Thread: Questions about a second hand set up.

Originally Posted by auscab

I wonder what its flow rate is. It looks big enough and powerful enough . But is it .

Straight Vanes = noisy but should have good efficiency
Straight (versus ramped) inlet wont have quite as good a separation - might need to use filters.
Back pressure will be higher than a BP design but large impeller size and motor power means it still should have plenty of suck.
My guess is it should do 2000 CFM in 9" ducting.

The inlet to the cyclone is 200mm diameter so that will have to be the diameter of the main line down the workshop I assume . with 150 branches off that to the big machines. and 150 down to 100 into things like band saw collection .

If you are a one man show and ducting runs are under about 10m then you could use 150mm ducting all the way.
Given the size of your shed larger trunk line is definitely worth doing. Unless you have a deep wallet 200 mm ducting and junctions will cost an arm and a leg so you might be better off going to 225mm (nominal, its actually 240 mm) PVC.

The collection drum at the bottom is sealed to the system so from what I know and read here, a trailer will have to be boxed in and sealed as well..

Standard trailers are notoriously useless as a receptacle as the sawdust builds up as cone and blocks the exit point from the cyclone and you do not want to be opening up the container and spreading the sawdust around inside the trailer every few days. If you don't want to be doing this then you need even more height between the trailer and the sawdust exit of the cyclone.

You might be better off using the 200L bin and setting up a lower effort system whereby the 200L drum is dumped into the trailer. BTW you should not wait for the bin to fill up but should be emptied at about the 150L mark, any more and you risk blocking the entrance and this will send all the sawdust out of the air exit.

There is an outlet that exits the cyclone above the inlet pipe which is connects to what looks like some sort of muffler . The air that exits here will need to be connected to a filter of some sort ?

If you plan on venting it inside the shed you will have to use filters. Venting outside depends on distance to your house and neighbours etc,

The air filters you have will add some back pressure but are worth trying.

Thanks Bob . You are a man of many talents !

"Standard trailers are notoriously useless" That's good to know . If the trailer isn't a good idea I may swap back to just keeping it inside and venting the exhaust outside. It would save a lot of work .
Then like you say , just park the tipping 6 x 4 I have outside the roller door and unload the 200 liter into that.
Maybe put it outside at a later date if its a pain inside.

The exhaust could go out through the wall and my nearest neighbor is about one kilometer away and not within eye sight so if its just a non visible amount of particles coming out it will just settle out across a paddock.

I used to have a 200 liter drum on the last system and it got to be a hassle emptying it but that was with more guys working . 3 or 4 at times . now its 2. The pain with that system was paying for the 200 liter bags . Here I can load a trailer and maybe keep a tarp over it, or put a roof over it . The shavings will get used on the property.

And if 255 mm is the best way to go then I can use that and use the existing 150mm from the old system off that . It will mean buying 225 to 150 branches as well as the 225 main line and I could possibly use my 150 to 150 branches to bring two lines into one before the 225 to 150 branch?

I'm pretty sure my old system is just the storm water type PVC . Id better check on that.
That should be OK in the 225 NB shouldn't it ? Is the storm water PVC what is normally used ?

Rob

The exhaust could go out through the wall and my nearest neighbor is about one kilometer away and not within eye sight so if its just a non visible amount of particles coming out it will just settle out across a paddock.

Yep - I would give that a go first up.

I used to have a 200 liter drum on the last system and it got to be a hassle emptying it but that was with more guys working . 3 or 4 at times . now its 2. The pain with that system was paying for the 200 liter bags . Here I can load a trailer and maybe keep a tarp over it, or put a roof over it .

That's what I would do,

And if 255 mm is the best way to go then I can use that and use the existing 150mm from the old system off that . It will mean buying 225 to 150 branches as well as the 225 main line and I could possibly use my 150 to 150 branches to bring two lines into one before the 225 to 150 branch?

Yeah the 225/150 mm PVC junctions are not cheap but they will be cheaper than anything else in that size range.

I'm pretty sure my old system is just the storm water type PVC . Id better check on that.
That should be OK in the 225 NB shouldn't it ? Is the storm water PVC what is normally used ?

Yes - Stormwater is the one.

Since you don't have the usual close neighbour issues you can mount the entire DC outside high enough to open the bottom of the collection bin to drop the dust into the trailer. You see lots of the bigger systems done that way for sawmills and larger cabinet shops. It would put all the noise outside too.

Pete

The noise would be good outside.
Ive come to my senses though and Ill put it inside and vent it outside . Its going to be to much work ATM to house it outside.
If I raised it to get a trailer under it , I cant imagine trying to put a roof on something 5.5 to 6 meters high 3M x 3 M square.
Ill just empty the drum into the trailer and it saves weeks of work . I can always shift it outside to the other side of the wall later and still keep it under the roof line of a later carport possibly.

