Sample holder, test chamber and test bench for performing corrosion and / or erosion tests, and method for performing corrosion and / or erosion tests using such a sample holder

Abstract

a sample holder adapted to rotate about an axis of rotation (X) within a test chamber for carrying out corrosion and / or erosion tests, having a side surface that rotates about the rotation axis (X); at least a first support for a first sample and a second support for a second sample are arranged on said side surface, a major surface of each sample extending radially relative to said axis of rotation (X) being exposed to the apparent flow of the particle-fluid mixture; the sample holder further comprising means for securing the first and second samples to the first and second supports, respectively; the first support and the second support are configured such that when the first sample and the second sample are fixed to the first support and the second support, respectively, the major surfaces of each sample are oriented at different respective angles with respect to a plane perpendicular to the rotation axis (X).

Description

[Technical Field]

[0001] The present application relates to a sample holder configured to rotate about an axis of rotation within a test chamber for performing corrosion and / or erosion tests, a test chamber having the sample holder, a test bench having such a test chamber, and a method of performing corrosion and / or erosion tests using such a sample holder. [Background technology]

[0002] Erosion is the progressive wear of materials due to the influence of high-velocity fluid and / or solid particle flows. Corrosion is the progressive degradation of materials caused by chemical and / or electrochemical reactions with the environment. Corrosion is a relatively well-known and predictable process. On the other hand, erosion is less well understood. Few attempts have been made to model the latter in very specific cases. Predicting the changes in materials undergoing both corrosion and erosion is more difficult and requires experimental evaluation. For example, simultaneous corrosion and erosion are often observed in centrifugal pumps, such as those used in the chemical, petrochemical, or hydrometallurgical industries, explaining their relatively rapid deterioration. As another example, this dual phenomenon is observed in centrifugal pumps used in the phosphate rock mining industry. These pumps can circulate a mixture containing phosphoric acid and phosphogypsum particles.

[0003] Thus, the test bench is used to simultaneously evaluate the erosion and corrosion resistance of materials (e.g., the materials constituting the components of the centrifugal pumps mentioned above).The erosive and corrosive conditions generated by such a test bench accelerate material degradation phenomena and make them easier to observe.

[0004] A slurry pot-type test bench has a test chamber, usually cylindrical, closed with a lid, and a sample holder placed inside the test chamber. Before the test begins, the experimenter fixes a sample of the material to be tested in the sample holder. The sample can be cylindrical or rectangular, and the chamber is filled with a mixture containing a corrosive liquid, such as an acid, and erosive particles.

[0005] At the start of the test, the sample holder is rotated within the test chamber, exposing the sample to the flow of the liquid-particle mixture. The hard particles erode the exposed surface of the sample under impact. The sample rotation speed, mass ratio of the liquid-particle mixture, size of the erosive particles, type of corrosive liquid, test time, and temperature are all parameters that the experimenter can vary to study their effects.

[0006] At the end of the test, the experimenter can retrieve the samples and carry out an analysis, in particular by measuring the mass loss they have undergone or by observing their surface morphology, for example by microscope.

[0007] However, the corrosive and erosive flows circulating in a centrifugal pump come into contact with various pump components at different impingement angles, and the value of the impingement angle of the corrosive / erosive flows on said components is an additional parameter that influences the erosion / corrosion phenomena of the materials that make up said components.

[0008] By using samples in a test chamber where the main surface is exposed to the corrosion / erosion flow, a single impact angle can be simulated per test. Therefore, to obtain a complete study of the erosion / erosion phenomenon, it is necessary to perform as many tests as there are impact angles of interest. Furthermore, when different tests are performed consecutively while changing the impact angle, other parameters may be introduced that are beyond the experimenter's control, making it difficult to compare the results obtained from these different tests.

[0009] The use of cylindrical samples allows for the simulation of different impact angles in a single test. However, the surface eroded at each impact angle is extremely small. This very small surface, combined with the sample shape itself, makes post-processing of the sample, especially profilometric analysis, difficult. Summary of the Invention [Problem to be solved by the invention]

[0010] One objective of the present invention is to design a sample holder that can evaluate the flow of fluids and / or solid particles impinging on a material in a more representative manner, while allowing for easy analysis of the sample and accurate interpretation of the results. [Means for solving the problem]

[0011] For this purpose, the present invention provides a sample holder adapted to rotate about an axis of rotation within a test chamber for conducting corrosion and / or erosion tests, a side surface that rotates about the axis of rotation; at least a first support for a first sample and a second support for a second sample are disposed on the side surface, a major surface of each sample extending radially relative to the axis of rotation being exposed to the apparent flow of the particle-fluid mixture; the sample holder further comprising means for securing the first and second samples to the first and second supports, respectively; A sample holder is provided, wherein the first support and the second support are configured such that when the first sample and the second sample are fixed to the first support and the second support, respectively, the major surfaces of each sample are oriented at different respective angles relative to a plane perpendicular to the rotation axis.

