DE102017100154A1 - Heater - Google Patents

Abstract

There is proposed a water heater for heating a liquid flowing through, which has a symmetrically along a longitudinal axis extending inner body having a heater, and an outer shell surrounding the inner body, wherein between inner body and outer shell a helically encircling around the inner body and delimited by the outer shell Flow channel is formed for the flowing liquid. The water heater is characterized in that the outer shell is composed of at least two separable in the direction of the longitudinal axis segment shells.

Description

The invention relates to a water heater for heating a liquid flowing through, with an inner body extending symmetrically along a longitudinal axis, which has a heater, and with an outer shell surrounding the inner body. In this case, between the inner body and outer shell a helically around the inner body encircling and bounded by the outer shell flow channel is formed for the liquid flowing through.

Furthermore, the invention relates to a beverage dispenser for dispensing hot drinks, with a brewing group for preparing freshly brewed coffee drinks and a milk system for the preparation of milk or milk-containing beverages.

From the publication WO 2013/189869 A1 a cylindrical water heater is known, which is formed of two concentrically arranged around an axis layers. The outer layer comprises a helical flow channel incorporated in a wall of the outer layer. The inner layer of the water heater contains an electric heating coil. The instantaneous water heater is designed to heat water, milk or other liquids.

The disadvantage of the operation of said continuous flow heater for heating milk, that residues of milk settle in the narrow and long helical channel and can bake there, so that they can not be eliminated by simply rinsing with a milk cleaner. For cleaning, the outer layer formed from two concentric sleeves can also be pulled apart in the axial direction so that the channel becomes accessible for cleaning. However, this requires an expansion of the water heater and proves to be less maintenance friendly. In addition, the concentric sleeves wear with frequent pulling apart and can be easily damaged.

The invention is therefore based on the object to provide an improved instantaneous water heater, which is particularly suitable for use in the heating of milk, and allows easy maintenance and cleaning of the flowed through by the liquid to be heated flow channel.

The object is solved by the features of claim 1. Advantageous embodiments are given in the dependent claims. These can be combined in a technologically meaningful way. The description, in particular in conjunction with the drawings, additionally characterizes and specifies the invention.

In a water heater of the aforementioned type, the invention provides that the outer shell is composed of at least two divisible in the direction of the longitudinal axis segment shells. In this way, the outer shell for cleaning and maintenance purposes much easier to remove from the inner body, possibly even without having to completely remove the water heater. Due to the elimination of the axial removal of the outer shell is required when removing the outer shell and thus also for the maintenance or cleaning of the helical flow channel only a small space around the water heater around.

When using more than two segment switching there is also the possibility when releasing the connection between the segmental shells in the course of cleaning or maintenance of the flow channel of the water heater not to remove all segment shells of the inner body, but only individual. This reduces the space required for cleaning or maintenance around the water heater.

The instantaneous water heater according to the invention can be installed in a space-saving manner in a hot drinks machine, in particular in a hot drinks machine according to claim 12.

The outer shell may be made of a plastic, for example in the form of an injection molded part, but may be made of metal. In this case, the outer shell advantageously for reasons of weight savings on a relatively small wall thickness and a low thermal mass. The inner body may preferably be made in at least a portion of a material having high thermal conductivity in order to allow a good heat transfer from the heater to the liquid to be heated.

In an advantageous embodiment of the instantaneous water heater according to the invention, the heater comprises an electric heating coil. Such a heating coil can be well adapted to the shape of the helical flow channel, whereby the heat transfer from the heater to the liquid to be heated can be done more efficiently. Preferably, a helical turn of the electric heating coil corresponds to a helical pitch of the flow channel. In other words, heating coil and flow channel can be arranged parallel to one another.

Advantageously, the heating coil is arranged in a region of the inner body which is radial located closer to the flow channel than on the longitudinal axis (central axis) of the water heater. Thereby, the thermal losses can be reduced along a Wärmeleitpfad from the heating coil to the liquid to be heated.

Preferably, the water heater at least two communicating with the flow channel connections for passing the liquid. The at least two connections can be arranged on the outer shell of the water heater. However, it is also possible within the scope of the invention that the at least two connections are arranged on end faces of the flow heater, or on the inner body or in a contact region of the outer shell and inner body both on the outer shell and on the inner body.

