Three-dimensional pickling method for top-discharge tank containers

Abstract

This invention provides a three-dimensional pickling method for top-discharge tank containers, comprising the following steps: S1: pre-coating the blind area of ​​the top-discharge tank container; S2: installing a siphon assembly at the top discharge flange of the top-discharge tank container; S3: rinsing and degreasing the interior of the top-discharge tank container with water; S4: installing a three-dimensional rotating acid spraying assembly to pickle the top-discharge tank container, creating a pressure difference within the tank to discharge the liquid accumulated at the bottom through the siphon assembly, and removing the three-dimensional rotating acid spraying assembly after pickling; S5: washing the top-discharge tank container with water, with the cleaning water discharged from the siphon assembly; S6: removing the siphon assembly. This invention's three-dimensional pickling method for top-discharge tank containers, through top-mounted siphon assembly drainage and three-dimensional acid spraying circulation, specifically solves the problems of lack of bottom discharge port for acid drainage in top-discharge tank containers and the low efficiency of traditional tumbling washing.

Description

Technical Field

[0001] This invention relates to the field of tank container passivation technology, and in particular to a three-dimensional pickling method for top-discharge tank containers. Background Technology

[0002] Tank containers, as standardized mobile pressure vessels, are widely used in chemical, logistics, and other fields. The corrosion resistance of their inner walls directly determines the service life and transportation safety of the equipment. Currently, the industry mainly uses the traditional tumbling method for pickling and passivation treatment of the inner walls of tank containers. This involves pouring a fixed amount of stainless steel pickling and passivation solution into the tank, then rotating the entire tank 360°, relying on centrifugal force to wet and clean the inner walls of the tank.

[0003] However, this traditional tumbling method has significant technical drawbacks:

[0004] Firstly, the operation is extremely inefficient and the quality is unstable. The tumble washing method relies on the rotation of the tank to drive the flow of acid, resulting in poor contact efficiency between the acid and the inner wall of the tank. The cleaning time is more than 2 hours. Especially in the low temperature environment of winter, the acid can only be heated by the external tank. As the tank rotation time is extended, the temperature of the acid inside the tank will drop rapidly. This not only leads to incomplete pickling and passivation chemical reactions and prolongs the operation time, but also easily causes defects such as acid drips and spots on the inner wall of the tank, which seriously affects the pickling quality. Secondly, the lack of structural adaptability prevents effective drainage. For top-discharge tank containers, which lack bottom discharge ports, traditional tumbling washing methods lack suitable drainage structures. After pickling, the acid is difficult to completely drain, and the residual acid will continue to corrode the inner wall of the tank, causing secondary damage.

[0005] In view of this, it is necessary to improve the existing pickling method for top-discharge tank containers in order to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a three-dimensional pickling method for top-discharge tank containers, so as to solve the problems of poor quality of existing pickling methods and difficulty in draining liquid from top-discharge tank containers.

[0007] To achieve the above objectives, the present invention provides a three-dimensional pickling method for top-discharge tank containers, comprising the following steps: S1: Pre-coat the blind area of ​​the top discharge tank container. The blind area includes all flange welds in the 180° semicircular area of ​​the top discharge flange facing away from the three-dimensional rotating acid spraying assembly, as well as the 360° full circumference welds on the inner side of the manhole flange. The coating range is to cover the welds and the base material within 10mm on both sides. S2: Install a siphon assembly at the top discharge flange on the top discharge tank container; the siphon assembly includes a fixed-length pipe, a fixed flange that surrounds the fixed-length pipe, an external adapter at one end of the fixed-length pipe, and a length adjustment pipe at the other end of the fixed-length pipe. The length adjustment pipe is detachably connected to the fixed-length pipe. When the siphon assembly is installed, the fixed flange is fixedly connected to the top discharge flange; the length of the length adjustment pipe is adjusted according to the volume of the top discharge tank container. After the siphon assembly is installed, the bottom of the length adjustment pipe is 10mm-20mm away from the bottom of the top discharge tank container. S3: Install a three-dimensional rotating water spray assembly to flush and degrease the inside of the top-discharge tank container and create a pressure difference inside the tank, causing the liquid accumulated at the bottom to be discharged through the siphon assembly. After the water flushing is completed, remove the three-dimensional rotating water spray assembly. S4: Install the three-dimensional rotating acid spraying assembly to pickle the top-discharge tank container and create a pressure difference inside the tank so that the liquid accumulated at the bottom is discharged through the siphon assembly. After pickling is completed, remove the three-dimensional rotating acid spraying assembly. S5: The top-discharge tank container is washed with water, and the washing water is discharged from the siphon assembly; S6: Remove the siphon assembly.