[0012] The sample holder according to the present invention allows two samples to be fixed so that the impact angle formed between the fluid and / or particle stream and the major surface of each of the two samples is different between the two samples. Thus, the sample holder according to the present invention allows two different impact angles to be tested during the same test, while all other experimental parameters are strictly equal. Furthermore, the sample holder allows for each impact angle to produce a complete surface of the sample corroded / eroded at that impact angle, which can then be easily analyzed, particularly in microscopy experiments.

[0013] Other optional features of the invention, taken alone or in combination where technically feasible: The second support is oriented at an angle of 180° from the first support relative to the axis of rotation of the sample holder in a plane perpendicular to the axis of rotation.

[0014] a third support for the third sample and a fourth support for the fourth sample are disposed on a side surface of the sample holder; major surfaces of the third sample and the fourth sample extending radially relative to the axis of rotation are exposed to a virtual flow of a particle-fluid mixture; the sample holder further comprising means for fixing the third and fourth samples to the third and fourth supports, respectively; The third support and the fourth support are configured such that when each of the four samples is fixed to its respective support, a major surface of each of the four samples is oriented at a different respective angle relative to a plane perpendicular to the rotation axis.

[0015] The second support, the third support, and the fourth support are oriented at angles of 90°, 180°, and 270°, respectively, from the first support relative to the axis of rotation of the sample holder in a plane perpendicular to the axis of rotation.

[0016] Each support has a groove formed in the side surface, the groove adapted to receive a respective sample.

[0017] Each support further: a bearing surface parallel to the groove; at least two orifices; and The orifice provides a passage for the fastening means from the seating surface to the groove.

[0018] The means for immobilizing each sample comprises: at least two polytetrafluoroethylene cylinders; At least two pressure screws; and the cylinder and the screw are adapted to be inserted into the orifices of the respective supports by the bearing surfaces of the supports; When the sample is secured to the respective supports, each of the polytetrafluoroethylene cylinders is inserted into one of the orifices of the respective support; Each of the pressure screws pressurizes the cylinder inserted into one of the orifices, keeping the sample fixed to the sample holder without any contact between the screw and the sample.

[0019] the means for fixing each sample comprise at least two grub screws adapted to be inserted into orifices of the respective supports through the bearing surfaces of the supports; When a sample is secured to a respective support, each of the grub screws is inserted into one of the orifices in the respective support, and contact with the sample maintains the sample secured to the sample holder.

[0020] The sample holder further has an upper surface perpendicular to the axis of rotation.

[0021] Each support further includes a notch extending from the side surface of the upper surface to the seating surface; The notch has sides perpendicular to the seating surface.

[0022] the sample holder further comprising a conical cover configured to fit over the top surface of the sample holder perpendicular to the axis of rotation; When the cover is fitted, the top of the cone is positioned on the axis of rotation of the sample holder.

[0023] The sample holder further has a lower surface perpendicular to the axis of rotation, and a volume defined by the upper surface, the side surface, and the lower surface is filled with a material.

[0024] The present invention also provides a test chamber suitable for carrying out corrosion and / or erosion tests, comprising: A test chamber having a sample holder as described above arranged to rotate within the chamber.

[0025] Other optional features of the invention, taken alone or in combination where technically feasible: the test chamber further comprising a lower wall, an upper wall, and at least one side wall extending between the lower wall and the upper wall; the upper wall forms a lid for the test chamber; the sample holder is disposed inside a space defined by the lower wall, the upper wall, and the side wall of the test chamber; The side walls of the test chamber and the axis of rotation of the sample holder are perpendicular to the lower side wall.

[0026] The test chamber further comprises: an inlet into which a circulating flow of the particle-fluid mixture is supplied; The exit and and When conducting a corrosion test and / or an erosion test, the circulating flow flows circulatingly through the test chamber from the inlet to the outlet, and the circulating flow is discharged through the outlet; the inlet and outlet of the test chamber are located on the upper and lower walls of the test chamber, respectively; The inlet is located at the intersection of the upper wall and the axis of rotation of the sample holder.

