top hat with inside filter

[lakrissen]

Has anyone tried making a top hat and placing a cylindrical filter as center suction ... i plan on trying it because i need the filter to protect the blower assembly from overflow ... but i also would like the extraction of particles to the bin for convinience

Plan is as follows:
Top hat cyclone 12 inches high 15 inches diameter with 4"round inlet gradually transitioning goind half way round to a thin slit about half inch ... the seperator slot would be 1 inch ... and the automotive filter i got is same height and outer diameter is 6,5 inches

Best regards from dk

[retired2]

Has anyone tried making a top hat and placing a cylindrical filter as center suction ... i plan on trying it because i need the filter to protect the blower assembly from overflow ... but i also would like the extraction of particles to the bin for convinience

Plan is as follows:
Top hat cyclone 12 inches high 15 inches diameter with 4"round inlet gradually transitioning goind half way round to a thin slit about half inch ... the seperator slot would be 1 inch ... and the automotive filter i got is same height and outer diameter is 6,5 inches

Best regards from dk

What are you using for a blower, a shop vac or a larger volume dust collector?

[phil (admin)]

I've been tempted to try it w/ my shop-vac based system but prefer having the bag in the shop vac act as the first line of defense.  No matter how good a separator you have, some always gets by and the vac bag (in my case) catches almost all of it and the final filter stays more-or-less clean.

[lakrissen]

The suction is a 10 hp high performance  side channel blower  ... mainly because i need the high pressure and air flow to move paperinsulation  ... max airflow is 600m3 pr hour  and max vacuum is 0.45 bar

[lakrissen]

I've been tempted to try it w/ my shop-vac based system but prefer having the bag in the shop vac act as the first line of defense.  No matter how good a separator you have, some always gets by and the vac bag (in my case) catches almost all of it and the final filter stays more-or-less clean.

I'd like the filter/protection inside the tophat to save space at the blower placement ... its tight enough there already :)

[lakrissen]

I can live with about 0.15 bar max vacuum at the intake side without losing too much pressure on the output of the blower ... which means i could use that to hopefully get even better fine dust seperation and perhaps not clog the filter to much to quickly

[jdon]

Call me thick headed (I don't mind  :) ), but I'm having a little difficulty visualizing how the filter would be situated in the separator chamber. It's not clear from your description, but it sounds as though the filter is the same height as the top hat (12 inches), so I picture it as sandwiched (and sealed) between the baffle and the top plate of the separator. If so, then all outlet air would pass through the filter side walls.

From what I've picked up on this site, I see a couple of potential problems with the design. First, I assume that the filter has exposed pleats, which will likely create a lot of turbulence, so will impair performance.

Second- and more critical- if air is passing through the entire height of the filter, you're going to get a lot of bypass: air (and dust) that will hit the filter before they get a chance to separate at the baffle.

Third- the transition from 4" round pipe (~12.6 sq in area) to a 1/2" slit (if 12" high = 6 sq in) sounds like a real bottleneck, creating a lot of resistance to air flow. Please verify my math, but 600 m3/hour =  10 m3/min = 353 cfm, which is just adequate for 4" duct. I'm not sure, even with the great vacuum your blower can draw, how much that resistance will affect performance.

Finally, to me the thought of disassembling a separator to clean or replace a filter, then making sure that its airtight on reassembly seems like a real chore.

Sorry, I don't mean to be a Debbie Downer- just want to throw out some potential pitfalls as I see them. If you have the time and energy, It would be interesting to see how your design actually works. Good luck!

[phil (admin)]

Well if you've ever seen the final filter stage on a 10-HP cyclone, now imagine putting that INTO the top hat.

I'm afraid it wouldn't be practical.

It would be doable on shop-vac based systems but not a 10-HP blower-based system.

[lakrissen]

The point is the blower is there to deliver enough volume to make airspeed in a 3inch hose move at around 7feet per second at various pressure due to length and height of hose for ceiling insulation .. for walls its constant pressure and various pressure dependig on blowertip size .... and the air for the blower is being sucked from the feeding chamber through the baffel/filter to keep dust from escaping the machine

[lakrissen]

Data is about max 50 cfm at 0,4 bar normal condition ... and tripple cfm at turbo mode

[lakrissen]

I have attached a sketch of my idea for the top hat .... it is massive i know but the barrel is 600mm in diameter ... the top hat rougly the same