A Cooling tower is the type of heat exchanger in which water and air are brought into contact naturally or forcefully depending upon the type of cooling tower you are using. The warm water comes in contact with cooled air and this heat is transferred to the air which flows outside of the cooling tower while the cold water remains in the basin of the cooling tower. A heat transfer phenomenon is taking place in the area where packing is installed. A small volume of water is evaporated while the remaining water is collected in the basin.
Why Cooling towers are installed in industries?
They are installed mainly for the following purposes:
- To remove heat from various machines and industrial processes
- Improve overall efficiency of the process
- Provide a cost-effective method to remove heat from the water
- Protects equipment from overheating as heat is dissipated
Cooling water systems are divided into two parts:
- Primary Cooling water system
- Secondary Cooling water system
Primary Cooling Water System:
Primary Cooling water systems have two types.
(a) Once through type:
The source of Once through type may be a canal, river, or sea. The Water from these sources will be passed through an Exchanger where water has to be cooled. After cooling this water will be sent to the back source. No Special treatment is required only sodium hypo chloride is added to kill and stop the growth of pathogens like bacteria, algae, etc.
(b) Open Recirculating
This method of cooling water will be used where fresh and cold water is short. The water passing through a heat exchanger for cooling will pass through a cooling tower where it will be cooled by evaporation. Here water will be lost due to evaporation. Overall there will be three types of losses.
- Drift or windage loss
- Evaporation loss
- Blowdown loss
Secondary Cooling Water System
A secondary Cooling water system is also called a closed cooling water system. The closed Cooling water is used for several purposes in the industry especially Powerplants like the cooling of generators, Lube Oil Cooling, and Pump cooling.
This Close Cooling water will be cooled by Auxiliary Cooling water which will be primary cooling water. The take is taken in an expansion tank and will used as closed cooling water. This closed-cooling water will used again and again. Make water will be added due loss of CCW water. A corrosion inhibitor will be added.
Important Terms related to Cooling Tower:
Cooling Range:
Cooling range is the difference between temperature of hot water entering and Temperature of cold water leaving.
Approach:
Difference between the temperature of Cold water leaving and Wet Bulb Temperature.
Pumping Head
The minimum head needed to lift water from basin to top of the tower and force it into distribution system.
Application
Types of Cooling Tower:
Natural draft cooling a Tower
In natural draft cooling tower, the air and water come in contact naturally. No external medium is required for their interconnection. Water comes from upward and air comes in contact naturally. Cooled water moves towards the basin while some of the water is evaporated.
- It has lower operating costs since no fan so there is no use of electricity usage
- It requires less maintenance cost.
- Strong draft when cold airflow
- High air flow
- Good thermal performance
- No power consumption to induce airflow
Mechanical draft Cooling Tower:
In a mechanical draft cooling tower air and water come in contact by mechanical means like Fan will be used.
• The air flow is induced by fans located at the air outlet (Induced draft) or at the air inlet (Forced draft).
• The air flow is almost constant regardless ambient air temperatures.
• Need mechanical equipment: fans, gearboxes, transmissions (shaft), motors Power consumption
Types of Mechanical Cooling Tower:
- Forced Draft Cooling Tower
- Induced Draft Cooling Tower
Forced Draft Cooling Tower
- Air is blown through tower by a centrifugal fan at air inlet
- Best suited for high air resistance
- Recirculation due to high air-entry and low air-exit velocities
Induced draft cooling tower
- Hot water enters at the top
- Air enters at the bottom and exits at top
Counter Flow & Cross Flow
Our Power plant has an Induced Draft counter Flow type Cooling tower.
Cooling Tower Technical Data
| Manufacturer | Hamon Korea |
| Type | Induced draft counter flow |
| No. of Cell | 6 (5 working, 1 standby) |
| No. of fan per cell | 1 |
| Size of cell | 14m x14m |
| Tower Dimensions | 84.2m x 14.2m |
| Flow | 2500m3/hr (for 1 cell) |
| Hot water inlet temperature | 35.65°C |
| Cold water outlet temperature | 25.92°C |
| Delta ΔT | 9.73°C |
Components of Cooling Tower
Main components of the cooling tower are as follows:
- Structure
- Drift Eliminator
- Sprinkler
- Fills
- Fan
- Motor
- Gearbox
- Fan Stack
- Basin
The cooling tower have structural frame that supports the exterior enclosures (casings), motors, fans, and other components. The material of the structural frame and casing is FRP which has the following advantages:
- Light-weight for transportation and construction
- No severe limitations on profile length
- Bracing in one piece
- No limitation in the water quality (any pH)
- Fire protected
Drift Eliminator
The drift eliminator is a device that prevents the circulating water losses in the exhaust air.
