Millimeter wave directional energy mining

Abstract

Apparatus and methods for excavating soil material with millimeter wave (MMW) radiation or a combination of MMW radiation and mechanical equipment are described. The MMW radiation may reduce the cost and risk associated with excavation using only mechanical devices and / or explosives. And compared with an optical or long-wavelength microwave excavation technology, the MMW-assisted excavation has a remarkable energy advantage.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. application No. 18 / 059,799, filed on November 29, 2022, entitled “Millimeter-Wave Directed-Energy Excavation.”

[0003] Government support

[0004] This invention was made with U.S. Government support under Grant DE-SC0012308 awarded by the U.S. Department of Energy. The Government has certain rights in this invention. Background Art

[0005] Lasers and long-wavelength microwave sources have been considered for mining applications. -5 Lasers with electromagnetic wavelengths of less than 1000 nm have disadvantages, including low electrical-to-laser power conversion efficiency, very short penetration lengths in earthy materials such as soil, sediment, or rock, and high levels of scattering from particles in the air. Long-wavelength microwaves, which have wavelengths longer than about 0.1 m and are used for communications and heating / cooking, have the disadvantages of not being able to provide a collimated and focused beam over a small area, high electric field strength, and strong localized heating. Summary of the Invention

[0006] A high-power millimeter wave (MMW) excavation beam generated by a high-power MMW source (e.g., a gyrotron) can excavate or assist in excavating earthen materials by fracturing, melting, and / or vaporizing the earthen material at the excavation site. Because MMW radiation is used, sufficiently high power densities and electric fields for fracturing, melting, and / or vaporizing earthen materials can be effectively delivered to volumes of earthen material that are not accessible using optical radiation or long-wavelength microwave radiation.

[0007] Some embodiments relate to a millimeter wave (MMW) excavation system for excavating earthen material. The system may include: a millimeter wave (MMW) source configured to generate and output MMW radiation having a free-space wavelength in the range of 0.1 millimeters (mm) to 30 mm; and a transmission line coupled to the MMW source to direct the MMW radiation to an excavation site having the earthen material and to emit the directed MMW radiation as an excavation beam from a distal end of the transmission line into the earthen material. The MMW source and the transmission line may be configured to transmit at least 10 kW / cm2 of the excavation beam. 2The MMW radiation is delivered to the excavation site such that the earthen material at the excavation site is disrupted by at least the excavation beam, and the MMW source and / or the transmission line may be further configured to move the distal end of the transmission line in a first direction perpendicular to a second direction in which the excavation beam propagates to the excavation site.

[0008] Some embodiments relate to a method for excavating earthen material using MMW radiation. The method may include the following acts: generating, with a millimeter wave (MMW) source, MMW radiation having a free-space wavelength in the range of 0.1 mm to 30 mm; coupling the MMW radiation to a transmission line; directing the MMW radiation with the transmission line to an excavation site having the earthen material; forming an excavation beam from the MMW radiation at a distal end of the transmission line; irradiating the earthen material at the excavation site with the excavation beam at an irradiance of at least 10 kW / cm2; disrupting the earthen material at the excavation site with the excavation beam; and removing the earthen material disrupted by the excavation beam from the excavation site with a mechanical device.

[0009] Some embodiments relate to a method of excavating a tunnel through earth material using MMW radiation. The method may include the following acts: generating a millimeter wave (MMW) radiation with a MMW source; coupling the MMW radiation to a transmission line; directing the MMW radiation with the transmission line to an excavation site on a surface of the earth material; directing an excavation beam formed by the MMW radiation at a distal end of the transmission line toward the earth material at the excavation site; melting the earth material at the excavation site with the excavation beam to form molten earth material; and sealing a hole in the surface of the tunnel with the molten earth material to prevent water from flowing through the hole.

[0010] All combinations of the foregoing concepts and the additional concepts discussed in more detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are considered to be part of the inventive subject matter disclosed herein. Terms explicitly used herein may also appear in any disclosure incorporated by reference and should be given a meaning most consistent with the specific concepts disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings are primarily for illustrative purposes and are not intended to limit the scope of the present subject matter. The drawings are not necessarily drawn to scale; in some cases, various aspects of the inventive subject matter disclosed herein may be exaggerated or enlarged in the drawings to aid in understanding different features. In the drawings, like reference symbols generally refer to like features (e.g., functionally similar and / or structurally similar elements).

[0012] Figure 1 Depicted is a MMW excavation system for excavating earthen material.

[0013] Figure 2A The distal end of a waveguide is shown which can launch an MMW excavation beam into a solid mass of rock.

[0014] Figure 2B Shows the MMW mining beam Figure 2A The fracturing and melting of solid rock.

[0015] Figure 3 A MMW excavation system including a sealing device for pressurizing an excavation site is depicted.

[0016] Figure 4A and Figure 4B Depicted and used Figure 1 or Figure 3 The MMW excavation system is used to remove blocks from a rock face.

[0017] Figure 5 Depicted is a modification of the cutting direction for excavating or removing blocks from a vertical rock wall.

