WO2023150814A1

WO2023150814A1 - Heating device

Info

Publication number: WO2023150814A1
Application number: PCT/AT2023/060038
Authority: WO
Inventors: Robert Ebner; Andreas Sauschlager
Original assignee: Ebner Industrieofenbau Gmbh
Priority date: 2022-02-09
Filing date: 2023-02-09
Publication date: 2023-08-17
Also published as: AT525036A4; AT525036B1

Abstract

The invention relates to a heating device (1) comprising at least one pipe register (3) consisting of a plurality of electric current-conducting pipes (5) which are arranged on the inside and are flown through by a fluid, wherein the pipe register (3) is arranged in a housing (6), flown around by a fluid on the outside.

Description

HEATER

The invention relates to a heating device comprising at least one tube register made up of a plurality of electrically conductive tubes which are arranged on the inside so that a fluid can flow through them.

The invention further relates to a thermal processing system comprising a chamber for an object to be processed and having a heating device which is at least partially arranged in the thermal processing system.

Electrical heating of industrial furnaces with resistance heating is known. To do this, electric current flows through a heating element with a corresponding electrical resistance, releasing heat. The heating element can have different shapes. Rod-shaped heating elements are used very often.

However, heating conductor tubes have also already been described in the prior art. For example, DE 102019 002 196 A1 describes an induction furnace for melting, keeping warm or casting metals with a furnace crucible and an induction coil surrounding it with at least one electrical conductor wound around the furnace crucible in the form of a coiled pipe designed as a coolant channel, in which a via an inlet coolant supplied and discharged via a drain is circulated.

In JP Hl 1-87024 A, the arrangement of a plurality of tubular heating elements in a heating furnace is described.

DE 42 06 851 A1 discloses a ceramic, porous heating tube for the electrical heating of an industrial furnace, which is designed at least at a first end with an adapter for connecting an inert gas supply and otherwise in such a way that the inert gas flow supplied via the adapter can flow exclusively via the outer surface of the heating pipe can escape.

EP 0 344 413 B1 describes a furnace for the heat treatment of batches of iron and steel parts with a furnace housing and a heating chamber arranged therein and electrically actuated heating elements arranged in the heating chamber for heating the Charge, wherein the heating elements arranged vertically in the heating chamber are tubular and gas can flow through them from top to bottom while being heated and are open at the bottom.

EP 2 467 662 B1 discloses a surface heating device for a substrate treatment device for mainly areal radiation of heat perpendicular to a main plane, comprising a tubular heater with at least three parallel and equidistantly arranged in a common plane, electrically by means of a resistance heating wire via two common heatable, straight pipe sections and curved pipe sections arranged at the two ends of the jacket pipe, with at least two straight pipe sections arranged parallel to one another in a main plane and at their ends with at least one adjacent straight pipe section, which is arranged in the main plane or a parallel secondary plane, in each case through bent pipe sections are connected to each other, and at least a part of the bent pipe sections is aligned inclined out of the main plane.

The object of the present invention is to improve the efficiency of the thermal processing of an object.

The object of the invention is achieved in the case of the heating device mentioned at the outset in that the tube register is arranged on the outside in a housing so that a fluid can flow around it.

Furthermore, the object of the invention is achieved with the thermal processing system mentioned at the outset, which has the heating device according to the invention.

The advantage here is that both surfaces of the tubes of the tube register are used to heat a fluid, which means that the surface area available for this purpose is significantly increased. This in turn leads to an improvement in the efficiency of the heating device, so that the size can be reduced if necessary. As a side effect, the tubes of the tube coil are better protected from external influences from the thermoprocessing plant, which means that their efficiency can be maintained for a longer period of time before maintenance is required. In addition, the heating device can be used to warm or heat two different fluids at the same time, in that the tubes of the heating register are in contact with different fluids on the inside and outside. According to one embodiment of the invention, it can be provided that the housing is channel-shaped, with which the heating device can not only be better integrated into the thermal processing system, but also more favorable flow conditions can be created for the fluid flowing around the heating register. A further improvement in efficiency can thus be achieved with this embodiment variant.