Sprinkler
Through the sprinkler head, hot water will be uniformly distributed over the PVC fills. They are designed for maximum water sprinkling through the nozzle tip .
Fills
Fill is the main heat exchange media of the cooling tower which maximize water air contact
There are two types of fill:
Film Fill Splash Fill
Fan
The fan is a device used to induce airflow through the cooling tower. In an induced draft cooling tower, the fan is located at the top of the tower in the exhaust air.
Fan Specs:
| Manufacturer | COFIMCO/ITLAY |
| Fan Speed | 129.7 rpm |
| No. of Blade | 6 |
| Blade Angel | 11.5° |
| Blade Material | FRP |
| Air Delivery | 442.6m/sec |
| Diameter | 7.925m |
Motor
The motor is a driving element which gives mechanical power to the gear – fan.
Gear Box
A gearbox is an enclosed system of assembled gears that transmits mechanical energy from a prime mover to an output device. A gearbox can also change the speed and direction.
Gear Box Specs;
| Manufacturer | SUMITOMO/JAPAN |
| No. of Reduction | 2 |
| Reduction Ratio | 11.375 (1470/129.25) |
| Type | Spiral Bevel |
| Lube Oil | OMALA 320 |
Fan Stack
A fan stack is a closed enclosure in which the fan rotates. Fan Stack is an integral part of the cooling tower. The height of fan stack plays an important role in cooling tower’s efficiency.
- Material of fan Stack: FRP
- Height of Fan Stack: 2.2 m
Basin
The cold-water basin is located at the bottom of the tower, and it receives the cooled water that flows down through the tower and fill.
Basin dimension(m): 84.6 x 17
Material of basin: RCC
Chemical dosing is done in cooling tower basin for following purposes:
- Sulphuric Acid: To maintain pH
- Sodium Hypochlorite Solution: To stop Biological growth
- Scale & Corrosion Inhibitor: To prevent Scaling & Corrosion
Important Terms Related to Cooling Tower:
Range
The difference between the temperature of Hot water entering the Cooling Tower and Cooled water leaving the cooling tower.
Range = Temperature of Hot water Entering – Temperature of Cold Water Leaving
Bonus
Download the API of Cooling tower for free from here .
58 Comments
Your comment is awaiting moderation.
Hi there! Quick question that’s entirely off topic. Do you know how to make your site mobile friendly? My web site looks weird when browsing from my iphone 4. I’m trying to find a theme or plugin that might be able to fix this problem. If you have any recommendations, please share. With thanks!
Your comment is awaiting moderation.
Write more, thats all I have to say. Literally, it seems as though you relied on the video to make your point. You definitely know what youre talking about, why throw away your intelligence on just posting videos to your blog when you could be giving us something enlightening to read?
Your comment is awaiting moderation.
Hello i am kavin, its my first occasion to commenting anyplace, when i read this paragraph i thought i could also make comment due to this brilliant paragraph.
Your comment is awaiting moderation.
Wonderful beat ! I wish to apprentice while you amend your website, how can i subscribe for a blog website? The account aided me a acceptable deal. I had been tiny bit acquainted of this your broadcast provided bright clear concept
Your comment is awaiting moderation.
Hi there! I could have sworn I’ve been to this blog before but after browsing through many of the articles I realized it’s new to me. Anyhow, I’m definitely delighted I came across it and I’ll be book-marking it and checking back regularly!
Your comment is awaiting moderation.
Hmm it looks like your blog ate my first comment (it was super long) so I guess I’ll just sum it up what I submitted and say, I’m thoroughly enjoying your blog. I too am an aspiring blog blogger but I’m still new to everything. Do you have any suggestions for novice blog writers? I’d really appreciate it.
Your comment is awaiting moderation.
We are a group of volunteers and opening a new scheme in our community. Your web site offered us with valuable info to work on. You have done a formidable job and our whole community will be thankful to you.
Your comment is awaiting moderation.
I was wondering if you ever considered changing the layout of your blog? Its very well written; I love what youve got to say. But maybe you could a little more in the way of content so people could connect with it better. Youve got an awful lot of text for only having one or two images. Maybe you could space it out better?
Your comment is awaiting moderation.
Everything is very open with a very clear clarification of the issues. It was really informative. Your site is very useful. Many thanks for sharing!
Your comment is awaiting moderation.
Greetings! Very useful advice in this particular article! It is the little changes which will make the largest changes. Thanks for sharing!
Your comment is awaiting moderation.
Pretty nice post. I simply stumbled upon your blog and wanted to mention that I’ve truly loved surfing around your weblog posts. After all I will be subscribing for your feed and I’m hoping you write again soon!
