Electrolytic system for de-fouling, structure comprising said system, and method for de-fouling underwater structures - Patents.com

Abstract

1. An electrolytic system (S) for removing deposits, comprising a first substrate (1), the first substrate (1) comprising titanium and defining a surface (11) intended to come into contact with water, a second conductive substrate (2) provided with a surface (21) intended to come into contact with water, and a power source (U), the power source (U) being connected in series between the first substrate (1) and the second substrate (2) such that an electrolytic circuit can be formed by the water, the first substrate (1), the second substrate (2) and the power source (U) providing electrical energy, the power source (U) being configured to provide a current density such that the first substrate (1) operates as an anode, to periodically reverse the polarity of the circuit and / or to provide a pulsed current density such that the first substrate (1) and the second substrate (2) alternately and periodically take on the functions of an anode or a cathode.

Description

[Technical field]

[0001] The present invention is in the field of electrolytic systems for degreasing submerged structures by applying an electric current to a submerged surface. [Background technology]

[0002] An electrolysis system known in the art comprises a first substrate, the first substrate comprising titanium, defining a surface intended to contact water, a second conductive substrate provided with a surface intended to contact water, and a power source connected in series between the first substrate and the second substrate such that an electrolysis circuit can be established by the water, the first substrate acting as an anode, the second substrate acting as a cathode, and the power source providing electrical energy.

[0003] An example of such an electrolytic system is disclosed in Patent Document 1, which is related to a method for preventing adhesion of marine organisms to titanium ships.

[0004] In Patent Document 1, various potentials (specifically, about 1.2 V vs. a reference electrode (silver Ag / silver chloride AgCl in seawater)) are measured against a substrate containing titanium in water. Ag / AgCl It is described that a reference voltage of 0.1 V is applied to the anode, with the aim of producing chemical species at the anode that kill microorganisms in order to reduce adhesion.

[0005] Patent Document 1 discloses an experiment to confirm the presence or absence of adhesion after immersing a 50 mm × 30 mm sample for three months. Ag / AgCl This indicates that no marine organisms were observed in the samples at . [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2003-328164 A [Non-patent literature]

[0007] [Non-Patent Document 1] "Development of an electrochemical antifouling system for seawater cooling pipelines of power plants using titanium" [Non-Patent Document 2] Matsunaga "Electrochemical Prevention of Biofouling" 2000-68_847 [Non-Patent Document 3] Hitoshi Wake, Toshihiro Takimoto, Hirokazu Takayanagi, Kinichi Ozawa, Hideo Kadoi, Shigeki Mukai, Yoshinari Komura, Mina Okouchi, Hiroyuki Honda, and Tadashi Matsunaga "Construction of an Electrochemical Antibiofouling System for Plate Heat Exchangers" Summary of the Invention [Problem to be solved by the invention]

[0008] The inventors of the present application attempted to replicate this result with a larger plate in order to obtain realistic measurements, since typically tens, hundreds or even thousands of square meters of a ship's hull are submerged in water. The plate used was 0.6 m 2 However, from 1.2 to 2 and even 3V Ag / AgCl Applying a control voltage of 1000 kV did not produce good results, with the titanium surface covered with algae and barnacles, suggesting that an electrolytic solution was not feasible on a larger scale and for a longer period of time.

[0009] It is important to mention that throughout this specification, the titanium electrodes are not activated titanium electrodes (MMO or platinum plated) whose surface has been modified for stabilization and to improve current output when subjected to an electrical signal.

[0010] Non-Patent Document 1 uses two types of signals to detect the presence of chloride or pH changes at a voltage of about 0.9 V. Ag / AgCl This invention discloses a titanium-based substrate that operates at a potential of One of the two signals is 50 / 100mA / m 2 This is a fixed signal that is constant current controlled at 0.9V. Ag / AgCl The current is then maintained at 6 / 7 V. Ag / AgCl (It is noted that this fact has been confirmed by the inventors of the present invention). The other of the two signals is 0.9V. Ag / AgCl Anode cycle of -0.3 / -0.9V Ag / AgCl The cathodic signal alternates between 0.1 V and 0.2 V. According to [1], the main objective is to avoid chloride formation and pH changes. It is noted that the current densities disclosed in [1] do not correspond to those shown in the study graphs.

