Water formed deposits result from naturally occurring minerals precipitating from the water to form scale. The most common scale are calcium carborrate, calcium sulfate and silica or silicate. Scale buildup on surfaces can be extremely hard and difficult to remove. Scaling will drastically reduce heat transfer capacity and system energy efficiency.
Cooling systems are exposed to many types of corrosion from general electrochemical corrosion, to pitting caused by deposit, electrolysis, or micro-organisms. Corrosion can reduce the life-span of equipment by years, requiring expensive replacement. It can lead to costly equipment repairs and product downtime. Corrosion related deposits leads to reduced capacity and waste energy because of heat transfer efficiency losses.
Fouling occurs when solid materials form or contribute to the formation of deposits on equipment surfaces. they are introduced to the systems as suspended solids and many enter by the make up of the water, from corrosion by-products, or as airborne materials. Examples include mud, sand, salt, clay, oils, debris, organics, microbes, etc. These materials adhere to heat transfer surfaces and reduce heat transfer and water flow.
Microbiological problems associated with industrial cooling water systems era caused by algae, fungi, and bacteria. They cause plugging, fouling, corrosion, and and destruction of wooden cooling tower components. Many different bacteria species may exist in cooling water systems. Some of the problems caused include severe bacterial slimes and fouling, sulfuric acid, under-deposit corrosion and health hazards.