially blocked by the flow restriction and can therefore accumulate in the flow restriction. The flow restriction can include a "dead zone" in which the particles can accumulate. The flow restriction can include a flow channel whose cross-section is too small for the particles to flow through. The main dimension of the scale particles can be, for example, 1 mm or more, and the cross-sectional dimension of the cross section can also be in the range of 1 or 2 mm, or less. In this way, scale particles may begin to accumulate in the flow restriction. Moreover, if the cross-sectional dimension of the flow restriction is larger than the main dimension of the scale particles, the scale particles may still be blocked, or clusters of scale particles may be blocked. Such a flow restriction can also be denoted as a scale-sensitive flow restriction. Furthermore, the flow restriction may for example comprise a scale sensitive surface, such as a curved wall, a sharp bend, a rough surface and / or a surface promoting scale adhesion. The scale sensitive flow restriction may for example comprise a valve, an orifice, a joint and / or a joint. The scale sensitive flow restriction may comprise a combination of the aforementioned flow restrictions.

[0054] The term "scale sensitive" in a scale sensitive restriction therefore relates to a restriction in which scale particles (transported by water or steam) can easily accumulate or upstream of the restriction. In the present context, such a scale sensitive restriction may also be referred to as just a "restriction". In particular, the restriction may comprise a restriction to the flow of one or more scale particles, in particular for scale particles with a particle size > 0.1 mm, such as > 0.3 mm, in particular > 0.5 mm, such as > 1 mm.

[0055] The term "flow restriction" may for example relate to a valve, a pipe or a tube having a change such as a reduced cross-sectional area, or having bends, bends, junctions or intersections, or locations where different elements of the hydraulic system are connected to each other etc. Flow restrictions may also include filters, gauze, orifices etc. Flow restrictions may in particular include elements or locations at which the cross-sectional area of ​​the flow path is changed, in particular reduced (such as valves, orifices etc.) and / or where the flow direction may be (suddenly) changed (such as junctions, intersections and / or joints) and / or where the flow of scale particles is at least partially inhibited (such as by attachment to and / or friction with the element).

[0056] The scale collector element can advantageously be arranged upstream of any (i.e. all) flow restrictions downstream of the heating unit. Preferably, the scale collector element is arranged upstream of the first (scale sensitive) flow restriction. Depending on the location of the flow restriction, the scale collector element can be arranged in the water treatment unit or upstream thereof.

[0057] The scale collector element is particularly configured for collecting scale particles from the fluid (water and / or steam) coming from the heating unit. In the present document, the term "capture" may also be used in relation to "collect" (scale particles). The scale collector element may not need to capture every and any particle or solid in the fluid. For example, very small scale crystals may not accumulate in a (scale sensitive) flow restriction. These small crystals may be transported through the device without causing malfunctions and therefore do not need to be captured.

[0058] In particular, scale particles having a particle size of 1 mm or more may cause malfunction of the device (over time). Therefore, the scale collector element may be configured to capture scale particles having a particle size equal to or greater than 1 mm. In a further embodiment, the scale collector element is configured to capture scale particles having a particle size ≥ 0.5 mm, or even ≥ 0.3 mm, in particular ≥ 0.1 mm.

[0059] Scale particles are mostly not spherical but relatively flat. Furthermore, scale particles may be elongated or rounded or have any further arbitrary shape. For example, a scale particle may be 2 mm in a first direction, 0.5 mm in a second direction and only 10 μm in a third direction (all directions being perpendicular to each other). The most relevant size of a particle that may cause particle accumulation may in particular be defined by the largest dimension of the particle, in particular the maximum distance along a straight line from one position of the edge of the particle to another position of the edge. Hence, the "size" or "dimension" in the terms "particle size" or in the "(largest) dimension of a scale particle" may in particular refer to the relevant (largest) dimension.

[0060] Scale particles may be collected by mechanically screening out the particles. The scale collector may, for example, comprise a flow-through element, wherein scale particles are blocked by the element, but a fluid may flow through. The scale collector may comprise a mechanical separator, such as a filter, a flow restrictor and / or a barrier, for separating scale particles from the fluid. Particles may be removed from the fluid, for example, by directly intercepting particles flowing through the scale collector. Additionally or alternatively, particles may be removed from the fluid by inertial impact. In such a case, the scale collector element may, for example, comprise a cyclone. Alternatively, a (determined) change of direction may be provided in the flow path, such as a bend, wherein the particles (due to inertial forces) continue to move along a straight line (where they are collected), while the fluid may follow the change of direction.