[0027] The invention further relates to a test bench for carrying out corrosion and / or erosion tests, comprising a test chamber as described above.

[0028] Finally, the present invention provides 1. A method for erosion / corrosion testing comprising: Fixing at least two samples to said sample holders, said sample holders being positioned within said test chamber; rotating the sample holder within the test chamber by exposing a major surface of each of the at least two samples to a nominal flow of a particle-fluid mixture, thereby eroding and / or corroding each of the surfaces; analyzing the major surface of each of the at least two samples; The present invention relates to a method comprising:

[0029] Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which: for reasons of readability, the drawings are not necessarily drawn to scale. [Brief explanation of the drawings]

[0030] [Figure 1A] 1 shows two viewing angles of an embodiment of a sample holder according to the invention, suitable for fixing four samples. FIG. [Figure 1B] 1 shows two viewing angles of an embodiment of a sample holder according to the invention, suitable for fixing four samples. FIG. [Figure 2A] 2A and 2B show an embodiment of a sample holder according to the invention suitable for clamping four samples, the sample holder having a conical cover. Fig. 2A corresponds to a view in which four samples are clamped in the sample holder and the cover is attached to the top surface of the sample holder. [Figure 2B] 2A and 2B show an embodiment of a sample holder according to the invention suitable for fixing four samples. The sample holder has a conical cover. Figure 2B corresponds to an exploded view of the same sample holder, cover, and four samples. [Figure 3] 1 shows an embodiment of a means for fixing a sample included in a sample holder of the present invention. FIG. [Figure 4] 1 shows a test bench with a test chamber and a sample holder according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention relates to a sample holder suitable for carrying out corrosion and / or erosion tests on a material to be tested, which is configured to hold at least two samples of said material to be tested and which is further configured to rotate itself in a test chamber which is filled with a particle-fluid mixture comprising erosive particles and / or a corrosive fluid.

[0032] The rotation of the sample holder itself, immersed in the particle-fluid mixture and having a sample of the material to be tested previously secured thereto, exposes each sample secured thereto to an apparent flow of the particle-fluid mixture having erosive and / or corrosive effects that mimic the operating conditions of centrifugal pumps used in the chemical, metallurgical, and / or mining industries. Thus, when the sample holder itself rotates at a predetermined rotational speed, the sample is impinged by an apparent flow of the particle-fluid mixture oriented tangentially to the axis of rotation of the sample holder. Furthermore, the velocity of the flow is the tangential velocity of the sample, which is directly related to the rotational speed of the sample holder.

[0033] Before and after the test, the samples are analyzed (e.g., by shape measurements and / or mass loss) and the materials comprising said samples are classified according to their resistance to corrosion and / or erosion under simulated conditions, thereby making it possible to determine which materials are best suited to the operating conditions of the centrifugal pump.

[0034] Additionally, the sample holder can be used to study erosive and / or corrosive damage modes, allowing experimenters to model said damage modes and guide the development process of new materials.

[0035] In the following, one embodiment of a sample holder according to the invention will be described more specifically, where the sample holder is adapted to hold four samples of the material to be tested. Such an embodiment of the sample holder is shown in Figures 1A to 3.

[0036] The sample holder according to the present invention has a side surface 1 that rotates about an axis of rotation (X). The sample holder may further have an upper surface 2 that is perpendicular to the axis of rotation (X). Finally, the sample holder may have a lower surface 3 that is perpendicular to the axis of rotation (X), and the internal volume defined by the upper surface 2, the side surface 1, and the lower surface 3 is filled with a material. Significantly, the sample holder is filled with a material and therefore cannot be penetrated by particles and / or fluids. Thus, the sample holder can prevent parasitic flow of the particle-fluid mixture from occurring inside the sample holder when the sample holder rotates about the axis of rotation (X) in a test chamber immersed in the particle-fluid mixture. In fact, such parasitic flow in the center of the chamber in the sample holder is not representative of the interior of a centrifugal pump and may distort measurement results. If such parasitic flows can be partially reduced by placing baffles on the walls of the test chamber containing the rotating sample holder, the use of a packed sample holder further significantly reduces said flows.

[0037] A first support, a second support, a third support, and a fourth support are arranged on the side surface 1, and each support accommodates a first sample, a second sample, a third sample, and a fourth sample, respectively. Preferably, the supports are evenly distributed on the sample holder, and in particular, the distances between adjacent supports around the circumference of the sample holder are equal. For example, the second support, the third support, and the fourth support are oriented at 90°, 180°, and 270° from the first support, respectively, in a plane perpendicular to the rotation axis (X) of the sample holder. Such a distribution of the four supports on the side surface 1 of the sample holder allows for good balancing of the sample holder, to which the four samples are pre-fixed, when the sample holder rotates around its rotation axis (X).

