Test bench for performing erosion and / or corrosion tests

Abstract

The invention relates to a test bench (1) for performing corrosion and / or erosion tests, comprising: - a mixing reactor (2) configured to mix new erosive particles (7) from a second inlet (22) and a corrosive fluid from a first inlet (21), so as to obtain a flow of a homogeneous particle-fluid mixture (8), - a test chamber (3) configured to receive and perform the test on at least one sample (6) under the impact of the mixture (8) from the outlet (11) of the reactor (2) flowing from the inlet (12) to the outlet (13a, 13b) of said chamber (3), - a settling system (4) configured to settle the mixture (8) from the outlet (13a, 13b) so as to separate the erosive particles used in the test from the corrosive fluid, - a recycling network (5) configured to convey the fluid corrosive from outlet (27) of system (4) to first inlet (21). Figure for abbreviation: Fig. 1

Description

Title of the invention: Test bench for carrying out erosion and / or corrosion tests technical field

[0001] The invention relates to a test bench for carrying out erosion and / or corrosion tests. STATE OF THE ART

[0002] Erosion refers to the progressive wear of a material under the effect of a high-speed flow of fluid and / or solid particles. Corrosion, on the other hand, refers to the progressive deterioration of a material caused by a chemical and / or electrochemical reaction with the environment. The phenomenon of corrosion is a relatively well-known and predictable process. In contrast, the phenomenon of erosion is not as well understood. Attempts to model the latter in very specific cases remain few. The evolution of a material undergoing both corrosion and erosion is even more difficult to predict and requires the implementation of experimental tests.For example, such a situation of simultaneous corrosion and erosion is frequently encountered inside centrifugal pumps, such as those used in the chemical, petrochemical, or hydrometallurgical industries, and explains their relatively rapid degradation. As another example, this dual phenomenon is found in centrifugal pumps used in phosphate mining, as these pumps can circulate mixtures containing phosphoric acid and phosphogypsum particles.

[0003] Test benches are therefore used to test the resistance of materials (for example, materials constituting components of the aforementioned centrifugal pumps) to erosion and corrosion simultaneously. The erosive and corrosive conditions created by such test benches accelerate the material degradation process and facilitate its observation.

[0004] Slurry pot type test benches comprise a test chamber, most often cylindrical in shape, closed by a lid. Before the start of a test, the experimenter places samples of the materials to be tested inside the test chamber, as well as a mixture comprising a liquid that may be corrosive, for example an acid, and erosive particles.

[0005] At the beginning of the test, the samples are rotated in the test chamber so that they are exposed to the flow of the liquid-particle mixture. The hard particles erode the surfaces of the exposed samples through impact. The speed of Sample rotation, the mass ratio of the liquid-particle mixture, the size of the erosive particles, the type of corrosive liquid, the duration of the test and the temperature are all parameters that the experimenter can vary to study their influence.

[0006] At the end of the test, the experimenter recovers the samples which he can analyze, in particular by measuring the mass loss suffered by said samples or by observing their profilometry, for example by microscopy.

[0007] One of the main drawbacks of the "slurry pot" type test benches described above lies in the progressive dulling of the erosive particles during the test. Indeed, the particles wear down under the effect of impacts, and their erosive action is therefore not constant throughout the test, but rather decreases progressively. Such a decrease in the erosion rate during the test makes the interpretation of the results difficult.

[0008] Another drawback of slurry pot test benches lies in the quality of the homogenization of the liquid-particle mixture within the test chamber. Indeed, the mixture is homogenized by the experimenter only before its introduction into the test chamber and the start of the test. Since the particles tend to fall to the bottom of the test chamber under gravity, the mass ratio of the liquid-particle mixture varies locally along the height of the test chamber during the test. Consequently, the mass ratio of the liquid-particle mixture to which the samples are locally subjected differs from that set globally by the experimenter for conducting the test, thus distorting the measurement. A possible improvement to slurry pot test benches consists of adding a turbine to the test chamber to homogenize the particle-fluid mixture within the chamber also during the duration of the test.However, simulations of such test chambers show that this single turbine does not completely eliminate the problem. Furthermore, adding a turbine complicates the assembly of the test chamber. BRIEF DESCRIPTION OF THE INVENTION

[0009] An object of the invention is to design a test bench for erosion / corrosion tests of materials which generates an erosive action on the samples tested which is controlled and constant throughout the test chamber and throughout the duration of the test, so as to obtain reproducible results which are easier to interpret.

