Cyclone Seperator Shootout

[Bruce Seidner]

The problem with the review is this is not apples to apples. Not that Mark did anything wrong. But there is only one cyclone in the bunch of three units and that is the one with the most lawyers and potential lawsuits being held over the head of ClearVue. This does nothing to diminish the success of the very affordable Oneida Dust Deputy.

BUT, truth be know the "old" ClearVue could no longer be produced because of the threat of "patent infringement" and what I want to know is where is free enterprise when you need it?

I purchased the new Clearvue design and it is essentially the top half of a cyclone that then uses a baffle to separate the hat from the bin. I did not realize that this was what I was getting when I pulled the trigger and purchased it. When it arrived I emailed both Clearvue and Bill Pentz about why they "forgot" the cone in my shipment. I considered sending it back but I was irritated about paying to send it back and I was irritated about assuming it was a cyclone when it is is just the top half of a very sophisticated cyclone without the cone to allow optimal separation and "cyclonic" effect.

Long story short I decided to keep the ClearVue unit and had a metal fab shop make a cone for me based on the ration I got from Pentz. The cone goes from 6" to mate to the bottom of the ClearVue unit down to a 2" bottom opening/discharge. The ratio for this cyclone top is 1 to 1.64 (6"x1.64") giving me an accelerating cone that I would aver beats the Dust Deputy because of the inlet design and internal baffling that routes the input like a greased pig at a bootlegger's picnic. It is very, very cool.

I have not had a chance to unite the ClearVue unit with the actual cone which threat of lawsuit foreshortened and it is my understanding that the baffle is a compromise. I am a sucker for the underdogs in a fight like this. So I spent an extra $30 to have a 26g sheet metal cone made. I am not much for picture taking and project sharing but I should really find the time to do this. This "shoot out" was a case of Clearvue being forced to bring a knife to a gunfight. And the results are what they are.

What I would like to see is a comparison of the Dust Deputy with the "old" pre-lawsuit threat Clearvue AND the current ClearVue with a proper cone bottom instead of this baffle device. I need to route some wood donut connectors to hook all this together but with all that is going on in the household and work-life I don't see that happening for a while. It anyone has the time and interest to play with this let me know and I will send it to you and pay for your time and postage. I am too snowed under at present to do much with this project at present.

[ian maybury]

Must say that I'm in the same camp as Phil in feeling that it's likely that these cyclones have preferred air flows at which they operate best, and that the 'whack a hose in and try 'em out with whatever dust you have to hand' approach to testing while appealing may as a result be a bit a bit of a lottery. It may endow some bragging rights, but in truth there's no point as a purchaser going for the 'winner' (so called) in this situation if it turns out that your set up is different enough to that in which the testing was done to significantly throw it's performance.

It'd be nice to think that the makers developed their designs to be insensitive to input conditions (and maybe they did), but I wouldn't bet my life on it. To my mind it just underlines what we have been saying here for ages - that until the separation performance of the various cyclones is tested (that's comprehensively and independently tested across the full range of likely operating conditions and dust type possibilities) and published that we're all betting on outcomes.

Testing costs money, risks outcomes the makers (and many of us) would prefer not to hear, raises the risk of claims for non performance, and perhaps most of all would put an end to the outrageous claims made by all and sundry. Best of all it should result in making available the data needed for us to purchase cyclones on spec to suit our situation rather than based on dubious claims.

On the original Clear Vue mini story. +1 that it's claimed that the original version had precedence (meaning if true that any subsequent claim by another party for a patent for the same invention if challenged would not stand), but that it was not patented because of the cost. When the alternative was patented it was then withdrawn from sale as they were not prepared to take the financial risk of being forced into court to defend their position.


ian

[Michael W. Clark]

Must say that I'm in the same camp as Phil in feeling that it's likely that these cyclones have preferred air flows at which they operate best, and that the 'whack a hose in and try 'em out with whatever dust you have to hand' approach to testing while appealing may as a result be a bit a bit of a lottery. It may endow some bragging rights, but in truth there's no point as a purchaser going for the 'winner' (so called) in this situation if it turns out that your set up is different enough to that in which the testing was done to significantly throw it's performance.

