Khalid Nawaz, profile picture
Uploaded byKhalid Nawaz
PPTX, PDF51,862 views

cooling towers

The document discusses cooling towers, which are used to transfer heat from cooling water to the atmosphere. There are two main types - natural draft towers which use convection to circulate air, and mechanical draft towers which use fans. Mechanical draft towers can be either counter-flow or cross-flow design. The cooling tower cools water by contacting it with air, allowing evaporation which removes heat from the water so it can be recirculated for cooling processes.

Embed presentation

Downloaded 2,363 times
Khalid nawaz cell no: (0300-7024407) institute of chemical engineering and technology Lahore Pakistan
The cooling tower is one of the most important device in chemical industries for example when the hot water come from heat exchanger we use the cooling tower to cool it. The purpose of cooling tower is to cool relatively warm water by contacting with unsaturated air. The evaporation of water mainly provides cooling. In a typical water cooling water tower, warm water flows countercurrent to an air stream. Typically, the warm water enters the top of packed tower and cascades down through the packing, leaving at the bottom.
Air enters at the bottom of the tower and flows upward through the descending water. The tower packing often consists of slats of plastic or of packed bed. The water is distributed by troughs and overflows to cascade over slat gratings or packing that provides large interfacial areas of contact between the water and air in the form of droplets and films of water. The flow of air upward through the tower can be induced by the buoyancy of the warm air in the tower (natural draft) or by the action of a fan. The water cannot be cooled below the wet bulb temperature. The driving force for the evaporation of the water is approximately the vapor pressure of the water less the vapor pressure it would have at the wet bulb temperature.
What Does A Cooling Tower Do?  Cooling Towers are used to transfer heat from cooling water to the atmosphere. – Promotes efficient water usage – Prevents environmental damage
Where cooling tower used Used in power stations, oil refineries, petrochemical plants and natural gas plants. Cooling water is continuously circulated through heat exchangers to absorb heat from process material and machinery. Because it's cost efficient to reuse water and plants can't dump excessive amounts of hot water into rivers and lakes, cooling towers are used to remove the heat from the water, so it can be recirculated.
How Does It Work?
Parts Of Cooling Tower  Frame and casing. Most towers have structural frames that support the exterior enclosures (casings), motors, fans, and other components. With some smaller designs, such as some glass fiber units, the casing may essentially be the frame.  Fill. Most towers employ fills (made of plastic or wood) to facilitate heat transfer by maximizing water and air contact. There are two types of fill:  Splash fill: water falls over successive layers of horizontal splash bars, continuously breaking into smaller droplets, while also wetting the fill surface. Plastic splash fills promote better heat transfer than wood splash fills.  Film fill: consists of thin, closely spaced plastic surfaces over which the water spreads, forming a thin film in contact with the air. These surfaces may be flat, corrugated, honeycombed, or other patterns. The film type of fill is the more efficient and provides same heat transfer in a smaller volume than the splash fill.  Cold-water basin. The cold-water basin is located at or near the bottom of the tower, and it receives the cooled water that flows down through the tower and fill. The basin usually has a sump or low point for the cold-water discharge connection. In many tower designs, the cold-water basin is beneath the entire fill. In some forced draft counter flow design, however, the water at the bottom of the fill is channeled to a perimeter trough that functions as the cold-water basin. Propeller fans are mounted beneath the fill to blow the air up through the tower. With this design, the tower is mounted on legs, providing easy access to the fans and their motors.
Fill: Most towers employ fills (made of plastic or wood) to facilitate heat transfer by maximizing water and air contact. Fill can either be splash or film type. With splash fill, water falls over successive layers of horizontal splash bars, continuously breaking into smaller droplets, while also wetting the fill surface. Plastic splash fill promotes better heat transfer than the wood splash fill. Film fill consists of thin, closely spaced plastic surfaces over which the water spreads, forming a thin film in contact with the air. These surfaces may be flat, corrugated, honeycombed, or other patterns. The film type of fill is the more efficient and provides same heat transfer in a smaller volume than the splash fill.
 Drift eliminators. These capture water droplets entrapped in the air stream that otherwise would be lost to the atmosphere.  Air inlet. This is the point of entry for the air entering a tower. The inlet may take up an entire side of a tower (cross-flow design) or be located low on the side or the bottom of the tower (counter-flow design).  Louvers. Generally, cross-flow towers have inlet louvers. The purpose of louvers is to equalize air flow into the fill and retain the water within the tower. Many counter flow tower designs do not require louvers.  Nozzles. These spray water to wet the fill. Uniform water distribution at the top of the fill is essential to achieve proper wetting of the entire fill surface. Nozzles can either be fixed and spray in a round or square patterns, or they can be part of a rotating assembly as found in some circular cross-section towers.  Fans. Both axial (propeller type) and centrifugal fans are used in towers. Generally, propeller fans are used in induced draft towers and both propeller and centrifugal fans are found in forced draft towers. Depending upon their size, the type of propeller fans used is either fixed or variable pitch. A fan with non-automatic adjustable pitch blades can be used over a wide kW range because the fan can be adjusted to deliver the desired air flow at the lowest power consumption. Automatic variable pitch blades can vary air flow in response to changing load conditions.
Cooling tower material  Wood--- frame, casing, louvers, fill, and cold water basin (or concrete)  Galvanised steel, various grades of stainless steel, glass fibre and concrete, aluminium and various types of plastics for some components  Large towers are made of CONCRETE  Plastics are widely used for FILL, including PVC, polypropylene and other polymers  Plastics also find wide use in nozzle materials
Cooling Tower Types  Cooling towers fall into two main categories: Natural draft and Mechanical draft. Mechanical draft towers are available in the following airflow arrangements:  1. 2. 3. Counter flows induced draft. Counter flow forced draft. Cross flow induced draft.
Cross flow Cross flow is a design in which the air flow is directed perpendicular to the water flow (see diagram below). Air flow enters one or more vertical faces of the cooling tower to meet the fill material. Water flows (perpendicular to the air) through the fill by gravity.
