Piping corrosion and abrasion test method and piping corrosion and abrasion test system

Abstract

To provide a corrosion abrasion testing method of piping and a corrosion abrasion testing system of piping capable of acquiring corrosion abrasion data of piping or the like under a condition suited for an actual machine.SOLUTION: A method for testing corrosion and abrasion of the inside of piping for transporting fluid by circulating a test fluid α in test piping 10 includes: a dissolved oxygen amount setting step S1 of setting a dissolved oxygen amount of the test fluid α by considering an actual machine dissolved oxygen amount include in fluid that is changed according to an actual usage condition and / or a use environment of piping; a gas-containing fluid supply step S2 of supplying a gas-containing fluid γ containing oxygen and / or inert gas in the test fluid α; a dissolved oxygen amount measurement step S3 of measuring a dissolved oxygen amount; and a control step S4 of controlling the amount of supply of the gas-containing fluid γ on the basis of the set dissolved oxygen amount and the measured dissolved oxygen amount.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method and system for testing corrosion and abrasion of a pipe, in which corrosion and abrasion of the inside of a pipe that transports a fluid are tested by circulating a test fluid through the test pipe. [Background technology]

[0002] In recent years, momentum for the development of seafloor mineral resources, such as hydrothermal deposits, manganese nodules, and cobalt-rich crusts, has been building both domestically and internationally, making it urgent to establish related technologies and accumulate data on the equipment and materials used. Metal pipes (including pumps and other equipment) are often used to transport ores extracted from the seabed, but when the pipes are made of a metal that corrodes easily, such as steel, it is believed that corrosion caused by the transport fluid (mainly seawater) plays a major role in the wear of the pipes during transportation. Pipe corrosion is highly dependent on the amount of dissolved oxygen (hereinafter referred to as "DO") in the transport fluid.

[0003] Furthermore, submerged air bubbles with a diameter of 100 μm or less are collectively called fine bubbles. Because fine bubbles have various special properties compared to air bubbles of normal size, a wide range of research has been conducted on their applications in recent years, and the range of industrial applications is expanding. For example, when oxygen is used as the gas to generate fine bubbles in water or seawater, it is possible to significantly increase the DO value in the liquid, which is known to have the effect of dramatically promoting the growth of farmed fish. On the other hand, when nitrogen is used as the gas to generate fine bubbles in water or seawater, the action of the nitrogen fine bubbles releases oxygen, reducing the DO value and creating a so-called deaeration effect, which has been reported to have a significant effect in preventing the loss of freshness and spoilage of caught fish.

[0004] Here, Patent Document 1 discloses an abrasion testing device in which a pressurizing section having a step section whose diameter decreases along a fixed direction is formed in part of a circulation path in which a test slurry fluid is circulated in a fixed direction by a fluid flow means, a test piece is placed facing the outlet of the pressurizing section and is removably attached, and a nozzle having a flow path whose diameter is further reduced than that of the outlet is removably attached to the outlet of the pressurizing section. Furthermore, Patent Document 2 discloses a corrosion testing device including a corrosive liquid tank for exposing a test piece in the corrosive liquid, a liquid tank for supplying the corrosive liquid to the corrosive liquid tank, a circulation mechanism for circulating the corrosive liquid between the liquid tank and the corrosive liquid tank, a bubbling mechanism for bubbling nitrogen gas into the corrosive liquid in the liquid tank to reduce the amount of dissolved oxygen in the corrosive liquid, an isolation chamber with nitrogen gas sealed inside, and a collection weir for collecting the corrosive liquid. Furthermore, Patent Document 3 discloses a corrosion testing apparatus including a water tank for storing high-concentration dissolved oxygen water, a dissolved oxygen concentration adjustment means for adjusting the dissolved oxygen concentration of the high-concentration dissolved oxygen water in the water tank, an autoclave in which high-concentration salt water is stored and in which test pieces are submerged in the high-concentration salt water, a supply means for supplying the high-concentration dissolved oxygen water into the autoclave, a vacuum exhaust means for drawing a vacuum inside the autoclave, a dissolved oxygen concentration measurement means for measuring the dissolved oxygen concentration of the high-concentration salt water, and a heating means for heating the autoclave. Patent Document 4 discloses a fine bubble water producing device that includes a pressure-resistant container filled with water, at least one micronozzle disposed in the pressure-resistant container, and a gas supply source connected to the micronozzle via a gas supply line, in which the micronozzle is formed by compressing one end of a metal pipe to form a flat closed end and polishing the closed end so as to have a plurality of microholes communicating with the inside of the metal pipe, and that produces fine bubble water by injecting high-pressure gas from the gas supply source into the pressure-resistant container through the microholes of the micronozzle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Jpn. Jpn. Published No. 62-17703 [Patent Document 2] Japanese Patent Application Publication No. 53-99995 [Patent Document 3] JP 2013-127389 A [Patent Document 4] JP 2019-136638 A Summary of the Invention [Problem to be solved by the invention]

[0006] When grasping the wear characteristics of pipes transporting ore slurry, a circulation wear test is usually performed using an ore slurry made by mixing simulated ore with water or artificial seawater. When experimentally acquiring wear data of pipes, etc., by a circulation wear test, it is necessary to roughly match the amount of dissolved oxygen in the transport fluid used in the test and the time until corrosion progresses in the pipes, etc., with those of the actual equipment. However, since the amount of dissolved oxygen in the actual equipment varies greatly depending on the water depth (water pressure), water area, transportation method (slurry type, gas lift type, etc.), operation period, etc., it was difficult to quantitatively control the amount of dissolved oxygen in the fluid circulating in the wear test device according to these. In addition, in a circulation wear test using an ore slurry, physical collisions with the ore and suspension of the circulating water by crushed ore powder occur, so it was difficult to accurately measure the amount of dissolved oxygen during the test. Furthermore, if corrosion of the pipes etc. progresses during the abrasion test, the consumption of dissolved oxygen increases with the corrosion phenomenon, and the amount of dissolved oxygen in the transported fluid gradually decreases. However, because the abrasion test is completed in a relatively short time, it is difficult to allow the time required for corrosion of the test area to progress. Furthermore, in the circulating wear tests using a test fluid such as an ore slurry, the Patent Documents 1 to 4 do not quantitatively control the amount of dissolved oxygen in the circulating water in accordance with the actual conditions. SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a method and system for testing corrosion and abrasion of piping, which are capable of acquiring corrosion and abrasion data of piping etc. under conditions that are in line with those of an actual machine. [Means for solving the problem]

[0007] A corrosion and abrasion test method for a pipe according to claim 1 is a method for testing corrosion and abrasion inside a pipe transporting a fluid by circulating a test fluid through the test pipe, and includes a dissolved oxygen amount setting step for setting a dissolved oxygen amount of the test fluid in consideration of an actual dissolved oxygen amount contained in the fluid that changes according to an actual use condition and / or use environment of the pipe, a gas-containing fluid supply step for supplying a gas-containing fluid containing oxygen and / or an inert gas to the test fluid, a dissolved oxygen amount measuring step for measuring the dissolved oxygen amount, and a control step for controlling the supply amount of the gas-containing fluid based on the set dissolved oxygen amount and the measured dissolved oxygen amount. At least the measurement result in the dissolved oxygen amount measuring step and the control state in the control step are displayed on the display means. It is characterized by: According to the present invention as set forth in claim 1, the amount of dissolved oxygen in the test fluid is set taking into consideration the amount of dissolved oxygen in the actual piping, and then a corrosion and wear test is performed while quantitatively controlling the amount of dissolved oxygen in the test fluid circulating through a circulation path in which the test piping is installed, thereby making it possible to obtain corrosion and wear data for the piping under conditions that correspond to the actual equipment. In addition, the person who performs the corrosion and wear test can accurately grasp the amount of dissolved oxygen in the test fluid and the control status thereof.

[0008] The present invention as described in claim 2 is characterized in that the usage conditions include at least one of the type, pressure, and transportation method of the fluid used in the actual piping, and the usage environment includes at least one of the water area and water depth. According to the present invention as set forth in claim 2, the amount of dissolved oxygen can be more appropriately set in the dissolved oxygen amount setting step by specifically considering the amount of dissolved oxygen, which varies greatly depending on the actual use conditions and environment of the piping.

[0009] The present invention as described in claim 3 is characterized in that, before performing a test, a gas-containing fluid supply step, a dissolved oxygen amount measurement step, and a control step are performed as a dissolved oxygen amount adjustment loop while circulating the test fluid. According to the present invention as set forth in claim 3, the influence of suspension of the test fluid due to the abrasion test and the like can be avoided, and the dissolved oxygen amount of the test fluid can be adjusted to a set dissolved oxygen amount.

[0010] According to the present invention as set forth in claim 4, after the dissolved oxygen amount set by the dissolved oxygen amount adjustment loop is obtained, a predetermined corrosion test time is performed. Test fluid The apparatus further comprises a corrosion test loop that continues to circulate. According to the present invention as set forth in claim 4, a corrosion test is performed while controlling the amount of dissolved oxygen in the test fluid to a set level, and the degree of corrosion progress of the test piping can be made closer to the conditions of an actual machine. 。

[0011] request request 5 The present invention described , melt After the set amount of dissolved oxygen is obtained in the dissolved oxygen adjustment loop, The test fluid is made into an ore slurry by adding ore. A given wear test time, Ore slurry The device further comprises a wear test loop that continues to circulate. Claim 5 According to the present invention described above, it is possible to carry out a corrosion and wear test of a pipe using an ore slurry by continuing circulation while controlling the dissolved oxygen content of the test fluid to a set value.

