An Oleum tank required repairs during a summer shutdown. Oleum is a solution of various compositions of sulfur trioxide in sulfuric acid which is not corrosive to carbon steel. The tank had to be emptied and cleaned before repairs could be made. Once the concentration of sulfuric acid drops below 100% sulfuric acid, it becomes very corrosive to the carbon steel tank. The air space above the Oleum is also corrosive on a hot humid day. I had the bolted cover removed and then the oleum emptied. I then had soda ash to the tank and flooded it with water. As a result, the tank was emptied and cleaned without further damage to the existing tank.
Author: steve@lessonline.com
HPCH Yield Improvement
A company manufactured High Purity Calcium Hydroxide that had low yields. The annual capacity of the plant was relatively low at less than 10 tons per year. I installed measuring devices to measure rinse water flows and had samples analyzed for product. This had accounted for a portion of the product loss. Steps were taken to reduce this loss. In addition, there were losses associated with the rotary filter and material handling that were identified and corrected. Because of the low annual production and the high density of the small spills of material on the process floor had a significant impact in yields. Steps were made to prevent this material from spilling or reworking the spilled material. After the measures were taken the yields were back up to design specifications.