[0038] The four supports disposed on the side surface 1 of the sample holder are arranged such that when each of the four samples is secured to its respective support, the major surface of each of the four samples is oriented at a respective angle relative to a plane perpendicular to the axis of rotation (X) that is different from the respective angles of the other three samples. Alternatively, two or three of the four samples may be oriented at the same respective angle when secured on the sample holder without departing from the scope of the invention.

[0039] For example, the major surfaces of the first, second, third, and fourth samples may be oriented at angles of 10°, 30°, 45°, and 90°, respectively, relative to a plane perpendicular to the rotation axis (X). In other words, as the sample holder in the particle-fluid mixture rotates about the axis (X), the major surfaces of the first, second, third, and fourth samples are impacted by the apparent flow of the particle-fluid mixture at impact angles of 10°, 30°, 45°, and 90°, respectively, where the impact angle is the angle between the direction of the apparent flow and the plane defined by the major surfaces. Thus, 90° corresponds to impact of the apparent flow normal to the major surfaces, and 10° corresponds to more grazing impact of the apparent flow.

[0040] Thus, the sample holder advantageously allows testing of up to four different impact angles of the apparent flow of a particle-fluid mixture having corrosive and / or erosive properties during one test, while all other experimental parameters are kept strictly the same (in particular, temperature, particle-to-fluid mass ratio, particle and fluid properties, etc.) Even more advantageously, the sample holder allows evaluation of four different impact angles on the same material under test, provided that the four samples are composed of the same said material.

[0041] Furthermore, for each impact angle, the sample holder can generate a complete surface of the sample corroded / eroded at that impact angle, and therefore damage to the surface that is fully representative of the impact angle investigated, which can then be easily analyzed, especially in microscopy experiments.

[0042] The sample holder further comprises means for securing the first sample, the second sample, the third sample and the fourth sample to the first, second, third and fourth supports, respectively.

[0043] In one particular embodiment of the first, second, third and fourth supports shown in Figures 1 and 2, each of said supports may have a groove 4a, 4b, 4c, 4d formed in the side surface 1 and adapted to receive a respective sample 5a, 5b, 5c, 5d. In other words, the shape of each groove 4a, 4b, 4c, 4d is adapted to allow a respective sample 5a, 5b, 5c, 5d to be inserted into said groove 4a, 4b, 4c, 4d.

[0044] For example, samples 5a, 5b, 5c, 5d having a parallelepiped shape and dimensions on the order of 30 mm x 30 mm x 10 mm may be used. Each groove 4a, 4b, 4c, 4d of the sample holder then forms an opening having dimensions of 30 mm x 10 mm in the side surface 1 of the sample holder, allowing the respective sample 5a, 5b, 5c, 5d to be inserted through one of the four faces having dimensions of 30 mm x 10 mm. The depth of each groove may be, for example, between 1 mm and 3 mm, depending on the size of the sample.

[0045] The grooves 4a, 4b, 4c, 4d are oriented at respective angles relative to a plane perpendicular to the axis of rotation (X); These are oriented at angles that are different from one another and equal to the impact angles to be tested, for example 10°, 30°, 45° and 90°. When the samples 5a, 5b, 5c, 5d are inserted into their respective grooves 4a, 4b, 4c, 4d, the major surfaces of each sample 5a, 5b, 5c, 5d are oriented at a respective angle relative to the plane, which is one of the directions of the grooves 4a, 4b, 4c, 4d of said samples 5a, 5b, 5c, 5d (according to the length but not the width of the groove).

[0046] In the example where samples 5a, 5b, 5c, 5d are parallelepiped shaped and have dimensions of 30 mm x 30 mm x 10 mm, whereby said samples are inserted into their respective grooves 4a, 4b, 4c, 4d by their faces measuring 30 mm x 10 mm, the main surface of each sample is its face measuring 30 mm x 30 mm that faces the apparent flow of the particle-fluid mixture when the sample holder is rotated about the axis of rotation (X) at an impact angle determined by the orientation of the respective grooves 4a, 4b, 4c, 4d.

