Physical Water Treatment For Cooling Towers

Introduction
The formation of scale (calcium carbonate or lime deposits) has been observed by mankind since hot water was first used for cooking. Nature has many examples of these deposits in the form of stalactites and stalagmites, and such natural deposits can be observed around faucets or in plumbing and heat exchanging devices. Water heaters, heat exchangers, cooling towers and chillers become fouled and lose efficiency, all because of scale deposits (primarily CaCO3).
The technologies used in many of today’s Physical Water Treatment systems (PWT) have been known for many years. These systems use a variety of techniques for controlling scale deposits (other minerals are involved but the focus is on CaCO3,) without the need for chemical additives. In some cases, direct electric fields are used, others use induced fields and some rely on physical properties of sheer force to accomplish their functions.
There are many well-known examples of technologies and natural processes that create physiochemical reactions, for instance, the microwave oven utilizes electromagnetic radiation (~2.5GHz) to cook food (a chemical process), and plants use electromagnetic energy (sunlight) through photosynthesis to process chemical reactions. People even use mechanical energy (stirring) to enhance the rate of chemical reactions or to dissolve a substance in a liquid.
The purpose of this paper is to review some of the basic types of Physical Water Treatment systems available today for cooling towers. The mechanism for these PWT’s is based on physicochemical principles we will briefly discuss, and supported by conclusions from sited scientific studies. These mechanisms are corroborated by the field data. We will start with a brief review of some of the fundamental principles behind the PWT phenomenon. These basic principles are some of the foundations of chemistry and will be italicized here so they can be reviewed in more detail if one chooses.