WO2020104595A1

WO2020104595A1 - Device for conditioning a fluid and method for operating said device

Info

Publication number: WO2020104595A1
Application number: PCT/EP2019/082101
Authority: WO
Inventors: Jürgen PROKOP; Felix JÜLCH; Frederik SAMENFINK
Original assignee: Dbk David + Baader Gmbh
Priority date: 2018-11-22
Filing date: 2019-11-21
Publication date: 2020-05-28
Also published as: DE102018129408A1; EP3883668A1

Abstract

The invention relates to a device for conditioning a fluid, comprising a PTC heating element which is arranged in an adsorbent bed, and to a method for operating said device.

Description

Device for air conditioning a fluid and method for operating such a device

description

The invention relates to a device for air conditioning a fluid according to the preamble of claim 1 and a method for operating such a device.

Such devices are used, for example, to remove components from a gas by adsorption. DE 198 17 546 A1 describes a solution in which a zeolite bed is used as the adsorbent, which surrounds a heating element designed as a resistance heater. By controlling the heating element, the adsorbed components can be desorbed from the loaded zeolite.

Zeolites are highly porous aluminosilicates, which are characterized by a very large porosity and an associated very large surface area of up to 1000 m ² / g. Such zeolites are predominantly made synthetically as pellets with diameters between 2.5 mm and 5 mm. A distinction is made between zeolites of groups A, X or Y, which differ in their molecular structure and have different pore sizes, so that, depending on the pore size, undesired components can be removed from a fluid. For example, zeolites with a pore size of 3 A (angstroms) are used to specifically remove water from a gas, while components with larger molecular diameters are not adsorbed. Because of these properties, the zeolites are also referred to as “molecular sieves”.

A disadvantage of the known solution is that a complex control must be seen in order to overheat the resistance heater and thus prevent it from to avoid damage to the device. Furthermore, the resistance heater described in DE 198 17 546 A1 has a very complex structure, so that on the one hand this takes up a considerable amount of installation space and furthermore the production costs are high.

DE 10 2009 048 005 A1 describes a zeolite dryer for a dishwasher, in which a resistance heater is also provided. This concept shows the same disadvantages as the DE 198 17 546 A1 described above.

The same applies to the zeolite dryer described in DE 10 2012 000 013 A1, in which, as in the solutions described above, a resistance heater is introduced into a zeolite bed. In one variant, this resistance heating is accommodated in the zeolite bed without insulation. Resistance heaters of this type, which are designed without insulation, are particularly problematic when the gas streams are loaded with moisture.

Document US 2014/0174295 A1 describes a dehumidifier in which the moist air is passed through an adsorption module. The latter has a bundle of hollow fibers, which in one embodiment have a multilayer structure, one layer being made of a zeolitic material and another layer being made of a PTC material. By energizing the PTC layer, the zeolite layer can be heated for desorbing. The disadvantage of this solution is that the flow resistance of such a hollow fiber module is considerable and, moreover, the production of the multilayered hollow fibers requires considerable outlay in terms of device and manufacturing technology.

In contrast, the invention has for its object to provide a device for air conditioning a gaseous fluid through which a fluid, in particular a gaseous fluid, can be heated or dehumidified / humidified with little effort in terms of directional engineering and improved operational safety. This object is achieved by a device with the features of patent claim 1 or by a method according to the independent claim 14.

Advantageous developments of the invention are the subject of the dependent claims.

The device according to the invention serves to air-condition a preferably gaseous fluid and has a fluid inlet and a fluid outlet. The device is also designed with an adsorbent which is designed to take a component from the fluid by adsorption or to release it by desorption into the fluid. The device is also designed with a pickling device for tempering the fluid and / or the adsorbent, so that, for example, a desorption process can be initiated by increasing the temperature. According to the invention, the pickling device is designed in such a way that its power consumption during the desorption decreases with decreasing load in a self-regulating manner. The power consumption of the heating device is thus greater when the adsorbent is loaded than when the adsorbent is unloaded or less saturated. The system is therefore extremely energy efficient.

