Electric heating device

Abstract

An electric heating device (1, 1000) for heating fluids, comprising an outer, tubular metal jacket (100, 1100) having a connection-side end face on which connection leads of the electric heating device are located, and in the interior of which at least one electric, preferably compressed, tubular heating element (200, 300, 400, 500, 600, 700, 1200) or at least two electric, preferably compressed, heating cartridges are arranged, wherein at least one end section of the electric tubular heating element (200, 300, 400, 500, 600, 700, 1200) or at least one electric heating cartridge is protected by a fuse (280, 380, 1280) arranged within the outer metal jacket (100, 1100) of the electric heating device (1, 1000), wherein at least one fuse is connected to the heating cartridge. (280,380, 1280) radially offset section of at least one electric tubular heating element (200,300,400,500, 600,700,1200) or a fuse (280,380, 1280) radially offset section of at least one electric heating cartridge, characterized in that a heat conductor (900, 1900) is provided which has at least one opening (902, 903, 904, 905, 906, 907, 1901, 1902) into which one of the end sections of an electric tubular heater (200, 300, 400, 500, 600, 700, 1200) or into which a section of one of the electric heating cartridges is received such that heated areas of the first end section of an electric tubular heater (200, 300, 400, 500, 600, 700, 1200) or of the first electric heating cartridge and heated areas of the second end section of a tubular heater (200, 300, 400, 500, 600, 700, 1200) or of the second electric heating cartridge are heated The heating cartridge is inserted to varying depths into the openings (901, 902, 903, 904, 905, 906, 907, 1901, 1902) of the heat conductor (900, 1900).

Description

[0001] The invention relates to an electric heating device for fluids having the features of the preamble of claim 1.

[0002] Electric heating devices are widely used for heating fluids. For example, it is known to deform electric tubular heaters for this purpose so that their central section, shaped into a desired form—for example, coiled or simply bent into a U-shape—extends into the fluid, while their end sections are guided through a passage in a flange. Of course, similar designs with multiple tubular heaters can also be used. This design principle is known, for example, from the applicant's EHK type screw-in heaters.

[0003] However, this design principle can cause problems, particularly when unusual operating conditions can arise when heating the liquids to be heated, for example when the electric heating device is temporarily not immersed in the fluid as far as intended for normal operation (e.g. in the event of fluid loss in a closed circuit) or when the heat dissipation from the electric heating device cannot take place properly for another reason, for example because deposits can occur on the electric heating device.

[0004] In this case, measures must be taken to prevent the electric heater from being destroyed by local overheating, causing damage to the appliance in which it is used or causing a fire.

[0005] One such measure is to protect the electric tubular heaters used with fuses. However, in practice, ensuring heat transfer to such a fuse in a way that ensures the fuse's timely response is problematic.

[0006] DE 10 2015 114 886 A1 discloses an electric heating device having the features of the preamble of patent claim 1. Another electric heating device is disclosed in US 2007 / 0145040 A1.

[0007] The object of the invention is therefore to provide an improved electrical heating device for fluids with at least one fuse, in which the response behavior of the fuse is precisely guaranteed and can be adapted over a wide range during the manufacture of the electrical heating device to its subsequent operating conditions.

[0008] This object is achieved by an electric heating device having the features of claim 1. Advantageous developments of the invention are the subject of the dependent claims.

[0009] The electric heating device according to the invention for heating fluids has an outer, tubular metal casing which has a connection-side end face on which electrical connections of the electric heating device are present and in the interior of which at least one electric, preferably compacted, tubular heating element or at least two electric, preferably compacted, heating cartridges are arranged, wherein at least one end section of the electric tubular heating element or at least one electric heating cartridge is protected by a fuse which is arranged within the outer tubular metal casing of the electric heating device.

[0010] According to the invention, at least one section of at least one electric tubular heater or at least one electric cartridge heater is provided that extends radially offset from the fuse. In other words, there is a section of an electric tubular heater or cartridge heater that, viewed in a sectional plane through the electric heating device in which the fuse and this section are located, runs next to the fuse, usually parallel to it.

[0011] In other words, this means that such a section overlaps with the fuse in the direction of extension of the electric heating device, so that a cross section through the electric heating device perpendicular to its direction of extension in the overlap region thus defined intersects both the fuse and this section of the electric tubular heater or the electric heating cartridge.

[0012] The technical effect of this measure is that, compared to previous practice, an additional energy input is provided into the fuse, which ensures rapid and reliable response of the fuse.

[0013] At this point, some explanations should also be given regarding the terminology used to describe the geometry and structure of the electric heating device: A suitable reference point for describing the geometry of the structure of the electric heating device is its outer, tubular metal casing, which is formed by a tube - usually, but not necessarily, with a circular cross-section - made of metal, at one end of which - the connection-side end - the electrical connections of the electric heating device are led out and at the other end of which a base surface is usually arranged, in particular formed, connected or inserted.

[0014] In the case of symmetrical pipe cross-sections, which are not mandatory but are nevertheless mostly present in practice, such a pipe has a center line which is formed by the points which, with respect to a cross-section, lie on an axis of symmetry of this cross-section - for example, in the case of a pipe with a circular cross-section, the circle centers, or in the case of a pipe with a square cross-section, the points of the four-fold axis of symmetry lying in the respective cross-sectional area.

[0015] This centerline then indicates the direction of the pipe's travel in space. If the pipe is straight, it is a central axis. If the pipe is curved, the centerline is also curved and is locally perpendicular to each pipe cross-section.

[0016] The radial directions emanating from a point on a line - for example, given by the course of a cylindrical fuse or a section of a connecting wire running essentially straight and locally parallel to the center line of the tubular metal sheath or a straight section of a heating wire - are given by the connecting lines between the point and the tubular sheath, which lie in a cross-sectional area of ​​the tubular sheath that is locally perpendicular to the center line.

[0017] When referring to unheated areas of an electric tubular heater or electric cartridge heater below, the term "unheated area" is not to be understood in an ideal sense, as a current flow through a wire with a resistance always leads to heating, but rather in a realistic sense, i.e., as an area in which the heat output of the electric heater is significantly lower than the rated heat output of the heater per unit length of the heated zone for which it is designed. In electric heaters with a winding body wound externally with an electric heating element, there is no heating element winding in an unheated area.

[0018] When we talk about a material that conducts heat well, the prerequisite for a material to meet this condition is that its specific thermal conductivity is greater than 4 W / m*K.

