Method and device for electropulsing material

Abstract

An electric pulse disruption device (12) and method are provided. The device includes a pulse transformer (26), one or more buffer capacitors (22), a plurality of IGBT modules (20), a storage capacitor (24), a spark gap (28), and a disruption chamber (32). The spark gap (28) is defined by first and second electrodes (15, 14) of the spark gap. The disruption chamber (32) includes first and second electrodes (2, 1) of the disruption chamber (32). The buffer capacitor (22) is electrically connected to a voltage rectifier (48). The buffer capacitor (22) is charged by a current received from the voltage rectifier (48). The IGBT module (20) controls the partial discharge of the buffer capacitor (22) and allows and limits the flow of current from the buffer capacitor (22) to a primary winding (19) of the transformer for the duration of a control pulse (49). The storage capacitor (24) is charged by current from the secondary winding (43) of the transformer. The storage capacitor (24) is adapted to discharge the current across the spark gap (28) to the electrodes (2, 1) of the crushing chamber (32). Green material (5) positioned between the crushing electrodes (2, 1) can be crushed.

Description

[Technical field]

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 310,379, filed February 15, 2022, the contents of which are incorporated by reference herein in their entirety.

[0002] The present invention relates generally to pulse spallation, and more particularly to methods and devices for electrical pulse spallation of materials. [Background technology]

[0003] Silicon is a light chemical element with metallic and non-metallic properties. Although silicon is an abundant element, it is rarely found alone in nature. Silicon is commonly found in the form of silicon dioxide (SiO2) in silicate minerals such as quartz. Silicon dioxide is also known as silica. Silica has a wide variety of industrial applications, including those related to semiconductors, concrete, hydraulic fracturing, glass, food, cosmetics, and pharmaceuticals, producing, for example, silicon-ferroalloys and silicon metal. Silicon metal can then be processed into products such as ultra-pure semiconductors or solar panels.

[0004] Silicon can be obtained in several ways, including, for example, by the purification of quartz. Quartz is purified by removing mineral impurities, particularly alkali metal impurities, from the crystal lattice structure of the quartz. Various techniques have been commonly used in an attempt to remove these impurities from the quartz. Such techniques include, for example, crushing, grinding, washing, and sieving. Other methods include heavy liquid separation, froth flotation, and chemical treatments and / or nuclear reaction techniques.

[0005] As another example, there are prior art devices and methods that rely on creating an electrical discharge in the solid that is intended to be fractured. Two examples of such discharge devices and methods are the "electrohydraulic mode of action" and the "electrodynamic mode of action". In the electrohydraulic mode of action, an electrical path travels through the treatment liquid, whereby shock waves are generated in the treatment liquid, which then act on the material. Since this mode involves acting indirectly on the material, not much of the electrical energy is transferred to the material. At best, this process is inefficient. At worst, this process is ineffective against hard materials. The force exerted must exceed the relatively strong compressive strength of the material to achieve fracture. Additionally, the fracture resulting from this method generally does not follow the boundary between the pure crystals and the impurities associated with the crystals. This result makes the separation of the two more difficult and expensive.

[0006] With the electrodynamic mode of action, the electrical path includes not only the treatment liquid but also the material to be fractured. Thus, shock waves are generated within the material itself. This treatment is therefore more effective than the electrohydraulic mode of action and can be used for harder materials, such as rocks. For example, US Patent No. 10,919,045 by Weh et al. provides a device for weakening pourable materials, such as slag from waste incineration. US Patent No. 10,029,262 by Jeanneret et al. provides an electrodynamic device for fracturing rocks or ores.

[0007] Although these and other electrodynamic methods often produce better results than electrohydraulic methods, these devices rely on conventional pulse generators, which are ineffective for generating shock waves of the nature and intensity that can spall certain materials, such as quartz, along their impurity boundaries. To spall a 100 mm sized piece of quartz, it is necessary to create a field strength of more than 300 kV / cm, and the duration of the current should be 30-70 nanoseconds. Prior art devices use a nearly century old technology in the form of a Marx pulse generator, which works by charging several parallel capacitors connected in series to generate a high voltage pulse. These high voltage pulse capacitors used in Marx generator circuits have an operating voltage of 40-100 kV and are made in the form of a continuous section of a low voltage capacitor. It is particularly impossible to provide the required current duration when using a Marx type pulse generator. Due to the dimensions of the Marx-type pulse capacitor itself, the conductive connections and the distance from the generator to the processing chamber, an unnecessarily high inductance in the discharge circuit is produced.

[0008] Furthermore, due to unequal voltage distribution among the sections of a Marx generator during operation, one of the sections will inevitably break through, which will result in the failure of the impulse capacitor. This, as well as the use of large amounts of gas dischargers, will result in failure of the Marx generators, increasing the financial cost of their use in industrial applications, and requiring highly qualified personnel for their maintenance, inspection, and repair.

[0009] It would therefore be desirable to have a device and method that can be used to crush 100 mm sized quartz pieces and that produces an electric field greater than 300 kV / cm, whereby the time to ramp the voltage to its maximum value is within the first tens of nanoseconds.

[0010] It would be desirable to have a device and method that consumes significantly less energy than conventional devices and methods.

[0011] It is desirable for the electrode system of such a device and method to be less susceptible to changes in geometry, thereby increasing the interval between routine maintenance checks.

[0012] It is desirable for the electrodes in such devices to be easy to manufacture and for the procedures for replacing them to be simple.

[0013] During use of such devices and methods, it is desirable for the crushing process to be continuous so that the crushing chamber can continue to produce crushed product of the desired size and so that there is a continuous supply of raw material.

[0014] It would be advantageous to be able to safely and economically generate electrical pulses of sufficient voltage rise rate to produce electric field strengths in excess of 300 kV / cm that can be directed into the interior of low purity crystalline silicon ore, or other raw materials, to take advantage of the relatively low tensile strength of the material and the natural boundaries between crystals and impurities.

