Salt mist dust difunctional environment simulation device and experimental method

Abstract

The invention aims to provide a salt mist dust difunctional environment simulation device and an experiment method, and belongs to the field of corrosion environment simulation. Comprising a feeding machine, a fan, a generation cavity and a test wind tunnel, a disc is arranged in the generation cavity, a circular cutting ring is installed outside the disc, a servo motor is connected below the disc through a coupler, the feeding machine is connected with a conveying pipeline, the tail end of the conveying pipeline extends into the generation cavity and is located above the disc, and a valve is installed on the conveying pipeline. The fan is connected with an air supply pipeline, the tail end of the air supply pipeline extends into the generation cavity and is located below the disc, the top of the generation cavity is connected with a flow guide cavity, the flow guide cavity is connected with a test wind tunnel through a flange and extends into the test wind tunnel, and a particle analyzer is arranged in the test wind tunnel. According to the invention, salt mist and dust generation functions are integrated, an environment simulation device capable of realizing dual-mode flexible switching can be realized, the test process is simplified, the cost is reduced, and the accuracy and reliability of test data are improved.

Description

Technical Field

[0001] The present invention relates to a test apparatus and method, specifically a salt spray dust simulation apparatus and test method. Background Technology

[0002] In fields such as marine engineering and aerospace, materials exposed to extreme environments such as salt spray and dust for extended periods experience a significant decline in their mechanical properties and corrosion resistance, directly impacting the safe operation and service life of equipment. Therefore, evaluating a material's resistance to salt spray and dust through environmental simulation tests is a crucial step in material development and equipment reliability verification.

[0003] In traditional environmental simulation equipment, salt spray and dust testing devices are typically set up independently: salt spray devices mostly use brine atomization technology to simulate marine corrosion environments, but cannot introduce dust particles; dust devices can generate dust through mechanical dispersion, but lack salt spray generation capabilities. To test materials under both environments, two separate sets of equipment must be purchased, increasing procurement and maintenance costs and consuming significant laboratory space. Furthermore, existing equipment has limitations in parameter control, exhibiting poor salt spray particle uniformity and insufficient dust dispersion, and cannot quickly switch between the two environmental modes, resulting in low testing efficiency and poor data repeatability, making it difficult to meet the needs of multi-environment collaborative testing of materials. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-function salt spray and dust environment simulation device and experimental method that can flexibly switch between two modes to meet the testing needs of materials in multiple extreme environments.

[0005] The objective of this invention is achieved as follows: This invention discloses a dual-function environmental simulation device for salt spray dust, characterized by comprising a feeder, a fan, a generating chamber, and a test wind tunnel. A disc is installed inside the generating chamber, and a circular cutting ring is mounted on the outside of the disc. A servo motor is connected to the bottom of the disc via a coupling. The feeder is connected to a conveying pipe, the tail end of which extends into the generating chamber and is positioned above the disc. A valve is installed on the conveying pipe. The fan is connected to an air supply pipe, the tail end of which extends into the generating chamber and is positioned below the disc. A guide chamber is connected to the top of the generating chamber, and the guide chamber is connected to the test wind tunnel via a flange and extends into the test wind tunnel. A particle size analyzer is installed inside the test wind tunnel.

[0006] The salt spray dust dual-function environment simulation device of the present invention may further include: 1. The inner wall of the generating cavity is fixed with a fixed bracket, and the circular cutting ring is connected to the fixed bracket by adjusting bolts distributed in the circumferential direction.

[0007] 2. The diameter of the disk is D, the inner diameter of the circular cutting ring is 1.05D, the circular cutting ring and the edge of the disk maintain a radial gap of 0.008D, and three rows of circular cutting holes with a diameter of 0.007D are evenly distributed on the inner side of the circular cutting ring, forming an annular cutting channel.

[0008] 3. The upper surface of the disc is sandblasted to create a rough structure.