[0019] In connection with the distinction between electric tubular heaters and electric heating cartridges, which are mentioned as alternative embodiments of the electric heating device according to the invention, reference is made to the description of the figures below for questions regarding their respective structures. However, it should already be pointed out at this point that the embodiment according to the invention can be realized with just one electric tubular heater, since this has two connection-side end regions, which, with a suitable shape of the electric tubular heater, can both be located on the connection side of the electric heating device, but requires two electric heating cartridges. Of course, the use of a larger number of electric tubular heaters or electric heating cartridges in an electric heating device according to the invention is possible and in many cases even preferred.

[0020] According to an advantageous development of the invention, the section radially offset from the fuse has an unheated area. This measure allows the additional energy input, which influences the response of the fuse, to be regulated by the length of the unheated section.

[0021] A further parameter that can be used to influence the response behavior is determined when the distance of the heated areas arranged within the outer, tubular metal casing of the at least two - in particular end-side - sections of an electric tubular heater - which can belong to the same or different electric tubular heaters - or of the at least two electric heating cartridges from the connection-side end face of the tubular metal casing is different.

[0022] In particular, this makes it possible not only to influence the heat input through the radially offset end section of the electric tubular heater or the electric heating cartridge, depending on the length of the heated area that is radially offset from the fuse, but also to influence the heat input through the end section that is directly connected to the fuse by varying the distance of a heated area provided in this area from the fuse that is arranged at a given distance from the edge of the outer tubular metal casing of the electric heating device.

[0023] However, heated areas of several or all electric tubular heaters or several or all electric heating cartridges can also be arranged at the same distance from the edge of the outer tubular metal casing of the electric heating device.

[0024] Another advantageous development of the invention provides that, in addition to the fuse, a resettable thermal switch, e.g., a bimetallic switch, is provided, which is configured to operate before the fuse. This avoids the need to replace a fuse every time a local overheating of the electric heating device is prevented, which can entail significant maintenance costs depending on the arrangement of the fuse or the electric heating device.

[0025] In particular, it is recommended that the resettable thermal switch is galvanically isolated from the heating circuit.

[0026] To control the response behavior of fuses and bimetallic switches, the invention provides a heat-conducting body having at least one opening into which one of the end sections of an electric tubular heater or into which a section of one of the electric heating cartridges is received. Optionally, the heat-conducting body can additionally have an opening into which the resettable thermal switch or the fuse is at least partially received.

[0027] The geometric design of such a heat conducting body, which can be made of copper or another metal with good heat conduction, allows the heat flow to be directed in a targeted manner.

[0028] The openings can in particular be designed as bores which pass through the heat conducting body from its connection-side side to the side of the heat conducting body opposite the connection-side side.

[0029] Preferably, the section of the electric tubular heater or electric heating cartridge received in an opening of the heat conducting body comprises 1 / 3, particularly preferably more than 1 / 2, very particularly preferably more than 2 / 3 and most preferably more than 3 / 4 of the - in particular heated - length of the electric tubular heater or electric heating cartridge.

[0030] In the openings of the heat conducting body, stops can also be provided which define the insertion depth for sections of the electric tubular heaters or the electric heating cartridges.

[0031] The heat conducting body can be used particularly effectively to introduce heat into the fuse to influence its response behavior if the fuse is connected in electrical series with the section - in particular the end section - of an electric tubular heater or one of the electric heating cartridges and is fully or partially immersed in an opening of the heat conducting body and / or overlaps it in sections.

[0032] It can be advantageous, in particular for influencing the heat flow through the heat conducting body in a desired manner, if at least parts of the unheated regions of a first section of an electric tubular heating element and of the second section of an electric tubular heating element are arranged in openings of the heat conducting body or that at least parts of unheated regions of the electric heating cartridges are arranged in openings of the heat conducting body.

[0033] Preferably, the cross-section of the openings or bores of the heat-conducting body is larger toward the connection side than toward the side opposite the connection side. This allows for the creation of installation space that, for example, enables more reliable electrical insulation of electrical (e.g., crimp) contacts arranged in this area toward the heat-conducting body.

[0034] In embodiments of the invention comprising a heat-conducting body and a resettable thermal switch, a particularly effective arrangement has proven to be the resettable thermal switch, which is preferably arranged in a tube, being inserted at least partially into a centrally or eccentrically arranged opening in the heat-conducting body. The insertion depth represents yet another degree of freedom for regulating the response behavior of the resettable thermal switch. The resettable thermal switch is preferably embedded in the interior of the tube in a material with good thermal conductivity, particularly electrical insulation, such as magnesium oxide powder.

[0035] It is particularly preferred if there is an overlap between the resettable thermal switch and an end section of an electric tubular heater or an electric heating cartridge, wherein these components are preferably pressed in the region of the overlap in the heat conducting body - in particular without a gap.

[0036] According to the invention, heated regions of the first end section of an electric tubular heater or of the first electric heating cartridge and heated regions of the second end section of a tubular heater or of the second electric heating cartridge are accommodated to different extents in openings of the heat conducting body.

[0037] It has proven advantageous if the heat-conducting element has a radial recess between two circumferentially adjacent end sections of electric tubular heaters or sections of electric heating cartridges that are housed within it. This facilitates filling the empty volume initially remaining in the outer metal casing, particularly during production.

[0038] It is considered particularly advantageous if the electric heating device has at least one pair of electric tubular heaters consisting of a first electric tubular heater with a heated section and an unheated section and a second electric tubular heater with a heated section and an unheated section,wherein the first electric tubular heater and the second electric tubular heater are connected in series with one another and are arranged, at least in sections, with their connection-side end sections extending within the heat-conducting body in such a way that a part of the unheated section of the first electric tubular heater runs alongside a part of the heated section of the second electric tubular heater, and that the resettable thermal switch is arranged in the space between the first electric tubular heater and the second electric tubular heater of the at least one pair of electric tubular heaters in such a way that the resettable thermal switch is located in the unheated area of ​​the first electric tubular heater and / or in the unheated area of ​​the second electric tubular heater of the respective pair of tubular heaters.

[0039] Such an arrangement is particularly easy to install when the first electric tubular heater and the second electric tubular heater of the at least one pair of electric tubular heaters are connected in series via an electrically conductive bridge, so that the pair of electrically conductive tubular heaters forms a U-shaped structure.

[0040] It should also be noted that an electric heating device according to the invention can, of course, comprise multiple electric tubular heaters or multiple electric heating cartridges. In a preferred embodiment of the invention, these are arranged such that they are aligned parallel to one another and define a circular circumference, as this leads to particularly homogeneous heat dissipation from the electric heating device. Preferably, there is no direct contact or only point-like or linear contact between the tube jackets of the electric tubular heaters and / or the electric heating cartridges.

