Method and apparatus for descaling fluid-carrying equipment

Abstract

Disclosed are a method and a device for descaling / cleaning / rinsing fluid-carrying or fluid-receiving equipment, in particular industrial pipelines.

Description

[0001] The invention relates to a method and a device for descaling fluid-carrying or fluid-receiving equipment, preferably industrial pipelines.

[0002] In industrial process engineering, particularly in food technology, limescale buildup in pipes is a major problem in regions where the water has a relatively high calcium content. This problem essentially arises from the deposits of limescale on the inner pipe walls, thus reducing the free cross-section of the pipe and consequently increasing the pressure loss within that section. Cleaning these limescaled pipe sections is currently only possible with considerable effort and significant plant downtime. Therefore, in breweries, for example, it is common practice to replace the limescale-encrusted stainless steel pipes at regular intervals, as this is more cost-effective than extensive cleaning.Replacing the pipelines is also only possible with a very high level of effort, requiring significant downtime, which reduces the productivity of the plant.

[0003] In German patent application DE 20 2019 003 089 U1, a method for descaling pipelines is described in which the scaled section of the pipeline is subjected to a pressure of 3 to 7 bar and an acidic descaling agent that chemically reacts with the limescale layer deposited on the inner wall of the pipeline. However, it was found that such a method can only be used to clean pipelines with a comparatively small cross-section and that complete removal of the limescale layer is not guaranteed.

[0004] Document US 3,281,268 A describes a process in which the removal of deposits is achieved using a non-aqueous, acid-based descaling agent. Such a concept is not suitable for use in food technology, particularly in a brewery.

[0005] DE 3 631 459 A1 discloses a method for cleaning branched pipelines, wherein devices for adjusting the flow rates are provided in the individual pipeline sections, so that the pipeline sections are flushed with the predetermined volume flow. This method also uses an acidic cleaning agent, and after completion of the cleaning process, the cleaned pipelines are neutralized and rinsed with fresh water for an extended period.

[0006] German patent application DE 694 13 017 T2 describes a method for cleaning a pipe section located between two fire hydrants, wherein this underground pipe section is sealed off from the fire hydrant and connected to a tank from which an acidic aqueous cleaning fluid is circulated through the pipe section. After this flushing with the cleaning fluid, the pipe section is neutralized again by rinsing with water or the like.

[0007] One disadvantage of all these solutions is that they cannot be used, or can only be used with very high technical effort, in industrial pipelines, especially in the food industry with comparatively large pipe diameters, and moreover, thorough cleaning of calcified or otherwise contaminated pipe sections is not guaranteed.

[0008] Utility model CN ​​2 02 169 263 U discloses a generic device and a method for descaling pipelines, in which an acidic cleaning solution is received in a suction chamber of a tank arrangement and is pumped from there via a feeder pump to the pipeline.

[0009] The loaded cleaning solution is returned via a return line to a settling chamber of the tank arrangement, which is in fluid communication with the intake chamber.

[0010] The problem with this concept is that, in practice, foam formation is unavoidable and the foam enters the intake chamber, so that the solution drawn in by the pump has a significant foam content, which hinders the descaling process.

[0011] In contrast, the invention is based on the objective of creating a method and a device for descaling or cleaning fluid-carrying or fluid-receiving equipment, in particular industrial pipelines, with which intensive cleaning can be carried out.

[0012] This problem is solved with regard to the method by the combination of features of claim 1 and with regard to the device by the features of dependent claim 7.

[0013] Advantageous further developments of the invention are the subject of the dependent claims.

[0014] The method according to the invention is suitable for descaling or cleaning fluid-carrying or fluid-receiving equipment, in particular industrial pipelines, which, for example, have a nominal diameter between DN 50 and DN 250. In this process, an acidic rinsing solution, hereinafter referred to as descaling solution, contained in a tank arrangement, is supplied to the scaled or contaminated equipment (pipeline) under pressure via a supply line and returned to the tank arrangement via a downstream return line. According to the invention, this tank arrangement has an intake chamber from which the descaling solution is pumped to the inlet by means of a pump, in particular a centrifugal pump. The return line opens into a settling chamber of the tank arrangement, which is in fluid communication with the intake chamber, so that the descaling solution can be circulated.The delivery volume flow rate of the feed pump is preferably selected such that a flow velocity of more than 1.0 m / s, preferably more than 1.5 m / s, is established within the device.

