Descaling with KALZITIN

To remove limescale deposits, acids with special corrosion inhibitors are used. These inhibitors protect the metallic materials from acid attack by selectively forming a monomolecular protective film on the metal surface without hindering the acid’s attack on the limescale deposits.

Je nach Metall im System bzw. Zusammensetzung des Belages muss ein entsprechend angepasstes Steinlösemittel verwendet werden. Wir liefern dafür die bereits optimal eingestellten Depending on the type of metal in the system or the composition of the coating, a suitably adapted descaling agent must be used. We supply optimally formulated combination products of acid and corrosion inhibitor so that you can start descaling your system immediately. Our most common product for limescale is KALZITIN.

KALZITIN comes in two versions:

KALZITIN – Most commonly used solvent for limescale and rust in boilers and water tanks, for iron or steel containers and pipelines.

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

The application procedure for boiler descaling

After determining the solubility of the stone coating and calculating the expected amount of KALZITIN required, it must be checked whether the container to be descaled has cooled down sufficiently (max. 30°C) and has been completely emptied.

After that, it continues as follows:

• I. The filling and dilution of KALZITIN:

For boilers with a large water space, the KALZITIN filling is carried out through the top manhole or a cleaning cover opening using an acid pump (e.g. BOY descaling pump).

In most of these cases, the amount of KALZITIN required for dissolving the stones is less than the capacity of the boiler. In such cases, the KALZITIN must be diluted with the appropriate amount of water to fill the entire boiler. For larger boilers, this is done by first adding some of the dilution water to the boiler, then (or even simultaneously) pumping in the calculated amount of KALZITIN, and finally filling the boiler to the lowest water level with dilution water.

To improve mixing during descaling, the water can be pumped in such a way that the pump’s suction hose is inserted as deep as possible into the water chamber and the outlet (of the pressure hose) is positioned as close as possible to the water level in the tank. If the pump remains switched on for one or more hours, depending on its power and the tank’s water volume, the KALZITIN-water mixture is continuously pumped from the bottom of the tank to the top, thus achieving thorough mixing.

In boilers with a narrow filling chamber (relatively small water space), such as all water-tube boilers (e.g., radiant boilers), rapid steam generators, etc., filling is most efficiently done by pumping at the lowest point. Since large quantities of carbon dioxide gas are usually released when the scale dissolves, an outlet must be provided at the highest point of the system (venting).

• II. The exposure time:

The contact time depends on the quantity and composition of the deposits to be dissolved. For easily soluble, carbonate-containing limescale or boiler scale that foams up considerably during dissolution, a contact time of a few hours or overnight is sufficient.
For limescale containing larger quantities of insoluble components, a contact time of 12–24 hours is necessary. When dissolving thicker rust layers, as well as deposits containing gypsum or silicates, heating the KALZITIN-solution may be necessary, in which case an addition of 1.5–3.0 kg of INHIBITOR-KFF per m³ of solution is required. However, it is essential to ensure that the maximum temperature does not exceed 60°C.

Heating the KALZITIN-Solution with the addition of INHIBITOR-KFF:

After adding INHIBITOR-KFF, the burner is switched on for a maximum of 2 minutes; after a waiting period of 10 minutes, the temperature of the boiler water is measured. This waiting period is necessary to ensure complete mixing of the KALZITIN-Solution. This procedure is repeated until the temperature of the KALZITIN-Solution reaches 60°C.

In all cases, thorough mixing is essential. The KALZITIN-Treatment is only complete when gas evolution has ceased and the KALZITIN-Solution is still active. (Bubble up with limestone, mortar).

• III. The aftercare:

After the KALZITIN-Treatment is complete, the boiler is emptied, leaving a residual solution that still contains free acid. This residual acid must be carefully neutralized before being discharged into a sewer.

The emptied tank is then refilled with clean water, emptied, and rinsed. Afterward, the system is filled with a 0.5–1% TRINEUTRAL-Solution for post-treatment. Neutralization of any remaining KALZITIN is achieved when the thoroughly mixed TRINEUTRAL-Solution in the tank has a pH value between 8 and 9. To ensure a uniform dissolution of the TRINEUTRAL, it is advisable to pump a TRINEUTRAL-Slurry into the tank, which should be approximately two-thirds full of water. For this purpose, the TRINEUTRAL is mixed with plenty of water (e.g., 1:10) in an open container, and the supernatant solution is pumped into the tank. Any undissolved residue is mixed with further water until it is completely dissolved and can then also be pumped into the tank. Under no circumstances should the solid TRINEUTRAL simply be thrown into the boiler, as it will then sink to the bottom and dissolve only very slowly.

Precautions when using KALZITIN and other limescale removers:

The relevant safety data sheets must be strictly observed!
KALZITIN is acidic and can therefore attack acid-sensitive surfaces. Skin and clothing must be protected from contact with KALZITIN. Splashes and spills of KALZITIN must be washed off immediately with plenty of water. After or during KALZITIN-Treatment, a boiler or container must not be illuminated with an open flame, as flammable gases may have been released. Furthermore, entering a boiler cleaned with KALZITIN is only permitted after thorough ventilation.

KALZITIN may only be added to cooled boiler systems.