| Pages:
1
2
3 |
halogenstruck
Hazard to Self
Posts: 61
Registered: 24-9-2009
Member Is Offline
Mood: No Mood
|
|
DIY 3000'C homemade electric Arc-for P,... production
very dangerous.be very careful and if you don`t know it completely,simply forget it.do it in your own risk.
all electric wires must be capable of at least 3kw,20Amper.
here i want to explain you how to have an easy homebuilt high temperature source of heat for your needs ver 3000 degree:eletric arch,without need of transformer:
it can be used for regular preparation of Phosphorus, calcium carbide, silicon carbide,...
100% practial and tested.
you should just buy an nichrome[nikel-chromium alloy] 3000Watts coil[like the one used in hot plates,heaters,...] and u should secure it on a fire
clay frame or base and then in serie you should connect two clips that keep the
graphite rods therefore when u just touch the graphite rods its like that electricity is passing simply through nichrome wire but when u take rods
back,electricity current get disconnected.in practice i used 220V and i did
not do that with 110V but it seems to me that it should work too but little bit weaker.
all the copper wiring should be from thick wires to be able to work with high current otherwise they get warm then insulator will burn and shortcut!!!
how to run it:simply connect the rods,it sparks,then gradually take it back,electric arch will be formed.don`t watch to arch with naked eyes.use
UV-lens or very-dark eye glasses,wear gloves!!!electric shock!!!
mixtures like phosphorus making mixture(C+Ca3(PO4)2+SiO2)contain C and are conductor.therefore if put the rods inside the retort made of fire
clay-fire cement,...in contact with each other,after some seconds they have spark then the mixture get warmed then rod contacts will be cut but
electricity will run through carbon content of mixture then because of created high temperature,mixture melts and pass electricity much better till
all the mixture is liquid.
i used this simple device for melting silver(100Gr),palladium ,platinum and even rhodium although not easily about the latter.
it can be used simply for preparation of sulphides from sulfate and charcoal too!!!
=============
before i had a powerful transformer and powerful diode(high amper)[can be made by paralleling diodes with lower current limit and making a rectifier]
and i used 50v electricity as DC for electric arch making with graphite rods and i melted NaCl and made Na althogh i did it in open air and it burnt
with yellow flame but some of its globules were surronded
inside salt and i made metallic sodium when i was just 14!
==============
a question:I want to use the reference&Whimsy
section of this forum but it is restricted.how i can access them?i couldn`t find any access method mentioned in site.thx
[Edited on 24-9-2009 by halogenstruck]
[Edited on 25-9-2009 by halogenstruck]
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by halogenstruck  | you should just buy an nichrome[nikel-chromium alloy] 3000Watts coil[like the one used in hot plates,heaters,...] and u should secure it on a fire
clay frame or base and then in serie you should connect two clips that keep the
graphite rods therefore when u just touch the graphite rods its like that electricity is passing simply through nichrome wire but when u take rods
back,electricity current get disconnected.in practice i used 220V and i did |
Please explain that part better... 
|
|
|
hissingnoise
International Hazard
Posts: 3940
Registered: 26-12-2002
Member Is Offline
Mood: Pulverulescent!
|
|
Blogfast25, I think it's about wasting 3kilowatts per hour in order to get some resistive heating or arcing going in a fire-clay pot, and doing it in
a way that will surely set fire to your house and home. . .
It sounds too dangerous and inefficient to be of any use.
[Edited on 24-9-2009 by hissingnoise]
|
|
|
halogenstruck
Hazard to Self
Posts: 61
Registered: 24-9-2009
Member Is Offline
Mood: No Mood
|
|
it uses less than 3kw for sure as in direct contact it is 3kw but when we have arch,it`s less than that.
if u don`t serie a resistor,then your home fuse box cut the electricity as a huge current want to pass.in fact it limits electricity current.
i did it many many times.
i tried to illustrate it on a jpg pic.sorry for low quality design.
|
|
|
hissingnoise
International Hazard
Posts: 3940
Registered: 26-12-2002
Member Is Offline
Mood: Pulverulescent!
|
|
Even so, it sounds wasteful, at best.
