Date: Tue Apr 22 16:44:31 2008

Author: Bill Norwood

Subject: Re: air tracks and air sources

Post:
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Hi Dan,



You really did a great job

of explaining an in-house air track blower system that works well,

along with explaining its several "mini-caveats."



Many thanks for the enlightenment.



Bill Norwood



_____

From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On
Behalf Of Dan Bernoulli
Sent: Thursday, April 17, 2008 8:23 PM
To: tap-l@lists.ncsu.edu
Subject: Re: [tap-l] air tracks and air sources



Finally catching up on my listserve reading. To add my two cents on air
sources: We have one blower that discharges about 2 psi at shut off head. We
use four inch pvc to pipe the air to four lab rooms. Each room has six
tables. The 4 inch piping runs around each room and we use 2" pvc with a
ball valve for each outlet. There are two outlets per table for each room.
We run vacuum cleaner hose from the valve outlet to the track. We used to
use barbed fittings but found that 1" smooth pvc pipe worked just as well
and is much easier to get on and off the hose. The vacuum hose gets tucked
conveniently on the "service" cabinets adjacent to each table (these are the
built in cabinets that have air, gas, water etc. In one room we have 1" pvc
"stubs" glued to the 4" piping. We simply connect the loose end of the hose
to the stub when not in use. Also, we don't put hoses on the outlets that
are not commonly used. Until this year we had never used more than one lab
room (6 air tracks). This year we added a second concurrent lab so we had
twelve tracks running at one time. We had no problems other then opening the
discharge valve/flapper ten degrees instead of 5 degrees. With the low
pressure, high velocity flow rate we have never had a condensation problem.
But we have a good ac system in the building so humidity stays a pretty
constant 60% or so. There is a foam filter like one finds for air cleaners
on lawn mowers on the input to the blower. It seems to work well. I cleaned
it once about five years ago but I am not sure it really needed to be
cleaned. Each semester we open all the taps and blow any crud out. Our
tracks have stayed very clean. By using vacuum hose we can make connections
usig 1 inch pvc. We have adapted all of our tracks with a 90 degree pvc
elbow and an o-ring seal so we don't have problems with twisted hoses
tipping the tracks.

The only thing I don't like about the blower is it is in our storage area
and, although not painfully loud it gets old listening to it for days on
end. If I were to do it again i would put the thing in a machine room and/or
sound proof it. Because of the noise i use a portable blower if I am doing
just one or two tracks or air tables. I used to have a modified shop vac but
it died. Having a little money I bought 1 each of the standard blowers
(Pasco and ???). As others have mentioned the ??? is quieter but the Pasco
unit puts out more air. I like the ??? one better but doesn't work as well
when running two tracks. Neither is extraordinarily loud.

Some things to consider:
If you use pvc piping be aware that codes forbid its use for compressed gas.
I don't know where the dividing line is between a "ventilation" system and a
compressed air system. The issue is that pvc explodes into shards when it
fails. Not a good thing. If yur shutoff head can absolutely never exceed a
pound gage or so you are probably okay. (Sorry, I can think in metric for
most everything except pressure. Somehow 101 kPa is just so much more
awkward than 14.7 psi ; )

With a large blower you can put out too much air. The air needed for one or
two tracks is much different than the air needed for several tracks. So
careful adjustment of the flow rate may be needed. I have long considered
putting some kind of flow regulator on my system (controlling pressure may
be too unstable). If you have the wrong flow rate the track carts will drag
or the air will howl out the vents - ok for photogates but not so good for
ultrasonic motion detectors.

The blower was installed many years prior to my going to work at IU. I have
been here ten years. My guess is it has been in operation around twenty
years. No maintenance has ever been done on the blower system. It does have
many hours on it as instructors get so used to hearing it they forget to
turn it off so it commonly runs all night. Often they don't know where the
on-off switch is even though I show them during our AI training (each
participant actually turns it on and off) and I again show them where it is
at our weekly lab AI meeting. So perhaps an on-off switch in each room would
be useful.

