Thread: Flow loss using a Dust Deputy

But, if I'm correct in the assumption, these types of units have been made for the use in conjunction with Vacuum cleaners, not 3hp duties. not only that the reduction from 150mm down to 50mm would reduce the air flow a huge amount as well. sorry just my thoughts

Originally Posted by Opelblues2

But, if I'm correct in the assumption, these types of units have been made for the use in conjunction with Vacuum cleaners, not 3hp duties.

Correct, but I have also seen them connected to small DCs.

]not only that the reduction from 150mm down to 50mm would reduce the air flow a huge amount as well. sorry just my thoughts

That's correct but I am comparing the flow through a 50 mm hose connected to the DC - with and without the DD.
I have a 50 mm hose connection to my DC to use with power tools as my testing shows it works as well or sometimes even better than a VC, especially if the power tool has a bit in fan and this determines the actual flow mo
It will be interesting to see what happens on a VC.

I think BobL measured the flow through 50mm hose with and without the DD connected so was measuring just the restriction presented by the DD. I think BobL will confirm

Originally Posted by ronboult

I think BobL measured the flow through 50mm hose with and without the DD connected so was measuring just the restriction presented by the DD. I think BobL will confirm

Correct.

Yes Bob we all know that you hate cyclones, unless they have your personal tick of approval of course. The subject line of your post is grossly misleading and should be amended to indicate that the equipment is not being used in the way intended by the manufacturer.

As has already been stated these small cyclones are designed to be used with vacuum systems. They should never be used with a low pressure system, read dust extractor. I'm sure you will acknowledge that high pressure and low pressure systems are totally different in their design and operation.

Although your 'test' may be of some interest it has no implications for 99% of users of these cyclones, who use them for what they are designed to do. When used for their intended purpose these small cyclones work extremely well. Only an idiot would hook up a cyclone of this size to a 3HP DE. This doesn't mean of course that such idiots don't exist, but isn't it the line 'that you can't protect an idiot from himself'?

I am currently installing a CDS-2/3 - Cyclone Dust Separator and DC-7 - Dust Collector for my shed with 6" PVC ducting. The units will be mounted in an outside seperate sound reduced shed to lessen the noise and dust in the shed. Initially to be used for a wood lathe, bandsaw and belt sander.

I have a ROS sander, Triton router and dovetail jig which are all set up with 1.1/2" and 2" dust collection points as apart of their build. If I connect to the 6" ducting, will I collect any dust, or because of the small ducting hose (1.1/2") will it almost stall or overload because of the small hose diameter. Am I in fact better off connecting to a shop vacuum system and perhaps using a small cyclone to separate the larger chips from the vacuum.

Rather then a shop vacuum, would it be better to use a ducted vacuum system (1200 watt), using 50 mm ducted PVC pipe so as it can be mounted in an outside shed with the other dust collector (less noise and all dust is outside of work shed).

Thank you in advance for comments and thoughts.

aldav
You may not like or agree with BobL's test or conclusions but the language used in you post was not really appropriate!
Ron

I recently installed a chiwanese cyclone thingo to my shopvac. the shopvac is 1800watts connected to the cyclone via a 50mm soft flexi and then i use a 9 meter long pool cleaner hose (~40mm diameter) to connect to my power tools.

I don't do any fancy technical testing, but I can hear and feel changes. Using a brand new fresh vacuum fine paper bag, there is definitely a drop in flow when using the cyclone. the drop isn't much and it hasn't stopped the overall vacuum system from removing 'enough' dust while sanding with my random orbital.

However, when using the shopvac without a cyclone, the paperbag fills up and as the bag fills up it loses the filtering surface area to pull air through which decreases the flow by a huge amount. I know when the paperbags are full just by feeling/hearing the flowrate drop without having to turn the shopvac off and physically check the bag.

Running the shopvac with the cyclone connected, the flowrate is lower but remains consistent because the paperbag is pretty much empty. Some bits and pieces get through, so the cyclone is simply delaying the inevitable and I will eventually have to change the paperbag as per the usual, but atleast that will hopefully be many months between drinks rather than every couple of days.

I installed the cyclone in the hope that if less dust makes it way to the shopvac, the shopvac will have less dust available to churn into an ultra-fine mist which is beginning to annoy the hell outta me. The results are, after a long session of sanding with my random orbital, I can still smell the ultrafine dust in the air, but there is much much much less than there was before when using shopvac without cyclone. Of course I could put the shopvac outside, but my neighbours are good people and noise is annoying, and most importantly, noise is a point of complaint

Originally Posted by aldav

Yes Bob we all know that you hate cyclones, unless they have your personal tick of approval of course. The subject line of your post is grossly misleading and should be amended to indicate that the equipment is not being used in the way intended by the manufacturer.

