Paraffin/liquid mixture
dbo...@mindspring.com
bubbles of liquid hydrocarbon are suspended. I would like to vary the
volume ratio of bubbles to paraffin. I have done some experimenting by
heating paraffin to liquid, mixing in diesel or other oil with a
motorized paint stirrer and allowing it to harden. Under a microscope,
I see tiny pores that I think are the diesel and when I squeeze it I
see what I think is diesel ooze out. I'd really like to know a little
more about the chemistry of this in order to choose my hydrocarbon
better. What does determine the solubility of a hydrocarbon in a
paraffin? I see a lot of material about solubility of paraffin in
hydrocarbons but not the other way around.
Basically, what I am looking for is liquid bubbles that will expand or
evaporate very rapidly as the paraffin burns thus causing the paraffin
surface to become tiny droplets with high ratio of surface area to
volume.
Any ideas?
Frank Logullo
<dbo...@mindspring.com> wrote in message
news:1107098974.5...@f14g2000cwb.googlegroups.com...
the answer may be to heat it up.
Cooling may give a desirable gel.
Frank
Uncle Al
>
> I am looking for a way to make a mixture of solid paraffin in which
> bubbles of liquid hydrocarbon are suspended.
Like dissolves like.
> I would like to vary the
> volume ratio of bubbles to paraffin. I have done some experimenting by
> heating paraffin to liquid, mixing in diesel or other oil with a
> motorized paint stirrer and allowing it to harden. Under a microscope,
> I see tiny pores that I think are the diesel and when I squeeze it I
> see what I think is diesel ooze out. I'd really like to know a little
> more about the chemistry of this in order to choose my hydrocarbon
> better. What does determine the solubility of a hydrocarbon in a
> paraffin?
One expects "miscible."
> I see a lot of material about solubility of paraffin in
> hydrocarbons but not the other way around.
Paraffin *is* hydrocarbon. It raises the pour point of fuels and is
therefore objectionable, espcailly in winter.
> Basically, what I am looking for is liquid bubbles that will expand or
> evaporate very rapidly as the paraffin burns thus causing the paraffin
> surface to become tiny droplets with high ratio of surface area to
> volume.
> Any ideas?
Analog of Pop Rocks.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
dbo...@mindspring.com
are liquid but the bubbles must remain liquid when the paraffin becomes
solid.
Uncle Al
NFL.
Steve Turner
A hydrocarbon liquid which is imiscible with paraffin ... I don't
think there is such a thing. Does the liquid have to be hydrocarbon?
Perhaps you could describe your application.
Steve Turner
dbo...@mindspring.com
It is rocket fuel. Specifically, hybrid rocket fuel. Solid rocket
fuels offer convenience but low specific impulse and no ability to
control the thrust in flight. They cannot be stopped and restarted.
OTOH, liquid fuel rocket engines (liquid oxygen/kerosene for example)
offer high specific impulse and ability to throttle and restart but are
difficult to make. Hybrid engines offer intermediate specific impulse,
ability to throttle and restart and are fairly easy to make.
A hybrid engine consists of a solid fuel with a passage for the
oxidizer to pass and burn the solid fuel. Oxidizers could be Liquid
Oxygen, Hydrogen peroxide or Nitrous oxide. Common fuels are rubber,
plastic and ........paraffin. The recent spaceship one used a rubber
fuel and nitrous oxide oxidizer. The problem with a hybrid is they
have low thrust for a single oxidizer/combustion passage because the
burn only takes place on the fuel surface. Multiport fuel systems are
possibel but are unreliable because as the ports burn toward each other
the chunk of remaining fuel can break free and clog things with
disastrous results.
It was noticed that some paraffin fuels gave much higher thrust than
expected and NASA found that this was because the burning caused
surface waves on the melting layer of paraffin fuel (literally candle
wax) and the flow of hot gas blew the tops off these waves causing tiny
droplets of fuel with very high ratio of surface area to volume.
So, I am after a way to get more of these these droplets to occurr. As
the burn progresses into the wax, the liquid hydrocarbon bubbles will
expand rapidly and burst causing tiny droplets of wax to be blown into
the burn. If the burn (called regression) can be made to happen fast
enough, high thrust engines can be built without unreliable
multi-ports.
So, the bubbles should be hydrocarbon to act as more fuel although you
might have bubbles near the outer edge to slow the burn down or mixed
types of bubbles to make thrust constant for a given flow of oxidizer,
etc.
Any ideas?
Uncle Al
Paraffin wax is not stiff or strong. Kraton thermoplastic elastomer
will give you any durometer you want, great strength, and go to mush
above the mp of polystyrene. Easy to injection mold, too - no waste.
Now you need an immiscible dispersed phase with a modest bp for
microexplosions.
