Process for keeping a surface clear which is susceptible to inorganic or organic deposits

Abstract

Ultrasonic generators fastened to a body are used as ultrasonic probes which, on account of the inverse piezoelectric effect, are thus used for emitting ultrasound and, on account of the piezoelectric effect, are also used for detecting (ultra)sound. In the process, a plurality of ultrasonic probes are initially fastened at predetermined positions on a surface, which positions likely ensure the largest possible surface area coverage, wherein this is thereby checked regarding whether a sound event emitted by a single ultrasonic probe can be detected by at least one other ultrasonic probe. Since in each case only one ultrasonic probe is connected for emitting a sound event and the remaining ultrasonic probes are connected for receiving, in each case the position of each ultrasonic probe can be adjusted, which leads to optimized surface area coverage. Optionally, the number of provided ultrasonic probes can also be increased or reduced.

Description

[0001] Method for keeping a surface susceptible to inorganic or organic deposits free

[0002] The invention relates to a method for keeping a surface of a body susceptible to deposits free and / or for removing deposits adhering to a surface of a body by means of ultrasound.

[0003] The use of ultrasound to remove inorganic or organic deposits adhering to surfaces, e.g., adhering biofilm, or to prevent their formation, for example on the outer hull of watercraft or on the inside of containers or pipes, is known, for example, from DE 10 2019 203 069 A1. To remove or keep free of such deposits on surfaces that carry liquids or are in contact with liquids using ultrasound, a piezo ultrasonic transducer is glued to the opposite side of the surface to be kept free or cleaned. A control unit equipped with an ultrasonic generator excites the ultrasonic transducer with a suitable frequency and power, the combination of which is generally below the cavitation limit to prevent damage caused by cavitation effects.Due to the rather limited power and the resulting short range of a single ultrasonic transmitter, several ultrasonic transmitters must be used for larger areas.

[0004] However, due to stiffeners, attachments, corners, edges or angles of the bodies comprising the surface to be treated, including different fill levels, flow velocities or pressure forces of the medium, which each influence the range of the emitted ultrasound, it is impossible to determine 100% area coverage in advance.

[0005] This problem is illustrated in Fig. 1, which depicts the surface of a body 10, which is to be sonicated as completely as possible using the two ultrasonic transducers 20, 20'. However, it can be seen that the ranges 25, 25' of the ultrasonic transducers 20, 20' at their predetermined positions differ due to the structural or material properties of the body 10, so that only patchy surface coverage is achieved, leaving the surface of the body susceptible to deposits, especially biogenic growth with (micro)organisms that form a biofilm.

[0006] The object of the invention is therefore to provide a method for keeping a surface of a body susceptible to deposits, in particular biogenic growth, free and / or for removing deposits adhering to a surface of a body, in particular adhering biofilm, by means of ultrasound, with the aid of which a surface coverage as close as possible to 100% can be achieved.

[0007] This object is achieved according to the invention by the method having the features of claim 1. The subclaims represent advantageous embodiments of the invention.

[0008] The basic idea of ​​the invention is to use the ultrasound transmitters attached to a body as ultrasound probes, which are thus configured to emit ultrasound due to the inverse piezoelectric effect and to detect (ultra)sound due to the piezoelectric effect. A plurality of ultrasound probes is initially attached to predetermined positions on a surface that are expected to ensure the greatest possible area coverage. According to the invention, this is checked by determining whether a sound event emitted by a single ultrasound probe can be detected by at least one other ultrasound probe.By setting only one ultrasound probe to emit a sound event at a time and the remaining ultrasound probes to receive, and by checking the position of each ultrasound probe preferentially, the position of each ultrasound probe can be adjusted, resulting in optimized area coverage. If necessary, the number of ultrasound probes provided can also be increased or decreased, thus providing an optimized method for keeping a body surface prone to deposits clear and / or for removing deposits adhering to a body surface using ultrasound.

