Method for descaling a flow pipe system and beverage dispenser for carrying out the method

Abstract

Method for descaling a fluid flow system as an automatically running process in a beverage maker, wherein a first quantity of the descaling agent (2) provided as a saturated solution in a storage container (1) is dispensed into the flow system in a first time interval for a first time period, characterized in that at least a further quantity of the descaling agent (2) provided as a saturated solution in the storage container (1) is dispensed into the flow system in a further time interval for a further time period, wherein the first quantity of the descaling agent (2) is dosed less than the further quantity.

Description

The invention relates to a method for decalcifying a flow guidance system and to a beverage machine for carrying out the method.Water has a wide variety of regional chemical compositions. Calcium carbonate (CaCO 3) and magnesium carbonate (MgCO 3) and chemical compounds thereof in particular present a particular problem because these substances settle in fluids and in particular in pipes and aggregates conducting water (H 2 O) and either put the pipes or aggregates out of operation over a longer period of time or at least significantly impede an unhindered fluid flow. This problem consequently exists not only in the case of water, but generally in the case of fluids, that is to say also in the case of gaseous substances based on water. Thus, vapor carrying conduits are as concerned as are liquid conduits. In order to remain in the example of the water, the carbonate hardness of the water is decisive for the determination of the properties of the water. The carbonate hardness of the water is formed by chemical compounds between calcium carbonate and magnesium carbonate on the one hand and the carbon dioxide (CO2) ("carbonic acid") present in the water on the other hand. Calcium carbonate reacts in water with carbon dioxide to form calcium bicarbonate (Ca(HCO 3)2). In the presence of magnesium, it can also be stated that this is reacted with the carbon dioxide present in the water to give magnesium bicarbonate (Mg(HCO 3)2). Calcium and magnesium hydrogen carbonates are respectively the causative factor of the carbonate hardness in water, which is measured in the unit mmol / I. To determine them, there are tests that function according to the color change method. A drop of the test agent is placed in a measured amount of water, which is repeated until a color change takes place in the water. The number of droplets corresponds to the degree of carbonate hardness. In this way, each user can determine the degree of hardness of the water itself, dividing the water into different degrees of hardness. Of course, this value can also be requested with the responsible waterworks. Depending on the carbonate hardness, a distinction is made between "soft" water and "hard" water. In general terms, however, a chemical subdivision between the depositing substances is less carried out, but rather generally referred to as "deposits of lime" or "low-lime" water or fluid. The measure of the carbonate hardness of the water or of a fluid permits very precise conclusions about the frequency with which pipes or fittings carrying fluids or water must be decalcified.In order to solve the problem of deposits of lime in flow guidance systems and industrial equipment, decalcifiers capable of dissolving "lime" due to a chemical reaction have already been known and used. Since this process has to be carried out more or less regularly depending on the already mentioned carbonate or water hardness, various approaches and solutions are known for bringing about a certain automaticness of the decalcification.EP 2 265 158 B1 discloses, for example, a decalcifying device for decalcifying a flow guidance system for fluids, using the example of a beverage machine, in which a storage container is present which can be supplied with water via a water inlet and in which a water-soluble decalcifying agent is located. A mixture outlet of the storage container ensures that the dissolved decalcifying agent is discharged into the flow guidance system and achieves its desired effect there. The principle of continuous flow is used here. This means that the water passes from the water inlet to the mixture outlet through the introduced dose of decalcifying agent, dissolves it and is discharged as a mixture at the mixture outlet into the flow guidance system. A control unit ensures the actual progress of decalcification. However, a disadvantage of this solution is that the user must first fill a prescribed dose of decalcifying agent and water into the storage container before the decalcifying process, in order to be able to carry out the decalcifying only subsequently. The control unit only has the task here of controlling the actual decalcification process, i.e. the circulation of the dissolved decalcifying agent in the flow guidance system. In other words, only partial automation has been achieved here. Moreover, the continuous flow described has proved to be disadvantageous because it is not always ensured that the water filled into the storage container actually dissolves the entire dose of decalcifying agent. The chemical reaction of the solution is very strongly temperature-dependent, so that variations can have a disadvantageous effect here. However, the consequences of an incompletely dissolved decalcifying agent are