[0018] Figure 6 A portion of an excavation system is depicted, the portion including a portion of a transmission line that allows a distal end of the transmission line to move relative to a MMW source and relative to earthen material to be excavated.

[0019] Figure 7 Depicts a system that also includes focusing optics Figure 6 Part of the mining system. DETAILED DESCRIPTION

[0020] For excavation of earthen materials, MMW radiation has advantages over optical and long-wavelength microwave radiation. High-power sources (e.g., gyrotrons) can be used to deliver at least 10 kW and up to 2 MW of MMW radiation in a continuous energy beam, or even higher peak power levels when the source is pulsed. Due to the range of available wavelengths (e.g., from 0.1 mm to 30 mm), the beam can be focused to a small area at the excavation site (e.g., from 1 cm to 30 mm). 2 to 100cm 2) to produce a higher intensity field than long wavelength microwaves. In addition, the majority of the energy of the MMW mining beam can be deposited and absorbed in earthen material at depths of 0.1 cm to 20 cm, which is much less than can be achieved with long wavelength microwaves and much deeper than can be achieved with optical radiation. In some cases, anywhere from 50% to 95% of the energy of the MMW mining beam can be deposited and absorbed in earthen material at depths of 0.1 cm to 20 cm. In some cases, high power concentrations in earthen material can induce electromagnetic, thermal, or pressure stresses (or some combination of these stresses) that fracture, melt, and / or vaporize rock. Long wavelength microwave radiation is unable to achieve such high power concentrations in earthen material.

[0021] Although optical radiation can melt and vaporize rock, it has a smaller working volume (due to its shorter penetration depth) and lower electrical-to-optical power conversion efficiency compared to MMW radiation. In addition, optical scattering from particles ablated from the excavation site can significantly reduce the amount of optical radiation available for excavation.

[0022] For some applications, the frequency of the MMW source can be approximately or exactly between 20 gigahertz (GHz) and 500 GHz, corresponding to a wavelength of 15 mm to 0.6 mm. A single gyrotron source can provide up to two megawatts (MW) of continuous wave (CW) power at 95 GHz, which is more than 20 times the power of a CW heat treatment microwave source at 2.45 GHz, or about 4 times the power of an infrared CW fiber laser. The conversion efficiency of electrical energy to MMW radiation is relatively high, exceeding 50%, which is greater than the conversion efficiency of a fiber laser. An MMW source can produce power intensities in rock that are 10 to 100 times the power intensities achievable with microwave sources, and over an area 4 to 100 times the area achievable with infrared lasers, and at depths significantly deeper than those achievable with infrared lasers. For example, an 80 cm 2 25kW / cm2 on the area 2 Continuous deposition can reach depths of up to 20 cm in a single shot. In comparison, a 500kW fiber laser will deposit 20 cm in a single shot. 2 Provides the same intensity over an area to a depth of several millimeters, provided that the particles ablated from the excavation site do not significantly interfere with the beam propagation into the earth material being excavated. A single shot can weaken, fracture, and / or melt a certain amount of native earth material in the excavation site that is within the absorption depth of the excavation beam.

[0023] Figure 1An excavation system 10 for excavating earthen material is depicted. The system includes a high-power MMW source 20 and a beam-steering transmission line 30 to direct MMW radiation from the MMW source 20 to an excavation site 5 in earthen material 200. The system may also include a beam conditioning and isolation system 40, monitoring instrumentation 70 for monitoring conditions at the excavation site 5, and a coupling interface 75 for coupling signals from and / or to the transmission line 30 for monitoring conditions at the excavation site 5. The excavation system 10 may optionally also include data acquisition electronics 105, a controller 100, data acquisition connections to the monitoring instrumentation 110, and a control line 120 communicatively coupling the controller 100 to the MMW source 20 so that the MMW source 20 can be remotely and / or automatically controlled by the controller 100. The excavation system 10 may also include a gas flow line 80 and a gas flow valve 85 for fluidly coupling the gas flow line 80 to the transmission line 30 via a gas inlet 86. Gas may be injected from flow line 80 into transmission line 30 through valve 85 and gas inlet 86. Introducing gas into transmission line 30 may prevent undesirable backflow of particles and / or vapors from excavation site 5 to source 20 and monitoring instrumentation 70.

[0024] The MMW source 20 (e.g., a gyrotron) can be operated in a continuous mode to continuously output high power (e.g., from 10 kW to 2 MW) MMW radiation. For some applications, the MMW source 20 can be operated in a pulsed mode to output a series of pulses, each with a peak power greater than 10 kW or up to 2 MW. The intensity (power / cm2) delivered to the excavation site 5 is 2 ) can be set by selecting the power level and beam size at the excavation site.

