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| holcombsv@hotmail.com 2006-04-18, 4:21 pm |
| I have a pipe I'm trying to determine if my purge is adequate. The pipe
is deadheaded and my purge gas enters the pipe about 9 feet from the
deadhead. The other side of the pipe is open to atmosphere after about
150 feet of pipe. Are there any calcualations or analysis available on
deadheaded purges?
Thanks
| |
| Noon-Air 2006-04-19, 12:21 am |
|
<holcombsv@hotmail.com> wrote in message
news:1145384588.784001.140100@u72g2000cwu.googlegroups.com...
>I have a pipe I'm trying to determine if my purge is adequate. The pipe
> is deadheaded and my purge gas enters the pipe about 9 feet from the
> deadhead. The other side of the pipe is open to atmosphere after about
> 150 feet of pipe. Are there any calcualations or analysis available on
> deadheaded purges?
> Thanks
Ask your professer
| |
| holcombsv@hotmail.com 2006-04-19, 11:21 am |
| Cute... If only it was that easy. I've dusted off my engineering books
from college and can't find any data. Do you have any real help or are
you just blowing me off as a student trying to cheat on homework?
| |
| .p.jm@see_my_sig_for_address.com 2006-04-19, 12:21 pm |
| On 19 Apr 2006 06:44:15 -0700, holcombsv@hotmail.com wrote:
>Cute... If only it was that easy. I've dusted off my engineering books
>from college and can't find any data. Do you have any real help or are
>you just blowing me off as a student trying to cheat on homework?
I'm just wondering what you're trying to get at, beyond
calculating your flow rate of purge gas vs the volume to be purged.
It seems simple enough.
--
Click here every day to feed an animal that needs you today !!!
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Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
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| |
| holcombsv@hotmail.com 2006-04-19, 1:21 pm |
| The problem is the area I need to purge is deadheaded.
________________________________________________open pipe
{
{I need to purge this area
{
{_________________________________ _____________
...........................purge gas enters here
How can I calculate the air exchange of the purge into the dead headed
region?
| |
| .p.jm@see_my_sig_for_address.com 2006-04-19, 1:21 pm |
| On 19 Apr 2006 08:39:20 -0700, holcombsv@hotmail.com wrote:
>The problem is the area I need to purge is deadheaded.
> ________________________________________________open pipe
>{
>{I need to purge this area
>{
>{_________________________________ _____________
> ...........................purge gas enters here
>
>How can I calculate the air exchange of the purge into the dead headed
>region?
Not sure I follow the ASCII, but if I understand that you have
a deadhead leg branched off the line where the purge gas is flowing, I
don't see how you're going to get any purge at all to it.
But your ASCII seems to show a straight path ( go to the
left, 90 up, go up, 90 right, go right, and out ), then it's a simple
flowrate vs volume calc.
I don't see in the ASCII what you're calling 'deadhead', I see
one path with 2 90's.
If you're saying this ;
[color=darkred]
^
^
^
^
^>>>>>>>>>>>>>>>>>>>>>deadhead capped
^
^
^
^>>>>>>>>>>>>>>>>>>>>>>>>>>>> inlet
And you want to purge that deadhead line - you're not going
to.
--
Click here every day to feed an animal that needs you today !!!
http://www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
| |
| holcombsv@hotmail.com 2006-04-19, 1:21 pm |
| No, my ASCII was showing a single pipe. I have a pipe about 9" in
diameter that has a cap on it on one end and the other end is open.
About 9 ft from the cap, I have a purge gas entering. The other side
is open about 150 feet from the purge gas entrance. I need to
calculate the air exchange of the space from where the purge gas enters
to the cap. I understand that the purge gas will tend to travel the
path of least resistance and therefore flow to the open end. However,
I'm assuming that some purging of the deadheaded section takes place.
Asperation due to the purge gas may help purge the deadheaded section.
I'd think the purge of the deadheaded section would be a gradient as a
function of the distance from the purge gas entrance. Is there a way to
calculate the purge of the deadheaded section? Do dead headed purge
tables exists that have been created based on emperical data?
Thanks for your help
| |
| .p.jm@see_my_sig_for_address.com 2006-04-19, 2:21 pm |
| On 19 Apr 2006 09:13:10 -0700, holcombsv@hotmail.com wrote:
>No, my ASCII was showing a single pipe. I have a pipe about 9" in
>diameter that has a cap on it on one end and the other end is open.
>About 9 ft from the cap, I have a purge gas entering. The other side
>is open about 150 feet from the purge gas entrance. I need to
>calculate the air exchange of the space from where the purge gas enters
>to the cap. I understand that the purge gas will tend to travel the
>path of least resistance and therefore flow to the open end. However,
>I'm assuming that some purging of the deadheaded section takes place.
Wrong. Minimal within the first foot or so, caused by
turbulence and venturi effect, nothing beyond that.
>Asperation due to the purge gas may help purge the deadheaded section.
>I'd think the purge of the deadheaded section would be a gradient as a
>function of the distance from the purge gas entrance. Is there a way to
>calculate the purge of the deadheaded section? Do dead headed purge
>tables exists that have been created based on emperical data?
