Dense liquid-solid two-phase rotating flow scouring corrosion simulation test device

Abstract

The application provides a dense liquid-solid two-phase rotating flow scouring corrosion simulation test device, which comprises a motor, a central rotating shaft, a stirring tank, a multilayer sample mounting rack and a stirring paddle. The top flange of the cylinder of the stirring tank is sealingly connected with a flange structure. The motor is fixed on the flange structure. The central rotating shaft is power-connected with the motor and extends into the cylinder of the stirring tank through the flange structure and is fixedly connected with the stirring paddle. A mounting sleeve is further connected downward at the central position of the flange structure and does not interfere with the central rotating shaft. The multilayer sample mounting rack is provided with at least two layers of mounting racks. Each layer of mounting racks has 4-12 pairs of mounting arms which radially extend out. The inner end of each pair of mounting arms is fixed on the mounting sleeve, and the outer end forms a pair of circular holes corresponding in upper and lower directions to fix the two ends of a sample piece. The device can be used for testing the coupling rule of dense particles and corrosion medium under scouring and corrosion.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the field of safety of petrochemical pressure equipment, and particularly relates to a dense liquid-solid two-phase rotating flow erosion-corrosion simulation test device. BACKGROUND

[0002] Erosion phenomenon is the result of the coupling of erosion and corrosion, which is easy to cause thinning, perforation and cracking of equipment and pipelines, and even cause leakage accidents, and even cause human, material and financial losses, and is a difficult problem for long-term safe operation of chemical equipment. Especially in petrochemical production equipment, the equipment is in a complex multiphase erosion environment, and the liquid-solid two-phase flow erosion and corrosion coupling is dominant, and the medium flow rate and particle concentration are relatively high, so that the thinning rate and position of the equipment / pipeline are difficult to predict.

[0003] The existing test and model research mainly aims at the erosion phenomenon, and less considers the influence of corrosion factors, and even less considers the dense liquid-solid two-phase erosion-corrosion simulation and test research of petrochemical production equipment. In order to study the erosion damage of liquid-solid fluid to the equipment in petrochemical production equipment, the erosion devices that can be selected include loop type, jet type and rotary stirring type. Among them, the loop type has the advantage of studying the influence of flow field, but the cost is high, the experimental period is long, and the coupling influence of corrosion on erosion is difficult to investigate; the jet type considers the influence of single factors such as erosion angle and rebound coefficient, but the simulated experimental results are more serious than the actual erosion wear; the rotary stirring type can more efficiently and conveniently perform dynamic corrosion and erosion test, and is the method adopted by the present application. The rotary stirring type erosion simulation device not only has small floor area, but also is convenient for adjusting fluid temperature, flow rate and particle concentration, and can investigate the coupling influence of corrosion factors on erosion.

[0004] Therefore, in view of the dense liquid-solid two-phase erosion mechanism and law in petrochemical production equipment, it is necessary to develop a dense liquid-solid two-phase rotating flow erosion-corrosion simulation test device, to simulate the coupling of erosion and corrosion by using a convenient and efficient rotary stirring method, to measure the erosion and corrosion weight loss rate and surface morphology change, and to further study the non-uniform dense liquid-solid two-phase flow erosion law in the industrial pipeline of petrochemical production equipment, to provide data support for erosion simulation research and risk assessment of petrochemical production equipment, and to guide the safe operation of the on-site device. SUMMARY

[0005] The present application aims to provide a dense liquid-solid two-phase rotating flow erosion-corrosion simulation test device for testing the coupling law of erosion and corrosion in the environment of dense particles and corrosion medium.

[0006] The technical solution adopted by the present application is as follows:

[0007] The dense liquid-solid two-phase rotating flow scouring corrosion simulation test device is characterized by comprising a motor, a central rotating shaft, a stirring kettle, a multi-layer sample mounting rack and a stirring paddle, wherein:

[0008] The top flange of the cylinder of the stirring kettle is sealingly connected with a flange structure, the motor is fixed on the flange structure, one end of the central rotating shaft is drivingly connected with the motor, the other end sealingly penetrates through the flange structure and extends into the cylinder of the stirring kettle, and is fixedly connected with the stirring paddle;

[0009] The central position of the flange structure is further connected downward with a mounting sleeve, and the mounting sleeve does not interfere with the central rotating shaft.