[0011] The current densities given in Non-Patent Document 1 do not correspond to the data shown in the graphs therein. In some of the photographs, the test exteriors are stained and are not free of coating, which is a prerequisite for achieving the described antifouling effect, unless they are conductive paints as described in another study by the same group (Non-Patent Document 2). In this document, they describe signals similar to those described in the article on conductive paints.

[0012] In any case, the paper does not specify anything about the iron counter electrode used, which would necessarily corrode under the conditions described in the anodic cycle and would, under galvanostatic conditions, result in the deposition of calcareous salts and attached organisms, such as those shown in Figures 18 and 19. Their proposal focuses on keeping substrate 1 clean, without considering substrate 2, which in many applications may limit the applicability of the technology, as will be seen later. [Means for solving the problem]

[0013] In order to overcome the above-mentioned limitations, the present invention provides an electrolytic system for removing deposits, comprising a first substrate, the first substrate comprising titanium, defining a surface intended to contact water, a second conductive substrate provided with a surface intended to contact water, and a power source, the power source being connected in series between the first substrate and the second substrate such that an electrolytic circuit can be formed by the water, the first substrate, the second substrate, and the power source providing electrical energy, the power source being further adapted to provide a current density such that the first substrate operates as an anode, Periodically reversing the polarity of the circuit so that the first and second substrates alternately and periodically assume the functions of anode or cathode; and / or Provides pulsed current density The present invention proposes an electrolysis system comprising:

[0014] In some embodiments, the second substrate is titanium, activated titanium, or a consumable electrode, and / or the electrolysis system may include a plurality of second substrates, with the electronics configured such that at least one of the second substrates is subjected to an anodic potential by the power source, with the at least one substrate acting as an anode to remove calcareous salts that may have accumulated on its surface.

[0015] In some embodiments, the power source is 30 mA / m 2 The present invention is configured to provide a current density of at least 100 .mu.m.

[0016] In some embodiments, the power source, in turn, a constant current for the first substrate to act as an anode and the second substrate to act as a cathode; A reverse current so that the first substrate acts as a cathode and the second substrate acts as an anode; The amplifier is configured to apply a periodic signal consisting of:

[0017] In some embodiments, the power source, in turn, a pulsed current for the first substrate to act as an anode and the second substrate to act as a cathode; A reverse current so that the first substrate acts as a cathode and the second substrate acts as an anode; The amplifier is configured to apply a periodic signal consisting of:

[0018] In some embodiments, the electrolysis system includes a base substrate upon which the first substrate is attached.

[0019] In some embodiments, the base substrate is made of steel, aluminum, or bronze and the first substrate is made of pure titanium, the first substrate being constructed of two layers, a thick outer layer and an attachment layer, the attachment layer forming an interface between the outer layer and the base substrate, and preferably the attachment layer being a PVD or CVD deposited layer.

[0020] In some embodiments, the base substrate is made of a titanium alloy and the first substrate is made of pure titanium.

[0021] In some embodiments, the base substrate is made of a composite material and the first substrate is a blank of pure titanium having a thickness between 0.1 and 4 mm.

[0022] In some embodiments, the composite material includes resin, fiberglass, carbon fiber, and / or structural plastic.

[0023] In some embodiments, the base substrate is comprised of an inner layer of metal and an outer layer of insulating material, the first substrate being a blank of pure titanium having a thickness between 0.1 and 4 mm, the blank being attached to the outer layer.

[0024] In some embodiments, the first substrate is divided into multiple substrates, whereby some of the substrates form the second substrate when a polarity reversal is applied.

[0025] This optional element is intended to prevent biofouling on both substrates 1 and 2, avoid salt deposition and biological growth on the counter electrode, and eliminate the need for an auxiliary counter electrode, which is often difficult to properly position.

[0026] An example is the case of plate heat exchangers, where the distance between the plates is very short, making it necessary to place the counter electrodes inside the piping, which makes the distribution of the electrical signal difficult, and which can become covered with salts and biofouling, clogging the piping, the heat exchanger, or the cooling circuit.

[0027] Meanwhile, a signal can be applied alternately between the plates by making each plate act as an anode and cathode which alters the signal transmission, so the plates remain clean, there is no salt build-up and the signal propagates uniformly by keeping the distance between the electrodes short.

