EP3702691B1 - Continuous flow heater for heating a fluid - Google Patents

Description

The present invention relates to a continuous-flow heater for heating a liquid, comprising a base body with a channel arrangement formed in the base body with a plurality of fluid-passing channels, wherein the fluid-passing channels are designed and set up to pass a fluid through, with at least two of the channels each being located in the base body Formation of channel openings extend on at least one end side of the base body, with deflection end faces being formed on the end side, which are designed to redirect the fluid between the channel openings, and at least one cover part, which corresponds to the deflection end faces, sealed to form sealing deflection bridge channels between associated channel openings on the End side is detachably arranged, the end side and the cover part each having sealant recesses surrounding the cross sections of the deflection bridge channels, which are each designed and set up to receive a sealant.

Known electric instantaneous water heaters of the type mentioned generally have a base body which includes several fluid-passing channels. The base body is manufactured, for example, as a plastic injection molded part that has sufficient strength and electrical insulating properties. The base body of the generic instantaneous water heater usually has at least one end side; as a rule, such instantaneous water heaters include two end sides. The end sides of the base body each have openings for the fluid-passing channels. So that the fluid-passing channels can be connected to one another or the fluid can be redirected, deflection end faces are formed on the end sides. Furthermore, the known instantaneous water heaters of the type mentioned have cover parts adapted to the end sides, which have channel openings corresponding to the end sides and are designed to deflect and seal the fluid-passing channels. The deflection end faces of the end sides and the cover parts are joined together in a watertight and pressure-tight manner. There are seals between the cover parts and the deflection end faces Deflection bridge channels are formed, which connect adjacent or mutually assigned channel openings.

Furthermore, the known generic instantaneous water heaters generally have further channel arrangements which include further components. For example, to control the flow rate or to regulate the water pressure within the instantaneous water heater, motor valves are provided, which also include fluid-passing channels. Between sections of fluid-passing channels of the further channel arrangements of the instantaneous water heaters there are sections which are also joined together in a watertight and pressure-tight manner.

Such instantaneous water heaters of the generic type are e.g. B. from the EP 2 489 951 A1 and the FR 2 803 372 A3 known.

Next is from the WO 2016/065418 A1 a water storage system is known with a seal that is arranged between two sealing surfaces.

The US 2010/199853 A1 discloses a boiler with at least one seal positioned between a first wall of a diffuser and the base body to ensure sealing of the heating space.

The base body of the known instantaneous water heaters is usually a cuboid structure. It can also be at least partially corner-free and therefore round-shaped. The water-carrying or fluid-passing channels are part of the base body.

Known electric instantaneous water heaters of the type mentioned have a base body or channel arrangements with broad sides or also called end sides forming two end faces, to which a cover part is attached over the entire surface or at least over a partial area of the broad side. The channel arrangement of such instantaneous water heaters is preferably designed over the entire width, length and height of the base body. However, it is also possible for the channel arrangement to be arranged only in a partial area of the base body. Water-carrying channels, also referred to as fluid-passing channels, are provided in the base body for guiding water or for carrying out a comparable fluid, which can be arranged in different orientations and formations.

The construction of such known base bodies, in particular the end sides, is associated with complex, elongated geometries of sealing surfaces, namely with sealing surfaces or sealing areas that extend over the entire width on the end sides. The base body regularly has a large cross section, which is why the cover parts are also relatively large and solid. This leads to significant problems with sealing the surfaces between the deflection end faces and the cover parts. In particular, the required seal between the base body and cover parts has a disadvantageous effect on an efficient and cost-effective design, since these must always have a high sealing effect in order to avoid the liquid, which is usually under pre-pressure, escaping in any case. In order to counteract this, complex fastening measures with a large number of fastening points and additional sealants and/or special coordination are required with regard to the force distribution on the cover parts for sealing over the entire width. Furthermore, complex sealant constructions or complex fastening means are regularly provided for fixing the cover parts to the base body.

