A kind of anti-corrosion lining of stainless steel reactor and its construction technology

Abstract

The present invention provides an anti-corrosion lining of a stainless steel reactor and a construction process thereof, comprising a reactor tank body and a plurality of alloy patch lining layers, wherein the inner wall of the reactor tank body is sprayed with an anti-corrosion coating, the plurality of alloy patch lining layers are layered and laid on the inner wall of the reactor tank body from the inside to the outside, the plurality of alloy patch lining layers comprise a plurality of alloy patches and a hot-melt adhesive layer, the plurality of alloy patches are welded and fixed to the inner wall of the reactor tank body or the alloy patches of adjacent alloy patch lining layers by resistance spot welding, the alloy patches are provided with mesh-arranged convex points, the present invention adopts softer and thinner alloy patches for splicing to form an inner lining structure, the alloy patches are welded to the reactor and adjacent alloy patches by the mesh-arranged convex points, a hot-melt adhesive layer is added between the inner lining layers, the stability of the inner lining structure and the anti-corrosion coating inside the inner lining layer is greatly improved, and the inner wall of the reactor is effectively protected.

Description

Technical Field

[0001] The invention relates to the technical field of corrosion-resistant linings for reactors, and in particular to corrosion-resistant linings for stainless steel reactors and a construction process thereof. Background Art

[0002] Reactors are common equipment in chemical plants. In a broad sense, they are containers for physical or chemical reactions. Through the structural design and parameter configuration of the container, the heating, evaporation, cooling and low-speed mixing functions required by the process are realized. Reactors are widely used in petroleum, chemical, rubber, pesticide, dye, medicine, and food. They are pressure vessels used to complete processes such as sulfidation, nitration, hydrogenation, hydrocarbonization, polymerization, and condensation. They are generally made of carbon-manganese steel, stainless steel, zirconium, nickel-based (Hastelloy, Monel, Inconel) alloys and other composite materials. Figure 2 The reaction tank in the reactor is a common stainless steel reactor, and the inner wall of the tank is made of stainless steel;

[0003] The stainless steel lining of the inner wall of the tank body is welded and assembled with multiple stainless steel plates. During use, it will be damaged by medium corrosion (pitting corrosion, intergranular corrosion) and thermal stress, which will cause cracks or alkali embrittlement, wear and thinning or uniform corrosion, which will lead to serious damage to the stainless steel lining, especially the welds. Therefore, it is necessary to regularly perform welding maintenance on the welds. After multiple welding maintenance, the mechanical and corrosion resistance of the welds decrease year by year. Usually, more corrosion-resistant alloy material panels with a certain thickness are used for welding maintenance. This method has a thicker panel and is limited by the size of the tank feeding port. The patch size is small and the welding workload is large, especially for the curved surface near the feeding port. There are many splicing welds and the serious weld corrosion problem still exists; and the alloy material itself is difficult to weld, the welding standard is high, and the welding quality is difficult to control. In particular, there are vertical welds and curved welds in the on-site welding of the tank body, so welding is difficult. Therefore, the traditional alloy material panel welding method cannot solve the weld corrosion problem and is difficult to operate.

[0004] In the prior art, there is an anti-corrosion container with application number "CN200910232205.1", in which glass fiber cloth is bonded to the inner wall of the container, and multiple anti-corrosion fluoroplastic plates are bonded to the glass fiber cloth; the multiple anti-corrosion fluoroplastic plates are spliced ​​into the shape of the inner cavity of the container; adjacent anti-corrosion fluoroplastic plates are hot-melt welded into one body. The core of the above device is to line the container with anti-corrosion material to achieve the purpose of corrosion resistance. The device can be used for large and extra-large chemical equipment, such as reaction towers, reactors, reaction tanks, storage tanks, pipelines, etc., and can also be used for general chemical equipment, and there is no environmental pollution in the production process and the energy consumption is extremely low.

