filtering help

[treycherry]

Hey all,

any help you can give me would be greatly appreciated. I am using a 10 sq meter velo to filter around 400-500 bbls weekly. can anyone help me with the following questions?:

at what pressures should the brite tank and the fermentation tank be?

what is your precoat & d.e. regimen?

what pressure do you keep the bell at when doing your precoat?

how high is the dosing pump turned to?

...also, I run a caustic on the filter weekly and sanitize it daily, as well as backflush the trap filter and keep it stored with paracetic nightly...any tips/pointers on cleaning regimen?

thank you,

trey

[chaser]

Trey,

It's been a little while but I'll see what my memory can muster up.

The bright tank was kept at about 15 psi so long as the filter was running good. The pressure in the bell is partially a function of the pressure in the bright tank, so if the bell pressure was rising to where I couldn't finish the filter I would drop some off the bright tank. We did not use a balancing line, which I think everyone should do, in which case I would keep both tanks at 10 psi (what I did on other filters at other breweries).

For pre-coat I would fill the dosing tank to the top of the paddle (about 1/3) with beer, then add 15 scoops of DE. I think then we would recirculate with the dosing pump off until the beer in the dosing tank was bright (10-15 minutes). The flow was at 100, and the bell pressure was at 1 (I think). At that point we were ready to filter and would go to the bright tank, turn on the dosing pump, and refill with DE as soon as possible. I liked to fill the dosing tank to the paddle, add DE, then top it off.

I dont remember there being a numeric value on the dosing pump, I remember gauging by the number of turns outwards on the knob, and really it was a visual thing that came from experience and knowing the brightness of the beer coming out of the fermenter. I want to say normal was 2 turns outwards. Dependent on the quality of the beer and the way the filter was running you would have to adjust. I generally started high, then turned it down until I saw the bell pressure rising. During a good filter the bell pressure would not go above 2. At 4 I would start to worry, and just below 5 I would break down and start over. We also always ran at the speed of 100.

We followed the same cleaning regimen, leaving a weak peracetic solution at post-filtration and packing it, and adding 32 oz. more peracetic before the filter run and sanitizing for 30 minutes. Not necessarily the way I personally would do it but I wasn't the boss and it worked fine in terms of lab results.

-Chase

[william.heinric]

Here's my "best practices method" for the 10sqm velo:

Clean before each use. I am amazed that brewers flip over dirty glassware, but pump whatever filth that was in the filter into each batch. And if you're using sanitizer instead of pasteurizing, you have to realize that many sani's will be denatured by the crap you left in there. Even if you do pasteurize, you still have the crud from the previous batches on the walls, screens, etc. The PAA sani is my preference, but you need to make sure that you're purging as much solution as possible (through the outlet and the top bell vent).

Precoat with either perlite or cellulose and de. The weight for the de precoat should be 5kg cellulose and 15kg de (as a mix between your high flow and filter grade). Allow to recirculate for at least 15 minutes on the de at high speed to build a good bed.

As for dosing, you should have about 7-8kg per 3hl dosing tank. Personally, I run that dosing pump full bore for the first 10-15% of the run. You should be seeing 50-70hl/hr during this stage, and under 1 bar pressure. If you're restricting flow with the valve between the bell and the pump, you should be able to increase flow once you see that the yeasty stuff is through. If you're increasing as you go, don't bother to slow the dosing, just build pressure with the main pump. You should be able to get through a tank in a reasonable amount of time.

I find a good 100bbl run passes in 120 minutes, with bell pressure maxing at 3.5 bars. We also don't carb inline, so our BBT pressure is 0. If you're carbing inline, 15psi with a balancing line seems to work the best. A rough (all right, very rough) formula for looking at bell pressure is

I+F+L+H=Bell Pressure

Where F is the degree of clogging in the filter bed, I is the pressure from the main pump, L is resistance across the line, either from lifts or drops or friction on the hose wall, and H is head pressure from the counter pressure as well as the downward force of the beer. So, invariably, you should see increases in bell pressure as the run progresses from at least F and H, and probably I if things are running well.

Just remember, Velo's don't respond well to yelling; PS labelers do, of course, but the Velo is touchy. Just remember not to overload the thing with de, but keep a good chunk of dirt going in there, and you should be a-ok.

Good luck
Bill

[treycherry]

thanks for the replies...it sounds like the pressure your bells get to are way lower than mine, and you run at higher speeds...which is disconcerting. I usually start running with the throttle at 80...and let pressure build up to around 6 bar until I reset. Maybe it's that I'm adding way too much de; my regimen is as follows:

5 kilos silica/2 kilos hyflo; precoat
recirc
5 k hyflo/5 k standard; still precoat
recirc
1 k hyflo/1 k standard; start pulling beer

then as I start filtering, I add 4 k hyflo/4 k standard and let the slurry bell fill close to the top.

...I have heard though that mixing de types can cause uneven beds, ie. some breweries use only hyflo. Any thoughts?

Again, thanks for the great advice thus far.

Trey

[william.heinric]

I mix de, but I'm not sure that we're mixing it in the same way.

