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Photo Engineer
04-19-2011, 09:22 AM
Rebalanced?

Ray;

Any rapidly rotating object must be in perfect balanced. Just as you balance the tires on your car or other similar objects, this high speed turbine must be balanced to prevent wobble or vibration at working speeds.

If you do not, the the wobble or vibration induced by the imbalance will be detrimental to your health by throwing the moving parts all over the place. ;)

PE

Ray Rogers
04-19-2011, 09:39 AM
Ray;

Any rapidly rotating object must be in perfect balanced. Just as you balance the tires on your car or other similar objects, this high speed turbine must be balanced to prevent wobble or vibration at working speeds.

If you do not, the the wobble or vibration induced by the imbalance will be detrimental to your health by throwing the moving parts all over the place. ;)

PE

Is the balance "adjustible"... or does it have to be reground or something?

Photo Engineer
04-19-2011, 11:15 AM
Is the balance "adjustible"... or does it have to be reground or something?

Ray;

This is done in much the same fashion as with other similar rotating machinery such as fans and tires, but unlike tires there is no wear on these which would change balance. They are more like fan blades.

Stay tuned. It will become clear with time. I am not at that point yet by any means. I am just at the point of testing and proving the adjustment is needed, I am not at the stage of even determining if it is harmful or what the speed limitation is (if any) let alone doing it, let alone having the designer do the adjustment.

PE

holmburgers
04-19-2011, 11:26 AM
Looking forward to the photos PE.

Photo Engineer
04-29-2011, 08:39 PM
To cross reference the thread on the shrouded turbine (not the Shroud of Turin :D ), I now have some results to compare with the reference there to my friend Ingo's web site, referenced in that thread.

I have now compared a shrouded turbine (PEPA) mixer with a propeller mixer and have the following pictures taken at 2000 RPM. The left photo is a propeller and the right is a Planar Emulsion Precipitation Apparatus (PEPA), both at the same speed. You can see the difference visually. To make them visually the same with respect to turbulence it is necessary to reduce prop speed to about 900 - 950 RPM or about 50% of the speed of the PEPA.

The prop mixer directs an approximately cylindrical vortex downward to the bottom and then upwards to create a "V" in the beaker. The PEPA creates a horizontal "T" vortex with 2 random cylinders that mix more effectively with less entrained air.

I now plan on making some complex emulsions that will benefit from the better mixing supplied by the PEPA.

PE

Ray Rogers
04-30-2011, 05:08 AM
Re prop pix:
What is the thing that looks like scotch tape on the beaker ?
Is it the same thing that is resting on the rod on top?

What is the Beaker size?

Photo Engineer
04-30-2011, 10:53 AM
The thing that looks like scotch tape is scotch tape! :D

The rod is a stainless steel rod with clips for other experiments being conducted at the same time. The tape is holding the rod. The entire experiment and many more photos will be in the book.

PE

Ray Rogers
04-30-2011, 02:09 PM
The thing that looks like scotch tape is scotch tape! :D

PE

That explains the Remarkable Similarity. :laugh:

Is that a 2 liter beaker?

Photo Engineer
04-30-2011, 02:36 PM
It is a 1 L heavyweight pyrex glass beaker with about 800 ml of water held at 20 deg C. Food dye was added to the water for visibility. The PEPA is custom built and the prop mixer is an off the shelf item. The Scotch tape was the wide version taken from a 3 pack. The tape had just been opened. The mixer is clamped to a standard heavy duty ring stand. Power leads go to the rear. The prop mixer is on the base of the ring stand on the right in the second photo. Both photos are digital images that were cropped to size for uploading and to remove extraneous material such as the pump which can be partially seen on the left of the photos. A sheet of white backing paper was used to block shelves and other equipment such as pH meters, test solutions, more beakers and a timer. That was just clutter that was not needed for this purpose.

Is that enough information Ray? I can look up the time and date stamp of the images if you wish. :D

PE

Ray Rogers
04-30-2011, 02:46 PM
Is that enough information Ray? I can look up the time and date stamp of the images if you wish. :D

PE

:laugh:

Excellent!

Ray Rogers
04-30-2011, 03:09 PM
I couldn't see the vortex as you described them...
my screen is set dark for night viewing.

Maybe another look tomorrow morning....

One word did throw me...
Random... in "2 random cylinders"

What is random about the cylinders?

Did you mean "Rambo" ?
:D


(hint for Rambo: cf. Japanese meaning and movie usage)

Photo Engineer
04-30-2011, 03:33 PM
The explanation is shown graphically on another reference in the shrouded turbine thread, but basically the PEPA throws out a thin plane of mixed materials from above and below by centrifugal force. The ejected fluid, when it hits the edge of the beaker at a perpendicular can go up or down and then, reaching the top or bottom it curls around forming two cylindrical mix patters of random fully mixed materials. In doing so, it works in a much smoother method with higher energy transfer and at higher speeds for faster maxing.

According to my translation, you mean "ranbo" or violence!

PE

Ray Rogers
04-30-2011, 05:29 PM
The ejected fluid, when it hits the edge of the beaker at a perpendicular can go up or down and then, reaching the top or bottom it curls around forming two cylindrical mix patters of random fully mixed materials. In doing so, it works in a much smoother method with higher energy transfer and at higher speeds for faster maxing.

PE

Faster Maxing?
Isn't that proprietary T-max technology ?

:D

Ray Rogers
04-30-2011, 05:49 PM
According to my translation, you mean "ranbo" or violence!

PE

Yes. Thanks for that good description of the PEPA mixer.
I am sure the pictures will look the way they are supposed to now.
They say a picture's worth a thousand words, but sometimes a few words go a long way to clarify pictures too. Thanks.

Ray

Photo Engineer
04-30-2011, 06:23 PM
Faster Maxing?
Isn't that proprietary T-max technology ?

:D

This was described by Herb Wilgus in a paper in an engineering jorunal in the 70s. I am not a member, and so I cannot read the journal but this was also described in other articles and patents. There are 3 version in use at EK AFAIK. It is virtually essential that high speed mixing take place in order to make any modern emulsion, but it is not essential to making a T-Grain emulsion.

PE