In order to achieve a reliable sealing effect between the base body and the at least one cover part, appropriate processing steps must be carried out on both the base body and the cover parts in order to produce a surface finish, which enables a sealing assembly. The surfaces processed in this way must have a high degree of precision in order to achieve an exact seal. For this purpose, a large number of processing steps are usually provided in order to produce base bodies or cover parts from the plastic injection-molded parts that can be further processed. In particular, machining to an exact size is labor-intensive and cost-intensive.

It is therefore the object of the present invention to propose an instantaneous water heater with a base body which has good sealing properties of the channel arrangements, in particular between the deflection end faces and cover parts. It is also the task of proposing an instantaneous water heater whose manufacturing process is simplified and therefore more cost-efficient.

The task is achieved by the aforementioned instantaneous water heater for heating a liquid in that each of the sealant recesses is between a sealing surface on the inside of the channel and a sealing surface on the outside of the channel is arranged, and the channel-outside sealing surfaces of the end side of the base body and the cover part are set up in such a way that they lie flat against one another in a sealing manner, while the channel-inside sealing surfaces of the end side of the base body and the cover part are spaced apart from one another, leaving a sealing gap.

Advantageously, a cost-effective and at the same time reliably sealed structural design of a base body for an instantaneous water heater is proposed. The production of the base body is simplified by spacing the sealing surfaces on the inside of the channel while leaving a sealing gap. Only the sealing surfaces on the outside of the duct lie flat against each other. This reduces the costs of the manufacturing process, since only the sealing surfaces on the outside of the channel have to be manufactured with a correspondingly precise dimension and with an extremely low tolerance, whereas the sealing surfaces on the inside of the channel can have a larger tolerance in the manufacturing process due to the sealing gap left. In addition, the costs for quality management for monitoring the adhered to tolerances are reduced because only the sealing surfaces on the outside of the channel have to be monitored to ensure compliance with the dimensions, since only these are in a flat seal against one another. The sealing gap in the area of the sealing surfaces on the inside of the channel offers a further advantage, namely that a further sealing means can be arranged in this sealing gap for additional sealing in order to achieve an additional seal.

An expedient embodiment of the invention is characterized in that a sealant is arranged in the sealant recesses. This offers the advantage that the seal between the end side and the cover part is improved. The sealant arranged in the sealant recess leads to a further seal, whereby a secure seal is always ensured even at higher pressures within the channel arrangement.

A preferred development of the invention is characterized in that the sealant comprises a molded part made of an elastic material. The elastic material of the sealant offers the advantage that it is deformable. Due to its deformability, the sealant conforms optimally to the surface geometry and thus creates an optimal seal. A preferred embodiment of the elastic material includes rubber and/or silicone and/or plastic.

According to a further preferred embodiment of the invention, the sealant comprises a surface seal. More preferably, this surface seal is made in one piece and made of an elastic material, or of a flowable but hardening material, for example silicone, and is designed and aligned. The sealant particularly preferably has the cross-sectional shape of a double trapezoid joined together on the longer of the opposite sides.

According to a further preferred embodiment of the invention, the elastic material of the sealant deforms during the passage of a fluid in the fluid-passing channels in the direction of or within the sealing gap of the surfaces on the inside of the channel. In other words, the elastic sealant is arranged in the sealant recess in such a way that it is designed to be deformable in the direction of or within the sealing gap when the fluid is passed through the fluid-passing channels. As the fluid pressure increases, the sealant is increasingly pressed into the sealant recess. In this way, the tightness between the end side and the cover part is even further increased as the pressure increases. The seal is therefore designed to be self-sealing.

