EP2219759A1

EP2219759A1 - Extractor hood with sorption unit for absorbing moisture and method for operating the extractor hood

Info

Publication number: EP2219759A1
Application number: EP08852997A
Authority: EP
Inventors: Joachim Damrath; Stefan Holzer
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2007-11-23
Filing date: 2008-10-23
Publication date: 2010-08-25
Also published as: DE102007056426A1; WO2009065697A1

Abstract

The present invention relates to an extractor hood (1) for discharging an airflow from a room, having a housing (2), at least one fan (3) for conveying the airflow through the extractor hood (1), sorption means (5) of a sorption unit (4) arranged in the airflow for absorbing moisture present in the airflow, and an identification device (6) for identifying the saturation level of the sorption means (5). The extractor hood (1) is characterized in that the identification device (6) has a detection unit (61) with at least one temperature-measuring point (612), which is arranged in the sorption means (5) in the sorption unit (4) and detects the temperature in at least one area of the sorption means (5) in the sorption unit (4). A method for operating such an extractor hood (1) is also described.

Description

Extractor hood with a sorption unit for sorbing

Moisture and method of operating the

Hood

The present invention relates to an extractor hood with a sorption unit for sorbing liquid and to a method for operating the extractor hood.

For the separation of liquids from an air stream, which is sucked, for example, above a cooking place by an extractor hood and cleaned in this, extractor hoods are known in which a sorption is provided, is separated by the moisture from the air stream.

From DE 102 59 345 A1, such a device for discharging air to a

Hotplate known. In this case, a sorbent for sorbing water in the air flow is provided in the device. Furthermore, should by a

Heating a regeneration of the sorbent be possible.

Furthermore, the use of sorbents from other devices for

Dehumidify air known. For example, in the

EP 0 856 707 A2 describes a device for dehumidifying air. In this device, the sorption is formed as a circular unit and can for

Regenerating areas are turned. The need to regenerate the

Sorbent is determined by a pressure, humidity or temperature difference of the air flowing through the device.

A disadvantage of this way of determining the need to regenerate the

Sorbent is that the temperature, which is usually measured at the outlet of the sorbent column, only allows to reach the degree of saturation of the sorbent, in which this is completely saturated.

The object of the present invention is therefore to provide an extractor hood and a method for operating the extractor hood, in which a reliable detection and monitoring of the current saturation state of the sorbent of a sorption unit is possible. The invention is based on the finding that this object can be achieved by using at least one temperature value of the sorbent as an indication of the degree of saturation.

According to a first aspect, the object is therefore achieved by a

An extractor hood for removing an airflow from a room comprising a housing, at least one fan for conveying the airflow through the extractor hood, a sorbent disposed in the airflow of a sorption unit for sorbing airborne moisture, and a recognition device for detecting the saturation level of the sorbent. The extractor hood is characterized in that the detection device comprises a detection unit with at least one temperature measuring point, which is arranged in the sorbent in the sorption and detects the temperature in at least a portion of the sorbent in the sorption.

The space from which air is to be dissipated with the extractor hood according to the invention is preferably the space via a hotplate. Preferably, the invention relates to an extractor hood, which can be operated in recirculation mode. The sorption unit is a unit filled with the sorbent or formed by the sorbent itself, which is also referred to below as a column. The material of the sorbent is also referred to below as sorbent material or sorbent. The sorption unit, in particular the container of the sorption unit in which the sorbent is held, can have a rectangular, round or oval cross-section. However, it is also possible to manufacture the container of the sorption unit with an octagonal cross-section. The shape of the sorption unit is chosen as a function of the space available for installing the sorption unit in the extractor hood. The size of the sorption unit is also sized according to the installation space; The sorption unit may, for example, have a width in the case of a rectangular cross section or a circumference diameter of, for example, 30 cm to 35 cm, in particular 32 cm, in the case of a polygonal cross section. The sorption unit is preferably flat for reception in the extractor hood, that is configured with a small height. The total height of the container of the sorption is for example 25cm to 30cm. A sorbent provided in the sorption unit, which may for example be in the form of a bed, may for example be provided in the sorption unit up to a height of 20 cm to 25 cm. As a recognition device, a device is referred to, with which an indication can be made, which allows a statement about the saturation state of the sorbent of the sorption. The detection device may consist of a detection unit, with which the temperature of the sorbent can be detected or measured. In the recognition device but also additional units may be provided.