The invention further relates to a method, preferably for operating a device according to one of the preceding claims. The adsorbent loaded with the component (or component mixture) to be removed is first heated by means of the heating device, the power consumption of the heating device decreasing in a self-regulating manner during this heating process as the load decreases. This heating is preferably carried out with the fan switched off, ie without fluid flow. After the adsorbent has been heated up and the associated partial desorption from the micropore and macropore volume of the adsorbent is carried out, a fluid stream is passed through the adsorbent, for example as a function of the adsorbent temperature and / or the residual adsorbent loading, so that the desorbed component via the fluid stream from the adsorbent, in particular the adsorbent bed is rinsed out. This fluid stream loaded with the component can then be derived from the device, for example into the environment.

Such a desorption process is much more energy efficient than conven union solutions, in which the adsorbent is flowed through by a heated fluid stream for desorbing. The desorption of the component from the adsorbent is significantly accelerated by this fluid flow. The fluid stream is somewhat cooled by the endothermic desorption process, but the temperature of the loaded fluid stream is generally higher at the fluid outlet at the fluid inlet.

The inventive design of the heating device makes it possible to dispense with complex control electronics to avoid overheating, so that the outlay in terms of device technology is significantly reduced compared to conventional solutions.

In a preferred embodiment of the invention, the at least one heating element is designed with radiators for increasing the heat exchange surface, the adsorbent surrounding these heat exchange surfaces / radiators at least in sections. This ensures a direct heat exchange between the radiators, the adsorbent and the fluid flowing through the arrangement or in this fluid.

In a preferred embodiment of the invention, the adsorbent is designed as a bed of adsorbent pellets. In principle, however, the adsorbent can also be designed as a solid.

The effectiveness of the device can be further improved if the Heizvor direction has at least one PTC heating element. Such PTC heating elements (PTC: Positive Temperature Coefficient) are temperature-dependent ceramic resistors and assign to the group of thermistors and have self-regulating properties, since the resistance increases with increasing temperature.

It is known per se from the prior art to provide such PTC heating elements in heating devices. For example, in the publication DE 10 2015 111 571 A1, which goes back to the applicant, a heating register is described, the heating elements of which are designed as PTC resistors, the heat exchange being carried out via radiators designed as corrugated fins, which are thermally contacted with the PTC resistance elements. In this solution, the corrugated rib elements are designed as delta ribs, the apexes of the corrugated ribs abutting one another or at least arranged at a short distance from one another.

DE 10 2016 110 023 A1, which also goes back to the applicant, describes a heater for a tumble dryer which also has heating elements designed as PTC resistance elements, the heat exchange taking place via corrugated fin elements, which in turn are designed as delta fins and with their apices lie flat against the heating element.

According to the invention, it is preferred if the adsorbent is a zeolite (molecular sieve), which is preferably designed with a pore size of more than 3 A, preferably about 7 A, so that water can be adsorbed.

In one embodiment of the invention, the radiators are designed as corrugated fins with rounded or sectionally straight vertices, the

Vertex width is larger than the average diameter of the pellet bed, preferably larger than the diameter of the largest pellets.

The construction of the device is particularly simple if the heating device has a plurality of heating elements arranged in parallel or one behind the other in the fluid flow path, which are combined to form a heating register. To increase the heating output, several such heating registers can also be arranged one behind the other or parallel to one another in the fluid flow path. The heating registers can be modular, ie vary in length or width.

In an application of the device according to the invention, it is designed with a housing in which a fan for conveying the fluid from the fluid inlet to the fluid outlet is arranged, the heating device having the adsorbent in the

Flow path is arranged between the inlet and the outlet. I.e. Via the fan, the fluid loaded with an undesirable component, for example with moisture, is conveyed through the adsorbent bed so that the undesired component is adsorbed depending on the pore size of the adsorbent. The desorption then takes place accordingly by heating the loaded adsor bens, which desorption can take place statically or dynamically.

In a particularly preferred embodiment of the invention, the device is designed with an air control, for example with a flap, via which the fluid flow can be directed downstream of the heating device and the adsorbent to the fluid outlet or a bypass connection.

