DEVICE FOR TAKING PARTICLES BY MEANS OF ELECTRICAL IMPULSES

Description

[0001] The invention relates to devices for subjecting particles to stress by means of electrical pulses, comprising a device for supplying particles, at least one vertically arranged pipe section with a reaction chamber for subjecting particles to stress, and a device for discharging particles.

[0002] The principle of comminuting solids using electrical pulses is well known. These electrical pulse processes have disadvantages, particularly when it comes to the continuous conveyance of solid feed material through the reaction chamber, as well as the required residence times in the reaction chamber, which vary depending on the material and particle size. Furthermore, there is a risk of damage to components due to the electrical pulses used.

[0003] From the publication FR 1 341 851 A (as well as US 3207447 A), a system for the continuous electro-hydraulic comminution and mixing of materials in a liquid medium is known. The electrical discharges occur through the liquid surrounding the material to be comminuted, usually water. The plasma channel created in the liquid generates a pressure wave that impacts the material to be comminuted and stresses it. The required electrical pulses are generated by oscillating circuits, resulting in a correspondingly slow pulse increase. The liquid reservoir is pressure-shock-resistant to withstand the indirect stress on the materials (pulverization) caused by the shock wave generated in the water by electrical pulses. The device also describes flat electrodes to maximize the effect of the shock wave.However, these protrude into the process chamber or are installed flat in a tapered pipe section. The liquid flow is impeded, and the electrodes experience increased wear. A liquid flows through the reactor to completely discharge the comminution products upwards or downwards.

[0004] Another method for comminuting solids using electrical impulses is electrodynamic comminution.

[0005] DE 10 2014 008 989 A1 discloses a device and method for the continuous comminution of solids using electrical pulses. This device comprises at least one reaction chamber, into which the solids are fed by means of a transport means. The reaction chamber is located in a reaction vessel. This vessel has at least one set of electrodes consisting of at least two electrodes arranged at a predetermined distance from each other, forming an interelectrode space in the reaction chamber. At least one central electrode and surrounding electrodes are present.A device for generating electrical pulses delivers the electrical pulses to the electrodes of the electrode set, with the solids remaining pressed against the electrode set until the solids resting there are reduced in size by the electrical pulses to such an extent that the reduced solids are smaller than the distance between the opposing electrodes. The reduced solids pass through the space between the electrodes together with the flowing transport medium. Continuous reduction is essentially only achieved with solids of approximately the same size. No or insufficient reduction can lead to solids blockage.

[0006] The publication WO 2012 129 713 A relates to an electrode arrangement for an electrodynamic fragmentation system with a passage opening or a passage channel for fragmentation material and with one or more pairs of electrodes. By applying high-voltage pulses from the electrodes to the fragmentation material, high-voltage discharges are generated within the passage opening or passage channel. Rod-shaped, pointed, or rounded electrodes protrude from the edge of a surrounding casing and, if appropriate, from a centrally arranged dome-shaped insulating body into the comminution chamber to obtain approximately spherical comminution material. For this purpose, the electrode spacing is smaller than the maximum particle size that can pass through the passage opening or passage channel.

[0007] JP 11-33 430 A discloses a comminution process and a device for carrying out the process. For this purpose, electrode plates are provided, inclined at an angle to one another, between which high-voltage discharges occur through voltage pulses. The electrode plates form a tapered gap. To pass through the tapered gap, the particles must be smaller than the distance between the electrode plates at the respective point. A solution consisting of comminution and classification functions is described. The material must therefore necessarily be comminuted to pass through the device.

[0008] The invention defined in claim 1 is based on the object of at least claiming particles in such a way that they are already better or completely broken down in coarser fractions for subsequent mechanical comminution.

[0009] This problem is solved with the features listed in patent claim 1.

[0010] The devices for stressing particles by means of electrical pulses with a device for feeding particles, at least one vertically arranged pipe section with a reaction chamber for stressing particles and a device for discharging particles are characterized in particular by the fact that the particles are already better or completely broken down into coarser fractions for subsequent comminution.

[0011] For this purpose, the pipe section and thus the reaction chamber are a flow channel for a flowable medium. Furthermore, a device conveying the medium is connected to the pipe section in such a way that the medium flows against the direction of movement of particles fed into the pipe section and sinking through the pipe section. The pipe section has at least two spaced-apart electrodes connected to at least one Marx generator as a pulse voltage generator, wherein the pulse rise time of the Marx generator is less than 500 ns. Furthermore, the electrodes end at or before the inner surface of the pipe section, so that the electrodes do not protrude into the pipe section and do not impede the flow of the medium within the pipe section.

