Vapor-Liquid Separator Nomograph

Nomographs can be used to quickly size vertical knockout drums, oil separator drums, compressor dry drums, flash drums or any other vertical vapor-liquid separator. 

Vertical separators eire used when there is small liquid load, limited plot space, or where ease of level control is desired. 

Vapor velocity sets minimum drum diameter. For each alternate method of reducing liquid entrainment, a different velocity applies. 

Rd is the ratio of the vapor velocity in drum area to a base velocity of 0.227 Pl-PvVPv That is. 

Mesh manufacturers recommend an Rd of 1.54 (manufacturers k divided by 0.227) for all usual process applications. They report excellent performance from 30% Rd = 0.46) to 110% Rd = 1.69) of their recommended velocity. To allow for pressure surges, they suggest an Rd of 1.15 (75% of recommended velocity). 

---

Scheiman, A.D. Size Vapor-Liquid Separators Quicker by Nomograph, Hydrocarbon Processing and Petroleum Refiner, Oct. 1963, p. 165. 

Scheiman, A.D. Use Nomographs to Size Horizontal Vapor-Liquid Separators. Hydrocarbon Processing Petroleum Refiner, 1964, p. 155. 

---