[0061] The scale collector may comprise a mesh, a filter, a gauze, a screen, a filter or a perforated plate. Such a mesh, a filter, a gauze, a screen, a filter or a perforated plate may comprise through holes having a minimum (mesh or hole) size, which is equal to or smaller than the size of the scale particles (to be captured). The through holes may essentially have any geometric shape. For example, they may be circular, elongated, rectangular or square. In a further embodiment, the scale collector element may comprise a filter with a mesh size (d), wherein the mesh size (d) is equal to or smaller than 2 mm, in particular equal to or smaller than 1 mm, such as equal to or smaller than 0.5 mm, in particular equal to or smaller than ≤ 0.3 mm. The term "size" in relation to mesh size and size of through holes, etc., may in particular relate to the smallest dimension of the mesh, through holes, etc., in particular the dimension most relevant to blocking scale particles. Furthermore, the terms "mesh size", "through opening size", "pore size" or even "size" in relation to openings, (through) holes, pores, etc. may be used interchangeably.

[0062] The through-holes in the scale collector element may be larger than 10 μm, such as at least 50 μm, to prevent clogging of the scale collector. The mesh size (or the minimum size of the through-holes in the scale collector element) may in particular be equal to or at least 0.1 mm, such as equal to or at least 0.2 mm. In an embodiment, the mesh size and / or the size of the through-openings (through-holes) in the scale collector element may be at least 0.5 mm. In an embodiment, the mesh size is selected from the range of 0.05 mm to 2 mm, in particular 0.05 mm to 1 mm, such as 0.1 mm to 1 mm.

[0063] The filter screen (or net, gauze, filter, etc.) may have a three-dimensional filter screen profile. This may increase the total scale (particle) holding capacity while maintaining (optimal) operating properties, such as flow through the scale collector and pressure drop across the scale collector. The three-dimensional profile may include a three-dimensional flow channel. Such a scale collector comprising a three-dimensional filter screen profile may also be referred to as a "depth filter" or "depth filter screen" and is characterized by an increased scale holding capacity. A "flat" filter screen, mesh or filter may collect scale on the surface of the filter or screen, whereas a depth filter or depth filter screen may collect scale particles in the body of the filter at the depth of the filter or screen. The scale collector may, for example, comprise a porous or sponge-like structure or a layered structure configured to capture particles. The depth filter may comprise through holes, in particular pores, from the upstream end to the downstream end of the filter.

[0064] The scale collector element, in particular the depth screen or depth filter, may comprise through holes or pores, the cross-sectional area of ​​which may gradually change, for example decrease in the flow direction (i.e. from the upstream side to the downstream side). Moreover, the direction of the longitudinal axis of the through hole may change along the length of the axis. For example, it may be curved. The pores may have the dimensions as described above for the through holes.

[0065] The scale collector, in particular the filter screen, may comprise a multilayer structure. Such a multilayer structure may comprise a plurality of layers, each layer comprising through holes, wherein the layers are connected to each other so that the through holes of adjacent layers are fluidly connected to each other and together define a through hole (from the upstream side to the downstream side).

[0066] Therefore, in an embodiment, the term "through hole" may relate to a pore. In this way, the layers of the multilayer structure may be arranged to form a gradient density pore structure, which in particular has larger pores on the upstream side and smaller pores on the downstream side. The ratio of the size of the pores or through holes on the upstream side to the size of the pores or through holes on the downstream side may be, for example, equal to or less than 100, such as equal to or less than 50, in particular equal to or less than 10, and in particular equal to or greater than 1. In an embodiment, the size of the through hole or pore on the upstream side may be in the range of 1 mm to 3 mm. In this context, the size of the pore or through hole is particularly related to the (minimum dimension of the) (local) cross-sectional area perpendicular to the flow direction or axis (of the through hole or pore).

