6. Details of Water-Cooling
System
•
•
•
Cooling towers and Reservoirs
Direct cooling to Dies
Indirect cooling to oil through Heat
Exchangers
• Pre-treatment of Water through Water
Softener
• No Blowdown facility from bottom of water
reservoirs
7. WHY DO COOLING
WATER PROBLEM
EXIST ?
If cooling water left untreated , cooling water
system provide an environment where the
four main cooling problems will exist:
• CORROSION
• SCALE
• FOULING
• MICRO BIOLOGICAL CONTAMINATION
8. WHAT TYPE OF WATER CHARACTERISTICS AFFECT
CORROSION
•
•
•
•
•
•
Oxygen and other dissolved gases
Dissolved or suspended solids
Alkalinity or acidity
Velocity
Temperature
Microbial activity
9. WHAT ARE THE EFFECTS OF THOSE PROBLEMS ?
• Increased maintenance cost
• Reduced heat transfer efficiency and
therefore greater energy losses
• Possible production cutbacks or
shutdowns
• Direct loss or abandon of plant &
machineries
10. Methods of Prevention and Control of
Scale
• Removal of scale forming minerals by pre-
treatment of makeup water.
• Limiting the concentration of scale forming
minerals by bleed control.
• Replacing scale-forming minerals with
soluble salts by acid dosing.
• Controlling the scale forming process
using scale-inhibiting chemicals.
11. Corrosion Control Concepts
The rate of attack by circulating cooling water on
steel is a function of temperature and pH. It
increases with temperature and depression of
pH.
Corrosion protection follows two rules:
High pH promotes scale and inhibits
corrosion
Low pH inhibits scale and promotes
corrosion
