I got a container that must be heated up to atleast 250 celsius, but I don't have alot of space to work with and I am also not so familiar with this kind of topic.
So I've attatched an image which shows my design. Everything in the color dark blue or red will be in iron or steel or even stainless steel, the red container will be in the same material as the blue discs, but I've colored them to visualize what that will be going to 250 celsius and what that should not be heated at all.
I was thinking about heating it up by using the container as a resistor, shown on the second image I would have a circuit of a copper cable going into red through the container out from green and then to a power supply unit (400W, same thing that powers most stationary computers) which leaves me at 12V and X amps. I do have an N-Channel MOSFET 60V 30A and an arduino and a Thermocouple Type-K for controlling the heating.
So my question to you is: Will it even work having the container as a heater? Or do I need some heating-resistors?
On the image below I've shown the diameter for calculation purposes. The resistance got something to do with the area through the material, and I'm sadly not sure how to exactly calculate it since it's going sideways rather than vertical.
I will be checking out this topic about once per day so if there's any extra information you need or even the model itself then I'm happy to give it to you, but since it's a blueprint of something very valueable to me I don't want to give it away unless it's necessary.
Best Answer
The problem with using the container as a resistor is that it's actually a very good conductor. Your wires will have more resistance, and will therefore get hotter than the container.
What would be amazing is if somehow you could deliver a very high current to the container, using a lower current flowing in the wires. Well, you can!
A very efficient way to heat an iron or steel object is by Induction Heating. It's used a lot in industry for heating bearings and things. It's also quite possible to do it yourself. Many people do.
It works by inducing an alternating current in the object to be heated. Essentially you're creating a transformer, where your object is the (single turn) secondary coil. Much more current can be made to flow in the secondary coil simply by using many turns in your primary.
An induction heater can get things really hot if you want:
And you can even use it to heat large containers: