Steam questions and calculations

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Steam questions and calculations

So I have a variety of questions about steam.

First is design. Using a 15 gallon keg boiler with a 5500 watt element. This would push through 2" stainless into a spear in another 15 gallon keg full of mash. Is a steam wand end necessary? Estimated power reaching the keg would be around 3500 watts, accounting for energy loss.

With regards to the process, my calculations yield that for every 1 g of EtOH brought from from 15 to 78 C, the would be 0.989 g of H20 (steam) required as input into the keg. (Assuming delta T of water is 85 C). Thus, in a 23 l mash of 10%, if you extracted 100% EtOH with no cuts, you would have 2.3 l removed with an input of 780ml H2O into the boiler.

Now, if the mash was strictly water, to have a rise of 80 C, it requires 148 g steam per liter. Or 3.4 l water inputted to bring the entire keg to boiling.

Does this make sense? Would you agree my calculations are roughly accurate?

The questions I have, is how to calculate steam pressure on such a system, how much water is required to produce the 780ml steam (only 780ml?) And is the amount of input water into the boiler from the steam condensing accurate?

Cp water 4.186
Cp ethanol 2.44
5500 watts = 5500 joules/second
Condensing steam releases around 2260 joules per gram
Wash is at 15 C

Thanks!
Novice

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Re: Steam questions and calculations

Not going to crunch numbers with you because we don't want pressure in the boiler. How ever there will be some power struggle over the system but not pressure. It is an open system. The energy is not stored.

AC

acfixer69
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Re: Steam questions and calculations

There are some steam threads around here somewhere. Doesn’t have to be that complicated but if math is your thing then go for it.

Basically though, it’s just a thumper being driven by a boiler filled with water instead of mash.

Kegg_jam
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Re: Steam questions and calculations

Dont feel like playing with a other man's numbers tonight, not had quite enough malt whisky for that! (Or maybe too much) But, the first keg will of course be under pressure. The 2nd should not be, obviously it should have a clear path out via condenser and vent. The amount of pressure will be equal to the height/weight of liquid in the 2nd keg that steam has to push through.

Just curious, why bother calculating it?
zapata
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Re: Steam questions and calculations

zapata wrote:Dont feel like playing with a other man's numbers tonight, not had quite enough malt whisky for that! (Or maybe too much) But, the first keg will of course be under pressure. The 2nd should not be, obviously it should have a clear path out via condenser and vent. The amount of pressure will be equal to the height/weight of liquid in the 2nd keg that steam has to push through.

Just curious, why bother calculating it?

Math keeps the brain fresh. Thanks for the info on the steam pressure. The system would end through a condenser thats open to the atmosphere.
Novice

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Re: Steam questions and calculations

As both Kegg-Jam and zapata say: the pressure in the boiler is needed to push the steam up through the mass in the thumper. Assuming that this mass is fluid, it is just the height of the watercolumn. Ten m of water is 1 atmosphere or bar. So if your thumper is 1 m high, the pressure is only 0.1 bar.

Kareltje
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