Counter flow In a counter flow design the air flow is directly opposite of the water flow (see diagram below). Air flow first enters an open area beneath the fill media and is then drawn up vertically. The water is sprayed through pressurized nozzles and flows downward through the fill, opposite to the air flow.
Natural draft, which utilizes buoyancy via a tall chimney. Warm, moist air naturally rises due to the density differential to the dry, cooler outside air. Warm moist air is less dense than drier air at the same temperature and pressure. This moist air buoyancy produces a current of air through the tower. This photo shows a single natural draft cooling tower as used at a European plant. Natural draft towers are typically about 400 ft (120 m) high, depending on the differential pressure between the cold outside air and the hot humid air on the inside of the tower as the driving force. No fans are used.
• The natural draft or hyperbolic cooling tower makes use of the difference in temperature between the ambient air and the hotter air inside the tower. It works as follows: • Hot air moves upwards through the tower (because hot air rises) • Fresh cool air is drawn into the tower through an air inlet at the bottom. • Due to the layout of the tower, no fan is required and there is almost no circulation of hot air that could affect the performance. Concrete is used for the tower shell with a height of up to 200 m. These cooling towers are mostly only for large heat duties because large concrete structures are expensive.
• Air drawn up of Cooling Towers through falling water • Fill located Natural Draft Cooling Towers tower inside • Air drawn across Types falling water • Fill located outside tower Cross flow (Gulf Coast Chemical Commercial Inc.) Counter flow 20 © UNEP 2006
Types of natural draft cooling tower  There are two main types of natural draft towers: • Cross flow tower (left figure): air is drawn across the falling water and the fill is located outside the tower • Counter flow tower (right figure): air is drawn up through the falling water and the fill is therefore located inside the tower, although design depends on specific site conditions
Types of Cooling Towers Mechanical Draft Cooling Towers • Large fans to force air through circulated water • Water falls over fill surfaces: maximum heat transfer • Cooling rates depend on many parameters • Large range of capacities • Can be grouped, e.g. 8-cell tower 22 © UNEP 2006
• Mechanical draft towers have large fans to force or draw air through circulated water. The water falls downwards over fill surfaces, which help increase the contact time between the water and the air - this helps maximize heat transfer between the two. • Cooling rates of mechanical draft towers depend upon various parameters such as fan diameter and speed of operation, fills for system resistance etc. • Mechanical draft towers are available in a large range of capacities. Towers can be either factory built or field erected – for example concrete towers are only field erected. • Many towers are constructed so that they can be grouped together to achieve the desired capacity. Thus, many cooling towers are assemblies of two or more individual cooling towers or “cells.” The number of cells they have, e.g., a eightcell tower, often refers to such towers.
Types of Cooling Towers Forced Draft Cooling Towers • • Advantages: suited for high air resistance & fans are relatively quiet • (GEO4VA) Air blown through tower by centrifugal fan at air inlet Disadvantages: recirculation due to high air-entry and low air-exit velocities 24 © UNEP 2006
A mechanical draft tower with a blower type fan at the intake. The fan forces air into the tower, creating high entering and low exiting air velocities. The low exiting velocity is much more susceptible to recirculation. With the fan on the air intake, the fan is more susceptible to complications due to freezing conditions. Another disadvantage is that a forced draft design typically requires more motor horsepower than an equivalent induced draft design. The forced draft benefit is its ability to work with high static pressure. They can be installed in more confined spaces and even in some indoor situations. This fan/fill geometry is also known as blow-through.
 Forced draft cooling tower • How it works: air is blown through the tower by a fan located in the air inlet • Advantages: • Suited for high air resistance due to centrifugal blower fans • Fans are relatively quiet • Disadvantages: Recirculation due to high air-entry and low air-exit velocities, which can be solved by locating towers in plant rooms combined with discharge ducts
Types of Cooling Towers Induced Draft Cooling Towers • Two types • Cross flow • Counter flow • Advantage: less recirculation than forced draft towers • Disadvantage: fans and motor drive mechanism require weather-proofinh 28 © UNEP 2006
• Two types of induced draft cooling towers: cross flow and counter flow • Advantage: Less recirculation than forced draft towers because the speed of exit air is 3-4 times higher than entering air • Disadvantage: Fans and the motor drive mechanism require weather-proofing against moisture and corrosion because they are in the path of humid exit air
Types of Cooling Towers Induced Draft Counter Flow CT • Hot water enters at the top • Air enters at bottom and exits at top • Uses forced and induced draft fans (GEO4VA) 30 © UNEP 2006
Types of Cooling Towers Induced Draft Cross Flow CT • Water enters top and passes over fill • Air enters on one side or opposite sides • Induced draft fan draws air across fill (GEO4VA) 31 © UNEP 2006
Air/water systems Dry-bulb and wet-bulb temperature wet cloth/wick Air flow Dry bulb temperature: the ordinary temperature you measure with e thermometer Evaporation requires energy. The wick and therefore the thermometer bulb decreases in temperature below the dry-bulb temperature until the rate of heat transfer from the warmer air to the wick is just equal to the rate of heat transfer needed to provide for the evaporation of water from the wick into the air stream. The temperature reached is called the wet-bulb temperature
Cooling tower Performance
Performance  These measured parameters and then used to determine the cooling tower performance in several ways. These are: 1. Range 2. Approach 3. Effectiveness 4. Cooling capacity 5. Evaporation loss 6. Cycles of concentration 7. Blow down losses 8. Liquid / Gas ratio  We will now go through each of these parameters on the next slides
Assessment of Cooling Towers 1. Range Hot Water Temperature (In) Range Difference between cooling water inlet and outlet temperature: Range (°C) = CW inlet temp – CW outlet temp (In) to the Tower (Out) from the Tower High range = good performance Approach Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) 35 © UNEP 2006
• The range is the difference between the cooling tower water inlet and outlet temperature. • The formula for cooling tower range in degrees Celcius is cooling water inlet temperature minus cooling water outlet temperature • A high CT Range means that the cooling tower has been able to reduce the water temperature effectively, and is thus performing well.
