3-2 Black Liquor Evaporator Design and Operation
3.2-2 Different two-phase flow schemes are created in the boiling zone, including slug flow, where a slug of liquor is followed by a slug of vapor, similar to the perking in a coffee percolator; annular flow, where a ring of liquor encases a center core of vapor and liquid mist; and mist flow, where vapor blankets the tube surface. Mist flow conditions should be avoided because poor heat