The device according to the invention can be designed, for example, as a dehumidifier for rooms or devices, devices. It is particularly preferred to use it as a control cabinet dehumidifier, as a dryer in a dishwasher or a clothes dryer. It can also be used in a drying cabinet, as a dryer for shoes or as a bath dehumidifier. In addition, there are also mobile applications, e.g. B. possible for dehumidification of vehicles.

In one embodiment of the invention, the device is designed with a control unit via which the heating elements and / or the fans and / or the air Control can be controlled. This control can take place, for example, as a function of the signal from sensors via which the temperature of the fluid at the inlet, at the outlet or in the adsorbent bed or the moisture of the fluid stream is detected. Alternatively, the control can also be time-controlled.

To increase operational safety, the at least one heating element can be insulated.

Preferred exemplary embodiments of the invention are explained in more detail below with the aid of schematic drawings. Show it:

FIG. 1 shows a view of a device according to the invention for air conditioning a fluid,

Figure 2 shows the device of Figure 1 with a removed cover

FIG. 3 shows a detailed view of the view according to FIG. 2,

FIG. 4 shows a diagram in which the power consumption of heating elements of the device according to FIGS. 1 to 3 is shown over time,

FIG. 5 shows a block diagram to explain an adsorption and desorption process by means of a variant of the device according to the invention designed as a control cabinet dehumidifier,

FIG. 6 shows a concrete exemplary embodiment of a device according to the invention designed as a control cabinet dehumidifier, Figure 7 shows the device according to Figure 6 in a sectional view

Figure 8 is a detailed representation of the device according to Figure 7 and

9 shows the device according to FIGS. 6 to 8 in a desorption function.

The basic structure and the basic function of a device according to the invention for air conditioning a fluid are described below with reference to FIGS. 1 to 4.

Figure 1 shows a plan view of a Fleizregister 1 of a device according to the invention. This has an approximately cuboid-shaped register housing 2, in which the pickling elements 4 (see FIG. 2), which are explained in more detail below, are accommodated. In the illustration according to FIG. 1, electrical connection lines are shown, only one of which is provided with the reference number 6.

A fluid flow or a standing fluid, for example air, can be heated, cooled (tempered) and / or dehumidified or humidified via the heating register 1. The flow is perpendicular to the plane of the drawing

According to Figure 1, the register housing 2 has a cover 8, which is designed as a perforated plate with a plurality of openings 10, which bil together form a fluid inlet. The bottom or back of the housing, not shown in Figure 1 is accordingly designed with a lid 22 formed as a perforated plate (see Figure 2). On the long side and front side, side parts 12, 14, 16, 18 are provided, which are designed as a closed wall or also as a perforated plate.

As explained in more detail below, the heating elements 4 and additionally an adsorbent 20 (see FIG. 3) are accommodated in this register housing 2. At the In the illustrated embodiment, a zeolite bed is used as the adsorbent, the diameter of the pellets being larger than the diameter d of the openings 10, so that the adsorbent bed 20 is reliably accommodated in the register housing 2. Further details are explained with reference to FIG. 3.

The register housing 2 is made, for example, of an aluminum perforated plate; Of course, other suitable materials, for example plastic or stainless steel, can also be used to form the register housing 2.

FIG. 2 shows the heating register 1 with the cover 8 removed, the zeolite bed being shown only in the corner regions of the heating register 1 at the top right and bottom. As explained, the adsorbent 20 consists of a pellet bed, the diameter of the pellets being between 2.5 mm and 5 mm, for example. A comparatively narrow particle size distribution is expediently chosen so that the bed has a homogeneous structure.

It is also possible to influence the pressure loss with the grain size. When using a coarser bed (larger pellet diameter) the pressure loss is lower. Alternatively, it is also possible to provide only partial areas of the heating register 1 with the pellet fill.

In the illustration according to FIG. 2, the bottom-side cover 22, which is not visible in FIG. 1, can be seen, which together with the side parts 12, 14, 16, 18 forms the receptacle for the heating elements 4.

