Apparatus for electrical discharge treatment of non-conductive liquids

Abstract

The present invention relates to an apparatus for electrical discharge treatment of non-conductive liquids, comprising at least one alternating series of essentially rectangular, parallel, and spaced apart n electrode plates and n+1 dielectric plates, where n≧2 and the electrode plates are numbered from 1 to n, characterized in that the apparatus comprises a first series of electrical connectors electrically connected near a first pair of diagonally opposed corners of all even-numbered electrode plates, and a second series of electrical connectors electrically connected near a second pair of diagonally opposed corners of all odd-numbered electrode plates. Furthermore, the present invention relates to a method for electrical discharge treatment of non-conductive liquids using said apparatus.

Description

[Technical Field]

[0001] The present invention relates to an apparatus for the electrical discharge treatment of non-conductive liquids, which may be, for example, hydrocarbons, silicon-containing compounds, and fatty substances of animal or vegetable origin.

[0002] By "liquid" we mean a compound that remains in a liquid state under the conditions of this electrical discharge treatment. By "non-conductive liquid" we mean a compound that has a relatively high electrical resistivity, in particular at least 1×10 at 25° C., preferably up to 125° C. 8 The term "non-conductive liquid" refers to a liquid having a resistivity of Ωcm. The non-conductive liquid may be, for example, a hydrocarbon oil or paraffin. Specifically, by "liquid silicon-containing compound," we mean a chemical substance containing at least one silicon atom. The term "fatty substance" according to the present invention refers to a substance having hydrophobic properties and composed of molecules mainly composed of triglycerides. Triglycerides are esters formed from a glycerol molecule and three fatty acids. These fatty substances include oils, waxes, and fats. Oils are preferred within the scope of the present invention because they are composed mainly of unsaturated fatty acids and therefore have a low melting point, i.e., below room temperature, and therefore are in a liquid state at room temperature. On the other hand, fats and waxes are composed mainly of saturated fatty acids and have a melting point above room temperature, and therefore are viscous or solid at room temperature. Due to the high melting points of fats and waxes, their use in the device according to the present invention must preferably be carried out at temperatures above room temperature so that they are in liquid form.

[0003] The treatment of non-conductive liquids, such as oils of vegetable or mineral origin in liquid form, by electrical discharge, also called voltolization, is a method involving an electrical discharge, a so-called silencer. The electrical discharge is generated between two electrodes or a series of parallel metal electrodes separated by an electrical insulator, also called a dielectric material. By applying an alternating voltage between the electrodes, a plasma is generated between them through the dielectric material. This plasma allows the treatment of the oil in the form of a thin film on the surfaces of the electrodes and the dielectric. [Background technology]

[0004] From the prior art, it is known to rely on electrical discharge treatment devices to remove the unpleasant odor characteristic of fish oil, in particular in French Patent No. 363078. In this patent, the fish oil is contained in a cylindrical enclosure and is in contact with hydrogen. The hydrogen then binds itself to the fish oil after an electrical discharge applied between electrodes in the enclosure, thereby gradually removing the unpleasant odor of the fish oil.

[0005] The hydrogen consumed during the reaction is quickly and manually reintroduced into the closed vessel thanks to a tap provided for this purpose. The operating conditions for the treatment of this fish oil are not described in this patent document.

[0006] Thus, there is evidence in the prior art that electrical treatment of liquid organic materials allows the modification of their physicochemical properties, and this method has also been applied in the past to "concentrate" vegetable or mineral oils, or mixtures thereof, in order to obtain properties suitable for use as additives in lubricants.

[0007] A known apparatus for electrical discharge treatment of liquid organic materials comprises: an electrode series comprising n substantially parallel electrodes (1 and 2), where n≧2, each electrode being arranged to be connected to a high voltage source and / or to ground; a dielectric material series comprising n+1 dielectric material elements substantially parallel to the electrodes and positioned on either side of each electrode of the series, such that each electrode is between two dielectric material elements; an enclosure arranged to receive the non-conductive liquid and surrounding the series of electrodes and the series of dielectric material elements; and an immersion device for the series of electrodes and the series of dielectric material arranged to at least partially immerse the series of electrodes and the series of dielectric material elements.

[0008] GB 407379 describes an apparatus for treating hydrocarbon oils and paraffins using electric discharges. The apparatus for electric discharge treatment (volatilization) shown in this patent document is a capacitor in the form of a tube containing multiple metal plates placed in series and 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, a second, opposite metal plate functions as a ground electrode. A glass plate is then positioned between the metal plate connected to the current source and the metal plate functioning as a ground electrode. The glass plate can be rotated around the central axis of the capacitor. The metal plate and the glass plate are immersed in the hydrocarbon to be treated.