[0015] What is needed are devices and methods that can safely and economically generate pulses of sufficient duration and field strength to cause silicon ore and other materials to fracture along a well-defined boundary between the desired product and associated impurities. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] U.S. Patent No. 10919045 [Patent Document 2] U.S. Patent No. 10029262 Summary of the Invention [Problem to be solved by the invention]

[0017] The devices and methods of the present invention are adapted to safely and economically generate electrical pulses of sufficient voltage rise rate that take advantage of the relatively low tensile strength of the material and the natural boundaries between crystals and impurities to produce electric field strengths in excess of 300 kV / cm that can be directed into low-purity crystalline silicon ore or other raw materials.

[0018] With the present invention, a discharge is developed through the solid object and fragmentation occurs due to tension. Energy consumption is significantly lower compared to conventional devices and methods. The electrodes in the device of the present invention are easy to manufacture and easy to replace. The device is not susceptible to changes in geometry, thus increasing the interval between routine maintenance checks. [Means for solving the problem]

[0019] The present invention allows for continuous processing of material. The crushing chamber can be continuously fed with raw material. The device can continuously produce products crushed to the desired size.

[0020] This Electric Pulse Fragmentation (EPF) of raw materials is carried out in a fracturing chamber of an Electric Pulse Fragmentation Device (sometimes referred to herein as an "EPF unit"). All other parts and accessories of the EPF unit are designed to provide the necessary parameters to supply the required voltage and current pulses at the required frequency to the fracturing chamber. The fracturing chamber operates in a continuous mode and is adapted to fracturing / breaking hard raw materials such as quartz to sizes of approximately 5-100 mm.

[0021] In a preferred embodiment, the electric pulse disruption device generally comprises a disruption chamber, a high voltage discharge tube, a storage capacitor, and a high voltage pulse transformer. The disruption chamber, the high voltage discharge tube, and the storage capacitor are separated by upper, middle, and lower partitions, respectively. In a preferred embodiment, the upper, middle, and lower partitions are made of a dielectric material.

[0022] The crush chamber body, the crush chamber cover, and the upper bulkhead define a crush chamber. The crush chamber includes a frame ground electrode and a central high voltage electrode. The frame ground electrode is part of the frame that is grounded to earth.

[0023] The frame ground electrode of the preferred embodiment is a truncated cone configuration whereby the frame ground electrode has a narrow lower end and a wider upper end. The frame ground electrode is positioned coaxially within the crushing chamber body and has an upwardly facing surface. The walls of the frame ground electrode are angled upwardly and outwardly, preferably at 50-70 degrees to vertical in the preferred embodiment.

[0024] The lower end of the central high voltage electrode is surrounded by a cylindrical polyurethane insert. The central high voltage electrode is located in the central part of the crushing chamber and fixed in place by an electrode holder. The preferred gap between the lower end of the central high voltage electrode and the narrow end of the cone of the frame ground electrode is 20-25 mm. This arrangement allows the interruption of the discharge gap of the crushing chamber even if there is no raw material in the crushing chamber or only small size raw material in the crushing chamber.

[0025] The central high voltage electrode has a vertically elongated configuration and is positioned within the cone such that its upper end is generally at the same height as the horizontal middle of the cone. In a preferred embodiment, the central high voltage electrode and the frame ground electrode share a central longitudinal axis. A preferred distance from the upper end of the central high voltage electrode to the surface of the cone is 50-80 mm. To increase the strength of the electric field at the upper end of the central high voltage electrode, the upper end has a smaller diameter than the lower end.

[0026] Desalinated process water, with a specific conductivity of less than 5 microsiemens / cm (preferably less than 1 microsiemens / cm), enters through an opening in the cover of the crushing chamber.

[0027] Above the frame ground electrode is a replaceable conical control screen which includes a grid having gaps between the grid members corresponding to the desired fragment size of the raw material.

[0028] In a preferred embodiment, a liquid storage capacitor is used to store energy. The liquid storage capacitor comprises a cylindrical electrode at an internal voltage and a cylindrical electrode at an external ground. The storage capacitor has a dielectric permeability greater than 20%. A preferred dielectric liquid is glycerin, which has a dielectric permeability of 40%. Deionized water, which has a dielectric permeability of 81%, can also be used.

[0029] The outer surface of the externally grounded cylindrical electrode is provided with a cooling jacket through which a coolant is pumped.

[0030] The storage capacitor is connected to the spallation chamber through a high voltage gas discharge tube with a gas discharge tube spark gap. The high voltage gas discharge tube has a discharge tube center electrode and a discharge tube negative electrode. The discharge tube negative electrode is located below the discharge tube center electrode. To ensure a stable interruption voltage in the discharge tube spark gap, each discharge tube electrode is toroidal and a needle is set at the discharge tube negative electrode.

[0031] The voltage across the storage capacitor increases from zero to a maximum value while charging from the high voltage pulse transformer. In a preferred embodiment, the high voltage gas discharge tube provides stable operation at voltages close to the desired maximum value. To reduce the deionization time in the spark gap of the discharge tube and its cooling, gas movement through a closed circulation loop equipped with fans, filters, and coolers is utilized.

[0032] The storage capacitor is connected to the high voltage pulse transformer through a resistor acting as a filter. The high voltage pulse transformer is made as a rod type transformer with improved output capacitance. This capacitance is selected to be less than the capacitance of the storage capacitor so that the energy loss associated with the presence of this capacitance is not significant. The size of the resistor is selected so that with a relatively long pulse that charges the storage capacitor, the resistor does not substantially affect its charging. When a fast vibration pulse appears, the resistor acts as a filter together with the output capacitance of the high voltage pulse transformer.

[0033] In a preferred embodiment, the electric pulse disruption device is arranged so that a three-phase mains voltage of 380-480V is stepped up through a step-up transformer to a voltage of 630-660V. This stepped up voltage provides galvanic isolation from the mains and is passed through a three-phase rectifier to one or more buffer capacitors. The buffer capacitors are charged up to an operating voltage of 920-1000V.

[0034] In a preferred embodiment, each of the primary windings of the high voltage pulse transformer consists of 1-5 turns of wire, with 2 turns being preferred. There are many of these primary windings, working in parallel. At a voltage of 1000V, a pulse current of 20-30kA is required to ensure charging of the storage capacitor with 100-250 Joules of energy for 10-20 microseconds.

[0035] To ensure a large cross-section of the primary winding, 30-60 primary windings connected in parallel are used. In a preferred embodiment, there are 44 primary windings. Such current switching is conveniently carried out by a number of insulated gate bipolar transistor (IGBT) modules, each of which is connected to each of the parallel primary windings. The secondary winding includes 400-800 turns of wire, so that the transformation ratio of the transformer is 200-400. When the voltage across the buffer capacitor is 1000V and it is operated in partial discharge mode, the charging voltage of the storage capacitor is doubled. This results in a charging of the storage capacitor to a level of 400-500 kV.

[0036] When a high voltage pulse is formed in the secondary winding, the glycerol energy storage unit is charged up to 450-500 kV. When the output spark gap is activated, this voltage is applied to the electrodes of the technological chamber of the electric pulse crusher.

[0037] The IGBT modules are adapted to control partial discharge of the buffer capacitors, thereby allowing current to flow from the respective buffer capacitors to the primary windings of the connected pulse transformers when the respective IGBT modules are in an open configuration, and preventing current from flowing from the respective buffer capacitors to the primary windings when the respective IGBT modules are in a closed configuration. Similarly, the IGBT modules are adapted to move from a closed configuration to an open configuration during the duration of a control pulse received by each of the plurality of IGBT modules. In a preferred embodiment, this duration is between 10 and 20 microseconds. The IGBT modules are adapted to move from an open position to a closed position when the control pulse ceases. In this way, the IGBT modules open and close in a controlled manner. During the operating pulse, the voltage at the buffer capacitors does not drop to zero (as with thyristors), but only drops by 5 to 10% of its value.

[0038] In a preferred embodiment, the IGBT modules and buffer capacitors for each primary winding are located directly on the housing of the high voltage pulse transformer, an arrangement that helps minimize dielectric losses.

[0039] The high voltage pulse transformer and filter resistors are filled with transformer oil.

[0040] In this way, the entire low voltage section is made into an accessible industrial element with a voltage class below 1000V, and the high voltage part is located inside the device and inaccessible to the operator. When the device is turned off, due to its own conductivity, a self-discharge of the storage capacitor occurs, ensuring the industrial safety of the electric pulse device.

[0041] The unit is assembled on a single frame and has small dimensions and weight. The set capacity of one unit is 25 kW, which is more than one ton per hour of raw material input. The continuous mode of the preferred embodiment lasts for hundreds of hours. Any required periodic maintenance requires very little effort and generally involves only replacement of consumables or easily replaceable components.

[0042] A method for electrical pulse fragmentation of materials is provided. The method may incorporate elements described herein in various combinations. A preferred embodiment method includes the steps of: providing a mains transformer, a pulse high voltage transformer, a voltage rectifier, one or more buffer capacitors, a plurality of IGBT modules, a storage capacitor, a spark gap, and a fragmentation chamber, the spark gap being defined by first and second electrodes of the spark gap, and the fragmentation chamber comprising the first and second electrodes of the fragmentation chamber; positioning raw material in the fragmentation chamber; converting an AC current input to a DC current output using the voltage rectifier; charging the one or more buffer capacitors using the voltage rectifier; providing control pulses to the plurality of IGBT modules to control at least a partial discharge of each of the one or more buffer capacitors using the plurality of IGBT modules, thereby allowing current to flow from each buffer capacitor to a primary winding of the pulse transformer when each IGBT module is in an open configuration. and preventing current from flowing from each buffer capacitor to the primary winding of the pulse transformer when each IGBT module is in a closed configuration; each of the plurality of IGBT modules is adapted to move from the closed configuration to an open configuration during the duration of the control pulse; each of the plurality of IGBT modules is further adapted to move from the open configuration to the closed configuration when the control pulse ceases; charging a storage capacitor with current using the secondary winding; automatically discharging the storage capacitor across a spark gap and to the first electrode of the crushing chamber and the second electrode of the crushing chamber when the storage capacitor reaches a discharge voltage value, wherein the first electrode of the crushing chamber and the second electrode of the crushing chamber are separated by a space and a portion of the plurality of raw materials are located in the space; and fracturing a portion of the raw materials using the first electrode of the crushing chamber and the second electrode of the crushing chamber.

[0043] In a particular embodiment of the method, the duration of the control pulse is 10-20 microseconds. In a particular embodiment of the method, the buffer capacitor is charged to a voltage of 920-1000 volts. In a particular embodiment of the method, the discharge voltage value of the storage capacitor is 450,000-500,000 volts. In a particular embodiment of the method, the buffer capacitor and the IGBT module are positioned in a pulse transformer housing directly connected to the respective primary windings. [Brief description of the drawings]

[0044] [Figure 1] FIG. 1 is a partial cross-sectional elevation view of an electric pulse disruption device of the present invention, according to a preferred embodiment. [Diagram 2] FIG. 2 is an enlarged view of the disruption chamber portion of the electric pulse disruption device of FIG. 1 showing the water supply and material flow. [Diagram 3] FIG. 2 is a cross-sectional view of a portion of the high voltage pulse transformer of FIG. 1. [Figure 4] FIG. 2 is an electrical circuit diagram of the electric pulse disruption device of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] With reference to Figures 1-4, an electric pulse disruption device 12 according to a preferred embodiment is shown. As used herein, the term "a" or "an" shall mean one or more than one. The term "plurality" shall mean two or more than two. The term "another" is defined as second or subsequent. The terms "including" and / or "having" are open ended (e.g., "comprising"). As used herein, the term "or" should be construed as inclusive or any one or any combination. Thus, "A, B, or C" means any of the following: "A, B, C; A and B; A and C; B and C; A, B, and C." Exceptions to this definition arise when a combination of elements, features, steps, or acts is somehow mutually exclusive in nature.

