Boiler Feed Water Hardness

If deposits of calcium and.

Boiler feed water hardness.

For industrial companies using a boiler for its facility some type of boiler feed water treatment system is usually necessary to ensure an efficient process and quality steam generation. The most appropriate boiler feed water treatment system will help the facility avoid costly plant downtime expensive maintenance fees and boiler failure as a result of scaling corrosion and fouling of the. It is desirable to keep the concentration of phosphates in the water to 30 50 ppm in order for complete reaction of the phosphates with the calcium hardness entering the boiler through the feedwater. Feed water boiler water characteristics as per is 10392 1982 1 feed water parameters upto 20 kg cm2 21 kg cm2 to 39 kg cm2 40 kg cm2 to 59 kg cm2 unit total hardness 10 1 0 0 5 ppm as caco 3 ph value 8 5 9 5 8 5 9 5 8 5 9 5 dissolved oxygen 0 1 0 02 0 01 as ppm silica 5 0 5 as ppm sio 2.

Boiler water is provided by the boiler feed water from the boiler as either heated water or steam. For boiler water ph is maintained between 11 11 8 and that of feed water between 7 9. Effects if either of the values increases water will accordingly become acidic or alkaline leading to detrimental effects caused due to acidic attack or caustic embrittlement. Boiler feed water is made of makeup water and return condensate.

The purity requirements for any feed water depend on how much feed water is used as well as what the particular boiler design pressure heat transfer rate. Internal treatment protects against feed water hardness by preventing. Therefore good internal boiler water treatment programs are necessary. Feed water purity is a matter both of quantity of impurities and nature of impurities.

Feedwater hardness usually ranges from 0 01 to 2 0 ppm but even water of this purity does not provide deposit free operation. 131 the internal treatment is for boiler feed water and external treatment is for make up feed water and the condensate part of the system. Boiler feedwater also contains metal salts such as chlorides magnesium sulphur and calcium bicarbonates. Boiler water is the term used specifically to refer to water which is heated inside the actual boiler.

Make water is the original raw water derived from. Some impurities such as hardness iron and silica are of more concern for example than sodium salts. The treatment of boiler water can be put into two parts. These are internal treatment and external treatment.

The water which directly enters the boiler.