[0025] The transmission line 30 may comprise a hollow cylindrical waveguide formed from a highly conductive material such as copper. Other waveguide shapes (rectangular, square, etc.) and materials (aluminum, copper-plated steel, etc.) are also possible. The MMW source 20 and / or transmission line 30 are further configured to allow the distal end 50 of the transmission line to move in a first direction perpendicular to a second direction in which the excavation beam 60 propagates to the excavation site 5 (e.g., in a direction parallel to the surface of the earthen material 200, so as to increase the diameter of a hole in the earthen material or to form a groove in the earthen material). In some embodiments, at least a portion of the transmission line (e.g., the distal end 50) is movable relative to the MMW source 20 and the earthen material 200 without requiring movement of the MMW source. For example, the transmission line 30 may include one or more rotatable couplers or rotatable miter bends and one or more sliding sections (which may also be rotatable) so that the MMW excavation beam 60 emitted from the distal end 50 can scan the surface of the earthen material 200, moving laterally and / or vertically. In some cases, a beam launching device (e.g., a mirror, lens, antenna, window, or some combination thereof) may be used at the distal end 50 of the transmission line 30 to collimate or focus the excavation beam 60 at the excavation site 5 and protect the transmission line. Alternatively or in addition, the distal end 50 of the transmission line 30 may be tapered to reduce the size of the excavation beam 60 at the excavation site 5.

[0026] The excavation site 5 is a region of earthen material 200 irradiated by the MMW excavation beam 60 emitted from the distal end 50 of the transmission line 30. A gas jet 90 may be ejected from the end of the gas flow line 80 at the excavation site 5 to blow away the fractured and melted earthen material 200 from the excavation site, which may produce a buildup of mined material 210. A pressure source 82 (e.g., a mechanical pump or turbine) may provide a source of pressurized gas to the gas flow line 80 for blowing away the excavated debris from the excavation site 5. The mined material 210 may be further removed by additional mechanical means 87 (e.g., a conveyor, auger, automated cart, or other equipment). In some cases, a mechanical means (e.g., a drill) may be used to remove the weakened earthen material 200 from the excavation site. In some embodiments, Figure 1 The excavation system 10 may also be used for rock weakening of removed rock during the size reduction process phase of excavation.

[0027] The beam adjustment and isolation system 40, the monitoring instrument 70, and the coupling interface 75 can be used to protect the source from strong reflections from the excavation site 5 and monitor conditions at the excavation site, as described in International Patent Application No. PCT / 2022 / 078254, filed on October 18, 2022, entitled “Continuous Emissions Monitor for Directed-Energy Borehole Drilling,” and International Patent Application No. PCT / 2022 / 078255, filed on October 18, 2022, entitled “Rate of Penetration Depth Monitor for a Millizer-Wave Beam Made Hole,” both of which are incorporated herein by reference in their entirety.

[0028] Figure 2A and Figure 2B Shown Figure 1 The effectiveness of the millimeter wave excavation system 10 in breaking rock without mechanical contact or chemical means such as explosives. The thermal stress generated by rapidly heating the localized light spot to a temperature above the rock melting temperature (>1,100°C) adjacent to the unheated rock causes Figure 2A Solid basalt in 250 melts and fractures, such as Figure 2B In this example, a 4 kW, 28 GHz excavation beam is diffracted to a size of 40 mm diameter after being launched from the distal end 50 of a 20 mm inner diameter cylindrical waveguide. The basalt fragments after being exposed to the excavation beam for several minutes.

[0029] The appropriate operating frequency of the MMW source 20 for various applications will depend on the type of earth material (solid rock, rock composition, gravel, sediment, sand, frozen soil, etc.) and the specific application (weakening, fracturing, or melting of a specific earth material). Operation at the lower end of the millimeter wave range (and possibly even slightly lower, such as 14 GHz) may be desirable in terms of penetration length into the rock and reducing the complexity and power requirements of the gyrotron magnet system.

[0030] One application of MMW excavation using the MMW excavation system 10 is in the rock removal phase, where the MMW excavation system weakens or breaks up the earthen material 200 prior to mechanical removal. MMW rock weakening reduces the demands on the mechanical systems used for material removal (e.g., reduces stress and wear on the mechanical removal systems) and can reduce the need for human involvement in the rock removal process. MMW rock weakening can also speed up the removal process by allowing the mechanical removal system to excavate the rock or earthen material more quickly.

[0031] Pure mechanical rock fragmentation (without explosives) is typically accomplished with a full-face or partial-face tunnel boring machine (TBM). Prior to TBM excavation, the MMW excavation system 10 is used to weaken the earthen material, primarily by introducing fractures created by rapid rock heating. This increases the TBM's advance rate. MMW directed energy can be used for this type of weakening without mechanical contact.

[0032] MMW rock weakening can be used in combination with mechanical abrasive tools, vibration, cavitation, water jets, or gas jets (or some combination of these methods) to remove rock. A scanning system for the excavation beam 60 can be used to select the appropriate distance between the earthen material 200 at the excavation site 5 and the distal end 50 of the transmission line 30. The selected distance between the earthen material 200 and the distal end 50 can be in the range of 10 mm to 300 mm. The scanning system can include a rotatable coupler or a rotatable miter bend and a slidable portion of the transmission line 30, for example, controlled by a stepper motor. The size and scanning rate of the MMW excavation beam can be controlled by the scanning system to provide the desired power density and heating required to weaken and / or fragment various rock types. Other parameters that can be varied include whether CW or pulsed operation of the MMW radiation source 20 is used, the pulse repetition rate of the MMW radiation output from the MMW source 20, and the power level. The frequency can also be varied using a dedicated gyrotron source to control penetration depth and interaction with specific heterogeneities within the rock formation.

