Maybe submersing in water bath would help even temp profile On Sunday, February 8, 2015, Bob Cook <frobertc...@hotmail.com> wrote:
> I think the failure was caused by a brittle fracture of the alumina tube > due to thermal stresses, internal micro stresses caused by micro bubble > formation and resulting embrittlement. > > Bob > > Sent from Windows Mail > > *From:* Bob Higgins > <javascript:_e(%7B%7D,'cvml','rj.bob.higg...@gmail.com');> > *Sent:* Friday, February 6, 2015 1:00 PM > *To:* vortex-l@eskimo.com > <javascript:_e(%7B%7D,'cvml','vortex-l@eskimo.com');> > > Ryan Hunt reports that the failure mode was NOT the compression fitting > giving way under pressure - the fitting remained intact. This experiment > was of the "easier Parkhomov" design, posted previously where the seal was > made with a compression fitting, in this case with the use of a soft > aluminum ferrule at the suggestion of Alan Goldwater. Alan's tests > suggested the compression fitting would hold and it did! Using the > compression fitting is a real win because it completely avoids the > problematic sealing of the ends with cement while providing an opportunity > to instrument the reaction vessel. > > When this failure occurred, it appeared to be a raw ceramic body failure. > This could easily have come from too much pressure coming from a too large > charge of LiAlH4 for the vacant volume inside the apparatus. MFMP will > extract that volume information and relate it to the weight of LiAlH4 that > was added, as being a benchmark for too much LiAlH4. The tube used was > 1/4" OD, but at the moment, I am not sure if it was a 4mm ID tube or a 1/8" > ID tube. The Parkhomov tube had an ID of half of its OD. > > Bob Higgins > > On Fri, Feb 6, 2015 at 11:39 AM, MarkI-ZeroPoint <zeropo...@charter.net > <javascript:_e(%7B%7D,'cvml','zeropo...@charter.net');>> wrote: > >> At 2:29/2:30 into the short segment posted by Craig, it looks like the >> right-side end-plug, or whatever is sticking out that end, blows out. And >> I use that term specifically since one also sees some hint of a pressure >> release. Whether that release is at an appropriate level is apparently >> debatable... >> -mark iverson >> >
