Apparatus for electro-discharge machining of non-conducting liquids

Abstract

The invention relates to an apparatus for electro-discharge machining of a non-conductive liquid, the apparatus comprising an alternating sequence of at least one substantially rectangular, parallel and spaced apart n number of electrode plates and n+1 number of dielectric plates, wherein n ≥ 2, the electrode plates being numbered from 1 to n; characterized in that the apparatus comprises a series of first electrical connectors electrically connected to all even numbered electrode plates in the vicinity of a first pair of opposite corners; and in that the apparatus comprises a series of second electrical connectors electrically connected to all odd numbered electrode plates in the vicinity of a second pair of opposite corners. The invention further relates to a method of electro-discharge machining of a non-conductive liquid using said apparatus.

Description

Technical Field

[0001] This invention relates to an apparatus for electrical discharge processing of non-conductive liquids. These non-conductive liquids may be, for example, hydrocarbons, silicon-containing compounds, and fatty substances of animal or plant origin.

[0002] "Liquid" means a compound that remains liquid under the electrical discharge processing conditions of this invention. "Non-conductive liquid" means a liquid with relatively high resistivity, particularly at 25°C and preferably up to 125°C, with a resistivity of at least 1 × 10⁻⁶. 8 ohm cm. The non-conductive liquid can be, for example, hydrocarbon oil or paraffin. Specifically, "liquid silicon-containing compound" means a chemical entity comprising at least one silicon atom. According to the invention, the term "fatty substance" refers to a substance composed of hydrophobic molecules and primarily composed of triglycerides. Triglycerides are esters formed from one glycerol molecule and three fatty acids. These fatty substances include oils, waxes, and fats. Oils are preferred within the scope of the invention because they are liquid at room temperature because they are primarily composed of unsaturated fatty acids and therefore have low melting points, i.e., below or equal to room temperature. On the other hand, fats and waxes are pastes or solids at room temperature because their melting points are above room temperature because they are primarily formed of saturated fatty acids. Due to their high melting points, the use of fats and waxes in the apparatus according to the invention must preferably be carried out at temperatures above room temperature to keep them in liquid form.

[0003] Discharge processing, which involves discharging non-conductive liquids such as liquid oils of plant or mineral origin, is also known as voltolisation. The discharge is generated between two or a series of parallel metal electrodes separated by an electrically insulating material (also called a dielectric material). Applying an alternating voltage between the electrodes allows plasma to be generated between them through the dielectric material. This plasma enables the processing of oil in the form of a thin film on the surfaces of the electrodes and the dielectric. Background Technology

[0004] The removal of the characteristic unpleasant odor of fish oil is known from existing technology, particularly in document FR363078, which utilizes electrical discharge machining (EDM) equipment. In this document, the fish oil is contained within a cylindrical shell and brought into contact with hydrogen gas. A discharge is then applied between electrodes within the shell, causing the hydrogen gas to bind to the fish oil, thereby allowing the unpleasant odor to be gradually removed.

[0005] The hydrogen consumed during the reaction is rapidly and manually reintroduced into the shell via a tap provided for this purpose. The operating conditions for this fish oil processing are not described in this document.

[0006] Evidence presented in the prior art suggests that electroprocessing of liquid organic materials can alter their physicochemical properties. Therefore, this method has also been applied in the past to "thicken" vegetable or mineral oils or mixtures thereof to obtain properties suitable for use as additives in lubricants.

[0007] An apparatus known for electrical discharge processing of liquid organic materials includes: a series of electrodes comprising n substantially parallel electrodes (1 and 2), wherein n ≥ 2, each electrode being arranged to be connected to a high-voltage power supply and / or ground; a series of dielectric material elements comprising n+1 dielectric material elements substantially parallel to the electrodes and positioned on either side of each electrode in the series of electrodes such that each electrode is located between two dielectric material elements; a housing arranged to receive the non-conductive liquid and surround the series of electrodes and the series of dielectric material elements; and an immersion apparatus for the series of electrodes and the series of dielectric material elements, the immersion apparatus being arranged to at least partially immerse the series of electrodes and the series of dielectric materials.

[0008] Document GB 407379 A describes an apparatus for processing hydrocarbon oils and paraffins via electrical discharge. The apparatus shown in this document for electrical discharge processing (silent discharge process) is a tubular condenser comprising multiple metal plates arranged in series, separated from each other by glass plates. The metal plates are alternately connected to a high-frequency current source, meaning that when a first metal plate is connected to the high-frequency current source, an opposite second metal plate acts as a ground electrode. A glass plate is then positioned between the metal plate connected to the current source and the metal plate serving as the ground electrode. The glass plate can rotate about the central axis of the condenser. The metal plates and glass plates are immersed in the hydrocarbons to be processed.