[0012] Claim 6 The present invention described is based on the following corrosion test loop: 2. Add ore to make the test fluid into an ore slurry, and continue circulating the ore slurry for a specified wear test time. A wear test loop is carried out. Claim 6 According to the present invention described above, a corrosion test is performed under conditions where the degree of corrosion progression of the test piping is close to the conditions of the actual equipment, and then a wear test is performed, thereby making it possible to perform a corrosion and wear test of the piping while controlling the amount of dissolved oxygen in the test fluid to a set amount of dissolved oxygen.

[0013] Claim 7 The present invention described above is characterized in that the dissolved oxygen amount measuring step of measuring the dissolved oxygen amount is not performed in the wear test loop. Claim 7 According to the present invention described above, it is possible to preserve the dissolved oxygen measurement equipment for test fluids containing ore and crushed ore powder, and it is also possible to prevent the measurement of the dissolved oxygen amount from becoming inaccurate due to the influence of suspension of the test fluid, etc., resulting in a deterioration in controllability.

[0014] Claim 8The present invention described herein is characterized in that the gas-containing fluid is fine bubble water that contains oxygen and / or an inert gas as fine bubbles. Claim 8 According to the present invention described above, the amount of dissolved oxygen in the test fluid can be controlled with high precision, and the amount of dissolved oxygen can be made close to that in an actual device.

[0015] Claim 9 The corrosion and abrasion testing system for piping according to the present invention described above is a system for testing corrosion and abrasion inside a piping that transports a fluid by circulating a test fluid through the test piping, and includes a circulation path having the test piping as a part thereof, a circulation means for circulating the test fluid, a dissolved oxygen amount setting means for setting the dissolved oxygen amount of the test fluid in consideration of the actual dissolved oxygen amount contained in the fluid that changes according to the actual use conditions and / or use environment of the piping, a gas-containing fluid supplying means for supplying a gas-containing fluid containing oxygen and / or an inert gas to the test fluid, a dissolved oxygen amount measuring means for measuring the amount of dissolved oxygen, and a control means for controlling the supply amount of the gas-containing fluid based on the set amount of dissolved oxygen and the measured amount of dissolved oxygen. a display means for displaying at least the measurement result of the dissolved oxygen amount measuring means and the control state of the control means; The present invention is characterized by comprising: Claim 9 According to the present invention described above, the amount of dissolved oxygen in the test fluid is set by a dissolved oxygen amount setting means taking into account the amount of dissolved oxygen in the actual piping, and then a corrosion and wear test is performed while quantitatively controlling the amount of dissolved oxygen in the test fluid circulating through a circulation path in which the test piping is provided, thereby making it possible to obtain corrosion and wear data for the piping under conditions that correspond to the actual equipment. In addition, the person who performs the corrosion and wear test can accurately grasp the amount of dissolved oxygen in the test fluid and the control status thereof.

[0016] Claim 10 The invention described is characterized in that the test fluid is an ore slurry and that the circulation path is provided with an ore supply means. Claim 10 According to the present invention described in the above, it is possible to carry out a corrosion wear test of a pipe using an ore slurry.

[0017] Claim 11The present invention described herein is characterized in that the gas-containing fluid supplied from the gas-containing fluid supply means is fine bubble water containing oxygen and / or an inert gas as fine bubbles. Claim 11 According to the present invention described above, the amount of dissolved oxygen in the test fluid can be controlled with high precision, and the amount of dissolved oxygen can be made close to that in an actual device.

[0018] Claim 12 The present invention described is characterized in that the gas-containing fluid supply means is an oxygen / inert gas fine bubble generator connected to a circulation path, which bubbles oxygen supplied from an oxygen supply source in water to produce oxygen fine bubble water and / or bubbles inert gas supplied from an inert gas supply source in water to produce inert gas fine bubble water. Claim 12 According to the present invention described above, fine bubble water can be efficiently generated and supplied to a circulation path.

[0019] Claim 13 The present invention is characterized in that the control means controls the supply amount of each of the oxygen fine bubble water and the inert gas fine bubble water to the test fluid. Claim 13 According to the present invention described above, the supply amounts of oxygen fine bubble water and inert gas fine bubble water can be controlled to mix them with the test fluid in an appropriate ratio, thereby approaching a set amount of dissolved oxygen.

[0020] Claim 14 The present invention described is characterized in that the gas-containing fluid supply means is an oxygen / inert gas fine bubble generator connected to a circulation path, which bubbles oxygen supplied from an oxygen source and / or inert gas supplied from an inert gas source in water to produce fine bubble water. Claim 14 According to the present invention described above, a single fine bubble generator can generate fine bubble water containing a mixture of oxygen and an inert gas and supply it to a circulation path, making it possible to miniaturize the device.

[0021] Claim 15 The present invention is characterized in that the control means controls the supply amounts of oxygen and inert gas to the oxygen / inert gas fine bubble generator. Claim 15 According to the present invention described above, oxygen and an inert gas are mixed in an appropriate ratio to generate fine bubble water, which is then supplied to a test fluid, thereby approaching a set amount of dissolved oxygen.

[0022] Claim 16 The present invention is characterized in that the dissolved oxygen amount measuring means is provided in the vicinity of the test pipe of the circulation path. Claim 16 According to the present invention described above, the amount of dissolved oxygen in the test piping can be appropriately grasped and controlled, so that the amount of dissolved oxygen approaches a set value.

[0023] Claim 17 The present invention is characterized in that a dissolved oxygen meter of the dissolved oxygen amount measuring means having a measuring container connected via a valve to an extraction pipe attached to the circulation path is provided facing the measuring container. Claim 17 According to the present invention described above, the amount of dissolved oxygen in a test fluid can be measured with high accuracy.

[0024] Claim 18 The present invention is characterized in that the dissolved oxygen amount measuring means is detachably provided in the circulation path. Claim 18 According to the present invention described above, the number of devices for measuring the amount of dissolved oxygen in the test fluid can be reduced, thereby simplifying the configuration.

[0025] Claim 19 The present invention is characterized in that the dissolved oxygen amount measuring means is detachably attached to a flange portion provided in the circulation path, and the dissolved oxygen meter of the dissolved oxygen amount measuring means is provided facing the circulation path. Claim 19According to the present invention described in , the dissolved oxygen amount measuring means can be easily attached and detached by mounting it on a flange, for example, by easily removing the dissolved oxygen amount measuring means together with the flange from the circulation path. In addition, by placing the dissolved oxygen meter of the dissolved oxygen amount measuring means facing the circulation path, the amount of dissolved oxygen in the test fluid can be measured more directly, thereby improving the response and accuracy of the measurement value. 。 Effect of the Invention

[0026] Books According to the corrosion and abrasion testing method for piping of the invention, the amount of dissolved oxygen in the test fluid is set taking into account the amount of dissolved oxygen in the actual piping, and a corrosion and abrasion test is then performed while quantitatively controlling the amount of dissolved oxygen in the test fluid circulating through a circulation path in which the test piping is installed, making it possible to obtain corrosion and abrasion data for the piping under conditions that are in line with the actual equipment. In addition, the person who performs the corrosion and wear test can accurately grasp the amount of dissolved oxygen in the test fluid and the control status thereof.

[0027] In addition, when the usage conditions include at least one of the type, pressure, and transportation method of the fluid using the actual piping, and the usage environment includes at least one of the water area and water depth, the amount of dissolved oxygen, which varies greatly depending on the actual usage conditions and usage environment of the piping, can be specifically taken into consideration, and the amount of dissolved oxygen can be more appropriately set in the dissolved oxygen amount setting step.

[0028] In addition, if the gas-containing fluid supply step, the dissolved oxygen measurement step, and the control step are performed as a dissolved oxygen adjustment loop while circulating the test fluid before performing the test, the effects of suspension of the test fluid due to the abrasion test, etc. can be avoided and the dissolved oxygen amount of the test fluid can be adjusted to the set dissolved oxygen amount.

[0029] After the amount of dissolved oxygen set by the dissolved oxygen amount adjustment loop is obtained, the corrosion test time is determined. Test fluid If a corrosion test loop that continues to circulate is further provided, the corrosion test can be performed with the dissolved oxygen content of the test fluid controlled to a set level, allowing the degree of corrosion progression of the test piping to be closer to the conditions of the actual equipment. 。

[0030] Ma Ta , melt After the set amount of dissolved oxygen is obtained in the dissolved oxygen adjustment loop, The test fluid is made into an ore slurry by adding ore. A given wear test time, Ore slurry If the apparatus further includes a wear test loop that continues circulation, the circulation can be continued while controlling the amount of dissolved oxygen in the test fluid to a set level, allowing corrosion and wear tests of the piping to be performed using an ore slurry.

[0031] Also, after the corrosion test loop 2. Add ore to make the test fluid into an ore slurry, and continue circulating the ore slurry for a specified wear test time. When performing an abrasion test loop, a corrosion test is performed under conditions where the degree of corrosion progression of the test piping is close to the conditions of the actual equipment, and then an abrasion test is performed, thereby enabling a corrosion and abrasion test of the piping to be performed under conditions where the amount of dissolved oxygen in the test fluid is controlled to a set amount of dissolved oxygen.