[0009] A similar device for applying an electric discharge to a liquid is described in GB 190507101. The device described therein also consists of a rotatable cylindrical enclosure in which the gas pressure can be maintained relatively constant thanks to a complementary device having a mercury manometer inside. As a result, gas can be reintroduced into the enclosure when the gas pressure in the enclosure measured by the mercury manometer drops. The gas pressure in the enclosure therefore increases to return to its initial value so that the gas pressure in the enclosure remains relatively constant. A series of metal disks and insulating disks are alternately placed on the rotating shaft of the enclosure, i.e., they are placed successively along the rotating shaft in the order of metal disk, insulating disk, metal disk, insulating disk, etc. The insulating material, also called a dielectric material, placed between the electrodes can reduce the formation of local arc discharges, which can cause excessively strong localized treatment of the liquid and result in degradation of the treated liquid.

[0010] Unfortunately, previous devices give highly random results when used to process vegetable or mineral oils. The physicochemical properties of the treated oil are unpredictable and uncontrollable. In addition, the implementation of the disclosed devices is not described, making any industrial development impossible. It has been reported that the disclosed devices have not been industrially developed because the undisclosed operating conditions are specific to these particular devices and give random results.

[0011] Also, in other prior art, the connections to the power supply are always only on one side of each plate, although possibly alternately, and the electrodes in these documents are covered in insulators, making them not adapted for treating non-conductive liquids. International Patent Application Publication No. 9815357, European Patent Application Publication No. 1809082, and Chinese Patent Application Publication No. 106793435 describe apparatus for plasma treating gases and aqueous solutions.

[0012] International Patent Application Publication No. 2018002329 describes an apparatus for relatively controllable electrical discharge treatment of plant-derived fatty materials, in which electrodes are individually connected in a manner that ensures the same current flow distance between any electrode and an electrical connector located on the outer surface of an enclosed vessel. This method of connecting electrodes significantly complicates upscaling of such an apparatus, since every electrode requires its own electrical connector. Furthermore, it has been found that on large electrodes, e.g., greater than 0.2 square meters, the plasma is not uniformly distributed across the electrode. Summary of the Invention [Problem to be solved by the invention]

[0013] It is an object of the present invention to provide an apparatus that has the ability to be easily scaled up and in which the electrical discharge treatment of non-conductive liquids is controlled, reproducible and uniform. [Means for solving the problem]

[0014] To solve this problem, the present invention provides an apparatus for electrical discharge treatment of non-conductive liquids, the apparatus comprising at least one alternating series of essentially rectangular, parallel, and spaced apart n electrode plates and n+1 dielectric plates, where n≧2, the electrode plates being numbered from 1 to n, the apparatus comprising: a first series of electrical connectors electrically connected near a first pair of diagonally opposite corners of all even-numbered electrode plates; and a second series of electrical connectors electrically connected near a second pair of diagonally opposite corners of all odd-numbered electrode plates; and the apparatus further comprising an AC power source having a first pole connected to the first series of electrical connectors and a second pole connected to the second series of electrode connectors.

[0015] To improve the repeatability, control, and uniformity of electrical discharge treatment of non-conductive liquids when implementing an apparatus according to the present invention, the inventors surprisingly discovered that by simultaneously supplying current to each electrode at diagonally opposite corners, a plasma is established uniformly on the electrode plates, limiting and in some cases avoiding any electric arcing and non-uniform treatment of non-conductive liquids, such as vegetable oils, present in the form of a thin film on the surfaces of the electrodes and dielectric plates. This result is achieved despite the fact that the length of the electrical path between the power source and the electrode plates may vary from plate to plate.

[0016] As a result, the treatment of non-conductive liquids in the apparatus according to the invention is relatively fast and relatively effective, while allowing the physicochemical properties of the resulting treated non-conductive liquid to be controlled. Indeed, the application of excessively aggressive treatments to non-conductive liquids, such as vegetable oils, such as those that occur when arcing occurs, can result in excessively rapid thickening of the oil and the formation of insoluble lumps and therefore deposits.

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

[0018] The n electrode plates and n+1 dielectric plates are positioned in an alternating sequence, which means that the dielectric and electrode plates are alternated with each other such that any electrode plate is between two dielectric plates.

[0019] The n electrode plates and n+1 dielectric plates are spaced apart, meaning that they are not in direct contact with each other.

[0020] The apparatus of the present invention is preferably configured to distribute said non-conductive liquid over the surfaces of said n electrode plates and optionally n+1 dielectric plates, and to form a thin film of said non-conductive liquid over the surfaces of said electrodes and optionally said dielectric plates. The apparatus may comprise a distributor for said non-conductive liquid above each electrode plate and optionally each dielectric plate.

[0021] According to one embodiment of the present invention, the surface area of ​​the dielectric plate is greater than the surface area of ​​the electrode plate. Advantageously, as shown in Figure 4, the dielectric plate (3) extends further than the electrode plate (1) in both directions along both the X and Z axes. The inventors have found that by having the dielectric plate extend beyond the electrode plate, direct arcing between adjacent electrode plates can be relatively easily avoided.

[0022] The odd-numbered and even-numbered electrode plates are arranged in an alternating manner with respect to one another, such that an odd-numbered electrode faces an even-numbered electrode, with a dielectric plate between the respective electrode plates, so that no two electrodes of the same type are adjacent, and so on.

