Patent Application
20230074184
Microwave energy can be radiated within an enclosure to process materials. Molecular agitation within the material resulting from its exposure to microwave energy provides energy to heat, dry, weaken, expand, fracture, etc. the material. Applying a desired amount of microwave energy to the material can take a certain amount of time based on various factors, e.g., general or specific to the intended use of the material in its final processed form.
Many industrial microwave heating applications require that there be access apertures into the enclosure so that materials may be continuously transported utilizing such as, for example, a conveyor unit or other mechanism. Some government agencies allocate frequency bands centered at 915 MHz and 2450 MHz for use in microwave heating systems. The intensity of the microwave energy that is permitted to leak is sometimes restricted to less than 10 milliwatts (mW) per centimeter squared.
There is a desire for suppression of microwave energy from these apertures. Continuous microwave heating arrangements have presented a problem that is more complex than the suppression of microwave energy from a simpler batch microwave system.
While applying microwave heating to materials, such as moisture-containing particles, a problem can include preventing microwaves from escaping to an inlet and/or an outlet/discharge region from a channel or region where the microwaves are applied. This can be handled at present by introducing material through a metal grate including two by two inch (5.1 by 5.1 cm) square channels. The same type of grate and channels can be employed on an outlet end. However, these grates have limitations. For example, granular materials or particles (such as moisture-laden granular materials) are sometimes introduced through a square channel system. In these systems, a blockage or slowdown in the process can occur. For instance, larger chunks of material may have difficulty passing through the grates unless the size of the grate's square metal channels are increased accordingly.
Other technological approaches are currently used to prevent potential harmful effects of microwave emissions, but can be less flexible than desirable. For example, other ways of suppressing microwave energy from escaping from a microwave system as a product or material is moving through can include, for example, water jackets or reflectors.
There remains a desire to improve microwave suppression, especially in continuous microwave heating systems. There also remains a desire to provide modular and/or portable heating systems that can be flexibly deployed as needed.
It is also known that at present, mining operations and sometimes related material processing often leads to large stockpiles of unused and/or mining materials (e.g., gangue, tailings, overburden, slurries, etc.) that result from mining of desirable minerals for extraction from ore or the like. Material recovery and mining can use heat to improve mineral, metal, gemstone, etc. separation or extraction, e.g., copper from copper tailings.
There also exist challenges related to mobile deployment of heating systems for mining and related material processing, particularly in areas where a reliable permanent power source may not be present or accessible.
Furthermore, where heat is used to assist mineral and material extraction, much energy is used and often wasted. Heating of mining related materials is often very energy intensive. Processing costs can therefore be improved for mining when by making heating more efficient. Therefore, many challenges remain.
This disclosure relates to microwave-based heating methods and systems for improving mineral, metal, gemstone, rock and other valuable material or natural resource extraction from various precursor materials especially as applied to various mining and processing operations. Microwave heating can be used for various mining uses and can provide effective and efficient improvements to mining, separation, extraction, and other processing of otherwise difficult and/or expensive to process materials, including minerals, metals, and the like.
In particular, aspects of this disclosure relate to a continuous system for using a microwave heating process at the point of extraction, such as at or near a mining site or precursor material repository, such as a pile, silo, vessel, trucking operations, or railroad car or facility. Alternatively, the microwave heating process can be conducted at a processing facility located a distance from a mining site, for example. The disclosed material processing systems can be used in any suitable location, and can be stationary/permanent or mobile in various embodiments. Also disclosed and contemplated are batch-type systems for heating and/or fracturing various raw precursor materials from which desirable minerals, metals, materials, and the like can be extracted.
According to the present disclosure, modular heating systems can be arranged to be sequentially configured as multiple conveyor units, mechanical processors, and lifting units. Further arrangements provide at least partially parallel arrangements of multiple conveyor units, optionally in combination with sequential arrangements. Disclosed embodiments are fully scalable according to particular desired requirements, specifications, and circumstances.
Also disclosed are embodiments of a microwave energy suppression tunnel and system with one or more flexible or bendable (e.g., steel) microwave reflecting components, such as mesh flaps, for substantially reducing or preventing the leakage of microwave energy from a microwave vessel, e.g., on a conveyor unit, while having a continuous flow of material through the vessel and suppression tunnels. The suppression tunnels can be installed on the inlet and the outlet side of the vessel and are sized to suppress leakage of the microwaves produced by the microwave system, whatever the size of the constituent parts or chunks of the material.
Stated differently, embodiments of the invention include the addition of at least one microwave energy suppression tunnel configured for substantially preventing the leakage of microwave energy from one or more access openings in a microwave energized system while the material to be heated is flowing, e.g., continuously, through the microwave vessel, including, for example, a trough of a conveyor unit also fitted with a helical auger. The suppression tunnel can be used at inlets and/or outlets of the microwave energy system, and in some embodiments each suppression tunnel comprises a rectangular, U-shaped, or other suitably shaped tunnel about three feet or more in length installed flat or at an angle of preferably no more than about 45 degrees with multiple plies or layers of steel or other microwave material, such as metallic shielding mesh attached to the inner top of the rectangular or U-shaped tunnel or trough. The size of materials to be heated can be used as a guideline for adjusting tunnel or trough size for various embodiments. The tunnel and trough of the heating system can be sized and shaped differently in various embodiments.
Flexible or bendable mesh shielding (e.g., in the form of flaps) can be spaced at various intervals and be the same cross-sectional size as the tunnel in which they are mounted. The shielding mesh preferably operates to absorb, deflect, or block various frequency ranges, preferably from about 1 MHz to 50 GHz in radio frequency (RF) and low frequency (LF) electric fields.
Comminution (e.g., crushing or grinding), mixing, sizing, sorting, screening, transporting, filtering, blending, cooling/freezing, and/or introduction of liquids (e.g., quenching or saturation for freezing) steps are also contemplated in order to improve material processing and extraction performance. Optionally, the application of microwave energy and heating as disclosed herein can be continuous and/or pulsed or otherwise varied according to various material characteristics and the like.
According to a first aspect of the present disclosure, a system for processing precursor material is disclosed. According to the first aspect, the system includes a material inlet and a material outlet. The system also includes at least a first conveyor unit associated with at least one of the material inlet and the material outlet. The system also includes at least one microwave generator. The system also includes at least a first microwave guide operatively connecting the at least one microwave generator to at least the first conveyor unit. According to the first aspect, the first conveyor unit is provided in a first housing that includes at least one microwave opening configured to receive microwave energy via at least the first microwave guide. Also, according to the first aspect, at least one microwave suppression system is associated with the first conveyor unit. According to the first aspect, each microwave suppression system includes a tunnel associated with at least one of the material inlet and the material outlet, and at least one flexible and/or movable microwave reflecting component included within the tunnel, where at least a portion of the at least one microwave reflecting component is configured to be deflected as a quantity of precursor material passes through the tunnel and then to return to a resting, closed position when the precursor material is no longer passing through the tunnel. Also, according to the first aspect, the first conveyor unit is configured to receive and process the precursor material, the processing including heating the precursor material to at least a first temperature by applying microwave energy to the precursor material within the first housing.