serious, since the effect does not take place to a required extent. Thus, there is a need to use the decalcifying agent in a very accurately meterable manner and to provide a reservoir which enables an effective decalcification of the flow guidance system over a long period of time. Further methods for decalcifying flow guidance systems are evident from the publications WO 2006 / 090 183 A2 and US 2011 / 0 030 732 A1.The invention thus addresses the problem of providing a method for decalcifying a flow guidance system for fluids which works effectively over a long period of time with little effort. In addition, a beverage machine for carrying out the method is to be provided, which has a simple structure.According to the invention, this problem is solved by a method for decalcifying a flow guidance system having the features of patent claim 1 and by a beverage machine for carrying out the method having the features of patent claim 10.Advantageous embodiments and further developments of the invention are evident from the respectively following dependent claims.The method according to the invention for decalcifying a flow guidance system for fluids consists in a first quantity of decalcifying agent provided as saturated solution in a storage container being dispensed into the flow guidance system in a first time interval for a first period of time and at least one further quantity of decalcifying agent provided as saturated solution in the storage container being dispensed into the flow guidance system in a further time interval for a further period of time.In other words, the teaching according to the invention assumes that two different concentrations of the decalcifying agent provided as a saturated solution are used at different time intervals and for a respective time duration of the action of the decalcifying agent on the flow guidance system.Since lower concentrations of the decalcifying agent are also used in this case, this measure has an overall effect in terms of an optimum decalcifying and a saving of the decalcifying agent. Furthermore, the storage container is not only used once, which is why the decalcification process can take place again and again over a long period of time. This is because only a part of the decalcifying agent contained in the storage container is always used in the form of a saturated solution for the decalcifying process. This results in a very precise dosability of the decalcifier, which has the advantage that the required amount of dissolved decalcifier, which is supplied to the fluid flow guidance system, can be adjusted exactly to the carbonate hardness or the degree of hardness of the locally given water. A particularly economical management of the available resources thus also makes a substantial contribution to environmental protection. The storage container requires a small overall size due to the concentration of the decalcifying agent, so that valuable installation space can also be saved.According to a first embodiment of the method according to the invention, the first time interval in which a decalcification process takes place can be between 18 and 48 hours. Preferably, a decalcification process is carried out at least once within a time interval of 24 hours.The teaching of the invention is directed here to the fact that the first amount of decalcifying agent is metered in less than the further amount. In other words, with a less dosed decalcifier, the decalcifier process is performed at regular, short-term consecutive intervals than with a higher dosed decalcifier. The higher dosage in this case brings about a "descaling agent impact" in a manner of speaking.Accordingly, a development of the method for decalcifying a flow guidance system consists in the fact that the first quantity of decalcifying agent corresponds to a concentration of 15 to 25 mmol / l, in particular of 20 mmol / l, while the further quantity of decalcifying agent corresponds to a concentration of 30 to 40 mmol / l, which means a higher, concentrated dose with a stronger effect on the chalk present in the flow guidance system.Since the higher-dose decalcifier can be used less frequently than the lower-dose decalcifier, it is proposed according to a further proposal according to the invention that the further time interval in which a decalcifier process takes place is between one week and one month. Here too, the degree of hardness of the water or of the fluid is again deposited. The higher the degree of hardness of the locally present water, the more frequently a decalcifying process must also be carried out with the higher concentration of decalcifying agent.In order to be able to fully utilize the effectiveness of the decalcifying agent, it is furthermore advantageous if the time duration of the decalcifying process is in each case approximately between 1 and 3 hours. Naturally, this time period can be shortened with less calcification or extended with severe calcification. The data relate to average experience values determined by experiments.As already explained at the beginning, the carbonate hardness of the water represents a decisive criterion for the descaling process. Moreover, the progress of the deposits of lime in the flow guidance system is directly dependent on the frequency of use. Accordingly, it is an important advantage for achieving optimum results if the time duration of the action of the decalcifying agent on the flow guidance system is determined or can be