[0023] In the following description, the term "non-conductive liquid" will often be expressed by the term "oil" for the sake of clarity. The term "oil" is used for the sake of clarity because the non-conductive liquid used according to the present invention is in liquid form under the processing conditions, regardless of whether it is derived from animal or vegetable oils, fats, or waxes, or from natural or synthetic hydrocarbons, or from silicon-containing compounds. As mentioned above, when fats or waxes are used, the operating temperature is preferably adapted to be in liquid form.

[0024] Fatty substances of plant origin can be derived, for example, from rapeseed, linseed, argan, and the like.

[0025] Preferably, the non-conductive liquid has a certain degree of unsaturation, specifically an iodine value in the range of 100-180 before treatment.

[0026] According to the invention, the term "high voltage" means a voltage, also called potential, preferably ranging from 1 kV to 10 kV, advantageously from 2 kV to 3 kV, at a current density preferably between 0.5 and 2 mA / cm 2 and characterized by a small alternating current whose frequency is advantageously between 3 and 100 kHz, advantageously between 5 and 70 kHz, and even more advantageously between 10 and 40 kHz.

[0027] In accordance with the present invention, the device comprises a series of electrode plates comprising at least n=2 electrode plates, the electrode plates preferably being electrically connected via an AC power source in such a manner that when a current is supplied to any odd-numbered electrode plate, an opposite current is supplied to any even-numbered electrode plate. Preferably, none of the electrode plates are grounded.

[0028] "AC power" should be interpreted to mean electrical power from an alternating current source in which the voltage varies at some frequency in a sinusoidal, square-wave, pulsed, or other waveform manner. The voltage fluctuation is often negative to positive. The average current per cycle averages to 0 A. In a bipolar configuration, the power output provided by the two leads is generally approximately 180° out of phase. The AC power supply provides a fluctuating or alternating bipolar voltage to the two electrodes. The AC power supply or AC power source initially drives the odd-numbered electrode plates to a negative voltage, thereby enabling plasma formation, while the even-numbered electrode plates are driven to a positive voltage to function as the anode for the voltage application circuit. This then drives the first electrode to a positive voltage, reversing the roles of cathode and anode.

[0029] In a preferred embodiment, the power supply of the present invention combines a solid-state power supply with a transformer, thereby maintaining the economic and technical advantages of solid-state power supplies, and the advanced levels of control, flexibility, and facility design that they offer, while compensating for the relatively low voltage of typical solid-state power supplies, typically around 800-1000V, to reach the required kV range described above. [Brief explanation of the drawings]

[0030] These and further aspects of the invention will now be described in more detail, by way of example and with reference to the accompanying drawings in which:

[0031] [Figure 1] FIG. 1 shows a schematic three-dimensional view of an alternating sequence of parallel, rectangular, spaced apart dielectric and electrode plates according to an embodiment of the present invention.

[0032] [Figure 2] 1 shows a schematic three-dimensional view of an illustrative embodiment of the electrical connection between the electrode plates and the power supply according to an embodiment of the present invention.

[0033] [Figure 3] 1 shows a schematic diagram of the notation used for the four corners of the electrode plate.

[0034] [Figure 4] FIG. 2 shows a front view of the electrode plate and the dielectric plate.

[0035] The figure is not to scale. DETAILED DESCRIPTION OF THE INVENTION

[0036] According to the present invention, the electrode plates and dielectric plates are spaced apart and therefore all lie in separate planes parallel to the XZ plane, as shown in Figure 1. Figure 1 shows an alternating sequence of parallel, rectangular, spaced apart dielectric plates (5) and electrode plates (1, 2, 3, 4) according to one embodiment of the present invention. The electrode plates (1, 2, 3, 4) and dielectric plates (5) are arranged in separate XZ planes and are spaced apart along the axis Y. Every electrode plate (1, 2, 3, 4) is located between two dielectric plates (5). The electrode plates are aligned with respect to each other, and the dielectric plates are aligned with respect to each other.

[0037] According to an advantageous embodiment of the invention, the spacing between the electrode plate and the dielectric plate is advantageously between 4 and 10 mm, more advantageously between 5 and 7 mm.

[0038] According to an advantageous embodiment of the invention, the number n of electrode plates is between 2 and 100, more advantageously between 5 and 50, even more advantageously between 8 and 30, preferably between 12 and 22.

[0039] According to one embodiment of the present invention, the electrode plates and dielectric plates are held apart by one or more guide rails located on the bottom, top, and / or sides of the plates. The guide rails can, for example, be provided with notches into which the electrodes and dielectric plates can be easily positioned. The n electrode plates and n+1 dielectric plates of this device can be held together in a rack, preferably equipped with the above-mentioned guide rails, which can function to hold the plates in place.

[0040] Figure 2 shows the electrical connections of the electrode plates according to one embodiment of the present invention. A series of first electrical connectors (6) are electrically connected to a first pair of diagonally opposite corners of all even-numbered electrode plates (2, 4), and a series of second electrical connectors (7) are electrically connected to a second pair of diagonally opposite corners of all odd-numbered electrode plates (1, 3). In this figure, only the outline of the dielectric plate (5) is shown by dashed lines to better illustrate the electrical connectors. The first and second electrical connectors (6, 7) are electrically connected to an AC power source (8).

