The Salt Spray Tester uses the method of salt spray corrosion to test the reliability of the corrosion resistance of the sample. Salt spray refers to the diffusion system composed of salt-containing droplets. As one of the three-proof series of artificial environment, many enterprise products need to simulate the damage caused by the climate around the ocean, so the equipment must be transported according to regulations. The spray system of the test bench is mainly composed of nozzles, salt tanks, tower spray devices, etc. The gas generated by the compressor enters the nozzle after purification, preheating and decompression treatment, and the brine supply system injects brine into the nozzle suction pipe. During the water spraying process of the equipment, the compressed air rushes to the nozzle, and a certain negative pressure is generated above the input pipe. Under the action of the negative pressure, the salt water is quickly shot by the nozzle to the top cone, and extends to the entire working room, forming a dispersed state , imitating a salt spray to complete the spray.
In the test of the salt spray collector, there are strict requirements for the test box, salt solution pool, and salt solution injection system. In order to better display the results of salt spray collection, these requirements are met.
1. Characteristics of the equipment
1. The materials used should not affect the corrosion effect of salt spray.
2. Use a holder (sample holder) that does not affect the characteristics of the salt spray.
3. Any parts in contact with the sample shall not cause electrochemical corrosion.
4. The concentrate must not drip onto the sample.
5. Any test solution in contact with the equipment or sample shall not be returned to the salt bath.
6. The test chamber should be equipped with an exhaust device to prevent the pressure of the test site from rising.
7. The waste liquid should be treated in accordance with the relevant laws and regulations of our country.
2. Salt solution tank in Salt Spray Tester
Salt pools are made from substances that do not react with salt solutions, such as glass, hard rubber, or plastic.
3. Salt solution injection system
1. The salt solution is filtered and sent to the test chamber. Equipped with an atomizer, which can produce a dense mist of dispersed fine moisture; atomizing nozzles and piping systems should be made of substances that will not react with salt solutions; prevent salt deposits from clogging the nozzles.
2. Appropriate salt spray can be obtained in an equipment box with a volume of less than 0.34m in the following cases:
①The pressure of the nozzle is as small as possible to the required spray speed;
②Nozzle aperture is between 0.5-0.76mm;
③In each 0.28m test box, about 2.8L of salt solution should be atomized every 24 hours.
If a box with a volume much larger than 0.34m is used, the above situation needs to be modified.
4. Salt mist collection device
At least 2 salt spray collectors are placed in the salt solution sample box in the Salt Spray Tester, one near the edge of the sample and the other near the sample port, but away from the nozzle. The same principle applies if multiple nozzles are used. The collection device should not be placed in a position to cover it with the sample, or to allow the collector to collect saline dripping from the sample.
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