[0067] The scale collector element may also be configured to block and screen scale particles and allow the particles to settle without substantially blocking the fluid flow. In particular, if flat scale particles are captured in a three-dimensional filter profile, flow channels may be formed between the scale particles, thereby preventing (complete) blockage of the fluid. The size of the through-holes on a first side of the scale collector element may be smaller than the size on the opposite side. The scale collector element, such as a filter, a screen or a filter, is advantageously arranged so that all fluid from the heating unit has to flow through the scale collector without bypassing the scale collector. To this end, the scale collector element may, for example, be arranged sealingly in the flow path of the fluid.

[0068] The scale collector element, such as a filter or a perforated plate, may comprise or be made of a hydrophobic material to reduce possible adhesion of scale particles and to facilitate cleaning of the scale collector element. The scale collector element may comprise a hydrophobic coating comprising a hydrophobic material. Examples of hydrophobic materials are, for example, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polytetrafluoroethylene, polydimethylsiloxane and polyethylene terephthalate.

[0069] The scale collector element may be removably arranged in the device. Thus, the collected scale particles can be removed from the scale collector element. After cleaning, the scale collector element can be re-arranged in the device. Alternatively, the scale collector element may be a disposable scale collector element. After removal, a new scale collector element may be used to replace the used scale collector element.

[0070] In yet another embodiment, the scale collector element and one or more of the scale inhibitor dosing element and the ion exchange element may be arranged in a single unit, such as the aforementioned scale treatment unit. One or more of the ion exchange element, the scale inhibitor dosing unit and the scale collector element may be removably arranged in the scale treatment unit.

[0071] The term "scaling treatment unit" may in particular relate to a plurality of (different) scale treatment units. A scale treatment unit or a part thereof may be integrated in the device. Alternatively, the scale treatment unit may be removable. The device may comprise one or more scale treatment units. The scale treatment unit may be a disposable scale treatment unit. The scale treatment unit may be regenerated, cleaned and / or refilled. Alternatively, it may be replaced by another (fresh / new) scale treatment unit. It may be replaced after a determined operating time of the device. In a further embodiment, the device may be configured to indicate when the scale treatment unit (or the ion exchange element and / or the scale inhibitor dosing element and / or the scale collector element) needs to be replaced and / or cleaned.

[0072] The term "scaling treatment unit" may refer to a unit having different functionalities as described above. One embodiment of a scale treatment unit may, for example, comprise a scale inhibitor dosing unit and an ion exchange element, whereas another embodiment of a scale treatment unit may comprise a scale inhibitor dosing element and a scale collector element. These different scale reduction elements may be functionally arranged in different positions relative to the fluid flow path through the device. For example, the scale inhibitor dosing element may be arranged upstream of or in the heating unit, whereas the scale inhibitor collector element may be arranged downstream of the heating unit. However, physically, the scale inhibitor dosing element and the scale collector element may both be arranged in the same scale treatment unit. The fluid flow path may be arranged such that it passes through the scale treatment unit twice: first along the scale inhibitor dosing element, then, for example, along the heater, and then back through the scale treatment unit, but this time along the scale collector element.

[0073] Therefore, the scale disposal unit may include a plurality of scale reduction elements, which may be arranged in sections of the scale disposal unit and are not necessarily directly fluidically connected to each other (i.e., there are no further functional elements arranged between the scale reduction elements). Each of the scale reduction elements of the scale disposal unit (or each of the sections of the scale disposal unit) may include a fluid inlet and a fluid outlet for the corresponding element or section. Therefore, the scale disposal unit may include a plurality of fluid inlets and / or fluid outlets. The fluid inlet may be fluidly connected to the upstream end of the corresponding scale reduction element. Similarly, the fluid outlet may be fluidly connected to the downstream end of the corresponding scale reduction element. The total number of fluid inlets and outlets does not necessarily correspond to the total number of scale reduction elements of the scale disposal unit. For example, two of the scale reduction elements may be configured in a section of the scale reduction unit and may therefore share an inlet and / or outlet. In other specific embodiments, for example, including only ion exchange elements and scale inhibitor dosing elements, the scale treatment unit may include only one scale treatment unit fluid inlet and one fluid outlet, wherein, for example, the fluid entering the scale treatment unit may first flow through the ion exchange element and then flow through the scale inhibitor dosing element. It should be understood that other embodiments may include other configurations regarding the number of fluid inlets and outlets, the number of scale reduction elements, and the number of sections of the scale treatment unit.

