EP3479660B1 - Device for electrically processing a fatty substance of plant origin - Google Patents

Description

The present invention relates to a device for the electrical treatment of a fatty substance of vegetable origin.

The terms “fatty substances” according to the present invention refer to substances composed of molecules having hydrophobic properties and being predominantly composed of triglycerides. Triglycerides are esters made up of one molecule of glycerol and three fatty acids. These fatty substances include oils, waxes and fats. In the context of the present invention, oils are preferred because they are in the liquid state at room temperature since they are mainly composed of unsaturated fatty acids and therefore have low melting points, namely lower or equal to room temperature. Fats and waxes are pasty or solid at room temperature because they have a higher melting point than room temperature since they are mainly composed of saturated fatty acids. The melting point being higher for fats and waxes, their use in the device according to the present invention should preferably be carried out at a temperature above room temperature so that they are in the liquid form.

The treatment by electric discharges of an oil of vegetable or mineral origin in the liquid form, also called voltolization, is a process involving so-called silent electric discharges. The electrical discharges are carried out between two metallic electrodes or succession of parallel metallic electrodes which are separated by an electrical insulator, also called dielectric material. The application of an alternating electric voltage between the electrodes makes it possible to create a plasma between them through the dielectric material. This plasma will allow the treatment of the oil present in the form of a film on the surface of the electrodes and of the dielectric.

It is known from the state of the art, in particular in the document FR363078 , to use an electrical treatment device to eliminate the characteristic and unpleasant odor of fish oil. In this document, the fish oil is contained in a cylindrical enclosure and is brought into contact with hydrogen. The hydrogen then binds to the fish oil following the electrical discharges applied between the electrodes in the enclosure, thereby gradually removing the unpleasant odor from the fish oil.

The hydrogen consumed during this reaction is punctually and manually reintroduced into the enclosure thanks to a tap provided for this purpose. The operating conditions for this treatment of fish oil are not described in the document.

It was then demonstrated in the prior art that an electrical treatment of liquid organic materials made it possible to modify the physico-chemical properties of the latter. This process has therefore also been applied in the past to "thicken" vegetable or mineral oils or a mixture of these in order to provide them with properties suitable for use as additives in lubricants.

A known device for the electrical treatment of liquid organic matter comprises a series of electrodes comprising a number n of electrodes (1 and 2), with n ≥ 2, substantially parallel, each electrode being arranged to be connected to a source of high voltage and / or ground, a series of elements of dielectric material comprising n + 1 elements of dielectric material substantially parallel to said electrodes and placed on either side of each electrode of the series of electrodes so that each electrode is located between two elements of dielectric material, an enclosure arranged to receive said fatty substance, and surrounding said series of electrodes and said series of elements of dielectric material and a device for immersing said series of electrodes and said series dielectric material element arranged to at least partially immerse said series of electrodes and said series of dielectric materials.

The document GB407379 describes a treatment device for oils and paraffins of hydrocarbons by means of electric discharges. The device for treatment by electrical discharges (voltolization) illustrated in this document is a condenser, in the form of a tube, containing a plurality of metal plates placed in series, separated from each other by glass plates.

The metal plates are alternately connected to a high frequency current source, which means that when a first metal plate is connected to a high frequency current source, the second metal plate facing it, serves as ground electrode. A glass plate is then located between a metal plate connected to a current source and a metal plate serving as a ground electrode. The glass plates can be rotated about a central axis of the condenser. The metal plates and the glass plates are immersed in the hydrocarbon to be treated.

A similar device for applying electrical discharges to a liquid is also described in the document. GB190507101 . The device described in this document also consists of a cylindrical enclosure which can be rotated in which the gas pressure can be kept relatively constant by virtue of an additional device having a mercury manometer. In this way when the gas pressure in the enclosure, measured by the mercury manometer, decreases, gas can be reintroduced into the enclosure. Therefore, the gas pressure in the enclosure increases to reach its initial value again so that the gas pressure in the enclosure is kept relatively constant.

A series of metal discs and discs of insulating material are placed alternately on a rotation shaft of the enclosure, namely that along from the rotation shaft are successively placed a metal disc, a disc of insulating material, a metal disc, a disc of insulating material and so on. The insulating material, also called dielectric material, placed between the electrodes makes it possible to reduce the formation of local electric arcs which would cause too intensive local treatment of the liquid which could result in the degradation of the treated liquid.

However, no conditions for using this device are disclosed in this document.

Unfortunately, the prior devices give very random results when they are used to treat vegetable or mineral oils. The physicochemical properties of the treated oils are neither predictable nor controllable / controlled. In addition, the implementation of the disclosed devices is not described, which does not allow industrial exploitation. After long developments to reproduce the technology disclosed in the documents GB407379 and GB190507101 , it appeared that the industrial exploitation of the disclosed devices was not possible because the undisclosed operating conditions were unique and gave random results.

The inventors of the present patent application have therefore researched and developed a device which makes it possible to be implemented industrially and in which the electrical treatment of the fatty substance of plant origin is controlled and reproducible while improving the effectiveness of the treatment.

To solve this problem, there is provided according to the invention, a device as indicated at the beginning in which the enclosure is further provided with at least one electrical connector placed on the outer surface of the enclosure, with a series of electrical connections comprising at least n electrical connections so as to connect each electrode of said series of electrodes to said electrical connector, each electrical connection having a predetermined current flow distance, the current flow distances of the electrical connections being equal relative to each other, from a first entry of the fatty substance and of a first outlet of the fatty substance and, of a second inlet for a first gas and of a second outlet for a second gas, said device further comprising a high voltage source connected to said electrical connector for supplying said first electrode and a filter having an inlet in fluid connection with said first outlet of the fatty substance from the enclosure and an outlet in fluid connection with said first inlet of the fatty substance of the enclosure.

In the following description, the expression “fatty substance of vegetable origin” will, for reasons of simplicity, also sometimes be expressed by the terms “fatty substance”, “vegetable oil” or simply oil. The term “oil” is used for reasons of simplicity because the fatty substance used according to the present invention is in the liquid form whether it comes from a vegetable oil or from a vegetable fat or wax. As explained above, when a fat or a wax is used, the temperature of use is preferably adapted so that the fatty substance is in the liquid form. The term "oil" according to the present invention can therefore be an oil, a fat or a vegetable wax in the liquid form.

The fatty substances of vegetable origin come for example from rapeseed, flax seeds, argan ...

Preferably, it is a fatty substance of vegetable origin having, before treatment, an iodine index of between 100 and 180 mg.

According to the present invention, the term "high voltage" means a voltage, also called a potential, preferably between 500 V and 10 kV and characterized by a low alternating current, the current density of which is preferably between 0 , 5 and 2 mA / cm ² and whose frequency is advantageously between 1 kHz and 500 kHz.

According to the present invention, the device comprises a series of electrodes comprising at least two electrodes so that, when a first electrode is supplied with current, a second electrode serves as a ground electrode.

The alternating current applied to the electrodes is a current which changes direction twice per period. Therefore, when an alternating current is applied to the electrodes of the device according to the invention, all the electrodes are connected to the high voltage source. In this way, the current arrives at a first electrode when a second electrode serves as a ground electrode and conversely when the current changes direction, the second electrode is supplied with current when the first electrode serves as a ground electrode and thus immediately after each change of direction of the current.

It is also possible to alternately connect a first electrode to the high voltage source and a second electrode to ground so as to have an element of dielectric material, an electrode connected to the high voltage source, an element of dielectric material, an electrode connected to ground and an element of dielectric material, and so on.

