Hey guys,
We just started using a 3m^2 Velo Export DE filter (vertical leaves) a few weeks ago. I've filtered one 60bbl batch with it so far, and it was sort of a disaster. We had to break the filter down twice during the course of the filtration because the filter kept getting clogged. I tried filtering another 60bbl batch yesterday, but I gave up after spending 3 hours filtering about 5bbl.
Things would start out ok - the flows we had in the first 5-10 minutes were pretty good. The filter manual suggests that we should aim for 20 hectoliters (~17bbls) of beer per hour, and we've tried to maintain that flow rate (as measured by a sanitary flowmeter we have going into the BT). But within 30 minutes or so, the pressure in the filter chamber starts gradually rising until I have to throttle down the pump so much that the flow slows to barely a trickle. I'm hoping some people with experience can take a look at our process and let me know if I'm doing something wrong.
Here is the process we've been using:
-Run a caustic cycle through every nook and cranny of the filter
-Rinse the entire filter, and then run sanitizer through every nook and cranny
-Drain the filter of sanitizer, and purge out remaining sanitizer with CO2
-Purge out the O2 in the filter chamber with CO2, bleeding off some CO2 through the top valve in order to send a blanket of CO2 into the slurry chamber
-Gravity feed cold beer (usually 32-34 degrees) into the filter chamber until it's completely full (it's pretty obvious when the chamber is full - there is condensation almost immediately on the outside of the chamber)
-Fill slurry chamber with beer just to the top of the agitator (this is about 1/3 of the slurry chamber)
-Add 5 lbs of Perlite 27M to the slurry chamber and allow to thoroughly mix with the beer (the manual indicates that we should use 4.5 kg of DE, I'm adding roughly half that weight in Perlite)
-Precoat filter leaves and recirculate until the beer runs clear (this only takes like 3-4 minutes, which is encouraging because I feel like we're at least getting precoat right!)
-Recirculate the filtered beer while loading the slurry tank with beer (to the top) and 15 lbs of Perlite 27M; mix well (slurry tank is completely isolated during this step)
-Begin filtering beer at a rate of around 20 hectoliters (~17bbls)/hr
-Open the dosing pump wheel fully in the beginning of filtration; back it down when the incoming beer is a bit clearer
At the beginning of filtration, the pressure gauge reads around .5 bar. After about 30 minutes, however, it starts going up - not rapidly, but steadily. It gets to around 3-4 bar within 10-20 minutes if I don't throttle down the valve after the filter pump. I can only get about 2-3 bbls filtered before the pressure gauge hits 5 bar and the flow decreases to a trickle. When I broke down the filter yesterday, I removed the leaves to examine the caking. There was definitely a thicker cake at the bottom of the leaves, and I'm not sure how to correct this to get more even caking.
I should also mention that the beer I tried to filter yesterday had been cold crashing at 32-34F for 7 days prior to filtration. And, I cropped off all of the yeast (San Fran lager) prior to starting filtration from the racking arm. So, it was fairly clear going into the filter.
Any suggestions on where I'm going wrong? I have to believe that this filter is capable of a greater throughput rate than what we've been getting.
Cheers,
Matt
We just started using a 3m^2 Velo Export DE filter (vertical leaves) a few weeks ago. I've filtered one 60bbl batch with it so far, and it was sort of a disaster. We had to break the filter down twice during the course of the filtration because the filter kept getting clogged. I tried filtering another 60bbl batch yesterday, but I gave up after spending 3 hours filtering about 5bbl.
Things would start out ok - the flows we had in the first 5-10 minutes were pretty good. The filter manual suggests that we should aim for 20 hectoliters (~17bbls) of beer per hour, and we've tried to maintain that flow rate (as measured by a sanitary flowmeter we have going into the BT). But within 30 minutes or so, the pressure in the filter chamber starts gradually rising until I have to throttle down the pump so much that the flow slows to barely a trickle. I'm hoping some people with experience can take a look at our process and let me know if I'm doing something wrong.
Here is the process we've been using:
-Run a caustic cycle through every nook and cranny of the filter
-Rinse the entire filter, and then run sanitizer through every nook and cranny
-Drain the filter of sanitizer, and purge out remaining sanitizer with CO2
-Purge out the O2 in the filter chamber with CO2, bleeding off some CO2 through the top valve in order to send a blanket of CO2 into the slurry chamber
-Gravity feed cold beer (usually 32-34 degrees) into the filter chamber until it's completely full (it's pretty obvious when the chamber is full - there is condensation almost immediately on the outside of the chamber)
-Fill slurry chamber with beer just to the top of the agitator (this is about 1/3 of the slurry chamber)
-Add 5 lbs of Perlite 27M to the slurry chamber and allow to thoroughly mix with the beer (the manual indicates that we should use 4.5 kg of DE, I'm adding roughly half that weight in Perlite)
-Precoat filter leaves and recirculate until the beer runs clear (this only takes like 3-4 minutes, which is encouraging because I feel like we're at least getting precoat right!)
-Recirculate the filtered beer while loading the slurry tank with beer (to the top) and 15 lbs of Perlite 27M; mix well (slurry tank is completely isolated during this step)
-Begin filtering beer at a rate of around 20 hectoliters (~17bbls)/hr
-Open the dosing pump wheel fully in the beginning of filtration; back it down when the incoming beer is a bit clearer
At the beginning of filtration, the pressure gauge reads around .5 bar. After about 30 minutes, however, it starts going up - not rapidly, but steadily. It gets to around 3-4 bar within 10-20 minutes if I don't throttle down the valve after the filter pump. I can only get about 2-3 bbls filtered before the pressure gauge hits 5 bar and the flow decreases to a trickle. When I broke down the filter yesterday, I removed the leaves to examine the caking. There was definitely a thicker cake at the bottom of the leaves, and I'm not sure how to correct this to get more even caking.
I should also mention that the beer I tried to filter yesterday had been cold crashing at 32-34F for 7 days prior to filtration. And, I cropped off all of the yeast (San Fran lager) prior to starting filtration from the racking arm. So, it was fairly clear going into the filter.
Any suggestions on where I'm going wrong? I have to believe that this filter is capable of a greater throughput rate than what we've been getting.
Cheers,
Matt
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