Material of the liquid level tank in the reflux condenser of the desorption hydrolysis system
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What is the material of the liquid level tank in the reflux condenser of the hydrolysis system for the carbon dioxide stripping process in the Stamicarbon process? 304L? 316? 316L? Let’s discuss this!
The reflux liquid is corrosive; 316L should be used
Our reflux condensation system’s equipment, pipes, and valves are made of 304L, but severe corrosion has been observed. Pipes and valves have been gradually replaced with 316L, while the reflux condenser and its level tank are still in use due to the absence of leaks at present and the high cost associated with replacing them. If building new, it is recommended to choose 316L directly.
Hehe, we’ve installed a new unit for the treatment of purified ammonia water here. The gas pipelines are made of 304L material, but within just one month, corrosion and perforations occurred in those pipelines, requiring frequent stops to repair the leaks – it’s really troublesome. For the original poster, it is recommended to use 316L material to avoid the need for replacement after corrosion leads to thinning of the material; there is no need for that.
The 304L material we used before suffered from severe corrosion; now we’ve switched to 316L. Is that sufficient to ensure protection?
It is definitely designed to be 304L, but to ensure long-term operation and taking into account the actual conditions of various manufacturers, 316L should be chosen instead.
The corrosion in this area is similar to that in the liquid level tank of the low-pressure ammonium methanate condenser; it is recommended to use 316L material. Last edited by ymtuegj12 on 2008-12-24 at 15:39.]
The hydrolysis unit designed by our company, along with those designed by others, uses 316L material for the liquid level tank
Based on the process package requirements of Stamicke & Seifert and the preliminary design data provided by China Fifth Ring Engineering Company, 304L was chosen as the material for the liquid level tank of the reflux condenser. The reason for this is that the concentration of ammonium methylate in this tank is relatively low and the temperature is not high; therefore, 304L is sufficient to meet the requirements. If 306L were used, the equipment cost would increase significantly, as the price of 306L is much higher than that of 304L. This post was last edited by qiwu9981 on 2008-12-24 at 16:13
316L is prone to corrosion due to the high levels of ammonia and urea in the reflux condenser; if it is 304L, it is acceptable for the equipment to operate for a few more years. Anyway, it needs to be overhauled, and anyway, a portion of it has to be phased out.
Since the concentration of the return fluid is close to that of the methylammonium solution, it is better to use 316L material.
The reflux liquid is quite corrosive, similar to methylammonium solution; it is best to use 316L material for all relevant pipes, valves, and equipment.