J. Phil Thien's Projects

It is kinda like what I alluded to in another post - limiting the exhaust charge to compensate for the dust load and raising the floor of the outlet same as you lower it - just not in the "middle" - seems to work for me - empirical data based only on observation and filter load.

Perhaps if you can't change but wish to experiment

I may have an issue with my post, and am going to clarify a sidepost, that came up today as I was responding in a thread by retired2 to keep everything together.

It had to be done - a new 4" hole in my bandsaw!

Basically, yes, I understand the restrictive nature of friction. But I have done a few real world seat-of-the-pants builds leading me to this proposal. Per my other "side post in the other thread":

"......my spiral with eleven feet internal with less than 10' of run to any of my equipment equates to less than........ I would add the internal of the spiral is smooth walled and area compensated - not enough to be a "free flow" air column calculation but enough to outflow the restriction in a vacuum situation versus my fan abilities - and larger area than my fan inlet. Yes, keeping up speed is not as important in that [should have been "this"] situation.................."

In my case the DC is close to the equipment - in my case less than 10' to everything - bandsaw, CNC, spindle sander, drum sander +, with the CNC and drum sander the closest.

The internal frictional component and airspeed is less based on a slightly larger area than the fan intake and in a top hat application there is vacuum present rather than pressure. Semantics - less pressure - as there is always pressure/relative to ATM. The path is longer with less speed, yet still building centrifugal force on the particulate. The purpose being to allow it to drop and not remain air entrained in a pressure/velocity front. I am not attempting to convince anyone, the proof as they say is in the pudding. It will need to be proved. I will need to finish it. It will take me some time due to a few other nagging everyday life obstructions.

Friction is present always, but there may be some trade off between "free air column flow" versus restricted flows - how and how much they are restricted as in quantify and qualify. Anyone with HVAC ducting or other experience will understand the free air moving ability versus.......and we all know runs to the equipment and distances are just as important in the scheme of things. All things equal, speaking for me I do not have an ideal situation either by any means. I have only my seat-of-the-pants and cleaning schedule to advise me.

In the past [and now] I have placed glass plates with and without the the thinnest of Vaseline around my work area. They appear clear/transparent when clean. Observing them may not reflect the ability of my dust collector as it relates to speed and such, but one of my builds left a lot more dust in the air - the kind I did not see with my eyes until it built up on the glass enough to "fog" it after three hours of CNC work. Very telling fines that were invisible to my eyes. I did not see the dust in the room - but could feel something in my nasal area and coughed a little. I found out, although it was collecting dust, either placement of the collection or the DC were at fault. Turns out the DC was passing more fines to the filter area - I ran my bag inside my filter as I do during testing and found a large cake of fines in the bag slowing my airflow dramatically thus not collecting properly. So changed the design, cleaned the bag, problem solved. This was due to my "increasing air tube" flowing too much combined with a too small can. In that design I found too much airflow to the filter which changed in the larger can or scaled design - the fines in the first iteration were too close to the exhaust and could not drop out before simply exiting to the filter area, so I passed more to the filter and clogged my bag.

So yes, throwing this out there for thought too. Sometimes there are other issues that are not discussed but perhaps should be when we post results - such as distance and plumbing to equipment - as a "system" and not as a "unit". I hope this comes across as helpful and not as arrogant. Some of these issues may help us to understand why some of the same type builds for others sometimes work and sometimes don't . Me included.

If you are speaking about mine - yes, not 40 feet - that's a long, long way. I feel for you.

But if you consider 40' of pipe and you apparently are still collecting the dust, then my spiral with eleven feet internal with less than 10' of run to any of my equipment equates to less than your simple pipe run. That makes a difference for me. I would add the internal of the spiral is smooth walled and area compensated - not enough to be a "free flow" air column calculation but enough to outflow the restriction in a vacuum situation versus my fan abilities - and larger area than my fan inlet. Yes, keeping up speed is not as important in that situation. I should not post this here, but you bring up some relevant information about friction and such. Just opening the airways. I will side post this in my other:

Proposed Spiral Build - why - and a few of my observations

I hope since your post about 40' was a long time ago you have been able to rectify the distance issue. I too have issues, not being distance related.

Throwing my bandsaw pics out was actually for others, not the Powermatic, note I plugged my ineffective 2" port and moved it above my lower guide bearing setup. This was due to dust collecting on and above the bearings before ever getting to the port below them - I was buying bearings in twenty packs due to that fact and replacing them every five days as they seized regularly. Now, they last about a month. Yes, I only use a 4" that is split for both ports and it works great. I also restricted my 4" port by experimenting with the required flow - posting pic of that. Made a big difference. I do not know if you still full flow your 4".

Hope this helps someone else that finds themselves in the same situation as I found myself.

