Naked Science Forum

Non Life Sciences => Technology => Topic started by: NTYNUT on 09/08/2018 14:27:44

Title: How does an induction heater device work?
Post by: NTYNUT on 09/08/2018 14:27:44

hello - how does this induction heater device work?

Induction-Heater-.jpg (92.57 kB . 550x400 - viewed 3762 times)

Title: Re: How does an induction heater device work?
Post by: Bored chemist on 09/08/2018 18:53:32

http://bfy.tw/JLEE

Title: Re: How does an induction heater device work?
Post by: wolfekeeper on 10/08/2018 20:15:30

There's a many-turn 'Litz wire' flat electromagnet coil inside which is driven with a large AC current at high frequency (about 20-100 kHz or so- it's not at very critical). When you put a magnetisable pan on top (made of steel, iron or magnetisable stainless steels) the alternating magnetic field sets up a massive AC current in a thin layer (about 1mm) in the bottom of the pan (in accordance with Faraday's law) which directly heats the pan.

Litz wire (a sort of internally insulated platted or twisted wire) is used for the coil because it can be thicker and still carry the high frequency current with very little restive loss, so most of the heating is in the (relatively high) resistance of the bottom of the pan which is where you want the heat. Also, because the pan is heated directly, you get very little heat lost to the room- with gas for example, about 60-70% of the heat bypasses the pan and just heats the room up.

Title: Re: How does an induction heater device work?
Post by: NTYNUT on 11/08/2018 10:06:54

ok, how it is controlled by chip

Title: Re: How does an induction heater device work?
Post by: alancalverd on 11/08/2018 11:10:32

Most culinary induction heaters are controlled by duty cycle, with cutouts for surface overtemperature (sensor),"no pan" (no-load feedback), or inverter overtemperature (sensor). The duty cycle controller may be electronic or a simple bimetal strip, as in a conventional radiant plate heater.

Title: Re: How does an induction heater device work?
Post by: NTYNUT on 11/08/2018 14:58:11

Hello
how much electricity does it consume

Title: Re: How does an induction heater device work?
Post by: alancalverd on 11/08/2018 15:33:52

All sorts are available, generally around 1 kW for domestic or 2 - 3kW for catering use.

Title: Re: How does an induction heater device work?
Post by: wolfekeeper on 11/08/2018 17:13:15

Actually, I've bought a couple, both were stand-alone domestic and over 2 kW (in America they're max 1.5 kW units because they use 110V). You might be able to get a 1 kW unit, but you probably shouldn't.

The main advantage of them is that they can boil a pan in about a minute and a half, whereas the same pan on gas will take over 5 minutes. The built-in domestic hobs are more like 2.3-3.7kW per pan and need serious wiring.

Title: Re: How does an induction heater device work?
Post by: NTYNUT on 13/08/2018 10:39:06

Quote

The main advantage of them is that they can boil a pan in about a minute and a half, whereas the same pan on gas will take over 5 minutes.

hello
that the main advantage of it and does it cause any damage or not

Title: Re: How does an induction heater device work?
Post by: NTYNUT on 13/08/2018 12:31:32

thanks i have understand it

Title: Re: How does an induction heater device work?
Post by: Colin2B on 13/08/2018 14:57:29

Quote from: NTYNUT on 13/08/2018 10:39:06

..... does it cause any damage or not

If you let the pan boil dry it will overheat and burn the food and possibly damage the pan.

Title: Re: How does an induction heater device work?
Post by: NTYNUT on 13/08/2018 15:02:00

ok which type pan to use

Title: Re: How does an induction heater device work?
Post by: alancalverd on 13/08/2018 16:34:13

Any magnetic steel pan will work if it makes contact over most of the coil area- a flatbottomed wok is excellent.

More sophisticated cookware should say "induction" or have a coil symbol embossed on the underside.

Title: Re: How does an induction heater device work?
Post by: alancalverd on 13/08/2018 16:37:56

Quote from: Colin2B on 13/08/2018 14:57:29

Quote from: NTYNUT on 13/08/2018 10:39:06

..... does it cause any damage or not

If you let the pan boil dry it will overheat and burn the food and possibly damage the pan.

Shouldn't damage the pan with a good induction cooker - the sensor should protect the cooker top.

Title: Re: How does an induction heater device work?
Post by: wolfekeeper on 13/08/2018 17:19:03

Sadly that's not guaranteed, the main purpose of the sensor is to avoid damaging the hob and minimise the chances of fire. I've got a couple of pans where I didn't add enough water, and they boiled dry and the stainless steel started glowing red hot and they have never been the same. Also, you have to be really careful with non stick pans at high power settings, it burns off the coating and the fumes are seriously poisonous.