Method for coating inner wall of long-length aluminum alloy thin-wall storage tank with fusion-bonded epoxy heavy-duty anti-corrosion coating

Abstract

The present invention provides a method for coating the inner wall of a long-length aluminum alloy thin-walled storage tank with a sintered epoxy heavy-duty anti-corrosion coating, comprising: S1, arranging a silicone heating belt on the outer wall of the storage tank, turning on the silicone heating belt to heat the storage tank, and keeping the temperature for a first process time after reaching the temperature; S2, moving a spray gun in a unidirectional linear motion along the central axis of the storage tank, and rotating the nozzle of the spray gun with the central axis of the storage tank as the rotation center axis, to coat the inner wall of the storage tank with a low-temperature curing sintered epoxy heavy-duty anti-corrosion coating; S3, maintaining the heating state of the storage tank by the silicone heating belt in step S1, and keeping the temperature for a second process time; the present invention improves the sintering quality of the sintered epoxy heavy-duty anti-corrosion coating and the aluminum alloy thin-walled storage tank, the coating thickening efficiency, and also improves the safety of the coating process, and greatly simplifies the inner wall coating process flow and related operations, thereby reducing the coating process cost.

Description

Technical Field

[0001] The invention relates to the field of preparation technology of heavy-duty anti-corrosion coating on the inner surface of a storage tank, and in particular to a method for coating the inner wall of a long-length aluminum alloy thin-wall storage tank with a sintered epoxy heavy-duty anti-corrosion coating. Background Art

[0002] Aluminum alloy has the characteristics of low density and high specific strength, and is often used as a storage tank for liquid fuel, chemical reagents, etc. However, when storing highly corrosive solutions, it is necessary to coat the inner wall with a certain thickness of heavy-duty anti-corrosion coating such as fused epoxy. The molten coating of the inner wall is a very important process, which directly affects the quality of the cured film between the heavy-duty anti-corrosion coating and the metal substrate after coating. The quality of the cured film is an important factor affecting the service life of the heavy-duty anti-corrosion coating.

[0003] Existing fusion-bonded epoxy heavy-duty corrosion-resistant coating technology involves applying a single-component, heat-curing, modified epoxy powder coating to the workpiece surface to be coated, allowing it to fuse and solidify into a film, forming a uniformly thick, smooth, heavy-duty corrosion-resistant coating. The existing fusion-bonded epoxy coating process typically involves preheating the workpiece in an oven. After preheating, the workpiece is removed from the oven and an electrostatic spray gun is used to apply the fusion-bonded epoxy coating to the surface to be coated. Finally, the coated workpiece is placed in an oven for heating and curing.

[0004] However, for long (about 3 meters) aluminum alloy thin-walled tanks, due to their large size, if the inner wall is treated according to the existing coating process of fusion-bonded epoxy anti-corrosion coating, the following problems will arise:

[0005] (1) After a long aluminum alloy thin-walled tank is placed in an oven and preheated to a certain temperature, it is taken out of the heating oven. On the one hand, the tank cools naturally, and on the other hand, the long time of powder feeding and spraying air flow during the electrostatic spraying process cools the tank. This will cause the temperature of the inner wall of the aluminum alloy thin-walled tank to drop rapidly, especially the inner wall to be sprayed that is far away from the initial spraying position. This makes it difficult for at least part of the tank inner wall to meet the requirements of high-quality film formation and efficient thickening. At the same time, the existing technology also makes it difficult to ensure the uniformity of the coating.

[0006] (2) After the long aluminum alloy thin-walled tank is coated, during the process of transferring it into the oven, due to its large size, the transfer time is often long, which can easily lead to the failure of the fused epoxy coating curing, poor leveling effect and curing quality.

[0007] (3) During the coating process of aluminum alloy thin-walled tanks, the ovens and transfer equipment required for preheating and curing are large in size, the heating cost is high, and the transfer requires a large number of supporting resources, resulting in high overall costs. It is not suitable for scientific research trial production or small-batch production.

[0008] (4) When using electrostatic spraying technology to prepare thick anti-corrosion coatings, due to the high-voltage electrostatic effect, breakdown sparks are easily generated, which may cause quality defects in the coating layer at the least and fire during the coating process at the worst. Summary of the Invention

[0009] In view of this, the present invention aims to propose a method for coating the inner wall of a long-length aluminum alloy thin-walled storage tank with a fused epoxy heavy-duty anti-corrosion coating. The method aims to solve the problems existing in the prior art of coating the inner wall of a long-length aluminum alloy thin-walled storage tank with a fused epoxy anti-corrosion coating, such as poor coating quality caused by tank cooling, poor coating uniformity, coating quality defects and safety hazards caused by high-voltage electrostatic coating, and poor leveling effect and curing quality caused by long tank transfer time.

