EP2354349B1 - Device for drying and decontaminating masonry, concrete, wood and other solids - Google Patents

Description

The invention relates to a device for drying and / or decontaminating a solid, preferably masonry, concrete or wood by increasing the temperature of the structure in which the water and / or pollutants are bound. The device has at least one electrode for introducing high-frequency energy, in the region of influence of which the solid to be treated is located at least partially, the electrode being connected to a high-frequency voltage source. The apparatus further comprises a structure having a medium adapted to receive the water and / or the pollutants and control means for monitoring and influencing the drying and / or decontamination process.

The dehumidification of masonry, concrete or wood is a widespread task in the renovation of old and historic buildings, but also in new buildings due to planning and design errors and after unwanted water ingress or water damage. In addition to the prevention of re-entry of water by appropriate structural or other measures, the dehumidification of already soaked materials is an essential task.

For example, the content of pore water in building materials must be reduced as a prerequisite for the introduction of other chemicals that serve to rehabilitate the material. An example of such chemicals are substances that make the building material more hydrophobic and thus less sensitive to water. The agents used preferably contain acrylates, resins, paraffins or siloxanes. Such injection methods are generally only useful if the pore water content has not exceeded a value of 60% of the maximum value or if this value was previously achieved by preparatory measures such as thermal drying.

An alternative possible target parameter for the rehabilitation success is also the achievement of the so-called compensatory moisture, which is an equilibrium value for the respective building material at a corresponding external air humidity and Temperature represents. However, the equilibrium moisture content in particular and the final moisture to be achieved in general are influenced by a number of material, environmental and usage-specific factors. The corresponding values can be found in the relevant specialist literature.

The decontamination of solids, such as masonry, concrete or wood, is necessary when using contaminated materials or external influences, e.g. Disasters of fuel oil tanks or flood damage, pollutants in the solids are present, the concentrations of which require remediation or removal. It is known that a temperature increase can greatly accelerate the release of pollutants such as hydrocarbons by thermal desorption. The reason for this is the advantageous influencing of numerous parameters of the pollutants such as vapor pressure, water solubility, diffusivity or surface tension. Thermal processes for pollutant removal are already established in the field of soil remediation.

Heating and dehydration of wood can also be used to damage or kill wood pests such as dry rot, or to deprive them of their livelihood. In this area too, the choice of the parameters to be set, such as final temperature, duration of heating or residual moisture depends on the concrete problematic case and in particular on the type of wood pests.

There are already a number of methods for masonry drying, which prevent or restrict the transport of water in the relevant areas. The spectrum ranges from invasive procedures, such as the introduction of barrier layers, electrokinetic methods, to methods whose physical mode of action is unknown and whose effectiveness is critical in many cases.

According to the prior art, the dehumidification of masonry can be achieved for example by increasing the temperature by means of infrared radiators. In this case, electromagnetic radiation of a certain frequency or a specific frequency range, in this case in the area of infrared radiation, is directed onto the material. As a result, the surface of the material is heated and Water evaporates in this area, then escapes as water vapor into the room air and must be removed from it. The disadvantage of this method is that only the surface area is heated, since the infrared radiation can not practically penetrate into the material. The temperature inside the material is increased only by heat conduction. As a result, water from this area can be released only very slowly. Also disadvantageous are the large temperature gradients which can lead to damage to the material. Typical plants operating on this principle are designed for wall surfaces of less than 1 m ² .

For the decontamination of components, this technique can be used in an analogous way, if the pollutants pass through the increase in temperature in the gas phase and transported to the surface analogous to water. In the same way, however, the low penetration depths and the corresponding large temperature gradients are also disadvantageous here.

The use of heating rods for drying is technically easier and better to realize and control the positioning of the rods in the inner volume of the component, but the component is mechanically damaged by the introduction of the heating elements. The large temperature gradients in the vicinity of the rod can additionally lead to thermal damage to the material. However, the volume between the heating elements can also be achieved only by heat conduction, ie in an indirect manner. The heating rods currently used have outputs of 100 to 200 W. They are introduced into boreholes of typically 15 to 20 mm in diameter.

While the use of this method is generally associated only with a generally reversible, but significant damage to the masonry, concrete or wood and therefore leads to increased expenses in the course of restoration, the use of heating elements in the conservation area often completely forbids. There, as a rule, non-invasive procedures must be used.

