Producing a vacuum using a turbine?

[jimhebert]

Hi:

I’ve been trying to figure out how does the spinning action of the turbine blades in the video produce a vacuum so as to draw air down the shaft? I don’t see any venturi effect taking place. A bit puzzling on how this gadget works?




http://www.toring.com/What_is_ToringTurbine.html

 

[256bits]

I think it works just like any centrifugal pump is supposed to work - it is pumping air into the water.

 

[jimhebert]

I had thought about that but the blades on the centrifugal pumps I've seen are always kind of curved all the way toward the center of the pump in order to scoop the water as it enters the center input. The blades on this gadget are "straight" and don't appear to extend very far inward toward the center. It's difficult to conceive how and where does it scoop water or the air to produce the suction effect.

 

[russ_watters]

I think it works just like any centrifugal pump is supposed to work - it is pumping air into the water.

That was my thought as well, but it is tough to see past the marketing bs in that link.

 

[jimhebert]

I would like to buy the thing but Europe is too far away to order, so I was going to try to build one similar. I want to aerate a fish pond with it. Thanks for all your inputs.

 

[russ_watters]

I had thought about that but the blades on the centrifugal pumps I've seen are always kind of curved all the way toward the center of the pump in order to scoop the water as it enters the center input. The blades on this gadget are "straight" ...

No, blades on a centrifugal fan/pump don't need to be curved. The exact shape will depend on the particular requirements.

 

[RonL]

The same principles as used by Tesla's Turbine and Pump, and why few people really grasp the operation as claimed by Tesla in his patents.

Ron

 

[jimhebert]

I don't know about the Tesla pump. Does it have flat impellar blades like this one? The only thing I can come up with is that there is water that freely comes up into the unit through a hole in the bottom center, and the flat spinning blades fling this water outward faster than the rate of water coming in, thus causing a vacuum which sucks the air in through the top shaft to mix with the water that's entering from the bottom.

 

[RonL]

I don't know about the Tesla pump. Does it have flat impellar blades like this one? The only thing I can come up with is that there is water that freely comes up into the unit through a hole in the bottom center, and the flat spinning blades fling this water outward faster than the rate of water coming in, thus causing a vacuum which sucks the air in through the top shaft to mix with the water that's entering from the bottom.

Viscosity and adhesion of water against the spinning blade surface, causes a pressure force outward and a low pressure area at the shaft, atmospheric pressure pushes air into the low pressure area, where spin velocity distributes the air into the water. The diffusion of air looks very impressive and is a curiosity for me.

Corrections if needed, please.:shy:

Ron

 

[DickL]

It is a centrifugal pump and works the same as all centrifugal pumps. How long the blades are (along the radius) will effect the head (pressure or suction) developed. The curvature of the blades (or lack) will have some effect on the performance versus speed and the noise output. When the pump is started the blades start spinning the water and accelerating it in the direction of the rotation, as it gains speed centrifugal force moves the water out of the turbine, that creates a partial vacuum that draws air down the shaft. As with any pump there will be a maximum head it can create and therefore a maximum depth that it can pull air down.

 

[russ_watters]

The same principles as used by Tesla's Turbine and Pump, and why few people really grasp the operation as claimed by Tesla in his patents.

It doesn't look to me like it bears any resemblance to a Tesla turbine/pump: it looks like a pretty normal centrifugal pump to me. Could you explain what you are seeing that others are missing?

Here's an example of a centrifugal blower with flat blades: http://www.nyb.com/Catalog/Bulletins/589.pdf

Here's some flat pump impellers: http://www.marineengineparts.com/shopsite_sc/store/html/page310.html

 

[jimhebert]

It is a centrifugal pump and works the same as all centrifugal pumps. How long the blades are (along the radius) will effect the head (pressure or suction) developed. The curvature of the blades (or lack) will have some effect on the performance versus speed and the noise output. When the pump is started the blades start spinning the water and accelerating it in the direction of the rotation, as it gains speed centrifugal force moves the water out of the turbine, that creates a partial vacuum that draws air down the shaft. As with any pump there will be a maximum head it can create and therefore a maximum depth that it can pull air down.

Do you believe that the water that is forced out of the spinning turbine will be replaced by water and air to fill the partial vacuum? Or will only air from the shaft be filling the partial vacuum and the spinning blades will then fling that air to the outer edge of the blades where it will contact the outside water and at that point mix with that water to form all those tiny air bubbles? I personally don't think the air has enough viscosity to develop the centrifugal force needed to go slamming into the wall of water on the outer edge of the spinning blades. I am more of the opinion that it is both air and water that continuously come into fill a portion of the partial vacuum and the majority of the mixing action takes place within the area of the spinning blades. Please tell me if my reasoning is incorrect and how do you see it?

 

[DickL]

jimhebert, you raise a good point. You are probably right that air and water are mixed prior to entering the turbine. The mixing and creation of small bubbles probably occurs mostly right in the entry of to the turbine (that's my guess). Water could be brought into the shaft by a hole, or series of holes, in the shaft. The mixing would start in the shaft, but I'm guessing the real mixing would occur in the turbulent region at the entry of the turbine.

