Method for maintaining surfaces susceptible to inorganic or organic deposits free of deposits

Abstract

An ultrasonic generator fastened to the object is used as an ultrasonic probe. Thus, the ultrasonic probe is used to emit ultrasonic waves by the inverse piezoelectric effect and also to detect (ultrasound) waves by the piezoelectric effect. In this method, multiple ultrasonic probes are first fastened at predetermined positions on the surface that can ensure maximum surface area coverage, which is checked as to whether an acoustic event emitted by a single ultrasonic probe can be detected by at least one other ultrasonic probe. In each, only one ultrasonic probe is connected to emit acoustic events and the remaining ultrasonic probes are connected to receive, and in each, the position of each ultrasonic probe can be adjusted, leading to an optimization of the surface area coverage. Optionally, the number of ultrasonic probes provided can also be increased or decreased.

Description

[Technical Field]

[0001] The present invention relates to a method for maintaining the surface of a body susceptible to deposits clear of deposits and / or for removing deposits adhering to the surface of the body by means of ultrasound. [Background technology]

[0002] The use of ultrasound to remove inorganic or organic deposits attached to surfaces, such as attached biofilms, or to prevent the formation of deposits, for example, on the hull of a ship or the inside of a vessel or pipe, is known, for example, from U.S. Pat. No. 5,623,399. To ultrasonically remove or keep free of such deposits on a liquid-transporting surface or a surface in contact with a liquid, a piezoelectric ultrasonic transducer is attached to the side opposite the surface to be kept free of deposits or cleaned. A control unit equipped with an ultrasonic generator excites the ultrasonic transducer at a suitable frequency and power, the frequency and power combination usually being below the cavitation limit to prevent damage caused by cavitation effects. Therefore, due to the somewhat limited power and associated short range of a single ultrasonic transducer, multiple ultrasonic transducers must be used for larger areas.

[0003] However, due to reinforcements, attachments, corners, edges or angles of the object comprising the surface to be treated, including different filling levels, medium flow rates or pressures (each of which affects the range of the emitted ultrasound), it is not possible to determine 100% area coverage in advance.

[0004] This problem is illustrated in Figure 1, which shows the surface of an object 10 being sonicated as fully as possible using two ultrasonic transducers 20, 20'. However, it can be seen that because the ranges 25, 25' of the ultrasonic transducers 20, 20' differ at given locations due to the structural or material properties of the object 10, only a sparse surface coverage is achieved and the surface of the object is still susceptible to deposits, in particular the biological growth of biofilm-forming (micro)organisms. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] German Patent Application Publication No. 102019203069 Summary of the Invention [Problem to be solved by the invention]

[0006] It is therefore an object of the present invention to create a method for removing deposits, in particular biological growth, from the surface of an object and / or removing deposits, in particular attached biofilms, attached to the surface of an object by means of ultrasound, which is capable of achieving an area coverage as close to 100% as possible. [Means for solving the problem]

[0007] According to the invention, this object is solved by a method having the features of claim 1. The dependent claims describe advantageous embodiments of the invention.

[0008] The basic concept of the present invention is to use an ultrasonic transducer attached to an object as an ultrasonic probe, which is configured to emit ultrasonic waves due to the inverse piezoelectric effect and detect (ultrasound) waves due to the piezoelectric effect. First, multiple ultrasonic probes are attached to a surface at predetermined locations that can ensure maximum area coverage, which is checked in accordance with the present invention by determining whether an acoustic event emitted by a single ultrasonic probe can be detected by at least one other ultrasonic probe. By switching only one ultrasonic probe at a time to emit acoustic events and the other ultrasonic probes to receive them, and preferably by checking the position of each ultrasonic probe, the position of each ultrasonic probe can be adjusted to optimize area coverage. If necessary, the number of ultrasonic probes provided can be increased or decreased to provide an optimized method for maintaining the surface of an object susceptible to deposits free of deposits and / or removing deposits from the object's surface using ultrasound.