In the illustrated embodiment, the heating register 1 has six Heizele elements 4a, 4b, 4c, 4d, 4e and 4f, which are each formed with extruded profiles 24, which consist for example of aluminum. In these extruded profiles 24, the actual heating components, ie the PTC modules, contact plates and the associated insulating sleeve are provided. The latter surrounds the PTC modules and the contact Sheets and insulates them from the extruded profile 24 designed as a housing. The entire arrangement with the extruded profile and the actual Heizkom components is then pressed.

Radiators are attached to these heating elements 4a, 4b, 4c, 4d, 4e, 4f, which in the exemplary embodiment shown are designed as delta ribs 26. The structure of such a delta rib 26 is explained in the prior art described at the outset and is described again below with reference to FIG. 3.

The PTC elements are designed in such a way that they ensure rapid and safe regeneration (see the following explanations) of the zeolitic adsorbent 20. The PTC elements can be designed depending on the residual moisture. To achieve a low residual moisture level, for example, PTC elements with a surface temperature of 260 ° C can be used. If a higher residual moisture is permitted, for example PTC elements with a surface temperature of 240 ° C can be used. In the exemplary embodiment shown, the heating register 1 is cascaded from changing layers of extruded profiles 24, delta fins 26 (corrugated fins), the inner delta fins 26 each being assigned to two heating elements 4 or extruded profiles 24. The delta ribs 26 can be connected in a heat-conducting manner to extruded profiles 24, for example by rolling on lateral webs. In principle, soldering or another material and / or positive connection is also possible.

Instead of the delta fins 26, other radiators can of course also be formed, for example corrugated fins with rounded vertices or other heat exchange surfaces. The geometry should be chosen so that the pellets can be arranged in the flow areas.

In the illustrated embodiment, end profiles 28, 30 are provided in the region of the two longitudinal side parts 12, 18, which laterally support the outer delta ribs 26. In principle, instead of such a closing profile 28, 30 a pellet bed are also formed in this area, on which the delta rib 26 is then supported laterally.

The extruded profiles 24 and end profiles 28, 30 can be made of aluminum, for example. A coating can be provided to optimize the chemical resistance. Other suitable materials are also possible.

Figure 3 shows a detailed view of the lower right part of the heating register 1 shown in Figure 2, only a part of the adsorbent bed is Darge. One can see in the illustration according to FIG. 3 the shape of the delta ribs 26, with two approximately V-shaped slanted rib walls 32, 34, each of which is connected via a vertex 36, which - as explained above - press profile 24 of the extrudate surface respective heating element 4 is present. In the rib walls 32, 34 indicated beads / openings 38 can be formed in Figure 3, which allow cross-mixing of the flow. With regard to further details of such delta ribs 26, reference is made to the prior art mentioned at the outset according to FIG

DE 10 2015 1 1 1 571 A1.

The pellets of the adsorbent 20 are introduced into the space spanned by the delta ribs 26, so that the bed is also thermally contacted with the delta ribs 26 and thus with the heating elements 4a to 4f.

As shown schematically in FIG. 3, the geometry of the delta rib 26 and the diameter D of the pellets are so matched in the embodiment described that the latter is less than or equal to the apex width S of the apex 36 of the delta rib 26. This ensures that the pellets also come into contact with the respective heating element 4 or the end profile 28, 30 in the apex region, so that no cavities are formed which enable an undesired fluid flow without predetermined heat / material exchange. In the illustrated embodiment, zeolites are preferably the

Group X or Y used, which have a slightly larger pore size than the group A zeolites. The zeolites of groups X, Y have the advantage of higher water absorption, better robustness and higher hydrothermal stability compared to the zeolite structures of group A. In addition, the zeolites of group X or Y have a larger pore diameter, so that in addition to water molecules, other constituents , for example hydrocarbons are adsorbed.

If such a heating register is opened with humid air when the heating is switched off, this loading being able to take place statically or via an air stream, the water molecules are adsorbed by the adsorbent 20 (molecular sieve).

When a certain moisture saturation of the adsorbent is reached, the heating elements 4 are activated with an initially interrupted air flow, so that the temperature increase leads to desorption. The amount of heat given off by the heating elements 4 is homogeneously transferred to the adsorbent via the delta ribs 26 of the heating register 1, even without forced air circulation, so that after a relatively short time the adsorbent 20 regenerates and the adsorbed constituents, in particular the water molecules be desorbed.

