DE filtration issue

[BelgianBrewer]

I have used DE filters for well over 6 years now so I should know how the system works. At least that is what I thought.
Recently I purchased a used DE filter and when I started working with it I ran into some problems.
The coating with the rough DE works great, liquid clarifief, no problem.
The inline adding of the fine DE goes fine for the first barrel and a half, then the beer becomes cloudy.
It happens always around the same time. There is also getting a small amount of fine DE into the beer, but not a lot.
Any ideas? I have some myself but want to get some feedback before I get into this.

BelgianBrewer
www.sbmbrew.com

[Twonk]

This is exactly whats happened to my last few filtrations as well! Its been driving me demented so any help would be very much appreciated by me too.
Cheers,
Dave

[LCSam]

Hey guys, I was running into this problem with my DE filter for a while too. I found out that I had a bad seal on my dosing pump which was pumping a small bit of air through with the dose, causing the very problem that both of you mentioned. Air pressure built up at the top of the filter housing, and I surmise that it does not allow the filtration to take place with the same effect of consistent liquid pressure.
The other thing I would check is the seals in the filter housing itself. It would be really easy for DE/dirty beer to pass through if a seal is bad, unseated, or the column is just not tight enough.
I'm waiting on seals for the dosing unit currently, and have a filter on loan from another local brewery, so I guess I will know more once I rebuild the dosing pump.

Just my $.02
Cheers,
Sam

[BelgianBrewer]

LCSam,

Thanks for your valuable input.

When you say you had a bad seal on the dosing pump, are you talking about a seal in the pump itself or some gaskets in the DE line feed that ties into the beer line after the pump?

And how did you notice that there was air as the DE bas being dosed? It goes in pulses and is hard to impossible to see. Could you give me some advice on this?

I have never taken the "tree" down. Any recommendations before I get into this?

All help is appreciated...

BelgianBrewer
www.sbmbrew.com

[RobZamites]

I used a Velo 5 and 3 and the symptoms you describe happened when the nut holding the plates in place loosened. Repeated cycles of hot/cold with caustic and acid sanitizer cause the nut to back off, allowing DE to leach throuth the gaps and screw up the filtration run. Run a hot caustic cycle, drain, pop off the bell and crank down the nut. I can almost guarantee a flawless run next time out. I made the "nut cranking" a part of my CIP procedure on the filter *every* time after that, and had no further issues.

Cheers,

Rob

[BelgianBrewer]

I used a Velo 5 and 3 and the symptoms you describe happened when the nut holding the plates in place loosened. Repeated cycles of hot/cold with caustic and acid sanitizer cause the nut to back off, allowing DE to leach throuth the gaps and screw up the filtration run. Run a hot caustic cycle, drain, pop off the bell and crank down the nut. I can almost guarantee a flawless run next time out. I made the "nut cranking" a part of my CIP procedure on the filter *every* time after that, and had no further issues.

Cheers,

Rob

Why do you tighten the nut after hot caustic? With heat things expand and you filter around 34F? Will this not allow more room between the seals and filtering disks when filtering?

Two more questions: is there any risk of overtightening and how often do you replace your seals in the "tree"?

I am shooting for filtering on Saturday. I will give you an update afterwards.

Thanks for all your help!

BelgianBrewer
www.sbmbrew.com

[RobZamites]

It's the cycles of hot/cold that seemed to make the nut loosen. I tighten after the hot cycle because after that, I flush and sanitize cold, and don't like popping the bell off and exposing the freshly sanitized innards.
I suppose it's possible to overtighten, but I'd just crank it down until it was "arm-tight" (as opposed to '"finger-tight", I guess) -- I haven't owned a Velo long enough to worry about the gaskets, but they seem pretty damned durable.

[Twonk]

Caustic'd it, cranked it, filtered it - bright as a button!
Thanks Rob.

[RobZamites]

Yay! The great thing about these forums is the free flow of ideas/information and the willingness of the members to share with each other -- glad I could help :)

Now, go have a beer :cool:

[BelgianBrewer]

Thank you guys for all the help. We filtered yesterday and it went great!

BelgianBrewer
www.sbmbrew.com

[LCSam]

Congrats BelgianBrewer!

Glad it worked.