In order to improve the reproducibility and the control of the electrical treatment of the fatty substance of vegetable origin during the implementation of the device according to the present invention, the inventors have surprisingly noticed that it is ideally to reduce any loss of energy. and optimizing the current flow by symmetrizing the current flow distance between the high voltage source and the electrodes of the series of electrodes. Thus, surprisingly, it has been imagined that this optimization could take place, not necessarily at the level of the high voltage source but within the enclosure itself. The electrodes being placed substantially parallel to each other in the enclosure of the device, it was not obvious to symmetricize the distance of current flow between the high voltage source and each electrode.

Indeed, in the configuration of the device according to the present invention, the electrical connector placed on the outer surface of the enclosure is therefore of a firstly connected to a high voltage source, for example to an electrical transformer, and secondly to the electrodes of the series of electrodes.

The electrodes being placed parallel to each other in the enclosure, they are increasingly distant from the electrical connector placed on the exterior surface of the enclosure and the electrical connections tend to be longer for the electrodes. further away from the electrical connector than those located in a closer environment.

In the device according to the present invention, as mentioned previously, each electrical connection having a predetermined current passage distance, the current passage distances of the electrical connections being equal with respect to each other. The electrodes are therefore connected to the electrical connector by means of electrical connections of identical length so that the distance traveled by the current between said electrical connector and the electrodes of the series of electrodes is identical for each electrode.

By the terms "symmetrizing the distance of current flow between the high voltage source and each electrode", it is therefore understood in the sense of the present invention, that the distance of current flow (traveled by the current) between the high source voltage and the electrodes is identical for each electrode. The symmetrization of the current flow distance also makes it possible to limit the energy losses and to improve the control of the current applied to the electrodes.

In this way, thanks to the device according to the present invention, for each electrode of the series of electrodes, the current travels the same distance between the high voltage source and said electrode. Consequently, the current is distributed more homogeneously on each electrode of the series of electrodes.

This better distribution of the current also makes it possible to limit the edge effects on an electrode which can cause a non-homogeneous distribution of the current on this electrode. By thus avoiding the non-homogeneous distribution of the current on an electrode, it is avoided that it in turn causes the formation of electric arcs and a non-homogeneous treatment of the vegetable oil present in the form of film on the surface of this electrode and dielectric material elements.

Since the current losses are limited and identical on each electrode and the control of the amount of current applied to the electrodes is improved, the uniformity of the electric discharge between the electrodes through an element of dielectric material is improved.

In addition, the current losses linked to a phase shift are limited, which makes it possible to reduce the heating during the oil treatment. The heating is limited, it is no longer necessary to use a constraining and expensive cooling device as described in the prior art.

Since the fatty substance is in the form of a film on the surface of the electrodes and of the elements of dielectric material, the treatment of this fatty substance using the device according to the present invention is also more uniform. This uniformity of treatment also makes it possible to further improve the reduction in the formation of local electric arcs which, as explained above, would cause too intensive local treatment of the oil which could result in the degradation of the treated fatty substance.

Consequently, the treatment of the fatty substance in the device according to the present invention is faster and more effective while making it possible to control the physico-chemical properties of the fatty substance resulting from the treatment.

However, as described in the documents FR828933 and GB488026 , applying too intensive a treatment to a vegetable oil leads to too rapid thickening of the oil and can cause the formation insoluble agglomerate and therefore to the formation of a sediment. In addition, the devices of the prior art are not suitable for the treatment of all vegetable oils. Indeed, the document FR828933 advise to avoid the use of linseed oil or Chinese wood oil while the document GB488026 reports the formation of a jelly following the treatment of a mixture of rapeseed oil with a mineral oil.

According to the present invention, despite the application of an intense and very effective plasma to the oil, which can lead to a specific and localized thickening of the oil, the viscosity qualities of the treated oil are homogeneous throughout the liquid vegetable phase. Indeed, the device according to the invention is provided with a circulation external to the enclosure. The presence of a first inlet and a first outlet for the liquid fatty substance in the enclosure makes it possible to circulate the liquid fatty substance outside the enclosure and to pass it through a filter, for example a metallic filter placed outside the enclosure. 'pregnant. The circulation of the oil outside the enclosure and its passage through a filter makes it possible to maintain the homogeneity of the material treated following the intense and effective plasma applied to the oil. For example, the filter has meshes whose size is between 0.5 and 1 mm, preferably about 0.8 mm. Advantageously, the filter is a metal filter.

The circulation of the fatty substance outside the enclosure and its passage between the meshes of the filter therefore makes it possible, moreover, to eliminate aggregates, or even agglomerates which could have formed in the fatty substance during treatment with intense plasma and effective obtained in the enclosure of the device according to the present invention. The mesh of the filter indeed makes it possible to retain and / or reduce the size of the aggregates or agglomerates so as to homogenize the oil and to avoid the formation of aggregates or agglomerates of too large size which could lead to the gelation of the fatty substance.

It has been demonstrated in the context of the present invention that there is therefore a synergy between the presence of the electrical connector on the enclosure and the symmetrization of the current flow distance between the high voltage source and the electrodes and the circulation of the fatty substance outside the enclosure and its passage through a filter. Indeed, this results in an improvement in the control and reproducibility of the electrical treatment of the liquid fatty substance while improving the effectiveness of this treatment.

Another quite unexpected advantage of the device according to the present invention is that it also makes it possible to reduce, or even eliminate, the characteristic smell of vegetable oils. As mentioned previously, the state of the art discloses devices and methods for voltolizing fish oil to reduce its characteristic odor. The implementation of this device makes it possible to reduce, or even eliminate, the odor of fatty substances of vegetable origin. This reduction in the odor of fatty substances of vegetable origin is, for example, advantageous for applications in the cosmetic or food field where too pronounced odors of fatty substances of vegetable origin, used for example as a lubricating base, are to be avoided.

The device according to the present invention therefore makes it possible to produce and reproduce a fatty substance of vegetable origin treated by electrical discharges having controllable, controlled and advantageously deodorized characteristics.

Preferably, n is greater than or equal to 4, advantageously greater than or equal to 5, more preferably greater than or equal to 6, more advantageously greater than or equal to 7. The increase in the number of electrodes and the number of dielectric materials makes it possible to further increase the efficiency of the treatment of the fatty substance by increasing the contact surface between the electrical discharge and the fatty substance present in the form of a film on the electrodes and the elements of dielectric material.

The enclosure according to the present invention is advantageously a metallic cylindrical enclosure, preferably made of stainless steel.

In a particular embodiment of the device according to the invention, the enclosure is a parallelepiped enclosure, preferably made of stainless steel.

Advantageously, the device has at least one electrode, preferably each electrode of the series of electrodes, which is a metal plate having a thickness of between 0.5 mm and 5 mm, preferably between 1 mm and 3 mm.

For example, the metal used to make the electrodes is a metal which does not degrade in the face of corrosion, such as, for example, stainless steel or aluminum.

In a particular embodiment of the device according to the invention, at least one electrode, preferably each electrode is a metal disc having a diameter between 5 and 40 cm, preferably between 10 and 30 cm and a thickness between 0, 5 and 10 mm, preferably between 1 and 3 mm.

In another embodiment, at least one electrode, preferably each electrode is a polygon, preferably a rectangle having a thickness between 0.5 and 10 mm, preferably between 1 and 3 mm.

Preferably, the immersion device of the device according to the invention further comprises a rotation shaft secured to said electrodes and secured to said elements of dielectric material.

Preferably, the rotation shaft is integral with the enclosure.

In this particular embodiment, the electrodes and the dielectric material elements are arranged along the rotation shaft. Along the rotation shaft are therefore successively placed an element of dielectric material, a first electrode, an element of dielectric material, a second electrode, an element of dielectric material and so on. The electrodes and dielectric materials have a common axis of rotation placed on the rotation shaft.

This configuration of the device therefore provides, in particular, for rotating the enclosure and / or the electrodes and elements of dielectric material.