[0032] In addition, in the wear test loop, if the dissolved oxygen measurement step for measuring the amount of dissolved oxygen is not performed, the dissolved oxygen measurement equipment can be preserved for test fluids containing ore or crushed ore powder, and it is possible to prevent the measurement of the dissolved oxygen amount from becoming inaccurate due to the influence of suspension of the test fluid, which can lead to a deterioration in controllability.

[0033] Furthermore, when the gas-containing fluid is fine bubble water that contains oxygen and / or an inert gas as fine bubbles, the amount of dissolved oxygen in the test fluid can be precisely controlled and can be made to approach the amount of dissolved oxygen in the actual device.

[0034] Furthermore, according to the piping corrosion and wear testing system of the present invention, the amount of dissolved oxygen in the test fluid is set by a dissolved oxygen amount setting means taking into account the amount of dissolved oxygen in the actual piping, and a corrosion and wear test is then performed while quantitatively controlling the amount of dissolved oxygen in the test fluid circulating through a circulation path in which the test piping is provided, thereby making it possible to obtain corrosion and wear data for the piping under conditions that correspond to the actual equipment. In addition, the person who performs the corrosion and wear test can accurately grasp the amount of dissolved oxygen in the test fluid and the control status thereof.

[0035] Furthermore, when the test fluid is an ore slurry and an ore supply means is provided in the circulation path, a corrosion and wear test of the piping can be carried out using the ore slurry.

[0036] Furthermore, when the gas-containing fluid supplied from the gas-containing fluid supply means is fine bubble water containing oxygen and / or an inert gas as fine bubbles, the amount of dissolved oxygen in the test fluid can be precisely controlled and can be made to approach the amount of dissolved oxygen in the actual device.

[0037] In addition, when the gas-containing fluid supply means is an oxygen / inert gas fine bubble generator connected to the circulation path, which bubbles oxygen supplied from an oxygen supply source in water to produce oxygen fine bubble water and / or bubbles in water supplied from an inert gas supply source to produce inert gas fine bubble water, the fine bubble water can be efficiently produced and supplied to the circulation path.

[0038] In addition, when the control means controls the supply amount of each of the oxygen fine bubble water and inert gas fine bubble water to be supplied to the test fluid, the control means controls the supply amount of each of the oxygen fine bubble water and inert gas fine bubble water to mix them with the test fluid in an appropriate ratio, thereby approaching the set dissolved oxygen amount.

[0039] In addition, when the gas-containing fluid supply means is an oxygen / inert gas fine bubble generator connected to a circulation path, which bubbles oxygen supplied from an oxygen source and / or inert gas supplied from an inert gas source in water to produce fine bubble water, a single fine bubble generator can produce fine bubble water containing a mixture of oxygen and inert gas and supply it to the circulation path, making it possible to miniaturize the device.

[0040] In addition, when the control means controls the supply amount of oxygen and inert gas to be supplied to the oxygen / inert gas fine bubble generator, the control means mixes oxygen and inert gas in an appropriate ratio to generate fine bubble water and supplies it to the test fluid, thereby approaching the set amount of dissolved oxygen.

[0041] Furthermore, if a dissolved oxygen amount measuring means is provided near the test piping of the circulation path, the amount of dissolved oxygen in the test piping can be appropriately grasped and controlled to approach a set dissolved oxygen amount.

[0042] In addition, when a dissolved oxygen meter of the dissolved oxygen amount measuring means having a measuring container connected via a valve to an extraction pipe attached to the circulation path is provided facing the measuring container, the amount of dissolved oxygen in the test fluid can be measured with high accuracy.

[0043] Furthermore, in the case where the dissolved oxygen amount measuring means is detachably provided in the circulation path, the number of devices for measuring the amount of dissolved oxygen in the test fluid can be reduced, thereby simplifying the configuration.

[0044] Furthermore, when the dissolved oxygen amount measuring means is detachably attached to a flange portion provided in the circulation path and the dissolved oxygen meter of the dissolved oxygen amount measuring means is provided facing the circulation path, the flange attachment makes it possible to easily remove the dissolved oxygen amount measuring means together with the flange from the circulation path, making it easy to attach and detach the dissolved oxygen amount measuring means. Furthermore, by having the dissolved oxygen meter of the dissolved oxygen amount measuring means facing the circulation path, the amount of dissolved oxygen in the test fluid can be measured more directly, improving the response and accuracy of the measurement value. 。 [Brief description of the drawings]

[0045] [Figure 1] FIG. 1 is a block diagram of a corrosive wear test system according to a first embodiment of the present invention. [Diagram 2] Flow of corrosion wear test method using the corrosion wear test system [Diagram 3] Detailed flow of the dissolved oxygen setting steps [Figure 4] Detailed flow after the dissolved oxygen amount setting step [Diagram 5] FIG. 1 is a block diagram of a corrosive wear test system according to a second embodiment of the present invention. [Figure 6] Detailed flow after the dissolved oxygen amount setting step [Figure 7]Photograph showing the experimental results of the first embodiment of the present invention, showing the appearance from the outside of the container after 4 hours of immersion. [Figure 8] FIG. 13 is a graph showing the change in the amount of dissolved oxygen over time in Example 1-3. [Figure 9] FIG. 13 is a graph showing the change in the amount of dissolved oxygen over time in Example 4-6. [Figure 10] FIG. 1 is a block diagram of a corrosion wear test system according to a second embodiment of the present invention. [Figure 11] Overview of the corrosion and wear test system [Figure 12] A diagram showing the removal of the dissolved oxygen measurement means from the circulation path. [Figure 13] Appearance of the bubble generator [Figure 14] Graph showing the change over time in the amount of dissolved oxygen in the test fluid measured during the test in Comparative Example 1. [Figure 15] Graph showing the change over time in the amount of dissolved oxygen in the test fluid measured during the test in Example 7. [Figure 16] Graph showing the change over time in the amount of dissolved oxygen in the test fluid measured during the test in Example 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] A method for testing a piping against corrosion and abrasion and a system for testing a piping against corrosion and abrasion according to a first embodiment of the present invention will be described.

[0047] FIG. 1 is a configuration diagram of a corrosive wear test system according to the first embodiment. The corrosion and wear test system includes a circulation path 1 having a test pipe 10 as a part thereof, a circulation means 20 provided in the circulation path 1 for circulating the test fluid α, a dissolved oxygen amount setting means 30 for setting the amount of dissolved oxygen in the test fluid α, a gas-containing fluid supply means 40 for supplying a gas-containing fluid γ to the test fluid α, a dissolved oxygen amount measuring means 50 for measuring the amount of dissolved oxygen in the test fluid α flowing through the circulation path 1, a control means 60 for controlling the supply amount of the gas-containing fluid γ, an ore supply means 70 provided in the circulation path 1 for supplying ore, and a display means 80. By circulating the test fluid α through the test pipe 10 of the corrosion and wear test system and performing a test, it is possible to predict the corrosion and wear inside the pipe that transports the actual fluid. The pipe includes all parts related to the pipe, such as pumps and joints. The test pipe 10 has flanges on both ends and can be attached to and detached from the circulation path 1 . A water tank 90 and a slurry tank 100 are connected to the circulation path 1. The water tank 90 stores water β, such as tap water or seawater, which serves as a base for the test fluid α. The slurry tank 100 is connected to an ore supplying means 70, and the water β and ore are mixed in the slurry tank 100, turning the test fluid α into an ore slurry. This makes it possible to carry out a corrosion and wear test of the piping using the ore slurry. The circulation means 20 is, for example, a slurry pump.

[0048] When the dissolved oxygen amount of the test fluid α is set by the dissolved oxygen amount setting means 30, the actual dissolved oxygen amount contained in the fluid, which changes depending on the actual use conditions and environment of the piping, is taken into consideration. The target dissolved oxygen amount of the test fluid α can be arbitrarily set by a person by inputting it into the dissolved oxygen amount setting means 30, or it can be automatically set by the dissolved oxygen amount setting means 30. In the following, the set dissolved oxygen amount is referred to as the "target value DO TG " may be written as ".