[0009] Document GB 190507101 A describes a similar device for applying a discharge to a liquid. The device described in this document also consists of a rotatable cylindrical housing, within which the gas pressure can be kept relatively constant by a supplementary device having a mercury manometer. Thus, when the gas pressure in the housing, as measured by the mercury manometer, decreases, the gas can be reintroduced into the housing. Therefore, the gas pressure in the housing increases to return to its initial value, thereby maintaining the gas pressure in the housing relatively constant. A series of metal discs and insulating material discs are alternately placed on the rotation axis of the housing, i.e., they are arranged along the rotation axis in the following order: metal disc, insulating material disc, metal disc, insulating material disc, and so on. The insulating material (also called dielectric material) placed between the electrodes allows for the reduction of the formation of localized arc discharges, which can lead to overly concentrated localized processing of the liquid, resulting in the deterioration of the processed liquid.

[0010] Unfortunately, previous equipment produced highly random results when used for processing vegetable or mineral oils. The physicochemical properties of the processed oils were neither predictable nor controllable / uncontrollable. Furthermore, the implementation of the disclosed equipment was not described, making any industrial development impossible. It has been reported that industrial development of the disclosed equipment is impossible because the undisclosed operating conditions are specific to these particular devices and produce random results.

[0011] Other existing technologies propose connections to the power supply that may be alternating, but always only on one side of each plate, and the electrodes in these documents are not suitable for processing non-conductive liquids because the non-conductive liquids are covered in an insulator. Documents WO 9815357 A1, EP1809082 A1 and CN 106793435 A describe apparatus for plasma processing of gases and aqueous solutions.

[0012] Document WO 2018002329 A1 describes a device for more controlled electrical processing of plant-derived fatty substances, wherein the electrodes are individually connected such that the current distance between the electrical connector placed on the outer surface of the housing and any electrode is the same. This method of connecting the electrodes makes scaling up the device very complicated, as each electrode requires its own electrical connector. Furthermore, it has been found that on large electrodes, such as those larger than 0.2 square meters, the plasma is not uniformly distributed across the entire electrode. Summary of the Invention

[0013] The object of the present invention is to provide an apparatus that can be easily scaled up, wherein the discharge processing of non-conductive liquids is controlled, reproducible and uniform.

[0014] To address this problem, the present invention provides an apparatus for electrical discharge machining of a non-conductive liquid, the apparatus comprising an alternating sequence of at least n substantially rectangular, parallel, and spaced-apart electrode plates and n+1 dielectric plates, wherein n ≥ 2, the electrode plates being numbered from 1 to n; characterized in that the apparatus includes a series of first electrical connectors electrically connected to all even-numbered electrode plates near a first pair of diagonals; and characterized in that the apparatus includes a series of second electrical connectors electrically connected to all odd-numbered electrode plates near a second pair of diagonals. The apparatus further includes an AC power supply having a first pole connected to the series of first electrical connectors and a second pole connected to the series of second electrical connectors.

[0015] In order to improve the reproducibility, control, and uniformity of electrical discharge processing of non-conductive liquids during the implementation of the device according to the invention, the inventors surprisingly noted that by simultaneously supplying current to each electrode diagonally, plasma is uniformly established on the electrode plates, limiting or even avoiding any arcing and non-uniform processing of non-conductive liquids (e.g., vegetable oil) present in thin film form on the electrode and dielectric plate surfaces. This result is achieved even if the length of the electrical path between the power source and the electrode plates may vary between the electrode plates.

[0016] Therefore, the processing of non-conductive liquids in the device according to the invention is faster and more efficient, while allowing control over the physicochemical properties of the processed non-conductive liquid. In fact, applying overly intensive processing to non-conductive liquids (such as vegetable oils) (as occurs when an electric arc is present) causes the oil to thicken too quickly and may lead to the formation of insoluble agglomerates, and thus precipitates.

[0017] Another additional advantage of the device of the present invention is that it can be easily scaled up by avoiding the need for precise control of the current path length between the power supply and the electrode plates.

[0018] n electrode plates and n+1 dielectric plates are positioned in an alternating sequence. This means that the dielectric plates and electrode plates are placed alternately, such that any electrode plate is between two dielectric plates.

[0019] The n electrode plates and n+1 dielectric plates are spaced apart. This means that they do not directly contact each other.

[0020] The device of the present invention is preferably configured to distribute the non-conductive liquid onto the surfaces of the n electrode plates and optionally n+1 dielectric plates, and to form a non-conductive liquid film on the surfaces of the electrodes and optionally the dielectric plates. The device may include a dispenser for the non-conductive liquid above each electrode plate and optionally each dielectric plate.

[0021] According to an embodiment of the invention, the surface area of ​​the dielectric plate is larger than the surface area of ​​the electrode plate. Advantageously, such as Figure 4 As shown, the dielectric plate (3) extends further than the electrode plate (1) in both directions along the X and Z axes. The inventors have found that by extending the dielectric plate beyond the electrode plate, it is easier to avoid direct arcing between adjacent electrode plates.

[0022] Odd-numbered electrode plates and even-numbered electrode plates are placed alternately. Thus, the odd-numbered electrodes face the even-numbered second electrodes, and so on, so that two electrodes of the same type are not arranged in sequence, and there is a dielectric plate between each electrode plate.