[0015] According to the invention, the settling chamber is in fluid communication with a collection basin in which the volume increase resulting from the chemical reaction, in particular the foaming of the descaling solution, is collected and returned to the intake chamber after defoaming. In this concept according to the invention, the descaling solution, which is in the broadest sense "regenerated" (free of solids), is thus supplied to the intake chamber both directly from the settling chamber and via the collection basin, ensuring that the descaling solution is largely free of foam and solids.

[0016] This process involves the removal of impurities or limescale in two ways: firstly, through the chemical reaction of the acidic descaling solution with the deposit, which is known per se; and secondly, through the high flow rate of the descaling solution, which mechanically abrases the deposit or the reaction products formed by the chemical reaction.

[0017] The device according to the invention is specifically designed for carrying out this method and accordingly has a tank arrangement comprising an intake chamber and a settling basin, which are in fluid communication with each other. An acidic descaling solution is contained in the intake chamber and can be pumped by a feed pump connected to a pump port of the intake chamber into a feed line connected to the equipment (pipeline) to be cleaned. The pump is designed such that the descaling solution is conveyed through the equipment at a flow rate of preferably more than 1.0 m / s, and particularly more than 1.5 m / s. Advantageously, the feed pump can also be designed such that the descaling solution is pressurized to a pressure of more than 3 bar, preferably between 4 and 9 bar.According to the invention, the settling chamber is in fluid communication with a collection basin in which portions resulting from an increase in volume due to the chemical reaction or mechanical interactions, in particular from foaming of the descaling solution, are collected and returned from there to the intake chamber.

[0018] As explained in more detail below, the portion resulting from the increase in volume can also be guided from the intake chamber into the collection basin via an overflow, while the return from the collection basin to the intake chamber is carried out, for example, by a circulation pump.

[0019] In a particularly preferred embodiment of the invention, the fluid connection between the settling chamber and the intake chamber is formed by an overflow. The solids of the loaded descaling solution settle in the settling chamber, and the portion of the descaling solution freed of solids can then flow back into the intake chamber via the overflow, thus circulating the descaling solution.

[0020] According to the invention, it is preferred if the descaling solution has a pH value between 0.5 and 4.0.

[0021] The pump is advantageously set so that a pressure of more than 3 bar, in particular a pressure between 4 bar and 9 bar, is established in the device to be cleaned.

[0022] The cleaning process is particularly effective if the descaling solution is circulated several times and, at the end of these cleaning cycles, compressed air with a pressure of more than 5 bar, preferably between 8 and 10 bar, is supplied downstream of the feed pump.

[0023] Particularly effective cleaning can be achieved if the descaling solution is an aqueous mixture with approximately 5 volume parts water and approximately one volume part "chemical", wherein this is preferably a mixture of formic acid and aminosulfonic acid, wherein the volume part of formic acid is more than 70%, preferably about 90%.

[0024] As explained above, the tank arrangement has a collection basin which is in fluid connection with the intake chamber in such a way that the portions of the backflowing descaling solution resulting from an increase in volume are absorbed and can be returned to the intake chamber after a decrease in volume by means of a circulation pump or the like.

[0025] The fluid connection between the settling chamber and the intake chamber on the one hand and / or between the intake chamber and the collection basin on the other hand can be formed by an overflow.

[0026] The device according to the invention can be designed to be particularly compact if the intake chamber, the settling basin and the overflow basin are integrated in a common tank, wherein the volume of the collection basin is preferably significantly larger than the volume of the intake chamber and the settling basin.

[0027] The total volume of the tank can be approximately 6000 liters, with the volume of the collection basin being about half of that.

[0028] For effective cleaning and adjustment of the composition of the descaling solution, the device according to the invention can be equipped with a compressed air connection arranged in the supply line and / or a chemical connection that can be connected to a circulation pump via a directional control valve arrangement and / or a clear water connection formed in the supply line.

