Camfill Farr Hemipleat filters

R

R and D Nikkel

New member
We needed to replace filters and the old #125154-005 filters (comparable with the Wynn 9L300BL ones)were replaced with the "new and improved" #211736-1 HemiPleat filter about 3 years ago, so we got a couple of those. Got them up and running today, and the dust coming through these is setting our Dylos meter to over 2000 at the 1 micron setting. The old ones had the dust levels less than 200. Rod lasted about an hour using the bandsaw and changed to venting outside again, but it is already at freezing and winter is coming! Their specs say they get 99.99% of 0.1 microns. These ones sure don't.
Is anyone else using these filters (Don01 said he bought some last year)? Any problems? How are they working for you?
 
Farr Tenkay Mark IV Cartridge

Farr Tenkay Mark IV Cartridge

I don't have mine running yet. The spec sheet I have for the 211736-1 rates them at 99.99% @ 0.5 micron. They are 177 sq ft per cartridge. I have attached the brochure I received.

This guy has answered all of my questions

Jonathan Cooper
Aftermarket Technical Support
FARR Air Pollution Control
Proud Member of the Camfil Farr Group
Phone - 870-910-7176
Fax - 866-639-7151
cooperj@farrapc.com
www.farrapc.com

There shouldn't be much over 1 micron coming through. Is there possibly a rupture in the media or a leak?

Don
 

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Don,
Thanks for your reply. Yes, it is 0.5 microns. This amount of dust was coming from both filters. No visible damage to them. The readings come by holding the dust meter right over the exit from the filters. And you can see it climb when he makes a cut. Haven't heard back from the company yet. I'll have to call them today.
 
Filters

Filters

Hello Rod,
Have you had any response from Camfill Farr re your filters. I have been monitoring this thread and it seems few are using these filters as there have been no comments.

Fred Alexander
 
We have talked with them. The reginal manager in Winnepeg was quite concerned since they shouldn't be doing this, but we can't figure out why this is happening, especially since it is both filters that are putting through a lot of dust. We did a test with the side grinder in the dirty room and the numbers were over 12,000 of the 1 micron dust particles coming through in 0.01 cubic feet of air. He was going to get his dust tech people to contact us, but that hasn't happened yet. With both filters doing this, it makes you wonder about our set up, but we sure can't see how the dust is getting around the filters - not when we are testing the air stream coming out of the filters themselves. He did order more filters for us and is willing to send them out, but they take 2 weeks to get to Winnepeg from the US, then up to us. Good thing the weather is still unseasonably warm!
 
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Filters

Filters

Those numbers are way off the richter scale so there must be some fault in them. This is your second set of filters I think, did the first set "blow a hole" or just that they were cleaned the maximum number of times? I think that you mentioned way back that the system is used in a business so the filters are getting daily use. How long did the originals actually last and work effectively?

Fred
 
Fred,
We use a large sander a lot, and a carbide carving disc on a side grinder in a special "dirty room" (6 x 8) made for that purpose even more. The grinder especially can be in use 4 plus hours a day. I believe we make a lot more fine dust with these compared to what is commonly made by a hobby woodworker. (Comparing the readings of 2000 with the band saw to 12,000 within a minute of using the grider tells us the comparative quantities of fine dust produced.) The problem is with the amount of fine dust we make and the difficulty and time spent cleaning in the inside of the filters because our system had two of the old style Camfill Farr filters with the air flowing inside to out like Clear Vue suggests. We decided to build a box where we can filter the air outside to in, the way they were meant to work, which would make cleaning much easier and more efficient. We have also figured out a way to back flush, not as the professionals do, but simply by hooking up the outflow from the cyclone (making sure it is only sucking CLEAN air) to the outflow side of the filters one at a time while blocking the other one. The normal inflow tube to our filter box will be temporarily hooked up to our outside vent. We figured that if we put a few minutes of air from the cyclone "backwards" through the filters once a month, that would do a much more efficient job cleaning them than we do with a compressor and vacuum. We hope that most of the dust will vent outside. Anything else we can vacuum from the inside of the box, and then connect it to run normally again.
So, we can't use our old filters because they are very dirty on the inside now, so we bought the new, improved model from Camfill Farr, and are getting horrible readings through the filters. It only has had about an hour max collecting from the bandsaw and about 5 minutes testing from the grinder in the dirty room. And we can't use the old set up since we scavenged the bases from those filters to make our cleaning system and thus they are destroyed now.
So, our question is - has anyone tested the Wynn or Farr filters when they were brand new? Do they pass more dust than their literature claims until they are "seasoned" or did we just happen to get two defective filters? Or is there another answer we haven't thought of?
 
