Industrial boilers generate steam which is used to generate power and heat. Heat from the boiler’s furnace heats up water in the boiler proper and turns it into steam which is then circulated out of the boiler and used in various processes in heating applications.
Water, called feedwater, is fed into the boiler proper from external sources. Boilers require high quality feedwater in order to function efficiently. Feedwater quality needs to meet a number of specifications in order to ensure that the boiler’s functionality is not adversely affected.
How poor feedwater affects the boiler
Steam is produced by the boiler and condenses. Some of this condensed water is fed back into the boiler as feedwater and some is lost through the process. The higher this loss, the more fresh water needs to be added to make up for it which increases the likelihood of impurities entering the boiler system.
Impurities in the water become concentrated and settle at the bottom of the boiler which results in poor heat transfer, which in turn reduces the efficiency of the boiler. On top of this, dissolved gases such as carbon dioxide and oxygen react with the metallic surfaces and causes corrosion
Feedwater quality specifications
It is important to ensure that the water entering the boiler is of a high quality. The main considerations in determining the quality of the water are:
- The hardness of the water
- Caustic and soda alkalinity
- Water turbidity
- Sediments in the feedwater
- Organic matter, oil and grease in the feedwater
The boiler treatment process works by removing as many of the impurities as possible from the feedwater before it enters the boiler. Internal and external treatments are used to soften the water and protect the boiler from the harmful effects of corrosion, scale and carryover.
For effective boiler water treatment solutions, get in touch with NCH Asia today.