[0041] It is also considered advantageous if, in addition to the heat conducting body, there is another structure which positions and / or fixes the geometric arrangement of the electric tubular heaters or electric heating cartridges in the interior of the electric heating device in order to achieve a defined and reproducible positioning of these components.

[0042] Electric heating devices constructed according to the invention allow, in particular, the use of unusual materials for the casings—the tubular metal structures that form the boundary between the electric tubular heaters and the electric heating cartridges—that would otherwise be unsuitable for a person skilled in the art. For example, instead of stainless steel, the much cheaper standard steel can be used. Heat transfer can also be optimized by selecting a material with good thermal conductivity, particularly copper, brass, or aluminum, for these casings.

[0043] According to an advantageous development of the invention, it is provided that at least one fuse is arranged within the metal casing of an electric tubular heater or within the metal casing of an electric heating cartridge, which in particular results in the fuse being protected from negative mechanical influences.

[0044] If the electrical and / or mechanical connections of heating conductor with connecting bolt, connecting bolt with fuse and fuse with leading out electrical cable are located within the metal casing of an electric tubular heater or within the metal casing of an electric heating cartridge, additional protection for these components can be achieved, in particular against the ingress of moisture.

[0045] It is also advantageous if the outer tube is filled with different granules / powders along its length. In particular, it may prove advantageous in this context to use a material with good thermal conductivity but poor electrical conductivity, e.g., magnesium oxide powder, in the area of ​​the connections of the electric heating device. In the opposite area, where the electrical insulation is already ensured within the tube jacket of the electric tubular heater or electric heating cartridge and no bare live parts are present, the even better thermal conductivity properties of metal powders or granules, particularly copper, are utilized.

[0046] Because, according to a preferred development of the invention, the heat conducting body lies at least partially directly against the outer, tubular metal casing of the electric heating device, it can be ensured that the heat released into the heat conducting body can be properly dissipated and can also be used to heat the fluid.

[0047] If a layer, in particular a ceramic layer, is present at least in sections between the heat conducting body and the electric tubular heater or electric heating cartridge and / or between the heat conducting body and the outer metal casing of the electric heating device, it is possible to meet even high requirements regarding the dielectric strength or high voltage strength of the electric heating device.

[0048] It has also proven advantageous to provide the electric tubular heater or electric heating cartridge with a second, outer jacket, at least in one section, which encompasses both the end of the heated zone and the area of ​​the fuse. This jacket can be used to further improve heat conduction in this area.

[0049] A further parameter for optimising the response behaviour of the fuse under given operating parameters can be obtained if the heated areas of at least one of the electric tubular heating elements or at least one of the electric heating cartridges have an increased power density towards the connection side and in particular in an area in which they run within an opening of the heat conducting element.

[0050] A particularly effective heat dissipation to the outer tubular metal casing of the electric heating device is achieved if the electric heating device is compacted at least in the heated area of ​​the electric tubular heaters or the electric heating cartridges.

[0051] It is further advantageous if the electric heating device has a larger outer diameter in the region where the heat-conducting body is arranged than in the region of the electric heating device extending away from the connection side, wherein the electric heating device preferably has a lower compression in the region of the larger diameter than in the region with the smaller diameter. This allows, on the one hand, installation space to be provided in the region of the heat-conducting body, while, conversely, installation volume and weight can be saved in the actual heated area of ​​the electric heating device.

[0052] In order to ensure protection against the penetration of moisture or liquids to be heated, in particular from the connection side, it has proven advantageous if the electrical heating device has a potting layer, in particular a potting layer made of epoxy resin or silicone rubber, which is at most in indirect thermal contact with the heat conducting body in order to avoid degeneration of the potting layer due to long-term thermal loads.

[0053] The invention is explained in more detail below with reference to figures showing exemplary embodiments. It shows: Fig. 1: a partially opened view of a first embodiment of an electric heating device, Fig. 2: an enlarged view of a first detail A1 from Fig. 1, Fig. 3: an enlarged view of a second detail B1 from Fig. 1, Fig. 4: an enlarged view of a third detail C1 from Fig. 1, Fig. 5: a cross-section through the Fig. 1 shown electric heating device along a sectional plane in which the central axis of the electric heating device lies, Fig. 6: an enlarged view of a first detail A5 from Fig. 5, Fig. 7: an enlarged view of a first detail B5 from Fig. 5, Fig. 8a: a first view of the heat conducting body of the electric heating device from Fig. 1, Fig. 8b: a second view of the heat conducting body from Fig. 8a, which shows its connection-side face, Fig. 8c: a third view of the heat conducting body from Fig. 8a, which shows the end face opposite its connection-side end face, Fig. 9: the partially opened heat conducting body of the electric heater from Fig. 1 with a pair of electric tubular heaters inserted therein, Fig. 10: a second embodiment of an electric heating device in cross section, Fig. 11: a third example of an electric heating device in cross section, and Fig. 12: a non-claimed fourth example of an electric heating device in cross section.

[0054] It should first be noted that not all reference symbols are shown in all figures to improve clarity. However, identical components of identical embodiments are always identified by the same reference symbols.

[0055] Fig. 1 shows a partially opened view of a first embodiment of an electric heating device 1 for heating fluids with an outer tubular metal shell 100, designed here as a hollow cylinder, with a base 110. In the interior of the outer tubular metal shell 100, in the interior of which six electric tubular heating elements 200, 300, 400, 500, 600, 700 are arranged, which in this embodiment are connected in pairs in series, as will be explained in more detail below.

[0056] Furthermore, there is a heat conducting body 900 and a total of four temperature fuses, namely the fuses 280, 380 accommodated in the electrical tubular heating elements 200, 300 and 500 and a further temperature fuse arranged within a tube 820 which, as will also be explained in more detail below, are arranged in the interior of the outer tubular metal jacket 100.

