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DFliyerz
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[*] posted on 30-12-2014 at 12:38
Hot Plate Overnight


I'm planning to use an electrolysis cell to make potassium chlorate from potassium chloride, but due to the location of my lab (my garage), it will get very cold at night, even with 5 amps of power. Would it be safe to leave my hot plate on overnight, at warm or low settings?
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macckone
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[*] posted on 30-12-2014 at 14:10


It really depends on the quality of the hotplate.
Good ones can run continuously for years.

Ps. A cheap space heater may be preferable if the hotplate is questionable.

[Edited on 30-12-2014 by macckone]
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DFliyerz
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[*] posted on 30-12-2014 at 14:16


The hotplate is an Aroma single burner, which so far has proven to be pretty good quality.
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gdflp
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[*] posted on 30-12-2014 at 14:55


The problem wouldn't be the normal function of the hot plate, theoretically it should be fine. However, hot plates sometimes fail and spontaneously burst into flames, even at low temperatures. It even occurs when the hot plates are off, but still plugged in, though I would assume this is reasonably rare. Generally potassium chlorate cells get very hot, so the cell should keep itself warm overnight.
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violet sin
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[*] posted on 30-12-2014 at 15:56


how about a small 3$ styrofoam cooler around the vessel itself. you can get them at many grocery stores, they only hold enough food for a picnic or so. this doesn't actually address the hotplate issue, but it may help with the overall temp at night.
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forgottenpassword
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[*] posted on 31-12-2014 at 13:56


Thousands of hotplates in thousands of laboratories are left on overnight on a daily basis.
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Fulmen
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[*] posted on 31-12-2014 at 14:44


A quality hotplate should withstand a few years of continuous service, we used a common "dorm-type" single burner and it ran on full power IIRC 24/7/365. But that was on a manned lab, unsupervised you should strive for as few powered devices as possible. Anything like a hot plate should be avoided if possible, and in your case the power output should be more than enough with some insulation. I'm currently running a 500ml cell at 4A/3,2V and it produces more than enough heat for this to work.
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g1ng3rbr34d_m4n
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[*] posted on 4-1-2015 at 12:00


You could stick a heating pad under your cell...
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unionised
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[*] posted on 4-1-2015 at 13:58


Quote: Originally posted by DFliyerz  
it will get very cold at night, ?


It's not really my field.
Does it matter if the cell gets cold?
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Mailinmypocket
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[*] posted on 5-1-2015 at 07:16


If there is sufficient current running through the cell it should not need external heating. Sometimes I have had to put the cell in a bowl of cool water to allow better heat dissipation because it was getting too hot to touch.

[Edited on 5-1-2015 by Mailinmypocket]
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Bert
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[*] posted on 5-1-2015 at 08:31


There is a thing called "insulation".



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phlogiston
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[*] posted on 5-1-2015 at 12:07


1. increase the distance between the electrodes
2. increase the voltage to restore the current to its previous level

This way you can increase the ohmic heating to any desired level
Normally, this is avoided as it is detrimental to efficiency (you are spending electric power on heating rather then electrolysis).

But first take Berts advice and add insulation.




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dermolotov
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[*] posted on 10-1-2015 at 13:09
Magic!


I do the same with my hotplate/stirrer (Corning PC 420) for overnight oxidation sometimes. Since it is outside, I put the heating on 1 or 2 in the winter and place it in a large belljar with the vacuum adapter open. This has prevented a sudden ignition of ether vapours before (not sure how that happened). It had obviously set on fire as the wood underneath was burnt.
Miraculously, the hot plate was fine.

Not sure how much belljars are... But it is worth the investment if you need to stir/ heat things like ether or hexanes solutions overnight.

[Edited on 10-1-2015 by dermolotov]
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