[0005] However, the above-mentioned corrosion-resistant container still has obvious defects during use: although the above-mentioned hot-melt anti-corrosion fluoroplastic plate can play a certain protective role on the inner wall of the tank, the hot-melt anti-corrosion fluoroplastic plate is exposed in the tank. Since high-temperature reaction is usually required inside the reactor, the hot-melt anti-corrosion fluoroplastic plate will melt and fall off under high temperature conditions, causing the anti-corrosion lining to fail after long-term use. At the same time, the fallen fluoroplastic plate will affect the internal reaction. Summary of the invention

[0006] The object of the present invention is to provide a corrosion-resistant lining of a stainless steel reactor and a construction process thereof, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A stainless steel reactor anti-corrosion lining, comprising a reactor tank body and a plurality of alloy patch lining layers, wherein the inner wall of the reactor tank body is sprayed with an anti-corrosion coating, and the plurality of alloy patch lining layers are layered and laid on the inner wall of the reactor tank body from the inside to the outside, and a hot-melt adhesive layer is attached between adjacent alloy patch lining layers and between the innermost alloy patch lining layer and the inner wall of the reactor tank body;

[0009] Several of the alloy patch lining layers include multiple alloy patches and a hot-melt adhesive layer. The multiple alloy patches are welded and fixed to the inner wall of the reactor tank or the alloy patches of the adjacent alloy patch lining layer by resistance spot welding. The alloy patches are provided with ridged bumps, and the hot-melt adhesive layer is provided with avoidance holes corresponding to the bumps of the alloy patches.

[0010] Preferably, a metal primer coating is sprayed between the reactor tank body and the anti-corrosion coating.

[0011] Preferably, a pretreatment combining sandblasting and grinding is performed between the reactor tank body and the metal primer coating.

[0012] Preferably, the feature is that the bumps arranged in a grid on the alloy patch are densely packed near the edge of the alloy patch.

[0013] Preferably, the joints of the inner lining layers of the plurality of alloy patches are filled and sealed by ceramic repairing agent.

[0014] Preferably, the hot melt adhesive layer is a PFA composite hot melt layer or a metal hot melt adhesive film layer.

[0015] Preferably, the alloy patch inner lining has two layers.

[0016] Preferably, the protrusions formed on the alloy patches between adjacent alloy patch lining layers are arranged in a staggered manner.

[0017] Preferably, an agitator and a discharge pipe are provided in the reactor tank.

[0018] A construction process for the above-mentioned anti-corrosion lining of the stainless steel reactor comprises the following steps:

[0019] Step 1: Pre-treat the inner wall of the reactor tank by combining sandblasting and grinding to remove the corrosion layer to the greatest extent, expose the defects, and minimize the damage to the tank base material;

[0020] Step 2: According to the parent material of the inner wall of the reactor tank, the corresponding spray alloy powder is selected to thermally spray the inner wall of the reactor to form a metal primer coating with a certain thickness, thereby repairing the parent material and ensuring that the metal primer coating has a good bonding strength with the reactor tank, preparing for the subsequent alloy patch spot welding to ensure the bonding strength;

[0021] Step 3: spraying an anti-corrosion coating on the metal primer coating formed in step 2 by thermal spraying, and applying a sealing agent to seal the holes after the anti-corrosion coating is sprayed. The anti-corrosion coating has a strong anti-corrosion ability;

[0022] Step 4: Punch out convex points arranged in a mesh on the alloy patch, increase the density of convex points near the edge of the alloy patch, make corresponding avoidance holes in the hot melt adhesive layer, and weld the alloy patch to the steel of the reactor tank body by resistance spot welding. After welding, heat up to bond the hot melt adhesive layer;

[0023] Step 5: Use ceramic repair agent to fill and seal the joints of the alloy patches to form an alloy patch lining layer;