According to another embodiment of the invention, it can be provided that the pipe register and the housing have at least one change in the flow direction in order to increase the surface area available for heating the fluid and still be able to design the heating device compactly.

According to a further embodiment of the invention, it can be provided that the tube register is arranged to follow the flow of the fluid in the channel. With this embodiment variant, in which the tube register does not necessarily follow the change in direction of the channel exactly, a reduction in the flow pressure loss of the fluid on the outside and also inside the tubes can be achieved, which in turn can further improve the efficiency of the heating device.

The tubes of the tube register are preferably arranged in rows and columns, since this makes it easier to electrically contact the tubes.

To further improve the flow behavior of the fluid on the outside of the pipe register, according to one embodiment of the invention, it can be provided that the number of rows of the pipe register is selected from a range of 2 to 200 and/or that the number of columns of the pipe register is selected from one Range from 2 to 200.

In order to further reduce the pressure loss of the fluid in the heating device, according to one embodiment of the invention, the distance between the rows of the pipe register is the same as the distance between the columns of the pipe register.

The tubes of the tube register are preferably electrically connected in series and connected to one another via first connecting elements. Due to the electrical series connection of the tubes, a relatively high electrical resistance is achieved, which means that the current Voltage ratio can be set in a favorable ratio for increasing the efficiency of the heater.

To further reduce the flow resistance of the fluid flowing around the outside of the tubes of the tube register, according to another embodiment variant of the invention, it can be provided that the first connecting elements have an area in longitudinal section selected from a range of 100 mm ² and 2500 mm ² .

To further improve the flow behavior of the fluid or fluids in the heating device, it can also be provided according to one embodiment of the invention that the pipes are connected to one another via second connecting elements having electrical insulators. Any vibrations that may occur in the pipes can thus be reduced.

An increase in the efficiency of the heating device can also be achieved if, according to embodiment variants of the invention, it is provided that the tubes have a circular cross-section with an inside diameter selected from a range of 5 mm to 150 mm and/or that the tubes have a wall thickness selected from a range of 0.1 mm to 5 mm and/or that the tubes have a friction-reducing and/or self-cleaning coating on the inside and/or outside and/or that the tubes have a round, in particular circular, cross-section or a cross-section in the form of a regular polygon with more than five corners.

For a better understanding of the invention, it is explained in more detail with reference to the following figures.

They each show in a simplified, schematic representation:

1 shows a first embodiment variant of a heating device in a side view;

2 shows a second embodiment variant of a heating device in an oblique view;

3 shows a third embodiment variant of a heating device in an end view;

FIG. 4 shows the heating device according to FIG. 3 in an oblique view; FIG.

5 shows a detail of a fourth embodiment variant of the heating device; 6 shows a detail of a fifth embodiment variant of the heating device;

7 shows a detail of a sixth embodiment variant of the heating device;

8 shows a detail from a further embodiment variant of the heating device;

9 shows an embodiment variant of a thermoprocessing system.

As an introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numbers or the same component designations, it being possible for the disclosures contained throughout the description to be applied to the same parts with the same reference numbers or the same component designations. The position information selected in the description, such as top, bottom, side, etc., is related to the figure directly described and shown and these position information are to be transferred to the new position in the event of a change of position.

In Fig. 1 a section of a heating device 1 is shown.

The heating device 1 can be used in particular in electrically heated convection ovens or also for converting ovens with burner heating into at least partially electrically heated ovens. The heating device 1 can be used, for example, in so-called standing ovens or in continuous ovens, ie in so-called industrial ovens. An industrial furnace is defined as a walled space in which heat is applied to an object, particularly to allow processes to take place in the object or on its surface. The object can be a product, such as sheet metal or a circuit board, etc., or a raw material, such as metal, etc. The process in the thermal processing system 2 can be, for example, the melting of the object or a specific reaction in or on or with the object, such as a phase transformation, hardening of a metallic object, annealing of an object, etc. This list is only of an exemplary nature and should not be understood as limiting. In general, the heating device 1 can be used in a thermal processing system 2, as is shown by way of example in FIG. 8, in order to process an object thermally, ie at an elevated temperature, in batches or continuously. An industrial furnace within the meaning of the invention is in particular a furnace that is used in metallurgy or the processing of inorganic objects or objects that are or have been produced exclusively from inorganic raw materials.

