PTFE lined towers

Gases from the outlet of the CHE/Economiser after CHE are taken to a 25% oleum tower before IPAT. The circulating oleum is boiled to produce SO3 vapors which are absorbed in a glass/Teflon-lined steel (MS-PTFE) absorption tower. A glass acid cooling system is generally employed. The unabsorbed gases are led to IPAT. 

Battery grade/Analytical Reagent grade sulfuric acid this will need PTFE lined/ glass absorption towers, special PTFE lined pumps, glass heat exchangers, etc. 

In summary, modifications to the generally practiced DCDA process are primarily the use of cesium activated catalyst an additional fifth pass to increase conversion efficiency, the use of twin oleum tower system and replacing PHE s by special alloy steel heat exchangers, an efficient acid distribution system, and PTFE lined piping for acid circulation. 

Flat bottomed towers with more than one layer of acid resistant bricks and two such layers on the side walls. The acid outlet nozzle at the bottom was lined with a cast iron pipe which was changed to lining with PTFE pipe. 

Better materials of construction (MOC) for important equipment like acid towers (MS-PTFE towers and lines), heat exchangers, and converter internals Better designs for equipment... 

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See also in sourсe #XX -- [ , , ]

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