
Burning Out: What Really Happens Inside a Crematorium - aaronbrethorst
https://www.popularmechanics.com/science/health/a18923323/cremation/
======
nimbius
As a former machinist and mechanical maintenance engineer by trade, I can
attest crematoriums are a strange beast to work on. Bone fragments are left
over because the crucible like structures in which bodies are immolated reach
a relatively low temperature. Industrial processes routinely eclipse these by
orders of magnitude and in doing so effectively vaporize and destroy anything
left over. Alas, customers want proof and so certain inefficiencies are
tolerated in order to deliberately generate an ash byproduct.

Most crematoriums include elaborate air filtration systems. These are far and
away better scrubber systems than you would find at a chemical refinery but
the media lifespan is very low, and the maintenance cost of these devices is
nontrivial. The cost is worth it however...the stench of burning bodies is to
be avoided in any way considering most crematoriums are adjacent to fairly
residential areas. Most furnaces have a 'hard stop' at a certain number of
operations to prevent any possibility of overwhelming the filters. There is
also a specific mass limit to each cremation chamber, not unlike a normalizing
furnace or heat treatment furnace.

Crematoriums hate two things as far as i can gather: medical implants and the
obese. If enough furnace matter includes exotic plastics and metals, some
fairly dangerous conditions can occur. certain plastics and magnesium parts
for example can trigger a fire inside the furnace that can easily damage or
destroy it. Crematorium furnaces are equipped with, in my opinion, a very
limited amount of thermal refractory material compared to other industrial
furnaces.

Finally the sad truth about obesity is that you'll pay triple for a cremation.
Obesity increases the combustion byproduct and shortens the furnace filter and
burner lifespan as it increases the time required to properly cremate the
remains. large enough people require multiple furnaces.

~~~
runeb
Multiple furnaces?? Please tell me they don't divide the corpse before hand.

~~~
Consultant32452
When they cremate pets they just toss a bunch of animals in the bin at the
same time and then give each pet owner a proportionate amount of combined ash.

~~~
chiph
That's the low-cost option. When I had my cat cremated I opted for private
cremation where each pet gets their own vessel in the crematory. (There can
still be a tiny bit of ash mingling, as sometimes air currents will carry some
flakes into adjacent vessels.)

[https://thepetlosscenter.com/our-
locations/austin/](https://thepetlosscenter.com/our-locations/austin/)

She was with me almost 20 years, and it was worth the extra cost to be able to
have a remembrance of her.

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LgWoodenBadger
My family used to be in the funeral business, and as a kid I've gone on rides
to pick up bodies in Hearses, dug and filled graves, and visited a
crematorium.

My aunt was friends with the crematorium operator, and we got to visit one in
operation. The operator was retelling the story about the big stain on the
concrete floor near the furnace.

TLDR: There is a "formula" using body mass to determine whether they go in
head- or feet-first. If you get it wrong, the fat sometimes liquefies and runs
out onto the floor.

Whether this is true or whether he was just f'ing with a young kid, I don't
know.

~~~
SpikeDad
I just saw the construction of a crematorium on "How It's Made". Very
interesting - this one had two chambers. The primary chamber for the body and
then a secondary one connected with a sloping tunnel which was designed to
incinerate any fluidic remains.

Perhaps this is a modern construction. It seems very logical that fluids would
render from a body and need to be re-burned so this crematory accounted for
that.

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towb
I believe we have a few crematoriums connected to the heat networks here in
Sweden. Kind of creepy to think about, but creepy isn't a good argument
against it so why not, I guess.

My father passed last week, maybe he heated up a small part of Stockholm
already. I don't really know what happens next. Personally I don't care that
much, I got my memories and that is enough for me. But based on what happened
to the rest of my dead relatives he'll get a small plate with his name on at
the corner of some church yard. It will be up for x years until they have to
make room for the next batch. You can always pay to keep it up for maybe five
or ten more years, but what is the point? Memories are free and worth way more
than the tiny nameplate.

~~~
styfle
Are you suggesting that the furnace that heats your home is fueled by burning
deceased people?

~~~
fencepost
> Are you suggesting that the furnace that heats your home is fueled by
> burning deceased people?

The furnace that heats his home is more likely fueled by natural gas, however
the combustion chamber where that gas is being burned may also be used for
cremations.