Another non-invasive method for masonry drying is based on the use of microwaves with frequencies in the GHz range. Devices for the treatment of materials are for example in EP 1 374 676 A2 . DE 94 13 736 U1 . EP 0 928 855 A1 and DE 195 44 889 A1 disclosed. The warming is due here to the direct energy coupling into the water molecules or other polar structures in the masonry. However, here too, the penetration depths are relatively low and the heating thus likewise focuses on the surface area of the component. This is associated with the disadvantages already described, ie the formation of high temperature gradients and inhomogeneous dehydration.

It is thus the object of the present invention to provide a device which overcomes the disadvantages of the prior art and can be efficiently thermally dried and / or decontaminated with the solids from materials such as stone, concrete or wood. The device is intended to enable a non-invasive procedure and avoid the formation of local temperature gradients. Furthermore, the device according to the invention should also be suitable for controlling wood pests.

The object of the invention is achieved with a device according to the main claim, advantageous embodiments are described in the subclaims.

According to the invention, a device for drying and / or decontaminating a solid is provided, wherein the solid contains at least one liquid and / or a pollutant, comprising at least one electrode, wherein the solid is at least partially in the sphere of influence of the at least one electrode and wherein the at least one Electrode is connected to a feed means for supplying a high-frequency voltage and a control means and a structure comprising a substance which is adapted to receive the liquid and / or the pollutant, wherein the at least one electrode is designed so that it flows from the substance to be treated Allowed solid to the structure with the receiving substance. The at least one electrode is permeable to the at least one liquid and / or the pollutant, preferably perforated, or a mesh electrode. In a preferred embodiment of the device, this contains at least one temperature sensor suitable for determining the temperature of the solid, the temperature sensor positioned in the solid and with an evaluation unit is connected and / or at least one control means for controlling the feed means for feeding the high-frequency voltage, wherein the control means is connected to the feed means and the evaluation unit for the temperature sensor.

Preferably, the structure is arranged on the second side of the at least one electrode. Preferably, a temperature sensor is arranged on the first side of the at least one electrode.

Preferably, the solid is in particulate form.

Preferably, the temperature sensor is a fiber optic temperature sensor, an infrared sensor or an infrared camera for determining the surface temperature of the solid.

The terms liquid and pollutant are used here and below in summary for water and other substances which may be present in the solid to be treated both in adsorbed and absorbed form and as a liquid phase. For the application of the device according to the invention are given by the nature of the interaction of the substances with the solid no principal limits. The term pollutant is also used in the general form when several pollutants are present as individual substances simultaneously and are to be released by the device.

The device according to the invention is thus a device for dielectric heating. Although similar basic principles as in microwave application, eg orientation polarization of dipole molecules or other polar structures in solids, are relevant for heating, the use of high frequency energy offers the advantage of greater penetration depths for the relevant materials. In this way, practically homogeneous temperature profiles in the masonry or in the solid to be treated can generally be adjusted, which leads to the avoidance of the problems existing in the prior art. Another significant advantage of the device according to the invention is the potential of a non-invasive application, which also opens up the possibility of using valuable historic buildings and generally in the field of historic preservation.

The device according to the invention can therefore always be used when the moisture content and / or the content of pollutants in a solid body are to be reduced efficiently. Preferred solids that can be dried and / or decontaminated with the device according to the invention are textiles, food, wood, building materials, masonry. Under construction material according to the invention preferably sand, clay, gravel, cement, concrete, brick, gypsum, plasterboard or a mixture thereof understood.

The device according to the invention is particularly preferably used for drying and / or decontaminating masonry, building material or wood. In this case, by dielectric heating of the solid whose temperature is increased so far that the water and / or pollutants desorb and / or evaporate and are released from the matrix of the solid. The device can also be used to kill by increasing the temperature and / or dehydration wood pests or worsen the life and development basis permanently.

The device according to the invention has at least one electrode which is connected to a means for supplying a high-frequency voltage. The feed means is preferably a radio frequency (RF) generator. Between the at least one electrode and the RF generator, an electronic matching network is preferably arranged, which allows the adjustment of the variable impedance of the solid, for example, due to fluctuating humidity to the internal resistance of the HF generator. This results in the possibility of a very energy-efficient heating of the solid, since the emitted RF energy can be almost completely converted into process heat. The energy efficiency is therefore significantly increased by the use of the matching network. Continuous regulation of the electronic matching network during the drying and / or decontamination process makes it possible to maintain these favorable conditions even when the moisture content of the material changes. The temperature increase in the material then leads to the mobilization of water and / or pollutants and thus to the desired treatment success.

