1. University Of Salahaddin
College Of Engineering
(Types Of Cooling Tower)
Prepared :
1-Ahmed Naseh – 2-Ibrahim Abdullah
3- Ismail Farhad Kareem – 4-Muhamad Abdullah
Fourth Grade – Group B
Supervised by
Dr.Eng.Ramzi R.Ibraheem barwari
2. What’s Cooling Tower
A cooling tower is a specialized heat exchanger in
which air and water are brought into direct contact with
each other in order to reduce the water's temperature.
As this occurs, a small volume of water is evaporated,
reducing the temperature of the water being circulated
through the tower.
3. How The Process Works
Water, which has been heated by an industrial
process or in an air-conditioning condenser, is
pumped to the cooling tower through pipes. The
water sprays through nozzles onto banks of material
called “fill,” which slows the flow of water through the
cooling tower, and exposes as much water surface
area as possible for maximum air-water contact. As
the water flows through the cooling tower, it is
exposed to air, which is being pulled through the
tower by the electric motor-driven fan.
4. When the water and air meet, a small amount of water
is evaporated, creating a cooling action. The cooled
water is then pumped back to the condenser or process
equipment where it absorbs heat. It will then be pumped
back to the cooling tower to be cooled once again.
Cooling Tower Fundamentals provides a level of basic
cooling tower knowledge and is a great resource for
those wanting to learn more.
How The Process Works
5.
6. Components Of A Cooling Tower
Using a total system approach, every cooling tower and
component is designed and engineered to work
together as an integrated system for efficient
performance and long life.
HVAC Free Cooling – A free cooling system allows the
tower to directly satisfy a building’s cooling needs
without the need of operating the chiller in cold
weather. The goal of a free cooling system is to save
energy. There are specific types of free cooling
systems and certain elements that must be in place for
a free cooling system to be considered.
7. Variable Flow – There may be significant energy
savings opportunities if the cooling tower can be
operated under variable flow in off-peak conditions.
Variable flow is a way to maximize the effectiveness of
the installed tower capacity for whatever flow the
process has.
Fill – One of the single most important components of a
cooling tower is the fill. Its ability to promote both the
maximum contact surface and the maximum contact
time between air and water determines the efficiency of
the cooling tower. The two basic fill classifications
are splash type fill (breaks up the water) and film type
fill (spreads the water into a thin layer).
Components Of A Cooling Tower
8. Components Of A Cooling Tower
Drift eliminators – Designed to remove water droplets from the
discharged air and reduce loss of process water, drift
eliminators cause the air and droplets to make sudden
changes in direction. This causes the drops of water to be
separated from the air and deposited back into the tower.
Nozzles – Crossflow configuration permits the use of a gravity-
flow distribution system with a nozzle. With this system, the
supply water is elevated to hot water distribution basins above
the fill and then flows over the fill (by gravity) through nozzles
located in the distribution basin floor
9. Components Of A Cooling Tower
Fans – Cooling tower fans must move large volumes of air
efficiently, and with minimum vibration. The materials of
manufacture must not only be compatible with their design,
but must also be capable of withstanding the corrosive effects
of the environment in which the fans are required to operate.
Driveshafts – The driveshaft transmits power from the
output shaft of the motor to the input shaft of the Geareducer.
Because the driveshaft operates within the tower, it must be
highly corrosion resistant. Turning at full motor speed, it must
be well balanced and capable of being re-balanced.
10. How to pick a cooling tower
Cooling towers for HVAC systems come in either
crossflow or counterflow configurations. This is defined by
the way the water meets the heat transfer surface, more
commonly known as the “fill” surface. Crossflow cooling
towers distribute the hot water perpendicularly to the air
flow. Water flows from the top of the cooling tower through
the hot water gravity distribution basin and into the fill
while the cooling tower fan draws air horizontally across
the fill.
11. Crossflow Cooling Towers
In crossflow towers the water flows vertically through the fill
while the air flows horizontally, across the flow of the falling
water. Because of this, air does not have to pass through the
distribution system, permitting the use of gravity flow hot water
distribution basins mounted at the top of the unit above the fill.
These basins are universally applied on all crossflow towers.
12. Serviceability is a big bonus when it comes to crossflow towers. Crossflow
towers have an internal access plenum that can be fitted with an internal
platform from which the drive system can be serviced, and the entire fill
assembly inspected. These towers can also be fitted with an external service
platform or a ladder with handrails that provides safe maintenance access to
the hot water basin. The spray nozzles do not require any additional
pressurization, which saves pump energy. At reduced water flow rates, weir
dams help to fully distribute the water across the fill surface.
Crossflow Cooling Towers
13. Counterflow Cooling Towers
Counterflow towers are designed so that air flows vertically
upward, counter to the flow of falling water in the fill.
Because of this vertical airflow, it is not possible to use the
open, gravity-flow basins typical in crossflow designs.
Instead, counterflow towers use pressurized, pipe-type
spray systems to spray water onto the top of the fill.
Since air must be able to pass through the spray system,
the pipes and nozzles must be farther apart so as not to
restrict airflow
14. Counterflow Cooling Towers
In addition to being taller and more compact than crossflow
towers, counterflow towers have pressurized hot water nozzles
which increases the pump head requirement and total system
operating costs. Counterflow towers also have limited internal
accessibility for service and inspection. An external service
platform and ladder is usually required for access to the hot water
spray distribution and drive system.
15. Factory Assembled (FAP) vs.
Field Erected (FEP) Cooling Towers
Factory-assembled towers (FAP) are built and shipped in as
few sections as the mode of transportation will permit. A
relatively small tower will ship essentially intact. A larger,
multi-cell cooling tower is manufactured as modules at the
factory, and shipped ready for final assembly. Factory-
assembled towers are also known as “packaged” or “FAP”
(factory-assembled product). Factory-assembled cooling
towers can be crossflow or counterflow, induced draft or
forced draft, depending on the application. While all
applications are different, the factory-assembled Marley NC
crossflow, induced draft tower is widely used for HVAC and
light industrial applications.
17. Field Erected (FEP) Cooling Tower
Field-erected cooling towers (FEP) Field-erected towers are
primarily constructed at the site of ultimate use. All large
cooling towers, and many of the smaller towers, are
prefabricated, piece-marked, and shipped to the site for final
assembly. The manufacturer usually provides labor and
supervision for final assembly. Field-erected towers can be
crossflow or counterflow, depending on the application. For
power and heavy industrial applications, the field-
erected Marley F400 counterflow tower can be customized
to meet your exact specifications for performance, structure,
drift and plume abatement.