Figure 4 shows the power consumption of the heating elements 4 during the desorption process as a function of time. The curve above shows the

Power consumption in the case of an adsorbent 20 loaded with high moisture. The curve below shows the power consumption in the case of a comparatively lightly loaded adsorbent 20. It can be seen from this illustration that the power consumption is in principle greater at a given time for a loaded adsorbent than for a less loaded adsorbent . In addition, you can clearly see that the power consumption decreases with increasing desorption time and thus decreasing loading due to the PTC characteristics. In other words, the power consumption of the heating register 1 arises when it is used. fertilize a PTC heating element 4 depending on the moisture content or the loading of the zeolite, without the need for complex control. In addition, no additional protection of the heating system is required, because exceeding a maximum temperature is practically impossible due to the PTC characteristics.

During the desorption process there is an approximately constant upper surface temperature on the heating elements 4 even with decreasing moisture content. Another advantage of the system according to the invention is that due to the insulation directly on the heating elements there are no open voltages and thus there is no risk of short-circuiting with high moisture saturation.

The mode of operation of the device according to the invention will be explained in the following on the basis of a specific exemplary embodiment. Figure 5 shows an example of the functional structure of a control cabinet dehumidifier 40. Accordingly, such a dehumidifier 40 has three main components.

A first main component is the heating register 1 described above, which contains the PTC heating elements 4 and the adsorbent 20 consisting of a zeolite bed. The dehumidifier 40 also has a fan 42, via which an air flow is fed to the heating register 1. The dehumidifier 40 also has an air control 44, via which the air dehumidified by means of the heating register 1 can either be supplied to a switching cabinet or the air which arises during a desorption process is released to the environment.

In the adsorption process shown in FIG. 5 above, moist air is first drawn in via the fan 42 and conveyed to the heating register 1. This moist air is dehumidified by means of the zeolite bed of the heating register 1 when the heating is deactivated (heating elements 4 switched off) by adsorption, so that the water molecules are adsorbed in the micro and macro pore volume of the zeolite bed. During this exothermic adsorption process, due to the released adsorption tion heat of the air flow is heated, so that there is ent humidified and heated air at the outlet of the heating register. The air control 44 is set such that this dehumidified and heated air flow is conducted into the control cabinet.

The loading of the zeolite or the moisture content of the air can be controlled using suitable temperature and humidity sensors. The desorption process is then initiated when a predetermined moisture saturation / load is reached. This desorption takes place in that the heating register, more precisely the heating elements 4, is first activated, so that the zeolite bed is heated accordingly. After a heating-up time (static desorption), the fan 42 can be activated temporarily in order to support the desorption process by means of an air flow (cold, moist air), so that the dehumidification performance / desorption is significantly increased or accelerated. The heat supplied via the heating register 1 desorbs / evaporates the water molecules adsorbed in the pore system of the adsorbent 20 or the bed and then leads them out of the pore system via the supplied air. This air, which is heated via the heating elements 4, is somewhat cooled by the endothermic desorption process, but warm, laden with water vapor is present at the outlet of the heating register 1 after the desorption process with activated heating elements 4. This air flow is then passed into the environment by suitable control of the air control 44.

As indicated in FIG. 5 below, the fan 42, the heating register 1 and the air control 44 are controlled via a control / regulating unit 46. This emits the control signals, for example, as a function of the measurement signals from sensors, for example from temperature and humidity sensors to regulate the ad and desorption process. The heating register 1 can be switched, for example, via a relay. The air flow control, which will be explained in more detail below, can be brought into the respective position by a stepper motor or an actuator in the form of an expansion wax element, which may be electrically heated and thus externally controlled, in order to direct the air flow into the control cabinet or to the surroundings . The fan speed can be controlled, for example, by means of pulse width modulation (PWM). Figure 6 shows a specific embodiment of a dehumidifier 40, which is executed in the illustrated embodiment with a multi-part, approximately cuboid Ge housing 48. The three components described above are included in this: the fan 42, the heating register 1 identified by a dashed reference line and the air control 44. Between the fan 42 and the heating register 1 in the embodiment shown in FIG. 6, an intermediate piece 50 is also provided, which is used to generate a homogeneous air flow.