[0029] The device is particularly versatile when used as a mobile unit, for example mounted on a trailer or vehicle.

[0030] Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. These show: Fig. 1 a system diagram of a device according to the invention for carrying out the method according to the invention for cleaning, in particular descaling, an industrial pipeline; Fig. 2 a top view of a tank of the device according to Fig. 1 and Fig. 3a to 3c several operating states of the device according to Fig. 1.

[0031] One in Fig. The flushing or descaling system shown in Figure 1 (hereinafter referred to as Device 1) can, in principle, be used to clean pipelines 2; in the following, the use of this Device 1 for descaling a stainless steel pipeline 2 in a brewery is described. The brewing water, which typically has a pH value between 5.3 and 5.7, flows through this pipeline 2. In regions where the brewing water used has a comparatively high calcium content, limescale deposits form inside the pipeline 2. These deposits increase both the pressure loss within the pipeline 2 and the pH value, thus impairing the quality of the beer. For this reason, careful attention is paid to ensuring that the limescale deposits in the pipeline 2 remain within predetermined tolerances. A common procedure when the limescale buildup in the pipeline 2 becomes unacceptable is—as mentioned at the outset—to replace it with a new pipeline.This replacement is very costly, as either a parallel pipeline must be used or the system must be shut down during the replacement. Furthermore, the stainless steel pipelines 2 are very expensive, so that in addition to production downtime or reduction, considerable investment costs are incurred. These disadvantages can be eliminated by descaling / cleaning using the device 1 according to the invention.

[0032] In the illustrated embodiment, the device 1 is designed as a mobile unit and is mounted, for example, on a trailer 4 or a vehicle, so that no complex permanent installation is required. This device 1 is then connected to the pipeline 2 via a supply line 6 and a return line 8. In the case of a mobile device 1, it is preferred that the supply line 6 and the return line 8 are acid hoses, for example, with a nominal diameter of DN 75. These acid hoses are then each connected to the pipeline 2 via a suitable fitting 10, 12.

[0033] The device 1 according to the invention has a tank 14, which is preferably designed with three chambers, namely an intake chamber 16, a settling chamber 18 and a collection basin 20, which is in Fig. 1 is only indicated and is essentially presented according to Fig. 1 is located behind the intake chamber 16. The function of these three tank chambers 16, 18, 20 will be discussed in more detail below.

[0034] In a preferred embodiment, the tank has a total volume of approximately 6000 liters, with the intake chamber 16 and, optionally, the settling chamber 18 being filled with an aqueous and acidic chemical descaling / rinsing solution at the beginning of the rinsing process. When used in brewing, this solution consists of 5 parts by volume of water and 1 part by volume of "chemicals," the "chemicals" preferably being a mixture of two acids, in this case formic acid and aminosulfonic acid, wherein the mixture preferably consists of 90% formic acid and the smaller portion, preferably 10%, of aminosulfonic acid.

[0035] This descaling solution is pumped via a feed pump, in this case an acid centrifugal pump 24, connected to a pump connection 22 of the tank 14, into a pressure line 26, which can be shut off (closed) by means of a shut-off valve, hereinafter referred to as shut-off valve 28, so that in the shut-off / closed position no descaling solution can flow from the feed pump to the pipeline 2. The centrifugal pump 24 is designed to deliver a flow rate of between 30 m³ / h at a delivery head of 90 m. 3 / h up to 230 m 3The pump can deliver a flow rate of / h at a pressure between 4.0 and 9.0 bar. In other words, the centrifugal pump 24, or other hydrodynamic or hydrostatic pump, is designed with an adjustable delivery volume / pressure, whereby the delivery volume flow rate is measured by a flow meter 30 (volume flow meter) and a pressure measuring device 32. The pump can then be controlled based on these measured values ​​(see dashed line in the figure). Fig. 1).