[0041] In one embodiment, the device further comprises an AC power supply, through which at least n=2 electrode plates are connected to one another. The average current per cycle is averaged to 0 A. The AC power supply supplies a fluctuating 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 enabling plasma formation, while the even-numbered electrode plates are driven to a positive voltage so that they function as anodes for the voltage application circuit. This then drives the odd-numbered electrode plates to a positive voltage, reversing the roles of cathode and anode. A plasma is established between the odd-numbered and even-numbered electrode plates. The other cathode then forms an anode, allowing electrons to escape from the plasma and migrate to the other side, completing the electrical circuit.

[0042] According to one embodiment of the present invention, the AC power source may comprise a power source regulated in amplitude and frequency, and may further comprise a high voltage and high frequency transformer.

[0043] According to one embodiment of the present invention, the AC power supply may be configured to provide current at a frequency between 3 and 300 kHz and at a high voltage between 1 and 5 kV.

[0044] It is also possible, although not preferred, to alternately connect the even-numbered electrode plates to the high voltage source and the odd-numbered electrode plates to ground, to have an alternating sequence of dielectric plate, electrode plate connected to a high voltage source, dielectric plate, electrode plate connected to a high voltage source, and dielectric material element, and so on, and vice versa.

[0045] According to one embodiment of the present invention, the apparatus further comprises an enclosure within which the alternating series of electrode plates and dielectric plates is disposed.

[0046] The enclosure according to the invention advantageously has an essentially rectangular prismatic shape, preferably made from metal, more preferably made from stainless steel.

[0047] Advantageously, the enclosure further comprises a non-conductive liquid outlet located in a lower portion of the enclosure and a non-conductive liquid inlet located in an upper portion of the enclosure. According to an advantageous embodiment of the invention, the enclosure comprises a plurality of non-conductive liquid inlets.

[0048] According to one embodiment of the present invention, the enclosure comprises at least two separate electrical feedthrough connectors through which the odd- and even-numbered electrode plates are electrically connected to the power supply, respectively. The electrical feedthrough connectors advantageously comprise electrical insulators that electrically isolate them from the enclosure. The electrical feedthrough connectors are advantageously spaced from each other by at least 3 cm, at least 5 cm, or at least 10 cm. Each of the two separate electrical feedthrough connectors supplies an opposing alternating current to the electrodes.

[0049] According to one embodiment of the present invention, the enclosure is lined on the inside with an electrically insulating lining, so that arcing between the electrode plates and the enclosure can be avoided.

[0050] According to one embodiment of the present invention, the enclosure is capable of operating at a pressure of 10 to 400 Torr, preferably 80 to 300 Torr, and more preferably 100 to 260 Torr.

[0051] According to one embodiment of the present invention, the enclosure of the present invention advantageously further comprises a gas exhaust port which may be connected to a vacuum pump.

[0052] According to one embodiment of the present invention, the enclosure of the present invention may further comprise at least one gas inlet for the entry of one or more process gases required to carry out the process within the enclosure. The process gas may advantageously be selected from one or more of any noble gas, oxygen, and hydrogen. During oil processing, process gases such as hydrogen may be consumed, and therefore the pressure within the enclosure may tend to decrease as a result of the oil processing time. A pressure gauge may allow measurement of the gas pressure within the enclosure, thereby controlling the injection of additional amounts of process gas.

[0053] According to one embodiment of the present invention, a pressure of 10 to 400 Torr, preferably 80 to 300 Torr, and more preferably 100 to 260 Torr can be maintained during processing of the non-conductive liquid. Lower pressures facilitate plasma formation, especially in the presence of the non-conductive liquid on the electrodes.

[0054] Also, in an advantageous embodiment of the device according to the invention, the enclosure has at least one inclined surface for guiding the non-conductive liquid to a first non-conductive liquid outlet of the enclosure, the inclined guiding surface enabling the non-conductive liquid to be supplied to the non-conductive liquid outlet in the enclosure so as to further promote the circulation of the non-conductive liquid outside the enclosure.

[0055] In an advantageous embodiment, the apparatus according to the present invention further comprises a pressure gauge positioned within the enclosed vessel and configured to measure the gas pressure within the enclosed vessel. The pressure gauge may be, for example, an MKS brand capacitive vacuum gauge, which allows for measurement of the gas pressure within the enclosed vessel. During oil treatment, the first gas, e.g., hydrogen, may be consumed, and therefore the pressure within the enclosed vessel may tend to decrease over time. The pressure gauge allows for measurement of the gas pressure within the enclosed vessel, thereby making it possible to know when a predetermined amount of the first supplemental gas needs to be injected to maintain a constant gas pressure within the enclosed vessel.

[0056] Additionally, one embodiment of the apparatus further comprises a controller arranged to be connected to the pressure gauge and to be connected to a flow meter or a fast response leak valve, the controller arranged to control the flow meter, the leak valve, and the flow meter arranged to be in fluid communication with the second inlet for a first gas of the enclosed container to measure the amount of the first gas injected into the enclosed container by the second inlet for the first gas of the enclosed container.