[0074] The apparatus may be configured to provide a fluid flow path from the water supply (or from a location upstream of the water supply) to or through the water treatment unit and to one or more fluid outlets of the water treatment unit.

[0075] The device may comprise or be connectable to a water supply element, such as a water container. The water supply element may be fluidly connected to the water supply opening. The scale inhibitor dosing element may be arranged in the water supply element. Optionally, the ion exchange element and / or the scale treatment unit may also be arranged in the water supply element.

[0076] The water treatment unit may comprise any type of unit in which water is functionally used or treated, in particular in liquid and / or gaseous state. The type of water treatment unit may depend on the type of device, in particular the type of household appliance. As discussed above, the device may, for example, comprise a household appliance selected from the group consisting of: a coffee maker, an espresso machine (or espresso maker), a tea maker, a kettle, a cappuccino maker, a steam iron, a steam generating device, a food steamer and a steam cleaner. Thus, for example, in a cappuccino maker, the water treatment unit may comprise a brewing unit and a steam pipe for frothing milk; in a steam iron, the water treatment unit may comprise an ironing board and / or an opening for providing steam; in a steam cleaner, the water treatment unit may comprise a steam applicator, etc.

[0077] The device may comprise a controller or control system or unit.The control unit or controller may for example be configured to control one or more of a flow control device (eg a pump or a valve), a heating unit, a scale inhibitor dosing element or other (functional) components of the device.

[0078] The present invention also provides a scale disposal unit, in particular for arrangement in an apparatus as described herein. The (disposable) scale disposal unit may thus comprise a scale inhibitor dosing element, which is configured for providing scale inhibitor to the fluid at a position upstream of (or in) a heating unit of the apparatus during operation (when arranged in the apparatus). The (disposable) scale disposal unit may also comprise an ion exchange element, which is configured for removing calcium ions from water in contact with the ion exchange element. Additionally or alternatively, the (disposable) scale disposal may comprise a scale collector element, which is configured for collecting scale particles from a fluid, in particular water, which flows from the heating unit through the scale collector element to the flow restriction during operation (of the apparatus).

[0079] A disposable scale management unit may be configured according to the embodiments of the scale management unit described herein.

[0080] In a specific embodiment, for example, the disposable scale treatment unit comprises (at least) a scale inhibitor dosing element and an ion exchange element, wherein the scale inhibitor dosing element comprises a total inhibitor volume (Vi) of the scale inhibitor, wherein the ion exchange element comprises an ion exchange resin, which comprises a total resin volume (Vr), in particular wherein the ratio of the resin volume (Vr) to the inhibitor volume (Vi) is selected from the range of 500:1-50:1.

[0081] In yet another aspect, the present invention also provides a method for collecting scale in a device with steam functionality as described herein, in particular wherein the device comprises a heating unit configured for heating water in a heating mode and for converting water into steam in a steam generating mode.

[0082] In a specific embodiment, the method includes (i) controlling a fluid including water to flow from a water supply port via a heating unit to a water treatment unit of the device, and providing a scale inhibitor to the water at a position upstream of the heating unit and / or in the heating unit; (ii) heating the water by the heating unit in a heating mode to release scale particles that (may have been) deposited at a position in the heating unit and / or at a position downstream of the heating unit in a steam forming mode, and the water carries the released scale particles toward the water treatment unit; and (iii) collecting scale particles from the water by a scale collector element, which is arranged downstream of the heating unit and upstream of a flow restricting member, and more preferably arranged upstream of any flow restricting member of the device (at a position downstream of the heating unit). BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference characters indicate corresponding parts and in which:

[0084] Figure 1 An embodiment of the apparatus is schematically depicted;

[0085] Figure 2 Another embodiment of the apparatus is schematically depicted;

[0086] Figure 3 schematically depicting various aspects of embodiments of a scale collector; and

[0087] Figure 4 Some further aspects of the screen collector element are schematically described.

