anybody ever make a dual inlet baffel design.

Started by alan m, June 30, 2012, 09:18:57 AM

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alan m

sorry .
it is hard to show what i mean.
the bottom 6 inchs (of a 12" high seperater) is a cylender . the wall of the cylender follows the slot around . the inside edge of the blue  part is the inside edge of that lower section.
the blue parts then get wider  out over the lower section. there will be a step  or shelf that i hope will act like the section in the baffel with no slot.

if i can come up with an easy way of doing it i might slope that shelf  for the last few (6-8") inchs to allow th eair to lower down into the lower section and avoid the second inlet.

retired2

Quote from: alan m on July 01, 2012, 01:46:59 PM
sorry .
it is hard to show what i mean.
the bottom 6 inchs (of a 12" high seperater) is a cylender . the wall of the cylender follows the slot around . the inside edge of the blue  part is the inside edge of that lower section.
the blue parts then get wider  out over the lower section. there will be a step  or shelf that i hope will act like the section in the baffel with no slot.

if i can come up with an easy way of doing it i might slope that shelf  for the last few (6-8") inchs to allow th eair to lower down into the lower section and avoid the second inlet.

I hope it works because that is going to be a complicated fabrication.

alan m

when i lay it out full scale on the material i will try and make the green parts the same on both sides and use a router tempate to make them all the same.

the bottom 6 " section (just round donut shapes will still be able to be used for the normal design if this doesnt work . all i would have to do is make  another top section with one inlet.


i wish phil would comment  (and a few more) to add a few ideas or catch an obvious mistake etc.
i am not sure if it will work or not but i will give it a go anyway.

any ideas on how to make it better.

retired2

Quote from: alan m link=topic=729.msg4183#msg4183 date=1341182694

any ideas on how to make it better.
/quote]


Yeah, one inlet!  :)

alan m

Quote from: retired2 on July 01, 2012, 05:55:54 PM
Quote from: alan m link=topic=729.msg4183#msg4183 date=1341182694

any ideas on how to make it better.
/quote]


Yeah, one inlet!  :)

very funny.
i wish i could.
.


phil (admin)

I think the picture shows drops slots that are too wide, and improperly positioned.

If I were you, I'd figure out a way to go with a single inlet.  Multiple inlets are all about compromises.

alan m

that picture isnt to scale . the slot would be the normal 1.25 ".
your opinion on where the slot should go  is what i want your help on.

i think that the solid part of the slot needs to be where the air and dust  would hit the baffel as it comes down off of the shelf and around the  lower section. i am hoping that the slot  on one side is where the air will hit coming around from the other inlet.

do you think that doing a dual inlet design will result in a slightly less efficient seperation or a total loss of seperation.

if phil or anyone else can find a solution to avoid this i am open to it. i cant work out a way to join one line into the other without a very severe u section of pipe.

alan m

hi me again.
i thimk i will try thise.
i am someone that would rather try and see it fail than not try but always wonder.  something is only imposable when a solution hasnt been found and if people dont try  then the solution will never be found.
i havent read anything that puts me off trying it

as i am venting the last of the fines outside i am not too worried about if the efficiency is 95 or 98 % as long as there are no big bits going out.
i am thinking of putting a second baffel inside the ring of my dc unit to try and seperate out anything that  gets past the dual input one.

on the slot detail

i am not sure where that spot  (for the solid part of the the slot ) should be  when the seperater is double the normal height. let alone where it should be for a dual inlet.
i am thinking of using a 3/4 inch baffel but with no solid part. then rebate the bottom of it by 1-2" (creates a thin edge all around as well) and make a coresponding ring to fill the slot where i want no slot.
this piece would be rebated on the top to fit into the rebate on the baffel . so i should be able to put the piece (or pieces ) where ever i want. i will play with the alignment and shape/size etc untill i am satisfied or fed up ;).

at least i will know i tried.

phil (admin)

The baffle right after the inlet should always be snug to the wall of the bin.  For twin slots, I'd do 75 (larger, right under the first inlet), 105 (reduced drop slot), 75 (larger again, right under the 2nd inlet) 105 (reduced drop slot).  Those are in degrees.

alan m

thanks phil . i will start wil that and see how it works

alan m

not sure what to do. i want to build this  (just to prove it to myself that it might work)   but cant afford to redo it straight away . so i am thinking of building 2 normal ones but one going clock wise  and the other anti clockwise. i planed on getting a bigger  dc power scource  but i might use both . one on each .
i was planning on making them the same in every other way  so that we can see if the direction makes a difference.

retired2

Alan, 

Building one separator is a lot of work.  I would never build two just to see if there is a difference in performance between one that rotates with the DC fan rotation and one that is opposite.

If there is a difference, it will not show up in the efficiency of the separation, it will show up in how much air the fan is moving, and unless you have an anemometer or some other way of measuring air flow you will not be able to see or hear the difference. 

I believe rotation direction only makes a difference if you are close-coupled like my separator, and in that situation, rotation in either direction is a problem (see the information I posted several times from Cincinnati Fan).  If you are planning to have a very short length of pipe from the separator outlet to the fan inlet, then just build the separator to best suit your duct configuration and use an air straightener for maximum fan performance.

alan m

i wouldnt build 2 unless it was the only way.
i need 2 because i cant efficiently put the 2 branchs into 1 inlet without a tight u turn. i think i would use the opertunity  of having to buold 2  to test the diffewrence.

i am planig on getting a anemometer to see whats going on

retired2

#28
Quote from: alan m on July 11, 2012, 01:42:13 AM
i wouldnt build 2 unless it was the only way.
i need 2 because i cant efficiently put the 2 branchs into 1 inlet without a tight u turn. i think i would use the opertunity  of having to buold 2  to test the diffewrence.

i am planig on getting a anemometer to see whats going on

I forgot your "U" turn problem, but if two separators solve the problem it is worth the trouble.  Try to avoid a hard turn at the entrance to the fan.

alan m

i am planing on mounding the dc  housing up over one baffel  and using a short piece of flex hose (almost none)  . something like what you have done. . i am not sure about the second seperater  and its dc unit (not bought yet). i might tamperaerally raise the 1st dc unit up  and flex pipe across to the second seperater . the second one wont be as efficient but at least i can  use it untill i can afford to buy another dc unit.

i will make the two the same so that i can conect both to the 1 dc (not at the same time) and cmpare rotational direction.