[0033] Both open-loop and closed-loop control can be used to adjust various system parameters (e.g., power level, pulse repetition rate, MMW frequency, distance between earthen material 200 and distal end 50 of transmission line 30, etc.) to improve the effectiveness of MMW heating and excavation. Closed-loop control utilizes real-time measurements of rock parameters. These parameters include the temperature at the excavation site 5, which can be measured by an MMW radiometer. Monitored parameters can also include removal rate, which can be measured using MMW radar and / or long-wavelength microwave radar technology, and spectrochemical analysis, which can be measured using radiation emissions from the excavation site 5.

[0034] A second application of the excavation system 10 is drilling holes for rock excavation. Drilling and blasting operations are standard procedures for excavating rock. A borehole (typically between 2 and 5 cm in diameter, and larger in excavation and mining) is drilled at a penetration rate of approximately 2 m / min. Drilling parameters (e.g., at least one of power, beam size, pulse duration, pulse repetition rate, and drilling rate) can be adjusted to avoid excessive pressure in the hole, which could fracture or deform the hole. The hole is then filled with explosives to blast the rock from the work area. The MMW excavation beam 60 from the excavation system 10 can be used to drill holes for explosive placement more quickly and at a lower cost, without the need for mechanical drilling equipment.

[0035] A third application is to use millimeter wave energy to reduce or eliminate the use of chemical explosives when breaking or removing rock, which is critical for rock removal in densely populated areas. For example, rock can be explosively removed from earthen material 200 using only the MMW excavation source 10 without the use of chemical explosives that may produce hazardous gases. In such applications, Figure 3 A seal 310 in the can be formed around the excavation site 5 to create a sealed chamber around the excavation site. The seal 310 may include a metal shell to limit stray MMW radiation. The chamber may contain a small opening to the atmosphere (e.g., where the transmission line 30 and the gas flow line 80 pass through the seal 310). Gas injected through the gas flow line 80 can partially pressurize the chamber. Alternatively, the chamber can be pressurized by gas injected into the transmission line via the gas inlet 86. In some cases, the transmission line 30 may not pass through the seal 310. Alternatively, the excavation beam 60 can pass through an MMW-transmitting window in the seal. During the rapid heating of the excavation site 5 by the excavation beam 60, the pressure at the excavation site 5 inside the sealed chamber 310 can increase to a value proportional to the temperature rise in the finite volume, which is consistent with the gas law PV=nRT. For example, if the initial cold pressure caused by the gas flow from transmission line 30 and / or gas flow line 80 is 100 atmospheres, a tenfold increase in temperature within seal 310 can increase the pressure to 1,000 atmospheres. The electric field breakdown threshold will increase roughly proportionally to the gas molecule number density corresponding to the pressure increase, which in turn will increase the power intensity that can be applied to the rock surface. This increased power intensity will increase excavation speed. As described above, open-loop or closed-loop control of various millimeter-wave source parameters can be used in such applications. Figure 3 The tapered distal end 50 of the transmission line 30 is also shown.

[0036] A fourth application is the use of the excavation system 10 to selectively remove high-value materials from a rock surface or from loosened rock through localized weakening and vaporization. Real-time monitoring of the elemental composition of the rock can be used to control the positioning of the excavation beam 60 and the operating characteristics of the MMW source 20. Molecular and / or elemental composition can be measured by infrared or optical spectroscopy of the material ablated by the MMW excavation beam 60. The characteristics of the excavation beam 60 can be temporarily altered to improve measurements. For example, the peak power can be increased to induce atomic emission and / or vaporize material for analysis. Alternatively, a slipstream of exhaust vapor and / or particulates from the excavation site 5 can be directed through analytical chemistry instrumentation.

[0037] A fifth application involves using the mining system 10 to extract precious metals, particularly gold, which are typically found in relatively thin ore seams, or so-called reefs. Accessing and extracting minerals from thin seams involves large amounts of waste rock and can be hazardous to miners. Using the robotic mining system 10 in conjunction with MMW directed energy and mechanical removal can reduce costs and improve safety when extracting precious metals from thin seams.

[0038] A sixth application is the processing of minerals using the mining system 10. Mineral processing typically involves breaking rock into smaller particles, followed by chemical processing, melting, or both. Rock size reduction and crushing is often referred to as "comminution" and is typically accomplished mechanically in a milling operation. Milling operations can consume the majority of the energy required to extract minerals from the rock. Such milling operations can be replaced by or combined with MMW processing using the mining system 10. For example, the MMW mining system 10 can be used to further break up and / or melt removed earthen material transported via a conveyor system for size reduction and / or melting steps.