Assessment of Cooling Towers 2. Approach Approach (°C) = CW outlet temp – Wet bulb temp Low approach = good performance Range Hot Water Temperature (In) Approach Difference between cooling tower outlet cold water temperature and ambient wet bulb temperature: (In) to the Tower (Out) from the Tower Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) 37 © UNEP 2006
• Approach is the difference between the cooling tower outlet cold-water temperature and ambient wet bulb temperature. • The formula for approach is CT Approach in degrees Celcius is cold water outlet temperature minus the wet bulb temperature • The lower the approach the better the cooling tower performance. Although, both range and approach should be monitored, the `Approach’ is a better indicator of cooling tower performance.
Assessment of Cooling Towers 3. Effectiveness Hot Water Temperature (In) = Range / (Range + Approach) Range Effectiveness in % High effectiveness = good performance Approach = 100 x (CW temp – CW out temp) / (CW in temp – Wet bulb temp) (In) to the Tower (Out) from the Tower Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) 39 © UNEP 2006
• Cooling tower effectiveness is the ratio between the range and the ideal range (in percentage), i.e. difference between cooling water inlet temperature and ambient wet bulb temperature • Effectiveness = Range / (Range + Approach) • The formula for cooling tower effectiveness is: CT Effectiveness (%) = 100 x (CW temp – CW out temp) / (CW in temp – WB temp) • The higher this ratio, the higher the cooling tower effectiveness.
Assessment of Cooling Towers 4. Cooling Capacity = mass flow rate of water X specific heat X temperature difference High cooling capacity = good performance Approach Heat rejected in kCal/hr or tons of refrigeration (TR) Range Hot Water Temperature (In) (In) to the Tower (Out) from the Tower Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) 41 © UNEP 2006
Assessment of Cooling Towers 5. Evaporation Loss Hot Water Temperature (In) = 0.00085 x 1.8 x circulation rate (m3/hr) x (T1-T2) Approach = theoretically, 1.8 m3 for every 10,000,000 kCal heat rejected Range Water quantity (m3/hr) evaporated for cooling duty (In) to the Tower (Out) from the Tower Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) T1-T2 = Temp. difference between inlet and outlet water 42 © UNEP 2006
 The main areas for improving the energy efficiency of cooling towers are: 1. Selecting the right cooling tower (because the structural aspects of the cooling tower cannot be changed after it is installed) 2. Fills 3. Pumps and water distribution system 4.Fans and motors  We will go through these one by one on the next slides.
• Once a cooling tower is in place it is very difficult to significantly improve its energy performance. A number of factors are of influence on the cooling tower’s performance and should be considered when choosing a cooling tower: capacity, range, approach, heat load, wet bulb temperature, and the relationship between these factors. We will start with capacity. • Capacity, in terms of heat dissipation (in kCal/hour) and circulated flow rate (m3/hr), are an indication of the capacity of cooling towers. However, these design parameters are not sufficient to understand the cooling tower performance. • For example, a cooling tower sized to cool 4540 m3/hr through a 13.9 0C range might be larger than a cooling tower to cool 4540 m3/hr through 19.5 0C range. Therefore other design parameters are also needed.
Factors affecting Cooling tower performance Wet Bulb Temperature  WBT of air entering the cooling tower determines operating temperature levels throughout the plant, process or system.  Recirculation raises the effective WBT of the air entering the tower with corresponding increase in cold water temperature.
  • • • • • Wet bulb temperature is an important factor in performance of evaporative water cooling equipment, because it is the lowest temperature to which water can be cooled. For this reason, the wet bulb temperature of the air entering the cooling tower determines the minimum operating temperature level throughout the plant, process, or system. The following should be considered when pre-selecting a cooling tower based on the wet bulb temperature: Theoretically, a cooling tower will cool water to the entering wet bulb temperature. In practice, however, water is cooled to a temperature higher than the wet bulb temperature because heat needs to be rejected from the cooling tower. A pre-selection of towers based on the design wet bulb temperature must consider conditions at the tower site. The design wet bulb temperature also should not be exceeded for more than 5 percent of the time. In general, the design temperature selected is close to the average maximum wet bulb temperature in summer. Confirm whether the wet bulb temperature is specified as ambient (the temperature in the cooling tower area) or inlet (the temperature of the air entering the tower, which is often affected by discharge vapors recirculated into the tower). As the impact of recirculation cannot be known in advance, the ambient wet bulb temperature is preferred. Confirm with the supplier if the cooling tower is able to deal with the effects of increased wet bulb temperatures. The cold-water temperature must be low enough to exchange heat or to condense vapors at the optimum temperature level. The quantity and temperature of heat exchanged can be considered when choosing the right size cooling tower and heat exchangers at the lowest costs. .
Factors affecting Cooling tower performance Fill Media Effects  Function: Heat exchange between air and water is influenced by surface area of heat exchange, time of heat exchange and turbulence in water effecting thoroughness of intermixing.  Due to fewer requirements of air and pumping head, there is a tremendous saving in power with the intervention of film fill.  Recently, low clog film fills with higher flute sizes have been developed to handle high turbid waters. (sea water)
Facts  The flow rate through a cooling tower in a typical 700 MW power plant is about 315,000 gal/min.  Cooling towers have 95% efficiency, losing only 5% of circulating water to evaporation.  Power consumption is minimal due to few moving parts.  Cooling towers save plants thousands to millions of dollars per year in water consumption and recycling costs.
Energy Saving Opportunities in Cooling Towers Follow manufacturer’s recommended clearances around cooling towers and relocate or modify structures that interfere with the air intake or exhaust. Optimise cooling tower fan blade angle on a seasonal and/or load basis. Correct excessive and/or uneven fan blade tip clearance and poor fan balance. On old counter-flow cooling towers, replace old spray type nozzles with new square spray ABS practically non-clogging nozzles. Replace splash bars with self-extinguishing PVC cellular film fill. Install new nozzles to obtain a more uniform water pattern Periodically clean plugged cooling tower distribution nozzles. Balance flow to cooling tower hot water basins. Cover hot water basins to minimise algae growth that contributes to fouling. Optimise blow down flow rate, as per COC limit. Replace slat type drift eliminators with low pressure drop, self extinguishing, PVC cellular units. Restrict flows through large loads to design values.
cooling towers