I see no reference to why a DD should NOT be used on DCs on the DD home page and wonder how many folks have bought one thinking they can be used effectively on a DC.
http://www.oneida-air.com/category.asp?Id={CC6B6F2A-E3D7-4F18-A53C-B5C357DFE131}

Anyway all I'm doing is providing precisely the sort of numerical evidence as to why why the DD should not be used in this way.
It's one thing to just tell people not to use it this way and another to provide an actual independent measurement (not one made by a manufacturer) to reinforce the point.

My thread title is not misleading, there will also be some loss of flow when a DD is used on a VC - the question is how much.

I have also never seen any independent testing of the dust removal efficiency of a DD.
99+% removal of dust means nothing unless it is accompanied by a micron rating.

I will continue to make my measurements and folks can use the info as they wish.

Originally Posted by ronboult

aldav
You may not like or agree with BobL's test or conclusions but the language used in you post was not really appropriate!
Ron

Hi Ron,

I guess your objection is to my comments about 'only an idiot connecting one of these small cyclones to a DE'?

If that is the case, BobL is well aware that that I don't consider him an idiot. I know, and he knows that I know, that he would never hook up a small cyclone like this in his dust collection system.

I simply don't see the point of conducting a test on a piece of equipment that is being used in a way the manufacturer never intended it to be. It's like complaining that your jigsaw can't do the job of a table saw.

As you can see above Bob is more than capable of looking after himself.

Originally Posted by Kuffy

I recently installed a chiwanese cyclone thingo to my shopvac. the shopvac is 1800watts connected to the cyclone via a 50mm soft flexi and then i use a 9 meter long pool cleaner hose (~40mm diameter) to connect to my power tools.

I don't do any fancy technical testing, but I can hear and feel changes. Using a brand new fresh vacuum fine paper bag, there is definitely a drop in flow when using the cyclone. the drop isn't much and it hasn't stopped the overall vacuum system from removing 'enough' dust while sanding with my random orbital.

However, when using the shopvac without a cyclone, the paperbag fills up and as the bag fills up it loses the filtering surface area to pull air through which decreases the flow by a huge amount. I know when the paperbags are full just by feeling/hearing the flowrate drop without having to turn the shopvac off and physically check the bag.

Running the shopvac with the cyclone connected, the flowrate is lower but remains consistent because the paperbag is pretty much empty. Some bits and pieces get through, so the cyclone is simply delaying the inevitable and I will eventually have to change the paperbag as per the usual, but atleast that will hopefully be many months between drinks rather than every couple of days.

I installed the cyclone in the hope that if less dust makes it way to the shopvac, the shopvac will have less dust available to churn into an ultra-fine mist which is beginning to annoy the hell outta me. The results are, after a long session of sanding with my random orbital, I can still smell the ultrafine dust in the air, but there is much much much less than there was before when using shopvac without cyclone. Of course I could put the shopvac outside, but my neighbours are good people and noise is annoying, and most importantly, noise is a point of complaint

My findings also.

I have 2 units - one is a home built Thein. One is on 35mm hose to a 2000W Pirahna cyclone vac for connection to my ROS, Track saw, SCMS, 18v circular saw or guard outlet on my homemade table saw. The other is on 50mm hose to a chamber under my home made table saw or router table connected to a 1800W Shop Vac.

There are thousands of people who use these small cyclones the way they are intended to be used and are more than happy with them. I still don't see the practical point of the test. As far as the manufacturer recommendation for the use of these goes we can probably take a lead from the statement "will transform your vacuum" as a pretty clear indication of their intended purpose for their equipment.

I'm missing something here.

Why is the reduction in flow bad? With the coarse particles out of the system via cyclone you don't need high airflow to shift the fines - they just float along the pipe in the breeze don't they? 90% of the air flow is only ever there to shift the largest 10% of particulate.

Originally Posted by Kuffy

I recently installed a chiwanese cyclone thingo to my shopvac. the shopvac is 1800watts connected to the cyclone via a 50mm soft flexi and then i use a 9 meter long pool cleaner hose (~40mm diameter) to connect to my power tools.

I don't do any fancy technical testing, but I can hear and feel changes.

I agree with you about the bags etc but hearing and feeling are no substitute for measurement especially where sanding is concerned.
The dust to worry about is so fine you can't see it and even a 1/4 of a thimble full is enough to contaminate a 100 m^2 shed well above OHS levels.