Chemical remediation – water and boiler scale

Problems and malfunctions caused by boiler or limescale deposits

The formation of deposits in water-bearing systems leads to a reduction in heat transfer, as stone coverings have very poor thermal conductivity – energy consumption increases, performance decreases.

The energy loss caused by the different coatings can be seen in the following diagram:

In addition to increased energy costs, thicker stone coverings cause thermal stresses because the coefficient of thermal expansion of the stone covering is significantly lower than that of the underlying metallic material. This can lead to cracks (particularly common in sectional boilers or steam boilers), resulting in expensive repairs.

But even without significant heat stress, if your water has a corresponding salt content, your water pipes can look like this after some time:

The DIS-Solution to the problem

To remove limescale deposits, acids containing special corrosion inhibitors are used. These corrosion inhibitors protect the metallic materials from acid attack. A monomolecular protective film forms selectively on the metal surface without hindering the dissolution of the deposit by the acids.

Depending on the type of metal present in the system and the composition of the coating, a suitably adapted stone removal agent must be used. We supply optimally formulated combination products of acid and corrosion inhibitor, allowing our customers to begin the chemical remediation of their systems immediately.

The implementation of chemical remediation

Since carbonic acid is produced when limescale deposits are dissolved by acids, which causes the solution to foam, it is necessary to create a way for these gases to escape during the destoning process.
The reaction with the stone deposits requires a certain minimum time, therefore the solvent must be circulated within the system. This pumping process through an open intermediate container also allows the gases produced during the stone removal to escape.

After chemical remediation, the cleaned system should be treated to prevent further corrosion in the short term – this is done with our TRINEUTRAL.

The cleaning solutions must be neutralized before disposal – for more details see our information sheet “Neutralization of wastewater after chemical remediation”.

The following products are available for chemical remediation:

KALZITIN
most commonly used solvent for limescale and rust in boilers and water tanks, for containers and pipes made of iron or steel

KALZITIN-K
Limescale remover specifically for heat exchangers (and other containers) made of copper and iron

ZINKOFIX
Water scale remover for galvanized containers, cooling towers, pipelines, etc.

WABOL
Chlorine-free limescale remover with all-round inhibitors, suitable for all metallic materials

ALUFIX
Water scale remover, especially for containers and pipelines made of non-ferrous metals such as aluminum and stainless steel

LÖSER-P
Descaling and rust removal agent in one, prevents re-rusting; not suitable for zinc or galvanized surfaces and low-alloy stainless steels.

The following products can be used to remove the various components of limescale or boiler scale that are present in addition to the limescale itself:

ANTISIL
Solvent for the breakdown of silicate coatings – contains hydrofluoric acid

SULFATEX-A
for loosening and removing gypsum-rich limescale

SULFATEX-B
for the extraction or dissolution of gypsum in predominantly gypsum-containing limescale