A welding transformer would be better. . .surely?
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Thanks for the clarification, Halogenstruck. The 3 kW resistor reduces current strength and if you can safely (by insulating yourself) manipulate the
graphite electrodes, this should be relatively safe to use for an AC arc. Max. current about 14 A.
|
|
|
halogenstruck
Hazard to Self
Posts: 61
Registered: 24-9-2009
Member Is Offline
Mood: No Mood
|
|
you are welcome blogfast25.
in fact in practice you should put the arch on a heat resistant board.in past i fixed one rod inside the crucible from clay and just moved one
electrode.i used glove and well insulated plier[handle had a thick plastic insulator][600v safe].the distance between electrodes can rich between
1-2cm i think.
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
Well, it's all heat, so it's all 100% inefficient. But maybe you count heat as efficiency? In which case, it's 100% efficient. Well, not with the
resistive ballast, then maybe only 50% tops, but hey, it's cheap as hell, and it's not going to be running for days, who cares.
FYI, "arch" is an architectural feature. "Arc" is a thermoelectric discharge. ("Spark" is either a short duration arc, or an ionizing discharge not
at thermal equilibrium.)
Tim
|
|
|
Sedit
International Hazard
Posts: 1939
Registered: 23-11-2008
Member Is Offline
Mood: Manic Expressive
|
|
If hes speaking of what I think he is(Hard to tell due to the confusing opening post) I have also done something simular using an old electric stove
top burner as the resistor. This is nothing more then a thin piece of Nichrome wraped in ceramic, wraped in a metal sheth. It prevents blowing the
breaker but I always found it hard to sustain an arc. I only toyed with it for a while but Im sure I could get something up and running if I continued
to work with it.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
|
|
|
halogenstruck
Hazard to Self
Posts: 61
Registered: 24-9-2009
Member Is Offline
Mood: No Mood
|
|
thx for correcting me,u r absolutely right.arc
the resistor element does not emit hit a lot,it`s only there to avoid shortcut and power out,when we have arc then R of arc is much higher than
nichrome wire 3KW as arc is a 1 cm distance of air,therefore heat loss from 3kw coil is low
|
|
|
barbs09
Hazard to Others
Posts: 113
Registered: 22-1-2009
Location: Australia
Member Is Offline
Mood: No Mood
|
|
Well arc furnaces (and arc lights) have been around for a while and may still have a place in a DIY lab for making Phosphorus or carbide. The link to
the old article below is a good read. For a resistive load they use a conductive solution. Perhaps their method of striking an arc is better/safer
than using pliers and gloves.
http://blog.modernmechanix.com/2007/08/02/arc-furnace-incase...
Another
http://blog.modernmechanix.com/2007/03/19/experimental-arc-f...
The guy in the above article can't have any eyes left!!
Lots of other good stuff an the Modern Mechanics web site as well
Halogenstruck once the arc is struck do you have to constantly move the electrode in to make up for carbon erosion? I guess gouging rods are adequate
since they are designed to withstand high-temperature arcs?
[Edited on 25-9-2009 by barbs09]
|
|
|
garage chemist
chemical wizard
Posts: 1803
Registered: 16-8-2004
Location: Germany
Member Is Offline
Mood: No Mood
|
|
Phosphorus from phosphate, silica and carbon needs just 1500°C and is therefore one of the least temperature-demanding applications of an arc
furnace. Temperatures above 2000°C are needed e.g. for calcium carbide production and melting down alumina for abrasives production.
Go to 4:20 to see alumina being melted and poured:
http://www.youtube.com/watch?v=fopD-QA1YY0
Using an inductive current limiter is a good improvement over a resistor, as it doesn't waste power and limits the current just as well. A transformer
that produces about 40-60V secondary would be even better- it's mostly the current in the arc that decides how powerful the furnace is.
The difficulty in building such a furnace lies in catching the phosphorus vapor. The whole thing must be gastight and the outer shell must be kept
above 280°C to avoid the phosphorus condensing in the furnace.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
barbs09 and garage chemist:
Thanks for the links. Now I know all about hot dogs too and am even less inclined to eat them!