[0046] Throughout this document, references to "one embodiment," "particular embodiment," "embodiment," or similar terms mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment in the present disclosure. Thus, appearances of such phrases in various places throughout this specification do not necessarily all refer to the same embodiment. Moreover, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, without limitation. The detailed description illustrates the principles of the invention by way of example, not limitation. The description clearly enables one skilled in the art to utilize the invention and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is currently believed to be the best mode of carrying out the invention.

[0047] 1 and 2, the provided process of electric pulse fragmentation (EPF) of raw material 5 (FIG. 2) is carried out in a fragmentation chamber 32 of an electric pulse fragmentation device 12 (sometimes referred to herein as "EPF unit" 12). All other parts and accessories of the EPF unit 12 are designed to provide the necessary parameters to supply the required voltage and current pulses at the required frequency to the fragmentation chamber 32. The fragmentation chamber 32 operates in a continuous mode and is adapted to fragment / break hard raw material 5, such as quartz, into pieces of size approximately 5-100 mm.

[0048] In a preferred embodiment, the electric pulse disruption device 12 generally comprises a disruption chamber 32, a high voltage discharge tube 30, a storage capacitor 24, and a high voltage pulse transformer 26. The disruption chamber 32, the high voltage discharge tube 30, and the storage capacitor 24 are separated by upper, middle, and lower partitions 13a, 13b, and 13c, respectively. In a preferred embodiment, the upper, middle, and lower partitions 13a, 13b, and 13c are made from a dielectric material.

[0049] The crushing chamber body 3, the crushing chamber cover 7 and the upper partition wall 13a define a crushing chamber 32. The crushing chamber 32 includes a frame ground electrode 1 and a central high voltage electrode 2. The frame ground electrode 1 is part of a frame 29 that is mounted to the earth.

[0050] The frame ground electrode 1 in the preferred embodiment is a truncated cone configuration with a narrow lower end and a wider upper end. The frame ground electrode 1 is positioned coaxially within the crushing chamber body 3 and has an upwardly facing surface 34. The walls of the frame ground electrode 1 are angled upwardly and outwardly, preferably at 50-70° to vertical in the preferred embodiment.

[0051] The lower end 38 of the central high voltage electrode 2 is surrounded by a cylindrical polyurethane insert 4. The central high voltage electrode 2 is located in the central part of the crushing chamber 32 and fixed in place by an electrode holder 9. The preferred minimum gap between the lower end 38 of the central high voltage electrode 2 and the narrow end of the cone 34 of the frame ground electrode 1 is 20-25 mm. This arrangement makes it possible to block the discharge gap of the crushing chamber 32 even if there is no raw material 5 in the crushing chamber 32 or if there is only small size raw material 5 in the crushing chamber 32.

[0052] The central high voltage electrode 2 has a vertically elongated configuration and is positioned within the cone 34 such that the upper end 36 is approximately at the same height as the horizontal middle portion 35 of the cone (the horizontal middle portion 35 of the cone is represented by a dashed line in FIG. 1). In a preferred embodiment, the central high voltage electrode 2 and the frame ground electrode 1 share a central longitudinal axis (the central longitudinal axis is represented by a line 44 in FIG. 1). The preferred distance from the upper end 36 of the central high voltage electrode 2 to the surface of the cone 34 is 50-80 mm. To increase the strength of the electric field at the upper end 36 of the central high voltage electrode 2, the upper end 36 has a smaller diameter than the lower end 38. When large pieces of raw material 5 enter the crushing chamber 32, they necessarily contact both the frame ground electrode 1 and the central high voltage electrode 2 simultaneously. When a high voltage is applied to the central high voltage electrode 2, an electric field is generated across the entire surface of the central high voltage electrode 2. However, it has been found that the delay in crushing with larger pieces of raw material 5 lying at the top end 36 is less than the delay in crushing with smaller pieces of raw material 5 at the middle portion 35, and crushing occurs through the larger pieces of raw material 5 with high crushing efficiency. With this geometry of the central high voltage electrode 2, there is no susceptibility to dimensional changes due to electrolytic corrosion. With a decrease in diameter at the top end 36 of the central high voltage electrode 2, only the electric field strength increases, and with the larger middle portion 35, an increase in the treatment gap of the crushing chamber 32 beyond 25 mm occurs only after an extended period of time. This construction advantageously allows the electric pulse crushing device 12 to operate continuously for hundreds of hours before scheduled maintenance is required.

[0053] Demineralized water enters through an opening in the cover 7 of the crushing chamber with a specific conductivity of less than 5 microsiemens / cm (preferably less than 1 microsiemens / cm). Further, through the space between the crushing chamber body 3 and the cylindrical polyurethane insert 4, the demineralized water enters the lower part of the electrode holder 9, where holes are made to allow the water to pass into the area where the central high voltage electrode 2 is located. Thus, the water rises from the bottom in the crushing chamber 32. The internal space formed by the central high voltage electrode 2 and the inner surface of the cylindrical polyurethane liner is filled with relatively finely crushed material 45, which acts as additional insulation. Thus, the lower end 38 of the central high voltage electrode 2 has multiple layers of insulation against the crushing chamber body 3 in the form of water and finely crushed material 45, the cylindrical polyurethane insert 4, and the incoming clean demineralized water.

