Device and method for pre-damaging rock

Abstract

The invention relates to a device for pre-damaging rock, comprising at least one microwave generator and at least one antenna unit (200) for introducing the microwaves into the rock (140), said antenna unit being connected to the at least one microwave generator (240) in a wave-conducting manner, wherein the microwave generator (240) is designed to generate microwaves having at least one wavelength, and the antenna unit (200) has at least two antennas (210). According to the invention, the at least two antennas (210) are arranged at an antenna distance (d) from one another such that the microwaves are constructively superimposed in the rock (140) such that at least one main power lobe (220) is formed in the rock (140) with the superimposition of the emitted microwaves, wherein the antenna distance (d) is dependent on the wavelength of the microwave generated by the microwave generator (240) in that the antenna distance (d) = m * the generated wavelength.

Description

[0001] Device and method for pre-damaging rock

[0002] The invention relates to a device for pre-damaging rock, comprising at least one microwave generator and at least one antenna unit for introducing microwaves into the rock, which is connected to the microwave generator in a wave-conducting manner, wherein the microwave generator is configured to generate microwaves of at least one wavelength, and wherein the antenna unit comprises at least two antennas, as well as a device for excavating a cavity with a device for pre-damaging rock. The invention further relates to a method for pre-damaging rock.

[0003] Microwaves is a common name for electromagnetic waves, for example, with a frequency of 1 to 300 GHz, which corresponds to a wavelength of approximately 30 cm to 1 mm. Microwaves are electromagnetic waves generated by a microwave generator / microwave source (these terms are used synonymously in this application). They can be reflected, refracted, and interfere with each other.

[0004] Due to their wavelength, microwaves are particularly well-suited for exciting dipole and multipole vibrations in molecules. This effect is especially evident in the vibrational excitation of water molecules in a microwave oven. The heating of water is not based on absorption at a specific resonant frequency, but rather the water molecules, as dipoles, constantly align themselves with the alternating electromagnetic field, generating heat through dielectric loss. The dielectric loss factor, the specific electrical resistance, and magnetic losses determine the frequency-dependent absorption of microwaves by or in materials, and thus their heating. The penetration depth and absorption of microwaves in a material depend on the frequency and wavelength of the microwaves.

[0005] When rock is irradiated with microwaves, the microwaves propagate through the material and are absorbed depending on the frequency and rock properties (for example, the rock's permittivity). As the microwaves penetrate the rock, they excite vibrations at the molecular level, thereby generating heat.

[0006] Microwave pretreatment is based on dielectric heating, the generation of thermal stresses, and the resulting rock fracture. The dominant effect is so-called "global damage" in the form of large cracks caused by the volumetric expansion of the irradiated rock mass. The rock is a dielectric material in this process.

[0007] It is generally known that when loosening rock (in this disclosure, rock is always used synonymously with soil), for example, when driving a tunnel or shaft, or in mining when extracting valuable minerals or driving roadways in mines, the loosening process can be carried out with less wear by weakening / pre-damaging the rock ("weakened" and "pre-damaged" are used synonymously in this disclosure). One way to achieve this weakening / pre-damaging is to introduce microwaves into the rock, thereby heating it intensely.

[0008] It is known from the prior art that after the introduction of microwaves to further weaken the rock, an additional cooling step can be carried out by applying a cooling medium such as water to quench the rock. However, it has been shown that the cooling itself offers no additional benefit in terms of weakening the rock and only creates additional problems, for example, when extracting the rock, especially in dry mining operations, or incurs costs without achieving any significant advantage in rock extraction.

[0009] ON 107218054A, for example, discloses a partial-face cutting machine in which a microwave device is provided on the pivoting arm. This device heats and weakens the rock in a separate operation by introducing microwaves. The microwave device has an antenna and is entirely mounted on the pivoting arm. The microwave device is equipped with a movement mechanism on the pivoting arm that allows the antenna to be moved section by section across the tunnel face while the cutting process is stopped. The heated and weakened area is then removed by the cutting tool. The next section is then accessed and heated with the antenna while the cutting process is again stopped. In this way, the entire tunnel face is successively treated and subsequently cut away.

[0010] JPS4742085Y1 discloses a tunnel boring machine with a backhoe as the excavation tool. Also disclosed is a microwave device consisting of a microwave generator, a waveguide, and a microwave output device connected to the waveguide. The microwave output device is mounted on an arm consisting of two rotatably connected arm sections. The arm is mounted on the tunnel boring machine via a horizontal rotary element, allowing it to rotate horizontally relative to the machine. Furthermore, the arm sections have hydraulic cylinders that allow the microwave output device to be moved up and down. The microwave device is also pivoted to the right and left via the rotary element.

[0011] JPS4813660B1 shows a horizontal tunnel boring machine with a horseshoe-shaped shield connected to it. The tunnel boring machine can be moved via crawler tracks. It has a roller mounted on an arm that can pivot and is capable of both lateral and penetrating excavation. The device also features a microwave antenna mounted on an arm consisting of three parts, which can be raised, lowered, or tilted via hydraulic cylinders, but cannot be pivoted. The excavation tool is pivotally mounted on an arm, which in turn can be pivoted in a plane via a hydraulic cylinder. Both arms are fixed to a rotary element, which allows the pivot plane of the excavation tool to be rotated.Regarding the mechanism of action, JPS4813660B1 states that when rock is irradiated with microwaves, the moisture within the rock (water of crystallization and free water of the rock component) absorbs the microwave energy, and the temperature rises. This thermal stress and thermal transformation makes the rock brittle.

[0012] JPH06264689A discloses a tunnel construction method in which the tunnel face is heated and crushed exclusively using microwaves. Electromagnetic waves of a specific frequency are set into oscillation by means of an oscillator, and these oscillating waves are applied to a rock mass via an antenna to erode the rock mass. When the electromagnetic waves of a specific frequency, oscillated by the antenna, act on the rock mass, the molecules of the rock mass's components vibrate, generating heat within the rock mass through dielectric loss. This heat generation leads to a rapid temperature increase at the rock's surface. However, the heat generation decreases with increasing depth within the rock.This temperature change leads to thermal stresses in the near-surface rock mass, causing cracks that divide into finer fractures, thus fracturing the rock mass. The antenna is disclosed as an aperture radiator or as a group of several antennas. It is further disclosed that the microwave frequency is tuned to the resonant frequency of the rock being mined, and the oscillator is adjusted accordingly by the operator. A magnetron or a klystron is disclosed as the oscillator. The connection between the oscillator and the antenna is made via a waveguide. The antenna is mounted on a movable arm, which can be positioned to irradiate the entire mine face. An operator in the control room monitors the rock, operates the control handle of the boom arm, and positions the antenna on the rock to be irradiated with electromagnetic waves.Furthermore, shielding is provided between the operator and the antenna. JPH06264689A thus discloses the introduction of microwaves into the surface of the rock to loosen it.

[0013] CN108060927A shows a device for breaking up boulders in the path of a tunnel bore. A first drilling rig bores a hole into the boulder. A microwave emitter is then inserted into the borehole, and the hole is sealed with a cover. The microwave emitter heats the stone to temperatures of, for example, 600°C. A waterjet cutter is then inserted into the borehole, which simultaneously cuts and cools the boulder, further breaking it down through thermal stress.