[0057] When the pressure gauge measures an excessively low gas pressure in the enclosure, gas injection can be carried out via the gas inlet of the enclosure, and the amount of injected gas is advantageously controlled due to a flow meter.

[0058] In accordance with the present invention, a series of first electrical connectors are electrically connected to a first pair of diagonally opposite corners of all even-numbered electrode plates, and a series of second electrical connectors are electrically connected to a second pair of diagonally opposite corners of all odd-numbered electrode plates. Figure 3 illustrates how the corners of electrode plates (1, 2) may be labeled. For clarity, only the outline of dielectric plate (5) is shown in dashed lines in this figure. In both odd-numbered electrode plate (1) and even-numbered electrode plate (2), the corners are labeled in a clockwise fashion with "N," "W," "S," and "E." Corners (N) and (S) form a diagonally opposite corner pair, and corners (E) and (W) form a diagonally opposite corner pair. The pair of corners (N, S) of the odd-numbered electrode plates (1) and the pair of corners (E, W) of the even-numbered electrode plates (2) are positioned transverse to each other.

[0059] According to an exemplary embodiment of the present invention, a first electrical connector is electrically connected to all odd-numbered electrode plates in a first pair of diagonally opposite corners (E, W) or (N, S), and a second electrical connector is electrically connected to all even-numbered electrode plates in a second pair of diagonally opposite corners (E, W) or (N, S).

[0060] In a preferred embodiment of the present invention, the first pair of diagonally opposed corners and the second pair of diagonally opposed corners are positioned transversely relative to each other, such as the first pair of diagonally opposed corners (E,W) on the odd-numbered electrode plates and the second pair of diagonally opposed corners (N,S) on the even-numbered electrode plates in Figure 2. In Figure 2, the diagonally opposed corner pairs (E,W) and (S,N) are in transverse positions relative to each other.

[0061] The electrode plates and dielectric plates are preferably in a vertical position, i.e., they are held in an essentially vertical position, preferably with two sides along the vertical axis Z and two sides along the horizontal axis X. This allows the non-conductive liquid being treated to freely fall along the electrode plates due to gravity alone.

[0062] The first and second electrical connectors are electrically connected to at least the edges of the electrode plate near the corners or to the plate surface adjacent to the edges, i.e., no more than 5 cm from the edges. The electrical connectors may be, for example, soldered, screwed, clamped, or press-fit onto the edges.

[0063] According to one embodiment of the present invention, the first and second electrical connectors are electrically connected to the electrode plates in the vicinity of the corners of their respective electrode plates, i.e., at a distance from the respective corners that corresponds to a maximum of 15% of the length of the longer of the two sides that meet at the respective corners. According to particularly advantageous embodiments, the first and second electrical connectors can be electrically connected to the electrode plates at a distance from the respective corners that corresponds to a maximum of 10% of the length of the longer of the two sides that meet at the respective corners.

[0064] According to one embodiment of the present invention, the odd-numbered electrode plates are connected to a first terminal of the AC power source via a first electrical connector, and the even-numbered electrode plates are connected to a second terminal of the AC power source via a second electrical connector.

[0065] According to one embodiment of the present invention, the device may be provided with two first electrical collectors electrically connected to the first electrical connector and two second electrical collectors electrically connected to the second electrical connector.

[0066] According to one 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 a diagonally opposite corner of the odd-numbered electrode plates. Similarly, according to one 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 a diagonally opposite corner of the even-numbered electrode plates.

[0067] According to one embodiment of the present invention, the apparatus includes a distributor for a non-conductive liquid. The distributor can be configured to distribute the non-conductive liquid to be treated along the surfaces of the electrode plate and, optionally, the dielectric plate. Several types of distributors are known in the art, and these may be, for example, channel-type distributors or splash-plate-type distributors. The liquid distributor used in this apparatus is preferably adapted to distribute liquids with a wide range of viscosities. In certain embodiments, the distributor can be located above the electrode plate and, optionally, above the dielectric plate, and can be configured for a downward flow of the liquid.

[0068] According to one embodiment of the present invention, the device is provided with a circulation circuit outside the enclosure. The presence of a first inlet and a first outlet for the non-conductive liquid in the enclosure allows the non-conductive liquid to circulate outside the enclosure.

[0069] According to an advantageous embodiment of the present invention, the apparatus is provided with a temperature control system comprising one or more of a cooling device, a heating device, and a temperature measurement system. Advantageously, since plasma treatment tends to increase the temperature of the non-conductive liquid, the non-conductive liquid can be circulated through a cooling device to avoid overheating of the non-conductive liquid. The cooling device can include a heat exchanger and / or a three-way valve for injecting cooler non-conductive liquid to maintain the treatment temperature within a desired range. The heating system can include a heating device arranged around the enclosure containing the non-conductive liquid to heat the enclosure. The heating system can control and maintain the temperature of the enclosure constant despite temperature fluctuations that may occur in the environment of the enclosure. Furthermore, when a non-conductive liquid of the fat or wax type is used, the heating system allows the non-conductive liquid to be supplied above its melting temperature so that it is in liquid form within the enclosure. Advantageously, the temperature measurement system includes a temperature probe immersed directly in the non-conductive liquid in the enclosure, at the outlet of the enclosure 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, the temperature probe may be connected to a controller which is itself connected to the heating and / or cooling system to control the heating and / or cooling so that the temperature of the non-conductive liquid within the device is controlled and maintained constant.

