Re: [Phys-l] Heat transfer lab

[brian whatcott <betwys1@sbcglobal.net>]

On 11/17/2010 9:43 AM, LaMontagne, Bob wrote:
> Steam systems, like the one in my old house, use no aids. The boiler turns water to steam and it travels through the pipes to the radiators. There are small vents on the radiator that pop open when the pressure rises and produce a dressure differential allowing the steam to travel to the radiator. After condensation in the radiator, the water flows back to the furnace purely by gravity - the pipes are pitched to allow the return.
>
> Bob at PC

I am intrigued by the mechanism of the one pipe steam radiators. My 
youth provided no opportunity to examine such a system - though the two 
pipe pumped water boiler radiator, with plain flow controls or flow 
thermostats on each radiator were  and are a familiar site in England. 
[Quiet, clean, comfortable, but unfitted to cool the room if needed]

I can easily visualize a series one pipe arrangement, with return water 
flowing everywhere downhill.
I can even comprehend the possibility of a one pipe one port steam 
radiator, where steam condenses, and runs back down the same pipe that 
it entered, and the reduced volume is made good by an air vent allowing 
air into the radiator.
I'm pretty sure this is just a creature of my imagination though: how 
does a steam one pipe system really work, and what does the vent 
actually do? Does it meter steam into the radiator, in fact?

Brian W