Subject: Process Safety
From: "Andrew Posner"
Date: 15 Nov 1996 21:15:36 GMT
Chilworth Technology, Inc. is an independent firm of scientists and
engineers providing testing services and impartial advice in the specialist
area of Process Safety throughout the chemical and processing industries,
with no links to any equipment suppliers or other manufacturers. We invite
you to contact us for more information and complimentary technical
documents in our areas of expertise. Thank you.
--
Chilworth Technology, Inc.
Princeton Corporate Plaza
11 Deer Park Drive, Suite 204
Monmouth Junction, NJ 08852
tel: (908)274-0900
http://www.chilworth.com
Subject: Pharmaceutical raw material sourcing agents
From: patron@ciao.it (Paolo Aizza)
Date: Fri, 15 Nov 96 17:51:04 GMT
Hemsi, Spier & Future S.r.l.
Pharmaceutical raw material sourcing agents
SOME GOOD REASONS TO WORK WITH US
FOR PHARMACEUTICAL RAW MATERIALS
WE ACT AS YOUR OWN COMPANY IN ITALY.
We do what you'd be doing if you were in Italy.
Please note: Due to the full assistance we give our customers, we try to
work as much as possible, with only one or few firms in each country, to
avoid conflicts.
If you have pharmaceutical raw materials you wish to export, we would
be glad to offer them to our customers.
Our "Bible-Computer" contains 1850 products, mostly with prices,
sources, etc...
We also have a big databank which contains sources for further 8000
products.
Conclusion: Let us try each other. Send us your enquiries.
And when you come to Italy, try to spend an evening, better a week-end
with us (one hour is not sufficient).
We may become: YOUR OFFICE IN ITALY
http://www.ciao.it/hfs
Subject: Re: Help with wastewater
From: miles@mail.utexas.edu (Miles Abernathy)
Date: Fri, 15 Nov 1996 22:06:11 -0600
>> Will someone please point me in the right direction? We have a problem
with our wastwater effluent. It contains lead, cadmium, zinc, nickel and
a host of other nasties. We do not want to just dump it.
>
>----
>
>You might want to post your request to the BioGroup, a bioremediation
>newsgroup. The focus is obviously bio but there are alot of generic
And you might try the SEWER-LIST, which has a lot of sewage-treatment
plant designers and operators. Send a message
subscribe sewer-list YourFirstName YourLastName
to the address
listproc@mcfeeley.cc.utexas.edu
and you will be subscribed and can post to the list. Good luck!
--
Miles Abernathy, miles@mail.utexas.edu, http://klingon.util.utexas.edu/
Subject: Re: PSV Design Basis for Dowtherm A?
From: "Jack A. Bush"
Date: Fri, 15 Nov 1996 22:49:43 -0800
Samuel D. Goldman wrote:
>
> I am specifying safety reliefs for vessels and exchanger jackets filled
> with Dowtherm A liquid at 250-600Fand want to know whether or not I
>should
> consider two phase flow for the blocked-in fire case. I can't really answer the Dowtherm A question, but Dow has a
Web page at http://www.dow.com/. (The period ended the sentence,
not the URL.) If you can't find the answer there, you should be
able to find out whom to ask.
Typically the
> ... the safety valves
> with rupture disks underneath ...
> I'm probably preaching to the choir here, but be sure to leave
an OPEN bleed between the disk and the safety valve. Most rup-
ture disk installations leak by a little, and, without a bleed,
the pressure can equalize on the two sides of the disk. If this
happens, the pressure in the vessel (relative to ambient) would
have to exceed TWICE the disk rating to rupture the disk. This
could easily lead to undesirable effects.
Sorry if I have belabored the obvious, or acted like I was try-
to teach freshman algebra to graduate engineers, but this is a
point that was pounded into us when I was in a production area,
and it's a trap too easy to fall into.
10/Q,
Jack
Obviously, these opinions are entirely my own. If my employers wanted
me to express theirs, they would pay me to do so--and they aren't!!
Subject: Debunking the "Fume Theory" of the TWA 800 Explosion
From: msb@netcom.com (Mark S. Bilk)
Date: Sat, 16 Nov 1996 11:16:20 GMT
According to recent stories on CNN, the Fume Theory says
that because the central fuel tank was nearly empty, it was
filled with an explosive mixture of "fumes" (fuel vapor)
and air, which blew up due to some unknown source of
ignition (unknown, but definitely not that missile that
over a hundred people saw rising toward the plane) -- maybe
a spark from a fuel pump or sensor.