Are you adding the silica and the hiflow together in the dosing tank, and then precoating? Same question for the hiflow/standard step.

When I precoat, I hit it with the cellulose (4kg) first, recirc for 10 or so minutes to establish a cellulose layer, then chase it with either all hiflow (for dry hopped beers; 11-15kg), or only 7kg hiflow (for red and blonde as another precoat) and recirc for 10ish minutes. Then I hit is with another 4-6kg standard for 10 minutes so that there are three mostly separate layers: cellulose (15mm), hiflow (20mm), and standard (10mm). Precoat at full speed, with the top bell valve cracked and returning to the dosing tank (this keeps air from building up). DO NOT allow the bell pressure to drop below 0.2 bar, as I believe that 0 bar allows the bed to sag.

For the dosing slurry, pick the smallest grade that you've used. If you precoat with standard, don't bother dosing with hiflow; you're not going to increase the pore size.

I think that the important thing to remember is that you cannot filter slurry. I've tried. It does not go. Make sure you're filtering beer, and start relatively slowly (40-50hl/hr). You can artificially add pressure by partially closing the output valve on the filter, and keep it at about 1 bar. Dose the hell out of it. Once your bell is full of beer (make sure you're dumping sani solution out of the top bell valve), you will have natural resistance in the bed, so you can open the output valve.

Keep it slow, slow, slow, for the first 15+% of the tank, then gradually increase the flow up beer until you're comfy with the rate and bars. A good run for me allows me to run it at about 130+/-hl/hr after I get 15 bbl across. At this point, bell pressure is generally about 0.8-1.2 bar.

Bill

[enickohasan]

I was told by several DE suppliers not to mix DE types during individual precoat stages. You will not gain any advantage and actually can disrupt the matrix. I used to precoat with Hyflo, then run until flow was clear, then add a tighter grade of DE and allow it to have time to settle. Then use the tighter grade for your dosing.

And the most important thing about the DE filter isn't so much the bell pressure, but the pressure differential across the bed. If your pressure differential is low your filter bed is in good shape and any significant pressure is a result of downstream restrictions and backpressure, like the pressure in the bright tank. If you're getting to 6 bar and your pressure differential across the bed is 5 bar, your filter is blind. If you're at 6 bar and your pressure differential across the bed is 1 bar, there's something downstream adding pressure to the system.

[BrewinLou]

Sounds like you are running yours faster than it can remove yeast, or you are not running enough dose/adding enough to the doser.

If your bell pressure is going up, it is telling you either slow down or add more dose. I find the sweet spot is right above one bar. I precoat at one bar, ( you can tell by the sound of the pump when you hit the sweet spot), the filter auto tunes itself to one bar on the CIP run, and runs all around best at one bar. Although as you have found it will run fine at higher pressures during filtration. I do use counter pressure lines. I start both tanks at 9 psi b/c we do force carbonate inline.

[treycherry]

Thanks to all that have replied to this post. You have helped me incredibly and have saved hours of work for me! There is definitely something to be said about not mixing DE types in the precoat...layering them has helped alot.

One more thing though...should the trap filter ever get a caustic wash?

Yesterday I noticed that once I start pushing beer, the pressure immediately rises...and there is no pressure differential. The bbt is also at a low pressure, so I know the trap filter is getting clogged. I've backflushed it, but it seems to keep happening.

So I guess the question is, what do you guys do to prevent the trap from clogging? Cleaning regimen? Backflushing while velo is in recirc?

Many thanks!

[BrewinLou]

Your cartridges may be toast. Sounds like you have been abusing them pretty well. When was the last time you changed them and what type are you using?

[treycherry]

we last changed them on August 30th...I'll have to check as to what kind they were

[Filter Milt]

Trey,
I never saw a response to your issue with your traps clogging, and was wondering if you ever got it resolved?

[treycherry]

I did get it resolved...i'm almost positive a caustic wash would be terrible for the cartridges, and simply replacing them goes a loooooong way. We are running perfectly using the 10 sq meter velo as of now. We pull beer at 175 Hl/hr with much more DE in the precoat. thanks again to all who have helped. Happy brewing!

[schmogger]

I did get it resolved...i'm almost positive a caustic wash would be terrible for the cartridges, and simply replacing them goes a loooooong way. We are running perfectly using the 10 sq meter velo as of now. We pull beer at 175 Hl/hr with much more DE in the precoat. thanks again to all who have helped. Happy brewing!

What is your precoat and dosing rates now?

[treycherry]

schmogger,

sorry about the delayed response.

precoat is 5 kilos cellulose & 2 kilos hyflo.

Then 8 kilos hyflo & 8 kilos standard.

the body feed starts with 2 kilos standard and 2 kilos hyflo

once beer is moving, i fill up the slurry bell and add 7 kilos hyflo & 7 kilos standard.

the dosing rate is all feel...the dosing meter falls out when we vibrate the filter, and it breaks quickly. but I do start with the dosing rate fairly strong.

[yukonbeer]

Just wanted to check what you are using for a trap filter. I've been wanting to add something in some of our filtering circumstances to capture wayward DE, which I asuume is what you are using a trap filter for.