[0010] To this end, the invention proposes a test bench for carrying out corrosion and / or erosion tests comprising: - a mixing reactor comprising a first inlet, a second inlet and an outlet, the first inlet of the mixing reactor being fed by a flow of a corrosive fluid and the second inlet being fed by new erosive particles, the mixing reactor being configured to mix the new erosive particles and the corrosive fluid, so as to obtain, at the outlet of the mixing reactor, a circulation flow of a homogeneous particle-fluid mixture, - a test chamber comprising an inlet in fluidic connection with the outlet of the mixing reactor and an outlet, the test chamber being configured to accommodate at least one sample and to carry out the corrosion and / or erosion test of the at least sample under the impact of the homogeneous particle-fluid mixture from the mixing reactor circulating from the inlet of the test chamber to the outlet of said chamber, - a settling system comprising an inlet in fluidic connection with the outlet of the test chamber and an outlet, the settling system being configured to decant the homogeneous particle-fluid mixture from the test chamber so as to separate the erosive particles used to carry out the test and the corrosive fluid of said mixture, - a fluid recycling network configured to convey the corrosive fluid separated from the erosive particles used to carry out the test from the outlet of the settling system to the first inlet of the mixing reactor, so that the flow of corrosive fluid that feeds the mixing reactor includes the recycled corrosive fluid.

[0011] The test bench according to the invention generates a continuous flow of the liquid-particle mixture: new erosive particles, whose erosive characteristics are known, are mixed with the corrosive fluid in the mixing reactor before entering the test chamber where they are used to perform the test. The new particles become blunt under the effect of impacts with the samples and / or with the walls of the test chamber. However, under the effect of the flow, they are carried away to the outlet of the test chamber: the settling system then allows them to be removed while recycling the corrosive fluid. This recycled fluid is remixed with new erosive particles upon its return to the mixing reactor before entering the test chamber again.Thus, the test chamber is constantly supplied with unblunted erosive particles, which guarantees a constant erosion rate throughout the test under the conditions chosen for the test.

[0012] In addition, the continuous flow of the liquid-particle mixture between the mixing reactor and the settling system through the test chamber ensures a more fluid and homogeneous liquid-particle mixture between the top and bottom of the test chamber than in the prior art "slurry pot" configuration where only the rotation of the sample holder and possible additional turbines ensure the homogenization of the mixture.

[0013] According to other optional features of the invention taken alone or in combination where technically possible:

[0014] - the test chamber is located below the mixing reactor and above the settling system, the outlet of the mixing reactor being located in a lower part of said mixing reactor, the inlet of the test chamber being located in an upper part of the test chamber and the outlet of the test chamber being located in a lower part of the test chamber;

[0015] - the test bench further includes a first valve adapted to control the flow rate of the circulation flow of the homogeneous particle-fluid mixture entering the test chamber and a second valve adapted to control the flow rate of the circulation flow of the homogeneous particle-fluid mixture exiting the test chamber, so as to maintain a constant level of the particle-fluid mixture in the test chamber;

[0016] - the test bench further comprises a reservoir of new erosive particles arranged so as to supply the second inlet of the mixing reactor, preferably located above the mixing reactor;

[0017] - the test bench further comprises a third variable opening valve allowing control of the flow rate of a stream of new erosive particles conveyed from the reservoir of new erosive particles to the second inlet of the mixing reactor;

[0018] - the test bench further includes a peristaltic pump connected to the mains recycling, the peristaltic pump being adapted to pump the corrosive fluid separated from the erosive particles used to carry out the test from the outlet of the settling system to the first inlet of the mixing reactor, the peristaltic pump being further adapted to control the flow rate of the corrosive fluid supplying the first inlet of the mixing reactor;

[0019] - the test chamber comprises a lower wall, an upper wall and at least a side wall extending between the lower wall and the upper wall, the upper wall forming a lid for the test chamber and the outlet of the test chamber being located in the lower wall of said test chamber;

[0020] - at least one side wall of the test chamber comprises PVC and / or the wall The lower and upper walls comprise polyamide;

[0021] - at least one side wall of the test chamber is separable from the wall in lower and upper wall;

[0022] - the test chamber further comprises baffles arranged on at least one side wall of the test chamber so as to limit the formation of turbulent flows in the homogeneous particle-fluid mixture in the test chamber;

[0023] - the test chamber further comprises a sample holder, the sample holder being configured to be assembled with at least one sample, the sample holder being further configured to be driven in rotation relative to the lower wall of the test chamber about an axis of rotation of the sample holder, said axis of rotation being perpendicular to the lower wall of the test chamber and passing through the center of gravity of the sample holder;

[0024] - the test bench further comprises a first variable speed motor, the first variable speed motor being configured to drive the sample holder in rotation around the axis of rotation of the sample holder at a rotational speed chosen for carrying out the test;

[0025] - the entrance to the test chamber is located in the upper wall of the chamber test, at the intersection between said upper wall and the axis of rotation of the sample holder;

