Sulfuric acid plant process gas dewpoint/moisture leak detection measurement system

摘要

In sulfuric acid manufacturing process,SO3 gas is generally present without moisture and therefore process gas dewpoint is well below process gas temperatures and,condensation/corrosion is not present.However,there are many sections of the process where there exists a potential for moisture leakage,from the drying tower,through the final stage of conversion and economizer outlet.When there is a moisture leak of some kind,it leads to rapid downstream corrosion and early indication of such leaks is desired.Breen has collaborated with the sulphuric acid manufacturing industry and have released a commercial instrument that will measure the process gas dew point at the converting tower economizer outlet.During this project,a process gas dewpoint meter was placed downstream of the converting tower economizer in two different sulfuric acid manufacturing facilities.This paper summarizes the dew point meter design,installation,maintenance and real-time response to changing process conditions and moisture ingress into the process gas.Sulfuric Acid is manufactured by oxidizing SO2 gas to SO3 in a converter through a catalytic oxidation process.The most common sources of SO2 are: 1.Burning elemental Sulfur.2.SO2 off-gas from a primary process such as a copper smelter.3.Decomposition of H2SO2 in a spent acid regeneration process.The SO2 gas as-produced above is passed over a catalyst in the presence of Oxygen to oxidize it to SO3.The SO3 gas is then is absorbed into 97–98% H2SO4 to form oleum(H2S2O7),also known as fuming sulfuric acid.The oleum is then diluted with water to form concentrated sulfuric acid.