[0088] The schematic diagrams are not necessarily drawn to scale. DETAILED DESCRIPTION

[0089] exist Figure 1, an embodiment of a device 1000 is depicted. The embodiment comprises a water supply port 101, a flow control device 300, a heating unit 400 and a water treatment unit 600. The device 1000 comprises a steam function, meaning that it can convert water 10 into steam 11. The heating unit 400 is configured for heating water 10 in a heating mode and for converting water 10 into steam 11 in a steam forming mode. The selection of modes and switching between modes etc. can be done manually. Alternatively or additionally, it can be controlled by a control system 900.

[0090] When heating water 10, scale 20 may form, particularly in and downstream of the heating unit 400. In order to reduce scale formation and / or scale deposition, the illustrated apparatus 1000 includes three scale reduction elements: an ion exchange element 700, a scale inhibitor dosing element 200, and a scale collector element 500. The scale reduction elements, each individually and together, help prevent scale particles 21 from accumulating in any flow restrictions 650 downstream of the heating unit 400, and in this way can help achieve a desired constant flow of fluid 19 through the water treatment unit 600. The scale inhibitor dosing element 200, the scale collector element 500, and / or the ion exchange element 700 may be removably arranged in the apparatus 1000, individually or in combination, for example in a single removable scale disposal unit 800, as will be described below with reference to Figure 2 Described.

[0091] The scale inhibitor dosing element 200 is configured to provide a scale inhibitor 250 to the water 10 during use at a location upstream of the heating unit 400 (as shown) or in the heating unit 400 (not shown). The scale inhibitor dosing element 200 may provide the water 10 with a scale inhibitor 250 in the range of, for example, 1 ppm to 10 ppm. The ion exchange element 700 is configured to remove calcium ions from the water 10. It may be arranged upstream of the heating unit 400 (as shown) or in the heating unit 400 (not shown). The scale collector element 500 is configured to collect scale particles 21 from the fluid 19 flowing therethrough. It is arranged upstream of the flow restriction 650 downstream of the heating unit 400, and more generally, upstream of any flow restriction 650 downstream of the heating unit 400. The scale collector element may be removable, thereby allowing the collected scale particles 21 to be easily removed from the device.

[0092] The flow control device 300 is configured to provide a fluid 19 including water 10 (liquid water 10 and / or steam 11) to flow from the water supply port 101 to the water treatment unit 600 via the heating unit 400. In the illustrated embodiment, the flow control device 300 is arranged in the device 1000, i.e. it forms a part of the device 1000. In an alternative embodiment (not shown), the flow control device 300 may be a separate component to which the water supply port 101 can be fluidly connected. The flow control device 300 may, for example, include a pump 301, as depicted in the figure. Alternatively or additionally, it may, for example, include a valve 302 (such as Figure 2 depicted).

[0093] In the embodiment shown, the water supply port 101 of the device 1000 is fluidly connected to a water supply element 100, here a water container. In a specific embodiment (not shown), the water supply element 100 may include a scale inhibitor dosing element 200, optionally in combination with an ion exchange element 700, for example in a scale treatment unit 800.

[0094] All (functional) elements starting from upstream of the water supply element 100 up to the water treatment unit 600 define a hydraulic circuit 110 having a continuous fluid flow path from the upstream side to the downstream side.

[0095] The control system 900 may for example control the flow control device 300, the water treatment unit 600 etc. If one or more of the scale reduction elements 200, 500, 700 are not or incorrectly arranged in the device 1000, the heating unit and / or the flow control device may further be disabled.

[0096] As described above, scale 20 may be formed in particular in the steam generation mode. In the steam generation mode, a layer of scale 20 may be deposited in the heating unit 400 and / or downstream of the heating unit 400. In the heating mode, the layer of deposited scale 20 may be broken into scale particles 21. These scale particles 21, in particular when having a particle size of 1 mm or more, may accumulate in the flow restriction 650. Therefore, the scale collector element 500 may be particularly configured to at least capture scale particles 21 having a particle size equal to or greater than 1 mm.

[0097] The device 1000 may be a household appliance or a part thereof, such as a coffee maker, an espresso machine, a tea maker, a kettle, a cappuccino maker, a steam iron, a steam generating device, a food steamer and a steam cleaner. Thus, the household appliance may be used to prepare food or beverages. In such a case, the scale inhibitor 250 preferably comprises a food-approved scale inhibitor 250, in particular comprising a polyphosphate compound 255.

