Induction for brewing

[JackStark]

Hello all,

I am wanting to make a large induction heater to boil large pot of water (25 gallons). I understand induction is a very efficient way to do it with electricity, which is good cause my ultimate goal is to automate the whole process.

In poking around online ive found a number of schematics for smelting metal, though I am thinking I need a much larger coil to fit around a pot.

Though ive done some independent study regarding circuit design and components, I am a complete novice practically speaking, and any advice is appreciated.

1) How do I calculate the sizes I need for this project? I'd imagine the coil would need to wrap around the base of the pot. Does the size of the coil affect resonance? How much amperage does the whole thing needs to heat the water in an efficient amount of time?

2) Correct me if I am wrong, but that coil has a solid charge running around it. Is that to say it is electrified to the touch, and how do I make this safer for being around. Much as I love beer, im not trying to kill myself over it.

3) Any books or tools (circuit design programs specifically) you'd recommend would be greatly appreciated.

Thanks for looking at this,

-Jack

 

[kubeek]

Induction is more efficient than a standard electric stove, but that only applies if you are boiling a pot on a stove. A directly immersed heater right inside the container will be more efficient than both, especially if you are getting more towards a permanent setup it should be a better and cheaper solution.

 

[JackStark]

I guess that saves me some trouble since weve already rigged up a water heating elemwnt through a pot witg a pid thermometer dealy which works. Is there any power factors that can be used to compare efficiencies?

 

[kubeek]

I dont have any numbers to back it up, but a resistive heating element will convert all the energy into heat, and since it is submerged inside the water all the energy will go into that water.
An induction heater first converts mains AC to DC, then again to high frequency AC. This voltage gets converted to high frequency magnetic field in the induction coil, and then gets converted to heat in the bottom of the vessel. You can see that there is quite a lot of energy converisons involved and sure you can imagine some loss at each stage, so my guess would be about 80% efficiency at best.
Direct heating will be damn close to 100% efficient. (and much cheaper and simpler)

With a pot on regular electric stove you get losses on the contact between the stove and the pot, which is eliminated with induction heating as it heats the bttom of the pot directly. That´s why some people might say that induction heating is more efficient, but this does not translate too well to industrial conditions where you likely want to heat a vessel that is fixed in place.

 

[Nigel Goodwin]

I guess that saves me some trouble since weve already rigged up a water heating elemwnt through a pot witg a pid thermometer dealy which works. Is there any power factors that can be used to compare efficiencies?

I'm with kubeek, why swap a simple, cheap, efficient and reliable method for a vastly more expensive, VERY complicated, (almost certainly) unreliable and less efficient method?.

 

[dr pepper]

Welcome to the forum.
You say you are a novice, a induction heater to heat 25 galls of water at anything like a reasonable pace would likely require an industrial type power supply and some serious volatges and currents for the work coil, this is a fairly involved project even for a seasoned engineer.
A resistive heater if your looking for a simpler solution would be a lot easier and safer to do.
There are very reliable induction heaters, I maintained a machine that heat treated crankshafts using the method and the generator was very reliable, it just needed new workcoils time to time, however gec who made it would have spent a lot of cash and time developing it.

 

[JackStark]

Thanks for the helpful answers, ill stick with the resistive heating element. it wont be quite a direct conversion from the element to the wort, as we dont want the element to scorch our precious wort through direct contact, though it will heat water we run through a copper coil to transfer the heat to the wort. Glad for the explanations thoguh, certainly saved me some trouble.