[0010] The multi-layer sample mounting rack is provided with at least two layers of mounting racks, each layer of mounting rack has 4-12 pairs of mounting arms extending radially, the inner end of each pair of mounting arms is fixed on the mounting sleeve, and the outer end forms a pair of circular holes corresponding in upper and lower directions, and each pair of circular holes can fix the two ends of a sample member.

[0011] The dense liquid-solid two-phase rotating flow scouring corrosion simulation test device, wherein: the diameters of the adjacent two layers of mounting racks are different by 1-3 times, and the different material sample members and the parallel sample members of the same material are simultaneously installed and tested.

[0012] The dense liquid-solid two-phase rotating flow scouring corrosion simulation test device, wherein: baffles are additionally arranged in the cylinder in the axial direction.

[0013] The dense liquid-solid two-phase rotating flow scouring corrosion simulation test device, wherein: positioning holes are formed at the two ends of the sample member, so that a stable structure is formed by penetrating the circular holes and the positioning holes with bolts or screws.

[0014] The dense liquid-solid two-phase rotating flow scouring corrosion simulation test device, wherein: the sample member is a cylinder, a circular truncated cone, a cuboid or an arcuate body; the positioning holes are internally threaded, and are fixed in the outer end circular holes of the mounting arms by anti-falling bolts.

[0015] The dense liquid-solid two-phase rotating flow scouring corrosion simulation test device, wherein: the stirring paddle is a propeller type, the flow type is an axial flow type, the number of blades is not less than two, and the diameter of the stirring paddle is 0.15-0.5 times the inner diameter of the stirring kettle.

[0016] The dense liquid-solid two-phase rotating flow erosion corrosion simulation test device, wherein: the optical fiber sensor is arranged on the side of the barrel of the stirring kettle; the flange structure is provided with an electric heater and a temperature sensor which are inserted into the stirring kettle; the motor, the optical fiber sensor, the electric heater and the temperature sensor are electrically connected with a data acquisition control box to form an automatic control and emergency interlocking system.

[0017] The dense liquid-solid two-phase rotating flow erosion corrosion simulation test device, wherein: the optical fiber sensor is arranged at a distance of 1-3 cm from the sample in the barrel; the front end of the optical fiber sensor is provided with a protective cover, and only a probe with a length of 1-3 mm is exposed.

[0018] The dense liquid-solid two-phase rotating flow erosion corrosion simulation test device, wherein: the electric heater is inserted into the fluid in the stirring kettle through the reserved hole of the flange structure, is 1-2 cm away from the inner wall of the barrel and is 5 cm below the liquid level, and the heating temperature ranges from 25 to 200 DEG C; the temperature sensor is inserted into the fluid close to the edge of the inner wall of the stirring kettle through the reserved hole of the flange structure, is 1-2 cm away from the inner wall of the barrel and is 5 cm below the liquid level, and the temperature test range is 0-250 DEG C.

[0019] The dense liquid-solid two-phase rotating flow erosion corrosion simulation test device, wherein: the outer surface of the stirring kettle is provided with a circumferentially wrapped outer thermal insulation layer made of thermal insulation material and internally provided with a high-temperature resistant hose or metal pipe, the high-temperature resistant hose or metal pipe is a serpentine coil pipe, an axial vertical pipe, a circumferential ring pipe or a spiral pipe, and the high-temperature resistant hose or metal pipe is provided with a thermal insulation medium.

[0020] The present application can synchronously measure the erosion weight loss rate of samples under various materials, particle concentrations and flow rates, can measure the particle concentration and flow rate near the sample in real time, can realize synchronous linkage control of temperature, particle concentration and flow rate, and can perform emergency control and release on the unstable condition, thereby providing data support for erosion simulation research and risk assessment of petroleum and chemical production equipment, and guiding the safe operation of the on-site device. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a whole structure schematic view of the dense liquid-solid two-phase rotating flow erosion corrosion simulation test device.

[0022] Figure 2 It is a main structure schematic view of the present application;

[0023] Figure 3 , Figure 4 They are respectively a top view and a longitudinal sectional view of a multi-layer sample mounting rack;

[0024] Figures 5a-5e They are respectively structure schematic views of sample pieces with different structures;

[0025] Figure 6 is a perspective view of the stirring paddle;

[0026] Figure 7 、 Figure 8 are respectively a side view and a top view of the stirring kettle;

[0027] Figure 9 is a structural schematic view of the optical fiber sensor;

[0028] Figure 10 is a structural schematic view of the external insulation layer.

