Combustion of Donut in Liquid Oxygen
oxygen, donut, sugar, grease, fat, combustion, LOX, liquid oxygen
This experiment is
not available beginning Summer semester 2005
due to incident of detonation and glass schrapnel
reinstated effective Nov 13, 2006.
not given effective 20061113, the experiment may be is reinstated. Items noted below in red are modifications to be strictly followed in response to the Spring 2005 incident.
donut* (standard glazed, use about
1.5 1.0 inch cube piece max)
Liquid Oxygen, ~1-2 L, in Dewar flask
Unsilvered Dewar Flasks (2)
beaker, 4 L
ringstand, ring clamp (4L size), iron ring
long tongs, bend as needed to use in conjunction with
secondary shield for hand protection
Meker or Fisher burner
blast shield for class and experimenter
secondary shield for demonstrator
for hand protection
Cryogenic - Liquid Oxygen
Oxidizer - Liquid Oxygen
Explosive - Liquid Oxygen (in presence of fuel)
Implosion - Glass Dewar Flasks
Detonation - *high density or too large piece of donut
Glass schrapnel - from beaker upon detonation, 5 meter radius minimum
Caution - use about 3 inches deep of liquid oxygen - donut should never touch bottom of beaker. Use of too large or high density piece of donut may (and has) result in detonation.
Smoldering donut will at times stick to the tongs, making it
difficult to release the donut piece into the LOX. If the tongs are tapped on a protective ring just above the 4L beaker, additional downward velocity may be imparted on
the donut. The additional velocity may promote an unplanned violent explosion.
A metal rod, bent strategically, should be used to dislodge a sticky donut
piece. Tong should be retracted promptly to prevent pressure build-up over
* typical donut holes work well and are the correct size