Liquid heating system

Abstract

Liquid heating system (1) comprising at least one tank (2) for storing heated liquid, a pump (3) and piping (4-7) for transporting liquid to and fro said at least one tank (2), and further a flow-through heater (8) that is fluidly connectable with said at least one tank (2), and at least one liquid outlet (10) that is fluidly connectable with said at least one tank (2), and a switching unit (9) for controlling the flow in a first circuit between said at least one tank (2) and the flow-through heater (8), and in a second circuit between said at least one tank (2) and said at least one liquid outlet (10), wherein the liquid heating system (1) comprises a single tank (2), and wherein the first circuit is a closed liquid circulation circuit to direct the liquid from the single tank (2) to the pump (3), and then from the pump (3) to the flow-through heater (8), and from the flow-through heater (8) back to the single tank (2).

Description

[0001] Liquid heating system

[0002] The invention relates to a liquid heating system comprising a tank for storing heated liquid, a pump and piping for transporting liquid to and fro said tank, and further a flow- through heater that is f luidly connectable with said tank, and at least one liquid outlet that is fluidly connectable with said tank, and a switching unit for control ling the f low in a first circuit between said at least one tank and the flow-through heater, and in a second circuit between said at least one tank and said at least one liquid outlet .

[0003] WO2015 / 062882 discloses such a liquid heating system . The known liquid heating system comprises a flow through heater ; a f irst tank for receiving liquid to be heated; a second tank for temporarily storing pre-heated liquid; a liquid outlet for releasing heated liquid; and a switching unit which is configured to switch a l iquid- flow cycle o f the l iquid heating device between a pre-heating cycle , in which liquid flows from the first tank through the flow through heater and into the second tank in order to temporarily store pre-heated liquid in the second tank, and an end-heating cycle , in which the preheated liquid flows from the second tank through the flow through heater to the liquid outlet .

[0004] The known liquid heating system of WO2015 / 062882 is intended to supply heated liquid for a hot beverage machine that enables to produce a hot liquid at high flow rates and, i f needed, also at high pressures , wherein the liquid heating device may be operated at comparatively low power level .

[0005] WO2022 / 038283 discloses a liquid heating system comprising a single tank for storing heated liquid, a pump and piping for transporting liquid to and fro said tank through one wal l only of the tank, and further a flow-through heater that is f luidly connectable with said tank, and at least one liquid outlet that is fluidly connectable with said tank, and a switching unit for controlling the flow in a first circulation circuit to direct the liquid from the single tank to the pump, and then from the pump to the flow-through heater, and from the flow-through heater back to the s ingle tank, wherein said switching unit is further arranged for controlling the flow in a second circuit between said tank and said at least one liquid outlet .

[0006] The invention has as an obj ect to improve the known liquid heating system, in particular its energy ef ficiency .

[0007] A further obj ect is to provide a flexible liquid heating system with low manufacturing cost . The flexibility of the liquid heating system of the invention is particularly aimed at the system being equipped to provide heated liquid at a selectable pressure and / or temperature .

[0008] The liquid heating system o f the invention has the features of one or more of the appended claims .

[0009] According to a first aspect of the invention the liquid heating system comprises a single tank which is embodied with heat insulating double walls , wherein the switching unit is equipped with a house in which a stationary disc and a rotatable disc are provided, wherein the stationary disc is equipped with plural liquid outlets , and the rotatable disc has at least one liquid channel that by a de fined rotation of the rotatable disc is at least in part or ful ly alignable with a selected liquid outlet of the stationary disc, and that the at least one liquid channel of the rotatable disc forms part o f the second circuit between the tank and said at least one liquid outlet .

[0010] Not only the single tank with heat insulating double walls , but also the house with the stationary disc and rotatable di sc provided therein serve the purpose of energy ef ficiency . The switching unit of the invention is much more compact than a regular outlet block . The compactness of the switching unit benefits the energy ef ficiency because of a reduced radiation surface . The switching unit can also be heated quicker . Another advantage not to be forgotten is that the reliability of the switching unit of the invention with the stationary disc and rotatable this is high .

[0011] User- friendliness of the switching unit of the invention benefits from the feature that the rotatable disc is preferably motor driven .

[0012] The appl ication o f a single tank only saves on costs . Moreover a relatively cost friendly flow-through heater can be used to elevate the liquid stored in the single tank to a desired storage temperature .

[0013] Another energy-ef ficient measure is that preferably the piping for transporting liquid to and fro the tank connects to the bottom wall of the tank only . Using the bottom wall rather than the top wall is beneficial since the heat has the tendency to move upwards , and when the top wall is not pierced through with piping that connects to the tank, the isolation value of the top wall can be optimi zed .

[0014] Another beneficial feature is that the switching unit is preferably provided downstream of the flow-through heater for selecting the liquid received from the flow-through heater either to return back to the single tank in the first circuit , or to continue towards said at least one liquid outlet in the second circuit . The first circuit and the second circuit may partly or entirely coincide .