[0029] The figure mark explanation: 1-fast disassembly type flange structure; 2 feed and discharge pipe; 3-stirring kettle; 4-high temperature sealing structure; 5-fixed base; 6-data acquisition control box; 7-multilayer sample mounting rack; 8-sample; 9-central rotating shaft; 10-stirring paddle; 11-optical fiber sensor; 12-motor; 13-baffle; 14-external insulation layer; 15-electric heater; 16-top flange; 17-mounting sleeve; 18-temperature sensor; 19-connection sleeve. DETAILED DESCRIPTION

[0030] The present application provides a kind of dense liquid solid two-phase rotating flow erosion corrosion simulation test device, as shown in Figure 1 、 Figure 2 , mainly includes motor 12, central rotating shaft 9, stirring kettle 3, multilayer sample mounting rack 7 and stirring paddle 10, wherein:

[0031] As shown in Figure 7 、 Figure 8 , the length-diameter ratio (H / D) of the stirring kettle 3 is not less than 2, H / D is 2~3 when more applicable to high flow rate dense liquid solid two-phase flow condition;The material of the barrel is recommended to choose 316L stainless steel, 304 stainless steel or hastelloy alloy etc. erosion, corrosion material, barrel inner surface is coated with erosion and wear resistant coating, bottom is welded on fixed base 5 to slow down vibration;The top flange 16 of the barrel is sealed by fast disassembly type flange structure 1 in cooperation with high temperature sealing structure 4 (such as non-metallic polytetrafluoroethylene material gasket);Fast disassembly type flange structure 1 adopts bolt fastening, the optical fiber sensor 11 (used for measuring the flow velocity and particle concentration around the sample, which needs to be calibrated with known concentration and flow velocity before measurement) is arranged on the side of the barrel, is screwed into the barrel by virtue of thread and is sealed by using high temperature sealing glue, needs to be tested for air pressure and water pressure sealing performance before use;For low viscosity high speed material, baffle 13 is arranged in the barrel along the axial direction, which can eliminate edge vortex and change the tangential flow into axial flow and radial flow, increase the turbulence degree of liquid;The barrel is provided with a glass window on the front surface, for observing the internal experiment of the barrel, the barrel side is welded with valve feed and discharge pipe 2;

[0032] As shown in Figure 1 , Figure 2 , the quick-release flange structure 1 is also provided with a reserved hole for the power heater 15, the center rotating shaft 9, and the temperature sensor 18 to pass through, the motor 12 is fixed on the quick-release flange structure 1, one end of the center rotating shaft 9 is connected with the motor 12, and the other end extends into the barrel of the stirred tank 3 through the quick-release flange structure 1 (through a mechanical seal); the center rotating shaft 9 can be solid or hollow, and a hollow form is preferred because the hollow rotating shaft has a larger diameter, lower maximum deflection, higher rotational stability, and larger first-order critical speed under the same mass;

[0033] A connecting sleeve 19 made of the same material as the quick-release flange structure 1 is fixed at the center of the quick-release flange structure 1 downward, the connecting sleeve 19 is coaxially connected with a hanging sleeve 17 downward through a connecting flange, the inner diameter of the connecting sleeve 19 and the hanging sleeve 17 is 0.03-0.05mm larger than the outer diameter of the center rotating shaft 9, and the hanging sleeve 17 is used to fix the multi-layer sample mounting rack 7;

[0034] The multi-layer sample mounting rack 7 and the hanging sleeve 17 are made of PPL or polytetrafluoroethylene material and are integrally machined and manufactured, have good high-temperature resistance, corrosion resistance, and wear resistance, and can also be made of metal material and then welded together; as shown in Figure 3 , Figure 4 , the multi-layer sample mounting rack 7 is provided with at least two layers of hanging racks, each layer of hanging rack has 4-12 pairs of hanging arms extending radially, the inner end of each pair of hanging arms is fixed on the hanging sleeve 17, and the outer end forms a pair of circular holes corresponding in upper and lower directions, each pair of circular holes can fix two ends of a sample piece 8; the diameters of adjacent two layers of hanging racks can differ by 1-3 times, and different material sample pieces 8 and parallel sample pieces 8 of the same material can be simultaneously installed and tested;