[0057] The basic structure of the electric tubular heaters 200, 300, 400, 500, 600, 700 and their connection to pairs can be seen particularly clearly in the example of the Fig. 9, in which the pair formed from the tubular heating elements 600 and 700 is shown with the heat conducting element 900 shown open. They each have a tubular metal casing 210, 310, 410, 510, 610, 710, designed in this case as a cylindrical tube, in the interior of which a heating wire coil 220, 320, 420, 520, 620, 720 is guided essentially along the cylindrical axis of the metal casing 210, 310, 410, 510, 610, 710, which is electrically insulated from the metal casing 210, 310, 410, 510, 610, 710 by being embedded in an electrically non-conductive but highly thermally conductive material 215, 315, 415, 515, 615, 715, typically MgO. At both ends of the respective heating wire coil 220,320,420,520,620,720, an electrical contact is made via connecting bolts 221,222,321,322,421,422,521,522,621, 622,721,722, which are fixed and positioned in the tubular metal casing 210,310,410,510,610,710 with centering pieces 223,224,323, 324,423,424,523, 524,623,624,723,724.

[0058] This electrical contact is even more detailed in the detailed enlargement according to Fig. 2 shown.

[0059] In the embodiment of the electric heating device 1 shown here, the electrical connection to the connecting cables 230, 330, 430, 530, 630, 730 of each of the electric tubular heaters belonging to a pair of electric tubular heaters, namely the electric tubular heaters 200, 300 and 500, is established via fuses 280, 380, which are also arranged within the tubular metal casings 210, 310 and 510. For this purpose, the associated connection-side terminal bolts 222, 322 and 522 are connected to the fuses 280, 380 via a first crimping element 225, 325 and 525, which can be seen from the enlarged detail of the Fig. 3 in more detail. On the other hand, the fuses 280,380 are connected to the corresponding connecting cable 230,330,530 via a second crimping element 226,326,526, as shown in the detailed enlargement of the Fig. 4 is shown in more detail.

[0060] The electrical connection of the other of the electric tubular heaters belonging to a pair of electric tubular heaters, namely the electric tubular heaters 400, 600 and 700, is made by connecting the connection-side connection bolts 422, 622 and 722 to the associated connection cables 430, 630, 730 via a crimping element 426, 626, 726.

[0061] The connection of the electric tubular heaters 200 and 500, 300 and 400 as well as 600 and 700 to form a pair each is effected via electrically conductive bridges 235, 335 and 635, which are each electrically conductively connected to the connection bolts 221, 321, 421, 521, 621, 721 opposite the connection side connected to the connection cables 230, 330, 430, 530, 630, 730 and an approximately U-shaped configuration of the pairs of electric tubular heaters 200 and 500, 300 and 400 as well as 600 and 700 is preconfigured.

[0062] This structure is particularly associated with the fact that each of the electric tubular heating elements 200, 300, 400, 500, 600, 700 has two unheated areas 241, 242, 341, 342, 441, 442, 541, 542, 641, 642, 741, 742 in the area of ​​connecting bolts 221, 222, 321, 322, 421, 422, 521, 522, 621, 622, 721, 722 and fuses 280, 380 as well as a heated area 245, 345, 445, 545, 645, 745 in which the heating wire coil 220, 320, 420, 520, 620, 720 extends. It should be noted here that heated areas 245, 345, 445, 545, 645, 745, different electrical tubular heaters 200, 300, 400, 500, 600, 700 can be accommodated to different extents in the heat conducting body 900, so that the degree of direct heat introduction from a heated area into the heat conducting body 900 can be adapted to the respective requirements. This fact is also particularly well illustrated in the sectional view of the Fig. 5 and in the detailed enlargements according to Fig. 2 and Fig. 6 can be seen.

[0063] Obviously, the electric heating device 1 therefore has a plurality of electric tubular heaters 200, 300, 400, 500, 600, 700, the sections of which are each received in openings 902, 903, 904, 905, 906, 907 of the heat conducting body 900 and which are arranged such that they are aligned parallel to one another and define a circular circumference, wherein there is no direct contact between the tubular metal casings 210, 310, 410, 510, 610, 710 of the electric tubular heaters 200, 300, 400, 500, 600, 700.

[0064] In particular from the Fig. 1 and Fig. 9 shows that sections, in particular end sections of the electric tubular heating elements 200, 300, 400, 500, 600, 700 are accommodated in the heat conducting body, wherein the accommodated sections in this embodiment each comprise a part of a heated area 245, 345, 445, 545, 645, 745 and the connection-side unheated area 222, 322, 422, 522, 622, 722. The shape of this heat conducting body 900 will be described next with reference to the Fig. 8a to 8c, which show a view of the heat conducting body 900 from an angle from above as well as of its connection-side end face 910 and of the end face 920 opposite its connection-side end face 910.

[0065] The heat conducting body 900, which can preferably be made of copper, has a central opening 901, which in this embodiment is designed as a cylindrical opening with a bottom and is accessible from the connection-side end face 910, and six openings 902, 903, 904, 905, 906, 907, which pass through the heat conducting body essentially parallel to its longitudinal axis L from the connection-side end face 910 to the opposite end face 920. As can be seen in particular by comparing the Fig. 8b and Fig. As is clear from Figure 8c, these openings in this example are shaped such that their cross section on the connection-side end face 910 is larger than on the opposite end face 920, which can be realized by a conical or stepped inner contour of the openings 902, 903, 904, 905, 906.

[0066] Furthermore, radial recesses 925 are arranged on the outside of the heat conducting body 900 in such a way that they each run between two adjacent openings 902, 903, 904, 905, 906, 907 and parallel to them.

[0067] As one can see especially in the Fig. 4 to 6, the central opening 901 of the heat conducting body 900 serves to accommodate a further temperature fuse, namely the resettable thermal switch 810, which can be designed, for example, as a bimetallic switch, which is arranged in a tube 820 filled with a material 830 with good heat conduction, and is connected to electrical connecting lines 841. This construction allows, in particular, a simple adaptation of the response behavior of the resettable thermal switch 810 for a specific application when optimizing the electrical heating device to the desired response conditions, depending on how far it is inserted into the tube 820 and depending on how far the tube 820 is inserted into the central opening 901 of the heat conducting body 900.

[0068] In the electric heating device 1, on the one hand, a first temperature fuse in the form of the resettable thermal switch 810 is at least partially in a first opening, namely the central opening 901 of the heat conducting body 900, while the openings 902, 903, 904, 905, 906, 907 of the heat conducting body 900 can each be understood as a second opening of the heat conducting body 900, in each of which a section of an electric tubular heating element 200, 300, 400, 500, 600, 700 is arranged, offset in a radial direction relative to the first opening 901.

