Page 1 on 2

How to calculate a copper heating resistor ?!

published: 22/04/09, 20:13
by the boulle
Hello

I would like to know how to calculate the number of turns to be wound (copper) to create a heating resistance which works in 220volts

the goal would be to create a preheater on the injection line of an oil burner to burn oil

I already realize a winding which works very well under 12 volts,

the goal would be to remove the transformer to facilitate and reduce the transformation neck of a classic oil burner

Image


Image

published: 22/04/09, 20:30
by Christophe
Uh I'm not sure that copper is the best material to make a heating resistance since it is precisely one of the best conductor. It is therefore one of the worst materials for making resistance ...

Otherwise the method is quite simple I think:

U = R * I
P=U*I
P=R*I²

So just measure R to get the power dissipated ...

In your place I would rather buy a heating "wire" which is given for X Watts / m linear ...

published: 22/04/09, 20:35
by the boulle
precisely the copper wire is very good because it is insulated and can be wound directly on steel tube

the high number of turns allows the heating to be distributed over great lengths;

thank you for your formulas

published: 22/04/09, 20:43
by Christophe
In recupe I do not know too much ... but new it costs between 10 and 15 € ... it's 240V directly I think ...

I believe but I am not sure that we can even cut it according to the desired power :)

There are sellers of oil kits who sell them I believe ...

published: 22/04/09, 20:47
by chatelot16
copper is not the best material for resistance but it works, so in some cases it's not that bad

lre problem is the quality of the isolation if it overheats: in 12v you do not risk anything, in 220v it is less on

the higher the tension, the greater the length of the wire will be very fine: the thermal contact with the part to be heated will be bad and the wire will overheat before the part is hot

it is therefore necessary to distribute the heating resistance over a long length of pipes: in the photo it seems a little short

published: 22/04/09, 20:50
by the boulle
ideal would be very fine wire wound in a single layer.

I plan to put thermostats to avoid overheating

published: 22/04/09, 21:35
by boubka
hello the ball
in fact with the copper wire you do not make a resistance but an induction heating.
you are doing a tranfo with the secondary in short circuit.
it is not too suitable because if it heats up too much the varnish will melt and put the primer in short circuit, in addition it consumes a lot.
the classic line heater (resistance) and more suitable.

published: 22/04/09, 21:50
by boubka
the goal would be to create a preheater on the injection line of an oil burner to burn oil

the burner chooses to air a lot, especially the pump provided you modify it a little. (chgt of the discharge spring)
the ideal is to heat the oil before pump to 140 degrees minimum or 100 if in line heater, to raise the pump pressure to at least 30 bars and to put a bigger nozzle with a spraying to be determined according to tests.
basically this is the description of a heavy fuel oil burner.

published: 22/04/09, 22:12
by elephant
Sorry, I am also of the opinion that copper is not the right material: you are proposing a dangerous DIY.

Nichrome + high temperature resistant sheath or porcelain beads

published: 22/04/09, 22:20
by Flytox
Hello ball

Why not tear down an old electric heater, there are plenty at the recycling center. You recover the resistances and the ceramic supports, you modify in the direction that you want, it is not a handyman like you who let oneself get carried away by a resistance : Mrgreen: .