[0014] US2023194386A1 and DE212021000274U1 disclose a test rig for rock loosening, for example, for tunnel construction in conjunction with microwave irradiation of the tunnel face, whereby the rock is loosened in a full-face cut using a rotating cutting wheel. Several individual antennas are provided on the circumference of the cutting wheel, which can irradiate the rock when stationary or rotating.

[0015] DE102022101731A1 discloses a device for sinking a shaft with at least one mining device for extracting rock from a shaft bottom, wherein the at least one mining device comprises at least one mining tool arranged on at least one pivot arm movable relative to the shaft bottom, and wherein the device comprises at least one device for generating and emitting microwaves into the rock of the shaft bottom, which has at least one applicator for introducing the microwaves into the rock, which is movable relative to the shaft bottom. According to the invention, the applicator is arranged separately from the at least one pivot arm of the mining tool relative to the shaft bottom.

[0016] DE102023119717A1 discloses a device for creating a cavity in the ground with at least one excavation tool for loosening rock or soil from a surface to be removed in the cavity to be created, wherein the at least one excavation tool for loosening the rock is arranged on at least one pivot arm movable relative to the surface, and wherein the device has at least one microwave device for generating and emitting microwaves into the rock of the surface, which has at least one applicator for introducing the microwaves into the rock, and wherein the at least one applicator is movable relative to the surface separately from the excavation tool relative to the surface to be removed, characterized in that the at least one applicator is connected to a movement element that is movable on a guide.so that at least one applicator on the guide around the mining tool can be moved separately from the movement of the mining tool.

[0017] EP1471773A2 discloses distributed high-power solid-state microwave sources designed to improve the efficiency of microwave heating applications. A multitude of solid-state microwave sources are distributed around and / or adjacent to a chamber within a microwave environment, with the microwave power of the solid-state microwave sources directed towards the chamber. The distribution of the multitude of solid-state microwave devices can be adapted to the specific size and shape of the microwave chamber and / or to specific regions / compartments within the microwave chamber. Rock damage is not disclosed.

[0018] DE102012100591A1 builds upon EP1471773A2 and discloses an arrangement and a method for heating media using microwave radiation in a working chamber, a chamber consisting of metal walls. A signal is generated by means of a tunable generator, applied to a number of radiation sources, and emitted as microwave radiation into a working chamber. The radiation sources each comprise at least one power amplifier, a waveguide, and a measuring device for acquiring measurement data. Measurement data, which is mandatory in each radiation source and optional in the working chamber and connected to a control system, can be acquired and evaluated by means of the measuring devices, which are mandatory in each radiation source and optional in the working chamber. This data serves to individually control at least the power amplifiers. The arrangement and method according to the invention also make it possible to investigate the behavior of a medium when heated by microwave radiation.The damage to rock is not apparent.

[0019] U S20180361348A1 discloses a microwave treatment device, for example for treating the human body, comprising an irradiation section that performs microwave irradiation from multiple emitting sections; a movement section that moves the multiple emitting sections individually; and a control section that controls the movements of the emitting sections through the movement section, wherein the phases of the microwaves emitted by the multiple emitting sections are variable, and the control section controls the phases of the microwaves emitted by the multiple emitting sections from the irradiation section. The emitting sections are arranged around the target object. The damaging of rock is not disclosed.

[0020] The methods known from the prior art can be summarized as follows, using Fig. 1. Microwaves (6) are introduced into the rock to be damaged by an antenna (3) or a plurality of antennas. A microwave source (1) is provided for generating the microwaves (6), optionally one for each antenna. This source is conductively connected to an antenna / applicator (3) (these terms are used synonymously in this disclosure) via a hollow waveguide (2). This waveguide can be a waveguide or a horn antenna. To minimize free-space propagation losses and to optimize power coupling, the antenna (3) is positioned a short distance of a few millimeters (e.g., 50–100 mm, depending on the frequency used and the antenna design) from the rock (5). After coupling, the propagation (5) of the microwaves (6) in the rock (4) is isotropic (hemispherical) from the coupling point.This behavior is due to physical limitations and can only be influenced to a limited extent by the geometry of the antenna (3). If necessary, more than one antenna (3) is used (for example, US2023194386A1). In this case, a splitter may also be used.

[0021] Applicators / antennas are generally known as horn antennas, standard waveguides, and convergent waveguides. These suffer from the problem that the highest power density—and thus the greatest heating—occurs in the near-surface rock layers of the rock being damaged and decreases exponentially with penetration depth. The heated rock volume at the surface can expand towards the applicator, therefore causing only minor damage to the rock. The geometry of a single antenna can only influence the temperature distribution in the rock in its immediate vicinity. Furthermore, practical performance limitations exist due to reduced dielectric strength in humid and dusty environments, which significantly restricts the power input and the rate of pretreatment.

[0022] Furthermore, to pre-damage a larger area, such as the tunnel face in mining or tunneling applications, it is necessary to mechanically guide the antenna across the surface. This is technically complex, as the power supply, due to the high power levels, typically requires hollow waveguides, which necessitate complicated and potentially fragile joint technology. Alternatively, the entire microwave source could be moved, but this is currently impractical due to its size and complexity. Moreover, the microwave power inevitably penetrates the near-surface rock layers in front of the antenna as it travels into the material. A significant portion of the power is absorbed there, resulting in a large part of the thermal effect occurring near the surface.

[0023] The object of the invention is to improve the pre-damaging of rock by introducing microwaves.

[0024] The problem is solved according to the invention in that the at least two antennas are arranged with an antenna distance from each other, so that the microwaves in the rock constructively superimpose, so that at least one main power lobe is formed with the superposition of the emitted microwaves in the rock, wherein the antenna distance (d) depends on the wavelength of the microwave generated by the microwave generator, in that the antenna distance (d) = m * the generated wavelength.

[0025] For the sake of clarity, the distance in this revelation is understood here as the distance between the centers of the antennas. Furthermore, in this revelation, main lobe, main power lobe, and main signal lobe are considered synonymous.

[0026] Surprisingly, it has been shown that for maximum efficiency in rock weakening, a small volume within the rock, especially deep below the rock surface, must be heated as intensely as possible in order to generate the highest possible temperature differences with minimal energy expenditure, leading to a weakening of the rock.

[0027] It has also been surprisingly shown that deep-lying rock volumes can be heated in this way. Furthermore, it has been surprisingly shown that this is easily possible with the inventive setup, namely that the microwaves emitted by the at least two antennas can be focused into a main beam, for example by means of the so-called "beamforming" process, by the emitted microwaves superimposing constructively and destructively to achieve the aforementioned effect. The main beam preferably has a focal point (a power range) and a direction where the greatest effect of the superimposed microwaves occurs.

[0028] Surprisingly, it has been shown that the individual microwaves superimpose constructively and destructively in the antenna unit, defined by the antenna spacing, resulting in a directional effect of the combined electromagnetic field emitted by the antenna unit, particularly in deeper rock below the surface.

[0029] A further aspect of the invention provides that the antenna unit has more than two antennas, which have an antenna spacing from the adjacent antennas. This allows the structural superposition to be improved.

[0030] A further aspect of the invention provides that the antennas of the antenna unit are arranged in a two- or three-dimensional configuration, preferably linear, circular, or square. It is advantageous that no antenna is provided in the center of the antenna unit. This improves the structural overlap.

