Pneumatic Tubes
M C Hamster
stations. They seem to work very well... I've never seen an "Out of
Order" sign at a lane. It's hard to visualize the distances they are
travelling to get from the drive in station inside to the bank, but at
my bank this is a pretty considerable distance. It's also hard to
visualize how many curves or turns there are but there must be at
least three. I wonder how shallow those curves must be, or what the
most acute permissible curves are.
I wonder if they ever break down, and if the canister ever gets stuck
or jammed somehow, and if so, how they recover it if it's somewhere in
the middle of the tube. And I wonder what kind of routine
preventative maintenance they do.
And I wonder what sort of device does the sucking... and does it suck
when it pulls the canister from you into the bank, and blow when it
returns the canister back to you, and whether sucking or blowing is
easier and/or more effective. And I wonder what the most complicated
and/or longest tubes are.
These are some things I wonder about, but not the only things.
--
M C Hamster "Big Wheel Keep on Turnin'" -- Creedence Clearwater Revival
Don K
news:lb3dg6119jeqg6unf...@4ax.com...
> I'm kind of amazed at the pneumatic tubes at the drive-in banking
> stations. They seem to work very well... I've never seen an "Out of
> Order" sign at a lane. It's hard to visualize the distances they are
> travelling to get from the drive in station inside to the bank, but at
> my bank this is a pretty considerable distance. It's also hard to
> visualize how many curves or turns there are but there must be at
> least three. I wonder how shallow those curves must be, or what the
> most acute permissible curves are.
>
> I wonder if they ever break down, and if the canister ever gets stuck
> or jammed somehow, and if so, how they recover it if it's somewhere in
> the middle of the tube. And I wonder what kind of routine
> preventative maintenance they do.
I believe they periodically run a hamster through the tube.
>
> And I wonder what sort of device does the sucking... and does it suck
> when it pulls the canister from you into the bank, and blow when it
> returns the canister back to you, and whether sucking or blowing is
> easier and/or more effective. And I wonder what the most complicated
> and/or longest tubes are.
I would think sucking would be safest.
In case of failure, the maximum pressure differential would be limited
to 1 atmosphere, and at worst, there would be an implosion, not an
explosion.
> These are some things I wonder about, but not the only things.
Sometimes I wonder about things too.
Don
Paul
> "M C Hamster" <davol...@nospam.speakeasy.net> wrote in messagenews:lb3dg6119jeqg6unf...@4ax.com...
Apparently pneumatic tubes is one of the many things said to originate
with Hero of Alexandra. They are also called Lamson Tubes. It was used
by the London Stock Exchange in 1853.
Paul
Charles Wm. Dimmick
Pneumatic tubes have been around a long, long time. I remember when I
was a wee lad visiting Gimbel's Department Store in Manhattan [this was
during the War] and being fascinated by the system whereby the store
clerk would take your money and put it into a container along with a
sales slip, and it would zip up into the tube system, across the ceiling
and disappear into the floor above, and shortly it would return with
your change and a sales slip marked paid. I seem to remember Paris
having a mail system that worked via pneumatic tubes, under the streets,
going from one part of the city to another.
Charles
Mac
So did NYC; Paris's just lasted longer. The Pentagon had a system
fairly late, also, as did a good many smaller office systems.
danny burstein
>Pneumatic tubes have been around a long, long time. I remember when I
>was a wee lad visiting Gimbel's Department Store in Manhattan [this was
>during the War] and being fascinated by the system whereby the store
>clerk would take your money and put it into a container along with a
>sales slip, and it would zip up into the tube system, across the ceiling
>and disappear into the floor above, and shortly it would return with
>your change and a sales slip marked paid. I seem to remember Paris
>having a mail system that worked via pneumatic tubes, under the streets,
>going from one part of the city to another.
NYC, too:
http://www.barrypopik.com/index.php/new_york_city/entry/rocketeer_postal_worker_with_pneumatic_tube/
--
_____________________________________________________
Knowledge may be power, but communications is the key
dan...@panix.com
[to foil spammers, my address has been double rot-13 encoded]
Jack Campin - bogus address
> I wonder what the most complicated and/or longest tubes are.