Rob

Just a few thoughts from me.....
Given that the motor is 5.5kw, (2 pole=2900 rpm) a good size fan and a 200mm inlet indicates to me that it will have plenty of suck.
My cyclone empties into ~~ a 1m3 box with a door on the front, when it fills up I empty it out with a shovel/wheel barrow, not the best bit of design there! to improve this I want to make a box that goes inside the main box which the dust then empties into, then to empty I remove inner box (on wheels) and take to unload (compost making spot) and just upend to empty, the important thing here tho is to make a good seal between top of inner box and underside of outerbox.
I also find that the dust exits the btm of the cone at a wide angle (probably a fuction of exit dia/speed of rotation/etc) this means it fills the box nearly full before it starts filling up the cone, it will still be separating until the sawdust reaches the inner tube where it will start going out the exhaust, if dust is getting near full a quick shove with the rake to move dust away from cone btm will give me quite a bit more work time before empty.
Personally I think 200l is too small for a collection container, but you got to work with what you got!!!
Pete

Yes Pete I agree with the 200lt being on the small side. My old system worked well with its 200 lt but if it was left to long and not checked the shavings backed up along the pipes and was a real PITB to clear out . The whole lot was under a wooden floor and joints had to be pulled apart sometimes and cleared. If we checked it before starting a big run we knew when to go check and change just by instinct after a while . like i said before I used to have 200 lt bin liners and these cost me around $2.50 to $3.00 ea . There were plenty of times I had them stacked 20 high though . And I liked to treat the bags with care and get three uses from them . I had to take it to the horse poeple who liked it for stables . Unless it was full of Walnut shavings.

Its going to be great not having to buy bags ,and being able to use it all for compost and pathways and with the chooks. What I may do is get a few more 200 lt drums and have them waiting as a empty quick change over for when Im really going at it .

And thee "Plenty of suck" opinions are good to hear . I had stretched my old system as far as I could for years and it was failing at some of the later extra machines I was using out the back of the old workshop.

Rob

Rob you obviously need to upgrade your machinery from that old grey stuff.
How about I come down and give you a load of nice shiny new stuff in exchange for it.
H.
Good to see you're nearly up and running.

Originally Posted by clear out

Rob you obviously need to upgrade your machinery from that old grey stuff.
How about I come down and give you a load of nice shiny new stuff in exchange for it.
H.
Good to see you're nearly up and running.

No shiny new stuff needed thanks Henry
Still a bit to do but we're running and doing shed stuff on the side when we can from now on .
Im just feeling at home on the PK after four weeks of use and it's pretty strange walking up and handling the little Bursgreen table saw now . It's tiny in comparison .

I got the unit together with the help from a block and tackle or two.

Welded a couple of pieces of steel across the base and the whole assembled lot now wheels around on the pallet jack . Every machine in the workshop is on blocks for moving around like this . I haven't settled on any positions yet and the introduction of any one thing can change the lot. Which is what happened when the Dust extractor went in close to where I think it belongs.

I wired up the motor and fired it up . Its loud!!

Without the drum fitted down below its sucking hard through the bottom . placing a thin board over it quietened it a little and so will the muffler on the outlet .

Im just wondering how dust manages to fall down into a bin with air going through this thing like it is ?
The air still has to come in and go out up a pipe through the middle.

The pipes and gates are going to slow things a bit, but really!!

It obviously must work , seems incredible though. This thing running open had the whole shed atmosphere rotating in no time .

Ive picked up reading here talk about back pressure but don't understand . Is it a good thing that helps them work and a way of tuning these machines ? or the less back pressure the better ?

Also , Im going to have the horizontal outlet, the muffler, running from the outlet on the cyclone to the right hand shed wall and out between the roof and the first purlin down . The whole unit is going to be moved to the center of that right end wall section right of the roller door, so that the main 245mm inlet pipe runs down the middle of the right hand side of the shed, the way its pointing now. The whole thing will be raised from its base as well to line the outlet up with the wall sheet above the high purlin and below the final gutter purlin or roof purlin . I forget the name of it .


I'm just wondering what happens in the event of the system over filling and if material blocked things up and settled in the muffler , the horizontal pipe ? once it gets cleaned out below will it just blow it outside and clean itself?
I was unsure which direction to mount the outlet at first. Horizontal or turn it right and go down close to the cyclone and then out . There is an L shaped pipe for the outlet and I couldn't work out which end it belonged at but I think now its supposed to go at the far end of muffler and point at the ground on what will be the other side of the wall sheeting .

Here is some pictures.