[0035] As shown in Figures 5a-5e , the two ends of the sample piece 8 each form a positioning hole, and a stable structure can be formed by bolts or screws passing through the circular holes and the positioning holes to prevent the sample from shaking due to fluid impact; the sample piece 8 can be a cylinder, a circular cone, a cuboid, or an arcuate body; a cylindrical sample is preferred, which can increase the erosion area and accelerate cutting erosion within a 0-45° erosion angle range; the diameter of the cylindrical sample piece 8 is recommended to be not less than 6mm, the length is recommended to be higher than 30mm, the center adopts a center through-hole structure to reduce the weight, the center through-hole diameter is not less than 1.5mm, and internal threads are cut on both ends of the center through-hole in the axial direction and fixed in the outer end circular holes of the hanging arms through anti-falling bolts;

[0036] The lower end of the central rotating shaft 9 penetrates the mounting sleeve 17, and the end installs the stirring paddle 10, as shown in the figure. Figure 6 As shown in the figure, the stirring paddle 10 is preferably a propeller type, the flow pattern is mainly axial flow type, and is suitable for mixing of low viscosity fluid, solid suspension and other operations, the number of blades is not less than two, and three blades are recommended to make the liquid-solid mixing more uniform. The overall material of the stirring paddle 10 is stainless steel, which is fixed at the end of the central rotating shaft 9 through a nut; the diameter of the stirring paddle 10 is preferably 0.15-0.5 times the inner diameter of the stirring kettle 3 (preferably 0.33 times the inner diameter of the stirring kettle 3); the lowest point of the stirring paddle 10 is spaced apart from the bottom of the stirring kettle 3 by 2-5 cm to prevent particle accumulation and damage to the bottom of the stirring kettle 3 due to shaft swing;

[0037] The application also includes an automatic control and emergency interlocking system, which comprises a data acquisition control box 6 electrically connected with the motor 12, the optical fiber sensor 11, the electric heater 15 and the temperature sensor 18, wherein the optical fiber sensor 11 penetrates into the cylinder at a distance of 3 cm from the sample 81, a protective cover is arranged at the front end of the optical fiber sensor 11, only a probe with a length of 1-3 mm is exposed, and the optical fiber sensor 11 is prevented from being damaged by particle impact; the electric heater 15 penetrates through the reserved hole (gap sealed by a polytetrafluoroethylene sealing ring) of the quick-release flange structure 1 and is inserted into the fluid in the stirring kettle 3, is spaced apart from the inner wall of the cylinder by 1-2 cm, has a length lower than 5 cm of the liquid level, and has a heating temperature range of 25-200℃; the motor 12 can drive the central rotating shaft 9 to rotate, and the maximum rotating speed can reach 2000 r / min; the temperature sensor 18 penetrates through the reserved hole (gap sealed by a polytetrafluoroethylene sealing ring) of the quick-release flange structure 1 and is inserted into the fluid close to the edge of the inner wall of the stirring kettle 3, is spaced apart from the inner wall of the cylinder by 1-2 cm, has a length lower than 5 cm of the liquid level, and has a temperature test range of 0-250℃;

[0038] The data acquisition control box 6 can collect, process and display corresponding data in real time, automatically control experimental conditions (particle concentration near the sample 8, rotating speed) through rotating speed and temperature, and also can monitor temperature, pressure and vibration, and perform safety emergency interlocking braking and safety relief. When the temperature, pressure and vibration are unstable, that is, higher than the set pressure of the safety valve or the temperature is greater than the set value by 5℃ or more or the vibration frequency is unstable, the system performs emergency control on the electric heater 15 and the central rotating shaft 9 through the emergency interlocking function and realizes safety relief of the stirring kettle 3;

[0039] As shown in the figure, Figure 10As shown, the outer surface of the stirred tank 3 is provided with a circumferentially-coated outer insulation layer 14 made of insulation material and internally provided with high-temperature-resistant hoses or metal pipes, which are serpentine coils (or axial vertical pipes or circumferential ring pipes or spiral pipes), and the insulation medium in the pipes can be normal temperature water, hot water or heat conducting oil, for insulating the corrosion medium in the stirred tank 3.