[0008] As a further improvement of the present invention, the length adjustment tube is a PTFE connecting tube.

[0009] As a further improvement of the present invention, the top-discharge tank container has a manhole, and step S2 further includes installing a flat manhole adapter flange at the manhole, installing a flushing tool manhole cover; and / or installing blind covers at the remaining interfaces of the top-discharge tank container.

[0010] As a further improvement of the present invention, the rinsing time in step S3 is 5 min to 10 min, the rinsing water temperature is 35 to 60°C, and the water pressure is 25 bar.

[0011] As a further improvement of the present invention, in step S4, before pickling the top-discharge tank container, the top-discharge tank container is pressurized to discharge the rinsing water from step S3 from the siphon assembly.

[0012] As a further improvement of the present invention, the pickling step in step S4 includes: S41: the three-dimensional rotating acid spraying assembly sprays passivating acid into the top discharge tank container, and the acid is discharged from the siphon assembly; S42: the three-dimensional rotating acid spraying assembly sprays water into the top discharge tank container, and the water is discharged from the siphon assembly; S43: the acid mist is sucked out from the siphon assembly by the suction device.

[0013] As a further improvement of the present invention, in step S41, the acid spraying time is 8 min to 20 min, the temperature is 62℃ to 72℃, and the pressure inside the tank is 6 bar; and / or in step S42, the rinsing time is 1 min to 3 min, the temperature is 35℃ to 60℃, and the pressure inside the tank is 5.8 bar; and / or in step S43, the adsorption time is 2 min to 6 min.

[0014] As a further improvement of the present invention, the water washing step of step S5 includes S51: spraying hot water at 35°C-60°C into the top discharge tank container through the water washing nozzle; S52: spraying cold water at a temperature lower than the hot water in step S51 into the top discharge tank container through the water washing nozzle and pressurizing the top discharge tank container to discharge the water from the siphon assembly.

[0015] The beneficial effects of the present invention are as follows: The three-dimensional pickling method for top-discharge tank containers of the present invention solves the problems of the lack of bottom discharge port for acid discharge and the low efficiency of traditional tumbling washing by using a top-mounted siphon pipe assembly for liquid drainage and three-dimensional acid spraying circulation. It achieves three-dimensional all-round pickling without dead angles and more uniform hot acid circulation reaction. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart of the three-dimensional pickling method for top-discharge tank containers of the present invention; Figure 2 This is a diagram showing the flow direction of the container during the three-dimensional pickling process of the top-discharge tank container according to the present invention. Figure 3 This is a front sectional view of the top-discharge tank container during the three-dimensional pickling method of the top-discharge tank container of the present invention. Figure 4 This is a schematic diagram of the siphon assembly used in the three-dimensional pickling method for top-discharge tank containers of the present invention.