[0049] The gas-containing fluid γ supplied from the gas-containing fluid supply means 40 contains at least one of oxygen and an inert gas. Air can be used instead of oxygen. The inert gas is nitrogen gas or the like. In this embodiment, the gas-containing fluid γ is fine bubble water containing at least one of oxygen and an inert gas as fine bubbles. By using fine bubble water γ generated from oxygen and an inert gas to control the amount of dissolved oxygen in the circulating test fluid α, the amount of dissolved oxygen in the test fluid α can be controlled with high precision and can be made close to the amount of dissolved oxygen in the actual device. Note that it is preferable that the relationship between the amount of oxygen contained in the fine bubble water and the actual amount of dissolved oxygen is confirmed in advance. The gas-containing fluid supply means 40 in this embodiment is an oxygen / inert gas fine bubble generator that generates at least one of oxygen fine bubble water γ1 and inert gas fine bubble water γ2. The oxygen / inert gas fine bubble generator 40 consists of two fine bubble generators. One is an oxygen fine bubble generator 41 that generates oxygen fine bubble water γ1, and the other is an inert gas fine bubble generator 42 that generates inert gas fine bubble water γ2. The oxygen fine bubble generator 41 is connected to an oxygen supply source 43 such as a compressed cylinder, and the inert gas fine bubble generator 42 is connected to an inert gas supply source 45 such as a compressed cylinder. In addition, the oxygen fine bubble generator 41 and the inert gas fine bubble generator 42 are connected to an oxygen fine bubble water supply pipe 47A and an inert gas fine bubble water supply pipe 47B that lead the generated fine bubble water γ to the slurry tank 100, respectively. Water β stored in a water tank 90 flows into the oxygen / inert gas fine bubble generator 40 through a tank water introduction pipe 48. The oxygen fine bubble generator 41 bubbles oxygen supplied from an oxygen supply source 43 in the water β to generate oxygen fine bubble water γ1, and the inert gas fine bubble generator 42 bubbles in the water β with inert gas supplied from an inert gas supply source 45 to generate inert gas fine bubble water γ2. The oxygen fine bubble water γ1 is supplied to the test fluid α through an oxygen fine bubble water supply pipe 47A, and the inert gas fine bubble water γ2 is supplied to the test fluid α through an inert gas fine bubble water supply pipe 47B. By separately generating the oxygen fine bubble water γ1 and the inert gas fine bubble water γ2, the fine bubble water γ can be efficiently generated and supplied to the circulation path 1. When air is used as the gas for generating fine bubbles, it is not necessary to use a compressed gas cylinder as the supply source. Fine bubbles can be generated by simply drawing in air at atmospheric pressure or by using a compressor to create pressurized air.

[0050] The dissolved oxygen amount measuring means 50 has a measuring container 51 for storing the test fluid α taken out from the circulation path 1, an extraction pipe 52 connecting the measuring container 51 and the circulation path 1, a valve 53 provided on the extraction pipe 52, and a dissolved oxygen meter 54 provided on the measuring container 51. The measuring container 51 is connected to the extraction pipe 52 attached to the circulation path 1 via the valve 53. The dissolved oxygen amount measuring means 50 is provided in the vicinity of the test pipe 10. The vicinity of the test pipe 10 refers to a range from the inlet or outlet of the test pipe 10 to approximately twice the length of the test pipe 10. The amount of dissolved oxygen in the circulating test fluid α is measured in the vicinity of the test pipe 10, and the measured value is used as the main feedback signal, thereby appropriately grasping and controlling the amount of dissolved oxygen in the test pipe 10 and adjusting it to the target value DO TG can be approached. Moreover, it is preferable that the dissolved oxygen meter 54 of the dissolved oxygen amount measuring means 50 is provided facing the measurement container 51 as shown in Fig. 1. This makes it possible to measure the amount of dissolved oxygen in the test fluid α with high accuracy.

[0051] The dissolved oxygen meter 54 of the dissolved oxygen amount measuring means 50 can be detachably provided on the circulation path 1. In this case, since there is no need to provide the measurement container 51, the extraction pipe 52, etc., the number of devices for measuring the amount of dissolved oxygen in the test fluid α can be reduced, and the configuration can be simplified. In addition, when the dissolved oxygen amount measuring means 50 is provided detachably on the circulation path 1, it is preferable that the dissolved oxygen meter 54 of the dissolved oxygen amount measuring means 50 faces the circulation path 1 when the dissolved oxygen amount measuring means 50 is attached to a flange portion provided on the circulation path 1 via a packing. By attaching the dissolved oxygen amount measuring means 50 to the flange portion of the circulation path 1, the dissolved oxygen amount measuring means 50 can be easily removed together with the flange, and the dissolved oxygen amount measuring means 50 can be easily attached and removed. In addition, by having the dissolved oxygen meter 54 of the dissolved oxygen amount measuring means 50 face the circulation path 1, the dissolved oxygen amount in the test fluid α can be measured more directly, and the response and accuracy of the measurement value can be improved. In addition, when performing a corrosion wear test of a pipe using an ore slurry, the dissolved oxygen amount measuring means 50 that is not used is removed to prevent the dissolved oxygen amount measuring means 50 from being damaged or stained by the slurry. Further, the configuration for detachably mounting the dissolved oxygen amount measuring means 50 on the circulation path 1 can employ various configurations such as a flange type, a screw type, an O-ring mounting type, and the like.

[0052] The control means 60 controls the set amount of dissolved oxygen (target value DO TG ) and the amount of dissolved oxygen measured, the supply amount of the gas-containing fluid γ is controlled. In this embodiment, the control means 60 controls the amount of dissolved oxygen in the test fluid α to a target value DO TG The supply amount of the oxygen fine bubble water γ1 supplied from the oxygen fine bubble generator 41 and the inert gas fine bubble water γ2 supplied from the inert gas fine bubble generator 42 are controlled so that the amount of dissolved oxygen in the test fluid α matches the target value DO. TG can be approached.

[0053] The display means 80 is, for example, a monitor, and displays the measurement results of the dissolved oxygen amount measuring means 50 and the control state of the control means 60. This allows the person conducting the corrosion and abrasion test, etc., to accurately grasp the amount of dissolved oxygen in the test fluid α and its control state. It is preferable that the display means 80 display the measured amount of dissolved oxygen in real time, as well as the operating status of the gas-containing fluid supply means 40, the flow rate of the test fluid α, and the like.

[0054] Figure 2 shows the flow of the corrosive wear test method using the corrosive wear test system. First, the dissolved oxygen amount of the test fluid α is set by using the dissolved oxygen amount setting means 30, taking into consideration the actual dissolved oxygen amount contained in the actual fluid (S1: dissolved oxygen amount setting step). TG The actual dissolved oxygen amount to be considered when setting the DO varies depending on at least one of the actual usage conditions and the usage environment of the piping. Therefore, by setting the DO based on the actual dissolved oxygen amount taking into account the usage conditions and the usage environment, the target value DO TG can be made appropriate. Additionally, as of March 30, 2020, the Japan Meteorological Agency's website (https: / / www.data.jma.go.jp / gmd / kaiyou / db / mar_env / knowledge / koyusui / yozonox.html) states that when comparing the amount of dissolved oxygen in deep layers deeper than 500m, the amount of dissolved oxygen in the Sea of ​​Japan (Japan Sea proper waters) is much higher than in the North Equatorial Current basin and the Oyashio basin. In addition, the amount of dissolved oxygen not only in the Sea of ​​Japan but also in the North Equatorial Current and Oyashio regions often varies depending on the water depth. For this reason, for example, in piping used for mining of seabed resources, the amount of dissolved oxygen in the actual equipment varies greatly depending on the water area and water depth of the usage environment, so in corrosion and wear tests, it is necessary to set the amount of dissolved oxygen taking into account the amount of dissolved oxygen in the actual equipment that differs depending on the water area and water depth. In addition, the amount of dissolved oxygen in the actual equipment varies depending on the conditions of use, such as the type of fluid used in the actual piping, the pressure, and the transportation method (mineral lifting method). The amount of dissolved oxygen in the actual equipment varies depending on the type of fluid actually used (seawater, water, oil, etc.), the pressure in the piping, the temperature of the fluid, etc. In addition, when a gas lift method is used as the ore lifting transportation method, the amount of dissolved oxygen in the actual equipment varies greatly depending on the type of gas used (air, nitrogen gas, etc.). Therefore, it is preferable to consider at least one of the type, pressure, and transportation method of the fluid used in the actual piping as the usage conditions, and at least one of the water area and water depth as the usage environment. In this way, it is possible to specifically consider the amount of dissolved oxygen, which varies greatly depending on the actual usage conditions and usage environment of the piping, and to set the target value DO TG can be set more appropriately.

[0055] After the dissolved oxygen amount setting step S1, the gas-containing fluid γ is supplied to the test fluid α using the gas-containing fluid supplying means 40 (S2: gas-containing fluid supplying step). After the gas-containing fluid supply step S2, the amount of dissolved oxygen is measured by the dissolved oxygen amount measuring means 50 (S3: dissolved oxygen amount measuring step). After the dissolved oxygen amount measuring step S3, the supply amount of the gas-containing fluid γ is controlled using the control means 60 based on the set dissolved oxygen amount and the measured dissolved oxygen amount (S4: control step). The gas-containing fluid supply step S2, the dissolved oxygen amount measurement step S3, and the control step S4 are executed as a dissolved oxygen amount adjustment loop L1 before the abrasion test is started. Before the abrasion test is started by putting ore (simulated ore) into the slurry tank 100, the amount of dissolved oxygen in the test fluid α is measured and controlled to the target value DO TG By providing a dissolved oxygen adjustment loop L1 for stabilizing the dissolved oxygen amount in the vicinity of the test fluid, the effect of suspension of the test fluid α due to ore powder during the abrasion test can be avoided, and the dissolved oxygen amount of the test fluid α can be adjusted to the target value DO TG can be adjusted to. After the set amount of dissolved oxygen is obtained in the dissolved oxygen amount adjustment loop L1, circulation is continued for a predetermined corrosion test time (L2: corrosion test loop). This allows the corrosion test to be performed while controlling the dissolved oxygen amount of the test fluid α to the set amount, and the degree of corrosion progress of the test pipe 10 can be made closer to the conditions of the actual equipment.

