Corrosion Resistance Methods Of Low-temperature Multi-effect Desalination Device

Where there is water there is life, water is the source of life, and it is one of the important and indispensable material resources for the survival and development of all living organisms on the earth. The lack of fresh water resources has attracted more and more public attention. It is generally believed that seawater desalination is one of the important and inevitable measures to solve the shortage of fresh water resources. However, the device of seawater desalination and facilities of seawater using are facing the problem of seawater corrosion. Manufacturing material of desalination equipment not only affects the cost, but also directly affects the operating life of equipment. Therefore, to carry out the study of anticorrosion materials for seawater desalination and using engineering is of great significance.This paper studies the anticorrosion performance of function surface material, and provides the basic experimental data for the application of the antiseptic function surface. The effect of nano-modified PFA coating on aluminum corrosion resistance in saline has been studied, and the conclusion is that the corrosion resistance effect of aluminium improves a lot by adding O2O3 nanoparticles modified PFA coating. Through the optimization process, it finds that coating with 3% Cr2O3 nanoparticles dispersing 24h shows better corrosion resistance performance than other adding content. Adding thermal conductive particles reduces the thermal resistance of the coating, so it greatly increases the application possibility of aluminous material. This method can be applied in column bottom to improve the corrosion resistance performance effectively.The paper studies corrosion state of carbon steel, stainless steel, aluminum brass and aluminum immersed in NaCl solutions with different concentration. Corrosion rate was calculated by using weight loss method. By comparing the corrosion rate of the metals we find that the corrosion of carbon steel without pretreatment is most serious. Corrosion rate decreased with the increasing of NaCl concentration. Deoxidation treatment can be used to control carbon steel corrosion. The experiments show that corrosion resistance performance of aluminum and stainless steel is better, but they are deprecated in low-temperature multi-effect desalination device because of high pitting corrosion rate. Electrochemical noise spectral shows the noise of these metals obeys a Gaussian distribution with pitting corrosion.The effect of different seawater pretreatment conditions on the corrosion and scaling property of the pipe was studied. The hardness of the water through ion exchange pretreatment is much smaller than not pretreated water, so this method reduces the production of the scaling. In the seawater after acid method decarbonization pretreatment, the corrosion type of the test-pieces is uniform corrosion, with no pitting corrosion or partial corrosion on the surface, and the corrosion rate is very low. Therefore seawater pretreatment can reduce the corrosion and scaling rate effectively and make the operation efficiency of the entire low-temperature multi-effect desalination platform improve a lot.