Dunno. But what you need is a purge exit port at the cap. At
which point, you might as well close off the purge entry you have now,
and use the new opening as purge inlet. Drill and tap a hole in the
cap, put a fitting on it. If needed, run a small tube from that point
to wherever you have access to for applying the purge gas.
Don't know the specifics, but if it were possible, I could see
you pushing a small vinyl tube through the existing purge port, get it
to angle towards the capped end, run it all the way of the deadhead
length - 1 ", seal around where it goes in, and put a fitting on to
purge with. Then I would say purge to 3 x's the volume of the
deadhead.
Why does this deadhead need to be there at all ?
Either that, or make your purge directional within the pipe,
so that it's 'blasting' towards the capped end. This would require a
90 INSIDE the 9 " pipe. Then, with sufficent pressure ( velocity )
you would get a purging effect in the deadhead, but it would be
somewhat unpredictable, so you would have to over-purge to whatever
extent you SWAG it at.
>Thanks for your help
--
Click here every day to feed an animal that needs you today !!!
http://www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
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| |
| holcombsv@hotmail.com 2006-04-19, 2:21 pm |
| I'm hoping that more than the first foot or two is purged. I'd like to
be able to calculate it.
The purge enters the pipe tangental to the pipe wall.
The purge is 268 SCFM for 106 seconds. This equates to 472 cubic feet.
The deadheaded volume is 1.5 cubic feet. (1 foot section of 7" pipe and
8.5 foot section of 5.12" pipe)
That equate to enough purge gas for 315 volume exchanges.
However, the space is deadheaded so all 472 cubic feet are not moving
through the space being purged.
Anyway to calculate the volume exchange in the deadheaded section?
| |
| .p.jm@see_my_sig_for_address.com 2006-04-19, 2:21 pm |
| On 19 Apr 2006 09:57:43 -0700, holcombsv@hotmail.com wrote:
>I'm hoping that more than the first foot or two is purged. I'd like to
>be able to calculate it.
>
>The purge enters the pipe tangental to the pipe wall.
>The purge is 268 SCFM for 106 seconds. This equates to 472 cubic feet.
>The deadheaded volume is 1.5 cubic feet. (1 foot section of 7" pipe and
>8.5 foot section of 5.12" pipe)
>That equate to enough purge gas for 315 volume exchanges.
>However, the space is deadheaded so all 472 cubic feet are not moving
>through the space being purged.
In fact, none of them are.
>Anyway to calculate the volume exchange in the deadheaded section?
No, because there is none.
--
Click here every day to feed an animal that needs you today !!!
http://www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
| |
|
|
holcombsv@hotmail.com wrote:
> I have a pipe I'm trying to determine if my purge is adequate. The pipe
> is deadheaded and my purge gas enters the pipe about 9 feet from the
> deadhead. The other side of the pipe is open to atmosphere after about
> 150 feet of pipe. Are there any calcualations or analysis available on
> deadheaded purges?
> Thanks
If I understand you correctly you have a nine ft section of nine inch
pipe that is deadheaded with respect to your purge gas entry point.
Because of the behavior of gasses (Dalton Law), any gas that you inject
into the line will expand uniformly to fill the entire volume,
independently of any other types of gasses present. This includes the
gas in the deadheaded portion of the pipe. In other words, as you
inject gas it will travel down the deadheaded length of pipe, even
though there is no outlet. Likewise, gas already in that portion will
equalize itself through out the line. Since your line is open to the
atmosphere there will be air in the deadheaded portion at 14.7psia. As
you purge, the air in the main line will pushed out the open end, and
as a result the air in the deadheaded portion will expand along the
pipe in order to equalize its own pressure throughout the pipe. You'll
only need to inject enough gas to purge the total volume of the pipe at
sufficient velocity to prevent counter-migration of air back into the
line. Because of the long length of line leading to the outlet, in
this case tye deadheaded portion will purge nearly as quickly as the
nine foot section downstream of it. Velocity is the number you're
looking for, but I don't know off hand how to calcultate required
velocity. The formula, if it exists will include parameters such as
mean free path, viscocity, volume, temperature, pressure, etc.
Is there any reason that you can't evacuate the pipe?
Richard Perry
| |
| .p.jm@see_my_sig_for_address.com 2006-04-19, 4:21 pm |
| On 19 Apr 2006 11:06:47 -0700, "RP" <no_mail_no_spam@yahoo.com> wrote:
>
>holcombsv@hotmail.com wrote:
>
>If I understand you correctly you have a nine ft section of nine inch
>pipe that is deadheaded with respect to your purge gas entry point.
>Because of the behavior of gasses (Dalton Law), any gas that you inject
>into the line will expand uniformly to fill the entire volume,
>independently of any other types of gasses present. This includes the
>gas in the deadheaded portion of the pipe. In other words, as you
>inject gas it will travel down the deadheaded length of pipe, even
No it won't.
>though there is no outlet. Likewise, gas already in that portion will
>equalize itself through out the line. Since your line is open to the
>atmosphere there will be air in the deadheaded portion at 14.7psia. As
>you purge, the air in the main line will pushed out the open end, and
>as a result the air in the deadheaded portion will expand along the
>pipe in order to equalize its own pressure throughout the pipe.