I suppose the carbon electrodes used in most ordinary batteries are out of the question, huh? I imagine these to fritter away in record time. What
type of carbon to use and where to get it?
|
|
|
garage chemist
chemical wizard
Posts: 1803
Registered: 16-8-2004
Location: Germany
Member Is Offline
Mood: No Mood
|
|
The carbon "gouging rods" for arc welding would probably be a good choice here, as they are specially made to be used as arc electrodes.
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
Ace Hardware has gouging rods.
http://www.sciencemadness.org/talk/viewthread.php?tid=2680&a...
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
halogenstruck
Hazard to Self
Posts: 61
Registered: 24-9-2009
Member Is Offline
Mood: No Mood
|
|
graphite rod inside spent dry cells work well.yes as arc run graphite rod burn very very slowly and evaporate,for some period electricity still keep
the arc running as distance grows but after sometime you need to aproach them a little bit,but in practice when arc starts it create heat then mixture
melts and by conductivity heat is made in following.in fact mostly arc is needed till mixture melt then molten lava conduct electricity and create
enough heat to stay molten and warm up even more as for sure they conduct electricity better than hot air.
in fact if container is insulated very well smallest heat can keep the temperature constant just to compensate lost heat from insulant.because of this
fact,even with a nichrome wire coil alone you can make a 1000'c furnace and even 2000 if use a very good insulator but in fact over 1000 it melts and
does not work and u need SiC resistor.
for leakage you can simply put an inert stream of neutral gas like CO2 or burnt gas from a gas burner.
for inductive oven,u can use a reactor or retort made from mixture of fire clay and graphite powder inside a microwave.as graphite absorb
electromagtetic waves it warms up and get red.
|
|
|
halogenstruck
Hazard to Self
Posts: 61
Registered: 24-9-2009
Member Is Offline
Mood: No Mood
|
|
yes possibly if u use strong electrodes and in an inert atmosphere,it should work the best.
an idea:
how if we make a coil from thick copper and at end we connect it to graphite road and put it inside microwave.
first electricity get induced on coil and makes arc then mixture is getting warm and melt.when melted and red,it`s conductor and absorb
electromagnetic waves directly from microwave and stays warm and melted and no need to arc anymore.therefore don`t care to move rods anymore.just as
an innitiator[like catalyst!!]
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by halogenstruck |
before i had a powerful transformer and powerful diode(high amper)[can be made by paralleling diodes with lower current limit and making a rectifier]
and i used 50v electricity as DC for electric arch making with graphite rods and i melted NaCl and made Na althogh i did it in open air and it burnt
with yellow flame but some of its globules were surronded
inside salt and i made metallic sodium when i was just 14!
|
And you made sodium with an arc, how?
Oh, I see: DC arc! (must get those reading glasses...)
[Edited on 25-9-2009 by blogfast25]
|
|
|
S.C. Wack
bibliomaster
Posts: 2419
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline
Mood: Enhanced
|
|
And I thought that the rhodium, etc. would be the most questionable part.
It's all out there, from dead people I trust a little more.
http://books.google.com/books?id=H_RUAAAAMAAJ
http://books.google.com/books?id=WDUKAAAAIAAJ
http://books.google.com/books?id=ah9DAAAAIAAJ
http://books.google.com/books?id=Lx9DAAAAIAAJ
http://pubs.acs.org/search/advanced
title search furnace, or don't.
|
|
|
User
Hazard to Others
Posts: 339
Registered: 7-11-2008
Location: Earth
Member Is Offline
Mood: Passionate
|
|
@halogenstruck
It's some nice DIY stuff.
Can you explain to me how you constructed the heat transfer between the arc and the reactor.
And do you have pictures of youre device.
I have 2 neon trans. laying around doing nothing.
It is quite easy to draw long and hot sparks with it.
Might be uesfull stuff.