[0023] In the following description, for simplicity, the term "non-conductive liquid" will occasionally be referred to as "oil." The term "oil" is used for simplicity because the non-conductive liquid used according to the invention is in liquid form under processing conditions, regardless of whether it is derived from animal or vegetable oils, fats or waxes, or from natural or synthetic hydrocarbons or silicon-containing compounds. As explained above, when using fats or waxes, it is preferable to adjust the operating temperature to make it in liquid form.

[0024] Plant-based fatty acids can come from sources such as rapeseed, flaxseed, and argan oil.

[0025] Preferably, the non-conductive liquid has an unsaturation degree, particularly a pre-processed iodine value in the range of 100 to 180.

[0026] According to the invention, the term "high voltage" refers to voltage, also known as electric potential, preferably in the range of 1 kV to 10 kV, advantageously between 2 kV and 3 kV, and characterized by low alternating current, the current density of which is preferably between 0.5 mA / cm² and 2 mA / cm², and its frequency is advantageously between 3 kHz and 100 kHz, advantageously between 5 kHz and 70 kHz, and more advantageously between 10 kHz and 40 kHz.

[0027] According to the invention, the device includes a series of electrode plates, comprising at least n=2 electrode plates electrically connected via an AC power supply, preferably arranged such that when current is supplied to any odd-numbered electrode plate, an opposite current is supplied to any even-numbered electrode plate. Preferably, no electrode plate is grounded.

[0028] "AC power" refers to electricity from an alternating current source, where the voltage varies at a certain frequency in the form of a sine wave, square wave, pulse, or some other waveform. The voltage change is typically from negative to positive. The average current per cycle is 0 A. In bipolar form, the power output transmitted by the two wires is typically about 180° out of phase. The AC power supply supplies a varying or alternating bipolar voltage to these two electrodes. The AC power supply or AC power source initially drives the odd-numbered electrode plates to a negative voltage, allowing plasma formation, while driving the even-numbered electrode plates to a positive voltage to act as the anode of the voltage application circuit. The AC power supply then drives the first electrode to a positive voltage, reversing the roles of the cathode and anode.

[0029] In a preferred embodiment, the power supply of the present invention combines a solid-state power supply with a transformer. Therefore, the economic and technological advantages, advanced control levels, flexibility, and facility design of solid-state power supplies are maintained, and the relatively low voltage of ordinary solid-state power supplies, typically around 800 V to 1000 V, is compensated for by combining with a transformer, thereby achieving the aforementioned required kV range. Attached Figure Description

[0030] These and further aspects of the invention will be explained in more detail by way of example and with reference to the accompanying drawings, in which: Figure 1 A schematic three-dimensional view of an alternating sequence of parallel, rectangular, spaced dielectric plates and electrode plates according to an embodiment of the present invention is shown.

[0031] Figure 2 A schematic three-dimensional view illustrating an example embodiment of the electrical connection between an electrode plate and a power source according to an embodiment of the present invention is shown.

[0032] Figure 3 A schematic diagram is shown for naming the four corners of the electrode plate.

[0033] Figure 4 A front view of the electrode plate and dielectric plate is shown.

[0034] These figures are not drawn to scale. Detailed Implementation

[0035] According to the invention, the electrode plate and the dielectric plate are spaced apart and therefore both lie in separate planes parallel to the XZ plane, such as... Figure 1 As shown. Figure 1 An alternating sequence of parallel, rectangular, spaced-apart dielectric plates (5) and electrode plates (1, 2, 3, 4) according to an embodiment of the present invention is shown. The electrode plates (1, 2, 3, 4) and dielectric plates (5) are arranged in different XZ planes and spaced apart along the Y axis. Each electrode plate (1, 2, 3, 4) is located between two dielectric plates (5). The electrode plates are aligned relative to each other, and the dielectric plates are aligned relative to each other.

[0036] According to an advantageous embodiment of the invention, the spacing between the electrode plate and the dielectric plate is advantageously between 4 mm and 10 mm, and more advantageously between 5 mm and 7 mm.

[0037] According to an advantageous embodiment of the invention, the number n of electrode plates is included between 2 and 100, more advantageously between 5 and 50, even more advantageously between 8 and 30, and preferably between 12 and 22.

[0038] According to an embodiment of the invention, the electrode plate and the dielectric plate are held apart by one or more guide rails positioned at the bottom, top, and / or sides of the plate. The guide rails may, for example, be provided with notches in which the electrode plate and the dielectric plate can be easily positioned. The n electrode plates and n+1 dielectric plates of this device can be held together in a frame, which preferably includes the aforementioned guide rails for holding the plates in place.

[0039] Figure 2 Electrical connections of the electrode plates according to an embodiment of the invention are shown. A series of first electrical connectors (6) are electrically connected at a pair of first diagonals to all even-numbered electrode plates (2, 4), and a series of second electrical connectors (7) are electrically connected at a pair of second diagonals to all odd-numbered electrode plates (1, 3). In this figure, the outline of the dielectric plate (5) is indicated only by dashed lines to better illustrate the electrical connectors. The first and second electrical connectors (6, 7) are electrically connected to an AC power supply (8).