Even if that made any sense, it would still be wrong.
What exactly is going to cause the DH gas to expand ? Last
time I checked, a drop in pressure or a rise in temperature coupled
with an increase in volume is the only thing that causes that, and
neither is postulated here. In fact, the opposite - a higher pressure
purge is introduced. The gas in the DH will compress ( slightly ) not
expand.
> You'll
>only need to inject enough gas to purge the total volume of the pipe at
>sufficient velocity to prevent counter-migration of air back into the
>line.
For the non-DH portion, as long as you choose arbitrarily to
ignore mixing, OK.
> Because of the long length of line leading to the outlet, in
>this case tye deadheaded portion will purge nearly as quickly as the
>nine foot section downstream of it.
Bullshit.
> Velocity is the number you're
>looking for, but I don't know off hand how to calcultate required
>velocity. The formula, if it exists will include parameters such as
>mean free path, viscocity, volume, temperature, pressure, etc.
Ahem..... bullshit :-)
Rich, WTF are you talking about ? The purge gas will flow,
under pressure, from the entry point to the exit point. Period.
barring the near-field effects of turbulence and venturi, it will not
flow up the DH section against equal ( or lessor ) pressure.
>Is there any reason that you can't evacuate the pipe?
Or put the purge inlet in the right place to begin with ?
>
>Richard Perry
--
Click here every day to feed an animal that needs you today !!!
http://www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
| |
| Mark and Gloria Hagwood 2006-04-19, 7:21 pm |
| holcombsv@hotmail.com wrote:
> Cute... If only it was that easy. I've dusted off my engineering books
> from college and can't find any data. Do you have any real help or are
> you just blowing me off as a student trying to cheat on homework?
>
If evacuation is not possible before the purge, is
pressurizing the pipe possible? You could pressurize with
the purge gas, then blow it. Repeating this a few times
would possibly purge more of the deadheaded part of the pipe
than just blowing the gas through and hoping for a slight
venturi effect.
If you could build an adapter, you might also introduce a
flexible pipe through the purge port and run it back to the
end of the deadheaded part. If you flared the end toward
the purging gas flow, a flow through the flexible pipe would
be induced and that might also push out the gas in the
deadheaded end.
Mark
| |
|
| please accuse my ignorance but what in world
you are trying to purge, you are giving all
kind measurements but you are not saying
what are trying to purge?>
Did you eat lot of Mexican bean and you trying
to purge your farts? Hello
Good luck from Dido
| |
|
|
..p.jm@see_my_sig_for_address.com wrote:
> On 19 Apr 2006 11:06:47 -0700, "RP" <no_mail_no_spam@yahoo.com> wrote:
>
>
> No it won't.
Upon what do you base your arguments? I'll mention *partial pressures*
one more time, after which I'll leave you to research it on your own.
Hint: Dalton's Law.
You're entitled to opinions about thermodynamic processes, but I
prefer a bit of empirical validation.
>
>
> Even if that made any sense, it would still be wrong.
More correctly, that didn't make sense *to you*.
>
> What exactly is going to cause the DH gas to expand ?
It's always expanding due to thermal agitation, the reason that it
doesn't go anywhere in a closed container is that when a molucule is
displaced from one end of the container to the other, then it is
replaced by one that has moved similarly in the opposite direction.
When there is no longer gas present in one end to replace those
displaced molecules, then the momentum flux becomes non-zero and there
is a net flow of gas in one direction. Because of the behavior of gases
quantified in Dalton's Law of Partial Pressures, an ideal gas will
exert a pressure independently of other gases present. The net pressure
in the container of mixed gases will be the algebraic sum of the
partial pressures of the gases in the container. If you introduce a
second gas into a container that initially has only one type of gas,
then it's pressure will tend to equalize over the volume, independently
of the pressure of the other gas. Thus, if you have displaced some of
the preexisting gas with the injected gas, in one region of the
container, then the original gas won't exist in that portion of the
volume to exert its partial pressure. The pressure in this region, by
Dalton's Law, would be lower than the pressure in the region where both
gases exist in a mixture. A net flow from higher to lower pressure
would occur. IOW, from the deadheaded pipe into the main pipe.
This will continue until a uniform mixture exists in the whole volume.
Of course this won't occur until only the injected gas exists in the
pipe.
> Last
> time I checked, a drop in pressure or a rise in temperature coupled
> with an increase in volume is the only thing that causes that, and
> neither is postulated here. In fact, the opposite - a higher pressure
> purge is introduced. The gas in the DH will compress ( slightly ) not
> expand.
Diffusion. Here's a cut and pasted definition to save you the effort
that you didn't exert before posting your, er, sentiments:
Diffusion, in physical science, flow of energy or matter from a
higher concentration to a lower concentration, resulting in an even
distribution. Diffusion of matter occurs most rapidly in gases, more
slowly in liquids, and most slowly in solids. The spreading of a smell
is an example of gaseous diffusion, a lump of sugar placed in water is
an example of a solid dissolving and diffusing in a liquid, and gold
plated on copper is an example of a solid diffusing into a solid.
