EP3894080B1 - Device for stressing particles by means of electric pulses - Google Patents

Description

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

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.

Through the printed matter FR 1 341 851 A (as well as US 3207447 A ) is a system for the continuous electro-hydraulic comminution and mixing of materials in a liquid medium. 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 electrical pulses required for this are generated using oscillating circuits, resulting in a correspondingly slow pulse increase. The liquid reservoir is pressure-shock-resistant in order 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 extend into the process chamber or are installed flat in a tapered section of pipe. The liquid flow is impeded, and the electrodes therefore experience increased wear. A liquid flows through the reactor in order to completely discharge the comminution products upwards or downwards.

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

Through the printed matter DE 10 2014 008 989 A1 A device and method for the continuous comminution of solids by means of electrical impulses is known. This device has at least one reaction chamber, to which the solids are fed by means of a transport means, wherein the reaction chamber is located in a reaction vessel. This has at least one set of electrodes consisting of at least two electrodes arranged at a predetermined distance from one another, which form an electrode gap in the reaction chamber. There is at least one central electrode and electrodes surrounding it. A device for generating electrical pulses delivers the electrical pulses to the electrodes of the electrode set, whereby the solids rest pressed against the electrode set until the solids resting there are comminuted by the electrical pulses in such a way that the dimensions of the comminuted solids are smaller than the distance between the opposing electrodes. The comminuted solids pass through the electrode gap together with the flowing transport medium. Continuous comminution is essentially only achieved with solids of approximately the same size. No or insufficient comminution can lead to a blockage of the solids.

The printed matter 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 in order 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.

The printed matter JP 11-33 430 A discloses a comminution method and a device for carrying out the method. 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 a comminution and classification function is described. The material must therefore necessarily be comminuted in order to pass through the device.

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.

This problem is solved by the features listed in patent claim 1.

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.

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 to the pipe section and sinking through the pipe section. The pipe section has at least two electrodes arranged at a distance from one another and 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 in the pipe section.

The particles passing through the pipe section are subjected to electrodynamic stress by means of electrical pulses, which also includes the electrodynamic fragmentation of particles. The 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 preferably occurs 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 particle to be stressed is energy-efficient and advantageously does not require a pressure-shock-resistant pipe section as a reaction chamber for stressing the particles. The pipe section can have a constant cross-section along its length, so that the flow of the medium is not affected. The particles can be removed in a controlled and size-selective manner. Continuous operation is easily achieved.

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.

The device is also 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 discharged from the reaction chamber by the flowing medium, counter to the direction of fall of the particles to be damaged.

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 of 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.

The particles, also known as mineral grains, are thus advantageously available in coarser fractions, better or completely broken down for subsequent comminution, which can also require less energy. This allows, for example, the metal-bearing minerals in ores to be recovered 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.

Advantageous embodiments of the invention are specified in claims 2 to 11.

The device for feeding particles can optionally be arranged so that the particles to be treated sink from top to bottom through the pipe section. the particles are also fed in continuously, so that a continuous stress on particles with electrical impulses in the pipe section can be realized.

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.

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). Thus, the particles can be subjected to stress at multiple levels during their descent.

In one embodiment, electrodes are arranged in a single 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.

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 one another.

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

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.

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.

The device for feeding particles, the vertically arranged pipe section, the device conveying the medium and lines form a circuit carrying the medium.

The medium can in particular be a gas or a liquid.

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

Fig. 1

eine Einrichtung zur Beanspruchung von Partikeln mittels Elektroimpulsen und

Fig. 2

ein Rohrstück mit Elektroden und einem Reaktionsraum.

They show:

Fig. 1

a device for stressing particles by means of electrical impulses and

Fig. 2

a piece of pipe with electrodes and a reaction chamber.

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.

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

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.

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

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 connected 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.

The pipe section 2 has electrodes 5 arranged at a distance from one another and connected to the Marx generator 6, wherein 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.

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 each case 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.

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 continuation, the device 3 for discharging particles 9 can also be integrated into this circuit.

The medium 10 is a gas or a liquid.

List of reference symbols

1. 1 Device for feeding particles
2. 2 pipe sections
3. 3 Device for discharging particles
4. 4 Medium-promoting facility
5. 5 Electrode
6. 6 Marx Generator
7. 7 Control device
8. 8 Device for the discharge of fine and/or ultrafine particles
9. 9 particles
10. 10 Medium
11. 11 Electric impulse

Claims (11)

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.

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