3 replies to this topic

[Rhodri]

Hi

A while ago some of us were talking about Roman Canldes and the pressures generated.

I'd said that I'd post up some data about the pressures generated from a BP composition.

Well here it is:

100 g of BP at NTP will produce:

386 Litres of gaseous products.

This equates to a pressure of 18.7 Kg/cm.

This information was collected by Bichel in 1902, using a 15-Litre nickel-steel 'charge' chamber.

No wonder a star shoots out so fast from a candle!



[Edited on 7-6-2003 by Rhodri]

[bernie]

useful information. Empirically speaking, it's more fun to just give it a whirl. Having a base line to start from is a very important though.
The SPEED has to do with granulation size. Volume of gaseous product I suppose is pretty close regardless of size.
Stored energy.

[Rhodri]

Absolutely Bernie. The push is from the rapid solid to gas transformation.

I've got some excellent books on thermodynamics - I'll dig them out - it'll remind me of college though and the horrible anticipation of exams.

Still gives me the shudders after all these years,

[Pyromaster2003]

pretty impressive stuff, im going to have another go at making a roman candle again tomorow.