Steam generator (railroad)

From Wikipedia, the free encyclopedia

For other uses, see Steam generator (disambiguation).

A steam generator is used in trains to provide heat, and sometimes air conditioning (via the "steam jet system" ) to passenger cars. Usually the steam generator is located in the locomotive. Sometimes a separate steam generator car is used. Previously, steam for passenger cars was obtained from the boilers of steam locomotives. With the coming of diesel or sometimes electric locomotives a small boiler for this purpose was provided.

1 Types of boiler
- 1.1 Oil-fired
- 1.2 Electrically-heated
2 Modern times
3 External links

[edit] Types of boiler

[edit] Oil-fired

These burned diesel fuel, which is a lightweight fuel oil. The term steam generator, as opposed to boiler, usually refers to a fairly automated unit whose heart consists of a long spiral tube that water is pumped into and is surrounded by flame and hot gases, steam issuing out the end. There is no pressure vessel in the ordinary sense of a boiler. Because there is no capacity for storage the steam generator's production of steam must vary directly in proportion to demand and automatic regulatory systems were employed to raise or lower the rate that water was pumped into the coil, fuel was burned, and combustion air blown through the generator. By pumping slightly more water in than can be evaporated, the output was actually a mixture of steam and a bit of water with concentrated dissolved solids. A steam separator removed the water before the steam passed along to the train. The purpose of this method was to reduce limescale buildup by hard water. Such scale buildup that did occur had to be removed via acid washout of the coils.

[edit] Electrically-heated

In British electric locomotives the steam generator was usually heated by a large electric immersion heater running at the (then) line voltages of 600 volts from a third rail or 1,500 volts from an overhead wire.

[edit] Modern times

Steam heated or cooled rail cars have been replaced or converted to fully electric systems. Wisps of steam coming from under cars is now part of the past in the USA, Canada, and much of the rest of the world.