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Corrosion in the Steam Boiler

User: Citro misr in Cairo, Egypt

In the chemical industry big amounts of steam are needed to heat up different processes. The client uses several steam boilers, with a total capacity of more then 100m3 per hour. The feed water is treated chemically. Under high temperatures inside the boiler the demineralized water attacks the surface. This causes corrosion. Even chemicals used to prevent corrosion don’t work in these harsh conditions.

Rust particles are transported through the system in the steam, so the corrosion is not limited to one area. The result is material abrasion throughout the whole system, reducing the life time of the boiler.

 

Merus Ring installation in the steam boiler

We installed one Merus Ring at the feeding pipe of the boulder. To ensure the heating process no matter how the trial phase will go, the same amount of corrosion inhibitors was added as before.

The iron content in the steam and the blow down pipe was checked regularly. In just a few weeks the iron content in the steam diminished and stabilized at a very low level. From the outside it was clearly visible, that there was less corrosion and rust.

 

To avoid any risk the system was operated under the existing conditions until 6 weeks before the yearly inspection. Now we were able to evaluate the performance of the Merus Ring in the boiler. Parts of the surface in the boiler where black due to iron oxide. Compared to the last inspection only few red  spots where left.

The customer decided to stop adding chemicals. The iron content in the steam would be monitored in the future to verify the results.

As a result, today the customer not only saves the costs for chemicals but also service costs in the dosing system. Additionally we assume the life time of each boiler is enhanced as no iron was found in the steam so far. This means that no material was eroded.