The Post Office railway in London, at a guess:
http://www.bbc.co.uk/dna/h2g2/A3826019
http://www.capsu.org/library/documents/0040.html
-----------------------------------------------------------------------------
e m a i l : j a c k @ c a m p i n . m e . u k
Jack Campin, 11 Third Street, Newtongrange, Midlothian EH22 4PU, Scotland
mobile: 07800 739 557 <http://www.campin.me.uk> Twitter: JackCampin
John Hatpin
<cdim...@snet.net> wrote:
They were in use in department stores here in the 1960s, by my
recollection.
--
John Hatpin
I'm terrified that people will find out my Imposter
Syndrome's not quite real.
Paul Ciszek
In article <0t9dg6p9dp0jq2ci5...@4ax.com>,
Mac <anmc...@alumdotwpi.edu> wrote:
>>
>>Pneumatic tubes have been around a long, long time. I remember when I
>>was a wee lad visiting Gimbel's Department Store in Manhattan [this was
>>during the War] and being fascinated by the system whereby the store
>>clerk would take your money and put it into a container along with a
>>sales slip, and it would zip up into the tube system, across the ceiling
>>and disappear into the floor above, and shortly it would return with
>>your change and a sales slip marked paid. I seem to remember Paris
>>having a mail system that worked via pneumatic tubes, under the streets,
>>going from one part of the city to another.
>
>So did NYC; Paris's just lasted longer. The Pentagon had a system
>fairly late, also, as did a good many smaller office systems.
It's a shame these things went out of style when they did...imagine
what you could have done with the combination of pneumatic tubes and
cheap logic chips! Or better yet, a little RFID sort of thing in each
cannister that would give its destination when querried, so each exchange
could route it appropriately without the need for central control. As
paper mail became less important, they could still be used to deliver
prescriptions, spare parts, even sandwiches. Files too big to be e-mailed
reliably could be sent on thumb drives.
--
Please reply to: | "The anti-regulation business ethos is based on
pciszek at panix dot com | the charmingly naive notion that people will not
Autoreply is disabled | do unspeakable things for money." -Dana Carpender
N Jill Marsh
<davo...@nospam.speakeasy.net> wrote:
>I'm kind of amazed at the pneumatic tubes at the drive-in banking
>stations. They seem to work very well... I've never seen an "Out of
>Order" sign at a lane. It's hard to visualize the distances they are
>travelling to get from the drive in station inside to the bank, but at
>my bank this is a pretty considerable distance. It's also hard to
>visualize how many curves or turns there are but there must be at
>least three. I wonder how shallow those curves must be, or what the
>most acute permissible curves are.
I haven't seen one in years, I worked at a hospital that still used
them, though, at least until a few years ago.
>I wonder if they ever break down, and if the canister ever gets stuck
>or jammed somehow, and if so, how they recover it if it's somewhere in
>the middle of the tube. And I wonder what kind of routine
>preventative maintenance they do.
I never saw ours break down, ever, and we never had a jam, and they
always worked. So I can't say anything about your last two
wonderments, other than to say if there was routine maintenance it
wasn't intrusive.
>And I wonder what sort of device does the sucking... and does it suck
>when it pulls the canister from you into the bank, and blow when it
>returns the canister back to you, and whether sucking or blowing is
>easier and/or more effective. And I wonder what the most complicated
>and/or longest tubes are.
The away tube always sucks, and the to tube always blows, although out
to tube was aided a great deal by gravity. I always assumed that they
both sucked at the source, the sorting station or whatever it was
called.
The building was three stories tall, and had a good basement. The
mail room was in the basement, so the things managed to travel around
pretty effectively. Movement was mostly vertical, however.
nj"wondering"m
--
"All I can say is that the work has been done well in every way."
Mac
wrote:
PS: Google Books has Popular Mechanics Mar 1945, which has a short
article on pneumatic systems on pare 25, and an amazing amount of
other kewl stuff throughout. Seems to be a veritable pleonasm of
pneumatic tube articles in other issues. Prague appears to be a
winner for longevity, abnd at least a contender for distance.
