DE Filtration- Vertical Velo 3

[EdmontonBrewer]

Hello all. I never used a DE filter before today and I need some help.
Had some troubles getting an even precoat over the vertical screens. When I cleaned the filter afterwards the DE cake only reached half way up the screens.
Here's some further info:
-15 hl filtered in about 20 minutes (looked clear)
-Pressure never climbed above 2 bar- with no dosing
- followed the manual step by step (for what it's worth)
- Recirc's for precoats seemed to be okay
- As I filled the unit beer drained out of the bleeding valve before I closed it (no entrained air pockets).
- Didn't crack valves..if the manual said they needed to be opened they were opened full bore.

Anybody have any tips to improve next run so that I can actually filter through DE instead of just screens?

Thanks,
Joe

[bruboss]

DE filter

Hi Joe

Sounds like you do not have enough DE in your setup.
If your recirc. is right then you should see a rise in pressure when the screens are fully coated.
How clear is your beer prior to filtration?
If you are filtering just through the screens then you are not really filtering at all, as the DE is what closes the mesh gaps to fitration size.
Experiment with water to see how much DE you should need to coat your screens.
You could also try different grades of De to see which is best for you in terms of speed of filtration and clarity of product, your De supplier should be able to help you with this.

Good luck and let me know what happens, I am always interested in filtration issues.,

Chris

[sbradt]

Are you using any kind of a coarse cellulose in your precoat? I've found, with a vertical velo, that it can be difficult to get good, even precoating of the screens using D.E. alone. We currently use the Celite #BH-100 in our precoat, adding in one lb. with the DE. It forms a bridge over the screens for the DE to pile up on

[EdmontonBrewer]

Still seeing issues

Thanks for the advice so far but I'm still having issues. How do you properly use the "Bleed Valve" on the top of the filter bell for precoat? The manual says to close it once the dose tank and the filter bell are full, then add your DE and start precoating. Following this method-no go.

I was told by a few people that you have to bleed while precoating which logically makes sense. The water/DE mix from the dose tank is pumped to the filter bell, bleeds out the top and back into the dose tank. Within 5 minutes using this method the liquid is clear so you'd think that the liquid/DE contact moving up the screen would apply the DE to the screen?

I did try the 1lb cellulose mixed with DE which helped a bit but the top 40% of the screens look pretty clean when I open the unit. Is it possible that as the water drains from the filter bell that it drags the DE off of the screen making it appear that it wasn't applied? I am seeing nice application for part of the screen but at the bottom of the bell is a blob... so it doesn't appear that I'm using too little DE.


For those of you who use vertical DE filters, when you remove the screens do you see an even coat over the screen, if so how thick?

I think it'll be a late night

[EdmontonBrewer]

Solved

Figured it out, just had to adjust the valve leading to the dose tank from the filter bell during precoating. Throttled until it was 2 bar and got a beautiful cake.
JOE

[oppigards]

de filtration

after sterilizing,

fill filter bell completly by circulating water through dosing chamber and open the bleeding valve on the top of the bell to remove all air from the bell.

fill half of the dosing chamber

start dosing pump

add pre coat (hyflo or similar) (I add 1 kilo / sqm, might be too much but it works) and let it circulate for a few minutes. This should make an even layer of all screens.

Stop pumps and empty the dosing chamber first, then you can empty the bell with co2 from top of the bell, drain the water backwards to the connection of the lagering tank, then you have purged both filter and hoses with co2.

Purge the dosing chamber with co2, bleed the dosing chamber with co2 during the hole filtration

[Woolsocks]

Water precoat

I've always precoated with beer, not water. Doesn't draining the water after precoat and then filling with beer mess up your DE coat? Or can you just add beer and then recirculate for a while?

[oppigards]

yes, when filling the bell with beer after co2 purging out the water, I fill the beel with beer by gravity and start dosing in kiselguhr. I have no problem with uneven layers with precoat. Of cource you get some´precout out with the water but not that much.

[dick murton]

Hang on Oppigards - I thought you had a horizontal leaf filter, not a vertical leaf filter. There is a world of difference in what you can do between the two.

[oppigards]

I am sorry

Yes Dick, you´re right. I have read this thread badly. My comments above is my experience from a horisontal DE filter.......

/Bjorn

[EdmontonBrewer]

Clarification

I should clarify, my precoating practice rounds were with water but "in real life" I use beer. Did not precoat then empty to bring in beer for filtration...when the vertical screens are coated I don't want to screw with 'em.
Joe