The fan 42 is designed in such a way that it conveys air from below (see arrow in FIG. 6) into the interior of the housing 48, so that an air stream directed to the heating register 1 is produced. In the above-described adsorption process, a flap 52 of the air control 44 is set in such a way that the dehumidified air flow which is warmed due to the heat of adsorption is passed through an outlet into the interior of the control cabinet. During the desorption process, the flap 52, which is pivotably mounted on a rotary bearing 55 of the air control 44, is brought into a position shown in FIG. 9, in which the air flow to the outlet 54 is interrupted and is led to a bypass outlet 56, through which the warm, moist loaded air flow is released to the environment (see dashed arrow in Figure 6).

The control of the fan 42, the heating elements 4 and the flap 52 as well as the processing of the measurement signals of the sensors (moisture sensor, temperature sensor, etc.) is carried out - as described above - via the control unit 46 which, for example - as indicated by dashed lines in FIG. 6 - can be attached laterally to the housing 48. Of course, this control unit 46 can also be mounted separately from the actual dehumidifier 40.

As can also be seen in FIG. 6, the individual components of the dehumidifier according to the invention, ie the fan 42, the intermediate piece 50, the heating register 1 and the air control 44 are connected to one another via a screw connection 58, the fan 42 on a base plate 60 is supported and the outlet 54 opens into a cover plate 62, which allows blowing out into the control cabinet. The screw connection 58 is designed such that the aforementioned components 42, 50, 48 are braced with the cover plate 62 and the base plate 60.

FIG. 7 shows a section along the line A-A through the dehumidifier 40 according to FIG. 6. It can be seen in this illustration that in this exemplary embodiment two partial heating registers 1 .1, 1 .2 of the above-described type form a common heating register 1 one behind the other in the flow direction. In this illustration, the beads 38 of the delta ribs 26 can also be clearly seen.

Upstream and downstream of the heating register 1, in the exemplary embodiment shown in FIG. 7, a cover 8, 22 designed as a perforated plate is provided, the cover explained with reference to FIGS. 1 and 2 in the contact area of the two partial heating registers 1 .1 and 1 .2 Simplification of the expenditure on device technology are omitted. In the middle area of the heating register 1 according to FIG. 7, the extruded profiles 24.1 and 24.2 of the heating elements 4.1 and 4.2 of the partial heating register 1 .1 and 1 .2 are visible. Both partial heating registers 1 .1 and 1 .2, which together form heating register 1, are assigned a common zeolite bed, which is not shown in FIG. 7, however.

FIG. 8 shows an enlarged sectional view of the heating register 1 with the two partial heating registers 1 .1 and 1 .2, which are connected in series as seen in the direction of flow. Each of these partial heating registers 1 .1 and 1 .2 has the structure as explained in principle with reference to FIGS. 1 to 3, so that reference can largely be made to these statements. The bottom cover 22 of the heating register 1 is shown in the illustration according to FIG. 8; the cover 8 visible at the top in FIG. 7 has been omitted for the sake of clarity.

As described above, each partial heating register 1 .1 (1 .2) has four heating elements, of which only a few can be seen in FIG. 8 (in FIG. 8, only the heating elements of the partial heating register 1 .1 with the reference numerals 4c, 4d, 4e and 4f ver see), each of which is connected to connecting lines 6 for contacting. As described above, each heating element has 4 PTC modules which are contacted via contact plates and are insulated from the respective extruded profile 24a, 24b, 24c (the fourth extruded profile of the partial heating element 1.1 is not visible in FIG. 8) via insulation. The heat exchange takes place, as described, via the delta fins 26. The zeolite bed is also omitted in the illustration according to FIG. 8. This zeolite fill fills the entire space visible in FIG. 8 between the heating elements 4a to 4c of both partial heating registers 1.1 and 1.2.