Veronique
They are still in use at the local Costco. (Or were within recent
memory.)
V.
--
Veronique Chez Sheep
Hactar
ISTR them being at Home Depot in the last ~10 years. AIR bank
drive-throughs still use them.
--
-eben QebWe...@vTerYizUonI.nOetP royalty.mine.nu:81
Hi! I'm a .sig virus! Copy me to your .sig!
Nick Spalding
on Mon, 13 Dec 2010 15:12:00 -0800:
The hospital I was in recently had this. It had a bore of four or five
inches and the containers were about ten inches long, big enough for
sample bottles and such like to be sent around.
--
Nick Spalding
Greg Goss
>>Pneumatic tubes have been around a long, long time. I remember when I
>>was a wee lad visiting Gimbel's Department Store in Manhattan [this was
>>during the War] and being fascinated by the system whereby the store
>>clerk would take your money and put it into a container along with a
>>sales slip, and it would zip up into the tube system, across the ceiling
>>and disappear into the floor above, and shortly it would return with
>>your change and a sales slip marked paid. I seem to remember Paris
>>having a mail system that worked via pneumatic tubes, under the streets,
>>going from one part of the city to another.
>
>They were in use in department stores here in the 1960s, by my
>recollection.
I think that my local Costco still uses them.
--
Tomorrow is today already.
Greg Goss, 1989-01-27
Mark Brader
> > I wonder what the most complicated and/or longest tubes are.
> The Post Office railway in London, at a guess:
Hell no. The PO Railway, called MailRail in its last years, was electric.
You're thinking of the Pneumatic Despatch Railway.
> http://www.bbc.co.uk/dna/h2g2/A3826019
> http://www.capsu.org/library/documents/0040.html
*Harrumph*. You mean: http://www.davros.org/rail/atmospheric.html
There's one error in that piece, which I should get around to correcting.
Beach did in fact have permission to build his demonstration subway --
he later claimed for political reasons that he hadn't. See the full
story at book length at: <http://www.columbia.edu/~brennan/beach/>.
Anyway, the little pneumatic tubes that started this thread came in
much longer and more complex systems than the big ones ever did,
because it was so much easier and more convenient to build them.
I don't know offhand which city's system was the biggest.
--
Mark Brader, Toronto | I am a mathematician, sir. I never permit myself
m...@vex.net | to think. --Stuart Mills (Carr: The Three Coffins)
My text in this article is in the public domain.
Mark Brader
> And I wonder what sort of device does the sucking... and does it suck
> when it pulls the canister from you into the bank, and blow when it
> returns the canister back to you,
Sure. Or vice versa if the fan's at your end, of course.
> and whether sucking or blowing is easier and/or more effective.
I don't think there's much difference as long as the pressures used are
moderate. In a high-powered system sucking (negative pressure) would
be limited to 1 atmosphere; blowing (positive pressure) could use a
higher pressure if the pipe was strong enough, but could be dangerous
in case of a pipe failure.
Air brake systems on modern trains need a considerable amount of air
and use positive pressure, but British trains used to use vacuum brakes
(negative pressure), and I think the possibility of a failure was one
reason for this. (In both cases the brake is triggered by the pressure
in the brake line returning to normal, so either one is fail-safe.)
--
Mark Brader "You have a truly warped mind.
Toronto I admire that in a person."
m...@vex.net -- Bill Davidsen
Lee Ayrton
> It's a shame these things went out of style when they did...imagine what
> you could have done with the combination of pneumatic tubes and cheap
> logic chips! Or better yet, a little RFID sort of thing in each
> cannister that would give its destination when querried, so each
> exchange could route it appropriately without the need for central
> control. As paper mail became less important, they could still be used
> to deliver prescriptions, spare parts, even sandwiches. Files too big
> to be e-mailed reliably could be sent on thumb drives.