[0040] In an embodiment, the device of the present invention further includes an AC power supply, and at least n=2 electrode plates are connected to each other via the AC power supply. The average current per cycle is 0 A. The AC power supply supplies a variable or alternating bipolar voltage to the at least two electrodes. The bipolar power supply initially drives all odd-numbered electrode plates to a negative voltage, thereby allowing plasma formation, while driving even-numbered electrode plates to a positive voltage to serve as the anode of the voltage application circuit. Then, the bipolar power supply drives the odd-numbered electrode plates to a positive voltage and reverses the roles of the cathode and anode. Plasma is established between the odd-numbered and even-numbered electrode plates, forming in the corresponding cavities. Then, another cathode forms the anode, causing electrons to bypass the plasma and travel to the other side, thereby completing the circuit.

[0041] According to embodiments of the present invention, the AC power supply may include a power supply component with stable amplitude and frequency, and may further include high-voltage and high-frequency transformers.

[0042] According to an embodiment of the present invention, the AC power supply can be configured to supply a frequency between 3 kHz and 300 kHz and a high voltage supply current between 1 kV and 5 kV.

[0043] Although not preferred, it is also possible to alternately connect even-numbered electrode plates to the high-voltage power supply and connect odd-numbered electrode plates to ground, or vice versa, thereby having an alternating sequence of dielectric plates, electrode plates connected to the high-voltage power supply, dielectric plates, electrode plates connected to the high-voltage power supply, and dielectric material elements, etc.

[0044] According to an embodiment of the invention, the device further includes a housing, and a plurality of alternating sequences of electrode plates and dielectric plates disposed within the housing.

[0045] The housing according to the invention is advantageously substantially rectangular prism-shaped, preferably made of metal, more preferably of stainless steel.

[0046] Advantageously, the housing further includes a non-conductive liquid outlet located at the lower part of the housing and a non-conductive liquid inlet located at the upper part of the housing. According to an advantageous embodiment of the invention, the housing includes more than one non-conductive liquid inlet.

[0047] According to an embodiment of the invention, the housing includes at least two separate electrical feed connectors, through which odd-numbered and even-numbered electrode plates are electrically connected to a power source. The electrical feed connectors advantageously include electrical insulators for electrically isolating them from the housing. The electrical feed connectors are advantageously spaced at least 3 cm, at least 5 cm, and at least 10 cm apart. The two separate electrical feed connectors feed opposing alternating currents to the electrodes.

[0048] According to an embodiment of the present invention, the interior of the housing is lined with an electrically insulating lining. This prevents arcing between the electrode plates and the housing.

[0049] According to embodiments of the invention, the housing is capable of operating at pressures of 10 to 400 Torr, preferably 80 to 300 Torr, and more preferably 100 to 260 Torr.

[0050] According to an embodiment of the invention, the housing of the invention advantageously further includes an exhaust port that can be connected to a vacuum pump.

[0051] According to embodiments of the invention, the housing may further include at least one gas inlet port for allowing one or more process gases required to perform the process to enter the housing. The process gas may advantageously be selected from one or more of any rare gas, nitrogen, oxygen, and hydrogen. During oiling, process gases, such as hydrogen, may be consumed; therefore, as a result of the oiling time, the pressure within the housing may tend to decrease. A pressure gauge may allow measurement of the gas pressure within the housing and thereby control of the injection of additional amounts of process gas.

[0052] According to embodiments of the invention, during the processing of non-conductive liquids, the pressure can be maintained between 10 Torr and 400 Torr, preferably between 80 Torr and 300 Torr, and more preferably between 100 Torr and 260 Torr. Lower pressures are beneficial for plasma formation, especially when a non-conductive liquid is present on the electrodes.

[0053] In an advantageous embodiment of the device according to the invention, the housing further has at least one inclined surface for guiding a non-conductive liquid to a first non-conductive liquid outlet of the container. This guiding inclined surface allows the non-conductive liquid to be supplied to the non-conductive liquid outlet within the housing, thereby further facilitating the circulation of the non-conductive liquid outside the housing.

[0054] In an advantageous embodiment of the device according to the invention, a pressure gauge is further included, placed within the housing and arranged to measure the gas pressure within the housing. The pressure gauge may be a capacitive vacuum gauge, such as a MKS brand vacuum gauge, which allows for the measurement of gas pressure within the housing. During oiling, a first gas, such as hydrogen, may be consumed; therefore, as a result of the oiling time, the pressure within the housing may tend to decrease. The pressure gauge allows for the measurement of the gas pressure within the housing, and thus indicates when a certain amount of first replenishment gas needs to be injected to maintain a constant gas pressure within the housing.

[0055] Additionally, in embodiments of the invention, the device further includes a controller arranged to be connected to the pressure gauge and to a flow meter or a fast-response leak valve, the controller being arranged to control the flow meter and the leak valve, the flow meter being arranged to be fluidly connected to a second inlet of the first gas in the housing to measure the amount of the first gas injected into the housing through the second inlet of the first gas in the housing.

