nannah - 29-12-2013 at 10:23
Hey everybody. I just wonder if there is some way for me to proof a kitchen hot plate from explosion danger?
I have found a hot plate over at the local science supply store that i am thinking about getting, but i am a little bit worried about the danger of
fire and exploding vapors.
I googled it, and i tried it here too, but i couldn´t find anything on the subject.
Have a nice day, guys. ![:)](./images/smilies/smile.gif)
![8755_a.jpg - 21kB](https://www.sciencemadness.org/whisper/files.php?pid=313202&aid=28298)
Zyklon-A - 29-12-2013 at 10:35
What kind of explosives are we talking about?
Metacelsus - 29-12-2013 at 10:45
I think he means solvent vapors. The solvent that you are working with dictates the precautions you must take: for example, CS2 will
autoignite from boiling water, but something like DMSO won't autoignite until 300 C.
cyanureeves - 29-12-2013 at 11:37
hmmm,i never gave that much thought,all of my burners are coil type that get cherry red.i guess now i have justifiable reason to buy a heat/stirrer
plate.
Dr.Bob - 29-12-2013 at 13:01
I will remind the people here that even most laboratory hotplates are not "explostion proof" ones, in that most have exposed motors and switches.
They are normally designed to not have large sparks, but they are all labelled to be used with suitable ventilation, etc. There are some sealed
hotplates, as well as many stirrers that operate with compressed air for hazardous enviroments. But it is very hard to create a "safe" heating
element, which is why most people used to use steam bathes for heating flammable solvents, now many people use either water bathes or oil bathes for
the reason that they are generally safer around solvents. It would be difficult to get steam to ignite most chemicals, other than sodium...
The best way to avoid fires is to have good ventilation, thus avoiding any concentration of flammable vapors. Even the slightest static spark can
ignite ether or CS2 vapors in almost any real concentration. And most hydrocarbons are also pretty bad that way. That is one great advantage of
using DCM, chloroform, and other less flammable solvents.
chemrox - 29-12-2013 at 14:10
As an add-on because Dr Bob pretty much said it all ... explosion proof is expensive and usually not needed. You always need good ventilation! If
you have that the other shouldn't be a worry unless you're making large volumes of explosive gas. That is usually not the case and something you'd
know.
nannah - 30-12-2013 at 02:23
Thanx for all your replies, guys. I appreciate it. I am especially thankful for pointing out that ventilation is a key.
I will go ahead in buying this hot plate then. Could i place a mag stirrer under it you think?
I have sort of like a indoor, propagator tent that i bought from my uncle. In there i was thinking about doing my experimentation. There are ready cut
holes both in the "roof" and in the back that you can install with ducting, and exhaust fans. Really great, but i don´t think its very fire proof if
it catches on fire.
BromicAcid - 30-12-2013 at 09:15
I would wager that hotplate is too thick to get good stirring through with most magnetic stirrers. You will keep decoupling your magnet. Also on the
subject of XP equipment, in industry many items are rendered temporarily explosion proof by giving a through N<sub>2</sub> sweep. Case in
point, some solid model heating mantles (for 22, 50, and 72 liter sizes) are made with a N<sub>2</sub> port on the side to keep a steady
slow nitrogen flow out from the mantle and around the flask so that a flammable environment could not exist within the mantle space itself.
nannah - 31-12-2013 at 10:29
Interesting, i never knew that. Thats too big for me, thou. I need two liters maximum capacity.
I have an american hot plate from Fisher that doesn´t work over here in europe. Can i just connect it to a us-->europe traver transformer, or
whvt?