Steam boiler vs hot water boiler

[Roger]

I was wondering if anyone has researched using hot water vs steam in a jacketed still designed for steam?

The differences would seem to be that the water boiler would of course require a pump and would be about 20 degrees less hot, but it would allow for the integration of a facility heating system by putting a couple of closed loop radiators in-line.

Pros , cons ?

Thanks

[Sherman]

A mass of 100° steam does contain more heat than an equal mass of 100° water. This is due to the heat of vaporization needed to convert water to steam. This works out to being ~540 kilo-calories per kilogram. Put another way, it takes over 5 times as much heat to convert water to steam than it does to initially raise the water's temperature from 0 to 100°. That heat is released when the steam condenses. The steam becomes a media to carry lots of heat. If you had a boiler you could circulate the condensate return to heat the facility or just use steam radiators.

There are some real nice charts specifying the btu carries by saturated steam and the amount. One I know off hand is that 15 psi steam carries 9111 btu per lb. Water doesn't even come close.

[Swede]

I wouldn't use water. With steam, you have 970 btu per lb of latent heat in the wet steam. With water, you don't have this. Most systems that use a double boiler would use a HEX fluid with a higher boiling point that water and this would get you over the 100 degree celcius plateau...

[John McKee]

Roger,

A hot water boiler would work fine if you ran vacuum based distillation. If however you intend to run atmospheric distillation systems, then you need steam, electric heat, or hot oil utility to effectively run the columns.

Cheers.

[Brothers Vilgalys Spirits]

You can also use steam radiators / heaters to heat your facility, if that's why you're interested in hot water for radiators. And steam would still require a pump for the condensate return.

[Kristian]

If you use water at higher pressures you can get more heat energy and it works. Spring 44 uses this type of system and it seems to be fairly energy efficient. I use steam and am happy.

[Roger]

Thanks for all the help. Just trying to be energy conscious from the environmental side, and if it also makes sense from a production side all the better.

Bottoms up

[adamg]

Depending on where you live you can probably find used steam radiators at salvage and reuse places. These are old heavy cast iron ones that radiate well. Also think about how you run your pipes because you can use those to help heat the space as well.