Selection of anti-corrosion materials for the inner wall of the high-tower nitro regranulation tower
Thread Content
It is understood that due to the high corrosivity and penetration properties of *ao acid an contained in nitrate-based fertilizers, very high requirements are placed on the anti-corrosion materials used for the inner walls of high-tower nitrate granulation towers. Question: To prevent corrosion of the inner wall of the granulation tower used in high-tower compound fertilizer production, what anti-corrosion materials should be used to meet the anti-corrosion requirements?
The anti-corrosion treatment for the inner walls of tall towers is usually designed to use epoxy fiberglass, that is, a three-layer fabric with five layers of resin coating or a two-layer fabric with four layers of resin coating. Epoxy fiberglass provides good anti-corrosion properties, but its temperature resistance is poor; it generally cannot withstand temperatures above 100°C. Other new types of anti-corrosion materials are also used, such as polyurea spraying, but they are relatively more expensive and their effectiveness is not ideal.
The traditional technique is epoxy fiberglass, while the most practical method nowadays for corrosion protection is vinyl glass flake putty
Is the cost of corrosion protection using vinyl glass flake mortar high? What is the anti-corrosion effect? How long can its effectiveness be guaranteed?
The results of polyurea spraying are not very satisfactory – in what ways does that manifest itself?
After polyurea spraying, the surface becomes smooth, but it tends to peel off, meaning it does not bond well with the substrate; if the inner wall of the tower is made of concrete and not treated properly, it will easily peel off. We previously applied polyurea to the bottom tank of our tower, but it almost completely peeled off after a short time, and the fertilizer on it was also difficult to clean away.
The cost of applying vinyl resin + glass flakes depends mainly on the thickness of the coating; the unit price is roughly between 100 and 280 yuan per square meter. The cost of applying the material by scraping is higher than that of spraying. As for the resin, it depends on whether you choose a domestic or imported version – the price can only be determined once the type of resin is selected.