[0098] In the illustrated embodiment, the scale inhibitor dosing element 200 may be configured to provide scale inhibitor 250 to the water 10 via a scale inhibitor liquid comprising the scale inhibitor. In other embodiments, the scale inhibitor dosing unit 200 may, for example, be configured as a flow-through unit, wherein the flowing scale inhibitor is provided to the water as the water flows through the scale inhibitor dosing unit. The scale inhibitor 250 may be provided at a location downstream of the ion exchange element 700, as shown. In other embodiments, the arrangement of the ion exchange element 700 and the scale inhibitor dosing element 200 relative to each other and / or the heating unit 400 may be different.

[0099] exist Figure 2 , another embodiment of the device 1000 is depicted. In this embodiment, the configuration of the hydraulic circuit 110 is structurally different from Figure 1 Configuration. Figure 1 In the example, all structural / physical elements are configured in series, and these structural elements are connected in Figure 2 However, the arrangement of the functional components of the hydraulic circuit 110 (the flow directions are indicated by arrows) has not changed significantly. Figure 2 The embodiment of the invention comprises a scale treatment unit 800, which comprises a scale inhibitor dosing element 200, a scale collector element 500 and an ion exchange element 700. In particular, the ion exchange element 700 and the scale inhibitor dosing element 200 are arranged in a first section 801 of the scale treatment unit 800. The scale collector element 500 is arranged in a second section 802. The two sections 801, 802 are not directly fluidly connected to each other. Water 10 first flows through the first section 801, then flows through the heating unit 400, and then flows through the second section 802, more specifically through the scale collector element 500.

[0100] The scale treatment unit 800 may include two or more of the scale reduction elements, i.e. the scale inhibitor dosing element 200, the scale collector element 500 and the ion exchange element 700. Thus, the arrangement of the scale treatment unit 800 may depend on the scale reduction elements it comprises. Preferably, the scale treatment unit 800 or at least a part thereof is removably arranged in the device 1000. The scale treatment unit 800 may in particular be a disposable scale treatment unit 800.

[0101] In order to provide the desired functionality, the total ion exchange volume Vr can be significantly larger than the total scale inhibitor volume Vi. Figure 2 In the scale treatment unit 800 in FIG. 1 , the ratio of the total resin volume Vr to the total inhibitor volume Vi may be in the range of 500:1 to 50:1 (since the ion exchange resin 750 and the scale inhibitor 250 are mixed, Figure 2Only the combined volume Vi+Vr) is shown.

[0102] exist Figure 2 In the embodiment of the present invention, the water supply port 101 of the device 1000 is fluidly connected to the water supply element 100, which is a faucet. Because the water supply element 100 can force water 10 through the water supply port 101, the flow control device 300 in this embodiment can include a simple valve 302 to control the fluid flow.

[0103] exist Figure 2 In the embodiment of FIG. 6 , there is no flow restrictor 650 between the outlet of the heating unit 400 and the inlet of the water treatment unit 600 . Instead, the flow restrictor 650 may be included in the water treatment unit 600 .

[0104] Figure 1 and Figure 2 An embodiment of a method for collecting scale 20 in the device 1000 is also shown. In the method, a fluid 19 including water 10 is controlled to flow from the water supply port 101 to the water treatment unit 600 via the heating unit 400, while a scale inhibitor 250 is provided to the fluid 19 at a position upstream of the heating unit 400. In the heating unit 400, the water 10 is heated in the heating mode, and scale particles 21 that have been deposited in the heating unit 400 and / or downstream of the heating unit 400 during the steam generation mode may be caused to be released. The water 10 carries the released particles 21 in the direction of the water treatment unit 600 and is collected from the water 10 by the scale collector element 500 arranged downstream of the heating unit 400 and upstream of the flow restriction 650.