In that the detection device has a detection unit for detecting the temperature and at least one temperature measurement point in the sorption means of the

Sorptionseinheit is arranged, the current temperature of at least a portion of the sorbent can be reliably determined. The temperature measuring points can be formed by jacket thermocouples or other water-tight temperature sensors. Sorbent materials, such as zeolites, release heat upon absorption of moisture due to binding enthalpy. By determining the temperature of the sorbent can therefore be detected whether moisture is absorbed. In addition, by the location of the temperature measuring point and the place where a moisture absorption occurs can be detected. Based on this information, it is possible to give an indication of the degree of saturation of the sorbent. The temperature measured in the sorbent reflects the current state of the sorbent particularly reliable again, since external influences, as they are to be considered in a temperature measurement outside the sorption, do not occur. In particular, by measuring the temperature of the sorbent, a temperature change resulting from chemical reactions of the sorbent, in particular the temperature increase upon deposition of liquid, can be more reliably detected than when the temperature outside the sorbent is measured. Also, the place where the temperature increase occurs can be reliably determined by a temperature measurement within the sorbent. Thus, a reliable statement about the degree of saturation of the sorbent can be made. Also, in an optional regeneration process in which the sorbent is desorbed, that is, the liquid absorbed in the sorbent is discharged therefrom, the measurement of the temperature in the sorbent can provide important information.

According to a preferred embodiment, a temperature measuring point is at a distance from the inlet surface of the sorbent for the air flow in the sorbent in the Near the entrance surface arranged. The entry surface of the sorbent is the surface through which air taken in by the blower of the extractor hood and optionally pre-cleaned enters the sorption material of the sorption unit. The inlet surface of the sorbent may be preceded by an air distribution space. Since the temperature difference between the sorbent and the air introduced into the sorption unit in the air flow is greatest in the area of the inlet surface of the sorbent, the absorption of liquid into the sorbent is the fastest here. By providing a temperature measuring location in this area, the saturation of the sorbent in this area can be monitored. If the distance to the entrance surface is minimized, the temperature measuring point located near the entrance surface may serve to detect the temperature of the vapor entering the sorbent. Particularly in the case of zeolites, the sorption of the liquid at the entry surface takes place so rapidly that the associated increase in temperature can only be recognized for a short time. Subsequently, the temperature of the Wrasens, which enters the entrance surface is detected at the temperature measuring point.

In addition or as an alternative to the temperature measuring point in the region of the inlet surface of the sorbent, according to one embodiment, a temperature measuring point at a distance from the outlet surface of the sorbent for the air flow in the

Sorbent be arranged in the vicinity of the exit surface. Also, this area is the recognition of the degree of saturation of the sorbent of importance. If there is no increase in temperature in the area of the outlet surface, ie no liquid is absorbed in this area, the sorbent is saturated. By including in this area, the temperature measuring point in the sorbent, a reliable measurement can be achieved here, which is not possible in a measurement outside of the sorbent. In addition, a temperature measuring point arranged in the region of the exit surface can also be of importance for a regeneration process which may be carried out. When regenerating the sorbent, in which, for example, by introducing hot air the

Sorbent is desorbed, that is, the moisture is removed from the sorbent, a temperature measuring point in the area of the exit surface serve to recognize the end of the regeneration process. Upon detection of a certain temperature indicative of the complete regeneration of the sorbent, the regeneration process can be terminated to prevent overheating of the device. According to one embodiment, the detection unit protrudes from the exit surface of the sorbent for the air flow into the sorbent in the sorption unit. In particular, the part of the detection unit on which the at least one temperature measurement point is provided is introduced from above into the sorption agent. Such introduction is possible in the present invention, since the height of the