FIG. 9 shows a representation corresponding to FIG. 7, the desorption for

The flap 52 is adjusted such that the outlet 54 is blocked off from the control cabinet, and the relatively warm air laden with water vapor during the desorption process is passed through the bypass outlet 56 into the surroundings. Otherwise, the illustration according to FIG. 9 corresponds to that in FIGS. 7 and 8, so that further explanations are unnecessary.

Disclosed are a device for air conditioning a fluid with a PTC bleeding element, which is arranged in an adsorbent bed, and a method for operating such a device.

Reference list:

1 heating register

2 register housings

4 heating element

6 connecting cable

8 lids

10 opening

12 side part

14 side panel

16 side panel

18 side panel

20 adsorbent

22 bottom cover 24 extruded profile

26 delta rib

28 end profile

30 end profile

32 rib wall

34 rib wall

36 crowns

38 surround

40 dehumidifiers

42 fans

44 Air control

46 control unit

48 housing

50 intermediate piece

52 flap

54 outlet

55 pivot bearings

56 Bypass outlet Screw connection base plate cover plate

Claims

1. A device for air conditioning a fluid, in particular an air stream, with a fluid inlet and a fluid outlet and with an adsorbent (20), which is designed to absorb a component by adsorption from the fluid or by desorption to the fluid and with a heating device for Tempering the adsorbent and / or the fluid, characterized in that a heating element (4) of the heating device is designed in such a way that a power consumption of the heating element (4) decreases in a self-regulating manner as the loading of the adsorbent (20) decreases.

2. Device according to claim 1, wherein the at least one heating element (4) has radiators for increasing the heat exchange surface and the adsorbent (20) surrounds the radiators at least in sections.

3. Device according to claim 2, wherein the adsorbent (20) is a bed of adsorbent pellets.

4. Device according to one of the preceding claims, wherein the Heizvor direction has at least one PTC heating element (4).

5. Device according to one of the preceding claims, wherein the adsor bens (20) is a zeolite, preferably of type X or Y.

6. Device according to one of the claims 2 to 5, wherein the radiators are corrugated fins with rounded or sectionally straight vertices (36), wherein a vertex width (S) is larger than the mean diameter, preferably larger than the largest diameter (D), a pellet.

7. Device according to one of the preceding claims, wherein the Heizvor direction has a plurality of in the fluid flow pad parallel or one behind the other arranged heating elements (4) which are surrounded by the adsorbent (20) and are combined to form a heating register (1) .

8. The device according to claim 7, wherein the heating device is formed modularly with heating registers (1) lying parallel or one behind the other in the fluid flow path, wherein the heating registers (1) can vary in length and / or width.

9. Device according to one of the preceding claims, wherein the at least one heating element (4) is provided with insulation.

10. Device according to one of the preceding claims, with a housing (48) in which a fan (42) for conveying the fluid from the fluid inlet to

Fluid outlet is arranged, wherein the heating device with the adsorbent (20) is arranged in the flow path between the fluid inlet and the fluid outlet.

11. Device according to one of the preceding claims, with an air control (44), via which the fluid flow downstream of the heating device and

Adsorbent (20) is optionally directed to the fluid outlet or to a bypass outlet (56).

12. Device according to one of the preceding claims, wherein this is a dehumidifier for rooms or devices, devices, preferably a control cabinet dehumidifier (40), a dryer of a dishwasher or a clothes dryer.

13. Device according to one of the preceding claims, with a control unit (46) for controlling the heating elements (4) and / or a fan (42) and / or an air control (44) and with sensors for detecting operating parameters, such as the temperature or humidity of the fluid.

14. A method, in particular for operating a device according to one of the preceding claims, with the steps:

Heating the adsorbent (20) loaded with the component for desorption by means of the heating device, the power consumption of a heating element (4) of the heating device decreasing in a self-regulating manner as the load decreases,

- switching off the heating element (4) after reaching a predetermined adsor ben temperature or a residual loading of the adsorbent or a portion of the desorbed component in a fluid space,

- Flow through the heated adsorbent (20) by means of a fluid flow to further reduce the adsorbent load and

- Deriving the fluid stream loaded with the component from the device.