[0069] On the other hand, one of the fuses 280, 380 can also be understood as a first temperature fuse, which is arranged in the opening 902, 903 or 905 of the heat conducting body 900, while the remaining openings 902, 903, 904, 905, 906, 907 of the heat conducting body 900 can then each be understood as a second opening of the heat conducting body 900, in each of which a section of an electric tubular heating element 200, 300, 400, 500, 600, 700 is arranged, also offset in a radial direction relative to the first opening 901, wherein radial can be understood in particular in the sense of a direction predetermined by a connecting line which lies in a plane to which the longitudinal axis of the fuse 280, 380 is perpendicular and which, starting from a point on the longitudinal axis L of the fuse, forms a connecting line to the outer tubular metal casing 100.

[0070] In the electric heating device 1, there is therefore in particular a temperature fuse in the form of any one of the fuses 280, 380, relative to which a section of an electric heating cartridge 200, 300, 400, 500, 600, 700 is arranged radially offset, specifically in a radial direction relative to the longitudinal axis L of the respective fuse 280, 380. Radial is to be understood in particular in the sense of a direction predetermined by a connecting line which lies in a plane to which the longitudinal axis of the fuse 280, 380 is perpendicular and which, starting from a point on the longitudinal axis L of the fuse, forms a connecting line to the outer tubular metal casing 100.

[0071] Fig. 10 shows a cross section of a second embodiment of an electric heating device 1000 for heating fluids along a sectional plane in which its extension direction predetermined by the longitudinal axis of the electric heating device 1000 lies.

[0072] The electric heating device has an outer tubular metal casing 1100, designed here as a hollow cylinder, with a base 1110. In the interior of the outer tubular metal casing 1000, a U-shaped electric tubular heating element 1200 is arranged.

[0073] Furthermore, a heat conducting body 1900 and a temperature fuse, namely the fuse 1280 which is included in the electric tubular heating element 1200 in this exemplary embodiment but not necessarily not, are present, which, as will be explained in more detail below, are arranged in the interior of the outer tubular metal jacket 1100.

[0074] The basic structure of the electric tubular heater 1200 essentially corresponds to the structure already described above with a tubular metal casing 1210 designed as a cylindrical tube, in the interior of which a heating wire coil 1220 is accommodated, which is electrically insulated from the metal casing 1210 by being embedded in an electrically non-conductive but highly thermally conductive material 1215, typically MgO. At both ends of the heating wire coil 1220, an electrical contact is established via connecting bolts 1221, 1222, which are provided with centering pieces 1223, 1224 in the tubular metal casing 1210.

[0075] In Fig. In the embodiment of the electric heating device 1000 shown in Figure 10, the electrical connection to the connecting cables 1230 of the electric tubular heater 1200 is established at one of its connection-side end sections 1250, 1251 via a fuse 1280, which in this embodiment, however, is not arranged within the tubular metal casing 1210. For this purpose, the associated connection-side terminal bolt 1221 is connected to the fuse 1280 via a first crimping element 1225. On the other hand, the fuse 1280 is connected to the associated connecting cable 1230 via a second crimping element 1226.

[0076] The electrical connection of the other connection-side end section 1251 of the electric tubular heater 1280 is made by connecting the connection-side connection bolt 1222 to the associated connection cable 1230 via a crimping element 1227.

[0077] This design is particularly associated with the fact that the electric tubular heating element 1200 has an unheated region 1241, 1242 in each of its connection-side end sections 1251, 1252 in the region of the connection bolts 1221, 1222. In particular, a section, more precisely the connection-side end section 1251 of the electric tubular heating element 1280, lies in a radial direction to the fuse 1280, wherein radial can be understood in particular in the sense of a direction predetermined by a connecting line which lies in a plane to which the longitudinal axis of the fuse 1280 is perpendicular and which, starting from a point on the longitudinal axis L of the fuse, forms a connecting line to the outer tubular metal casing 1100.

[0078] Furthermore, it can be seen that the connection-side end section 1251 of the electric tubular heater 1200 has a heated area 1245 that is accommodated in the heat-conducting body 1900. It should be noted here that both connection-side end sections 1250, 1251 of the electric tubular heater 1200 can also have heated areas that can be accommodated to different extents in the heat-conducting body 900, so that the degree of direct heat introduction from a heated area into the heat-conducting body 1900 can be adapted to the respective requirements.

[0079] The heat conducting body 1900, which can preferably be made of copper, has two stepped openings 1901, 1902 which pass through it essentially parallel to its longitudinal axis L from the connection-side end face 1910 to the opposite end face 1920 and each have a section 1901a, 1902b with a larger opening diameter D2 on the connection side and a section 1901b, 1902b with a smaller opening diameter D1 on the side opposite the connection side.

[0080] The electric heating device 1000 therefore has a temperature fuse in the form of the fuse 1280, which is arranged in a first opening 1901 of the heat conducting body 1900, while a section of the electric tubular heating element 1200 is arranged in a second opening 1902 of the heat conducting body 1900, offset in a radial direction relative to the first opening 1901, wherein radial can be understood in particular in the sense of a direction predetermined by a connecting line which lies in a plane to which the longitudinal axis of the fuse 1280 is perpendicular and which, starting from a point on the longitudinal axis L of the fuse, forms a connecting line to the outer tubular metal casing 1100.

[0081] Furthermore, the electric heating device 1000 has, in particular, a temperature fuse in the form of the fuses 1280, relative to which a section of an electric heating cartridge 1200 is arranged radially offset, specifically in a radial direction relative to the longitudinal axis L of the fuse 1280. Radial is to be understood in particular in the sense of a direction predetermined by a connecting line which lies in a plane to which the longitudinal axis of the fuse 1280 is perpendicular and which, starting from a point on the longitudinal axis L of the fuse 1280, forms a connecting line to the outer tubular metal casing 1100.

[0082] Fig. 11 shows an unclaimed example of an electric heating device 2000 for fluids with an outer tubular metal shell 2100, here designed as a hollow cylinder, with a base 2110. Two electric tubular heating elements 2200, 2300 are arranged in the interior of the outer tubular metal shell 2100, which in this embodiment are connected in series. Furthermore, the electric heating device 2000 has two thermal fuses, namely the fuses 2280 and 2380 incorporated into the electric tubular heating elements 2200 and 2300.

[0083] The basic design of the electric tubular heaters 2200, 2300 corresponds to the principle described above in the first exemplary embodiment: They each have a tubular metal casing 2210, 2310, in this case designed as a cylindrical tube, in the interior of which a heating wire coil 2220, 2320 is guided essentially along the cylindrical axis of the metal casing 2210, 2310. The heating wire coil 2220, 2320 is electrically insulated from the metal casing 2210, 2310 by being embedded in an electrically non-conductive but highly thermally conductive material 2215, 2315, typically MgO. At both ends of the respective heating wire coil 2220, 2320, an electrical contact is established via connecting bolts 2221, 2222, 2321, 2322.

