Question of the Day: Maximizing Cooling Tower Cycles

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Question of the Day: Maximizing Cooling Tower Cycles
How can cooling tower cycles of concentration be maximized, and what should be considered in choosing maximum cycles?

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6 Answers

  1. The maximum cycles of concentration will be dependent on the makeup water quality, the risks to the process from corrosion and fouling by the concentrated cooling water, and the costs of treatment (chemical and mechanical, such as periodic cleaning or repair of corroded components) to manage these risks. Since the quality of the makeup water may vary, particularly from river sources, the maximum cycles may vary and the control may be based on chemistry parameters such as conductivity or a parameter based on avoiding precipitation (eg. Langelier Saturation Index for Calcium Carbonate scale). Some margin should be provided to protect against short-term upsets such as the loss of chemical feed, to prevent precipitation of the time period required to detect and correct the upset.

  2. There are many methods to maximize the cycle of concentration such as improving the feedwater and using chemical additives. and there are many limitations for cycle of concentration such as chloride or sulfate concentration(which can cause corrosion), or total hardness and silica concentration which can cause scale

  3. In most reduced water areas, the water authority may set the minimum cycles. At the same time the Air Quality board, may set the maximum TDS in the circulating water. In these cases an agency creates the bumpers in your road, you are then expected to find ways to comply.

    2 Comments

    1. The fun part is convincing the authorities that PM10 is not violated when going with blow-down closed 40-100 cycles of concentration on soft (really soft) water, with silicate from raw water as the primary and only corrosion inhibitor needed (

    2. If you do have these bumps, especially on the high side, shoot me an email at Larson.mike@appliedspecialties.com.  I have tested an alternative disinfection product that increases cycles by as much as 50%.

  4. As James Stewart mentioned, you must start with your source water, this is what will allow you to calculate your maximum admissible cycles. In addition to what has been said, be aware that biological fouling is highly impacted by concentration cycles, so keep that in mind when performing your calculation.

  5. You do  not maximize cooling water cycles of concentration by starting with the blow-down valve and working backward on treatment or pretreatment.  One begins with the source water, and consider what must be done to render the water benign corrosion tendency  toward metal, and stable in regard to forming scale.  You may consider such things as "chemical sinks", essentially high pH zones where a cathodic electrode increases local pH enough to precipitate group II metals, calcium and magnesium as carbonates, and/or silicates.  You may consider high efficiency softening of the water then close the blow-down so the silicate residual climbs to 100-200 ppm, protects the steel with a nano-atomic layer of silica, SiO2, possibly the best corrosion inhibitor ever designed for steel.

    You may consider not doing much to pretreat the water, and pay for it heavily in high tech polymers and corrosion inhibitors, but only after running software projections (or have it done by professionals), where the scale forming tendencies are predicted ahead of time, thereby creating a best operational window.

    You may consider losing heat transfer, in which case, the company will or should fire you, and will be out untold quantities of capital cleaning or replacing damaged equipment.

  6. Our unique IVG-CT solution enables to increase COC up to 12, reducing water usage by 50% as well as totally eliminating all chemical usage. This water can be further used ass grey water for irrigation, further enhancing savings. More info on alain.mestat@h2ovortex.com