The device allows different modes of energy input and in particular the heating of the fixed bed and the realization of different temperature profiles. In particular, it is possible to heat the solid homogeneously, with technically relevant volumes can be treated to the cubic meter scale. Preferably, the volume of the solid to be dried and / or decontaminated is in the range of 0.001 to 100 cubic meters, more preferably in the range of 0.1 to 10 cubic meters.

Preferably, the RF generator provides a voltage with a frequency between 500 kHz and 100 MHz, further preferred are frequencies between 1 MHz and 30 MHz. Particularly preferred is the use of frequencies that are approved for use in the industrial, scientific and medical fields. Particularly preferred are the ISM frequencies of about 6.9 MHz, 13.56 MHz or 27 MHz.

The invention at least one electrode has a side which faces the solid to be heated and forms an interface with this. The term "interface" encompasses both the embodiment that the solid and the at least one electrode touch, as well as the configuration that the interface is a layer of a transmission medium, preferably air. In the latter embodiment, the thickness of the layer (transition region) from a transmission medium is limited by the range of the at least one electrode. Small layer thicknesses, i. Distances between electrode and solid in the range of 0.1 to 50 cm are preferred.

Preferably, the at least one electrode is a plate electrode. Plate electrodes are preferably arranged such that the surface of the at least one electrode facing the solid to be treated is aligned parallel or substantially parallel to the solid to be dried and / or decontaminated. By "substantially parallel" is meant according to the invention a mean deviation angle in the range of 0 to 20 °, preferably an angle in the range of 0 to 5 ° and particularly preferably an angle in the range of 0 to 1 °. Preferably, the electrode is oriented so that on uneven surfaces as large as possible amounts of Electrode surface and solid surface are arranged in parallel. Preferably, the electrodes are arranged in parallel, wherein the solid body is located between the electrodes.

The areal extent of the at least one electrode is preferably in the range from 0.1 to 10 m ² and particularly preferably in the range from 0.5 to 2 m ² .

The at least one electrode is permeable to the at least one liquid and / or the pollutant. The embodiments are particularly preferred as a perforated electrode or as a mesh electrode. By a permeable design ensures that the water and / or the at least one pollutant escape from the solid and then can be removed from the surface of the solid.

In a further preferred embodiment, the device according to the invention has two electrodes. Preferably, one of the two electrodes is a cold electrode and one of the two electrodes is a hot electrode. In this case, the electrode which is grounded is defined as the cold electrode. In a particularly preferred embodiment, the cold electrode is electrically conductively connected to the housings of the HF generator and the electronic matching network.

In a particularly preferred embodiment of the invention, parallel plate electrodes are used. Parallel plate electrodes ensure a temperature profile with small gradients for homogeneous solids and are thus best suited for homogeneous heating. Preferably, both electrodes each have an interface with the solid (solid).

In a preferred embodiment of the device, the electrodes are arranged such that the surfaces of the plate electrodes form a common interface with the solid, wherein the electrodes are arranged side by side electrically isolated from each other and the common interface is a flat surface. In this arrangement, the electrodes are on the same side of the solid. This arrangement is particularly suitable when the total expansion of the solid is greater than the range of influence of the one or more electrodes. Then, the device according to the invention can be moved along the solid and the drying and / or

Decontamination is carried out sequentially. Preferred solids that are dried with this electrode assembly are structures and masonry.

Alternatively, the electrodes are preferably arranged in parallel so that the solid is between the electrodes. This arrangement is particularly suitable for solid bodies, the spatial extent of which lies at least in one dimension within the influence range of the two electrodes at the present electrode spacing. This arrangement is suitable for example in wood, with a wooden beam is then positioned between the electrodes. If the beam is longer than the electrodes are wide, the device is moved along the beam and the drying and / or decontamination is also performed sequentially. The choice of the electrode geometry, of which further variants are possible, is determined by the requirements of the respective process (arrangement of the solid to be treated in a structure such as a building, necessary temperature homogeneity, mechanical requirements on the arrangement, heating rates to be achieved, etc.). and may optionally be optimized by the skilled person.