[0039] Conventional mechanical means for material size reduction and refining (e.g., grinding with a grinder or crushing with a rock crusher) and chemical means (e.g., grinding with solvents or leaching with sulfuric acid) are very inefficient, energy-intensive, and can be harmful to the environment. MMW radiation can be used to weaken and pre-treat rock prior to mechanical and / or chemical treatment, thereby enabling more efficient and environmentally friendly processing. This can result in a significant reduction in overall processing costs.

[0040] A number of MMW characteristics can be adjusted to improve the efficiency of mineral processing. For example, operating parameters can be adjusted to selectively treat areas of the removed earth material where desired products (e.g., valuable minerals or precious metals) are located, thereby saving more energy. Adjustable operating parameters include the frequency of the mining beam 60, CW or pulsed operation, pulse length, pulse repetition rate, peak power level, average power level, and selection of spot or beam size. The parameters will be adjusted based on the characteristics of the removed earth material (e.g., the percentage composition of valuable metals or minerals) and the goal of MMW weakening (e.g., further fracturing, melting, or gasification). Closed-loop control using various sensors and / or monitoring instruments 70 can be used to detect the characteristics of the removed earth material (e.g., temperature and composition). Open-loop control can also be used.

[0041] An illustrative MMW-generated temperature variation in earthen materials that will be utilized in the size reduction process step is a temperature in the range of 20 to 1200 degrees Celsius. The temperature variation will vary based on the treatment target and the type of earthen material being irradiated. If desired, temperatures greater than 10 kW / cm2 may be used. 2 The MMW power intensity is used to achieve these temperature changes.

[0042] The MMW excavation system 10 may be particularly suitable for deployment in harsh conditions (e.g., in extremely cold climates where the soil is frozen) or in applications where there is little or no direct human involvement. The robotically controlled excavation system 10 may be mounted on a vehicle with tires or equipped with flanged rail wheels for transportation on a railway.

[0043] A seventh application is block cutting and removal (e.g., in quarrying and excavation) using the excavation system 10. Use of the excavation system 10 can reduce energy consumption compared to conventional methods by making only two to four narrow side cuts (or a series of holes) in the solid rock wall that will define the block edges. Figure 4A and Figure 4B Block 440 is depicted being removed from rock wall 410. The back side 444 of block 440 remains attached to rock wall 410 to hold block 440 in place until the block breaks from the wall. Block 440 can be broken from the wall, exposing back side 444, by one or more hydraulic devices 430 (e.g., hydraulic jacks or cylinders), which are placed into a horizontal side cut 420, preferably into the top cut of the block, or into one or more holes drilled into rock wall 410. The horizontal side cuts 420, vertical side cuts 422, the depth of the holes, and the length of each side cut or the number of holes vary depending on the economics and size or weight limitations of the handling equipment, the crushing force from hydraulic devices 430, and the strength of the rock. Once block 440 is released, it can be removed from the area by gravity and / or mechanical means (e.g., conveyor belts, trolleys or slide systems, towing by cables or chains, etc.) for further processing, use, or recycling as fill or construction material.

[0044] Side cuts 420, 422 may be formed as trenches by scanning the excavation beam across rock wall 410. The width of each trench or side cut may be approximately or exactly equal to the width of excavation beam 60 at excavation location 5. In some cases, the width of the side cuts may be less than the width of excavation beam 60 at excavation location 5.

[0045] To remove the first block from the solid rock wall (e.g., at the lower corner of the wall), four side cuts 420, 422 may be made. For the first block in each subsequent row of blocks (extending laterally across the wall) or column of blocks (rising vertically up the wall) or hole drilled into the rock wall 410, only three side cuts 420, 422 are sufficient to remove each block because one side of the block to be removed is already exposed to the gap left by the previous side cuts 420, 422 and the adjacent previously removed block 440. For the remaining blocks in the row or column from which the first block has been removed, only two side cuts 420, 422 are sufficient to remove the blocks because both sides of the block to be removed are already exposed to the gaps left by the previous side cuts 420, 422 and the two adjacent previously removed blocks 440. Although Figure 4AThe block 440 is depicted as being broken from the bottom of the rock wall 410 to the top of the rock wall, but the block 440 can also be removed starting from the top of the rock wall 410. When removed from the top of the rock wall 410, the removed block 440 can fall a short distance and come to rest on the lower ledge of the rock wall created by the bottom side cut 420. Depending on the aspect ratio and orientation of the block 440 when the side cuts 420, 422 are formed, a hydraulic device 430 can be placed in either the vertical side cut 422 or the top side cut 420 to break or peel the block 440 from the rock wall 410. At least one of the side cuts 420, 422, or a portion thereof, should be wide enough to allow a suitably powerful hydraulic device to be inserted into the cut to break the block 440 from the rock wall 410 along its back side 444.

