Retrotec USACE - Manual (Page 204)

D74 ENERGY & PROCESS ASSESSMENT PROTOCOL
If there is an imbalance of fl ow over the tower’s fi ll or from one tower to
an adjacent one, balance of the water fl ow through the tower no longer takes
place. In the area or tower with excess fl ow, the cooling effectiveness is re-
duced and the temperature of the leaving water is warmer. This may be caused
by poor adjustments of distribution system valves, plugged distribution piping,
or dirty nozzles. Additional fan energy would be required to reduce the water
temperature to the desired value. This represents an energy waste that could
be avoided.
D.4.2.20 Splash Bars and Drift Eliminators in Poor Condition
(Ineffi ciency)
Splash bars and drift eliminators are baffl es placed in the air stream of the cool-
ing tower to remove water droplets. Without them, excessive water lost can
cause a requirement for extra water fl ow to the tower and require additional
pump motor horsepower to be used. Also, the water droplets can be a major
problem to things downstream of the cooling tower. Spotting of cars and win-
dows would occur, and electrical devices such as power lines and substations
would be wet during operation. In the tower, these baffl es cause a change in
the direction of air fl ow for the droplet removal. This adds a static pressure loss
to the air fl ow, increasing the tower fan motor energy being used. The baffl es
are made of treated wood or various plastics and can deteriorate over time.
If they become plugged and more restrictive to air fl ow, excessive fan motor
energy is used and the cooling provided by the tower may not be adequate.
If larger openings develop between the baffl es than their design specifi es, in-
creased water loss and drift result. This will affect the quantity of water being
returned from the tower, which, again, could reduce the amount of cooling
being done and increase the pumping energy being used.
D.4.2.21 Blowdown from Supply Header or Cooling Tower Basin
(Ineffi ciency)
Figure D124. Cooling tower showing return
water pipe exiting basin.
The blowdown water is used to keep the concentration of dissolved salts in the
cooling water at a proper level. This water can be thrown away from anywhere in
the system. If done at the tower (from the supply header or tower basin), pump-
ing energy has been wasted sending the water to the tower (Figure D124).