Fill Pack or Filling material or Heat exchange surface.

Set of sheets or grilles of plastic material that separate the water in the tower and activate the contact between the fluids and therefore the cooling process. The fill pack’s purpose is to divide the air and water flows in the most uniform and targeted way possible. This would allow the most extensive contact between the fluids. The other purpose of a filling material is to slow down the fall of the water to allow a time when water can remain in the tower, thus creating a thorough cooling. There are two main types of fill packs, defined by the way in which they produce a large contact surface between water and air: film and spray.

• Film fill pack. This type of fill pack distributes the water over a large surface dividing it into thin films or dispersed droplets. The film fill can be constituted by mobile or grating packs.
• Spray fill pack. This type of filling material is formed with grates or bars arranged in horizontal planes over which the water falls, breaking into numerous droplets. These, by falling from one level to another, divide further. The grates or the levels below, are placed so as to continuously break the fall of water droplets.