Cooling Water Treatment Requirement 1

[hhmh2004]

I have a closed circuit cooling tower. In this tower water to be cooled comes, passes through the tubes, gets cooled and goes out.

These tubes are sprayed by water which is in continuous re circulation i-e water is sprayed on the tubes, gets collected in the basin, pumped again to the spray header and this goes on and on.

During this re circulation water gets evaporated and makeup water is added to the loop.

Recirculation Flow Rate is 3280 GPM and Makeup water based on 08 cycle of concentration is 85 GPM.

I have attached the makeup water analysis as well.

Kindly suggest if water treatment based on blowdown is enough or should i add some scale inhibitor as well.

Thanks

 

[bimr]

With 8 cycles of concentration, you will be dealing with a TDS of 40,000. That is a higher concentration of salts than sea water.

You will have an extremely corrosive water. Unless your system is constructed of plastics or the unattainable alloy, your system will rapidly corrode away.

This water supply (RO reject) is not acceptable for your use.

 

[hhmh2004]

Hi,

I have shifted the water makeup supply from RO Reject to Soft Water. Attached is the analysis of Soft Water. This water is high in concentration of Chlorides and TDS.

Chlorides = 1610 wppm

TDS = 4882 wppm

What will be the effect of this water on galvanized CS tubes? what is the appropriate cycle of concentration for this case?

Thanks..

 

[bimr]

To control scaling in cooling towers, the alkalinity is generally controlled to approximately 200 with the addition of acid.

Therefore, the alkalinity will limit the cycles of concentration.

Softened water absent of hardness tends to be corrosive as shown by a langelier calculation.

This water will be corrosive to galvanized cs tubes and the tubes will not have an acceptable service life.