[0031] A further teaching of the invention provides that m is in a range of values ​​from 0.2 to 1.2, preferably in a range of values ​​from 0.25 to 1.0, or substantially 0.25, or particularly preferably in a range of values ​​from 0.4 to 0.6, or from 0.45 to 0.55, or substantially 0.5. It has surprisingly been found that the constructive overlap is improved in this range, particularly in the range around 0.5, or, depending on the rock to be weakened, also in the range around 0.25 and 0.75.

[0032] Another teaching of the invention provides that m > 2. This can be advantageous if adjustments in the phases of the microwaves are also provided.

[0033] A further aspect of the invention provides for a control system with which the frequency, amplitude, and / or phase of the microwaves emitted by the antenna can be adjusted. Preferably, this is achieved by the control system controlling the microwave generator. The main power beam is steered by actively adjusting the phase and / or amplitude of at least one antenna, for example, by the control system. The focal point and the direction of the main beam are changed accordingly in or on the rock. Thus, different points on or in the rock surface can be irradiated without mechanical movement of the antenna unit.

[0034] It is advantageous for the controller to control or regulate the microwave generator, a phase shifter, the length of a waveguide, and / or the proportional distribution of the generator's power to the n antennas of the antenna unit. The n antennas are, for example, fed by as many microwave generators, which can be easily synchronized in phase coherence by a central controller. Both the output power Pi and the phase epi of each source can be controlled individually.

[0035] Another teaching of the invention provides that the control / regulation is set up in such a way that only a part of the antennas of an antenna unit are controlled / transmit at the same time as one or more groups.

[0036] A further aspect of the invention provides that an antenna unit comprises at least two groups, each consisting of at least one, preferably at least two, antennas, with one group of antennas being controlled together. This makes it possible to simultaneously, but independently, introduce more than one main lobe distributed across the rock face into the rock or to direct it towards the tunnel face. It is also advantageous, for example, that the antenna unit extends substantially across the width of the tunnel face. The antenna unit can be divided into individual groups, which are then preferably controlled separately.

[0037] Another teaching of the invention provides that the antenna unit has at least two antennas, each of which is connected to exactly one microwave generator.

[0038] A further aspect of the invention provides that at least one group of two antennas is provided, which is connected to exactly one microwave generator, and that a distributor in the form of a power divider is provided between the microwave generator and the antenna group. It is advantageous that a phase shift between the microwaves emitted by the at least two antennas can be adjusted via waveguides of different lengths or a phase shifter. For example, the length of a waveguide can be adjusted by making it telescopic. A further aspect of the invention provides that an automatic tuning unit is provided between the antenna unit and the power supply. This makes it possible to continuously and easily achieve the best possible match between the antenna and the load.The tuning unit, for example, automatically varies the geometry of a waveguide to minimize reflection at the load. This allows, for instance, variations in the distance of an antenna to the rock at an unstructured geological face or variations in the rock's composition to be partially compensated.

[0039] Another aspect of the invention is that the microwave generator is a solid-state microwave generator. These are particularly easy to control and adjust.

[0040] Another aspect of the invention is that the antenna is a horn antenna. This allows for a simple additional manipulation of the superposition.

[0041] A further aspect of the invention provides that at least one antenna is connected to a dielectric lens. This allows for a simple additional manipulation of the superposition.

[0042] A further aspect of the invention provides that the at least one antenna unit is movable relative to a surface of the rock. This allows the effective range with respect to the rock to be weakened to be increased in a simple manner.

[0043] Another teaching of the invention provides that the at least one antenna unit is arranged in a fixed position relative to a surface of the rock.

[0044] Another teaching of the invention provides that the antenna unit is arranged in the near field to the rock to weaken the rock, preferably with a distance D less than five times the wavelength.

[0045] It has been surprisingly found that the microwave power is coupled into the rock with minimal loss in the near field, enabling the beamforming according to the invention to achieve very good attenuation results, particularly below the surface within the rock. Furthermore, this makes it possible to achieve microwave superposition within the rock and concentrate the available power on a small volume of rock. In one embodiment, the focal point is preferably changed within or on the rock by actively adjusting the phase and / or amplitude of at least one antenna to steer the main power beam.

[0046] A further aspect of the invention provides that the antenna unit is arranged in the far field relative to the rock, preferably at a distance D significantly greater than five times the wavelength. This allows a swiveling signal or power beam to be formed, with which the largest possible proportion of the power can be projected onto a variable point on the rock surface. Here, beamforming according to the invention takes place in the air gap.

[0047] In one variant, the focal point is preferably changed in or on the rock by actively adjusting the phases and / or amplitudes of at least one antenna to swivel the main power beam.

[0048] A further teaching of the invention provides that a dielectric is provided on the antenna unit (200) on the antenna side, with which a surface gap between the antenna unit and the surface of the rock to be weakened is filled, wherein the dielectric is preferably microwave-transparent and / or flexible.

[0049] The air gap between the antenna unit and the rock has a significant influence on microwave propagation and coupling into the rock. During the transition of the waves from the antennas into the air gap and subsequently into the rock, distortions can occur in the superposition / overlap patterns of the waves and reflections. To reduce these distortions, a dielectric is provided as a coupling element between the antenna unit and the rock surface, i.e., in the air gap at the surface distance. Preferably, the air gap is filled with this dielectric, allowing for a smoother transition of the microwaves from the antennas through the dielectric into the rock, thus minimizing distortion of the superposition / overlap patterns.

[0050] If the permittivity jumps between the dielectric and the rock are chosen cleverly, a better adaptation of the arrangement with lower (air gap and reflection) losses can be achieved.

[0051] Preferably, the dielectric is microwave-transparent to achieve transmission with low losses / distortion. Preferably, the dielectric is robust and / or flexible so that it can conform to an uneven rock surface, for example like a foam, allowing the antenna unit with the dielectric to be pressed against the wall.

[0052] A further aspect of the invention provides that the antenna spacing can be varied by at least one actuator, preferably depending on changes in the rock to be weakened. This can preferably be done either manually or remotely (electrically / hydraulically) to allow for rapid adjustments as needed. For precision and rigidity, a spindle drive can preferably also be used. This allows for simple adaptation to changes in the permittivity of the rock caused by changes in the rock type or composition.

[0053] The problem according to the invention is further solved with a device for creating a cavity in the ground with at least one excavation tool for loosening rock or soil from a surface to be removed in the cavity to be created, wherein the at least one excavation tool for loosening the rock is arranged on at least one pivot arm movable relative to the surface, characterized in that a previously described device for pre-damaging rock is provided.

[0054] In particular, hard rock layers can then be weakened and mined more easily.

[0055] A further teaching of the invention provides that the at least one antenna unit is rigidly attached to the device or relative to the surface to be removed and is movable separately from the removal tool.

[0056] A further teaching of the invention provides that the at least one antenna unit is connected to a movement element which is movable on a guide, so that the at least one antenna unit can be moved on the guide around the mining tool separately from the movement of the mining tool.