[0028] It is worth mentioning Non-Patent Document 3 to highlight the differences of this embodiment of the invention with respect to those already reported. Firstly, Non-Patent Document 3 proposes to work with active titanium in the plate, which is expensive and, unlike the concept of the present invention, leads to a lower exchange performance (hence the lower potentials given in the document). It also proposes to add auxiliary counter and reference electrodes. According to their method, the above solution is difficult to realize. The important difference is that the aim is only the cleanliness of electrode 1, whereas according to the present invention, both electrodes are kept clean through a switching signal using different parts of the structure as working and counter electrodes.

[0029] That is, the present invention is significantly simplified and more feasible, since it involves operation with non-active titanium, avoiding problems with counter electrodes and making it easier to apply signals.

[0030] The same can be true for piping, where the separation of the piping allows the distance between the electrodes to be maintained in a controlled manner. The auxiliary counter electrode is omitted and the structure is separated into parts electrically isolated from each other, resulting in the results of figures 24 and 25. In fact, similar results have been observed, such that the titanium interior is completely clean. The invention further relates in particular to a vessel, a piping, a heat exchanger, a propeller or a shaft, provided with an electrolysis system according to any of the various embodiments described above.

[0031] The invention further relates to an assembly comprising a piping and an electrolysis system according to any of the above disclosed embodiments, the assembly comprising an inner layer corresponding to a first substrate, a middle layer corresponding to a structural material for providing a rigid mounting for the piping, and an outer metallic layer corresponding to a second substrate.

[0032] The present invention further relates to a method for de-fouling ships, piping, heat exchangers, propellers, shafts, turbines, in particular tidal turbines, sea chests (for cooling ships), hydrofoils, and / or pump components using an electrolytic system according to any of the various aspects of the present invention, the method comprising: Calculating an area of ​​a first substrate; setting the power supply to provide an anodic potential, preferably above a limit, to prevent biofouling on the first substrate; a plurality of second substrates, the electrolysis being configured such that at least one of the second substrates receives the same potential from the power supply as the first substrate, whereby said at least one of the substrates acts as an anode to remove calcareous salts that may have accumulated on its surface.

[0033] Finally, the present invention further relates to a method for de-fouling ships, piping, heat exchangers, propellers, shafts, turbines, in particular tidal turbines, sea chests (for cooling ships), hydrofoils, and / or pump components using an electrolytic system according to any of the various aspects of the present invention, the method comprising: Calculating an area of ​​a first substrate; setting the power supply to provide an anodic potential, preferably above a limit, to prevent biofouling on the first substrate; splitting the first substrate into several substrates and inverting the polarity between them so that all substrates are anodes and cathodes, avoiding biofouling growth on their surfaces, the deposition of calcareous salts on their surfaces, eliminating the need for additional counter electrodes and reducing the active area and therefore the energy consumption; Includes.

[0034] To complete the description and to provide a better understanding of the invention, a set of drawings are provided. The drawings form an integral part of the description and show embodiments of the invention. The embodiments should not be construed as limiting the scope of the invention, but are merely examples of how the invention can be practiced. The drawings consist of the following figures: [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 is a diagram of a system according to the present invention. [Diagram 2] FIG. 1 shows a layer scheme according to an embodiment of the invention, in which a titanium layer is applied to a third substrate. [Diagram 3] FIG. 2 shows a layer scheme according to an embodiment of the invention, in this example the underlying substrate is formed by a third substrate and an interface layer. [Figure 4] FIG. 1 shows a layer scheme according to an embodiment of the present invention in which titanium is a blank attached to a substrate with an insulating material between them. [Diagram 5] FIG. 1 shows a titanium plate in water with a potential of 3VAg / AgCl applied. [Figure 6] FIG. 1 shows the experimental setup on a ship's hull and the adhesion results after several months of submersion. [Figure 7] FIG. 7 is an enlarged photograph of FIG. [Figure 8] FIG. 1 shows the plates of a system with a voltage of less than 6V applied. [Figure 9]FIG. 1 shows the plates of a system with a voltage of less than 6V applied. [Figure 10] FIG. 1 shows the plates of a system with a voltage of less than 6V applied. [Figure 11] FIG. 1 shows the plates of a system with a voltage of less than 6V applied. [Figure 12] FIG. 2 shows a plate of the system according to the invention. [Figure 13] FIG. 2 shows a plate of the system according to the invention. [Figure 14] FIG. 2 shows a plate of the system according to the invention. [Figure 15] FIG. 2 shows a plate of the system according to the invention. [Figure 16] FIG. 2 shows a plate of the system according to the invention. [Figure 17] FIG. 13 shows another plate used in the invention conditions with a switching signal applied. [Figure 18] FIG. 13 shows calcareous deposits at the cathode when no inversion is applied. [Figure 19] FIG. 13 shows calcareous deposits at the cathode when no inversion is applied. [Figure 20] FIG. 13 illustrates an applied pulse signal that allows energy savings. [Figure 21] FIG. 13 shows a pulse signal combined with cathodic cleaning. [Figure 22] FIG. 13 shows a pulse signal combined with cathodic cleaning. [Diagram 23] FIG. 1 illustrates a method for renewing the anode surface. [Figure 24] FIG. 13 is a diagram showing the result of application of the present invention to the inside of a pipe. [Diagram 25] FIG. 13 is a diagram showing the result of application of the present invention to the inside of a pipe. [Figure 26] FIG. 26 shows the result of application of the invention inside a pipe, showing the exterior of the pipe (FIG. 25) without the antifouling system. [Figure 27] FIG. 1 illustrates what happens to an alloy when subjected to more than its rupture potential. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] As shown in Fig. 1, 20, 21, 22 or 23, according to an embodiment, an electrolytic system S for removing deposits comprises a first substrate 1, which comprises titanium and defines a surface 11 intended to be in contact with water, a second conductive substrate 2 provided with a surface 21 intended to be in contact with water, and a power source U, which is connected in series between the first substrate 1 and the second substrate 2 so that an electrolytic circuit can be formed by the water, the first substrate 1, the second substrate 2 and the power source U providing electrical energy, the power source U being: to provide a current density such that the first substrate 1 acts as an anode, preferably applied in pulses to save energy; and The polarity of the circuit is periodically reversed so that the first substrate 1 and the second substrate 2 alternately and periodically assume the functions of an anode or cathode, It is composed.