What a fine day for chemistry this is.
|
|
|
halogenstruck
Hazard to Self
Posts: 61
Registered: 24-9-2009
Member Is Offline
Mood: No Mood
|
|
in fact i did the arc in a graphite crucible or in normal crucible.
in case of silver i fixed one rod inside crucible in contact with silver powder and arced between graphite rods.i arced between rods many times to
melt it.in case of Rh i melted around 1 or 2 gr with some difficulties as its melting point is very high.
in case of salt i did it on the brick.u can do it inside a normal crucible.
i think if u use a graphite crucible as - electrode,cathode and a rod as anode and use CO2 current around it when u work u can prepare good amount of
Na especially if u use NaOH.
i did not use it for P preparation but surely it`s the commercial process for making P and works very well.
in P case like many other cases u don`t need arc always,remember, ARC IS NEEDED FIRST WHEN THE MIXTURE IS COLD,AFTER ARC
MELTED A LITTLE BIT OF MIXTURE,THEN CURRENT WILL PASS THROUGH THE MELT AND CREATE ENOUGH HEAT EVEN MORE THAN ARC TO MELT WHOLE MIX AND KEEP IT IN
MOLTEN STATUS.
sorrily it was a long time ago and i did not take any picture that time.it`s a simple thing u can master it easily but be a little careful and regard
safety issues like goggle/glove/mask/heat insulators/don`t allow wires even with insulator touch each other as they warm up then insulator may melt
and a shortcut is possible.
|
|
|
halogenstruck
Hazard to Self
Posts: 61
Registered: 24-9-2009
Member Is Offline
Mood: No Mood
|
|
about neon trans i don`t know it exactly but it think it won`t work in this way as it increase the voltage but u don`t need it.u need only current.
|
|
|
chloric1
International Hazard
Posts: 1140
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Offline
Mood: Stoichiometrically Balanced
|
|
| Quote: Originally posted by User | @halogenstruck
It's some nice DIY stuff.
Can you explain to me how you constructed the heat transfer between the arc and the reactor.
And do you have pictures of youre device.
I have 2 neon trans. laying around doing nothing.
It is quite easy to draw long and hot sparks with it.
Might be uesfull stuff. |
Neon sign tranformers are better designed for building Tesla Coils not arc furnaces. There are several books on building thoughs. What you ideally
need is a step down transformer. One that produces 30 to 40 volts and 50 to 80 amps. This way it can run off a 115V. It is the same as a 115V stick
welder.
Fellow molecular manipulator
|
|
|
Sedit
International Hazard
Posts: 1939
Registered: 23-11-2008
Member Is Offline
Mood: Manic Expressive
|
|
Here is an old paper from my website. It was published in an old science magazine known as The experimentor and it talks about making
something just like this only with one major difference that I feel is better then the nichrome resistor mentioned here.
In this article they use a salt water bath for the resistor where the depth of the electrode and the concentration of salt can change the desired
current to what ever one desires. Just though I would track this down for ya'll as I read it sometime ago and knew I had to have it uploaded already.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
|
|
|
densest
Hazard to Others
Posts: 359
Registered: 1-10-2005
Location: in the lehr
Member Is Offline
Mood: slowly warming to strain point
|
|
The suggestion of an electric welding apparatus for this sort of work is probably the best idea. For example, a used 115V (input) 50A (output) welder
is for sale locally for $US 35. I looked on the Internet for about 30 seconds to find that one. Not free, but much safer than any direct connection to
the mains!!!! For more money one can get 100s of amperes at 10-50V AC or DC.
The big advantages of the welder are (a) isolated from mains (b) knob to adjust current (and some have a knob for voltage too) and (c) big thick
cables and big thick power cord and big thick electrode clamps already attached. The case, wires, and clamps alone are worth paying for if you believe
in safety or convenience. I believe that the older units use an adjustable series inductor to limit current; more modern ones use semiconductor
inverters with current limiting.
For arcs or resistance heating the cheapest ancient electric welder will work very well and save a great deal of trouble and electric cost.
Besides, if you don't want it any more you can sell it, as opposed to an improvised apparatus.
[Edited on 27-9-2009 by densest]
|
|
|
| Pages:
1
2
3 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