[0047] Each support may further have a seating surface 6a, 6b, 6c, 6d parallel to the grooves 4a, 4b, 4c, 4d and at least two orifices 7a1, 7a2, 7b1, 7b2, 7c1, 7c2, 7d1, 7d2 for passing the fastening means from the seating surface 6a, 6b, 6c, 6d to the grooves 4a, 4b, 4c, 4d.

[0048] In one variation of the fixing means shown in Fig. 3, the means for fixing each sample may comprise at least two cylinders 8 made of polytetrafluoroethylene, polyamide, or any other material with a certain corrosion resistance, and at least two pressure screws 9, preferably metal screws, for example screws made of 304L or 316L stainless steel. Metal screws have a significantly greater resistance to centrifugal forces than non-metallic screws. The cylinders 8 and screws 9 are adapted to be inserted into orifices 7a1, 7a2, 7b1, 7b2, 7c1, 7c2, 7d1, 7d2 of the respective supports by means of bearing surfaces 6a, 6b, 6c, 6d of the supports, so that the samples 5a, 5b, 5c, 5d are fixed to the respective supports, and each of the cylinders 8 is inserted into one of the orifices 7a1, 7a2, 7b1, 7b2, 7c1, 7c1, 7d1, 7d2 of the respective supports. When this is done, each of the pressure screws 9 applies pressure through the orifices 7a1, 7a2, 7b1, 7b2, 7c1, 7d1, 7d2 to the cylinders 8 inserted into the orifices 7a1, 7a2, 7b1, 7b1, 7b2, 7c1, 7c1, 7d1, 7d2, so that no contact occurs between the screws 9 and the samples 5a, 5b, 5c, 5d, and the samples 5a, 5b, 5c, 5d are maintained fixed to the sample holder.

[0049] By interposing a cylinder made of a polymer or any other material with good corrosion resistance between the pressure screw and the sample, if the sample is metallic, metal-metal contact is significantly avoided, which can be a source of galvanic corrosion in the presence of a corrosive fluid that can act as a corrosive electrolyte, such as a 3.5% by mass salt solution or an acidic solution including, but not limited to, sulfuric acid, nitric acid, and / or hydrochloric acid.

[0050] In another variant of the fixing means (not shown), the means for fixing each sample comprise at least two grub screws adapted to be inserted into orifices 7a1, 7a2, 7b1, 7b2, 7c1, 7c2, 7d1, 7d2 of the respective support by means of the bearing surfaces 6a, 6b, 6c, 6d of the support, so that when the sample 5a, 5b, 5c, 5d is fixed to the respective support, each grub screw is inserted into one of the orifices 7a1, 7a2, 7b1, 7b2, 7c1, 7c2, 7d1, 7d2 of the respective support and maintains the sample fixed to the sample holder by contact with the sample. The grub screws are preferably made of 304L, 316L or 904L stainless steel or any other material with certain corrosion resistance.

[0051] Each sample 5a, 5b, 5c, 5d may further have two drilled holes configured such that, when the sample 5a, 5b, 5c, 5d is fixed to its respective support, the bearing surfaces 6a, 6b, 6c, 6d of the support allow the cylinders 8 or grub screws inserted in the orifices 7a1, 7a2, 7b1, 7b2, 7c1, 7c2, 7d1, 7d2 to be inserted into the drilled holes as well. In such a configuration, each sample is held firmly in its respective support, even at high rotational speeds of the sample holder, for example between 10 m / s and 25 m / s.

[0052] Also, if the sample holder has an upper surface 2, each support may have a notch 10a, 10b, 10c, 10d which extends to the seating surface 6a, 6b, 6c, 6d in the side surface 1 of the upper surface 2, said notches 10a, 10b, 10c, 10d having sides perpendicular to the seating surface. The notches 10a, 10b, 10c, 10d allow easy access to the seating surfaces 6a, 6b, 6c, 6d when inserting the fixing means 8, 9.

[0053] Advantageously, the sample holder may further have a conical cover 11 configured to fit onto the upper surface 2 of the sample holder perpendicular to the rotation axis (X), such that when the cover 11 is fitted, the top of the cone is positioned on the rotation axis (X) of the sample holder.

[0054] In other alternative embodiments not shown in this disclosure, the sample holder may be suitable for mounting two or more samples other than four, and may have a number of suitable supports for this purpose. The supports are configured so that, when different samples are mounted on each support, the major surface of a first sample is oriented at a different angle relative to a plane perpendicular to the rotation axis of the sample holder than the angles of the other samples. In other words, the sample holder allows for the evaluation of at least two different impact angles. In certain embodiments, the sample holder allows for the evaluation of as many impact angles as the number of samples included in the sample supports, with the major surface of each sample oriented at a different angle relative to a plane perpendicular to the rotation axis of the sample holder than the angles of all other samples.