[0057] The problem according to the invention is further solved by a method for pre-damaging rock comprising the following steps:

[0058] • Providing a previously described device for pre-damaging rock, comprising at least one microwave generator and an antenna unit with n > 2 antennas arranged in the antenna unit at a distance from each other of an m-fold wavelength of the microwaves generated by the microwave generator;

[0059] • Arrange the antenna unit at a distance from the rock,

[0060] • Generating microwaves with at least one microwave generator operating at a frequency;

[0061] • Adjusting the amplitude and / or phase of the microwaves to be emitted at an antenna of the antenna unit;

[0062] • Directing the microwaves to the antenna unit;

[0063] • Radiating microwaves towards the rock to be damaged at the antennas;

[0064] • Constructive superposition of the emitted microwaves in an air gap and / or in the rock.

[0065] Another teaching of the invention provides that, by superimposing the emitted microwaves, at least one main power lobe is formed with a focal point and with a direction.

[0066] Another teaching of the invention provides that the focal point is moved by changing the phase and / or amplitude of the microwave emitted at at least one antenna.

[0067] Another teaching of the invention provides that only a part of the antennas of an antenna unit are controlled / transmit at the same time as one or more groups.

[0068] A further aspect of the invention provides that an antenna unit comprises at least two groups, each consisting of at least one, preferably at least two, antennas, with one group of antennas being controlled together. This makes it possible to simultaneously, but independently, introduce more than one main lobe distributed across the rock face into the rock or to direct it towards the tunnel face. It is also advantageous, for example, that the antenna unit extends substantially across the width of the tunnel face. The antenna unit can be divided into individual groups, which are then preferably controlled separately.

[0069] A further teaching of the invention provides the following step: providing exactly one microwave generator per antenna of the antenna unit. A further teaching of the invention provides the following step: dividing the microwaves emitted by the at least one microwave generator to a group of at least two antennas.

[0070] Another teaching of the invention provides for the step of synchronizing the frequency of the microwaves when at least two microwave generators are provided by synchronizing the microwave generators.

[0071] Another teaching of the invention provides that the distance between the rock and the antenna unit is set to a distance in the near field to the rock, preferably less than five times the wavelength of the microwave.

[0072] Another teaching of the invention provides that the distance between the rock and the antenna unit is set to a distance in the far field to the rock, preferably significantly greater than five times the wavelength of the microwave.

[0073] Another teaching of the invention provides that the phase is set by controlling or regulating the microwave generator, by providing a waveguide between the microwave generator and the antenna with a specific length, by changing the length of the waveguide, and / or by adjusting a phase shifter.

[0074] Another aspect of the invention provides that the microwaves are guided from the antennas into a dielectric that sits on top of the rock.

[0075] Another teaching of the invention provides that the antenna spacing is changed with at least one actuator, preferably depending on changes in the rock to be weakened.

[0076] The invention is explained in more detail below with reference to a preferred embodiment in conjunction with a drawing. The drawing shows...

[0077] Figure 1 shows a schematic view of a method known from the prior art,

[0078] Figure 2a shows a spatial schematic representation of an antenna unit according to the invention with a planar arrangement of 3x3 antennas with a central main power lobe essentially in the air in the far field; Figure 2b shows a spatial schematic representation of an antenna unit according to the invention with a planar arrangement of 3x3 antennas with a deflected main power lobe essentially in the air in the far field.

[0079] Figure 3a shows a lateral schematic representation of an antenna unit according to the invention with a linear arrangement of 5 antennas with a central main power lobe and 4 side lobes for targeted transmission of the power to the satellite face in the far field.

[0080] Figure 3b shows a lateral schematic representation of an antenna unit according to the invention with a linear arrangement of 5 antennas with a central main power lobe and 4 side lobes for targeted transmission of the power to the satellite face in the far field.

[0081] Figure 4 shows a schematic representation of the superposition of wavefronts in the rock in an antenna unit according to the invention with a linear arrangement of 5 antennas for targeted transmission of power to the rock face in the near field.

[0082] Figure 5 shows a lateral schematic representation of an antenna unit according to the invention with a linear arrangement of 5 antennas with a central main power lobe and 4 side lobes in the rock for targeted transmission of power to the tunnel face in the near field.

[0083] Figures 6a to 6c are spatial schematic representations of an antenna unit according to the invention with a planar arrangement of 3x3 antennas with a central main power lobe in the near field with a focusing in the rock.

[0084] Figures 7a and 7b are spatial schematic representations of an antenna unit according to the invention with a planar arrangement of 6 antennas in a downward, center-free arrangement with a central main power lobe in the near field with a focusing in the rock.

[0085] Figure 8 shows an antenna according to the invention in the form of a schematic representation of a

[0086] Horn antenna with dielectric lens for power coupling into the rock, Figure 9 a schematic side view of an embodiment of a device for driving a vertical cavity into the ground with a device according to the invention with a movable antenna unit in the near field,

[0087] Figure 10 shows a schematic side view of an embodiment of a device for creating a vertical cavity in the ground with a device according to the invention having a movable antenna unit in the far field.

[0088] Figure 11 shows a schematic side view of an embodiment of a device for creating a vertical cavity in the ground with a device according to the invention having a stationary antenna unit in the far field.

[0089] Figure 12 shows a schematic side view of an embodiment of a device for creating a vertical cavity in the ground with a device according to the invention with an alternative movable antenna unit in the near field,

[0090] Figure 13a shows a schematic side view of an embodiment of a first device for creating a horizontal cavity in the ground with a device according to the invention having a movable antenna unit in the near field,

[0091] Figure 13b is a detail view of Fig. 13a,

[0092] Figure 14a shows a schematic side view of an embodiment of the first device for creating a horizontal cavity in the ground with a device according to the invention having an antenna unit in the far field.

[0093] Figure 14b is a detail view of Fig. 14a.

[0094] Figure 15 shows a schematic side view of an embodiment of a second device for creating a horizontal cavity in the ground with a device according to the invention with an alternative movable antenna unit in the near field.

[0095] Figure 16 shows a schematic side view of an embodiment of the second device for creating a horizontal cavity in the ground with a device according to the invention having an alternative antenna unit in the far field; Figure 17 shows a schematic side view of an embodiment of a third device for creating a horizontal cavity in the ground with a device according to the invention having an alternative movable antenna unit in the near field.

[0096] Figure 18 shows a schematic side view of an embodiment of the third device for creating a horizontal cavity in the ground with a device according to the invention with an alternative antenna unit in the far field,

[0097] Figure 19a shows a spatial representation of an antenna unit according to the invention with a 2x2 antenna.

[0098] Figure 19b is a top view of Figure 19b with different arrangement positions of the antennas,

[0099] Figure 20 shows a further embodiment of an antenna unit according to the invention consisting of 3x3 antennas in the form of patch antennas with connected microwave generators for emitting microwaves into the rock in the near field.

[0100] Figure 21 shows a further embodiment of an antenna unit according to the invention consisting of 3x3 antennas in the form of slotted antennas with connected waveguides, and

[0101] Figure 22 shows another embodiment of an antenna unit according to the invention consisting of 2x2 antennas with an introduction element between the antennas and the rock.

[0102] Figures 2a and 2b show an antenna unit 200 in a far-field arrangement with a surface distance D to the surface of a rock 140 and an air gap 160 between the antenna unit 200 and the surface of the rock 140, where the surface distance D is significantly greater than five times the wavelength A of the emitted microwaves. The antenna unit 200 consists, by way of example, of nine antennas 210 arranged in a 3 x 3 matrix, which are shown here schematically as horn antennas. Beamforming in the air between the antenna unit 200 and the surface of the rock 140 is shown.