In this way, a relatively homogeneous film of fatty substances is formed on the surface of the electrodes and of the elements of dielectric material, which further improves the efficiency of the treatment and the maintenance of a liquid whose physicochemical properties are more homogeneous. .

In another embodiment of the device according to the invention, the immersion device further comprises in the enclosure, a disc fixed to the rotation shaft and arranged to be rotated by said shaft and provided with a series of blades placed on the periphery of said disk, each of said blades having a longitudinal axis parallel to an axis of rotation of said disk, said disk having an axis of rotation common with said electrodes and with said dielectric materials so that said blades surround said electrodes and said elements of dielectric material.

The disc fitted with a series of blades also makes it possible, when it is rotated by the rotation shaft, to take the fatty substance in liquid form contained in the lower part of the enclosure and to bring it back into the upper part of the enclosure so that the fatty substance is distributed over the electrodes and over the elements of dielectric material. In this way, the film of fatty substance formed on the surface of the electrodes and of the dielectric material elements is continuously renewed, which further improves the efficiency of the treatment of the fatty substance.

Advantageously, the immersion device of the device according to the invention further comprises said first outlet of the fatty substance, located in a lower part of the enclosure and said first inlet of the fatty substance, located in an upper portion of the enclosure.

In this way, the circulation of the oil outside the enclosure and its return via the first inlet of the fatty substance of the enclosure also makes it possible to pour out said fatty substance on the upper part of the electrodes and elements of dielectric material.

In an advantageous embodiment of the device according to the present invention, said enclosure also has at least one inclined surface for guiding the fatty substance towards said first outlet of the fatty substance from the enclosure.

This inclined guide surface makes it possible to bring the fatty substance to said first outlet of the fatty substance from the enclosure so as to further facilitate the circulation of said fatty substance outside the enclosure.

Preferably, each element of dielectric material is chosen from the group consisting of a glass, a pyrex, a rigid polymer and their mixtures. For example, the rigid polymer has a dielectric constant at 50 Hz greater than or equal to 1.9 and advantageously a temperature of use greater than or equal to 80 ° C.

In a particular embodiment of the device according to the invention, at least one, preferably each element of dielectric material is in the form of a disc having a diameter between 5 cm and 40 cm, preferably between 10 cm and 30 cm, advantageously between 10 cm and 35 cm and a thickness between 0.5 mm and 10 mm, preferably between 1 mm and 6 mm.

In another embodiment, at least one, preferably each element of dielectric material is in the form of a polygon, preferably a rectangle having a thickness between 0.5 mm and 10 mm, preferably between 1 mm and 3 mm.

The invention advantageously further comprises a pressure gauge placed in the enclosure and arranged to measure the gas pressure in the enclosure.

The pressure gauge is a capacitive vacuum gauge, for example of the brand MKS which makes it possible to measure the gas pressure in the enclosure.

When processing the oil, the first gas, for example hydrogen, is consumed, the pressure in the enclosure therefore tends to decrease depending on the oil treatment time. The pressure gauge measures the gas pressure in the enclosure and therefore makes it possible to know when it is necessary to inject a quantity of the first additional gas to maintain a constant pressure of gas in the enclosure.

In addition, in a particular embodiment, the device further comprises a controller arranged to be connected to said pressure gauge and connected to a flow meter, said controller being arranged to control the flow meter, said flow meter being arranged to be in fluid connection with said second inlet for a first gas from the enclosure for measuring the quantity of said first gas injected into the enclosure by said second inlet for a first gas from the enclosure.

When the pressure gauge measures a gas pressure in the enclosure which is too low, a gas injection is made by the second gas inlet of the enclosure and the quantity of gas injected is advantageously controlled by means of the flow meter.

In a particular embodiment, the device further comprises a viscometer having a first inlet arranged to be in fluid connection with said first outlet of liquid vegetable material from the enclosure and a first outlet arranged to be in fluid connection with said inlet of the filter, said viscometer being arranged to measure the viscosity of said liquid plant material between said enclosure and said metal filter.

The viscometer placed between the first outlet of the enclosure and the metal filter therefore makes it possible to measure the viscosity of the fatty substance during its circulation outside the enclosure in order to obtain measurements throughout the duration of the treatment of the fatty substance. This viscosity measurement makes it possible to further improve the control of the viscosity properties of the treated fatty substance. For example, the viscometer is of the Sofraser MIVI type with an internal temperature measurement, the viscosity is then measured via a vibrating rod of the stainless steel type.

The invention advantageously further comprises a circulation pump having a first inlet in fluid connection with said first outlet from the enclosure and a first outlet in fluid connection with said first inlet of the viscometer, said circulation pump being arranged to circulate said liquid vegetable matter between said first outlet and said first inlet of the enclosure.

For example, the circulation pump is a circulation pump of the corma BMF5 type working, for example, at 1400 rpm.

In addition, advantageously the device according to the invention also has an electric heating system placed around the enclosure for heating said enclosure containing said fatty substance.

The heating system also makes it possible to control the temperature of the enclosure and to keep it constant despite the temperature fluctuations which may occur in the environment of the enclosure. In addition, when fatty substances of the grease or wax type are used, this heating system makes it possible to bring said fatty substance to its melting point so that it is present in liquid form in the enclosure.

Advantageously, said device according to the present invention also comprises a temperature probe directly immersed in the fatty substance contained in the enclosure in order to be able to continuously measure the temperature of the fatty substance. Preferably, the fatty substance in the tank is maintained at a temperature preferably between 50 ° C and 70 ° C. The temperature probe is connected to a controller, itself connected to the heating system in order to control the heating of the enclosure so that the temperature of the fatty substance it contains is controlled and kept constant.

In a particularly advantageous embodiment of the device according to the invention, said enclosure has a draw-off valve arranged to extract said liquid plant material from the enclosure.

Advantageously, the high voltage source is directly connected to the electrical connector of the device according to the present invention.

The direct connection of the high voltage source to the electrical connector placed on the enclosure minimizes the transport distance of the high voltage, and therefore further minimizes energy losses. The connector is therefore on the one hand connected via the electrical connections to the electrodes and on the other hand directly connected to the high voltage source.

Thanks to the fact that the high voltage source is directly connected to the electrical connector placed on the enclosure in the device according to the present invention, the control of the amount of current applied to the electrodes is improved, the electrical losses are more limited because the distance traversed by the high voltage is minimized.

Another advantage linked to the reduction in the distance traveled by the high voltage between the source and the electrical connector, is the reduction in risks for operators. In fact, high voltage is a source of serious accident for operators working on such devices.

Advantageously, the device according to the invention further comprises a motor arranged to drive the rotation shaft.

For example, the drive motor of the rotation shaft is a cage motor, for example of the brand bonfilogli, working up to 3000 revolutions per minute. Preferably, the motor is coupled to a box of bearings making it possible to gear down and thus reduce the speed so as to be able to work at a speed of between 1 and 10 revolutions per minute.

Preferably, the device according to the present invention further comprises a rotary electrical connector for supplying the high voltage source with low voltage, said rotary connector being placed on the rotation shaft and having a first part integral with the rotation shaft arranged to be put in electrical connection with the high voltage source and a second independent part of the rotation shaft arranged to be put in electrical connection with a low voltage source.

The rotary electrical connector is a circular connector comprising, for example, a 10-channel MOFLON slip ring.

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

The present invention also relates to a system for the electrical treatment of a fatty substance of vegetable origin comprising a plurality of devices according to the invention, said devices being placed in series and / or in parallel with each other.