We have to replace the vacuum cleaner hoses about every five years due to
deterioration and cracking of the tubing.

The only other issue we have is sometimes people forget to close the valves
in all the rooms so when the blower is started a hgorrendous roar of air
comes out someplace very unexpectedly. This can scare the s__t out of
someone if it happens in another classroom. More than once i have had a
student or professor come running into my office saying there was some knd
of explosion in thier lab room. We now carefully check all the lab rooms to
insure their supply valves are closed. We also send warning messages the air
will be used during the labs that week.

It is nice to have the large system but it won't eliminate the need to have
some smaller blowers as well. And keep in mind that a 5 hp blower has a
bigger carbon signature than tweve or even 24 1/10 HP blowers.

I think I have spent my two bits.

Dan Beeker

> From: bnorwood@umd.edu
> To: tap-l@lists.ncsu.edu
> CC: teg@physics.umd.edu
> Subject: Re: [tap-l] air tracks and air sources
> Date: Thu, 10 Apr 2008 16:33:33 -0400
>
> Hi Taplers,
>
> So - - if you were contemplating a new building
> (for us perhaps 10 years off)
>
> 1. Would you without second thought install an in-house blower system for
> your air tracks and air tables?
>
> 2. Have you found the labor and maintenance to be less than it tends to be
> for in-lab blower systems?
>
> 3. Do you just butt the ends of the lab tables up against a wall along
which
> there might be 6-8 air outlets (same of opposite side of room), or is
there
> snaking of the air hoses throughout the lab, as might be needed in
parallel
> rows of 3 tables, for example?
>
> Thanks for any guidance,
>
> Bill Norwood
> U of MD at College Park
>
>
> -----Original Message-----
> From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On
> Behalf Of Bernard Cleyet
> Sent: Tuesday, April 08, 2008 12:31 AM
> To: tap-l@lists.ncsu.edu
> Cc: Nancy Seese
> Subject: Re: [tap-l] air tracks and air sources
>
> If you have the room, use a shop vac. in another room, e.g. the stock
> or storage room and pipe in w/ pvc pipe*. Berkeley used Sears in the
> basement vacuums (have a low potential remote relay) in boxes w/
> sound absorbent blanket. I think each "powered" four of their
> machine shop constructed tracks**. This is practical only if you
> have student workers or a subsidized shop.
>
>
> * UCSC has a powerful blower in the mechanical room that powers about
> 20X. IIRC, 6 inch pipe to the manifolds (two classrooms).
>
> **The best design ever; a U w/ the holes in flat bottom. Not
> sensitive to dings or warping. If any are interested, I'll send a
> photo'.
>
> bc
>
>
> On 2008, Apr 07, , at 10:38, mklasse1@swarthmore.edu wrote:
> > Any recommendations on good quality air track/blower systems? I'm
> > particularly
> > interested in finding a quiet air source. We have a couple of Pasco
> > tracks and variable
> > air sources. The catalog copy says the air source is "exceptionally
> > quiet", but that term,
> > I do not think it means what they think it means. (To be fair, our
> > sources are probably
> > about 15 years old, so maybe they've improved since then. The
> > picture in the catalog
> > looks the same, though.) I just can't imagine spending an afternoon
> > in a lab with 4 or 5
> > of them running.
> >
> > Any experience with the Cenco "Quiet Air Source"?
> >
> > Thanks!
> > Mary Ann
> >
> > ***********************************************
> > Mary Ann Hickman Klassen
> > Lecturer
> > Dept. of Physics & Astronomy
> > Swarthmore College
> > 500 College Ave.
> > Swarthmore, PA 19081
> > phone: 610-328-8384 fax: 610-328-7895
> > **********************************************
> >
> >
> >
>
>

_____

Going green? See the top 12 foods to eat organic.



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charset="US-ASCII"
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Hi =
Dan,

=


You really did a great job =


of explaining an in-house air =
track
blower system that works well,

along with explaining its several =
“mini-caveats.”


=


Many thanks for the =
enlightenment.