In a particularly advantageous embodiment of the invention, the outer shell is composed of two half-shells. This design of the outer shell can allow a particularly simple cleaning and maintenance of the flow channel.

The two half shells preferably have corresponding sealing surfaces, preferably abutment edges extending parallel to the longitudinal axis of the flow heater, on which the half shells are joined together in a fluid-tight manner. In this case, in particular a seal can be arranged between the sealing surfaces. This advantageous development allows a particularly simple opening and fluid-tight joining of the outer shell.

Particularly preferably, the segment shells are releasably sealingly connected to one another by means of bracing means. For example, the segment shells can be screwed against each other with screws. By means of the clamping devices, the segmental shells can be connected to each other in a simple manner and with comparatively little time after cleaning or maintenance of the flow channel again. Suitable bracing devices are, for example, screws, screw-nut combinations, clamps, clamps or the like. On the sealing surfaces of the segmental shells, a tongue-and-groove toothing can also be provided.

In an advantageous embodiment of the water heater, the inner body comprises a radiator and an insulating body. The radiator is disposed in an outer region of the inner body and contains the heater. The insulating body is arranged in an inner region of the inner body. Its task is to thermally insulate the radiator, in particular the heater, radially inwards. A heat conduction in the inner region of the flow heater contributes not or only slightly to the heating of the liquid in the flow channel and is therefore to be regarded as a loss process. The insulating body ensures that the heat output given off by the heater is transmitted essentially as intended to the liquid flowing through the helical flow channel. It also reduces the thermal mass, which must be first warmed up when turning on the water heater, so that the lead time is shortened.

The insulating body may be made for example of a heat-resistant, thermally insulating ceramic material. But it is also possible to form the insulating body as a hollow tube or the like, wherein the interior of the hollow tube may be filled, for example, with air or a thermally less conductive inert gas.

Conveniently, the insulating body is not only thermal, but also electrically insulating. This can facilitate electrical contacting of the water heater or the power line through the heater.

The radiator may be made of a single electrically insulating and thermally conductive material, such as ceramic, in which the heater is inserted or embedded and on the outside of a helical recess is formed, which in conjunction with the outer shell of the water heater the flow channel for forms the liquid to be heated. But it is also possible to form an outer region of the radiator, which comprises the helical recess, as a kind of sleeve of a stable material with high thermal conductivity such as aluminum or copper. The inner portion of the heater in which the heater is disposed may in this case be filled with a (compressed) powdery material such as magnesium oxide, which functions as an electrical insulator to prevent conduction of current to the outside of the inner body.

In another embodiment of the invention, the heater may be formed as a wound around the insulating heating wire.

A temperature of the liquid to be heated can be changed at a constant heat output of the heater, that a flow rate of the liquid, for example by means of a continuous valve or by regulating the pumping capacity of the fluid pump, is regulated. An increase in the flow rate leads to a lower final temperature of the liquid after flowing through the water heater. Conversely, a reduction in the flow rate leads to a higher end temperature. Of course, it is also possible to keep the volume flow constant and To regulate the heating power of the heater to obtain a defined increase in temperature for the liquid as it flows through the water heater.

The water heater may comprise at least one temperature sensor for determining a temperature of the liquid to be heated in order to be able to carry out a desired-actual value comparison for the temperature of the liquid. Advantageously, in each case a temperature sensor is arranged upstream and downstream of the helical flow channel in order to be able to determine the inlet temperature and the end temperature of the liquid flowing through the instantaneous water heater.

Particularly preferably, the or the temperature sensors are connected to a control unit in such a way that the heating power of the heating or the flow rate for the liquid is predetermined by the control unit depending on the temperature or temperatures of the liquid to be heated by means of the or the temperature sensors , Hereby, an even more accurate adjustment of the temperature increase of the liquid can be made possible by the water heater.

In a further advantageous embodiment, the water heater is designed as a plug-in or plug-in module. For this purpose, it has an electrical connector for the electrical connection of the heater. In addition, the line connections for the liquid flowing through are provided with a pluggable quick-release system, wherein quick-release system and connectors are arranged in the same direction, so that the water heater can be plugged onto corresponding mating connections to a support assembly. Preferably, the water heater is also provided with a handle on which it can be manually withdrawn from its anchorage from the mating connections of the carrier assembly.