It should also be noted, purely by way of example, that the heating device 1 can be used for objects made of aluminum or an aluminum alloy or non-ferrous metals in general or made of steel.

The heating device 1 comprises at least one tube register 3, in which several tubes 4 are combined to form a group. Several pipe registers 3 can also be arranged in the heating device 1, for example two or three or four, etc. The several pipe registers 3 can be arranged one behind the other or next to one another in a flow direction 5 through the pipes 4. Furthermore, the plurality of tube registers 3 can be independent of one another or can be connected. The latter means that the several tube registers 3 or their tubes 4 are flow-connected to one another. Accordingly, “independent” means that the several tube registers 3 or their tubes 4 are not flow-connected to one another.

The tubes 4 comprise or consist of an electrically conductive material. For example, the tubes 4 can be made of a metallic material, such as an iron material, copper, etc. The tubes 4 preferably have or consist of a material that has a specific electrical resistance of at least 0.5 [Q mm ² /m], in particular between 1 [Q mm ² /m] and 1.5 [Q mm ^{2 /m} ]. m], has. For example, chromium-nickel alloys (CrNi), ferritic chromium-iron-aluminium alloys (CrFeAl) or nickel-chromium-iron alloys, such as e.g. B.

NiCr23Fel5, can be used. Such materials also have the advantage that they have good oxidation resistance even at higher temperatures.

The tube register 3 or the tube register 3 are arranged in a housing 6 that is closed on all sides. In particular, the housing 6 consists of a metallic material.

An inflow element 7 or several inflow elements 7 and an outflow element 8 or several outflow elements 8 can be arranged on the housing 6 or in at least one wall of the housing 6, through which a fluid can be introduced into the housing 6 and discharged therefrom again. The fluid can be a gas or a liquid, such as air, various protective gases or inert gases such as nitrogen, hydrogen, and argon percentage mixtures of these gases. The fluid can optionally also be a reactant with which the object to be processed in the thermal processing system 2 is reacted. This reaction can be, for example, carburization and/or nitration or surface treatment, etc.

The at least one inflow element 7 and/or the at least one outflow element 8 can be configured without a direct flow connection to the pipes 4 of the at least one pipe register 3 . The fluid can thus be introduced directly into the housing 6. In this case, the tubes 4 can be designed to be open at the beginning and at the end in the direction of flow 5 , so that the fluid from the housing 6 can also flow into the tubes 4 .

Alternatively, there is also the possibility that the at least one inflow element 7 is/are formed on at least one first collecting duct 9 at the beginning of the tubes 4 and/or the at least one outflow element 8 is/are formed on at least one second collecting duct 10 at the end of the tubes 4, and that the tubes 4 are arranged to extend from the first collecting channel 9 to the second collecting channel 10 . The fluid introduced via the inflow element 7 is introduced into the first collection channel 9 from which the fluid is introduced further into the tubes 4 . The fluid emerges from the tubes 4 into the second collecting channel 10 and from there out of the outflow element 8 again out of the heating device 1 .

Alternatively or additionally, it can be provided that the first collecting channel 9 has openings that open directly into the interior of the housing 6 and/or that the second collecting channel 10 has openings that are flow-connected directly to the interior of the housing 6 .

According to a further embodiment variant, as an alternative to or in addition to the above embodiment variants, it can also be provided that the tubes 4 of the at least one raw register 3 are routed directly to the outside through the walls of the housing 6 .