According to this theory, the plane was in unusual danger
specifically because that tank was empty; otherwise fuel
tank explosions would be blowing up aircraft left and right.
I think there is a major hole in this theory, even if it
were normal practice to avoid letting any fuel tank get
completely empty (does anyone know if that is the case?).
Any volatile liquid in a closed space will emit vapor until
an equilibrium exists between the liquid and the vapor above
it. At that point, the number of molecules per second con-
densing from the vapor back into the liquid equals the num-
ber of molecules per second vaporizing from the liquid into
the space above it. The unchanging partial pressure of the
vapor at equilibrium is called the "vapor pressure" of the
liquid. ("Partial pressure" means the pressure due to the
vapor molecules, exclusive of the pressure due to the air
molecules mixed with them.)
Note also that the concentration of the vapor (as measured
in, e.g., grams/liter) is directly proportional to its
partial pressure (whether at equilibrium or not).
In regard to the "Fume Theory", the important thing about
vapor pressure (and thus vapor concentration) is that it is
*independent* of the amount of liquid in the tank--it
depends only on the temperature. Therefore, a fuel tank
that is, say, 1% full will have the same fuel-air mixture
above it as a tank that is 50% full, or one that is 99%
full.
True, a tank that is 1% full will contain about twice as
much of that constant fuel-air mixture as one that is 50%
full, since there will be about twice as much space in the
tank unoccupied by liquid fuel. But the ability of the
mixture to explode will be the *same* in both cases, since
that depends only on the ratio of fuel vapor to air in the
mix.
Thus, contrary to the "Fume Theory", an empty tank would be
no more likely to explode than a half-full one. The tank's
being empty would *not* constitute a hazardous condition.
It's also necessary to inquire whether the fuel-air mixture
in the tank could have exploded at all. In general, such
mixtures are explosive only between some minimum and maxi-
mum fuel-to-air ratios. For some hypothetical fuel, the
explosive range might be 12% to 45% fuel/air (I'm not sure
whether the upper and lower limits vary with temperature).
For that fuel, a mixture with less than 12%, or greater
than 45%, fuel could not explode. The explosive range for
the actual fuel used by TWA 800 should be well known.
The vapor pressure of this fuel as a function of temperature
should also be well known.
I don't know whether aircraft fuel tanks have heaters to
keep the fuel at a constant temperature. If not, the fuel
temperature in the tank (and thus its vapor pressure, and
therefore the fuel/air ratio) would depend upon the temper-
ature of the plane's environment for the last few hours.
Anyone familiar with jet fuel technology should be able to
estimate the fuel tank temperature, find the vapor pressure
for the fuel as a function of that temperature, and deter-
mine whether the resulting fuel/air mixture was capable of
exploding at all.
Subject: Re: Latent Heat Storage for Automotive Use
From: trautwei@twe.stuttgart.netsurf.de (T. Trautwein)
Date: Fri, 15 Nov 1996 11:19:39 GMT
Rikard GEBART wrote:
(snip)
>I remember reading in a Swedish newspaper many years ago of a system for houses where a salt
>was used to absorb heat from the indoor air during the (warm) day. This was accomplished
>by melting of the salt (phase change). During the night when the temperature decreased
>the salt solidified and released its heat again to the indoor air, thereby saving some
>energy for heating. I have not heard anything recently about this system so I assume
>that it is not competitive to ordinary heat exchangers and similar systems which are
>widely used in Sweden. It is possible that the same system could be used for engine
>heating. The newspaper article probably mentioned what salt they used but I have no clue.
>Its melting point has to be somewhere close to room temperature (20 degree C). Maybe a
>chemist can tell you which salt would be suitable.
Yes, but the "melting" point should be at about 80C and boiling higher than 120C
>Finally, if you just want to have something for your own car you should definitely buy
>existing equipment and not build something yourself. If you buy it in Europe the cost
>of a complete solution with engine and passenger compartment heating and a timer would
>probably be less than the cost of the parts only for something you build yourself (not
>mentioning that the reliability and safety would be much higher).
Well, I agree in general. But you have to know I'm a mechanical engineer with
own design and prototyping business working for medical and automotive
industrie. I guess I'd manage to calc., design and manufacture a proper heat
exchanger, fill it with the apropriate liquid and mount it in a car. Moneywise I
completely agree.