A further aspect of the invention relates to a hot drinks machine having a milk system for preparing milk or milk-containing hot drinks, the milk system having a water heater of the type described above. In particular, such a water heater can serve for a milk system of a coffee machine for preparing freshly brewed coffee drinks. Such a coffee machine has a brewing group for preparing freshly brewed coffee drinks. By means of the milk system, heated milk and / or milk froth may be added to the coffee beverages, e.g. for making milk coffee, cappuccino or latte macchiato, or in addition to coffee drinks, milk drinks, such as cocoa, are prepared.

Exemplary embodiments of the instantaneous water heater will be explained in more detail below with reference to figures, wherein the invention is not limited to the exemplary embodiments shown. Features that can be taken from the figures are also included in the scope of the invention and can advantageously further develop the invention alone or in the combination shown.

• 1 eine Seitenansicht eines erfindungsgemäßen Durchlauferhitzers mit nach oben und unten geöffneter Außenhülle;
• 2 einen Längsschnitt des Durchlauferhitzers aus 1 in der Schnittebene D-D;
• 3 eine Seitenansicht des erfindungsgemäßen Durchlauferhitzers in zusammengebautem Zustand;
• 4 einen Längsschnitt des Durchlauferhitzers aus 3 in der Schnittebene C-C;
• 5 einen Querschnitt des Durchlauferhitzers aus 3 in der Schnittebene E-E;
• 6 den Durchlauferhitzer aus 3 in einer isometrischen Ansicht; und
• 7 einen Durchlauferhitzer eines weiteren Ausführungsbeispiels, welcher als Einschubmodul ausgebildet ist.

Show it:

• 1 a side view of a flow heater according to the invention with upwardly and downwardly open outer shell;
• 2 a longitudinal section of the water heater 1 in the section plane DD;
• 3 a side view of the flow heater according to the invention in the assembled state;
• 4 a longitudinal section of the water heater 3 in the sectional plane CC;
• 5 a cross section of the water heater 3 in the section plane EE;
• 6 the water heater 3 in an isometric view; and
• 7 a water heater of another embodiment, which is designed as a plug-in module.

In 1 is an instantaneous water heater according to the invention 1 shown having an inner body 2 and one in two half-shells 3a . 3b split outer shell 3 includes. The outer shell 3 forms as it were a housing for the water heater. 1

The two half shells 3a . 3b the outer shell 3 are on their inner body 2 facing inner sides 4a . 4b smooth and form in the assembled state of a kind of hollow cylinder having a smooth inner surface. Furthermore, on the half shells 3a . 3b Clamping device in the form of screws 5a . 5b . 5c . 5d with corresponding mating threads 5a ' . 5b ' . 5c ' 5d '(in 1 are only two screws 5a . 5b visible). With the screws 5a . 5b . 5c . 5d be the two half shells 3a . 3b screwed together. The water heater 1 is then ready for use. In addition, the two half shells 3a . 3b one connection each 6a . 6b for introducing and discharging the liquid to be heated, wherein the flow direction through the water heater in the exemplary embodiment is arbitrary.

The cylindrical inner body 2 has on its outer wall on a helically encircling ribbing. Along with the on the inner body 2 attached and interconnected two half shells 3a . 3b forms the helical ribbing 7 a helical flow channel through which the liquid to be heated flows.

The inner body is cylindrical and extends along its longitudinal axis L. At its end faces 10 towards the inner body each have an annular circumferential projection 8a . 8b on. These projections limit that of the ribbing 7 formed helical flow channel in the axial direction. The two projections 8a . 8b each have an annular circumferential groove, in each of which a sealing ring 9a . 9b is used, for a seal between inner body 2 and outer shell 3 and thus ensures an axial seal of the flow channel.

At the in 1 left front side 10 are on the inner body 2 three electrical contacts 11a . 11b . 11c arranged ( 11b is in 1 not shown) for heating one in the inner body 2 serve heating located. The contacts 11a, 11c are connected to a suitable power source; the contact 11b serves as a protective conductor for a potential residual current event. It would also be possible, the electrical contact on opposite end faces of the inner body 2 provided.

