View Full Version : What am I doing wrong?

01-17-2011, 07:45 PM
All right, here's the deal...

I'm having big trouble getting more than 10 barrels across our 10 square meter Velo without blinding the thing. I've tried DE (Pre-coat with cellulose, follow with FW14 and then FW12) which blinds generally in 7 barrels, and Perlite (cellulose plus perlite pre-coat, I'm not sure about the grade) which takes about 15 barrels to blind.

Things to note: there are two screens in the main body of the filter that are warped. They were warped when I started playing with this thing, but my filtration has taken a strong downward turn with DE and is starting to jam up on the Perlite.

I've found that over-dosing has been an issue, but I don't think that I'm pushing too much into the body feed any more. So, what the hell is going on? Turbidity is variable, and there is of course a correlation between the turbidity on the inlet side and rapid pressure builds.

I'm pre-coating at 100-110 hL/hr, with 0 bars pressure (I've done it with DE at 0.5 bars and 60 hL/hr during the pre-coat with similar results), at the Velo-recommended level of 5 kg cellulose and 15 kg DE, but I've done less (20% by weight) and more (5% by weight). Even after taking notes, I'm not seeing any trends in the data, and I think that I'm going to have to go after the thing with a hammer just to keep my sanity.

If anybody has any leads, please let me know.


01-18-2011, 02:28 AM
Have you checked the filterability of your beer? The warped plate could cause a problem but a 10 sqm filter should be able to for 10bbl very comfortably

01-18-2011, 06:38 AM
I guess the first question is ' Has anything changed recently?' (new yeast, new tanks, new sprayballs, new filter)

Was your current regime working for you before?

Have you caustic/acid washed your filter recently?

The one thing I would suggest is varying your speed/pressure between precoats to to ensure each precoat is firmly packed on the last before proceeding.

Also, I guess, to ensure you are dosing at the highest possible setting during initial fill with beer after precoating with water and blowing it out. Adjust dosing downwards based on relative incoming clarity.

I find that initial 10 minutes of filtration can be dangerous in terms of 'slugs' of yeast blinding the filter cake. Mega-dosing can alleviate/mitigate that somewhat.

Good luck.



01-18-2011, 11:22 AM
I've only worked with this particular Velo for 3 months (I have played with a 5 square meter for quite a bit longer), and there was no cleaning regimen in place when I started on it. The 'cleaning' consisted of pasteurizing the unit before each use, then rinsing it out after the pass. Soil loads were very high when I started on it.

Now we're caustic cleaning before each filtration, with an acid cycle included on every fourth or fifth filtration.

Tank CIPs are constant, yeast is fresh from the lab (biggest problem has been with Koelsch yeast).

Liam, I will start dosing the hell out of it on the first 10 bbls, then cut it back to more reasonable levels on the final 90 bbls. I'm hoping that will work.

Thanks, and any other suggestions would be appreciated.


01-25-2011, 09:35 AM
1. Of course make sure the beer your filtering is as clear as possible. Are you using irish moss in the kettle? I've seen this make a significant difference. Use a more flocculant yeast. Get all that yeast out of the tank your filtering from.

2. Use significantly more DE/perlite in the pre coat.

3. Slow down your flow rate during the filtration.

4. Increase your dosing rate to maximum. I never noticed such a thing as "over dosing".

5. Increase the concentration of DE/ perlite in your dosing tank

6. Most importantly allow no yeast to enter the filter. Even small amounts will bind the filter.

Good Luck!