[0055] If the sample holder is suitable for fixing two samples, the second support is preferably oriented at an angle of 180° to the rotation axis of the sample holder in a plane perpendicular to said rotation axis. If the sample holder is suitable for fixing three samples, the second and third support are preferably oriented at 60° and 120° from the first support, respectively, to the rotation axis of the sample holder in a plane perpendicular to said rotation axis. Such a distribution of the supports, when comprising two to four supports, ensures a good balance of the sample holder around its rotation axis and can be easily adapted by a person skilled in the art, regardless of the number of supports.

[0056] Finally, all features of the sample holder and its supports, as described above for the case where the sample holder includes four supports, can be applied to sample holders including a different number of supports without departing from the scope of the present invention.

[0057] The invention also extends to a test chamber having a sample holder manufactured according to any one of the preceding embodiments, configured such that during the performance of a corrosion and / or erosion resistance test, the sample holder and a sample fixed thereto are immersed in a particle-fluid mixture containing erosive particles and / or a corrosive fluid, and the sample holder itself can rotate about its axis of rotation (X). Due to the rotation of the sample holder itself along the axis of rotation (X) of the particle-fluid mixture, the sample is subjected to the impact of a virtual flow of the particle-fluid mixture, which exerts a corrosive and / or erosive action on the sample.

[0058] In one particularly advantageous embodiment of the test chamber 21 shown in FIG. 4 , the test chamber 21 may have an inlet 23 through which a circulating flow of particle-fluid mixture 22 is supplied and an outlet 24 through which said flow is discharged. Thus, during corrosion and / or erosion tests, the circulating flow of particle-fluid mixture 22 circulates from the test chamber inlet 23 to the outlet 24 of said chamber 21. If necessary, the test chamber 21 may further include a first valve and a second valve, the first valve adapted to control the flow rate of the circulating flow of particle-fluid mixture 22 entering the test chamber 21, and the second valve adapted to control the flow rate of the circulating flow of particle-fluid mixture 22 exiting the test chamber 21, to maintain a constant level of particle-fluid mixture 22 in the test chamber 21 throughout the test period. The level of particle-fluid mixture 22 in the test chamber 21 is selected to maintain the sample holder 20 fully immersed.

[0059] The rotation speed of the sample holder 20 is high compared to the speed of the circulating flow of the particle-fluid mixture 22 through the test chamber 21, so that the apparent flow speed of the particle-fluid mixture 22 impinging on the samples 5a, 5b, 5c, 5d is approximately the same as the rotation speed of the sample holder 20 (in the absence of impingement of the circulating flow of the particle-fluid mixture 22 through the test chamber 21).

[0060] Advantageously, such an embodiment of the test chamber 21 allows the erosive particles used to conduct the test to be evacuated and the test chamber 21 to be constantly supplied with new erosive particles, so that the erosive action of the particles does not change during the test and can be fully controlled by the experimenter. Such an embodiment of the test chamber 21 also allows for a smoother and more homogeneous distribution of the particle-fluid mixture throughout the entire area of ​​the test chamber. In particular, even if the erosive particles used are very large, the possibility of them falling to the bottom of the test chamber 21 under the influence of gravity during the test is reduced.

[0061] In another embodiment of the test chamber (not shown), the test chamber may resemble a pot that has neither an inlet through which a circulating flow of particle-fluid mixture can be supplied during a test nor an outlet for draining said circulating flow, and therefore the test chamber must be filled with the particle-fluid mixture by the experimenter before the test is performed, so that the sample holder and sample are immersed.

[0062] Geometrically, test chamber 21 may have a lower wall 25, an upper wall 26, and at least one side wall 27 extending between lower wall 25 and upper wall 26. Lower wall 25, side wall 27, and upper wall 26 then form an interior space of test chamber 21, and sample holder 20 is disposed within this space. Furthermore, during testing, this space is filled with particle-fluid mixture 22.

[0063] The rotation axis (X) of the sample holder 20 is, for example, arranged perpendicular to the lower wall 25 of the test chamber 21. Therefore, if the sample holder 20 has a lower surface 3, the lower surface 3 is arranged facing and parallel to the lower wall 25 of the test chamber 21. If the sample holder 20 has an upper surface 2, the upper surface 2 is arranged facing and parallel to the upper wall 26 of the test chamber 21.