[0009] Therefore, according to the present invention, there is provided a method for maintaining the surface of an object susceptible to deposits free of deposits and / or for removing deposits attached to the surface of the object by means of ultrasound, the method comprising the steps of: a. attaching a predetermined plurality of ultrasonic probes to predetermined locations on an object having at least one surface susceptible to or having deposits; b. subjecting the object to ultrasound waves with a single ultrasonic probe selected from a predetermined plurality of ultrasonic probes; c. detecting ultrasound waves emitted by one ultrasound probe as ultrasound events by remaining ultrasound probes of the plurality of ultrasound probes; d. repeating step b. and step c. as necessary, exposing the object to ultrasound waves with additional ultrasonic probes determined as selected ultrasonic probes, until each ultrasonic probe of the plurality of ultrasonic probes has exposed the object to ultrasound waves; e. repositioning at least selected ultrasound probes if an expected ultrasound event is not present in at least one of the remaining ultrasound probes or if an ultrasound event is detected by at least one of the remaining ultrasound probes with a sound energy lower than a predetermined sound energy; f. repeating steps b. through e. until at least one of the remaining ultrasound probes detects an ultrasound event with at least the predetermined sound energy; g. exposing the object to ultrasound waves by all ultrasonic probes attached to the object; A method is proposed, including:

[0010] The deposits to be prevented or removed may be inorganic and / or organic deposits, in particular of biological origin. It is particularly preferred that the object to be treated has a surface that is susceptible to biological growth or on which biofilms adhere. Therefore, it is preferred that the deposits to which the method is applied are inorganic and / or organic deposits and / or biofilm-forming deposits.

[0011] The repositioning process preferably includes reattaching the selected ultrasonic probe to the same predetermined position. If at least one of the remaining ultrasonic probes is not generating the expected ultrasonic events, the selected ultrasonic probe may not be properly attached to the object at the predetermined position. Therefore, the correct attachment of the selected ultrasonic probe should be checked and, if necessary, reattached.

[0012] Alternatively, or optionally, repositioning may also include reattaching an ultrasound probe in which an expected ultrasound event did not occur. It is possible that one of the remaining ultrasound probes among the multiple ultrasound probes recording an ultrasound event, rather than the selected ultrasound probe, is not properly attached to the object. Therefore, it is also necessary to check that this ultrasound probe is properly attached, and preferably reattached.

[0013] In any case, repositioning may also include replacing a defective ultrasonic probe with a non-defective ultrasonic probe, particularly if no other effects are produced by repositioning the selected or remaining ultrasonic probes, in which case the selected and / or remaining ultrasonic probes are deemed defective and replaced with the non-defective ultrasonic probes.

[0014] While it is not necessary for each of the remaining ultrasonic probes to detect the acoustic event generated by the selected ultrasonic probe, it is preferable that at least one of the remaining ultrasonic probes, preferably located directly adjacent to the selected ultrasonic probe, must detect the acoustic event. To this end, a predetermined radius or distance can be defined from one of the remaining ultrasonic probes to the selected ultrasonic probe within which an acoustic event with acoustic energy lower than a predetermined acoustic energy must be detected in order to trigger repositioning. For example, a specified number of remaining ultrasonic probes located adjacent to the selected ultrasonic probe within a predetermined radius can be required to detect an acoustic event with acoustic energy lower than a predetermined acoustic energy in order to initiate repositioning.

[0015] More preferably, the object is a wall or wall material and the ultrasonic probe is located on a side or surface of the wall or wall material opposite to the surface of the wall or wall material that is susceptible to or has deposits, particularly where the ultrasonic probe is located on a surface of the wall or wall material that is largely protected from and does not come into contact with moisture, and the surface to be treated is the surface that is in direct contact with moisture.

[0016] In particular, the object is a ship's hull and the ultrasonic probes are attached to the inside of the hull to remove deposits from and / or to remove deposits adhering to the exterior surface of the hull. Thus, in this case, the ultrasonic probes are located inside the hull.

[0017] However, the object can also preferably be a liquid-containing container or a liquid-transporting pipe. Most preferably, the object is a cooling tower, a tank in a sewage treatment plant, or a tank in a biogas plant. In this case, the ultrasonic probe is located outside the respective object. The method according to the invention is therefore particularly suitable in the field of maritime transport, in particular for the treatment of all kinds of cooling systems (sea chests, filter housings, pipes, plate heat exchangers, box / box coolers), all kinds of propellers, fresh water generators, and ship hulls. In the industrial sector, the method according to the invention is particularly suitable for the treatment of evaporative cooling systems, plate heat exchangers conveying cooling / process media, in particular concentrated juice coolers, raw juice heaters, juice purifiers, milk heaters, machines conveying cooling / process media, pipes and tanks, wet separators, bottle washers, pasteurizers, and paper-making machines, in particular glue spreaders and color coating machines. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram of the prior art. [Figure 2] 1 is a diagram of a preferred embodiment of the result of the method according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0019] The invention will now be explained in more detail with reference to a particularly preferred embodiment example shown in the accompanying Figure 2. Figure 2 shows the same object 10 known from Figure 1 with a modified configuration of ultrasound probes 20, 20' as a result of the method according to the invention.

