Tower Classifications

Cooling towers are classified according to the method by which air is introduced to the tower. The principal types are atmospheric spray, natural-draft, mechanical-draft, deck-filled, spray-filled, coil shed and hyperbolic towers. Most industrial cooling tower installations are field-erected units designed for specific thermal characteristics. 

In an atmospheric spray tower the air movement - is dependent on atmospheric conditions and the aspirating effect of the spray nozzles. Natural-draft cooling tower operation depends on a chimney or stack to induce air movement. Mechanical-draft cboling towers utilize fans to move ambient air through the tower. Deck-filled towers contain tiers of splash bars or decks to assist in the breakup of water drops to increase the total water surface and subsequently the evaporation rate. Spray-filled towers depend only on spray nozzles for water breakup. Coil shed towers are comprised of a combination structure of a cooling tower installed on top of a substructure that contains atmospheric section coils. Hyperbolic natural-draft cooling towers are typically large-capacity systems. 

There is also a separate class of towers based on a dry cooling principle. Each of these major designs is described below. 

---

For plant layout, in addition to tower sequence, every equipment item has an optimum location for minimum pipe runs. For exchanger, drum and pump locations the following general classifications can be made. 

National Association of Demolition Contractors North American Industry Classification Standard National Academy of Sciences National Association of Tower Erectors National Center for Health Statistics... 

A vertical mill was developed in Japan for grinding fine minerals. The tower mill is a combination of vertical tanks, a screw mixer, a mill, and a classifier. From a chute on the side of the mill, the rocks, steel balls, and liquid are introduced. The vertical screw rotates around a vertical shaft and creates an upward vertical counterflow. The finer materials float to the top and are led to a side chamber for classification, while the heavier and coarser solids sink with the steel balls (Figure 7-22). 

The wind roses for the 200<>foot level at the Meteorology Tower are suanarised in Tables A-5 through A-9 These tables show the per cent of time the 200-foot wind blew from each of 16 directions and with an hourly mean speed in each of 7 class intervals of speed during each season and diuring the entire year for four atmospheric stability classifications. 

The importance classification of towers, masts, and chiirmeys (CEN 2005c) is similar to that of buildings of reduced importance for... 

---