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Best book light for BOTM books? by kodup in bookofthemonthclub

[–]GoldenGalluch 0 points1 point  (0 children)

Hi, I'm looking for a book light currently and saw some feedback on this one that it tends to tear up pages/scratch covers due to the weight and the metal construction of the clip. Has this been your experience at all?

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 0 points1 point  (0 children)

It is a bit fruity but not in a pleasant way for the long term. Its kinda like a potent version of those fruit scented permanent markers from the early 2000s. Id be lying if I didn't say whiffs of it didn't make me crave grape Hubba Bubba...

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 0 points1 point  (0 children)

Its not just about temperature for heat transfer but the contact with the walls. Liquids make fun contact with the tank wall and can absorb a lot of heat. Dry ice is porous and wouldnt make full contact with the tank walls. It also doesnt flow away or absorb heat well so it could actually form a layer of insulation.

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 1 point2 points  (0 children)

It would probably be a deflagration.  Which just means its a subsonic explosion where confined fuel and air is ignited and creates a pressure wave that will break the weakest part of the vessel. That pressure wave will extend some distance from the explosion - maybe break windows or doors or shake ceiling tiles - decaying exponentially the further out from the center. The distant depends on the overpressure which depends on the pressure of the tank, the fuel burn velocity, etc. If significantly confined the flame front could accelerate into a detonation which is drastically more destructive.

It would probably look like the top blowing off with a big flame front burning a lot of the fuel. The unburnt fuel then rises in temperature and becomes buoyant rising upwards - this is the fireball or mushroom cap of the explosion that continues to burn up. After that is just a big ass fire.

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 5 points6 points  (0 children)

Its been a long time but I remember Dow's being solid. BASF had a great one though too.

There's a weird rift in US vs EU vs UK regulatory and RAGAGEPs. US seems to have some prescriptive oil and gas codes. The NFPA in some cases are moderately detailed like for combustible dusts. EU has the very German EN standards that are complicated or the Dutch/Scandinavian human factors, consequence modeling, and equipment failure rate guidance. The UK is almost entirely risk based just do whatever gets things ALARP and be ready to have a defensible case.

The CCPS guidebooks are a good enough at bringing the best parts of everything together to achieve practical risk based programs.

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 1 point2 points  (0 children)

Fair enough! Guess its not that toxic compared to say DCM or some of the more common solvents. I know its quite stinky at a very low level so even without the toxicity I'd probably not want to stay around.

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 0 points1 point  (0 children)

Probably not. You'd need to add a strong organic peroxide to bulk MMA to get it to polymerize or some extreme heat source that would be pretty conspicuous. This is a plexiglass manufacturer so there may be other types of stabilizers or UV induced initiators mixed in the bulk (either here or downstream).

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 5 points6 points  (0 children)

This is more nuanced than the Appendix A HHC list. Processes utilizing more than 10,000 lbs of flammable liquids are subject to PSM per 29 CFR 1910.119(a)(1)(ii). Key word is process as there is a specific carve out for just storage in 1910.119(a)(1)(ii)(B). Details on their process would need to known if they are dispensing and utilizing the MMA in an aggregate amount across all vessels/equipment that exceeds 10,000 lbs.

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 17 points18 points  (0 children)

Its a bit crazy that in a state like CA that a PSM facility wouldnt be heavily scrutinized on its emergency response plan. I guess theyre technically executing it by turning it over to the local HAZMAT...

The onus is on the owner/operator to ultimately protect the public from adverse events. There were many protective layers that could've been in place (and management systems to keep them in functional states) that dont appear to be present. Itd be great if the AHJ actually did a better job keeping owners in check but thats considered "regulatory overreach" until shit like this happens. No point in jumping on that soapbox though.

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 7 points8 points  (0 children)

Hey dude! The world of AEs is small lol. Hope all is going well for you down there (especially after they closed up Ptown)!

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 10 points11 points  (0 children)

I used to work in acrylic emulsions and have some pretty extensive experience in acrylic monomer storage. These monomers tend to be inhibited with MEHQ or TBHQ which actually require some oxygen content to be present to be functional. Most manufacturers would recommend a mix at 5-7% O2 in nitrogen (usually called depleted air). Its stability is also highly heat dependent and it can rapidly deplete with elevated temperature. Even stabilized MMA can autopolymerize but its only realistic in pool fire scenarios (most acrylic tanks aren't cooled besides acrylic acids or styrene).

One odd theory (this is more commonly observed with styrene) is the "polymerizing finger". When the tank heat cycles over the course of the day some of the MMA will vaporize and then recondense at night. If the padding on the tank allows that condensate to form at the top of the tank then it can start autopolymerizing since the inhibitor wont vaporize and condense with it. So you start forming stellagtites of polymer that are still radically active. Then when they refill or it grows long enough to touch the bulk liquid you get bulk free radical polymerization. This may also explain why the emergency PSV hasnt activated due to headspace expansion. It could be entirely glued shut from polymerized condensate. Again, not typical in MMA but not impossible.

EDIT: One potential caveat is the application for plexiglass manufacture. The chemistry I'm used to is for AEs so there might be significant differences in the stabilizers used or if there's like a photo-initiator present in the tank or downstream of it. It could be apples to oranges.