More Related Content

PPT
Cooling towers
byctlin5
 
PPTX
Cooling tower
byAjeetSaini3
 
PPTX
Presentation cooling tower
byALOK KUMAR SWAIN
 
PPTX
Cooling Towers - An Extensive Approach
byNoaman Ahmed
 
PPT
Cooling tower
byAshish Kumar Jain
 
PPTX
Cooling tower
byAshif AR
 
PPTX
Cooling tower
byAyush Singh
 
PDF
cooling towers system .pdf
byKarnav Rana
 
Cooling towers
byctlin5
 
Cooling tower
byAjeetSaini3
 
Presentation cooling tower
byALOK KUMAR SWAIN
 
Cooling Towers - An Extensive Approach
byNoaman Ahmed
 
Cooling tower
byAshish Kumar Jain
 
Cooling tower
byAshif AR
 
Cooling tower
byAyush Singh
 
cooling towers system .pdf
byKarnav Rana
 

What's hot

PPTX
Condensors and evaporators
byMohammad Azam Khan
 
PPS
Steam Boilers OR Steam Generators
byHrishikesh Devan
 
PDF
Boiler ppt
byEr Ramgarhia
 
PPT
Pump
byPrasadroshan Mythin
 
PPTX
Ppt on boilers
byIndian Institute of Technology Delhi
 
PPTX
Boiler circulation theory
byNaumanKalshekar
 
PPT
Feedwater heaters in thermal power plants
bySHIVAJI CHOUDHURY
 
PPT
Types of compressors
bySalman Abid
 
PPTX
BOILER DRAUGHT
byHemanth Krishnan R
 
PPTX
Heat exchangers
byAmmar Ashraf
 
PPSX
Cooling water (CW) system
byMohammad Shoeb Siddiqui
 
PPTX
Steam jet refrigeration system.pptx
bySANIA BAISOYA
 
PDF
Cooling water system presentation
byumar farooq
 
PPTX
A complete presentation on Boiler.
byAnuj Maurya
 
PPTX
Boiler performance (Part 2) - Boiler efficiency, Boiler trial and Heat balance
byAVDHESH TYAGI
 
PPT
Super critical boiler
bySHIVAJI CHOUDHURY
 
PPTX
Compressor and Types
byMuhammad Usama
 
PPTX
Heat exchangers
bySANT LONGOWAL INSTITUTE OF ENGINEERING AND TECHNOLOGY
 
PPTX
Vapour Absorption Refrigeration System
byJaswanth Gejjala
 
PPTX
Boiler Presentation
byanshsmartstud
 
Condensors and evaporators
byMohammad Azam Khan
 
Steam Boilers OR Steam Generators
byHrishikesh Devan
 
Boiler ppt
byEr Ramgarhia
 
Pump
byPrasadroshan Mythin
 
Ppt on boilers
byIndian Institute of Technology Delhi
 
Boiler circulation theory
byNaumanKalshekar
 
Feedwater heaters in thermal power plants
bySHIVAJI CHOUDHURY
 
Types of compressors
bySalman Abid
 
BOILER DRAUGHT
byHemanth Krishnan R
 
Heat exchangers
byAmmar Ashraf
 
Cooling water (CW) system
byMohammad Shoeb Siddiqui
 
Steam jet refrigeration system.pptx
bySANIA BAISOYA
 
Cooling water system presentation
byumar farooq
 
A complete presentation on Boiler.
byAnuj Maurya
 
Boiler performance (Part 2) - Boiler efficiency, Boiler trial and Heat balance
byAVDHESH TYAGI
 
Super critical boiler
bySHIVAJI CHOUDHURY
 
Compressor and Types
byMuhammad Usama
 
Heat exchangers
bySANT LONGOWAL INSTITUTE OF ENGINEERING AND TECHNOLOGY
 
Vapour Absorption Refrigeration System
byJaswanth Gejjala
 
Boiler Presentation
byanshsmartstud
 

Viewers also liked

PPTX
Steam jet ejectors 1
byKareem Tharaa
 
DOCX
Steam jet ejectors
byshehzad hussain
 
DOCX
How do ejectors work
bytraigalang1991
 
DOCX
note ejector
byBamidele Soyingbe LCGI
 
PDF
Cooling tower-handbook final
byRupan Guha
 
PDF
Cooling tower Inspection Guide
byCooling Tower Depot, Inc.
 
PDF
Индустриальные редукторы серии Paramax SFC Cooling Tower Drives Sumitomo
byArve
 
PPT
Presentation on cooling tower
bySummit Power International https://summitpowerinternational.com/
 
PPS
Cooling Towers
bycoolmonty
 
Steam jet ejectors 1
byKareem Tharaa
 
Steam jet ejectors
byshehzad hussain
 
How do ejectors work
bytraigalang1991
 
note ejector
byBamidele Soyingbe LCGI
 
Cooling tower-handbook final
byRupan Guha
 
Cooling tower Inspection Guide
byCooling Tower Depot, Inc.
 
Индустриальные редукторы серии Paramax SFC Cooling Tower Drives Sumitomo
byArve
 
Presentation on cooling tower
bySummit Power International https://summitpowerinternational.com/
 
Cooling Towers
bycoolmonty
 

Similar to cooling towers

PDF
Study the factors on which efficiency of cooling tower can be critically accl...
byIJERA Editor
 
PDF
Cooling Tower
byPramodShriwastava1
 
PDF
3Ch7.pdf
byDr. Ahamed Saleel C
 
PDF
Cooling tower
byPranavmaruti
 
PDF
cooling tower
byKarnav Rana
 
PDF
cooling tower, Factors Affecting Cooling Tower Performance,Efficient System O...
bySalman Jailani
 
DOCX
Cooling Tower
byAyush Singh
 
PDF
mini-cooling-tower
byKani Vel
 
PDF
AC end.pdf
byMahamad Jawhar
 
PPTX
Cooling Towers - Classifications and working
byMohammed Ashique
 
DOCX
AC.docx
byMahamad Jawhar
 
PPTX
cooling tower
byDeepak prajapati
 
PPTX
Cooling tower
byAdnanAli399
 
PPTX
Cooling Towers - Classifications and Working
bymohammed ashique
 
PPTX
Cooling towers
by8109962012
 
RTF
Project report study of cooling tower
byYoginderKumar12
 
PPTX
presentation on cooling tower (Detailed).pptx
byJunaidJohnson2
 
PDF
Cooling tower
byhyder mohammed
 
PPTX
cooling tower
bySadam Shahani
 
DOCX
final project1.docx
byMahamad Jawhar
 
Study the factors on which efficiency of cooling tower can be critically accl...
byIJERA Editor
 
Cooling Tower
byPramodShriwastava1
 
3Ch7.pdf
byDr. Ahamed Saleel C
 
Cooling tower
byPranavmaruti
 
cooling tower
byKarnav Rana
 
cooling tower, Factors Affecting Cooling Tower Performance,Efficient System O...
bySalman Jailani
 