 

[RonL]

It doesn't look to me like it bears any resemblance to a Tesla turbine/pump: it looks like a pretty normal centrifugal pump to me. Could you explain what you are seeing that others are missing?

Here's an example of a centrifugal blower with flat blades: http://www.nyb.com/Catalog/Bulletins/589.pdf

Here's some flat pump impellers: http://www.marineengineparts.com/shopsite_sc/store/html/page310.html

Russ, I'll retract my Tesla comments for the time being.

My first thoughts were related to the lack of a housing and volute chamber, but the surrounding water functions as a housing. The close spacing of a large number of vertical triangle blades should impart the same basic transfer as flat horizontal disc plates.
The bottom of the impeller looks to be a solid plate and the absence of water and air being sucked back into some port opening around the top side where shaft and impeller are joined, leaves me puzzled.
In fact there is little to indicate some amount of suck-back, top or bottom.

The air entrance holes can be seen at the top of the main shaft, just below the motor.

I did find that VaraCorp, the sole distributor for the USA is in Austin, I'll see if I can get a unit or find a little better visual aid on the design.

Your link to the marine impeller, is a positive displacement pump system, the other link was all volute style, then I thought of all the Amtek 1,2, and 3 stage vacuum cleaner units I have, they are flow through and do not have a volute design (the impellers are dead center inside the housing).

Ron

 

[jimhebert]

Thanks to all of you for contributing. Later.

 

[jimhebert]

I have just found this page that shows construction.

http://www.toring.com/How_to_connect_turbine_and_hollow_drive_shaft.html

Seems like the only thing that is being sucked into the turbines is air and not water and air as I had originally thought.

 

[RonL]

I have just found this page that shows construction.

http://www.toring.com/How_to_connect_turbine_and_hollow_drive_shaft.html

Seems like the only thing that is being sucked into the turbines is air and not water and air as I had originally thought.

Thanks for the link,
There in frame 1, is a single hole visible, that should be the water intake...there has to be an intake for the impeller to produce a flow.
The holes for air and the 1, 2?, or 3? for water, I would think, produce a metering effect much like a carburetor on a internal combustion engine.

Ron

 

[jimhebert]

Are you referring to the hole on the shaft next to his thumb? If so, that is a hole that a pin slips into. There's a matching hole on the black piece also. Scroll down the page and watch 54 seconds into the video and he will insert the pin.

 

[RonL]

Are you referring to the hole on the shaft next to his thumb? If so, that is a hole that a pin slips into. There's a matching hole on the black piece also. Scroll down the page and watch 54 seconds into the video and he will insert the pin.

Sorry the first time I looked the video did not appear, my scroll stopped at the bottom of the drawings.
Guess I better throw in the towel, the only thing left that I can see is the shape of the blades produce a high and low pressure zone around the outer diameter.
In one video there seemed to be a pulsing effect of air discharge ?

Ron

 

[jimhebert]

I agree it is weird how that thing works. Assuming that there is only air being sucked into the turbine area, then I see only 2 possible ways for a partial vacuum to be formed. One way may be by the centrifugal force produced by the blades thus expelling the air out into the water and leaving a partial vacuum behind. This seems very hard for me to conceive that these flat blades (not curved like a fan) could produce that kind of effect. The second possibility would be if the rapidly moving extreme outer edges of the blades produce at the point of contact with the still outside water, a venturi effect. I have never seen this type of venturi depicted in this way. This would be similar to holding or placing one end of a small plastic air line tube in the center stream of fast flowing water (garden water hose) such that the center line of the air tube is perpendicular to the water flow. Would a vacuum develop in the tube? I tried at my kitchen water faucet but didn't notice any vacuum in the tube. Maybe not enough water pressure in the faucet to produce a fast enough flow.

 

[RonL]

I agree it is weird how that thing works. Assuming that there is only air being sucked into the turbine area, then I see only 2 possible ways for a partial vacuum to be formed. One way may be by the centrifugal force produced by the blades thus expelling the air out into the water and leaving a partial vacuum behind. This seems very hard for me to conceive that these flat blades (not curved like a fan) could produce that kind of effect. The second possibility would be if the rapidly moving extreme outer edges of the blades produce at the point of contact with the still outside water, a venturi effect. I have never seen this type of venturi depicted in this way. This would be similar to holding or placing one end of a small plastic air line tube in the center stream of fast flowing water (garden water hose) such that the center line of the air tube is perpendicular to the water flow. Would a vacuum develop in the tube? I tried at my kitchen water faucet but didn't notice any vacuum in the tube. Maybe not enough water pressure in the faucet to produce a fast enough flow.

You might look around your kitchen, if there is a food processor that has a business end similar to this unit, you might find a clue? just a thought.