[0009] 4. The feeder includes a plunger-type metering feeder for salt spray generation and an electromagnetic vibrating feeder for dust simulation. The conveying pipe corresponding to the plunger-type metering feeder is made of polytetrafluoroethylene, and the conveying pipe corresponding to the electromagnetic vibrating feeder is made of stainless steel with polished inner wall.

[0010] This invention provides a dual-function environment simulation experimental method for salt spray and dust, characterized in that: the above-mentioned dual-function environment simulation device for salt spray and dust is used; (1) Select salt spray or dust mode according to test requirements and check the storage of corresponding materials in the feeding system. In salt spray mode, confirm that the liquid level of 5%-10% sodium chloride solution in the storage tank is not lower than 1 / 3 of the total capacity. In dust mode, ensure that the dust in the storage bin is free of clumps and that the filling amount meets the test duration. At the same time, check the sealing status of each connection part. (2) In salt spray mode, set the liquid supply rate to 5-15 mL / min, the disc rotation speed to 10000-14000 rpm, and the fan speed to 4-6 m / s. In dust mode, set the feed rate to 1-3 g / min, the disc rotation speed to 12000-15000 rpm, and the fan speed to 5-8 m / s. Also, preset the target temperature and humidity in the test wind tunnel. (3) First turn on the fan and let the clean air circulate for 3-5 minutes. After the airflow in the test wind tunnel is stable, start the servo motor to make the disc reach the set speed and keep it running stably. Then turn on the feeder and valve. In salt spray mode, the salt solution is transported to the center of the disc through the conveying pipe by the plunger metering feeder. In dust mode, the dust is sent into the disc area through the conveying pipe by the electromagnetic vibration feeder. (4) Monitor the particle size analyzer and sensor data in the test wind tunnel in real time. After the salt spray particle concentration is stable at 5-20 mg / m³, the proportion of particles with a diameter of 5-10 μm is ≥90%, or the dust concentration is stable at 50-200 mg / m³, the dispersion is ≥90%, and the temperature and humidity parameters reach the preset range, put the sample to be tested into the test area through the side door of the test wind tunnel, ensure that the sample surface is perpendicular to the airflow direction, and start timing after closing the side door; (5) During the test, the particle concentration, temperature and humidity and equipment operating parameters are recorded every 30 minutes. If the parameter fluctuations exceed the allowable range, the feed rate or fan speed is adjusted to compensate. (6) After the test reaches the preset time, first close the valve and feeder, keep the servo motor and fan running for 5-10 minutes to ensure that the residual material in the air supply pipe, generating chamber and guiding chamber completely enters the test wind tunnel. Then turn off the servo motor and keep the fan running for 30 minutes to remove the residual salt spray or dust in the test wind tunnel. Finally, turn off the fan. (7) Open the side door of the test wind tunnel to take out the sample, observe and record the corrosion, deposition or performance changes on the sample surface; (8) Perform cleaning and maintenance, including cleaning residual salt stains or dust on the disc and circular cutting ring, rinsing the salt solution pipes, and checking the wear of each component to prepare for the next test.

[0011] The dual-function environmental simulation experimental method for salt spray and dust of the present invention may further include: 1. The target temperature inside the test wind tunnel is 25±2℃, and the humidity is: 90%-95%RH in salt spray mode and 40%-60%RH in dust mode.

[0012] The advantages of this invention are: 1. Dual-function integration, cost and space optimization: Salt spray and dust simulation can be achieved in the same device, eliminating the need to purchase two sets of equipment, reducing procurement and maintenance costs, and saving more than 50% of laboratory space; 2. Quick mode switching for improved efficiency: The switch between salt spray and dust modes can be completed simply by switching the feeding system (liquid pipeline / dust feeder), reducing the switching time to within 5 minutes and significantly improving test efficiency; 3. High particle uniformity and reliable test accuracy: Through the composite structure of "disc centrifugal dispersion + secondary dispersion by cutting ring", the particle size deviation of salt spray particles is ≤10% and the dust dispersion is ≥90%, ensuring the repeatability and accuracy of test data. 4. Safe, stable, and highly adaptable: The core components are made of corrosion-resistant and wear-resistant materials, and the fan and motor are waterproof and dustproof, ensuring long-term stable operation; parameters such as speed, airflow velocity, and material supply are all adjustable to meet the testing needs of different materials. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of a circular cut ring. Detailed Implementation