According to a second aspect of the present disclosure an apparatus for processing precursor material is disclosed. According to the second aspect, the apparatus includes a material inlet and a material outlet. The apparatus also includes a conveyor unit including an auger having an auger shaft provided along an auger rotational axis, the auger configured to rotate in a direction such that a quantity of precursor material received at the conveyor unit is caused to be transported according to the auger rotational axis. The apparatus also includes at least one microwave energy generator, each microwave energy generator being operatively connected to at least a respective microwave guide configured to cause microwaves emitted by the microwave energy generator to heat the precursor material within the conveyor unit by converting the microwaves to heat when absorbed by at least a portion of the precursor material within the conveyor unit. The apparatus also includes at least a first microwave suppression system including a tunnel associated with at least one of the material inlet and material outlet, where the first microwave suppression system includes at least one flexible and/or movable microwave reflecting component within the tunnel, where the at least one microwave reflecting component is configured to absorb, deflect, or block microwave energy, and where the at least one microwave reflecting component is configured to be deflected as the precursor material passes through the tunnel and then to return to a resting, closed position when the precursor material is no longer passing through the tunnel. Also, according to the second aspect, the precursor material is heated using the microwave energy, and where the precursor material is caused to a) be heated to at least a first temperature or b) to receive sufficient energy to reach a first reaction point, by the microwaves emitted by the at least one microwave generator.
According to a third aspect of the present disclosure, a method of processing precursor material using microwave energy is disclosed. According to the third aspect, the method includes receiving a quantity of precursor material at a conveyor unit, where the precursor material passes through at an inlet microwave suppression tunnel before entering the conveyor unit, where the inlet microwave suppression tunnel includes at least one flexible and/or movable inlet microwave reflecting component within the inlet microwave suppression tunnel, and where the at least one inlet microwave reflecting component is configured to absorb, deflect, or block microwave energy. The method also includes deflecting the at least one inlet microwave reflecting component as the precursor material passes through the inlet microwave suppression tunnel and then optionally returning the at least one inlet microwave reflecting component to a resting, closed position when the precursor material is no longer passing through the inlet microwave suppression tunnel. The method also includes transporting the precursor material using at least the conveyor unit. The method also includes heating the precursor material within at least the conveyor unit using at least one microwave generator operatively connected to a respective microwave guide configured to cause microwaves emitted by the microwave energy generator to heat the precursor material within at least the conveyor unit by converting the microwaves to heat when absorbed by at least a portion of the precursor material within at least the conveyor unit. The method also includes causing the precursor material to exit through an outlet microwave suppression tunnel after the precursor material is heated such that at least a portion of the precursor material: a) reaches a first temperature and/or b) undergoes a reaction within at least the conveyor unit.
According to the present disclosure, many challenges currently exist in processing materials, particularly mined materials, metals, and minerals which in initial or raw/rough form are generally referred to more generally as precursor materials in this disclosure. Precursor materials, such as copper tailings, can be received for processing before (or in some cases after) initial breakage, mining, removal, or extraction, such as rough extraction. For example, pure copper can be extracted from copper tailings, which can contain desirable copper in addition to other substances and materials. In some cases, precursor materials can contain more than one desirable constituent substances, which may be desirable to extract and/or isolate from other substances within a precursor material, e.g., both copper and nickel.
Processing materials as contemplated herein includes heating (or otherwise applying energy to) an extracted mineral-based material or composition, e.g., based on a quantity, chemical composition of material, moisture content, a desired final heating temperature, fracture point, other physical or chemical reaction, desired or observed temperature, state, or the like, using microwave energy while continuously moving the material during processing.
As used herein, material can refer to any mineral or substance of value that can be removed, extracted, mined, or otherwise sourced from natural or artificial deposits as known in the art, for example in rough precursor material form. For example, material can refer to any geological mineral, metal, gemstone, and other valuable material especially that is found naturally in the ground or any type of deposit. Desirable minerals can be found in various assemblages of various mineralizations and the like, including various ores, lodes, veins, seams, reefs, placer deposits, tailings, overburden, and the like. Deposits containing primary and any number of secondary ores and assemblages of materials are contemplated herein. It is common that at least some desirable material would be discarded incidentally during various stages of mining and/or processing. Furthermore, a precursor material in some cases can be previously processed, such as copper tailings and the like. In such a case a precursor material is in a second (or third, etc.) processing phase, and can be beneficially reprocessed according to embodiments herein.
Although various forms of material processing using microwave energy are contemplated in this disclosure, removal of precursor materials from a source (e.g., a mine or other deposit, including natural deposits, is generally referred to as “removal” in this disclosure, and processing and further breaking down and separation of materials once removed is referred to herein as “extraction,” among other terminology such as “fracturing,” “liberation,” “loosening,” etc. According to various embodiments of the present disclosure it is possible to use microwave heating methods and systems to more fully extract the valuable portions from the non-valuable (or secondary) portions of mined precursor materials. It is known that most materials contain at least some electrons and are thus able to be heated using microwave energy.
Precursor materials, or materials more generally in this disclosure, include minerals and ores among any number of other materials, any of which include metals, coals, oil shales, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, clay, among others. Examples of metals that can be extracted and/or processed as described herein, include but are not limited to gold, silver, platinum, copper (e.g., as found incorporated in copper tailings, porphyry copper deposits, etc.), aluminum, and nickel, among many others. Materials as used in this disclosure can include one or more of the following, combinations and variations thereof, among any other material that can be sourced or mined; barium, bauxite, cobalt, fluorite, halite, iron ore, lead, lithium, manganese (including ore), mica, pickle, pyrite, quartz, silica/silicon, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, sodium carbonate, sulfur, tantalum, titanium, uranium, vanadium, zeolite, zinc, gypsum, rhodium. Gems are also contemplated, such as amethyst, diamond, emerald, opal, ruby, turquoise, rose quartz, sapphire, etc. Yet other materials contemplated include sand, phosphate rock and other phosphors, feldspar, beryllium, molybdenum, zirconium, magnesium, chromium, strontium, bismuth, mercury, tin, tungsten, niobium, cadmium, gallium, iridium, tellurium, sulfide ores, cassiterite, and any rare earth elements, metals, etc.