The rate of diffusion is proportional to the cross-sectional area and
to the gradient of concentration, temperature, or charge. The rate of
diffusion is also proportional to a quality of the substance, which in
the case of heat or electricity is called conductivity and in the case
of matter is called diffusivity or diffusion coefficient (see
Conductor, Electrical; Resistance). The amount of material that
diffuses in a certain time, or the distance it travels, is proportional
to the square root of the time. Because diffusion of matter depends on
the random motion of individual molecules, the rate is directly
proportional to the average velocity of the molecules.
>
>
> For the non-DH portion, as long as you choose arbitrarily to
> ignore mixing, OK.
>
>
> Bullshit.
Disturbances in the line will propagate at the speed of sound in the
existing gas. The injected gas will flow equally in both directions
(assuming that it enters through a symetrical T fitting, for a time
equal to ds/u, where ds is the length of the deadheaded portion, and u
is the speed of of sound in the existing gas. Since the injected gas is
moving at near the speed of sound, the deadheaded pipe will be nearly
saturated with the injected gas almost immediately. At t=ds/u the
partial pressure of the injected gas will be equal in both directions,
the existing gas will have been compressed to some degree and diffused
to some degree. At the T the partial pressure of the existing gas will
be low and it will thus tend to migrate toward the T, while the
injected gas is migrating away from it. The rate at which the existing
gas diffuses depends upon the molecular weights, temperatures, partial
pressures, and a second order chemical affinity of the two gases if
they are non reactive, and upon the flow rate (velocity) of the
injected gas.
>
>
> Ahem..... bullshit :-)
>
> Rich, WTF are you talking about ? The purge gas will flow,
> under pressure, from the entry point to the exit point. Period.
> barring the near-field effects of turbulence and venturi, it will not
> flow up the DH section against equal ( or lessor ) pressure.
Ah, but it will nonetheless.
Richard Perry
| |
| .p.jm@see_my_sig_for_address.com 2006-04-20, 1:21 am |
| On 19 Apr 2006 20:25:54 -0700, "RP" <no_mail_no_spam@yahoo.com> wrote:
>
>.p.jm@see_my_sig_for_address.com wrote:
>
>Upon what do you base your arguments? I'll mention *partial pressures*
>one more time, after which I'll leave you to research it on your own.
>Hint: Dalton's Law.
>You're entitled to opinions about thermodynamic processes, but I
>prefer a bit of empirical validation.
>
>
>More correctly, that didn't make sense *to you*.
Or anyone else. It was utter nonsense. Read it closely. It
starts out ( in the DH section ) at 14.7, then you introduce, let's
SWAG 2 PSI purge to the system, resulting in the system ( both DH and
open sides ) now being at 16.7. An increase in pressure. Applied to
the existing gas in the existing volume of the DH. This causes it to
COMPRESS, not expand ! Increase in pressure, coupled with no change
in containment volume or substance mass, results in COMPRESSION !
>
>
>It's always expanding due to thermal agitation, the reason that it
>doesn't go anywhere in a closed container
This an open container.
> is that when a molucule is
>displaced from one end of the container to the other, then it is
>replaced by one that has moved similarly in the opposite direction.
>When there is no longer gas present in one end to replace those
>displaced molecules, then the momentum flux becomes non-zero and there
>is a net flow of gas in one direction. Because of the behavior of gases
>quantified in Dalton's Law of Partial Pressures, an ideal gas will
>exert a pressure independently of other gases present. The net pressure
>in the container of mixed gases will be the algebraic sum of the
>partial pressures of the gases in the container.
Unless acted upon by an external force.
> If you introduce a
>second gas into a container that initially has only one type of gas,
>then it's pressure will tend to equalize over the volume, independently
>of the pressure of the other gas. Thus, if you have displaced some of
>the preexisting gas with the injected gas, in one region of the
>container, then the original gas won't exist in that portion of the
>volume to exert its partial pressure. The pressure in this region, by
>Dalton's Law, would be lower than the pressure in the region where both
>gases exist in a mixture. A net flow from higher to lower pressure
Yes, and that's exactly where you're going off track, both.
Because your'e talking about STATIC behavior. The purge gas
is under pressure, it has velocity and directionality. Even 1 PSI of
externally applied pressure is a far greater influence than partial
pressures. And I suspect the purge is at a higher DT than that.
>would occur. IOW, from the deadheaded pipe into the main pipe.
>This will continue until a uniform mixture exists in the whole volume.
>Of course this won't occur until only the injected gas exists in the
>pipe.
>
>
>Diffusion. Here's a cut and pasted definition to save you the effort
>that you didn't exert before posting your, er, sentiments:
> Diffusion, in physical science, flow of energy or matter from a
>higher concentration to a lower concentration, resulting in an even
Snipped, because it ignore the case in question. It refers to
STATIC behavior, NOT behavior controlled by external application of
force.
>Disturbances in the line will propagate at the speed of sound in the
>existing gas. The injected gas will flow equally in both directions
>(assuming that it enters through a symetrical T fitting, for a time
>equal to ds/u, where ds is the length of the deadheaded portion, and u
>is the speed of of sound in the existing gas.
