In-situ control experimental device and method for gas single factor corrosion in composite corrosion factors

Abstract

The present invention discloses an in-situ control experimental device for gas single factor corrosion in a composite corrosion factor, comprising a main chamber for composite corrosion and at least one sub-chamber for gas single factor corrosion, wherein the top of the main chamber is connected to the top of the sub-chamber through a gas pipe. The present invention also discloses an in-situ control experimental method for gas single factor corrosion in a composite corrosion factor. The present invention realizes real-time in-situ research on the corrosion performance of each gas in a reaction system where corrosive gas is generated on a material, reduces the intermediate steps of measuring gas content, and has the characteristics of being fast and reliable.

Description

Technical Field

[0001] The invention relates to an in-situ control experimental device and method for gas single factor corrosion in composite corrosion factors. Background Art

[0002] The research on the corrosion of materials by sulfate-reducing bacteria (SRB) has been a hot topic in recent years. SRB is an anaerobic microorganism widely present in the environment, and nearly half of the microbial corrosion is caused by it. Simulated corrosion experiments are necessary to explore its corrosion mechanism, characterize corrosion characteristics and predict corrosion life. During the experiment, SRB bacteria and H2S gas produced during its metabolism jointly form a composite corrosion environment for metals. With the change of SRB growth cycle, the amount of H2S gas produced by it presents a dynamic change process. The effect of SRB activity and H2S concentration on metal corrosion rate in this process is unknown. In order to accurately characterize the corrosion effect of SRB activity on metal materials, a control group study under the corresponding H2S concentration conditions is required. The conventional experimental operation first determines the concentration of H2S in the system at multiple different time periods, and secondly uses exogenous H2S gas to conduct separate experiments. The experimental process is complicated and dangerous, and it pollutes the environment greatly. Summary of the invention

[0003] To solve the above problems, the present invention provides an in-situ control experimental device for single-factor corrosion of gas in a composite corrosion factor and a corresponding experimental method, which directly connects the headspace of the control group and the experimental group, and uses the gas generated in situ by SRB as the gas source of the control group, thereby restoring the real corrosion environment and the real-time corrosion process to the greatest extent, and the experimental process is convenient and safe.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] The invention discloses an in-situ control experimental device for gas single factor corrosion in composite corrosion factors, comprising a main chamber for composite corrosion and at least one sub-chamber for gas single factor corrosion, wherein the top of the main chamber is connected with the top of the sub-chamber through an air pipe.

[0006] Furthermore, the main chamber and the sub-chamber each comprise a container with an opening at the top and a cover for sealing the container, the cover is provided with at least one opening, and the air pipe is detachably and airtightly connected to the opening.

[0007] As an improvement of the present invention, the container is made of ordinary glass, high borosilicate glass or polytetrafluoroethylene, and the cover is made of polytetrafluoroethylene or rubber.

[0008] As an improvement of the present invention, the lid and the container are airtightly connected by means of threads, snaps or adhesives.

[0009] As an improvement of the present invention, the cover is equipped with a hollow bolt and an O-ring, the opening is a stepped hole that is larger at the top and smaller at the bottom, the diameter of the large hole matches the outer diameter of the O-ring, the upper half of the large hole is provided with an internal thread for screwing with the bolt, the diameter of the small hole matches the outer diameter of the trachea, the trachea is inserted into the small hole, and when the hollow bolt is screwed with the large hole, the bottom surface squeezes the O-ring to clamp the trachea to achieve an airtight connection between the trachea and the opening.

[0010] As an improvement of the present invention, the cover is also equipped with a solid bolt for sealing the opening.

[0011] As an improvement of the present invention, the air pipe is also equipped with a gas filter and / or a gas dryer.

[0012] As an improvement of the present invention, the cover is also equipped with a thermometer and / or a test electrode.

[0013] As an improvement of the present invention, the container is further equipped with a heating device and / or a stirring device.

[0014] An in-situ control experimental device for gas single-factor corrosion in a composite corrosion factor is carried out using the above-mentioned experimental device, and includes the following steps:

[0015] 1) Place equal amounts of corrosive media into each chamber and place the sample in the media;

[0016] 2) Assemble each chamber;

[0017] 3) Connect the main chamber and each sub-chamber through a gas path to achieve the same gas environment in each chamber;

[0018] 4) Place the entire device in a suitable temperature environment for corrosion testing;

[0019] 5) Take out the samples that have been corroded for a certain period of time and measure the required data.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention realizes the detection of the corrosion situation of in-situ corrosive gas. The device can directly utilize the corrosive gas generated in-situ, and the gas concentration and gas composition of the control group during the experiment are exactly the same as those in the complex factor corrosion environment, ensuring the authenticity of the corrosion effect.

[0022] 2. The present invention simplifies the experimental device and experimental steps, and the device and principle can be used to make flexible changes according to actual conditions, which is highly practical.