[0036] Downstream of these measuring devices, the pressure line 26 is connected to the acid hose of the supply line 6 via a valve 34 and a connection. In the area between the measuring devices 30, 32 and the valve 34, a connection 36 is indicated, through which compressed air can be supplied. The downstream end section of the pipeline 2 is connected – as explained above – to the return line 8, which in turn is connected via a return valve 38 to a T-piece 40 of a return channel 42. This is connected via a return connection 44 to the settling chamber 18 of the tank 14, so that the descaling solution loaded with limescale and / or other impurities – as explained in more detail below – is returned to the settling chamber 18.

[0037] The further outlet of the T-piece 40 can be connected via a shut-off valve 46 to a 3-way water distribution system, which is equipped with a flushing channel 48. This channel is connected on one side to the shut-off valve 46 and on the other side, via another shut-off valve 50, to the pressure line 26. In the area between the two valves 46 and 50, the flushing channel 48 is connected via a clear water valve 52 to a clear water inlet 54, so that when the clear water valve 52 is opened, clear water flows into the flushing channel 48. From this, a branch, as shown in the illustration, is formed. Fig. 1 a branch flushing channel 56, which is connected via a third shut-off valve 58 to a connection 60, which opens into the suction chamber 16.

[0038] Further details of the device according to the invention (flushing system) will be provided with reference to Fig. Figure 2 explains, showing a top view of tank 14 and the conveying components associated with it.

[0039] As explained above, the tank 14 is divided into the intake chamber 16, the settling chamber 18 and the collection basin 20, the wall sections of which are divided into Fig. 2 are indicated by dashed lines. Accordingly, the collection basin 20 has a base area approximately half the tank's base area. The intake chamber 16, which receives fresh descaling solution at the beginning of the rinsing process, has a larger base area than the settling chamber 18, into which the loaded descaling solution is returned via the return line 8, the return valve 38, the return channel 42, and the return connection 44. In the illustrated embodiment, an end section 62 of the return channel 42 is extended beyond the return connection 44, so that this end section 62 extends into the interior of the settling chamber 18, thus creating an opening at a distance from the top surface and the walls of the tank 14 (as shown in the illustration). Fig. 2 (pointing towards the viewer). A partition wall 64 between the settling chamber 18 and the intake chamber 16 is designed as an overflow 66 (see Fig. 1) through which the descaling solution can flow / overflow into the adjacent intake chamber 16. This overflowing volume flow is subject to a very low solids load, as the solids settle out in the settling chamber 18 due to the density differences.

[0040] However, it must be taken into account that, due to the chemical reaction between the acid components and the limescale deposits on the inner circumferential wall of the pipe 2, and also due to the mechanical stress on the descaling solution as it flows through the pipe 2, an increase in volume occurs, for example through foam formation, so that the total volume of the backflowing descaling solution is greater than the volume of the inflowing descaling solution. According to the invention, this expansion caused by foam formation and other chemical reactions is compensated for by the fact that the intake chamber 16 is connected to the collection basin 20 via a further overflow 68, which, as explained, has a comparatively large volume. This overflow 68 is formed on a wall 70 that separates the collection basin 20 from the settling chamber 18 and from the intake chamber 16 and is – as shown in the illustration Fig. The first overflow 66 is removable and positioned offset from the first overflow 66, so that there is no direct fluid connection between the settling chamber 18 and the collection basin 20. The comparatively large volume of the collection basin 20 ensures that no descaling solution can flow back into the intake chamber 16 via the overflow 66. Accordingly, the foam content in the collection basin 20 is reduced, and further settling of solids / reaction products may occur at the bottom of the collection basin 20, thus supporting the effect of the settling chamber 18.

[0041] A circulation device 72 is provided for returning the descaling solution from the collection basin 20 to the suction chamber 16, via which a circulation connection 74 of the collection basin 20 can be connected to a return connection 76 of the suction chamber 16.

