X-Message-Number: 2072
Date: 07 Apr 93 02:58:54 EDT
From: "Steven B. Harris" <>
Subject: CRYONICS Cold Room Psychology


   To Brian W:  Why have 4 reservoirs when you can have one
central one?  I personally don't see the problem with LOx
buildup: every so often you can just let your central reservoir
boil just short of dry to make sure that all the O2 is gone.  
For the last 10 % you can speed things up by lowering a heating
element (such as a lit ordinary 100 watt light bulb) into the
liquid.  I've seen this done for 20 or 30 seconds, and I would be
willing to bet there is no time limit of operation.  If there is,
you can always use a jimmied toaster <g> (I'm only partly
kidding-- a toaster will probably work just fine for this).  For
safety, the last part of boildown will require someone standing
by with multiple LS-160 dewars, ready to fill `er up again if
anything goes wrong, but this is not an unduly unsafe require-
ment.  Things get a lot more scary when we transfer patients!

   Your design with the LN2 in a lot of gravity fed horizontal
floor pipes and upright pipes looks a lot more complicated than a
simple metal plate, and moreover is likely to fill up with cold,
and stratified air like those low open-top supermarket ice cream
freezers, if you insist on getting "cold" in through the bottom
and sides, and out through the top (i.e., having heat come
through the top to be removed through bottom and sides of cell). 
Is this all worth it for top access?  Might be better to cool
everything through one thick top plate (with some -196 C re-bar
running between the insulated sides of each cell, as necessary),
and have each cell equipped with an individual square metal "roof
access" plate which makes good thermal contact with the rest of
the roof metal "grid" which is in turn part of the bottom of the
nitrogen tank.  When you need a patient you then take up a foam
cap, lift out a square metal thermal contact plate in the main
metal -196 C conductor grid/plate, lift up yet more foam (the -
196 to -135 gradient foam), and then access the patient.

   A refrigeration system that removes 400 watts at LN2 temps
could be used only as a backup, in order to drastically reduce
LN2 use in emergencies (we ought to see if they have a 40 or 50
Watt one for our bigfoots).  You then wouldn't have to run it all
the time, and with a Diesel-generator powered one, you'd gain a
big safety margin in disasters in which your LN2 deliveries are
slow but your structure is intact.  

   One of these things running all the time, on the other hand,
might make land away from cities usable for cryonics (with LN2
deliveries maybe only every month or so), and we could pay for
the refrigerator with the savings in real-estate, as Clarissa
suggests.  Of course, this goes also for refrigeration systems
that work simply at -135, and use a large ethyl chloride ballast
(I'm working to get those ethyl chloride numbers, Brian).  Still,
Brian may be right about the reliability of mechanical refrigera-

   To Clarissa:  Ah the difference between men and boys is the
expense of their toys, eh?  "Gosh, you guys-- your cryoroom is
much bigger than mine, and thermoelectric, too.  It's so em-
barrassing.  I'm beginning to suffer from Peltier envy......"

   Doubtless there is some deep psychology here, and it is clear
than human males do indeed enjoy a particular sort of aesthetic
delight in making mechanisms, engines, projectiles, and 
generally bigger, better, and more powerful and self contained
whatnots and gizmos.  Whereas women seem to be more into nur-
turant biological sorts of activities which involve maintaining
environments and nutrition to living organisms.  And, especially,
nest cleaning.  I'm sure all this is hormonally related, and
there is in every one of our brains a dirt sensor which is
estrogen driven, and another module for spacial tasks, throwing
projectiles, and destroying things, which is testosterone driven. 

   But let's not knock this division of labor-- both outlooks and
sets of priorities have been historically tremendously important
to the development of the human race and the modern world, and to
my mind both men and women are equally biased, and equally weird
about how they see the universe.  The best we (each sex) can do
is to try to sell each other our viewpoints so that we do not
make the worst mistakes, and I hope we can do that on this forum
without too much snobbery or sexual Chauvinism (on either side).

   Yes, R. Ettinger's perlite tanks are not smooth and metallic
and high tech dead machine looking.  In fact, they're sort of
organic and formless and handmade.  Gosh, they are a little like
birdsnests.  Eh...   Are you sure it isn't YOUR biological bias
operating here, Clarissa, rather than ours?

   The problem with evaluating professor Ettinger's designs
rationally is that they are one-of-a-kind things, and I'm not
sure if anybody (even Ettinger) really knows how many hours of
labor it would take to duplicate them.  The other problem is that
all of Ettinger's designs depend on a vacuum pump running
constantly, and they all increase boiloff by a factor of 10 or
something if that pump fails.  This doesn't sound nearly as nice
as passively insulated systems which don't require much tending.

   As to strictly mechanical refrigerators, the problem with
mechanical refrigerators is that (perhaps until recently) nobody
has made off the shelf units to work below -110 C or so (I'm not
counting the ones that run on liquid nitrogen-- if we have to use
liquid nitrogen, we can do this project better ourselves).  It
might well be possible to get -135 with -110 freezers sitting
around on the floor in a large room-sized freezer at 0 C., as
CLarissa suggests, but that would be rather inefficient of space. 
Perhaps Brian can tell us if the people he talked to, with the
mechanical refrigeration units that go down to -196, have any
off-the-shelf refrigerators made up to use them.     


P.S.  To Steve Jackson: I've been informally chronicling and
critiquing fiction with resurrection themes (including cryonics
fiction) for some years now, and have at least one summary
article about the subject.  I will also be reviewing "resurrec-
tion from the cold" stories by Edgar Rice Burroughs (1937) and
Jack London (1899) soon for Cryonics Mag, when I can get to it
past all my other work.  Send me you address by email, and I'll
let you have material as it becomes ready.


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