[0020] In this example, the selected ultrasonic probe 20, located on the left side, exposed the object 10 to ultrasonic waves that could not be detected by the ultrasonic probe 20' located on the right side, i.e., lacking the required acoustic energy, as shown in FIG. 1 . Furthermore, the reverse functional check due to the acoustic emission by the right ultrasonic probe 20' and the insufficient detection of acoustic events by the left ultrasonic probe 20 resulted in no detection or detection with insufficient acoustic energy. By iteratively adjusting the position, the state shown in FIG. 2 was finally achieved. On the one hand, it can be seen that the ultrasonic probes 20, 20' have changed their positions compared to FIG. 1 . On the other hand, it can be seen that the ranges 25, 25' of the ultrasonic probes 20, 20' have changed due to the change in position. Generally, this leads to improved area coverage of the ultrasonic waves compared to FIG. 1 and, therefore, improved prevention of deposits, such as biofilms, on the surface of the object 10. Positioning the ultrasonic probes 20, 20' in this manner allows ultrasonic waves to be applied over a wide area to effectively prevent or remove deposits, especially biofilm growth.

[0021] Drawing translation Figure 1 (STAND DER TECHNIK) (PRIOR ART) [Explanation of symbols]

[0022] 10 objects 20 Ultrasonic transducer Ultrasonic probe 20' Ultrasonic Transducer Ultrasonic Probe 25 Ultrasonic transducer 20 range Ultrasonic probe 20 range 25' Ultrasonic Transducer 20' Range Ultrasonic Probe 20' Range

Claims

1. 1. A method for maintaining a surface of an object (10) susceptible to deposits free of deposits and / or removing deposits from the surface of the object (10) by means of ultrasound, comprising: a. attaching a predetermined number of ultrasonic probes (20, 20') to predetermined locations on an object (10) having at least one surface susceptible to or having deposits; b. subjecting the object (10) to ultrasound waves by a single ultrasonic probe selected from the predetermined plurality of ultrasonic probes (20, 20'); c. detecting ultrasonic waves emitted by the single ultrasonic probe as ultrasonic events by the remaining ultrasonic probes of the plurality of ultrasonic probes (20, 20'); d. repeating steps b. and c. as necessary, exposing the object to ultrasound waves by additional ultrasonic probes determined as selected ultrasonic probes, until each ultrasonic probe of the plurality of ultrasonic probes (20, 20') has exposed the object to ultrasound waves; e. repositioning at least the selected ultrasound probe if an expected ultrasound event is not present in at least one of the remaining ultrasound probes or if an ultrasound event having an acoustic energy lower than a predetermined acoustic energy is detected by at least one of the remaining ultrasound probes; f. repeating steps b. through e. until at least one of the remaining ultrasound probes detects an ultrasound event with at least the predetermined sound energy; g. exposing the object (10) to ultrasound waves by all ultrasonic probes (20, 20') attached to the object; A method comprising:

2. 2. The method according to claim 1, characterized in that the deposits are inorganic and / or organic deposits and / or deposits that form biofilms.

3. 3. The method of claim 1 or 2, wherein the repositioning comprises reattaching the selected ultrasound probe to the same predetermined location.

4. 3. The method of claim 1 or 2, wherein the repositioning comprises reattaching the ultrasound probe in which the expected ultrasound event did not occur.

5. 3. The method of claim 1 or 2, wherein the repositioning comprises replacing a defective ultrasonic probe with a non-defective ultrasonic probe.

6. 3. The method of claim 1, wherein at least one of the remaining ultrasound probes that detects acoustic events with acoustic energy lower than a predetermined acoustic energy is positioned directly adjacent to the selected ultrasound probe.

7. 3. The method according to claim 1 or 2, characterized in that the object (10) is a ship hull and the plurality of ultrasonic probes (20, 20') are fixed inside the hull for removing deposits from an outer surface of the hull that is susceptible to deposits and / or for removing deposits that have adhered to the outer surface of the hull.

8. 3. The method according to claim 1, wherein the object is a liquid container or a liquid transport pipe.

9. 9. The method according to claim 8, characterized in that the object (10) is a cooling tower, a tank of a sewage treatment plant or a tank of a biogas plant.

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