A composite steel plate and tank body for high-corrosive industrial wastewater treatment

Abstract

This utility model belongs to the technical field of water treatment and composite steel plates, and discloses a composite steel plate and tank for treating highly corrosive industrial wastewater. The composite steel plate includes a steel plate base layer; an inorganic enamel layer disposed on one side surface of the steel plate base layer; an organic adhesive layer disposed on the other side surface of the steel plate base layer; and an organic anti-corrosion layer disposed on the side surface of the organic adhesive layer away from the steel plate base layer. The organic anti-corrosion layer is fixedly connected to the steel plate base layer through the organic adhesive layer. This utility model has a simple structure and is easy to manufacture. By constructing a dual independent protection system, it accurately matches the requirements of internal and external environments, greatly improving the leak-proof reliability and safety of the system, extending the safe operation cycle of the wastewater treatment equipment by a factor of two, and significantly reducing the overall cost throughout the entire life cycle.

Description

Technical Field

[0001] This utility model relates to the technical field of water treatment and composite steel plates, and more specifically, to a composite steel plate and tank for treating highly corrosive industrial wastewater. Background Technology

[0002] In the field of industrial wastewater treatment, enamel-lined prefabricated tanks are widely used due to their advantages such as convenient installation and long service life. Traditional enamel-lined prefabricated tanks typically have walls made of steel plates with double-sided sintered enamel coating. While enamel coating, as an inorganic silicate glassy material, possesses excellent resistance to atmospheric aging, UV radiation, and conventional acids and alkalis, its inherent limitations become increasingly apparent when dealing with high-salt, highly corrosive wastewater containing high concentrations of chloride ions, fluoride ions, and nitrate ions—media with strong permeability and corrosiveness—in modern industrial processes.

[0003] First, enamel coatings are essentially brittle inorganic films. In practical engineering applications, on the one hand, due to limitations in the sintering process, it is difficult to completely eliminate microscopic pores and bubble defects within the coating; on the other hand, during tank transportation, on-site assembly, and long-term exposure to alternating water pressure, mechanical stress and minor deformations are inevitably generated. This stress can easily lead to microcracks or localized peeling (enamel chipping) in the brittle enamel layer.

[0004] Secondly, once the enamel coating suffers microscopic damage, highly permeable corrosive media (especially chloride ions) will directly contact the underlying steel plate. Because the remaining intact enamel layer is insulating, the exposed micro-steel plate area at the damaged point forms a typical "large cathode-small anode" electrochemical corrosion micro-cell. This highly concentrated corrosion current leads to a highly destructive "pitting corrosion" effect, causing perforation and leakage in thick steel plates within a very short time, resulting in catastrophic environmental pollution and safety accidents.

[0005] To address these issues, existing technologies typically employ conventional methods such as "thickening the enamel coating" or "multi-layer sintering." However, this approach has reached a technical bottleneck: the thicker the enamel layer, the greater the internal stress resulting from the mismatch in the coefficient of thermal expansion (CTE) between it and the steel substrate. This not only significantly increases manufacturing costs but also leads to decreased coating adhesion and a greater susceptibility to large-area brittle cracking and peeling. Therefore, simply relying on improving inorganic enamel coatings cannot fundamentally resolve the physical contradiction between "high corrosion resistance requirements" and "coating brittleness and vulnerability." Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a composite steel plate and tank body that can greatly improve the service life of sewage treatment tanks when treating highly corrosive industrial wastewater. The technical solution is as follows: A composite steel plate for treating highly corrosive industrial wastewater includes a steel plate base layer and further comprises: An inorganic enamel layer is disposed on one side surface of the steel plate base layer; An organic adhesive layer is disposed on the other side surface of the steel plate base layer; An organic anti-corrosion layer is disposed on the side of the organic adhesive layer away from the steel plate base layer, and the organic anti-corrosion layer is fixedly connected to the steel plate base layer through the organic adhesive layer.

[0007] As a further improvement to the above-mentioned composite steel plate: the surface roughness Ra value of both sides of the steel plate base layer is 30 to 70 micrometers; the thickness of the steel plate base layer is 4 to 10 millimeters.

