What is Scale Formation?



Scale formations in boilers are responsible for lost efficiency, increased maintenance and operating costs not to mention lost revenue due to outages and downtime. Most scale formations in boilers can be traced to the presence of hardness in the make-up water. This hardness reacts in the high temperatures environment within the boiler to form an insoluble scale. This insoluble scale coats the heat transfer surfaces, acting as an insulator to impede heat transfer. Hardness isn’t the only cause of scale formation in boilers, other impurities such as iron, silica, copper oil, etc. are often found in samples of boiler scale. In fact, it is rare to find scale which isn’t the result of several of these impurities. Normally pre-softening the water before feeding it to the boiler is the first step in eliminating scale formations. Even when the make-up is soft, there is still a need for chemical scale inhibitors inside the boiler. With proper treatment the problems of lost efficiency, tube damage and lost production can be avoided or greatly reduced. Proper treatment requires the right balance of chemical treatment and control.