[0009] According to the invention, a method for keeping a surface of a body prone to deposits free and / or for removing deposits adhering to a surface of a body by means of ultrasound is proposed, comprising the following steps: a. Attaching a predetermined plurality of ultrasound probes at predetermined positions on a body having at least one surface prone to deposits or having deposits; b. Exposing the body to ultrasound using a single ultrasound probe selected from the predetermined plurality of ultrasound probes; c. Detecting the ultrasound emitted by one ultrasound probe by the remaining ultrasound probes of the plurality of ultrasound probes as an ultrasound event; d. If necessary, repeating steps b. and c., wherein the exposure of the body to ultrasound is carried out by means of a further ultrasound probe designated as the selected ultrasound probe until each ultrasound probe of the plurality of ultrasound probes has exposed the body to ultrasound; e. repositioning at least the selected ultrasound probe if an ultrasound event expected from at least one of the remaining ultrasound probes does not occur 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. to e. until at least one of the remaining ultrasound probes detects an ultrasound event with at least the predetermined sound energy; and g. exposure of the body to ultrasound using all ultrasound probes attached to the body.

[0010] The deposits to be prevented or removed can be inorganic and / or organic deposits, which can in particular be of biogenic origin. The bodies to be treated particularly preferably have surfaces that are susceptible to biogenic growth or to which biofilm adheres. The deposits for which the method is applied are accordingly preferably inorganic and / or organic deposits and / or deposits that form a biofilm. The repositioning process preferably comprises reattaching the selected ultrasound probe to the same predetermined position. In the event that an ultrasound event expected from at least one of the remaining ultrasound probes fails to occur, there is a possibility that the selected ultrasound probe has not been properly attached to the predetermined position on the body.It is therefore necessary to check that the selected ultrasound probe is properly attached and reattached if necessary.

[0011] Alternatively, or possibly additionally, repositioning also includes reattaching the ultrasound probe for which the expected ultrasound event did not occur. It is also possible that not the selected ultrasound probe, but one of the remaining ultrasound probes of the plurality of ultrasound probes intended to record the ultrasound event, is not properly attached to the body. Therefore, if necessary, the proper attachment of this ultrasound probe must also be checked and, if possible, reattached.

[0012] In any case, repositioning also includes replacing a defective ultrasound probe with an intact one, especially if repositioning the selected or remaining ultrasound probe does not produce any other effect. In this case, the selected and / or remaining ultrasound probe is considered defective and replaced with an intact ultrasound probe.

[0013] It is preferably provided that not every one of the remaining ultrasound probes has to detect a sound event generated by the selected ultrasound probe, but preferably at least one of the remaining ultrasound probes that is arranged immediately adjacent to the selected ultrasound probe. For this purpose, a predetermined radius or distance can be defined from one of the remaining ultrasound probes to the selected ultrasound probe, which must detect a sound event with a sound energy lower than a predetermined sound energy in order to trigger repositioning. Thus, it can be specifically provided that a defined plurality of remaining ultrasound probes that are arranged adjacent to the selected ultrasound probe within a predetermined radius must detect a sound event with a sound energy lower than a predetermined sound energy in order to trigger repositioning.Furthermore, it is preferably provided that the body is a wall or a partition, wherein the ultrasonic probes are arranged on the side or surface of the wall or partition opposite the surface of the same wall or partition that is susceptible to deposits or has deposits. In particular, the ultrasonic probes are located on the surface of the wall or partition that is largely protected from moisture and does not come into contact with it, wherein the surface to be treated is the surface that comes into direct contact with moisture.

[0014] Specifically, the body is a ship's hull, with the majority of ultrasonic probes mounted on the inside of the hull to keep the outer surface of the hull free of deposits and / or to remove deposits adhering to the outer surface of the hull. In this case, the ultrasonic probes are located on the inside of the (ship's) hull.

[0015] However, the body can also preferably be a liquid-holding container or a liquid-carrying pipe. Most preferably, the body is a cooling tower, a tank of a sewage treatment plant, or the tank of a biogas plant. In this case, the ultrasonic probes are located on the outside of the respective body. Thus, the method according to the invention is particularly suitable in the shipping sector, particularly for the treatment of all types of cooling systems (sea chests, filter housings, pipes, plate heat exchangers, box / box coolers), propellers of all types, freshwater generators, and ship hulls.In the industrial sector, the process according to the invention is used for the treatment of evaporative cooling systems, plate heat exchangers carrying cooling / process media, especially thick juice coolers, raw juice warmers, juice cleaners, milk heaters, cooling / process media carrying machines, lines and tanks, wet separators, bottle washing machines, pasteurizers and paper production machines, especially glue spreaders and paint coating machines.

