Boiling over 2000 litres

[Horatio]

Well, after we sparge it goes through an underback and is pumped over. By the time its half full and hitting the probe, its aroh 55*. From the moment the elements kick in (we have an annoying sensor that wont let them come on until we hit 310L) its around 2 hours. Maybe a little less.

We have two elements installed one above the other, and a probe above the second one which has to be covered for them to power on.

I wish they were side by side, and I had the oiption to just power one or both, to get the boil started earlier. Actually the main problem is, were limited to full size batches. Cant do an experimental half batch as we cant boil it! Not too much of a prob as 2.5bbl isnt huge anyway, but still a pain.

Also, sorry for the typos. My first day off tomorrwo for a coupel weeks so, bit worse for wear already

That's really helpful, many thanks.

[darkonnis]

If you go for steam you really want an internal coil. A jacket is a nice idea but even insulated you lose efficiency due to the fact that over half your surface area isn't even touching the wort. Steam is probably the ideal choice, you can then use it to sterilise casks/kegs and in cleaning.

Zgoda, if you don't mind my asking, how is oil cheaper than steam to operate? I was always under the impression that steam was the universal choice in industry (chemicals, fertilisers, just about anything I can think of) because of how much energy you could transfer with it and in heavy industrial applications you can use it for combined heat/power. Not picking an argument, really am interested

[john luc]

What do you think of this guy. His web site does not appear to exist and I would be concerned with the quality of the steam that is pumped into the wort. He claims that the steam replaces the boil off so you end up with roughly the same amount of wort you start with.
https://www.youtube.com/watch?v=MM_Hvj3xOoo

[john luc]

Following this idea to conclusion has anyone here got the sciency mind to work out how much steam would be required to bring 2000 litres to a boil. Was thinking a boil kettle with the injector pipe for the gas fitted as a ring around the inner wall at the bottom of the boil kettle. This would create a good rolling action and when the boil is complete the wort can be whirlpooled in situ then drained via a side valve fitted to the floor. The advantage of this is a clean boil and a easier clean up of the boil kettle.

[Eric]

He's right, although from a brewer's point of view there are significant problems that he's not considered.
In terms of calories, by definition it takes one kilocalorie to raise one kilogram of water by one degree centigrade. However, it takes about 540 kilocalories to convert one kilogram of water at 100 degrees centigrade and 1 bar pressure to one kilogram of steam at 100C at 1 bar. This means it will take about 75 gram of steam at atmospheric pressure to heat a litre of water from 60C to boiling point. More steam needed to overcome losses and to keep the wort boiling for the required duration but it does seem possible that it wouldn't be greatly different to losses by evaporation. He said the boiler was rated at 1.5 bar meaning the steam output would be superheated up to going on for 130C and would have a little more energy.

That steam boiler was powered by a 8 or 10 kW electric element and it would need to be up to pressure before the system would work. One with a large storage capacity for steam would be able to heat the copper more quickly but that has historically been the drawback to steam powered systems of every kind.

[millmaster]

Very roughly about 350 kg of moderate temperature and pressure steam will bring about 2000 litres water from 20C to 100C. No account is taken of heat loss or evaporation as the temperature rises nor residual heat in the condensate in that guesstimate, so in the real world the amount of steam needed could well be more

This figure is just to get it to boiling point, more will be needed to keep the 2000 litres at boiling point and to evaporate off whatever fraction you need

Steam comes at a temperature ( like 170 degrees C ) and pressure ( like 8 bar ) and is saturated or superheated. Given the steam temperature, steam pressure and the amount of superheat ( if any ), an idea of the heat loss through the insulation of the vessel you are using to hold the 2000 litres you want to boil, how much evaporation there is as the water heats up, how much you need to boil off, then someone with more up to date engineering knowledge than me ( and a set of steam tables ) could produce a better figure for you.