[0046] Figure 5 A modification for removing a block from a vertical rock wall 410 is depicted. Side cuts 420, 422 can be made or initiated at positive angles, upward into the rock wall 410, as depicted. This angled orientation can aid in removing rock melt before solidification and in removing fractured particles. The upward cutting angle can range from 2 degrees to 30 degrees.

[0047] Combine Figures 4A to 5 Variations on the block removal method are possible. The side cuts 420, 422 can be formed by rock weakening combined with mechanical removal, rock fracturing, melting, partial gasification, complete gasification, explosive thermal fracturing, or a combination of these methods. Specifically, certain minerals in the rock and any fluids in the pores have lower melting and gasification temperatures than other components of the rock structure. This can cause differential stresses near the excavation beam 60 and the heating point, thereby fracturing the rock. The resulting stress can reach a level that causes the local rock to either melt or break into a plurality of particles having a certain velocity imparted by any expanding gas. In a fixed narrow cut, the primary direction of the traveling particles is outward, resulting in high velocity particles that can potentially damage the distal end 50 of the transmission line 30, which may contain a beam emitting device (e.g., a mirror, lens, antenna, window, or some combination thereof). The beam emitting device can be used to collimate or focus the excavation beam 60 at the excavation site 5.

[0048] Figure 6The angle of the transmission line 30 and the MMW beam axis relative to the rock wall 410 is depicted with an offset distance to prevent potential damage to the excavation system 10. The beam axis can be tilted toward the previous side cut 422 or hole and away from the original uncut rock. The distal end 50 of the transmission line 30 for the side cuts 420, 422 is advanced toward the original uncut rock to allow escaping rock particles to be ejected into the previous void and reduce ejection toward the distal end 50 of the transmission line 30. If the distal end 50 is tilted upward, the scan direction can be downward for vertical side cuts 422. If the distal end 50 is tilted downward, the scan direction can be upward for vertical side cuts 422. For vertical cuts using rock melt, it may be necessary to advance the distal end 50 in a downward direction to reduce or prevent melt from refilling the cut and solidifying within the cut.

[0049] Figure 6 Portions of the transmission line 30 are depicted that allow the distal end 50 of the transmission line 30 to be moved relative to the MMW source 20 and the rock wall 410 or earthen material without moving the source, as discussed above. The transmission line 30 may include one or more rotatable couplers or rotatable miter bends 610 (which redirect the MMW radiation at a fixed bend angle of 20 to 90 degrees from the incoming beam axis of the incoming transmission line). Rotation of the rotatable coupler or miter bend 610 can cause the outgoing beam to rotate around the incoming beam axis of the incoming transmission line at a fixed bend angle. The transmission line 30 may also include one or more sliding sections 620 along the transmission line 30, as shown. The sliding sections, which may also be rotatable, can change the length of the transmission line incorporating the sliding sections 620. The rotatable miter bends 610 and sliding sections 620 can allow vertical and horizontal movement, as well as angular changes, of the distal end 50 of the transmission line 30 relative to the earthen material 200 without moving the source 20. Such movement and angular changes may be achieved and controlled by one or some combination of mechanical, electrical, and hydraulic devices and methods.

[0050] Figure 7 Another excavation method is shown using a focusing optical device 640 (e.g., a parabolic mirror) to focus the excavation beam 60 onto the excavation site 5. The use of a mirror can further remove the distal end 50 of the transmission line 30 from the excavation site 5, thereby reducing the possibility of damage to the transmission line due to ejected debris. The focusing optical device 640 and the distal end of the transmission line can be different from Figure 7 In some cases, the focusing optics 640 may be located above the excavation site 5 so that no downwardly traveling debris can strike the focusing optics 640 .

[0051] An eighth application of the MMW excavation system 10 is to melt rock and / or soil for stabilizing, strengthening, and / or surface treatment of rock surfaces or structures. For example, the surface of an excavated bank can be melted and fused together to form a retaining wall that can help prevent the bank from collapsing. The surface of an excavated pit can be melted and fused together to allow the surface to hold water for an extended period of time. The surface of an excavated tunnel or borehole can be melted and fused together to form a finished wall and / or roof, thereby increasing strength and preventing water from flowing into the tunnel or borehole. The surface of a block 440 removed from a rock wall can be melted to provide a smoother and more durable finished surface for the block.

[0052] A ninth application of the MMW excavation system 10 is to melt the rock or earth material at the excavation site 5 to seal or block the fluid flow path in the rock or earth material. Sealing the excavation surface can be achieved by forcing the generated melt into the void spaces of the rock or earth material (e.g., using the above-described method in conjunction with Figure 3 The pressurized chamber described above or using gravity can be used to accomplish this. The pressure from the pressurized chamber can force the melt into the void space. The void space can include rock pores, cracks, karst features, boreholes, fissures, cavities, etc. in and / or on exposed rock surfaces or earthen materials. Gravity can be used to form a seal on the bottom, ground and / or horizontal surfaces, which can be inclined up to 45 degrees or more, because the molten earthen material can quickly solidify when it flows onto the cooler solid material. When excavating under a body of water or in a humid area, a method of sealing the excavation surface can be useful so that the walls, roof and bottom surfaces of the tunnel or borehole are impermeable to water flow through the sealed surface. The overpressure of the enclosed space when the MMW excavation beam 60 is applied for melting can create a pressure differential that creates a force on the melt in the direction from the pressurized space into the rock hole to overcome the hydraulic pore pressure. This can be very useful in tunnel construction where water influx is a concern.