OK, 7 feet / 1000 FPS = .007 seconds. End of
external-pressure driven flow into DH section.
> Since the injected gas is
>moving at near the speed of sound, the deadheaded pipe will be nearly
>saturated with the injected gas almost immediately.
Wrong. The PRESSURE will equalize, but that does NOT say that
the pre-existing gas has gone anywhere, nor has saturation occured.
> At t=ds/u the
>partial pressure of the injected gas will be equal in both directions,
>the existing gas will have been compressed to some degree and diffused
>to some degree. At the T the partial pressure of the existing gas will
>be low and it will thus tend to migrate toward the T, while the
>injected gas is migrating away from it. The rate at which the existing
>gas diffuses depends upon the molecular weights, temperatures, partial
>pressures, and a second order chemical affinity of the two gases if
>they are non reactive, and upon the flow rate (velocity) of the
>injected gas.
And, at best, you get a MIX controlled by partial pressure,
not a PURGE. Which again is not the question at hand.
Read that again - you have a MIX, not a PURGE !!!!!!
Let's say you start out with gas # 1, and purge with gas # 2.
What you will end up with in the DH section is a MIX of # 1 & # 2,
based on partial pressure, assuming sufficient time has elapsed to
allow full mixing. THIS IS NOT A PURGE ! Gas # 1 is still in there !
Kapich ? :-)
Would like like a few hundred lines of meaningless BASIC code,
just so you feel like you're arguing witih Nick ? :-)
--
Click here every day to feed an animal that needs you today !!!
http://www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
| |
| PrecisionMechanical 2006-04-20, 3:21 am |
|
<.p.jm@see_my_sig_for_address.com> wrote in message
news:1d0e42tj7idm0k1bi87ukm7u865033kd76@4ax.com...
Sheesh, just snake a piece of tubing to the end of the deadhead, and begin
injecting you purge from there....
Slowly....you withdraw....the tube...
--
SVL
| |
| .p.jm@see_my_sig_for_address.com 2006-04-20, 3:21 am |
| On Wed, 19 Apr 2006 22:25:09 -0700, "PrecisionMechanical"
<precisionmachinist@hotmail.com> wrote:
>
><.p.jm@see_my_sig_for_address.com> wrote in message
>news:1d0e42tj7idm0k1bi87ukm7u865033kd76@4ax.com...
>
>Sheesh, just snake a piece of tubing to the end of the deadhead, and begin
>injecting you purge from there....
>
>Slowly....you withdraw....the tube...
Or leave it in, like I suggested :-)
--
Click here every day to feed an animal that needs you today !!!
http://www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
| |
| PrecisionMechanical 2006-04-20, 3:21 am |
|
"DIDO" <a.seput@verizon.net> wrote in message
news:pUz1g.7157$_w6.1241@trndny09...
> please accuse my ignorance but what in world
> you are trying to purge, you are giving all
> kind measurements but you are not saying
> what are trying to purge?>
> Did you eat lot of Mexican bean and you trying
> to purge your farts? Hello
> Good luck from Dido
>
Go fuck you self, you XXXXXXX.
As it stands, your a total waste of bandwidth in the most liberal sense.
Even you hate Jews, too--if hadda guess..
--
SVL
--
| |
| PrecisionMechanical 2006-04-20, 5:21 am |
|
<.p.jm@see_my_sig_for_address.com> wrote in message
news:707e42tbnborfm036tcdos2qku688c51f2@4ax.com...
> On Wed, 19 Apr 2006 22:25:09 -0700, "PrecisionMechanical"
> <precisionmachinist@hotmail.com> wrote:
>
begin[color=darkred]
>
> Or leave it in, like I suggested :-)
>
Sorry, like I said earlier...server problems...been .missing lotsa posts
currently.
--
SVL
| |
|
|
..p.jm@see_my_sig_for_address.com wrote:
> On 19 Apr 2006 20:25:54 -0700, "RP" <no_mail_no_spam@yahoo.com> wrote:
>
>
> Or anyone else. It was utter nonsense. Read it closely. It
> starts out ( in the DH section ) at 14.7, then you introduce, let's
> SWAG 2 PSI purge to the system, resulting in the system ( both DH and
> open sides ) now being at 16.7. An increase in pressure. Applied to
> the existing gas in the existing volume of the DH. This causes it to
> COMPRESS, not expand ! Increase in pressure, coupled with no change
> in containment volume or substance mass, results in COMPRESSION !
>
>
> This an open container.
>
>
> Unless acted upon by an external force.
>
>
> Yes, and that's exactly where you're going off track, both.
>
> Because your'e talking about STATIC behavior. The purge gas
> is under pressure, it has velocity and directionality. Even 1 PSI of
> externally applied pressure is a far greater influence than partial
> pressures. And I suspect the purge is at a higher DT than that.
>
>
> Snipped, because it ignore the case in question. It refers to
> STATIC behavior, NOT behavior controlled by external application of
> force.
