2. PRIMING
●Due to rapid boiling, the steam
may carry some water droplets
along with it. This is called wet
steam
●The process of wet steam
production is called Priming.
3. CAUSES OF PRIMING
➢Priming can reduce the heat
of the steam
➢Priming can cause corrosion
in the pipelines
4. PRIMING IS DUE TO
a) Improper design of boiler
b) High water level
c) High velocity of steam
d) Uneven boiling
5. PRIMING CAN BE CONTROLLED
BY
❖Proper boiler design
❖Maintaining proper water
level
❖Proper boiling
6. FOAMING
If oils and greases are present, they
produce stable bubbles on the water
surface.
This will increase the wet steam
production. This is known as
“Foaming
7. FOAMING IS PREVENTED BY
ADDING
➢ Anti foaming agents (e.g.)
synthetic poly amides , castor oil
➢ Coagulants (e.g.) Aluminium
hydroxide