A further expedient embodiment of the invention is characterized in that at least one further sealant recess is designed and set up to accommodate a further sealant with further sealing surfaces between the sealing surface on the inside of the channel and the sealing surface on the outside of the channel of the sealant recesses of the end side or the cover part. This creates an additional sealing level between the end side and the cover part. The seal is therefore designed to be redundant, which increases the reliability of the overall seal and results in a significantly increased average service life of the instantaneous water heater. Furthermore, in the event of a possible defect in one of the seals or damage to one of the sealing surfaces, there is an additional sealing level that reliably counteracts leaks.

According to a further preferred embodiment, a further sealant is contained in the at least one further sealant recess, wherein in a further preferred embodiment the further sealant comprises a molded part made of an elastic material. “Moulded part” in the sense of the invention means that it is designed according to the dimensions of the sealant recesses and the deformation of the Sealant is designed accordingly. This offers the advantage that the molded part is elastically prestressed between the cover part and the end side and achieves a high sealing effect.

A preferred development of the invention is characterized in that the end side and the cover part are connected in a force-fitting, material- or form-fitting manner. In this way, a reliable fixation between the end side and the cover part is provided in a simple manner. Preferably, not only one end side and a cover part are connected in a force-fitting, material- or form-fitting manner, but all end sides and cover parts present on the channel arrangement are connected in a force-fitting, material-fitting or form-fitting manner. This creates a channel arrangement with a closed internal fluid space, which is suitable for passing a fluid through or heating a fluid in this fluid space.

According to a further preferred embodiment of the invention, the fixation between the end side and the cover part takes place by means of screw connections. Screw connections offer the advantage that they are easy to handle, cost-effective and generally reversible, which makes it possible, for example, to replace the sealants used.

A further expedient embodiment of the invention is characterized in that the sealing gap of the sealing surfaces on the inside of the channel has a smaller sealing gap width than the width of the sealant recess. Due to the smaller sealing gap width of the sealing gap of the sealing surfaces on the inside of the channel than the width of the sealant recess, a barrier is created for any contaminants contained in the fluid. Furthermore, the smaller gap in the sealing surfaces on the inside of the channel ensures that the largest gap width lies within the sealant recess, which is intended to accommodate a sealant. The different gap width also enables the sealant to be preferably elastically deformed into the sealing gap of the sealing surfaces on the inside of the channel, which further increases the sealing effect.

A preferred development of the invention is characterized in that the sealing surfaces on the outside of the channel are at least essentially gap-free. If necessary, the channel arrangement is sealed by the sealing surfaces on the outside of the channel. Furthermore, the essentially gap-free sealing surfaces prevent unwanted contaminants from penetrating the area of the sealant recess, which could, for example, lead to damage or corrosion of the sealant. At least essentially gap-free in the sense of the invention means gap-free or with a gap whose maximum width is a few µm.

According to a further preferred embodiment, sealant recesses are arranged between fluid-passing channels on the inside of the channel arrangement, with sealing surfaces on the inside of the channel being formed and set up on both sides, the sealing surfaces on the inside of the channel having a sealing gap. Further preferably, a sealant made of an elastic material is arranged in the sealant recess. This offers the advantage that the sealant can escape into the sealing gap of the sealing surfaces on the inside of the channel if the prevailing pressure requires this.

Fig. 1

eine perspektivische Explosionsansicht eines Ausschnitts des Grundkörpers und des Deckelteils des erfindungsgemäßen Durchlauferhitzers,

Fig. 2

eine Seitenansicht des in Fig. 1 gezeigten Grundkörpers und des Deckelteils im zusammengesetzten Zustand;

Fig. 3

eine vergrößerte Seitenansicht der in den Fig. 1 und Fig. 2 gezeigten Dichtflächen mit den Dichtmittelausnehmungen
und

Fig. 4

eine vergrößerte perspektivische Explosionsansicht der in Fig. 3 gezeigten Dichtflächen mit den Dichtmittelausnehmungen.