[0015] In the second option that the liquid is continued towards the at least one liquid outlet in the second circuit , the liquid originates from the single tank and is received immediately after passing the flow-through heater where it is subj ected to a final heating stage aimed at arriving at the required temperature for the at least one liquid outlet .

[0016] In a preferred embodiment each of the liquid outlets of the switching unit are arranged with an individual pressure and / or temperature setting of the liquid to be further processed, corresponding to one selected from the group comprising espresso, fresh brew, instant cof fee , steam, hot water, ambient water .

[0017] The system is provided with a mains inlet for the replenishment of water . This water can be fed directly into the tank . The water will then be pumped around repetitively through the flash heater so as to arrange that the temperature di f ference between the desired temperature of the water in the tank and the actual temperature of the water in the tank quickly disappears . Preferably the pump operates then at an increased rate . This arrangement i s benef icial for the proper operation and control of the flash heater .

[0018] In an alternative embodiment the mains inlet is provided between the single tank and the pump . The pump may then be arranged to be operating when the mains inlet is operative for replenishing water through the flash heater and into the tank . The tank will then immediately be refilled with hot water .

[0019] Preferably the single tank is a vacuum vessel with an air inlet to enable liquid to be retracted from the vacuum vessel .

[0020] The accompanying drawing, which is incorporated into and forms a part of the speci fication, illustrates one or more embodiments of the present invention and, together with the description, serves to explain the principles of the invention . The drawing is only for the purpose of illustrating one or more embodiments of the invention and is not to be construed as limiting the invention .

[0021] In the drawing : figure 1 shows schematically a first embodiment of a liquid heating system according to the invention; figure 2 shows schematically a second embodiment of a liquid heating system according to the invention; and figure 3 shows the switching unit to be used in the first embodiment or second embodiment of the liquid heating system of the invention .

[0022] Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts .

[0023] Both figure 1 and figure 2 show a liquid heating system 1 according to the invention based on the same principles . The di f ference between the embodiment of figure 1 and the embodiment of figure 2 is that in figure 1 the placement of the pump 3 that forms part of the system 1 is such that gravity assists in retracting liquid from the tank 2 of the system 1 .

[0024] In detail the liquid heating system 1 of the invention comprises a single tank 2 for storing heated liquid, a pump 3 and piping 4 - 7 connecting di f ferent parts of the liquid heating system 1 .

[0025] Piping 4 is used for transporting liquid from the single tank 2 to the pump 3 . Piping 5 is used for transporting liquid from the pump 3 to a flow-through heater 8 . Piping 6 is used for transporting liquid from the flow-through heater 8 to a switching unit 9 . Further there is piping 7 to return heated liquid back to the single tank 2 . Said piping 4 - 7 in combination forms a closed liquid circulation circuit to direct the liquid from the single tank 2 to the pump 3 , and then from the pump 3 to the flow-through heater 8 , and from the flow- through heater 8 back to the single tank 2 . The advantage of this is that it requires only a hole at the top or at the bottom of the tank to return the liquid back into the tank 2 . This i s advantageous because especially with vacuum insulation vessels , making extra wall penetrations is di f ficult and would come at the expense of the insulating capacity .

[0026] Comparing the embodiments of figure 1 and figure 2 , there is preference for the embodiment of figure 1 , wherein all piping connecting to the tank 2 connects to the bottom wal l of the tank 2 . Thi s ensures a better energy ef ficiency than is the case in the embodiment of figure 2 , wherein the concerning piping connects to the tank 2 at the top wall .

[0027] Figures 1 and 2 each show that the switching unit 9 is provided downstream of the flow-through heater 8 . The switching unit 9 is used for selecting either that the liquid received from the flow-through heater 8 is returned back to the single tank 2 , or that the liquid continues towards at least one liquid outlet 10 . Accordingly apart from the closed liquid circulation circuit ( : the first circuit ) there is a second circuit between the single tank 2 and said at least one liquid outlet 10 .

[0028] As will be clear from the foregoing disclosure the switching unit 9 is preferably equipped with said at least one liquid outlet 10 . It is however preferred that the switching unit 9 is equipped with plural liquid outlets 10 .

[0029] In accordance with the invention and shown in figure 3 the switching unit 9 is equipped with a house 12 in which a stationary disc 13 and a rotatable disc 14 are provided, wherein the stationary disc 13 is equipped with plural liquid outlets 10 , and the rotatable disc 14 has at least one liquid channel 15 that by a defined rotation of the rotatable disc 14 is at least in part or ful ly alignable with a selected liquid outlet 10 ' of the stationary disc 13 , and that the at least one liquid channel 15 of the rotatable disc 14 forms part of the second circuit between the tank 2 ( as shown in f ig . 1 and 2 ) and said at least one liquid outlet 10 .

