Fluid Cooler Adiabatic cooling Vs Cooling Tower

The main technologies, diffused in industrial application, that use the ambient air for the cooling of process water are: the cooling towers and the Free Cooling systems (called also Fluid coolers or Dry coolers).

The cooling tower puts in direct contact the ambient air with the process water.

The process water is directly nebulised in a forced air flow; the cooling power is obtained by the evaporation of a certain quantity of the process water.

The main advantages of the cooling tower solution are:

• lower temperature of the process water (related to the ambient wet bulb temperature),
• lower floor space needed
• lower investment.

The main disadvantages of the cooling tower are:

• high quantity of impurities,
• high growth of alga and bacteria,
• formation of rust along the circuit
• high running costs.

The Fluid cooler “Free Cooler” permits the complete separation between the process water and the ambient.

The heat exchange happens through one finned coil battery made of copper and aluminium, crossed by an adequate air flow.

So the process water remains bounded into the circuit itself, with no contact with ambient: in this way it is possible to avoid all the faults due to this: high impurities content, high oxygenation of the water with consequent high formation of rust along the circuit, high proliferation of alga and bacteria, high evaporation or water loss with consequent increase of the hardness and necessity of continuous water refill, and so on.

Moreover the running costs of this kind of unit are surely lower.

The main disadvantages are: higher water temperature (related to the ambient dry bulb temperature), higher floor space needed and higher investment.

The higher cleanness, the lower maintenance requested and the lower running costs make the Free Cooling system a winning solution for this kind of application.

The main obstacle for the Free Cooler to replace completely the cooling towers concerns the higher temperature reachable for the process water.

Let’s suppose a climate in which, during the hottest days of the year, it is possible to reach a dry bulb temperature of 35°C with a coincident wet bulb temperature of 24°C (ambient conditions typical of the South of Europe and of the Mediterranean area).

One evaporative cooling tower, with such kind of ambient conditions, is able to produce water at 27-28°C. One Fluid Cooler “Free Cooler”, fitted with traditional mist spraying system, cannot produce water at temperature lower than 34-35°C.

Today one Adiabatic Fluid-cooler “Free Cooler” FC/90 SSS by Green Box is able, at the same operating conditions described above, to produce water at 29-30°C.

The main improvement that permits this result is a new high efficiency adiabatic spraying system (SSS Super Spray System).

This adiabatic cooling device can, through one high pressure pump, increase consistently the quantity of water sprayed really adsorbed by the air: in this way it is possible to have the air around the Adiabatic Fluid cooler “Free Cooler” in condition of saturation by water.

Over the 80% of the water sprayed is adsorbed by the air, against the 20-30% of one traditional spraying system, avoiding puddles below the Free Cooler and waste of water. Moreover this adiabatic cooling system is automatically switched on only when the Fluid Cooler “Free Cooler” is not able to maintain the set temperature. In the end, the particular disposition of the nozzles together with the polyurethane filters avoid any direct wet of the finned coil battery, wiping out the problem of scaling.

Green Box srl, production plant in Italy, is the Adiabatic cooling system manufacturer and the Adiabatic Super Spray System manufacturer. We produce successfully Fluid Cooler with adiabatic systems since years and, only in the last 2 years we installed all over the world more that 100 Adiabatic cooling systems Fluid Coolers.