In a further embodiment of the invention more than two electrodes are provided, which are fed with a high-frequency AC voltage. Preferably, one hot and a plurality of cold electrodes are provided.

In a further embodiment of the device, the solid to be treated is passed through the area of action of the at least one electrode. In this case, preferably conveying devices such as belts can be used as mechanical aids. Optionally, the solid, for example a building material or natural mineral substance, is brought before the treatment in a form which allows the described mode of promotion by the influence of the at least one electrode.

The device according to the invention has, in spatial proximity to the at least one electrode for dielectric heating, a structure with a substance which absorbs the released water and / or the at least one released pollutant. This substance is generically called Adsorbermaterial and may be in solid, liquid or gaseous form. The positioning of a suitable adsorber material in the vicinity of the at least one electrode allows an effective discharge of the problem substances by their rapid absorption into the adsorbent material and the initiation of advantageous concentration gradients.

The material transport between the solid to be treated and the adsorber material can be mediated in one embodiment of the device by an active gas flow, which allows an improved, convective transport of the released water and / or the liberated at least one pollutant.

The material to be removed from the solid is preferably a substance which is in the pure phase at ambient temperature as a liquid. Liquids which are removed according to the invention are preferably water and pollutants with different chemical, physical and toxicological properties. Contaminants which may preferably be removed from the solid with the apparatus of the present invention are preferably hydrocarbons or halogenated hydrocarbons, more preferably mineral oil hydrocarbons, organic solvents, paint ingredients, flame retardants, wood preservatives and other substances used to protect building materials against pests.

In a preferred embodiment, the structure with the adsorbing substance is a hollow body with the outer shape of a cylinder or cuboid. However, the invention is fundamentally not bound to any particular form of structure, any other geometries are possible without the functionality of the arrangements would be limited. Advantageously, the container is permeable to the liquids or pollutants to be adsorbed. Alternatively, the container has openings through which the water and / or pollutants can enter. Most preferably, the container is a mesh container, i. a cage, wherein the holes in the grid are chosen such that the adsorbent material remains in the container.

In a preferred embodiment of the invention, the substance contained in the container is an adsorbing material, preferably a porous material, such as a suitable γ-alumina, silica gel, Activated carbon, a zeolite or a mixture of these materials. Particularly preferred in the case of drying a solid is a hydrophilic zeolite, in particular an A, X or Y zeolite. For nonpolar or slightly polar organic pollutants, hydrophobic zeolites or activated carbon are preferably to be used as adsorbent materials. Particularly preferred is a dealuminated Y zeolite with a high Si / Al ratio. In the search for suitable Adsorbermedien can be used in the prior art.

The adsorbents used preferably have a high porosity with large specific surface areas of preferably more than 100 m ² / g, more preferably more than 250 m ² / g and even more preferably more than 500 m ² / g. In many cases, a binder is added to these materials before pressing in order to achieve better mechanical stability. In the following, however, these mixed materials are referred to simply as the adsorption-active component.

In the context of a modular device according to the invention, a component for eliminating the pollutants released from the solid can be used. The supply of the desorbed pollutants to the corresponding component can preferably again be effected by a gas stream. In a further advantageous embodiment of the device, the use of an additional catalyst component in the adsorbent material is advantageous. The catalysts used are, for example, metals, preferably platinum, palladium or other transition metals or noble metals, or perovskite. The catalytically active noble metals are preferably applied to porous support materials. These porous materials typically have porosities between 0.2 and 0.7.

The substance which is used as an adsorber and / or as a catalyst is in particular a granulate or other bulk material, wherein the grain diameters are preferably in the millimeter range. Particularly suitable according to the invention are particle sizes in the range from 0.1 to 10 mm, preferably from 1 to 5 mm, more preferably from 1 to 3 mm.

Preferably, the bulk material is arranged in a container, particularly preferably in a cage-like container.

The arrangement preferably contains at least one temperature sensor which is suitable for determining its temperature during the dielectric heating of the solid. Preferably, this is a fiber optic temperature sensor, which can be used under the present conditions of an electromagnetic field and thus allows a continuous measurement during operation of the device. The temperature sensor is preferably arranged directly in the volume of the solid. Particularly preferred is the use of multiple temperature sensors that allow the detection of a representative three-dimensional temperature profile in the solid.