Looking at the blade design, the angle on the inside must play an important part of how pressure is used.
Getting back to the Tesla comment, I might try putting some hard drive platters together with each inside bore larger than the one above it, so that it has the same basic inside hollow. I suspect it will give exactly the same results.

Ron

 

[RonL]

It doesn't look to me like it bears any resemblance to a Tesla turbine/pump: it looks like a pretty normal centrifugal pump to me. Could you explain what you are seeing that others are missing?

Here's an example of a centrifugal blower with flat blades: http://www.nyb.com/Catalog/Bulletins/589.pdf

Here's some flat pump impellers: http://www.marineengineparts.com/shopsite_sc/store/html/page310.html

Hi Russ,
I'll try in as few words as possible, to explain my thoughts.
Almost any centrifugal pump that sucks in even the least amount of air will generally lose prime and cease to pump.
This pump receives air and disperses it at an extreme small bubble size.
Power needed, is proportional to speed and depth of operation. At a depth of say one meter, power is transformed into pressure on the liquid inside the impeller and until this energy becomes great enough to overcome the surrounding water pressure, there will be no flow, it will be much like a centrifuge.
When speed and pressure from energy transfer reach the point of being greater than the enclosing water, an outward flow will take place, water dispelled will leave a void, or low pressure area in the center of rotation, this will become lower than atmosphere, allowing air to be pushed in. At the same time, the lower side of the impeller, because of a very small blade area, water is returned to the center of rotation, where it mixes with the air and again is increased in pressure as it moves through the upper and increasing blade area.

The comparison to Tesla's Turbine pump, is based on the pressure and sliding physics of the air and water mix as it is being pushed through the ever increasing blade surface, (top cover plate and angle of blades toward the outer diameter).

The pressure on the moving liquid and air mix, due to different viscosity of each, should result in air moving to the top cover plate surface and the increasing blade surface area, where it is spread into a very thin layer by the hydraulic action of the water. Friction and different viscosity of the water and air as they slide inside the inverted U shaped chamber, is what I think gives such a fine diffusion to the air.

These actions are, in my mind, the same that takes place in this or a Tesla design.

The high pressure flow out of the top portion of the impeller set, and the return water flow inward at the bottom, in my mind is much like shear-lines between upper atmosphere jet streams.

I have already been wrong in this thread, this is what I see, so let's hear it from anyone, agreed or not.

Ron

 

[jimhebert]

Seems like a logical explanation, RonL. I would think that the incoming water flowing on the bottom plate, and towards the center, has to reach a high enough level at least to cover the air holes. If not only air would be drawn in and it would cavitate. Am I on track? I'm also thinking that there has to be a maximum rpm. If the max rpm is exceeded, not enough water would come into replace what is going out and the pump action would begin to cavitate since it would be drawing in only air. Spinning my wheels? Another thing I was wondering about was the immediate back part of the blades. Won't there be a void there, especially as we get nearer the top of the blade? What will fill that void, outside water or air from the center?

 

[RonL]

Seems like a logical explanation, RonL. I would think that the incoming water flowing on the bottom plate, and towards the center, has to reach a high enough level at least to cover the air holes. If not only air would be drawn in and it would cavitate. Am I on track? I'm also thinking that there has to be a maximum rpm. If the max rpm is exceeded, not enough water would come into replace what is going out and the pump action would begin to cavitate since it would be drawing in only air. Spinning my wheels? Another thing I was wondering about was the immediate back part of the blades. Won't there be a void there, especially as we get nearer the top of the blade? What will fill that void, outside water or air from the center?

Hi jimhebert,
I did make a call to VaraCorp, and as expected they would only consider having a dealer contact me with any information and prices. The person I talked with was an engineer and did agree with the carburetor venturi comparison, he said the motor, shaft, impeller, speed, and depth of operation, were all so well refined and critical to operation, that selling an individual part would not be likely considered and I fully agree with this reasoning if I were to put myself in their place. His insistence on proper speed, seemed more focused on 60 HZ AC that we have in the US.

The water out and water being drawn back in, I think can have different pressures without having an air pocket in the center, but there has to be some cycle in pressure to allow air to be pushed in.
There might be the slightest of cavitation, which might explain the appearance of pulses of air that I was seeing in the video of it working under water, and also would be reason to think RPM and depth are very crucial to proper aeration.

I will try to find out more from a dealer, but I'm sure a complete unit will be in excess of $500 which is more than I can pay to aerate the water for my goldfish and water lilies, my wife has been making stronger suggestions about getting her swimming pool back to it's design function. (the pond has been fun)

Ron

 

[jimhebert]

Yes, a bit expensive unless one has a large operation that would make it worthwhile since it does seem to work very efficiently. All the other youtube videos on aerators work but no where as efficient in producing a cloud of tiny bubbles like this one. I think it may have been pulsing in the video because I don't think it was fully submerged and may have been cavitating excessively. The horizontal shear line that you mentioned, I believe would tend to move downward as rpm increases until no water would enter at all.