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RogueRose
International Hazard
Posts: 1596
Registered: 16-6-2014
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Quote: Originally posted by Refinery  | | Of course the concept is to enclose the flask inside the mantle so when heat is generated, it mostly stays in the mantle and is only absorbed through
the reaction flask. This is why the construction must involve an enclosure into which a hole is made just enough to lower a flask in. I would rather
want a low conductive material against a glass vessel to minimize hotspots. Placing a flask directly on heating element will cause huge thermal
gradients. |
Are you talking about enclosing more than the bottom ~1/2 of the flask with this fabric?
Yeah, I totally agree about the element not contacting the glass, I've never seen an element contact glass unless maybe it was a quartz tube.
Have you decided what gauge, length and voltage you are planning on using? If you choose the correct gauge you can create a maximum temp the wire can
get with a given voltage, but you are also limited to wattage. If you want higher wattage but retain the same temp, you need a larger gauge wire and
longer length (I think).
What temp are you shooting for? I found the calculations for temp & wattage are usually when the wire is in a straight line in open air so if you
are going to coil it, I'm not sure how much this effects the max temp and I'm guessing it shouldn't effect wattage much if at all.
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macckone
Dispenser of practical lab wisdom
Posts: 2168
Registered: 1-3-2013
Location: Over a mile high
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Mood: Electrical
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Professional ceramic mantles are made from magnesium oxide/oxychloride/chlorocarbonate
Sorel cement is easy to make and works like plaster.
Getting the properties exactly right could take some work but the basic preparation is easy.
The basic ingredients are going to be readily available to most chemists.
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wg48temp9
National Hazard
Posts: 786
Registered: 30-12-2018
Location: not so United Kingdom
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| Quote: Originally posted by RogueRose |
I'd really like to maybe start a project with others to make a temp controller that would ideally have a digital readout and a temp setting so the
unit keeps the temp where it needs to be. I think a standard K-type thermocouple would probably work and it might be ideal to have 2 inputs for
these, one for the heating surface and one for the reaction vessel. You could set a max temp for the element and a max or target temp for the
reaction and it would turn the element on/off as needed to keep the target temp. I think this could be pretty easily done with an arduino or maybe
even a custom PCB made for the project. If anyone is interested LMK as I have a few applications I'd like to use this for. I'm also working on a
similar setup but would also incorporate a pressure/vacuum sensor and control a pump as well. It would probably be easier to build one unit that has
the pressure sensor incorporated (they are inexpensive) than building 2 different models. |
As you can buy a basic controller or even PID controller for <£10 I don't think its worth the effort unless its for fun or education.
More complicated controllers with ramp, soak and power limits are more like £100 and most don't have a PC interface or multi temperature sensor
inputs. I would be interested in collaborating on a project for one of those.
I have already started it but lost interest as I found the programming of a Arduino frustrating. There are almost ready to go PID sketches available.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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