How does scaling occur in sulfuric acid production boiler tubes?
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This post was last edited by “I Love Chemical Engineering” on April 16, 2012, at 10:29. Does adding calcium oxide to the system during sulfur melting have any effect? How significant is its impact on the output? How to avoid it.
It is recommended that a sodium-alkali additive be used in the sulfur melting system; high ash content can also lead to blockages in the fire tubes
The fine sulfur ash content is 0.1%, which is high. Adding lime is also based on the experience of those in the same field; it can maintain its effect for a long time. After the Spring Festival, we switched to lime, and now there is a very high level of resistance. NaOH is better; could the teacher upstairs explain it in more detail?
1. CaCO3 is added to neutralize the free acids in liquid sulfur and keep it neutral. Has your plant added too much CaCO3? 2 Ash content: 0.1%, which is high. Is a pressurized vane-type liquid sulfur filter being used for the filtration of liquid sulfur? 3 Has your factory experienced the sublimation of sulfur due to improper operations? 4 Is the airflow velocity inside the fire tube boiler too low?
Past experience shows that if soda ash is used for neutralization during sulfur melting, scaling will form inside the fire tubes of the waste boiler, and it is very difficult to remove. It is highly suspected that it was caused by sodium sulfate dissolving in liquid sulfur; unfortunately, no relevant literature was found.
Adding lime powder to neutralize free acid is a conventional method; I do not approve of using soda ash, as a low ash content is beneficial for production. I miss the waste heat boilers used in water pipes.
The cost of adding alkali is also a bit too high; after adding lime and filtering through a fluid bed filter, the amount of ash should not exceed the specified limits
Under no circumstances should lime be used; alkali must be employed, and the higher cost is worth it.