[0056] When the pressure gauge measures that the gas pressure in the housing is too low, gas can be injected through the gas inlet of the housing, and the amount of gas injected can be advantageously controlled by a flow meter.

[0057] According to the present invention, a series of first electrical connectors are electrically connected at a pair of first diagonals to all even-numbered electrode plates, and a series of second electrical connectors are electrically connected at a pair of second diagonals to all odd-numbered electrode plates. Figure 3 The diagram illustrates how the corners of the electrode plates (1, 2) can be named. In this diagram, for clarity, the outline of the dielectric plate (5) is indicated only by dashed lines. In the odd-numbered electrode plates (1) and the even-numbered electrode plates (2), the corners are labeled 'N', 'W', 'S', and 'E' in a clockwise direction. Corners (N) and (S) form a pair of opposite corners, and corners (E) and (W) form a pair of opposite corners. The pair of corners (N, S) of the odd-numbered electrode plate (1) and the pair of corners (E, W) of the even-numbered electrode plate (2) are laterally positioned relative to each other.

[0058] According to an exemplary embodiment of the present invention, a first electrical connector is electrically connected to all odd-numbered electrode plates at the same first pair of diagonals (E, W) or (N, S), and a second electrical connector is electrically connected to all even-numbered electrode plates at the same second pair of diagonals (E, W) or (N, S).

[0059] In a preferred embodiment of the invention, the first pair of diagonals and the second pair of diagonals are positioned laterally relative to each other, for example in... Figure 2 In the diagram, the first pair of diagonals (E, W) are on the odd-numbered electrode plates, and the second pair of diagonals (N, S) are on the even-numbered electrode plates. Figure 2 In the diagram, the paired diagonals (E, W) and (S, N) are positioned laterally relative to each other.

[0060] The electrode plates and dielectric plates are preferably in an upright position, i.e., they are held substantially vertically, preferably with two sides along the vertical axis Z and two sides along the horizontal axis X. This allows the non-conductive liquid being processed to fall freely along the electrode plates solely by gravity.

[0061] The first and second electrical connectors are electrically connected to the edge or the plate surface adjacent to the edge (i.e., no more than 5 cm from the edge) at least near the corner of the electrode plate. The electrical connectors can be, for example, soldered, threaded, bundled, or press-fitted to the edge.

[0062] According to embodiments of the invention, the first and second electrical connectors are electrically connected near the corners of their respective electrode plates, with the distance from the corner reaching up to 15% of the length of the longest of the two sides that meet at the corner. According to some advantageous embodiments, the first and second electrical connectors may be electrically connected at a distance from the corresponding corner, said distance being up to 10% of the length of the longest of the two sides that meet at the corner.

[0063] According to an embodiment of the present invention, odd-numbered electrode plates are connected to a first terminal of an AC power supply via a first electrical connector, and even-numbered electrode plates are connected to a second terminal of an AC power supply via a second electrical connector.

[0064] According to an embodiment of the present invention, the device may be provided with two first electrical collectors electrically connected to a first electrical connector and two second electrical collectors electrically connected to a second electrical connector.

[0065] According to an embodiment of the present invention, one of the two first electrical connectors is electrically connected to a first electrical connector electrically connected to the same corner of the odd-numbered electrode plates, and the other of the two first electrical connectors is electrically connected to a first electrical connector electrically connected to the opposite corner of the odd-numbered electrode plates. Similarly, according to an embodiment of the present invention, one of the two second electrical connectors is electrically connected to a second electrical connector electrically connected to the same corner of the even-numbered electrode plates, and the other of the two second electrical connectors is electrically connected to a second electrical connector electrically connected to the opposite corner of the even-numbered electrode plates.

[0066] According to embodiments of the invention, the device includes a dispenser for non-conductive liquids. The dispenser can be configured to dispense the non-conductive liquid to be processed along the surfaces of an electrode plate and optionally a dielectric plate. Several types of dispensers are known in the prior art, which may be, for example, channel-type dispensers or splash-proof plate dispensers. The liquid dispenser used in the present device is preferably adapted to dispense liquids with a wide viscosity range. In some embodiments, the dispenser may be located above the electrode plate and optionally above the dielectric plate, and is configured for downward flow of the liquid.

[0067] According to an embodiment of the present invention, the device has a circulation circuit outside the housing. The presence of a first inlet and a first outlet for the non-conductive liquid in the housing allows the non-conductive liquid to circulate outside the housing.