[0017] Reference numerals: 100, Top-discharge tank container; 1, Siphon assembly; 11, Fixed-length pipe; 12, Fixed flange; 13, External adapter; 14, Length adjustment pipe; 2, Top-discharge flange; 3, Three-dimensional rotating acid spray assembly; 31, Nozzle; 4, Manhole flange. Detailed Implementation

[0018] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] like Figures 1 to 4 As shown, the three-dimensional pickling method for a top-discharge tank container 100 of the present invention includes the following steps: S1: Pre-coating is performed on the spraying blind areas of the top-discharge tank container 100; the spraying blind areas are pre-coated to eliminate local pickling blind areas, ensuring that the entire inner wall of the top-discharge tank container 100 is pickled and passivated without omission, solving the pain points of blind area omission and local anti-corrosion failure caused by traditional roller washing. In this embodiment, passivation paste is used for coating.

[0022] In the pickling process of tank containers, the coverage of the spray system has physical limitations, making it difficult for acid to evenly reach all weld areas inside the tank, creating pickling "spray dead zones." If these dead zone welds are not effectively protected, insufficient pickling or acid residue can lead to defects such as pitting and unpickled flange welds in subsequent processes, directly affecting the tank's corrosion resistance and service life. To compensate for the coverage blind spots of the standard container pre-coating process and ensure the pickling protection effect of all critical welds inside the tank, a targeted local pre-coating protection process is applied to the flange welds facing away from the spray head.

[0023] S2: Install a siphon assembly 1 at the top discharge flange 2 on the top discharge tank container 100; to address the structural defect of the top discharge tank container 100 lacking a bottom discharge port, establish a top-mounted drainage channel to achieve stable collection and discharge of pickling solution and cleaning water, providing the necessary process conditions for three-dimensional circulating pickling. In this embodiment, the siphon assembly 1 protrudes into the tank body near the bottom, and the liquid inside the tank is discharged from the siphon assembly 1 under high pressure. This process is completed at one location.

[0024] S3: The interior of the top-discharge tank container 100 is degreased by water rinsing; water rinsing effectively removes oil, impurities, and oxide scale precursors from the inner wall of the tank, providing a clean base for subsequent pickling, improving the reaction efficiency between the acid and the metal surface, reducing acid consumption and by-product residue, and lowering the risk of pickling defects. This process is completed at position two.

[0025] S4: Install the three-dimensional rotating acid spraying assembly 3 to perform acid washing on the top-discharge tank container 100, creating a pressure difference within the tank. This causes the liquid accumulated at the bottom to be discharged through the siphon assembly 1. After acid washing, remove the three-dimensional rotating acid spraying assembly 3. In this embodiment, the three-dimensional rotating acid spraying assembly 3 is a three-dimensional acid spraying system. Its core is to use a three-dimensional nozzle 31 that can rotate 360° to spray hot acid washing liquid into the tank, achieving efficient acid washing and passivation within the tank. The combination of three-dimensional acid spraying and top-mounted acid discharge significantly improves the reaction rate and uniformity. The acid liquid is sprayed and discharged simultaneously, avoiding concentration decay and excessive local reaction, resulting in a significant improvement in work efficiency, approximately 10 minutes per tank. Simultaneously, it achieves a high-quality appearance with no color difference, no boundary lines, and uniform whitening. This process is completed at three locations on the tank.

[0026] S5: The top-discharge tank container 100 is washed with water, and the washing water is discharged from the siphon assembly 1. The siphon assembly 1 is used to quickly drain the washing water, achieving thorough removal of acid and impurities, avoiding secondary corrosion of the tank body by residual acid. At the same time, the circulating flushing improves the cleanliness, providing a safe and clean tank environment for subsequent processes. This process requires two cleanings, completed at positions four and five respectively.

[0027] S6: Remove siphon assembly 1. After completing the operation, dismantle the tooling in an orderly manner, restore the tank to its original state, and ensure a closed-loop process that can be standardized to guarantee production line cycle time and operational safety, while facilitating subsequent process connections and equipment maintenance.