determined as a function of the frequency of use and / or the carbonate hardness of the water. For the user, this realization means that he must at least once query, determine or ascertain the carbonate hardness of the water in order to store it in a control device, for example.Therefore, a further embodiment of the method according to the invention is based on the fact that the beginning of a decalcification process and / or the duration of the action and / or the carbonate hardness of the water can be adjusted in a programmable or manual manner in a control device. Due to the possibility of programming or manual input, the user is always able to influence his sense in a process which is automatically carried out per se. For example, in a beverage machine, the decalcifying process can always be carried out at times when no beverage is drawn. It is conceivable that the decalcification is thus transferred to the night hours, for example.A beverage machine for carrying out the method described above is characterized in that the beverage machine has a flow guidance system for fluids with at least one water container containing water or a water connection, at least one pump, at least one valve and at least one removal device, wherein a storage container to which water can be applied via a water inlet and having a water-soluble decalcifying agent contained therein, which forms a solution, is present, the solution of which can be discharged via a mixture outlet of the storage container.In the context of the invention, a "removal device" is understood to mean, for example, a steam nozzle, a dispensing point for hot water or, for example, the coffee dispensing nozzle in a beverage machine designed as a coffee machine. Likewise, other beverage machines can be quite generally the dispensing point of the beverage. The pump serves for conveying the liquids and / or gases within the flow guidance system and for the required pressure build-up. A water container can be used in a simple manner as a source for the fresh water, which serves for preparing the beverage and / or for carrying out the decalcification. Other solutions have a fixed water connection, which is not explicitly excluded here and is to be understood as synonymous.Metering valves can advantageously serve for regulating an exact dispensing quantity of the processed mixture of the decalcifying agent from the storage container, wherein fresh water is simultaneously replenished via the water inlet. In this way, the chemical equilibrium is maintained within the storage container. The principle of volume displacement is consequently used in this case.In the context of the invention, at least one controllable valve will also be used in order to separate the decalcification branch of the flow guidance system from the part which serves exclusively for beverage preparation. In other words, the valve controls that the decalcifying agent enters the flow guidance system only when the beverage machine is out of operation, that is to say is not used for preparing beverages.A saturated solution is preferably used, since this can be advantageously stored and allows a long service life of the storage container filled therewith.A specific characteristic of this automatic beverage machine is that the automatic beverage machine has a control device for the timing of the tournous execution of the decalcification. This measure enables extensive automation of the decalcification process. The dosage of the decalcifying agent to be dissolved can likewise also be automated. Thus, the beverage machine automatically takes over the monitoring of a required decalcification. The user is completely free from regular checks of the state of the automatic beverage machine and from manual execution of the decalcification. This ensures a long service life of the apparatus and a satisfactory operation.The use of a preferably pulverulent decalcifying agent which is present pressed in tablet form or forms a concentrated solution and which together with water has an acid-forming property enables, for example, advantageous portioning. The decalcifying agent forms an acid in a mixture with water, because acid is particularly advantageously suitable for dissolving calcium carbonate or "lime". The more dissociation the acid, the faster the removal of lime residues from the flow guidance system. However, the tablet form or, expressed more generally, the compressed and thus compressed presentation of the decalcifying agent, or a pulverulent decalcifying agent, offers further advantages. First, the reservoir can be made relatively small compared to liquid decalcifiers or cation exchangers. In addition, in the case of liquid decalcifiers, there is an export problem which arises from the prohibition of transfer of liquids which exceeds the limit. Here, usually complicated approval processes are required in order to be able to carry out exploratory processes that exceed the limit. Another advantage of pulverulent decalcifiers is also that powder does not undergo any changes in state of aggregation even under extreme thermal conditions. Storage or transport conditions in the range from -20° C. to +70° C. are thus not rare and can be easily exceeded exclusively by pulverulent decalcifiers without any risk of quality losses. Liquid decalcifiers also entail the risk that the decalcifier runs out if the packaging is damaged. The damage caused thereby can be avoided by pulverulent decalcifiers.According