[0026] - the mixing reactor comprises a turbine and a second speed motor variable, the second variable speed motor being configured to drive the rotating turbine, the mixing of new erosive particles with the corrosive fluid being carried out under the effect of the rotation of said turbine;

[0027] - the mixing reactor includes a heating system configured to heat the corrosive fluid during the mixing of said fluid with the new erosive particles, so that the homogeneous particle-fluid mixture at the outlet of the mixing reactor is brought to a temperature chosen for carrying out the test;

[0028] - the mixing reactor comprises an inner wall and an outer wall, the inner wall and outer wall forming a double wall of the mixing reactor, and in which the heating system includes a heat transfer fluid which circulates between the inner wall and the outer wall, so that the heating of the corrosive fluid in the mixing reactor is achieved by heat transfer between the heat transfer fluid and the corrosive fluid through the inner wall;

[0029] - the settling system includes a first settling tank comprising a an inlet forming the inlet of the settling system and a second settling tank comprising an outlet forming the outlet of the settling system, the first tank further comprising an outlet fluidically connected to an inlet of the second tank, the outlet of the first tank being located in an upper part of said first tank), so that only an upper part of the particle-fluid mixture decanted in the first tank flows into the second tank, the outlet of the settling system being located in an upper part of the second tank, so as to collect only the corrosive fluid separated from the erosive particles used to carry out the test, said particles remaining at the bottom of the first and second tanks;

[0030] - the first settling tank is located above the second settling tank. BRIEF DESCRIPTION OF THE FIGURES

[0031] Other features and advantages of the invention will become apparent from the detailed description that follows, with reference to the accompanying drawings, in which:

[0032] - Figure 1 represents an embodiment of a test bench for carrying out erosion and / or corrosion tests according to the invention comprising a mixing reactor, a test chamber, a settling system and a recycling network.

[0033] - [Fig.2] represents the interior of the test chamber with sample holder and chicanes according to a particular embodiment of the invention.

[0034] For reasons of legibility, the drawings are not necessarily drawn to scale. DETAILED DESCRIPTION OF IMPLEMENTATION METHODS

[0035] The invention relates to a test bench 1 for performing corrosion and / or erosion resistance tests on various materials. In particular, the test bench 1 allows one or more samples of the material(s) to be tested to be subjected to a flow exhibiting an erosive and / or corrosive action mimicking the operating conditions of centrifugal pumps in the chemical, metallurgical, and / or mining industries. Before and after the test, the samples can be analyzed (for example, by profilometry and / or mass loss) so as to classify the materials constituting said samples according to their resistance to corrosion and / or erosion under the simulated conditions and thus determine which of the materials is best suited to the operating conditions of the centrifugal pump.

[0036] In addition, the test bench 1 can be used to study erosive and / or corrosive damage modes and thus enable the experimenter to model said damage modes and guide the process of developing new materials.

[0037] With reference to [Fig.1], the test bench 1 according to the invention comprises a mixing reactor 2, a test chamber 3, a settling system 4 and a fluid recycling network 5.

[0038] Prior to carrying out a corrosion and / or erosion test on at least one sample 6 on said test bench 1, the experimenter positions the sample 6 in the test chamber 3. During the test, the mixing reactor 2 continuously homogenizes a corrosive fluid with new erosive particles 7. A circulation flow of said homogenized mixture 8 flows from the mixing reactor through the test chamber 3 into the settling system 4. Thus, the erosive particles which, under the effect of impacts with the walls of the test chamber 3 and / or the sample(s) 6, have lost their sharpness, are carried away by the circulation flow and systematically removed in the settling system 4, so that each sample 6 is impacted throughout the entire duration of the test only by new erosive particles 7.This open reactor operating mode, rather than a closed reactor mode, allows for the simulation of an erosive action on the samples that is constant and controlled throughout the entire duration of the test.

[0039] The recycling network 5, for its part, allows for the recovery, at the system level of In decantation 4, the corrosive fluid is separated from the worn erosive particles to supply the mixing reactor 2 with corrosive fluid. Thus, unlike the erosive particles, the corrosive fluid circulates continuously in a closed loop within the test bench 1 between the mixing reactor 2, the test chamber 3, the decantation system 4, and the recycling network 5. This recycling allows for lower fluid consumption. Furthermore, if the mixing reactor 2 includes a heating system, as described below, enabling the test to be performed at a set temperature of the homogeneous particle-fluid mixture 8, recycling provides better control of this temperature than the constant introduction of cold corrosive fluid. Indeed, heating the cold fluid would require considerable time and energy.

[0040] In the remainder of this presentation, we will detail in more detail an embodiment of each element included in the test bench 1. Test chamber 3

[0041] The test chamber 3 is configured to accommodate the sample(s) 6 and to carry out the corrosion and / or erosion test of the sample(s) 6 under the impact of an erosive and / or corrosive flow of the homogeneous particle-fluid mixture 8. For this purpose, the test chamber 3 may include a sample holder 9 configured to be assembled with each sample 6.