[0010] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0011] A method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fused epoxy heavy-duty anti-corrosion coating, comprising: S1, online preheating: arranging a silicone heating belt on the outer wall of the tank so that the silicone heating belt covers and adheres to the outer wall surface of the tank; turning on the silicone heating belt to heat the tank, and keeping it warm for a first process time after reaching temperature; S2, rotary atomization spraying: moving a spray gun in a unidirectional linear motion along the central axis of the tank, and rotating the nozzle of the spray gun with the central axis of the tank as the rotation center axis to coat the inner wall of the tank with a low-temperature curing fused epoxy heavy-duty anti-corrosion coating; S3, in-situ thermal curing: maintaining the heating state of the tank with the silicone heating belt in step S1, keeping it warm for a second process time, and completing the coating of the fused epoxy heavy-duty anti-corrosion coating on the inner wall of the tank.

[0012] Furthermore, the heating temperature of the storage tank by the silica gel heating belt in step S1 is 30°C-230°C.

[0013] Furthermore, the temperature reaching condition in step S1 is that the inner wall surface temperature of the storage tank reaches the process temperature.

[0014] Furthermore, in step S2, the spray gun performs unidirectional linear motion at a uniform speed, and the spray head rotates at a uniform speed.

[0015] The travel speed of the spray gun is 10 mm / min-15 mm / min, and the rotation speed of the spray head is 5 r / min-10 r / min.

[0016] Furthermore, the powder feeding air flow pressure of the spray gun is 0.05MPa-0.15MPa, and the powder feeding amount is 50g / min-80g / min.

[0017] Furthermore, during the rotary atomization spraying process in step S2, the silicone heating belt always maintains the heat preservation and heating state of the storage tank in step S1.

[0018] Furthermore, the method includes: before performing step S1, pre-treating the inner wall of the storage tank, wherein the pre-treatment includes at least one of micro-arc oxidation pre-treatment, sandblasting pre-treatment, and laser etching pre-treatment.

[0019] Furthermore, for the tank whose inner wall is coated with a sintered epoxy heavy-duty anti-corrosion coating, the tensile bonding strength between the sintered epoxy heavy-duty anti-corrosion coating and the aluminum alloy substrate of the inner wall of the tank is greater than 29 MPa, the coating thickness is 0.9 mm-1.5 mm, the coating porosity is less than 0.2%, and the deposition efficiency is greater than 70%.

[0020] Compared with the prior art, the method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating according to the present invention has the following advantages:

[0021] The method for coating the inner wall of a long-length aluminum alloy thin-walled storage tank with a sintered epoxy heavy-duty anti-corrosion coating described in the present invention improves the sintering quality and coating thickening efficiency of the sintered epoxy heavy-duty anti-corrosion coating and the aluminum alloy thin-walled storage tank, improves the safety of the coating process, greatly simplifies the inner wall coating process flow and related operations, and reduces the coating process cost.

[0022] Specifically, the present application achieves online preheating and temperature control by wrapping a silicone heating tape around the outer wall of the aluminum alloy thin-walled tank, thereby solving the problem of rapid cooling during the transfer and coating process of the aluminum alloy thin-walled tank, so that the wall surface of the tank is always maintained in a constant temperature range, so that the spraying situation can meet the requirements of high-quality film formation and efficient thickening; by designing a rotary atomizing spray gun, the inner wall of the tank can be uniformly coated without the aluminum alloy thin-walled tank rotating or moving. Compared with the existing high-voltage electrostatic coating, it not only avoids the efficient thickening and safety problems caused by high-voltage electrostatic coating of the inner wall, but also improves the coating efficiency of the inner wall of the tank, and can fully ensure the uniformity of spraying; through in-situ thermal curing, high-quality film formation of the fused epoxy heavy anti-corrosion coating on the inner wall of the aluminum alloy thin-walled tank is achieved, solving the problems of poor leveling effect and curing quality caused by long transfer time, while also simplifying the inner wall coating process and related operations, significantly reducing the coating process cost, and is particularly suitable for scientific research trial production or small batch production. DETAILED DESCRIPTION

[0023] The inventive concepts of the present disclosure will be described below using terms commonly used by those skilled in the art to convey the essence of their work to other persons skilled in the art. However, these inventive concepts can be embodied in many different forms and should not be considered limited to the embodiments described herein.

