How to get the most out of a steam system
Not keeping on top of the maintenance of your steam boiler could be affecting its performance – leading to reduced efficiency and higher production costs.
Water treatment can be a really simple way to help your system to operate at its full potential. When steam is generated, chemical reactions affect the performance of a steam boiler. Scaling, sludge formation, metal corrosion and carryover of contaminants into the steam are unavoidable so it is vital that the correct boiler water conditions are maintained.
Clean your act up
Scale is a rock-like coating on the boiler tubes which reduces heat transfer, reducing the efficiency of the steam boiler and causing the boiler tubes to overheat. It can even cause a steam boiler to rupture.
So how can you prevent it from forming?
- Remove as much hardness from the steam boiler feed water as possible using a boiler water softener.
- Chemical treatments such as phosphate treatments and polymer sludge conditioners can also be used to improve the quality of the incoming water supply. These convert hardness slippage into a mobile sludge which can be removed by steam boiler blowdown.
Corrosion is another key problem for boiler efficiency and is usually caused by a low pH within the boiler. Often, dissolved oxygen enters the system via the feed-water causing corrosion in the form of pitting (small but deep pinpoint holes which can eventually go through the tube walls).
Raise the feed water temperature so the oxygen can escape. A well-designed feedtank or hotwell is a good first line of defence in protecting the boiler.
Maintain the feedtank temperature at a minimum of 80°C by returning as much hot condensate as possible and by steam injection. A feed temperature of 85-90°C is ideal but avoid pushing the temperature too high as it will encourage cavitation damage of the feed pump.
Steam generation is at the heart of any industrial power plant. With such a heavy reliance on your steam boiler being operational 24 hours a day, you really would be mad not to pay close attention to your boiler water quality and its role in the efficiency of your system.
Pete Mills, Commercial Technical Operations Manager at Bosch Commercial and Industrial