Further preferred and/or expedient features and refinements of the invention emerge from the subclaims and the description. Particularly preferred embodiments are explained in more detail with reference to the accompanying drawing. In the drawing shows:

Fig. 1

a perspective exploded view of a section of the base body and the cover part of the instantaneous water heater according to the invention,

Fig. 2

a side view of the in Fig. 1 shown base body and the cover part in the assembled state;

Fig. 3

an enlarged side view of the in the Fig. 1 and Fig. 2 shown sealing surfaces with the sealant recesses
and

Fig. 4

an enlarged perspective exploded view of the in Fig. 3 shown sealing surfaces with the sealant recesses.

Fig. 1 shows a perspective exploded view of a section of a base body 10 and a cover part 16 of the instantaneous water heater according to the invention - not shown in the figures. The instantaneous water heater includes the base body 10 with a channel arrangement 11 formed in the base body 10 with several fluid passages Channels 12, wherein the fluid-passing channels 12 are designed and set up to pass a fluid through. In the base body 10 of the instantaneous water heater, at least two of the channels 12 extend on at least one end side 14, forming channel openings 13. On the end side 14 of the base body 10, deflection end faces 15 are formed, which are set up to divert the fluid between channel openings 13. The base body 10 is expediently a body made of plastic using an injection molding process.

The instantaneous water heater includes at least one cover part 16. As in particular Fig. 2 As can be seen, the cover part 16 is sealingly arranged on the base body 10 and can be detached from it. The deflection end faces 15 form sealing deflection bridge channels 17 between associated channel openings 13. The deflection bridge channels 17 redirect the fluid-passing channels 12 within the instantaneous water heater. The deflection bridge channels 17 are formed in particular within the cover part 16. The detachable arrangement of the cover part 16 on the base body 10 is preferably carried out by means of detachable connecting elements (not shown in the figures), particularly preferably by means of screw connections. Such connecting elements are arranged within connecting element receptacles provided for this purpose in the base body 10 and the cover part 16, whereby the cover part 16 is detachably arranged on the end side 14.

As continues from the Fig. 1 As can be seen, the end side 14 and the cover part 16 each have sealant recesses 18 surrounding the cross sections of the deflection bridge channels 17. The sealant recesses 18 are also designed and set up to accommodate a sealant 19. Each of the sealant recesses 18, that is to say both the sealant recesses 18 on the end side 14 of the base body 10 and on the cover part 16, is arranged between a sealing surface 20 on the inside of the channel and a sealing surface 21 on the outside of the channel.

Based on Fig. 3 is shown that the sealing surfaces 21 of the end side 14 of the base body 10 and the cover part 16 on the outside of the channel are set up in such a way that they lie flat against one another in a sealing manner. Preferably, the surface-sealing lying on top of one another between the sealing surfaces 21 on the outside of the channel is realized in such a way that they lie on top of one another at least essentially without a gap. At least essentially without a gap in the sense of the invention means gap-free or with a gap whose maximum width is a few µm. Furthermore, the ones on the inside of the channel Sealing surfaces 20 of the end side 14 of the base body 10 and the cover part 16 are spaced apart from one another, leaving a sealing gap 22.

In the Fig. 1 to 3 It is shown that the sealing gap 22 of the sealing surfaces 20 on the inside of the channel has a smaller sealing gap width than the width of the sealant recesses 18. The sealant recesses 18 are a multiple of the width of the sealing gap 22.

Like in particular from the Fig. 3 and Fig. 4 As can be seen, a sealant 19 is preferably arranged in the sealant recesses 18 of the base body 10 and the cover part 16. For this purpose, the sealant 19 is inserted into one of the sealant recesses 18 and automatically fixed therein when the cover part 16 is attached to the base body 10. The sealant 19 is preferably reversible in the sealant recess 18. “Reversible” in the sense of the invention means that the sealant 19 can be removed without leaving any residue if necessary and can be replaced by a desired additional sealant 19. Furthermore, the dimensions of the sealant 19 essentially correspond to the dimensions of the interior of the adjacent sealant recesses 18 in the assembled state. Where “essentially the dimensions of the interior of the adjacent sealant recesses 18 in the assembled state” means either exactly the dimensions of the interior of the sealant recesses 18 or slightly smaller or larger. In other words, the sealant 19 is set up in such a way that its cross-sectional area, when assembled and thus subjected to pressure, at least substantially fills the cross-sectional area of the sealing seat or the sealant recess 18 over the entire surface.