As used herein, an initial material to be processed for extraction can be referred to as a precursor, raw, or rough material, tailing, or the like. A desirable and/or valuable material, such as a mineral or metal, to be extracted can be generally referred to in this disclosure as a resulting extracted or separated material or constituent substance or material thereof. Various materials for processing can be flowable, or partially flowable, whether in liquid or solid form, including dust or very small particles. Comminution or other mechanical processing of materials can further make materials relatively more flowable (e.g., smaller particle or chunk size of the material) as desired.
In various embodiments of processing using the application of microwave energy, a precursor material containing one or more type of desired material to be extracted is heated to a point such that the component minerals, metals, or the like of the precursor material matrix fracture more easily for separation and/or sorting; making desired material(s) more accessible in the process. One concept of heat-assisted materials processing is referred to as thermally-assisted liberation (TAL). For instance, various materials have corresponding coefficients of thermal expansion that vary from other materials, causing relative movement and separation during heating and extraction.
Optionally, water or other liquid is added to a precursor material, before, during, or after microwave heating/processing. For example, water or other liquid or fluid can be used to rapidly cool or “quench” the heated materials to further assist fracture and/or separation of valuable materials from non-valuable parts to be discarded and/or processed further for various purposes. In other embodiments, liquid can optionally be added to precursor materials, after which the precursor materials with or without the liquid are intentionally cooled below ambient temperature (e.g., freezing). This rapid cooling process can occur before or after heating to allow for easier extraction. Various cooling steps can occur before or after introduction of precursor material to one or more conveyor units described herein. Liquids such as water typically expand upon reaching their freezing point(s), converting thermal energy to mechanical energy; thus, providing a mechanism for size reduction of precursor materials. In some embodiments, the liquid is introduced to the precursor materials to partially or fully saturate the precursor material (e.g., into a slurry or slurry-like flowable composition), followed a freezing step, and then followed by a rapid heating (e.g., using microwaves) to the point of a phase change of at least he introduced liquid into gaseous steam.
Although liberation, separation, and extraction are contemplated, any form thermally-assisted processing of any material for any purpose, including removal, is also contemplated herein. Microwave heat-assisted comminution or other types of microwave-assisted mechanical processing more generally are also contemplated herein.
Certain alternative contemplated configurations use a “batch” style heating and processing system. In batch systems, a quantity of material is heated and/or mixed together as a single stage and then is dispensed. It is often desirable to have more flexibility than a batch-style heating system affords because flexible operation of the heating and/or mixing system is preferred. Continuous-type heating and/or mixing systems (as shown in embodiments herein) can be preferable because they can provide greater efficiency, control, and flexible scalability and operation, among other benefits. Batch-type systems for heating mineral-laden materials for use in mining removal, extraction, liberation, and other processing are also contemplated herein.
Using microwave-based heating of precursor materials for extraction has many benefits over other forms of energy application, e.g., heating. An overview of heating as it applies to mining and material processing is provided in “The Development and Application of Microwave Heating” (2012) by S. M. Javad Koleini and Kianoush Barani (“Koleini et al.”). Koleini et al. includes Chapter 4, titled “Microwave Heating Applications in Material Processing,” which is hereby incorporated by reference in its entirety for all purposes. Koleini et al. provides a brief history of heating as it pertains to material processing, including various applications of microwave heating to material processing applications and further citations to other scholarly works referenced therein up to contemporary times.
Also incorporated by reference for all purposes herein is “The influence of microwave irradiation on rocks for microwave-assisted underground excavation” (2015) by Ferry Hassani, Pejman M. Nekoovaght, and Nima Gharib in the Journal of Rock Mechanics and Geotechnical Engineering 8 (2016) 1-15. Also incorporated by reference for all purposes herein is “Recent developments in microwave processing of minerals) (2006) by Samuel Kingman in the International Materials Reviews—February 2006. “Twenty years of experimental and numerical studies on microwave-assisted breakage of rocks and minerals—a review” by Khashayar Teimooi and Ferri Hassani. (2020) is also incorporated by reference for all purposes herein.
More generally, and separate from the details of materials processing using microwave energy, challenges also exist relating to microwave emissions escaping a material processing and heating system. At high material flow rates in a continuous microwave material processing system, microwave energy leakage can be particularly undesirable and challenging.
Another common complication for materials processing relates to rapid distribution and deployment of heating apparatuses to remote or non-grid-connected regions or situations. Microwave-based heating is generally more portable than other types of heating apparatuses and allows for portable generator use to power the microwave heating units (e.g., microwave generators) and systems if grid power is not readily accessible. Some examples of situations where grid power is not available include rural or remote areas, or other areas that have temporarily lost a grid power connection. Some mining processing sites may be located at a distance from any grid power connections or other energy storage solutions.
According to the present disclosure, portable, modular, parallel, and/or sequential heating and/or processing conveyor units can provide a modular, scalable, and portable system for heating extracted materials even in remote, or otherwise off-grid mining or processing locations. In some embodiments, sharing of portable material processing systems between multiple mining locations and/or processing facilities is also contemplated. Stationary, semi-permanent, and permanent embodiments are also contemplated. Various mechanical processing apparatuses and/or lifting conveyors can also be used in-line at any location with the conveyor units as suitable. Packaging various operative components within or attached to containers or other housings, such as shipping containers, can further simplify and streamline rapid and simple distribution, setup, and operation.
Further, various microwave suppression systems and features, such as included in or related to inlet/outlet tunnels can be sized to accommodate the size of the flow of whatever received or raw material is being processed (e.g., heated), such as various precursor materials and the like. Crushing, comminution, screening, filtering, sorting, blending, mixing, transporting, mechanically homogenizing, and the like are also contemplated and can be performed before or after receiving materials at the processing system.
In some embodiments, a microwave heating system of the present disclosure can be configured to process/heat about 100 U.S. tons (90.7 metric tons) of received precursor material per hour or more according to various specifications and standards, although the process could be scaled to accommodate quantities of less than 100 U.S. tons (90.7 metric tons) of material per hour and reach target specifications. For example, certain types of material can comprise a greater amount of moisture than other types of material. A rated capacity of a system can be configured based on an end goal of a particular facility and/or site. For instance, one goal may be to assist material processing by fracturing the various materials according to desired and known specifications. These specifications may therefore require less energy and allow for higher throughput than certain other specifications. It is known that various substances can react differently to microwave heating. Some materials readily absorb microwave energy and heat, and others are nearly inert to microwave energy. Some substances are more susceptible to pulsed or varied intensity of microwave energy received. Throughputs and configurations can be determined based on end goals and targeted specification of a user, entity, regulation, or standard.