>
>
> OK, 7 feet / 1000 FPS = .007 seconds. End of
> external-pressure driven flow into DH section.
>
>
> Wrong. The PRESSURE will equalize, but that does NOT say that
> the pre-existing gas has gone anywhere, nor has saturation occured.
>
>
> And, at best, you get a MIX controlled by partial pressure,
> not a PURGE. Which again is not the question at hand.
>
> Read that again - you have a MIX, not a PURGE !!!!!!
>
> Let's say you start out with gas # 1, and purge with gas # 2.
> What you will end up with in the DH section is a MIX of # 1 & # 2,
> based on partial pressure, assuming sufficient time has elapsed to
> allow full mixing. THIS IS NOT A PURGE ! Gas # 1 is still in there !
>
> Kapich ? :-)
>
> Would like like a few hundred lines of meaningless BASIC code,
> just so you feel like you're arguing witih Nick ? :-)
Recall that I said initially that velocity was the number that he was
after. IOW, a complete purge wil require the injected gas velocity (in
the line) to be greater than the diffusion velocity. When this
condition is met, even though air is attempting to diffuse into the
injected stream Icounter flow) it still has a net motion in the same
direction as the injected stream. The air in the deadheaded pipe will
diffuse into the injected stream at *static* rates. While the injected
stream has velocity down the pipe toward the outlet, it has no net
velocity into the deadheaded portion, it has a diffusion rate into that
portion. This is more or less a static diffusion then, taking place
within the deadheaded pipe. I expect that a few seconds of purge would
clear the deadheaded portion by close to 100%.
The diffusion rate will actually be accellerated greatly by the
injected stream over the static situation, however. The existing gas
will more or less evaporate from the deadheaded pipe. The molecules are
bouncing around at sonic speeds, right into the injected stream, which
is anything but solid. It isn't a rigid barrier as a stream of water
might present itself to a gas. With X molecules of air leaving the
deadheaded pipe per second, and zero molecules returning, the deadhead
will very quickly purge. A small fraction of one second.
Richard Perry
| |
| Noon-Air 2006-04-20, 11:21 am |
|
>
>
> Recall that I said initially that velocity was the number that he was
> after. IOW, a complete purge wil require the injected gas velocity (in
> the line) to be greater than the diffusion velocity. When this
> condition is met, even though air is attempting to diffuse into the
> injected stream Icounter flow) it still has a net motion in the same
> direction as the injected stream. The air in the deadheaded pipe will
> diffuse into the injected stream at *static* rates. While the injected
> stream has velocity down the pipe toward the outlet, it has no net
> velocity into the deadheaded portion, it has a diffusion rate into that
> portion. This is more or less a static diffusion then, taking place
> within the deadheaded pipe. I expect that a few seconds of purge would
> clear the deadheaded portion by close to 100%.
"a few seconds of purge"???
At what pressure? and what volume?
There are a couple of basic questions that still haven't been answered
yet....
What is the gas that is in the pipe??
What is the purge gas??
What is the application??
> The diffusion rate will actually be accellerated greatly by the
> injected stream over the static situation, however. The existing gas
> will more or less evaporate from the deadheaded pipe. The molecules are
> bouncing around at sonic speeds, right into the injected stream, which
> is anything but solid. It isn't a rigid barrier as a stream of water
> might present itself to a gas. With X molecules of air leaving the
> deadheaded pipe per second, and zero molecules returning, the deadhead
> will very quickly purge. A small fraction of one second.
For the size of pipe that was initially described, to do a complete purge in
"A small fraction of one second", the resulting interchange would happen
with explosive force, or a detonation.
> Richard Perry
>
| |
|
| Please change you name to:
PRECISION JERK!!!!!!!!!!!
| |
| .p.jm@see_my_sig_for_address.com 2006-04-20, 12:21 pm |
| On 20 Apr 2006 05:36:49 -0700, "RP" <no_mail_no_spam@yahoo.com> wrote:
>
>.p.jm@see_my_sig_for_address.com wrote:
>
>
>
>Recall that I said initially that velocity was the number that he was
>after. IOW, a complete purge wil require the injected gas velocity (in
>the line) to be greater than the diffusion velocity. When this
>condition is met, even though air is attempting to diffuse into the
>injected stream Icounter flow) it still has a net motion in the same
>direction as the injected stream. The air in the deadheaded pipe will
>diffuse into the injected stream at *static* rates. While the injected
>stream has velocity down the pipe toward the outlet, it has no net
>velocity into the deadheaded portion, it has a diffusion rate into that
>portion. This is more or less a static diffusion then, taking place
>within the deadheaded pipe. I expect that a few seconds of purge would
>clear the deadheaded portion by close to 100%.
>
>The diffusion rate will actually be accellerated greatly by the
>injected stream over the static situation, however. The existing gas
>will more or less evaporate from the deadheaded pipe. The molecules are
>bouncing around at sonic speeds, right into the injected stream, which
>is anything but solid. It isn't a rigid barrier as a stream of water
>might present itself to a gas. With X molecules of air leaving the
>deadheaded pipe per second, and zero molecules returning, the deadhead
>will very quickly purge. A small fraction of one second.