In the operating state of the instantaneous water heater, the liquid flows through the fluid-passing channels 11, whereby the liquid is under pre-pressure and so the areas of the instantaneous water heater through which liquid flows are subjected to the corresponding liquid pressure. The liquid flows through the channel arrangement 11 of the base body 10, that is, the fluid-passing channels 12 as well as the deflection bridge channels 17 in the area of the cover part 16. For this purpose, the sealing surfaces 21 on the outside of the channel, which lie close together, seal the remaining instantaneous water heater from unwanted water leakage. Furthermore, the sealant 19 inserted into the sealant recesses 18 supplements the tightness. When pressed, the preferably elastic sealant 19 can achieve a further additional sealing effect by moving in the direction of the Sealing gap 22 between the inner channel sealing surfaces 20 is designed and set up to be movable, whereby a further water shut-off effect is achieved.

In Fig. 4 The sealant 19 arranged in the sealant recesses 18 preferably has the cross-sectional shape of a double trapezoid joined together on the longer of the opposite sides.

Claims (8)

1. Continuous-flow heater for heating a liquid comprising

   a base body (10) with a channel arrangement (11) formed in the base body (10) with a plurality of fluid passable channels (12), wherein the fluid passable channels (12) are configured and adapted for passing a fluid,

   wherein at least two of the channels (12) each extend in the base body (10) forming channel openings (13) at at least one end side (14) of the base body (10), wherein deflection end faces (15) are configured at the end side (14) which are adapted to deflect the fluid between the channel openings (13), and

   at least one cover member (16), which is detachably arranged corresponding to the deflection end faces (15) in a sealed manner forming sealing deflection bridge channels (17) between corresponding channel openings (13) at the end side (14),

   wherein the end side (14) as well as the cover member (16) each have sealant recesses (18) circumferentially surrounding the cross-sections of the deflection bridge channels (17), which are each configured and adapted to receive a sealant (19),

   characterised in that

   each of the sealant recesses (18) is arranged between a channel-internal sealing surface (20) and a channel-external sealing surface (21), and the channel-external sealing surfaces (21) of the end side (14) of the base body (10) and of the cover member (16) are respectively adaptet in such a manner that they are sealingly adjacent to each other in a planar manner, while the respective channel-internal sealing surfaces (20) of the end side (14) of the base body (10) and of the cover member (16) are spaced apart from each other, leaving a sealing gap (22).
2. Continuous-flow heater according to claim 1, characterised in that a sealant (19) is arranged in the sealant recesses (18).
3. Continuous-flow heater according to claim 1 or 2, characterised in that the sealant (19) comprises an elastic material.
4. Continuous-flow heater according to any one of claims 1 to 3, characterised in that the sealant (19) comprises a moulded part or a surface seal.
5. Continuous-flow heater according to one of the claims 1 to 4, characterised in that in between the channel-internal sealing surface (20) and the channel-external sealing surface (21) of the sealant recesses (18) of the end side (14) or the cover member (16), at least one further sealant recess is configured and adapted to receive a further sealant having further sealing surfaces.
6. Continuous-flow heater according to one of claims 1 to 5, characterised in that the end side (14) and the cover member (16) are non-positively, materially or positively connected.
7. Continuous-flow heater according to one of claims 1 to 6, characterised in that the sealing gap (22) of the channel-internal sealing surfaces (20) has a smaller sealing gap width than the width of the sealant recess (18).
8. Continuous-flow heater according to one of claims 1 to 7, characterised in that the channel-external sealing surfaces (21) are at least substantially free of gaps.

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