1 shows the water heater in the disassembled state, ie in which the two half shells 3a . 3b the outer shell 3 detached from each other and up and down from the inner body 2 are removed. The disassembly is done for example for the purpose of maintenance and cleaning. In this state, the helical ribbing can 7 or the entire flow channel, including the insides 4a . 4b the two half-shells 3a . 3b , in a simple way machanisch, for example, with a brush to be cleaned. To remove the outer shell 2 gets around the water heater 1 only relatively little space needed.

In 2 is the water heater 1 according to 1 represented in a cross section in the sectional plane DD. To recognize are in 2 two of the four screws 5a . 5c and the corresponding mating threads 5a ' . 5c ' on the opposite half-shell. At the lower half shell 3b is one of the two connections 6b to see.

In the in 2 shown cross-section can also be seen that the inner body 2 a radiator 12 and an insulating body 13 having. The radiator 12 includes, viewed radially from the inside to the outside, a heating layer 14 , in which a heating in the form of a heating coil 15 is inserted, and a metallic outer layer 16 , on the outside of the helical ribbing 7 formed - for example, embossed - is. The heating layer 14 is formed of a material with high thermal conductivity, such as magnesium oxide, and serves to transfer heat from the heating coil 15 into the metallic outer layer 16 , Alternatively, the heater 15 also as one around the insulator 13 wound heating wire to be formed.

The insulator 13 inside the inner body 2 consists of a thermally and electrically insulating material, such as a heat-resistant plastic. The thermal insulation of the insulating body 13 ensures that much of the in the heating coil 15 generated heat as intended in the helical recess 7 , More specifically, is passed into the liquid to be heated and the water heater thus has a low thermal mass, so that it heats up very quickly. The electrical insulation capability allows or facilitates the electrical contacting of the heating coil 15 over the electrical contacts 11a . 11b . 11c ,

The 3 to 6 show the water heater 1 in its assembled state for operation. Here are the two half shells 3a . 3b connected together and enclose the inner body 2 fluid-tight. The half shells form the outside boundary of the helical ribbing 7 of the inner body 1 formed flow channel.

In 3 is a side view of the water heater 1 in a similar way as in 1 shown - with the difference that the two half-shells 3a, 3b, as mentioned, the inner body 2 enclose.

At their longitudinal edges have the two half-shells 3a . 3b mutually corresponding sealing surfaces, which lie in the assembled state to each other and a fluid-tight connection between the two half-shells 3a . 3b form. It can at the edges 18a . 18b additional provided a seal. In addition, at the corresponding sealing surfaces extending in the direction of the longitudinal edges tongue and groove connection may be formed.

In the embodiment, the length of the water heater 1 without the invention being limited thereto, about 100 mm with a diameter of about 70 mm. The size of the instantaneous water heater is in this case adapted in particular to the intended volume flow rate of water or milk to be heated, which can be, for example, for a typical fully automatic coffee machine in the order of 100 to 1000 ml / min.

In 4 is the water heater 1 out 3 shown in a longitudinal section in the sectional plane CC. In this illustration, all four screws 5a , 5b, 5c, 5d to recognize the two shells 3a . 3b connect in operation. At the front 10 of the water heater 1 , in which also the electrical contact through the contacts 11a . 11b . 11c takes place, an opening extends 17 about in about one half of the longitudinal extent of the inner body 2 into this. In the opening 17 a holding means (not shown) can be inserted, through which the water heater 1 can be held or attached.

In 5 is the water heater 1 out 3 shown in a cross section in the sectional plane EE. In this view, it can be seen that the opening 17 has a circular cross section with a lateral groove. In this a pin with a suitable key spring can be inserted rotatably. Thus, the water heater can not rotate relative to its holder.

It can be seen in 5 Furthermore, that acting as a protective conductor contact 11b with the heating layer 14 in which the heating coil 15 is inserted, is in electrical contact, so that in the fault current case, a fault current through the protective conductor or the contact 11b can drain away.

In 6 is a perspective view of the water heater 1 out 3 shown. In this view, the three electrical contacts 11a . 11b . 11c to recognize.