[0014] The invention will now be described in more detail with reference to the accompanying drawings: Combination Figure 1-2 The invention consists of four parts: a generating system, a feeding system, an airflow conveying system, and a test wind tunnel. The structure and connection relationship of each part are as follows: Generation system: This is the core component of the device, including a high-speed rotating disk 7, a circular cutting ring 8, a generation chamber, and a flow guiding chamber 9. High-speed rotating disk 7: Diameter denoted as D, preferably made of 316L stainless steel or ceramic material to avoid corrosion by salt solution. Driven by a motor, the speed can be adjusted to 12000-15000rpm, used to spin salt solution into liquid film or disperse dust. Circular hole type cutting ring 8: Coaxially mounted on the outer edge of the disk, with an inner diameter of 1.05D, maintaining a radial clearance of 0.008D with the edge of the disk, a ring thickness of 0.08D, a hole diameter of 0.007D, and an opening rate of 20%. It is made of wear-resistant alloy or engineering plastic material and is used for secondary dispersion of liquid film or dust to ensure particle uniformity. Generating chamber and guiding chamber 9: Enclosed around the disk, with an axial height of 0.25D and an outlet channel width of 0.25D, used to guide the salt spray or dust to be transported directionally into the test chamber.

[0015] Feeding system 1: includes liquid feed pipelines and dust feeders, corresponding to salt spray and dust modes respectively. Liquid supply pipeline: PTFE hose is used, with a nozzle diameter of 0.03D and a distance of 0.015-0.02D from the center surface of the disc. The drip rate of the salt solution is controlled by a solenoid valve to achieve quantitative liquid supply. Dust feeder: An electromagnetic vibrating feeder is installed directly above the disc, which can accurately control the conveying amount of standard test dust and prevent dust agglomeration.

[0016] Airflow delivery system: Located at the bottom of the device, including centrifugal fan 6 and air duct 5: Centrifugal fan 6: impeller diameter 0.6D, casing made of corrosion-resistant aluminum alloy or steel plate coated with corrosion-resistant coating, generates stable airflow from bottom to top, and the wind speed can be adjusted by frequency converter; Duct 5: Connects the fan to the guide cavity. The inner wall is smoothed to reduce airflow resistance and ensure that salt spray or dust is evenly delivered to the test chamber.

[0017] Wind Tunnel 3: Made of transparent and corrosion-resistant materials (such as polycarbonate) to facilitate observation of the test process. Multiple temperature and humidity sensors and particle concentration detectors are installed inside the chamber. The sensors are encapsulated in ceramic or polytetrafluoroethylene to ensure stable operation in salt spray and dust environments and to provide real-time feedback of test parameters.

