Corrosion of sulfuric acid demister
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During maintenance at our plant, we found that the sulfuric acid demister was severely corroded. Does anyone know why this happened?
Is the acid mist content in the smoke too high?
What type of demister is it, domestic or imported? Is the corrosion in the frame or the fibers?
It is imported from Monsanto; a wire foam remover
Are you referring to the wire mesh demister at the top of the drying tower? This phenomenon generally does not occur; first of all, if the opening time is too long and dilute acid is formed, it can cause corrosion. Another issue is the material used; foam eliminators made of screen filters are all constructed from 316L stainless steel, so it might be a problem with the manufacturer you ordered from.
This post was last edited by melao on 2011-11-1 08:48. If the corrosion of the sulfuric acid demister is severe, polypropylene demisters or demisters made from materials such as INCO825 and INCO600 can be considered.
The demister also has a lifespan of 2-3 years; it becomes unusable due to corrosion and thinning, and needs to be replaced in a timely manner.
Reply to 1# zhanqijun: What was said above is correct. Either there’s an issue with the material or with the medium; let’s check the material first
There is almost certainly corrosion in 316L in dryers; I’ve heard of PTFE being used for this purpose. It should get much better
In normal operation, sulfuric acid drying towers use 316L metal wire mesh demisters, which are widely used by sulfuric acid manufacturers in China. Fiber bed mist eliminators are used for the first absorption tower and the second absorption tower. There should be no doubt about this. When problems arise, first, it is necessary to determine whether there are significant fluctuations in operating conditions; second, ensure that the material used for the equipment is consistent; third, analyze aspects such as margin control and gas flow rate settings during the design and selection process. That being said, every product has a lifespan and is prone to defects; it’s necessary to work together with the workshop and suppliers to figure this out...
Check whether the chlorine-containing elements in the smoke exceed the permissible levels. There was once a case where, during the cleaning of the mesh, it was placed directly in a tank containing liquid alkali (which contains chloride ions); the mesh became completely unusable the next day, with only the frame remaining usable；