[0054] The maximum electric field strength is in the upper portion of the disruption chamber 32. Thus, electrolysis occurs primarily in this region. Moreover, despite the large gap adjacent the upper end 36 of the central high voltage electrode 2, electrolysis preferably occurs in this region where the large pieces 45 of raw material are present.

[0055] Above the frame ground electrode 1 is a replaceable conical control screen 41 with a grid having gaps between the grid members corresponding to the desired crush size of the raw material 5. This control screen 41 can be easily replaced with a similar screen with other grid spaces, for example to allow larger particles to exit the device 12. The crushed raw material 45 particles leave the electric pulse crushing device 12 through the outlet 6 together with the fluid flowing out of the crushing chamber 32. The input raw material 5 continuously enters the apparatus through the inlet pipe 8.

[0056] In a preferred embodiment, there is little non-free flowing fluid in the crushing chamber 32. In other embodiments, there is free flowing fluid in the crushing chamber 32. In a preferred embodiment, there is an oscillating fluid flow in the crushing chamber 32, similar to the fluid flow resulting from the shock waves. The vibrations and shock waves help the crushed raw material 45 to rise in the crushing chamber 32. If the crushed raw material 45 is smaller than a predetermined size, it passes through the outlet 6 through the control screen 41. The crushing occurs first in the larger pieces of raw material 5 by the discharge through the body of some of the raw material 5, and then in the smaller pieces of raw material 5 by the impact of the shock waves, the duration of which is determined by the duration of the current pulse.

[0057] Referring to Figure 1, in a preferred embodiment, a liquid storage capacitor 24 is used to store energy. The liquid storage capacitor 24 comprises a cylindrical electrode 10 at an internal voltage and a cylindrical electrode 11 at an external ground. The storage capacitor 24 has a dielectric permeability greater than 20%. A preferred dielectric liquid is glycerin with a dielectric permeability of 40%. Deionized water with a dielectric permeability of 81% can also be used.

[0058] To reduce the specific conductivity of the liquid dielectric, further cooling at the outer surface of the storage capacitor 24 is used, preferably to a temperature of 2-5° C. At the outer surface of the externally grounded cylindrical electrode 11, a cooling jacket 40 is provided, through which a coolant is pumped.

[0059] An embodiment using deionized water for the liquid dielectric continuously pumps high resistivity water through the storage capacitor 24 by an auxiliary pump (not shown). This water then enters the fracturing chamber 32 and mixes with the main process water.

[0060] Since the liquid dielectric has a relatively high conductivity, it is able to hold the operating voltage for a fairly short period of time. Thus, pulse charging of the storage capacitor 24 is utilized. Such pulse charging of the storage capacitor 24 is provided by a pulse high voltage transformer 26. In a preferred embodiment, the storage capacitor 24 is charged for 50 microseconds or less, preferably 10 to 20 microseconds.

[0061] The storage capacitor 24 is connected to the spallation chamber 32 through a high voltage gas discharge tube 30 with a gas discharge tube spark gap 28. The high voltage gas discharge tube 30 has a discharge tube center electrode 14 and a discharge tube negative electrode 15. The discharge tube negative electrode 15 is located under the discharge tube center electrode 14. To ensure a stable interruption voltage in the discharge tube 30 spark gap, each discharge tube 30 electrode 14, 15 is toroidal and a needle 16 is set to the discharge tube negative electrode 15. The needle 16 of the discharge tube negative electrode 15 is located on the face of the discharge tube center electrode 14. A high voltage pulse transformer 26 generates a negative operating pulse, so that the needle 16 is set to and electrically connected to the discharge tube negative electrode 15.

[0062] The voltage across the storage capacitor 24, charging from the high voltage pulse transformer 26, increases from zero to a maximum value. When the gas ionization voltage reaches the top end of the needle 16, incomplete electrolytic spallation occurs, characterized by the presence of UV radiation and the generation of gas-conducting ions. The free electrons, which have pre-ionized the discharge tube spark gap 28 and stabilized the cutoff voltage, eliminate any changes in the cutoff voltage of the spark gap 28. Since the discharge energy depends on the square of the voltage across the storage capacitor 24, changes in the cutoff voltage of the discharge tube spark gap 28 are undesirable. In the preferred embodiment, the high voltage gas discharge tube 30 provides stable operation at voltages close to the desired maximum value. To reduce the deionization time in the discharge tube spark gap 28 and its cooling, gas movement through a closed circulation loop 17 equipped with a fan, filter, and cooler 23 is utilized. The working gas pressure in the high voltage gas discharge tube 30 in the preferred embodiment is set at 2-5 bar. Both nitrogen and compressed air are used. The presence of oxygen as an electro-negative gas stabilizes the operation of the spark gap 28 of the discharge tube. Part of the gas is vented to the atmosphere and these losses are compensated by the addition of compressed gas. This arrangement allows the high voltage gas discharge tube 30 to have a switching frequency of up to 100 Hz.

[0063] When the spark gap 28 of the gas discharge tube is activated, the storage capacitor 24 generates powerful current and voltage pulses with reverse polarity and durations of several tens of nanoseconds. In fact, the storage capacitor 24 itself becomes a powerful pulse generator. These pulses, if applied to the secondary winding 43 of the high-voltage pulse transformer 26, may disable the storage capacitor 26 by breakdown of the inter-turn insulation in the winding. To prevent this, the storage capacitor 24 is connected to the high-voltage pulse transformer 26 through a resistor 18 acting as a filter. This high-voltage pulse transformer 26 is made as a rod-type transformer with improved output capacitance. This capacitance is selected to be less than the capacitance of the storage capacitor 24, so that the energy losses associated with the presence of this capacitance are not significant. The size of the resistor 18 is selected so that with relatively long pulses that charge the storage capacitor 24, the resistor 18 does not substantially affect its charging. When a fast oscillation pulse is present, resistor 18 acts as a filter in conjunction with the output capacitance of high voltage pulse transformer 26. In a preferred embodiment, this resistor 18 is selected with a value between 300 and 700 ohms. In this embodiment, the time constant formed by this resistor 18 and the value of the storage capacitance is between 0.5 and 2 microseconds, which is an order of magnitude shorter than the charging time of storage capacitor 24 and an order of magnitude longer than the voltage oscillation time across the storage capacitance.

