Sciencemadness Discussion Board

Electricity generated pyrotechnically.

Tacho - 19-8-2005 at 03:48

I read somewhere about this cells that generated power for missiles. Can't remember the refs. They are sort of a rocket fuel in a can. Ignite the fuel and power will flow through electrodes placed inside.

Any refs? Links? Memories? Names? Plain lies?

Mr. Wizard - 19-8-2005 at 05:44

There was a US hand held rocket launcher that used a heat generating pyrotechnic package to supply heat to a thermoelectric generator for the launcher at the time of it's use. It was a single use only and I don't now what composition was. The pyrotechnic was activated and you would have a minute or so (no idea how long) of electricity.

neutrino - 19-8-2005 at 08:19

This wouldn't happen to be a hydrogen/oxygen fuel cell, would it?

The only thing I can think of that might be similar would be the production of electricity by fine powders being blown through metal tubes. I'm looking at a book here that has an excerpt of a 1932 paper on this:
Quote:
When powdered materials are blown through metal tubes by means of compressed air, considerable quantities of electricity are produced by contact electrification. It was found that 6 e-6 Coulombs could be produces per gram of diatomaceous earth, a form of silica, blown through a short length of copper tube. A generator of extremely high voltage is proposed, and a small scale model of such a generator is described, by means of which currents of 8 e-5 amperes at 260 kV were generated.


It's probably not the same thing, but I thought I might as well throw the idea out there.

12AX7 - 19-8-2005 at 09:06

I think said device works like clouds. I forget how it works. But the OP is probably thinking of thermoelectric generators.

Tim

Thermocouple elements may be used.

Lambda - 19-8-2005 at 12:07

Just an idea:

If you would heat ceramic isolated thermocouple elements by the heat of a burning rocket motor, then this would generate electricity towards the cold juction thermocouple elements section. Burning rocket fuel is electrically conductive, for this reason they would have to be electrically isolated. By arranging them in series, higher voltages may thus be obtained. Due to the very low internal resistance, the currents would be expected to be very high. Electricity should be generated after a short warm up periode, which may be started before the main rocket charge is set of, by a special thermocouple laced igniter.

vulture - 19-8-2005 at 12:30

I wouldn't use rocket fuel for this application, too much heat loss through exhaust gas and forced convection.

Controlled oxidation of, for example, amalgated aluminium powder seems like a better idea, certainly because your oxidizer is in the air, meaning less weight.

No additional chemicals required

Lambda - 19-8-2005 at 13:45

Vulture, I was reffering to the electricly powerd rocket, that is fired off only once.

amalgated aluminium powder has weight, heat from the rocket motor needs no additional chemicals. The system will be almost dead, untill the rocket motor has been fired, and thus heat is produced. Absorbing heat in this way from hot gasses produced in a rocket motor, would only slightly deminish the thrust by a fraction.

FPMAGEL - 19-8-2005 at 23:20

It might be a magnetic hydro dynamics generator, its about 60% loss converting heat to electricity, which is about the top a turbine can make.
It would take to long to explain everything but basic when electrons flows throught a medium wither metal or air generates a magnetic field,if you have copper wire around the medium a current will be made.In the case of a metal medium, would be a electric motor. Air medium would be iodized gas, such as from a discharge or gunpowder burning.

[Edited on 20-8-2005 by FPMAGEL]

darkflame89 - 20-8-2005 at 01:51

An idea, you could fill a comtainer with hydrogen and chlorine gases. The reaction between the two could certainly provide heat to be converted into electricity. Though, you probably can only use this kind of thing once though. THe gases can be regenerated by electrolysis, but the efficiency is not worth it.