In order to reduce microwave leakage from a processing system, one or more microwave suppression systems (e.g., tunnels or chutes) comprising one or more (e.g., flexible and/or movable) microwave-blocking fabric and/or mesh flaps can be used at one or more openings within a microwave-based heating system in order to reduce microwave emissions that would otherwise reach the outside of the microwave heating system. Each microwave suppression system can comprise a flap or series of flaps that are capable of and configured to cover one or more inlets and/or exits from a microwave heating system. The microwave suppression systems can prevent or suppress the escape of microwave emissions from the material heating system. Therefore, one or more of the microwave-blocking fabric and/or mesh flaps can be positioned at outlets and/or inlets of the continuous microwave material heating system. Each flap can be generally shaped to conform to a shape of a corresponding suppression tunnel, chute, or the like. Outlets and/or inlets of the continuous microwave heating system can include one or more suppression tunnels. In particular, moisture-laden or dry material, mineral, or other component particles or precursor material can be allowed to enter into the heating region of microwave heating while microwaves are simultaneously substantially prevented from escaping a heating trough via the suppression tunnels within the system. As multiple modular heating and processing conveyor units (e.g., including augers) can be arranged sequentially and/or in parallel, various material inlets and outlets are particularly suitable for microwave suppression systems, including tunnels and other related features. In preferable embodiments, separate suppression systems such as tunnels are supplied and connected to both an inlet and an outlet of a system. In other embodiments, additional suppression tunnels or related features can be included intermediately within a precursor material flow path or otherwise to the system such that more than two such suppression systems are included in order to maximize microwave suppression from any number of openings in the system.
It is known that microwave energy is particularly efficient for heating water (e.g., water molecules), which leads to efficient microwave heating of materials that include at least some of such water molecules. Precursor materials (including slurries thereof) in some embodiments disclosed in this disclosure can contain about 2-10% water, although embodiments containing less than 2% (even 0%) or more than 10% water are also contemplated herein. Water can escape a material in the gaseous form of steam when the water is heated to its boiling point (e.g., about 212 degrees Fahrenheit [° F.] or 100° C.). Steam can escape from a heating system through natural convective ventilation, and in some cases by forced ventilation, through positive or negative pressure applied to the system (e.g., an air blower or fan to expedite or assist ventilation). Vents can also be added to improve ventilation and facilitate steam escape characteristics. However, excessive quantities of water can have a negative effect on heating mineral or other materials. Furthermore, heat exchangers can be used to reclaim heat released as steam (or otherwise) during microwave heating processes, and in particular heat that is emitted from the phase change (e.g., boiling) of water when the material containing at least some water is heated.
In some typical cases, extracted or reprocessed precursor material can be about 4-7% water content by weight, or any other percentage according to each situation. In other examples, precursor material can be less than 4% or greater than 7% water content by weight. In cases where a liquid is introduced to the precursor material for freezing, a water content can be relatively higher prior to heating.
Heating a quantity of precursor material to a temperature above the boiling point of water (about 212° F. or 100° C.) can therefore in some cases be less efficient because the water particles boil off and escape as steam. During heating organic or inorganic precursor materials (or compounds) to certain temperatures (or other reaction, such as at a reaction point, or a total quantity of energy received or absorbed), e.g., at or above a boiling point of water, the water that the microwaves can easily heat through molecular oscillation can decrease. Heating of the precursor material then becomes reliant on the microwaves' oscillation of materials other than water and require more energy.
A phase change of liquid water to gaseous steam can occur around 180-212° F. (82-100° C.) depending on air pressure or vacuum, and it can be desirable to heat a material, e.g., a precursor material, to any temperature (or other reaction point) such that the precursor material reaches a temperature (and optionally for a certain time). Heating to a temperature or reaction point as used herein can include applying microwave energy to a precursor material such that, e.g., a dielectric stress between various constituent materials of the precursor material, such as between precious metal(s) and a conglomerated material containing the metal(s), becomes sufficient to assist extraction, according to various embodiments. Steam that is produced from the heating can escape the heating system via vents once the phase change occurs.
As used herein, a “reaction point” can be any stage of reaction of at least one precursor material, including any reaction from a complete fracture or liberation, or any measurable reaction of at least one precursor material as a result of applied microwave or any other energy to the precursor material. It is also contemplated that a precursor material can contain more than one constituent substance, and thus each substance can have one or more reaction points, and any number of substances and reaction points are therefore contemplated herein.
According to various embodiments contemplated in this disclosure, steam and/or other heat produced and/or emitted during microwave heating can be captured for re-use using one or more air-air, and air-liquid heat exchangers or the like. The steam can exit the system by natural and/or forced ventilation. In some embodiments a carbon scrubber or other filtration or emission capture system can be implemented that is configured to trap or scrub emitted steam, vapor, particulates, and/or odors that result from material processing. In various embodiments, carbon scrubber technology can be used in combination with one or more condensate units.
According to various embodiments the material to be heated and/or processed is a precursor material or other material. In certain embodiments the material can comprise various particles, such as particles to be heated. The material, e.g., extracted or mined precursor materials, can have an initial, first maximum particle or chunk size or hardness. The initial, first particle or chunk size or hardness can be reduced to a second, smaller size by a component or feature of or operatively coupled to at least one of the first and second conveyor units, such as a mechanical processing apparatus or baffle as described herein. Any other suitable mechanical processing apparatus or component for reducing particle size, such as a crushing device, screen, filter, sorter, separator, shredder, mixer, mesh, brush, mill, press, or the like, is also optionally included in various embodiments. If present, the mechanical processing apparatus, can be separate from the first and second conveyor units. Sensed torque load (or motor rotational speed, etc.) on a motor in a conveyor unit can be used as a proxy for hardness, viscosity, density, type, mix, composition, and/or size of precursor materials being processed.
According to various embodiments, and as discussed above, the precursor material typically contains at least some water. Optionally, the precursor material contains less than 7 percent water by weight, and in other embodiments less than 4 percent water by weight. In various further embodiments, the precursor material contains at least 7 percent water by weight. In yet further embodiments, the precursor material contains less than 4 percent water by weight. In yet further embodiments, the precursor material contains between 2-10 percent water by weight. In even yet further embodiments, the precursor material contains between about 1-15 percent water by weight. As discussed herein, in at least some embodiments, one heat exchanger apparatus configured to recover a heat byproduct from the precursor material. In some embodiments the heat byproduct is recovered from the steam resulting from a heating of the water within the precursor material.
In some embodiments, one or more additives, such as water, can be added to precursor material to be heated and at various stages before, during, and/or after processing. Examples of additives contemplated herein include cyanide, sodium cyanide, potassium cyanide, hydrocyanic acid, nitriles, any other compound from the cyano group and the like or combinations thereof. Another example of an additive contemplated herein is NaCl (sodium chloride, or table salt). Various additives can provide a number of different properties when added to material before, while, or after being processed. For example, additives can increase microwave energy absorption and efficiency during heating or can reduce odor or other material processing emissions. In other examples, additives like cyanide, can be added to precursor materials before processing, in various quantities, and for various periods of time.
