Hydraulic self-driven anticorrosion structure at ring type steel pipe joint

Abstract

The application discloses a kind of ring type steel pipe interface place hydraulic self-driven anticorrosion layer structure, annular groove is equipped in pipe wall at ring type steel pipe interface place, anticorrosion layer structure is equipped at annular groove, including the anode metal layer being equipped in the outside of steel pipe, CNF film as nanometer friction generator positive pole and PDMS film as nanometer friction generator negative pole being sequentially equipped in the inside of steel pipe, wire is arranged in the inside of CNF film and is connected with copper foil contact piece in the inside of anode metal layer, wire is arranged in the inside of PDMS film and is connected with copper foil contact piece in the inside of steel pipe.The application fuses the dual mechanism of physical anticorrosion and electrochemical anticorrosion, provides more comprehensive and efficient solution for pipeline anticorrosion.Not only significantly prolongs the service life of steel structure pipeline, but also continuously guarantees the water quality safety of drinking water in the long-term service process of pipeline.Meanwhile, the design also has potential steel pipe repair function, provides additional protection for long-term stable operation of pipeline.

Description

Technical Field

[0001] This invention belongs to the field of anti-corrosion pipeline lining manufacturing technology, specifically relating to a hydraulically self-driven anti-corrosion layer structure at a ring-type steel pipe interface. Background Technology

[0002] Pipe scale is a type of substance containing iron compounds, organic matter, and silicon-aluminum compounds, formed in pipes by suspended solids that are not completely removed during drinking water treatment through processes such as flocculation, sedimentation, and resuspension. Its content in ductile iron pipes ranges from 0.1 to 40 g·m³. -1 Pipe scale easily breeds bacteria and microorganisms, which may produce problems such as odor and discoloration. In severe cases, it can even cause food poisoning symptoms such as diarrhea and vomiting, posing a potential threat to human health. Long-term sedimentary sludge contains heavy metals such as arsenic, cadmium, and mercury. These toxic substances can be absorbed by the human body through water flow, and long-term consumption may lead to developmental delays and poor health in children, as well as various chronic diseases and even cancer in the elderly. Compared to the pipe body, pipe joints are more prone to corrosion. Pipe joints often involve welding or connecting different materials, such as steel pipes with valves and flanges. The potential difference between these materials can lead to electrochemical corrosion. Data shows that the corrosion rate at joints between different materials is often higher than that of pipes made of a single material. Furthermore, pipe joints typically have complex geometries and stress distributions, such as welds and threads. These structural differences can cause corrosive media to accumulate at the joints, accelerating the corrosion process. Localized corrosion accounts for about 80% of all corrosion, and pipe joints are often high-incidence areas for localized corrosion, with corrosion rates at pipe joints potentially several times or even tens of times higher than those at the pipe body.

[0003] Current pipeline joint corrosion protection designs mostly employ physical structures. The principle involves covering the inner surface of the pipeline joint with a layer of material with special properties to form a physical barrier protecting the pipeline. This can be divided into coating corrosion protection structures, internal lining corrosion protection, and external outer lining corrosion protection. Its advantages include simple construction, low cost, and wide applicability, but it also has drawbacks such as relatively poor protective performance, susceptibility to mechanical damage, acid and alkali corrosion, and low durability. Electrochemical corrosion protection technology, based on electrochemical principles, implements specific measures on metal equipment to transform it into the cathode in a corrosion cell system, thereby preventing or mitigating metal corrosion. It has advantages such as significant corrosion protection effect, convenient construction, and effective extension of the service life of metal workpieces. Due to the special environment of pipeline joints, a hydraulic self-driven system can be combined to automate the electrochemical reaction, thereby achieving comprehensive management and control of pipeline corrosion protection processes. As a clean energy utilization method, the hydraulic self-driven system has significant environmental friendliness. It does not require an additional energy supply, relying entirely on water power, thus avoiding energy consumption and environmental pollution. This characteristic makes hydraulically self-driven systems of significant value in sustainable development and green energy utilization. Therefore, it is necessary to design hydraulically self-driven corrosion protection for pipelines to effectively inhibit the formation and transformation of scale, thereby preventing any impact on drinking water quality. Summary of the Invention

[0004] To address the above problems, the present invention aims to provide a hydraulically self-driven anti-corrosion layer structure for ring-type steel pipe interfaces.

[0005] To effectively inhibit pipeline corrosion, this invention adopts a novel approach: a multi-layered anti-corrosion structure installed inside the pipeline utilizes the pressure generated by the flow of water to cause the cellulose (CNF) aerogel membrane and the porous polydimethylsiloxane (PDMS) aerogel membrane to press against each other, forming a nano-triboelectric generator (TENG) structure. This generates alternating current, which is then integrated into direct current by a power management system and used as a protective current for the metal pipeline. The negative electrode is connected to the protected object, and the positive electrode is connected to the auxiliary anode. The current loop is formed through the electrolyte environment inside the pipeline, thereby preventing pipeline corrosion.