The water heater 1 can be part of a milk system of a coffee machine and used to heat milk or milk foam for the preparation of milk-containing coffee drinks such as cappuccino or latte macchiato. A suitable milk system is for example in the Scriptures EP2987435A1 to which reference is made in full to avoid unnecessary repetition. The milk system has a milk pump, which sucks milk from a milk container arranged in a refrigerator. In addition, an air line provided with a valve opens into the intake line, so that air can also be sucked in at the same time as the milk. Behind the pump can then the water heater 1 be arranged. Optionally, warm milk may be dispensed when the air valve is closed, or warm milk froth when the air valve is opened.

In 7 a further embodiment is shown in which the water heater 1 in development of the above-described design is designed as a plug-in or plug-in module. These are both connections 6a . 6b for the milk to be heated on the left in the figure housing shell 6a arranged and provided with quick fasteners which can be plugged onto corresponding mating terminals 22a, 22b of a quick-release system, which are arranged on the coffee machine. On the right housing shell 3b is a handle 20 attached to the on the plug connections 22a . 22b plugged water heater can be pulled out of its anchorage. Also the electrical contacts 11a . 11b . 11c are in a three-pole electrical plug-in system 11 integrated, which on a corresponding electrical plug connection 21 is attached to the coffee machine. Electrical plug-in system 11 . 21 and quick-release system 6a . 6b . 22a . 22b are shown here only schematically.

Equipped with such a plug and quick release system, the water heater can be removed quickly and without tools from the coffee machine for cleaning, opened for cleaning in the manner described above and then re-inserted into the coffee machine.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2013/189869 A1 [0003]
• EP 2987435A1

Claims (13)

Instantaneous water heater (1) for heating a liquid flowing through, with an inner body (2) extending symmetrically along a longitudinal axis (L), which has a heater (15), and an outer casing (3) surrounding the inner body (2), wherein between inner body (2) and outer shell (3) is a helically around the inner body (2) and surrounding of the outer shell (3) limited flow channel for the flowing liquid is formed, characterized in that the outer shell (3) from at least two in the direction of the longitudinal axis ( L) divisible segment shells (3a, 3b) is composed. Instantaneous water heater (1) to Claim 1 in which the heater comprises an electric heating coil (15). Flow heater (1) according to one of the preceding claims, comprising at least two communicating with the flow channel connections (6a, 6b) for passing the liquid. Instantaneous water heater (1) to Claim 3 in which the at least two terminals (6a, 6b) are arranged on the outer shell (3). Instantaneous water heater (1) according to one of the preceding claims, in which the outer casing (3) is composed of two half-shells (3a, 3b). Water heater after Claim 5 in which the two half shells (3a, 3b) have corresponding sealing surfaces, preferably abutment edges (18a, 18b) extending parallel to the longitudinal axis (L) of the flow heater (1), on which the half shells (3a, 3b) are joined together in a fluid-tight manner , preferably using a seal arranged between the sealing surfaces (18a, 18b). Flow heater (1) according to any one of the preceding claims, wherein the inner body (2) and the outer shell (3) have a cylindrical shape. A water heater (1) according to any one of the preceding claims, wherein the inner body (2) comprises a heater body (12) and an insulating body (13), the heater body (12) being disposed in an outer region of the inner body (2) the radiator (12) the heater (15) is housed and wherein the insulating body (13) in an inner region of the inner body (2) is arranged. Instantaneous water heater (1) after at least Claim 8 in which the heater (15) is designed as a heating wire wound around the insulating body (13). A flow heater (1) according to any one of the preceding claims comprising a temperature sensor for determining a temperature of the liquid to be heated. Instantaneous water heater (1) to Claim 10 in which the temperature sensor is connected to a control unit, such that a heating power of the heater (15) or a flow rate for the fluid is predetermined by the control unit as a function of the temperature of the liquid to be heated by means of the temperature sensor. Instantaneous water heater (1) according to one of the preceding claims, which has an electrical connector (11) for electrical connection of the heater as well as line connections (6a, 6b) provided with a pluggable quick-release system for the liquid flowing through, wherein the quick-release system (6a, 6b) and plug connector (6) 11) are arranged in the same direction, so that the water heater (1) forms a plug-in or plug-on module. Hot beverage machine with a milk system for preparing milk or milk-containing hot drinks, characterized in that the milk system a continuous flow heater (1) according to one of Claims 1 to 12 includes.

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