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I have design a liquid distributor for non-foaming system and design liquid load of 5.1 m3/m2.hr and vapor load of 2640 m3/m2.hr. The desired turndown is 50% and turnup is 110%. The column ID is 300mm. The distributor details areas follows:
1. The distributor is 2 - level deck type distributor i.e. instead of punching orifices/holes in the distributor deck, there are pipes fixed to the distributor deck with each pipe having two holes (bottom and top) at a distance of 50mm. This ensures wider operating ranges. distributor deck is circular one piece sheet of 2mm thick
2. The number of drip points (no. of pipes) is 3 and at turndown the liquid head from the bottom orifice is 35mm.
3. The dia of lower orifice is 3 mm and upper orifice is 4mm.
Could someone please advise if the type of distributor selected is proper and the design is adequate to ensure uniform liquid distribution.
 
Answers
16/07/2015 A: Nupur Jadhav, Student, nupur1234@hotmail.com
Design with 3 mm holes also on drip tube is somehow not used in plant design. Sometimes design specs specify min specs as 5 mm of orifice due to chances of plugging. To ensure good uniform flow, try to design the distributor with 5 mm of orifice. Inform the client, that at TD flow of 50 % there is some flow variation ( more than 25 %, head across each distributor holes). At normal operation go with minimum of 30 mm liquid head on distributor.
Also if possible you can try different type of distributor such as pipe arm type or spray type design.