| 摘要 |
PURPOSE:To manufacture high purity sulfuric acid for the electronic industry having a very low dust content in an industrially advantageous manner by filtering liq. sulfur trioxide with a filter medium having a specified pore size, gasifying the filtered liq. sulfur trioxide, and allowing the resulting gas to be absorbed in water or sulfuric acid. CONSTITUTION:Liq. SO3 is introduced into a filter 2 through a duct 1 and filtered with a filter medium having 0.01-2mum pore size such as a sintered metallic filter. The filtered liq. SO3 is introduced into a gasifier 3, where 90-60wt% of it is gasified, and the remainder is taken out through a purge pipe 5. The resulting gaseous SO3 is introduced into an absorption tower 6, 98% sulfuric acid is fed from the top of the tower 6 through a circulating sulfuric acid duct 7, and pure water is properly supplied through a pure water duct 8 to produce sulfuric acid by the absorption of the gaseous SO3. This sulfuric acid is drawn from the bottom of the tower 6 through a drawing pipe 9, and part of it is drawn through a drawing pipe 11 as a product and taken out of an outlet 13 through a filter 12.
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