[0024] Step 6: Repeat steps 4 to 5, and add another layer of alloy patch lining layer on the basis of the original alloy patch lining layer. The second layer of alloy patch lining layer covers the joint seam of the first layer of alloy patch lining layer.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention adopts softer and thinner alloy patches to splice to form the lining structure. The alloy patches can be curled and sent into the tank body to reduce the splicing density. At the same time, a multi-layer alloy patch lining layer is adopted. By adding a hot-melt adhesive layer between the lining layers, the bonding strength of the multi-layer alloy patch lining is ensured, which effectively provides protection for the inner wall of the reactor;

[0027] 2. The alloy patch of the present invention is welded to the reactor and adjacent alloy patches through mesh-arranged protrusions, so that the alloy patch is more firmly attached to the tank wall to avoid bulging and subsequent fatigue failure. The medium erosion distance is lengthened by combining dot matrix welding and hot-melt adhesive layer bonding. Even if the alloy patch is corroded, it is still pitting damage, and a mesh protective layer will be formed. The PFA composite material or metal hot-melt adhesive film will not be exposed to the corrosive liquid as a whole and be washed away by the fluid, which greatly improves the stability of the lining structure and the anti-corrosion coating inside the lining layer, thereby effectively protecting the inner wall of the reactor.

[0028] The present invention adopts softer and thinner alloy patches to splice to form the inner lining structure. The alloy patches are welded to the reactor and adjacent alloy patches through mesh-arranged protrusions. A hot-melt adhesive layer is added between the inner lining layers, which greatly improves the stability of the inner lining structure and the anti-corrosion coating inside the inner lining layer, thereby effectively protecting the inner wall of the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the anti-corrosion structure of the inner wall of the reactor of the present invention;

[0030] Figure 2 It is a schematic cross-sectional view of the interior of the reactor of the present invention;

[0031] Figure 3 It is a schematic diagram of the structure of the convex point and the avoidance hole arrangement of the present invention.

[0032] In the figure: 1 reactor tank body, 2 alloy patch lining layer, 3 stirrer, 4 discharge pipe, 5 metal base layer, 6 anti-corrosion coating, 7 alloy patch, 8 hot melt adhesive layer, 9 bumps, 10 joint seam, 11 avoidance hole. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0034] See also Figure 1-3 , the present invention provides a technical solution:

[0035] A stainless steel reactor anti-corrosion lining comprises a reactor tank body 1 and a plurality of alloy patch lining layers 2, the inner wall of the reactor tank body 1 is sprayed with an anti-corrosion coating 6, the plurality of alloy patch lining layers 2 are layered and laid on the inner wall of the reactor tank body 1 from the inside to the outside, a hot melt adhesive layer 8 is attached between adjacent alloy patch lining layers 2 and between the innermost alloy patch lining layer 2 and the inner wall of the reactor tank body 1, the inner wall of the reactor tank body 1 is protected by the anti-corrosion coating 6, and the alloy patch lining layer 2 is used to protect the anti-corrosion coating 6 and the reactor tank body 1;

[0036] The plurality of alloy patch lining layers 2 include a plurality of alloy patches 7 and a hot melt adhesive layer 8. The plurality of alloy patches 7 are welded and fixed to the inner wall of the reactor tank body 1 or the alloy patches 7 of the adjacent alloy patch lining layer 2 by resistance spot welding. The alloy patches 7 are provided with mesh-shaped convex points 9. The hot melt adhesive layer 8 is provided with avoidance holes 11 corresponding to the convex points 9 of the alloy patches 7. The alloy patches 7 are fixed by spot welding. It is welded with the steel material of the reactor tank body 1, and the temperature is raised after welding to make the hot-melt adhesive layer 8 bonded. The advantage of this is that a dot matrix welding network is formed, and the line fixation of the traditional welding is changed to surface fixation, so that the alloy patch 7 is more firmly attached to the tank wall, avoiding the formation of bulges and subsequent fatigue failure. The hot-melt adhesive layer 8 is filled between the alloy patch 7 and the reactor tank body 1, and the bonding between the alloy layer and the tank body is enhanced; in addition, the hot-melt adhesive layer 8 material itself has corrosion resistance and can have a certain protective effect on the anti-corrosion coating 6; thirdly, the hot-melt adhesive layer 8 plays a sealing role at the spot welding point, so that the medium erosion distance is lengthened; fourthly, the hot-melt adhesive layer 8 is a heat-insulating material, even if the medium breaks through the PFA material, the temperature reaching the anti-corrosion coating 6 will also decrease, and the erosion rate decreases exponentially with the decrease in temperature; fifthly, the dot matrix welding and the hot-melt adhesive layer 8 bonding are combined, even if the alloy patch 7 is corroded, it is still pitting damage, and a mesh protective layer will be formed, and the hot-melt adhesive layer 8 will not be exposed to the corrosive liquid as a whole and be washed off by the fluid.