[0008] As a further improvement to the above-mentioned composite steel plate, the thickness of the inorganic enamel layer is 200-600 micrometers.

[0009] As a further improvement to the above-mentioned composite steel plate: the organic adhesive layer is a two-component epoxy resin adhesive coating, a polyurethane adhesive coating, or a modified silane polymer adhesive coating; the thickness of the organic adhesive layer is 0.2 to 1 mm.

[0010] As a further improvement to the above-mentioned composite steel plate: a transition coating is provided between the steel plate base layer and the organic adhesive layer, the transition coating being a silane coupling agent coating or an epoxy zinc-rich coating.

[0011] As a further improvement to the above-mentioned composite steel plate: the organic anti-corrosion layer is a PP plate, PE plate, PVC plate, PVDF plate, ETFE plate or PFA plate; the thickness of the organic anti-corrosion layer is 1 to 5 mm.

[0012] A tank for treating highly corrosive industrial wastewater is assembled from the aforementioned composite steel plates.

[0013] The advantages of the composite steel plate and tank body for treating highly corrosive industrial wastewater of this invention are: (1) An inorganic enamel layer is set on the outer side of the steel plate base, which can perfectly cope with the harsh external natural environment by utilizing its excellent weather resistance, UV resistance and temperature change resistance; a continuous and flexible organic anti-corrosion layer is set on the inner side, which can play its excellent anti-seepage performance by isolating strong corrosive media such as chloride ions and fluoride ions, completely blocking the contact between sewage and steel plate, and fundamentally eliminating the risk of perforation and leakage caused by damage to a single coating. At the same time, the inner side design avoids the direct action of ultraviolet rays and oxygen, and avoids the shortcoming of easy aging of organic materials.

[0014] (2) The organic adhesive layer between the steel plate base layer and the organic anti-corrosion layer not only provides a high-strength interfacial bond, but its own elasticity and toughness can also effectively absorb external impact energy. In addition, this layer can effectively buffer and release the interfacial internal stress caused by the difference in thermal expansion between the rigid steel plate and the flexible anti-corrosion layer, preventing the anti-corrosion layer from blistering or peeling.

[0015] As can be seen, this utility model has a simple structure and is easy to process and manufacture. By constructing a dual independent protection system, it accurately matches the needs of internal and external environments, greatly improves the system's leak prevention reliability and safety, extends the safe operation cycle of sewage treatment equipment by several times, and significantly reduces the overall cost of the entire life cycle.

[0016] The embodiments of the invention provided in this specification will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the embodiments of the invention provided in this specification will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the embodiments of the invention provided in this specification. Attached Figure Description

[0017] The accompanying drawings, which form part of the embodiments of the invention provided in this specification, are used to aid in understanding the embodiments of the invention provided in this specification. The content provided in the drawings and the related descriptions in the embodiments of the invention provided in this specification can be used to explain the embodiments of the invention provided in this specification, but do not constitute an undue limitation on the embodiments of the invention provided in this specification. In the drawings: Figure 1 This is a schematic diagram of the composite steel plate for treating highly corrosive industrial wastewater according to Embodiment 1 of this utility model.

[0018] Figure 2 This is a schematic diagram of the composite steel plate for treating highly corrosive industrial wastewater according to Embodiment 2 of this utility model.

[0019] The relevant markings in the above figures are: 100 - Steel plate base layer, 200 - Inorganic enamel layer, 300 - Organic adhesive layer, 400 - Organic anti-corrosion layer, 500 - Transition coating. Detailed Implementation

[0020] The embodiments of the invention provided in this specification will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the embodiments of the invention provided in this specification based on these descriptions. Before describing the embodiments of the invention provided in this specification in conjunction with the accompanying drawings, it should be particularly noted that: The technical solutions and features provided in the embodiments of the invention provided in this specification, including the following description, can be combined with each other without conflict.