With all of these design variants it can be achieved that the tubes 4 of the raw register 3 both have a fluid flowing through them on the inside and a fluid flowing around them on the outside, with the result that the surface area available for heating the fluid or fluids is significantly increased . The tubes 4 are connected to an electrical circuit via connections 11, 12 (only indicated in FIG. 1), so that the tubes 4 are connected to one electric current can flow through it in order to generate heat for heating the fluid due to the electrical resistance (resistance heating). The heated fluid can then be introduced into a process chamber 13 (shown in FIG. 8) in the thermal processing system 2, for example, in order to heat the object to be processed therein and/or to carry out the corresponding chemical reaction with or on the object.

In the case of the heating device 1 designed as a resistance heater, the tubes 4 themselves are used instead of wires for heating the fluid. As a result, a relatively large amount of energy can be transferred to the fluid in a very small space. The heat transferred to the fluid is primarily (more than 50%) removed with it directly from the heating device 1 .

The heating device 1 can also be used to heat different fluids, for example two different gases, or a gas and a liquid, at the same time. For this purpose, provision can be made, for example, for a gas to flow through the interior of the housing 6 and for a further gas or liquid to flow through the tubes 4 . Appropriate separating elements or a separation of the fluid flows are to be provided for such designs with different fluids. For example, both the at least one inflow element 7 and the at least one outflow element 8 for heating a fluid can be provided on the outer surface of the tubes 4, and the tubes 4 can also be routed to the outside of one wall of the housing 6, optionally with a collecting duct , so that the fluid for the flow through the tubes 4 can be supplied directly to them. Likewise, the first collecting channel 9 and the second collecting channel 10 can be formed with separating elements, which enable the supply of two different fluids.

These can optionally also be divided among the tubes 4 of the tube register 3, so that the tubes 4 can be flowed through by different fluids. The second or another fluid can be fed directly to the interior of the housing 6 via the above-mentioned openings in the first collecting channel 9 and can be removed directly from it via the above-mentioned openings in the two collecting channels 9 . Further constructive configurations of separate flow paths for several fluids are conceivable and executable. In principle, the housing 6 can have any suitable shape, for example a cubic design. In the preferred embodiment variant of the heating device 1, however, the housing 6 is designed in the form of a channel, as can be seen from FIG. The term “channel-like” refers to a geometry of the housing 6, in particular cuboid, in which a length of the housing 6 in the direction of flow 5 is at least four times greater than a largest dimension of the cross-sectional area of the housing 6 (viewed in the direction of flow 5). , for example the width of the housing 6. The length of the housing 6 can be between four times and thirty times greater than the largest dimension of the cross-sectional area of the housing 6.

In order to increase the length of the housing 6 and thus to increase the available heating surface for heating the at least one fluid, according to a further embodiment variant of the heating device 1 it can be provided that the tube register 3 and the housing 6 have at least one change in the flow direction 5. In Fig. 1 only a 90 ° - change in flow direction 5 is shown as an example. In general, the heating device 1 can also have no or multiple changes in the flow direction 5, for example between one and three, in particular between one or two. The angle of the change in flow direction 5 can be between ^10° and 135°, in particular between ^10° and 90°. However, the number and/or the angle of the changes in the flow direction 5 is/are preferably not designed in such a way that the heating device is designed coiled in order to be able to provide improved flow conditions for the at least one fluid in the heating device 1.

As can be seen from FIG. 1, the embodiment variant with the multiple changes in flow direction 5 consists of at least two straight sections 14, 15 and at least one curved section 16, which is arranged between the straight sections 14, 15. If there are more than two straight sections 14, 15, a curved section 16 is arranged between each of these sections.

As can be seen from FIG. 1, the tubes 4 of the tube register 3 also run in a straight line in the straight sections 15, 16, in particular parallel to the longitudinal extension of the housing 6 (to the stated length of the housing 6). In the curved section 16 the course can follow the course of the housing 6 . In the preferred embodiment variant shown in FIG. 1, the pipe register 3 or are to reduce the flow resistance whose tubes 4 are arranged to follow the flow of the fluid in the channel, i.e. the housing 6, whereby at least some of the tubes 4, in particular the outer tubes 4 in relation to the change in direction, are designed with a larger radius of curvature than corresponds to the curvature of the directly adjoining housing wall would.