[0064] With reference to FIG. 4, the electric pulse disruption device 12 in a preferred embodiment is arranged such that the voltage of the three-phase mains 46 of 380-480V is stepped up to a voltage of 630-660V through a step-up transformer 47. This stepped up voltage provides galvanic isolation from the mains 46 and is sent through a three-phase rectifier 48 to one or more buffer capacitors 22. Each of the one or more buffer capacitors 22 is charged up to an operating voltage of 920-1000V. The buffer capacitors 22 in the preferred embodiment are operated in a partial discharge mode and their capacitance value is selected to be an order of magnitude larger than the capacitance of the storage capacitor 24 reduced to the primary side of the high voltage pulse transformer 26. For this reason, these capacitors 22 are substantially indestructible.

[0065] In the preferred embodiment, each of the primary windings 19 of the high voltage pulse transformer 26 consists of 1-5 turns of wire, with 2 turns being preferred. There are many of these primary windings 19, and they work in parallel. At 1000V, 100-250 Joules of energy in 10-20 microseconds requires a pulse current of 20-30 kA to ensure charging of the storage capacitor.

[0066] To ensure a large cross section of the primary windings 19, 30-60 primary windings 19 connected in parallel are used. With reference to FIG. 4, in a preferred embodiment, there are 44 primary windings 19 connected to the winding end connectors 45. This arrangement reduces the magnitude of the impulse current in each primary winding 19 to 600-800 amperes. Such current switching is conveniently carried out by a number of insulated gate bipolar transistor (IGBT) modules 20, each of which is connected to one of the parallel primary windings. The secondary winding 43 includes 400-800 turns of wire, so that the transformation ratio of the transformer 26 is 200-400. When the voltage across the buffer capacitor 22 is 1000V and it is operated in partial discharge mode, the charging voltage of the storage capacitor 24 is doubled. Thus, the storage capacitor 24 is charged to a level of 400-500 kV. In a preferred embodiment, the pulse transformer comprises, for example, silicon sheet rod 42 material and magnetic steel formed from an iron alloy having a silicon content.

[0067] Structurally, the secondary winding 43 is wound on the central core magnetic circuit, which performs the function of the output capacitance of the high-voltage pulse transformer 26. The value of this capacitance is selected to be approximately equal to 10% of the value of the main storage device in a liquid dielectric made of glycerin. Furthermore, the output of the high-voltage pulse transformer is connected to the glycerin energy storage device through a protective resistor. When a high-voltage pulse is formed in the secondary winding, the glycerin energy storage unit is charged up to 450-500 kV. When the output spark gap is activated, this voltage is applied to the electrodes of the technological chamber of the electric pulse crusher.

[0068] Due to the low inductance of the discharge circuit, the half-wave of the discharge circuit is 40-70 nanoseconds, while the polarity can be reversed at the glycerol reservoir. If no special measures are taken, these voltage surges will be applied directly to the output windings of the pulse transformer, which may suffer damage due to breakdown of the inter-turn insulation. It is for this reason that the protective resistors are earthed. The protective resistors, together with the output capacitance of the high-voltage transformer, form a high-frequency filter, so that certain high-frequency oscillating voltages are applied to the protective resistors and not to the turns of the high-voltage transformer.

[0069] The IGBT modules 20 are adapted to control partial discharge of the buffer capacitors 22, thereby allowing current to flow from the respective buffer capacitors 22 to the primary winding 19 of the transformer 26 when the respective IGBT modules 20 are in an open configuration, and preventing current from flowing from the respective buffer capacitors 22 to the primary winding 19 when the respective IGBT modules 20 are in a closed configuration. Similarly, the IGBT modules 20 are adapted to move from the closed configuration to the open configuration during the duration of a control pulse 49 received by each of the plurality of IGBT modules 20. In a preferred embodiment, this duration is between 10 and 20 microseconds. In a preferred embodiment, the control pulse 49 is generated by a main generator 50.

[0070] The IGBT module 20 is adapted to move from an open position to a closed position when the control pulse stops. In this way, the IGBT module 20 opens and closes in a controlled manner. During the operating pulse, the voltage on the buffer capacitor 22 does not drop to zero (as with a thyristor), but only by 5-10% of its value.

[0071] In a preferred embodiment, the IGBT module 20 and buffer capacitor 22 are located directly on the housing of the high voltage pulse transformer 26. This arrangement helps to minimize dielectric losses.

[0072] The high voltage pulse transformer 26 and the filter resistor 18 are filled with transformer oil 21 .

[0073] Naturally, the duration of the discharge current of the circuit is determined as the square root of the product of the discharge capacitance and the inductance of the circuit: the higher the operating voltage of the generator, the smaller the capacitance of the capacitor with the same amount of energy storage.

[0074] In preferred embodiments, the spallation chamber 32 is connected directly to the storage capacitor 24 through only a single switched spark gap 28, and no conventional Marx pattern is used. The storage capacitor 24 is charged to a level of 400-500 kV, resulting in a power reserve of 150-300 Joules and a capacitance value of 1000-3000 picofarads. In these embodiments, the inductance of the discharge circuit is only 120-250 nanohenries (nH). As a result, the duration of the half-wave of the current is 30-70 nanoseconds.

