Industrial steam boilers are used in many fields and cover several technical processes where heat is a key component. Steam can be used for peeling potatoes, creating corrugated cardboard, removing stains on clothes, just to mention a few.
The quality of the feed water and makeup water are of great importance to obtain operational reliability and protect and extend the life cycle of pipe systems and boilers.
The flow chart shows the optimum water treatment for industrial steam boilers.
Optimum industrial boiler water treatment
The use of common hard mains water as make-up water for a steam boiler, will cause precipitation of lime stone on the boiler heat area which increase the energy loss and the use of acid for cleaning the boiler inside.
By water softening the boiler scaling is prevented, but the content of bicarbonate of the raw water passes the softening plant without hindrance. In the boiler the bicarbonate splits into carbon dioxide (CO2) and sodium hydroxide (NaOH) creating corrosive condensate and increase the need for blow down. The problem can be avoided by removing the salt content of the makeup water in a reverse osmosis plant or in a two-column ion exchange plant to get demineralized water.
Dissolved oxygen is highly corrosive and is one of the unwanted impurities to consider when choosing correct makeup water treatment for industrial boilers. Since softening and demineralization do not reduce the partial pressure of gases it means that water often will be saturated with oxygen from the waterworks.
To remove nearly 100 % of the gasses (CO2 and O2) a thermal deaerator is used to heat the water, since the solubility of gas in the water is a decreasing function of the temperature.
Minimize boiler blowdown and save water and energy
Blowdown of steam boilers is necessary to comply with the specifications of the boiler suppliers as to the contents of salt (specific gravity) and the alkalinity (P-value) in the boiler water. The volume of blowdown is determined by the boiler type, operating pressure and water treatment quality of feed and makeup water.
In high quality boiler water, levels of suspended and total dissolved solids (TDS) are down to a minimum. This will minimize blowdown volume and hereby reduce energy loss, as the temperature of the blowdown liquid is the same as the steam generated in the boiler. Lower blowdown rate will also reduce makeup water and chemical use, saving you money and water.
Arla, the largest food company within dairy products in Denmark, has reduced their water waste by more than 75 % with the RO-PLUS technology from EUROWATER. Demineralised water is used as makeup water for steam boiler, laboratory use, and internal cooling on filling machine. The amount of water recovery also reduces their consumption of salt and energy and lower the operational cost.
90,000 m³ water is treated every year at this Arla dairy production.
Rent a mobile water treatment plant tailored according to your need
If a temporarily water treatment problem arise, you can easily take care of it by renting a EUROWATER mobile water treatment plant. The video (2 min.) gives an example of, how the mobile water treatment plant handles a filling of thermal energy storage.
Whether you need drinking, disinfected, softened or demineralized water, we have a mobile solution. Read more about our mobile water treatment plants or contact us for further information and reservation.