[0021] Furthermore, the embodiments of the inventions provided in this specification mentioned below are generally only a portion of the embodiments of the inventions provided in this specification, and not all of them. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the inventions provided in this specification without creative effort should fall within the scope of protection of the embodiments of the inventions provided in this specification.

[0022] Regarding the terminology and units in the embodiments of the invention provided in this specification: The terms "comprising," "including," "having," and any variations thereof in the description, claims, and related parts of the embodiments of the invention provided in this specification are intended to cover non-exclusive inclusion. Furthermore, other relevant terms and units in the embodiments of the invention provided in this specification can be reasonably interpreted based on the relevant content of the embodiments of the invention provided in this specification.

[0023] Example 1

[0024] Figure 1 This is a schematic diagram of the composite steel plate used for treating highly corrosive industrial wastewater in this embodiment.

[0025] like Figure 1 The composite steel plate shown for treating highly corrosive industrial wastewater includes a steel plate base layer 100, an inorganic enamel layer 200, an organic adhesive layer 300, and an organic anti-corrosion layer 400. The surface roughness Ra value of both sides of the steel plate base layer 100 is 30-70 micrometers; the thickness of the steel plate base layer 100 is 4-10 millimeters, and the material can be Q235B low-carbon steel plate.

[0026] The inorganic enamel layer 200 is disposed on one side surface of the steel plate base layer 100 (located on the outside of the tank body during use); the thickness of the inorganic enamel layer 200 is 200-600 micrometers.

[0027] The organic adhesive layer 300 is disposed on the other side surface of the steel plate base layer 100 (located inside the tank during use); the organic adhesive layer 300 is a two-component epoxy resin adhesive coating, a polyurethane adhesive coating, or a modified silane polymer adhesive coating; the thickness of the organic adhesive layer 300 is 0.2 to 1 mm.

[0028] The organic anti-corrosion layer 400 is disposed on the side of the organic adhesive layer 300 away from the steel plate base 100, and the organic anti-corrosion layer 400 is fixedly connected to the steel plate base 100 through the organic adhesive layer 300; the organic anti-corrosion layer 400 is a PP (polypropylene) board, PE (polyethylene) board, PVC (polyvinyl chloride) board, PVDF (polyvinylidene fluoride) board, ETFE (ethylene-tetrafluoroethylene copolymer) board or PFA (soluble polytetrafluoroethylene) board; the thickness of the organic anti-corrosion layer 400 is 1 to 5 mm.

[0029] A preferred processing method includes the following steps: After cutting the steel plate base layer to the required size, sandblasting is performed on both sides to achieve the required roughness.

[0030] Weather-resistant enamel slurry is automatically sprayed onto the outside of the steel plate base layer 100, and then sent into a tunnel kiln to be sintered at 850℃ for 8 minutes to form a dense and smooth inorganic enamel layer 200.

[0031] After cleaning the inner side of the steel plate base layer 100, the selected adhesive, such as a two-component epoxy resin adhesive (Araldite® series), is mixed in proportion and then evenly applied to the inner surface of the steel plate base layer 100 using a notched scraper to form an organic adhesive layer 300.

[0032] Taking PVDF board as an example, the bonding surface of the PVDF board is corona treated to increase surface energy; the treated PVDF board is immediately aligned with the organic adhesive layer 300 and slowly rolled with a heavy-duty roller press under a pressure of 0.5MPa to ensure the removal of air bubbles and achieve full-area bonding; it is then kept under pressure and cured at 25℃ for 24 hours to allow the adhesive to fully cure, thus obtaining a composite steel plate for the treatment of highly corrosive industrial wastewater.

[0033] Example 2

[0034] Figure 2 This is a schematic diagram of the composite steel plate used for treating highly corrosive industrial wastewater in this embodiment.

[0035] Compared with Example 1, the composite steel plate for treating highly corrosive industrial wastewater in this embodiment differs in that: Figure 2 As shown, a transition coating 500 is also provided between the steel plate base layer and the organic adhesive layer. The transition coating 500 is a silane coupling agent coating. The construction process is as follows: the silane coupling agent is dissolved in a solvent (such as water or alcohol) and uniformly adhered to the inner side of the treated steel plate base layer by physical spraying.

