Tubular heating surface

Section through the long boiler of a superheated steam locomotive with heating and smoke pipes

The pipe heating surface is the part of the heating surface of a steam locomotive boiler that is formed by the smoke pipes installed in the boiler through which flue gas flows . In this part of the boiler, the heat is transferred (to the heating surface), unlike in the case of the radiant heating surface , mainly by convection .

calculation

The inner diameter of the pipes is used as a basis for the mathematical calculation of the pipe heating surface.

This means that in wet steam locomotives the tubular heating surface

• ${\displaystyle \pi }$x di xl _h xn

where di is the inner diameter of the heating tubes, l _{h is} the length of a heating tube and n is the number of heating tubes.

In the case of superheated steam locomotives , the smoke tubes carrying the superheater tubes are added, so that the tube heating surface

• ${\displaystyle \pi }$di _h xl _h xn _h + x di _r xl _r xn _r ${\displaystyle \pi }$

where di _{h is} the inside diameter of the heating tubes, l _{h is} the length of the heating tubes, n _{h is} the number of heating tubes, di _{r is} the inside diameter of the smoke tubes, l _{r is} the length of the smoke tubes and n _{r is} the number of smoke tubes.

history

With the first steam locomotives up to the end of the Länderbahn era , this tubular heating surface was practically the only evaporation heating surface of the boiler on locomotives from southern Germany. Only locomotives of the Prussian State Railways had a water-flushed fire box , which led to a more significant proportion of the radiant heating surface.

literature

• Dr. Ing. F. Meineke "The Steam Locomotive", Springer-Verlag Göttingen, 1949

Web links

• Scientific consideration of the design of the tubular heating surface by Robert Garbe

Individual evidence

1. ↑ Dr. Ing. F. Meineke "Die Dampflokomotive", Springer-Verlag Göttingen, 1949, page 22.