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

• une introduction du corps gras dans ladite enceinte par la première entrée de ladite enceinte,
• une extraction d'un deuxième gaz hors de ladite enceinte par ladite première sortie de l'enceinte,
• une introduction d'un premier gaz dans ladite enceinte par ladite deuxième entrée de l'enceinte,
• une immersion de ladite série d'électrodes et de ladite série d'éléments de matériau diélectrique dans le corps gras et la formation d'un film de corps gras à la surface desdites électrodes et desdits éléments de matériau diélectrique,

ledit procédé étant caractérisé en ce qu'il comprend :

• une application d'un courant constant et stable à ladite série d'électrodes reliées à un connecteur électrique placé sur la surface extérieure de l'enceinte au moyen d'une série de connexions électriques de manière à appliquer une même quantité de courant sur chaque électrode de la série d'électrodes, ledit connecteur électrique étant lui-même relié à une source de haute tension,
• une filtration dudit corps gras dans un filtre présentant une entrée en connexion fluidique avec ladite première sortie du corps gras de l'enceinte et une sortie en connexion fluidique avec ladite première entrée du corps gras de l'enceinte.

The present invention also relates to a method of treatment by electrical discharges of a fatty substance of vegetable origin by means of a device comprising a series of electrodes comprising a number n of electrodes, with ≥ 2, of a series of elements of dielectric material comprising n + 1 elements of dielectric material, of an enclosure arranged to receive said fatty substance, and surrounding said series of electrodes and said series of elements of dielectric material, said method comprising:

• introduction of the fatty substance into said enclosure by the first entry of said enclosure,
• an extraction of a second gas from said enclosure by said first outlet from the enclosure,
• an introduction of a first gas into said enclosure through said second inlet of the enclosure,
• immersion of said series of electrodes and of said series of elements of dielectric material in the fatty substance and the formation of a film of fatty substance on the surface of said electrodes and of said elements of dielectric material,

said process being characterized in that it comprises:

• applying a constant and stable current to said series of electrodes connected to an electrical connector placed on the exterior surface of the enclosure by means of a series of electrical connections so as to apply the same amount of current to each electrode from the series of electrodes, said electrical connector being itself connected to a high voltage source,
• filtration of said fatty substance in a filter having an inlet in fluid connection with said first outlet of the fatty substance from the enclosure and an outlet in fluid connection with said first inlet of the fatty substance of the enclosure.

The method according to the present invention makes it possible to carry out the treatment with a fatty substance of vegetable origin in a chamber containing a first gas, for example an inert gas, preferably hydrogen at reduced pressure. Plasma is created between the electrodes which are partially immersed in the oil.

The application of a constant and stable high voltage directly to said first electrode by means of a connector makes it possible to improve the voltage control applied to the electrodes. This results in the formation of an intense and very effective plasma on the oil which improves the efficiency of the oil treatment.

A homogeneous low pressure plasma is therefore created in the enclosure and the formation of electric arc is minimized.

Another advantage of the method according to the invention is that it allows, during the entire duration of the plasma treatment, a circulation of the oil outside the treatment enclosure so that it passes through a filter to eliminate potentially agglomerates. trained during treatment. The liquid plant material is then reinjected into the enclosure where its treatment can be continued when it passes between the electrodes before being transported again to the metal filter and so on throughout the treatment period. It the result is an improvement in the efficiency of the oil treatment and an improvement in the quality and control of the physico-chemical properties of the resulting lubricant product.

This results in obtaining a lubricating oil whose properties are adjustable and controlled according to the desired subsequent application.

The oil obtained after treatment in the device according to the present invention is preferably characterized by a relaxation time less than or equal to 200 s measured at 40 ° C. by a cone-plane viscometer, according to ISO standard 2884-1. The relaxation time corresponds to the time necessary for the lubricating substance, which has a viscoelastic character, to return to its initial state when it is subjected to a shear stress. A stress is applied to a sample of the lubricating vegetable oil and the resulting response of this stress is followed over time.

The device according to the present invention therefore makes it possible to treat an oil and to obtain a treated oil having suitable viscoelastic characteristics. For example, the oil treated in the device according to the invention, even when it is subjected to a stress, in particular in engines, quickly regains its initial viscosity after the application of this stress. This characteristic of relaxation time less than or equal to 200 s therefore allows the oil to maintain a relatively stable and constant viscosity over time despite the application of constraints.

Advantageously, the method according to the invention is characterized in that the high voltage applied to the first electrode is between 500 V and 10 kV at a frequency between 1Hz and 500kHz.

The plasma is formed by the application of an alternating high voltage between 500 V and 10 kV having a frequency between 1 kHz and 500 kHz between the first and second electrodes.

In a particular embodiment method according to the invention, the formation of a film of fatty substance on the surface of said electrodes and said dielectric materials is obtained by sprinkling said electrodes and said dielectric materials by circulation of said fatty substance between the first outlet of the fatty substance from the enclosure and said first inlet of the fatty substance from the enclosure.

Preferably, the device according to the invention further comprises an axis of rotation passing through an axis of rotation of said electrodes of said series of electrodes, through an axis of rotation of said dielectric materials from the series of dielectric materials and through an axis of rotation of said enclosure and the method further comprises the formation of a film of fatty substance on the surface of said electrodes and said dielectric materials is obtained by a rotation by means of a rotation shaft of said electrodes and said dielectric materials.

The enclosure, the electrodes and the dielectric material elements are rotated by means of the rotation shaft. This rotation shaft in fact makes it possible to rotate in a single and predetermined direction of rotation the enclosure and / or the electrodes and the elements of dielectric material. The speed of rotation of the enclosure and / or of the electrodes and of the dielectric material can be between 1 and 20 revolutions per minute. Since preferably one third of the surface of the electrodes is immersed in oil, when the electrodes are rotated around the rotation shaft, the formation of a relatively homogeneous film of oil is observed on the surface electrodes. This film uniformly distributed on the surface of the electrodes and of the dielectric material elements makes it possible to increase the contact surface between the oil and the plasma and therefore makes it possible to improve the yield of the treatment.

Preferably, the method of treatment by electrical discharges of the fatty substance of vegetable origin is carried out by means of the device according to the present invention.

Other embodiments of the method according to the invention are indicated in the appended claims.

• La figure 1 est une vue en coupe d'un détail du dispositif selon l'invention dont l'enceinte présent une section circulaire.
• La figure 2 représente une vue d'en haut d'une forme de réalisation particulière du dispositif selon la présente invention.
• La figure 3 schématise une autre forme de réalisation du dispositif selon la présente invention.
• La figure 4 est une vue en perspective de l'enceinte du dispositif selon la présente invention.
• La Figure 5 illustre schématiquement les connexions électriques représentées sur la Figure 1.
• Le Figure 6 illustre une vue en coupe d'un détail du dispositif pour le traitement électrique d'un corps gras d'origine végétale dont l'enceinte présente une section rectangulaire.
• La Figure 7 illustre schématiquement les connexions électriques représentées sur la Figure 6.
• La Figure 8 schématise une autre forme de réalisation du dispositif selon la présente invention.

Other characteristics, details and advantages of the invention will emerge from the description given below, without implied limitation and with reference to the attached drawings.

• The figure 1 is a sectional view of a detail of the device according to the invention, the enclosure of which has a circular section.
• The figure 2 shows a top view of a particular embodiment of the device according to the present invention.
• The figure 3 shows schematically another embodiment of the device according to the present invention.
• The figure 4 is a perspective view of the enclosure of the device according to the present invention.
• The Figure 5 schematically illustrates the electrical connections shown on the Figure 1 .
• The Figure 6 illustrates a sectional view of a detail of the device for the electrical treatment of a fatty substance of vegetable origin, the enclosure of which has a rectangular section.
• The Figure 7 schematically illustrates the electrical connections shown on the Figure 6 .
• The Figure 8 shows schematically another embodiment of the device according to the present invention.

In the figures, identical or similar elements have the same references.

