Water is good for us but is naturally corrosive and can eat away the inside of equipment. Boilers with a deposit of just 1/16th of an inch can lead to an efficiency loss of up to 20%. When deposits become heavier than that, it can result in tube overheating and failure. The most important function of specifically boiler water treatment, is scale control. You can prevent these issues with a variety of boiler water treating compounds that are designed to help control oxygen corrosion, scale and sludge deposits, condensate corrosion, and more. There are also products that can be used in water softeners and reverse osmosis units. Water softeners can be affected by iron or manganese that can reduce the capacity of the softener and lead to higher hardness and boiler deposits. Reverse osmosis systems can also become fouled with mineral deposits resulting in reduced capacity, more cleaning and deterioration of the system. Hal Mechanical outlines some of the effects of hard water scaling.
Oxygen Pitting Corrosion in Boilers
Oxygen corrosion in boilers will show itself as pits. These pits are covered by raised mounds or iron oxide. It may appear superficial, but it can penetrate the tube wall and result in failure. This problem can be prevented by adding chemical oxygen scavengers and using mechanical deaeration. It is important to pay attention to boilers that are idle as the problem cam get worse when boilers are shut down. There are storage procedures that can be taken to avoid problems in the future.
Boiler Scale Formation
Scale and sludge buildup can affect the efficiency of your boiler, as well as possible failure from overheating. These deposits are typically calcium salts from excessive hardness in the boiler water. Other minerals that can buildup in the boiler include magnesium, iron and silicates. The iron can result in corrosion. The problem can be treated with chemicals but will need further treatment as well. High-quality feed water needs to be maintained through pretreatment and a program to maintain low levels of contaminants.
Boiler Heating Efficiency Loss
Heat transfer is affected when mineral deposits form on boiler tubes. The scaled boiler water will need to produce the same amount of steam as a clean tube and will need to use more fuel to do so. This will result in higher operating costs and extra energy consumption. Installing a proper water treatment program will reduce operational costs and the waste of excess fuel.
Boiler Condensate Corrosion
Bicarbonate and carbonate in your boiler will cause alkalinity in the feedwater and will then breakdown to form carbon dioxide. The carbon dioxide will travel with the steam and will condense in the condensate system. It will then form carbonic acid and reduce the pH that results in corrosion. Chemical treatment programs will utilize filming agents, oxygen scavengers and neutralizing to combat the effect of condensate corrosion. The best way to combat the cost of treating your boiler water is through dealkalization, demineralization and reverse osmosis.