>If, on the other hand, you want to invent something new you may have a pretty interesting
>idea....
Unfortunately it's developed already :-(
Only seems to be not too popular and cost/value for the user is not
overwhelmingly great. I suspect there are some problems with keeping the liquid
absolutely clean so it doesn't crystalize when the temperature drops but does so
when I start the car. I'll do some patent research ad see how BMW and other
manufacturers did it.
Thanks for all the interesting replies so far,
Frank
Subject: Re: Help With AlCl3 & Carbonated H2O
From: dwilkins@orion.polaristel.net (Don Wilkins)
Date: Sat, 16 Nov 1996 14:22:56 GMT
On Fri, 15 Nov 96 00:24:08 GMT, Corsond@Agresearch.cri.nz (Dean C
Corson) wrote:
>I have tried in vain to get any answers regarding the properties of AlCl3, the
>kinds of properties I need are:
>
>1. Does 400oC AlCl3 react with water/steam the same way as AlCl3 at STP
>reacts with water, or does it react at all?.
I would expect HCl to leave in a hurry.
>2. Does molten salts (ie AlCl3) act like a solvent for higher melting point
>salts to form a molten like solution?.
Yes but look in
Phase Diagrams for Ceramists.
Lots of AlCl3-MeClx diagrams there.
>3. How corrosive do you think a molten salt mixture fo AlCl3 & NaCl would be
>at 400oC?. What sort of metal could I use to hold such a molten mix?.
I would be inclined to use quartz or SiC. Look up references to work
done in molten salts in the 50's & 60's.
>
>And for somthing a bit different:
>
>4. Does anyone have any idea what carbonated water at 30-40oC could be used
>for, as I could have large amouts of the stuff and would like to find some use
>for it, ie alge growth for live stock feed etc.
Ad a bit of lemon flavor, bottle it, and sell it by the liter.
>
>Any answers to the above question would be muchly appreciated. Note: I have in
>the past asked the same question but have had NO responce, if the question
>are too hard could someone point me to a webb site that might. I do not mean
>to affend anyone with that last comment it's just that I am desparate for
>answers to the first three questions.
>
>Thank, Deano
>
>
>You can e-mail me on: corsond@agresearch.cri.nz
Subject: Re: Debunking the "Fume Theory" of the TWA 800 Explosion
From: "Steve M."
Date: 16 Nov 1996 08:26:05 -0700
Here's my theory:
50% paranoid + 50% skeptic = 100% nuts
> In regard to the "Fume Theory", the important thing about
> vapor pressure (and thus vapor concentration) is that it is
> *independent* of the amount of liquid in the tank--it
> depends only on the temperature. Therefore, a fuel tank
> that is, say, 1% full will have the same fuel-air mixture
> above it as a tank that is 50% full, or one that is 99%
> full.
>
> True, a tank that is 1% full will contain about twice as
> much of that constant fuel-air mixture as one that is 50%
> full, since there will be about twice as much space in the
> tank unoccupied by liquid fuel. But the ability of the
> mixture to explode will be the *same* in both cases, since
> that depends only on the ratio of fuel vapor to air in the
> mix.
>
> Thus, contrary to the "Fume Theory", an empty tank would be
> no more likely to explode than a half-full one. The tank's
> being empty would *not* constitute a hazardous condition.
>
> It's also necessary to inquire whether the fuel-air mixture
> in the tank could have exploded at all. In general, such
> mixtures are explosive only between some minimum and maxi-
> mum fuel-to-air ratios. For some hypothetical fuel, the
> explosive range might be 12% to 45% fuel/air (I'm not sure
> whether the upper and lower limits vary with temperature).
> For that fuel, a mixture with less than 12%, or greater
> than 45%, fuel could not explode. The explosive range for
> the actual fuel used by TWA 800 should be well known.
>
> The vapor pressure of this fuel as a function of temperature
> should also be well known.
>
> I don't know whether aircraft fuel tanks have heaters to
> keep the fuel at a constant temperature. If not, the fuel
> temperature in the tank (and thus its vapor pressure, and
> therefore the fuel/air ratio) would depend upon the temper-
> ature of the plane's environment for the last few hours.
>
> Anyone familiar with jet fuel technology should be able to
> estimate the fuel tank temperature, find the vapor pressure
> for the fuel as a function of that temperature, and deter-
> mine whether the resulting fuel/air mixture was capable of
> exploding at all.