Optionally, water or other liquid can be added to a heated material during or after a microwave (or any other) heating process. This added liquid can rapidly cool the heated material is a process known in the art as “quenching.” As discussed herein, in various embodiments precursor materials can be cooled below ambient temperatures, and in some cases frozen, before or after heating for improved ease of material extraction, fracture, and separation.
In some embodiments, a continuous microwave heating process can include ramp-up time, hold time, process time (e.g., based on time and temperature of processing), and various heating peaks. Mixing of precursor materials of differing physical properties can improve performance during microwave heating, according to some embodiments.
A continuous microwave heating system can be sized in order to get a desired material processing throughput and to accommodate the physical size of the precursor material being processed. This can be due to limitations, such as with existing heating, mixing, and tunnel design in view of target processing specifications as described herein. An example of (e.g., steel) mesh or fabric flap design of a microwave outlet suppression tunnel 200, as shown in
Heating, treating, cooling, freezing, wetting, drying/dehydrating, condensing, breaking, shredding, filtering, fracturing, loosening, separating, liberating, crushing, milling, sorting, sifting, shaping, lifting, moving/transporting, extracting, mixing, etc. (collectively “processing”) of materials such as precursor materials is contemplated herein. Processing steps can involve naturally occurring (e.g., freezing) and/or artificial or human-made steps (e.g., microwave heating). However, any one type of suitable material or tailing, chunk, or clump including one or more materials can be heated, such as any other mineral that can be heated, and conveyed or flowed through a microwave heating system. For example, mining material can include any type of mined or sourced material, especially found at sites in a mine. Other applications of the microwave heating of materials are also contemplated. Various applications of microwave-based processing of materials discussed herein are applicable on Earth as well as other celestial bodies (e.g., moons, asteroids, etc.), spacecraft, and/or in space according to various embodiments. As discussed herein, a post-processed (or in some cases at least partially processed) precursor material can be referred to as a product or the like.
One usage of microwave-based processing of various materials, such as mined minerals, is for microwave-assisted breaking. For example, norite, granite, and basalt can have high strength and therefore associated difficulties related to breaking and comminution absent assistance, such as heat-related comminution assistance. Tensile and uniaxial strengths, such as compressive strengths of materials, can be reduced with increased exposure time and power levels of microwave-based heating and processing. Therefore, a microwave power level correlates to a level of heat at a material (e.g., rock) surface during mining and/or processing. Microwave-based mining and applications can reduce energy consumption, e.g., during comminution of various materials (e.g., ores) and can also make removing and separating the desirable portions from undesirable portions of mined or sourced rock material easier.
Embodiments of the present disclosure can be applied to hard rock material breakage. Hard rock breakage, a type of material processing, involves separating a portion of rock from a larger, parent, (e.g., precursor material) deposit. Hard rock breakage can include material extraction and/or removal, as used herein. Typically, various bits and tools are used for boring and mining extraction (including removal and/or extraction). These bits and tools often are subject to intense wear and need to be replaced frequently. By using heat, and especially microwave-based heat, various rocks and deposits can be softened or weakened such that bit and tool wear is reduced. Fuel and energy consumption can also be reduced, in addition to less time requirements for mining or material processing. Contemplated in this disclosure is processing of chunks of material such that desirable portion or portions of the chunks are more easily separated and extracted (or removed) from a larger chunk received at a microwave-based material processing system.
For processing, a deposit or chunk of rock or other precursor material can be heated through the application of energy and therefore weakening or broken to a degree based on time and power of a microwave generator. The compositions of the rock or material being processed also affect breaking and processing characteristics. Some materials, such as calcite, are fully transparent to microwaves, while others, such as pyrite, are efficient microwave absorbers. Roughly 3-200 kW of microwave power can be used in a particular system, but any power level is contemplated according to situation and specifications. Microwaves heat up materials based on various dielectric properties, and different portions of different rocks and materials are therefore heated at different levels according to the varying dielectric properties thereof.
Certain embodiments of the present disclosure are more specifically directed to microwave-assisted comminution of materials. Various materials, such as rocks and ores, can be more easily ground into smaller pieces with the assistance of microwave-based processing and heating as described herein. In various embodiments, cutters or grinders, such as disc-based cutters, can also be incorporated for material breaking and separation for reducing size or otherwise breaking down material deposits into small pieces or various shapes and the like according to various system constraints.
Various embodiments of heating and/or processing systems discussed in this disclosure can have various total weight, and/or throughput capacities, depending on dimensions, power capacity, arrangements, and the like. In some embodiments, a continuous material processing system discussed herein has a capacity of about 10-1000 U.S. tons (9.1-907.2 metric tons) of precursor material per hour. In further embodiments, the capacity can be between 50-100 U.S. tons (45.4-90.7 metric tons) of precursor material per hour.
According to
Shown in
In one embodiment, microwave heating unit 151 can be a microwave power system sourced from Thermax Thermatron. The microwave heating units 151 can have a variety of shapes and sizes according to the requirements of the continuous heating process and system 100. Each microwave heating unit can apply about 100 kW of power to the precursor material being heated and preferably operates at about 915 MHz. In various embodiments, various quantities of microwave energy can be received by the precursor material while in a conveyor unit. Various conveyor units described in this disclosure (e.g., conveyor unit 152) can have a nominal weight capacity of about 500-40,000 lbs (227-18,144 kg). In some embodiments, the conveyor units can each have a weight capacity of about 8,500 lbs (3,856 kg) of precursor material at a point in time.
Various embodiment waveguide 153 configurations and embodiments for a single conveyor unit 152 are shown in
Still referring to
Various entry points for microwaves via the multiple waveguides 153 in a top of trough 102 are shown in
In the conveyor unit 152 configuration of
As shown, the auger 106 can be helical, and in some embodiments the auger 106 can be single helical or double helical, among other variations. In yet further variations, a single trough 104 can comprise two separate augers 106, which can be counter-rotating or otherwise (not shown). As shown, a fluid connection can be attached to one or more ends of the auger 106, which can be used for additional auger-based heating or cooling of precursor material being produced.
A first conveyor unit 152 receives a precursor material to be heated, and the system 150 operates sequentially by passing the precursor material to a second conveyor unit 154 following the first conveyor unit 152, and to a third conveyor unit 156 following the second conveyor unit 154. One (optionally more than one) optional mechanical processing apparatus, e.g., mixer 158 (described in greater detail with reference to
In particular, the mixer 158, an example of a mechanical processing apparatus, can be located sequentially after an outlet of the second conveyor unit 154, and the lifting conveyor 160 can be located sequentially after the mixer 158 and before the third conveyor unit 156. The mixer 158 can be a pugmill, a drum mixer, mixing chamber, or any other type of suitable mixer or other mechanical processing apparatus, as known in the art.