[0103] The individual microwaves emitted by the antennas 210 superimpose constructively and destructively, resulting in a directional effect of the combined electromagnetic field. This creates a main power lobe 220, which is configured such that its focal point 225 is preferably located in the irradiation area on or in the rock 140. The individual antennas 210 are arranged with an antenna spacing d, preferably relative to their antenna centers. Optimally, this antenna spacing d is A / 2, i.e., half the wavelength of the wavelength emitted by a microwave generator.

[0104] Should the main power lobe 220 form in the rock 140, it is particularly preferred that the antenna spacing d A / 2 of the wavelength prevailing in the rock 140 after the penetration of the microwaves emitted by the microwave generator.

[0105] Additionally, potentially undesirable weaker side lobes 221-224 may form, as shown in Figure 3a. Preferably, the antenna spacing d and the individual phases epi of the individual antennas are selected and adjusted such that the main lobe 220 is optimally pronounced and the side lobes 221-224 are minimized.

[0106] By adjusting the output power, phases, and, if necessary, wavelengths of the individual microwave generators 240, the secondary power lobes 221-224 can be suppressed and the main power lobe 220 amplified. An optimum must be found here, since the amplification increases the width of the main power lobe 220, which means that the power is projected onto a larger area, thus reducing the focusing.

[0107] It has been shown that by arranging a large number of antennas 210 with an antenna spacing d, the focusing of the main power lobe 220 at the focal point 225 can be increased, and the development of secondary power lobes 221-224 can be suppressed.

[0108] In Figure 2a, the main power lobe is centrally aligned. The orientation of the main power lobe 220 can be controlled by adjusting the phases epi of the microwaves emitted by the individual microwave generators 240. This allows the main power lobe 220 to be swiveled in all spatial directions from the center of the antenna unit 200, as shown in Figure 2b.

[0109] Another embodiment for the far-field arrangement of an antenna unit 200 is shown in Figures 3a and 3b. Here, a linear arrangement of the antennas 210 is provided for an antenna unit 200. The antennas 210 are arranged with an antenna spacing d, which is preferably A / 2, i.e., half the wavelength of the wavelength emitted by a microwave generator.

[0110] The antennas 210 are preferably connected to each of a microwave generator 240 via a waveguide 230. This is represented here by Pi epi for a microwave generator 240 and a wave symbol for a waveguide 230. The individual microwave generators 240 are adjusted, for example by a controller (not shown), so that they can emit a microwave with a wavelength A, a power P, and a phase (p). In this example, this is represented by P1 to P5 and cp1 to <p5 dargestellt. Die Leistung P und die Phase cp werden dabei von der Steuerung so eingestellt, dass sich die Hauptleistungskeule 220 in optimaler Form und mit der entsprechend gewünschten Ausrichtung einstellt und gleichzeitig die Nebenleistungskeulen 221-224 möglichst unterdrückt auftreten.

[0111] The wavelength A is preferably chosen depending on the rock to be weakened.

[0112] The direction 250 and the focal point 225 are then set via the individual phases epi, which then superimpose constructively and destructively. Depending on the selected phase, the direction can then be centered, as shown in Figure 3a, or deviate spatially from the centered setting by an angle a, as shown in Figure 3b.

[0113] In this way, an entire site face 150 can be irradiated with microwaves for pre-damage from a stationary antenna unit 200 without having to change the position of the antenna unit 200.

[0114] Figures 4 to 7b show beamforming in rock. The antenna unit 200 is arranged in the near field. The surface distance D between the antenna unit 200 and the surface of the rock 140 is significantly smaller, preferably, for example, D < 5 Å.

[0115] The formation of the main power lobe 220 does not occur in the air as in the far field, but in the rock 140 itself, so that the focal point 225 lies deep below the surface / face 150 of the rock 140. This is shown in Figure 5.

[0116] It has been shown that by arranging a large number of antennas 210 with an antenna spacing d, the focusing of the main power lobe 220 at the focal point 225 can be increased, and the development of secondary power lobes 221-224 can be suppressed.

[0117] Each individual antenna 210 is preferably designed to achieve optimal power coupling of the microwaves into the rock without excessively heating the near-surface layers. The coupling process is shown in Figure 4. The respective introduced wavefronts 131 and the resulting wavefront 132 are depicted. Here again, several microwave generators 240 are present, each connected to the antennas 210 via a conductor 230.

[0118] The corresponding individual antennas 210 can, for example, be designed in the form of a horn antenna with a dielectric lens 260, as shown in Figure 8.

[0119] Instead of using one microwave generator 240 per antenna 210, several antennas 210 can also be supplied by a single microwave generator 240. The microwaves are then divided using microwave splitters (not shown) and other devices such as frequency tuners (not shown). This allows the respective phases and power levels for each individual antenna 210 to be set. This is also possible in the far-field application shown previously.

[0120] A shift in direction can be achieved here by adjusting the phases and performance levels as described previously. However, this is not shown in the figures.

[0121] For near-field applications over a larger surface area, it is necessary to move the antenna unit 200 across the rock face 150 to irradiate and pre-damage a larger area of ​​the rock than would be possible by moving the main power lobe 220 within the rock. Alternatively, an arrangement with a very large number of antennas 210 can be used, covering the entire surface of the rock face, with each subset being fed with microwave power.

[0122] Figures 6a to 6c again show a 3 x 3 matrix arrangement of the individual antennas 210 of an antenna unit 200. Also shown is the focal point 225 in the rock 140 in the main power lobe 220.

[0123] Figures 7a and 7b show a circular arrangement of, for example, six individual antennas 210 of an antenna unit 200, with one antenna in the center remaining free.

[0124] Figure 8 shows an antenna 210 in conjunction with a dielectric lens 260 arranged on it.

[0125] Antenna 210, for example, can be a waveguide, horn, double-flange horn, or parabolic antenna. The dielectric material of the dielectric lens is characterized by its minimal power absorption and thermal and mechanical stability.

[0126] The antenna spreads out the microwave signal in such a way that the electric field strength is reduced compared to wave propagation in the waveguide. This lower field strength prevents strong, localized heating at the rock surface.

[0127] The lens refracts the wavefronts so that they propagate as parallel as possible, thus bridging the air gap 160 between antenna 210 and rock 140 with minimal propagation losses in other directions. This allows the distance between antenna 210 / antenna unit 200 and the wall to be relatively large without significantly reducing the transmitted power.

[0128] Figures 19a and 19b show an antenna unit 200 with four antennas 200 arranged in a 2x2 matrix. The directivity and focusing depth of the main beam 220 depend heavily on the rock properties, particularly the permittivity of the rock 140 to be attenuated, and the geometric arrangement of the antennas 210, especially their spacing d. Since the composition (e.g., quartz content) or type of rock to be attenuated can change during tunneling, the invention preferably provides that the spacing d of the antennas 200 within the antenna unit 200 is adjustable. This allows for adjustments to improve attenuation depending on the rock type, for example, by changing the spacing d of the antennas to each other, such as the distance between the centers of the antennas 210.

[0129] For example, the permittivity of the rock may change slowly, or the focal point 225 in rock 140 might need to be adjusted to a lower / shallower depth to accommodate the damage caused by the advance of the drilling equipment, such as a tunnel boring machine or shaft drill. In extreme cases, however, two different geologies might be present at the tunnel face, requiring different geometries in the antenna unit.