[0042] During a test, the sample holder 9 is driven in rotation relative to the walls of the test chamber 3 around an axis of rotation (X) of the sample holder 9, said axis (X) passing through the center of gravity of the sample holder 9, for example by means of a first variable speed motor 10 and an elastic coupling 33, at a rotation speed chosen for carrying out the test.

[0043] The rotation of the sample holder 9 rotates each sample 6 in the particle-fluid mixture 8, thus simulating the movement of an erosive and / or corrosive flow impinging on the sample 6. The rotation speed of the sample holder 9, corresponding to the speed of the corrosive and / or erosive flow impinging on the sample, is therefore an interesting parameter for the experimenter to control and / or test on the test bench: the higher the speed of the corrosive and / or erosive flow, the faster the material erodes and / or corrodes. Preferably, the rotation speed of the sample holder 9 can be controlled, so that the speed of the corrosive and / or erosive flow impinging on the sample is chosen to be between 0 m / s and 50 m / s.The rotational speed of the sample holder 9 is much greater than the circulation speed of the homogeneous particle-fluid mixture 8, so that the erosive and / or corrosive flux speed affecting the sample 6 is overall that of the rotational speed of the sample holder 9 (without impact of the circulation flow of the particle-fluid mixture 8 through the test chamber).

[0044] The test chamber 3 further comprises an inlet 12 in fluidic connection with a outlet 11 of the mixing reactor and an outlet 13 in fluidic connection with an inlet 14 of the settling system 4. During a test, the circulation flow of the particle-homogeneous fluid mixture 8 exits the mixing reactor 2 continuously through outlet 11 of said reactor 2 to feed the inlet 12 of the test chamber 6. The flow rate of said circulation flow not exceeding 50 mL / s, the velocity of the circulation flow of the particle-homogeneous fluid mixture 8 is generally negligible compared to the rotational speed of the sample holder 9. In the test chamber 3, the circulation flow of the particle-homogeneous fluid mixture 8 flows from the inlet 12 of the test chamber to the outlet 13 of said chamber 3, where it is discharged to the inlet 14 of the settling system 4.

[0045] Optionally, the test bench 1 further comprises a first valve 15 adapted to control the flow rate of the homogeneous particle-fluid mixture 8 entering the test chamber 3 and a second valve 16 adapted to control the flow rate of the homogeneous particle-fluid mixture 8 exiting the test chamber 3, so as to maintain a constant level of the particle-fluid mixture 8 in the test chamber 3 throughout the test. The level of the particle-fluid mixture 8 in the test chamber 3 is chosen so as to keep the sample holder 9 completely immersed.

[0046] Preferably, the test chamber 3 is located below the mixing reactor 2 and above the settling system 4. According to this embodiment, the inlet 12 of the test chamber 3 is located in an upper part of the test chamber 3 and the outlet 13 of the test chamber 3 is located in a lower part of the test chamber 3, so that the circulation of the particle-homogeneous fluid mixture 8 in the test chamber 3 is facilitated by the action of gravity, so that a pump is not necessary to ensure the circulation of the particle-homogeneous fluid mixture 8. According to this embodiment, the outlet 11 of the mixing reactor 2 is advantageously located in a lower part of said mixing reactor 2.

[0047] More specifically, the test chamber 3 may include a lower wall 17, an upper wall 18, and at least one side wall 19 extending between the lower wall 17 and the upper wall 18 (for example, a generally cylindrical shape). The lower wall 17, the upper wall 18, and the side wall 19 define an internal volume in which the homogeneous particle-fluid mixture 8 is temporarily held. The level of the homogeneous particle-fluid mixture 8 in said volume is preferably kept constant throughout the test. The sample holder 9 is disposed in the internal volume defined by the lower wall 17, the upper wall 18, and at least one side wall 19, such that the axis of rotation (X) of the sample holder 19 is perpendicular to the lower wall 17 of the chamber. test 3. The upper wall 18 can form a lid allowing at least one sample 6 to be placed in the test chamber 3 before the start of the test and removed at the end of the test.

[0048] The inlet of the test chamber 3 can be located in the upper wall 18 of the test chamber, at the intersection between said upper wall 18 and the axis of rotation (X) of the sample holder 9, and the outlet 13 of the test chamber 3 in the lower wall 17 of the test chamber 3. According to this embodiment, the sample holder 9 can advantageously include a conical-shaped hood configured to fit onto an upper surface of the sample holder perpendicular to the axis of rotation (X), the apex of the cone, when the hood is fitted, being located on the axis of rotation (X) of the sample holder (see the representation of the sample holder 9 in [Fig. 1]). In this way, the particle-fluid mixture 8 is introduced directly into the center of the upper cone of the sample holder 9, which allows, in the case of large / heavy particles, the distribution of said particles uniformly in the test chamber 3.Optionally, the outlet 13 of the test chamber 3 includes two drain pipes 13a and 13b. Increasing the number of drain pipes advantageously prevents the formation of areas in the test chamber 3 where particles would remain trapped and not be properly drained.

