Producing a vacuum using a turbine?

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

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

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

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 in to 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

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.