[0056] After the corrosion test loop L2, the abrasion test loop L3 is executed. The corrosion test is performed under conditions where the degree of corrosion of the test pipe 10 is close to the conditions of the actual equipment, and then the abrasion test is performed. TG It is possible to carry out corrosion and wear tests on piping under precisely controlled conditions. It is also possible to execute the abrasion test loop L3 without inserting the corrosion test loop L2 after the dissolved oxygen amount adjustment loop L1. In this case, after the ore is charged and the amount of dissolved oxygen set in the dissolved oxygen amount adjustment loop L1 is obtained, the abrasion test loop L3, which continues circulation for a predetermined abrasion test time, is executed, so that the circulation is continued while controlling the dissolved oxygen amount of the test fluid α to the set amount, and a corrosion and abrasion test of the piping using the ore slurry can be performed.

[0057] Figure 3 shows a detailed flow of the dissolved oxygen amount setting step. The dissolved oxygen amount setting means 30 sets the target value DO TG When setting, first, it is determined whether the transportation method (mineral lifting method) is a gas lift type (S10: transportation method determination step). Transportation methods other than the gas lift type include, for example, a slurry type, a pump pressure transfer type, and a water jet type. If it is determined in the transportation method determination step S10 that the transportation method is not gas lift type, it is further determined whether or not there is data on the amount of dissolved oxygen in the water area or water depth where the piping etc. (actual equipment) is operating (S11: DO data presence determination step). If it is determined in the DO data presence / absence determination step S11 that there is no data on the amount of dissolved oxygen in the water area or water depth, the target DO TG is set to the maximum value (saturation state) at the water depth (water pressure) in the water area where the pipes, etc. (actual equipment) are operating. On the other hand, if it is determined in the DO data presence / absence determination step S11 that data on the amount of dissolved oxygen in the water area or water depth is available, the target DO value is set based on the data on the amount of dissolved oxygen. TG Set. Moreover, when it is determined in the transportation method determination step S10 that the transportation method is the gas lift type, it is further determined whether the type of gas is oxygen or an inert gas (S12: gas type determination step). When the type of gas is determined to be oxygen in the gas type determination step S12, the target value DO TG Set to the maximum value (saturation). On the other hand, if the type of gas is determined to be an inert gas in the gas type determination step S12, the target value DO TG Set to minimum (degassed state). In addition, the target value DO TG can be set to an intermediate value between the maximum (saturated) and minimum (deaerated) values ​​if desired. In addition, when performing accelerated testing, the target value DO TG The target value DO can be set to a value different from the actual dissolved oxygen amount. TG The relationship between the DO level and test time is correlated with the relationship between the amount of dissolved oxygen in the actual device and the usage time, and the target value DO is set according to the correspondence. TG It is preferable to determine the test time.

[0058] Figure 4 shows a detailed flow after the dissolved oxygen amount setting step. When the corrosion and abrasion test of the piping is started, first, the water tank 90 and the piping provided in the circulation path 1 are filled with new water β, and the water β is circulated by the circulation means 20 (S20: water circulation step). In addition, the control variable X relating to the mixing ratio of the oxygen fine bubble water γ1 and the inert gas fine bubble water γ2 is set to an initial value X0 (S21: control variable initial value setting step).

[0059] After the control variable initial value setting step S21, the process goes to the dissolved oxygen amount adjustment loop L1. In the dissolved oxygen amount adjustment loop L1, first, a gas-containing fluid supply step S2 is performed. In the gas-containing fluid supply step S2, oxygen fine bubble water γ1 and inert gas fine bubble water γ2 are generated by the oxygen / inert gas fine bubble generator 40 consisting of two fine bubble generators, and are injected into the slurry tank 100 so that they are mixed with the test fluid α at a mixing ratio of X:(1-X). The fine bubble water γ is continuously injected. In the dissolved oxygen amount measuring step S3 after the gas-containing fluid supplying step S2, the valve 53 provided on the extraction pipe 52 is opened to extract the test fluid α into the measuring container 51, and the amount of dissolved oxygen in the test fluid α is measured by the dissolved oxygen meter 54. In the control step S4 after the dissolved oxygen amount measurement step S3, the control means 60 executes a dissolved oxygen amount stability determination step S4-1 and a control variable update step S4-2 to stabilize the dissolved oxygen amount of the test fluid α at a target value DO TG In order to approach this, feedback control is performed to optimize the mixing ratio of oxygen fine bubble water γ1 and inert gas fine bubble water γ2. PID control is the preferred control method, but it is preferable to set the proportional, integral, and derivative gains in advance through preliminary tests, and it is even more preferable to optimize them during the actual tests. As described above, it is preferable that the dissolved oxygen amount measuring means 50 is provided near the test piping 10, but the amount of dissolved oxygen may be measured not only near the test piping 10 but also at the opening of the slurry tank 100 or the like as necessary, and this may be added as a feedback signal to the control means 60. It is also possible to grasp in advance the correlation between the amount of dissolved oxygen at these different measurement points and the amount of dissolved oxygen near the test piping 10 by preliminary tests or the like, and to substitute the measured value of the amount of dissolved oxygen near the test piping 10 for the measured value of the amount of dissolved oxygen at the different measurement points. In addition, if necessary, the air temperature, the temperature of the test fluid α, the flow rate of the test fluid α, the bubble concentration in the test fluid α (bubble count and volume ratio), the pressure / flow rate of each gas, the inflow rate of the fine bubble water γ, etc. can be added as feedback signals. This allows the amount of dissolved oxygen in the test fluid α to be more accurately adjusted to the target value DO TGOf these, it is preferable to provide instruments for measuring the temperature, flow rate, and bubble concentration of the test fluid α in the vicinity of the test piping 10. Incidentally, adding a feedback signal can be said to correct the measured value of the amount of dissolved oxygen. In the dissolved oxygen amount stability determination step S4-1, the dissolved oxygen amount of the test fluid α is determined to be equal to or greater than the target value DO TG In the dissolved oxygen amount stability determination step S4-1, it is determined whether the dissolved oxygen amount of the test fluid α is stable near the target value DO TG If it is determined that the control variable X is not stable in the vicinity, the control variable X is updated (optimized) in the control variable updating step S4-2, and the process returns to the gas-containing fluid supplying step S2. On the other hand, in the dissolved oxygen amount stability determination step S4-1, the dissolved oxygen amount of the test fluid α is equal to the target value DO TG If it is determined that the temperature has stabilized in the vicinity, it is further determined whether or not a predetermined corrosion test time has been reached, that is, whether or not the corrosion test loop L2 is to be ended (S22: corrosion test time end determination step).

[0060] If it is determined in the corrosion test time end determination step S22 that the predetermined corrosion test time has not been reached, the process returns to the gas-containing fluid supply step S2. On the other hand, when it is determined in the corrosion test time end determination step S22 that the predetermined corrosion test time has been reached, the dissolved oxygen amount adjustment loop L1 (and the corrosion test loop L2) is terminated. In this way, the dissolved oxygen amount adjustment loop L1 can also serve as the corrosion test loop L2 by performing the loop for a predetermined time. When the dissolved oxygen amount adjustment loop L1 is completed, the control means 60 sets the control variable X obtained in the dissolved oxygen amount adjustment loop L1 as the control variable X0 in the abrasion test loop L3 to be performed next (S23: control variable setting step).

[0061] In the next abrasion test loop L3, first, the valve 53 provided on the extraction pipe 52 is closed, and ore is charged into the slurry tank 100 to circulate the ore slurry as the test fluid α (S24: ore slurry circulation step). In addition, oxygen fine bubble water γ1 and inert gas fine bubble water γ2 are generated by the oxygen / inert gas fine bubble generator 40 and mixed at a mixing ratio of X0:(1-X0), and the resulting fine bubble water γ is injected into the slurry tank 100 (S25: abrasion test gas-containing fluid supply step). The fine bubble water γ is injected continuously. This causes the dissolved oxygen content of the test fluid α to reach the target value DO TG With the temperature controlled to a value close to the limit, the corrosion and wear test of the piping can be continued. In the abrasion test loop L3, it is preferable not to provide a step for measuring the amount of dissolved oxygen in the test fluid α as in the dissolved oxygen amount measuring step S3, but to control the amount of dissolved oxygen using the control variable X0 set in the control variable setting step S23 from the control variable X obtained in the dissolved oxygen amount adjusting loop L1. The amount of dissolved oxygen in the test fluid α is measured only in the dissolved oxygen amount adjusting loop L1 in which the water β is circulated, and is not measured in the abrasion test loop L3 in which the ore and its crushed powder are circulated together with the water β. This makes it possible to preserve the dissolved oxygen amount measuring means 50 for the test fluid α containing the ore and crushed ore powder, and also to prevent the measurement of the dissolved oxygen amount from becoming inaccurate due to the influence of the suspension of the test fluid α, and thus to prevent deterioration of controllability.