[0064] The upper sidewall 26 of the test chamber 21 may form a lid. In this case, the lid may be removed, for example, so that the samples 5a, 5b, 5c, 5d and / or sample holder 20 may be placed in the test chamber 21 before the start of the performance of the erosion and / or corrosion test, or removed at the end of the test. If the test chamber 21 does not have an inlet and an outlet for the circulating flow of the particle-fluid mixture 22, the lid may be removed and the test chamber 21 may be filled with the mixture 22 before the performance of the test. Conversely, the lid of the test chamber 21 may be fitted to the sidewall 27, closing the test chamber 21 during the performance of the corrosion and / or erosion test.

[0065] If the test chamber 21 has an inlet 23 and an outlet 24, the sample holder 20 advantageously has a conical cover as described above, and the inlet of the test chamber 21 is preferably located in the upper wall 26 of the test chamber 21, at the intersection between the upper wall 26 of the test chamber 21 and the axis of rotation (X) of the sample holder 20. In this case, the particle-fluid mixture 22 is introduced directly into the center of the upper cone of the sample holder 20, which in the case of large / heavy particles allows for a uniform distribution of said particles within the test chamber 21.

[0066] Additionally, the outlet 24 of the test chamber 21 may be formed in a lower wall 25 of the test chamber 21 .

[0067] The invention also extends to a test bench for carrying out corrosion and / or erosion tests, comprising a test chamber 21 according to any one of the preceding embodiments.

[0068] For example, if the test chamber has an inlet 23 and an outlet 24 for the circulation of a circulating flow of particle-fluid mixture 22 through said test chamber 21, the test bench may further have a mixer reactor 28 to which fresh erosive particles 29 and a corrosive fluid are supplied, said mixer reactor 28 being configured to mix the fresh erosive particles 29 and the corrosive fluid, and at the outlet of the mixer reactor 28 a circulating flow of particle-fluid mixture 22 is obtained, which is supplied to the inlet 23 of the test chamber 21. The mixer reactor may be equipped with a heating system 30, if necessary.

[0069] The test bench is also a settling system 31 in fluid communication with the outlet 24 of the test chamber 21, the settling system 31 being configured to settle the particle-fluid mixture 22 obtained from the test chamber 21, such that the erosive particles and corrosive fluid used in conducting the test are separated from the mixture 22; and a fluid recirculation network 32 configured to transport the corrosive fluid separated from the erosive particles used in conducting the test from the settling system 31 to the mixing reactor 28, whereby the corrosive fluid is recycled while the erosive particles used in conducting the test are systematically removed; may have

[0070] Finally, the present invention relates to a method for erosion / corrosion testing.

[0071] The testing method comprises the step of fixing a sample to be tested in a sample holder according to any one of the aforementioned sample holder embodiments, the sample holder being placed in a test chamber according to any one of the aforementioned test chamber embodiments, and if the test chamber has a lid, the lid being opened to allow the step of fixing the sample.

[0072] If the test chamber is a pot, the method further comprises filling the test chamber with a mixture of erosive particles and a corrosive fluid, with the sample and sample holder immersed in the mixture.

[0073] Alternatively, if the test chamber has an inlet and an outlet that allow circulation of the flow of the particle-fluid mixture, the method may include filling a particle reservoir and / or a corrosive fluid reservoir that is external to the test chamber.

[0074] The method further includes rotating the sample holder within the test chamber, as described above, so that each major surface of the sample is exposed to a stream of fluid and / or solid particles and is subjected to erosion and / or corrosion at at least two different impact angles.

[0075] The method finally comprises the steps of stopping the rotation of the sample holder, removing the fixing means, retrieving the samples, and analysing a major surface of each of said samples.

Claims

1. a sample holder adapted to rotate about an axis of rotation (X) in a test chamber for carrying out corrosion and / or erosion tests, having a side surface that rotates about the rotation axis (X); at least a first support for a first sample and a second support for a second sample are arranged on said side surface, a major surface of each sample extending radially relative to said axis of rotation (X) being exposed to the apparent flow of particle-fluid mixture; the sample holder further comprising means for securing the first and second samples to the first and second supports, respectively; the first support and the second support are configured such that when the first sample and the second sample are secured to the first support and the second support, respectively, the major surfaces of each sample are oriented at different respective angles with respect to a plane perpendicular to the rotation axis (X).

2. 2. The sample holder of claim 1, wherein the second support is oriented at an angle of 180° from the first support relative to the axis of rotation (X) of the sample holder in a plane perpendicular to the axis of rotation (X).