[0023] 3. The present invention realizes the demand for environmental protection and rationally utilizes the gas generated in situ to carry out the control group experiment without consuming a large amount of toxic and harmful gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the experimental device of this embodiment;

[0025] Figure 2 is a schematic diagram of the SRB corrosion process of the experimental device of this embodiment;

[0026] Figure 3 is a schematic diagram of the assembly of the lid and the container of this embodiment;

[0027] Figure 4 1 is a schematic diagram of the assembly of the cover, the hollow bolts, the solid bolts, and the air pipe of this embodiment;

[0028] Figure 5 It is a schematic diagram of the structure of the experimental device of this example when used for electrochemical testing;

[0029] Explanation of the reference numerals: 1-main chamber; 2-sub-chamber; 3-air pipe; 4-metal sample; 5-corrosive medium; 6-lid; 7-sealing ring; 8-container; 9-opening; 10-hollow bolt; 11-O-ring; 12-solid bolt; 13-working electrode; 14-reference electrode; 15-counter electrode. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1 As shown, an in-situ control experimental device for gas single factor corrosion in a composite corrosion factor of this embodiment includes a main chamber 1 for composite corrosion and at least one sub-chamber 2 for gas single factor corrosion, and the top of the main chamber 1 is connected to the top of the sub-chamber 2 through an air pipe 3.

[0032] In the study of microbial corrosion (SRB) of metals, Figure 2 As shown in the figure, metal samples 4 are placed in both the main chamber 1 and the sub-chamber 2. The main chamber 1 uses a culture medium inoculated with SRB as a corrosion medium 5, and SRB corrosion of the metal occurs. The sub-chamber 2 only adds the same corrosion medium 5 without inoculating SRB. During the corrosion reaction in the main chamber 1, a large amount of H 2 S gas, H 2 S gas enters the sub-chamber 2 through the gas pipe 3. As the reaction proceeds, H 2 S gas and H in the main chamber 12 The S gas reaches equilibrium, at which point the corrosion of the metal in the sub-chamber 2 is completely caused by the gas and has nothing to do with SRB, thus achieving an in-situ synchronous control experiment.

[0033] It is easy to understand that the present device and method can be applied to all corrosion experiments similar to the control group as described above, as long as a complex corrosion factor environment is formed during the corrosion process due to the generation of corrosive gases, the present device can be used to simultaneously and utilize the corrosive gases generated in situ to conduct corrosion experiments in the control group. To achieve this goal, the design of the present device must meet the following requirements: 1) Good airtightness: on the one hand, to ensure the establishment of the corrosion system, such as the normal growth of SRB, the maintenance of the anaerobic system, etc., and on the other hand, to prevent interference from other corrosive gases; 2) Interconnected gas exchange channels: to ensure that the gas is evenly distributed in the two groups of interconnected experimental chambers, and the content of corrosive gases directly affects the experimental results; 3) Isolation: to ensure that in addition to the uniform distribution of gas components in the main chamber and the sub-chamber, there is no contact and exchange between other corrosive media.

[0034] To achieve the above design requirements, please refer to Figure 3 and Figure 4 As shown, the main chamber 1 and the sub-chamber 2 have the same structure, and both include a container 8 with an opening on the top and a cover 6 for sealing.

[0035] The container 8 is made of an inert material such as ordinary glass, high borosilicate glass or polytetrafluoroethylene. There is no restriction on the shape and number of openings. It can be open or narrow-mouthed, multi-mouthed or single-mouthed. For example, single-mouthed flasks, multi-mouthed flasks, narrow-mouthed bottles, etc. commonly used in laboratories can be selected.

[0036] The material of the cover 6 can be polytetrafluoroethylene with excellent physical and chemical properties, or can be a rubber stopper or other material that meets the experimental requirements.

[0037] In order to ensure good airtightness, in this embodiment, the lid 6 and the container 8 are connected by a thread + sealing ring 7, and the sealing ring 7 can be made of fluororubber. Of course, the airtight connection can also be achieved by using a jaw aluminum cover, a buckle, an adhesive, etc., which are all conventional designs and the detailed structure will not be repeated.

[0038] In order to achieve the connection between the chambers, openings 9 are provided on the cover 6. The number of openings 9 is flexibly designed according to the experimental requirements. The openings 9 are not only used to connect the air pipe 3, but also to connect a thermometer, a stirrer or a test electrode.