[0006] The specific technical solution is as follows:

[0007] A hydraulically self-driven anti-corrosion layer structure for a ring-shaped steel pipe joint is disclosed. The ring-shaped steel pipe joint has an annular groove inside the pipe wall. The anti-corrosion layer structure is located in the annular groove and includes an anode metal layer on the outer surface of the steel pipe, a CNF film serving as the positive electrode of a nano-triboelectric generator and a PDMS film serving as the negative electrode of a nano-triboelectric generator, which are sequentially disposed on the inner surface of the steel pipe. A wire is disposed inside the CNF film and connected to a copper foil contact piece inside the anode metal layer. A wire is disposed inside the PDMS film and connected to a copper foil contact piece inside the steel pipe.

[0008] Furthermore, a chemical medium filling layer is provided between the anode metal layer and the steel pipe. The chemical medium filling layer is composed of 80% calcium sulfate, 15% bentonite and 5% sodium sulfate by mass fraction.

[0009] Furthermore, the length of the anti-corrosion layer structure at each ring-shaped steel pipe interface is not less than 50mm, the middle of the anti-corrosion layer structure is embedded in the annular groove, and the lengths of the annular grooves extending from both ends are equal.

[0010] Furthermore, the outer surface area of ​​the chemical medium filling layer is slightly larger than the inner surface area of ​​the anode metal layer.

[0011] Furthermore, the anode metal layer is made of AZ31B high-efficiency aluminum alloy.

[0012] Furthermore, the PDMS film thickness is 0.4-0.60 mm, the CNF film thickness is 0.3-0.50 mm, and the anode metal layer thickness is 25-35 mm.

[0013] Furthermore, the adhesion material between the CNF film and the anode metal layer is a low-whitening metal adhesive.

[0014] The beneficial effects of this invention are as follows:

[0015] 1) This invention can utilize the pressure generated when water flows through to cause CNF membrane and PDMS membrane to squeeze and contact each other, forming a nano-triboelectric generator (TENG) structure, which converts the kinetic energy of water into electrical energy, thereby generating a certain amount of alternating current. After integrating it into direct current, it can be used as a protective current for metals. The negative electrode is connected to the protected pipe section, and the positive electrode is connected to the auxiliary anode. The current loop is formed through the electrolyte environment in the pipe, thereby avoiding pipe corrosion.

[0016] 2) The cellulose membranes used in TENG structures typically have good biocompatibility and biodegradability, making them safer and more environmentally friendly for use in drinking water applications. Cellulose membranes are usually made from natural cellulose and starch as the main raw materials, which are relatively low in cost and help reduce the overall manufacturing cost of TENG. In addition, PDMS membranes have excellent performance in terms of elasticity, thermal stability, chemical inertness and triboelectricity, making them suitable for drinking water transportation and other applications that may require mechanical deformation.

[0017] 3) The preparation method of this invention is simple and convenient, low in cost, and no harmful substances are generated during the production process, which follows the principle of green environmental protection; and it can show better anti-corrosion effect than conventional methods under the action of protective current. Attached Figure Description

[0018] Figure 1 This is a cross-sectional schematic diagram of the anti-corrosion layer structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the ring-shaped steel pipe interface of the present invention;

[0020] Figure 3 The short-circuit current of the PDMS membrane changes over time;

[0021] Figure 4 The open-circuit voltage of the PDMS film changes over time;

[0022] In the diagram: 1. Annular groove; 2. Steel pipe; 3. Anode metal layer; 4. CNF film; 5. PDMS film; 6. Copper foil contact piece. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited thereto.

[0024] like Figure 1 and Figure 2 As shown, a hydraulically self-driven anti-corrosion layer structure for a ring-shaped steel pipe joint is disclosed. An annular groove 1 is provided inside the pipe wall at the ring-shaped steel pipe joint. The anti-corrosion layer structure is located at the annular groove 1. The length of the anti-corrosion layer structure at each ring-shaped steel pipe joint is not less than 50 mm. The middle of the anti-corrosion layer structure is embedded in the annular groove 1, and the two ends extending out of the annular groove 1 have equal lengths. The anti-corrosion layer structure includes an anode metal layer 3 on the outer surface of the steel pipe 2, a CNF film 4 serving as the positive electrode of a nano-triboelectric generator, and a PDMS film 5 serving as the negative electrode of a nano-triboelectric generator, sequentially disposed on the inner surface of the steel pipe 2. The CNF film 4 has a... The conductor is connected to the copper foil contact piece 6 inside the anode metal layer 3. The conductor inside the PDMS film 5 is connected to the copper foil contact piece 6 inside the steel pipe 2. A chemical medium filling layer is also provided between the anode metal layer 3 and the steel pipe 2. The composition of the chemical medium filling layer is 80% calcium sulfate, 15% bentonite and 5% sodium sulfate by mass fraction. The outer surface area of ​​the chemical medium filling layer is slightly larger than the inner surface area of ​​the anode metal layer 3. The material of the anode metal layer 3 is AZ31B high-efficiency aluminum alloy. The thickness of the PDMS film 5 is 0.4-0.60 mm, the thickness of the CNF film 4 is 0.3-0.50 mm, the thickness of the anode metal layer 3 is 25-35 mm, and the adhesion material between the CNF film 4 and the anode metal layer 3 is low whitening metal glue.