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0025] When applying fused epoxy anti-corrosion coating to the inner wall of long-length aluminum alloy thin-walled tanks, compared with the existing electrostatic spraying treatment technology and coating process operation process, in order to solve the problems existing in the existing technology such as poor coating quality caused by tank cooling, poor coating uniformity, coating quality defects and safety hazards caused by high-voltage electrostatic coating, and poor leveling effect and curing quality caused by long tank transfer time.

[0026] This application proposes a method for coating the inner wall of a long-length aluminum alloy thin-walled storage tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating, comprising:

[0027] S1. Online preheating: Install a silicone heating tape on the outer wall of the storage tank so that the silicone heating tape covers and adheres to the outer wall of the storage tank; turn on the silicone heating tape to heat the storage tank, and keep it warm for a first process time after reaching the temperature;

[0028] Although theoretically only one silicone heating tape can be used, due to the varying sizes of the storage tank and the silicone heating tape, multiple silicone heating tapes can be installed on the outer wall of the storage tank until the outer wall of the storage tank is completely covered. The first process duration is a preset parameter in the process and can be adjusted and determined based on the actual process design requirements. In this application, the first process duration can be 30 minutes.

[0029] The silicone heating belt includes a temperature sensor and a thermostat, which are used to control the operating status of the silicone heating belt according to the current heating temperature of the silicone heating belt, so that the silicone heating belt can provide a relatively stable and suitable heating temperature range for the storage tank. Preferably, the silicone heating belt can achieve online preheating and precise segmented temperature control.

[0030] The heating temperature of the storage tank by the silica gel heating belt is 30°C-230°C. At the same time, the temperature reaching condition in step S1 is that the inner wall surface temperature of the storage tank reaches the process temperature;

[0031] Preferably, the process temperature is a preset parameter in the process and can be adjusted and determined according to the actual process design requirements. The process temperature of the present application can be 160°C. Correspondingly, as the preferred heating state of the silicone heating belt, the heating temperature of the storage tank by the silicone heating belt can be maintained at 155°C-165°C. At the same time, in the heat preservation heating state, the silicone heating belt can also maintain this temperature range, which can not only meet the heating requirements before the storage tank reaches the temperature, but also ensure that the storage tank can be maintained at a constant target temperature after reaching the temperature, which also helps the smooth progress of the entire temperature control process without excessive temperature fluctuations.

[0032] Step S1 heats and insulates the outer wall of the tank by installing a silicone heating belt on it. On the one hand, it can meet the coating temperature requirements of the fused epoxy heavy anti-corrosion coating, and can also remove moisture from the tank wall, thereby improving the thickening efficiency of the fused epoxy anti-corrosion coating. On the other hand, it completely solves the cooling problem of the tank during the transfer and coating process in the prior art, so that the tank wall is always maintained in a constant temperature range, so that the spraying situation can meet the requirements of high-quality film formation and efficient thickening. At the same time, in the subsequent curing process, it also helps to improve the curing quality of the fused epoxy heavy anti-corrosion coating. Accordingly, for the insulation process after reaching the temperature, the operating state of the silicone heating belt can be adjusted to keep the surface temperature of the inner wall of the tank at around 160°C.

[0033] S2. Rotary atomization spraying: The spray gun is moved linearly along the central axis of the tank, and the nozzle of the spray gun is rotated about the central axis of the tank to apply a low-temperature curing fusion-bonded epoxy heavy-duty anti-corrosion coating to the inner wall of the tank;

[0034] Here, "one-way" means from one side to the other side along the central axis of the tank, such as from left to right, from right to left, etc.

[0035] The spray gun moves linearly in a uniform motion, while the spray head rotates at a uniform rotational speed. Preferably, the spray gun travel speed is 10 mm / min-15 mm / min, and the spray head rotation speed is 5 rpm-10 rpm. This eliminates the need to rotate or move the tank; instead, the tank remains stationary. The spray gun's rotary atomization allows for the coating of the tank's interior with a low-temperature-curing, fused-bonded epoxy heavy-duty anti-corrosion coating, ensuring uniformity and improving coating efficiency.

