Cyclone owners, a question

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JPG
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Post by JPG »

BuckeyeDennis wrote:Help me out here:
1. When you say "ss vac", do you mean the original one in the Mark 7?
2. And do I understand correctly that it works like an ordinary household vacuum, with some sort of impeller, through which the detrius must pass before being blown into a collection bag?
3. And that you want to place the cyclone separator downstream of the impeller?
I totally missed that! Now what he said makes sense. The cyclone will do nothing without a pressure difference between intake and outtake. So inserting it in the 'pressure' side of the vac will still have a pressure difference between the intake(vac pressure) and outlet(ambient).

A key point however is that there still must be no air flow in/out of the narrow end of the cyclone so the collection box must still be air tight.

Talk about thinking "outside of the box!".:D
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Post by nothungry3 »

Dennis,
Yes ss vac is the fan which was built into the Mark 7 headstock.
Yes the ss vac is very similar to a vacuum cleaner, except the motor spins in either direction with the same impeller output flow
The ss vac would inject flow into the cyclone air stream. An outside flow source would be required, essentially your system with a new dust box and a tee on the inlet line.
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Post by videobear »

The mass flow rate of the air is the same, everywhere in the system. If that were not so, you'd wind up with no air, a complete vacuum, somewhere. Which clearly does not happen!

What that means is that if the cross sectional area of the airflow changes, so does the flow's velocity. Larger cross section, the airstream slows down. Constricted area, airstream speeds up... because the same mass of air per second must pass each point in the system.
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JPG
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Post by JPG »

videobear wrote:The mass flow rate of the air is the same, everywhere in the system. If that were not so, you'd wind up with no air, a complete vacuum, somewhere. Which clearly does not happen!

What that means is that if the cross sectional area of the airflow changes, so does the flow's velocity. Larger cross section, the airstream slows down. Constricted area, airstream speeds up... because the same mass of air per second must pass each point in the system.
Pretty much!

However the 'stream' is both air and debris.

As the spin velocity increases as described above, the lighter air migrates towards the center as the heavier debris is forced to the 'outside'.

By the time the debris reaches the 'bottom' there is no longer any air flow in the stream.

The air exits through the center tube. The debris exits through the 'bottom'.

Since the 'rotary' velocity of the debris increases, the vertical(unless it is on its side:rolleyes:) velocity also increases. Guess that is why it will work horizontally. Not sure why I said that, but it is consistent with 'observation'.
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Post by nothungry3 »

GG,
I was thinking as the rotary (radial) velocity increases, the vertical (axial) velocity remains constant thru the cone, reaches a stagnation point (goes to 0) then reverses to exit. The axial response must be due to downstream pressure conditions.
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JPG
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Post by JPG »

I am on very spongey ground here(thinking without any substantial research nor prior knowledge) but as the 'stream' is rotating about the cone with both circumferential and 'axial'(for lack of a better word) velocity and since velocity is a vector thingie(has magnitude and direction) and the circumferential vector is tangent and constantly being altered by the cone, there must be some interaction between the two vectors. We know the cone is causing the tangential vector to increase in magnitude as the stream moves towards the smaller end. Since that vector is increasing in magnitude perhaps a similar effect occurs with the 'axial' vector.

However!

Having now just done minimal 'research' I see things a bit simpler.

Horizontal cyclones work by virtue of a secondary air flow which counteracts drag of the stream against the inside wall of the cone and thus allows it to work without dependency upon gravity. The secondary air flow directs the 'debris' to the collector.

A vertical cyclone like the Dust Deputy gets its initial 'downward' velocity by being directed so at the inlet. Gravity continues to exert its pull on the debris as it spends time within the cyclone(and after departing into a collection container). As the debris falls toward the smaller end, it's velocity around the wall increases, but the cone also tends to support the debris. Meantime the air separates from the debris, and travels directly down towards the air outlet tube. This air motion may help move the debris towards the bottom. The air spins less and accelerates towards the outlet thus moving down faster than the debris so it causes the downward velocity of the debris to increase.

Like I said initially, shakey ground!:D

Now just below the air outlet, the air must reverse direction!

I have not a clue what effect that has on the debris stream.;)
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E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
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Post by moose »

I have no idea what nationality or language you're using but don't you want to try that again in plain old fashioned english?
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JPG
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Post by JPG »

ashbury wrote:I have no idea what nationality or language you're using but don't you want to try that again in plain old fashioned english?
About as plain and direct english as it gets. Sorry if it requires visualization.;)

Multiple simultaneous thoughts inherent to understanding.
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Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10
E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
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Post by beeg »

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Post by "Wild Bad Bob" »

Now, if I am "Down Under", and my toilet flushes counter clock wise swirl, will my cyclonic dust collector work the same??
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