[0016] The invention is explained in more detail with reference to a particularly preferred embodiment shown in the attached Fig. 2. Fig. 2 shows the identical body 10 known from Fig. 1 with an arrangement of the ultrasound probes 20, 20' modified due to the method according to the invention. Using the selected ultrasound probe 20, arranged on the left in the example, the body 10 was subjected to ultrasound, which - as Fig. 1 shows - could not be detected by the ultrasound probe 20' arranged on the right, or could not be detected with the predetermined sound energy. The reverse functional test by sound emission by the right ultrasound probe 20' and the failure of the left ultrasound probe 20 to detect a sound event resulted in no detection or in detection with insufficient sound energy. By iteratively adjusting the positions, the state shown in Fig. 2 was finally achieved.Firstly, it can be seen that the ultrasound probes 20, 20' have taken up different positions compared to Fig. 1. Secondly, it can be seen that the ranges 25, 25' of the ultrasound probes 20, 20' have changed due to the changed positions. Overall, this leads to improved area coverage with ultrasound compared to Fig. 1 and thus to improved prevention of deposits, for example, biofilm on the surface of the body 10. With the positioning of the ultrasound probes 20, 20' thus determined, a largely area-wide ultrasound irradiation can be achieved, which effectively prevents or eliminates deposits, in particular biofilm growth.

Claims

- 7 - CLAIMS 1. A method for keeping a surface of a body (10) that is susceptible to deposits free and / or for removing deposits adhering to a surface of a body (10) by means of ultrasound, comprising the steps of: a. attaching a predetermined plurality of ultrasound probes (20, 20') to predetermined positions on a body (10) that has at least one surface that is susceptible to deposits or has deposits; b. subjecting the body (10) to ultrasound using a single ultrasound probe selected from the predetermined plurality of ultrasound probes (20, 20'); c. detecting the ultrasound emitted by the one ultrasound probe by the remaining ultrasound probes of the plurality of ultrasound probes (20, 20') as an ultrasound event; d. if necessary, repeating steps b. and c., wherein the subjecting of the body (10) to ultrasound is carried out by means of a further ultrasound probe designated as the selected ultrasound probe until each ultrasound probe of the plurality of ultrasound probes (20, 20') has subjected the body (10) to ultrasound; e. repositioning at least the selected ultrasound probe if an ultrasound event expected by at least one of the remaining ultrasound probes does not occur 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. to e. until at least one of the remaining ultrasound probes detects an ultrasound event with at least the predetermined sound energy; and g. subjecting the body to ultrasound by means of all ultrasound probes (20, 20') attached to the body (10). - 8 - Method according to claim 1, characterized in that the deposits are inorganic deposits and / or organic deposits and / or deposits forming a biofilm. Method according to one of the preceding claims, characterized in that the repositioning comprises reattaching the selected ultrasound probe to the same predetermined position. Method according to one of the preceding claims, characterized in that the repositioning comprises reattaching the ultrasound probe for which the expected ultrasound event did not occur. Method according to one of the preceding claims, characterized in that the repositioning comprises exchanging a defective ultrasound probe for an intact ultrasound probe.Method according to one of the preceding claims, characterized in that the at least one of the remaining ultrasonic probes that detects a sound event with a sound energy lower than a predetermined sound energy is arranged immediately adjacent to the selected ultrasonic probe. Method according to one of the preceding claims, characterized in that the body (10) is a ship's hull, wherein the plurality of ultrasonic probes (20, 20') are attached to the inside of the ship's hull to keep the outer surface of the ship's hull prone to deposits clear and / or to remove deposits adhering to the outer surface of the ship's hull. - 9 - Method according to one of claims 1 to 6, characterized in that the body (10) is a liquid-receiving container or a liquid-conducting conduit. Method according to claim 8, characterized in that the body (10) is a cooling tower, a basin of a sewage treatment plant, or the container of a biogas plant.