Ian, I see what you are saying and agree with you, but I look at the test a little differently. All three of these units are going to have a range in flow where they have their best efficiency. As the flow decreases, so will efficiency. As the flow increases, so will efficiency. This is true for any cyclone and cyclonic separator. You are limited on the upper end by too much velocity in the cyclone outlet that could cause re-entrainment. I would suspect the Vortex efficiency is largely dependant on a low velocity in the drum, allowing the particulate to settle. If this is true, the efficiency would fall off and it may even be lower than the cyclone (as a % of its sweet spot).

I agree we don't know that the flows were the same for each device, I only assume that Mark left the VS control on the extractor set the same for each device during the tests (maybe he said this). Varying differential pressure across the devices, may have resulted in a different CFM draw through the vac. Less differential pressure would equal more flow, if everything else is the same.

However, when we buy the units, we are not going to set our vac for the optimal CFM for collection efficiency across these devices. If we do not have a VS on the vac, then we will get whatever we get and we don't know the CFM of our vac. If we do have a VS, then the speed will be set by the application. For example sanding with Rotex, if you set the speed too high, you get a lot of swirlies, similar for an ROS. If you are collecting off a router table or track saw, then the VS will probably be 100% or else dust will escape from the hood.

Even if we know the optimum CFM for the CV, DD, or Vortex, it is likely that we will not set the vac for this and also likely that most people would not be able to repeat it if they wanted to. Stationary system cyclones would be different in that we are trying to put in a cyclone system that would usually operate at the same flow (inlet velocity), thus the performance would be consitent. We can estimate the CFM needed at the machines to determine the CFM/HP we need. The overall efficiency would vary depending on the dust size, but the efficiency at X micron would be similar because the inlet conditions are similar.

The bucket collapsing on the CV was not a bullet at the CV collection efficieny as much as it was at the materials of construction and overall quality. It may indicate a higher differential pressure, which would also mean less flow. This ruled the CV out for me too, as Van said. I would suspect a cyclone to be more efficient than the Vortex arrangement at a given flow, assuming I am correct in my understanding of how the Vortex works,

I think Mark did a pretty good job with a non-scientific evaluation. Probably as good of an evaluation as most of us would do in our own shop to determine if we liked the product or not. We would still have the filter bag in the vac, so any dust carryover is still caught. We just have to change the bag more often if performance is down. All of these got the big stuff, which is what is going to have the greatest impact on bag changes. That being said, whose to say the Vortex isn't the best bang for the buck when it is on-sale. However, I would expect the manufacturers to be set up to do a more scientific evaluation of their products. It would be good if they could publish some of this information, even if they have to define the operating conditions. 99.99% on 5 micron means nothing unless you define the operating conditions.

Mike

[Jeff Ranck]

On the original Clear Vue mini story. +1 that it's claimed that the original version had precedence (meaning if true that any subsequent claim by another party for a patent for the same invention if challenged would not stand), but that it was not patented because of the cost. When the alternative was patented it was then withdrawn from sale as they were not prepared to take the financial risk of being forced into court to defend their position.


ian

+1 There is a whole lot of misunderstanding on how patents work. ClearVue may well have had the first product that folks saw, but patents can take years (think 3-7 average, depending) to issue. If CV really had a product on the market before the other guys filed their patent (invented what the patent covered, actually), the patent wouldn't have been any threat to CV. Whether CV had a patent on their product is pretty much irrelevant. (Patents don't give you the right to do anything, only keep others from copying your invention.) For the patent to even have a possibility of applying, it is all a timing issue. When did the other guys invent their thing, when did CV create theirs?