[0130] One possibility, when using solid-state generators as microwave generators, is to vary the operating frequency within narrow limits. However, all waveguide components are frequency-tuned, so only minor adjustments are possible without changing the component geometry. Adjusting the phase would also not produce the desired effect with the symmetrical arrangement, as this would shift the beam.

[0131] Figures 19a and 19b schematically depict a 4-antenna unit 200, in which the distance d between the antennas 210, shown here, for example, as a circular waveguide, can be varied relative to the distance d' by moving the antenna diagonally outwards or inwards, along the direction of arrow A. This could be done either manually or remotely (electrically / hydraulically) to allow for rapid adjustments as needed. For precision and rigidity, spindle drives, for example, would also be suitable.

[0132] In Figure 19b, four antennas 210 are arranged around a central point M. There is an antenna spacing d between the antennas. Starting from the central point, four arrows A are shown, along which the centers M' of the antennas 210 can be moved diagonally from the central point M, so that the antenna spacing d changes to d'. The centers at the line lie on a circle K. After the movement, the centers at the line lie on a circle K'.

[0133] Figure 20 shows another embodiment of an antenna unit 200 according to the invention. Here, for example, antennas 210 are provided as patch antennas in a 3x3 arrangement. These are metal plates of a specific shape, which are, for example, mounted directly on printed circuit boards. Power is supplied, for example, via coaxial cables 230, which offers greater flexibility in mechanical arrangement compared to waveguides. However, the power output is limited to a few hundred watts per antenna. Therefore, it is preferable to increase the number of antennas. Accordingly, a corresponding number of small microwave generators 240 are preferably provided. Due to the higher number of antennas, the more antennas, the better the directivity of the main lobe 220.

[0134] Figure 21 shows another embodiment of an antenna unit 200 according to the invention. Here, for example, antennas 210 are provided as slot antennas in a 3x3 arrangement. These are connected to microwave generators 240 via preferably rectangular waveguides 230. Slot antennas are characterized by a higher power capacity. However, due to their rigid arrangement, they cannot be easily adapted after manufacturing.

[0135] Figure 21 shows another embodiment of an antenna unit 200 according to the invention.

[0136] For example, antennas 210 are provided in a 2x2 arrangement. The air gap between the antenna unit 200 and the rock 140 has a significant influence on the propagation of the microwaves and their coupling into the rock 140. During the transition of the waves from the antennas into the air gap 160 and subsequently into the rock 140, distortions occur in the superposition / overlap patterns of the waves and reflections. To reduce these distortions, a dielectric 270 is provided as a coupling element between the antenna unit 200 and the surface of the rock 140, i.e., in the air gap 160 at a surface distance D. Preferably, the air gap 160 is filled with this dielectric, thus enabling a smoother transition of the microwaves from the antennas 210 via the dielectric 270 into the rock 140, and consequently, the superposition / overlap patterns are less easily distorted.

[0137] If the permittivity jumps between dielectric 270 and rock 140 are cleverly chosen, a better adaptation of the arrangement with lower (air gap and reflection) losses can be achieved.

[0138] Preferably, the dielectric 270 is microwave-transparent to achieve transmission with low losses / distortions.

[0139] Preferably, the dielectric 270 is robust and / or flexible so that it can adapt to an uneven rock surface, for example like a foam, so that the antenna unit 200 with the dielectric 270 can be pressed against the wall.

[0140] Figures 9, 10, 11, and 12 show schematic, partially cutaway side views of a vertically extending shaft 100 in rock 140, each with a device 10 according to the invention for sinking a shaft as a cavity in the ground, each with, for example, an antenna unit 200 provided at a surface distance D. In Figures 9 and 12, the antenna unit 200 is arranged in a near-field configuration, whereas in Figures 10 and 11, the antenna unit 200 is arranged in a far-field configuration. The antenna unit 200 has at least two antennas 210 arranged at an antenna distance d from each other.

[0141] The device 10 according to the invention is shown only below a shielding plane 11. A bracing plane 12 is provided below the shielding plane 11. The bracing plane 12 has bracing elements 13 which (not shown here) are extended against the shaft wall 110 to brace the mining device in the shaft 10 and to stabilize it during the mining of the rock 140 while sinking the shaft 100. A mining device 20 is provided below the bracing plane 12 in a mining chamber 150 in the shaft 100. The mining device 20 has a pivoting arm 21. This pivoting arm 21, also referred to as a milling arm, has a mining tool 22 at its free end, here for example in the form of a milling drum / scraper. The milling drum has, for example, a drum body 25 which is rotatably mounted and rotationally driven.For example, chisels 24 are provided on the roller body 25, with which the underlying rock of a shaft floor 120, as the deepest area of ​​the shaft 100, is loosened. In the illustrated example according to the invention, the loosening of the rock takes place in the so-called partial cut.

[0142] Furthermore, the swivel arm can be pivoted via a joint 26 by means of an actuator, here a hydraulic cylinder 27. The swivel arm can also be telescopically extendable to remove a flat shaft base. Here, the shaft base 120 is radially arranged according to a (not shown) pivoting radius of the swivel arm 21 around the joint 26 when the actuator is actuated.

[0143] In the area of ​​the swivel arm 21, a stage 14 is further provided on and at which a device 30 according to the invention for generating and emitting microwaves for pre-damaging the rock 140 is arranged.

[0144] The generated and emitted microwaves heat the rock 140 within an irradiation area 130. This heating weakens the rock 140 or certain minerals within it, thereby reducing its strength.

[0145] The device 30, for example, has at least one power source, preferably a generator with corresponding power electronics for supplying voltage, at least one cooler, preferably a water cooler, at least one microwave generator or several microwave generators per antenna of the antenna unit 200 and at least one microwave conductor for directing the microwaves to the at least one antenna unit 200.

[0146] The at least one microwave generator is connected to the at least one power source via a cable. The cooling circuit for the microwave generator, which is supplied via the coolers, is not shown.

[0147] The aforementioned components preferably form a unit 38, which is arranged on a frame 40. The microwave conductor can preferably be telescopic in length (not shown) in order to bring the antenna unit 200 to the desired distance from the shaft base 120.

[0148] In a first embodiment (Figures 9, 10), the frame 40, for example, has a pivoting plane 42 on which the unit 38 can be moved to reach different irradiation zones 130 on the shaft floor 120. For this purpose, a rack 43 is arranged on the unit 38. Connected to this is an actuator 44, which has a drive (not shown) and a first gear 45 that engages with the rack 43.

[0149] Preferably, the unit 38 also has a rack 47 with which the actuator 44 is also engaged via a driven gear 46. This allows the unit 38 to be moved away from or towards the shaft bottom 120 during pivoting along the pivot plane 42 in order to maintain the optimal distance of the antenna unit 200 from the shaft bottom 120.

[0150] In a second embodiment (Figure 11), the antenna unit 200 is fixedly arranged on the frame 40 at a mounting plane 41. Alternatively, the antenna unit 200 can also be movably arranged analogously to Figure 9.

[0151] In the third embodiment (Figure 12) of the device 10 according to the invention, the frame 40 has a pivot joint 49 on which the unit 38 is pivotably arranged and about which the unit 38 is pivoted in order to reach different irradiation areas 130 on the shaft floor 120.