Bwahahahahaha !!!! :-)
>
>Richard Perry
--
Click here every day to feed an animal that needs you today !!!
http://www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
| |
| Cooltemp Industries 2006-04-20, 1:21 pm |
|
DIDO wrote:
> Please change you name to:
> PRECISION JERK!!!!!!!!!!!
You've been posting here for months.
You have yet to say anything close to intelligent.
You can't spell even the simplest words.
Your posts are rambling and disjointed.
You appear to post simply to see your own name in print.
Precision Mechanical has a firm grasp of the industry, and although I
may not agree with everything he posts, he can usually back up his
reasons for his stance on various issues.
You could learn from him.
| |
|
|
Noon-Air wrote:[color=darkred]
>
> "a few seconds of purge"???
> At what pressure? and what volume?
>
> There are a couple of basic questions that still haven't been answered
> yet....
> What is the gas that is in the pipe??
> What is the purge gas??
> What is the application??
>
>
> For the size of pipe that was initially described, to do a complete purge in
> "A small fraction of one second", the resulting interchange would happen
> with explosive force, or a detonation.
>
I was speaking of the nine foot deadheaded portion of the pipe in that
passage. Also, I don't know the specific velocity required to purge the
main line, but I'm certain that it will require far less than explosive
pressure to provide it. Lot's of volume though.
If on the other hand he's trying to purge some residual liquid of some
kind, then he's probably SOL anyway.
Richard Perry
| |
| Noon-Air 2006-04-20, 11:21 pm |
|
"RP" <no_mail_no_spam@yahoo.com> wrote in message
news:1145559105.865822.83400@z34g2000cwc.googlegroups.com...
>
> Noon-Air wrote:
>
> I was speaking of the nine foot deadheaded portion of the pipe in that
> passage. Also, I don't know the specific velocity required to purge the
> main line, but I'm certain that it will require far less than explosive
> pressure to provide it. Lot's of volume though.
>
> If on the other hand he's trying to purge some residual liquid of some
> kind, then he's probably SOL anyway.
>
> Richard Perry
Last time I ran across a purge problem, it was in a gun barrel(a very large
one), we used 3000psig compressed air.
| |
| gofish@gonefishin.net 2006-04-20, 11:21 pm |
| Cooltemp Industries <gbroderick@sunlife.com> wrote:
>
>
>DIDO wrote:
>
>
>You've been posting here for months.
>You have yet to say anything close to intelligent.
>You can't spell even the simplest words.
>Your posts are rambling and disjointed.
>You appear to post simply to see your own name in print.
>Precision Mechanical has a firm grasp of the industry, and although I
>may not agree with everything he posts, he can usually back up his
>reasons for his stance on various issues.
>You could learn from him.
if Dido is so offensive to you, why do you bother to read his posts?
so that you have something to piss & moan about?
here's a suggestion: the next time you are offended by a post of
Dido's, take your .357, chamber a round, press the barrel to your
forehead, and squeeze the trigger.
oh, and have a nice day.
| |
| Noon-Air 2006-04-21, 12:21 am |
|
<gofish@gonefishin.net> wrote in message
news:31fg421hl6i5rj3g3c2o1fgiiqti7fh3ek@4ax.com...
> Cooltemp Industries <gbroderick@sunlife.com> wrote:
>
>
> if Dido is so offensive to you, why do you bother to read his posts?
> so that you have something to piss & moan about?
>
> here's a suggestion: the next time you are offended by a post of
> Dido's, take your .357, chamber a round, press the barrel to your
> forehead, and squeeze the trigger.
>
> oh, and have a nice day.
Sheesh....what a waste of a perfectly good bullet.
| |
| PrecisionMechanical 2006-04-21, 12:21 am |
|
<gofish@gonefishin.net> wrote in message
news:31fg421hl6i5rj3g3c2o1fgiiqti7fh3ek@4ax.com...
> Cooltemp Industries <gbroderick@sunlife.com> wrote:
>
>
> if Dido is so offensive to you, why do you bother to read his posts?
> so that you have something to piss & moan about?
>
> here's a suggestion: the next time you are offended by a post of
> Dido's, take your .357, chamber a round, press the barrel to your
> forehead, and squeeze the trigger.
>
> oh, and have a nice day.
I only felt that it was just time for another test--sadly, Dido has yet
again failed.
--
SVL
| |
| Cooltemp Industries 2006-04-21, 12:21 am |
|
gofish@gonefishin.net wrote:
> if Dido is so offensive to you, why do you bother to read his posts?
> so that you have something to piss & moan about?
>
> here's a suggestion: the next time you are offended by a post of
> Dido's, take your .357, chamber a round, press the barrel to your
> forehead, and squeeze the trigger.
>
> oh, and have a nice day.
Dido was born a moron.
You have progessed to becoming one.
It took effort on your part.
I think you win a prize.
| |
| Cooltemp Industries 2006-04-21, 12:21 am |
|
PrecisionMechanical wrote:
> I only felt that it was just time for another test--sadly, Dido has yet
> again failed.
Dodo was issued to this group. Every group has a Dido.