to a further proposal of the invention, the decalcifying agent may be citric acid, acetic acid or another biodegradable acid.Since an acid may be a very aggressive medium depending on its concentration, the protection of health and environment plays a very particular role. For this reason, not every acid is freely usable for the purposes of the present invention. Finally, it must also be considered that with such a decalcifying device, lay-ups may possibly be bypassed. Accident risks must in principle be ruled out here. A further proposal according to the invention is therefore that the decalcifying agent is citric acid, acetic acid or another biodegradable acid. With this solution, no problems arise any longer when disposing of the end products of the decalcification process. The acid is also easy to handle and does not cause any extreme serious damage even in the case of improper use.The previously mentioned automation of the decalcification process can be implemented and controlled in a simple manner if the beverage machine has a pH value measuring device or a measuring device for detecting the electrical conductance of the water. Moreover, this measure offers the possibility of optimizing the acid content within the flow guidance system. In this way, the concentration of the acid can consequently be optimally adjusted in order to achieve the best possible decalcification results. In addition, this measured value acquisition can be used to determine the fill level of the storage container with decalcifying agent. If the acidity drops below a prescribed minimum, the user can be signalled that fresh decalcifying agent has to be replenished into the storage container or that this has to be completely replaced. It is particularly advantageous if the storage container is equipped with a closable opening or a closable lid. Of course, the use of disposable storage containers cannot be ruled out at this point. In this case, the empty storage container is replaced by a new storage container filled with decalcifying agent.The proposed control device within a beverage machine is versatile and can be used in particular in the sense according to the invention if it comprises a calendar and / or a clock. Under this precondition, the time intervals, the respective time duration or, if appropriate, a time for the decalcification process can be defined and determined precisely.In general, it is of course self-evident that, after decalcification and / or cleaning of the flow guidance system has taken place, a thorough rinsing with fresh water must then always be carried out in order to remove all residues of the decalcification process or of the cleaning process!The invention is explained in more detail below with reference to the attached drawings. The exemplary embodiments shown do not represent any restriction to the variants shown, but serve merely to explain a principle of the invention. Identical or similar components are denoted by the same reference numerals. In order to be able to illustrate the mode of operation according to the invention, only greatly simplified schematic diagrams are shown in the figures, in which the components which are not essential for the invention have been dispensed with. However, this does not mean that such components are not present in a solution according to the invention.It shows: FIG. 1 : a front view of a beverage machine with a decalcifying device, FIG. 2 : a schematically greatly simplified illustration of a storage container as an individual part illustration, FIG. 3 : a first variant of a part of a flow pattern of a flow guidance system in a beverage machine in a simplified illustration, and FIG. 4 : shows a second variant of a part of a flow pattern of a flow guidance system in a beverage machine in a simplified illustration.FIG. 1 shows the front view of a beverage machine having a decalcifying device using the example of a coffee machine inserted into a kitchen cabinet and serving for preparing coffee beverages or coffee mixed beverages.The front of the beverage machine formed by a panel 17 initially has a trough 18, in which a plurality of extraction devices 13, 14 are located. A dispensing unit 19 whose height can be adjusted here has, for example, in its lower region two extraction devices 14 for the dispensing of coffee beverages. The extraction device 13 in this case is a nozzle which is used for discharging water vapor. Laterally next to the extraction devices 13, 14, a liquid container 20 is suspended in the trough 18, from which, for example, milk can be extracted in order to produce coffee mixed beverages or to produce hot milk or cocoa beverages. The lower boundary of the trough 18 is formed by a drip plate 21 which discharges the residues dripping off from the removal device 13, 14 into a collecting container present below the drip plate 21. For this purpose, several openings 22 are made in the drip plate 21. Hidden by the cover 17 in the interior of the appliance is a storage container 1 with a decalcifying agent, which is only indicated by dashed lines in FIG. 1, the construction and functioning of which will be discussed in more detail below.In order to enable the user to input data, an input unit 24, which is a keyboard in the present case, is also integrated into the screen 17. In this way, data required for the proper decalcification can be input, which can be stored and processed in a control unit of the beverage machine. These data