Sorption unit and the sorbent therein is low due to the structural limitations of an extractor hood. An advantage of introducing the detection unit over the exit surface of the sorbent is that the walls of the sorption need not be changed, which would be necessary for a lateral introduction of temperature measuring points in the sorbent. In the case of extractor hoods, a large volume of air must be conveyed in the sorption unit at a relatively low pressure. For an extractor hood, a large volume of air typically needs to be conveyed 500m ³ / h and more at a relatively low pressure. In the sorbent air stream, for example, the pressure is 1000 Pa and less than 100 Pa in the undried air stream, that is, the vapor entering the sorbent. These pressure and air volume ratios of an extractor hood require a certain design of the sorption unit in the extractor hood. In particular, a large cross section of the sorption unit is required. In order to enable a uniform temperature distribution in the sorbent, in particular during the regeneration of the sorbent, despite the large cross section, it is preferably provided inter alia to provide the walls of the sorption unit with a heat insulation. Performing detection units with measuring points by such an insulated wall would lead to an increased effort to ensure the insulation also in the field of implementation. In addition, a replacement or replacement of the detection unit, for example, in case of defective temperature measuring point in this case only possible with considerable effort. These problems do not exist in an over the exit surface of the sorbent, that is from above introduced detection unit.

Preferably, the detection unit comprises at least two temperature measuring points. By measuring the temperature at two points in the sorbent, a difference value can be formed or the ratio of the two measured temperatures to one another can be determined. By virtue of this ratio, the detection of the degree of saturation can be made even more accurate in comparison with the measurement of only one absolute value. In addition, the comparison of the measured temperatures without accurate calculation of the difference value can be sufficient. The number of Temperature measuring points in the sorbent determines the number of Füllbezi eh ual saturation states that can be detected by the detection unit. The temperature measuring points are distributed over the height of the sorbent, thus forming a sorption front that forms in the sorbent, which will be explained in more detail later and whose progression can be monitored.

The two temperature measuring points may preferably be provided on a common device. For example, a rod-shaped end of the detection unit is possible, over the length of which several measuring points are provided. The use of a common device for several measuring points has the

Advantage that it can be easily inserted into the sorbent and also in particular the relative position of the individual temperature measuring points to each other safely maintained and can be easily preset. As a result, the position of the individual temperature measuring points in the sorbent is known even after the introduction of the detection unit in the sorbent.

According to a preferred embodiment, the sorbent is a bed, in particular a bed of zeolite. By using a bed of sorbent material, on the one hand, the weight of the sorbent can be kept lower than is the case, for example, with a gel as sorbent. A low weight is desirable, inter alia, due to the mounting options of a cooker hood.

In addition, the water absorption capacity of zeolite is high, so that the absorption of the required amount of water can be ensured. The absorption capacity that has to be provided by a sorption unit of an extractor hood is in the low liter range. For example, a sorption capacity of 2 liters may be sufficient. For this example, 10kg to 15kg, in particular 12 kg of zeolite can be used, resulting in a bulk volume of, for example, 12 liters to 18 liters, especially 16 liters.

Furthermore, the use of a bed provides an easy way to subsequently introduce a detection unit easily into the sorbent can or exchange the detection unit.

Particularly preferably, the sorbent represents a Zeolithschüttung. Zeolites, in particular zeolite 13X are characterized by the particularly strong affinity for water out. Therefore, water vapor entering the bed is stored at the next possible unsaturated site. The bed is therefore not uniformly saturated, but it forms a sorption front, which migrates from the air inlet to the outlet. In particular, by providing a plurality of temperature measuring points in the sorbent, this sorption front can be tracked and thereby inform the user before reaching the maximum saturation level or other suitable measures in the hood are triggered.