IMG_5126.jpgIMG_5131.jpgIMG_5135.jpgIMG_5137.jpg

Air power holding up the Spade
IMG_5147.jpg
This must be a dealer ?
IMG_5132.jpg
And the Makers label.
IMG_5128.jpg

Rob

Its a straight vaned impeller which is why it is loud and a good reason to have outside.

I'm just wondering what happens in the event of the system over filling

The sawdust will blow out of the exit past the muffler and into your yard.

BTW holding the spade is nothing special.
With an 8" cross section thats ~50 square inches.
If the vacuum pressure is 10" of WC, that's around 0.36 PSI so 50 square inches should hold around 18 lbs of flat object.
Even a 3HP can do that.

What really matters is what vacuum it can continue to hold while moving air.
This is where a bigger impeller wins over a smaller one.

Originally Posted by auscab

Im just wondering how dust manages to fall down into a bin with air going through this thing like it is ?
The air still has to come in and go out up a pipe through the middle.

With the inlet open and the cyclone btm open air will come in thru both and out the exhaust, if you seal off the cyclone btm air will come in the inlet and go out the exhaust, the same vacuum exists (for our purposes) at every point within the cyclone, even if you put a box/bin/bag under the cyclone the same vacumm exists within the box/bin/bag, your collection box/bin/bag has to be strong enough or have internal support to resist collapse, essentially when you turn it on you create vacumm on one side and atmospheric on the other which is trying to squash it and the bigger it is the more area the greater the squash.
Another point here is any leak thru the box/bin/bag will take with it a certain sized dust particle which will go out the exhaust.
A way to think about how a cyclone works is think of the eye of a cyclone (the storm type) being where the clean air comes thru and all the dust is flung out to the side walls of the cyclone/cone (spinning cloud) where gravity/friction works on the dust and it falls, there are some good animations out there in googleland, try how does a cyclone work.


Ive picked up reading here talk about back pressure but don't understand . Is it a good thing that helps them work and a way of tuning these machines ? or the less back pressure the better ?

Less is best here, basically it is resistance to movement, air is moved thru a pipe where it has to slide over the side walls of the pipe and the air itself has resistance to movement, so anytime you move air thru a pipe or bend or some sort of fitting or machine port the air is forced to to twist, turn and slide, we measure this resistance as a loss of pressure and the fan has to be able to produce pressure in excess of these losses to move any air. I doubt yours will have any issues but you still need to be aware of where these losses occour, for e.g sharp bends are bad, you want gradual changes to changes in pipe sizes or any machine hoods you make, good reading on Bill Pentz's site on all this.

Also , Im going to have the horizontal outlet, the muffler, running from the outlet on the cyclone to the right hand shed wall and out between the roof and the first purlin down . The whole unit is going to be moved to the center of that right end wall section right of the roller door, so that the main 245mm inlet pipe runs down the middle of the right hand side of the shed, the way its pointing now. The whole thing will be raised from its base as well to line the outlet up with the wall sheet above the high purlin and below the final gutter purlin or roof purlin . I forget the name of it .


I'm just wondering what happens in the event of the system over filling and if material blocked things up and settled in the muffler , the horizontal pipe ? once it gets cleaned out below will it just blow it outside and clean itself?

If it is coming out the exhaust in a steady stream in the event of a cone filling, when you empty the cone it will just blow out what was left in the exhaust.


I was unsure which direction to mount the outlet at first. Horizontal or turn it right and go down close to the cyclone and then out . There is an L shaped pipe for the outlet and I couldn't work out which end it belonged at but I think now its supposed to go at the far end of muffler and point at the ground on what will be the other side of the wall sheeting .

My guess would be to keep the exhaust up high in the shed then bring it down when outside the shed wall.





Rob

Pete

Thanks Pete , Thats very interesting!
The vacuum inside the system is the magic ? Amazing .
So if a fan in a system was spinning but not hard enough to create as big a vacuum , shavings could just fly in and out the exhaust ?
Not drop down?
I'm going to go read on how the storm type of Cyclone works as soon as I get the time.

Rob

Originally Posted by auscab

Thanks Pete , Thats very interesting!
The vacuum inside the system is the magic ? Amazing .
So if a fan in a system was spinning but not hard enough to create as big a vacuum , shavings could just fly in and out the exhaust ?
Not drop down?

Its more about maintaining sufficient centrifugal force to fling as much of the dust outwards onto the sides of the cyclone where it slides down and into the collection bin while only the air and the very finest dust is drawn in a spiral upwards in the middle of the cyclone and out of the impeller.

When the collection bin fills up the cyclone outlet is choked and sawdust then falls into the upwards air spiral and out of the impeller.