The figure 1 illustrates a preferred embodiment of the device according to the invention on which a cross section of a cylindrical enclosure 4 can be seen which can receive a fatty substance of vegetable origin. This enclosure 4 contains a series of electrodes in which first electrodes 1 are connected to the high voltage source and second electrodes 2 connected to the mass. The first 1 and second electrodes 2 are placed alternately with respect to each other. A first electrode 1 therefore faces a second electrode 2 and so on so that two electrodes of the same type do not succeed one another. Dielectric materials 3 are placed on either side of each of the electrodes 1 and 2 so that an electrode 1 or 2 is between two dielectric materials 3. On the Figure 1 , said first 1 and said second 2 electrodes are metal discs having a diameter between 10 and 30 cm and a thickness between 1 and 3 mm. On the Figure 1 , said elements of dielectric material 3 are also discs having an axis of rotation R common with said first 1 and said second 2 electrodes and having a diameter between 12 and 32 cm and a thickness between 1 and 6 mm. In addition, the dielectric material elements 3 are preferably made of glass, pyrex or rigid polymer.

The device according to the present invention is further characterized by the presence of an electrical connector 5 placed on the external surface 40 of the enclosure 4, the electrical connector 5 being connected to the electrodes 1 by electrical connections. The number of electrical connections is equal to the number of first 1 so that each first electrode is connected by an electrical connection to the electrical connector 5. The current flow distances of the electrical connections being equal to each other in order to limit the maximum electrical losses.

The figure 5 is a detail making it possible to illustrate diagrammatically the distances of current course which are identical for all the first electrodes 1. Indeed, one can notice on the figure 5 that the electrical connections A, B, C and D of each first electrode are made so that the current path distance is identical for each electrode. The first electrode 1 located furthest from the electrical connector 5 is therefore connected to an electrical connection A of identical length to the electrical connection D of the first electrode 1 closest to the electrical connector 5. In this way, the energy losses are limited and identical on each first electrode 1 and the current applied to these first electrode 1 is more stable and more homogeneous.

The enclosure 4 also includes a first inlet 6 of the fatty substance connected to a supply duct 6a and a first outlet 7 of the fatty substance connected to an outlet duct 7a. The fatty substance is therefore supplied via the supply duct 6a, through the first inlet of plant material and placed in the enclosure until it reaches a volume of approximately 1/3 to 1/2 of the volume of the 'pregnant.

On the figures 1 and 2 , a second electrical connector 24 is present on the outer surface 40 of the enclosure 4 so as to connect the second electrodes 2 serving as ground electrodes. In this way, the first electrodes 1 are connected to the high voltage source 11 and are therefore supplied with current while the second electrodes are connected to the ground and serve as ground electrodes.

The figure 2 is a top view of the device according to the present invention. We can see in this figure a high voltage source 11 arranged to be connected to the connector 5 present on the external surface 40 of the enclosure 4. The high voltage source 11 is therefore connected to the first electrodes 1 through the connector 5 placed on the enclosure and electrical connections.

The device represented on the figures 1 and 2 has a device for immersing the series of electrodes 1 and 2 and of the series of elements of dielectric material 3 comprising a rotation shaft 10 passing through an axis of rotation R of said first 1 and second 2 electrodes, through an axis of rotation R of said elements of dielectric material and by an axis of rotation R of the enclosure 4. In this embodiment the axes of rotation of the electrodes 1 and 2, elements of dielectric material 3 and of the enclosure 4 coincide for form a single and common axis of rotation R. As a result, the electrodes 1 and 2 and the elements of dielectric material 3 are placed on the rotation shaft 10 in the enclosure 4. The enclosure and / or the electrodes 1 and 2 and the dielectric materials 3 are integral with the rotation shaft 10 and can therefore enter into rotation when the shaft is driven by a motor 25. L the rotation shaft of the device therefore makes it possible to rotate either the enclosure 4 or the series of electrodes 1 and 2 and the series of elements of dielectric material 3 or the enclosure 4, the series of electrodes 1 and 2 and the series of elements of dielectric material 3. This means that the enclosure 4 can be rotated while keeping the electrodes 1 and 2 and the elements of dielectric material 3 fixed or vice versa keeping the enclosure 4 fixed and rotating the electrodes 1 and 2 and the dielectric material elements 3. The rotation, preferably at a speed of rotation of between 1 and 10 revolutions per minute, of the enclosure 4 and / or of the elements which it contains allows to form a film of fatty substance on the electrodes 1 and 2 and on the dielectric material elements 3 in order to be able to treat said fatty substance with the plasma created between said first 1 and said second 2 electrodes.

The rotation shaft 10 can be driven by a motor 25 to enter into rotation. In this way when the enclosure 4, the electrodes 1 and 2 and the dielectric materials 3 are integral with the rotation shaft 10, the rotation movement forms a homogeneous film of oil on the surface of the electrodes 1 and 2 and dielectric material elements 3. Indeed, by gravity, the oil remains in the lower part of the enclosure 4 while the electrodes rotate continuously around the axis of rotation R. Therefore, the submerged part of the electrodes are then found out of the oil while the part which was not immersed in the oil is immersed and so on so as to form a homogeneous film of oil on the surface of the electrodes and elements of dielectric material. . This film is maintained on the surface of the electrodes and of the dielectric material elements by the surface tension linked to the particular viscosity of the treated oil.

Preferably, the enclosure 4 represented on the figures 1 to 4 further contains a disc 27 fixed to the rotation shaft 10 and provided with a series of vanes 28 placed on the periphery of the disc 27 and each of said vanes 28 have a longitudinal axis L parallel to an axis of rotation of the disc 27. The disc 27 has an axis of rotation R common with the first 1 second 2 electrodes and with the elements of dielectric material 3 so that the vanes 28 surround the electrodes 1 and 2 and the elements of dielectric material 3.

When they are rotated by means of the rotation shaft 10, the vanes 28 plunge and then come out of the oil. By this rotational movement, the blades bring the oil withdrawn in the lower part of the enclosure 4 above the electrodes 1 and 2 and the dielectric material elements 3 so as to improve the formation of the oil film at the surface of the electrodes 1 and 2 of the dielectric material elements 3.

As we can see on the figures 1 and 2 , advantageously, the high voltage source 11 is directly connected to the electrical connector 5. The electrical losses are, therefore, more limited since the distance traveled by the high voltage is minimized, which ensures the control of the amount of current applied to the first electrodes 1.

As shown on the figure 2 , the device also also has a rotary electrical connector 26 for supplying the high voltage source with low voltage (not shown in the figure), said rotary connector 26 being placed on the rotation shaft 10 and having a first part integral with the rotation shaft 10 arranged to be put in electrical connection with the high voltage source 11 and a second part independent of the rotation shaft 10 arranged to be put in electrical connection with a low voltage source.

Preferably, the enclosure 4 is a cylindrical metallic enclosure, for example made of stainless steel. The enclosure 4 is also provided with portholes 29 made of transparent material making it possible to be able to observe the interior of the enclosure.

On the figure 3 , the first 1 and second 2 electrodes as well as the dielectric material elements 3 are, for reasons of simplicity, represented as a block 21 in the enclosure 4. We can see on this figure 3 , a filter 12, for example metallic, having a first inlet 13 connected in fluid connection with the first outlet 7 of the enclosure 4 by means of the pipe 7a and a first outlet 14 connected in fluid connection with the first inlet 6 of l enclosure 4 by means of line 6a. The liquid is pumped through line 22, leaves the enclosure through outlet 7 and is brought to inlet 13 of filter 12 through line 7a. The liquid then passes through the filter 12 and leaves through the outlet 14 to arrive in the line 6a before returning to the enclosure 4 through the inlet 6. The circulation of the oil through the meshes of the filter 12 allows 'eliminate the aggregates or even the agglomerates formed during the treatment in the enclosure 4. The meshes of the filter 12 are preferably between 0.5 mm and 1 mm. The oil is then brought back into the enclosure 4 via a line 23 in fluid connection with the first inlet 6 of the enclosure 4.