Paraffin or Kraton you need something polar for immiscibility,
possibly with some added inverse dispersant (e.g., Aerosol OT, dioctyl
sodium sulfosuccinate). A middling alcohol with a bp over process
temp ought to do it. Even dispersed water would be interesting (and
cheap, and Enviro-whiner invulnerable), though you'd have to cast and
cool under pressure.
As you know, the lower the average exhaust MW the bigger the specific
impulse. One then wonders about a rubber dispersed with finely
powdered commercial LiH. You must guard against moisture and humidity
during processing, and you don't want to go much above 250 C or the
stuff breaks down to metal and gas. Don't stand downwind of the
exhaust plume. It would be a bitchin' liftoff, especially at night.
dbo...@mindspring.com
AT LAST, someone who knows what I am talking about. Forgive my
ignorance of chemistry as I am not a chemist nor even a rocket
scientist. Normally, I do x-ray optics stuff (www.parallax-x-ray.com)
but this idea looked like too much fun to drop.
At first I considered water but that resulted in too much weight and no
increase in total impulse. Then I thought of just using H2 which has
some merits but I think various hydrocarbons will provide more hydrogen
for their volume.
I read that Ethanol is immiscible in "paraffin oil" which is kerosene
but a couple references seem to imply that it is also immiscible in
paraffin wax. Is this correct? What alchohol would you use?
As far as LiH goes breaking into Li and H, hmmmmmmm. Li is not as
reactive as many people think. I once used thin Li sheet in a sort of
"lost wax" casting process where the Li was dissolved in water. It
does not readily catch fire although hydrogen is released. I once ran
across a LiH foam used for nuke weapon apps......
Uncle Al
> AT LAST, someone who knows what I am talking about. Forgive my
> ignorance of chemistry as I am not a chemist nor even a rocket
> scientist. Normally, I do x-ray optics stuff (www.parallax-x-ray.com)
> but this idea looked like too much fun to drop.
The world is overflowing with wealth and ability. What it lacks is
new ideas.
Uncle Al says, "If it isn't fun it had better have a big consulting
fee attached."
> At first I considered water but that resulted in too much weight and no
> increase in total impulse. Then I thought of just using H2 which has
> some merits but I think various hydrocarbons will provide more hydrogen
> for their volume.
The greatest specific density storage of hydrogen atoms is
hydrocarbons. LiH comes very close and it has a big wollop for
energetics. Nice red flame color.
> I read that Ethanol is immiscible in "paraffin oil" which is kerosene
> but a couple references seem to imply that it is also immiscible in
> paraffin wax. Is this correct? What alchohol would you use?
Lower alcohols in general will be immiscible with hydrocarbons. The
longer the alcohol hydrocarbon chain the more will tend to dissolve,
especially when hot. Paraffin is extemely crystalline as the solid.
A pure paraffin casting (a candle) has huge initial shrinkage upon
solidification (almost 15%) and will continue to shrink a little more
for a week as it continues to crystallize. Stearic acid, beeswax, and
microcrystalline wax are typically added to paraffin candles to screw
up crystallization and its deformation of the casting. The alcohol
would segregate at crystal boundaries. If you found a system that was
soluble molten but not as the cooled solid, it might disperse itself.
Paraffin typically melts below 60 C. Denatured ethanol (78 C bp) is
kinda low. Dry n-propanol at 97 C ought to do it. Adding a little
water will reduce solubility in the wax. Remember what "flambe" means
in cooking. The vapors will be very flammable.
1-Butanol bp 118 C, 1-hexanol bp 156 C, 1-octanol bp 196 C are not
overmuch expensive. One might try soluble hot/insoluble cold with
them. As with TNT castings, try aging the cast wax composite warm for
a few days to get things equilibrium crystallized faster.
> As far as LiH goes breaking into Li and H, hmmmmmmm. Li is not as
> reactive as many people think. I once used thin Li sheet in a sort of
> "lost wax" casting process where the Li was dissolved in water. It
> does not readily catch fire although hydrogen is released. I once ran
> across a LiH foam used for nuke weapon apps......
Powdered LiH will inflame on contact with water - fast reaction, big
exotherm. It rapidly goes to crap in humid air. Casting densified
H-bomb secondaries with Li(6)D benefited from a deuterium atmosophere
to prevent thermal dissociation during sintering. Lithium is toxic by
ingestion. Alas, LiH is not apparently sold as a paraffin oil
dispersion.
The Space Scuttle is considerably over-stoichiometric in hydrogen for
its three H2/LOX engines. The specific impulse boost from lowering
exahust average MW was too good to pass up.
dbo...@mindspring.com
Thanks Al.