3. a third support for a third sample and a fourth support for a fourth sample are disposed on a side surface of the sample holder; major surfaces of the third sample and the fourth sample extending radially relative to the axis of rotation (X) are exposed to a pseudo-flow of a particle-fluid mixture; the sample holder further comprising means for fixing the third and fourth samples to the third and fourth supports, respectively; 2. The sample holder of claim 1, wherein the third support and the fourth support are configured such that, when each of the four samples is secured to a respective support, a major surface of each of the four samples is oriented at a different respective angle relative to a plane perpendicular to the rotation axis (X).

4. 4. The sample holder of claim 3, wherein the second support, the third support, and the fourth support are oriented at angles of 90°, 180°, and 270°, respectively, from the first support relative to the axis of rotation (X) of the sample holder in a plane perpendicular to the axis of rotation (X).

5. 5. A sample holder according to any one of claims 1 to 4, wherein each support has a groove formed in the side surface, the groove adapted to receive a respective sample.

6. Each support further: a bearing surface parallel to the groove; at least two orifices; and 6. The sample holder of claim 5, wherein the orifice provides a passage for the fastening means from the seating surface to the groove.

7. The means for immobilizing each sample comprises: at least two polytetrafluoroethylene cylinders; At least two pressure screws; and the cylinder and the screw are adapted to be inserted into the orifices of the respective supports by the bearing surfaces of the supports; When the sample is secured to the respective supports, each of the polytetrafluoroethylene cylinders is inserted into one of the orifices of the respective support; 7. The sample holder of claim 6, wherein each of the pressure screws pressurizes the cylinder inserted into one of the orifices through the orifice, and the sample remains fixed to the sample holder without any contact between the screw and the sample.

8. the means for fixing each sample comprise at least two grub screws adapted to be inserted into orifices of the respective supports through the bearing surfaces of the supports; 7. The sample holder of claim 6, wherein when a sample is secured to a respective support, each of the grub screws is inserted into one of the orifices in the respective support, and contact with the sample maintains fixation of the sample relative to the sample holder.

9. 9. The sample holder of claim 1, further comprising an upper surface perpendicular to the axis of rotation (X).

10. Each support further includes a notch extending from the side surface of the upper surface to the seating surface; 10. The sample holder of claim 9 in combination with any one of claims 6 to 8, wherein the notch has sides perpendicular to the seating surface.

11. the sample holder further comprises a conical cover configured to fit onto the top surface of the sample holder perpendicular to the axis of rotation (X); 11. A sample holder according to claim 9 or 10, wherein when the cover is fitted, the conical top is positioned on the axis of rotation (X) of the sample holder.

12. 12. The sample holder of claim 9, further comprising a lower surface perpendicular to the axis of rotation (X), wherein a volume defined by the upper surface, the side surfaces, and the lower surface is filled with a material.

13. 1. A test chamber suitable for carrying out corrosion and / or erosion tests, comprising: A test chamber having a sample holder according to any one of claims 1 to 12 arranged to rotate within the chamber.

14. further comprising a lower wall, an upper wall, and at least one side wall extending between the lower wall and the upper wall; the upper wall forms a lid for the test chamber; the sample holder is disposed inside a space defined by the lower wall, the upper wall, and the side wall of the test chamber; 14. The test chamber of claim 13, wherein the side walls of the test chamber and the axis of rotation (X) of the sample holder are perpendicular to the lower side wall.

15. moreover, an inlet into which a circulating flow of the particle-fluid mixture is supplied; The exit and and When conducting a corrosion test and / or an erosion test, the circulating flow flows circulatingly through the test chamber from the inlet to the outlet, and the circulating flow is discharged through the outlet; the inlet and outlet of the test chamber are located on the upper and lower walls of the test chamber, respectively; 15. The test chamber of claim 14, wherein the inlet is located at the intersection of the upper wall and the axis of rotation (X) of the sample holder.

16. A test bench for carrying out corrosion and / or erosion tests, comprising a test chamber according to any one of claims 13 to 15.

17. 1. A method for erosion / corrosion testing comprising: Fixing at least two samples to a sample holder according to any one of claims 1 to 12, said sample holder being placed in a test chamber according to any one of claims 13 to 15; rotating the sample holder within the test chamber by exposing a major surface of each of the at least two samples to a nominal flow of a particle-fluid mixture, thereby eroding and / or corroding each of the surfaces; analyzing the major surface of each of the at least two samples; A method comprising:

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