During the evaporative cooling liquid droplets are injected into the gas flow by means of spraying lances, serving for the heat reduction of gas during the evaporation process. A reliable operating mode of cooler requires the complete evaporation of droplets at low temperature fluctuations at the cooler outlet. The main features for a safe design of an evaporative cooler are:

• Spraying technology
• Homogeneous gas flow through the evaporation zone
• Control technology

In most of the cases two-component nozzles (water and compressed air) are used for the spraying. As an alternative, one-component nozzles can be used. This, however, requires conveying pumps with a definitely higher pressure rise.

For corrosion protection and for the separation of acid crude gas components, a sorption agent such as lime slurry or sodium hydroxide solution can additionally be injected into the evaporative cooler together with water and compressed air, if necessary. In case of use of sorption agents and due to the longer evaporation times of injected liquids, the size of evaporative cooler/spray absorber has to be adapted accordingly.