Cooling Tower
byAyush Singh
 
mini-cooling-tower
byKani Vel
 
AC end.pdf
byMahamad Jawhar
 
Cooling Towers - Classifications and working
byMohammed Ashique
 
AC.docx
byMahamad Jawhar
 
cooling tower
byDeepak prajapati
 
Cooling tower
byAdnanAli399
 
Cooling Towers - Classifications and Working
bymohammed ashique
 
Cooling towers
by8109962012
 
Project report study of cooling tower
byYoginderKumar12
 
presentation on cooling tower (Detailed).pptx
byJunaidJohnson2
 
Cooling tower
byhyder mohammed
 
cooling tower
bySadam Shahani
 
final project1.docx
byMahamad Jawhar
 

More from Khalid Nawaz

PPT
Distillation Column
byKhalid Nawaz
 
PDF
Wauquier, j. p._-_petroleum_refining_i_crude_oil_-_petroleum_products_-_proce...
byKhalid Nawaz
 
PPTX
Flash distallation by khalid
byKhalid Nawaz
 
DOC
Npsh
byKhalid Nawaz
 
DOC
Dynamic pressure
byKhalid Nawaz
 
DOC
Bernoulli equation
byKhalid Nawaz
 
PPTX
Khalid Nawaz
byKhalid Nawaz
 
DOCX
Test your knowedge in chemical engineering by khalid nawaz
byKhalid Nawaz
 
PPTX
Boilers
byKhalid Nawaz
 
PPTX
flow meters
byKhalid Nawaz
 
PPTX
prilling tower and granulation
byKhalid Nawaz
 
PPTX
Drying and dryers
byKhalid Nawaz
 
PPTX
Evaporators
byKhalid Nawaz
 
Distillation Column
byKhalid Nawaz
 
Wauquier, j. p._-_petroleum_refining_i_crude_oil_-_petroleum_products_-_proce...
byKhalid Nawaz
 
Flash distallation by khalid
byKhalid Nawaz
 
Npsh
byKhalid Nawaz
 
Dynamic pressure
byKhalid Nawaz
 
Bernoulli equation
byKhalid Nawaz
 
Khalid Nawaz
byKhalid Nawaz
 
Test your knowedge in chemical engineering by khalid nawaz
byKhalid Nawaz
 
Boilers
byKhalid Nawaz
 
flow meters
byKhalid Nawaz
 
prilling tower and granulation
byKhalid Nawaz
 
Drying and dryers
byKhalid Nawaz
 
Evaporators
byKhalid Nawaz
 

Recently uploaded

PPTX
Foundations for the Future: Auditing Digital Collections for Long-Term Preser...
byCONUL Conference
 
PPTX
LEARNING PART 1. SHILPA HOTAKAR PSYCHOLOGY NOTES pptx
bySHILPA HOTAKAR
 
PPTX
Bookish Bats: a unique sustainable delivery service in the Russell Library. A...
byCONUL Conference
 
PPTX
Spherocytosis_Heridetary Spherocytosis_ AIHA_Dr Dibyajyoti Prusty, MD.pptx
byDibyajyoti Prusty
 
PPTX
CHAPTER NO. 05 BIOLOGICAL SOURCE,CHEMICAL CONSTITUENTS AND THERAPEUTIC EFFICA...
byGanu Gavade
 
PPTX
Cardiovascular System or The Details of Heart.pptx
byAshish Umale
 
PPTX
Shaping Tomorrow: The Next Chapter for Irish Research Libraries
byCONUL Conference
 
PDF
Road Safety Calendar-2026 Courtesy - IYSO Team India - Safer Indian Roads
byIndian Youth Secured Organisation
 
PPTX
To Stand in Another’s Shoes: Using Archives, History and Performance to Enhan...
byCONUL Conference
 
PPTX
Empowering Equality: The Athena Swan Journey at Maynooth University Library. ...
byCONUL Conference
 
PDF
The Scientific Research Lifecycle From Concept to Publication.pdf
byMuhammad Fahad Bashir
 
PDF
Behind the Studioz Report by LDMMIA 2026
by©LDMMIA, ©Reiki Yoga
 
PDF
Pharmaceutical Organic Chemistry Unit 5 Cycloalkanes
bySandeshSul
 
PPTX
Thriving in Uncertain Times: Building on the past, positioning for the future...
byCONUL Conference
 
PPTX
Society mirrored in libraries – the naming, denaming and renaming of the Libr...
byCONUL Conference
 
PPTX
CHAPTER 4. Size Reduction, Size Separation, Mixing, Filtration, Drying, Extra...
bySharibJamal
 
PDF
BÀI TẬP TEST BỔ TRỢ THEO TỪNG CHỦ ĐỀ CỦA TỪNG UNIT KÈM BÀI TẬP NGHE - TIẾNG A...
byNguyen Thanh Tu Collection
 
PPTX
Digital Equity and inclusivity: Librarians connecting the unconnected rural ...
byCONUL Conference
 
PDF
How to Report Cyber Fraud in India: Your Digital First Aid Kit (2025 Guide)
bySanjay Rathod
 
PPTX
Growing the Imirce Collection through Public Participation. Caitríona Cannon...
byCONUL Conference
 
Foundations for the Future: Auditing Digital Collections for Long-Term Preser...
byCONUL Conference
 
LEARNING PART 1. SHILPA HOTAKAR PSYCHOLOGY NOTES pptx
bySHILPA HOTAKAR
 
Bookish Bats: a unique sustainable delivery service in the Russell Library. A...
byCONUL Conference
 
Spherocytosis_Heridetary Spherocytosis_ AIHA_Dr Dibyajyoti Prusty, MD.pptx
byDibyajyoti Prusty
 
CHAPTER NO. 05 BIOLOGICAL SOURCE,CHEMICAL CONSTITUENTS AND THERAPEUTIC EFFICA...
byGanu Gavade
 
Cardiovascular System or The Details of Heart.pptx
byAshish Umale
 
Shaping Tomorrow: The Next Chapter for Irish Research Libraries
byCONUL Conference
 
Road Safety Calendar-2026 Courtesy - IYSO Team India - Safer Indian Roads
byIndian Youth Secured Organisation
 
To Stand in Another’s Shoes: Using Archives, History and Performance to Enhan...
byCONUL Conference
 
Empowering Equality: The Athena Swan Journey at Maynooth University Library. ...
byCONUL Conference
 
The Scientific Research Lifecycle From Concept to Publication.pdf
byMuhammad Fahad Bashir
 
Behind the Studioz Report by LDMMIA 2026
by©LDMMIA, ©Reiki Yoga
 
Pharmaceutical Organic Chemistry Unit 5 Cycloalkanes
bySandeshSul
 
Thriving in Uncertain Times: Building on the past, positioning for the future...
byCONUL Conference
 
Society mirrored in libraries – the naming, denaming and renaming of the Libr...
byCONUL Conference
 