Wynn Filters

Wynn Filters

R and D Nikkel,
I noticed that my Wynn filters filter much better after seasoning but I do not have good numbers. I consistently get lower readings on my 0.5 um Dylos and the numbers drop faster with seasoned filters. It was a long gradual thing for me because I don't make all that much dust. The pressure drop also has risen from 0.35" to 0.5". If you go to the Wynn site (http://www.wynnenv.com/cartridge_filters.htm) and click on ASHRAE 52.2 Efficiency Chart you will see that there is a big difference in filtering between the first loading and the fifth loading. But the numbers you're getting seem overly high.
bababrown
 
Thanks. I hadn't studied the graph carefully before. So if I am reading it right, the filters will pass about 50% of the 1 micron dust when they are brand new. I wonder what they consider a "loading" to be - filled enough they need cleaning?
When we started up with the first ones we were going from 2" of dust on the floor at the end of the day to having a cyclone, so anything was better than that. Going from "fully seasoned" filters to new ones is obviously noticable. Maybe we just have to wear masks again for a while and then do a total shop clean when the filters work better. Not quite what we were expecting. And we will have to report back on what happened post cleaning too. I am sure our cleaning will be much more thorough with the cyclone doing it backward rather than us trying to vacuum from the inside.

Bababrown, what kind of numbers did you start out with and what are you getting now? Rough figures are fine. Just wanting to compare.
 
Rough Numbers

Rough Numbers

When I started I would run the CV-1800 as an air cleaner and I would go from about 1800 on the 0.5 um Dylos down to maybe 300. Now I commonly get down to 100 and if I blow the shop down well I get down to 20. When I sand hardwood bowls with a 2" disc in a high speed drill and with the lathe running I usually can keep it below 1500. At times I might get 2500 if I'm a little careless with the dust guards. I get about half those numbers if I turn pine bowls. I don't know why that happens but I would guess the particles are larger. It takes about 15 minutes in my small shop to clear the air after I stop sanding.
I think you should run the filters for a while (wearing a mask) and see what happens. Also, check for leaks at the bottom of the cyclone. It is almost unbelievable how little dust I get in the filters.
bababrown
 
Thanks for your answer, bababrown. It is hard to compare the .5 micron to the 1 micron tester results, but with the 1 micron, when our filters were "well seasoned" we were getting readings less than 200 and not uncommonly less than 100 when the system was running. So we know it was working.
After extensive work, testing, experimenting and getting good advice and help from both Ed and Bill Pentz, we have personally come to the conclusion that if you make a lot of FINE DUST - ie sanding with a belt sander and, in our case, using a side grinder with a carbide wood carving disc - you do get more dust in the filters WITH NO LEAKS than you would think from reading the forums. I'm interested in seeing how much goes into the filters, since we can now tell for sure with our new filters. I know it will be more than the teaspoon or even cup that we regularly hear about. But then our system gets used more heavily than most too.
When we hear back from the Farr people we will report back and let everyone know what we find out.
 
