Does Science have any Liquid Nitrogen Dewars? I’ve read posts from years back that they did but I just wanted to check now.
Also, is there a general use policy if we do have them? IE, obviously they have to be removed from DMS to go purchase the liquid nitrogen. How does that work? Is there a check out system for example.
Thanks
Do you have a cooled FLIR? Inquiring minds want to know … 
We have a dewar. I don’t remember how big it is. Probably, at least 10 liters.
Usually, you can go to the gas or welding store, and they pour nitrogen into it. Because it is hard to measure, they typically fill it up and charge for the total volume.
It is on the bottom shelf of the large middle rack.
Just let Kobin know when you pick it up. He is the head of the science committee.
Who is making ice cream? The cool way…
DMS has at least one but last time we used it it no longer had a vacuum. We used up the LN2 pretty quickly for a video shoot. Think it was 20-30 liter.
BTW, most places (looking at you AirGas) will no longer do small fills. Metroplex still did them a year ago but you may want to call first. Also you cannot transport in a Car/SUV. Need to use a truck with a open bed.
I have two 10 liter and one 3 liter dewars as well as a one liter open top dewar “for science!” It is great for making dipping dots.
How many people does it take to lift a 20-30 liter one?
Two people can carry it easily.
Thanks!
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Thanks so much for all the replies. I don’t actually need it right now but at some point in the next couple of months would like to try treating some tool steel just for the heck of it. My use case isn’t that exciting but I suppose I can make it a dual activity day… treat some steel then make some ice cream. ha ha. Thanks for all the info and I’ll reach out when I’m ready.
If I can find a place that will sell me a small fill, should I expect to pay $2-3 / liter or more?
I will see if I can find my old invoices. I remember it being in the $1-2/liter range forever but was surprised at the cost last time $3-4/liter.
It’s almost like Hogwarts: Lampy’s Instant Exploding Ice Cream! @Lampy
Even funnier than the surprised look on the Ice Cream Meister’s face was Mini Bene @TBJK scraping ice cream off his face to eat. IIRC he was wearing safety glasses.
If there is a copy of that event, it would be a good laugh for the day if someone posted. There’s probably still stains on the ceiling tiles.
This truly a classic DMS blooper. We really need a permanent collection tape that gets added to. @Julie-Harris For those of us that don’t take ourselves post some of our epic fails (that would be me in pottery … it was so bad someone threw it away to save on energy before firing)
I think there is a video, let me see if I can find it.
Ken Purcell, master of time and space! Note the frame before ‘it’ happens
and then when ‘it’ happens:
and once stopped:
Note, nary a drop on the “Miester”, all energy went into the crowd (to their delight, as Tim showed).
I think this was our third ice cream batch at open house. Let’s just say that PET water bottles do not hold up to repeated exposures to high pressure CO2 and super cold temps. Luckily the relief valves were just gorilla tape.
Nothing better that chocolate ice cream licked off of a pair of safety glasses!
Now where is that pulse jet?
These videos don’t do this justice. This thing was incredibly loud, way way over 120dB likely. It was low frequency, I’d guess ~ 30 - 40 hertz and bounced back and forth between the buildings, This was done a mid-night New Year’s so cops had other issues to attend. They could feel the table vibrating in what is now the CA.
Brandon built this, it drank fuel - we ended up tilting the propane tank so liquid fuel could go in.
I’m the other idiot holding the tank. That radiated a lot of heat.
Are there any photos or video of when we went in the field at night with the trebuchet? That was great, gallon milk cartons with chemical lights in them. The strap broke on one launch and went straight up … we realized it was coming back down on us.
I think there was a sizzle reel of videos that the Garland City Councilman used to skuttle the use of the old military base. I remember Robert Davidson asking if we could get a copy. Was never prouder of a lot of DMS projects!
The liquid nitrogen Dewar is on the bottom shelf in the right side shelving unit as you approach the science area. Metroplex welding supply on Northwest Highway will fill it up if we bring it in person. But you can’t transport it inside a vehicle so make sure you have a pickup truck