[0018] The feeding system, as the core unit of material supply, mainly consists of a feeder 1 adapted to different material characteristics, valves 2 for precise flow control, and conveying pipelines 4. Specifically, a plunger-type metering feeder 1 is configured for salt spray generation, which can stably convey 5%-10% concentration sodium chloride solution. For dust simulation, an electromagnetic vibrating feeder 1 is equipped, which can adapt to ISO 12103 series standard dust. Both feeders 1 are equipped with corresponding valves to adjust the supply volume—the salt solution pipeline uses a stainless steel solenoid valve with a response time ≤0.3s, which can achieve stepless adjustment within the range of 0-20mL / min. The dust pipeline is equipped with a wear-resistant ceramic gate valve, which works in conjunction with the vibration parameters of the feeder 1 (frequency 50Hz, amplitude 0-3mm) to ensure that the dust conveying accuracy reaches ±0.1g / min. The conveying pipelines 4 are made of acid and alkali resistant polytetrafluoroethylene (for salt solution, inner diameter 8mm, wall thickness 2mm) and 316L with polished inner walls, respectively. Made of stainless steel (for dust, inner diameter 15mm, surface roughness Ra≤0.8μm), the pipe ends are all designed with 90° elbows to ensure that the material falls vertically into the core working area of ​​the generation system. The generation system, as the key module for material atomization and dispersion, mainly consists of a disc 7 with a roughened upper surface (surface roughness Ra=3.2-6.3μm) and a circular cutting ring 8 directly fitted around the edge of the disc. The disc 7 is forged from 316L stainless steel (diameter 200mm, thickness 10mm), and its lower surface is rigidly connected to the output shaft of a servo motor via a coupling (coaxiality error ≤0.02mm). The motor speed can be steplessly adjusted within the range of 8000-15000rpm. The circular cutting ring 8 is made of WC-Co hard alloy (inner diameter 205mm, thickness 12mm), with 3 evenly distributed... A circular cutting hole (1.2-1.5mm in diameter, 5mm spacing between adjacent holes) is arranged, maintaining a radial gap of 2mm (±0.1mm error) with the outer edge of the disc 7, forming an annular cutting channel. When the material enters the generating system, the salt solution diffuses into a uniform liquid film on the high-speed rotating rough disc under the action of centrifugal force and friction. When it reaches the edge, it is sheared and broken into 5-10μm salt spray particles by the cutting ring. The dust is initially dispersed by the rough surface of the disc, and then further sheared by the cutting ring 8 to form a dust cloud with a dispersion of ≥90%. The generated salt spray or dust enters the test wind tunnel 3 through the inverted funnel-shaped guide cavity (transparent polycarbonate material, impact strength ≥60kJ / m², with 3 spiral guide ribs on the inner wall). The test wind tunnel 3 serves as the test area and adopts a combination structure of stainless steel frame and transparent acrylic panel. The front end is connected to the guide cavity 9 through flange 10. The flange 10 is fitted with a nitrile rubber sealing ring with a hardness of 60 Shore A to ensure a leakage rate ≤0.The system operates at a rate of 1% / h, with an adjustable air outlet at the rear. The static pressure inside the wind tunnel 3 is adjusted via a butterfly valve (range 50-500Pa). A laser particle size analyzer 11 (measuring range 0.1-100μm, accuracy ±2%) is installed on the side of the middle section of wind tunnel 3, enabling real-time monitoring of the particle size distribution and concentration of salt spray / dust particles. The airflow delivery system mainly consists of a corrosion-resistant centrifugal fan 6 (impeller material 316L stainless steel, airflow range 100-500m³ / h) and galvanized steel pipes (inner diameter 100mm). Fan 6 is installed directly below the generation system, and the air outlet is connected to the air inlet at the bottom of the generation system via a corrugated pipe. The connection is double-sealed using a flange and silicone gasket, ultimately forming a complete closed loop of "material supply - atomization / dispersion - airflow delivery - environmental testing".

[0019] The cutting ring 8 and the disc 7 are mounted via a fixed bracket (made of engineering plastic / aluminum alloy, connected to the inner wall of the sealed cavity). The center of the cutting ring 8 is perfectly aligned with the rotation axis (spindle axis) of the disc, with a coaxiality error controlled within 0.002D. The cutting ring is connected to the fixed bracket via 3-4 circumferentially evenly distributed adjusting bolts (made of stainless steel, 0.01D in diameter). The bolts are installed radially along the cutting ring (without passing through the borehole area).

[0020] Experimental procedure of the method of this invention: (1) First, prepare for the test. Select the salt spray or dust mode according to the test requirements and check the storage of the corresponding material in the feeding system. In the salt spray mode, it is necessary to confirm that the liquid level of 5%-10% sodium chloride solution in the storage tank is not lower than 1 / 3 of the total capacity. In the dust mode, it is necessary to ensure that the ISO 12103 series standard dust in the powder storage bin is free of lumps and that the filling amount meets the test duration. At the same time, check the sealing status of each connection part, especially the flange 10 connection between the test wind tunnel 3 and the guide cavity 9, and the pipeline interface of the airflow conveying system, to ensure that the sealing ring is intact and undamaged.