As described and shown in this disclosure, any number of conveyor units 152, 154, 156, etc. and any number of mixers 158, lifting conveyors 160 can be utilized in various systems such as 150. Various power levels to be applied at least conveyor unit 152 are also contemplated. Moreover, the various components within the system 150 can be arranged in any suitable order according to a desire or need. Furthermore, microwave suppression tunnels (e.g., 200, 202) are preferably utilized at various inlets and/or outlets of the system 150 according to various embodiments.
The various conveyor units 152, 154, 156 can positioned such that the first conveyor unit 152 is vertically elevated and that the second and/or third conveyor units 154, 156 are positioned sequentially lower than the first conveyor unit 152 so as to utilize gravity to facilitate movement of material being heated between the various conveyor units when in use. In some embodiments, one or more lifting conveyor 160 can also be utilized to lift or raise the precursor material being heated and reduce a total amount of height required for various conveyor units. Although not shown, additional lifting conveyors can be used before or after processing of the precursor material, such as to receive materials to be heated or to form a pile of processed materials after processing.
When arranged sequentially, the first conveyor unit 152 can heat the flowing precursor material to a first temperature (and/or a first reaction point of at least one precursor material or a constituent substance thereof), the second conveyor unit 154 can heat the material to a second temperature (and/or a second reaction point of at least one precursor material) greater than the first temperature, and the third conveyor unit 156 can heat the precursor material to a third temperature (and/or a third reaction point of at least one precursor material) that is greater than the second temperature according to various embodiments. Each conveyor unit preferably applies energy (e.g., heats) the precursor material using microwave energy as the material flows and such that a third or final desired temperature (and/or a final reaction point of at least one precursor material) is reached before the precursor material exits the heating and/or processing system, e.g., after achieving a desired heating, reaction, and/or time specification per various regulations.
The various conveyor units 152 can heat the material to the first temperature (and/or reaction point) for a first amount of time, and similar to the second, third, etc. temperatures (or reaction points). Each temperature can have an associated time therewith, such as to meet certain specifications of heating or an associated chemical, physical, or other reaction. Alternatively, a temperature and/or time can be set variably based on a sensed reaction or state of material being processed, e.g., when a certain state, point, fracture, separation, expansion or the like has been achieved, such as according to certain specifications, regardless of temperature and/or time for processing.
Any conveyor unit, such as the first conveyor unit 152, can further include a baffle 108 (see
In some embodiments, the precursor material to be processed, before or after passing the baffle 108, has a maximum material chunk diameter or size of about eight inches (20.32 cm). In other embodiments the maximum chunk diameter is about six inches (15.2 cm). In yet further embodiments, one or more mill or other mechanical processing apparatus is utilized (as described herein), which can include one or more mill, mixer, impactor, shredder, and/or comminution device, which can be used to reduce a maximum largest dimension of the precursor material chunk (e.g., an ore, etc.). In some embodiments at least some precursor material is crushed or reduced in size within or prior to entering the first conveyor unit 152. Other conveyor units can also include various types of baffles (e.g., baffle 108) or other restrictive or material guiding members or features. In other embodiments, the precursor material is received as a semi-solid, slurry, liquid, or any other at least minimally flowable state. During heating the precursor material can progressively become more solid and less flowable as water is evaporated or boiled off the precursor material, e.g., a slurry of the precursor material.
Mobile and/or modular multi-conveyor continuous processing systems, such as systems 180 or 190, can be beneficially modular and easily transported. With mobile and/or modular systems, scalability of production can be improved because additional mobile units can be added for a jobsite as needed, provided there is sufficient space, and without having to do any additional fabrication.
As shown in
Each mobile container unit 194, 196, 198 can further be provided with a mechanism for adjusting a vertical position of height of the mobile container unit operative components, such as the conveyor unit. The mechanism can include one or more adjustable height support structures 188, e.g., four with one positioned at each corner of each mobile container unit. The first mobile container unit 194 is positioned at a more raised position, the second mobile container unit 196 is positioned at a less raised position, and the third mobile container unit 198 is positioned at a fully lowered position, e.g., set on a ground or floor without use of the adjustable height support structures 188. Although a mixer (e.g., 158) or a lifting conveyor (e.g., 160) are not shown in the system 180, in other embodiments one or more mixers and/or lifting conveyors can be utilized with the system 180, and can be integrated into one or more mobile container units, such as 194, 196, and/or 198.
As shown in
Shown in perspective cross-sectional view in
An alternative embodiment of a flap 220 for use herein, is instead composed of multiple sub-portions 222, such as strips of microwave blocking, deflecting, or absorbing material, which are attached to an attachment flange 224 of the flap, which is usable for attachment (e.g., pivotable attachment) of flap 220 to an upper portion of the suppression tunnel 220. In yet further alternative embodiments of suppression flaps, chains, combinations of materials, or any other suitable microwave-suppression composition can be utilized.
Flap 214 as shown in
Turning now to
Inlet and/or outlet microwave suppression tunnels (e.g., 202, 200, etc.) can be positioned and connected relative to the continuous heating assembly or system as described herein. During heating operation, it is possible that at least some microwave energy will not be absorbed by material being heated or other components within the assembly. This non-absorbed, escaped, or “leaked,” microwave energy can be unsafe, undesirable, or otherwise beneficial to avoid in practice. In order to address this shortcoming, one or more movable and/or pivotable flaps can be positioned at the inlet tunnel, the outlet tunnel, or both.
In various embodiments, a microwave absorbing, deflecting, or blocking flap, for inlet or outlet of material, such as mineral, can comprise a flexible mesh configured to feely pivot when contacted by moving precursor material as described herein. Inlet and/or outlet microwave suppression tunnels can have rounded, rectilinear, or a combination of the two for an outline along the various tunnels.
In various embodiments, the various microwave suppression tunnels are preferably in a substantially horizontal position, but preferably at an angle of no more than 45 degrees from horizontal.
The embodiments shown in
Many other microwave suppression system flap and tunnel configurations are also contemplated in this disclosure, and the examples above are merely shown as selected embodiments. Various embodiments and alternative cross-section shapes of chute are shown at
Process 630 can start with operations 632 and/or 633. At operation 632 of process 630, one or more hoppers (e.g., containers, piles, trailers, train cars, etc.) or other source of precursor material are received and optionally weighed. At operation 632, the one or more hoppers or other source of precursor material are optionally received and also optionally weighed. Any other material, such as an additional precursor material, quantity of precursor material(s), or various additives as described herein can be received at operation 633. In various alternative embodiments, and as shown at 664, multiple bins of various precursor materials and/or additives can optionally be combined with different and/or other materials (e.g., an additive, a liquid to create a slurry, for freezing, etc.) to obtain a precursor material blend. The optional precursor material blend for processing is referred to as “precursor material” (or simply “material”) below for simplicity. In other optional and alternative embodiments, one or more precursor material can be combined with an additive such as cyanide, e.g., for a matter of time such as hours, days, or weeks in various embodiments, and in accordance with a pile of precursor materials. For example, certain types of precursor material may be mixed in small quantities to another precursor material for processing according to various properties.