[0036] The powder feeding air flow pressure of the spray gun is 0.05MPa-0.15MPa, and the powder feeding amount is 50g / min-80g / min, so that the spray gun can evenly spray a sufficient amount of powder on the inner wall of the storage tank during movement and rotation to meet the requirements of the final coating thickness and cured film quality.

[0037] At the same time, in step S2, by controlling the powder feeding amount, gun travel speed, and rotation speed, efficient thickening of the fused epoxy heavy anti-corrosion coating on the inner wall of the tank and one-time coating can be achieved.

[0038] Preferably, during the rotary atomization spraying process of step S2, the silicone heating belt can keep the storage tank in an insulating and heating state at all times. On the one hand, it avoids the cooling of the inner wall at the unsprayed position to ensure that the spraying conditions at various positions of the inner wall can meet the requirements of high-quality film formation and efficient thickening. On the other hand, for the inner wall positions where the spraying is completed, due to the insulating heating of the silicone heating belt, it can directly enter the curing process immediately after spraying. Compared with the existing technology, there is no transition interval between spraying and curing, which can effectively ensure the leveling effect and curing quality, improve the final coating quality, and also help to simplify the process flow and related operations, which can significantly reduce the coating process cost.

[0039] S3, in-situ heat curing: keep the heating state of the storage tank by the silicone heating belt in step S1, keep the temperature for the second process time, and complete the coating of the fusion-bonded epoxy heavy anti-corrosion coating on the inner wall of the storage tank.

[0040] Among them, since steps S1 and S2 do not remove the silicone heating belt on the outer wall of the storage tank, and there is no need to move or rotate the storage tank, so that the storage tank and the silicone heating belt are kept in place, in step S3, it is only necessary to maintain the operation of the silicone heating belt in step S1, and keep it warm for the second process time after reaching the temperature, and then the coating of the fused epoxy heavy anti-corrosion coating on the inner wall of the storage tank can be completed. Compared with the existing technology, the present application greatly simplifies the inner wall coating process and related operations, can significantly reduce the coating process cost, and is particularly suitable for scientific research trial production or small batch production. It should be noted that the heating temperature, temperature reaching conditions, and insulation temperature of the silicone heating belt in step S3 are consistent with those in step S1 and will not be repeated.

[0041] In addition, the second process duration is a preset parameter in the process, which can be adjusted and determined according to actual process design requirements. The second process duration of the present application can be 20 minutes.

[0042] After the processing process of steps S1-S3, for the tank with the inner wall coated with a sintered epoxy heavy-duty anti-corrosion coating, the tensile bonding strength between the sintered epoxy heavy-duty anti-corrosion coating and the aluminum alloy substrate of the inner wall of the tank is greater than 29 MPa, the coating thickness is 0.9 mm-1.5 mm, the coating porosity is less than 0.2%, and the deposition efficiency is greater than 70%.

[0043] After step S3 is completed, the tank with the inner wall coated can be transferred to the machining section of turning, milling, grinding, polishing, etc. of the fused epoxy heavy anti-corrosion coating for subsequent processing.

[0044] Before performing step S1, the method pre-treats the inner wall of the tank, wherein the pre-treatment includes at least one of micro-arc oxidation pre-treatment, sandblasting pre-treatment, and laser etching pre-treatment.

[0045] Therefore, the present application provides a coating process for the inner wall surface of the long-length aluminum alloy thin-walled storage tank with a sintered epoxy heavy-duty anti-corrosion coating, which improves the sintering quality and coating thickening efficiency of the sintered epoxy heavy-duty anti-corrosion coating and the aluminum alloy thin-walled storage tank, and also improves the safety of the coating process, and greatly simplifies the inner wall coating process flow and related operations, thereby reducing the coating process cost.

[0046] Specifically, the present application achieves online preheating and temperature control by wrapping a silicone heating tape around the outer wall of the aluminum alloy thin-walled tank, thereby solving the problem of rapid cooling during the transfer and coating process of the aluminum alloy thin-walled tank, so that the wall surface of the tank is always maintained in a constant temperature range, so that the spraying situation can meet the requirements of high-quality film formation and efficient thickening; by designing a rotary atomizing spray gun, the inner wall of the tank can be uniformly coated without the aluminum alloy thin-walled tank rotating or moving. Compared with the existing high-voltage electrostatic coating, it not only avoids the efficient thickening and safety problems caused by high-voltage electrostatic coating of the inner wall, but also improves the coating efficiency of the inner wall of the tank, and can fully ensure the uniformity of spraying; through in-situ thermal curing, high-quality film formation of the fused epoxy heavy anti-corrosion coating on the inner wall of the aluminum alloy thin-walled tank is achieved, solving the problems of poor leveling effect and curing quality caused by long transfer time, while also simplifying the inner wall coating process and related operations, significantly reducing the coating process cost, and is particularly suitable for scientific research trial production or small batch production.

