If the ice particles are like snow flakes, they may not conduct heat very well between the heated wall of the tube and the space within.
P.S.
How much heat is required to melt 1.6 grammes of ice at -40°C? (Tube opening diameter 10 mm, 20 s at TAS 250 m/s, TWC 4 gm^-3 (NPA 2011-03), 100% catchment efficiency)
Last edited by HazelNuts39; 4th Mar 2012 at 11:41.
Reason: P.S.