Your comment is awaiting moderation.
Pretty section of content. I just stumbled upon your blog and in accession capital to assert that I get in fact enjoyed account your blog posts. Anyway I’ll be subscribing to your augment and even I achievement you access consistently rapidly.
Your comment is awaiting moderation.
Howdy! Do you know if they make any plugins to safeguard against hackers? I’m kinda paranoid about losing everything I’ve worked hard on. Any suggestions?
Your comment is awaiting moderation.
What i do not realize is in truth how you’re now not actually a lot more smartly-preferred than you might be now. You are so intelligent. You realize thus significantly with regards to this subject, produced me individually believe it from a lot of various angles. Its like women and men don’t seem to be involved except it’s one thing to do with Lady gaga! Your individual stuffs outstanding. All the time maintain it up!
Your comment is awaiting moderation.
Hey I know this is off topic but I was wondering if you knew of any widgets I could add to my blog that automatically tweet my newest twitter updates. I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this. Please let me know if you run into anything. I truly enjoy reading your blog and I look forward to your new updates.
Your comment is awaiting moderation.
Yesterday, while I was at work, my cousin stole my iphone and tested to see if it can survive a twenty five foot drop, just so she can be a youtube sensation. My apple ipad is now broken and she has 83 views. I know this is totally off topic but I had to share it with someone!
Your comment is awaiting moderation.
You actually make it seem so easy with your presentation but I in finding this topic to be actually one thing that I feel I’d by no means understand. It seems too complicated and very vast for me. I’m having a look ahead to your subsequent publish, I’ll attempt to get the grasp of it!
Your comment is awaiting moderation.
What’s up it’s me, I am also visiting this web page regularly, this site is in fact good and the people are in fact sharing pleasant thoughts.
Your comment is awaiting moderation.
Your article helped me a lot, is there any more related content? Thanks!
Your comment is awaiting moderation.
Hmm it looks like your site ate my first comment (it was super long) so I guess I’ll just sum it up what I had written and say, I’m thoroughly enjoying your blog. I as well am an aspiring blog writer but I’m still new to everything. Do you have any helpful hints for rookie blog writers? I’d really appreciate it.
Your comment is awaiting moderation.
I don’t think the title of your article matches the content lol. Just kidding, mainly because I had some doubts after reading the article.
Your comment is awaiting moderation.
Hey there! Quick question that’s entirely off topic. Do you know how to make your site mobile friendly? My site looks weird when browsing from my iphone. I’m trying to find a template or plugin that might be able to fix this issue. If you have any suggestions, please share. Cheers!
Your comment is awaiting moderation.
My brother recommended I might like this blog. He was totally right. This put up actually made my day. You cann’t believe simply how so much time I had spent for this info! Thank you!
Your comment is awaiting moderation.
Asking questions are really pleasant thing if you are not understanding something completely, but this paragraph provides fastidious understanding even.
Your comment is awaiting moderation.
Have you ever thought about creating an ebook or guest authoring on other websites? I have a blog based on the same subjects you discuss and would love to have you share some stories/information. I know my readers would enjoy your work. If you’re even remotely interested, feel free to shoot me an email.
Your comment is awaiting moderation.
My spouse and I stumbled over here by a different website and thought I may as well check things out. I like what I see so now i am following you. Look forward to looking into your web page repeatedly.
Your comment is awaiting moderation.
An outstanding share! I have just forwarded this onto a co-worker who had been doing a little research on this. And he in fact ordered me lunch because I found it for him… lol. So let me reword this…. Thank YOU for the meal!! But yeah, thanx for spending the time to talk about this topic here on your blog.
Your comment is awaiting moderation.
Thanks for a marvelous posting! I seriously enjoyed reading it, you are a great author.I will make certain to bookmark your blog and will eventually come back sometime soon. I want to encourage one to continue your great job, have a nice morning!
Your comment is awaiting moderation.
bookmarked!!, I like your site!
Your comment is awaiting moderation.
Usually I don’t read post on blogs, however I would like to say that this write-up very compelled me to try and do it! Your writing style has been amazed me. Thanks, very nice article.
Your comment is awaiting moderation.
It’s hard to find knowledgeable people about this topic, but you sound like you know what you’re talking about! Thanks
Your comment is awaiting moderation.
Hello to every one, it’s in fact a fastidious for me to pay a quick visit this site, it contains helpful Information.
Your comment is awaiting moderation.
You should take part in a contest for one of the finest websites on the net. I am going to recommend this site!
Your comment is awaiting moderation.
I’m really impressed with your writing skills as well as with the layout on your blog. Is this a paid theme or did you modify it yourself? Anyway keep up the excellent quality writing, it’s rare to see a nice blog like this one today.