Ok, I had a 4" and a 2" - still had issues.

But changed my 2" to a hose with a common rigid nozzle - CLOSED the end of it and cut a slot in the side in line with the area to get ABOVE the blades.

The 4" does all the collection, the 2" keeps my blades/guide clear.

Works great, saves my bearings and put the suck where it needs to be.............

see pics

The image is the drawing of the build I have been gathering materials and refining since I joined the forum. Although I am considerably attempted to jump directly to the in-line separator build I have commented on in Phil's post, I feel I need to stick with some semblance of order in my goal. So I am throwing this out for a look and possible comments. Perhaps it will inspire someone......or not  ???

So this would be a true spiral separator, along with a secondary section that is a traditional Thien top-hat separator but all-in-one.

Some build dimensions for perspective:

   
• minimum dust collection bin of 20", with a split down the center to divide the two separation sections This may be the hardest part since I would need to build it.
• overall width as it sits at widest point ~ 26"
• inlet diameter is 6", guided into a 10"h x ~3"t rectangular transition
• Outlet is 6" and would be a top hat style with the fan assembly on the outlet
• Appears eBay has sheets [48" x 96"] of rolled up HIPs plastic that should be stiff enough and slick enough but still very flexible to bend in one direction - it comes in a roll - to form the walls/spiral of the can - ~ $29.  HIPs can be bent and glued - so the running length of ~149" of can wall can be two layered - offset where one sheet meets the next to form a single smooth and very slick can wall.
• Plan to CNC the slots in the tops and bottom to hold the HIPs can sheet in place.
• Wood 1/2" top and bottom plate - top removable - not depicting the offsets/actual fasteners in the top and bottom - but flush outside not in airflow

Why? This is based on previous experiments I have completed including the offset increasing area exhaust tube - off set from the bottom. The goal being to flow only as much air as is coming in to avoid simply drawing all the airflow immediately to the outlet - dust included - and into the fan thus to the filter. The bottom outlet extension allows me to control the height of the suction and amount [due to the cutout height around the perimeter of the tube] and therefor WHEN it occurs. I found in a build that had a solid tube with such a cutout that as you only draw some air off "slowly" but "in increasing amounts about the can FINAL interior" that you tend to drop dust out to the bottom of the flow by gradually slowing the air speed/pressure front - allowing the fines to propagate outward and not have as much a tendency to simply get trapped fighting against the next incoming airflow. As they drop they are now positioned below the exhaust [the bottom outlet ring] and will continue to circulate due to speed and the next time they emerge into the incoming airflow they are positioned low and below the air outlet position and tend to be "held" in the low position by the incoming majority higher airflow that wished to move down in order to get tot he slot in the outlet tube - and air is stripped off the top/inner airflow. FYI - final height of the upper outlet tube will be less area than the inlet. Starved if flowing just air - but able to flow all air out of a mixed stream as the dust and chips settled out to the bin below.

There are issues. by using areas and not including frictional components plus other consideration I have had to experiment with the idea. Seems, as a simple solution but not exact, if you consider area for flow and then remember that you are NOT flowing just air. Again, If your flow is 1% dust, then you do not flow the same area if it leaves the stream. Therefore inlet and outlet are not the same, outlet is LESS if you consider the dust must drop out of the stream before exiting. So, using percentages of airflow I find around 5% dust capacity allows me to drop the outlet area dimension so as to draw more fine dust produced by my CNC and drum sander. Again, Perhaps the "adjustable feature" of the outlet area will enable me to fine tune for what equipment I use or just dial it in better. But, most likely I will leave it wherever the best fines collection occurs. If your flow contains dust you actually flow more than the reduced area of the outlet. It may seem strange, but the dust is riding the airflow, not part of it in this scenario and it appears to work, for me.

There is a lot more I could talk about, but I am not writing a thesis. Basically, wondering if anyone else has comments about their experiences with this builds parameters that I have found to be advantageous - just have not put them all into one build before this proposed [proposed because although I have been gathering materials, well, plans change]:

   
• taller narrower can and stream - ~10"h and 2.8"w
• longer spiral paths to exit - over 149" of outward centrifugal force experienced.
• note: inlet positioned at the top of can - allowing flow to expand DOWN towards the bottom to encourage dropping of fines/chips
• two independent chambers both sealed to allow separated balance of suction - no return from one section to the other. This was not spoke of earlier - but the two slots are separate and NOT connected - do not wish any vacuuming from one slot to the next. So hopefully the larger [and fines] particles will drop out BEFORE they leave the ring and airflow towards the4 outlet tube is encountered - thus allowing them to remain forced to the outer wall of the spiral and allowed to fall out in the first slot.
• calculated outlet size - limiting flow out based on experiment and areas/percentage of flow is air versus debris.
• increasing by expanding area outlet cutout - helps the air swirl stay established "around" the can rather than "heading to the exit" and limiting outlet. I know everyone sees their dust through a window traveling around the can but I have had success with this method. Most important is the raised outlet bottom piece - match areas inlet/outlet and you may see some benefit in your existing can. You can just add a bottom ring and see what happens and take it out if you don't like it.
• riser off the bottom of the can for the outlet to keep fines in the lower pressure airflow at the bottom of the can to encourage complete scavenging - they are "trapped and can not propagate to the outlet [under it]
• note there is no way to use a bellmouth in this build, unless you can place two opposing - but I have not seen much improvement although the bottom bellmounth [facing up] seems to keep debris along the bottom of the swirl I think it is counterproductive on the "coming down from the upper position air that MAY still have suspended fines and promote moving to/into the outlet.

The simple can may still be the best - in the long run - as per retired2's build. But then we would not be having as much fun either  8)
If I change my mind and go that way I think I would still use the raised bottom outlet towards the center of the can drawing off the air from the stream limited to area calculations, with a taller can and narrower transitioned inlet.

That's it. Will advise as/if/when I finish. Also will be looking to do a better job of writing down measurements rather than just observations - will require the installation of several manometers/vacuum gauges to report. I intend to do that no matter what I build next. But I have been intrigued by this since  my initial drawing several months ago. I have been experimenting with the parameters since then. Now I am on iteration #24 and finally satisfied with it and the ability to build it fairly cheap.

I realized that my images have no everyday item to compare against - although that is an auto floor jack in the pictures [some stuff is getting tough to place, move and the builds are more involved].

FYI [if interested in another idea] I may be using a small hydraulic jack to raise my cans to my fan/Thien assemblies and leaving them in place as my way of doing can empties. Very cheap for a hydraulic or scissors jack at places like HF. Cheaper for me than building platforms......

So here is another image of the spears on top of a JET 6" spindle sander.
        Yes, the 6" bighorn 6" to 4" is the same outside diameter as the Spears 90. It will NOT slip fit.
        The Spears will fit over my 6" tube, it will not direct fit the bighorn.
        The bighorn will sort of - close enough for me - slip fit the tube.

Hard to believe the price of the Spears, I am going to get a few more of these long sweep 90s for myself. If anyone knows of a cheaper supply please let me know I would appreciate it. At $14.xx and free ship on Amaz per my post they appear to be a bargain.

Anyway, for your pleasure

Since no one else seems to have answered and I think I know why I'll bite the bullet.

I, and I am positive many others have considered water as a filter medium. It is widely used in some specialized larger scale separation units [mainly outdoors] but has a lot of drawbacks and issues for - at least my use. First, keeping the water contained and changing it often, unless you filter the water or have some form of deposition/gravity cleaning device, as it becomes more of a slurry it will become less of an available filter medium. Perhaps other fluids are best used. Then you could use it best by also spraying a fine mist into the air in the chamber to agglomerate the fines and other, but then you have a lot of moisture to deal with in your exhaust/fan/filter which you will really have an issue with if not immediately, soon. So if you change the media, fluid, admixtures to make it more "sticky" to dust, then will you also install a secondary baffle chamber with plates [all refrigerated to lower temps to cause the water vapor to gather and precipitate or some type of electrostatic removal [which could be used by itself too]..........and there are more issues after these.......are you going to raise the humidity with air flowing about water in your shop [will you then purchase a dehumidifier].......

I would suggest that perhaps as a final "after the final filter" air chamber in our use it may be more manageable if vented outside but then again you need to bring air in to allow air out or you will not have an optimal [for what you have] recirculating cleaner, but then the space it will take up and here we go again.......

Liquid/vapor separators are great devices, just on our scale a lot harder to make foolproof, manageable and practical. We are not running vacuum cleaners either that deal with limited dust on a carpet [I know of a few OEMs that have sold them]. That's why I, for one, am attempting to rid the stream of as much as possible before my final filter and let the filter deal with the [hopefully] little that gets through. It's just easier, workable and cheaper in the long run.

However, if you can solve the issues, I may be one of those that will jump onto the train with you. So my only comment after this would be please if you have ideas do experiment, and please let us know how you make out by all means.

A few photos, it is very hard to actually understand - for me - the difference between the stock HF fan inlet and the 6" inlet/spears long 90 degree from my earlier posts so I thought these may be interesting to some of you:

    "my best harbor freight mods, thoughts, intro."
    "6" LONG SWEEP PVC 90 degree elbowDWV [not tight bend] on Amazon - $14.60"

So here are a few images for both so you can see the difference and the reality of seeing them may actually be stunning. I bought two of the 6" to 4" so the one here is new, along with the 6" spears 90, while the HF original is still dusty and dirty off the shelf. You can see the stock HF gets lost in the 6" spears, and again, the new impeller per post makes a big difference. The pipe in the photo is a 6" hard cardboard tube for a new build to test a few thoughts - I find sonotube [concrete tube form] or packaging tube works fine for low cost testing.