[0037] The second substrate 2 may be titanium, activated titanium, or a consumable electrode, and / or the electrolysis system may comprise a plurality of second substrates, the electrolysis being configured such that at least one of the second substrates 2 is subjected to an anodic potential by the power source, the at least one substrate acting as an anode to remove calcareous salts that may have accumulated on its surface.

[0038] In addition, it is possible to split the first substrate into different electrically independent surfaces acting as substrate 1 and substrate 2, alternating between acting as anode and cathode. This eliminates the need for counter electrodes (as previously proposed) and keeps both substrates 1 and 2 clean from biofouling. Furthermore, the polarity change reverses the anodization of each surface, reducing the resistance of the system and facilitating the output of anodic current. The switching signal here can be symmetrical with respect to similar acting and counter electrodes, or can vary depending on the area of ​​substrates 1 and 2, but should certainly be sufficient to prevent biofouling on both surfaces.

[0039] The structure can be divided into different titanium regions that are electrically isolated from each other. This allows signals to be applied between them in an alternating fashion. Thus, salt deposition and biological growth on the counter electrodes is avoided and, moreover, counter electrodes, which are often difficult to place in the right position, are not necessary. An example is the case of plate heat exchangers. The distance between the plates is very short, which requires the placement of the counter electrodes inside the piping, making the distribution of the electrical signal difficult. Furthermore, the counter electrodes become covered with salts and biological fouling. On the other hand, if each plate is operated as an anode and a cathode that changes the signal transmission, signals can be applied between the plates in an alternating fashion, which keeps the plates clean. There is no salt deposition and the short distance between the electrodes allows the signal to be propagated uniformly.

[0040] In the embodiment shown in Figure 2, the electrolysis system comprises a base substrate 3 on which the first substrate 1 is attached, where the base substrate 3 is made of a titanium alloy and the first substrate 1 is made of pure titanium.

[0041] In another aspect of the embodiment shown in Figure 2, the base substrate 3 is made of a composite material and the first substrate 1 is a blank 14 of pure titanium having a thickness between 0.1 and 4 mm. The composite material 3 may include resin, fiberglass, carbon fiber, and / or structural plastic.

[0042] In the embodiment shown in Figure 3, the base substrate 3 is made of steel, aluminum or bronze and the first substrate 1 is made of pure titanium, which is composed of two layers: a thick outer layer 1E and an attachment layer 1A, which forms an interface between the outer layer 1E and the base substrate 3, and which is preferably a deposited layer by PVD or CVD.

[0043] In the embodiment shown in FIG. 4, the base substrate 3 consists of an inner layer 31 made of metal and an outer layer 32 made of insulating material, and the first substrate 1 is a blank 14 made of pure titanium having a thickness of between 0.1 and 4 mm, which blank 14 is attached to the outer layer.