[0028] The spraying blind zone in step S1 includes the area of ​​the top discharge flange 2 facing away from the three-dimensional rotating acid spraying assembly 3, as well as the weld of the manhole flange 4. More specifically, it includes the flange weld within the 180° area of ​​the top discharge flange 2 facing away from the three-dimensional rotating acid spraying assembly 3, the 360° circumferential weld of the manhole flange 4 (flat flange type manhole) inside the tank, and areas that cannot be directly covered by the three-dimensional acid spraying due to obstruction by the tank structure and the limited spray angle of the nozzle 31. These areas are typical pickling blind zones because the acid cannot be directly sprayed due to obstruction by the siphon assembly 1 and the flange structure itself. Pre-coating protection is necessary to avoid weld corrosion and oxide scale residue. After spraying, defects such as missed coating, runs, and bubbles should be eliminated.

[0029] By pre-coating the aforementioned natural spray blind areas, the defect that the three-dimensional nozzle 31 cannot directly spray into the area can be compensated, ensuring that key parts such as welds are fully pickled and passivated, eliminating pickling dead corners, avoiding local anti-corrosion failure, and making the overall pickling quality of the inner wall of the tank uniform and consistent, meeting the anti-corrosion and appearance requirements of high-end tank boxes.

[0030] It should be noted that the three-dimensional rotating acid spraying assembly 3 is installed at the manhole, so the direction facing away from the three-dimensional rotating acid spraying assembly 3 is fixed.

[0031] The siphon tube assembly 1 includes a fixed length tube 11, a fixed flange 12 that is fixedly surrounding the fixed length tube 11, an external adapter 13 disposed at one end of the fixed length tube 11, and a length adjusting tube 14 disposed at the other end of the fixed length tube 11. The length adjusting tube 14 is detachably connected to the fixed length tube 11. In step S2, when the siphon tube assembly 1 is installed, the fixed flange 12 is fixedly connected to the top discharge flange 2.

[0032] The top discharge flange 2 is sealed and connected to the fixed flange 12, enabling rapid sealing of the top discharge channel and adapting to the structure of the top discharge tank container 100 without a bottom discharge port. The fixed-length pipe 11 is fixedly connected to the fixed flange 12, thus adapting to tank containers of various sizes.

[0033] The external adapter 13 can be flexibly connected to acid storage tanks, sewage treatment tanks and acid mist spraying towers through a multi-way valve to achieve multi-path circulation and treatment.

[0034] The length adjustment tube 14 can be selected according to the size of the tank, avoiding the problem of it being too short to achieve the effect of sucking the acid from the bottom or too long to come into contact with the bottom of the tank and cause blockage.

[0035] The length of the length adjustment pipe 14 is adjusted according to the volume of the top discharge tank container 100. In step S2, after the siphon pipe assembly 1 is installed, the bottom of the length adjustment pipe 14 is 10mm-20mm away from the bottom of the top discharge tank container 100.

[0036] The gap control is based on fluid dynamics calculations: the siphon has a specification of φ48mm, its internal liquid flow diameter is 44mm, and the flow cross-sectional area is S=πr. 2 =3.1416×22 2 =1520mm 2 If the bottom of the tank is taken as the reference, the equivalent liquid flow height h=S / (2πr)=1520 / 44 / 3.1416≈11mm. Therefore, the gap of 10mm-20mm can perfectly match the effective flow section of the siphon pipe, forming a stable annular liquid inlet channel and ensuring the liquid discharge efficiency. If the bottom of the length adjustment pipe 14 is too far from the bottom of the top discharge tank container 100, there will be more liquid accumulation at the bottom of the tank, and the passivation degree of the liquid accumulation area will be too high, eventually leading to excessive passivation, large color difference, obvious boundary line and other defects.

