Tower packing and tower fill materials are used in cooling towers to provide a high surface area for steam condensation without restricting air flow. Tower packing is a mass of inert, solid shapes. Within a cylindrical column, it provides a greater surface area for the gas and liquid in a web scrubber to make contact.
Applications
Applications for tower packing include: aeration, acid gas scrubbing, catalytic gas scrubbing, Distillation, Precipitation, particulate removal and mist elimination.
Tower packing is also used in water treatment, direct-contact hot water production, oxygenation, degasification, absorption, desorption, rectification, extraction, desalting, drying, mixing, fish farming, biological filtering, and the treatment of greenhouse gases. Tower packing materials provide a high surface area with a low bulk density. A high surface area material is useful for coalescing steam and water in high humidity applications, while a low bulk density material allows a minimally-obstructed flow of the moisture-laden (and, possibly, particulate-laden) gas stream. As such, the hot exhaust gases and/or steam from a gas scrubber, incinerator, furnace, pollution control device, or similar equipment pass through a vertical column; the hot gases rise in the flue. Within the column, tower packing provides a surface for capturing moisture and/or particulates that then fall to a collection point at the bottom of the tower while the hot gases rise to an exit.
Types
There are many different types of tower packing and tower fill materials. Choices include: corrugated sheet, plastic balls, ceramic balls and mesh pads for particulate removal and mist elimination.
Typically, corrugated sheet is available as paper, foil, or film. Plastic, metal, and ceramic packing are also available.
Features
Depending on the application, packing may be random or structured. Random packings are a relatively inexpensive way to increase a cooling tower’s efficiency and capacity. Features include high distillation, absorption, and stripping efficiency; high strength to weight ratio; and a high specific heat transfer coefficient. Some products are comparable to pall rings in terms of mechanical strength and efficiency. Tower packing includes structure and gauze packings as well as high-performance trays and custom-designed internals. Structured packings provide higher efficiency and lower pressure-drop than either random packings or trays. Products that are made of metal wire or plastic gauze are suitable for applications where low pressure-drop is important. Ceramic structured packing is designed to promote the mixing and radial distribution of the liquid and gas streams. Other types of tower packing are also available.