Clogged pre-filter on a CDL vacuum filter

[jdircksen]

I am learning how to use the 9" CDL vacuum filter but I imagine there are people here who have faced the same predicament with the larger versions. I put the orlon filter + 3 prefilters under the ring and clamped it down. Then I started adding 1 gallon of syrup. The first 2/3 flowed through, but the last 1/3 got stuck because the prefilter had a good 1/16"-1/8" thick layer of niter. The vacuum didn't suck it through either. How am I supposed to remove the prefilter when it is clamped down? I ended up pouring the stuck syrup back out so I could unclamp and remove a prefilter, then put it back together.

83392786_10115247920941125_2562121762145828864_n.jpg

[maple flats]

If you have that much sugarsand (niter), just try smaller batches. I might even try using a conventional pre-filter or 2 to remove some before you pour it into the vacuum filter. This is a suggestion only, I have no experience using a vacuum filter.

[BAP]

Are you using any Filter Aid? I used filter filter aid with mine last year and it worked great. It helps keep the filter from plugging up.

[jdircksen]

I did add a tablespoon of diatomaceous earth and stir it up once the syrup started to collect on top of the filters. it didn't appear to make a difference. neither did turning the vacuum on.

[DrTimPerkins]

That photo doesn't look like the CDL vacuum filter we have? Way too much niter there. Was the syrup hot when you tried to filter it? You'll need a lot more DE than a tablespoon.

[jdircksen]

That photo doesn't look like the CDL vacuum filter we have? Way too much niter there. Was the syrup hot when you tried to filter it? You'll need a lot more DE than a tablespoon.

Yes it was hot. I poured the syrup in as soon as it hit 59 brix. The felt filter was damp and cold from rinsing it out a couple hours prior.

That is the new 9" one. The picture is after I removed the top ring that holds syrup and sits on top of the filters. When I removed the ring, the sediment stayed in place just like when you remove the ring around a cheesecake.
Would having an overly hot fire cause more niter? Or 7 drops of Leader's defoamer in this gallon batch?

the picture isn't showing up, but here is the 9" vacuum filter 82811255_2602003233250396_7023109640288206848_n.jpg

[DrTimPerkins]

Try using more DE and keep it stirred up as you turn on the vacuum. Looks like your filter is just clogging up too fast. More DE will slow the build-up down some and allow filtering to continue. Typically when clogging happens during pressure (or vacuum) filtering it means you need more DE. The DE is the filter media, not the cloths, so you want the cake to build up slowly and capture the niter as it does.

As Dave suggested earlier, coarse prefiltering might help.

[maple flats]

I also vote for more DE, try about 1/2 cup in 1 gal, if 2 gal, try 3/4 cup. Then adjust as you gain experience. Also, mix in the DE well before you add it to the filter reservoir.

[jdircksen]

Got it. Thanks for the tips. I'll give it another try next run.

[jdircksen]

I filtered another gallon batch today and I still don't have this fancy filter figured out. I discovered a pinhole leak in the weld holding the vacuum fitting (condensation drips out of it) and I'm wondering if that is affecting performance. I think what might be happening is that it isn't a clogged filter, rather the vacuum is lost due to the pinhole leak and syrup is no longer being drawn through the filter. Is that possible?

Also, should I expect to run the vacuum multiple times for 1 gallon or should once do the trick? And do you wait until all the syrup is filtered before bottling? I think the vacuum is affected by opening the valve to fill a bottle.