Kirchweger condenser

The Kirchweger - condensation device (also Kirchwegersche exhaust steam condensation ) was used to preheat the feed water for steam locomotives by the exhaust steam from the steam engine. It was invented around 1850 by Heinrich Kirchweger. A similar device was from Rohrbeck.

About a 100 mm thick line of withdrawn at the exhaust valve chest was performed under the locomotive to tender. There, the exhaust steam was introduced directly into the feed water, which was thereby heated to boiling. The rest of the exhaust steam could escape into the atmosphere via a second smokestack on the tender. About a cock on the tender, the amount of steam could be regulated.

The Rohrbecksche device differed in details from the church Weger 's design. Here the steam was taken only at the blowpipe and passed along above the boiler. Here, the regulation was carried out by a throttle valve on the blowpipe.

The potential fuel savings could be up to 30 % depending on the operating conditions at 10 to 20 %, in individual cases. The Niederschlesisch - märkische railway gave this value to their locomotives with 7.5%.

The problem was the enrichment of the boiler feed water with impurities. It is reported in old sources of pitting to the boiler sheets, caused by the fatty acids contained in the exhaust of the lubricant. On the other hand, the formation of scale in the boiler has been slowed down because part of Kesselsteinbildner eliminated already in the tender.

With the introduction of the injector boiler feed systems, the exhaust steam condensation came from the 1860s back into disuse because injectors due to work physically with cold water. Until 1880 about 900 German locomotives had been fitted with condensing apparatus.