3 replies to this topic

[trainspotter124]

Hi all,

 

I'm currently working on some options surrounding an overfill case on a cooling towers sump. The current set-up takes make-up water to control the level in the cooling tower basin via a ball cock valve. There is an internal overflow which goes to drain in case the ballcock valve fails/tower overfills etc.

 

The particular case I'm looking into is where the cooling tower overfills from the return header draining down into the cooling tower when it is not required by the process. Because of the length of the return pipework, this ends up being quite a significant amount going over the overfill.

 

What are some possible options to prevent this occurring? Introduce a lute at the cooling tower to ensure the return header remains flooded? Introduce a separate sump?

 

I've attached a schematic which should help provide some context to the issue.

 

 

 

Thanks

Attached Files

•  CT Problem Sketch.pdf   21.72KB   18 downloads

Edited by trainspotter124, 06 June 2023 - 11:03 AM.

[snickster]

I would consider installing an automatic butterfly shut off valve on the return line close to the cooling tower that is interlocked with the pumps to close when the pumps shut down.

[breizh]

Hi,

You should have a concrete sump underneath the tower to collect the water, the capacity of the sum should be sufficient enough to drain all the water from the process. If not, you are going to lose the water and the chemicals for treatment.

 

You may want to collect the overflow in a separate sump to recover the product and recycle it (additional pump and piping).

In many countries it's forbidden to release /drain/blow down cooling water to the sewage system, environment concern.

 

note:  The type of cooling water you described is for small system, "cheap and very basic".

 

Breizh 

[shvet1]

Option 1

Sprinklers has too small hole to suck air in. If this is true than a worker would have enough time to close a return valve. Option depends on sprinklers, water level (max minus norm) and worker.

 

Option 2

Provide a leg higher than highest point of water piping system plus head and velocity losses in sprinklers and pipe segment downstream of a leg. Normally open vent will prevent piping from siphoning. Option depends in worst hydraulic scenario and hydrocarbons entrainment rate.

Attached Files

•  doc05914720230607092116.pdf   186.91KB   12 downloads

Edited by shvet1, 07 June 2023 - 01:04 AM.