[0042] The circulation device 72 has a circulation line 78 connecting the two ports 74 and 76. A circulation pump 80 is arranged in this circulation line, through which the descaling / rinsing solution can be pumped from the collection basin 20 via the circulation port 74, the circulation line 78, and the return port 76 into the suction chamber 16. Upstream and downstream of the circulation pump 80 are circulation shut-off valves 82 and 84, through which the fluid connection to the circulation pump 80 can be shut off. An acid inlet valve 86 is arranged in the area between the circulation shut-off valve 84 and the circulation pump 80, through which the acidic chemical component, i.e., for example, formic acid and aminosulfonic acid, can be supplied. To determine the circulating or supplied quantity, a flow meter 88 is provided downstream of the circulation pump 80.The circulation device 72 also has a bypass line 90, via which the two connections 74 and 76 can be directly connected. A bypass shut-off valve 92 is arranged in this bypass line 90 to shut off the direct connection via the bypass line 90.

[0043] The circulation pump 80, designed for pumping acidic rinsing solutions, can, for example, be designed for a maximum flow rate of 60 l / min at a delivery head of 50 m.

[0044] For emptying the tank 14, in particular the suction chamber 16, the settling chamber 18 and the collection basin 20, the tank is also equipped with two drains 91, 93, 95, also called bottom drains, which can each be shut off via drain valves.

[0045] The device 1 according to the invention, or the rinsing system and the tank 14, are thus connected via a type of 3-way water distribution system, the function of which is described below with reference to Fig. 3 will be explained.

[0046] In the representation according to Fig. Figure 2 also shows the previously described acid centrifugal pump 24, which is connected to the supply line 6 via the valve 34. As explained, the flow rate is measured by the flow meter 30 (water meter) and the pressure measuring device 32, and the delivery volume of the centrifugal pump 24 is adjusted accordingly. The aforementioned connection 36 is located in the flow path between the centrifugal pump 24 and the valve 34, through which compressed air can be supplied at the end of the rinsing cycles. This compressed air is pressurized to 8 to 10 bar to create turbulence in the flow within the pipeline 2 and thus assist in dislodging the contaminants, especially the limescale, from the inner pipe wall.

[0047] As in Fig. As indicated in Figure 2, an intake channel 94 is provided within the intake chamber 16, which is connected to the pump connection 22, so that the descaling solution is drawn in at a distance from the pump connection 22. Similarly, a return channel 96 extends from the return connection 76 into the interior of the intake chamber 16, with the openings of the channels 94 and 96 being spaced apart to prevent direct interaction.

[0048] The inventive method for descaling or removing impurities from the pipeline 2 is briefly explained below.

[0049] Before the cleaning / rinsing process begins, tank 14 is filled with the descaling solution in the desired composition - this will be determined later based on Fig. 3c explained.

[0050] After tank 14 is filled, the centrifugal pump 24 is activated, drawing in descaling solution via the suction channel 94 and pumping it into pipe 2 via the supply line 6. As explained, the fluid flow rate is set to achieve a relatively high flow velocity within pipe 2, for example, more than 1.5 m / s at a pressure between 4 and 9 bar. This setting of the centrifugal pump 24 is achieved using the flow meter 30 and the pressure measuring device 32. The connection to the flushing channel 48 is closed off by the shut-off valves 46 and 50. Accordingly, the acidic descaling solution flows through pipe 2, so that the limescale deposits are both mechanically broken down and chemically react with the acidic components of the descaling solution.The descaling solution, laden with solids, especially limescale, is then conveyed via the return line 8 and the return channel 42 into the settling chamber 18, where the solid particles 98 settle at the bottom of the settling chamber 18. The descaling solution, now free of these solid particles 98, then flows via the overflow 66 into the intake chamber 16.

[0051] As explained above, the chemical reactions between the acidic components of the descaling solution and the limescale deposits on the inner circumferential wall of the pipe 2 result in an increase in volume in the form of foam formation. According to the invention, this foam can enter the collection basin 20 via the overflow 68, where foam formation is minimized. The descaling solution, reduced to a comparatively small foam content, is then conveyed back to the intake chamber 16 via the circulation device 72, specifically via the circulation connection 74, the circulation pump 80, the return connection 76, and the return channel 96 connected to it. During this process, the shut-off valves 82 and 84 are open, and the bypass shut-off valve 92 is closed.

[0052] By returning the chemical components of the descaling solution to the intake chamber 16, the efficiency of the process is improved - this return is comparable to a condensing boiler system in which the residual heat of the condensate is reused during combustion.