[0068] According to an advantageous embodiment of the invention, the device is provided with a temperature control system comprising one or more of the following: a cooling device, a heating system, and a temperature measurement system. Advantageously, the non-conductive liquid can be circulated through the cooling device to prevent overheating, as plasma processing tends to increase the temperature of the non-conductive liquid. The cooling device may include a heat exchanger and / or a 3-way valve for injecting a cooler non-conductive liquid to maintain the processing temperature within a desired range. The heating system may include heating devices placed around the housing to heat the housing containing the non-conductive liquid. The heating system may further allow control of the housing temperature and its maintenance, despite potential temperature fluctuations in the housing environment. Furthermore, when using a fatty or waxy non-conductive liquid, the heating system allows the liquid to be supplied at or above its melting temperature, so that it remains in liquid form within the housing. Advantageously, the temperature measurement system includes a temperature probe directly immersed in the non-conductive liquid within the housing, at the housing outlet, or in the circulation circuit. The temperature probe is preferably configured to continuously measure the temperature of the non-conductive liquid. Within a temperature control system, a temperature probe can be connected to a controller, which in turn is connected to a heating and / or cooling system to control heating and / or cooling, thereby controlling and maintaining a constant temperature of the non-conductive liquid within the device.

[0069] In a preferred embodiment of the invention, the temperature control system is configured to maintain the non-conductive liquid within a temperature range of 50°C to 100°C, and more preferably between 55°C and 85°C.

[0070] In another advantageous embodiment, the apparatus of the invention includes a filter for filtering the processed non-conductive liquid. The filter can be placed at the outlet to filter the processed liquid at the end of the process. Alternatively, the non-conductive liquid can be circulated through a filter placed outside the housing. The filter allows the homogeneity of the processed material to be maintained after a strong and effective plasma is applied to the non-conductive liquid. The filter can have a mesh size ranging from 0.01 mm to 1 mm, preferably from 0.015 mm to 0.8 mm. Advantageously, the filter is a metal filter.

[0071] In embodiments of the invention, the circulation of the non-conductive liquid outside the housing and its return via the inlet of the housing may also allow the non-conductive liquid to be distributed on the electrode plate, and optionally on the dielectric plate.

[0072] In embodiments of the invention, the device further includes a viscometer having a first inlet arranged in fluid connection with the first non-conductive liquid outlet of the housing and optionally a first outlet arranged in fluid connection with the aforementioned filter, the viscometer being configured to measure, for example, the viscosity of the non-conductive liquid between the housing and the metal filter. Therefore, the viscometer allows for the measurement of the viscosity of the non-conductive liquid throughout the processing. This viscosity measurement allows for further improvement in the control of the viscosity properties of the processed non-conductive liquid. For example, the viscometer, such as a Sofraser MIVI sensor, preferably with a temperature probe, can be directly inserted using vibration. Measurement can be performed using a rod vibrating at a resonant frequency, wherein the vibration amplitude varies according to the viscosity of the liquid into which the rod is immersed.

[0073] The invention advantageously further includes a circulation pump having a first inlet fluidly connected to the first outlet of the housing and a first outlet optionally fluidly connected to the aforementioned viscometer and / or the aforementioned filter, the circulation pump being arranged to circulate the non-conductive liquid between the first outlet and the first inlet of the housing.

[0074] According to an embodiment of the invention, the device further includes a sampling valve in a circulation circuit. This sampling valve allows for the extraction of samples of the treated material to monitor the quality and performance of the product during the processing. In a particularly advantageous embodiment of the device according to the invention, the housing has a discharge valve arranged to extract the liquid plant material from the housing.

[0075] According to a preferred embodiment of the invention, n is greater than or equal to 4, advantageously greater than or equal to 5, more advantageously greater than or equal to 6, and even more advantageously greater than or equal to 7. Increasing the number of electrodes and the amount of dielectric material allows for improved processing efficiency of the non-conductive liquid by increasing the contact surface between the discharge and the non-conductive liquid existing in the form of a film on the electrode plate and dielectric plate. In some embodiments of the invention, n may be equal to or less than 100, alternatively equal to or less than 50, or alternatively equal to or less than 30.

[0076] According to an embodiment of the present invention, the thickness of the electrode plate of the device is between 0.5 mm and 10 mm, preferably between 0.8 mm and 6 mm, and more preferably between 1 mm and 3 mm.

[0077] According to an embodiment of the invention, the device electrode plate and dielectric plate are substantially rectangular, having a surface area ranging from 0.2 m² to 4 m².

[0078] The construction material for the electrode plates preferably has sufficient conductivity to allow for rapid determination of voltage changes, thereby limiting the resistance heating of the electrode plates and enabling these electrode plates to carry the current required to sustain the discharge. According to embodiments of the invention, the electrode plate material includes metals, metal alloys, metal compounds, carbon, carbon compounds, conductive ceramics, or semiconductors. Advantageously used materials may include metal alloys or graphite carbon, particularly steel, stainless steel, copper, or aluminum.

[0079] According to embodiments of the invention, the material of each dielectric substrate can be selected from the group consisting of glass, quartz, mica, rigid polymers, and mixtures thereof. The glass can be, for example, soda-lime glass, borosilicate glass, or aluminosilicate glass. In an advantageous embodiment, the dielectric substrate material may include a rigid polymer. In an advantageous embodiment, the dielectric substrate material may have a dielectric constant greater than or equal to 1.9 at 10 Hz to 60 Hz. In an advantageous embodiment, the dielectric substrate material may have an operating temperature greater than or equal to 80°C, at which the material resists continuous operation. Preferably, the operating temperature is greater than or equal to 150°C, more preferably greater than or equal to 200°C. In an advantageous embodiment, according to standard IEC 60243, the dielectric strength of the dielectric substrate material is equal to or greater than 10 kV / mm.

