Water usually contains oxygen and carbon dioxide. Both leads to corrosion in the steam system. The concentration of oxygen and carbon dioxide drops with increasing temperature. This effect is used in the feed water containerto degas the feed water. In depressurised vessels where the temperature is usually at 90°C to 95°C, a large part of the oxygen and the carbon dioxide is driven from the water. However, not all gases that may continue to cause damage quickly escape while they are not bound with dosed solutions.
If the temperature of the feed water container is increased to more than 103°C, the concentration of oxygen and carbon dioxide is negligible. Much less dosed solution needs to be added. The reduced salt content of the dosage also has a positive influence on the blow down intervals.
To achieve a water temperature in excess of 103°C, the water must be pressurised. We then speak of pressure degassing or full degassing - in contrast to partial degassing at less than 100°C in depressurised vessels.
The advantages for you
- Savings in pressure degassing, particularly when there is lower consumption of dosed solutions, and a significantly lower risk of corrosion to the steam pipes and the steam boiler
- Additionally, a high share of condensate return flow due to the higher water temperature of up to 1.6% (in a JUMAG steam boiler DG560 this corresponds to 6.5 kW) saves energy
- JUMAG's patented regulation of the ventilation valve saves a lot of energy compared to other systems, as ventilation only takes place when there is oxygen in the system