Why is it said that the production and maintenance in many sulfuric acid plants are in a constant state of back-and-forth struggle?

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Over the years, I have inspected more than 200 sulfuric acid production plants both domestically and internationally, and found that the operation and maintenance of many of these plants involve a constant cycle of back-and-forth efforts. The annual maintenance tasks for sulfuric acid plants typically include replacing the conversion catalyst and sealing the leaking tube bundles in the conversion heat exchangers. After the unit is put back into operation following maintenance, the conversion rate increases and exhaust SO2 levels decrease; however, for many factories, these improvements only last for 3 months to half a year. Generally speaking, small and medium-sized sulfuric acid production plants in the global industry have a relatively low level of equipment specification, and it is also common for dry absorption towers to contain acid. Since the problem of acid carried by the dry absorption tower was not fundamentally resolved, the heat and cold exchange tubes downstream were corroded and punctured by the acid from the upstream dry absorption tower; as a result, the conversion rate and SO2 emissions dropped back to their levels before maintenance, completing a cycle of fluctuations. It is common to see peers in sulfuric acid plants busy with treating symptoms, with few focusing on addressing the root causes. To achieve continuous improvement in the production and maintenance of sulfuric acid plants, resolving the issue of acid accumulation on the demisters of the dry absorption towers is a necessary condition. Most of the problems related to the safety, environmental protection, operating costs, and maintenance costs of sulfuric acid plants can be traced back to acid present in the dew collectors of the dry absorption towers.