[0070] In one preferred embodiment of the present invention, the temperature control system is configured to maintain the non-conductive liquid at a temperature in the range of 50-100°C, more preferably 55-85°C.

[0071] In another advantageous embodiment, the device of the present invention comprises a filter for filtering the treated non-conductive liquid. The filter can be arranged at the outlet so as to filter the treated liquid at the end of the process. Alternatively, the non-conductive liquid can be circulated through a filter arranged outside the closed vessel. Passage through the filter allows the homogeneity of the treated material to be maintained after the strong and effective plasma is applied to the non-conductive liquid. The filter can have a mesh size ranging from 0.01 to 1 mm, preferably from 0.015 to 0.8 mm. Advantageously, the filter is a metal filter.

[0072] Also, in one embodiment of the present invention, circulation of the non-conductive liquid outside the enclosure and its return via the inlet of the enclosure can enable said non-conductive liquid to be distributed onto the electrode plates and optionally onto the dielectric plates.

[0073] In one embodiment of the present invention, the apparatus further comprises a viscometer having a first inlet arranged to be fluidly connected to the first non-conductive liquid outlet of the enclosure and, optionally, a first outlet arranged to be fluidly connected to the aforementioned filter, the viscometer being arranged to measure the viscosity of the non-conductive liquid, for example, between the enclosure and the metal filter. The viscometer thus allows the viscosity of the non-conductive liquid to be measured throughout the process. This viscosity measurement allows for further improved control of the viscosity characteristics of the processed non-conductive liquid. For example, a vibrating direct insertion viscometer, such as a Sofraser MiVI sensor, preferably with a temperature probe, can be used. The measurement may be performed by using a rod vibrating at a resonant frequency, where the vibration amplitude varies according to the viscosity of the liquid in which the rod is immersed.

[0074] The present invention advantageously further comprises a circulation pump having a first inlet in fluid communication with said first outlet of the enclosed container and optionally a second outlet in fluid communication with the above-mentioned viscometer and / or the above-mentioned filter, said circulation pump being arranged to circulate said non-conductive liquid between said first outlet and said second inlet of the enclosed container.

[0075] According to one embodiment of the invention, the device further comprises a sampling valve in the circulation circuit, which allows for the extraction of samples of the treated material for monitoring the quality and performance of the product during processing. In a particularly advantageous embodiment of the device according to the invention, the enclosure comprises a removal valve arranged to extract the liquid plant material out of the enclosure.

[0076] According to a preferred embodiment of the present invention, n is 4 or more, advantageously 5 or more, even more advantageously 6 or more, and even more advantageously 7 or more. Increasing the number of electrodes and the number of dielectric materials makes it possible to increase the effectiveness of the treatment of non-conductive liquids by increasing the contact surface between the electric discharge and the non-conductive liquid present in the form of a thin film on the electrode plates and dielectric plates. In particular embodiments of the present invention, n may be 100 or less, or 50 or less, or 30 or less.

[0077] According to one embodiment of the present invention, the electrode plates of the device have a thickness of 0.5 mm to 10 mm, preferably 0.8 to 6 mm, more preferably 1 mm to 3 mm.

[0078] According to one embodiment of the present invention, the electrode plates and dielectric plates of the device are essentially 0.2 m 2 ~4m 2 is a rectangle with a surface area of

[0079] The construction material of the electrode plates preferably has sufficient conductivity so that resistive heating of the electrode plates is limited and so that they can carry the current necessary to maintain the discharge and so that voltage fluctuations can be established quickly. According to one embodiment of the present invention, the material of the electrode plates includes metals, metal alloys, metal compounds, carbon, carbon compounds, conductive ceramics, or semiconductors. Advantageously, the material used can include metal alloys or graphitic carbon, in particular steel, stainless steel, copper, or aluminum.

[0080] According to one embodiment of the present invention, the material of each dielectric plate may be selected from the group consisting of glass, quartz, mica, hard polymers, and mixtures thereof. The glass may be, for example, soda-lime glass, borosilicate glass, or aluminosilicate glass. In one advantageous embodiment, the material of the dielectric plates may include a hard polymer. In one advantageous embodiment, the material of the dielectric plates may have a dielectric constant of 1.9 or greater at 10-60 Hz. In one advantageous embodiment, the material of the dielectric plates may have an operating temperature of 80°C or greater that can withstand continuous operation. Preferably, the operating temperature is 150°C or greater, and more preferably 200°C or greater. In one advantageous embodiment, the dielectric strength of the material of the dielectric plates according to IEC 60243 is 10 kV / mm or greater.

[0081] In one embodiment of the present invention, the dielectric plate is essentially rectangular and preferably has a thickness in the range of 0.5 mm to 10 mm, preferably 2 mm to 6 mm.