[0037] The length adjustment pipe 14 is a PTFE connecting pipe. PTFE (polytetrafluoroethylene) is chemically extremely stable, resistant to the strong corrosion of pickling and passivation solutions, and shows no aging or leaching even after long-term use, ensuring the reliability and service life of the drainage pipeline. PTFE material has low hardness and a smooth surface, preventing scratches on the inner wall of the tank, making it particularly suitable for high-precision tanks requiring lining, without affecting the subsequent processing accuracy and structural integrity of the tank. The non-stick surface of PTFE prevents acid and impurities from adhering, avoiding pipe blockage and facilitating cleaning and maintenance, thus reducing production line maintenance costs. The length can be flexibly customized according to the tank volume, perfectly matching the 10-20mm tank bottom clearance requirements, and is compatible with different specifications of top-discharge tank containers.

[0038] The top-discharge tank container 100 has a manhole. Step S2 also includes installing a flat manhole adapter flange and a flushing fixture manhole cover at the manhole. It should be noted that if the tank uses a standard flanged manhole, a flat manhole adapter flange is not required. The sealing gasket used for the flat manhole adapter flange is a self-made neoprene rubber gasket. Both the flat manhole adapter flange and the tank body flange must be installed. If the number of bolts is less than eight due to changes in the hole position and spacing, installation is prohibited. When tightening the bolts, first tighten them diagonally, and then tighten them circumferentially to ensure a tight seal.

[0039] The procedure for installing the flushing fixture manhole cover is as follows: Place the flushing fixture manhole cover onto the flat manhole adapter flange and tighten it using tooling wing bolts. Ensure that at least four wing bolts are installed, and that they are installed diagonally in a cross pattern and tightened diagonally to ensure a tight seal.

[0040] Install blind covers at the remaining interfaces of the top-discharge tank container 100. Install blind covers at the remaining interfaces according to the general process. The number of fasteners used for each interface shall not be less than 4 sets to ensure sealing.

[0041] In step S3, the water rinsing and degreasing of the inside of the top-discharge tank container is completed by installing a three-dimensional rotating water spray assembly at position two. The rinsing time is 5-10 minutes, the rinsing water temperature is 35-60℃, and the water pressure is 25 bar. Under these parameters, the degreasing and cleaning inside the tank can be completed efficiently, providing a clean base for subsequent pickling, while maintaining the tank temperature and compressing the process time, thus balancing pickling quality and production line efficiency.

[0042] In step S4, before pickling the top-discharge tank container 100, the container is pressurized to discharge the rinsing water from step S3 through the siphon assembly 1. By pressurizing the tank before pickling in step S4, the residual rinsing water from step S3 is quickly and thoroughly discharged through the siphon assembly 1. This prevents cold water from mixing with the subsequent hot pickling solution, which could cause a sudden drop in acid temperature and dilution of concentration, ensuring the reactivity and concentration stability of the hot acid and significantly improving pickling efficiency and passivation effect. Simultaneously, it completely empties the water from the tank, eliminating defects such as drips and spots caused by acid residue and water dilution, ensuring uniform pickling quality. Furthermore, the rapid pressurization and drainage speed perfectly matches the high-efficiency production line cycle of three-dimensional pickling.

[0043] The pickling step in step S4 includes: S41: The three-dimensional rotating acid spraying assembly 3 sprays passivating acid into the top-discharge tank container 100, and the acid is discharged from the siphon assembly 1; the three-dimensional rotating nozzle 31 achieves 360° spraying without dead angles, and with the hot acid circulation, the pickling efficiency is increased by more than 10 times, and a single tank only needs about 10 minutes, which is perfectly matched with the production line cycle. At this time, both the siphon assembly 1 and the nozzle 31 are connected to the acid storage tank, and the acid is sprayed and circulated back through the siphon assembly 1. The acid concentration in the tank is stable throughout the process, and the pickling quality of each tank is consistent and is not affected by the operation time.

[0044] S42: The three-dimensional rotating acid spraying component 3 sprays water into the top-discharge tank container 100, and the water is discharged from the siphon component 1. The high-pressure water quickly flushes away residual acid and impurities from the tank wall, paving the way for subsequent deep washing and shortening the overall process time. The flushing water is simultaneously discharged through the siphon component 1 to prevent water accumulation inside the tank from diluting the residual acid, preventing excessive local corrosion, and ensuring the safety of the tank. Here, the siphon component 1 is connected to a wastewater treatment plant, where acidic wastewater is discharged for further treatment.

