general ppt on cooloing towers for power engineer's.... thank you for reading

1. Cooling tower s
Operation and
water management

2. Forced Draft Cooling Towers

3. Forced Draft Cooling Towers

4. Forced Draft Cooling Towers

5. Forced Draft
Cooling Towers

9. Natural Draft Cooling Towers

11. Small cooling installations

14. Water Distribution Details

16. 1. Fan 2. Drift eliminator 3. Warm water
4. Water distribution 5. Water sprinkling nozzle 6. Fill packing
7. Air inlet 8. Water pool 9. Cooled water

17. Packing Materials

19. Cooling Tower Mass Balances

20. Water and Salt Balances
A water balance around the entire system is:
M=E+D+W
Since the evaporated water (E) has no salts,
a chloride balance around the system is:
M (XM) = D (XC) + W (XC) = XC (D + W)
and, therefore:
XC/XM = Cycles of concentration
= M/(D + W)
= M/(M – E) = 1 + [E ÷ (D + W)]

21. Windage Losses
Windage losses (W), in the absence of
manufacturer's data, may be assumed to be:
W = 0.3 to 1.0 percent of C for a natural draft
cooling tower without windage drift eliminators
W = 0.1 to 0.3 percent of C for an induced
draft cooling tower without windage drift
eliminators
W = about 0.01 percent of C (or less) if the
cooling tower has windage drift eliminators

22. Heat Balance
From a simplified heat balance around the cooling tower:
E HV = C · ΔT · cp
Hv = Latent heat of water evaporation
= 2260 kJ/kg
Δ T = Temperature difference top to bottom
Cp = Specific heat of water = 4.184 kJkg-1C-1

23. Biocides - The Ct Concept
In disinfection, the ability to inactivate
microorganisms is a function of both
disinfectant concentration and time.
Fractional removal = Cntm
This is generally simplified to
Fractional removal = Ct
Ct values have been determined for
99.99% virus and 99.9% Giardia removal

25. http://www.cti.org/downloads/legion_2000.pdf
http://www.pnl.gov/fta/6_ozone.htm

27. Chlorine Dioxide Production
ClO2 made from Sodium Chlorite:
Acidification of Chlorite
5 ClO2- + 4 H+ --> 4 ClO2 + 2 H2O + Cl-
Oxidation of Chlorite by Chlorine
2 NaClO2 + Cl2 --> 2 NaCl + 2 ClO2
Oxidation of Chlorite by Persulfate
2 NaClO2 + Na2S2O8 --> 2 ClO2 + 2 Na2SO4
From Sodium Hypochlorite and Sodium Chlorite
NaOCl + 2 NaClO2 + 2 HCl --> 2 ClO2 + 3 NaCl + H2O
Electrochemical oxidation of chlorite
ClO2- --> ClO2 + e-
Dry chlorine/chlorite (laboratory method)
NaClO2 + 1/2 Cl2 --> ClO2 + NaCl (solid)