Next, process 630 proceeds to operation 634, where a conveyor (e.g., a loader unit) carries precursor material to an optional pre-heater or drier at 635. The precursor (e.g., mined) materials and/or other materials from 632/633 can be assessed, and can be mechanically processed, such as being milled, screened, filtered, sorted, shredded, wetted, or crushed (comminution) at operation 636 (optionally before operation 635). In some cases, it may be beneficial to reduce a chunk size of a precursor material being processed. Optionally, a moisture/water content of the precursor material can be determined or an average moisture content level for the type of precursor material can be estimated and entered, particularly if the precursor material is received as a liquid-based, liquid-suspended, or otherwise finely crushed (e.g., comminution), flowable form, slurry or the like. Various slurries can include particle ranging in size from a grain of sand (or larger) to particles as small as a few micrometers (or smaller). By determining an initial moisture content, the initial weight of the precursor material can be used to predict or determine final dry weight and the mass of water to be removed. Also at 635, energy can be transferred to (or optionally away from) the pre-heater or dryer from a heated (or cooled) medium, such as air or glycol from operation 657, as discussed further below.
Following operation 635, the precursor material can be further moved using another conveyor at operation 637 until the precursor material reaches a microwave suppression inlet chute (or tunnel) at operation 638. Next, the precursor material can proceed to a microwave heating chamber (e.g., a trough of a conveyor unit), which can emit heated exhaust steam at 641, and can receive power via microwaves emitted by a microwave generator at 642 (e.g., via one or more waveguides as discussed herein).
Optionally, the precursor material for processing can then proceed to another microwave heating chamber of another conveyor unit at 640, which can also emit exhaust steam at 643 and/or receive microwave energy from another microwave generator at 644 (e.g., a microwave heating unit, etc.). As shown at 665, multiple heating sections can be added to get the required energy input to reach a specific throughput and/or reach a specification according to a regulation. After the precursor material is sufficiently heated in accordance with desired specifications, the material can proceed to as past a microwave suppression outlet chute (or tunnel) at 645.
As described herein, various mechanical processing steps are optionally performed. After the precursor material passes the microwave suppression outlet chute at 645, optionally the material can enter an agitator or mixer at 646. The precursor material when in the mixer 646 or other mechanical processing apparatus (if present) can emit exhaust steam at 647, and can optionally receive a liquid or other cooling substance for quenching at 648. It is contemplated that in some embodiments no mixer 646 is used, and the microwave heating chamber 640 can proceed to microwave heating chamber 650 without a mixer. If the mixer 646 is used, and once the precursor material is sufficiently mixed at 646, the material can proceed to another microwave suppression inlet chute (or tunnel) at 649.
At 650 (and similar to 639 and 640), the precursor material can proceed to a third microwave heating chamber at 650. The chamber 650 can also receive microwave energy via one or more microwave generator at 651, and exhaust steam can also be used to extract heat from the heated precursor material at 652. Once the precursor material is heated to a desired, final temperature (or final reaction point) and moisture content level at 650, the precursor material can proceed through another microwave suppression outlet chute at 653, and can proceed via a conveyor 654 to a storage medium, such as a silo or shipping truck at 655, among other destinations for storage or use, including at various remote locations or for additional processing locally or remotely. If the precursor material may benefit from additional processing (e.g., heating and/or drying), at 663, the precursor material being processed can be returned to, e.g., microwave heating chamber 639 (e.g., via microwave suppression inlet chute 638) for additional processing. Precursor material can be returned for additional processing two, three, four or any number of times and suitable based on target specifications of the precursor material. Final (or other additional) processing of the heated and/or fractured precursor material can then take place on-site or off-site at a specialized location. Mining-based precursor material processing can include multiple steps and the process 630 can provide more efficient and easier extraction of valuable purer minerals from ores, tailings, and the like.
Exhaust steam heat received at 641, 643, and/or 652 can be recovered as heat energy using one or more heat exchanger 656. The heat exchanger 656 can be an air-to-air heat exchanger, or an air-to-liquid (e.g., glycol) heat exchanger in various embodiments. The heat exchanger 656 can provide heat via a heated (or optionally cooled) medium at 657 to be used in the pre-heater (or optionally pre-cooler or freezer) or dryer 635 as discussed above.
Heat exchanger at 656 can discharge cooled water (from steam) at 658 and/or discharged cooled exhaust air at 659. The discharged cooled water at 658 can then proceed to a sanitary sewer or water processing at 660. Furthermore, the discharged cooled exhaust air at 659 can proceed to an optional scrubber at 661, and then to one or more exhaust stacks at 662. The optional scrubber at 661 can condense steam and reduce odors, emissions, and the like.
In some embodiments, a shielding mesh used for blocking or absorbing microwave emissions can be an aluminum mesh with a pitch or opening size of about 0.15″ (3.81 mm) or less. The shielding mesh can be optionally encapsulated or coated in a protective substance, such as silicone or the like. In some embodiments, such silicone can reduce the likelihood of screens touching and resulting arcing. Reducing arching between screens can prolong useful life of the screen. Also contemplated is an aluminum particle filled silicone structure. Other variations and types of shielding mesh also contemplated are discussed below. Various flaps described herein can utilize a shielding mesh, as described above.
The shielding mesh 700 can be sourced from Aaronia USA/Aaronia AG. The shielding mesh 700 can be an 80dB Stainless Steel RFI Shielding Aaronia X-Steel model, which can provide military or industrial grade screening to meet various demanding usage cases. In some embodiments, the shielding mesh 700 can be coated with a polytetrafluoroethylene (i.e., PTFE or “Teflon”) coating, silicone, polyurethane, plastic, or the like.
The steel mesh 700 is preferably durable, effective up to about 600° C., operates under a very high frequency (VHF) range, and be permeable to air. In more detail, shielding mesh 700 is an Aaronia X-Steel component that can operate to at least partially shield both radio frequency (RF) and low frequency (LF) electric fields.