According to a preferred embodiment, the recognition device has an evaluation unit, which is connected to the detection unit. In the

Evaluation unit can or the measured temperatures compared to other values are compared. For example, it is possible to compare a measured temperature with respect to a reference value that may be stored in the evaluation unit. However, it is particularly preferred if the at least one temperature is compared with a further measured temperature and the ratio of the measured temperatures is determined. In this case, the ratio may be greater than or equal to the mere statement.

The temperature detected by a temperature measuring point located in the sorbent is preferably compared to at least one temperature detected by another temperature measuring point located in the sorbent. Alternatively, however, it is also possible that a currently measured temperature of a temperature measuring point is compared with a temperature previously measured by this temperature measuring point. In this case, the temperature increase is detected at the position of the temperature measuring point. However, in addition to storing measured temperature values, the latter alternative also requires the calculation of the difference of the measured temperatures and the storage of a reference value. The difference must be compared with the predetermined reference value in order to detect whether at the position of the temperature measuring point, for example, a temperature increase has occurred, which was caused by a sorption front. However, as the actual temperature is determined by other factors, such as the actual temperature of the vapor or vapor entering the sorbent, this alternative is less reliable. In contrast, in the former alternative, measured values of different temperature measuring points are used to detect the degree of saturation. Because when measuring these temperatures all measuring points are exposed to the same conditions, this alternative is more reliable and preferred according to the invention.

Rules can also be stored in the evaluation unit or the evaluation unit can be connected to a control unit in which rules are stored which trigger certain actions within the extractor hood when a predefined situation in the sorption unit is detected. The situation can be detected, for example, by a specific relationship between measured temperatures. The actions which may be deposited in the rules may include, for example, the issuing of an indication, for example the display of a warning on the extractor hood.

Particularly preferably, the detection unit is connected to a regeneration device for regenerating the sorbent. The connection can be present directly or indirectly, for example via the evaluation unit. By using the output of the detection unit or of the evaluation unit, which provides information about at least one temperature within the sorbent, as an input for the regeneration device, an automatic start of a regeneration process can be carried out, for example, upon detection of reaching a maximum saturation level of the sorption agent. Additionally or alternatively, the regeneration process can be controlled by this connection and in particular be terminated. As a regeneration device, a device is referred to, over the sorbent for desorbed targeted heat, for example in the form of hot air, can be supplied.

According to a preferred embodiment, the regeneration device comprises at least one heating element and at least one heat distribution means. By providing a heat distribution means which may be, for example, a heat conducting sheet provided in the sorbent or an air swirling chamber upstream of the sorbent, a uniform temperature distribution in the sorbent is also ensured during the regeneration process, thereby minimizing measurement inaccuracies in the temperature measurement in the sorbent. In addition, this type of regeneration device is advantageous because it requires little space and thus can be easily integrated into the cooker hood. In particular, the space requirement is lower as in a regeneration device in which a compressor for compressing air, which comes from another process step is necessary.

According to a further aspect, the present invention relates to a method for operating an extractor hood comprising a housing, at least one fan for

Conveying the air flow through the extractor hood, a sorbent disposed in the airflow for sorbing moisture present in the airflow, and a recognition device for detecting the degree of saturation of the sorbent. The method is characterized in that a detection unit of the detection device for detecting the degree of saturation of the sorbent at at least one point in the sorption of the sorption measures the temperature.

The measurement of the temperature within the sorbent is preferably carried out continuously. As a result, the current state of the sorbent, in particular its degree of saturation, can be constantly monitored.

Depending on the measured temperature, a control device can be controlled. Dependent in this context means that the measured temperature itself or a value derived therefrom or derived therefrom serves as input for a control device. The control device may be a central control device, via which different components of the extractor hood can be controlled. However, it is also possible that the control unit is associated with a component of the hood, such as a display unit or a regeneration unit and controls only this.

Preferably, the temperature of the sorbent is measured at least at two locations in the sorbent. As already stated above, this allows a difference or a ratio of the temperatures to be determined, as a result of which specific information about the degree of saturation of the sorption agent is possible.