A viscometer 15 can be placed between the enclosure 4 and the metal filter 12. This viscometer has a first inlet 16 arranged to be in fluid connection with said first outlet 7 via said outlet duct 7a of the enclosure 4 and a first outlet 17 in fluid connection with said inlet 13 of the filter 12, said viscometer 15 being arranged to measure the viscosity of said fatty substance between.

Advantageously, a circulation pump 18 is present between the enclosure 4 and the viscometer 15. This circulation pump 18 has a first inlet 19 in fluid connection with the first outlet 7 of the enclosure 4 via the outlet pipe 7a and a first outlet 20 in fluid connection with the first inlet 16 of the viscometer 15. The circulation pump 18 is arranged to circulate said fatty substance between the first outlet 7 and the first inlet 6 of the enclosure 4.

The figure 4 shows a perspective view of the interior of the enclosure 4 on which we can see the dielectric materials 3. The enclosure 4 also has a second inlet 8 connected to a supply conduit 8a for a first gas and a second outlet 9 connected to an outlet conduit 9a for a second gas. The second outlet 9 makes it possible to extract the air contained in the enclosure 4 via the outlet conduit 9a when the latter contains oil and is closed in preparation for the electrical treatment. The air contained in the enclosure 4 is therefore extracted by means of a pumping system (not shown in the figures) in order to create a vacuum, for example of the order of 10 ^-2 mbar. Preferably, the pumping system used is a vane pump, for example of the brand Trivac E2. Once the depression observed in enclosure 4, an inert gas, preferably hydrogen, is injected through the second inlet 8 via the supply duct 8a of enclosure 4 until a pressure of less than 100 kPa is reached. , preferably less than 65 kPa in enclosure 4.

The Figure 6 shows another embodiment of the device according to the present invention in which the enclosure 4 has a rectangular cross section. The enclosure 4 contains a series of electrodes 1 and 2 in the form of rectangular metal plates. In this embodiment of the device, the two electrical connectors 5 and 24 placed on the outer surface 40 of the enclosure 4 are connected to the high voltage source (not shown). The electrical connector 5 is connected via electrical connections to the first electrodes 1 and the electrical connector 24 is connected via electrical connections to the second electrodes 2. The first 1 and second 2 are placed alternately. The current applied to the electrodes is an alternating current, which means that when the first electrodes 1 are supplied with current, the second electrodes serve as ground electrodes and vice versa when the current changes direction. Elements of material dielectric in the form of a rectangular plate are placed on either side of each electrode 1 and 2.

The enclosure 4 also includes a first inlet 6 of the fatty substance connected to a supply duct 6a and a first outlet 7 of the fatty substance connected to an outlet duct 7a. The fatty substance is therefore supplied via the supply duct 6a, through the first inlet of plant material and placed in the enclosure until it reaches a volume of approximately 1/3 to 1/2 of the volume of the 'pregnant.

Advantageously, the first fatty substance inlet 6 is located in an upper part of the enclosure and said first fatty substance outlet 7 is located in a lower part of the enclosure 4.

When the oil is brought into the enclosure 4 through the first inlet 6, the oil is poured through pipes 32 in the upper part of the enclosure 4 onto the electrodes 1 and 2 and onto the elements of dielectric material 3 thus improving the formation of an oil film thereon. This distribution of oil on the electrodes 1 and 2 and on the dielectric materials 3 makes it possible to further improve the efficiency of the oil treatment. Preferably, a screen 33 is present between the pipes 32 and the series of electrodes 1 and 2 and the series of elements of dielectric material 3. Thanks to gravity, the oil is then naturally brought to the kind 7 of body bold.

The enclosure 4 also comprises a second inlet 8 (not shown) for a first gas allowing the injection of a gas into the enclosure 4.

Preferably, the enclosure 4 has an inclined surface 29 for guiding the oil towards the first outlet 7 for fatty substances. This inclined surface 29 makes it possible to further improve the supply of oil to the first outlet 7 for fatty substances.

The figure 7 schematize like the figure 5 the electrical connections between the electrical connector 5 and the first electrodes 1. We can see on the figure 7 that the current flow distances A, B, C and D are all of identical length. The distance traveled by the current from the electrical connector 5 is therefore identical for each first electrode 1. These connections allowing an identical current passage distance is also valid for the second electrodes 2.

On the figure 8 are represented the same elements as on the figure 3 . In the embodiment illustrated in the figure 8 , we can see that the oil is taken from the lower part of the enclosure 4 through the first outlet for fatty substances 7 and, after having circulated in the filter 12, is brought back into the upper part of the enclosure 4. L the oil then arrives in the pipes 32, passes through the screen 33 is distributed and forms a film on the electrodes 1 and 2 and the elements of dielectric material 3. The oil is then found in the lower part of the enclosure 4 where it is guided by the guide surface 29 to the first outlet 7 for fatty substances where it can again start an external circulation through the filter, and so on during the entire time of treatment of the oil.

Advantageously, an electric heating system (not shown) is placed around the enclosure 4 to heat said enclosure 4 containing said fatty substance. In this way, the temperature of the fatty substance contained in the enclosure 4 can be regulated and kept constant.

In another embodiment, the enclosure 4 has a withdrawal valve (not shown) arranged to extract said fatty substance from the enclosure 4.

A pressure gauge (not shown) can be placed in the enclosure 4 so as to measure the gas pressure in the enclosure 4. The injection of the gas through the supply duct 8a is advantageously controlled by means of a mass flow meter (not shown) of MKS type calibrated for hydrogen with a high scale of 1000 sccm (standard cubic centimeter per minute) not shown in the figures.

The device may also include a controller (not shown) arranged to be connected to said pressure gauge and connected to the flow meter. The controller is arranged to control the flow meter and the flow meter is arranged to be in fluid connection with the supply conduit 8a for a first gas from the enclosure 4 through the second inlet 8. The flow meter therefore makes it possible to control the quantity of said first gas injected into enclosure 4 through the second inlet 8 via the inlet duct 8a of enclosure 4.

Examples

The device according to the present invention has been used to treat different oils of plant origin. This device comprises a circular enclosure containing a plurality of electrodes connected to a high voltage source and a plurality of ground electrodes connected to the ground. These electrodes are aluminum discs with a diameter of 25 cm and a thickness of 2 mm. The elements of dielectric material placed on either side of the electrodes are pyrex discs with a diameter of 28 cm and a thickness of 5 mm.

2 liters of oil are placed in the enclosure and it is put under vacuum until reaching a vacuum of 10 ^-2 mbar. Hydrogen is then introduced into the enclosure to reach a pressure of 180 Torr.

The tank is rotated around a rotation shaft at a speed of 5 revolutions per minute.

A voltage of 2900 V is applied to the electrodes, which corresponds to a discharge current of 2.5 A and a frequency of 35 kHz or 66 kHz is used, as specified in the following examples.

The filtration of the oil is carried out during the whole period of treatment of the oil by plasma by means of a circulation pump of a type of corma BMF5 working at 1400 revolutions per minute which makes it possible to convey the oil out of the enclosure. The oil is then filtered in a metal filter with 0.8 mm mesh.

The oils obtained after this treatment were analyzed in order to determine their physicochemical properties, in particular the dynamic viscosity, the thixotropy and the relaxation time.

The dynamic viscosity is measured using an Anton Paar viscometer equipped with a cone-plane system, CP50-0.5, according to ISO standard 2884-1 (Determination of the viscosity by means of rotary viscometers). The measurements are obtained under shear stress from 0 to 500 s ^-1 by taking 1 point every second, a hold for 1 minute at 500 s ^-1 and finally from 500 to 0 s ^-1 by taking 1 point every second at a temperature of 40 ° C.