[0084] In the third example of the electric heating device 2000 shown here, the electrical connection to the connecting cables 2230, 2330 of each of the electric tubular heaters 2200, 2300 belonging to a pair of electric tubular heaters is established via the fuses 2280, 2380, which are also arranged within the tubular metal casings 2210, 2310. For this purpose, the associated connection-side connecting bolts 2222, 2322 are connected to the fuses 2280, 2380 via a first crimping element 2225, 2325. On the other hand, the fuses 2280, 2380 are connected to the associated connecting cable 2230, 2330 via a second crimping element 2226, 2326.

[0085] The connection of the electric tubular heaters 2200 and 2300 to form a pair is effected via an electrically conductive bridge 2235,2335, which is each electrically conductively connected to the connection bolts 2221,2321 opposite the connection side connected to the connection cables 2230,2330 and preconfigures an approximately U-shaped configuration of the pairs of electric tubular heaters 2200 and 2300.

[0086] This structure is particularly associated with the fact that each of the electric tubular heating elements 2200, 2300 has two unheated areas 2241, 2242, 2341, 2342 in the area of ​​connecting bolts 2221, 2222, 2321, 2322 and fuses 2280, 2380 as well as a heated area 2245, 2345 in which the heating wire coil 2220, 2320 extends.

[0087] It should be noted here that heated areas 2245, 2345 of different electric tubular heaters 2200, 2300 can be spaced at different distances from the connection-side end of the outer tubular metal casing 2100, so that the degree of heat transfer from one heated area 2245, 2345 to the fuse 2380, 2280 of the other electric tubular heater 2300, 2200 can be adapted to the respective requirements. If this is the case, an electric heating device constructed according to this example also falls within the scope of the claimed invention.

[0088] In the electric heating device 2000, there is therefore in particular a temperature fuse in the form of any one of the fuses 2280, 2380, relative to which a section of an electric heating cartridge 2200, 2300 is arranged radially offset, specifically in a radial direction relative to the longitudinal axis L of the respective fuse 2280, 2380. Radial is to be understood in particular in the sense of a direction predetermined by a connecting line which lies in a plane to which the longitudinal axis of the fuse 2280, 2380 is perpendicular and which, starting from a point on the longitudinal axis L of the fuse, forms a connecting line to the outer tubular metal casing 2100.

[0089] Fig. 12 shows a cross section through another unclaimed example of an electric heating device 3000, along a sectional plane in which its extension direction predetermined by the longitudinal axis of the electric heating device 3000 lies.

[0090] The embodiment according to Fig. 12 differs from the first three embodiments in particular in that it has electric heating cartridges 3200,3300 instead of electric tubular heaters.

[0091] The electric heating device 3000 has an outer tubular metal shell 3100, designed here as a hollow cylinder, with a base 3110. Two electric heating cartridges 3200, 3300 are arranged in the interior of the outer tubular metal shell 3000.

[0092] Furthermore, a heat conducting body 3900 and two temperature fuses, namely the fuse 3280, 3380, are present, which, as will be explained in more detail below, are arranged in the interior of the outer tubular metal jacket 3100.

[0093] The basic design of the electric heating cartridges 3200, 3300 each comprises a tubular, cylindrical metal casing 3210, 3310 with a base, within the interior of which is a heating wire coil 3220, 3320 wound on a winding body 3211, 3311. The coil is electrically insulated from the metal casing 3210, 3310 by being embedded in an electrically non-conductive but highly thermally conductive material 3215, 3315, typically MgO. At both ends of the heating wire coil 3220, 3320, an electrical contact is typically established via connecting bolts 3221, 3222, 3321, 3322, which is often achieved by press-fitting within bores in the winding body 3211, 3311.

[0094] In Fig. In the embodiment of the electric heating device 3000 shown in Figure 12, the electrical connection to the connecting cables 3230, 3330 of the electric heating cartridges 3200, 3300 at the connecting bolt 3221 and 3321 is established via a fuse 3280 and 3380, respectively. For this purpose, the associated connection-side connecting bolts 3221 and 3321 are connected to the fuse 3280 and 3380, respectively, via a first crimping element 3225 and 3235, respectively. On the other hand, the fuse 3280 and 3380 is connected to the associated connecting cable 3230 and 3330, respectively, via a second crimping element 3226 and 3326, respectively.

[0095] The electrical connection of the other connection bolt 3222 or 3322 of the electric tubular heater 3280 or 3380 is made by connecting the connection-side connection bolt 3222 or 3322 to the associated connection cable 3230 or 3330 via a crimping element 3227 or 3327.

[0096] This design is also particularly associated with the fact that the electrical heating cartridges 3200,3300 each have an unheated area 3241,3341 on the connection side in the area of ​​the connection bolts 3221,3222 located within their tubular metal casing 3210,3310.

[0097] Furthermore, it can be seen that the connection-side end section 3250, 3350 of the electric heating cartridges 3200, 3300 each has a heated region 3245, 3345 that is accommodated in the heat-conducting body 3900. It should be noted here that, depending on the geometric design of the electric heating cartridges 3200, 3300, their two connection-side end sections 3250, 3350 can have heated regions that can be accommodated to varying degrees in the heat-conducting body 3900, so that the degree of direct heat introduction from a heated region into the heat-conducting body 3900 can be adapted to the respective requirements. If this is the case, an electric heating device constructed according to this example also falls within the claimed invention.

[0098] The heat conducting body 3900, which can preferably be made of copper, has two openings 3901, 3902 which pass through it essentially parallel to its longitudinal axis L from the connection-side end face 3910 to the opposite end face 3920.