[0053] In the event that insufficient or inappropriate melt (e.g., limestone) is available from the excavated earthen material, the melt can be supplemented with specific additives having the properties required to produce a vitrified sealing wall. The additives can be introduced in a fine-grained or powered form from a conduit adjacent to the transmission line 30 or via the gas flow line 80. For example, the gas input and additive material can be combined into the gas flow line 80 and supplied through the gas flow line. In another approach, the additives can be introduced into at least one fiber optic cable, similar to those used in 3D printing, but on a larger scale, and continuously supplied to the excavation site 5 when the MMW excavation beam 60 is active. The additives can include low-temperature melt materials with high MMW absorption to reduce the viscosity of the melt to improve flow relative to the earthen material to be excavated and melted into the earthen wall. The additives can include boron or barium compounds, thermoplastics, metals, or natural minerals such as pure quartz, potassium feldspar, sodium plagioclase, mica—all of which have melting points of approximately 600°C. In some embodiments, the additive may have a higher thermal conductivity than the native earth material to improve heat flow and heating of the native earth material. In some cases, the additive may reduce reflection of MMW radiation from the melt / surface interface at the excavation site 5.

[0054] Summarize

[0055] All parameters, dimensions, materials and configurations described herein are intended to be exemplary, and actual parameters, dimensions, materials and / or configurations will depend on the specific application or applications for which the present invention is taught. It will be understood that the foregoing embodiments are presented primarily by way of example, and that within the scope of the appended claims and their equivalents, embodiments of the present invention may be practiced in a manner different from that specifically described and claimed. Inventive embodiments of the present disclosure relate to each individual feature, system, article, material, kit and / or method described herein. In addition, if any combination of two or more such features, systems, articles, materials, kits and / or methods is not mutually inconsistent, such features, systems, articles, materials, kits and / or methods are included within the scope of the invention disclosed herein.

[0056] In addition, various inventive concepts can be embodied as one or more methods provided in at least one example. In some cases, the actions performed as part of the method can be sequenced in different ways. Thus, in some embodiments of the present invention, the corresponding actions of a given method can be performed in an order different from the order specifically shown, which can include performing some actions simultaneously (even if these actions are shown as continuous actions in the illustrative embodiments).

[0057] All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.

[0058] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0059] Unless expressly indicated to the contrary, the indefinite articles "a" and "an" as used herein in the specification and claims should be understood to mean "at least one."

[0060] As used herein in the specification and claims, the phrase "and / or" should be understood to mean "either or both" of the elements so combined, i.e., elements that are present in combination in some cases and separately in other cases. Multiple elements listed with "and / or" should be interpreted in the same manner, i.e., "one or more" elements so combined. In addition to the elements specifically identified by the "and / or" clause, other elements may optionally be present, whether related or unrelated to those specifically identified elements. Thus, as a non-limiting example, in one embodiment, when used in conjunction with open language such as "comprising," a reference to "A and / or B" may refer to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0061] As used herein in this specification and claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" should be interpreted as inclusive, i.e., including at least one, but also including multiple elements or more than one in a list of elements, and (optionally) other unlisted items. Only when a contrary term is explicitly indicated, such as "only one" or "exactly one", or when used in the claims, "consisting of..." will mean including multiple elements or exactly one element in a list of elements. In general, the term "or" as used herein should only be interpreted to mean an exclusive alternative (i.e., "one or the other but not both") if preceded by an exclusive term, such as "either", "one of", "only one" or "exactly one". "Substantially consisting of...", as used in the claims, should have the ordinary meaning used in the field of patent law.

[0062] As used herein in the specification and claims, the phrase "at least one" with respect to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the list of elements, but does not necessarily include at least one of each element specifically listed in the list of elements, and does not exclude any combination of elements in the list of elements. This definition also allows that elements other than the elements specifically identified in the list of elements to which the phrase "at least one" refers may optionally be present, whether or not related to those specifically identified elements. Thus, as a non-limiting example, in one embodiment, "at least one of A and B" (or equivalently, "at least one of A or B," or equivalently, "at least one of A and / or B") may refer to at least one that optionally includes more than one A, no B (and optionally includes elements other than B); in another embodiment, may refer to at least one that optionally includes more than one B, no A (and optionally includes elements other than A); in yet another embodiment, may refer to at least one that optionally includes more than one A and at least one that optionally includes more than one B (and optionally includes other elements); etc.