In a further preferred embodiment, the device has further sensors that allow the analysis of water and / or pollutants. The other sensors are preferably also connected to an evaluation unit. In this embodiment, it is advantageously possible to register the water and / or pollutant discharge from the solid and to tune the dielectric heating to this data. In particular, it can be easily determined when the dielectric heating can be stopped.

The device according to the invention also contains, in a preferred variant, a control means for controlling the HF generator, the control means being connected to the HF generator and preferably to the temperature sensor. This ensures that the dielectric heating is adapted to the temperature in the solid state and, for example, local overheating can be avoided. Preferably, the control means is a personal computer (PC) or similar electronic control unit with process control system.

In a further embodiment of the invention, the device has a means for determining the Baldung the adsorbent substance with respect to the liquid and / or the pollutant. This can advantageously be ensured that there is always sufficient adsorber for receiving the water and / or the pollutant available and the water and / or the pollutant from the Ambient air are removed. The determining means preferably has a sensor and an alarm system, which indicates the loading state when a predetermined limit value is exceeded and recommends an exchange of the adsorbent material.

Advantageously, the device according to the invention also includes means for reusing the adsorption and / or reaction heat of the released substances in their interaction with the adsorber material and the elevated temperature of the gas stream directed away from the heated solid to heat the solid. This can be, for example, heat exchangers of different types.

It should be understood that this invention is not limited to the specific devices, compositions, and conditions described herein as they may vary. It is further understood that the terminology used herein is for the sole purpose of describing particular embodiments and is not intended to limit the scope of the invention. As used herein in the specification including the appended claims, word forms in the singular, such as words, include For example, "a", "an", "an", "the", "the" or "the" may be equivalents in the plural unless the context clearly dictates otherwise.

Fig. 1

eine erfindungsgemäße Vorrichtung bei der ein Festkörper 12 zwischen zwei Elektroden 14, 16 angeordnet ist;

Fig. 2

eine erfindungsgemäße Vorrichtung bei der zwei Elektroden 14, 16 parallel auf einer Seite eines Festkörpers 12 angeordnet sind;

Fig. 3

Temperaturprofile in einem Festkörper 12 in einer mittleren Ebene bei verschiedenen Temperaturen gemäß Beispiel 1;

Fig. 4

die Abnahme des normierten Wasseranteils im Verlaufe der Zeit und mit steigender Temperatur in einem Festkörper 12 gemäß Beispiel 1;

Fig. 5

Temperaturprofile in einem Festkörper 12 in einer mittleren Ebene bei verschiedenen Temperaturen gemäß Beispiel 2;

Fig. 6

die Abnahme des normierten Wasseranteils im Verlaufe der Zeit und mit steigender Temperatur in einem Festkörper 12 gemäß Beispiel 2;

Fig. 7

Adsorptionsisothermen von Wasser an drei verschiedenen Substanzen 22; und

Fig. 8

eine erfindungsgemäße Vorrichtung mit einer Fördereinrichtung für den Feststoff 12 zwischen den Elektroden 14, 16.

In the following, the invention will be described by way of example with reference to figures and exemplary embodiments. Show it:

Fig. 1

a device according to the invention in which a solid body 12 between two electrodes 14, 16 is arranged;

Fig. 2

a device according to the invention in which two electrodes 14, 16 are arranged in parallel on one side of a solid 12;

Fig. 3

Temperature profiles in a solid 12 in a middle plane at different temperatures according to Example 1;

Fig. 4

the decrease in the normalized water content over time and with increasing temperature in a solid 12 according to Example 1;

Fig. 5

Temperature profiles in a solid 12 in a middle plane at different temperatures according to Example 2;

Fig. 6

the decrease in the normalized water content over time and with increasing temperature in a solid 12 according to Example 2;

Fig. 7

Adsorption isotherms of water on three different substances 22; and

Fig. 8

a device according to the invention with a conveying device for the solid material 12 between the electrodes 14, 16.