[0044] [Voltage and current density] Tests were performed by applying the electrical signal in various ways to achieve the desired voltage and current density: ranging from potentiostatic, galvanostatic, and constant voltage pulses, to alternating or cyclic pulses. The tests were normalized by using grade 2 titanium electrodes for both the anode and cathode. Tests were also performed with other materials for the cathode, e.g. steel.

[0045] In the initial stage, the system grows over time and the anode exhibits significant resistance variations due to anodization on its surface. The resistance of the system increases over time. Salts are deposited on the cathode. This is an expected effect.

[0046] The following tests were then carried out by applying a constant voltage. The system current must take into account that the system resistance changes over time according to Ohm's law, due to the reactions occurring on the electrodes. The reactions are mainly anodization reactions occurring on the titanium anode. In all tests, both the current and the voltage were measured.

[0047] In summary, the inventors have concluded through testing, as will become apparent below, that there exists a critical current below which the antifouling effect on titanium surfaces begins to be observed, below which algae continue to grow even when the electrode is anodically polarized.

[0048] At a constant signal, if the applied voltage is less than 6 V, the effect on fouling organisms is confirmed, but the eradication of fouling organisms is not realized because the minimum anodic current required to prevent biofouling is not reached.

[0049] The table below shows the parameters for which no effect was observed (the area of ​​the plate used was 0.6 m 2 (It was.) [Table 1]

[0050] Figures 8 to 11 show the plates under these conditions, none of which gives good results. It should be noted that these voltages are already significantly higher than those suggested in the prior art and disclosed as effective in preventing microbial adhesion. Under these polarized conditions, the plates shown had lower levels of biofouling than the non-polarized plates, but the results are not good.

[0051] Tests were then performed at voltages above 7 V. The results are summarized in the table below. [Table 2]

[0052] Figures 12 to 16 show plates under these conditions, all of which showed virtually no microbial adhesion.

[0053] [Comparative test] The effects of Figures 6 and 7 are shown for 8 months at 7.5 V and 30 mA / m 2 This was achieved by applying a current of 10 ...

[0054] Figure 17 shows another sample, this one submerged under alternating pulses for 4 months: the blank shows no fouling whatsoever, whereas the cable under the same conditions is completely covered with algae.

[0055] Finally, the inventors have developed a laminate structure that can be used in the context of the present invention. This laminate structure, which may be considered an invention in itself, comprises the following layers: The base substrate is made of steel. The first substrate is made of titanium, The first substrate is made up of two layers, a thick outer layer 1E and a mounting layer 1A which forms an interface between the outer layer 1E and the underlying substrate 3, the mounting layer 1A being a deposited layer by PVD or CVD.

[0056] The structures may be used in marine, piping, heat exchanger, propeller, shaft, turbine, sea chest, hydrofoil, and / or pump components, among others.

[0057] In this laminate structure, the first titanium substrate can be pure titanium and / or a titanium alloy.

[0058] This can also be applied to other metal substrates with an insulating system between the metal and titanium sheets, or other structural materials such as structural polymers or composites. It is important to emphasize that the application of these titanium coatings to prevent biofouling is not a trivial concept. In many cases it means making the technology accessible. It also requires special resins, mechanical reinforcements and special electrical connections, in addition to the necessity of being able to divide the surface of the component so that biofouling does not occur. This allows the application of a switching signal, making it possible to eliminate the need for a counter electrode, keeping both the electrode and the counter electrode clean, thus reducing energy consumption.

[0059] [Method of the present invention for renewing the anode surface] As mentioned above, preventing biofouling in underwater structures requires the application of a minimum anodic current.

[0060] However, when this anodic current is applied over time, the resistance of the system increases due to the anodic reaction occurring on the titanium surface (substrate 1). The operating potential required to maintain this current is a constant value of a positive few volts (i.e., the above-mentioned 6 V Ag / AgCl ) until it reaches a steady state where

[0061] For pure titanium, there is no problem in maintaining this operating potential. However, for titanium alloys containing different alloying elements, the alloying elements modify the properties of the natural oxide layer present on the surface of the titanium alloy, resulting in a lower rupture potential relative to the potential required to maintain the anodic current that would prevent the appearance of a biological oxide film. Degradation therefore occurs under these conditions. Figure 27 shows what happens to the alloy when operated above its rupture potential.