can be, for example, a date and / or a time for the beginning of a decalcification process or the carbonate or water hardness. To facilitate the control of the entered values and / or to communicate information from the automatic beverage maker to the user, a display device 23 is also present, which here has likewise been integrated into the panel 17 and in the simplest case can be a digital display. This can make displays of required inputs or prompts for specific actions visually visible.FIG. 2 shows a storage container 1 in a greatly simplified individual part illustration. The storage container 1 has a water inlet 15 via which water can be introduced into the storage container 1. In the region of the water inlet 15, there is also a metering valve, not designated in any more detail, by means of which the quantity of water supplied is regulated. The water inlet 15 is located in the lower region of the storage container 1 close to the base.Above the water inlet 15 a mixture outlet 16 is likewise arranged with a metering valve, not designated in any more detail, by means of which the quantity of the discharged saturated solution 3 of the decalcifying agent 2 can be regulated. The storage container 1 is filled with a pulverulent decalcifying agent 2. By introducing water via the water inlet 15 in the area of the storage container 1 close to the bottom, the water flows through the pulverulent decalcifying agent 2 and is thereby fluidized, as a result of which a part of the decalcifying agent 2 passes over into solution and forms a saturated solution 3 above the remaining remainder of the decalcifying agent 2, which solution serves for decalcifying a flow guidance system for fluids.FIGS. 3 and 4 show two different variants of a part of a flow pattern of a flow guidance system in a beverage machine in a simplified illustration. FIG. 3 first illustrates a flow diagram in which the storage container 1 is arranged between a water container 4 and a plurality of extraction devices 13, 14. Fresh water is present in the water container 4. The water container 4 is connected to the flow guidance system via a water line 25, wherein the water line 25 opens into a multiway valve 6, which with the further valve 7 separates the line system for preparing the beverages from the line system for decalcification.In a first position, this multiway valve 6 allows fresh water directly into the line system for preparing the beverages, while the decalcifying section of the flow guidance system is closed. In addition to the multiway valve 6 closed in this direction, a second valve 7 is provided at the end of the line system for decalcification formed by the water line 32, which valve is likewise closed in this switching position of the multiway valve 6. The extraction devices 13, 14 having valves 8, 9, on the other hand, are selectively open and can be used to prepare a beverage. To assist the flow guidance, a pump 5 is furthermore integrated into the line system for processing the beverages, which pump conveys the water removed from the water container 4 via a water line 26 to a heat exchanger or thermoblock 30 for heating the water. In addition, this section of the flow guidance system has a flowmeter 29.A second position of the multiway valve 6 leads, with the valve 7 simultaneously open, to fresh water from the water container 4 entering the line system for decalcification and thus the flow line 32. This has the consequence that water flows into the storage container 1 via the water inlet 15 of the storage container 1 and dissolves the decalcifying agent 2 present therein. To the same extent as fresh water is introduced into the storage container 1, solution 3 likewise present in the storage container 1 is discharged via the mixture outlet 16 according to the principle of volume displacement and introduced into the flow guidance system, where it reaches the valves 8 and 9 of the extraction devices 13, 14, so that these units also come into contact with the decalcifying agent and are decalcified.After there is a solution discharge at the extraction devices 13, 14, the valves 8 and 9 are closed in order that the solution 3 of the decalcifying agent 2 can develop its effect. Depending on the intensity of use and on the lime content of the water, the exposure time may be 1 hour or longer. During this time, a beverage intake is not possible, which is why the beverage machine is blocked and the solution 3 of the decalcifying agent 2 remains or circulates in the flow lines. During this decalcifying process, the multiway valve 6 is closed in the direction of the water tank 4, so that no solution 3 of the decalcifying agent 2 can enter the water tank 4 or the fresh water. Following the decalcification process, the entire flow guidance system is rinsed once again with fresh water, so that it is also cleaned.The flow diagram shown in FIG. 4 finally has a line system for processing the beverages, which line system is analogous to the illustration in FIG. 3. Here too, a pump 5 serves to convey the fresh water from the water container 4 into the line system. A flowmeter 29 and a heat exchanger 30 all make up the identical structure of this part of the flow guidance system. A removal device 14 serves here for dispensing a coffee beverage, while the removal device 13 can be used for preparing hot water vapor. In contrast to the illustration in FIG. 3, in this embodiment variant a bypass 33 was integrated, extending away from the