[0036] Compared with Example 1, the composite steel plate of this embodiment has a further advantage in that: one end of the silane coupling agent is coupled with the metal hydroxyl groups on the surface of the steel plate. A condensation reaction occurs to form The covalent bond at one end is cross-linked with an organic adhesive layer (such as epoxy resin or polyurethane), thereby greatly improving the peel strength of the composite steel plate under long-term water immersion through chemical bonding.

[0037] Example 3

[0038] Compared with Example 2, the composite steel plate for treating highly corrosive industrial wastewater in this example is different in that the transition coating 500 is an epoxy zinc-rich coating, and its construction process is as follows: after mixing the epoxy resin containing zinc powder with the curing agent, it is sprayed onto the inner side of the steel plate base layer by physical methods such as high-pressure airless spraying.

[0039] Compared to Example 1, the composite steel plate of this embodiment has the following advantages: On the one hand, the epoxy resin in the coating, with its abundant polar groups, forms strong intermolecular forces and mechanical anchoring effects with the metallic hydroxyl groups on the steel plate surface, providing extremely high initial interfacial bonding force; on the other hand, the zinc powder in the coating can play an electrochemical protective role as a "sacrificial anode" when corrosive media penetrate, fundamentally inhibiting the occurrence of under-film corrosion (rust propagation) at the interface, and the insoluble zinc salt generated by the reaction can seal micropores, forming a self-healing barrier layer. Thus, through the synergistic effect of the physical, chemical, and electrochemical processes, the peel strength of the composite steel plate in long-term immersion in highly corrosive sewage is greatly improved.

[0040] An embodiment of the tank for treating highly corrosive industrial wastewater of this utility model is assembled from the above-mentioned composite steel plates. The preferred assembly method is bolt connection, and the joints are sealed with sealing strips.

[0041] The embodiments of the invention provided in this specification have been described above. Those skilled in the art will be able to implement the embodiments of the invention provided in this specification based on these descriptions. All other preferred embodiments and implementations obtained by those skilled in the art based on the above description of the embodiments of the invention provided in this specification without inventive effort should fall within the protection scope of the embodiments of the invention provided in this specification.

Claims

1. A composite steel plate for treating highly corrosive industrial wastewater, comprising a steel plate base layer (100), characterized in that: Also includes: Inorganic enamel layer (200), the inorganic enamel layer (200) is disposed on one side surface of the steel plate base layer (100); An organic adhesive layer (300) is disposed on the other side surface of the steel plate base layer (100); An organic anti-corrosion layer (400) is disposed on the surface of the organic adhesive layer (300) away from the steel plate base layer (100), and the organic anti-corrosion layer (400) is fixedly connected to the steel plate base layer (100) through the organic adhesive layer (300); the organic anti-corrosion layer (400) is a PP board, PE board, PVC board, PVDF board, ETFE board or PFA board; the thickness of the organic anti-corrosion layer (400) is 1 to 5 mm.

2. The composite steel plate as described in claim 1, characterized in that: The surface roughness Ra of the two sides of the steel plate base (100) is 30 to 70 micrometers; the thickness of the steel plate base (100) is 4 to 10 millimeters.

3. The composite steel plate as described in claim 1, characterized in that: The thickness of the inorganic enamel layer (200) is 200-600 micrometers.

4. The composite steel plate as described in claim 1, characterized in that: The organic adhesive layer (300) is a two-component epoxy resin adhesive coating, a polyurethane adhesive coating, or a modified silane polymer adhesive coating; the thickness of the organic adhesive layer (300) is 0.2 to 1 mm.

5. The composite steel plate as described in claim 1, characterized in that: A transition coating (500) is further provided between the steel plate base layer (100) and the organic adhesive layer (300), and the transition coating (500) is a silane coupling agent coating or an epoxy zinc-rich coating.

6. A tank for treating highly corrosive industrial wastewater, characterized in that: It is assembled from the composite steel plates described in any one of claims 1-5.

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