Now, whether to try it or not. Flowing Oxygen through a tube filled
with an annular wax/hydrocarbon bubble mixture and setting it alight is
the definition of fun but maybe not too wise. Maybe write an SBIR to
get funds to figger the right stuff to use. However, although my SBIR
success rate is seriously high, I admit to knowing little chemistry and
little rocket engineering, so, I'll write it and provide the facilities
if there is someone who is qualified to be PI.
My success rate on SBIR proposals I write is over 80% in the past 9
years primarily because I do not write about anything I am not
convinced will work and be commercially viable. So, I do not run an
SBIR mill and will refuse to write a phase II if I cannot see
commercial success. I believe that another aspect of success in
writing these is communicating the excitement of the new technology
rather than the usual dull as watching paint dry usual scientific
paper.
Interested? If you know chemistry and some rocket stuff, check our
company web site (www.parallax-x-ray.com) for our e-mail address.
We'll have to start a new company cuz Parallax is overworked with x-ray
projects.
Uncle Al
>
> Uncle Al wrote:
> > dbo...@mindspring.com wrote:
> > > Uncle Al wrote:
> > > > dbo...@mindspring.com wrote:
> > > > > Steve Turner wrote:
> > > > > > On 30 Jan 2005 13:46:02 -0800, dbo...@mindspring.com wrote:
> Thanks Al.
> Now, whether to try it or not. Flowing Oxygen through a tube filled
> with an annular wax/hydrocarbon bubble mixture and setting it alight is
> the definition of fun but maybe not too wise.
It's generally done on a rocket test stand with suitable
instrumentation. The meat puppets are kept behind armor during the
test. It is rumored that the DoD tried a dimethylberyllium/liquid
fluorine rocket engine. I can't imagine how they pumped the oxidant
or how downrange was isolated forever after.
Ask Scaled Composites to give it whirl.
> Maybe write an SBIR to
> get funds to figger the right stuff to use. However, although my SBIR
> success rate is seriously high, I admit to knowing little chemistry and
> little rocket engineering, so, I'll write it and provide the facilities
> if there is someone who is qualified to be PI.
> My success rate on SBIR proposals I write is over 80% in the past 9
> years primarily because I do not write about anything I am not
> convinced will work and be commercially viable. So, I do not run an
> SBIR mill and will refuse to write a phase II if I cannot see
> commercial success. I believe that another aspect of success in
> writing these is communicating the excitement of the new technology
> rather than the usual dull as watching paint dry usual scientific
> paper.
> Interested? If you know chemistry and some rocket stuff, check our
> company web site (www.parallax-x-ray.com) for our e-mail address.
> We'll have to start a new company cuz Parallax is overworked with x-ray
> projects.
At the moment
http://www.mazepath.com/uncleal/qz.pdf
is running in PR China. In April I hope to start the third and final
series of experiments for chemical synthesis of diamond from molten
salt solution at ambient pressure. I finally got the reactor
engineering squared away and fabricated. The trick was to remove
stuff. Simple is good - and have a big rupture disk aimed at cheap
real estate.
Uncle Al, "The Mark I reactor can't grow anything much bigger than 100
carats, even if we get clever."
Management to Uncle Al, "Start with 100 carats."
If it works at all it will probably make abrasive. Maybe Norton wll
be interested in growing a tonne of abrasive diamond in 24 hrs on a
big sheet of metal suspended in a narrow vat of Devil Solvent.
Burt Rutan at Scaled Composites would be the best target. Not A Space
Agency is a bad joke.
dbo...@mindspring.com
Yes, but I know how to get SBIR money from NASA if I can get the right
person as PI whereas SC is likely to respond "Who the F are you"?
Uncle Al
> Yes, but I know how to get SBIR money from NASA if I can get the right
> person as PI whereas SC is likely to respond "Who the F are you"?
I've never done rocket fuel or engines. You might start by locating a
suitable test stand at ATK (Morton-Thiokol, the Space Scuttle
supplier), Orbital Sciences Corporation, Boeing/Rocketdyne, NASA,
Lockheed/Martin, or another entity that makes rocket-propelled
munitions or sounding rockets. If you have access to analytical
hardware the money will follow.
http://www.hobbyspace.com/Rocketry/rocketry3.html
<http://www.friends-partners.ru/partners/mwade/lvfam/souckets.htm>
Casting novel engine cores for insertion into an SOP procedure should
be high potential gain for small research risk. It is the right
patter.
Do you want a deliciously crazy idea? Take hollow glass
microballoons, put them in a Parr vessel, purge and pressurize with
1000 psi (or whatever - respect crush strength) hydrogen, and warm.
Hydrogen diffuses in to high pressure through the microwalls. Cool,
depressurize. There are your tiny bubbles of high pressure hydrogen
that burst at the burning front.
dbo...@mindspring.com
about microencapsulation of medicines in "Invention and Technology".