Some specifications of the shielding mesh 700 can include a frequency range of 1 MHz to 50 GHz, a damping in decibels (dB) of 80 dB, a shielding material including stainless steel, a carrier material including stainless steel, a color of stainless steel (silver), a width of 0.25 m or 1 m or some variation, a thickness of about 1 mm, available sizes of about 0.25 m2 or 1 m2, a mesh size of approximately 0.1 mm (multiple ply/layer), and a weight of approximately 1000 g/m2. The shielding mesh 700 can be suitably durable, and can be configured and rated for use in industrial or other applications, can have a temperature range up to 600° C., can be permeable to air, and permit easy handling.
In some embodiments, the shielding mesh 700 can be electromagnetic compatibility (EMC) screening Aaronia X-Steel from Aaronia AG, which can be made from 100% stainless steel fiber. The shielding mesh 700 can meet various industrial or military standards. The shielding mesh 700 can be very temperature stable for at least 600° C., does not rot, is permeable to air. The shielding mesh 700 can be suitable for EMC screening of air entrances and can be very high protective EMC clothing, etc. The shielding mesh 700 can protect against many kinds of RF fields and can offer a 1000-fold better shielding-performance and protection especially in the very high GHz range as compared to various other types of shielding mesh. The shielding mesh 700 provides high screening within the air permeable EMC screening materials. Application embodiments of the shielding mesh 700 include: Radio & TV, TETRA, ISM434, LTE800, ISM868, GSM900, GSM1800, GSM1900, DECT, UMTS, WLAN, etc.
Some example specifications of the fireproof shielding fabric mesh 800 include: lane Width: 1 m; thickness: 0.2 mm; mesh size: about 0.1 mm; color: stainless steel; weight: approx. 400 g/m; usable until about 1200° C.; yield strength: 220 MPa; tensile strength: 550 MPa; hardness: 180 HB; can be breathable; odorless; transparent; rot resistant; frost proof; washable; foldable; bendable; mesh material: stainless steel.
The fireproof shielding fabric mesh 800 has screening performance for static fields of: 99.9999% to 99.99999% (e.g., when grounded). The fireproof shielding fabric mesh 800 has screening performance for low electric fields of: 99.9999% to 99.99999% (e.g., when grounded). The fireproof shielding fabric mesh 800 is suitable for industrial applications as well as for research and development. The fireproof shielding fabric mesh 800 is designed for use under adverse conditions (e.g., salt air, extreme temperatures, vacuum, etc.).
The fireproof shielding fabric mesh 800 is made of 100% stainless steel, is temperature stable up to 1200° C., has a high microwave attenuation, and yet is breathable. The material of mesh 800 absorbs reliable E&H fields. In particular, in the kHz and low MHz range mesh 800 offers a high shielding factor of up to 108 dB (E-field). Mesh 800 is easy to process and can in some embodiments be cut with a standard pair of scissors or the like.
With reference to portable systems such as 900, in some embodiments a mining site or processing facility can be equipped with an auger configured to deliver precursor material from a pile or truck hauling material to be processed. In some cases, a clearance height of the auger can be insufficient to get system 900 unit under the auger. An additional conveyor can in such cases be implemented to bridge a gap or otherwise connect a storage facility or source of material to the system 900. It is contemplated that some additional form of material handling equipment can be used to adapt system 900 to an existing system, setup, or facility.
As described in this disclosure, precursor material is an embodiment of one or more material to be heated and/or processed as described herein. Material, such as any natural or human-made or human-modified material, or any liquid, solids, or slurries thereof, can be heated and/or processed using microwaves as described in further detail herein. As discussed above, various materials to be processed as contemplated herein can be sourced from a surface, can be unearthed or removed from below ground, or can be otherwise removed or sourced from natural or man-made deposits. A product as used herein can denote a material in a state post-processing, or at least partially processed as disclosed herein.
As used in this disclosure, a conveyor or conveyor unit can be any vessel or mechanism that moves precursor material from an inlet to an outlet. The material being heated can be carried in various embodiments by another type of conveyance mechanism, such as by an auger or various types of conveyor belts or chains or the like. Therefore, in some alternative embodiments a conveyorized modular industrial microwave power system can be employed instead of an auger-based system such as system 100. A conveyor unit can also be referred to more generally as an auger.
Based on power requirements, two or more microwave power modules or heating units can be installed on the same conveyor. To assure uniform heat distribution in a large variety of load configurations, a multimode cavity can be provided with a waveguide splitter with dual microwave feed points and mode stirrers.
In embodiments that use a conveyor belt, a belt material and configuration are selected based on the nature of the material to be heated. Each end of the conveyor is preferably also provided with a special vestibule to suppress any microwave leakage. Air intake and exhaust vents or ports are provided for circulating air to be used in cases where vapors or fumes are developed during the heating process.
Unlike home microwave ovens, examples of industrial microwave-based heating systems contemplated herein preferably separate microwave generation from a heating/drying cavity such as a trough or housing of a conveyor unit. An industrial microwave heating system can be constructed to use one or more microwave generator units. Examples of microwave generators and heating units come in 75 kW and 100 kW (output power) models. Using specialized ducts called waveguides or microwave guides, the microwave energy is carried to one or more industrial microwave cavities. In a conveyor belt-based embodiment, a conveyor belt, auger, etc. carries the material through the cavities. A simple system may include one microwave generator and one cavity, while a larger and/or more complex system may have a dozen generators and six cavities. This inherent modularity provides great flexibility in scaling a system, or building systems, which can be easily expanded in the future.
In alternative embodiments, microwave suppression flap(s) can be rigid and non-flexible, but can be attached to top portion using hinges or any other articulating hardware as known in the art. Alternative hardware and flap fastening arrangements are also contemplated.
These and other advantages will be apparent to those of ordinary skill in the art. While the various embodiments of the invention have been described, the invention is not so limited. Also, the method and apparatus of the present invention is not necessarily limited to any particular field, but can be applied to any field where an interface between a user and a computing device is applicable.
Unless otherwise defined, all technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods, and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety to the extent allowed by applicable law and regulations. In case of conflict, the present specification, including definitions, will control.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention. Those of ordinary skill in the art that have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.
The disclosures of published PCT patent applications, PCT/US2017/023840 (WO2017165664), PCT/US2013/039687 (WO2013166489), PCT/US2013/039696 (WO2013166490), PCT/US2020/040464 (WO2021003250), and PCT/US2021/033145 (filed May 19, 2021), PCT/US2021/034241 (filed May 26, 2021) are each hereby incorporated by reference in their respective entireties for all purposes herein.
Selected embodiments of the present disclosure:
at least one power generator configured to provide at least the first power output,
at least one microwave generator operatively coupled to the power generator,
at least one conveyor unit configured to receive and process a quantity of precursor material to achieve at least a target temperature for a target time; and
This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/241,745, filed Sep. 8, 2021, the entire contents of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63241745 | Sep 2021 | US |