>
>
>
Subject: Re: Debunking the "Fume Theory" of the TWA 800 Explosion
From: charliew@hal-pc.org (charliew)
Date: Sat, 16 Nov 96 15:08:22 GMT
In article , msb@netcom.com (Mark
S. Bilk) wrote:
>According to recent stories on CNN, the Fume Theory says
>that because the central fuel tank was nearly empty, it was
>filled with an explosive mixture of "fumes" (fuel vapor)
>and air, which blew up due to some unknown source of
>ignition (unknown, but definitely not that missile that
>over a hundred people saw rising toward the plane) -- maybe
>a spark from a fuel pump or sensor.
>
(cut)
>Any volatile liquid in a closed space will emit vapor until
>an equilibrium exists between the liquid and the vapor
above
>it.
(cut)
>Note also that the concentration of the vapor (as measured
>in, e.g., grams/liter) is directly proportional to its
>partial pressure (whether at equilibrium or not).
>
>In regard to the "Fume Theory", the important thing about
>vapor pressure (and thus vapor concentration) is that it is
>*independent* of the amount of liquid in the tank--it
>depends only on the temperature. Therefore, a fuel tank
>that is, say, 1% full will have the same fuel-air mixture
>above it as a tank that is 50% full, or one that is 99%
>full.
>
(cut)
>I don't know whether aircraft fuel tanks have heaters to
>keep the fuel at a constant temperature. If not, the fuel
>temperature in the tank (and thus its vapor pressure, and
>therefore the fuel/air ratio) would depend upon the temper-
>ature of the plane's environment for the last few hours.
>
>Anyone familiar with jet fuel technology should be able to
>estimate the fuel tank temperature, find the vapor pressure
>for the fuel as a function of that temperature, and deter-
>mine whether the resulting fuel/air mixture was capable of
>exploding at all.
>
>
I'm not certain about fuel tank heaters, but it is most
likely that there are none. Jet fuel has a freeze point
specification that is approximately -51 deg F, meaning that
this stuff doesn't need to be heated, because it will not
freeze at normal altitudes.
Also, there is a standard ASTM test for jet fuel volatility.
It is called the flash point test. This test is conducted
precisely in the manner required: a small sample of kerosene
(jet fuel) is slowly heated. As the sample is heated, a
technician periodically tries to ignite the vapors that
collect in the sample container. When the first small flash
of fire is seen, the temperature is noted. I don't remember
the exact specification for this stuff, but it is somewhere
around 120-140 deg F. Conclusion - it is very unlikely that
the plane's fuel tanks were heated to this temperature,
unless there was some sort of fire under the tank. If the
fuel was below this temperature, there is *no way* that
vapors could have ignited from a spark.
Subject: Re: "popcorn" polymerizations
From: anil1305@txnet.net (Anil Gupta)
Date: Sat, 16 Nov 1996 15:18:37 GMT
One of the cases, I know is Butadienes. I don't have much details
about it. I faced this problem couple of years ago. I do not work in
polymers but during the GC analysis of one process stream which had
1,3-Butadiene, we found that above 200 F, the butadiene forms
"popcorn" polymer which plugs up the GC column.
Sorry couldn't help you anymore. That's all the information I have.
fuzzy23320@aol.com wrote:
>Hi.
>Does anyone out there know anything about "popcorn" polymerizations? What
>polymers they occur in? Whether it is an interface issue or how it
>changes the characteristics of the polymer? Any references?
>
>Thanks,
>Carmela Bertrand
>
Subject: Re: Debunking the "Fume Theory" of the TWA 800 Explosion
From: m@ml.com (M Carling)
Date: 16 Nov 1996 17:14:45 GMT
msb@netcom.com (Mark S. Bilk) wrote:
>According to recent stories on CNN, the Fume Theory says
>that because the central fuel tank was nearly empty, it was
>filled with an explosive mixture of "fumes" (fuel vapor)
>and air, which blew up due to some unknown source of
>ignition -- maybe a spark from a fuel pump or sensor.
>
>According to this theory, the plane was in unusual danger
>specifically because that tank was empty; otherwise fuel
>tank explosions would be blowing up aircraft left and right.
>
>I think there is a major hole in this theory...
>
>Any volatile liquid in a closed space will emit vapor until
>an equilibrium exists between the liquid and the vapor above
>it. ... The unchanging partial pressure of the vapor at
>equilibrium is called the "vapor pressure" of the liquid.