Thixotropy is a measure of the change in viscosity when the oil is stressed. It is a physical property of a fluid whose viscosity varies over time when the fluid is subjected to a constant stress (or a speed gradient). Thixotropy is a physical phenomenon which results from the non-instantaneous process of destruction and re-construction of the microscopic structure by agitation and by rest of a substance such as oil. Thixotropic behavior is defined as time-dependent behavior and is correctly determined when considering the decomposition and regeneration of the substance tested under constant shear stress. According to the present invention, the thixotropy of vegetable oil was measured during a test carried out under constant shear stress of 1000s-1 at a temperature of 40 ° C using an Anton Paar viscometer equipped with a cone-plane system, CP50-0.5.

According to the present invention, the thixotropy of the oil is represented the variation of the viscosity between the initial state and the destructured state of the oil.

The relaxation time corresponds to the time necessary for the lubricating substance, which has a viscoelastic character, to return to its initial state when it is subjected to a shear stress. A stress is applied to a sample of the lubricating vegetable oil and the resulting response of this stress is followed over time.

According to the present invention, the relaxation time of the vegetable oil was measured in an Anton Paar viscometer equipped with a cone-plane system (CP50-0.5) by applying a constant shearing speed of 1000s-1 to a temperature of 40 ° C in vegetable oil.

The iodine index of a lipid is the mass of diiode (I ₂ ) capable of fixing itself on the unsaturations of the triglycerides contained in one hundred grams of fat.

According to the present invention, the ode index was measured by the Wijs method which consists in reacting a known excess of iodine monochloride (ICl) on the fatty substance to be analyzed, namely vegetable oil. The iodine monochloride fixes on the double bonds of the analyzed sample and the excess reagent remains in solution. Potassium iodide is then added in excess to this solution, thus causing the excess cation I + to return to the molecular state I2. The diiode can then be assayed with a solution of known molar concentration of sodium thiosulfate, in the presence of starch jobs.

The molar mass is expressed in polystyrene equivalent, as determined by steric exclusion chromatography (Agilent) operating at a flow rate of 1 ml.min ^-1 at a temperature of 30 ° C. The samples are dissolved in chloroform at 1 mg.mL ^-1 and are fractionated by passage through two PL GEL MIX-D 10 columns. The columns have been previously calibrated using polystyrenes of low dispersity with a molecular weight between 500 and 106 g.mol ^-1 . Detection is ensured by a refractive index detector (Agilent DRI).

Example 1

The treatment described above was carried out at a frequency of 66 kHz on a rapeseed oil of the brand AVENO and repeated for different predetermined treatment times in order to obtain treated vegetable oils also called lubricants with different physicochemical properties. These vegetable oils obtained after different treatment times have a visually homogeneous structure, without aggregates or agglomerates. These oils have been analyzed and have the characteristics listed in Table 1. Table 1 Processing time (min) Unsaturations - iodine value Disappearance of double bond (%) Mw (g / mol) Viscosity (mPas) Thixotropy (mPa s) Relaxation time (s) 0 114 0 1580 45 - - 460 99.9 11.6 2290 68 - - 925 90.3 17.7 2940 128 - - 1315 82.8 26.8 6160 374 110 105 1955 80.2 29.1 16260 1520 651 180 2065 75.6 33.1 48000 2650 1100 187

Example 2

The treatment described above was carried out at a frequency of 35 kHz on a rapeseed oil of the brand AVENO and repeated for different predetermined treatment times in order to obtain treated vegetable oils also called lubricants with different physicochemical properties. These vegetable oils obtained after different treatment times have a visually homogeneous structure, without aggregates or agglomerates. These oils have been analyzed and have the characteristics shown in Table 2. Table 2 Processing time (min) Unsaturations - iodine value Disappearance of double bond (%) Mw (g / mol) Viscosity (mPa s) Thixotropy (mPa s) Relaxation time (s) 0.0 113.0 0.0 1,580.0 45.0 - - 800.0 104.6 17.0 2,800.0 57.0 - - 1,220.0 87.1 9.7 3610.0 88.0 - - 1810.0 88.5 20.9 5590.0 207.0 35.0 <10 2410.0 74.9 19.6 20880.0 588.0 154.0 <10 2540.0 77.9 27.8 21,440.0 865.0 248.0 <10 2,628.0 77.9 25.3 24,900.0 1150.0 301.0 <10 2,780.0 78.2 26.9 44,700.0 2300.0 590.0 <10

Example 3

The treatment described above was carried out at a frequency of 66 kHz on a linseed oil and repeated for different predetermined treatment times in order to obtain treated vegetable oils also called lubricants with different physicochemical properties. These vegetable oils obtained after different treatment times have a visually homogeneous structure, without aggregates or agglomerates. These oils have been analyzed and have the characteristics shown in Table 3. Table 3 Processing time (min) Unsaturations - iodine value Disappearance of double bond (%) Mw (g / mol) Viscosity (mPa s) Thixotropy (mPa s) Relaxation time (s) 0 177.4 0 1800 40 0 0 560 147.3 17 3070 150 0 0 1160 128.9 27.4 13580 392 113 173 1255 133.3 24.9 18720 650 265 171 1315 130.4 26.5 19220 1260 500 170

Example 4

The treatment described above was carried out at a frequency of 35 kHz on linseed oil and repeated for different predetermined treatment times in order to obtain treated vegetable oils also called lubricants with different physicochemical properties. These vegetable oils obtained after different treatment times have a visually homogeneous structure, without aggregates or agglomerates. These oils have been analyzed and have the characteristics listed in Table 4. Table 4 Processing time (min) Unsaturations - iodine value Disappearance of double bond (%) Mw (g / mol) Viscosity (mPa s) Thixotropy (mPa s) Relaxation time (s) 0.0 - 0.0 1800.0 40.0 0.0 0.0 430.0 147.3 9.7 2260.0 50.0 0.0 0.0 980.0 160.3 20.9 3380.0 100.0 0.0 0.0 1490.0 140.4 19.6 9780.0 250.0 94.0 <10 1,730.0 142.7 27.8 19730.0 750.0 210.0 <10 1820.0 132.6 25.3 26,260.0 1520.0 615.0 <10

In general, based in particular on the results presented in these examples, it is observed that when the treatment time of the oil increases, the number of unsaturations, present initially in the oil before the treatment, decreases. The molar mass, M _w , as well as the viscosity increase as the treatment time increases.

These examples also make it possible to demonstrate that the device according to the present invention allows the production of a vegetable oil treated with plasma, the relaxation time of which is less than 200 s. The values of relaxation times less than 200 s and reproducible from one treatment to another are a good indication of the improved viscoelastic character of the lubricating vegetable oil obtained by means of the device according to the present invention. A short relaxation time has the advantage of allowing the oil to regain quickly return to initial condition when stressed, for example when used in an engine. In addition, this oil has a thixotropy of between and 5% and 30% of the viscosity. It can therefore be concluded that the device according to the present invention makes it possible to obtain a vegetable oil, lubricating, having an improved and controlled viscosity while having an adequate and controlled viscoelastic and thixotropic character.

Indeed, it can be noted in the examples given above that the device according to the present invention makes it possible to ensure the treatment of vegetable oils of different origins, in particular coming from rapeseed or flax seeds. As evidenced by the examples, it is possible by adjusting the treatment time to control in particular the viscosity of the oil obtained after treatment while maintaining a thixotropy of less than 30% of the viscosity and a relaxation time of less than 200 s . It is therefore possible thanks to the device according to the present invention to produce vegetable oils treated in a wide range of viscosities while controlling the physicochemical properties of these oils.

It is understood that the present invention is in no way limited to the embodiments described above and that many modifications can be made without departing from the scope of the appended claims.