All tubes 4 of the tube register 3 preferably have the same curvature (apart from the length of the respective curved tube section, which is naturally shorter at the inner radius than at the outer radius).

The tubes 4 of the tube register 3 can be arranged in rows 17 and columns 18, as can be seen better from the sections of embodiment variants of the heating device 1 shown in FIGS.

The variant embodiment of the heating device 1 according to FIG. 2 has 52 tubes 4 which are divided into four rows 17 and thirteen columns 18 . The embodiment variant of the heating device 1 according to FIG. 3 has 72 tubes 4 which are divided into twelve rows 17 and six columns 18 . In general, it can be provided within the scope of the invention that the number of rows 17 of the pipe register 3 is selected from a range of 2 to 200 and/or that the number of columns 18 of the pipe register is selected from a range of 2 to 200. About the number of the rows and/or columns, their space requirements in the flow channel, the existing electrical voltage and the required heating power can be predefined. For example, the electrical resistance can be determined via R=U ² /P via the length and the dimensions of the tubes 4 and if they are connected in series.

Another measure of the load on the tubes 4 is the watt load, ie how many watts can be transmitted per cm ² . This can be predefined by the temperature on the one hand and by the flow rate of the fluid on the other hand, so that a corresponding predefinition of the load can be made possible via these parameters. With an air speed of 10 m/s, for example, up to 2.5 W/cm ² can be assumed.

According to a further embodiment variant of the heating device 1 it can be provided that a distance 19 between the rows 17 of the tubes 4 of the tube register 3 is the same as a distance 20 between the columns 18 of the tubes 4 of the tube register 3. For example For example, distance 19 and distance 20 can be selected from a range of 2 cm to 20 cm.

According to one embodiment variant, the distance 19 between the rows 17 of the tubes 4 of the tube register 3 and/or the distance 20 between the columns 18 of the tubes 4 of the tube register 3 can be selected from a range of ± 20% of the outside diameter of the tubes 4 to ± 70 % of the pipe outer diameter of the pipes 4. For example, with a pipe outer diameter of 30 mm, the distance 19 and/or the distance 20 can be between 25 mm and 50 mm

In principle, however, it is possible for the distance 19 between the rows 17 of the tubes 4 of the tube register 3 to be unequal to the distance 20 between the columns 18 of the tubes 4 of the tube register 3. The distance 19 between the rows 17 can be larger or smaller be than the distance 20 between the columns 18. Mixed variants are also possible, in which the distances 19 between the rows 17 are partly larger or smaller than and partly the same as the distances 20 between the columns 18. Other divisions are also possible, although not preferred.

In the preferred embodiment variant of the heating devices, the distances 19 between the rows 17 and the distances 20 between the columns 18 do not change even in the curved section or sections 16 (see FIG. 1).

For the sake of completeness, it should be pointed out that the variant embodiment of the heating device 1 according to FIG. 3 has only one straight section 14 .

The tubes 4 are electrically connected to one another. In principle, the tubes 4 of the at least one tube register 3 can be electrically connected to one another in parallel. In the preferred embodiment variant of the heating device 1, however, the tubes 4 of the tube register 3 are electrically connected in series and connected to one another via the first connecting element 21, as is shown in FIG. The first tube 4 of the series connection is connected to the electrical connection 11 and the last tube 4 of the series connection is connected to the electrical connection 12 . At least one first connecting element 21 is arranged between two pipes 4 in each case. The connecting elements 21 forward the electric current from a pipe 4 to a directly adjacent pipe 4 in each case. For this purpose, the connecting elements 21 have an electrically conductive material or consist of it. For example, a material mentioned for pipes 4 or the material from which the pipes 4 are made can be used for the connecting elements 21 .