Lawrence & Memorial Hospitals in New London, CT, had a pneumatic system
that terminated in the lab, for transferring samples and lab results. On
the Floor end, each port had a warning sign: "Do not put urine samples in
pneumatic tube."
Lee Ayrton
>> > They were in use in department stores here in the 1960s, by my
>> > recollection.
>>
>> They are still in use at the local Costco. (Or were within recent
>> memory.)
>
> ISTR them being at Home Depot in the last ~10 years.
Yes. The HD in the southern New England area that I frequent all have
them. I believe they use them to transfer cash pouches from the office
to registers.
> AIR bank drive-throughs still use them.
Bringing us back to the top of the thread.
Lesmond
For some reason, this post made me horny.
--
If there's a nuclear winter, at least it'll snow.
dan
alt.fan.cecil-adams on 13 Dec 2010 15:31:02 -0600:
>These are some things I wonder about, but not the only things.
http://en.wikipedia.org/wiki/Pneumatic_tube
--
Dan H.
northshore MA.
Les Albert
Go wake him up.
Les
M C Hamster
>M C Hamster wrote in
>alt.fan.cecil-adams on 13 Dec 2010 15:31:02 -0600:
>
>>These are some things I wonder about, but not the only things.
>
>http://en.wikipedia.org/wiki/Pneumatic_tube
Thanks for posting this, but I still am getting very little
information pertaining to how they actually work. That they were used
back in the middle of the 19th century, before the widespread
availability of electricity, adds to my questions.
What powers these systems? I can simplistically imagine that at one
end of the sealed tube there is a compressor / vacuum thing. But in
the 19th century, what was that device? How was it switched on? Was
it steam-powered or something? And nowadays, where it's electrical,
I'm just curious how large the compressor needs to be.
Back in the 19th century, how was its on-off status triggered, by the
sender? It is still amazing to me that they seem to work so reliably,
given that the canister moves at a high rate of speed. If something
gunked up the sealing lip of the canister, I can imagine it getting
stuck. Compressors break down, but I've never seen a tube at a bank
drive in out of order... that just seems odd to me, I dunno.
Hactar
>
> >M C Hamster wrote in
> >alt.fan.cecil-adams on 13 Dec 2010 15:31:02 -0600:
> >
> >>These are some things I wonder about, but not the only things.
> >
> >http://en.wikipedia.org/wiki/Pneumatic_tube
>
> Thanks for posting this, but I still am getting very little
> information pertaining to how they actually work. That they were used
> back in the middle of the 19th century, before the widespread
> availability of electricity, adds to my questions.
>
> What powers these systems? I can simplistically imagine that at one
> end of the sealed tube there is a compressor / vacuum thing. But in
> the 19th century, what was that device? How was it switched on? Was
> it steam-powered or something?
Speaking _ex recta_, compressed air is a good transmitter of energy (ask
mechanics, especially Amish ones). Motors can be made using it.
This technology must have been known for a while otherwise the Amish
wouldn't use it. Alternatively, a blower could run all the time, and
have its output switched locally with a valve. That sounds noisy and
wasteful, unless blowers can be made quiet and cheap-to-run.
> And nowadays, where it's electrical,
> I'm just curious how large the compressor needs to be.
Guessing: not much bigger than a home vacuum cleaner. Maybe a little
bigger, since it's concerned with start-up time where a vacuum cleaner
isn't so much.
> Back in the 19th century, how was its on-off status triggered, by the
> sender? It is still amazing to me that they seem to work so reliably,
> given that the canister moves at a high rate of speed. If something
> gunked up the sealing lip of the canister, I can imagine it getting
> stuck. Compressors break down, but I've never seen a tube at a bank
> drive in out of order... that just seems odd to me, I dunno.
If one gets stuck, you probably send another behind it to push. And fix
or replace the one that failed.
--
-eben QebWe...@vTerYizUonI.nOetP royalty.mine.nu:81
And we never failed to fail / It was the easiest thing to do -- CSN
dan
>That they were used
>back in the middle of the 19th century, before the widespread
>availability of electricity, adds to my questions.
