News:

SMF - Just Installed!

Main Menu
Menu

Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Topics - banderton

#1
I finished a tophat build that started with a 55 gallon drum based dust collector that Cincinnati Fan sells as the model 200s, see pic below, as a 2 stage collector.  It had a 2HP Leeson motor with a 12.25" impeller and 6" inlet and outlets, which was an ok start, but its separation characteristics left a lot to be desired.  It scrubbed the contents of the drum badly and passed about 1/3 of what went into the drum on to the filter bag.  The manual even said to empty the drum when it was 1/3 full or it would start filling the filter bag faster. The bag was a 18 square foot bag of 5 micron knit polyester.  I attached a photo below of how the underside of the drum lid was designed.  There was an elbow on the inlet which would have started a rotational motion except there was also a big 10" diam shroud on the underside at the outlet that was up against the drum side, so any input air would have only gone 1/4 turn before hitting that shroud.
So, I figured this thing could really benefit from a tophat that would do a good job of separation, allow what went into the drum to stay in the drum, and that would enable putting a better filter on it since you'd no longer be sending everything to the filter.
I went with a design that didn't deviate too far from what others have shown on this forum.  My 6" round inlet hose transitions to a 3.5" x 10" rectangle using a floor register from Home Depot.  The body of the chamber is 12" high, so the body is either a 2X high tophat based on the diameter of the 6" inlet, or 1.2X high based on the height of the rectangular inlet.  Anyway, there is 2" of full circle that passes under the inlet rectangle.  I used 0.093" (3/32") PETG from McMaster Carr.  24x48" sheet was $26.  The PETG is very flexible and was easy to form into the tube to go inside the rings.  The interior space is a 21" diameter circle and the outside dimensions of the wooden rings was 24".  I epoxied the PETG into the plywood form and then used silicon caulk  around the outside to ensure a good seal.  The outlet at the top of the separator is a 8" to 10" reducer also from Home Depot.  It further tapers to 7" as it goes into the impeller housing.
I had some 3/8" plexiglass that I'd curb picked that I used to make the actual baffle.  By using clear material for both the sidewalls and the baffle I'm able to look through the side down into the drum and see how full it is directly.  Around the top of the tophat I've got 3 hoist points and I have a 7:1 block and tackle pully I got from Amazon for $14 that I can use to pull the entire tophat up off the drum and tie off with a cleat.  Inside the 55 gallon drum I've got a 55 gallon bag taped.  When the bag/drum is full I'm going to nylon zip tie it closed and tip the drum on its side and pull the bag out.  Haven't gotten that far yet as I haven't yet filled the drum the first time.
I used the 0.5 micron 300 square foot media 9L300NANO filter from Wynn Environmental.  I made an interface flange for it out of plywood and added a gamma lid ring to the bottom of it with a 5 gallon bucket cut off at about 6" so I've got a screw on dust basin at the bottom of the filter.
The entire collector is free standing on top of the drum, which I think is a nice attribute because I can scoot it around if I need to.  Right now I'm just running 6" flex to tools as needed as I don't have 6" ductwork up yet, but you have to start somewhere.
It seems to work really nicely.  Thanks to all the folks that posted their builds before me on this forum.
#2
Does anyone know a source for 6" PVC 2.0 or 2.5 R/D 90 degree bends for SDW pipe (6.275" OD)?  I've found metal long sweep 90s but not PVC.  Thanks in advance.  If I can't find any I may take a stab at making some.

#3
I thought this brochure of cyclone dimensions for various sized models was pretty informative in terms of sizing dust separator barrels, inlet sizes, cfm, and motor sizes.  I'd like to know what folks think about me using these as sort of rule of thumb guidelines for how to size the drum/baffle, inlets, etc.

Kind of putting together the pieces that I thought was useful is summarized in the table below

Diameter-------cfm------motor HP-----inlet size
12 inch--------300-500----3/4 HP-----4 inch
16 inch-------800-1200---2 HP--------6 inch
20 inch------1200-2000---3 HP-------8 inch
24 inch------2000-3500---7.5HP-----10 inch

I bring this up because I've got one of these Cincinnati Fan model 200s 2HP 1100 cfm barrel top collectors on a 55 gallon drum with 6" inlet.  I was thinking about adding a side inlet and a baffle to the barrel so it would have a 24" diameter inside the barrel for the separation chamber.  I am thinking now, based on the table above, I'd be better off making a 16" diameter tophat with a side inlet so I get the higher rotational speeds at the cfm range I'm at.  I'm thinking that for a given inlet airspeed a 16" drum is 50% higher rotation rate than a 24" drum, just based on the distance around, hence the need to match the vessel diameter to the CFM coming in.

Maybe as more of a direct question, is there a target rotation rate we are trying to achieve, which could be arrived at via linear airspeed at the inlet and drum circumference?