There's just too many fun things to do.
I have lots of machining and analytical equipment in-house.
Unfortunately, all my people are nano-tech or x-ray analytical types,
no chemists or rocket engineers. First tests should be fairly simple,
no pressure buildup even. Just a tube with the fuel, correct flow of
O2, allow it to burn and measure regression rate relative to no wax
additive.
Its the knowledge of chemistry and rocket science I lack as it is a
serious jump from x-rays to rockets.
You might consider it, working on crazy ideas is lotsa fun and
sometimes even pays the bills. You seem to generate crazy ideas too
so.....
Richard J Kinch
> Do you want a deliciously crazy idea? Take hollow glass
> microballoons, put them in a Parr vessel, purge and pressurize with
> 1000 psi (or whatever - respect crush strength) hydrogen, and warm.
> Hydrogen diffuses in to high pressure through the microwalls. Cool,
> depressurize. There are your tiny bubbles of high pressure hydrogen
> that burst at the burning front.
The advantage over turbopumping liquid hydrogen being ... what?
dbo...@mindspring.com
Call me at 850-580-5481 as I do not haave your # to call you.
David OHara
dbo...@mindspring.com
Uncle Al
>
> Not a bad idea, actually considered something similar after reading
> about microencapsulation of medicines in "Invention and Technology".
> There's just too many fun things to do.
> I have lots of machining and analytical equipment in-house.
> Unfortunately, all my people are nano-tech or x-ray analytical types,
> no chemists or rocket engineers. First tests should be fairly simple,
> no pressure buildup even. Just a tube with the fuel, correct flow of
> O2, allow it to burn and measure regression rate relative to no wax
> additive.
Robert Goddard. He had a lot of explosions before he had a liftoff.
Experimental rocket engines are truly dangerous. Solid fuels have
burning rates mostiy independent of chamber pressure. Black powder
kinetics is extremely sensitive to pressure. You might expect one and
get the other.
> Its the knowledge of chemistry and rocket science I lack as it is a
> serious jump from x-rays to rockets.
> You might consider it, working on crazy ideas is lotsa fun and
> sometimes even pays the bills. You seem to generate crazy ideas too
> so.....
I'll talk in public! I'll consult with proprietary input - especially
if you desire input beyond a least publishable bit. I won't accept
responsibility for the test stand. Given military interest I suspect
a tremendous volume of work has been logged. It probably includes
stuff like liquid ozone in silver tankage and the likely Me2Be/F2
trial. That doesn't mean everything clever has been considered.
Look what a little added rust (dispersed Fe2O3) does for Space Scuttle
solid fuel.
Uncle Al
On the A-list of things to do on Tuesday.
Uncle Al
Bubbles bursting just below the burning interface, atomizing "solid"
fuel into the oxidizer stream. All the good stuff must transpire
before the reacting mass exits the bell. Burning thereafter is simply
fireworks. There isn't much time allotted to get the job done. The
only reasonable way to throttle solid fuel is with a hybrid engine.
There is no obvious or efficient way to have the oxidizer be the solid
core.
Bubbles are good stuff. Gel ANFO won't do anything unless sensitized
by a volume-% of glass microballoons. For that a matter, degassed
nitroglycerine is remarkably difficult to initiate. After the fact
the phenomenon is well understood. Before the fact it was a marvelous
discovery.
Creating surface fizz for a solid rocket motor without simultaneously
reacting the bulk is difficult. A proffered solution must be economic
by the tonne as well as by the gram. It must be stable in proper
storage, and possibly stable to protracted storage and handling by the
military ("aim this end toward enemy"). Having 20% of RPGS explode in
your face at launch is bad for unit morale.
My personal expectation is that many good folks, and a whole lot of
others, have invested severe skull sweat powered by munificent budgets
to look at the problem. It doesn't mean an "obvious" good solution
has not evaded their search. A paraffin core as such in Canadian
winter or Iraqi summer is a bad idea all by itself for its intrinsic
physical properties. It doesn't have to be paraffin if the concept is
proven to be valid.
What can the SBIR say, "no?" If there is bench-scale proof of concept
by a known contractor, funding may shake loose. And who knows, the
donkey might learn how to sing.
dbo...@mindspring.com
found nothing. There is little risk to writing an SBIR as i am now
able to write them eyes closed almost. With a good idea and sufficient
info, I sit down and start and time stands still and a couple days
later its done.
SBIRs are strange, consider that 30% of them are rejected immediately
for not following the instructions, so follow instructions and you are
already ahead of 30%. Write well instead of being dull and I figger
your ahead of another 30%. Your average scientist or engineer bores
his audience before the end of the first page. I've seen SBIR
proposals written by acknowledged world experts on a topic that were
certain to fail due to simple dullness.