[0062] To prevent biological fouling on these alloys, it is necessary to ensure that the operating voltage can be maintained below the limits mentioned above (burst or breakdown potential) with sufficient safety margins, while ensuring sufficient anodic current circulation to prevent biofouling.

[0063] To achieve these two objectives, the inventors have investigated a method to renew the anodic surface of the substrate 1 by applying a sufficient cathodic signal that makes it possible to lower the resistance of the system, thus achieving operation at an operating potential below the burst potential of the alloy, while maintaining the minimum current necessary to avoid the occurrence of biofouling.

[0064] The magnitude and duration of cathodic polarization required to reduce the operating potential is proportional to the density of the anodic current preferably passed through the system, and the number of cathodic cycles required to be applied depends on the magnitude and duration of the anodic cycles.

[0065] Figure 23 shows an example of the effect of "cathodic cleaning" on the potential required to operate at a given anodic current, for cathodic currents applied for different times (and therefore different cathodic charges applied). If sufficient cathodic charge is applied, it is observed that the operating potential stabilizes at a constant value below the limit potential for a period of time.

[0066] In figure 23 the voltage to maintain the anode current is plotted against time, where the following phases are distinguished: The first phase of the anodizing voltage, which is positive and acts to protect the membrane on the main anodizing surface. During the anodic phase, the resistance of the system increases due to the anodic reactions that occur during the anodic cycle. In the second phase, the polarity is reversed by applying a cathodic cycle (resulting in a negative operating voltage) and the substrate starts acting as a cathode. During this second phase, surface renewal occurs, reversing the anodization that occurred during the anodization phase. In the third phase, the polarity is reversed again. Thus, a forced circulation of sufficient anodic current occurs and biofouling is prevented. The graph records the electrode potential required to maintain the indicated anodic current. It can be observed that insufficient cathodic cycles do not allow surface renewal and the working potential required to achieve the minimum anodic current required to avoid biofouling exceeds the limit potential of the alloy. However, if the cathodic cycles used are large enough, the required working potential stabilizes below the breakdown potential for the desired period of time.

[0067] These studies show that: If the surface is not completely renewed during the cathode cleaning phase, the required voltage may exceed the maximum permissible value (burst or breakdown potential) because it has not been cleaned sufficiently. The right combination of reversal voltage and its application time comes when the required subsequent voltage increase stops. By determining this combination for each material, the reversal signal can be optimized. This ensures the lowest anode voltage.

[0068] Accordingly, another invention is now disclosed, which comprises a method for renewing an anode surface, the method comprising: Applying sufficient anodic cycles to prevent biofouling; and applying a cathodic signal sufficient to cause a renewal of the surface of the substrate 1, at a potential below the limiting potential, allowing the application of a subsequent anodic current necessary to prevent biofouling; applying an anodic signal for a desired time to achieve an anodic current necessary to prevent biofouling at potentials below the breakdown potential; This includes periodically performing the steps.

[0069] Preferably, these steps are performed for different values ​​depending on the desired anode current.

[0070] Yet another effect is claimed: a sufficiently large cathodic polarization leads to the generation of hydrogen on the polarized surface. If this is done with sufficient intensity, mechanical cleaning of the surface is also feasible, since a large amount of gas bubbles can be generated that can mechanically detach biofilms and bacterial films.

[0071] However, if this cathodic cycling is carried out alone, salt deposits can occur and weaken the alloy, so it is better to combine it with an anodic cycle.

[0072] Finally, further disclosed herein is a method for eliminating biofouling by mechanically cleaning underwater surfaces by applying cathodic polarization with sufficient voltage to generate hydrogen bubbles.

[0073] In this document, the term "comprises" and its derivatives (such as "comprising") should not be understood as exclusive, i.e., these terms should not be interpreted as excluding the possibility that what is described and defined may include additional elements, steps, etc.

[0074] The present invention is obviously not limited to the particular embodiments described herein, but rather encompasses all modifications (e.g., with respect to selection of materials, dimensions, components, configurations, etc.) that may occur to one skilled in the art within the general scope of the invention as defined in the claims.