=


Bill =
Norwood

=










From: =
tap-l-owner@lists.ncsu.edu
[mailto:tap-l-owner@lists.ncsu.edu] On Behalf
Of Dan =
Bernoulli
Sent: Thursday, April 17, =
2008
8:23 PM
To: tap-l@lists.ncsu.edu
Subject: Re: [tap-l] air =
tracks
and air sources





Finally catching up on my =
listserve
reading. To add my two cents on air sources: We have one blower that =
discharges
about 2 psi at shut off head. We use four inch pvc to pipe the air to =
four lab
rooms. Each room has six tables. The 4 inch piping runs around each room =
and we
use 2" pvc with a ball valve for each outlet. There are two outlets =
per
table for each room. We run vacuum cleaner hose from the valve outlet to =
the
track. We used to use barbed fittings but found that 1" smooth pvc =
pipe
worked just as well and is much easier to get on and off the hose. The =
vacuum
hose gets tucked conveniently on the "service" cabinets =
adjacent to
each table (these are the built in cabinets that have air, gas, water =
etc. In
one room we have 1" pvc "stubs" glued to the 4" =
piping. We
simply connect the loose end of the hose to the stub when not in use. =
Also, we
don't put hoses on the outlets that are not commonly used. Until this =
year we
had never used more than one lab room (6 air tracks). This year we added =
a
second concurrent lab so we had twelve tracks running at one time. We =
had no
problems other then opening the discharge valve/flapper ten degrees =
instead of
5 degrees. With the low pressure, high velocity flow rate we have never =
had a
condensation problem. But we have a good ac system in the building so =
humidity
stays a pretty constant 60% or so. There is a foam filter like one finds =
for
air cleaners on lawn mowers on the input to the blower. It seems to work =
well.
I cleaned it once about five years ago but I am not sure it really =
needed to be
cleaned. Each semester we open all the taps and blow any crud out. Our =
tracks
have stayed very clean. By using vacuum hose we can make connections =
usig 1
inch pvc. We have adapted all of our tracks with a 90 degree pvc =
elbow
and an o-ring seal so we don't have problems with twisted hoses tipping =
the
tracks.

The only thing I don't like about the blower is it is in our storage =
area and,
although not painfully loud it gets old listening to it for days on end. =
If I
were to do it again i would put the thing in a machine room and/or sound =
proof
it. Because of the noise i use a portable blower if I am doing just one =
or two
tracks or air tables. I used to have a modified shop vac but it died. =
Having a
little money I bought 1 each of the standard blowers (Pasco and ???). As others have =
mentioned the
??? is quieter but the Pasco
unit puts out more air. I like the ??? one better but doesn't work as =
well when
running two tracks. Neither is extraordinarily loud.

Some things to consider:
If you use pvc piping be aware that codes forbid its use for compressed =
gas. I
don't know where the dividing line is between a "ventilation" =
system
and a compressed air system. The issue is that pvc explodes into shards =
when it
fails. Not a good thing. If yur shutoff head can absolutely never exceed =
a
pound gage or so you are probably okay. (Sorry, I can think in metric =
for most
everything except pressure. Somehow 101 kPa is just so much more awkward =
than
14.7 psi ; )

With a large blower you can put out too much air. The air needed for one =
or two
tracks is much different than the air needed for several tracks. So =
careful
adjustment of the flow rate may be needed. I have long considered =
putting some
kind of flow regulator on my system (controlling pressure may be too =
unstable).
If you have the wrong flow rate the track carts will drag or the air =
will howl
out the vents - ok for photogates but not so good for ultrasonic motion
detectors.

The blower was installed many years prior to my going to work at IU. I =
have
been here ten years. My guess is it has been in operation around twenty =
years.
No maintenance has ever been done on the blower system. It does have =
many hours
on it as instructors get so used to hearing it they forget to turn it =
off so it
commonly runs all night. Often they don't know where the on-off switch =
is even
though I show them during our AI training (each participant actually =
turns it
on and off) and I again show them where it is at our weekly lab AI =
meeting. So
perhaps an on-off switch in each room would be useful.