Claims (22)

1. Device for the electrical processing of a fatty substance of plant origin comprising:

   - a series of electrodes comprising a number n of electrodes (1 and 2), where n ≥ 2, substantially parallel, each electrode being arranged to be connected to a high-voltage source and/or the ground,

   - a series of dielectric material elements (3) comprising n+1 dielectric material elements substantially parallel to said electrodes (1 and 2) and placed on either side of each electrode (1 or 2) of the series of electrodes so that each electrode (1 or 2) is found between two dielectric material elements (3),

   - an enclosure (4) arranged to receive said fatty substance, and surrounding said series of electrodes (1 and 2) and said series of dielectric materials (3),

   - an immersion device of said series of electrodes (1 and 2) and said series of dielectric materials (3) arranged to submerge, at least partially, said series of electrodes (1 and 2) and said series of dielectric materials (3),

   the enclosure (4) is further provided with:

   - at least one electrical connector (5) placed on the outer surface (40) of the enclosure (4),

   - a series of electrical connections comprising n electrical connections so as to connect each electrode of said series of electrodes to said electrical connector (5), each electrical connection having a predetermined current flow distance, the current flow distances of the electrical connections being equal to one another,

   - a first fatty substance inlet (6) and a first fatty substance outlet (7), and

   - a second inlet (8) for a first gas and a second outlet (9) for a second gas,

   and in that said device further comprises:

   - a high-voltage source (11) connected to said connector (5),

   - a filter (12) having an inlet (13) in fluidic connection with said first fatty substance outlet (7) of the enclosure (4) and an outlet (14) in fluidic connection with said first fatty substance inlet (6) of the enclosure (4).
2. Device according to claim 1, wherein at least one electrode, preferably each electrode, of the series of electrodes is a metal plate having a thickness ranging between 0.5mm and 5mm, preferably 1mm and 3mm.
3. Device according to any one of claims 1 or 2, wherein said immersion device further comprises a rotating shaft (10) attached to said electrodes (1 and 2) and attached to said dielectric material elements (3).
4. Device according to any one of claims 1 to 3, wherein said immersion device further comprises a rotating shaft (10) attached to the enclosure (4).
5. Device according to claim 4, wherein said immersion device further comprises in the enclosure (4), a disc (27) fixed to the rotating shaft (10) and arranged to be rotated by said shaft (10), and provided with a series of blades (28) peripherally positioned on said disc (27), each of said blades (28) having a longitudinal axis (L) parallel to an axis of rotation of said disc (27), said disc (27) having a common axis of rotation (R) with said electrodes (1 and 2) and with said dielectric material elements (3) so that said blades (28) surround said electrodes (1 and 2) and said dielectric material elements (3).
6. Device according to any one of claims 1 or 2, wherein said immersion device further comprises said first fatty substance outlet (7), situated in a lower part of the enclosure (4) and said first fatty substance inlet (6), situated in an upper part of the enclosure (4).
7. Device according to any one the preceding claims, wherein said enclosure (4) also has at least one inclined surface for guiding the fatty substance towards said first fatty substance outlet (7) of the enclosure (4).
8. Device according to any one of the preceding claims, wherein said dielectric material (3) is chosen from the group composed of a glass, a Pyrex, a rigid polymer and mixtures thereof.
9. Device according to any one of the preceding claims, further comprising a pressure gauge placed in the enclosure (4) and arranged to measure the gas pressure in the enclosure (4).
10. Device according to any one of the preceding claims, further comprising a controller arranged to be connected to said pressure gauge and connected to a flowmeter, said controller being arranged to control the flowmeter, said flowmeter being arranged to be in fluidic connection with said second inlet (8) for a first gas of the enclosure (4) to measure the quantity of said gas injected into the enclosure (4) via said second inlet (8) for a first gas of the enclosure (4).
11. Device according to any one of the preceding claims, further comprising a viscometer (15) having a first inlet (16) arranged to be in fluidic connection with said first fatty substance outlet (7) of the enclosure (4) and a first outlet (17) arranged to be in fluidic connection with said inlet (13) of the filter (12), said viscometer (15) being arranged to measure the viscosity of said fatty substance between said enclosure (4) and said metal filter (12).
12. Device according to any one of the preceding claims, further having a circulation pump (18) having a first inlet (19) in fluidic connection with said first outlet (7) of the enclosure (4) and a first outlet (20) in fluidic connection with said first inlet (16) of the viscometer (15), said circulation pump (18) being arranged to circulate said fatty substance between said first outlet (7) and said first inlet (6) of the enclosure (4).
13. Device according to any one of the preceding claims, further having an electrical heating system placed around the enclosure (4) to heat said enclosure (4) containing said fatty substance.
14. Device according to any one of the preceding claims, wherein said enclosure (4) has a removal valve arranged to extract said fatty substance from the enclosure (4).
15. Device according to any one of the preceding claims, wherein the high-voltage source (11) is directly connected to said electrical connector (5).
16. Device according to any one of claims 3 to 15, further comprising an engine (25) arranged to drive the rotating shaft (10).
17. Device according to any one of claims 3 to 16, further comprising a rotating electrical connector (26) to ensure the supply of the high-voltage source at low voltage, said rotating electrical connector (26) being placed on the rotating shaft (10) and having a first part attached to the rotating shaft (10) arranged to be in electrical connection with the high-voltage source (11) and a second part independent from the rotating shaft (10) arranged to be in electrical connection with a low-voltage source.
18. System for the electrical processing of a fatty substance of plant origin comprising a plurality of devices according to any one of the preceding claims, said devices being placed in series and/or in parallel to one another.
19. Method for electrical discharge processing of a fatty substance of plant origin by means of a device, said method comprising:

    - introducing the fatty substance into said enclosure (4) via the first inlet (6) of said enclosure (4);

    - Coming out of the fatty substance into said enclosure (4) via the first outlet (7) of said enclosure (4);

    - extracting a second gas from said enclosure (4) via said first outlet (7) of the enclosure (4);

    - introducing a first gas into said enclosure (4) via said second inlet (6) of the enclosure (4);

    - submerging said series of electrodes and said series of dielectric materials (3) in the fatty substance and forming a film of fatty substance on the surface of said electrodes (1 and 2) and said dielectric materials (3),

    said method being characterised in that it comprises:

    - applying a constant and stable current to said series of electrodes connected to an electrical connector (5) placed on the outer surface (40) of the enclosure (4) by means of a series of electrical connections in order to apply a same current quantity to each electrode (1 and 2) of the series of electrodes, said electrical connector (5) itself being connected to a high-voltage source (11);

    - filtering said fatty substance through a filter (12) having an inlet (13) in fluidic connection with said fatty substance outlet (7) of the enclosure (4) and an outlet (14) in fluidic connection with said first fatty substance inlet (6) of the enclosure (4).
20. Method according to claim 19, characterised in that the high voltage applied to the first electrode ranges between 500V and 10kV at a frequency ranging between 1Hz and 500kHz.
21. Method according to any one of claims 19 or 20, wherein the step of submerging said series of electrodes and said series of dielectric materials (3) in the fatty substance and forming a film of fatty substance on the surface of said electrodes (1 and 2) and said dielectric material elements (3) is obtained by a spraying of said electrodes (1 and 2) and said dielectric materials (3) thanks to a circulation of said fatty substance between the first fatty substance outlet (7) of the enclosure (4) and said first fatty substance inlet (6) of the enclosure (4).
22. Method according to any one of claims 19 to 21, wherein said device further comprises a rotating shaft (10) attached to said electrodes (1 and 2) and said dielectric material elements (3), said method being characterised in that the step of submerging said series of electrodes (1 and 2) and said series of dielectric materials (3) in the fatty substance and forming a film of fatty substance on the surface of said electrodes (1 and 2) and said dielectric material elements (3) is obtained by rotating said electrodes (1 and 2) and said dielectric materials (3) by means of the rotating shaft (10).

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