[0049] Optionally, at least one side wall 19 of the test chamber 3 is separable from the lower wall 17 and the upper wall 18, which allows said wall 19 to be changed when it is worn (eroded and / or corroded) under the impact of the homogeneous particle-fluid mixture 8 after too many tests.

[0050] The high-speed rotation of the sample 6 can lead to the formation of turbulent flows, or vortices, in the homogeneous particle-fluid mixture 8 when it is in the test chamber 3. Advantageously, the test chamber 3 can include baffles 20 arranged on the side wall 19 of the test chamber 3 so as to limit the formation of said turbulent flows. By way of example, the test chamber 3 can include two (see [Fig. 2], which shows the interior of the test chamber 3), or four baffles respectively, distributed so as to ensure the symmetry of the test chamber 3 by rotation through 180°, or 90° respectively, by rotation about the axis of rotation (X) of the sample holder 9.According to a particular embodiment of the baffles 20, the baffles 20 are assembled on the upper wall 18 which forms a cover of the test chamber 3, so that when the test chamber 3 is closed, the baffles 20 are arranged on the side wall 19.

[0051] The side wall 19 of the test chamber 3 is made of one or more materials with high corrosion resistance, for example stainless steel, preferably 304 or 316 stainless steel. The inner face of the side wall 19 (the face facing the internal volume defined by the walls of the test chamber 3) may advantageously include elements, for example cylindrical components, made of polymers, such as PVC, rubber, polyamide, or any other material that offers particular corrosion resistance and thus effectively protects the inner face of the metal side wall 19. The lower wall 17 and the upper wall 18 include, for example, polyamide or any other corrosion-resistant material. If the test chamber 3 includes baffles 20, the baffles may also be made of polyamide or another corrosion-resistant material.

[0052] By way of example of an embodiment of the sample holder 9, the sample holder 9 may comprise, in addition to the upper surface, at least one lateral surface and one inner surface, such that the inner volume defined by the upper surface, the lateral surface, and the lower surface is filled with material. If it is filled with material, the sample holder 9 advantageously prevents the generation of parasitic flows of the particle-fluid mixture 8 inside the sample holder 9 when said sample holder 9 is rotating about its axis of rotation (X) in the test chamber 3, immersed in the particle-fluid mixture 8.

[0053] By way of further example, the sample holder 9 may comprise a single lateral surface of revolution about the axis of rotation (X) of the sample holder 9, as well as at least two supports arranged on said lateral surface, each to hold a sample. Advantageously, a first support and a second support among the at least two supports arranged on the lateral surface of the sample holder 9 may be configured such that, when the first and second samples are fixed respectively on the first and second supports, the principal surface of each sample is oriented at a different respective angle with respect to a plane perpendicular to the axis of rotation (X).This support configuration allows the experimenter to study at least two different angles of impact of the erosive and / or corrosive flux on the material samples under study during the same test, with all other parameters remaining strictly identical. Indeed, the angle of impact of the erosive and / or corrosive flux is another important parameter in the study of erosion and / or corrosion phenomena. Mixing reactor 2

[0054] As mentioned previously, the mixing reactor 2 includes an outlet 11 in fluidic connection with the inlet 12 of the test chamber 3.

[0055] The mixing reactor 2 further comprises a first inlet 21 supplied by a flow of a corrosive fluid and a second inlet 22 supplied by a flow of new erosive particles 7. By way of example, the flow rate of the corrosive fluid supplying the first inlet 21 is less than 50 mL / s. By way of further example, the flow rate of the flow of new erosive particles 7 supplying the second inlet 22 can be understood to be between 0.1 g / s and 0.6 g / s. Controlling these flow rates allows for control of the erosion rate and the test duration. Thus, increasing the flow rates of both the corrosive fluid and the new erosive particles advantageously increases the erosion rate and reduces the test duration. Beyond a threshold value for the new erosive particle flow rate, the erosion rate decreases. The choice of flow rates must be adapted according to the equipment used, particularly the piping and any pumps. The mixing reactor 2 is configured to mix the new erosive particles 7 from the second inlet 22 and the corrosive fluid from the first inlet 21, so as to obtain, at the outlet 11 of the mixing reactor 2, a circulation flow of a homogeneous particle-fluid mixture 8.