[0080] In embodiments of the present invention, the dielectric plate is substantially rectangular, preferably with a thickness between 0.5 mm and 10 mm, and more preferably between 2 mm and 6 mm.

[0081] In a preferred embodiment, the surface area of ​​the dielectric plate is 3% to 25% larger than that of the electrode plate, more preferably 6% to 15% larger.

[0082] Another advantage of the device according to the invention is that it also allows for the reduction or even elimination of the characteristic odor of animal or vegetable oils. This reduction in the odor of fatty substances from animal or plant sources is beneficial, for example, in applications in the cosmetics or food industries, where an overly strong odor from plant-derived fatty substances used as lubricating bases will be avoided.

[0083] Therefore, the device according to the invention allows for the large-scale production of animal or plant-derived fatty substances processed by electrical discharge, and the reproduction of controllable, controlled, and advantageously deodorizing characteristics.

[0084] Other embodiments of the device according to the invention are indicated in the appended claims.

[0085] The present invention also relates to a system for electrical discharge machining of non-conductive liquids, the system comprising multiple devices according to the invention, such as two, three, four or more devices, said devices being arranged in series and / or in parallel. Multiple devices may share the same housing.

[0086] Other embodiments of the system according to the invention are indicated in the appended claims.

[0087] The present invention also relates to a method for electrical discharge machining of non-conductive liquids using an apparatus for electrical discharge machining of non-conductive liquids according to any of the above embodiments or any possible combination of embodiments.

[0088] This invention particularly relates to a method for electrical discharge machining of non-conductive liquids, the method comprising: a. Provided in the housing an alternating sequence of at least n substantially rectangular, parallel and spaced-apart electrode plates and n+1 dielectric plates, wherein n ≥ 2, and the electrode plates are numbered from 1 to n; b. Provide an AC power supply that provides an AC bipolar voltage at the first terminal and an opposite AC bipolar voltage at the second terminal; c. Optionally, a hydrogen-containing vacuum atmosphere is provided in the enclosure; d. The non-conductive liquid is introduced into the housing via the first inlet of the housing. e. Distribute the non-conductive liquid on the surfaces of the n electrode plates and optionally n+1 dielectric plates, and form a non-conductive liquid film on the surfaces of the electrodes and optionally the dielectric plates. The method is characterized by: f. The alternating bipolar voltage is supplied to all even-numbered electrode plates near a pair of first diagonals, the first terminals being electrically connected to first electrical connectors, and these first electrical connectors being electrically connected to all even-numbered electrode plates near a pair of first diagonals. g. The opposite alternating bipolar voltage is supplied to all odd-numbered electrode plates near a pair of second diagonals, the second terminals being electrically connected to second electrical connectors; these second electrical connectors are electrically connected to all odd-numbered electrode plates near a pair of second diagonals.

[0089] The method according to the invention allows for the processing of non-conductive liquids using plasma established between electrode plates.

[0090] Applying an alternating voltage at the diagonal of the electrode plate results in the generation of a uniform plasma across the entire surface of the electrode plate, while minimizing the formation of electric arcs or other forms of hot spots.

[0091] This results in a uniformly treated non-conductive liquid.

[0092] According to ISO 2884-1, the treated non-conductive liquid obtained after processing in the apparatus according to the invention can be characterized by a relaxation time of less than or equal to 200 s, measured by a cone-plate viscometer at 40°C. The relaxation time corresponds to the time required for a viscoelastic lubricating substance to recover to its initial state under shear stress. Stress is applied to a sample of the treated non-conductive liquid, and the response to this stress can be monitored over time during the processing.

[0093] Therefore, the device according to the invention allows for the processing or handling of non-conductive liquids and the obtaining of processed or treated non-conductive liquids with suitable viscoelasticity. For example, non-conductive liquids processed in the device according to the invention can rapidly recover to their initial viscosity after the stress is applied, even when subjected to stress (particularly in an engine). This characteristic of a relaxation time of less than or equal to 200 s allows the non-conductive liquid to maintain a relatively stable and constant viscosity over time, even under stress.

[0094] Advantageously, the method according to the invention is characterized in that the high voltage range of the power supply applied to the electrode plate is between 1 kV and 10 kV, preferably between 2 kV and 3 kV, and the frequency is advantageously between 3 kHz and 100 kHz, more advantageously between 5 kHz and 70 kHz, and even more advantageously between 10 kHz and 40 kHz.

[0095] In a particular embodiment of the method according to the invention, the non-conductive liquid circulates between a first non-conductive liquid outlet of the housing and the non-conductive liquid inlet of the housing. Optionally, the non-conductive liquid may be filtered during circulation. Optionally, the non-conductive liquid may be heated or cooled during circulation to prevent overheating or to maintain appropriate flow characteristics, i.e., viscosity.