Correct
>In regard to the "Fume Theory", the important thing about
>vapor pressure (and thus vapor concentration) is that it is
>*independent* of the amount of liquid in the tank--it
>depends only on the temperature. Therefore, a fuel tank
>that is, say, 1% full will have the same fuel-air mixture
>above it as a tank that is 50% full, or one that is 99%
>full.
Also correct.
>True, a tank that is 1% full will contain about twice as
>much of that constant fuel-air mixture as one that is 50%
>full, since there will be about twice as much space in the
>tank unoccupied by liquid fuel. But the ability of the
>mixture to explode will be the *same* in both cases, since
>that depends only on the ratio of fuel vapor to air in the
>mix.
Correct only if the spark is introduced at a location in the tank where there
is vapor rather than fuel. For this reason and others, fuel tank fittings
such as plumbing and sensors are fitted at the base of the tanks, so that
they will contact fuel rather than vapor. Assuming the aircraft is not making
high-G maneuvers, any potential source of spark will not be exposed to vapor
unless that fuel tank is nearly empty.
Either a bomb onboard or a missile striking an aircraft would have left
tell-tale signatures in the debris. Nothing of the sort has been found,
according to all reports.
M Carling
Subject: Re: Ch.E for non majors
From: lga@tiac.net (George Randall)
Date: Sat, 16 Nov 1996 18:01:20 GMT
Previous posters discussed
> . . . are fluid mechanics and heat transfer. Bird, Stewart and
>Lightfoot's "Transport Phenomena" is the classic text in the area.
For a non-chemical engineer with a love for partial differential
equations, B, S, & L would be ideal. For others, a unit
operations text might be more useful. One that comes to
mind and is in print in its 5th edition is McCabe, Smith
and Harriott "Unit Operations of Chemical Engineering."
(McGraw-Hill)
Or at a more basic level, Shreve's "Chemical Process
Industries" presented an organized approach to the
application of chemical engineering in industrial
practice. I have NO idea if a current version of
that is available (McGraw-Hill again).
George
============================================
George A. Randall, P.E. lga@tiac.net
LGA Engineering Newburyport Mass USA
============================================
Subject: Re: Debunking the "Fume Theory" of the TWA 800 Explosion
From: 99@spies.com (Extremely Right )
Date: Sat, 16 Nov 1996 18:18:50 +0100
In article , msb@netcom.com (Mark S. Bilk) wrote:
> According to recent stories on CNN, the Fume Theory says
> that because the central fuel tank was nearly empty, it was
> filled with an explosive mixture of "fumes" (fuel vapor)
> and air, which blew up due to some unknown source of
> ignition (unknown, but definitely not that missile that
> over a hundred people saw rising toward the plane) -- maybe
> a spark from a fuel pump or sensor.
>
> Thus, contrary to the "Fume Theory", an empty tank would be
> no more likely to explode than a half-full one. The tank's
> being empty would *not* constitute a hazardous condition.
Good post. Fuel tanks are loaded to balance the plane, and a continual job
of the co-pilot is to monitor and balance the A/C fuel load. Empty (or
very low) tanks are typical at the end of a long flight. Besides needing
fuel/ air mixture, an ENERGETIC spark or _intense_ heat is needed for
combustion. The tanks are designed to eliminate those possibilities. I do
not know of *any* fuel tank related explosion in the last 30 years. People
may not realize that a cigarette cherry will not ignite gasoline (jet fuel
is similar to kerosene) in normal conditions. You can't even relight a
butane lighter with a cigarette. ###8up
Subject: MIXED ACID ANALYZER
From: hdanberg@aol.com
Date: 16 Nov 1996 23:21:24 GMT
I work in the Semiconductor indusrty where we use mixed acids
(nitric/hydrofluoric/acetic) to etch the wafers. The ratio of these acids
is critical to etcher performance.
I am looking for a simple analyzer that my operators can use to determine
the assay of the mixed acid in the bath. While an on-line instrument would
be ideal, an offline one that can produce a result in less than 30 minutes
(or so) is OK also. The instrument has to be simple to operate and
maintain. The output should not require a PHD to interpret.
While I am no expert, I am thinking a Fast Fourier IR, Raman IR, UV Spec
or sonic sensor may work. The instrument may actually have several of
these devices to sense all three components.
Any ideas?
Thanks in advance,
Harry Danberg
Mitsubishi Silicon America