[0056] Thus, unlike the configuration of a "slurry pot", the homogenization of the particle-fluid mixture is implemented, in a test bench 1 according to the invention, not in the test chamber, but upstream of the test chamber in the mixing reactor 2.

[0057] Optionally, the second inlet 22 of the mixing reactor 2 is connected to a reservoir 23 containing fresh erosive particles 7, so that the supply of fresh erosive particles 7 to the second inlet 22 is ensured by said reservoir 23. Before the start of the test, the experimenter can choose the size and shape of the particles he wishes to use for the test, said size and shape defining the erosive action of the particles, and place said particles in the reservoir 23. The particles will then be distributed to the mixing reactor 2 throughout the duration of the test without intervention from the experimenter.

[0058] Preferably, the reservoir 23 of new erosive particles 7 is located above the mixing reactor 2 and the second inlet 22 of the mixing reactor in an upper part of said mixture, so that the supply of new erosive particles to the mixing reactor 2 by the reservoir 23 comprising the new erosive particles 7 is facilitated by gravity, not requiring the use of a pump.

[0059] Optionally, a third variable opening valve 24 allows the experimenter to control the flow rate of the stream of new erosive particles 7 conveyed from the reservoir 23 of new erosive particles to the second inlet 22 of the mixing reactor 2.

[0060] By way of example, the homogenization of the corrosive fluid and the new erosive particles can be achieved in the mixing reactor 2 by means of a mixing reactor turbine and a second variable-speed motor, the second variable-speed motor being configured to drive the rotating turbine, the mixing of the new erosive particles with the corrosive fluid being carried out under the effect of the rotation of said turbine. The homogenization of the corrosive fluid and the new erosive particles is more or less difficult depending on the flow rate of the new erosive particles and the size and / or the mass of said particles. The use of the second variable-speed motor therefore advantageously allows testing on test bench 1 of several types of new erosive particles at various concentrations while maintaining good homogenization thanks to the adaptation of the second motor's rotation speed to the chosen particles. The rotation speed of the second variable-speed motor is, for example, between 0 rpm and 3000 rpm.

[0061] The mixing reactor 2 advantageously includes a heating system 25 configured to heat the corrosive fluid during the mixing of said fluid with the new erosive particles 7, so that the homogeneous particle-fluid mixture 8 exiting the mixing reactor 2 is brought to a temperature chosen for carrying out the test. Temperature is a parameter influencing the kinetics of erosion and / or corrosion phenomena. It is therefore very useful for the experimenter to be able to control and / or study the influence of this parameter on the test bench 1.

[0062] According to a particular embodiment, the mixing reactor 2 comprises an inner wall and an outer wall (not shown in [Fig. 1]), the inner wall and the outer wall forming a double wall of the mixing reactor 2. The heating system 25 then comprises a pump and a heat transfer fluid 26, for example water, the pump circulating the heat transfer fluid 26 between the inner wall and the outer wall, so that the heating of the corrosive fluid in the mixing reactor 2 is achieved by heat transfer between the heat transfer fluid 26 and the corrosive fluid through the inner wall.

[0063] This method of heating the fluid differs from that used in prior art slurry pots, where it is generally the test chamber itself that is heated. Heating the corrosive fluid using the mixing reactor 2 is a simple solution to implement, given the widespread availability of heated mixing reactors. Settling system 4

[0064] As previously described, the settling system 4 includes an inlet 14 in fluidic connection with the outlet 13 of the test chamber 3 which is supplied by the circulation flow of the homogeneous particle-fluid mixture 8 comprising the corrosive fluid and the erosive particles having previously been used to carry out the test in the test chamber 3.

[0065] The settling system 4 is configured to decant said homogeneous particle-fluid mixture 8 from the test chamber 3 so as to separate the erosive particles 7 used to carry out the test and the corrosive fluid of said mixture 8, and thus allow the removal of the used erosive particles and the recovery of the corrosive fluid by the recycling network 5.

[0066] For this purpose, the settling system 4 may include a settling tank comprising an inlet forming inlet 14 of settling system 4 and an outlet forming outlet 27 of settling system 4 (embody not shown). The erosive particles used in the test settle to the bottom of the settling tank. The outlet of the settling system is located in the upper part of the settling tank, so as to collect only the supernatant corrosive fluid separated from the worn erosive particles.