They say a picture is worth a thousand words  ::)

Found this on Amazon, just purchased, thought others may be interested. Be aware, most 6" PVC is not 6"ID, usually slightly less.

I intend to use this in a test of the inline separator per my comments on Phil's thread - "An inline separator idea".

Others may wish to use it for other reasons. It is the cheapest I have found so thought I'd throw it out since a lot of others use "6 inch" PVC for other items such as runs.

I do not represent/work or am in any other way associated or have any vested interest in this item other than stated.

http://www.amazon.com/gp/product/B009H4N4DU?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Spears P309 Series PVC DWV Pipe Fitting, 1/4 Bend, Long Sweep Elbow, 6" Hub x 6" Spigot

We know the effects of the bell-mouth, and how akin to a distorted bubble the air flows out between two opposed bell-mouths as two mirrored black holes if in a constant state [unit on and vacuum established]. So I am wondering if the spinning vortex of this may yield the separation I seek, allowing the dust to escape into the outer chamber, if not all, at least I am believing it would be a  very low loss first stage? I really think I need to try this. Maybe I have become not a bellmouth, but a blabbermouth due to the fact I have not slept today. Like all good things in life, I may just end up regretting it in the morning  :o Go ahead, trash me  :)

Well, you are making me crazy - I may have to build this. It would be SO simple.

A few more images, supports for the center intake tube, flange for the lower can, removable top hat to the fan.

Easy to check, easy if needed cleaned [can't actually see a reason anything would need to come apart]. I like it. I may just abandon my more complicated build and do this first. Thanks for the prod.

It should not require air straighteners because we would want the impeller to impart the vortex. Straighteners at the entrance - BEFORE the elbow may help in hoses or pie runs to curtail some circular flow losses, streamlining the flow to the device. Once past the elbow, particulate not thrown out from the elbow and now spinning vortex imparted by the impeller, would then be encouraged to the outer inner pipe wall and then thrown out at the NOW 360 degree slot with no re-entrainment to fall through the outer pipe wall to the bin! Could it be possible? The center of the vortex is somewhat negative, perhaps like the eye of a hurricane. So if the very light fines are not washed out, they may make it to the impeller and thus the filter. But it may work better than any other alternative?

Perhaps I am just too tired and will try to stay away until I sleep.

I just reviewed my post - the Rikon impeller does not look bigger because it is behind the HF. Check this pic. 9 versus 12 [always the back plate]

You are correct in that the Rikon is a reverse of the HF.

In reality, the HF impeller is small, does not provide the pressure and flow the Rikon does. Now that I have figured out the image attachment [guess is not part of a preview to post] I am posting this photo for your review. You are correct on the vane design, but do not be fooled in what size means versus design in a fan. Yes, I agree, and I always look for and exalt the benefits of proper design and use - but this fits my unit and does the trick so it is still the one best increase in base performance [air moving] of ANY other mod I have tried or found at the price/performance point.

If I take your point and add in the larger fan diameter - do I not achieve more flow, more pressure, more.......?

That is not to infer I am the most knowledgeable or otherwise - but it works. Check other designs in the higher performance models and compare/see what they actually do with their fans. I think you would be extremely satisfied with this mod as a "seat of the pants" you can tell it is better as soon as you hit the switch. The pressure increase is substantial. I did this as a first mod. When I blocked one 4" inlet on the stock unit leaving the other one open, the bag was not  that stiff. After this mod, the bag was harder than leaving both 4" inlets open with the original impeller versus only one 4" open with the new impeller. So I would suggest that you will gain losses over the HF which almost stalls if not running as "open air" rather than moving a filled stream. Add other mods and you gain back - in my case - more than I lost - personal experience. Very substantial.

If you require shaft diameter and other I would be willing [since I am in change] to remove my fan and send picks of the shaft and dimensions if you desire.

Please do not take any of my comments the wrong way - I am only trying to help if I can. As always is the case, I think everyone should always think for themselves. That's what I like about this forum and the differing designs. Sometimes expected does not match reality due to other constraints that are exacerbated to the point that they become significant in the new design/use. I call it the change one thing and affect another.

This mod works for me no matter what I change and I would not go back. I will sell/give my old impeller away but will not part with my Rikon impeller. Would anyone want my HF impeller as a spare - will sell for S&H [cost] - because I will never go back. I hope that does not violate any posting rules.

Just realized - not clear - the [intake] inner tube is 6" diameter minimum, the length is much greater in order to allow centrifuge separation.

Good night  :)