Particularly preferably, a control device is activated as a function of the ratio of the at least two measured temperatures. Dependent in this context means that the ratio itself or a value derived therefrom or derived therefrom serves as input for a control device. The ratio can be determined between two or more temperature values detected at the same temperature measuring point. However, it is also possible to determine the ratio between two or more temperature values recorded at different temperature measuring points at the same time. The ratio preferably represents the comparison of the size of the temperature values. The ratio is thus specified with the ratios smaller, greater or equal.

Depending on the measured temperature, a regeneration device is preferably activated. The control can be limited to the activation or deactivation of the regeneration device. However, it is also possible to control the regeneration process as a function of the measured temperature.

According to one embodiment, a display device is activated as a function of the measured temperature. This indication can serve to inform the user about the early attainment of the maximum saturation level of the sorbent. In particular, when providing more than two temperature measuring points, different states can be displayed to the user. Thus, for example, when reaching half the degree of saturation or degree of filling, a different indication than when reaching the maximum degree of saturation or degree of filling.

Preferably, a compensation parameter is added to the at least one measured temperature value before the further use of the temperature value. Added in this context means that the compensation parameter is added to the measured temperature that is added. The compensation parameter can in particular take into account the operational offset of the temperatures in the extractor hood. The compensation parameter can be determined by experimental measurements and stored in the evaluation unit or another unit of the extractor hood. The compensation parameter is particularly dependent on the speed of the fan of the hood, the air velocity, the porosity of the sorbent material used and the size of the particles of the sorbent material. For this reason, a plurality of compensation parameters that apply to the individual conditions are preferably stored, so that the corresponding compensation parameter is available for the respective state. The balance parameter is preferably expressed in degrees Celsius and may be, for example, 40 ⁰ C. Advantages and features which are described with regard to the extractor hood apply correspondingly and as far as applicable also for the method according to the invention and vice versa.

The invention will be explained again below with reference to the accompanying drawings. Show it:

FIG. 1 shows a schematic block diagram of an embodiment of the extractor hood according to the invention; and

FIG. 2 shows a schematic representation of the sorption unit of an embodiment of the extractor hood according to the invention.

FIG. 1 shows a schematic block diagram of an extractor hood 1. The construction of extractor hoods is known, so that in the figure, only the significant components for the present invention are shown schematically. In the extractor housing 2 of the hood 1, a fan 3 is provided. This generates in the extractor housing 2 of the hood 1 a negative pressure and ensures during normal operation of the hood 1 for sucking air from the space below the hood 1 via a covered with a grease filter 8

Suction opening 21 of the extractor housing 2. Above the grease filter 8 is a sorption unit 4, which is filled with a sorbent 5, arranged, through which the extracted air is passed. The sorption unit 4 is also referred to below as a column. The air purified by the grease filter 8 and the sorption unit 4 can leave the extractor housing 2 via an outlet opening 22 and be supplied to the surroundings of the extractor hood 1. In this case, the extractor hood 1 is an extractor hood 1, which is operated in recirculation mode. The arrangement of the individual components of the extractor hood 1 is shown only schematically in FIG. The dimensions of the components are not to scale in the figures.

The container of the sorption unit 4, in which the sorbent 5 is accommodated, may have a circumference diameter of, for example, 30 to 35 cm, in particular 32 cm. The height of the sorbent 5, that is to say the bed of the sorbent in the sorption unit 4 can be, for example, 25 cm. The total height of the container The sorption unit 4 with an air distribution chamber 72 connected thereto, which will be described in more detail later, is for example 35 cm.

The sorption unit 4 and in particular the sorbent 5 are flowed through by the suctioned into the extractor housing 2 air. Here, the air enters the sorbent 5 via the entrance surface 51, which is the lower surface of the sorbent 5 in the sorption unit 4. At the upper side of the sorbent 5, the air exits through the exit surface 52 of the sorbent 5 and is discharged from the extractor housing 2 via the blower 3.