[0037] As a preferred embodiment, a metal primer coating 5 is sprayed between the reactor tank body 1 and the anti-corrosion coating 6. Firstly, it serves to repair the base material. Secondly, the metal primer coating 5 has a good bonding strength with the reactor tank body 1, which prepares for the subsequent spot welding of the alloy patch 7 and ensures the bonding strength.

[0038] As a preferred embodiment, a pretreatment combining sandblasting and grinding is performed between the reactor tank body 1 and the metal primer coating 5, which can remove the corrosion layer to the greatest extent and expose the defects, while minimizing the damage to the substrate of the reactor tank body 1.

[0039] As a preferred embodiment, it is characterized in that: the bumps 9 arranged in a grid on the alloy patch 7 are encrypted near the edge of the alloy patch 7, and the bonding strength of the alloy patch 7 with the reactor tank body 1 or the adjacent alloy patch lining layer 2 is ensured by the encrypted bumps.

[0040] As a preferred embodiment, the joint seams 10 of the inner lining layers 2 of the alloy patches are filled and sealed by ceramic repairing agent.

[0041] As a preference, the hot melt adhesive layer 8 is a PFA composite hot melt layer or a metal hot melt adhesive film layer.

[0042] As a preference, the number of layers of the alloy patch lining layer 2 is two. The provision of two layers of the alloy patch lining layer 2 is sufficient to protect the anti-corrosion coating 6 and the inner wall of the reactor tank body 1 .

[0043] As a preferred embodiment, the protrusions formed on the alloy patches 7 between adjacent alloy patch lining layers 2 are arranged in a staggered manner.

[0044] As a preferred embodiment, a stirrer 3 and a discharge pipe 4 are provided in the reactor tank body 1 .

[0045] A construction process for the above-mentioned anti-corrosion lining of the stainless steel reactor comprises the following steps:

[0046] Step 1: Pre-treat the inner wall of the reactor tank body 1 by combining sandblasting and grinding to remove the corrosion layer to the greatest extent, expose the defects, and minimize the damage to the tank body substrate;

[0047] Step 2: According to the parent material of the inner wall of the reactor tank body 1, the corresponding spraying alloy powder is selected to thermally spray the inner wall of the reactor to form a metal primer coating 5 with a certain thickness, thereby repairing the parent material and ensuring that the metal primer coating 5 has a good bonding strength with the reactor tank body 1, preparing for the subsequent alloy patch spot welding to ensure the bonding strength;

[0048] Step 3: On the basis of the metal primer coating 5 formed in step 2, an anti-corrosion coating 6 is sprayed by a thermal spraying method. After the anti-corrosion coating 6 is sprayed, a sealing agent is applied to seal the holes. The anti-corrosion coating 6 has a strong anti-corrosion ability;

[0049] Step 4: punch out convex dots 9 arranged in a mesh on the alloy patch 7, increase the density of convex dots near the edge of the alloy patch 7, make corresponding avoidance holes 11 on the hot melt adhesive layer 8 and properly avoid them, and weld the alloy patch 7 to the steel material of the reactor tank body 1 by resistance spot welding, and heat the hot melt adhesive layer 8 after welding to bond it;

[0050] Step 5: Use ceramic repair agent to fill and seal the joints of the alloy patch 7, thereby forming a layer of alloy patch lining layer 2;