[0063] In the claims and the foregoing description, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "maintaining," "consisting of," and the like are to be construed as open-ended, meaning including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" are to be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

1. A system for excavating earthen material, the system comprising: a millimeter wave (MMW) source configured to generate and output MMW radiation having a free-space wavelength in the range of 0.1 millimeter (mm) to 30 mm; as well as a transmission line coupled to the MMW source to direct the MMW radiation to an excavation site having the earthen material and to emit the directed MMW radiation as an excavation beam from a distal end of the transmission line into the earthen material, wherein the MMW source and the transmission line are configured to deliver at least 10 kW / cm2 of the tapped beam. 2 delivering the MMW radiation to the excavation site such that the earthen material at the excavation site is disrupted by at least the excavation beam, and The MMW source and / or the transmission line is further configured to move the distal end of the transmission line in a first direction perpendicular to a second direction in which the excavation beam propagates to the excavation site.

2. The system of claim 1, wherein the MMW source and the transmission line are further configured to be greater than 1 cm 2 But not more than 100cm 2 The majority of the energy from the excavation beam is deposited into the earthen material in an area of ​​0.1 cm to 20 cm and to a depth of 0.1 cm to 20 cm.

3. The system of claim 1 further comprising mechanical equipment to remove the earthen material disrupted by the excavation beam from the excavation site.

4. The system of claim 3, wherein the mechanical device is configured to generate pressurized gas to blow away at least a portion of the earthen material and / or melted earthen material disrupted by the excavation beam from the excavation site.

5. The system of claim 1 , wherein the transmission line further comprises at least one movable portion to enable the excavation beam to be scanned laterally and / or vertically relative to the earthen material without moving the MMW source.

6. The system of claim 1, wherein the MMW source is further configured to output the MMW radiation in a series of pulses.

7. The system of claim 1 , further comprising: a gas inlet coupled to the transmission line to inject a gas into the transmission line; as well as A sealing device is provided for sealing the distal end of the transmission line to the excavation site so that the excavation site can be pressurized.

8. The system of claim 1 further comprising a mirror to focus the excavation beam from the distal end of the transmission line onto the excavation site.

9. The system of claim 1, wherein the distal end of the transmission line tapers from a larger diameter to a smaller diameter at the distal end.

10. A method of excavating earthen material, the method comprising: generating millimeter wave (MMW) radiation with a free-space wavelength in the range of 0.1 mm to 30 mm using a millimeter wave (MMW) source; coupling the MMW radiation to a transmission line; directing the MMW radiation to an excavation site having the earthen material using the transmission line; forming a tapped beam radiating from the MMW at a distal end of the transmission line; The digging beam is used to generate a beam with a power of at least 10 kW / cm 2 irradiating the soil material at the excavation site with an irradiance of fracturing the earthen material at the excavation site with the excavation beam; as well as The earthen material disrupted by the excavation beam is removed from the excavation site using mechanical equipment.

11. The method according to claim 10, further comprising: More than 1cm 2 But not more than 100cm 2 The majority of the energy from the excavation beam is deposited into the earthen material at the excavation site in an area of ​​the excavation site and to a depth of 0.1 cm to 20 cm in the earthen material.

12. The method according to claim 10, further comprising: forming a chamber to enclose the distal end of the transmission line and the excavation site; as well as Gas is injected into the chamber, causing the excavation site to be pressurized.

13. The method of claim 12, further comprising delivering energy from the excavation beam to the earthen material at the excavation site to increase the pressure of the excavation site to a pressure level that is 10 times or greater than the local ambient pressure outside the chamber.

14. The method of claim 10, further comprising moving the distal end of the transmission line relative to the earthen material without moving the MMW source.

15. The method according to claim 10, further comprising: forming a trench in the earthen material with the digging beam; inserting a hydraulic device into the groove; as well as A portion of the earthen material is broken from the trench using the hydraulic device.

16. The method of claim 10, further comprising reflecting the digging beam off a mirror to focus the digging beam at the digging site.

17. The method of claim 10, wherein removing the earthen material disrupted by the excavation beam comprises blowing at least a portion of the earthen material disrupted by the excavation beam and / or any melted earthen material away from the excavation site with pressurized gas.

18. The method of claim 10, further comprising delivering an additive to the excavation site to change the viscosity of the molten earthen material flowing at the excavation site.

19. A method of excavating a tunnel through earthen material, the method comprising: generating millimeter wave (MMW) radiation using a MMW source; coupling the MMW radiation to a transmission line; directing the MMW radiation to an excavation site on a surface of the earthen material using the transmission line; directing an excavation beam formed by the MMW radiation at the distal end of the transmission line toward the earthen material at the excavation site; melting the earth material at the excavation site with the excavation beam to form melted earth material; as well as The holes in the surface of the tunnel are sealed with the melted earthen material to prevent water from flowing through the holes.

20. The method according to claim 19, further comprising: forming a chamber enclosing the distal end of the transmission line and the excavation site; More than 1cm 2 But not more than 100cm 2 depositing a majority of the energy from the excavation beam into the earthen material at the excavation site and to a depth of 0.1 cm to 20 cm in the earthen material; and Gas is injected into the chamber so that the excavation site is pressurized to force the molten earthen material into the hole.

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