[0045] S43: Acid mist is extracted from siphon assembly 1 using a suction device. The suction device is a ventilation system used to draw the yellow fumes produced by the chemical reaction to the spray tower for treatment. This thoroughly removes residual acid mist from the tank, eliminates the risk of acid mist leakage, significantly improves operational safety, and complies with environmental and occupational health regulations. Negative pressure suction can simultaneously remove trace amounts of residual liquid from the tank, achieving dry emptying of the tank and preventing secondary corrosion caused by acid mist condensation.

[0046] The pickling process in this embodiment not only significantly improves pickling efficiency and quality through hot acid circulation, but also completely solves the drainage problem of the lack of a bottom outlet through siphon drainage, while ensuring operational safety and environmental compliance through acid mist adsorption, thus constructing a complete and efficient pickling solution.

[0047] In step S41, the acid spraying time is 8-20 minutes, the temperature is 62℃-72℃, and the pressure inside the tank is 6 bar. This ensures that the hot acid reacts fully and achieves efficient pickling and passivation without dead angles, while also precisely matching the production line cycle and avoiding excessive corrosion.

[0048] In step S42, the rinsing time is 1 min to 3 min, the temperature is 35℃ to 60℃, and the pressure inside the tank is 5.8 bar. This quickly removes residual acid from the tank wall, connects the pickling process with subsequent steps, and ensures the safety of the tank.

[0049] In step S43, the adsorption time is 2-6 minutes. This duration allows for the complete removal of residual acid mist from the tank, eliminating the risk of leakage.

[0050] The water washing step S5 includes S51: spraying hot water at 35℃-60℃ into the top discharge tank container 100 through the water washing nozzle 31; S52: spraying cold water at a temperature lower than the hot water in step S51 into the top discharge tank container 100 through the water washing nozzle 31 and pressurizing the top discharge tank container 100 to discharge the water from the siphon assembly 1. The water washing step is completed by installing three-dimensional rotating water spray assemblies at positions four and five.

[0051] Step S5 employs a two-stage water washing process: first, hot water rinsing, followed by pressurized cold water rinsing. First, hot water at 35℃-60℃ dilutes residual acid and acid mist, improving cleanliness and rapidly lowering the pH value. Then, pressurized cold water is used for rinsing, rapidly cooling the tank and stabilizing the pH value to neutral (approximately 7). This ensures no acid residue remains in the tank, preventing corrosion, and quickly achieving safe operating conditions, facilitating direct entry for personnel at the next work station. Hot water rinsing is completed at four locations on the tank, while cold water rinsing is completed at five locations.

[0052] In addition, preferably, the water rinsing degreasing in step S3 and the water washing in step S5 both require the use of the three-dimensional nozzle 31, so the three-dimensional nozzle 31 needs to be installed in each of the corresponding steps. Of course, in some embodiments, the three-dimensional rotating acid spraying assembly 3 can also be installed on the top discharge tank container 100 before step S3, and water spraying or acid spraying can be achieved by connecting different connectors.

[0053] The three-dimensional pickling method for top-discharge tank containers 100 of the present invention addresses the problems of the lack of bottom outlet for acid discharge in top-discharge tank containers 100 and the low efficiency of traditional tumbling washing by using a top-mounted siphon assembly 1 for liquid drainage and three-dimensional acid spraying circulation. It achieves three-dimensional all-round pickling without dead angles, more uniform hot acid circulation reaction, and only about 10 minutes per tank, improving efficiency by more than 10 times. It can be adapted to the batch standardized production of top-discharge tanks of various specifications, significantly improving pickling quality, capacity and safety, and meeting the stringent anti-corrosion and appearance requirements of high-end tank containers.

