Re: Nichrome wire heater
2Spoons, Fri Feb 21 2014, 04:39AM

If it were me I'd simply buy a ready made immersion heater, such as a jug heater. Already sealed and electrically insulated, with nice convenient connections, pre-defined power output, cheap, easily replaced. That's what I used on my alcohol still. If you are doing power and /or temperature control make sure you use a solid-state controller- no sparky contacts!

Regarding the nichrome wiki :

Applying only to straight wires stretched horizontally in free air.

This is a very important point, as you want to heat 100l of acetone/water - not air. Also you can not expect the current vs temp to be even remotely linear.

Re: Nichrome wire heater
Andy, Fri Feb 21 2014, 05:28AM

Thanks for the idea 2Spoons.

I'm checking out immersion heaters .Would a bank of infrared lamp work?

Re: Nichrome wire heater
Billybobjoe, Sat Feb 22 2014, 03:39AM

I have one of these immersion heaters and it is excellent. You may want to look for something similar (Vycor/quartz). Good for high purity applications and easy to clean.

Re: Nichrome wire heater
Andy, Sat Feb 22 2014, 05:39AM

Yeah I think it will be the way to go, emailed a company that deals in immersion heaters, and see if they would have a option that will fit.

Cheers, for the help

Re: Nichrome wire heater
Bored Chemist, Sat Feb 22 2014, 03:20PM

If you were in the business of designing stills, you wouldn't be asking here.
If you are not in that field and you build one, you may struggle to get insurance for using it.
Buy (or rent) a proper still.

Incidentally, the heat needed to get the solvent to 60C isn't the only criterion. You need data on heats of evaporation etc.

Re: Nichrome wire heater
Andy, Sun Feb 23 2014, 12:59AM

Hi Bored Chemist

I do have engineering qualification, but I'm still getting someone to construct it, and design some specs. Thanks for the tip about insurance, I will ask when I apply.

Re: Nichrome wire heater
Andy, Sat Mar 29 2014, 04:26AM

Just wondering what a stove top element ohms are, if I was going to use this to heat oil bath, with the water container in the oil how:
Is the resistance of nickel-chrome based on the wire and the series resistors, or just the series resistors.

Thanks

If you were in the business of designing stills, you wouldn't be asking here.
If you are not in that field and you build one, you may struggle to get insurance for using it.
Buy (or rent) a proper still.

It can only handle 4 litres and cost $300, I'm type of after 40Litres per 3 hours, and they would proable cost grands$


Edit
I've got these values for 40litres, if accurate
SFC 4.19kj/kg/k
T 110C
L 40

KJ = 18436

Heat of evaporation 2260kj/kg

kj = 90400

kwh = 30
@ 2kw 15 hours

Re: Nichrome wire heater
Ash Small, Sat Mar 29 2014, 05:03PM

Hot water tank with immersion heater?

I'm not sure what safety measures would be required though, so don't take my word for it without doing your homework, but you should be able to use standard copper plumbing fittings, etc.

Re: Nichrome wire heater
Andy, Sun Mar 30 2014, 07:51AM

Sorry Ash Small, I'll be useing coal/wood, it works out cheap for the power outputed, $30 electricity for 40litres to $5 wood

Re: Nichrome wire heater
Bored Chemist, Mon Mar 31 2014, 10:59AM

So, you plan to build an amateur designed still for a flammable liquid and run it with a wood fire?

Please call the fire service before you start- that way they will be ready to damp down the aftermath.

Re: Nichrome wire heater
Patrick, Wed Apr 09 2014, 05:08PM

100L acetone vessel, coal/wood heated !

You would have to use two radiators, circulating hot water from a 100m away fire, to the still/vessel. Even then, you could not do this within a mile + of any human presence, you would have to be in a green flat field.

I just don't know if you'd end up with a ballistic rocket, capable of leaving it's 1 mile exclusion zone. As the welding gas cylinder supply companies have learned.

What purpose needs such purity? Commercial acetone is pretty good...

Re: Nichrome wire heater
radiotech, Thu May 08 2014, 08:25PM

A safety issue in electric heaters is the spark when one of the element conductors
parts (burns out). Review the methods specified for rendering an electrical device
explosion-proof. It is fairly simple. Your electrical code shows these under hazardous
locations.

Re: Nichrome wire heater
Shrad, Fri May 09 2014, 06:33AM

this is not simple

ATEX gear and equipment would cost another price if it was so simple...