>
>What powers these systems? I can simplistically imagine that at one
>end of the sealed tube there is a compressor / vacuum thing. But in
>the 19th century, what was that device? How was it switched on? Was
>it steam-powered or something? And nowadays, where it's electrical,
>I'm just curious how large the compressor needs to be.
OK. I'll do my best.
The blower in some bank systems is about the size of a shop-vac, but
powered by a much quieter motor(un-like a shop-vac, it needn't be
small or light). The blower only blows, it doesn't suck. To pull a
canister back it blows down a smaller tube that attaches to the larger
tube. On some bank systems you can see the smaller tube next to the
larger tube.
The department store ones that I have seen do suck the canister into
the tube. They seam to have the suction turned on all the time, while
the bank ones are activated by a button.
As far as getting stuck going around corners, the canisters have two
rings at each end that fit the inside of the tube, but the canisters
are smaller than the tube. This keeps the canister(straight) from
binding in the tubes corners(curved).
Somewhere I've seen pics of a system that could switch tubes, similar
to the way train tracks are switched.
The power could come from any number of things. Water wheels, steam
engines, animal treadmills, slaves.
That's all I can remember.
Lee Ayrton
"Diverters", apparently.
Google returned a surprising number suppliers on
"_pneumatic_tube_system_"
Drilling down through this site shows system capabilities, including
simple A to B systems, central systems, diverters, and fully-addressable
stations:
http://www.airtubes.com/index.htm
And in the USofA, Home Depot uses these folks:
Don K
news:n28ig6loa70i8dp1n...@4ax.com...
> On Tue, 14 Dec 2010 23:42:40 GMT, no...@privacy.net (dan) wrote:
>
>>M C Hamster wrote in
>>alt.fan.cecil-adams on 13 Dec 2010 15:31:02 -0600:
>>
>>>These are some things I wonder about, but not the only things.
>>
>>http://en.wikipedia.org/wiki/Pneumatic_tube
>
> Thanks for posting this, but I still am getting very little
> information pertaining to how they actually work. That they were used
> back in the middle of the 19th century, before the widespread
> availability of electricity, adds to my questions.
>
> What powers these systems? I can simplistically imagine that at one
> end of the sealed tube there is a compressor / vacuum thing. But in
> the 19th century, what was that device? How was it switched on? Was
> it steam-powered or something? And nowadays, where it's electrical,
> I'm just curious how large the compressor needs to be.
You could power a pneumatic tube using 2 tanks of water at different
levels connected by a big siphon hose.
The lower tank would be open to the air.
The upper tank would be sealed and a pneumatic tube would connect
at the top of the tank.
When the pneumatic tube is "opened", water would flow thru the siphon
and air would be sucked thru the pneumatic tube. This would work as
long as there was water in the upper tank.
Hero of Alexandria invented this kind of stuff in the 1st century.
Don
danny burstein
>OK. I'll do my best.
>The blower in some bank systems is about the size of a shop-vac, but
>powered by a much quieter motor(un-like a shop-vac, it needn't be
>small or light).
Which gets us to the Urban Legend that many vacuum cleaners
are deliberately made louder than they need to be, so as to
make the buyers/owners think they're getting/they've got a
more powerful unit than the neighbor.
Hactar
Or, a weight and some string/chain, as in a grandfather clock. It's
probably a good idea if the string goes over a pulley. When the
string is released, the weight drops and starts turning the mechanism,
which is not a clock but a blower.
--
-eben QebWe...@vTerYizUonI.nOetP royalty.mine.nu:81
Hi! I'm a .sig virus! Copy me to your .sig!
Greg Goss
M C Hamster <davo...@nospam.speakeasy.net> wrote:
>It is still amazing to me that they seem to work so reliably,
>given that the canister moves at a high rate of speed. If something
>gunked up the sealing lip of the canister, I can imagine it getting
>stuck. Compressors break down, but I've never seen a tube at a bank
>drive in out of order... that just seems odd to me, I dunno.
and
no...@privacy.net (dan) wrote:
>it doesn't suck.
That's what he said in the original post.