In the figure 1, a detection device 6 for detecting the degree of saturation of the sorbent 5 is also shown schematically. The detection device 6 in this case comprises a detection unit 61, which has a lance 61 1. At the lance 611 three temperature measuring points 612 are provided in the illustrated embodiment. The temperature measuring points 612 may represent temperature sensors. The lance 611 of the detection unit 61 is connected to an evaluation unit 62. This evaluation unit 62 simultaneously represents a control unit in the illustrated embodiment. Via the control unit 62, a display provided on the housing 2 is activated. Furthermore, below the sorption unit 4, a regeneration device 7 is indicated schematically. In the illustrated embodiment, this consists of a heating grid 71 and a distributor space 72 adjoining the heating grid 71. Via the distributor space 72, hot air generated by the heating grid 71 can be conducted into the sorption unit 4 and serve to regenerate the sorbent 5. The regeneration device 7 is also connected to the evaluation unit or control unit 62 of the recognition device 6 in the illustrated embodiment.

FIG. 2 shows the sorption unit 4 of an embodiment of the extractor hood 1 according to the invention with the detection unit 61. As can be seen from this view, the sorption unit 4 is not completely filled with sorbent 5. In the bed of the sorbent 5, the lance 61 1 of the detection unit from above, that is introduced from the exit surface 52 of the sorbent 5. Over the length of the lance 611 three temperature measuring points 612 are provided in the illustrated embodiment. The lance 611 is inserted into the sorbent so far that the lower temperature measuring point 612 is located in the vicinity of the entrance surface 51 above the entrance surface 51. Measuring the temperature of the liquid acted upon by air, which also as Wrasen, before entering the sorption unit, which would lead to a falsified measurement result or evaluation result with respect to the degree of saturation, can not occur in this case. The distance to the entrance surface 51 may be 5mm, for example. The middle temperature measuring point 612 is located approximately at half the height of the sorbent 5. This measuring point may, for example, be at a distance from the entrance surface of the sorption unit of 125 mm. Finally, an upper measuring point 612 is provided, at which the outlet temperature of the sorption stream, that is to say the air flowing through the sorbent 5, is measured. This is preferably arranged below the surface of the sorbent bed, that is, below the exit surface 52. This prevents that the air present above the bed 5 in the sorption 4 and their temperature falsify the measurement result and thus the evaluation result with respect to the saturation of the sorbent 5. The distance of the measuring point to the entrance surface 51 may be, for example 230mm.

A further measuring point (not shown) may be provided, for example, in the upper third of the sorption unit and arranged, for example, at a distance of 186 mm from the entry surface 51.

The dashed horizontal guides in Figure 2 is another possible

Embodiment of the arrangement of the recognition device 6 shown. Here, a separate guide is provided for each temperature measuring point 612. These guides extend over the wall of the sorption unit 4 to the outside. The temperature measuring points 612 are respectively provided at the ends of the guides which are located in the sorbent 5.

The mode of operation of the illustrated embodiment of the extractor hood 1 and in particular of the recognition device 6 will be explained in more detail below.

The vapors, for example, when cooking on a hotplate (not shown) occurs after flowing through the grease filter 8 at the inlet surface 51 of the sorbent 5 in this. The sorbent 5 is preferably a zeolite bed. The moisture in the vapor is taken up by the sorbent 5. The absorption of the liquid, in particular of the water in the sorbent 51, releases binding enthalpy, which leads to heating of the sorption material. In the area extending across the cross section of the sorption Sorption front it comes in the sorbent 51 thus to a strong warming. This elevated temperature is detected by the temperature measuring point 612 and thereby the state of the sorbent 5 can be detected.

Is the sorbent 5 dry, so the incoming vapors in the

Entry surface, the liquid to the sorbent. The affinity of the zeolite is so great that the absorption of the liquid in the lower region at the entrance surface 51 takes place so rapidly that the heat released by the formation enthalpy only leads to a heating of the sorbent above the first temperature measurement point. The temperature T1 detected by the lower temperature measuring point 612 is thus lower than the temperatures T2 and T3 detected at the middle and upper temperature measuring points 612.

