Four anti-corrosion methods for heat exchangers

Four anti-corrosion methods for heat exchangers

There are four main anti-corrosion methods for heat exchangers: corrosion-resistant materials, electrochemical protection, adding corrosion inhibitors, and anti-corrosion coating methods. Among them, 1 and 4 are the anti-corrosion measures mainly used in chemical and other machinery industries. Shaanxi Ruite thermal heat exchangers are divided into steel-lined fluorine heat exchangers, perfluorinated plastic frame heat exchangers, stainless steel heat exchangers, etc., mainly to solve the corrosion problem in the heat exchange process from the fundamental problem of material.

　　 The following is a summary of anti-corrosion measures:

　　1, corrosion-resistant materials

Using corrosion-resistant materials (such as binocular stainless steel, Hastelloy, titanium, titanium alloy, copper and the more advanced fluoroplastic materials, etc.), they have strong corrosion resistance and can effectively increase the service life of the heat exchanger. However, materials with high corrosion resistance are more expensive than ordinary materials, have high manufacturing costs, and have a large single input cost, and their promotion is often hindered. However, under the current national development strategy of capacity reduction and equipment upgrade, long-term development is considered. According to statistics from the Institute of Chemical Industry in 2015: 65% of enterprises choose heat exchangers made of anticorrosive fluoroplastic materials.

　　2, anti-corrosion coating method

　　On the metal surface, a certain coating method is used to cover a layer of corrosion-resistant paint protection layer to avoid direct contact between the metal surface and the corrosive medium. This technical method z* is economical and effective. Z* was originally used to prevent corrosion in gaseous media. Most of the coatings used are organic polymer mixture solutions. Now people are gradually developing towards oil and solvent resistant coatings, high-temperature coatings, heavy-duty coatings and coatings for special environments.

　　3, add corrosion inhibitor method

　　In the corrosive medium, a small amount of certain substances are added, and these substances can greatly reduce or even stop the corrosion of metals. Such substances are called corrosion inhibitors. The addition of corrosion inhibitor should be based on the principle that it does not affect the production process and product quality.

　　 4. Electrochemical Protection Law

　　The electrochemical protection method is divided into cathode and anode protection. Cathodic protection is to use an external DC power supply to make the anode on the metal surface become a cathode and be protected. This method consumes a lot of power, is expensive, and uses very little. The anode protection method is to connect the protected equipment to the anode of an external power supply to form a passivation film on the metal surface to achieve protection. The carbon steel heat exchanger has low cost, but poor corrosion resistance. The service life of the heat exchanger can be increased by using sacrificial anode protection technology, but the protection effect of this technology is limited to the limited length of the tube entrance, and it is difficult to achieve cathodic protection in the depth of the tube, so the sacrificial anode protection method is used on the heat exchanger The application of is greatly restricted.

　　 The retrofit and purchase of large-scale industrial heat exchange equipment will affect the company's income and expenditure in the next few years. Therefore, under the concept of national advanced equipment introduction, we support companies to choose high-quality anti-corrosion heat exchangers (fluoroplastic heat exchangers), and abandon the old industrial history that is not environmentally friendly, does not save resources, and does not delve into new technologies.