[0105] Figure 3 Two embodiments of a scale collector element 500 with through holes 560, more specifically a filter screen 550 which may form part of such a scale collector 500, are shown. The filter screen 550 may, for example, comprise a randomly perforated plate with a more or less random pattern (as shown on the left-hand side) or a more symmetrical pattern (as shown on the right-hand side). In both embodiments, a filter screen 550 with a mesh size d is depicted. In this context, this may also be indicated as comprising through holes 560 (or pores) with a through hole size d (or pore size d). In further embodiments, the diagonals of the (e.g. rectangular and / or square) through holes 560 may be indicated as through holes or mesh size d.

[0106] exist Figure 4, some aspects of the scale collector element 500 are depicted. On the left hand side, a section of a flat screen or filter 550 is depicted. The flat filter 550 comprises through holes 560 of dimension d. Scale particles 21 can be blocked by the filter and accumulate at the surface. On the right hand side, a depth filter 550 is described, which comprises a three-dimensional (filter) profile, comprising through holes 560, which have a varying dimension d along the longitudinal axis of the through holes 560. In the figure, all through holes 560 are straight holes, so that the longitudinal axis of the through holes 560 is parallel to the depth direction 570 of the filter 550. In other embodiments, the through holes 560 may not be straight, but for example curved or bent. The dimension d of the through holes 560 is larger on the upstream side (see the arrow indicating the flow direction of the fluid 10, 11, 19) than on the downstream side. Due to this three-dimensional profile of the depth filter 550, scale particles 21 can be captured inside the filter 550 without hindering the flow of the fluid 19, as depicted very schematically. In the depicted embodiment, the depth filter 550 comprises three layers connected to each other. However, different configurations are also possible for the depth filter according to the invention. Essentially, the depth filter can have a higher dust holding capacity than the flat filter 550.

[0107] The terms "substantially" or "essentially" and similar terms herein will be understood by those skilled in the art. The terms "substantially" or "essentially" may also include embodiments with "completely", "completely", "all", etc. Therefore, in embodiments, the adjectives substantially or essentially may also be removed. Where applicable, the term "substantially" or the term "essentially" may also relate to 90% or higher, such as 95% or higher, particularly 99% or higher, even more particularly 99.5% or higher, including 100%.

[0108] These devices, apparatuses or systems may be described herein particularly during operation.It will be clear to those skilled in the art that the present invention is not limited to methods of operation, or devices, apparatuses or systems in operation.

[0109] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0110] The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0111] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0112] The present invention also provides a control system, which can control a device, an apparatus or a system, or can execute the method or process described herein.

[0113] The various aspects discussed in this patent can be combined to provide additional advantages. In addition, those skilled in the art will appreciate that embodiments can be combined, and more than two embodiments can also be combined. In addition, some features can form the basis of one or more divisional applications.

Claims

1. A coffee maker or espresso machine (1000) with steam function, wherein the coffee maker or espresso machine (1000) comprises a water supply port (101), a scale inhibitor dosing element (200), a heating unit (400), a scale collector element (500) and a water treatment unit (600), wherein: - a flow control device (300) configured to provide a fluid (19) including water (10) to flow from the water supply port (101) via the heating unit (400) to the water treatment unit (600); - the scale inhibitor dosing element (200) is configured to provide the scale inhibitor (250) to the fluid at a location in the heating unit (400) and / or upstream of the heating unit (400); - the coffee maker or espresso machine (1000) is configured to alternately generate hot water for brewing coffee and steam (11) for frothing milk; - the heating unit (400) is configured for heating the water (10) in a heating mode and for converting the water (10) into steam (11) in a steam generation mode; and The scale collector element (500) is arranged downstream of the heating unit (400) and upstream of any scale-sensitive flow restriction (650), wherein the scale collector element (500) is configured to collect scale particles (21) from the fluid (19) flowing through the scale collector element (500).

2. The coffee maker or espresso machine (1000) according to claim 1, wherein the scale collector element (500) is configured to capture scale particles (21) having a particle size equal to or greater than 1 mm.

3. The coffee maker or espresso machine (1000) according to claim 1 or 2, wherein the scale collector element (500) comprises a filter (550) having a mesh size (d), wherein the mesh size (d) is selected from the range of 0.1 mm to 1 mm.

4. The coffee maker or espresso machine (1000) according to claim 1 or 2, wherein the flow restriction (650) comprises one or more of the following: a valve (302), an orifice, a joint and a joint.