[0047] The technical solution of this application is described in detail below with reference to specific embodiments.

[0048] Example 1

[0049] The inner wall of the aluminum alloy thin-walled tank is pretreated by micro-arc oxidation, and then the following operations are carried out:

[0050] (1) Online preheating. Seven pieces of silicone heating tapes with built-in temperature sensors and thermostats and rated power of 1kW-3kW were used to tightly wrap the outer wall of the aluminum alloy thin-walled tank (1-meter long sample). The temperature of each section was set to 155℃-165℃. The actual measured value of the inner wall surface was used to make fine adjustments to each section. The inner wall surface temperature was controlled to 160℃ and kept warm for 30 minutes after reaching the temperature.

[0051] (2) Rotary atomization spraying. Use a rotary atomization spray gun, adjust the powder feeding air flow pressure to 0.05MPa, the powder feeding amount to 50g / min, and move the spray gun linearly from left to right along the center axis of the tank at a gun speed of 10mm / min and a nozzle rotation speed of 5r / min to coat the inner wall with a low-temperature curing fusion bonded epoxy heavy-duty anti-corrosion coating.

[0052] (3) In-situ heat curing. After coating the inner wall of the aluminum alloy thin-walled tank, maintain the heating parameters of the online preheating stage and keep warm for 20 minutes to complete the in-situ heat curing film formation.

[0053] After the above coating and curing film formation, the tensile bonding strength of the sintered epoxy heavy-duty anti-corrosion coating and the aluminum alloy substrate pretreated by micro-arc oxidation reaches 35.4MPa, the coating thickness is 0.9mm-1.2mm, the coating porosity is less than 0.2%, and the deposition efficiency is about 76%.

[0054] Example 2

[0055] The inner wall of the aluminum alloy thin-walled tank is pre-treated by sandblasting, and then the following operations are carried out:

[0056] (1) Online preheating. Use 20 pieces of silicone heating tapes with built-in temperature sensors and thermostats and rated power of 1-3kW to tightly wrap the outer wall of the aluminum alloy thin-walled storage tank (2.8 meters long). Set the temperature of each section to 155℃-165℃ respectively. Make fine adjustments to each section based on the actual measured value of the inner wall surface. Control the inner wall surface temperature to 160℃ and keep it warm for 30 minutes after reaching the temperature.

[0057] (2) Rotary atomization spraying. Use a rotary atomization spray gun, adjust the powder feeding air flow pressure to 0.1MPa, the powder feeding amount to 50g / min, and move the spray gun linearly from left to right along the center axis of the tank at a gun speed of 10mm / min and a nozzle rotation speed of 10r / min to coat the inner wall with a low-temperature curing fusion bonded epoxy heavy anti-corrosion coating.

[0058] (3) In-situ heat curing. After coating the inner wall of the aluminum alloy thin-walled tank, maintain the heating parameters of the online preheating stage and keep warm for 20 minutes to complete the in-situ heat curing film formation.

[0059] After the above coating and curing film formation, the tensile bonding strength of the fused epoxy heavy anti-corrosion coating and the aluminum alloy substrate after sandblasting pretreatment reaches 29.7MPa, the coating thickness is 1.0mm-1.3mm, the coating porosity is less than 0.2%, and the deposition efficiency is about 73%.

[0060] Example 3

[0061] The inner wall of the aluminum alloy thin-walled tank is pre-treated by laser etching, and then the following operations are carried out:

[0062] (1) Online preheating. Use 22 pieces of silicone heating tape with built-in temperature sensors and temperature controllers and rated power of 1-3kW to tightly wrap the outer wall of the aluminum alloy thin-walled storage tank tube (3.2 meters long). Set the temperature of each section to 155℃-165℃ respectively. Make fine adjustments to each section based on the actual measured value of the inner wall surface. Control the inner wall surface temperature to 160℃ and keep it warm for 30 minutes after reaching the temperature.

[0063] (2) Rotary atomization spraying. Use a rotary atomization spray gun, adjust the powder feeding air flow pressure to 0.15MPa, the powder feeding amount to 80g / min, and move the spray gun linearly from left to right along the center axis of the tank at a gun speed of 15mm / min and a nozzle rotation speed of 10r / min to coat the inner wall with a low-temperature curing fusion bonded epoxy heavy anti-corrosion coating.