He replaced another member who loved to read his own posts, and never
had anything intelligent to say. I think you know who I mean.
He left. Dido jumped in to fill his shoes, small that they were.
Fish hates the world because he longs for recognition, but lacks the
skills to aquire it legitimatley. Maybe some day, with practice.....nah!
Your turn Fish!
Jump up and down, hold your breath, stomp your feet....we've seen your
tricks before. Old and boring.
| |
|
|
..p.jm@see_my_sig_for_address.com wrote:
> On 20 Apr 2006 05:36:49 -0700, "RP" <no_mail_no_spam@yahoo.com> wrote:
>
>
> Bwahahahahaha !!!! :-)
At least you got a laugh out of it. Ok, I probably fudged the time
factpr a bit, probably take at least a few seconds, but the principles
are all sound. I found several papers afterward stating pretty much
the same as I stated, but not one of them provided actual numbers. The
formulas also varied considerably from one paper to another, and turns
out there are new papers still being published on this topic for
various specific situations such as given by the OP. The bottom line
seems to be "try it, and then you'll know what to expect next time".
On the other hand, who of us really gives a damn how long it'll take?
:-)
Richard Perry
| |
| gofish@gonefishin.net 2006-04-21, 3:21 am |
| "PrecisionMechanical" <precisionmachinist@hotmail.com> wrote:
>
><gofish@gonefishin.net> wrote in message
>news:31fg421hl6i5rj3g3c2o1fgiiqti7fh3ek@4ax.com...
>
>I only felt that it was just time for another test--sadly, Dido has yet
>again failed.
Ya think Dido drives around in a red buick with a green right front
fender? And spends his free time polishing instead of repainting it?
yeah, let him without fault heave the first stone
| |
| PrecisionMechanical 2006-04-21, 4:21 am |
|
<gofish@gonefishin.net> wrote in message
news:ciqg42dfdjpdnmgs3srhpmqiaf594ouho3@4ax.com...
> "PrecisionMechanical" <precisionmachinist@hotmail.com> wrote:
>
>
> Ya think Dido drives around in a red buick with a green right front
> fender? And spends his free time polishing instead of repainting it?
>
Actually haven't even licensed that one for many many years now....
>
> yeah, let him without fault heave the first stone
>
Key lies in observing the 'reaction'....
Duck !!!
<G>
--
SVL
| |
| gofish@gonefishin.net 2006-04-21, 10:21 am |
| On Thu, 20 Apr 2006 23:20:59 -0700, "PrecisionMechanical"
<precisionmachinist@hotmail.com> wrote:
>
><gofish@gonefishin.net> wrote in message
>news:ciqg42dfdjpdnmgs3srhpmqiaf594ouho3@4ax.com...
>
>Actually haven't even licensed that one for many many years now....
hmmmmm. Just out of curosity I had a buddy run the plates
(readable in the pic) thru the DMV, seems like the car is stolen? ;)
>
>
>Key lies in observing the 'reaction'....
>
>Duck !!!
>
><G>
quack quack quack <g>
| |
| PrecisionMechanical 2006-04-21, 12:21 pm |
|
<gofish@gonefishin.net> wrote in message
news:a0kh42lj20ekd0jna0oc5nqthcs3paij80@4ax.com...
> On Thu, 20 Apr 2006 23:20:59 -0700, "PrecisionMechanical"
> <precisionmachinist@hotmail.com> wrote:
>
I[color=darkred]
yet[color=darkred]
>
> hmmmmm. Just out of curosity I had a buddy run the plates
> (readable in the pic) thru the DMV, seems like the car is stolen? ;)
>
Nice try..
Originally was owned by an Air Force Doctor from Tennesee, he was stationed
in Tacoma when I picked it up~1980...had outa state plates, so title
transfer involved physical inspection vin and frame serial numbers by the
State Patrol.
IIRC, it showed ~33,000 miles at the time.
>
> quack quack quack <g>
A passing score then.
--
SVL
| |
|
| You see young PHD technician?
by reading my posting it is telling me if you knew
better then what I have posted you would not
been reading it, but do not fill bad my friend
you seem to have company O yeh! There is lot of personal
out there who do not care about posting they views, however;
they know what type of person you and some of you followers are?
So I am not going to dwell with you on small or large.
I have been in the field for 40 years I can close my shop on minute notice
YOU HAVE LONG WAY TO GO
Good luck from Dido
| |
| PrecisionMechanical 2006-04-22, 2:21 pm |
|
"DIDO" <a.seput@verizon.net> wrote in message
news:ueq2g.2296$Qe.529@trndny09...
> You see young PHD technician?
> by reading my posting it is telling me if you knew
> better then what I have posted you would not
> been reading it, but do not fill bad my friend
> you seem to have company O yeh! There is lot of personal
> out there who do not care about posting they views, however;
> they know what type of person you and some of you followers are?
> So I am not going to dwell with you on small or large.
> I have been in the field for 40 years I can close my shop on minute notice
> YOU HAVE LONG WAY TO GO
> Good luck from Dido
>
>
No idea what you're trying to say above.
But the text test will be in appx 6mo--do try and be prepared....
--
SVL
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