CHAPTER 4. Size Reduction, Size Separation, Mixing, Filtration, Drying, Extra...
bySharibJamal
 
BÀI TẬP TEST BỔ TRỢ THEO TỪNG CHỦ ĐỀ CỦA TỪNG UNIT KÈM BÀI TẬP NGHE - TIẾNG A...
byNguyen Thanh Tu Collection
 
Digital Equity and inclusivity: Librarians connecting the unconnected rural ...
byCONUL Conference
 
How to Report Cyber Fraud in India: Your Digital First Aid Kit (2025 Guide)
bySanjay Rathod
 
Growing the Imirce Collection through Public Participation. Caitríona Cannon...
byCONUL Conference
 

cooling towers

  • 2.
    Khalid nawaz cell no:(0300-7024407) institute of chemical engineering and technology Lahore Pakistan
  • 4.
    The cooling toweris one of the most important device in chemical industries for example when the hot water come from heat exchanger we use the cooling tower to cool it. The purpose of cooling tower is to cool relatively warm water by contacting with unsaturated air. The evaporation of water mainly provides cooling. In a typical water cooling water tower, warm water flows countercurrent to an air stream. Typically, the warm water enters the top of packed tower and cascades down through the packing, leaving at the bottom.
  • 5.
    Air enters atthe bottom of the tower and flows upward through the descending water. The tower packing often consists of slats of plastic or of packed bed. The water is distributed by troughs and overflows to cascade over slat gratings or packing that provides large interfacial areas of contact between the water and air in the form of droplets and films of water. The flow of air upward through the tower can be induced by the buoyancy of the warm air in the tower (natural draft) or by the action of a fan. The water cannot be cooled below the wet bulb temperature. The driving force for the evaporation of the water is approximately the vapor pressure of the water less the vapor pressure it would have at the wet bulb temperature.
  • 6.
    What Does ACooling Tower Do?  Cooling Towers are used to transfer heat from cooling water to the atmosphere. – Promotes efficient water usage – Prevents environmental damage
  • 7.
    Where cooling towerused Used in power stations, oil refineries, petrochemical plants and natural gas plants. Cooling water is continuously circulated through heat exchangers to absorb heat from process material and machinery. Because it's cost efficient to reuse water and plants can't dump excessive amounts of hot water into rivers and lakes, cooling towers are used to remove the heat from the water, so it can be recirculated.
  • 8.
  • 9.
    Parts Of CoolingTower  Frame and casing. Most towers have structural frames that support the exterior enclosures (casings), motors, fans, and other components. With some smaller designs, such as some glass fiber units, the casing may essentially be the frame.  Fill. Most towers employ fills (made of plastic or wood) to facilitate heat transfer by maximizing water and air contact. There are two types of fill:  Splash fill: water falls over successive layers of horizontal splash bars, continuously breaking into smaller droplets, while also wetting the fill surface. Plastic splash fills promote better heat transfer than wood splash fills.  Film fill: consists of thin, closely spaced plastic surfaces over which the water spreads, forming a thin film in contact with the air. These surfaces may be flat, corrugated, honeycombed, or other patterns. The film type of fill is the more efficient and provides same heat transfer in a smaller volume than the splash fill.  Cold-water basin. The cold-water basin is located at or near the bottom of the tower, and it receives the cooled water that flows down through the tower and fill. The basin usually has a sump or low point for the cold-water discharge connection. In many tower designs, the cold-water basin is beneath the entire fill. In some forced draft counter flow design, however, the water at the bottom of the fill is channeled to a perimeter trough that functions as the cold-water basin. Propeller fans are mounted beneath the fill to blow the air up through the tower. With this design, the tower is mounted on legs, providing easy access to the fans and their motors.
  • 10.
    Fill: Most towers employfills (made of plastic or wood) to facilitate heat transfer by maximizing water and air contact. Fill can either be splash or film type. With splash fill, water falls over successive layers of horizontal splash bars, continuously breaking into smaller droplets, while also wetting the fill surface. Plastic splash fill promotes better heat transfer than the wood splash fill. Film fill consists of thin, closely spaced plastic surfaces over which the water spreads, forming a thin film in contact with the air. These surfaces may be flat, corrugated, honeycombed, or other patterns. The film type of fill is the more efficient and provides same heat transfer in a smaller volume than the splash fill.
  • 11.
     Drift eliminators.These capture water droplets entrapped in the air stream that otherwise would be lost to the atmosphere.  Air inlet. This is the point of entry for the air entering a tower. The inlet may take up an entire side of a tower (cross-flow design) or be located low on the side or the bottom of the tower (counter-flow design).  Louvers. Generally, cross-flow towers have inlet louvers. The purpose of louvers is to equalize air flow into the fill and retain the water within the tower. Many counter flow tower designs do not require louvers.  Nozzles. These spray water to wet the fill. Uniform water distribution at the top of the fill is essential to achieve proper wetting of the entire fill surface. Nozzles can either be fixed and spray in a round or square patterns, or they can be part of a rotating assembly as found in some circular cross-section towers.  Fans. Both axial (propeller type) and centrifugal fans are used in towers. Generally, propeller fans are used in induced draft towers and both propeller and centrifugal fans are found in forced draft towers. Depending upon their size, the type of propeller fans used is either fixed or variable pitch. A fan with non-automatic adjustable pitch blades can be used over a wide kW range because the fan can be adjusted to deliver the desired air flow at the lowest power consumption. Automatic variable pitch blades can vary air flow in response to changing load conditions.
  • 12.
    Cooling tower material Wood--- frame, casing, louvers, fill, and cold water basin (or concrete)  Galvanised steel, various grades of stainless steel, glass fibre and concrete, aluminium and various types of plastics for some components  Large towers are made of CONCRETE  Plastics are widely used for FILL, including PVC, polypropylene and other polymers  Plastics also find wide use in nozzle materials
  • 13.
    Cooling Tower Types  Cooling towers fall into two main categories:Natural draft and Mechanical draft. Mechanical draft towers are available in the following airflow arrangements:  1. 2. 3. Counter flows induced draft. Counter flow forced draft. Cross flow induced draft.
  • 14.
    Cross flow Cross flowis a design in which the air flow is directed perpendicular to the water flow (see diagram below). Air flow enters one or more vertical faces of the cooling tower to meet the fill material. Water flows (perpendicular to the air) through the fill by gravity.
  • 15.
