Prev: Will heating the platters beyond curie temp make disk-splicing impossible?
Next: madell px3700
From: lektric.dan on 15 Apr 2010 20:59
I need help finding technology for a different kind of flow sensor. I
have a project where I need to monitor the flow of a ground organic
material (think oregano or pepper ground to 100-400 microns). It's
coming from a horizontal discharge tube (twin augers) down into a
vertical collector about 2" in dia. and 4" tall, then into a funnel
(with an opening just under 1/2"). There's a top on the collector
(everything's made of stainless), and everything is under 5-10 psi of
nitrogen. I need to 1) make sure the material is flowing down and
through the funnel, and 2) is not jammed up. I've got a
phototransister/IRLED set-up, and it can detect when the light beam is
blocked, but can't tell when there is a jam. Same with ultrasonic or
millimeter-wave radio (radar), a light beam reflective sensor, or a
capacitance/conductance sensor. I was thinking about some sort of
acoustic or impingement sensor (like a microphonic probe), but the gas
flow and feeder noise make that problematical, plus anything in the
stream can cause a plug/jam. Sensor needs to take up less than 1" of
process stream length.

Ideas? Have I missed anything?
From: John Larkin on 15 Apr 2010 21:10
On Thu, 15 Apr 2010 17:59:57 -0700 (PDT), "lektric.dan(a)gmail.com"
<lektric.dan(a)gmail.com> wrote:

>I need help finding technology for a different kind of flow sensor. I
>have a project where I need to monitor the flow of a ground organic
>material (think oregano or pepper ground to 100-400 microns). It's
>coming from a horizontal discharge tube (twin augers) down into a
>vertical collector about 2" in dia. and 4" tall, then into a funnel
>(with an opening just under 1/2"). There's a top on the collector
>(everything's made of stainless), and everything is under 5-10 psi of
>nitrogen. I need to 1) make sure the material is flowing down and
>through the funnel, and 2) is not jammed up. I've got a
>phototransister/IRLED set-up, and it can detect when the light beam is
>blocked, but can't tell when there is a jam. Same with ultrasonic or
>millimeter-wave radio (radar), a light beam reflective sensor, or a
>capacitance/conductance sensor. I was thinking about some sort of
>acoustic or impingement sensor (like a microphonic probe), but the gas
>flow and feeder noise make that problematical, plus anything in the
>stream can cause a plug/jam. Sensor needs to take up less than 1" of
>process stream length.
>
>Ideas? Have I missed anything?

Optical mouse.

John

From: mpm on 15 Apr 2010 21:55
On Apr 15, 7:59 pm, "lektric....(a)gmail.com" <lektric....(a)gmail.com>
wrote:
> I need help finding technology for a different kind of flow sensor.  I
> have a project where I need to monitor the flow of a ground organic
> material (think oregano or pepper ground to 100-400 microns).  It's
> coming from a horizontal discharge tube (twin augers) down into a
> vertical collector about 2" in dia. and 4" tall, then into a funnel
> (with an opening just under 1/2").  There's a top on the collector
> (everything's made of stainless), and everything is under 5-10 psi of
> nitrogen.  I need to 1) make sure the material is flowing down and
> through the funnel, and 2) is not jammed up.  I've got a
> phototransister/IRLED set-up, and it can detect when the light beam is
> blocked, but can't tell when there is a jam.  Same with ultrasonic or
> millimeter-wave radio (radar), a light beam reflective sensor, or a
> capacitance/conductance sensor.  I was thinking about some sort of
> acoustic or impingement sensor (like a microphonic probe), but the gas
> flow and feeder noise make that problematical, plus anything in the
> stream can cause a plug/jam.  Sensor needs to take up less than 1" of
> process stream length.
>
> Ideas?  Have I missed anything?

use microwaves?
You might have to modify your discharge tube / funnel, though,

Why can't you measure the system's dielectric strength (averaged over
an appropriate time).
Wouldn't that tell you "blocked" vs. "heavy flow"? (Static vs.
moving)
Or am I mising something here....?

Option 2.
Use a clear window, a video (frame capture) and just do sequential
frame compares. (??)
If the same image appears in several adjacent frames, then tube =
jammed.
If image not the same frame-to-frame, then tube = flow OK.
Use a solid color target, so that if tube is empty (i.e., no flow),
then tube = not in use or empty.

Option 2 sounds expensive, though.

Disclaimer: I dont' do this for a living.
For all I know, there's an off-the-shelf solution.
Did you check with Banner Engineering?

Best of luck.
-mpm




From: Sjouke Burry on 15 Apr 2010 21:56
lektric.dan(a)gmail.com wrote:
> I need help finding technology for a different kind of flow sensor. I
> have a project where I need to monitor the flow of a ground organic
> material (think oregano or pepper ground to 100-400 microns). It's
> coming from a horizontal discharge tube (twin augers) down into a
> vertical collector about 2" in dia. and 4" tall, then into a funnel
> (with an opening just under 1/2"). There's a top on the collector
> (everything's made of stainless), and everything is under 5-10 psi of
> nitrogen. I need to 1) make sure the material is flowing down and
> through the funnel, and 2) is not jammed up. I've got a
> phototransister/IRLED set-up, and it can detect when the light beam is
> blocked, but can't tell when there is a jam. Same with ultrasonic or
> millimeter-wave radio (radar), a light beam reflective sensor, or a
> capacitance/conductance sensor. I was thinking about some sort of
> acoustic or impingement sensor (like a microphonic probe), but the gas
> flow and feeder noise make that problematical, plus anything in the
> stream can cause a plug/jam. Sensor needs to take up less than 1" of
> process stream length.
>
> Ideas? Have I missed anything?
Put a scale under the container and monitor the weight of the container.
When a jam occurs, the weight stops increasing.
From: wrp0143 on 15 Apr 2010 22:15
On Apr 15, 5:59 pm, "lektric....(a)gmail.com" <lektric....(a)gmail.com>
wrote:
>  I've got a
> phototransister/IRLED set-up, and it can detect when the light beam is
> blocked, but can't tell when there is a jam.  

Since there's a drop through free air, shine an LED on a tangent to
the flow, through the edge of the falling stream. The photoreceptor
signal should be noisy, and go thru a high pass filter. When the flow
stops, the noise stops and the filter output signal goes to zero.

Dangerous Bill
 |  Next  |  Last
Pages: 1 2 3 4
Prev: Will heating the platters beyond curie temp make disk-splicing impossible?
Next: madell px3700