The amount and type of mist generated in a given location in a sulfuric acid plant can vary greatly depending on the type, age, design, and operation of the acid plant. There are many types of mist eliminators used in sulfuric acid plants.
Depending on the plant configuration, ducts, blowers, and heat exchangers can be directly affected by the acid mist carried out of the drying tower. Acid mist from the drying tower can also be vaporized in the downstream sulfur burner or catalyst converters, creating sub-micron mist when it re-condenses. DEMISTER® mist eliminators or FLEXIFIBER® type IC-K mist eliminators are used to remove entrained mist in the drying tower.
Interpass and final absorption towers
Interpass and final absorption towers typically use mist elimination equipment with high efficiency in the sub-micron range. Protection of downstream equipment and air pollution are primary areas of concern in these towers. For that reason, FLEXIFIBER® type BD mist eliminators are a common choice for this application. Operating costs related to pressure drop in these towers are often a concern. Utilizing a FLEXIFIBER® type BD-LdP mist eliminator can provide high efficiency while doing so at a much lower pressure drop compared to conventional Brownian diffusion elements.
Tail gas scrubbers
Single absorption plants that have added ammonia-based tail gas scrubbers to reduce SO2 emissions can create a high percentage of sub-micron particles that can be addressed by using the FLEXIFIBER® type BD mist eliminators.
Smelting of ores often produces fluoride concentrations that can corrode glass and glass fibers. This will have a negative impact on the performance of mist eliminators containing glass fibers. In these instances, FLEXIFIBER® type BD mist eliminators with special carbon fibers is recommended.
Oleum is produced or transferred in the manufacturing of sulfuric acid. Any free SO3 in the vent from the storage tank needs to be converted to sulfuric acid mist and removed before discharge to the atmosphere.
Koch-Glitsch provides skid-mounted oleum vent systems using the FLEXIFIBER® type BD mist eliminator technology. Koch-Glitsch also provides the blower and a hydrolysis section to convert oleum vapors to sulfuric acid.