[0051] Step 6: Repeat steps 4 to 5, and add another layer of alloy patch lining layer 2 on the basis of the original alloy patch lining layer 2, so that the second layer of alloy patch lining layer 2 covers the joint seam of the first layer of alloy patch lining layer 2.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A corrosion-resistant lining for a stainless steel reactor, comprising a reactor tank body (1) and a plurality of alloy patch lining layers (2), characterized in that: The inner wall of the reactor tank body (1) is sprayed with an anti-corrosion coating (6), and a plurality of alloy patch lining layers (2) are laid on the inner wall of the reactor tank body (1) in layers from the inside to the outside, and a hot melt adhesive layer (8) is attached between adjacent alloy patch lining layers (2) and between the innermost alloy patch lining layer (2) and the inner wall of the reactor tank body (1); The plurality of alloy patch inner lining layers (2) comprise a plurality of alloy patches (7) and a hot-melt adhesive layer (8); the plurality of alloy patches (7) are welded and fixed to the inner wall of the reactor tank body (1) or the alloy patches (7) of the adjacent alloy patch inner lining layer (2) by means of resistance spot welding; the alloy patches (7) are provided with protrusions (9) arranged in a mesh shape; and the hot-melt adhesive layer (8) is provided with avoidance holes (11) corresponding to the protrusions (9) of the alloy patches (7); A metal primer coating (5) is sprayed between the reactor tank body (1) and the anti-corrosion coating (6); A pretreatment combining sandblasting and grinding is performed between the reactor tank body (1) and the metal primer coating (5); The convex points (9) arranged in a grid on the alloy patch (7) are densely packed near the edge of the alloy patch (7); The joint seams (10) of the inner lining layers (2) of the alloy patches are filled and sealed by using a ceramic repairing agent; The hot melt adhesive layer (8) is a PFA composite hot melt layer or a metal hot melt adhesive film layer; The number of layers of the alloy patch inner lining layer (2) is 2; The convex points formed on the alloy patches (7) between adjacent alloy patch lining layers (2) are arranged in a staggered manner.

2. The anti-corrosion lining of a stainless steel reactor according to claim 1, characterized in that: The reactor tank body (1) is provided with an agitator (3) and a discharge pipe (4).

3. A construction process for the anti-corrosion lining of a stainless steel reactor according to any one of claims 1 to 2, characterized in that: The following steps are involved: Step 1: Pre-treating the inner wall of the reactor tank (1) by a combination of sandblasting and grinding to remove the corrosion layer to the greatest extent possible, expose defects, and minimize damage to the tank base material; Step 2: According to the parent material of the inner wall of the reactor tank body (1), a corresponding spraying alloy powder is selected to perform thermal spraying on the inner wall of the reactor tank body to form a metal primer coating (5) with a certain thickness, thereby repairing the parent material and ensuring that the metal primer coating (5) and the reactor tank body (1) have good bonding strength, preparing for the subsequent alloy patch spot welding to ensure bonding strength; Step 3: spraying an anti-corrosion coating (6) on the metal primer coating (5) formed in step 2 by a thermal spraying method, and coating a sealing agent to seal the pores after the anti-corrosion coating (6) is sprayed. The anti-corrosion coating (6) has a strong anti-corrosion ability; Step 4: punching out convex points (9) arranged in a grid on the alloy patch (7), increasing the density of convex points near the edge of the alloy patch (7), making corresponding avoidance holes (11) appropriately avoided on the hot melt adhesive layer (8), and welding the alloy patch (7) to the steel material of the reactor tank body (1) by resistance spot welding, and heating the hot melt adhesive layer (8) after welding to bond; Step 5: Using ceramic repair agent to fill and seal the joints of the alloy patch (7), thereby forming a layer of alloy patch lining layer (2); Step 6: Repeat steps 4 to 5, and add another layer of alloy patch lining layer (2) on the basis of the original alloy patch lining layer (2), so that the second layer of alloy patch lining layer (2) covers the joint seam of the first layer of alloy patch lining layer (2).

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