Thanks. I shall read more..
K2
K2
As the cherry on the cake, in 80's I have read a book about Ranque-Hilsch Vortex Tube - RHVT and its current (or intended) applications.De Laval Nozzle...
Watched a U-tube presentation on it...
Sorry, the maths didn't "click"...
I need a dictionary to translate the language into something I comprehend.
e.g. "Isentropic"? - My non-existent Latin and Greek can't translate this into something...
But I learned that sub-sonic gases slow down in the nozzle, whereas supersonic gases accelerate in the nozzle. Those words had meaning for me.
I Just don't understand what is happening in the centrifugal filter now..
Does air injected at the equator accelerate when injected tangentially into the sphere as it moves to the poles? (supersonic flow?) - or decelerate? (sub-sonic flow?).
I suspect the end of the tangential feed-in pipe is square ended, so creates turbulence at the periphery of the jet, and maybe some laminar flow towards the middle of the jet of gas? I.E. it is not a De Laval nozzle, so does not work the same way?
And when the air - less oil droplets - leaves the flow (upwards) at the middle of the sphere, how does the velocity of flow convert into the pressure of flowing air in the pipe?
All I can imagine is that there are some frictional losses inside the sphere, so air entering is from a pipe at pressure Pi, and leaving at a lower pressure Pe...?
Oil droplet mass at Vin has a momentum and energy exchange to the walls of the sphere so Vin is reduced to zero... But how does this help the air velocity and Pe?
So I shall give up on that one.... Life is too short.
I did get slightly involved with gas centrifuges separating U238 from U235...., I.E. the same technology as this oil separator, but I cannot discuss that...
K2
De Laval Nozzle...
Watched a U-tube presentation on it...
Sorry, the maths didn't "click"...
I need a dictionary to translate the language into something I comprehend.
e.g. "Isentropic"? - My non-existent Latin and Greek can't translate this into something...
But I learned that sub-sonic gases slow down in the nozzle, whereas supersonic gases accelerate in the nozzle. Those words had meaning for me.
I Just don't understand what is happening in the centrifugal filter now..
Does air injected at the equator accelerate when injected tangentially into the sphere as it moves to the poles? (supersonic flow?) - or decelerate? (sub-sonic flow?).
I suspect the end of the tangential feed-in pipe is square ended, so creates turbulence at the periphery of the jet, and maybe some laminar flow towards the middle of the jet of gas? I.E. it is not a De Laval nozzle, so does not work the same way?
And when the air - less oil droplets - leaves the flow (upwards) at the middle of the sphere, how does the velocity of flow convert into the pressure of flowing air in the pipe?
All I can imagine is that there are some frictional losses inside the sphere, so air entering is from a pipe at pressure Pi, and leaving at a lower pressure Pe...?
Oil droplet mass at Vin has a momentum and energy exchange to the walls of the sphere so Vin is reduced to zero... But how does this help the air velocity and Pe?
So I shall give up on that one.... Life is too short.
I did get slightly involved with gas centrifuges separating U238 from U235...., I.E. the same technology as this oil separator, but I cannot discuss that...
K2
Isentropic = same energy.De Laval Nozzle...
Watched a U-tube presentation on it...
Sorry, the maths didn't "click"...
I need a dictionary to translate the language into something I comprehend.
e.g. "Isentropic"? - My non-existent Latin and Greek can't translate this into something...
But I learned that sub-sonic gases slow down in the nozzle, whereas supersonic gases accelerate in the nozzle. Those words had meaning for me.
I Just don't understand what is happening in the centrifugal filter now..
Does air injected at the equator accelerate when injected tangentially into the sphere as it moves to the poles? (supersonic flow?) - or decelerate? (sub-sonic flow?).
I suspect the end of the tangential feed-in pipe is square ended, so creates turbulence at the periphery of the jet, and maybe some laminar flow towards the middle of the jet of gas? I.E. it is not a De Laval nozzle, so does not work the same way?
And when the air - less oil droplets - leaves the flow (upwards) at the middle of the sphere, how does the velocity of flow convert into the pressure of flowing air in the pipe?
All I can imagine is that there are some frictional losses inside the sphere, so air entering is from a pipe at pressure Pi, and leaving at a lower pressure Pe...?
Oil droplet mass at Vin has a momentum and energy exchange to the walls of the sphere so Vin is reduced to zero... But how does this help the air velocity and Pe?
So I shall give up on that one.... Life is too short.
I did get slightly involved with gas centrifuges separating U238 from U235...., I.E. the same technology as this oil separator, but I cannot discuss that...
K2
Hilsch vortex tube is in common use, especially in cooling instrument cabinets and hazmat suits which need cooling where the cool air is placed usually at the neck or helmet area. But energy use is quite high when considering you need high compressed air at least 100psi.As the cherry on the cake, in 80's I have read a book about Ranque-Hilsch Vortex Tube - RHVT and its current (or intended) applications.
https://www.airtx.net/airtx-vortex-tubes-review
Today you can struggle to find something about it....