[0082] In a preferred embodiment, the surface area of ​​the dielectric plate is larger than the surface area of ​​the electrode plate by 3 to 25%, more preferably by 6 to 15%.

[0083] Another advantage of the device according to the invention is that it allows the characteristic odor of animal or vegetable oils to be reduced or even eliminated, which is advantageous for example in the case of applications in the cosmetics or food sector, where excessively strong odors from vegetable-based fatty substances used as lubricating bases must be avoided.

[0084] The device according to the invention therefore allows fatty acids of animal or plant origin, treated by electrical discharge, to be produced on a large scale and regenerated with controllable, controlled and advantageously deodorized characteristics.

[0085] Further embodiments of the device according to the invention are set forth in the accompanying claims.

[0086] The present invention also relates to a system for the electrical discharge treatment of non-conductive liquids comprising a plurality of devices according to the invention, for example 2, 3, 4 or more devices, said devices being arranged in series and / or in parallel with one another, said devices being able to share one and the same enclosure.

[0087] Further embodiments of the system according to the invention are set forth in the accompanying claims.

[0088] The present invention also relates to a method for the electrical discharge treatment of non-conductive liquids using an apparatus for the electrical discharge treatment of non-conductive liquids according to any embodiment or any possible combination of embodiments described above.

[0089] The present invention specifically relates to a. providing at least one alternating series of essentially rectangular, parallel, and spaced apart n electrode plates and n+1 dielectric plates within an enclosure, where n≧2 and the electrode plates are numbered from 1 to n; b. providing an AC power source supplying an AC bipolar voltage to a first terminal and an opposite AC bipolar voltage to a second terminal; c. optionally providing a reduced pressure atmosphere comprising hydrogen within said enclosure; d. introducing the non-conductive liquid into the enclosure via a first inlet of the enclosure; e. dispensing the non-conductive liquid onto the surfaces of the n electrode plates and optionally n+1 dielectric plates to form a thin film of non-conductive liquid on the surfaces of the electrodes and optionally the dielectric plates; a method for the electrical discharge treatment of a non-conductive liquid, comprising: The method comprises: f. the alternating current bipolar voltage is provided adjacent a first pair of diagonally opposed corners of all even-numbered electrode plates, the first terminals are electrically connected to a first electrical connector, and the first electrical connector is electrically connected adjacent a first pair of diagonally opposed corners of all even-numbered electrode plates; and g. the opposite alternating current bipolar voltages are provided adjacent a second pair of diagonally opposed corners of all odd-numbered electrode plates, the second terminals are electrically connected to a second electrical connector, and the second electrical connector is electrically connected adjacent a second pair of diagonally opposed corners of all odd-numbered electrode plates; It is characterized by:

[0090] The method according to the invention allows the treatment of non-conductive liquids using a plasma established between electrode plates.

[0091] Application of AC voltages at diagonally opposite corners of the electrode plate results in a uniform plasma across the entire surface of the electrode plate with minimal formation of arcs or other forms of hot spots.

[0092] This results in obtaining a uniformly treated non-conductive liquid.

[0093] The treated non-conductive liquid obtained after processing in an apparatus according to the present invention may be characterized by a relaxation time of 200 seconds or less as measured at 40°C by a cone and plate viscometer according to the ISO 2884-1 standard. The relaxation time corresponds to the time required for a lubricating material having viscoelastic properties to return to its initial state when subjected to shear stress. While the process is running, stress can be applied to a sample of the treated non-conductive liquid, and the resulting response to this stress can be monitored over time.

[0094] Thus, the device according to the present invention allows a non-conductive liquid to be processed or treated and to obtain a processed or treated non-conductive liquid having suitable viscoelastic properties. For example, when a treated non-conductive liquid in the device according to the present invention is subjected to stress, particularly in an engine, it quickly returns to its initial viscosity after the application of this stress. This relaxation time of 200 seconds or less allows the non-conductive liquid to maintain a relatively stable and constant viscosity over time despite the application of stress.

[0095] Advantageously, the method according to the invention is characterized in that the high voltage of the power supply applied to the electrode plates is in the range of 1 kV to 10 kV, preferably 2 kV to 3 kV, and the frequency is advantageously in the range of 3 kHz to 100 kHz, more advantageously 5 kHz to 70 kHz, even more advantageously 10 kHz to 40 kHz.

[0096] In one particular embodiment of the method according to the invention, the non-conductive liquid is circulated between a first non-conductive liquid outlet of an enclosure and the non-conductive liquid inlet of the enclosure. Optionally, the non-conductive liquid can be filtered while being circulated. Optionally, the non-conductive liquid can also be heated or cooled while being circulated to prevent overheating or to maintain appropriate flow characteristics, i.e., viscosity.

[0097] In one embodiment of the invention, the distribution of the non-conductive liquid is obtained by forming a thin film of the non-conductive liquid on the surface of the electrode and optionally the dielectric material, which is obtained by spraying or by means of a channel type distributor or a splash plate type distributor.

[0098] The present invention further relates to any embodiment or combination of embodiments described above and set forth in the appended claims.