[0099] The electric heating device 3000 thus includes a thermal fuse in the form of fuses 3280, 3380, relative to which a section of an electric heating cartridge 3300 or 3200 is arranged radially offset, specifically in a radial direction relative to the longitudinal axis L of the respective fuse. Radial is to be understood in particular in the sense of a direction defined by a connecting line lying in a plane to which the longitudinal axis of the fuse 2280 or 2380 is perpendicular and, starting from a point on the longitudinal axis L of the fuse, forms a connecting line to the outer tubular metal casing 3100. List of reference symbols 1,1000,2000,3000 electric heater 100,1100,2100,3100 outer tubular metal jacket 110,1110,2110,3110 floor 200,300,400,500,600, 700,1200,2200,2300 electric tubular heater 210,310,410,510,610, 710,1210,2210,2310 metal jacket 215,315,415,515,616, 715,830,1215,2215,2315, 3215,3315 materials 220,320,420,520,620, 720,820,1220,2220,2320, 3220,3320 heating wire coil 221,222,321,322,421,422, 521,522,621,622,721,722, 1221,1222,2221,2222,2321, 2322,3221,3222,3321,3322 connecting bolts 223,224,323,324,423,424, 523,524,623,624,723,724 centering piece 230,330,430,530,630,730 1230,2230,2330,3230,3330 connection cable 225,226,325,326,425,426, 525,526,626,726,1225,1226, 1325,1326,2225,2226,2325, 2326 crimping element 235,335,635,2235 Bridge 241,242,341,342,441,442, 541,542,641,642,741,742, 1241,1242,2241,2242,2341, 2342,3241,3341 unheated area 245,345,445,545,645,745, 1245,2245,2345,3245,3345 heated area 280,380, 1280,2280, 2380,3280,3380 fuse 810 resettable thermal switch 841 connecting cable 900,1900,2900,3900 heat sinks 901,902,903,904,905,906, 907,1901,1902,2901,2902, 910,1910,2910,3910 connection-side face 920,1920,2920,3920 front face opposite the connection side 3901,3902 opening 1901a,1901b,1902a,1902b Section 2200,2300,3200,3300 electric heating cartridge 2211,2311,3211,3311 winding body L Longitudinal axis D1,D2 diameter