But at those days, mathematical description/modeling of processes involved was not possible; though research was on, theoretical and practical.
That would be interesting to understand entirely
A sphere is usually a poor shape for particulate separation and would not normally conform to separation physics. Has this geometry been tested for efficiency other then this one off use. Typically you inter with a high velocity and the walls pick up the particles and the exit is a much larger diameter with slower velocities as the entertainment is dependent on carrying velocity. Plus there is the need to remove the material on high load conditions.Hi Toymaker. I know you mention a swirl movement of air inside sphere, but have you thought about maximizing it?
Swirl effect separators are among the best in what concerns efficiency and reduced losses; and the trick is to lengthen as much as possible the travel of stream in spiral.
Personally I would see air admission in the spere in horizontal plane, tangent to the sphere's wall (not 90 degree), at the height where you have already fitted it; and exhaust vertical at the top (maybe continued inside sphere towards center) so not to affect swirl's movement and collect potential droplets.
Clean air has to make a steep turn at the bottom to go out upwards and you have (as much as possible) a general, coordinated movement of particles, which should be better.
View attachment 155246
A sphere is usually a poor shape for particulate separation and would not normally conform to separation physics. Has this geometry been tested for efficiency other then this one off use. Typically you inter with a high velocity and the walls pick up the particles and the exit is a much larger diameter with slower velocities as the entertainment is dependent on carrying velocity. Plus there is the need to remove the material on high load conditions.
Thanks Toymaker. I was envisioning the sphere as similar to a pair of cones - just non-linear - joined at their common large diameter. Air injected tangentially at the equator splits so half goes up and half down... both have reducing diameter vortices, depositing oil droplets on the inside walls as the swirl reduces diameter. The air going "generally upwards" turns at the top to pass downwards, and the air going generally down turns to go upwards, so I reckon the 2 streams of cleaned air would meet in the middle, and exchange velocity (kinetic energy) for pressure (very low momentum) so there is a local high pressure zone there, where air-streams meet? - Thus I would locate the exit orifice for clean air at the centre of the sphere.
Is this the right idea? - Or just too simple?
I successfully use simple oil separators on my steam engine exhausts: A simple piece of pipe, exhaust steam (with oil vapour and droplets) entering pointing downwards at one side of the closed cylinder, and exiting through a central pipe after a 180degree turn so the steam and water vapour goes upwards. That leaves me "clean air and water vapour" - free from oil droplets. Maybe I should now make a centrifugal separator - and see if this extracts more oil? - I have not detected oil in the exhaust after my simple separator, so probably unnecessary?
K2
Well I googled spherical separator and they were all quite large operating as dead space removal with entrained filters to capture oil and liquid products. None used the vortex principle as that requires the establishment of a low pressure area in the center. However did find similar designs for dry sump oil systems. Oil was introduced tangent to the cylinder walls. In addition to be an injector the nozzle must be diverging converging venturi using a motive force. Of these systems I have had more than just a common knowledge base from low pressure steam recovery, oil savaging, condensate recovery and emergency pumps. But it appears you have built a dry sump system which will work quite well for your system.I hope we can all agree that centrifugal force plays a major role in separating the oil particles from the air, so lets look at the math used to find centrifugal (or centripetal) force:
View attachment 155380
The air-oil mixture is injected near the equator of my sphere where the radius, r is greatest; the velocity, v of the air-oil mix will also be greatest at this point. As the air-oil mix circles the inside of the sphere, it's forced upwards towards the exit, and as the mixture moves upwards the radius, r becomes smaller and smaller, which, applying the formula, will cause the centrifugal force, F to increase. Clearly the mixture's velocity, v will slow and it's mass, m will also decrease as the oil is removed from the air, but the formula tells us that if the radius, r remained the same, as it would inside a straight tube, or if it became larger as it would in a conical shape, than the centrifugal force, F exerted on the air-oil mixture, would decrease compared to a sphere.
The proof of how well the sphere works is shown in the video in post #484.
If you Google: spherical separator you'll find they're often used where only a small space is available. However, I could not find any that use the same vortex principle I'm using.
OK, extrapolating (have I understood this and got the maths right?) - 21.4HP = 21.4 x 0.746kW? = 16kW. in "Metric", if anyone is bothered about Metric!
A pretty good "idle" boiler! - Like a 3 1/2 in steam loco? or small traction engine?
From fuel flow you can probably extrapolate "max power", though not a real expectation as life is never that good.
K2
Thanks. I wasn't sure if fuel was metered, or just supply air (pressure?) to the jet? I think you have mentioned instrumentation and control system, somewhere...
If you have 16 kW of steam, it would not be unreasonable to guess something like 20 ~25 kW of fuel?
Which sounds like a largish burner to me....
What is your max fuel rate expected to be? I was thinking you could estimate max steam power by comparing fuel feed rates, from your idle, to give a potential max steam power?
K2
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