With increasing duration of use of the sorption unit 4 or the extractor hood 1, the sorption front is up in the direction of the

Move exit surface 52 of the sorbent 5. The displacement of the sorption front can be detected reliably with the detection unit 61 according to the invention.

By simultaneously measuring temperatures in the lower, middle and upper regions of the sorbent 5, it can be determined in which of these three regions the higher temperature is present and, accordingly, the current position of the sorption front is determined. By knowing the location of the sorption front, it can be deduced how the degree of filling of the sorbent is. If the sorption front advances from the inlet surface 51 to the middle of the height of the sorbent 5 during prolonged use of the extractor hood 1, the temperature T1 becomes at the bottom

Temperature measuring point 612 and the temperature T2 at the middle temperature measuring point 612 be lower than the temperature T3, which is detected at the upper temperature measuring point 612.

In a further progression of the sorption front, the temperature T3 detected at the upper temperature measuring point 612 and the temperature T2 of the middle temperature measuring point 612 will be smaller than the temperature T1. By the time the sorbent is completely saturated, there is no further uptake of liquid in the sorbent and, therefore, no bond heat is produced. In this state, the temperature T1 is greater than the temperatures T2 and T3, as the Temperature measuring point 612 measured at the T1 is reached as the first of the hot vapors.

If it is detected that the temperatures T1 and T2 are lower than the temperature T3, this state shows that the sorbent 5 is partially saturated. At this time, for example, the display 63 on the hood 1 can be activated and the user informed about an early saturation of the sorbent 5. Such information of the user before actually reaching the maximum saturation level of the sorbent 5 is advantageous because the user can plan the necessary measures. In particular, the user may include the regeneration of the sorbent 5 in his scheduling. Regeneration operations on the extractor hood 1 can be particularly advantageous, for example at night, since at this time a normal operation of the hood 1 is not required. In addition, the power required for regeneration at night is cheaper.

If it is detected by detecting the fact that the temperature T1 is greater than the temperatures T2 and T3 that the sorbent 1 is saturated, a corresponding display 63 can also be activated, the indication visible to the user being preferably different from that partially saturated state of the sorbent 5. Alternatively, upon detection of this circumstance of reaching the maximum saturation state of the sorbent 5 directly provided in the hood 1 regeneration device 7 can be activated. In the embodiment shown, hot air can be generated for this purpose, in particular via the heating grid 71, which can be passed through the sorbent 5 and leads to desorbing of the sorbent 5.

Via the temperature measuring points 612, in particular via the middle or the upper temperature measuring point 612, the end of the regeneration process can be reliably detected. This can be prevented in a simple manner overheating of the device that could occur in continuation of a regeneration process after complete regeneration of the sorbent 5.

Since different temperature sensors or temperature measuring points 612 are provided in the sorbent 5, the progress of the regeneration in the sorbent 5 can also be detected and optionally controlled with the extractor hood 1 according to the invention. Also can be a gradual regeneration the sorbent 5 monitored and optionally controlled. However, such a stepwise process is energetically very expensive.

In the embodiment of the invention just described, the ratio of the three temperatures T3, T2> T1 for the dry zeolite, T3> T1, T2 for the partially saturated zeolite and T2, T3 <T1 for the fully saturated zeolite. However, it is also within the scope of the invention in the determination of the different states of the sorbent to take into account a compensation parameter. In this case, the initial state of the Zeolithschüttung in which the zeolite is dry, at a state T3, T2> T1 + x be recognized or deposited in the scheme. In the case of a partial saturation, the state T3> T1 + x, T2 + x and, for a saturated bed of zeolite, the state T2, T3 <T1 + x is present. X is here a compensation parameter, which may be, for example, at 40 ⁰ C.

In order to regenerate the sorbent of a sorption unit of an extractor hood, the bed of the sorption material must always be completely heated, regardless of the degree of saturation. Therefore, this process takes place advantageously only at largely saturated bed. With the present invention, the possibility is created of a comparison of the temperatures and temperature tendencies at different points in the sorbent a criterion for the beginning of the

Derive regeneration process. With the present invention, a new regulation or system monitoring of a domestic appliance with sorptive air dehumidification is thus created. These are required for the safe and energy-optimized operation of such a device.