[0062] Next, it is determined whether or not a predetermined abrasion test time has been reached (S26: abrasion test end determination step). The predetermined abrasion test time is determined based on the predicted time until the ore is rounded off due to collision with the pipe, the amount of dissolved oxygen in the test fluid α reaches the target value DO TG It is set based on the expected time until it deviates from the predetermined amount. If it is determined in the wear test end determination step S26 that the predetermined wear test time has not been reached, the wear test is continued. On the other hand, when it is determined in the abrasion test end determination step S26 that the predetermined abrasion test time has been reached, it is further determined whether or not to end the corrosion abrasion test (S27: corrosion abrasion test end determination step). Whether or not to end the corrosion abrasion test is determined, for example, based on whether or not the planned corrosion abrasion test time for the piping has been reached. If it is determined in step S27 that the corrosive wear test is to be ended, the corrosive wear test is ended. On the other hand, if it is determined in step S27 that the corrosive wear test is not to be ended, the ore and test fluid α in the circulation path 1 are discharged, and the process returns to step S20 for circulating water. In this way, by alternately repeating the dissolved oxygen amount adjustment loop L1 and the wear test loop L3 as many times as necessary, the control variables are optimized according to the progress of corrosion and wear in the test pipe 10, and the amount of dissolved oxygen in the test fluid α is adjusted to the target value DO TG This enables a corrosion and wear test to be performed in a state where the dissolved oxygen amount of the test fluid α is controlled to a value close to the actual dissolved oxygen amount of the piping. By setting the dissolved oxygen amount of the test fluid α by the dissolved oxygen amount setting means 30 in consideration of the dissolved oxygen amount of the actual piping, and then performing a corrosion and wear test in a state where the dissolved oxygen amount of the test fluid α circulating through the circulation path 1 in which the test piping 10 is provided is quantitatively controlled, corrosion and wear data of the piping (including pumps, joints, etc.) can be obtained under conditions that correspond to the actual equipment and reflected in the design, material selection, setting of operating conditions, etc., thereby improving the safety and reliability of the piping in the actual equipment.

[0063] Next, a corrosion and abrasion test method for piping and a corrosion and abrasion test system for piping according to a second embodiment of the present invention will be described. The second embodiment differs from the first embodiment in that fine bubble water, which is a gas-containing fluid γ, is generated using a gas in which oxygen and an inert gas are mixed at an appropriate ratio. Note that the same functional members as those in the first embodiment are given the same reference numerals and their descriptions are omitted.

[0064] FIG. 5 is a configuration diagram of a corrosive wear test system according to the second embodiment. The gas-containing fluid supplying means 40 of this embodiment is an oxygen / inert gas fine bubble generator that generates fine bubble water γ by bubbling at least one of oxygen and an inert gas in water β. The oxygen supply pipe 44 connecting the oxygen / inert gas fine bubble generator 40 and the oxygen supply source 43, and the inert gas supply pipe 46 connecting the oxygen / inert gas fine bubble generator 40 and the inert gas supply source 45 are each provided with a regulator 110. The oxygen supply pipe 44 and the inert gas supply pipe 46 merge into one gas supply pipe 49 midway, and the oxygen, inert gas, or mixed gas of oxygen and inert gas flowing through the gas supply pipe 49 flows into the oxygen / inert gas fine bubble generator 40 at a predetermined flow rate Q or pressure P. The oxygen / inert gas fine bubble generator 40 generates fine bubble water γ by bubbling oxygen supplied from an oxygen source 43, inert gas supplied from an inert gas source 45, or a mixture of oxygen and inert gas in water, and supplies the fine bubble water γ to the test fluid α through a fine bubble water supply pipe 47 connected to the circulation path 1. The oxygen / inert gas fine bubble generator 40 of this embodiment requires only one fine bubble generator, so it is easier to make the device smaller than the first embodiment, which requires two fine bubble generators.

[0065] FIG. 6 shows a detailed flow after the dissolved oxygen amount setting step. In the dissolved oxygen amount adjustment loop L1, under the control of the control means 60, oxygen and inert gas are mixed at a mixing ratio X:(1-X) by two regulators 110, and are allowed to flow into the oxygen / inert gas fine bubble generator 40 at an appropriate flow rate Q or pressure P (S2-1: gas mixing step), and fine bubble water γ is generated in the oxygen / inert gas fine bubble generator 40 and injected into the slurry tank 100 (S2-2: fine bubble water generation step). As a result, fine bubble water γ, in which oxygen and inert gas are mixed at an appropriate ratio, is supplied to the test fluid α, and the dissolved oxygen amount of the test fluid α is adjusted to the target value DO TG The gas mixing step S2-1 and the fine bubble water generating step S2-2 constitute the gas-containing fluid supplying step S2. In the abrasion test loop L3, after the ore slurry circulation step S24, under the control of the control means 60, oxygen and inert gas are mixed at a mixing ratio X0:(1-X0) by two regulators 110 and flowed into the oxygen / inert gas fine bubble generator 40 (S25-1: abrasion test gas mixing step), and fine bubble water γ is generated in the oxygen / inert gas fine bubble generator 40 and injected into the slurry tank 100 (S25-2: abrasion test fine bubble water generation step). The abrasion test gas mixing step S25-1 and the abrasion test fine bubble water generation step S25-2 are the abrasion test gas-containing fluid supply step S25. As a result, the dissolved oxygen amount of the test fluid α is increased to the target value DO TG With the temperature controlled to a value close to the limit, the corrosion and wear test of the piping can be continued. EXAMPLES

[0066] [First Example] For the first embodiment described above, various types of fine bubble water γ shown in Table 1 were generated using tap water or artificial seawater as the base fluid and fine air bubbles and fine nitrogen bubbles, and then each was filled into a transparent container, and a steel plate, which is a source of dissolved oxygen consumption, was immersed in it and the changes over time were observed. During the observation, the amount of dissolved oxygen (DO) in the liquid was measured at appropriate time intervals and photographs were taken from outside the container. In Table 1 below, "FB" stands for fine bubble. Air-bubble water and air-bubble artificial seawater are types of oxygen-bubble water γ1, while nitrogen-bubble water and nitrogen-bubble artificial seawater are types of inert gas-bubble water γ2. [Table 1]

[0067] A commercially available fine bubble generator (FU5 model, manufactured by Living Energy) was used to generate fine bubbles. According to the manufacturer's specifications, this device can generate fine bubbles that are a mixture of ultrafine bubbles (diameter 1 μm or less) and microbubbles (diameter 1 to 60 μm). In addition, it uses a hybrid generation method that combines multiple microbubble generation methods (shear method + swirling flow method), which allows for the stable generation of high-concentration, micro-uniform bubbles. The basic specifications are that it can generate approximately 190 million fine bubbles per mL, and the processing capacity is 15 to 20 L / min. Artificial seawater was prepared using pure water and a commercially available artificial seawater preparation kit, “Aquamarine for Metal Corrosion Testing” (manufactured by Yashima Pharmaceutical Co., Ltd.), and was adjusted to a weak alkaline pH (pH=8) using the pH adjustment solution provided with the kit. The steel plate used was a pickled JIS SS400 general-purpose structural steel (dimensions: 71 mm x 150 mm, plate thickness: 30 mm). The surface of the steel plate was polished with emery paper (#240) and degreased with a parts cleaner before immersion. The amount of dissolved oxygen in the liquid was measured using a commercially available small dissolved oxygen meter (AS ONE AS720, measurement range: dissolved oxygen 0-20.00 mg / L, temperature 0-45°C, accuracy: ±0.30 mg / L).

[0068] Fig. 7 shows external photographs of the container four hours after immersion, with Fig. 7(a) showing the case where tap water was used as the fluid (Examples 1-3) and Fig. 7(b) showing the case where artificial seawater was used as the fluid (Examples 4-6). Comparing the discoloration of the liquid caused by rust on the steel sheet surface, it can be seen that the degree of discoloration of the liquid was deeper in Examples 1 and 4, in which the amount of dissolved oxygen was increased using fine air bubbles, whereas the discoloration of the liquid was slight in Examples 3 and 6, in which deaeration was performed using fine nitrogen bubbles.

[0069] FIG. 8 is a graph showing the change in the amount of dissolved oxygen over time in Examples 1-3, and FIG. 9 is a graph showing the change in the amount of dissolved oxygen over time in Examples 4-6. Figures 8 and 9 show how the amount of dissolved oxygen changed over time after immersion in the steel plate when tap water was used as the fluid (Figure 8) and when artificial seawater was used as the fluid (Figure 9). 8, the results of Example 2, in which fine air bubble water and fine nitrogen bubble water were mixed at a volume ratio of 1:1, were intermediate between Example 1, which had the maximum amount of dissolved oxygen, and Example 3, which had the minimum amount of dissolved oxygen after deaeration with fine nitrogen bubbles, and the relationship between the amounts did not change even after 20 hours or more had passed since immersion. It was also found that the amount of dissolved oxygen in Example 2 was maintained at roughly the same level as immediately after the start of immersion if it was only for a few hours after immersion. Similarly, looking at Figure 9, the results of Example 5, in which air-bubbled artificial seawater and nitrogen-bubbled artificial seawater were mixed at a volume ratio of 1:1, are intermediate between Example 4, which has the maximum amount of dissolved oxygen, and Example 6, which has the minimum amount of dissolved oxygen after degassing with nitrogen fine bubbles, and the magnitude relationship does not change even after 10 hours or more have passed since immersion. Also, it can be seen that if it is about several hours after immersion, the amount of dissolved oxygen in Example 5 is maintained at almost the same level as immediately after the start of immersion. From the above results, it can be said that the quantitative control of dissolved oxygen content by mixing fine air bubble water or fine air bubble artificial seawater with fine nitrogen bubble water or fine nitrogen bubble artificial seawater in Examples 2 and 5 is particularly preferable for a period of several hours. In the above-described first and second embodiments, examples have been shown in which the fluid is an ore slurry. However, the fluid to be transported may be any fluid in which dissolved oxygen is present as in the piping of an actual machine, such as ordinary water or seawater, or a suspension or slurry.