Claims

[1] Electric heating device (1,1000) for heating fluids, with an outer, tubular metal casing (100,1100) which has a connection-side end face on which connection lines of the electric heating device are present, and in the interior of which at least one electric, preferably compacted, tubular heating element (200, 300, 400, 500, 600, 700, 1200) or at least two electric, preferably compacted, heating cartridges are arranged, wherein at least one end section of the electric tubular heating element (200,300,400,500,600, 700,1200) or at least one electric heating cartridge is protected by a fuse (280,380, 1280) which is arranged within the outer metal casing (100,1100) of the electric heating device (1,1000), wherein at least one (280,380, 1280) radially offset section of at least one electric tubular heating element (200,300,400,500, 600,700,1200) or a section of at least one electric heating cartridge which is radially offset from the fuse (280,380, 1280) is present, , characterized by that a heat conducting body (900, 1900) is provided which has at least one opening (902, 903, 904, 905, 906, 907, 1901, 1902) into which one of the end sections of an electric tubular heating element (200, 300, 400, 500, 600, 700, 1200) or into which a section of one of the electric heating cartridges is received such that heated regions of the first end section of an electric tubular heating element (200, 300, 400, 500, 600, 700, 1200) or of the first electric heating cartridge and heated regions of the second end section of a tubular heating element (200, 300, 400, 500, 600, 700, 1200) or of the second electric heating cartridge are arranged at different distances in openings (901,902,903,904,905,906,907,1901,1902) of the heat conducting body (900,1900). [2] Electric heating device (1,1000) according to claim 1, characterized bythat the section radially offset from the fuse (280,380,1280) has an unheated area (241,242,341, 342,441,442,541,542,641,642,741,742,1241,1242). [3] Electric heating device (1,1000) according to claim 1 or 2, characterized by that the distance of heated areas arranged within the outer, tubular metal casing (100, 1100) of at least two sections of an electric tubular heating element (200, 300, 400, 500, 600, 700, 1200) or of the at least two electric heating cartridges from the connection-side end face of the tubular metal casing (100, 1100) is different. [4] Electric heating device (1,1000) according to one of claims 1 to 3, characterized by that in addition to the fuse (280,380,1280) there is a resettable thermal switch (810) which is configured to respond before the fuse (280,380, 1280). [5] Electric heating device (1,1000) according to claim 4, characterized by that the resettable thermal switch (810) is galvanically isolated from the heating circuit. [6] Electric heating device (1,1000) according to one of claims 4 or 5, characterized by in that the resettable thermal switch (810) is arranged in a tube (820) which is inserted at least a short distance into a centrally or eccentrically arranged opening (901,902,903,904,905,906,907) in the heat-conducting body (900), wherein the resettable thermal switch (810) is preferably embedded in the interior of the tube (820) in a material (830) which conducts heat well. [7] Electric heating device (1,1000) according to claim 6, characterized by that the resettable thermal switch (810) is embedded in the interior of the tube (820) in a material (830) with good heat conduction. [8] Electric heating device (1,1000) according to one of claims 5 to 7, characterized bythat there is an overlap between the resettable thermal switch (810) and a section of an electric tubular heating element (200, 300, 400, 500, 600, 700, 1200) or an electric heating cartridge, wherein these components are preferably pressed in the region of the overlap in the heat conducting element (900, 1900). [9] Electric heating device (1,1000) according to one of claims 1 to 8, characterized by that the fuse (280,380,1280) is connected in electrical series to the end section of an electric tubular heating element (200,300,400,500,600,700, 1200) or one of the electric heating cartridges and is completely or partially immersed in an opening of the heat conducting element (900,1900) and / or overlaps therewith in sections. [10] Electric heating device (1,1000) according to one of claims 2 to 9, characterized bythat at least parts of the unheated areas (241, 242, 341, 342, 441, 442, 541, 542, 641, 642, 741, 742, 1241, 1242) of a first section of an electric tubular heating element (200, 300, 400, 500, 600, 700, 1200) and of the second section of an electric tubular heating element (200, 300, 400, 500, 600, 700, 1200) are arranged in openings (902, 903, 904, 905, 906, 907, 1901, 1902) of the heat conducting body (900, 1900) or that at least parts of unheated areas of the electric heating cartridges are arranged in openings of the heat conducting body, wherein preferably the cross section of these openings (902,903,904,905,906,907,1901,1902) of the heat conducting body (900,1900) is greater towards the connection side than towards the side opposite the connection side. [11] Electric heating device (1,1000) according to one of claims 1 to 10, characterized bythat the heat conducting body (900,1900) has a radial recess (925) between two circumferentially adjacent sections of electric tubular heating elements (200,300,400,500,600,700,1200) or sections of electric heating cartridges which are accommodated in it. [12] Electric heating device (1,1000) according to one of claims 4 to 11, characterized bythat the electric heating device (1,1000) has at least one pair of electric tubular heaters (200,500;300,400;600,700) consisting of a first electric tubular heater (200,300,400,500,600,700) with a heated area (245,345,445,545,645,745) and an unheated area (241,242,341,342,441,442,541,542,641,642,741,742) and a second electric tubular heater (200,300,400,500,600,700) with a heated area (245,345,445,545,645,745) and an unheated area (241, 242, 341, 342, 441, 442, 541, 542, 641, 642, 741, 742), wherein the first electric tubular heating element (200, 300, 400, 500, 600, 700) and the second electric tubular heating element (200, 300, 400, 500, 600, 700) are connected in series with one another and are arranged at least in sections with their connection-side sections extending within the heat conducting body (900, 1900) in such a way that a part of the unheated area (241, 242, 341, 342, 441, 442, 541, 542, 641, 642, 741,742) of the first electric tubular heater (200,300,400,500,600, 700) runs next to a part of the heated area (245,345, 445,545,645,745) of the second electric tubular heater (200,300,400,500,600,700) and that the resettable thermal switch is arranged in the space between the first electric tubular heater (200,300,400,500,600,700) and the second electric tubular heater (200,300,400,500, 600,700) of the at least one pair of electric tubular heaters (200,500;300,400;600,700) such that the resettable thermal switch in the unheated area (241, 242, 341, 342, 441, 442, 541, 542, 641, 642, 741, 742) of the first electric tubular heater (200, 300, 400, 500, 600, 700) and / or in the unheated area (241, 242, 341, 342, 441, 442, 541, 542, 641, 642, 741, 742) of the second electric tubular heater (200, 300, 400, 500, 600, 700) of the respective pair of electric tubular heaters (200, 500; 300, 400; 600, 700). [13] Electric heating device (1,1000) according to claim 12, characterized by that the first electric tubular heater (200, 300, 400, 500, 600, 700) and the second electric tubular heater (200, 300, 400, 500, 600, 700) of the at least one pair of electric tubular heaters are connected in series via an electrically conductive bridge (235, 335, 535), so that the pair of electrically conductive tubular heaters forms a U-shaped structure. [14] Electric heating device (1,1000) according to one of claims 1 to 13, characterized byin that the electric heating device (1,1000) has a plurality of electric tubular heating elements (200,300,400,500,600,700,1200) or a plurality of electric heating cartridges, the sections or sections of which are each received in the openings of the heat conducting element (900,1900) and which are arranged such that they are aligned parallel to one another and define a circular circumference, wherein preferably there is no direct contact or only a point-like or linear contact between the tubular metal casings (210,310,410,510,610, 710,1210) of the electric tubular heating elements (200,300,400,500,600,700) or the electric heating cartridges. [15] Electric heating device (1,1000) according to one of claims 12 to 14, characterized bythat in addition to the heat conducting body (900,1900) there is a further structure which positions and / or fixes the geometric arrangement of the electric tubular heating elements (200,300,400,500,600,700,1200) or electric heating cartridges in the interior of the electric heating device (1,1000). [16] Electric heating device (1,1000) according to one of claims 1 to 15, characterized in that the metal casing (210,310,410,510,610,710,1210) of the electric tubular heating elements (200,300,400,500,600,700,1200) or the metal casing of the electric heating cartridges consists of stainless steel, normal steel or a material with good thermal conductivity, in particular of copper, brass or aluminum. [17] Electric heating device (1,1000) according to one of claims 1 to 16, characterized bythat at least one fuse (280,380) is arranged within the metal casing (210,310,410,510,610,710,1210) of an electric tubular heating element (200,300,400,500,600,700,1200) or within the metal casing of an electric heating cartridge. [18] Electric heating device (1,1000) according to one of claims 1 to 17, characterized by that the electrical and / or mechanical connections of heating wire coil (220,320,420,520,620,720,1220) with connecting bolts (221,222,321,322,421,422,521, 522,621,622,721,722, 1221,1222), connecting bolts (221,222,321,322,421,422,521, 522,621,622,721,722,1221,1222) with fuse (280, 380,1280) and fuse (280,380,1280) with leading-out connecting cable (230,330,430,530,630,730, 1230) within the metal casing (210,310,410,510,610, 710,1210) of an electric tubular heater (200,300,400, 500,600,700,1200) or within the metal casing of an electric heating cartridge. [19] Electric heating device (1,1000) according to one of claims 1 to 18, characterized by that the outer tubular metal casing (1,1100) of the electric heating device (1,1000) is filled with different granules / powders in its direction of extension. [20] Electric heating device (1,1000) according to one of claims 1 to 19, characterized by that the heat conducting body (900,1900) lies at least in sections directly against the outer, tubular metal casing (100,1100) of the electric heating device (1,1000). [21] Electric heating device (1,1000) according to one of claims 1 to 19, characterized bythat a layer, in particular a ceramic layer, is present at least in sections between the heat conducting body (900,1900) and the electric tubular heating element (200,300,400,500,600,700, 1200) or electric heating cartridge and / or between the heat conducting body (900,1900) and the outer tubular metal casing (100,1100) of the electric heating device (1,1000). [22] Electric heating device (1,1000) according to one of claims 1 to 21, characterized by that the electric tubular heating element (200,300,400,500,600,700,1200) or the electric heating cartridge is provided with a second, outer jacket at least in a section which comprises both at least the end of the heated area (245,345,445,545,645,745,1245) and the area of ​​the fuse (280,380,1280). [23] Electric heating device (1,1000) according to one of claims 1 to 22, characterized bythat the heated areas (245,345,445,545,645,745,1245) of at least one of the electric tubular heating elements (200,300,400,500, 600,700,1200) or at least one of the electric heating cartridges have an increased power density towards the connection side. [24] Electric heating device (1,1000) according to one of claims 1 to 23, characterized by that the electric heating device (1,1000) is compacted at least in the heated area (245,345,445,545,645,745,1245) of the electric tubular heating elements (200,300, 400,500,600,700,1200) or the electric heating cartridges. [25] Electric heating device (1,1000) according to one of claims 1 to 24, characterized bythat the electrical heating device (1,1000) has a larger outer diameter in the region in which the heat-conducting body (900,1900) is arranged than in the region of the electrical heating device (1,1000) extending away from the connection side, wherein preferably the electrical heating device (1,1000) has a lower compression in the region of the larger diameter than in the region with the smaller diameter. [26] Electric heating device (1,1000) according to one of claims 1 to 25, characterized by that the electric heating device (1,1000) has a potting layer, in particular a potting layer made of epoxy resin or silicone rubber, which is at most in indirect thermal contact with the heat conducting body (900,1900).

Images