[0067] Advantageously, the settling system 4 may include a first settling tank 28 comprising an inlet forming the inlet 14 of the settling system 4 and a second settling tank 29 comprising an outlet forming the outlet 27 of the settling system (see [Fig. 1]). According to this embodiment of the settling system 4, the first tank 28 further includes an outlet 30 fluidly connected to an inlet 31 of the second tank 29, the outlet 30 of the first tank 28 being located in an upper part of said first tank 28, so that only an upper part of the particle-fluid mixture settled in the first tank 28 flows into the second tank 29. Indeed, since the particles are heavy, the upper part of the settled particle-fluid mixture essentially comprises corrosive fluid.Similarly, the outlet 27 of the settling system 4, for example a slot, is located in the upper part of the second tank 29, so that only the liquid exits the settling system 4. The use of a second settling tank in series with a first settling tank improves the separation between the corrosive liquid and the particles by performing a second settling phase. In particular, the use of two settling tanks allows for better removal of the particles. Recycling Network 5

[0068] The corrosive fluid recycling network 5 is configured to convey the corrosive fluid separated from the erosive particles used to carry out the test from the outlet 27 of the settling system 4 to the first inlet 21 of the mixing reactor 2, so that the flow of corrosive fluid which feeds the mixing reactor 2 includes the recycled corrosive fluid.

[0069] A peristaltic pump 32 can advantageously be connected to the recycling network 5, the peristaltic pump 32 being adapted to pump the corrosive fluid separated from the erosive particles used to carry out the test from the outlet 27 of the settling system 4 to the first inlet 21 of the mixing reactor 2, the peristaltic pump 32 being further adapted to control the flow rate of the corrosive fluid supplying the first inlet 21 of the mixing reactor 2.

[0070] Advantageously, the first settling tank is located above the second settling tank, so as to reduce the effort that must be provided by the peristaltic pump 32.

[0071] Controlling the flow rate of the corrosive fluid supplying the first inlet 21 of the The mixing reactor 2, relative to the flow rate of the new erosive particles 7 feeding the second inlet 22 of the mixing reactor 2, allows the experimenter to control the particle-to-fluid mass ratio of the homogeneous particle-fluid mixture 8 feeding the inlet 12 of the test chamber 3, which is another important parameter for the experimenter. The particle-to-fluid mass ratio is advantageously less than 30%. Above this particle concentration, the erosive action of the particle-homogeneous fluid mixture 8 is artificially reduced due to the increased collision rate between particles, these collisions dissipating some of the particles' kinetic energy before impact with the samples.

[0072] The recycling network 5 is configured to protect the peristaltic pump from the erosive effect of the particles and to prevent the same, potentially dulled, particles from being used multiple times, which would lead to an uncontrolled decrease in the erosive action of the particle-fluid mixture. To this end, the recycling network 5 pumps the liquid into an upper part of the settling system 4.

Claims

Demands

1. Test bench (1) for performing corrosion and / or erosion tests on at least one sample, comprising: - a mixing reactor (2) comprising a first inlet (21), a second inlet (22) and an outlet (11), the first inlet (21) of the mixing reactor (2) being supplied with a flow of a corrosive fluid and the second inlet (22) being supplied with new erosive particles (7), the mixing reactor (2) being configured to mix the new erosive particles (7) and the corrosive fluid, so as to obtain, at the outlet (11) of the mixing reactor (2), a circulation flow of a homogeneous particle-fluid mixture (8), - a test chamber (3) comprising an inlet (12) of the homogeneous particle-fluid mixture (8) in fluidic connection with the outlet (11) of the mixing reactor (2) and an outlet (13a, 13b) of said mixture, the test chamber (3) comprising a sample holder (9) configured to be assembled with each sample (6) and to be driven in rotation about an axis of rotation (X) of the sample holder (9) passing through the center of gravity of the sample holder (9), the rotation of the sample holder (9) rotating each sample (6) in the homogeneous particle-fluid mixture (8) circulating in the test chamber so as to simulate the movement of an erosive and / or corrosive flow impacting each sample (6), - a settling system (4) comprising an inlet (14) in fluidic connection with the outlet (13a, 13b) of the test chamber (3) and an outlet (27), the settling system (4) being configured to decant the homogeneous particle-fluid mixture (8) from the test chamber (3) so as to separate the erosive particles used to carry out the test and the corrosive fluid of said mixture, - a fluid recycling network (5) configured to convey the corrosive fluid separated from the erosive particles used to carry out the test from the outlet (27) of the settling system (4) to the first inlet (21) of the mixing reactor (2), so that the flow of corrosive fluid which feeds the mixing reactor (2) includes the recycled corrosive fluid.

2. Test bench (1) according to claim 1, wherein the test chamber (3) is located below the mixing reactor (2) and above the settling system (4), the outlet (11) of the mixing reactor (2) being located in a lower part of said mixing reactor (2), the inlet (12) of the test chamber (3) being located in an upper part of the test chamber (3) and the outlet (11) of the test chamber (3) being located in a lower part of the test chamber (3).

