Cooling Tower distribution piping pressure

[harvey13]

What is a recommended pressure in the distribution header of a packaged cooling tower with 6-8 cells? The flow is balanced at each cell by a manual butterfly valve. I've been told to use 30 psig, but that seems like a lot of pump HP to waste. Will there be problems if I design the header pressure to be 10 psig?

 

[Artisi]

A lot more information must be given regarding the installation before we can even guess at an answer.

 

[katmar]

The only sure way is to get the data from the original supplier of the tower.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[MJCronin]

Harvey....

My gut tells me you are probably right with the 10 psig.

Some residual pump pressure must be "wasted" in order for you to to be able to balance the flow between cells of the tower.

30 psig is probably too high, but I am guessing that 5-7 might be too low.

The pump curve should be studied at this point...

My opinion only

-MJC

 

[katmar]

I have worked on towers where the water gravitated from open launders with a head of around 10 ft (4.3psi), and the towers worked perfectly well. There is no single correct answer because there are a variety of nozzle types that can be used. Do not guess. Ask the supplier. There can be operational problems if the pressure is either too high or too low.



Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[nickelkid]

30 psig is typical cooling water pressure supplied to plant with process equipment. I would make sure the equipment and piping head losses are understood before making any change (and understand what you will gain). Also, I think you will find that a typical plant with heat exchangers, compressors, throttle valves, etc... will require a 30 psig cooling water supply. Take note, cooling water systems are not clean for very long.

 

[MJCronin]

OOOpps

Did I misunderstand...????

Are we talking about the Cooling tower water FROM the tower into the plant users or are we talking about the Cooling tower RETURN system ???

It was my understanding that we were talking about the pressure in the distribution header RETURNING to the tower..

_MJC

 

[Artisi]

See first response from myself - plus harvey has vanished so why are we ever concerned at this stage.

 

[harvey13]

Sorry about the "vanishing", but I was out of the office w/o internet connection. I was asking about the water distribution basins in the tower, but we can let this thread die.

Thanks for your help.

Harvey13

 

[IanFletcher]

Harvey13,

Assuming you have a cross flow cooling tower (open hot water basins up near the fan level) all you need to do is make sure you have a few inches (4-5") of water over the nozzles & make sure the hot water basins are completely flooded. The only head pressure you need is to 1. get the water to the basins and 2. Overcome the loss from the distribution valve. Everything else is wasted energy.