[0152] For this purpose, a mounting level 50" is provided on the frame 40, on which at least one pivot joint 51", preferably four pivot joints 51", are provided. At least one actuator 52", preferably a linear actuator, is arranged on the pivot joint 51", which is movable about the pivot joint 51". Preferably, four actuators 52" are provided. The actuators 52" can be hydraulic cylinders, electric linear drives, or the like.

[0153] The at least one actuator 52" is connected to the unit 38 via a further pivot joint 53" which is arranged on the antenna unit 200 or the waveguide. Preferably, four pivot joints 53" are provided for the preferably four actuators. By extending and retracting the actuator 52"(s), the antenna unit 200 is positioned at the respective irradiation areas 130 of the shaft floor 120 at the required distance.

[0154] Not shown in the area of ​​antenna unit 200 is a cleaning device with which the irradiation area to be heated can be cleaned of potentially interfering materials such as dust or moisture before the final arrangement of antenna unit 200. This device could, for example, be a scraper, a broom, or a compressed air supply.

[0155] In the movable antenna units in the near field, the unit 38 is moved via the pivot plane 42 by the actuator 44. The antenna units 200 are arranged accordingly over the individual irradiation areas 130. This can be done, for example, in a checkerboard pattern or directly adjacent to each other along the pivot planes 42.

[0156] In a stationary antenna unit 200, the irradiation areas 130 are covered by swiveling the main power lobe.

[0157] By rotating the mining tool 22 via the rotary drive 23, the platform 14 is also rotated, so that the unit 38 is also rotated above the shaft bottom and the next row of irradiation areas 130 is reached. Preferably, the rotation takes place in such a way that the mining tool 22 only operates in cooled rock at the shaft bottom, which has ideally already been heated and then cooled again.

[0158] Figures 13a to 14b show a device 50 as a second embodiment of the device according to the invention for creating a cavity. The device 50 is a horizontal tunnel boring machine, for example, for creating a tunnel as an opening / cavity in the ground.

[0159] This assembly includes, for example, a shield 51, a base 59 for a cutting device 60, and the cutting device 60, which may be horizontally movable on the base 59, with a pivoting arm 61 on which a cutting tool 62 is provided. The cutting tool 62 has a rotary drive 63 with which the pivoting arm 61 can be horizontally pivoted. The shield 51 is preferably equipped with cutting shoes 53 at its front end. The cutting device 60 is axially movable forwards and backwards on the base 59 in order to engage the cutting tool with a tunnel face 150 or to retract it into a parked position. The cutting tool 62 has a drill head 65, which is fitted with cutting tools 64. The drill head 65 has a front surface 65a fitted with cutting tools 64 and an annular side surface 65b, which is also fitted with cutting tools 64.Behind the side surface 65b, a screw conveyor 68 is preferably provided on the mining tool 62, with which loosened rock is transported from a tunnel face 150 to a conveying device 52.

[0160] The swivel arm 61 is mounted on a rotary drive 63 via a joint 66. The swivel arm 61, or the drill head 65, can be moved vertically by means of a hydraulic cylinder 67 as an actuator.

[0161] A microwave device 70 is provided on a rear part 69 of the swivel arm 61. A guide 55 is provided on the rear part 69, on which a movement element 71 can be moved around the swivel arm 61.

[0162] A frame 80 is provided on the movement element 71, on which a unit 78 of the microwave device 70 is arranged. The unit 78 preferably comprises a microwave generator and a control / regulation unit, optionally with further components of the device 70. The unit can be moved on the frame 80 between a rear parking position and a front irradiation position by means of an actuator, here a hydraulic cylinder 72.

[0163] The device 70 comprises at least one power source (not shown), preferably a generator with corresponding power electronics for voltage supply, at least one cooler (not shown), preferably a water cooler, at least one magnetron (not shown), at least one frequency tuner (not shown) for adjusting the frequency of the microwaves, and at least one microwave conductor 75 for directing the microwaves to the antenna unit 200 for emitting the microwaves into the rock.

[0164] A microwave conductor 75 is arranged on the unit 78, preferably pivoting vertically relative to the unit 78 via a joint 75e. The vertical movement of the microwave conductor 75 is effected by an actuator 77, preferably a hydraulic cylinder.

[0165] Preferably, the rear joint 75e is provided on a rotating element 79, so that the microwave conductor 75 can be pivoted horizontally relative to the unit 78.

[0166] The microwave conductor 75 is preferably composed of several parts. A three-part assembly consisting of conductor sections 75a, 75b, and 75c is shown here. Conductor section 75a is connected to the joint 75e. The three conductor sections 75a, 75b, and 75c can be moved into or out of each other via at least one longitudinal actuator 74, preferably a hydraulic cylinder, so that the length of the microwave conductor 75 can be changed, for example, in the direction of the tunnel face.

[0167] On the side of the microwave conductor 75 facing away from the joint 75e, a joint 75d is provided, on which the antenna unit 200 is arranged.

[0168] In the embodiment according to Figures 14a, 14b, a far-field arrangement of the antenna unit 200 is shown. Here, either a movement analogous to Figures 13a, 13b is given, as shown, or the antenna unit 200 is fixedly arranged on the guide 55 and thus still rotatable about the extraction arm 61, or simply generally fixed in position on the device 50, so that the irradiation areas 130 are achieved exclusively by deflecting the main power lobe over the working face 150.

[0169] Figures 15 and 16 show a device 50' as a third embodiment of the device according to the invention. The device 50' is a horizontal tunnel boring machine, for example for driving a tunnel as an opening / cavity in the ground.

[0170] The dismantling device 60 and the microwave device 70 are constructed as previously described. However, the guide for the movement element 71 is not arranged on the pivot arm 61. Instead, a guide 56 for the movement element 71 is provided on an inner surface 54 of the shield 51. As shown in Fig. 15, the guide 56 is curved on the inner surface, so that the antenna unit 200 is completely unaffected by the dismantling of the mine face.

[0171] The movement element 71 is provided on the inner side 57 of the guide 56, so that it can be moved along the guide 56 in the direction of the double arrow D. The operation and construction of the dismantling device 60 and the microwave device 70 are as described above.

[0172] Furthermore, the antenna unit 200 can also be permanently attached to the device 50, separate from the dismantling device 60.

[0173] Figures 17 and 18 show a device 90 as a fourth embodiment of the device according to the invention. The device 90 is a partial-face cutting machine, movable on a tracked chassis 91, for example, for driving a roadway in a mine, a tunnel, or a cavity, for example, in a deposit as an opening / cavity in the ground. In the embodiment shown in Figures 17 and 18, the partial-face cutting machine 90 is depicted without a shield. Alternatively, a separate shield can also be provided.

[0174] In the embodiment of the device 90 shown in Figures 17 and 18, the dismantling device 60 and the microwave device 70 are constructed as previously shown and described in Figures 13a and 13b. A construction according to Figures 14a and 14b with a separate shield is also possible. Furthermore, the antenna unit 200 can also be permanently attached to the device 90, separate from the dismantling device 60.