Claims

1. 1. An apparatus for electrical discharge treatment of non-conductive liquids, the apparatus comprising at least one alternating series of essentially rectangular, parallel, and spaced apart n electrode plates and n+1 dielectric plates, n≧2, the electrode plates being numbered 1 through n; the apparatus comprising: a first series of electrical connectors electrically connected adjacent a first pair of diagonally opposed corners of all even-numbered electrode plates; and a second series of electrical connectors electrically connected adjacent a second pair of diagonally opposed corners of all odd-numbered electrode plates; and an AC power source having a first pole connected to the first series of electrical connectors and a second pole connected to the second series of electrode connectors.

2. 2. The apparatus for electrical discharge treatment of non-conductive liquids according to claim 1, characterized in that the electrode plate and the dielectric plate are held apart by one or more guide rails located on the bottom, top, and / or sides of the plates.

3. 3. The apparatus for electrical discharge treatment of non-conductive liquids according to claim 1 or 2, characterized in that the surface area of ​​the dielectric plates is larger than the surface area of ​​the electrode plates.

4. 4. The apparatus for electrical discharge treatment of non-conductive liquids according to any one of claims 1 to 3, characterized in that the apparatus further comprises an enclosure in which the at least one alternating series of electrode plates and dielectric plates is placed.

5. 5. The apparatus for electrical discharge treatment of non-conductive liquids according to claim 4, characterized in that the enclosure further comprises a first non-conductive liquid outlet located in a lower portion of the enclosure and a first non-conductive liquid inlet located in an upper portion of the enclosure.

6. 6. An apparatus for electrical discharge treatment of non-conductive liquids according to claim 4 or 5, characterized in that the enclosure comprises at least two separate electrical feed-through connectors through which the odd- and even-numbered electrode plates are electrically connected to the power supply, respectively.

7. 7. Apparatus for electrical discharge treatment of non-conductive liquids according to any one of claims 4 to 6, characterized in that the enclosure further comprises at least one gas inlet port for the entry of one or more process gases.

8. 8. The apparatus for electrical discharge treatment of non-conductive liquids according to claim 1, wherein the first pair of diagonally opposite corners and the second pair of diagonally opposite corners are positioned transversely relative to each other.

9. 9. The apparatus for electrical discharge treatment of non-conductive liquids according to claim 1, wherein the first and second electrical connectors are electrically connected to the electrode plates at a distance from each corner that corresponds to a maximum of 15% of the length of the longer of the two sides that intersect at each corner.

10. Apparatus for electrical discharge treatment of non-conductive liquids according to any one of claims 1 to 9, characterized in that the apparatus further comprises a liquid distributor.

11. The electrode plate is 0.2 to 4 m ２ 11. The device for electrical discharge treatment of non-conductive liquids according to claim 1, characterized in that it has a surface area of ​​0.01 .mu.m.

12. 12. The apparatus for electrical discharge treatment according to any one of claims 1 to 11, characterized in that the electrode plates comprise a metal, a metal alloy, a metal compound, carbon, a carbon compound, a conductive ceramic, or a semiconductor.

13. 13. The device for electrical discharge treatment of non-conductive liquids according to any one of claims 1 to 12, characterized in that the surface area of ​​the dielectric plates is 10 to 25% larger than the surface area of ​​the electrode plates.

14. The device for electrical discharge treatment of non-conductive liquids according to any one of claims 1 to 13, characterized in that the dielectric plate comprises glass, quartz, mica, hard polymers and mixtures thereof.

15. Device for electrical discharge treatment of non-conductive liquids according to any one of claims 1 to 14, characterized in that the device comprises a distributor for the non-conductive liquid.

16. 1. A method for electrical discharge treatment of a non-conductive liquid, comprising: a. providing at least one alternating series of essentially rectangular, parallel, and spaced apart n electrode plates and n+1 dielectric plates within an enclosure, wherein n≧2, and said electrode plates are numbered from 1 to n; b. providing an AC power source supplying an AC bipolar voltage to a first terminal and an opposite AC bipolar voltage to a second terminal; c. Optionally, providing a reduced pressure atmosphere comprising hydrogen within the enclosure; d. introducing the non-conductive liquid into the enclosure via a first inlet of the enclosure; e. dispensing the non-conductive liquid onto the surfaces of the n electrode plates and optionally n+1 dielectric plates to form a thin film of non-conductive liquid on the surfaces of the electrodes and optionally the dielectric plates; In a method comprising: f. the alternating current bipolar voltage is provided adjacent a first pair of diagonally opposed corners of all even-numbered electrode plates, the first terminals are electrically connected to a first electrical connector, and the first electrical connector is electrically connected adjacent a first pair of diagonally opposed corners of all even-numbered electrode plates; g. the opposite alternating current bipolar voltages are provided adjacent a second pair of diagonally opposed corners of all odd-numbered electrode plates, the second terminals are electrically connected to a second electrical connector, and the second electrical connector is electrically connected adjacent a second pair of diagonally opposed corners of all odd-numbered electrode plates; A method characterized by:

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