[0012] The particles passing through the pipe section are subjected to electrodynamic stress by means of electrical pulses, which also includes the electrodynamic comminution of particles. A so-called Marx generator, a surge voltage generator, is used. This generates pulses with a pulse rise time of less than 500 ns. With these short rise times, the discharge between the spaced-apart electrodes occurs, preferably directly through the particle or several particles simultaneously. The resulting plasma channel leads to immediate stress on the particle. The plasma channel within the particle is accompanied by high pressures and temperatures, which weaken or completely break the bonds along the discharge channel and are degraded within the particle. This reduces the strength of the particle and thus also supports selective decomposition into different components.The direct energy input into the particles to be stressed is energy-efficient and advantageously eliminates the need for a pressure-shock-resistant pipe section as a reaction chamber for the stressing of the particles. The pipe section can have a constant cross-section along its length, so that the flow of the medium is not influenced. The particles can be discharged in a controlled and size-selective manner. Continuous operation is easily implemented.

[0013] The voltage of the Marx generator, for example, can be 400 kV to 600 kV. The frequency can be equal to or greater than 25 Hz. The energy range can be greater than or equal to 7 J to less than or equal to 700 J.

[0014] The device is further characterized by the fact that no movable conveying devices are required in the reaction chamber. Furthermore, the particles can pass through the process chamber without stress and the associated damage or comminution. The residence time of the particles in the reaction chamber can advantageously be adjusted depending on the material, throughput, and / or size using the medium-conveying device, with the medium flowing against the direction of movement of the particles fed into and falling through the pipe section. Unintentionally formed fine particles and ultrafine particles can be continuously removed from the reaction chamber by the flowing medium, counter to the direction of fall of the particles to be damaged.

[0015] The electrodes do not protrude into the reaction chamber, thus largely avoiding contact between the particles to be treated and the electrodes, thus preventing abrasive wear on the electrodes. The electrodes can advantageously be controlled individually. Electrode pairs can be controlled simultaneously or sequentially, with electrode pairs being arranged side by side and / or one below the other.

[0016] The particles, also known as mineral grains, are thus advantageously available in coarser fractions, better or completely broken down for subsequent comminution, so that less energy is required. This allows, for example, the metal-bearing minerals in ores to be extracted more effectively and enriched more completely and in higher concentrations. This allows even deposit areas with lower ore grades to be used economically, increasing the required completeness of deposit utilization and improving the sustainability of raw material processing.

[0017] Advantageous embodiments of the invention are specified in patent claims 2 to 11.

[0018] The particle feeder can optionally be arranged so that the particles to be stressed descend from top to bottom through the pipe section. This allows the particles to be fed continuously, allowing continuous stressing of particles with electrical pulses in the pipe section.

[0019] In one embodiment, several electrodes are distributed around the inner circumference of the pipe section and arranged at a distance from each other. Furthermore, the electrodes are connected to pulse voltage generators.

[0020] Two electrodes are optionally arranged in at least two spaced-apart levels of the pipe section, with these electrodes connected to the Marx generator(s). The stress on the particles can thus occur at multiple levels during the descent.

[0021] Electrodes are arranged in one plane and / or in spaced-apart planes around the inner circumference of the pipe section. Furthermore, the electrodes are connected to the Marx generator(s). The electrodes can also be arranged helically.

[0022] The electrodes of a level can be connected to the Marx generator or Marx generators. Furthermore, the Marx generator or Marx generators are interconnected with a control device in such a way that the voltages and / or pulses simultaneously applied to the electrodes of the levels differ from each other.

[0023] The particle discharge device is optionally arranged so that the particles sinking through the pipe section are transported away from the particle loading device.

[0024] In one embodiment, the device conveying the medium is connected to a control device so that the flow velocity of the medium and thus the velocity of the particles sinking through the pipe section can be influenced.

[0025] Outside the reaction chamber, in the direction of the particle supply device, a device for discharging fine and / or ultrafine particles is optionally arranged. This can be an opening in the wall of the pipe section, which can be connected to a suction device.

[0026] The device for supplying particles, the vertically arranged pipe section, the device conveying the medium and lines form a medium-conveying circuit.

[0027] The medium can in particular be a gas or a liquid.

[0028] An embodiment of the invention is shown in principle in the drawings and is described in more detail below.

[0029] They show: Fig. 1 a device for stressing particles by means of electrical impulses and Fig. 2 a pipe section with electrodes and a reaction chamber.

[0030] A device for subjecting particles 9 to stress by means of electrical pulses 11 essentially consists of a device 1 for supplying particles 9, a vertically arranged pipe section 2 with a reaction chamber, a device 3 for discharging particles 9, a medium 10 conveying device 4, electrodes 5, a Marx generator 6 and a control device 7.

[0031] The Fig. 1 shows a device for stressing particles 9 by means of electrical impulses 11 in a basic representation.

[0032] The device 1 for supplying particles 9 is arranged such that the particles 9 sink from top to bottom through the pipe section 2. The device 3 for discharging particles 9 is located such that the particles 9 that have sunk through the pipe section 2 are transported away by the device for stressing particles 9. The device 4 conveying the medium 10 is connected to the control device 7 so that the flow velocity of the medium 11 and thus the velocity of the particles 9 sinking through the pipe section 2 can be influenced. A device 8 for discharging fine and / or ultrafine particles 9 can be arranged in the direction of the device 1 for supplying particles 9.

[0033] The Fig. 2 shows a pipe section 2 with electrodes 5 and a reaction chamber in a basic representation.