According to an embodiment variant of the heating device 1, it can be provided that the first connecting elements 21 have a surface 22 in longitudinal section, which is selected from a range of 100 mm ² and 2500 mm ^2. Reference is made to FIG 3 shows. The connecting elements 21 are therefore designed to be relatively small, so that they do not represent a large flow resistance for the fluid flowing around the tubes 4 .

The channel itself, ie the housing 6 in which the tubes 4 are arranged, can have a cross-sectional area of between 2500 mm ² (for tubes 4 with a smaller diameter) and 2 m ² (for tubes 4 with a large diameter).

The first connecting elements 21 can have a wall thickness 23 between 3 times the wall thickness of the tubes 4 and 5 times the wall thickness of the tubes 4 . It can thus be achieved that the connecting elements 21 do not also heat up.

The first connecting element 21 can be designed, for example, in the form of small plates and/or in the form of rods. They can also have a flow-optimized cross-sectional shape, for example they can be designed at least approximately in the cross-sectional shape of a wing of an aircraft.

It can also be seen from FIG. 4 that the first connecting elements 21 are arranged alternately at one end and at the other end of the tubes 4 (top and bottom in FIG. 4).

Although the exclusive electrical series connection of the tubes 4 is the preferred one for the heating device 1, the tubes 4 can also be connected to one another in a combination of electrical series connection and electrical parallel connection via the first connecting element 21 within the scope of the invention.

According to a further embodiment variant of the heating device 1, it can be provided that the tubes 4 are connected to one another via second connecting elements 24 which have or consist of electrical insulators, as can be seen from FIG.

Alternatively, these second connecting elements 24 can also be used to connect the pipe register 3 to the housing 6 as required. The exact The arrangement of the second connecting elements 24 in the heating device 1 depends, among other things, on the static design of the heating device 1, so that the arrangement shown in FIG. 1 is only of an exemplary nature.

In particular, a ceramic material can be used as the material for the electrical insulators.

The second connecting element 24 can correspond to the first connecting element 21 in shape and/or size. However, they can also be larger or smaller than the first connecting element 21 .

The first and the second first connecting element 21, 24 can be connected to the pipes 4 in a materially bonded manner, in particular by welding or soldering or gluing, and/or in a form-fitting and/or force-fitting manner.

The tubes 4 can have a circular cross-section, which is best seen in FIG. According to one embodiment of the heating device 1, it can be provided that the tubes 4 have an inside width 25 selected from a range of 5 mm to 150 mm.

As FIGS. 5 and 6 show by way of example, the tubes 4 can also have a cross section that deviates from the circular shape, which can still be round, but which can also have a cross section in the form of a regular polygon with more than five corners, for example in Shape of a regular hexagon (Fig. 5) or in the shape of a regular octagon (Fig. 6). In the case of these cross-sectional shapes, the details of the clear width 25 are to be understood as the diameter of the circle that just fits into the inner circumference of the respective cross-section, as indicated by way of example in FIG. 5 .

According to a further embodiment variant of the heating device, also shown in FIG. 3, it can be provided that the tubes 4 have a wall thickness 26 selected from a range of 0.1 mm to 5 mm.

As can be seen from FIG. 7, the tubes 4 can have a friction-reducing and/or self-cleaning coating 27 on the inside and/or outside. With the coating 27, an increase in the flow resistance due to deposits on the surface of the tubes 4 can be prevented and the flow resistance in the tube register 3 can thus be reduced become. A ceramic layer, such as TiCh, for example, or an enamel layer can be used as the coating 27 . If necessary, the electrical insulation of the tubes 4 from one another in the area of the second connecting elements 24 can also be achieved in this way. The coating 27 can optionally also act as a protection against corrosion.

FIG. 8 shows a detail from a further embodiment variant of the heating device 1 . In particular, an embodiment of the electrically insulating attachment or connection of the pipes 4 can be seen from this illustration. The connecting elements 24 have a sleeve-shaped connecting element 28 for each pipe 4 connected thereto, through which the respective pipe 4 is guided. An annular space is formed between the inner lateral surface of the connection element 28 and the outer lateral surface of the pipe 4 . In this embodiment variant of the heating device 1, this is filled with an insulator, in particular ceramic, or an insulator bushing 29, e.g. a ceramic sleeve, is arranged in this.

