Application limitations of structured packing
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Over the past decade, the use of structured packing in the sulfuric acid industry has been on the rise. At the same time, problems associated with the use of structured packing are also common; after replacing random-packed materials with structured packing, a decline in mass transfer efficiency and an increase in the amount of acid mist generated within the dry absorber occur quite frequently. Compared to randomly packed packing, regularly packed packing has a larger flow cross-section, which is a double-edged sword; it also has a poorer ability to redistribute acids. The acid-drop density required for structured packing is much higher than the 43 drops/m2 commonly seen in the sulfuric acid industry; as a result, uneven conditions occur across the tower cross-section, with the flow channels of the structured packing at the locations where acid drops form experiencing excessive fluid volume ； At the same time, some flow channels lack acid spraying or are not soaked by the acid, showing a \"dry\" condition. “\"Flood\" conditions lead to a sharp increase in the amount of mist carried within the tower, while \"drought\" conditions result in a decline in the tower’s mass transfer efficiency.
There is another factor: the packing layer also requires a certain level of resistance. The resistance of structured packing is low; especially under low-load conditions, the mass transfer performance of dry scrubbers equipped with structured packing, as well as the formation of acid mist inside the tower, will deteriorate further.
The main application limitations of structured packing include: 1. Poor performance in redistributing acids, which can lead to uneven conditions inside the tower. 2. The required acid separation point density is high, and uneven acid separation may lead to a decline in mass transfer performance within the tower. 3. A high flow cross-section may lead to an increased amount of acid mist entrained. 4. The mass transfer efficiency inside the tower decreases under conditions of non-uniform spraying or when it is not wetted by acid. .
President Yu is worried; the advantage of using structured packing is its lower resistance
The persistently high moisture levels after using structured packing also confirm what you said.
When using structured packing, it is essential to combine it properly with random packing, in order to achieve a balance among mass transfer, pressure drop, moisture content, and acid mist
Our installation is currently facing this problem: when the load increases, the moisture level in the drying tower exceeds the allowed limit
The resistance is too low, which is not conducive to the distribution of air flow