Claims

1. A device for simulating erosion-corrosion in a dense liquid-solid two-phase rotational flow, characterized in that, It comprises a motor, a central rotating shaft, a stirring kettle, a multi-layer sample mounting rack and a stirring paddle, wherein: The top flange of the cylinder body of the stirring kettle is sealingly connected with a flange structure, the motor is fixed on the flange structure, one end of the central rotating shaft is power-connected with the motor, the other end sealingly penetrates through the flange structure and extends into the cylinder body of the stirring kettle and is fixedly connected with the stirring paddle; The central position of the flange structure is also downwardly connected with a mounting sleeve which does not interfere with the central rotating shaft; The multi-layer sample mounting rack is provided with at least two layers of mounting racks, each layer of mounting rack has 4-12 pairs of mounting arms which radially extend out, the inner end of each pair of mounting arms is fixed on the mounting sleeve, and the outer end forms a pair of circular holes corresponding in upper and lower directions, each pair of circular holes can fix the two ends of a sample member; The diameter of the adjacent two layers of mounting racks is different by 1-3 times, so as to simultaneously mount and test sample members of different materials and parallel sample members of the same material.

2. The apparatus for simulating erosion corrosion by dense liquid-solid two-phase rotational flow according to claim 1, wherein: A baffle is arranged in the cylinder body in the axial direction.

3. The apparatus for simulating erosion corrosion of a rotating flow of a dense liquid-solid two-phase according to claim 1, wherein: The two ends of the sample member each form a positioning hole, so as to form a stable structure by penetrating through the circular hole and the positioning hole by a bolt or a screw.

4. The apparatus for simulating erosion corrosion of a rotating flow of a dense liquid-solid two-phase according to claim 3, wherein: The sample member is a cylinder, a circular truncated cone, a cuboid or an arcuate body, the positioning hole is processed with an internal thread and is fixed in the outer end circular hole of the mounting arm by an anti-falling bolt.

5. The apparatus for simulating erosion corrosion of a rotating flow of a dense liquid-solid two-phase according to claim 1, wherein: The stirring paddle is a propeller type, the flow pattern is an axial flow pattern, the number of blades is not less than two, and the diameter of the stirring paddle is 0.15-0.5 times the inner diameter of the stirring kettle.

6. The apparatus for simulating erosion corrosion of a rotating flow of a dense liquid-solid two-phase according to claim 1, wherein: An optical fiber sensor is arranged on the side surface of the cylinder body of the stirring kettle, an electric heater and a temperature sensor are arranged on the flange structure and extend into the stirring kettle, the motor, the optical fiber sensor, the electric heater and the temperature sensor are electrically connected with a data acquisition control box to form an automatic control and emergency interlocking system.

7. The apparatus for dense fluid-solid two-phase rotating flow erosion corrosion simulation test according to claim 6, characterized in that: The optical fiber sensor is arranged at a position 1-3 cm away from the sample member in the cylinder body, a protective cover is arranged at the front end of the optical fiber sensor, and only a probe with a length of 1-3 mm is exposed.

8. The apparatus for dense fluid-solid two-phase rotating flow erosion corrosion simulation test according to claim 6, characterized in that: The electric heater penetrates through a reserved hole of the flange structure and is inserted into the fluid in the stirring kettle at a position 1-2 cm away from the inner wall of the cylinder body and 5 cm below the liquid surface, and the heating temperature range is 25-200℃; the temperature sensor penetrates through a reserved hole of the flange structure and is inserted into the fluid close to the edge of the inner wall of the stirring kettle, the temperature sensor is arranged at a position 1-2 cm away from the inner wall of the cylinder body and 5 cm below the liquid surface, and the temperature test range is 0-250℃.

9. The apparatus for simulating erosion corrosion of a rotating liquid-solid two-phase flow according to claim 6, wherein: An outer heat preservation layer is arranged on the outer surface of the stirring kettle in a circumferential wrapping manner, the outer heat preservation layer is made of a heat preservation material and internally provided with a high-temperature resistant hose or a metal pipe, the high-temperature resistant hose or the metal pipe is a serpentine coil pipe, an axial vertical pipe, a circumferential ring pipe or a spiral pipe, and the high-temperature resistant hose or the metal pipe is internally provided with a heat preservation medium.

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