Greg Goss
>Don K <d...@comcast.net> wrote:
>> When the pneumatic tube is "opened", water would flow thru the siphon
>> and air would be sucked thru the pneumatic tube. This would work as
>> long as there was water in the upper tank.
>
>Or, a weight and some string/chain, as in a grandfather clock. It's
>probably a good idea if the string goes over a pulley. When the
>string is released, the weight drops and starts turning the mechanism,
>which is not a clock but a blower.
The water tank is much more elegant, without a blower. The only
moving parts are the valve and the message cylinder.
M C Hamster
Here's a YouTube video showing schematically what some of the
complicated systems look like:
http://www.youtube.com/watch?v=sNorqvuBbE0
Snidely
Turning a blower fast enough long enough might be tricky with a pulley-
weight setup.
/dps
Lee Ayrton
> In <4d094b0d...@news20.forteinc.com> no...@privacy.net (dan)
> writes:
>
>>OK. I'll do my best.
>
>>The blower in some bank systems is about the size of a shop-vac, but
>>powered by a much quieter motor(un-like a shop-vac, it needn't be small
>>or light).
>
> Which gets us to the Urban Legend that many vacuum cleaners are
> deliberately made louder than they need to be, so as to make the
> buyers/owners think they're getting/they've got a more powerful unit
> than the neighbor.
For a while we had a bread-making machine, it was re-gifted to us by
family. The instruction booklet had a recurring phrase "Remember! Noise
equals power!"
We didn't believe it, either.
Lee Ayrton
>> What powers these systems? I can simplistically imagine that at one
>> end of the sealed tube there is a compressor / vacuum thing. But in
>> the 19th century, what was that device? How was it switched on? Was
>> it steam-powered or something? And nowadays, where it's electrical,
>> I'm just curious how large the compressor needs to be.
>
> You could power a pneumatic tube using 2 tanks of water at different
> levels connected by a big siphon hose. The lower tank would be open to
> the air. The upper tank would be sealed and a pneumatic tube would
> connect at the top of the tank.
>
> When the pneumatic tube is "opened", water would flow thru the siphon
> and air would be sucked thru the pneumatic tube. This would work as long
> as there was water in the upper tank.
I was told that Pfizer in Groton, CT uses/used water tanks to generate
suction used in processes that needed it.
Hactar
Big honkin' weight. Or multiple smaller weights. Or tall building. Or
skip it, and go with water.
--
-eben QebWe...@vTerYizUonI.nOetP royalty.mine.nu:81
If you need someone to blame
Throw a rock in the air
You'll hit someone guilty -- U2, _Zooropa_, "Dirty Day"
Don K
My invention has been stolen already?
I knew I shouldn't have posted it on AFCA.
Don
Paul Madarasz
wrote, perhaps among other things:
>PS: Google Books has Popular Mechanics Mar 1945, which has a short
>article on pneumatic systems on pare 25, and an amazing amount of
>other kewl stuff throughout. Seems to be a veritable pleonasm of
>pneumatic tube articles in other issues.
Maybe even a plethora.
Lee Ayrton
> In article
> <4ecce68a-8943-4d8b...@l34g2000pro.googlegroups.com>,
> Snidely <snide...@gmail.com> wrote:
>> On Dec 16, 5:58 am, Greg Goss <go...@gossg.org> wrote:
>> > ebenZERO...@verizon.net (Hactar) wrote:
>> > >Don K <d...@comcast.net> wrote:
>> > >> When the pneumatic tube is "opened", water would flow thru the
>> > >> siphon and air would be sucked thru the pneumatic tube. This would
>> > >> work as long as there was water in the upper tank.
>> >
>> > >Or, a weight and some string/chain, as in a grandfather clock. It's
>> > >probably a good idea if the string goes over a pulley. When the
>> > >string is released, the weight drops and starts turning the
>> > >mechanism, which is not a clock but a blower.
>> >
>> > The water tank is much more elegant, without a blower. The only
>> > moving parts are the valve and the message cylinder.
>>
>> Turning a blower fast enough long enough might be tricky with a pulley-
>> weight setup.