[0075] In this way, the entire low voltage section is made into an accessible industrial element with a voltage class below 1000V, and the high voltage part is located inside the device and inaccessible to the operator. When the device is turned off, due to its own conductivity, a self-discharge of the storage capacity occurs, ensuring the industrial safety of the electric pulse device.

[0076] The unit is assembled on a single frame and has small dimensions and weight. The set capacity of one unit is 25 kW, which is more than one ton per hour of raw material input. The continuous mode of the preferred embodiment lasts for hundreds of hours. Any required periodic maintenance requires very little effort and generally involves only replacement of consumables or easily replaceable components.

[0077] Methods for electropulse disruption of materials are provided, which may incorporate elements described herein in various combinations. The method of the preferred embodiment includes the steps of: providing a pulse transformer 26, a voltage rectifier 48, one or more buffer capacitors 22, a plurality of IGBT modules 20, a storage capacitor 24, a spark gap 28, and a crushing chamber 32, where the spark gap 28 is defined by spark gap first and second electrodes 15, 14 and the crushing chamber 32 includes the crushing chamber first and second electrodes 2, 1; positioning raw material 5 within the crushing chamber 32; converting an AC current input to a DC current output using the voltage rectifier 48; charging the one or more buffer capacitors 22 using the voltage rectifier 48; providing control pulses 49 to the plurality of IGBT modules 20 to at least partially control each of the one or more buffer capacitors 22 to allow current to flow from each buffer capacitor 22 to a primary winding 19 of the pulse transformer 26 when each IGBT module 20 is in an open configuration, and charging each IGBT module 20 to a DC current output. the steps of: preventing current from flowing from each buffer capacitor 22 to the primary winding 19 of the pulse transformer when the IGBT modules 20 are in a closed configuration; adapting each of the plurality of IGBT modules 20 to move from the closed configuration to the open configuration during the duration of the control pulse 49; further adapting each of the plurality of IGBT modules 20 to move from the open configuration to the closed configuration when the control pulse 49 ceases; charging the storage capacitor 24 with current using the secondary winding 43; automatically discharging the storage capacitor 24 across the spark gap 28 to the first electrode 2 of the crushing chamber and the second electrode 1 of the crushing chamber when the storage capacitor 24 reaches a discharge voltage value, the first electrode 2 of the crushing chamber and the second electrode 1 of the crushing chamber being separated by a space and portions of the plurality of raw materials 5 being located in the space; and crushing portions of the raw materials 5 using the first electrode 2 of the crushing chamber and the second electrode 1 of the crushing chamber.

[0078] In a particular embodiment of the method, the duration of the control pulse 49 is between 10 and 20 microseconds. In a particular embodiment of the method, the buffer capacitor 22 is charged to a voltage between 920 and 1000 volts. In a particular embodiment of the method, the discharge voltage value of the storage capacitor 24 is between 450,000 and 500,000 volts. In a particular embodiment of the method, the buffer capacitor 22 and the IGBT module 20 are positioned in a housing of the pulse transformer 26.

[0079] While what are presently considered to be the preferred embodiments of the invention have been illustrated and described, it will be understood by those skilled in the art that various changes and modifications can be made and equivalents can be substituted for those elements without departing from the scope of the invention. Accordingly, the invention is not limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but the invention is intended to include all embodiments that fall within the scope of this disclosure.

Claims

1. 1. An electric pulse disruption device comprising: a main transformer, a high voltage pulse transformer, a voltage rectifier, one or more buffer capacitors, a plurality of insulated gate bipolar transistor (IGBT) modules, a storage capacitor, a spark gap, and a spallation chamber, the spark gap being defined by spark gap first and second electrodes, the spallation chamber comprising spallation chamber first and second electrodes; the one or more buffer capacitors are electrically connected to the voltage rectifier, the voltage rectifier being adapted to convert an AC current input received from the main transformer to a DC current output, the one or more buffer capacitors being constructed and arranged to be charged by current received from the voltage rectifier; the pulse transformer comprises primary and secondary windings constructed and arranged to transform an input voltage into an output voltage, the output voltage being greater than the input voltage; each of the plurality of IGBT modules is adapted to at least partially control the discharge of a respective one or more of the buffer capacitors, thereby allowing current to flow from the respective buffer capacitor to the primary winding of the pulse transformer when the respective IGBT module is in an open configuration, and preventing current from flowing from the respective buffer capacitor to the primary winding of the pulse transformer when the respective IGBT module is in a closed configuration; each of the plurality of IGBT modules is further adapted to move from the closed configuration to the open configuration during a duration of a control pulse received by each of the plurality of IGBT modules; the plurality of IGBT modules are further adapted to move from the open position to the closed position when the control pulse ceases; the reservoir capacitor is adapted to be charged by current from the secondary winding of the pulse transformer; the storage capacitor is further adapted to discharge current across the spark gap to a second electrode of the spark gap when a first electrode of the spark gap reaches a discharge voltage value; a second electrode of the spark gap electrically connected to a first electrode of the spallation chamber; the disruption chamber is adapted to receive raw material such that a portion of the raw material is located between a first electrode of the disruption chamber and a second electrode of the disruption chamber; An electric pulse disruption device, wherein the first electrode of the disruption chamber and the second electrode of the disruption chamber are constructed and arranged to disrupt a portion of the raw material when the storage capacitor discharges.

2. The electric pulse disruption device of claim 1 , wherein the control pulse has a duration of 10 to 20 microseconds.

3. 10. The electric pulse disruption device of claim 1, further comprising one or more resistors electrically connected and positioned between said secondary winding and said storage capacitor.

4. 10. The electric pulse spallation device of claim 1, further comprising a discharge tube, said pyrotechnic gap being positioned within said discharge tube.