    Counter flow In acounter flow design the air flow is directly opposite of the water flow (see diagram below). Air flow first enters an open area beneath the fill media and is then drawn up vertically. The water is sprayed through pressurized nozzles and flows downward through the fill, opposite to the air flow.
  • 16.
    Natural draft, whichutilizes buoyancy via a tall chimney. Warm, moist air naturally rises due to the density differential to the dry, cooler outside air. Warm moist air is less dense than drier air at the same temperature and pressure. This moist air buoyancy produces a current of air through the tower. This photo shows a single natural draft cooling tower as used at a European plant. Natural draft towers are typically about 400 ft (120 m) high, depending on the differential pressure between the cold outside air and the hot humid air on the inside of the tower as the driving force. No fans are used.
  • 17.
    • The naturaldraft or hyperbolic cooling tower makes use of the difference in temperature between the ambient air and the hotter air inside the tower. It works as follows: • Hot air moves upwards through the tower (because hot air rises) • Fresh cool air is drawn into the tower through an air inlet at the bottom. • Due to the layout of the tower, no fan is required and there is almost no circulation of hot air that could affect the performance. Concrete is used for the tower shell with a height of up to 200 m. These cooling towers are mostly only for large heat duties because large concrete structures are expensive.
  • 20.
    • Air drawnup of Cooling Towers through falling water • Fill located Natural Draft Cooling Towers tower inside • Air drawn across Types falling water • Fill located outside tower Cross flow (Gulf Coast Chemical Commercial Inc.) Counter flow 20 © UNEP 2006
  • 21.
    Types of naturaldraft cooling tower  There are two main types of natural draft towers: • Cross flow tower (left figure): air is drawn across the falling water and the fill is located outside the tower • Counter flow tower (right figure): air is drawn up through the falling water and the fill is therefore located inside the tower, although design depends on specific site conditions
  • 22.
    Types of CoolingTowers Mechanical Draft Cooling Towers • Large fans to force air through circulated water • Water falls over fill surfaces: maximum heat transfer • Cooling rates depend on many parameters • Large range of capacities • Can be grouped, e.g. 8-cell tower 22 © UNEP 2006
  • 23.
    • Mechanical drafttowers have large fans to force or draw air through circulated water. The water falls downwards over fill surfaces, which help increase the contact time between the water and the air - this helps maximize heat transfer between the two. • Cooling rates of mechanical draft towers depend upon various parameters such as fan diameter and speed of operation, fills for system resistance etc. • Mechanical draft towers are available in a large range of capacities. Towers can be either factory built or field erected – for example concrete towers are only field erected. • Many towers are constructed so that they can be grouped together to achieve the desired capacity. Thus, many cooling towers are assemblies of two or more individual cooling towers or “cells.” The number of cells they have, e.g., a eightcell tower, often refers to such towers.
  • 24.
    Types of CoolingTowers Forced Draft Cooling Towers • • Advantages: suited for high air resistance & fans are relatively quiet • (GEO4VA) Air blown through tower by centrifugal fan at air inlet Disadvantages: recirculation due to high air-entry and low air-exit velocities 24 © UNEP 2006
  • 25.
    A mechanical drafttower with a blower type fan at the intake. The fan forces air into the tower, creating high entering and low exiting air velocities. The low exiting velocity is much more susceptible to recirculation. With the fan on the air intake, the fan is more susceptible to complications due to freezing conditions. Another disadvantage is that a forced draft design typically requires more motor horsepower than an equivalent induced draft design. The forced draft benefit is its ability to work with high static pressure. They can be installed in more confined spaces and even in some indoor situations. This fan/fill geometry is also known as blow-through.
  • 26.
     Forced draftcooling tower • How it works: air is blown through the tower by a fan located in the air inlet • Advantages: • Suited for high air resistance due to centrifugal blower fans • Fans are relatively quiet • Disadvantages: Recirculation due to high air-entry and low air-exit velocities, which can be solved by locating towers in plant rooms combined with discharge ducts
  • 28.
    Types of CoolingTowers Induced Draft Cooling Towers • Two types • Cross flow • Counter flow • Advantage: less recirculation than forced draft towers • Disadvantage: fans and motor drive mechanism require weather-proofinh 28 © UNEP 2006
  • 29.
    • Two typesof induced draft cooling towers: cross flow and counter flow • Advantage: Less recirculation than forced draft towers because the speed of exit air is 3-4 times higher than entering air • Disadvantage: Fans and the motor drive mechanism require weather-proofing against moisture and corrosion because they are in the path of humid exit air
  • 30.
    Types of CoolingTowers Induced Draft Counter Flow CT • Hot water enters at the top • Air enters at bottom and exits at top • Uses forced and induced draft fans (GEO4VA) 30 © UNEP 2006
  • 31.
    Types of CoolingTowers Induced Draft Cross Flow CT • Water enters top and passes over fill • Air enters on one side or opposite sides • Induced draft fan draws air across fill (GEO4VA) 31 © UNEP 2006
  • 32.
    Air/water systems Dry-bulb andwet-bulb temperature wet cloth/wick Air flow Dry bulb temperature: the ordinary temperature you measure with e thermometer Evaporation requires energy. The wick and therefore the thermometer bulb decreases in temperature below the dry-bulb temperature until the rate of heat transfer from the warmer air to the wick is just equal to the rate of heat transfer needed to provide for the evaporation of water from the wick into the air stream. The temperature reached is called the wet-bulb temperature
  • 33.
  • 34.
    Performance  These measuredparameters and then used to determine the cooling tower performance in several ways. These are: 1. Range 2. Approach 3. Effectiveness 4. Cooling capacity 5. Evaporation loss 6. Cycles of concentration 7. Blow down losses 8. Liquid / Gas ratio  We will now go through each of these parameters on the next slides
  • 35.
    Assessment of CoolingTowers 1. Range Hot Water Temperature (In) Range Difference between cooling water inlet and outlet temperature: Range (°C) = CW inlet temp – CW outlet temp (In) to the Tower (Out) from the Tower High range = good performance Approach Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) 35 © UNEP 2006
  • 36.
    • The rangeis the difference between the cooling tower water inlet and outlet temperature. • The formula for cooling tower range in degrees Celcius is cooling water inlet temperature minus cooling water outlet temperature • A high CT Range means that the cooling tower has been able to reduce the water temperature effectively, and is thus performing well.
  • 37.