Fig. 1 shows a device according to the invention in which a solid body 12 between two plate electrodes 14, 16 is arranged. Thus, the solid body 12 is at least partially in the influence of the electrodes 14, 16. The two electrodes 14, 16 each have a first side 15 and a second side 17, wherein the first side 15 forms an interface 20 with the solid 12. On the second side 17 of at least one electrode 16, a container 34 is arranged, which is filled with an adsorbing substance 22. Preferably, at least the electrode 16 is perforated, designed as a mesh electrode or otherwise permeable to gas.

The adsorbing substance 22 is suitable for adsorbing a liquid 10 and / or a pollutant 11 which has been released from the solid 12 by the dielectric heating of the solid 12, which in turn is realized by means of the electrodes 14, 16. The adsorbent 22 is here in particle form with a grain size of about 3 mm as a bed in the container 34 before. The container 34 is designed as a cage-like container 34 (also referred to as a structure), so that the liquid 10 and / or the pollutant 11 can easily flow into the container 34 and is then adsorbed by the adsorbent 22. Inside the container 34, a means 36 for determining the loading state of the adsorbent 22 with the liquid 10 and / or the pollutant 11 is arranged. After exceeding a predetermined threshold value, a signal indicating that the adsorbent 22 must be replaced is sent by the determination means 36. This is always a sufficient amount of unloaded or not fully loaded adsorbent 22 is present.

In the solid body 12 fiber optic temperature sensors 24 are arranged, which are connected to an evaluation unit 26. The temperature sensors 24 monitor the temperature of the solid 12 during the dielectric heating so that the process is monitored and, for example, local overheating is avoided. Advantageously, further sensors 28 are provided which register the degree of humidity or the state of contamination of the solid 12 or also the temperature at additional measuring points. The further sensors 28 are likewise connected to the evaluation unit 26 or optionally to another evaluation unit.

The electrodes 14, 16 are connected via an electronic matching network 32 to a means 18 for supplying high-frequency voltage. The feed means 18 is preferably an HF generator. With the help of an electronic matching network 32, the internal resistance of the HF generator 18 and the variable impedance of the solid 12 are matched due to the changing temperature and fluctuating moisture and / or pollutant content. The control of the device is carried out by means of a control means 30. The control means 30 is preferably a personal computer (PC) with process control system, which is connected to the RF generator 18 and the evaluation unit 26.

Fig. 2 shows an alternative arrangement of the device according to the invention. Reference numerals apply analogously. The plate electrodes 14, 16 are arranged side by side in a plane in this embodiment. At least one of the electrodes 14, 16 is perforated, designed as a mesh electrode or otherwise permeable to gas. The first side 15 of the plate electrodes 14, 16 faces towards the solid 12 and forms the interface 20 (not shown). On the second side 17 of the electrodes 14, 16, the cage-like container 34 is arranged with the adsorbent 22. The adsorbent 22 is suitable for adsorbing the liquid 10 and / or the pollutant 11. The temperature of the solid 12 is monitored by temperature sensors 24 and the data becomes passed from an evaluation unit 26 to the PC with process control technology 30. Preferably, further sensors 28 are provided which monitor temperatures or the moisture content and / or pollutant content 11 of the solid 12 and also pass on the data via the evaluation unit 26 to the PC 30 with process control technology. The PC controls the RF generator 18 and thus the dielectric heating, wherein via an electronic matching network 32 an optimal energy transfer from the RF generator 18 to the solid body 12 is realized with changing humidity.

The electrode shape and arrangement can be varied for the many possible uses of the device according to the invention so that even complicated-shaped components and wooden structures can be effectively heated. The device is preferably designed so that the most homogeneous possible energy input into the solid 12 can be realized and thus a temperature profile with low gradients arises. In principle, the arrangements for the applications drying, decontamination and pest control are not significantly different.

example 1

The device according to the invention was tested on a solid block 12 (50 cm × 50 cm × 20 cm) of sandstone having an initial moisture content of about 4.5% by weight. The stone block 12 was provided on both sides with massive plate electrodes 14, 16 of copper sheet. These contained on one side holes (diameter about 5 mm) for the implementation of fiber optic temperature sensors 24, with which the temperature profile in stone block 12 could be continuously monitored. For dielectric heating, an HF generator 18 with a maximum power of 5 kW and a constant operating frequency of 13.56 MHz was used. The continuously introduced during the heating phase RF power was 1.3 kW. After reaching an average temperature of 105 ° C, this was kept constant by the power was only temporarily introduced. As the adsorbing substance 22 in the container 34, a bed of zeolite 13X having an average grain size of 3 mm was used.

