Internal feed water treatment
The interior feed water treatment is a process which, inter alia, in steam engines for preventing scale deposits is used.
The principle of the inner feed water treatment is by controlled addition of sodium carbonate or sodium hydrogen carbonate and a wood extract, which consists for the most part lignosulfonic acid is: that (trade names NALCO, TIA, Loktan, Skiantan) hardness components specifically as flowable sludge ( colloid ) in the vessel to deposit . In this way, a solid layer cannot form, which can lead to emaciation or overheating of the heating surfaces or a kettle crack . The amount of chemicals added to the feed water depends, among other things, on the hardness of the water and the salt content of the tender water. The sludge is regularly removed from the boiler through a special valve ( blowdown valve ).
This can also be done while driving, as the heater can operate the valve remotely from the driver's cab.
In addition, the addition of sodium carbonate / sodium hydrogen carbonate increases the pH of the boiler water. Thus, the hydrogen type corrosion is reduced. In addition, it prevents foaming boiling of water ( alkaline solutions tend during boiling for pushing), so that the water tearing is prevented. The wood extract also adsorbs free oxygen from the water, which reduces oxygen-type corrosion .
See also
literature
- Leopold Niederstrasser: Guide for the steam locomotive service . ISBN 3-921700-26-4
- Author collective: The steam locomotive . Transpress, ISBN 3-344-70791-4