[0053] The descaling solution is then drawn from the intake chamber 16 via the intake channel 94 and the centrifugal pump 24 in the manner described above and conveyed towards the pipeline 2. This cycle is repeated several times, for example 20 times, whereby at the end of the rinsing / descaling process compressed air at a pressure of approximately 8 to 10 bar is supplied via connection 36, thus intensifying the mechanical action on the limescale deposits within the pipeline 2.

[0054] After this multitude of flushing cycles, pipe 2 is then flushed clean. This is done using Fig. 3a explained.

[0055] For this in Fig. In the rinse cycle shown in Figure 3a, the centrifugal pump 24 is switched off and the shut-off valve 28 is closed. The shut-off valves 58 and 46 in the rinse channel 48 and the branch rinse channel 56, respectively, remain in the closed or shut-off position. With the clear water valve 52 open, clear water is then supplied via the clear water inlet 54, which flows into the pipeline 2 via the open shut-off valve 50, valve 34, and the supply line 6. The pressure and fluid flow rate are measured and regulated by the flow meter 30 and the pressure measuring device 32. The loaded clear water rinse solution then flows via the return line 8, the open return valve 38, and the return connection 44 into the settling chamber 18, from where it can be discharged via the outlet 91. This rinsing process is carried out until it is ensured that pipe 2 is no longer exposed to components of the descaling solution.

[0056] In a further procedural step, according to Fig. 3b The centrifugal pump 24 and the other pipelines of the device 1 according to the invention are flushed. For this purpose, clear water is again supplied via the clear water inlet 54 and the clear water valve 52, whereby this clear water is then guided via the flushing channel 48 and the open shut-off valve 58 and the connection 60 into the suction chamber 16. From this, the centrifugal pump 24 then pumps clear water via the pump connection 22 and the open valves 28, 34 into the supply line 6 and thus into the pipeline 2. From this, the "clear water" loaded with components of the descaling solution then flows back via the return line 8, the return valve 38 and the return connection 44 into the settling chamber 18 and out of the tank via the open outlet 91. The shut-off valve 46 in the flushing channel 48 is closed during this process.

[0057] This flushing process is carried out until it is ensured that the pipelines and the centrifugal pump 24 are clean, during which time the clear water can also flow into the collection basin 20 via the return channel 96 and the open bypass line 90, and then out via the drain 93. The shut-off valves 82 and 84 are closed, thus interrupting the connection to the circulation pump 80.

[0058] As explained above, the chemical components, i.e., the formic acid and the aminosulfonic acid, are supplied via the acid inlet with the acid inlet valve 86 by means of the circulation pump 80, whereby the supplied volume is monitored and controlled by the flow meter 88. This "chemical" is then conveyed into the intake chamber 16. As in Fig.As shown in Figure 3c, the clear water is supplied to the rinse channel 48 via the clear water inlet 54 and the clear water valve 52 before the start of the descaling process. During filling, the shut-off valves 28, 58 and 38 are closed, so that the clear water is pumped via the rinse channel 48 and the return connection 44 into the settling chamber 18 and then flows back via the overflow 66 into the intake chamber 16, where the clear water is "mixed" with the chemicals.

[0059] The centrifugal pump 24 and, in principle, also the circulation pump 80 can be operated in an internal circuit via the 3-way water distribution system described above, in order to vent and cool them.

[0060] The device and method according to the invention enable reliable descaling / cleaning / flushing of industrial pipelines with very little equipment and process engineering effort and is therefore superior to previously known solutions in terms of efficiency and investment costs.