LIST OF REFERENCE NUMBERS

1 Extractor hood 2 Extractor hood

21 intake opening

22 outlet opening

3 blowers

4 sorption unit 5 sorbents

51 entrance area

52 exit surface

6 recognition device

61 detection unit 611 lance

612 temperature measuring point

62 evaluation unit / control unit

63 display

7 Regenerating device 71 Heating grid

72 distribution room

8 grease filters

Claims

claims

An extractor hood for removing an air flow from a room, the housing (2), at least one fan (3) for conveying the air flow through the

An extractor hood (1), a sorbent (5) disposed in the airflow, a sorption unit (4) for sorbing moisture present in the airstream and a recognition device (6) for detecting the degree of saturation of the sorbent (5), characterized in that the recognition device ( 6) a detection unit (61) with at least one

Temperature measuring point (612), which is arranged in the sorbent (5) in the sorption unit (4) and detects the temperature in at least a portion of the sorbent (5) in the Sorptionseinheit (4).

2. Extractor hood according to claim 1, characterized in that a

Temperature measuring point (612) spaced from the inlet surface (51) of the sorbent (5) for the air flow in the sorbent (5) in the vicinity of the inlet surface (51) is arranged.

3. Extractor hood according to one of claims 1 or 2, characterized in that a temperature measuring point (612) at a distance from the outlet surface (52) of the sorbent (5) for the air flow in the sorbent (5) in the vicinity of the exit surface (52). is arranged.

4. Extractor hood according to one of claims 1 to 3, characterized in that the detection unit (61) protrudes from the outlet surface (52) of the sorbent (5) for the air flow in the sorbent (5) in the sorption (4).

5. Extractor hood according to one of claims 1 to 4, characterized in that the detection unit (61) comprises at least two temperature measuring points (612).

6. Extractor hood according to one of claims 1 to 5, characterized in that the sorbent (5) constitutes a bed, in particular a

Zeolite packing.

7. Extractor hood according to one of claims 1 to 6, characterized in that the detection device (6) comprises an evaluation unit (62) which is connected to the detection unit (61).

8. Extractor hood according to one of claims 1 to 7, characterized in that the detection unit (61) is connected to a regeneration device (7) for regenerating the sorbent (5).

9. Extractor hood according to claim 8, characterized in that the regeneration device (7) at least one heating element (71) and at least one

Heat distribution means (72).

10. A method for operating a cooker hood (1) comprising a housing (2), at least one fan (3) for conveying the air flow through the extractor hood (1), a sorbent (5) arranged in the air flow for sorbing in the air flow Humidity and a recognition device (6) for detecting the degree of saturation of the sorbent (5), characterized in that a detection unit (61) of the recognition device (6) for detecting the degree of saturation of the sorbent (5) at at least one point in the

Sorbent (5) of the sorption unit (4) measures the temperature (T1, T2, T3).

1 1. A method according to claim 10, characterized in that in dependence on the measured temperature (T1, T2, T3), a control device (62) is driven.

12. The method according to any one of claims 10 or 11, characterized in that at least at two points in the sorbent (5), the temperature of the sorbent (5) is measured.

13. The method according to claim 12, characterized in that a control device (62) in response to the ratio of the at least two measured temperatures (T1, T2, T3) is driven.

14. The method according to any one of claims 10 to 13, characterized in that depending on the measured temperature (T1, T2, T3) a regeneration device (7) is driven.

15. The method according to any one of claims 10 to 14, characterized in that in

Dependence of the measured temperature (T1, T2, T3) a display device (63) is driven.

16. The method according to any one of claims 10 to 15, characterized in that the at least one measured temperature value (T1, T2, T3) before the other

Using the temperature value (T1, T2, T3) a compensation parameter (x) is added.