Building Shiny - Questions to the Wise ones!!

[mrfrosty]

My current plastic setup has a 3kw element with thermostat removed and works great, so two in a 100l pot should be quite substantial. Do you know if NO stock pots would accommodate them? Just a concern with sealing them on a curved steel surface. There was no problem on my poly bin as it just bends in to place. :)

Are you suggesting no thermostat for the boiler and a pt100 and pid for the hlt?

Rob

 

[Profesor Neurus]

...My other current question is heating the boiler? electric or gas? I'm tempted by gas as a friend of mine heats a 50l boiler with gas and he says its rapid, but i would like to know how long it takes you guys with gas to boil 80-100l of wort? and what size burners do you have to achieve this? If i was to go electric, from the How-tos i notice Vossy's excellent build is with 2 x 2.4kw heaters on a 100l boiler. Again what sort of times are you guys getting to boil the same quantity of wort?...

Hello everybody,

let's do a little math:

Q = m * c * (t2 - t1)

where:

Q = sensible heat (in Joules [J])
m = mass (in grams [g])
c = specific heat (in Joules per gram per Kelvin degree [J/(g K)])
t2 = end temperature (in Kelvin degrees [K])
t1 = start temperature (in Kelvin degrees [K])

specific heat of water = 4.1813 J/(g K)
(assume, for practical terms, that wort has the same specific heat of water)

P = E/T

where:

P = power (in Watts [W])
E = energy (in Joules [J])
T = time (in seconds )

Example 1:

I have a kettle with 50L of 1.045 OG wort at 55C. The heating element is 3KW. How much time
would take to bring it to a boil (100C) ?

Q = (50000 g * 1.045) * 4.1813 J/(g K) * (100 C - 55 C)
Q = 9831281.625 J

T = 9831281.625 J / 3000 W
T = 3277 s = 54.6 min

Example 2:

I want to replace the heating element to boil the wort of the previous example in 15 min.
What power is needed for the new element?

Q = 9831281.625 J (same as previous example)

P = 9831281.625 J / (15 min * 60)
P = 10923 W = 11 KW (approx.)

As you can see, the time required for boiling has nothing to do with the kind of heat source (electric/gas/induction) but its size (power). These numbers do not take in account the losses to the environment but are a good approximation.
The gas burners have the power expressed in BTU/h. The math is the same (1 BTU = 1055 J)

Hope this help.

Neurus

 

[BarnsleyBrewer]

Kin-Hell.

Way over a simple lad from Barnsley's head.

 

[aneray]

Way over a simple lad from Barnsley's head.

And from an ex pat of Sunny Scunny.

I just did a little dribble with a gob full of coffee when reading that lot.

 

[Dronfieldbrewer]

Double the Phookin Ell...

Fat lad from Dronfield scratching his bonce...

 

[BeerEagle]

They don't call him the professor for nothing!

 

[Laurin]

Does anybody have nay experience with these immersion heaters RokDok was talking about? I was thinking of using these ones to bring the water faster to a boil. I want to get a 33l pot to use on a hob because I won't have much space/money for more equipment. Or would that be an overkill and hob by itself is fine for a 5 gallon brew?

Here is the link again: http://www.ece-ehlers.de/content.php?se ... 9&produkte[first]=6

 

[hedgerow pete]

cooking on the hob is perfectly ok, been doing it for years,

the main thing with electric elements , tesco or other wise is to add to the set a temp controler to make things simpler.

where most people go wrong with large gas rings and we are talking here the larger ones, is that they buy the ring, hose and 32mbar butane regulator as a lump. this limits the power of the ring to its sencible safe max, by swapping the regulator to a varible propane one and change gas we can massively increase the burners power, i when using larger gas rings and my other gas powered tools much prefer a varible reg as i only use propane gas rather than butane and it gives me the choice to whallop its power if i wish

i would love the convienience of electric but i cant do the boiling inside so it has to go outside, i dont want a fully loaded mains extention lead so i use gas when i am outside, means i can also brew in the rain without frying myself.

it does also mean i can controll the temp when things cool slightly