3. Test bench (1) according to any one of claims 1 or 2, further comprising a first valve (15) adapted to control the flow rate of the circulation of the homogeneous particle-fluid mixture (8) entering the test chamber (3) and a second valve (16) adapted to control the flow rate of the circulation of the homogeneous particle-fluid mixture (8) exiting the test chamber (3), so as to maintain a constant level of the particle-fluid mixture (8) in the test chamber (3), and the sample holder (9) completely immersed.

4. Test bench (1) according to any one of claims 1 to 3, further comprising a reservoir (23) of new erosive particles (7) arranged to feed the second inlet (22) of the mixing reactor (2), preferably located above the mixing reactor (2).

5. Test bench (1) according to claim 4, further comprising a third variable opening valve (24) for controlling the flow of a stream of new erosive particles (7) conveyed from the reservoir (23) of new erosive particles (7) to the second inlet (22) of the mixing reactor (2).

6. Test bench (1) according to any one of claims 1 to 5, further comprising a peristaltic pump (32) connected to the recycling network (5), the peristaltic pump (32) being adapted to pump the corrosive fluid separated from the erosive particles used to carry out the test from the outlet (27) of the settling system (4) to the first inlet (21) of the mixing reactor (2), the peristaltic pump (32) being further adapted to control the flow rate of the corrosive fluid supplying the first inlet (21) of the mixing reactor (2).

7. Test bench (1) according to any one of claims 1 to 6, wherein the test chamber (3) comprises a lower wall (17), an upper wall (18) and at least one side wall (19) extending between the lower wall (17) and the upper wall (18), the upper wall (18) forming a cover of the test chamber (3) and the outlet (13) of the test chamber (3) being located in the lower wall (17) of said test chamber (3).

8. Test bench (1) according to claim 7, wherein at least one side wall (19) of the test chamber (3) comprises PVC and / or the lower wall (17) and upper wall (18) comprise polyamide.

9. Test bench (1) according to any one of claims 7 or 8, wherein at least one side wall (19) of the test chamber (3) is separable from the lower wall (17) and the upper wall (18).

10. Test bench (1) according to any one of claims 7 to 9, wherein the test chamber (3) further comprises baffles (20) arranged on at least one side wall (19) of the test chamber (3) so as to limit the formation of turbulent flows in the homogeneous particle-fluid mixture (8) in the test chamber (3).

11. Test bench (1) according to any one of claims 7 to 10, wherein the axis of rotation (X) of the sample holder is perpendicular to the lower wall (17) of the test chamber (3).

12. Test bench (1) according to claim 11, further comprising a first variable speed motor (10), the first variable speed motor (10) being configured to drive the sample holder (9) in rotation around the axis of rotation (X) of the sample holder (9) at a rotational speed chosen for carrying out the test.

13. Test bench (1) according to any one of claims 11 or 12, wherein the inlet (12) of the test chamber (3) is located in the upper wall (18) of the test chamber (3), at the intersection between said upper wall (18) and the axis of rotation (X) of the sample holder (9).

14. Test bench (1) according to any one of claims 1 to 13, wherein the mixing reactor (2) comprises a turbine and a second variable speed motor, the second variable speed motor being configured to drive the turbine in rotation, the mixing of the new erosive particles (7) with the corrosive fluid being carried out under the effect of the rotation of said turbine.

15. Test bench (1) according to any one of claims 1 to 14, wherein the mixing reactor (2) includes a heating system (25) configured to heat the corrosive fluid during the mixing of said fluid with the new erosive particles (7), so that the homogeneous particle-fluid mixture (8) at the outlet of the mixing reactor (2) is brought to a temperature chosen for carrying out the test.

16. Test bench (1) according to claim 15, wherein the mixing reactor (2) comprises an inner wall and an outer wall, the inner wall and the outer wall forming a double wall of the mixing reactor (2), and wherein the heating system (25) includes a heat transfer fluid (26) which circulates between the inner wall and the outer wall, so that the heating of the corrosive fluid in the mixing reactor (2) is achieved by heat transfer between the heat transfer fluid (26) and the corrosive fluid through the inner wall.

17. Test bench (1) according to any one of claims 1 to 16, wherein the settling system (4) comprises a first settling tank (28) including an inlet forming the inlet (14) of the settling system (4) and a second settling tank (29) including an outlet forming the outlet (27) of the settling system (4), the first tank (28) further comprising an outlet (30) fluidly connected to an inlet (31) of the second tank (29), the outlet (30) of the first tank (28) being located in an upper part of said first tank (28), so that only an upper part of the particle-fluid mixture settled in the first tank (28) flows into the second tank (29), the outlet (27) of the settling system (4) being located in an upper part of the second tank (29), so as to collect only the corrosive fluid separated from the erosive particles having been used to carry out the test, the said particles remaining at the bottom of the first tank (28) and the second tank (29).

18. Test bench (1) according to claim 17, wherein the first settling tank (28) is located above the second settling tank (29).

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