water line 25, which bypass runs starting from a branch 27 to a branch 28. A valve 10 is arranged behind the branch 27, while a further valve 11 is present in front of the branch 28, so that the bypass 33 can be separated overall from the water-conducting part of the water line 25, 26 or can be connected to this part of the water line. The reservoir 1 is integrated into the bypass 33, which reservoir is supplied with fresh water in this way when the valve 10 is open, so that the decalcifying agent 2 contained therein changes over into a solution 3 and the quantity of solution 3 of the decalcifying agent 2 corresponding to the supplied water is discharged via the mixture outlet 16 and the feed line 31. The likewise open valve 11 enables the solution 3 of the decalcifying agent 2 to be fed into the flow guidance system via the branch 28. Thus, the decalcifying operation can be initiated in the manner described above. A shut-off valve 12 in the water line 25 serves to prevent the solution 3 of the decalcifying agent 2 from entering the water tank 4.LIST OF REFERENCE CHARACTERS:1 Storage container 2 Decalcifier 3 Saturated solution 4 Water container 5 Pump 6 (multiway) valve 7 Valve 8 Valve 9 Valve 10 Valve 11 Valve 12 (shut-off) valve 13 Extraction device 14 Extraction device 15 Water inlet 16 Mixture outlet 17 Orifice 18 Trough 19 Output unit 20 Liquid container 21 Drip plate 22 Openings 23 Display device 24 Input unit 25 Water line 26 Water line 27 Branch 28 Branch 29 Flow meter (flowmeter) 30 Heat exchanger (thermoblock) 31 Feed line 32 Water line 33 Bypass

Claims

Method for decalcifying a flow guidance system for fluids as an automatically executing process in a beverage maker, wherein a first quantity of decalcifying agent (2) provided as saturated solution in a storage container (1) is discharged into the flow guidance system in a first time interval for a first period of time, characterized in that at least one further quantity of decalcifying agent (2) provided as saturated solution in the storage container (1) is discharged into the flow guidance system in a further time interval for a further period of time, wherein the first quantity of decalcifying agent (2) is dosed less than the further quantity.Decalcification method according to claim 1, characterised in that the first time interval during which a decalcification process takes place is between 18 and 48 hours.Method for decalcification according to one of the preceding claims, characterized in that the first quantity of decalcifying agent (2) corresponds to a concentration of 15 to 25 mmol / l, in particular of 20 mmol / l, in the flow guidance system.Method for decalcifying according to one of the preceding claims, characterized in that the further quantity of decalcifying agent (2) corresponds to a concentration of 30 to 40 mmol / I in the flow guidance system.Method for decalcifying according to one of the preceding claims, characterized in that the further time interval in which a decalcifying operation takes place is one week to one month.A decalcification method according to any one of the preceding claims, characterized in that the time duration of the decalcification process is between 1 and 3 hours each.Method for decalcifying according to one of the preceding claims, characterized in that the duration of the action of the decalcifying agent (2) on the flow guidance system is determined or determined as a function of the frequency of use and / or the carbonate hardness of the water.Method for decalcifying according to one of the preceding claims, characterized in that the start of a decalcifying process and / or the duration of the action and / or the carbonate hardness of the water can be adjusted in a programmable or manual manner with the aid of a control device.Beverage machine comprising a flow guidance system for fluids with at least one water container (3) or a water connection, at least one pump (4), at least one valve (5, 6, 7, 8, 9, 10, 11) and at least one extraction device (13, 14), wherein a storage container (1) which can be supplied with water via a water inlet (14) and has a water-soluble decalcifying agent (2) contained therein and forms a solution, the solution of which decalcifying agent can be discharged via a mixture outlet (15) of the storage container (1), characterized in that the beverage machine has a control device for the time control of the tournusal execution of the decalcifying according to the method according to one of Claims 1 to 8.Beverage machine according to claim 9, characterised in that the solution formed or contained in the storage container (1) is a saturated solution.Beverage machine according to any one of claims 9 to 10, characterised in that the decalcifying agent (2) is powder-shaped, compressed into tablet form or provided as a concentrated solution and has an acid-forming property together with water.Beverage machine according to any one of claims 9 to 11, characterised in that the decalcifying agent (2) is citric acid, acetic acid or another biodegradable acid.Beverage machine according to one of claims 9 to 12, characterised in that the beverage machine has a pH value measuring device or a measuring device for detecting the electrical conductivity value of the water.Beverage machine according to one of claims 9 to 13, characterised in that the control device of the beverage machine comprises a calendar and a clock.

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