The temperature profiles in a middle level in the stone block are in Fig. 3 presented for different phases of the experiment. The occurring at higher temperatures to the edge of the stone 12 towards temperature gradients are mainly due to the lack of thermal insulation. During the heating, the weight of the stone 12 positioned on a scale was continuously determined. Fig. 4 Figure 12 shows the decrease in normalized water content, measured as weight loss due to drying, in correlation with the average temperature of stone 12 during drying. In the course of the experiment, a degree of drying of about 94% was achieved. It should be noted that the final moisture reached may not correspond to the equilibrium moisture content, which should be aimed for in a practical application. In order to avoid damage to the material, it may then be desirable to lower the discharge of water and the drying would therefore rather be stopped. As expected, when the temperature reached 100 ° C. in the solid-state block 12, a significant increase in the water discharge rate by about a factor of 4 was recorded. The energy efficiency, ie the efficiency of the conversion of HF energy into heat in sandstone 12 was 91% in this experiment. Improved thermal insulation could increase this value.

Example 2

In Example 2, a solid body 12 of the same material as in Example 1 with the aid of grid electrodes 14, 16 was dried with the device according to the invention. The grid electrodes 14, 16 were designed as a stainless steel mesh with a mesh size of about 6 mm. This design of the electrodes 14, 16 offers greater flexibility in practical use and can be adapted to the outer shape of the solid 12 easier. The HF heating and the measured value acquisition were carried out analogously to Example 1. The power input was 1.6 kW. Fig. 5 shows the temperature profiles at different times of the experiment at a middle level in the solid 12. Fig. 6 represents the course of the drying of the stone block 12 with the development of the mean temperature during the experiment. The achieved degree of drying was about 91% and the energy efficiency, ie the efficiency, was 89%. Both values are for this Electrode shape in the same range as for solid copper electrodes, which emphasizes the flexibility in terms of electrode design.

The potential of using various adsorbent materials 22 to bind the water 10 removed from the masonry or other solid 12 (as demonstrated in Examples 1 and 2) is disclosed in U.S. Patent Nos. 3,846,066 Fig. 7 illustrated. Here, the equilibrium adsorption of water on three different zeolites of the type 3A, 5A and 13X is given for different water partial pressures. Water adsorption is given in milliliters of water per gram of adsorbent material. Such curves are referred to as adsorption isotherms and can be found in the literature for the binding capacity of organic pollutants 11 to zeolites or other potential Adsorbermaterialien 22 such as activated carbon or silica gels. Depending on the application of the device according to the invention, the person skilled in the art can then select the adsorptive substance 22 accordingly.

In Fig. 8 a variant of the device according to the invention is shown, in which the material to be treated 12 is moved by means of a conveyor 40 between the electrodes 14, 16 such that the material 12 is at least temporarily in the range of action of the at least one electrode 14, 16. Preferably, the material is applied to the conveyor 40 before treatment by means of a suitable, particularly preferably funnel-shaped device 50. The collection of the material 12 after treatment with a corresponding device 52 is preferred. In a preferred variant, the surface temperature of the material 14 is preferably measured continuously by means of a sensor 46. Preferably, the material 14 is flowed through during the movement by means of the conveyor 40 by a gas flow 42 such that the released substances 10, 12 are received by this. The sensor is preferably connected to an evaluation unit 26. The feed of the RF energy is, as in the other variants by an RF voltage source 18, which is preferably connected via an electronic matching network 32 to the electrodes 14, 16 realized. The conveyor 40 is preferably at least partially perforated for the flow. In a particularly preferred variant, the gas stream 42 flows through after receiving the components 10, 12 a solid 22 located in a suitable at least partially open container 34. Preferably, the material for receiving the released substances 22 also has a component 44 which, under suitable boundary conditions (eg temperature), is able to render pollutants 11 harmless.