[0070] [Second Example] Targeting the above-mentioned first embodiment, tap water was used as a base fluid, and the amount of dissolved oxygen in the test fluid α in the corrosion and wear test system was controlled as an example of the dissolved oxygen amount adjustment loop L1. Fig. 10 is a configuration diagram of the corrosive wear test system of this embodiment. Also, Fig. 11 is an overview photograph of the corrosive wear test system, in which Fig. 11(a) shows the whole system, Fig. 11(b) shows the front side of the gas-containing fluid supply means, Fig. 11(c) shows the gas-containing fluid mixing tank, Fig. 11(d) shows the dissolved oxygen amount measuring means, Fig. 11(e) shows the circulation means (slurry pump), Fig. 11(f) shows the slurry tank (mixed fluid supply section), and Fig. 11(g) shows the supply pump. The gas-containing fluid γ supplied from the gas-containing fluid supply means 40 was of two types: oxygen fine bubble water γ1 (oxygen-containing fluid, oxygen-saturated water) and inert gas fine bubble water γ2 (inert gas-containing fluid, nitrogen-deaerated water). The oxygen fine bubble water γ1 was produced using a compressor (not shown in FIG. 10) as the oxygen supply source 43 and a bubble generator with a built-in porous sintered metal filter as the oxygen fine bubble generator 41, while the inert gas fine bubble water γ2 was produced using a nitrogen cylinder (not shown in FIG. 10) as the inert gas supply source 45 and a fine bubble generator as the inert gas fine bubble generator 42. In the first embodiment, as shown in FIG. 1, the oxygen fine bubble water γ1 and the inert gas fine bubble water γ2 are sent to the slurry tank 100 and mixed, but in this embodiment, the oxygen fine bubble water supply pipe 47A and the inert gas fine bubble water supply pipe 47B join in the mixing tank 120, and after the oxygen fine bubble water γ1 and the inert gas fine bubble water γ2 are mixed in the mixing tank 120, they are sent from the supply pump 130 to the slurry tank 100. In addition, an oxygen fine bubble water supply valve 121 is provided in the oxygen fine bubble water supply pipe 47A at a portion located within the mixing tank 120, and an inert gas fine bubble water supply valve 122 is provided in the inert gas fine bubble water supply pipe 47B at a portion located within the mixing tank 120. By opening and closing the oxygen fine bubble water supply valve 121 and the inert gas fine bubble water supply valve 122, it is possible to supply only either the oxygen fine bubble water γ1 or the inert gas fine bubble water γ2 to the slurry tank 100.

[0071] The details and specifications of the main components and equipment that make up the corrosive wear test system are shown below. {Pipe hoses that form the main flow paths} Soft PVC hose (transparent) Inner diameter 32mm Toyox Corporation Toyoron Hose TR-32 {A pipe in the circulation path where the dissolved oxygen measurement device is installed} PVC pipe (transparent) with an inner diameter of 52 mm (catalog value) In addition, this pipe had a larger inner diameter than the above-mentioned piping hose in order to attach a dissolved oxygen meter 54 thereto. Here, FIG. 12 is a diagram showing removal of the dissolved oxygen amount measuring means from the circulation path. In the dissolved oxygen amount adjustment loop L1, the dissolved oxygen amount measuring means 50 measures with the dissolved oxygen meter 54 protruding into the inside of this pipe (into the circulation path 1) as shown in Fig. 11(d). Then, before moving to the corrosion test loop L2, as shown in Fig. 12, the bolts 55 (see Fig. 11(d)) used to fasten the dissolved oxygen meter 54 to the flange portion 2 provided on the pipe are removed, the dissolved oxygen meter 54 is pulled out together with the flange 56, and the opening of the flange portion 2 of the pipe is closed with a closing flange. {Dissolved oxygen meter} The following controller and electrodes were used in combination (manufactured by Hanna Instruments): Panel-mounted dissolved oxygen controller HI 8410 ·DO electrode HI76410 / 4 Measurement range: 0.0 to 50.0 mg / L, Accuracy: ±1% of measured value {Air bubble generator with built-in porous sintered metal filter} Figure 13 is a photograph showing the appearance of the air bubble generating device. The right side is the compressor side. The short transparent tube on the left side is submerged in water, and air bubbles are generated from the openings on both sides. {Fine bubble generator} As in the first example, a commercially available fine bubble generator (FU5 model, manufactured by Living Energy) was used. {Circulation means (main slurry pump)} Horizontal sand pump VS4-7.5U manufactured by Toyo Denki Kogyo Co., Ltd. Diameter: 80mm, Head: 15m, Pumping capacity: 0.5m 3 / min, output: 5.5kW {Supply pump} MP2N-0021TR manufactured by Terada Pump Manufacturing Co., Ltd. Total head: 8.0 / 7.0 / 6.0m, discharge amount: 0.055 / 0.08 / 0.1 m 3 / min, output: 0.2kW {Digital I / O Device} The following I / O devices were used for communication between the measurement / measuring instruments and the control PC. National Instruments NI USB-6259 {Oxygen fine bubble water supply valve, inert gas fine bubble water supply valve} To control the supply amount of fine bubble water, the following combination was used (manufactured by Koganei Corporation). ·Proportional control valve KFPV050-2-40-FM-S4-02-39 ·Proportional control valve controller KFPC1-F07-DN

[0072] The test methods in the present examples are as follows. (1) Tap water is stored in the oxygen-containing fluid tank 140, and compressed air supplied from a compressor is passed through a bubble generator with a porous sintered metal filter submerged in water to generate fine bubbles, producing oxygen fine bubble water γ1 (oxygen-containing fluid, oxygen-saturated water). Similarly, tap water is stored in the inert gas-containing fluid tank 150, and nitrogen fine bubbles are generated in the water using a nitrogen cylinder and a fine bubble generator, followed by degassing, producing inert gas fine bubble water γ2 (inert gas-containing fluid, nitrogen-deaerated water). (2) Tap water is supplied from the slurry tank 100 (mixed fluid supply section), and the circulation means 20 (slurry pump) is operated to circulate the water. (3) Operate the supply pump 130, measure the amount of dissolved oxygen in the test fluid α, and start flow control of the oxygen fine bubble water γ1 and the inert gas fine bubble water γ2 using a control PC, proportional control valve, etc. (4) At an appropriate time, data collection and control are terminated, each pump is stopped, and the test is completed.

[0073] The control program in this embodiment will be outlined below. Based on the measured amount of dissolved oxygen in the test fluid α, the supply amount of oxygen fine bubble water γ1 and inert gas fine bubble water γ2 was controlled by a control PC. The following theoretical formula and control program for PID control were used. First, the theoretical formula for PID control will be explained. In PID control, if the manipulated variable at a certain time t is u(t) and the deviation between the measured value and the target value is e(t), the manipulated variable is calculated using the following equation (1).

number

number

number

[0074] Next, the control program will be described in detail. In the PID control program used in this embodiment, the deviation e(t) between the measured value and the target value at time t in the above equation (1) and the manipulated variable u(t) are defined as follows: Deviation e(t) = <target dissolved oxygen amount> - <measured dissolved oxygen amount at time t> Operation amount u(t) = <Opening degree B of oxygen fine bubble water supply valve 121> - <Opening degree A of inert gas fine bubble water supply valve 122> Here, the valve openings A and B each take continuous values ​​from 0 to 10, which directly correspond to the control voltages of 0 to 10V of each valve (proportional control valve). In addition, in order to keep the supply amount of the mixed fluid of oxygen fine bubble water γ1 and inert gas fine bubble water γ2 constant, A+B=10 (constant).

[0075] Next, the software used to create the control program will be described. The control program was created using National Instruments' LabVIEW 2016 ver16.0f2. The PID module pre-installed in LabVIEW was used for the PID control portion. The main function of the module is to set the target value (the target value of the amount of dissolved oxygen in this embodiment), the process variable (the amount of dissolved oxygen being measured in this embodiment), and the PID gain, and to obtain the corresponding PID control output.

[0076] The test results of this embodiment will be described. As Comparative Example 1, Example 7, and Example 8, a control test for the amount of dissolved oxygen in the test fluid α was carried out. The flow rate was calculated by measuring the actual discharge weight and discharge time in each test, and the average flow rate was 3.01 m 3 / h. In each example, the target value of the amount of dissolved oxygen in the test fluid α, DO TG = 6 mg / L. The test conditions for each example and the PID control parameters for Examples 7 and 8 are summarized in Table 2 below. [Table 2]

[0077] In the seventh and eighth embodiments, the proportional gain is K p = 5.0 and a preliminary control test was performed. i , T d The default settings were slightly changed so that only inert gas fine bubble water γ2 was supplied when the deviation between the target and measured values ​​of the amount of dissolved oxygen was large (at the early stage of the test). The details of the tests for each example are explained below.

