prometheus1970 - 20-7-2011 at 19:58
Does anybody know the combustion temperature (as opposed to ignition temp.) of Al based flash powder (either KCLO4 or KMNO4)? I've Googled the dookie
out of this to no avail... This does not really effect me I was just curious.
Actually I was just idly curious which would make a better charge for multi-break shells with components in them that have fuses that must
ignite when the main, outer shell breaks apart. On the one hand, Black powder burns much more slowly than flash, giving it alot more time to ignite
fuses, but on the other, flash burns so insanely hot(I believe) that it may ignite those fuses in the few milliseconds during which it is producing
heat...
hissingnoise - 21-7-2011 at 01:00
Chlorate and perchlorate-based flash comps can detonate when confined and are unsuitable as bursting charges in aerial shells . . .
QHarryQ - 21-7-2011 at 04:20
Pure potassium chlorate can be detonate by a powerful detonater,and the mixture of potassium chlorate,sulfur and diesel fuel is also a powerless
explosive ,no more pwerful than ANFO.
Bot0nist - 21-7-2011 at 05:50
If your having trouble getting the fuses on your break-aways to ignite try doping the ends of the fuses in a high sulfur BP mix(low ingition temp).
Also, I use rice hulls coated in BP for bursting. If you want to increase the temp of the burst charge without the the high VOD of flash, you can add
a little
<a href="http://www.skylighter.com/mall/product-details.asp?id=350">fine mesh silicone</a> powder. That really brings up the temp of the
composition.
[Edited on 21-7-2011 by Bot0nist]
quicksilver - 21-7-2011 at 08:05
I believe Shimizu's "Fireworks, the Art & Science" may also point to silicone as bringing the heat up substantially. There is also the issues of
Al form, physical mixing configuration, application of ignition,detonation or envelopment, and particulate size. There are many methods you could use
to bring up heat.
[Edited on 21-7-2011 by quicksilver]
prometheus1970 - 21-7-2011 at 08:20
I was just daydreaming/wondering, mostly, but thanks for all the good info! I am curious about the combustion temp of flash powder though, if anybody
knows it...
The WiZard helps those who help themselves
The WiZard is In - 21-7-2011 at 08:22
First better break charge - given that most use black powder
a few more exotic ones (See Shimizu, Fireworks Art and Science
for details) I would go with common wisdom.
Temperature - The late Fred L McIntyre ** for 40/60 aluminium/
potassium perchlorate.
Heat of combustion 2 768 cal/g
Heat or reaction 1 802 cal/g
Using these numbers with a little elementary chemistry you can
calculate temperature.
I would as a help mention two refs.
------------
Accession Number : AD0817071
Title : ENGINEERING DESIGN HANDBOOK MILITARY
PYROTECHNICS SERIES. PART ONE. THEORY AND APPLICATION
Corporate Author : ARMY MATERIEL COMMAND ALEXANDRIA VA
Handle / proxy Url : http://handle.dtic.mil/100.2/AD817071
Report Date : APR 1967
Pagination or Media Count : 265
Descriptors : *SMOKE MUNITIONS, *INCENDIARY AMMUNITION,
*HANDBOOKS, *PYROTECHNICS, PRODUCTION, CHEMICAL
PROPERTIES, PHYSICAL PROPERTIES, INTENSITY, LIGHT, ARMY
EQUIPMENT, SMOKE, VISIBILITY, HISTORY, HEAT.
Subject Categories : PYROTECHNICS
-----------
Accession Number : AD0830394
Title : ENGINEERING DESIGN HANDBOOK. MILITARY
PYROTECHNICS SERIES. PART THREE. PROPERTIES OF MATERIALS
USED IN PYROTECHNIC COMPOSITIONS
Corporate Author : ARMY MATERIEL COMMAND ALEXANDRIA VA
Handle / proxy Url : http://handle.dtic.mil/100.2/AD830394
Report Date : OCT 1963
Pagination or Media Count : 353
Abstract : The handbook is devoted to the presentation of data on
the principal ingredients of pyrotechnic compositions. The
information is presented on data sheets, representing a total of
128 ingredients.
Descriptors : *HANDBOOKS, *PYROTECHNICS, THERMAL
PROPERTIES, PHYSICAL PROPERTIES, THERMODYNAMICS,
MATERIALS, ORGANIC COMPOUNDS, INORGANIC COMPOUNDS.
Subject Categories : PYROTECHNICS
===========
** Accession Number : ADA096248
Title : A Compilation of Hazard and Test Data for Pyrotechnic Compositions
Descriptive Note : Final rept. Jan 69-Mar 79
Corporate Author : COMPUTER SCIENCES CORP NSTL STATION MS
Personal Author(s) : McIntyre, Fred L. ; Rindner, Richard M.
Handle / proxy Url : http://handle.dtic.mil/100.2/ADA096248
Report Date : OCT 1980
Pagination or Media Count : 382
Abstract : This report is a compilation of parametric, stability,
sensitivity, and output data on selected pyrotechnic compositions
derived from hazards evaluation and classification testing.
Additional results of manufacturing processes and process
equipment were studied, and the results of an incident/accident
survey are included in this report. This report provides a readily
accessible source of data for some 180 pyrotechnic compositions.
Descriptors : *HAZARDS, *PYROTECHNICS, MANUFACTURING,
PRIMERS, DUST, SMOKE, CLASSIFICATION, INDUSTRIAL PLANTS,
ACCIDENTS, DETONATORS, EXPLOSIVES INITIATORS,
ILLUMINANTS.
Subject Categories : SAFETY ENGINEERING
PYROTECHNICS
[Edited on 21-7-2011 by The WiZard is In]