5. The coffee maker or espresso machine (1000) of claim 1 or 2, wherein the scale inhibitor (250) comprises a food-approved scale inhibitor (250), the food-approved scale inhibitor (250) comprising a polyphosphate compound (255).

6. The coffee maker or espresso machine (1000) according to claim 1 or 2, wherein the scale inhibitor dosing element (200) is configured to provide the water (10) with the scale inhibitor (250) in the range of 1 ppm-10 ppm.

7. The coffee maker or espresso machine (1000) according to claim 1 or 2, further comprising an ion exchange element (700), the ion exchange element (700) being configured to remove calcium ions from the water (10).

8. A coffee maker or espresso machine according to claim 7, wherein the ion exchange element (700) is arranged upstream of the scale inhibitor dosing element (200) or upstream of a first position where the scale inhibitor dosing element (200) provides scale inhibitor (250) to the water (10).

9. The coffee maker or espresso machine (1000) according to claim 1 or 2, wherein one or more of the scale inhibitor dosing element (200), the scale collector element (500) and the ion exchange element (700) in the coffee maker or espresso machine according to claim 7 or 8 are removably arranged in the coffee maker or espresso machine (1000).

10. A coffee maker or espresso machine (1000) according to claim 1 or 2, wherein the scale collector element comprises a filter (550), the filter (550) having a three-dimensional filter profile, the filter being a depth filter or a depth filter, configured to collect scale particles in the body of the filter or the filter across the depth of the filter or the filter.

11. The coffee maker or espresso machine (1000) according to claim 7, wherein the scale inhibitor dosing element (200) comprises a scale inhibitor (250) of a total inhibitor volume (Vi), wherein the ion exchange element (700) comprises an ion exchange resin (750), the ion exchange resin (750) comprising a total resin volume (Vr), wherein a ratio of the total resin volume (Vr) to the total inhibitor volume (Vi) is selected from the range of 500:1-50:

1.

12. The coffee maker or espresso machine (1000) according to claim 1 or 2, wherein the coffee maker or espresso machine (1000) comprises a scale treatment unit (800), wherein the scale treatment unit (800) comprises two or more of (i) the scale inhibitor dosing element (200), (ii) the scale collector element (500) and (iii) the ion exchange element (700) in the coffee maker or espresso machine according to claim 7, 8 or 11, and wherein the scale treatment unit (800) is a disposable scale treatment unit.

13. A disposable scale treatment unit (800) for being arranged in a coffee maker or espresso machine (1000) according to any one of claims 1 to 12, wherein the scale treatment unit (800) comprises: A scale inhibitor dosing element (200) configured to provide a scale inhibitor (250) to water at a location upstream of and / or in the heating unit (400) of the coffee maker or espresso machine (1000) during operation; and (i) a scale collector element (500) configured to collect scale particles (21) from a fluid (19) flowing through the scale collection element downstream of the heating unit (400).

14. The disposable scale treatment unit (800) according to claim 13, wherein the scale treatment unit further comprises (ii) an ion exchange element (700) configured to remove calcium ions from water contacting the ion exchange element (700).

15. A method for collecting scale (20) in a coffee maker or espresso machine (1000) with steam functionality, wherein the coffee maker or espresso machine (1000) comprises a heating unit (400), the heating unit (400) being configured for heating water (10) to a temperature below the boiling temperature of the water (10) in a heating mode, wherein substantially no water (10) is evaporated, and for converting the water (10) into steam (11) in a steam generating mode, the method comprising: - controlling the flow of a fluid (19) comprising water (10) from a water supply (101) via the heating unit (400) to a water treatment unit (600) of the coffee maker or espresso machine (1000), and providing a scale inhibitor (250) to the water (10) at a location upstream of and / or in the heating unit (400); - heating the water (10) by the heating unit (400) in the heating mode to release scale particles (21) deposited at a position in the heating unit (400) and / or at a position downstream of the heating unit (400) in the steam generation mode, and carrying the released scale particles (21) toward the water treatment unit (600) by means of the water (10); as well as - collecting the scale particles (21) from the water (10) by means of a scale collector element (500), the scale collector element (500) being arranged downstream of the heating unit (400) and upstream of a flow restriction (650) of the coffee maker or espresso machine (1000).

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