[0034] The pipe section 2 and thus the reaction chamber represents a flow channel of the flowable medium 10. For this purpose, the device 4 conveying the medium 10 is connected to the pipe section 2 in such a way that the medium 10 flows against the direction of movement of particles 9 supplied to the pipe section 2 and falling through the pipe section 2.

[0035] The pipe section 2 has electrodes 5 arranged at a distance from one another and connected to the Marx generator 6. The electrodes 5 end at or in front of the inner surface of the pipe section 2, so that the electrodes 5 do not protrude into the pipe section 2 and do not impede the flow of the medium 10 in the pipe section 2. Electrodes 5 can also be connected to multiple Marx generators 6. This allows pulses to be generated that differ in frequency and / or pulse duration. The voltage can be, for example, 400 kV to 600 kV. The frequency can be equal to or greater than 25 Hz. The energy range can be greater than or equal to 7 J to equal to or less than 700 J.

[0036] For this purpose, a plurality of electrodes 5 can be distributed around the inner circumference of the pipe section 2 and arranged at a distance from one another. For this purpose, one electrode 5 can be located in at least two planes of the pipe section 2 arranged at a distance from one another. In one embodiment, electrodes 5 can also be arranged distributed in one plane and / or in planes arranged at a distance from one another around the inner circumference of the pipe section 2, so that the electrodes 5 are arranged in a helical shape.

[0037] At least the device 1 for supplying particles, the vertically arranged pipe section 2, the device 4 conveying the medium 10, and lines can form a circuit carrying the medium 10. In a continuation, the device 3 for discharging particles 9 can also be integrated into this circuit.

[0038] The medium 10 is a gas or a liquid. List of reference symbols

[0039] 1 Device for feeding particles 2 Pipe section 3 Device for discharging particles 4 Medium conveying device 5 Electrode 6 Marx generator 7 Control device 8 Device for discharging fine and / or ultrafine particles 9 Particle 10 Medium 11 Electric pulse

Claims

1. A device for loading particles (9) by means of electrical pulses (11), having an apparatus (1) for supplying particles (9), at least one vertically arranged pipe section (2) with a reaction chamber for loading particles (9) and an apparatus (3) for removing particles (9), wherein the pipe section (2) and thus the reaction chamber is a flow channel of a fluid medium (10), wherein a device (4) conveying the medium (10) is connected to the pipe section (2) such that the medium (10) flows counter to the movement direction of particles (9) supplied to the pipe section (2) and sinking through the pipe section (2), wherein the pipe section (2) has at least two electrodes (5), which are arranged spaced from one another and connected to at least one Marx generator (6), wherein the pulse rise time of the Marx generator (6) is less than 500 ns, and wherein the electrodes (5) end with or before the inner surface of the pipe section (2), so that the electrodes (5) do not project into the pipe section (2) and do not impede the flow of the medium (10) in the pipe section (2).

2. The device according to Patent Claim 1, characterized in that the apparatus (1) for supplying particles (9) is arranged such that the particles (9) to be loaded sink from above downwards through the pipe section (2).

3. The device according to Patent Claim 1, characterized in that a plurality of electrodes (5) are arranged distributed around the inner circumference of the pipe section (2) and spaced from one another and in that the electrodes (5) are connected to the Marx generator or to Marx generators (6).

4. The device according to Patent Claim 1, characterized in that in each case two electrodes (5) are arranged in at least two planes of the pipe section (2), which planes are spaced from one another, and in that these electrodes (5) are connected to the Marx generator (6).

5. The device according to Patent Claim 1, characterized in that electrodes (5) are arranged in a distributed manner around the inner circumference of the pipe section (2) in one plane and / or in planes that are arranged spaced from one another and in that the electrodes (5) are connected to the Marx generator (6) or to Marx generators (6).

6. The device according to Patent Claims 1, 2 and 5, characterized in that the electrodes (5) of a plane are connected to the Marx generator (6) or to Marx generators (6), in that the Marx generator (6) or the Marx generators (6) is or are connected to a control device (7) in such a manner that the voltages simultaneously applied at the electrodes (5) and / or pulses of the planes differ from one another.

7. The device according to Patent Claim 1, characterized in that the apparatus (3) for removing particles (9) is arranged such that the particles (9) sunk through the pipe section (2) are transported away from the device for loading particles (9).

8. The device according to Patent Claim 1, characterized in that the device (4) conveying the medium (10) is connected to a control device (7), so that the flow rate of the medium (10) and therefore the speed of the particles (9) sinking through the pipe section (2) can be influenced.

9. The device according to Patent Claim 1, characterized in that a device (8) for removing fine and / or very fine particles (9) is arranged outside of the reaction chamber in the direction of the apparatus (1) for supplying particles (9).

10. The device according to Patent Claim 1, characterized in that the apparatus (1) for supplying particles (9), the vertically arranged pipe section (9), the device (4) conveying the medium (10) and lines are a circuit conveying the medium (10).

11. The device according to Patent Claim 1, characterized in that the medium (10) is a gas or a liquid.