What coating should be used on the surface of the heat pipes in the air preheater of a heating furnace to provide corrosion resistance against flue gas?
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What coating should be used on the surface of the heat pipes in the air preheater of a heating furnace to provide corrosion resistance against flue gas?
Check your temperature! If the temperature is not high, ND steel can be used
As an acid-resistant steel, ND steel is the preferred material for heat exchange tubes in heating furnaces. However, it performs poorly in environments with low-temperature, humid flue gas; in some cases, the fins suffer severe corrosion after just over half a year of use, causing some of them to become ineffective.
The heat exchangers in heating furnaces are designed with corrosion temperatures in mind, but in order to recover heat energy to the greatest extent possible by lowering the temperature below the dew point, corrosion becomes a serious issue! Decades of industrial experience have shown that no material can resist corrosion below its dew point! Even double-phase steel! Is there still any way to solve it? There is a way! That is by using inexpensive cast iron material! Using materials to achieve energy savings – is it truly effective in saving energy, or does it not result in cost savings? It depends on each specific operating condition. Wish Haiyou success!
A metal nano-polymer alloy coating is used to prevent corrosion of the finned tubes on the outer surface of GGH heat exchange tubes; practical application has shown that this approach can effectively address the issue of corrosion caused by low-temperature, humid flue gases, with good results.
Polymer materials can effectively solve these problems, with both the solutions and processes being highly mature
Now, many polymer materials should be able to handle this, it just depends on the operating temperature.
This post was last edited by Wang Wei2 on 2019-2-20 08:30. Attention should be paid to the corrosion caused by the low dew point of wet flue gas.
Polyurea cannot be used in such environments because the coating is not corrosion-resistant.