1. electrochemical protection method
       Electrochemical protection methods are divided into cathodic protection and anodic protection. Cathodic protection uses an external DC power source to turn the anode on the metal surface into a cathode to protect it. This method consumes a lot of power, is expensive and rarely used. The anode protection method is to connect the protected equipment to the anode of an external power supply, so that a passivation film is formed on the metal surface to achieve protection. Carbon steel spiral plate heat exchangers have low cost but poor corrosion resistance. The service life of the spiral plate heat exchanger can be improved by using sacrificial anode protection technology, but the protection effect of this technology is limited to a limited length at the tube inlet. Cathodic protection is difficult to achieve deep inside the tube, so the application of sacrificial anode protection method in spiral plate heat exchangers is greatly limited.
       2. Corrosion-resistant materials
       Use corrosion-resistant materials (such as binocular stainless steel, Hastelloy, titanium, titanium alloy, copper, etc.). These materials have strong corrosion resistance and can extend the service life of spiral plate heat exchangers. However, these highly corrosion-resistant materials are expensive, have high manufacturing costs, and have high one-time investment costs. They are generally difficult for enterprises to accept and difficult to promote.
       3. Anti-corrosion coating method
       The metal surface is covered with a corrosion-resistant coating protective layer through a certain coating method to avoid direct contact between the metal surface and the corrosive medium. This technical method is economical and effective and is used to prevent gas medium corrosion. Most of the coatings used are organic polymer mixture solutions. People are gradually developing towards oil-proof and solvent-proof coatings, high-temperature coatings, heavy-duty anti-corrosion coatings and coatings for special environments.
       4. Adding corrosion inhibitor method
       In corrosive media, adding a small amount of certain substances can greatly reduce or even stop the corrosion of metals. Such substances are called corrosion inhibitors. The addition of corrosion inhibitors should be based on the principle of not affecting the production process and product quality.
       The phenomenon and mechanism of metal corrosion are complex and cover a wide range of areas. According to the reaction mechanism, metal corrosion can be divided into chemical corrosion and electrochemical corrosion. The electrochemical corrosion caused by the electrochemical interaction between the metal surface and the electrolyte solution is a common and common corrosion. Electrochemical corrosion usually occurs in the form of local corrosion such as stress corrosion cracking, pitting corrosion (small hole corrosion), and crevice corrosion.
       The main purpose of erosion and protection is to increase production and save money.