boiling point rise. Forward feed is to be used. Steam is available at 120oC, and the vacuum in the last effect corresponds to a boiling temperature of 40oC. The overall coefficient, in W/m2 . oC, are 2950 in I, 2670 in II, and 1360 in III; all specific heats may be taken as 4.2 J/(g.oC); and radiation is negligible. Condensate leaves at condensing temperature. The feed enters at 90 oC. a) Sketch the process and locate different variables listed above within the evaporator setup. b) Calculate the steam consumption in kg/h. c) Calculate the mass of 4-% liquor that can be concentrated in an hour
A triple-effect standard vertical-tube evaporator, each effect of which has 140 m2
of heating
surface, is to be used to concentrate from 4% to 35% solids a solution possessing a negligible
boiling point rise. Forward feed is to be used. Steam is available at 120oC, and the vacuum in the
last effect corresponds to a boiling temperature of 40oC. The overall coefficient, in W/m2
.
oC, are
2950 in I, 2670 in II, and 1360 in III; all specific heats may be taken as 4.2 J/(g.oC); and radiation
is negligible. Condensate leaves at condensing temperature. The feed enters at 90 oC.
a) Sketch the process and locate different variables listed above within the evaporator setup.
b) Calculate the steam consumption in kg/h.
c) Calculate the mass of 4-% liquor that can be concentrated in an hour
Step by step
Solved in 5 steps with 5 images
