3D Printed Cyclone Air/Dust Separator

Testing various 3D printed cyclone separator designs.

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IG: danielriley_

[lukearts]

Awesome video!! Pro tip: (seriously, I'm a dust collection engineer) Make sure to earth that collapsing flex hoze. The metal wire in there is not to make it springy, but to function as earth wire to avoid static buildup and discharge... I live in a country of merely 11 million people and each year we have 34 dust collection explosions (and consequent total shop losses) caused by failure to properly earth sections that build up static charge... :) I thought that might be a stat that could spark your interest ;) =P (swidt? haha)

[WilliamEades_Frostbite]

We used separators extensively in the lab and found through our experimentation that an inlet angle declination of 7 to 10 degrees made for the greatest debris drop-out.

[_sunsor]

A feature of many cyclone separators is what is termed a 'vortex finder' or 'outlet length'. The outlet pipe dips down into the inside volume of filter. This forces air from the inlet to orbit around the separator surface before exiting the top of the filter. This length is important for adjusting filter performance for pressure drop vs. fractional efficiency.

Many papers use terms designated as 1D2D, 1D3D etc to describe the cyclone separator dimensions. The numbers represent the ratio between the cyclone diameter and cone length. Many papers are published which compare filtration fractional efficiency (as a function of particle diameter), pressure drop, and flow rate through the filter for a given Mean Particle Diameter.

In general, a higher aspect ratio of cyclone with a large outlet length will filter better because it exposes the air flow stream to longer linear lengths of surface area. The principle is that at the boundary layer, air velocities are slow enough to drop out material against the surface, and the slope of the surface keeps the material from re-entering the fast air stream. Lower cyclone diameters will filter out smaller particles better, at the expense of significant pressure drop.

According to ASHRAE, saw dust has an approx mean diameter of 600 micron, and flour dust has an approx mean diameter of 50 micron, for your reference.

This was a paper we used to guide our design of these separators.

You should check out papers on the subject if you really want to optimize your filter.

[MStrickkk]

"It became clear I needed to vacuum my floor more often" Even a genius needs a little help from technology to learn life skills.
Love your content and your passion for everything you do.

[radpugguy]

Hey! i've actually done these experiments myself a few months ago. I found that, as you mentioned, a steeper slope was better for larger particulates. But my results were also greatly improved when I elongated the cone and allowed the air more time to circulate. Additionally, I found that sanding the inside to be as smooth as possible helped. Great video, love ur channel.

[DanBowkley]

The velocity of the air stream, size and density of particles, and slope and diameter of the cyclone matter a LOT more than you'd think. The multi cyclone is essentially optimized for three different particle sizes, since it was done more or less randomly there's no telling what exactly those particles might be.

[HFMarlo]

If I remember my lectures correctly, you usually have the outlet not at the top but a bit further down the cyclone so the particles are slower. Maybe adding a small tube in the center will help. Would also be a quick print, if not just a cutted pipe is enough.

[beetlejuicex]

This is why I made two separate units in series. The first is your typical dust collector, the second is literally a giant bong. The air goes into water this making it super clean.

[Kubulek]

If you look at a Dyson vacuum, each tier of cyclones has a separate collection chamber separated by a seal, also rather than multiple similar sized cyclones each one is reduced in size in order to filter different sized debris, the main shroud for large debris the subsequent in size for finer particles. The diffusion method might be effective as lower airspeed but you have to keep in mind you want maximum power rather than an obstruction on purpose as that not only reduces cleaning performance but also puts strain on the motor which in a non-shop vac vacuum relies on pass through air for cooling.

[AdamSmith-kqys]

Point to note: the multi-stage design _should_ allow you to tune the first stage to remove big chunks at a cost of letting the fine stuff through, to be dealt with in stages 2 and 3.

[ordian]

You should test combining the big mono and a smaller mono, since they both filter out different size particles.

[Entropic]

Simply routing the air through a larger tube will drop the air velocity since Q/A=V where V is velocity, A is area and Q is flowrate. If you bump up the area the velocity goes down proportionally. The middle of the tube will have a much higher velocity (especially since this is 3D printed and doesn't have a smooth surface) so it would require a series of diffusers to make sure the velocity field is uniform. You'll need the bottom to be open to the bucket for the dust particles to descend and accumulate. If you get an anemometer (they are like 20 bucks) you can measure the velocity of the flow in your vacuum tube which combined with the cross sectional area can give you an estimate of how large the dust collector tube would need to be to drop the air velocity. The surface area of the opening in the diffusers should be equal to the original (non enlarged) tubing size. Basically the particles fall downward at a fixed rate decided by gravity and their drag. The velocity inside the collector must be low enough that a large portion of particles (>95-99%) have plenty of time to fall downward out of the moving air stream.

[wiredforstereo]

This whole video I was screaming out loud "WHY ARE YOU TRYING TO REINVENT THE

I took "Air Pollution Control" in my Master's program for Civil Engineering. Cyclone separators are very simple and easy to engineer, build, and understand. I'm sure you can find stuff online about how to design and build them and what performance to expect based on particle size and density. You could even dissect nearly any bagless vacuum cleaner to get ideas on how they work and the proper proportions.

One feature I noticed that was neglected in most if not all the designs, is that the exit pipe in the top center should extend into the cyclone chamber, a certain number of diameters of the pipe, like 1 or maybe a half, I don't remember. I think it's called a "vortex finder."

This is a great practical video, I'm glad you made it, and I mostly enjoyed watching it, but you could have started much further ahead than you did with just 5-10 minutes of reading.

[-George-Wood-]

The slow motion sexy CNC and cyclone shots to the music was absolutely hilarious and I replayed it about 5 times, great video! I love 3D printing but never thought I'd sit through a video on a DIY shop vacuum, you made what should be a relatively boring thing into engaging content! Great vid!

[Project-Air]

Can't wait to see what you cut out with this magnificent thing - level up!

[psedach]

I appreciate this. I've been using a 20$ Oneida cyclone for almost 10 years and it's nice to see why it works. The other attempts don't add to the science but they really do help to see why the original design is so effective.

[jsj]

So cool, how 3D printing gives "garage inventors" ability to design and test ideas. Daniel, I have a feeling that 3D printing combined with the Stepcraft router will be taking you to a whole new creative level. Go for it!

[drknsss]

@12:45 you got bars!!! I see you also are channeling the spirit of Rick Flair Wooo!

[survantjames]

We’ve done a fair amount of research on these cyclones for our projects. There are a lot of academic papers out there which pretty thoroughly describe the performance characteristics of these things given different geometries and boundary conditions. A given geometry tends to preferentially separate out particles with a particular density. In other words, a given cyclone might perform great for steel grinding dust but not so well for sawdust. So your results will depend on what you’re trying to separate out. Fun project, thanks for sharing!

[MaxTheBoomer]

This is exactly the kind of DIY video i likee and would like to see more often: passion, skill, creativity, and well-executed objective tests. I really appreciated your video, because over the years i have also built and experimented with various types of separators for my home tiny workshop, in order to filter well especially the critical MDF dust: i have long since found an excellent solution, which includes 3 different stages (first a Thien separator for large and medium parts, then a small cone cyclone for very fine dust, and third a simple and cheap polyester filter, which remains clean for months on.