[0030] Preferably the rotatable disc 14 is motor driven by a (not shown) motor which a user can activate by making a proper selection of a drink to be dispensed . In the connection therewith it is further preferred that each of the liquid outlets 10 is arranged with a pressure and / or temperature setting of the liquid to be further processed to an end product corresponding to one selected from the group comprising espresso , fresh brew, instant cof fee , steam, hot water, ambient water .

[0031] The system 1 is provided with a mains inlet 11 for the replenishment of water . In one (not shown) embodiment this water can be fed directly into the tank 2 . The water will then have to be pumped around repetitively, preferably at an increased pump rate . As the water passes repetitively through the flash heater 8 the temperature di f ference between the desired temperature of the water in the tank 2 and the actual temperature of the water in the tank 2 quickly disappears . This arrangement is beneficial for the proper operation and control of the flash heater 8 .

[0032] Figure 1 and figure 2 show an alternative embodiment wherein a mains inlet 11 is provided to the piping 4 between the single tank 2 and the pump 3 for replenishment of the amount of liquid in the system 1 . By running the pump 3 during replenishment , the cold water from the mains inlet 11 will first be passed through and immediately heated by the flash heater 8 . The tank 2 will then be refilled with hot water . It is to be remarked that the single tank 2 is embodied with heat insulating walls . Particularly suitable is that the single tank 2 is a vacuum vessel with an air inlet to enable liquid to exit the vacuum vessel . Since the way this can be embodied is completely known to the skilled person, this is not further shown in the drawing .

[0033] Embodiments of the present invention can include every combination of features that are disclosed herein independently from each other . Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the invention . The discussed exemplary embodiment shall therefore not be used to construe the append-ed claims strictly in accordance therewith . On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment . The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment .

[0034] Variations and modi fications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modi fications and equivalents . The entire disclosures of all references , applications , patents , and publications cited above are hereby incorporated by reference . Unless speci fically stated as being "essential" above , none of the various components or the interrelationship thereof are essential to the operation of the invention . Rather , desirable results can be achieved by substituting various components and / or reconfiguration of their relationships with one another .

Claims

CLAIMS1. Liquid heating system (1) comprising a single tank (2) for storing heated liquid, a pump (3) and piping (4-7) for transporting liquid to and fro said tank (2) through one wall only of the tank (2) , and further a flow-through heater (8) that is fluidly connectable with said tank (2) , and at least one liquid outlet (10) that is fluidly connectable with said tank (2) , and a switching unit (9) for controlling the flow in a first circulation circuit to direct the liquid from the single tank (2) to the pump (3) , and then from the pump (3) to the flow-through heater (8) , and from the flow-through heater (8) back to the single tank (2) , and said switching unit (9) further being arranged for controlling the flow in a second circuit between said tank (2) and said at least one liquid outlet (10) , characterized in that the single tank (2) is embodied with heat insulating double walls, and that the switching unit (9) is equipped with a house (12) in which a stationary disc (13) and a rotatable disc (14) are provided, wherein the stationary disc (13) is equipped with plural liquid outlets (10) , and the rotatable disc (14) has at least one liquid channel (15) that by a defined rotation of the rotatable disc (14) is at least in part or fully alignable with a selected liquid outlet (10' ) of the stationary disc (13) , and that the at least one liquid channel (15) of the rotatable disc (14) forms part of the second circuit between the tank (2) and said at least one liquid outlet (10) .

2. Liquid heating system according to claim 1, characterized in that the rotatable disc of the switching unit (9) is motor driven.

3. Liquid heating system according to the preamble of claim 1 or to any one of claim 1 or 2, characterized in that the piping (4-7) for transporting liquid to and fro said tank (2) connects to the bottom wall of the tank (2) only.

4. Liquid heating system according to any one ofclaims 1-3, characterized in that the switching unit(9) is provided downstream of the flow-through heater (8) for selecting that either the liquid received from the flow-through heater (8) is returned back in the first circuit to the single tank (2) , or that said liquid continues towards said at least one liquid outlet (10) in the second circuit.

5. Liquid heating system according to any one of claims 1-4, characterized in that each of the liquid outlets(10) is arranged with an individual pressure and / or temperature setting of the liquid to be further processed to an end product corresponding to one selected from the group comprising espresso, fresh brew, instant coffee, steam, hot water, ambient water .

6. Liquid heating system according to any one of claims 1-5, characterized in that a mains inlet (11) is provided to the tank (2) and the pump (3) is operational, preferably at an increased pump rate, when the mains inlet (11) is active for replenishment of water in the tank (2) .

7. Liquid heating system according to any one of claims 1-5, characterized in that a mains inlet (11) is provided to the piping (4) connecting the single tank (2) and the pump (3) .

8. Liquid heating system according to claim 7, characterized in that the pump (3) is arranged to be operating when the mains inlet (11) is operative for replenishing water into the tank (2) .

9. Liquid heating system according to any one of claims 1-8, characterized in that the single tank (2) is a vacuum vessel with an air inlet to enable liquid to exit the vacuum vessel .

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