On Friday 30 December 2016 11:06:08 Jon Elson wrote: > On 12/30/2016 05:56 AM, Gene Heskett wrote: > > Makes me ask what "genius" is running such a place. :) I am amazed > > at the inefficiency of such places. > > They pipe liquid helium all over too cool the > superconducting magnets to 7 K or below. EVERYTHING is > supercon. They use a commercial Kaeser rotary screw air > compressor to compress the helium for the liquifier. It is > a big unit, I think 130 HP. They have the most intricate > monitoring and control system that manages the whole place > (EPICS). But, somehow, a sensor failed and caused the > control system to NOT alarm on a loss of helium, due to a > leak at the compressor. They lost the whole inventory of > helium before other systems started alarming. They had to > shut down the whole facility and warm up the magnets, and > ended up losing something like $10 million of helium. Well, > THAT wasn't supposed to happen. > > Jon
And I suppose the real schematic for that was top secret. And typical of the security agencies, such clearances weren't available to the like of me. The best they could do for me, as a Field Checkout Tech while putting a titan site in western S.D. together in 1960 was a Confidential. I think they work on the principle that if your IQ is greater than the eyelet count in you tennie's, you can't be trusted. When in the joyous project of ringing out all the wiring in a titan 1, I found 2 feedback signals from the first stage motor positioners were crossed and on launch, it likely would have screwed itself into the ground before clearing the parking lot. I reported the error, they kept telling me I was wrong and finally had another crew to recheck it, wasted 33 days trying to convince us with the 630's in our hands that Martin Marietta does NOT make mistakes, just to get permission to interchange 2 wires on adjacent terminals in the connector skirting wrapped around the 2nd stage engines. I can certainly see that in a project of that magnitude, they'd want every i dotted with a round dot, but at the time it was damned frustrating. AIUI, that warmup also damaged some of the magnets. Too fast. Since the cooldown had to be staged for the same reason, I assume they started with GN2, then LN2 a week later, etc etc. Then as fast as they could, evacuate the LN2 and switch to gaseous helium, gradually cooling it until they got to liquid. They would I assume do some gas separation with a big Cardox or similar to get rid of the residual nitrogen. A complex process to be sure. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
