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Re: [multimachine] Re: 1/2 OT // Toward No Big Booms

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  • Nenad Mandic
    ________________________________ From: BRIAN GLACKIN To: multimachine@yahoogroups.com Sent: Wednesday, 3 August 2011, 18:01 Subject:
    Message 1 of 11 , Aug 4, 2011
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      From: BRIAN GLACKIN <glackin.brian@...>
      To: multimachine@yahoogroups.com
      Sent: Wednesday, 3 August 2011, 18:01
      Subject: Re: [multimachine] Re: 1/2 OT // Toward No Big Booms

       
      A fert/FO mix is relatively stable and according to what I am used to (in the mining industry) is considered to be a "low ex" in that it needs high pressure AND temperature to initiate a reaction.  So in that regards it is a "relatively" safe energy source from a handling perspective.  The big issue is the the volume of gas generated from this type of reaction.  It would be pretty hard to measure a wetted solid accurately in the tiny quantities involved with each discrete stroke of the engine.  Liquid fuels on the other hand are very easy to handle and meter accurately.  That is why we use that mix in our vehicles.


    • David G. LeVine
      ... Okay, so carburetted cars (which store an FAE in the intake runners) don t count either then. ... The question is what do you call an explosion. Spinning
      Message 2 of 11 , Aug 4, 2011
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        On 08/03/2011 12:34 PM, Keith Mc wrote:
        > David G. LeVine<dlevine@...> wrote:
        >> Keith, you appear to be confused, please check your facts BEFORE you go
        >> off on rants like this.
        > I am sure of it. And BTW, I've worked in R&D at car companies for many years
        > and have been in the complex when many accidents and explosions happen,
        > so I'm sorry to say I DO know what I'm talking about.
        >
        > On 08/03/2011 01:07 AM, Keith Mc wrote:
        >>> IMHO, there is NO sane reason to mix an oxidizer with a fuel up front
        >>> for any reason. That's a recipe for disaster!
        >> Funny, I do it all the time. My fuel injection mixes oxidizer (air)
        >> with fuel (gasoline) before it enters the combustion chamber.
        >> My vehicles have not blown up due to that, yet.
        > Read what I said again. That's not "up front", with the purpose of
        > STORING it in that state. That is "at point of usage", a MUCH different thing.

        Okay, so carburetted cars (which store an FAE in the intake runners)
        don't count either then.

        > BTW... You obviously have never never been at a drag strip or at an engine
        > dynamometer cell, when the engine exploded...<grin> I have... They don't
        > NORMALLY explode for you under "normal usage" because we regularly
        > deliberately run things to destruction, and crash and blow them up first,
        > just to make sure the materials are strong enough and the designs are
        > correct, and it won't do it once in YOUR hands...<grin>

        The question is what do you call an explosion. Spinning a disk at high
        enough speed will cause it to self destruct, but that is not an
        explosion in the sense of the chemical reaction of high explosives.
        Just because we call a balloon's catastrophic failure an explosion does
        not make it a bomb.

        > Also many silos and chemical plants often explode from "dust explosions",
        > which are by definition due to "oxygen and fuel being stored premixed".
        > If it gets too dry, it can be easily detonated by a static discharge or self
        > heating. It's a known hazard. That's why modern silos have some of the
        > features they have, to help prevent it (vent fans, moisture systems, etc.).

        Yes, that is true, and the INTENT is not to store a fuel/air mixture.
        The same applies to TBI/carburetted engines.

        > No. Trust me, there is a lot of tech to air bags to help keep them from
        > being repurposed, and there were a LOT of heated discussions about them
        > at the labs when they were first proposed and developed. Over their history
        > there have also been several airbag recalls because of defects risking
        > the chance of premature misfiring.
        >
        > Like many things air bags have had a rough technical history. Air bags
        > are also a "relative risk" thing, where the life saving benefits of it FAR
        > outweigh the lesser risks of misuse, repurposing, and failures.
        >
        > That is not the case with deliberately designing an engine to use a
        > prefab oxidizer and fuel mix, when other, much safer tech is already available.

        First of all, the air (actually gas) bag is only marginally effective as
        an initiator, you are correct.

        >> Yup, proliferation of gasoline sprays into air and air bags will result in much
        >> more terrorism.:-P
        > Actually, there was a problem with IEDs being too easily made from old chemistry
        > air bags. The chemistry had to be updated to make that much tougher to do.
        > It's still possible, but it's a LOT more difficult than it used to be.

        See, QED.

        > Also FYI, gasoline, diesel and fertilizer nitrates are all now routinely chemically
        > tagged to allow for determining its source, should it ever be used in explosives.

        That does not help the victims of such an IED.

        > You can still do it, but you're now MUCH more likely to be caught if you're
        > dumb enough to try it. So yup, though your statement sounds pretty facetious,
        > it HAS already happened in reality, and has been responded to.
        > (The new chem tagging rules occurred shortly after the OK city bombing.)

        If you are a Jihadist who believes that he will die in the explosion and
        will be transported to Paradise, how does that help? "Yes, someone
        siphoned gasoline from a State Police vehicle and used it to kill high
        ranking official's children." Can't happen? How much is needed, a few
        gallons?

        > Absolutely. Although gasoline is NOT explosive, unless you have a strong
        > container AND have the right air/fuel mix. FYI one of the gas stations near
        > my home detonated a gas tank with vapor still in it, when they attempted
        > to weld repair an "empty one" without first flushing it and filling it with water.
        > The shrapnel seriously injured the tech, and the resulting fire destroyed
        > the entire gas station.

        This is also a problem with propane tanks used on grills. However, you
        are mistaken here.

        Using a low brisance explosive to disperse the gasoline and a high
        brisance explosive to initiate the explosion is the most common way to
        make an FAE with inertial confinement (the propagation is supersonic,
        the gasses in front of the shock wave are compressed against the
        air/fuel cloud.) The results for only a gallon of gasoline are quite
        amazing. Gasoline is about 45 MJ/KG (as is propane), nitromethane is
        only about 11 MJ/KG.

        > So yes, I do know what I'm talking about... Over my years in automotive
        > research I've see a LOT of stuff blown up by "simple auto tech", way too
        > many times for my taste. I've also been in safety, policy, and tech discussions
        > on this technology. It is not a rant. It is cautionary tale, from experience,
        > seeing too many of my friends and neighbors caught by it, and being there
        > for those tech discussions about risks vs benefits while at work.
        >
        > - Keith Mc.

        Okay, I can accept that. Had you started out with qualifications, it
        would have been more obvious.

        Dave 8{)
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