[0039] In order to prevent the gas inside the chamber from escaping through the opening 9, the air pipe 3 needs to be connected to the opening 9 in an airtight manner. In this embodiment, the air pipe 3 is connected to the opening 9 in an airtight manner by means of a hollow bolt + O-ring. Specifically, the opening 9 is a stepped hole with a large top and a small bottom. The diameter of the large hole is slightly larger than the outer diameter of the O-ring 11, and the diameter of the small hole is slightly smaller than the inner diameter of the O-ring 11, and is also slightly larger than the outer diameter of the air pipe 3, so as to facilitate the insertion of the air pipe 3. An internal thread for screwing with the hollow bolt 10 is provided in the upper half of the large hole. During installation, the O-ring 11 is placed on the step of the opening 9, and the hollow bolt 10 is screwed in, and the bottom surface contacts the O-ring 11. Then, the air pipe 3 is inserted into the small hole through the hollow bolt 10 and the O-ring 11, and finally the hollow bolt 10 is tightened to squeeze the O-ring 11 to deform and clamp the air pipe 3 to achieve a sealing effect.

[0040] It should be noted that when the opening 9 does not need to be connected to the air pipe 3 or other components, it can be sealed by a solid bolt 12 + O-ring 11.

[0041] In addition, gas filtering, gas drying and other processing devices can be set on the gas pipe 3, as well as various simple or complex equipment and devices to make the gas entering the sub-chamber 2 meet the requirements. Some simple treatments that help the reaction in the main chamber 1 can also be set, such as water bath, oil bath heating, magnetic rotor stirring and other heating and stirring devices. These are all conventional technologies and will not be repeated here.

[0042] The method of using the experimental device of this embodiment to perform SRB corrosion on a metal sample is as follows:

[0043] 1. Pour the prepared SRB culture medium as the corrosion medium 5 into the main chamber 1 and the sub-chamber 2 in equal amounts, and place the metal sample 4 flat on the bottom of the chamber;

[0044] 2. Inoculate the main chamber 1 with SRB bacteria, and then close the lid 6. Figure 3 Assembled in the manner of;

[0045] 3. Use the air pipe 3 to connect the main chamber 1 and the sub-chamber 2 Figure 4 Assembled by the method;

[0046] 4. High-purity sterile nitrogen is introduced through the opening 9 of the main chamber 1 that is not connected to the air pipe 3 to remove oxygen in the system. The gas flows out through the opening 9 of the sub-chamber 2 that is not connected to the air pipe 3. After 30 minutes, the two openings 9 are sealed with solid bolts;

[0047] 5. Place the entire device in a 37°C constant temperature incubator for culture and corrosion.

[0048] 6. Open the corrosion system regularly and take out the corrosion samples for further testing and characterization.

[0049] It is easy to understand that in addition to using this device for immersion corrosion experiments, it can also be used for electrochemical experiments. The specific device structure is as follows Figure 5 shown.

[0050] The holes in the cover can form a classic three-electrode system: working electrode 13, reference electrode 14 and counter electrode 15. Multiple holes can also be opened to design multiple working electrodes at the same time. The hollow bolt + O-ring design facilitates the rotation of the Luggin capillary, and the Luggin capillary can be rotated to the vicinity of the corresponding working electrode when measuring different working electrodes.

[0051] The above detailed description is a specific description of a feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the patent scope of this case.

Claims

1. An in-situ control experimental device for gas single factor corrosion in a composite corrosion factor, characterized by: It includes a main chamber for composite corrosion and at least one sub-chamber for gas single-factor corrosion, and the top of the main chamber is connected with the top of the sub-chamber through a gas pipe; The main chamber and the sub-chamber each comprise a container with an opening at the top and a cover for sealing the container, the cover is provided with at least one opening, and the air pipe is detachably connected to the opening in an airtight manner; The cover is equipped with a hollow bolt and an O-ring. The opening is a stepped hole with a larger upper portion and a smaller lower portion. The diameter of the large hole matches the outer diameter of the O-ring. The upper half of the large hole is provided with an internal thread for screwing with the bolt. The diameter of the small hole matches the outer diameter of the air pipe. The air pipe is inserted into the small hole. When the hollow bolt is screwed with the large hole, the bottom surface squeezes the O-ring to clamp the air pipe to achieve an airtight connection between the air pipe and the opening. The cover is also equipped with a solid bolt for sealing the opening; The container is made of ordinary glass, high borosilicate glass or polytetrafluoroethylene, and the cover is made of polytetrafluoroethylene or rubber; The lid and the container are connected airtightly by means of threads, snaps or adhesives; The air pipe is also equipped with a gas filter and / or a gas dryer; The cover is also equipped with a thermometer and / or a test electrode; The container is also equipped with a heating device and / or a stirring device.

2. An in-situ control experimental method for gas single factor corrosion in a composite corrosion factor, using the experimental device described in claim 1, characterized in that: The following steps are involved: 1) Place equal amounts of corrosive media into each chamber and place the sample in the media; 2) Assemble each chamber; 3) Connect the main chamber and each sub-chamber through a gas path to achieve the same gas environment in each chamber; 4) Place the entire device in a suitable temperature environment for corrosion testing; 5) Take out the samples that have been corroded for a certain period of time and measure the required data.

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