Claims

1. An electrolytic system (S) for removing deposits, comprising: a first substrate (1), the first substrate (1) containing titanium and having a defined surface (11) intended to come into contact with water; a second conductive substrate (2) having a surface (21) intended to come into contact with water; and a power supply (U), wherein the power supply (U) is connected in series between the first substrate (1) and the second substrate (2) so that an electrolytic circuit can be constructed using water, the first substrate (1), the second substrate (2), and the power supply (U) providing electrical energy, and further, the power supply (U) provides a current density such that the first substrate (1) acts as the anode. - The polarity of the electrolytic circuit is periodically reversed so that the first substrate (1) and the second substrate (2) alternately and periodically function as anode or cathode, and / or - To provide pulsed current density, An electrolytic system (S) characterized by being configured as follows.

2. The electrolytic system according to claim 1, wherein the second substrate (2) is titanium, activated titanium, or a consumable electrode, and / or the electrolytic system may comprise a plurality of second substrates, and the electrolysis is configured such that at least one of the second substrates (2) receives an anode potential from the power supply and acts as an anode to remove calcareous salts that may have accumulated on its surface.

3. The power supply (U) is 30 mA / m² relative to the surface. 2 The electrolytic system (S) according to claim 1, configured to provide the above current density.

4. The aforementioned power supply (U) is, in order, - A constant current is provided for the first substrate (1) to operate as the anode and the second substrate (2) to operate as the cathode, - The reverse current required for the first substrate (1) to act as the cathode and the second substrate (2) to act as the anode, The electrolytic system (S) according to claim 1, configured to apply a periodic signal consisting of the following.

5. The aforementioned power supply (U) is, in order, - A pulse current for the first substrate (1) to act as the anode and the second substrate (2) to act as the cathode, - The reverse current required for the first substrate (1) to act as the cathode and the second substrate (2) to act as the anode, The electrolytic system (S) according to claim 1, configured to apply a periodic signal consisting of the following.

6. The electrolytic system according to claim 1, further comprising a base substrate (3) on which the first substrate (1) is attached.

7. The electrolytic system according to claim 6, wherein the base substrate (3) is made of steel, aluminum, or bronze, the first substrate (1) is made of pure titanium, the first substrate is composed of two layers: a thick outer layer (1E) and a mounting layer (1A), the mounting layer (1A) forms an interface between the outer layer (1E) and the base substrate (3), and preferably the mounting layer (1A) is a PVD or CVD deposited layer.

8. The electrolytic system according to claim 6, wherein the base substrate (3) is made of a titanium alloy, and the first substrate (1) is made of pure titanium.

9. The electrolytic system according to claim 6, wherein the base substrate (3) is made of a composite material, and the first substrate (1) is a blank (14) made of pure titanium having a thickness between 0.1 and 4 mm.

10. The electrolytic system according to claim 9, wherein the composite material (3) includes a resin, glass fiber, carbon fiber, and / or structural plastic.

11. The electrolytic system according to claim 6, wherein the base substrate (3) is composed of a metal inner layer (31) and an insulating outer layer (32), the first substrate (1) is a blank (14) made of pure titanium having a thickness between 0.1 and 4 mm, and the blank (14) is attached to the outer layer.

12. The electrolytic system according to claim 1, wherein the first substrate (1) is divided into a plurality of substrates, and a portion of these substrates forms the second substrate (2) when polarity reversal is applied.

13. A ship, piping, heat exchanger, propeller, shaft, turbine, sea chest, hydrofoil ship, and / or pump component provided with the electrolytic system (S) described in claim 1.

14. An assembly comprising piping and an electrolytic system according to claim 1, wherein the assembly comprises an inner layer corresponding to the first substrate (1), the piping comprising an intermediate layer corresponding to a structural material for firmly mounting it, and a metallic outer layer corresponding to the second substrate (2).

15. A method for removing deposits from a ship, piping, heat exchanger, propeller, shaft, turbine, sea chest, hydrofoil ship, and / or pump component (S) according to any one of claims 1 to 12, - Calculate the area of ​​the first substrate, - In order to prevent biological adhesion to the first substrate, the power supply (U) is preferably set to provide an anode potential exceeding a limit, - Multiple second substrates are provided, and the electrolysis is configured such that at least one of the second substrates (2) receives the same potential from the power supply as the first substrate (1), thereby causing at least one of the substrates to act as an anode to remove calcareous salts that may have accumulated on its surface. Alternatively, by dividing the first substrate into multiple substrates and reversing the polarity between them, all the substrates can become anodes and cathodes, thereby avoiding biological adhesion and growth on their surfaces, depositing calcareous salts on their surfaces, eliminating the need for additional counter electrodes, and reducing the working area and therefore energy consumption. Methods that include...

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