Claims

Patent claims 1. Device for pre-damaging rock with at least one microwave generator and with at least one antenna unit (200) for introducing the microwaves into the rock (140), which is wave-conductingly connected to the at least one microwave generator (240), wherein the microwave generator (240) is configured to generate microwaves with at least one wavelength, and wherein the antenna unit (200) has at least two antennas (210), characterized in that the at least two antennas (210) are arranged with an antenna spacing (d) from each other, so that the microwaves in the rock (140) superimpose constructively, so that at least one main power lobe (220) is formed by the superposition of the emitted microwaves in the rock (140), wherein the antenna spacing (d) depends on the wavelength of the microwave generated by the microwave generator (240), in that the antenna spacing (d) = m is the generated wavelength. 2 Device according to claim 1 , characterized in that the antenna unit (200) has more than two antennas (210) which have an antenna spacing (d) to the adjacent antennas (210). 3 Device according to claim 1 or 2, characterized in that the antennas (210) of the antenna unit (200) are arranged in a two- or three-dimensional arrangement, preferably linear, circular or square. 4 Device according to claim 3, characterized in that no antenna (210) is provided in the middle of the antenna unit (200).

5. Device according to one of claims 1 to 4, characterized in that m is in a range of values ​​from 0.2 to 1.2, preferably in a range of values ​​from 0.25 to 1.0, or substantially 0.25, or particularly preferably in a range of values ​​from 0.4 to 0.6, or from 0.45 to 0.55 or substantially 0.

5.

6. Device according to one of claims 1 to 4, characterized in that m = 0.5 * the wavelength of the microwave that settles in the rock, divided by the wavelength of the microwave generated by the generator.

7. Device according to one of claims 1 to 4, characterized in that m >2.

8. Device according to one of claims 1 to 7, characterized in that a control is provided with which the frequency, amplitude and / or phase of microwaves emitted at the antenna (210) can be adjusted.

9. Device according to claim 8, characterized in that the control unit controls or regulates the microwave generator, a phase shifter, a length of a waveguide and / or the proportional distribution of the generator's power to the n antennas (210) of the antenna unit (200).

10. Device according to one of claims 1 to 9, characterized in that the antenna unit (200) has at least two antennas (210), each of which is connected to exactly one microwave generator (240).

11. Device according to one of claims 1 to 10, characterized in that at least one group of two antennas (210) is provided which is connected to exactly one microwave generator (240), and that a distributor in the form of a power divider is provided between the microwave generator (240) and the antenna group.

12. Device according to claim 11, characterized in that a phase shift between the microwaves emitted at the at least two antennas (210) can be adjusted via waveguides of different lengths or a phase shifter.

13. Device according to one of claims 1 to 12, characterized in that an automatic tuning unit is provided between the antenna unit (200) and the power supply.

14. Device according to one of claims 1 to 13, characterized in that the microwave generator is a solid-state microwave generator (240). 15 Device according to one of claims 1 to 14, characterized in that the antenna (210) is a horn antenna.

16. Device according to one of claims 1 to 15, characterized in that at least one antenna (210) is connected to a dielectric lens (260).

17. Device according to one of claims 1 to 16, characterized in that the at least one antenna unit (200) is movable relative to a surface (150) of the rock (140).

18. Device according to one of claims 1 to 17, characterized in that the at least one antenna unit (200) is arranged in a fixed position relative to a surface (150) of the rock (140).

19. Device according to one of claims 1 to 18, characterized in that the antenna unit for attenuating the rock (140) is arranged in the near field to the rock (150), preferably with a distance (D) less than five times the wavelength.

20. Device according to one of claims 1 to 19, characterized in that the antenna unit is arranged in the far field to the rock (140), preferably with a distance (D) significantly greater than five times the wavelength.

21. Device according to one of claims 1 to 20, characterized in that a dielectric (270) is provided on the antenna side of the antenna unit (200), with which a gap (D) between the antenna unit (200) and the surface of the rock (140) to be weakened is filled, wherein the dielectric (270) is preferably microwave-transparent and / or flexible.

22. Device according to one of claims 1 to 20, characterized in that the antenna spacing (d) can be changed by at least one actuator, preferably depending on changes in the rock to be weakened.

23. Device for creating a cavity in the ground with at least one excavation tool (60) for loosening rock (140) or soil of a surface (150) to be removed from the cavity to be created, wherein the at least one excavation tool (22, 62) is for loosening the rock (140) is arranged on at least one pivot arm (21 , 61) movable relative to the surface (150), characterized in that a device (10) for pre-damaging rock according to one of claims 1 to 22 is provided.

24. Device according to claim 23, characterized in that the at least one antenna unit (200) is rigidly movable on the device or relative to the surface (150) to be removed and separately from the removal tool (22, 62).

25. Device according to claim 23 or 24, characterized in that the at least one antenna unit (200) is connected to a movement element (71) that is movable on a guide (55), so that the at least one antenna unit (200) is movable on the guide (55) about the dismantling tool (22, 62) separately from the movement of the dismantling tool (22, 62).

26. Method for pre-damaging rock with the following steps: • Providing a device for pre-damaging rock (140) according to one of claims 1 to 22, comprising at least one microwave generator and an antenna unit (200) with n > 2 antennas arranged in the antenna unit at a distance from each other of an m-fold wavelength of the microwaves generated by the microwave generator; • Arrange the antenna unit at a distance (D) from the rock (140), • Generating microwaves with the at least one microwave generator (240) at a frequency; • Adjusting the amplitude and / or phase of the microwaves to be emitted at an antenna (210) of the antenna unit (200); • Directing the microwaves to the antenna unit (200); • Radiating microwaves in the direction (260) of the rock to be damaged (140) at the antennas (210); • Constructive superposition of the emitted microwaves in an air gap (160) and / or in the rock (150).

27. Method according to claim 26, characterized in that at least one main power lobe (220) and one direction (260) is formed by the superposition of the emitted microwaves.

28. Method according to claim 27, characterized in that the main power lobe (220) is moved by changing the phase and / or amplitude of the microwave emitted at at least one antenna (210).

29. Method according to one of claims 26 to 28, characterized by the step of providing exactly one microwave generator (240) per antenna of the antenna unit or providing one microwave generator (240) for a number of antennas (210) of the antenna unit (200).

30. Method according to one of claims 26 to 29, characterized by the step: Dividing the microwaves emitted by the at least one microwave generator (240) into a group of at least two antennas (240).

31. Method according to one of claims 26 to 30, characterized by the step: synchronizing the frequency of the microwaves when at least two microwave generators (240) are provided by synchronizing the microwave generators (240), preferably via a provided control / regulation system.

32. Method according to one of claims 26 to 31, characterized in that the distance between rock (140) and antenna unit (200) is set to a distance (D) in the near field to the rock (140), preferably less than five times the wavelength of the microwave.

33. Method according to one of claims 26 to 32, characterized in that the distance (D) between rock (140) and antenna unit (200) is set to a distance (D) in the far field to the rock (140), preferably significantly greater than five times the wavelength of the microwave.

34. Method according to one of claims 26 to 33, characterized in that the phase is set by controlling or regulating the microwave generator (240), by providing a waveguide between microwave generator (240) and antenna (210) with a specific length, by changing the length of the waveguide, and / or by setting a phase shifter.

35. Method according to one of claims 26 to 34, characterized in that the microwaves are directed from the antennas (210) into a dielectric (270) which is located on the rock (140).

36. Method according to one of claims 26 to 35, characterized in that the antenna spacing (d) is changed by at least one actuator, preferably depending on changes in the rock to be weakened.

Images