[0021] (2) Then start the control system and set the core parameters. In the salt spray mode, set the liquid supply rate to 5-15 mL / min, the disc rotation speed to 10000-14000 rpm, and the fan speed to 4-6 m / s. In the dust mode, set the feed rate to 1-3 g / min, the disc rotation speed to 12000-15000 rpm, and the fan speed to 5-8 m / s. Also, preset the target temperature (25±2℃) and humidity (90%-95%RH in salt spray mode and 40%-60%RH in dust mode) in the test wind tunnel 3.

[0022] (3) After confirming the parameters, start the equipment. First, turn on the fan 6 of the airflow conveying system and let the clean air circulate in the pipeline and the generating system for 3-5 minutes. After the airflow in the wind tunnel 3 is stable, start the motor of the generating system so that the disc 7 reaches the set speed and keeps running stably. Then turn on the corresponding feeder 1 and valve 2 of the feeding system. In the salt spray mode, the salt solution is transported to the center of the disc 7 through the PTFE 4-pipe by the plunger metering pump. In the dust mode, the dust is sent into the area of ​​the disc 7 through the stainless steel pipe 4 by the electromagnetic vibrating feeder.

[0023] (4) After the material enters the generation system, the particle size analyzer 11 and sensor data in the test wind tunnel 3 are monitored in real time. When the salt spray particle concentration is stable at 5-20 mg / m³ (particle size 5-10 μm accounts for ≥90%) or the dust concentration is stable at 50-200 mg / m³ (dispersion ≥90%), and the temperature and humidity parameters reach the preset range, the sample to be tested (such as metal plate, coating sample, etc.) is placed into the test area through the side door of the wind tunnel 3. Ensure that the sample surface is perpendicular to the airflow direction, and start timing after closing the side door.

[0024] (5) During the test, the particle concentration, temperature and humidity and equipment operating parameters are recorded every 30 minutes. If the parameter fluctuations exceed the allowable range (such as concentration deviation ±10% or temperature deviation ±1℃), the system will automatically adjust the feed rate or the fan speed to compensate.

[0025] (6) After the test reaches the preset duration (e.g., 24-168 hours for salt spray test, 10-50 hours for dust test), first close valve 2 and feeder 1 of the feeding system, keep the generator motor and fan 6 running for 5-10 minutes to ensure that the pipeline 5 and the residual material in the generator system completely enter the wind tunnel 3, then turn off the motor, keep the fan 6 running for 30 minutes to remove the residual salt spray or dust in the wind tunnel 3, and finally turn off the fan 6 and the control system.

[0026] (7) After the equipment is completely shut down, open the side door of the wind tunnel 3 to take out the sample, observe and record the corrosion, deposition or performance changes on the sample surface, and clean and maintain the equipment after the test, including cleaning the residual salt stains or dust on the disc 7 and the cutting ring 8, rinsing the salt solution pipeline, and checking the wear of each component to prepare for the next test.

Claims

1. A dual-function environmental simulation device for salt spray and dust, characterized in that: The system includes a feeder, a blower, a generating chamber, and a test wind tunnel. A disc is installed inside the generating chamber, and a circular cutting ring is installed on the outside of the disc. A servo motor is connected to the bottom of the disc via a coupling. The feeder is connected to a conveying pipe, the tail end of which extends into the generating chamber and is located above the disc. A valve is installed on the conveying pipe. The blower is connected to an air supply pipe, the tail end of which extends into the generating chamber and is located below the disc. A guide chamber is connected to the top of the generating chamber. The guide chamber is connected to the test wind tunnel via a flange and extends into the test wind tunnel. A particle size analyzer is installed inside the test wind tunnel.

2. The dual-function salt spray and dust environment simulation device according to claim 1, characterized in that: The inner wall of the generating cavity is fixed with a fixed bracket, and the circular cutting ring is connected to the fixed bracket by adjusting bolts distributed in the circumferential direction.

