Page 176 - Process Equipment and Plant Design Principles and Practices by Subhabrata Ray Gargi Das

174 Chapter 6 Evaporators

Steam
Product
Steam section
Steam section
section

Feed

Product
from
separator
Vapour &
product to
separator

Condensate
outlet Final product to sump
FIGURE 6.12
Plate type evaporator (Falling film).

suited for evaporating heat-sensitive, viscous and foamy materials, (B) compact with low headroom,
and (C) easy to clean and modify. Typical applications are stripping applications, removing monomers
from polymers and deodorization. Nevertheless, there are large gasketed areas that are weak and may
be prone to leakages. Gasket material also limits the maximum temperature of the equipment.
Flash evaporators suppress evaporation on the heat transfer surface. The superheated liquor enters
a separator where flashing occurs due to reduced pressure. Scheme of a typical flash evaporator system
is shown in Fig. 6.13.

7 9
CW out Seal water
CW in
5
8
Condensate
Steam
4
6
Product

1
Condensate
3
2

Condensate
FIGURE 6.13
A flash evaporation system.