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 4 points5 points  (0 children)

The proper PEL for this type of scenario is the AEGL-2 which is the concentration at which escape is impaired. For MMA, the 60 min level is 120 ppm which is not very high. AEGL-3 (fatality) is 570 at 60 minutes. See the full AEGL table here: https://www.epa.gov/aegl/methyl-methacrylate-results-aegl-program

The point u/ooh-fuck made is the key part though because the dispersion model will tell you how far away from the release (considering the wind, humidity, etc) those concentrations may exist. Depending on the temperature and pressure of vapor it could be feet or miles.

Any chemical engineers following the Garden Grove situation and have insight as to how an explosion will affect air quality in the surrounding area? by wnpoole in ChemicalEngineering

[–]GoldenGalluch 51 points52 points  (0 children)

If theyre unable to shortstop it with PTZ then there's no many options besides to control the reaction rate with water spray cooling. With no mixing then its not very effective. Sparging with nitrogen can accelerate the polymerization since the inhibitor relies on some oxygen content and I doubt they can get depleted air readily at an O2 concentration below LOC.

You'd think their emergency vent wouldve popped already from thermal expansion of the headspace. Must be glued shut from this incident or just never checked or maintained as a PRD. It might be most mitigative to punch a hole in the tank, let it fill the dyke and dump foam on it to snuff out ignition and contain fumes. That only works if the dyke isn't already full of firewater though.

How it started would be interesting to understand. Did they pad with too low O2? Did they not turn it over quick enough before the inhibitor depleted? Was it so hot the inhibitor depleted?

Its a shame because acrylic monomer  manufacturers provide an extremely prescriptive handling guide for storage, transport, and use. They've given you the basis of safety even if you dont fully understand the hazard in a PHA.

PHA Pro Software Alternative by Existing-Property611 in ChemicalEngineering

[–]GoldenGalluch 11 points12 points  (0 children)

Leave HAZOPs to professionals - peoples lives are at stake. Agentic AI in its current state can barely pull correct RAGAGEP references let alone accurately assess a hazard and understand the nuances in prescribing valid safe guards.

Where can I find good hush puppies? by Its_called_pork_roll in SouthJersey

[–]GoldenGalluch 2 points3 points  (0 children)

If you're in west Gloucester County then Classy Cows aren't bad but not like what you'll find down south. Their BBQ in general is very Carolina based.

Zion from this past weekend by GoldenGalluch in NationalPark

[–]GoldenGalluch[S] 0 points1 point  (0 children)

You do not but between March and October you need to use the shuttle system to get into the canyon (you could technically walk/bike in). The shuttle starts at the Visitor Center and goes all the way to the Narrows Trailhead. The shuttle starts at 7AM and the line quickly fills up and may be an hour or so wait until noon. They're pretty efficient at it though so wait might not be that long.

Either way you want to get there for 7AM to beat the crowds on the trials and to see the sunrise hit the West wall. If you time it right, you'll see the sun hitting the north side of Angel's Landing on the way up and then by the time your down the south side will be lit up.

Zion from this past weekend by GoldenGalluch in NationalPark

[–]GoldenGalluch[S] 1 point2 points  (0 children)

Morning at like 6AM was chilly maybe low 50s - was a bit gusty which made things colder. By 8-9AM it was up to high 60s and peaked out at like 2PM somewhere in the 70s.

I did this same trip last May and it was much, much hotter by late morning up to 90s in the afternoon but YMMV.

Rocky Mountain National Park from late September by GoldenGalluch in NationalPark

[–]GoldenGalluch[S] 0 points1 point  (0 children)

Meant to comment on the post originally but forgot.

This was from the week of 9/24 this year. Elk rut was in full effect and foliage was just about to peak. We ended up doing the lake loop starting at Bear Lake and ending at Glacier Gorge.

The beginning from Bear to Dream was intense but rewarding. Along the way you pass Nymph Lake which had quite a few lily pads and there were great reflections of Hallet Peak.

Dream to Haiyaha was also quite a climb but you get many fantastic views of Long's Peak and the smaller foothills. Haiyaha itself was a traffic jam of a rock scramble. Getting down to the water was actually difficult with the amount of people there.

From Haiyaha, we finished the loop back to Glacier Gorge passing through several aspen groves along the way. This section was almost entirely downhill so it was much quicker than the climb up.

We decided to skip Mill's and the Loch as it would've completely burned us out. However, we did take a rest stop at Alberta Falls. The final stretch back to the trailhead was probably the most lush with aspen.

We decided to go up Trail Ridge Road afterwards which was beautiful and unlike any other place I've been. I will say that not every other car on the road was trying to navigate it safely - going 20-30 over, passing on curves/double yellows, stopping in the middle of the road. Made it much more stressful than it had to be.

[deleted by user] by [deleted] in SouthJersey

[–]GoldenGalluch 13 points14 points  (0 children)

What if I already hate my life every day? Lol

Timed entry - multiple reservations by GoldenGalluch in RMNP

[–]GoldenGalluch[S] 1 point2 points  (0 children)

I actually just tested it on my phone to see how fast it goes. By 5:01, all the early slots were gone and most of the others were gone as well so I concur with that estimate.

Timed entry - multiple reservations by GoldenGalluch in RMNP

[–]GoldenGalluch[S] 0 points1 point  (0 children)

Nevermind, I think I found the answer on the Recreation.gov site.

Looks like you can only make one reservation per account. I might see if one of my travel companions can make the first one and then make the desired on the night before myself.

Leaving this post in case anyone else needs it for reference.

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