[0096] In embodiments of the invention, the distribution of the non-conductive liquid is obtained by forming a film of the non-conductive liquid on the surface of the electrode and optionally on the dielectric material, either by spraying or by a channel-type dispenser or a splash-proof dispenser.

[0097] The present invention further relates to any embodiment or combination of embodiments pointed out in the foregoing and appended claims.

Claims

1. An apparatus for electrical discharge machining of a non-conductive liquid, the apparatus comprising at least an alternating sequence of at least n rectangular, parallel, and spaced-apart electrode plates and n+1 dielectric plates, wherein n ≥ 2, and the electrode plates are numbered from 1 to n; characterized in that, The device includes a series of first electrical connectors electrically connected to all even-numbered electrode plates near a first pair of diagonals; and is characterized in that the device includes a series of second electrical connectors electrically connected to all odd-numbered electrode plates near a second pair of diagonals, and the device further includes an AC power supply having a first pole connected to the series of first electrical connectors and a second pole connected to the series of second electrical connectors.

2. The apparatus for electrical discharge machining of non-conductive liquids according to claim 1, characterized in that, The electrode plate and the dielectric plate are kept separate by one or more rails positioned at the bottom, top and / or sides of the plate.

3. The apparatus for electrical discharge processing of non-conductive liquids according to claim 1 or 2, wherein the surface area of ​​the dielectric plate is larger than the surface area of ​​the electrode plate.

4. The apparatus for electrical discharge processing of a non-conductive liquid according to claim 1 or 2, further comprising a housing, wherein an alternating sequence of at least one electrode plate and a dielectric plate is disposed within the housing.

5. The apparatus for electrical discharge machining of non-conductive liquids according to claim 4, characterized in that, The housing further includes a first non-conductive liquid outlet located at the lower part of the housing and a non-conductive liquid inlet located at the upper part of the housing.

6. The apparatus for electrical discharge machining of non-conductive liquids according to claim 4, characterized in that, The housing includes at least two separate electrical feed connectors, with the odd-numbered electrode plates and the even-numbered electrode plates respectively electrically connected to the power source via the electrical feed connectors.

7. The apparatus for electrical discharge machining of non-conductive liquids according to claim 4, characterized in that, The housing further includes at least one gas inlet port for allowing one or more process gases to enter.

8. The apparatus for electrical discharge machining of non-conductive liquids according to claim 1 or 2, characterized in that, The first pair of diagonals and the second pair of diagonals are positioned laterally relative to each other.

9. The apparatus for electrical discharge machining of non-conductive liquids according to claim 1 or 2, characterized in that, The first electrical connector and the second electrical connector are electrically connected at a distance from the corresponding angle, the distance being at most 15% of the length of the longest of the two sides that meet at the angle.

10. The apparatus for electrical discharge processing of a non-conductive liquid according to claim 1 or 2, further comprising a liquid distributor.

11. The apparatus for electrical discharge machining of non-conductive liquids according to claim 1 or 2, characterized in that, The electrode plate has a surface area between 0.2 m² and 4 m².

12. The apparatus for electrical discharge machining of non-conductive liquids according to claim 1 or 2, characterized in that, Electrode plates may be made of metal, metal alloy, metal compound, carbon, carbon compound, conductive ceramic or semiconductor.

13. The apparatus for electrical discharge machining of non-conductive liquids according to claim 1 or 2, characterized in that, The surface area of ​​the dielectric plate is 10% to 25% larger than that of the electrode plate.

14. The apparatus for electrical discharge machining of non-conductive liquids according to claim 1 or 2, characterized in that, The dielectric material includes glass, quartz, mica, rigid polymer, or mixtures thereof.

15. The apparatus for electrical discharge machining of non-conductive liquids according to claim 1 or 2, characterized in that, The device includes a dispenser for the non-conductive liquid.

16. A method for electrical discharge machining of a non-conductive liquid, the method comprising: a. Provide in the housing an alternating sequence of at least n rectangular, parallel and spaced-apart electrode plates and n+1 dielectric plates, where n ≥ 2, and the electrode plates are numbered from 1 to n; b. Provide an AC power source, wherein the AC power source provides an AC bipolar voltage at a first terminal and an opposite AC bipolar voltage at a second terminal; c. A hydrogen-containing vacuum atmosphere is provided within the housing; d. The non-conductive liquid is introduced into the housing via a first inlet of the housing. e. Distribute the non-conductive liquid on the surfaces of the n electrode plates and n+1 dielectric plates, and form a non-conductive liquid film on the surfaces of the electrode plates and the dielectric plates. The method is characterized by: f. The alternating bipolar voltage is supplied to all even-numbered electrode plates near a pair of first diagonals, the first terminal is electrically connected to a first electrical connector, and the first electrical connector is electrically connected to all even-numbered electrode plates near a pair of first diagonals, and is characterized in that... g. The opposite AC bipolar voltage is supplied to all odd-numbered electrode plates near a pair of second diagonals, the second terminal being electrically connected to a second electrical connector; the second electrical connector being electrically connected to all odd-numbered electrode plates near a pair of second diagonals.

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