We have to replace the vacuum cleaner hoses about every five years due =
to
deterioration and cracking of the tubing.

The only other issue we have is sometimes people forget to close the =
valves in
all the rooms so when the blower is started a hgorrendous roar of air =
comes out
someplace very unexpectedly. This can scare the s__t out of someone if =
it
happens in another classroom. More than once i have had a student or =
professor
come running into my office saying there was some knd of explosion in =
thier lab
room. We now carefully check all the lab rooms to insure their supply =
valves
are closed. We also send warning messages the air will be used during =
the labs
that week.

It is nice to have the large system but it won't eliminate the need to =
have
some smaller blowers as well. And keep in mind that a 5 hp blower has a =
bigger
carbon signature than tweve or even 24 1/10 HP blowers.

I think I have spent my two bits.

Dan Beeker

> From: bnorwood@umd.edu
> To: tap-l@lists.ncsu.edu
> CC: teg@physics.umd.edu
> Subject: Re: [tap-l] air tracks and air sources
> Date: Thu, 10 Apr 2008 16:33:33 -0400
>
> Hi Taplers,
>
> So - - if you were contemplating a new building
> (for us perhaps 10 years off)
>
> 1. Would you without second thought install an in-house blower =
system for
> your air tracks and air tables?
>
> 2. Have you found the labor and maintenance to be less than it =
tends to be
> for in-lab blower systems?
>
> 3. Do you just butt the ends of the lab tables up against a wall =
along
which
> there might be 6-8 air outlets (same of opposite side of room), or =
is
there
> snaking of the air hoses throughout the lab, as might be needed in
parallel
> rows of 3 tables, for example?
>
> Thanks for any guidance,
>
> Bill Norwood
> U of MD at College =
Park
>
>
> -----Original Message-----
> From: tap-l-owner@lists.ncsu.edu =
[mailto:tap-l-owner@lists.ncsu.edu] On
> Behalf Of Bernard Cleyet
> Sent: Tuesday, April 08, 2008 12:31 AM
> To: tap-l@lists.ncsu.edu
> Cc: Nancy Seese
> Subject: Re: [tap-l] air tracks and air sources
>
> If you have the room, use a shop vac. in another room, e.g. the =
stock
> or storage room and pipe in w/ pvc pipe*. Berkeley used Sears in the
> basement vacuums (have a low potential remote relay) in boxes w/ =

> sound absorbent blanket. I think each "powered" four of =
their
> machine shop constructed tracks**. This is practical only if you =

> have student workers or a subsidized shop.
>
>
> * UCSC has a powerful blower in the mechanical room that powers =
about
> 20X. IIRC, 6 inch pipe to the manifolds (two classrooms).
>
> **The best design ever; a U w/ the holes in flat bottom. Not
> sensitive to dings or warping. If any are interested, I'll send a =

> photo'.
>
> bc
>
>
> On 2008, Apr 07, , at 10:38, mklasse1@swarthmore.edu wrote:
> > Any recommendations on good quality air track/blower systems? =
I'm
> > particularly
> > interested in finding a quiet air source. We have a couple of =
Pasco
> > tracks and variable
> > air sources. The catalog copy says the air source is
"exceptionally
> > quiet", but that term,
> > I do not think it means what they think it means. (To be fair, =
our
> > sources are probably
> > about 15 years old, so maybe they've improved since then. The =

> > picture in the catalog
> > looks the same, though.) I just can't imagine spending an =
afternoon
> > in a lab with 4 or 5
> > of them running.
> >
> > Any experience with the Cenco "Quiet Air =
Source"?
> >
> > Thanks!
> > Mary Ann
> >
> > ***********************************************
> > Mary Ann Hickman Klassen
> > Lecturer
> > Dept. of Physics & Astronomy
> > Swarthmore
College
> > 500 College Ave.
> > Swarthmore, PA 19081
> > phone: 610-328-8384 fax: 610-328-7895
> > **********************************************
> >
> >
> >
>
>







Going green? See the top 12 foods to eat =
organic.







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