5. 5. The electric pulse disruption device of claim 4, wherein the discharge tube is supplied with pressurized gas.

6. 2. The electric pulse disruption device of claim 1, wherein the disruption chamber comprises a wall, the wall being in a truncated cone configuration.

7. 7. The electric pulse disruption device of claim 6, wherein an upper portion of the first electrode of the disruption chamber extends upwardly between the walls.

8. 8. The electric pulse disruption device of claim 7, wherein the second electrode of the disruption chamber is a grounded portion of a frame housing.

9. 10. The electric pulse disruption device of claim 1, wherein the buffer capacitor is charged to a voltage of 920 to 1000 volts.

10. 10. The electric pulse disruption device of claim 9, wherein the storage capacitor discharges a voltage between 450,000 and 500,000 volts.

11. The electric pulse disruption device of claim 1 , wherein the buffer capacitor and the IGBT module are positioned in a housing of the pulse transformer.

12. 1. An electric pulse disruption device comprising: a pulse transformer, one or more buffer capacitors, one or more resistors, a plurality of insulated gate bipolar transistor (IGBT) modules, a reservoir capacitor, a spark gap, and a spallation chamber; the buffer capacitor and the IGBT module are positioned in a housing of the pulse transformer; the spark gap is defined by spark gap first and second electrodes and is positioned within a discharge tube, the discharge tube being supplied with one or more pressurized gases; the disruption chamber comprising disruption chamber first and second electrodes; the one or more buffer capacitors are electrically connected to a voltage rectifier adapted to convert an AC input to a DC output, the one or more buffer capacitors being constructed and arranged to be charged to a voltage between 920 and 1000 volts by current received from the voltage rectifier; the pulse transformer comprises primary and secondary windings constructed and arranged to transform an input voltage into an output voltage, the output voltage being greater than the input voltage; one or more of the resistors are electrically connected and positioned between the secondary winding and the reservoir capacitor; each of the plurality of IGBT modules is adapted to at least partially control discharge in a respective one or more of the buffer capacitors, thereby allowing current to flow from the respective buffer capacitor to the primary winding of the pulse transformer when the respective IGBT module is in an open configuration, and preventing current from flowing from the respective buffer capacitor to the primary winding of the pulse transformer when the respective IGBT module is in a closed configuration; each of the plurality of IGBT modules is further adapted to move from the closed configuration to the open configuration during a duration of a control pulse received by each of the plurality of IGBT modules; each of the plurality of IGBT modules is further adapted to move from the open position to the closed position when the control pulse ceases; the reservoir capacitor is adapted to be charged by current from the secondary winding of the pulse transformer; the storage capacitor is further adapted to discharge current across the spark gap to a second electrode of the spark gap when the first electrode of the spark gap reaches a discharge voltage value, the discharge voltage value being between 450,000 and 500,000 volts; a second electrode of the spark gap electrically connected to a first electrode of the spallation chamber; the disruption chamber is adapted to receive raw material, whereby a portion of the raw material is positioned between a first electrode of the disruption chamber and a second electrode of the disruption chamber; An electric pulse disruption device, wherein the first electrode of the disruption chamber and the second electrode of the disruption chamber are constructed and arranged to disrupt a portion of the raw material when the storage capacitor discharges.

13. The electric pulse disruption device of claim 12, wherein the control pulse has a duration of 10 to 20 microseconds.

14. 13. The electric pulse disruption device of claim 12, wherein the disruption chamber comprises a wall, the wall defining a truncated cone configuration.

15. 15. The electric pulse disruption device of claim 14, wherein an upper portion of the first electrode of the disruption chamber extends upwardly between the walls.

16. 16. The electric pulse disruption device of claim 15, wherein the second electrode of the disruption chamber is a grounded portion of a frame housing.

17. 1. A method for electric pulse disruption of a material, comprising: providing a voltage rectifier, a pulse transformer, one or more buffer capacitors, a plurality of insulated gate bipolar transistor (IGBT) modules, a storage capacitor, a spark gap, and a spallation chamber, the spark gap being defined by spark gap first and second electrodes, and the spallation chamber comprising spallation chamber first and second electrodes; Positioning raw material in the crushing chamber; converting an AC current input to a DC current output using the voltage rectifier; charging one or more of the buffer capacitors using the voltage rectifier; providing control pulses to a plurality of said IGBT modules to at least partially control discharging of each of one or more of said buffer capacitors using a plurality of said IGBTs, thereby allowing current to flow from each of said buffer capacitors to a primary winding of said pulse transformer when each of said IGBT modules is in an open configuration and preventing current from flowing from each of said buffer capacitors to the primary winding of said pulse transformer when each of said IGBT modules is in a closed configuration; each of a plurality of said IGBT modules being adapted to move from said open position to said closed position for the duration of said control pulse; a plurality of said IGBT modules are further adapted to move from said open position to said closed position when said control pulses cease; charging the reservoir capacitor with a current using the secondary winding; automatically discharging a storage capacitor across the spark gap to a first electrode of the crushing chamber and a second electrode of the crushing chamber when the storage capacitor reaches a discharge voltage value, the first electrode of the crushing chamber and the second electrode of the crushing chamber being separated by a space and a portion of the raw material being located within the space; disrupting a portion of the raw material using a first electrode in the disruption chamber and a second electrode in the disruption chamber; 13. A method for electric pulse fracturing of a material comprising:

18. The method of claim 17, wherein the control pulse has a duration of 10 to 20 microseconds.

19. 18. The method of claim 17, wherein the buffer capacitor is charged to a voltage between 920 and 1000 volts.

20. 18. The method of claim 17, wherein the discharge voltage value of the storage capacitor is between 450,000 and 500,000 volts.

21. The method of claim 17 , wherein the buffer capacitor and the IGBT module are positioned in a housing of the pulse transformer.

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