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Re evaluate caking process

Re evaluate caking process

DENISE & ROD,
It seems like most of you dust is well under what the filter nominal pore size is AND what the cyclone is capable of physically separating.
Typically filter media is not .5, 1.0 or what ever the stamped rating is right out of the box. The number is usually nominal.
The dust stream is a mixture of particulate. Then the cakes builds as successive layers of particles begining to cling to the surface, coarser traps less coarse all the way up. You dust stream is not typical due to the type of material you work with, but I will guess that the particle distribution is very predictable. If I recall you use a resin type product not wood- correct?

I would suggest you blow these filters out, then run as much sawdust as you can get you hands on through the cyclone. You will need lots because according to Pentz, mores than 90% should never see the filters. And you folks generate more fine dust in 4 hours than most of us will in our lifetimes. :eek:
As strange as it may seem, I think you need some in the 1 micron to .6 micron range, and quite a bit of it to start.
If I am right, your air quality should start to improve soon. The down side is the filters may require cleaning more often, but as long as you have a good cake,the media pores will not get plugged with fine dust. You vacuum off the cake and start again with sawdust or perhaps some similar material that will cake but not clog. Perhaps Camfil-Farr can advise. If they think you are dealing with wood dust they to are going to be baffled.

When I was a lifeguard, we had to backwash the pool filters at least twice a day, sometimes more depending on the crowds. The media was coated with diatomaceous earth (DE). When we backwashed, all kinds of bugs, gum, crud and yuck would come off and go down the drain. We would then re-season the media with DE solution. This recycle would continue until the media was trapping all visible DE and the sight glass was clear. We would then switch the circuit from the DE unit to the main pool and go until the gauges showed flow reduction.
Obviously, had we not coated the media with a good cake, all of the bugs, gum, hair, body and sun tan oil would clog the media in no time.

A long wind explanation as to why a good cake is important for all of us and especially you folks as your dust is likely consistently finer than most wood working output.

Some thoughts for a Saturday.

Don
 
Don,
You must have us mixed up with someone else. We're doing woodwork in our shop - pine, yellow poplar, birch and maple mainly.
I understand how seaoning a filter will make less come through it. But really, "seasoning" is just a nice word for "starting to clog", right? And clogging, to whatever level, affects the air flow (or water flow in your example) enough to affect the efficiency of the whole system. So I guess walking that line is what decision about when to clean is all about. And what happens after you clean too.
The regional manager actually e-mailed me again today (on a Saturday - I'm impressed! He's back in town) with some interesting material on the testing procedure. I'll post more when I get a better understanding. Let's just say that for now I understand more about how you have to know the terminology used pretty well to figure out what they are really saying in terms of test results.
 
R and D Nikkel said:
Don,
You must have us mixed up with someone else. We're doing woodwork in our shop - pine, yellow poplar, birch and maple mainly.
Click to expand...

Sorry, I thought you made saddle trees out of something other than 100% wood.

I understand how seaoning a filter will make less come through it. But really, "seasoning" is just a nice word for "starting to clog", right? And clogging, to whatever level, affects the air flow (or water flow in your example) enough to affect the efficiency of the whole system. So I guess walking that line is what decision about when to clean is all about. And what happens after you clean too.
Click to expand...

It may sound like seasoning is clogging, but as in my swimming pool filter example, it is the seasoning that protects the media. If you can season your filter with dust that is greater than 1 micron or so, the dust fibres will bridge the pores in the media, trapping the finer particles in the outer surface of the cake. You want the clogging to occur on the surface of the cake not in the pores of the media.

The regional manager actually e-mailed me again today (on a Saturday - I'm impressed! He's back in town) with some interesting material on the testing procedure. I'll post more when I get a better understanding. Let's just say that for now I understand more about how you have to know the terminology used pretty well to figure out what they are really saying in terms of test results.
Click to expand...