>
> Big honkin' weight. Or multiple smaller weights. Or tall building. Or
> skip it, and go with water.
Don't forget to bleed off some of the power generated to pump the water
back up into the tank.
Xho Jingleheimerschmidt
It would surprise me if they used the hydrostatic tank based method
described above. But using a hydrodynamic Bernoulli aspirator device is
quite common in the lab, from just a small plastic nozzle with a
side-tube that screws onto an ordinary faucet, to large scaled up
versions which provide "house vacuum" to an entire campus.
In drought-prone Berkeley they didn't want us running tap water to drain
to provide the suction, so we had little water pumps that sit in a tank
and recycle water through the aspirator. I don't know they just didn't
hook the lab up to house vacuum, maybe retrofitting the plumbing was
more expensive than buying a few contraptions.
Xho
Lee Ayrton
> Lee Ayrton wrote:
>> On Wed, 15 Dec 2010 20:19:04 -0500, Don K wrote:
>>
>>
>>>> What powers these systems? I can simplistically imagine that at one
>>>> end of the sealed tube there is a compressor / vacuum thing. But in
>>>> the 19th century, what was that device? How was it switched on? Was
>>>> it steam-powered or something? And nowadays, where it's electrical,
>>>> I'm just curious how large the compressor needs to be.
>>> You could power a pneumatic tube using 2 tanks of water at different
>>> levels connected by a big siphon hose. The lower tank would be open to
>>> the air. The upper tank would be sealed and a pneumatic tube would
>>> connect at the top of the tank.
>>>
>>> When the pneumatic tube is "opened", water would flow thru the siphon
>>> and air would be sucked thru the pneumatic tube. This would work as
>>> long as there was water in the upper tank.
>>
>> I was told that Pfizer in Groton, CT uses/used water tanks to generate
>> suction used in processes that needed it.
>
> It would surprise me if they used the hydrostatic tank based method
> described above. But using a hydrodynamic Bernoulli aspirator device is
> quite common in the lab, from just a small plastic nozzle with a
> side-tube that screws onto an ordinary faucet, to large scaled up
> versions which provide "house vacuum" to an entire campus.
These were for large-volume production processes that required low
pressure for drying.
Mac
Well beyond yer plethora. The re-tooled article, dusted off,
wordsmithed a little, and presented again for new once the rubes have
forgotten, isn't that new.
Mark Brader
> Thanks for posting this, but I still am getting very little
> information pertaining to how they actually work. That they were used
> back in the middle of the 19th century, before the widespread
> availability of electricity, adds to my questions.
>
> What powers these systems? I can simplistically imagine that at one
> end of the sealed tube there is a compressor / vacuum thing. But in
> the 19th century, what was that device? How was it switched on? Was
> it steam-powered or something? And nowadays, where it's electrical,
> I'm just curious how large the compressor needs to be.
Well, when George Medhurst was writing about pneumatic propulsion in
the early 19th century, he certainly envisioned steam power -- you can
read his publications at Google Books. I imagine that steam would
have been used until suitable electric motors became available.
> Back in the 19th century, how was its on-off status triggered, by the
> sender?
I expect that if they didn't yet have reliable electric communications
with the other end, they would have used unidirectional pipes and left
the pump running all the time during working hours. Then you just pop
the capsule in through the door and close it, and it'll go until it
hits the stop at the other end (or bumps into the previous capsule,
which the guy at the other end hasn't removed yet).
+---[[[door]]]-------------------------------[[[door]]]+
+----+ | |
|PUMP==== (capsul)-> -> ->(capsul)-> -> =====\\
+----+ +------------------------------------------------------+ ||
||
+[[[door]]]------------------------------[[[door]]]----+ ||
| | ||
VENT <=(capsul)(capsul)(capsul) <- <- (capsul) =====//
+------------------------------------------------------+ air pipe
--
Mark Brader "Inventions reached their limit long ago,
Toronto and I see no hope for further development."
m...@vex.net -- Julius Frontinus, 1st century A.D.
My text in this article is in the public domain.