An embodiment variant of the thermoprocessing system 2 is shown in FIG. 9 as an example only, as has already been explained above. This includes the process chamber 13 for receiving at least one object to be processed. Furthermore, the thermoprocessing system 2 comprises at least one heating device 1 according to the invention. The heating device 1 can be arranged inside the process chamber 13 and/or outside the process chamber 13 and at least partially surround it. The at least one heating device 1 is arranged at least partially, preferably entirely, within a housing 30 of the thermal processing system 2 . Fluid supply lines can also be partially routed to the outside, as shown in dashed lines.

The exemplary embodiments show or describe possible embodiment variants, it being noted at this point that combinations of the individual embodiment variants with one another are also possible.

Finally, for the sake of clarity, it should be pointed out that elements of the heating device 1 or the thermoprocessing system 2 are not necessarily shown to scale for a better understanding of the structure. list of reference numbers

heater 30 housing

Thermoprocess s plant

pipe register

Pipe

flow direction

Housing

inflow element

Outflow element

collection channel

Connection

process chamber

Section

Row

Split

Distance

connecting element

Area

Wall thickness

connecting element

width

Wall thickness

coating

connection element

isolator bushing

Claims

P atentClaims

1. A heating device (1) comprising at least one tube register (3) made of a plurality of electrically conductive tubes (5) which are arranged on the inside so that a fluid can flow through them, characterized in that the tube register (3) can have a fluid flow around it on the outside in a housing ( 6) is arranged.

2. Heating device (1) according to claim 1, characterized in that the housing (6) is channel-shaped.

3. Heating device (1) according to claim 1 or 2, characterized in that the tube register (3) and the housing (6) have at least one change in the flow direction (5).

4. Heating device (1) according to claim 3, characterized in that the pipe register (3) is arranged to follow the flow of the fluid in the channel.

5. Heating device (1) according to one of claims 1 to 4, characterized in that the tubes (4) of the tube register (3) are arranged in rows (17) and columns (18).

6. Heating device (1) according to claim 5, characterized in that the number of rows (17) of the pipe register (3) is selected from a range from 2 to 200 and/or that the number of columns (18) of the pipe register (3) is selected from a range of 2 to 200.

7. Heating device (1) according to claim 5 or 6, characterized in that a distance (19) between the rows (17) of the pipe register (3) is the same as the distance (20) between the columns (18) of the pipe register ( 2).

8. Heating device (1) according to one of claims 1 to 7, characterized in that the tubes (4) of the tube register (3) are electrically connected in series via the first connecting element (21) are connected to one another.

9. Heating device (1) according to one of claims 1 to 8, characterized in that the first connecting elements (21) have a surface (22) in longitudinal section selected from a range of 100 mm ² and 2500 mm ² .

10. Heating device (1) according to one of Claims 1 to 9, characterized in that the tubes (4) are connected to one another via second connecting elements (24) having electrical insulators.

11. Heating device (1) according to one of claims 1 to 10, characterized in that the tubes (4) have a circular cross-section with an inside width (25) selected from a range of 5 mm to 150 mm.

12. Heating device (1) according to any one of claims 1 to 11, characterized in that the tubes (4) have a wall thickness (26) selected from a range of 0.1 mm to 5 mm.

13. Heating device (1) according to one of claims 1 to 12, characterized in that the tubes (4) have a friction-reducing and/or self-cleaning coating (27) on the inside and/or outside.

14. Heating device (1) according to one of claims 1 to 13, characterized in that the tubes (4) have a round, in particular circular, cross section or a cross section in the form of a regular polygon with more than five corners.

15. Thermal processing system (2) comprising a process chamber (13) for an object to be processed and having a heating device (1) which is at least partially arranged in the thermal processing system (2), characterized in that the heating device (1) according to one of the claims 1 to 14 is formed.