You will soon be the official filter guru :D
 
So here's the scoop. Straight out of the box, the 80/20 blend filters (the Wynn 9L300BL or the Camfil Farr 211736-1 HemiPleat) only capture about 50% of the 1 micron dust, and less than 30% of the .5 micron dust. This link on the Wynn site http://www.wynnenv.com/filter_efficiency.htm shows the actual results when the filters are tested when brand new, and I have received information from Camfil Farr about their filters which show very similar results. This means that until the filters are used or pre-seasoned, they pass a LOT of the very dangerous dust. The rating given to them is MERV 10 (despite what the Camfil Farr brochure says about them being MERV 12 - that is old data). This is a good link that helps to understand what a MERV rating means: http://allergyclean.com/article-understandingmerv.htm

So then, why do they claim 99.99% efficiency at 0.5 microns as Wynn does on the link above and Camfil Farr does here http://www.farrapc.com/literature/products/hemipleat.pdf ? This last link gives the answer in the added word "by weight". This is part of the old ASHRAE 52.1 test. I quote from a Camfil Farr Technical Service Bulletin: "A 5-micron size particle has a relative weight of 125. 125 1-micron size particles have a relative weight of 125. If 126 particles (one 5-micron & 125 1-micron particles) are fed to this filter, the one 5-micron size particle is captured and the 125 1-micron size particles pass through. This filter may be deemed efficient at removing 50% contaminant by weight. However, the efficiency of this filter by particle count is 1/126 of 0.088% or less than 1%." (Italics added) So the newer test checks actual particles while the older one tests weight. So when using this test, it can look like most dust is being caught when actually most of the smallest (more worrisome) dust is passing through but almost all of the larger, heavier particles are being caught. This is still a very common way of describing the capacity of filters in the industry, but then people in the industry should know what it really means. The rest of us are mislead because we don't understand what it means and expect it to mean 99.99% of the particles down to 0.5 microns (and the Wynn site doesn't even use the words "by weight").

Now this is BRAND NEW. The Wynn links shows (and Camfil Farr has sent me the testing on theirs) that as the filters are loaded their efficiency increases. The test puts 30 gms of material into the filter (doesn't seem to depend on size of filter and they don't say what size particles are in that 30 gms) initially, and then repeats that 4 more times without cleaning the filters. As there is more material in the filters, they work better. Neither give data on the increase in resistance, and therefore the decrease in air flow, due to the loading. But this is what is happening in practice in our shops, and I know that our old filters did keep the air really clean as tested by the Dylos.

In fact, these companies (at least Camfil Farr) actually sell "precoat material" to season your filters with before you use them. This dust has an average size of 40 microns, and the instructions say: "If the material to be collected is small in particle size (predominantly under 5 microns), oily, sticky or otherwise unfriendly to the cartridge, longer cartridge life and higher initial efficiency can be achieved by pre-coating the cartridges." The idea is, as Don01 stated, to coat the filters with larger particles that trap the smaller ones and, from the sounds of it, make it easier to clean the smaller particles out.

It finally got cold enough that we had to start using the filters. Within a couple of hours using the grinder the number of 1 micron particles coming out of the filter was between 3500 and 4500 as opposed to the 12,000 right at the beginning. Still far from good, but a whole pile better. And they will continue to get better as we get more dust into them. We don't have the ability to test to see increase in resistance or decrease in air flow due to the loading, but lots of air is still moving for sure. It will be interesting to see what comes through after we clean them the first time - if they stay relatively good or go back to passing more fine dust again.

So the practical application of all this? Brand new filters of this type still spew a lot of fine dust for a little while. So wear your masks for a while when starting new filters and be prepared to do a good shop clean after they get seasoned enough to trap the smaller particles. Or go the extra bucks and buy the filters labelled MERV 15 (Wynn 9L300NANO) or MERV 16 (Camfil Farr PTU-Poly-Tech Ultra High Efficiency) that really do trap 95% plus of the 1 micron sized dust when they are right out of the box. And look forward to spring when you can vent outside again.
 
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