[0054] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A three-dimensional pickling method for top-discharge tank containers, characterized in that: Includes the following steps: S1: Pre-coat the blind area of ​​the top discharge tank container. The blind area includes all flange welds in the 180° semicircular area of ​​the top discharge flange facing away from the three-dimensional rotating acid spraying assembly, as well as the 360° full circumference welds on the inner side of the manhole flange. The coating range is to cover the welds and the base material within 10mm on both sides. S2: Install a siphon assembly at the top discharge flange on the top discharge tank container; the siphon assembly includes a fixed-length pipe, a fixed flange that surrounds the fixed-length pipe, an external adapter at one end of the fixed-length pipe, and a length adjustment pipe at the other end of the fixed-length pipe. The length adjustment pipe is detachably connected to the fixed-length pipe. When the siphon assembly is installed, the fixed flange is fixedly connected to the top discharge flange; the length of the length adjustment pipe is adjusted according to the volume of the top discharge tank container. After the siphon assembly is installed, the bottom of the length adjustment pipe is 10mm-20mm away from the bottom of the top discharge tank container. S3: Install a three-dimensional rotating water spray assembly to flush and degrease the inside of the top-discharge tank container and create a pressure difference inside the tank, causing the liquid accumulated at the bottom to be discharged through the siphon assembly. After the water flushing is completed, remove the three-dimensional rotating water spray assembly. S4: Install the three-dimensional rotating acid spraying assembly to pickle the top-discharge tank container and create a pressure difference inside the tank so that the liquid accumulated at the bottom is discharged through the siphon assembly. After pickling is completed, remove the three-dimensional rotating acid spraying assembly. S5: The top-discharge tank container is washed with water, and the washing water is discharged from the siphon assembly; S6: Remove the siphon assembly.

2. The three-dimensional pickling method for top-discharge tank containers according to claim 1, characterized in that: The length adjustment pipe is a PTFE connecting pipe.

3. The three-dimensional pickling method for top-discharge tank containers according to claim 1, characterized in that: The top-discharge tank container has a manhole, and step S2 further includes installing a flat manhole adapter flange at the manhole, installing a flushing tool manhole cover; and / or installing blind covers at the remaining interfaces of the top-discharge tank container.

4. The three-dimensional pickling method for top-discharge tank containers according to claim 1, characterized in that: In step S3, the rinsing time is 5-10 minutes, the rinsing water temperature is 35-60℃, and the water pressure is 25 bar.

5. The three-dimensional pickling method for top-discharge tank containers according to claim 1, characterized in that: In step S4, before pickling the top-discharge tank container, the container is pressurized to discharge the rinsing water from step S3 from the siphon assembly.

6. The three-dimensional pickling method for top-discharge tank containers according to claim 1, characterized in that: The pickling step in step S4 includes: S41: The three-dimensional rotating acid spraying assembly sprays passivating acid into the top-discharge tank container, and the acid is discharged from the siphon assembly; S42: The three-dimensional rotating acid spraying assembly sprays water into the top-discharge tank container, and the water is discharged from the siphon assembly; S43: Acid mist is sucked out from the siphon assembly by a suction device.

7. The three-dimensional pickling method for top-discharge tank containers according to claim 6, characterized in that: In step S41, the acid spraying time is 8 min–20 min, the temperature is 62℃–72℃, and the pressure inside the tank is 6 bar; and / or in step S42, the rinsing time is 1 min–3 min, the temperature is 35℃–60℃, and the pressure inside the tank is 5.8 bar; and / or in step S43, the adsorption time is 2 min–6 min.

8. The three-dimensional pickling method for top-discharge tank containers according to claim 1, characterized in that: The water washing step in step S5 includes S51: spraying hot water at 35℃-60℃ into the top discharge tank container through the water washing nozzle; S52: spraying cold water at a temperature lower than the hot water in step S51 into the top discharge tank container through the water washing nozzle and pressurizing the top discharge tank container to discharge the water from the siphon assembly.

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