What causes pitting corrosion at the carbonization absorption exhaust pipe?
Thread Content
We just replaced the carbonization absorption exhaust pipes with aluminum-magnesium alloy tubes, but pitting corrosion occurred within less than half a month. We also tried using a slow-release descaling agent, but with little effect. Could you recommend one that works well?
It was replaced with stainless steel a few years ago, and corrosion is no longer an issue. Controlling the quality of circulating water is quite crucial; scale testing is used to determine the corrosiveness of the water. Corrosion inhibitors and scale preventers can only reduce corrosion, and it is also necessary to maintain the appropriate concentration of these substances; it would be best to use stainless steel instead.
Could you please provide information on replacing the carbonized absorption exhaust pipes with stainless steel, as well as details regarding corrosion issues and the available types of stainless steel, along with their pipe diameters?
May I ask which department shares the circulating water used for the carbonization cooling coils with you? Is there any trace of copper in that circulating water? We have encountered similar problems before; the cause was found to be the sharing of the circulating water with the copper cleaning department, which resulted in traces of copper in the water and accelerated the corrosion of the carbonization cooling coil pipes.
Generally speaking, carbonization systems contain ammonia, making it difficult to control the quality of the circulating water; moreover, increasing the frequency of replacement is necessary, but the cost of switching to stainless steel is too high
Has your problem been solved? What caused it?
That system is an independent circulating water system for the carbonization process; no copper melt enters it. Since the circulating water contains ammonia, corrosion caused by substances such as nitrate can occur during prolonged operation in summer.