[0064] (3) In-situ heat curing: After coating the inner wall of the aluminum alloy thin-walled storage tank tube, maintain the online preheating heating parameters and keep warm for 20 minutes to complete the in-situ heat curing film formation.

[0065] After the above coating and curing film formation, the tensile bonding strength of the fused epoxy heavy anti-corrosion coating and the aluminum alloy tube blank substrate after laser etching pretreatment reaches 46.3MPa, the coating thickness is 1.1mm-1.5mm, the coating porosity is less than 0.2%, and the deposition efficiency is about 72%.

[0066] By adopting the coating technical solution and specific implementation process of the sintered epoxy heavy-duty anti-corrosion coating on the inner wall of the tank provided by the present invention, high-quality heavy-duty anti-corrosion coating can be achieved on the inner wall of a long-length aluminum alloy thin-wall tank. Compared with the current electrostatic spraying treatment technology, it has the advantages of high efficiency, safety, low cost, and high quality. At the same time, the present application solves the technical problems of constant temperature in the transfer, coating, and curing processes of aluminum alloy thin-walled tanks, improves the curing quality of the sintered epoxy heavy-duty anti-corrosion coating, simplifies the coating process equipment, reduces production costs, and is conducive to the linear amplification production of small batches of workpieces in the future. In addition, the present application realizes the control of the inner wall coating uniformity of the aluminum alloy thin-walled tank under non-rotating conditions through rotary atomization spraying, and also improves the inner wall coating efficiency, solving the safety problems and coating quality defects that may arise from high-voltage electrostatic spraying of thick anti-corrosion coatings.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating, characterized in that: The method comprises: S1. Online preheating: Install a silicone heating tape on the outer wall of the storage tank so that the silicone heating tape covers and adheres to the outer wall of the storage tank; turn on the silicone heating tape to heat the storage tank, and keep it warm for a first process time after reaching the temperature; S2. Rotary atomization spraying: The spray gun is moved linearly along the central axis of the tank, and the nozzle of the spray gun rotates around the central axis of the tank, thereby coating the inner wall of the tank with a low-temperature curing fusion-bonded epoxy heavy-duty anti-corrosion coating; S3, in-situ heat curing: keep the heating state of the storage tank by the silicone heating belt in step S1, keep the temperature for the second process time, and complete the coating of the fusion-bonded epoxy heavy anti-corrosion coating on the inner wall of the storage tank.

2. The method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating according to claim 1 is characterized in that: The heating temperature of the storage tank by the silica gel heating belt in step S1 is 30°C-230°C.

3. The method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating according to claim 1 is characterized in that: The temperature reaching condition in step S1 is that the inner wall surface temperature of the storage tank reaches the process temperature.

4. The method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating according to claim 1 is characterized in that: In step S2, the spray gun performs unidirectional linear motion at a uniform speed, and the spray head rotates at a uniform speed.

5. The method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating according to claim 4 is characterized in that: The travel speed of the spray gun is 10 mm / min-15 mm / min, and the rotation speed of the spray head is 5 r / min-10 r / min.

6. The method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating according to claim 1 is characterized in that: The powder feeding air flow pressure of the spray gun is 0.05MPa-0.15MPa, and the powder feeding amount is 50g / min-80g / min.

7. The method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating according to claim 1 is characterized in that: During the rotary atomization spraying process in step S2, the silicone heating belt always maintains the heat preservation and heating state of the storage tank in step S1.

8. The method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating according to claim 1 is characterized in that: The method includes: before performing step S1, pre-treating the inner wall of the tank, wherein the pre-treatment includes at least one of micro-arc oxidation pre-treatment, sandblasting pre-treatment, and laser etching pre-treatment.

9. The method for coating the inner wall of a long-length aluminum alloy thin-walled tank with a fusion-bonded epoxy heavy-duty anti-corrosion coating according to claim 1, characterized in that: For the tank with the inner wall coated with a sintered epoxy heavy-duty anti-corrosion coating, the tensile bonding strength between the sintered epoxy heavy-duty anti-corrosion coating and the aluminum alloy substrate of the tank inner wall is greater than 29 MPa, the coating thickness is 0.9 mm-1.5 mm, the coating porosity is less than 0.2%, and the deposition efficiency is greater than 70%.