[0025] Example 1

[0026] In this embodiment, the specific steps for testing the short-circuit current of the PDMS film material are as follows:

[0027] (1) A polymethyl methacrylate substrate is used as a support layer. A copper foil with a thickness of 0.1 mm (bottom copper electrode) is pasted on the polymethyl methacrylate substrate, and a PDMS film is pasted on the copper foil.

[0028] (2) Attach another 3 mm wide and 0.1 mm thick copper foil (top copper electrode) to the membrane surface. Use a peristaltic pump to drip liquid onto the membrane at a certain flow rate.

[0029] (3) Use an electrometer (Keithley 6514) to connect two electrodes to measure the short-circuit current.

[0030] Example 2

[0031] In this embodiment, the specific steps for testing the open-circuit voltage of the PDMS film material are as follows:

[0032] (1) A polymethyl methacrylate substrate is used as a support layer. A copper foil with a thickness of 0.1 mm (bottom copper electrode) is pasted on the polymethyl methacrylate substrate, and a PDMS film is pasted on the copper foil.

[0033] (2) Attach another 3 mm wide and 0.1 mm thick copper foil (top copper electrode) to the membrane surface. Use a peristaltic pump to drip liquid onto the membrane at a certain flow rate.

[0034] (3) Use an electrometer (Keithley 6514) to connect two electrodes to measure the open circuit voltage.

[0035] Short-circuit current and open-circuit voltage measurement tests were conducted according to Examples 1 and 2, respectively. The test results are as follows: Figure 3 and Figure 4 As shown. Observing Example 1, it can be found that the short-circuit current of the PDMS film fluctuates only slightly over time within the experimental period of 200 s, and remains stable at 0.8-0.9 A. Observing Example 2, it can be found that the open-circuit voltage of the PDMS film fluctuates only slightly over time within the experimental period of 200 s, and remains stable at 17.0-17.2 A.

[0036] It can be seen that the current and voltage generated by this PDMS membrane are relatively stable, and the current is large enough to serve as a protective current. It can effectively prevent pipe corrosion and inhibit the formation of scale by combining cathodic protection with an external power supply and a hydraulic self-driving system.

Claims

1. A hydraulically self-driven anti-corrosion layer structure for a ring-shaped steel pipe joint, wherein an annular groove (1) is provided inside the pipe wall at the ring-shaped steel pipe joint, characterized in that, The anti-corrosion layer structure is located in the annular groove (1), including an anode metal layer (3) on the outer surface of the steel pipe (2), a CNF film (4) serving as the positive electrode of the nano-triboelectric generator and a PDMS film (5) serving as the negative electrode of the nano-triboelectric generator, which are sequentially located on the inner surface of the steel pipe (2). A wire is provided on the inner side of the CNF film (4) to connect with the copper foil contact piece (6) in the anode metal layer (3), and a wire is provided on the inner side of the PDMS film (5) to connect with the copper foil contact piece (6) in the steel pipe (2). The length of the anti-corrosion layer structure at each ring-shaped steel pipe interface is not less than 50mm. The anti-corrosion layer structure is embedded in the annular groove (1) in the middle, and the lengths of the annular groove (1) extending from both ends are equal. The material of the anode metal layer (3) is AZ31B high-efficiency aluminum alloy; The PDMS film (5) has a thickness of 0.4-0.60 mm, the CNF film (4) has a thickness of 0.3-0.50 mm, and the anode metal layer (3) has a thickness of 25-35 mm.

2. The hydraulically self-driven anti-corrosion layer structure at the ring-type steel pipe interface as described in claim 1, characterized in that, A chemical medium filling layer is also provided between the anode metal layer (3) and the steel pipe (2). The chemical medium filling layer is composed of 80% calcium sulfate, 15% bentonite and 5% sodium sulfate by mass fraction.

3. The hydraulically self-driven anti-corrosion layer structure at the ring-type steel pipe interface as described in claim 1, characterized in that, The outer surface area of ​​the chemical medium filling layer is slightly larger than the inner surface area of ​​the anode metal layer (3).

4. The hydraulically self-driven anti-corrosion layer structure at the ring-type steel pipe interface as described in claim 1, characterized in that, The adhesive material between the CNF film (4) and the anode metal layer (3) is a low-whitening metal adhesive.

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