LIST OF REFERENCE NUMBERS

10

Water (liquid)

11

pollutant

12

Solid / solid

14, 16

electrode

15

first page

17

second page

18

Means for feeding RF energy

20

Interface / transition area

22

Substance for receiving released liquid / pollutant

24

temperature sensor

26

evaluation

28

Liquid / pollutant or temperature sensors

30

control means

32

electronic matching network

34

Container / structure

36

Means for determining adsorber loading

40

Conveyor

42

gas flow

44

Agent for reactive gas purification

46

Infrared sensor / infrared camera

50

Means for dispensing the material to be treated

52

Means for collecting the treated material

Claims (13)

1. Device for drying and/or decontaminating a solid (12), which contains at least one fluid (10) and/or one hazardous substance (11),
   comprising

   - at least one electrode (14, 16) comprising a first side (15) and a second side (17), wherein the first side (15) is exposed and forms an outer part of the device, and the at least one electrode (14, 16) is connected to a supply means (18) for supplying a high-frequency voltage,

   - a structure (34) comprising a substance (22), which is suitable for holding a fluid (10) and/or a hazardous substance (11), wherein the structure (34) is arranged and designed in such a manner that the substance flow from the solid substance (12) to be treated to the structure (34) is permitted,

   - at least one control means (30) for controlling the supply means (18) for supplying the high-frequency voltage, wherein the control means (30) is connected to the supply means (18),

   characterized in that
   the at least one electrode (14, 16) for the at least one fluid (10) and/or the hazardous substance (11) is designed to be permeable, preferably perforated, or is a mesh electrode.
2. Device according to Claim 1, characterized in that in addition, at least one temperature sensor (24) is provided, which is suitable for determining the temperature of the solid (12), wherein the temperature sensor (24) is connected to an evaluation unit (26).
3. Device according to any of the preceding claims, characterized in that the solid (12) is a textile, a foodstuff, a construction material, wood, sand, loam, gravel, cement, concrete, brick, plaster, gypsum board, a mixture of the above materials, masonry or another at least partially mineral material.
4. Device according to any of the preceding claims, characterized in that a transport facility (40) for guiding through the solid (12), which is preferably present in particular form, is provided between the electrodes (14, 16).
5. Device according to any of the preceding claims, characterized in that means for generating an additional gas flow (42) and for removing the substances (10, 11) released from the solid (12) are provided and/or that the hazardous substances (11) released from the solid (12) are added to means for reactive gas purification (44).
6. Device according to any of the preceding claims, characterized in that the fluid (10) is an organic or anorganic solvent, preferably an organic or anorganic polar solvent, particularly preferably, water and/or that the hazardous substance (11) is a hydrocarbon or a halogenated hydrocarbon, preferably a mineral oil hydrocarbon, an organic solvent, an element of paint substances, flame inhibitor, wood protection agent and other substances which serve to protect construction materials against pests, or a mixture of at least two of these components.
7. Device according to any of the preceding claims, characterized in that the substance (22) is an adsorbent material, preferably a porous material, in particular a γ-aluminium oxide, silica gel, activated carbon, a zeolite or a mixture of these, particularly preferably a hydrophile zeolite, in particular an NaY-, NaX-, KA-, NaA- or CaA- zeolite or a hydrophobic zeolite, preferably a de-aluminized Y-zeolite with a high Si/AI ratio.
8. Device according to any of the preceding claims, characterized in that the at least one electrode (14, 16) comprises a spatial expansion in the range of 0.1 to 10 m², particularly preferably 0.5 to 2 m².
9. Device according to any of the preceding claims, characterized in that the at least one electrode (14, 16) is a plate electrode.
10. Device according to any of the preceding claims, characterized in that the device comprises two electrodes (14, 16), wherein preferably, one of the two electrodes (14, 16) is a cold, grounded electrode (14) and one of the two electrodes (14, 16) is a hot electrode (16).
11. Device according to Claim 10, characterized in that the electrodes (14, 16) are arranged adjacent to each other, wherein the first sides (15) of the electrodes (14, 16) lie in one plane and the electrodes (14, 16) are arranged on the same side of the solid (12).
12. Device according to any of the preceding claims, characterized in that an electronic matching network (32) is arranged between the supply means (18) for supplying a high-frequency voltage and the at least one electrode (14, 16).
13. Device according to any of the preceding claims, characterized in that the device comprises determination means (36) for determining the loading of the substance (22) in relation to the fluid (10) and/or the hazardous substance (11) and/or that a heat exchanger for using the energy of the removed gas flow (42) and/or the adsorption and/or reaction heat during the interaction with the adsorbing substance (22) or a catalyst for heating the solid (12) is provided.

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