A pipe for leading the hot fumes from the top of fun furnace downward to your regenerators, boilers, etc.
in certain water-tube boilers, a tube larger in diameter compared to water pipes to conduct water from each top drum to a bottom drum, therefore finishing the blood supply.
Any pipe or passageway for leading solids or fluids downward.
The descending part of a sectional boiler, whereby the cooler or thicker liquid descends in the process of blood circulation.
In a blast-furnace for smelting metal from the ore, a big pipeline which takes combustible gasoline from the the surface of the furnace-shaft and brings it down seriously to boilers, stoves, machines, etc., which it's burned as a source of temperature.