[0061] Disclosed are a method and a device for descaling / cleaning / rinsing fluid-carrying or fluid-receiving equipment, in particular industrial pipelines. Reference symbol list: 1 Device 2 Pipeline 4 trailers 6 preliminary run 8 Return 10 Fitting 12 fittings 14 Tank 16 Intake chamber 18 Settling chamber 20 collection basins 22 Pump connection 24 centrifugal pump 26 Pressure line 28 shut-off valve 30 Flow meter 32 Pressure measuring device 34 valve 36 connection 38 Return valve 40 T-piece 42 Return channel 44 Return connection 46 shut-off valve 48 Flushing channel 50 additional shut-off valves 52 Clear water valve 54 Clear water inlet 56 Branch flushing channel 58 third shut-off valve 60 connection 62 Final section 64 Partition wall 66 Overflow 68 Overflow 70 wall 72 Circulation device 74 Circulation connection 76 Return port 78 Circulation line 80 Circulation pump 82 Circulation shut-off valve 84 Circulation shut-off valve 86 Acid inlet valve 88 flow meters 90 Bypass line 91 Procedure 92 Bypass shut-off valve 93 Procedure 94 Intake manifold 95 Expiry 96 Feedback channel 98% solids content

Claims

[1] Method for descaling fluid-carrying or fluid-receiving equipment, in particular industrial pipelines (2), preferably with a nominal diameter between DN 50 and DN 250, wherein an acidic rinsing or descaling solution contained in a tank arrangement is supplied to the equipment under pressure via a supply line (6) and is returned to the tank arrangement via a downstream return line (8), wherein the tank arrangement has a suction chamber (16) from which the descaling solution is pumped to the supply line (6) by means of a feed pump, in particular a centrifugal pump (24), and wherein the return line (8) opens into a settling chamber (18) of the tank arrangement, which is in fluid communication with the suction chamber (16), wherein a delivery volume flow rate of the feed pump (24) is selected such that a flow velocity of more than 1.0 m / s, preferably with more than 1.5 m / s and wherein the settling chamber (18) is in fluid communication with a collection basin (20) in which proportions of the backflowing descaling solution resulting from an increase in volume, in particular from foam formation, are absorbed and returned from this to the intake chamber (16). [2] Method according to claim 1, wherein the fluid connection is formed by an overflow (66). [3] Method according to any of the preceding claims, wherein the descaling solution has a pH value between 0.5 and 4.

0. [4] Method according to one of the preceding claims, wherein the pressure in the device is more than 3 bar, in particular between 4 and 9 bar. [5] Method according to one of the preceding claims, wherein the descaling solution is circulated several times and compressed air, preferably with a pressure of more than 5 bar, in particular between 8 and 10 bar, is supplied downstream of the feed pump (24) at the end of the circulation cycles. [6] Method according to one of the preceding claims, wherein the descaling solution consists of a mixture of about 5 volume parts water and about one volume part chemical, wherein the chemical is preferably a mixture of formic acid and aminosulfonic acid, wherein the volume part of formic acid is more than 70%, preferably about 90%. [7] Device for descaling fluid-carrying or -receiving equipment, preferably industrial pipelines (2), in particular for carrying out the method according to one of the preceding claims, with a tank arrangement comprising an intake chamber (16) and a settling chamber (18) which are in fluid communication with each other, wherein at least in the intake chamber (16) an acidic rinsing or descaling solution is received, which can be conveyed via a feed pump, in particular a centrifugal pump (24) connected to a pump connection (22), into a feed line (6) connected to the device, wherein a return line (8) is provided downstream of the device to be descaled, which opens into the settling chamber (18), wherein the feed pump (24) is designed to deliver descaling solution at a flow rate of more than 1 m / s, in particular more than 1.to convey 5 m / s through the device, and wherein the tank arrangement has a collection basin (20) which is in fluid communication with the settling chamber (18) such that portions of the backflowing descaling solution resulting from an increase in volume, in particular from foam formation, are absorbed and can be returned from this to the intake chamber (16) by means of a circulation pump (80) or the like. [8] Device according to claim 7, wherein an overflow (66, 68) is formed between the settling chamber (18) and the intake chamber (16) and / or between the intake chamber (16) and the collection basin (20), wherein preferably the intake chamber (16), the settling chamber (18) and the collection basin (20) are integrated into a tank (14). [9] Device according to one of claims 7 or 8, comprising a compressed air connection (36) arranged in the inlet to the device to be cleaned and / or an acid connection and / or a clear water inlet (54) that can be connected to a circulation pump (80) via a valve arrangement. [10] Device according to one of claims 7 to 9, wherein it is mounted as a mobile unit, for example on a trailer (4) or a vehicle.

Images