Sciencemadness Discussion Board

Generating lots of heat for high-temperature reactions

AlchemistMage - 5-8-2015 at 15:42

(I apologize in advance if there's a thread regarding this already. Didn't have much luck with the search engine on this one.)

What are some of the best/most efficient ways to generate lots of heat? Such as those needed to push high-temperature reactions forward and/or utilize a large amount of energy (say, to melt something with a very high melting point.)

Also, what are good ways to improve on heat efficiency? For instance, heating something on a hot plate obviously wastes a lot of energy since much of it is lost to the atmosphere. Surely there are better ways to manage such energy.

I'm definitely talking in excess of 1200C.

I've been looking into using solar energy with the aid of a fresnel lens to generate high temperatures. There is a video on YT wherein someone created a solar foundry, able to slice through steel and the like. Definitely the most efficient solution I see, both in terms of energy cost and utilization, but looks to take a bit of setup.

Obviously one can get propane/acetylene torches, but surely that gets costly after awhile by eating up fuel. Also, for some purposes, there's the issue of applying direct flame to certain substances (though perhaps as long as not too much energy is lost in the process, the flame can be used indirectly.)

Oscilllator - 5-8-2015 at 16:38

Microwave oven transformer. Quick, cheap, and combined with some carbon electrodes in a concrete box can melt just about anything. There is a huge amount of information on this, but the "Grant Thompson" youtube channel has great videos on all parts of this process.

James Ikanov - 5-8-2015 at 17:26

An alternate to the microwave transformer might be to use a slightly modified arc welder, but that can get pretty expensive.

battoussai114 - 5-8-2015 at 19:30

Let's get fancy, OxyHydrogen torch or induction heating on a metallic crucible maybe.
But overall a MOT is probably the only feasible option I could think of.

j_sum1 - 5-8-2015 at 19:36

Well, I am eventually going to build myself a charcoal furnace with forced air flow. It should take care of a few high temp applications and won't be to technical or cost too much.

kecskesajt - 5-8-2015 at 23:51

In old millitary packs(good old communist :D) there is a food heater,if you add water,it makes a lot of heat.
It consists of 2 things that i dont freaking dont know.

[Edited on 6-8-2015 by kecskesajt]

Bert - 6-8-2015 at 05:58

Magnesium powder, iron powder & salt were used for the ration heaters.

Not going to get much hotter than the boiling point of water with these-

Look in the oleum related threads.

http://www.sciencemadness.org/talk/viewthread.php?tid=5495&a...

[Edited on 6-8-2015 by Bert]

aga - 6-8-2015 at 09:41

Quote: Originally posted by j_sum1  
Well, I am eventually going to build myself a charcoal furnace with forced air flow. It should take care of a few high temp applications and won't be to technical or cost too much.

Mine melts Steel with just charcoal and a hairdryer.

Not tried using Coke yet.

kecskesajt - 6-8-2015 at 11:25

Coke is too nasty.It is capable of melting steel. But grill charcoal or the cheapest coal tipe.Just an air flow and its good.

WGTR - 6-8-2015 at 13:41

An electric furnace can be built inside "low"-temp insulative firebrick. The brick may be good up to 1200-1300°C, but is more insulative than the higher temp versions. Kanthal heating elements maintain the bulk of the chamber up around 1200°C. In the center of the chamber, a tungsten filament can be made to enclose a "hot zone", the small area where you'll be running at much hotter temperatures. Due to the thermal conductivity of the system, a temperature gradient exists between the hot zone and the outer walls of the firebrick. With proper design, none of the components will exceed their maximum temperature ratings.

For tungsten filaments, the furnace would need to be purged with an inert gas, or else it will oxidize very rapidly.

As an illustration of the preceding idea, think of an incandescent light bulb. The filament glows very, very, hot in the center of the bulb, yet the outer glass envelope may be cool enough to touch. If something small was fully enclosed by the filament, it would glow just as brightly as the filament itself.

Oscilllator - 6-8-2015 at 16:30

Quote: Originally posted by kecskesajt  
Coke is too nasty.It is capable of melting steel. But grill charcoal or the cheapest coal tipe.Just an air flow and its good.

I have used coke in the past and it is great if you can get it. It does produce a bit of clinker/ash, however I imagine charcoal does the same.
It can also be a little tricky to light if you are inexperienced, but overall I think it is a great fuel.

PHILOU Zrealone - 7-8-2015 at 09:00

Plenty of solutions....depending on aim, conditions and availability...
-Microwave heating.
-Inductive heating.
-Thermite reactions.
-Solar LASER with Corundum (ruby) reflector.
-Dicyanoacethylene (N#C-C#C-C#N) and O2 burning very hot.
...

kecskesajt - 7-8-2015 at 11:10

Quote: Originally posted by Oscilllator  
Quote: Originally posted by kecskesajt  
Coke is too nasty.It is capable of melting steel. But grill charcoal or the cheapest coal tipe.Just an air flow and its good.

I have used coke in the past and it is great if you can get it. It does produce a bit of clinker/ash, however I imagine charcoal does the same.
It can also be a little tricky to light if you are inexperienced, but overall I think it is a great fuel.

Can get it.But very pricey in small quanities.
I lighted the house's furnace since I was 8.Not unexperienced.
First wood with ligher fluid,second coal with airflow,third is coke with stronger airflow.