3. The dual-function salt spray and dust environment simulation device according to claim 1, characterized in that: The disc has a diameter of D, the inner diameter of the circular cutting ring is 1.05D, the circular cutting ring maintains a radial gap of 0.008D with the edge of the disc, and three rows of circular cutting holes with a diameter of 0.007D are evenly distributed on the inner side of the circular cutting ring, forming an annular cutting channel.

4. The dual-function salt spray and dust environment simulation device according to claim 1, characterized in that: The upper surface of the disk is sandblasted to create a rough texture.

5. The dual-function salt spray and dust environment simulation device according to claim 1, characterized in that: The feeder includes a plunger-type metering feeder for salt spray generation and an electromagnetic vibrating feeder for dust simulation. The conveying pipe corresponding to the plunger-type metering feeder is made of polytetrafluoroethylene, and the conveying pipe corresponding to the electromagnetic vibrating feeder is made of stainless steel with polished inner wall.

6. A dual-function environmental simulation experimental method for salt spray dust, characterized in that: The dual-function salt spray and dust environment simulation device as described in claim 1 is used; (1) Select salt spray or dust mode according to test requirements and check the storage of corresponding materials in the feeding system. In salt spray mode, confirm that the liquid level of 5%-10% sodium chloride solution in the storage tank is not lower than 1 / 3 of the total capacity. In dust mode, ensure that the dust in the storage bin is free of clumps and that the filling amount meets the test duration. At the same time, check the sealing status of each connection part. (2) In salt spray mode, set the liquid supply rate to 5-15 mL / min, the disc rotation speed to 10000-14000 rpm, and the fan speed to 4-6 m / s. In dust mode, set the feed rate to 1-3 g / min, the disc rotation speed to 12000-15000 rpm, and the fan speed to 5-8 m / s. Also, preset the target temperature and humidity in the test wind tunnel. (3) First turn on the fan and let the clean air circulate for 3-5 minutes. After the airflow in the test wind tunnel is stable, start the servo motor to make the disc reach the set speed and keep it running stably. Then turn on the feeder and valve. In salt spray mode, the salt solution is transported to the center of the disc through the conveying pipe by the plunger metering feeder. In dust mode, the dust is sent into the disc area through the conveying pipe by the electromagnetic vibration feeder. (4) Monitor the particle size analyzer and sensor data in the test wind tunnel in real time. After the salt spray particle concentration is stable at 5-20 mg / m³, the proportion of particles with a diameter of 5-10 μm is ≥90%, or the dust concentration is stable at 50-200 mg / m³, the dispersion is ≥90%, and the temperature and humidity parameters reach the preset range, put the sample to be tested into the test area through the side door of the test wind tunnel, ensure that the sample surface is perpendicular to the airflow direction, and start timing after closing the side door; (5) During the test, the particle concentration, temperature and humidity and equipment operating parameters are recorded every 30 minutes. If the parameter fluctuations exceed the allowable range, the feed rate or fan speed is adjusted to compensate. (6) After the test reaches the preset time, first close the valve and feeder, keep the servo motor and fan running for 5-10 minutes to ensure that the residual material in the air supply pipe, generating chamber and guiding chamber completely enters the test wind tunnel. Then turn off the servo motor and keep the fan running for 30 minutes to remove the residual salt spray or dust in the test wind tunnel. Finally, turn off the fan. (7) Open the side door of the test wind tunnel to take out the sample, observe and record the corrosion, deposition or performance changes on the sample surface; (8) Perform cleaning and maintenance, including cleaning residual salt stains or dust on the disc and circular cutting ring, rinsing the salt solution pipes, and checking the wear of each component to prepare for the next test.

7. The dual-function environmental simulation experimental method for salt spray dust according to claim 6, characterized in that: The target temperature inside the test wind tunnel is 25±2℃, and the humidity is 90%-95%RH in salt spray mode and 40%-60%RH in dust mode.

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