I'm pretty sure that humans make pretty lousy fuel.

~~~
liveoneggs
“I shall not speak of the railway, for it is like any other railway—I shall
only say that the fuel they use for the locomotive is composed of mummies
three thousand years old, purchased by the ton or by the graveyard for that
purpose, and that sometimes one hears the profane engineer call out pettishly,
"D--n these plebeians, they don't burn worth a cent—pass out a King …”

twain

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ilkan
What a well written article. But from personal experience, it's missing
something. My dad's funeral service was held in the crematorium. Afterwards
they invited the closest family members to watch. Didn't warn us about what we
were about to witness. First, instead of the "nice" coffin with flowers on
top, he was put into a cheap-looking, thin plywood crate filled with thin,
twisted strips of paper. It looked like the paper equivalent of styrofoam
peanuts. The gurney was carelessly lying crooked against a wall as if it had
just rolled over and bumped to a stop. Then they rolled it into the furnace in
workmanlike manner and closed the room's blinds to block our view.

We all swore off cremation after that. Please leave after the service. Don't
watch your loved one's cremation, it'll be a horrible last memory that taints
everything that came before.

Second, the cremains are in a sealed plastic bag, inside a cardboard box.
After you scatter the ashes, what do you do with the box, the bag, and the
last ashes in the bag? Throw them in your household garbage? (Illegal, btw) It
was my reminder that not everything has a "nice" interface.

~~~
burfog
I haven't been there, but I really don't think I can agree with that.

I would want to keep my eye on my relative until the body is no longer
molestable. After that, I don't think I really give a damn, and they can just
chuck the crispy blackened half-done body in the trash.

------
skosch
Unrelated to the article, but related to crematoria, and a very fun 15-minute
read: [https://www.laphamsquarterly.org/roundtable/my-first-
mistake](https://www.laphamsquarterly.org/roundtable/my-first-mistake)

~~~
op00to
Chair legs!

------
pmoriarty
If you're in the SF Bay Area, I strongly recommend visiting The Chapel of the
Chimes in Oakland.[1] It's one of the most amazing buildings I've ever visited
in my life. It doesn't look like much from the outside, but inside it's like a
labyrinth of urns. It's one of my favorite places to visit in the Bay Area.
Very quiet and meditative place.

[1] -
[http://www.chapelofthechimesoakland.com/](http://www.chapelofthechimesoakland.com/)

~~~
strictnein
Do you need an appointment or can you just go and visit?

~~~
pmoriarty
No appointment necessary. Just show up during its hours of operation (which
are on its website) and go on in.

------
kolinko
Reminded me of a book written by a lady who worked at a crematorium - "Smoke
gets in your eyes"

[https://www.amazon.com/Smoke-Gets-Your-Eyes-Crematory-
ebook/...](https://www.amazon.com/Smoke-Gets-Your-Eyes-Crematory-
ebook/dp/B00J8R3MYW/)

~~~
jxub
And burnout is pretty quick too...

------
devy
Another interesting read about green/bio cremation/water cremation/alkaline
hydrolysis. [1]

[https://news.ycombinator.com/item?id=15060177](https://news.ycombinator.com/item?id=15060177)

~~~
xkcd-sucks
AKA the soap factory

------
fngo
> “What is that?” I ask, pointing to one of the silver trays of remains.

> “That’s a bone fragment. Probably a disc vertebrae,” Koslovski says, adding,
> “You can learn anatomy here.”

> “These are green,” I say.

> “I don’t know why. It could be something the person was treated with. It’s
> hard to say. It could have been cancer.”

> The crematorium puts the bones and ash that remain into a pulverizer, not
> unlike a food processor. The remains are then put through a sieve and into a
> container for the family—but not always.

If the average person knew this, would they still regard cryonics as creepy
and gross by comparison?

------
itworker7
I would have expected to see this in the Atlantic, surprising that it was in
Popular Mechanics. Very nicely written. Having lost my father-in-law late last
fall, the story was a little difficult but it made me realize how much in
common we all have when facing the loss of a loved one. And yes, my family is
planning on spreading at least some of his ashes at his favorite golf course.

------
pasbesoin
I've long wondered what happens to the mercury in amalgam fillings. I guess
I'll have to have a look at this.

~~~
pmyteh
It is released into the atmosphere, and is a very significant source of
environmental mercury pollution. More recent crematoria have scrubbers to
specifically remove it from the flue stream.

~~~
pasbesoin
I couldn't imagine what else would happen, nor that it's being removed
beforehand. At least they're starting to scrub it.

I also wonder about it with respect to burial. There are arguments about just
how inert/stable it is, in one's mouth.

Fill a field with small deposits that will reside for decades if not
centuries...

Long term problem. But, like other metal toxins, one that doesn't simply decay
and go away.

