For pall ring packed towers, liquid redistributors are placed every 6 meters or 5-10 times column diameter, whichever is smaller. Max pall ring size should not exceed _______________________ of column diameter?
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Answer: A. 1/10-1/15th
Explanation
Pall ring packing size must remain small relative to the column diameter for good efficiency. Limiting the maximum ring size to one-tenth or one-fifteenth of diameter prevents wall channeling. Proper size selection ensures uniform void fraction and optimal gas-liquid contact. Pall rings are high-efficiency random packings used in industrial absorption and stripping columns. Packing size affects both interfacial mass transfer area and pressure drop characteristics. Using oversized rings in small columns causes severe liquid bypass along the vessel walls.
Design engineers select random packing dimensions based on the internal diameter of the tower. Incorrect packing size selection leads to poor separation performance and high operating costs. Packed towers provide lower pressure drops than tray columns in vacuum distillation service. Option B allows packing sizes that are too large for smaller diameter towers. Option C specifies extremely small packings that create excessively high pressure drops. Option D proposes massive packing dimensions that would destroy column separation efficiency.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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