    Assessment of CoolingTowers 2. Approach Approach (°C) = CW outlet temp – Wet bulb temp Low approach = good performance Range Hot Water Temperature (In) Approach Difference between cooling tower outlet cold water temperature and ambient wet bulb temperature: (In) to the Tower (Out) from the Tower Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) 37 © UNEP 2006
  • 38.
    • Approach isthe difference between the cooling tower outlet cold-water temperature and ambient wet bulb temperature. • The formula for approach is CT Approach in degrees Celcius is cold water outlet temperature minus the wet bulb temperature • The lower the approach the better the cooling tower performance. Although, both range and approach should be monitored, the `Approach’ is a better indicator of cooling tower performance.
  • 39.
    Assessment of CoolingTowers 3. Effectiveness Hot Water Temperature (In) = Range / (Range + Approach) Range Effectiveness in % High effectiveness = good performance Approach = 100 x (CW temp – CW out temp) / (CW in temp – Wet bulb temp) (In) to the Tower (Out) from the Tower Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) 39 © UNEP 2006
  • 40.
    • Cooling towereffectiveness is the ratio between the range and the ideal range (in percentage), i.e. difference between cooling water inlet temperature and ambient wet bulb temperature • Effectiveness = Range / (Range + Approach) • The formula for cooling tower effectiveness is: CT Effectiveness (%) = 100 x (CW temp – CW out temp) / (CW in temp – WB temp) • The higher this ratio, the higher the cooling tower effectiveness.
  • 41.
    Assessment of CoolingTowers 4. Cooling Capacity = mass flow rate of water X specific heat X temperature difference High cooling capacity = good performance Approach Heat rejected in kCal/hr or tons of refrigeration (TR) Range Hot Water Temperature (In) (In) to the Tower (Out) from the Tower Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) 41 © UNEP 2006
  • 42.
    Assessment of CoolingTowers 5. Evaporation Loss Hot Water Temperature (In) = 0.00085 x 1.8 x circulation rate (m3/hr) x (T1-T2) Approach = theoretically, 1.8 m3 for every 10,000,000 kCal heat rejected Range Water quantity (m3/hr) evaporated for cooling duty (In) to the Tower (Out) from the Tower Cold Water Temperature (Out) Wet Bulb Temperature (Ambient) T1-T2 = Temp. difference between inlet and outlet water 42 © UNEP 2006
  • 43.
     The mainareas for improving the energy efficiency of cooling towers are: 1. Selecting the right cooling tower (because the structural aspects of the cooling tower cannot be changed after it is installed) 2. Fills 3. Pumps and water distribution system 4.Fans and motors  We will go through these one by one on the next slides.
  • 44.
    • Once acooling tower is in place it is very difficult to significantly improve its energy performance. A number of factors are of influence on the cooling tower’s performance and should be considered when choosing a cooling tower: capacity, range, approach, heat load, wet bulb temperature, and the relationship between these factors. We will start with capacity. • Capacity, in terms of heat dissipation (in kCal/hour) and circulated flow rate (m3/hr), are an indication of the capacity of cooling towers. However, these design parameters are not sufficient to understand the cooling tower performance. • For example, a cooling tower sized to cool 4540 m3/hr through a 13.9 0C range might be larger than a cooling tower to cool 4540 m3/hr through 19.5 0C range. Therefore other design parameters are also needed.
  • 45.
    Factors affecting Coolingtower performance Wet Bulb Temperature  WBT of air entering the cooling tower determines operating temperature levels throughout the plant, process or system.  Recirculation raises the effective WBT of the air entering the tower with corresponding increase in cold water temperature.
  • 46.
      • • • • • Wet bulb temperatureis an important factor in performance of evaporative water cooling equipment, because it is the lowest temperature to which water can be cooled. For this reason, the wet bulb temperature of the air entering the cooling tower determines the minimum operating temperature level throughout the plant, process, or system. The following should be considered when pre-selecting a cooling tower based on the wet bulb temperature: Theoretically, a cooling tower will cool water to the entering wet bulb temperature. In practice, however, water is cooled to a temperature higher than the wet bulb temperature because heat needs to be rejected from the cooling tower. A pre-selection of towers based on the design wet bulb temperature must consider conditions at the tower site. The design wet bulb temperature also should not be exceeded for more than 5 percent of the time. In general, the design temperature selected is close to the average maximum wet bulb temperature in summer. Confirm whether the wet bulb temperature is specified as ambient (the temperature in the cooling tower area) or inlet (the temperature of the air entering the tower, which is often affected by discharge vapors recirculated into the tower). As the impact of recirculation cannot be known in advance, the ambient wet bulb temperature is preferred. Confirm with the supplier if the cooling tower is able to deal with the effects of increased wet bulb temperatures. The cold-water temperature must be low enough to exchange heat or to condense vapors at the optimum temperature level. The quantity and temperature of heat exchanged can be considered when choosing the right size cooling tower and heat exchangers at the lowest costs. .
  • 47.
    Factors affecting Coolingtower performance Fill Media Effects  Function: Heat exchange between air and water is influenced by surface area of heat exchange, time of heat exchange and turbulence in water effecting thoroughness of intermixing.  Due to fewer requirements of air and pumping head, there is a tremendous saving in power with the intervention of film fill.  Recently, low clog film fills with higher flute sizes have been developed to handle high turbid waters. (sea water)
  • 48.
    Facts  The flowrate through a cooling tower in a typical 700 MW power plant is about 315,000 gal/min.  Cooling towers have 95% efficiency, losing only 5% of circulating water to evaporation.  Power consumption is minimal due to few moving parts.  Cooling towers save plants thousands to millions of dollars per year in water consumption and recycling costs.
  • 49.
    Energy Saving Opportunitiesin Cooling Towers Follow manufacturer’s recommended clearances around cooling towers and relocate or modify structures that interfere with the air intake or exhaust. Optimise cooling tower fan blade angle on a seasonal and/or load basis. Correct excessive and/or uneven fan blade tip clearance and poor fan balance. On old counter-flow cooling towers, replace old spray type nozzles with new square spray ABS practically non-clogging nozzles. Replace splash bars with self-extinguishing PVC cellular film fill. Install new nozzles to obtain a more uniform water pattern Periodically clean plugged cooling tower distribution nozzles. Balance flow to cooling tower hot water basins. Cover hot water basins to minimise algae growth that contributes to fouling. Optimise blow down flow rate, as per COC limit. Replace slat type drift eliminators with low pressure drop, self extinguishing, PVC cellular units. Restrict flows through large loads to design values.