[0078] {Comparative Example 1} In Comparative Example 1, the PID control described above was not performed, and only the inert gas fine bubble water γ2 was supplied to the test fluid α by manually adjusting the opening A of the inert gas fine bubble water supply valve 122. The amount of dissolved oxygen in the test fluid α was reduced to the target value DO TG When the oxygen concentration in the inert gas fine bubble water γ2 was slightly below 6 mg / L, the opening A of the inert gas fine bubble water supply valve 122 was set to zero, and the supply of the inert gas fine bubble water γ2 was stopped. In other words, this example intentionally simulates a case where the timing of manually stopping the supply of the inert gas fine bubble water γ2 was delayed, causing the amount of dissolved oxygen to overshoot below the target value. The amount of dissolved oxygen in the inert gas fine bubble water γ2 that was generated in advance was 0.56 mg / L, as shown in Table 2. FIG. 14 is a graph showing the change over time in the amount of dissolved oxygen in the test fluid measured during the test in Comparative Example 1. After the supply of inert gas fine bubble water γ2 started, the amount of dissolved oxygen decreased linearly and reached the target value DO TG When the valve opening A of the inert gas fine bubble water γ2 was set to zero when the dissolved oxygen level fell slightly below 6 mg / L (approximately 6 minutes and 40 seconds after the measurement), the amount of dissolved oxygen continued to remain below the target value and did not naturally rise to approach the target value. In this example, because oxygen fine bubble water γ1 was not supplied, it was not possible to intentionally raise the dissolved oxygen level back to the target value once it had fallen below the target value. In other words, in this example, the amount of dissolved oxygen in the test fluid α could not be well controlled.

[0079] Example 7 In Example 7, a mixed fluid of oxygen fine bubble water γ1 and inert gas fine bubble water γ2 was supplied and controlled. FIG. 15 is a graph showing the change over time in the amount of dissolved oxygen in the test fluid measured during the test in Example 7. The amount of dissolved oxygen, which was about 9.5 mg / L at the start of the test, decreased linearly toward the target value of 6 mg / L as soon as control started, and after about 5 minutes 40 seconds, it slightly overshot and fell below the target value, but then increased the supply of oxygen fine bubble water γ1 to rise to near the target value and become almost stable. In other words, in this example, the amount of dissolved oxygen in the test fluid α was well controlled by supplying the oxygen fine bubble water γ1 and the inert gas fine bubble water γ2 while controlling the mixture.

[0080] {Example 8} In Example 8, similar to Example 7, a mixed fluid of oxygen fine bubble water γ1 and inert gas fine bubble water γ2 was supplied and controlled. FIG. 16 is a graph showing the change over time in the amount of dissolved oxygen in the test fluid measured during the test in Example 8. The amount of dissolved oxygen, which was about 8.3 mg / L at the start of the test, decreased linearly toward the target value of 6 mg / L as control began, and after about 9 minutes, it slightly overshot and fell below the target value, but then increased the supply of oxygen fine bubble water γ1 to rise to near the target value and become almost stable. In other words, in this example, as in Example 7, the amount of dissolved oxygen in the test fluid α was well controlled by supplying the oxygen fine bubble water γ1 and the inert gas fine bubble water γ2 while controlling the mixture. [Industrial Applicability]

[0081] The present invention makes it possible to obtain corrosion and wear data on pipes, etc. under conditions that resemble those of an actual machine and reflect this in the design, material selection, operating condition settings, etc., thereby improving the safety and reliability of pipes, etc. [Explanation of symbols]

[0082] 1 Circulation route 2 Flange 10 Test piping 20 Circulation means 30 Dissolved oxygen amount setting means 40 Gas-containing fluid supply means (oxygen / inert gas fine bubble generator) 43 Oxygen Source 45 Inert Gas Supply Source 50 Dissolved oxygen measurement means 54 Dissolved oxygen meter 60 Control Means 70 Ore Supply Means 80 Display means S1 Dissolved oxygen setting step S2 Gas-containing fluid supply step S3 Dissolved oxygen measurement step S4 Control Step L1 Dissolved oxygen adjustment loop L2 Corrosion Test Loop L3 Wear Test Loop α Test fluid γ Gas-containing fluid (fine bubble water) γ1 Oxygen Fine Bubble Water γ2 Inert gas fine bubble water

Claims

1. 1. A method for testing the internal corrosion and wear of a pipe transporting a fluid by circulating a test fluid through the test pipe, comprising: a dissolved oxygen amount setting step of setting the dissolved oxygen amount of the test fluid in consideration of the actual dissolved oxygen amount contained in the fluid, which varies depending on the actual use conditions and / or use environment of the piping; A gas-containing fluid supply step of supplying a gas-containing fluid containing oxygen and / or an inert gas to the test fluid; a dissolved oxygen amount measuring step of measuring the amount of dissolved oxygen; and a control step of controlling a supply amount of the gas-containing fluid based on the set amount of dissolved oxygen and the measured amount of dissolved oxygen, A method for testing corrosion and abrasion of piping, comprising displaying at least the measurement results in said dissolved oxygen amount measuring step and the control state in said control step on a display means.

2. 2. The method for testing corrosion and wear of piping according to claim 1, wherein the usage conditions include at least one of the type, pressure, and transportation method of the fluid using the actual piping, and the usage environment includes at least one of the water area and water depth.

3. The corrosion and wear testing method for piping described in claim 1 or claim 2, characterized in that before performing the test, the gas-containing fluid supply step, the dissolved oxygen measurement step, and the control step are performed as a dissolved oxygen adjustment loop while circulating the test fluid.

4. 4. The method for testing corrosion and abrasion of piping according to claim 3, further comprising a corrosion test loop for continuing circulation of the test fluid for a predetermined corrosion test time after the amount of dissolved oxygen set by the dissolved oxygen amount adjustment loop is obtained.

5. The corrosion and wear testing method for piping as described in Claim 3, further characterized in that it further comprises an abrasion test loop in which, after the amount of dissolved oxygen set by the dissolved oxygen amount adjustment loop is obtained, ore is added to turn the test fluid into an ore slurry, and the ore slurry is continued to circulate for a predetermined abrasion test time.

6. 5. The method for testing piping for corrosion and abrasion as described in claim 4, further comprising: after the corrosion test loop, introducing ore to make the test fluid into an ore slurry, and then performing an abrasion test loop in which the ore slurry is continuously circulated for a predetermined abrasion test time.

7. 7. The method for testing corrosion and abrasion of a pipe according to claim 5, wherein the dissolved oxygen amount measuring step of measuring the amount of dissolved oxygen is not performed in the abrasion test loop.

8. 8. The corrosion and abrasion testing method for piping according to claim 1, wherein the gas-containing fluid is fine bubble water containing the oxygen and / or the inert gas as fine bubbles.

9. A system for testing internal corrosion and wear of a piping that transports a fluid by circulating a test fluid through the test piping, comprising: a circulation path having the test piping as a part thereof; A circulation means for circulating the test fluid; a dissolved oxygen amount setting means for setting the dissolved oxygen amount of the test fluid in consideration of the actual dissolved oxygen amount contained in the fluid, which varies depending on the actual use conditions and / or use environment of the piping; A gas-containing fluid supply means for supplying a gas-containing fluid containing oxygen and / or an inert gas to the test fluid; a dissolved oxygen amount measuring means for measuring the amount of dissolved oxygen; A control means for controlling the supply amount of the gas-containing fluid based on the set amount of dissolved oxygen and the measured amount of dissolved oxygen; A piping corrosion and abrasion testing system comprising: a display means for displaying at least the measurement result of said dissolved oxygen amount measuring means and the control state of said control means.

10. 10. The piping corrosion and wear testing system according to claim 9, wherein the test fluid is an ore slurry, and the circulation path is provided with an ore supply means.

11. The corrosion and wear testing system for piping as described in claim 9 or claim 10, characterized in that the gas-containing fluid supplied from the gas-containing fluid supply means is fine bubble water containing the oxygen and / or the inert gas as fine bubbles.

12. The gas-containing fluid supply means is an oxygen / inert gas fine bubble generator connected to the circulation path, which bubbles the oxygen supplied from an oxygen supply source in water to produce oxygen fine bubble water and / or bubbles the inert gas supplied from an inert gas supply source in water to produce inert gas fine bubble water. The corrosion and wear testing system for piping described in claim 11, characterized in that

13. The corrosion and wear testing system for piping according to claim 12, characterized in that the control means controls the supply amount of each of the oxygen fine bubble water and the inert gas fine bubble water to the test fluid.

14. The gas-containing fluid supply means is an oxygen / inert gas fine bubble generator connected to the circulation path, which bubbles the oxygen supplied from an oxygen source and / or the inert gas supplied from an inert gas source in water to produce the fine bubble water. The corrosion and wear testing system for piping described in claim 11.

15. The piping corrosion and wear testing system according to claim 14, characterized in that the control means controls the supply amount of each of the oxygen and the inert gas to the oxygen / inert gas fine bubble generator.

16. 16. The piping corrosion and abrasion testing system according to claim 9, wherein the dissolved oxygen amount measuring means is provided in the vicinity of the test piping in the circulation path.

17. The piping corrosion and abrasion testing system according to claim 16, characterized in that a dissolved oxygen meter of the dissolved oxygen amount measuring means having a measuring container connected via a valve to an extraction pipe attached to the circulation path is provided facing the measuring container.

18. 17. The piping corrosion and abrasion testing system according to claim 16, wherein the dissolved oxygen amount measuring means is detachably provided in the circulation path.

19. The piping corrosion and wear testing system according to claim 18, characterized in that the dissolved oxygen amount measuring means is detachably attached to a flange portion provided in the circulation path, and a dissolved oxygen meter of the dissolved oxygen amount measuring means is provided facing the circulation path.

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