Recirculating Cooling Water Systems are ideal incubators for promoting the growth and proliferation of micro organisms, waters saturated with oxygen, exposed to sunlight, maintained at a temperature of 30 deg.C to 60 deg.C and having a pH of 6 to 9 ensure abundant nutrients and appropriate environment for life sustaining growth.
The build up of a bio film is initiated with the adsorption of organic material on the metal surface from the bulk water. The micro organisms attach to the surface and grow through the assimilation of nutrients. Eventually, some of the bio film is sheared away and re-entrained in the water stream to repeat the bio film development process else where.
The bio film can cause losses in heat transfer because of its insulating property. The soft elastic rippled surface of the bio film absorbs kinetic energy form the flowing water. Increased pumping energy is required to overcome the functional resistance of the bio film