Slack's favorite way to do a Al/Hg Nitro :)

slackdaddy · Fri May 06, 2005 9:29 am

I will keep this short.

Follow Methyl Man's writeup except...

All reagents X3 with the exception of MeOH X2.

Here's the beauty part-

Do it in a modified 6 quart steel pressure cooker rocking in a water bath when needed. When pressure starts to fall, transfer to beaker, stir/heat 30 minutes. Standard workup.

I don't even know what the yields are anymore, but they're better than anything in the glass flask/condenser setup. Much, much, much better.

It makes good sense though- no methylamine escaping, no volcanoes, and lots of hydrogen under pressure. Aluminum is always completely eaten up.

It's easier to set up and clean up too. Swim can't be the only one doing this, right?
Laughing

bio · Working Bee

Yep, does work quite nicely and sooo easy, no hoses, pumps, condensors. fragile glassware etc. Tested my SS cooker to 45PSI just to make sure it wouldn't blow up and fitted a guage, relief valve and schrader.

What is the max pressure you observe with MeOH and Nitro??? pressure is less and yield is more using premade MeNH2 and heating on the water bath for at least 6 hours after pressure drops eeks out the last little bit.

slackdaddy · Fri May 06, 2005 7:04 pm

I don't know what the pressure is - there is no guage on this Ch*f's D*sign cooker. The only mod I made was sealing off the safety valve as it leaked slightly after a couple runs.

I'm not worried about the dangers of this since this has been done quite a few times now, and even if there was an overload of pressure, I'm fairly sure that the rubber seal would blow out long before the vessel deformed.

bio · Working Bee

>>>>>>>>>>I'm fairly sure that the rubber seal would blow out long before the vessel deformed.>>>>>>>>>

Depends on the type of gasket I think. I'm not 100% positive but I believe the flat type gaskets will not blow but could actually seal tighter as designed to do in operation. These types have a fusible blowout plug in the lid. These safety plugs should NOT be removed unless another type of relief valve is installed. An air relief valve from a small tank compressor which A .....E hardware sells are set too high but I was able to accurately adjust a 125PSI one w/o changing the spring down to around 30PSI minimum. The stop needs to be drilled out but the spring screw is plainly visible.
The spring type also has a manual lifting ring which is handy.

The one I use has the hollow type gasket with a slot in the lid where it blows out at around 20PSI but this is the WRONG way to do it as it leaks first, won't reset if the pressure drops and would dump the entire contents into the room very quickly under a fast overpressure situation. This was blocked off.

BTW anyone reading this, the pressure valves on pressure cookers are designed to leak and the cooker may flat blow-up catastrophically before any signs of immenent failure if all the safety devices are defeated. There is a very good reason that Express Labs who certifies pressure cookers now requires 3 separate safety blow offs. Now just what do you think that very good reason might be???

Although I investigated the structural designs of these contraptions when doing testing it was kinda hairy for me running the thing 3x over rating. I had the pot under a wood picnic table covered with a heavy blanket with my refrigeration manifold hoses ganged together and me around the corner looking at the guage. Damn that must have been a funny sight. All I could think off was, shit anyindustrial vessel over 30PSIG steam must be ASME rated and this little thin piece of shit!?? Rolling Eyes

MargaretThatcher · Sat May 07, 2005 4:48 am

3x overrating! Once the manufacturer finds this out they will say 'over-engineering' and start using thinner steel.

Be interesting to see exactly what happens when a cooker fails. They are probably designed to fail safely. I hope so.

IndoleAmine · Dreamreader Deluxe

Ah, now I know which rxn vessels you guys prefer for that temmler patent.. Very Happy

bio · Working Bee

.................Once the manufacturer finds this out they will say 'over-engineering' and start using thinner steel. ........

Unfortunately they probably are already using the thinnest possible steel and cheapest alloy that will pass the codes. The standards are stamped on the bottom and vary from country to country. This reminds me of 3 washers and 5 lug nuts on your GM car wheel. Guess they figured out that only 2 and the wheel would fall off.

300% over pressure is a sort of rule of thumb for structural pipe design and burst pressures are 500% and over working and standard field test pressures are 150% for a few hours. This is depending of course on the code followed. So please don;t anyone try 500% on your pressure cooker except maybe at the bottom of a swimming pool..

But seriously folks please do not defeat all the safeties it's very dangerous.
Many people have been very seriously injured just by the escaping steam
due to opening their pot roast before venting and that is why new ones have the handle interlock.

The one I use is rated 13PSI and I run it 20-25PSI which is well within the limits of a new , unblemished unit.and was tested for a couple hours at 45PSI to have at least a little peace of mind, however I don't stand near the thing any longer than neccesary using adequate precautions. If you are not mechanically inclined
have a friend help or take it to a machine shop. A DIY fitting blowing out into the face even at a few PSI could..........enough already. You get the idea.

Paint pots are better IA get a SS one with a stirriing gland.

anime · Tue May 10, 2005 11:30 pm

So let me get this straight,
the ketone, and nitromethane are added at the same time as everything to the pot? Only modification is the sealing of the safety valve?

What are the yields like on a 3x sca;e? (for reference).

lurker4711 · Fri Jun 10, 2005 7:18 pm

In the EU all presurized containers must stand by law an 8-fold overpressure over the rated pressure (with blocked safety valve, etc) before they rupture. Rupture is word here, it defines that these vessels by no way may explode but that they MUST have a weak part where the vessel breaks open. This says: A quality pressure cooker will at least take 8 bar - in reality it takes more, I contacted a manufacturer on this and they told me that they are at least 2x over what the law demands to make up for any flaws which *might* occor in the process of munufacturing. The refused to give this infomation written, only by phone for obvious reasons.

A (EU) pressure vessel will take 5 bar with ease.
It will never explode shrapnel style.
It is a good idea to apply a bigger safety container where the pressure vessel is put into for the contents might splash when anything happens.
The sealings are the weak point in special when aggressive compounds are processed - ah would I love some Viton here!

3 bar are not even elevated pressure by definition. Who has a problem with 3 bar must live a life in fear as evrytime he passes a car he is in deadly danger! 4 rubber thingies on the car and everyone blown up to this terribel pressure! And rubbed over the street in cold and heat by 150hp engines! Hello!

In reality overdone (pseudo)security measures create more trouble and dangers then they prevent. I learned this quick.

PS: A splashscreen/plate over the top of the cooker is good idea. As thats where the shit comes out when it comes and you can´t do much when this happens (swearing is an option though) but you can prevent from start that the shit hits the ceiling and then you. What will make you very lonely for some days when it was methylamine.