Clogged pre-filter on a CDL vacuum filter

[maple flats]

I just read thru this entire thread to refresh my memory and to see what has been suggested. 1st, if you use just the pre-filter (1,2 or 3) and the main filter I see no way for it not to clog up if you have very much niter. The niter forms a cake that will prevent any passage. 2nd, I still think you are not using enough filter aid. I use a 7" 5 plate filter press. Early in the season I usually start with 1.5 cups FA in 2.5-3 gal of hot syrup (over 200, usually at 210+). Then I run that thru and send the filtered syrup back to the tank I mixed the FA (or DE if you wish) until it sparkles. I then move the discharge hose to my bottler or a SS barrel and filter the rest that is in my finisher, in 5-6 gal batches.
This past year I needed to use almost 2x the FA of most years.
I suggest you try this, into 2 qts hot syrup add 3/4 cup FA , mix it well, then pour it into the vacuum filter. Once thru, draw it off and put it into the next batch of that + whatever else you have ready to filter. Heat it to 200 or more, add 1/3 cup/gal, mix well and filter that.
Starting with the larger around on the first batch will give you a starting filter cake, then you can use less on the next batch. Once you get good results, you can try adjusting the amount of FA, but may still want the higher amount in that first batch to give you a filter cake.
Next season, let us know how you make out.

[Conococheague]

Very nice. Thanks for that information. I look forward to your pictures and video. A few questions:
-Was your filter setup one orlon + one pre-filter or something else?
-What kind of gallon jars did you refrigerate the syrup in? I am thinking of giving mine a month before bottling.
-After you heated it to 185 and sent it through the filter, did you reheat it again to bottle?

To answer your questions:
- Yes, it was one orlon filter for 1 micron (started with a 5 micron orlon but it went through so fast when the vacuum was applied that we changed to the thicker 1-micron filter. This was the main filter clamped between the upper reservoir and the grid plate. A prefilter cut to the inner dimensions of the reservoir tube was laid on top of that.
- I don't know who made the gallon jars - I bought them at Walmart but a better option might be the 1/2 gallon jars that Ball/Mason sells - I have several cases of them for next year
- No, didn't reheat. We only canned the syrup the first year we did it. Bottled right off the filter into clean syrup jars in various sizes that were washed and always put brand new caps on. Our syrup stays refrigerated and we tell those we give it to to keep it regrigerated.

Conococheague

[Schaefer's Sugar]

I got the 9in CDL vacuum filter last year, near the end of the season. I experienced the same issues with the filter clogging. I Also tried several things, less filter, making the fpaper filters smaller so I could take them out one at a time as they clogged, DE. Last year sryup did seem different with more niter. I do not mind the clogging as much (same as my old gavity system) but for me, trying to pick it up and dump it out is a real mess. I am not tall and depending how much I get through it is bulky. I am thinking of adding a small spigot to the ring for drainage, not to loss all my sryup. This way draining and changing of filters will be easier.
I do have one question. DO you bottle right from this unit? I would light to add a small burner under it (low heat) to maintain temp for bottling. Has anyone tried that?

[jdircksen]

Filtered my first batch of the season today and was reminded of my previous issues. I used a heaping teaspoon of DE in 1.5 gallons of syrup and it clogged after 0.5 gallons. I started looking around and found this:

https://bascommaple.com/collections/...p-filter-press

Round 9" Vacuum Syrup Filter Press. Good for producers making small amounts of syrup each day. There is not much surface area on one of these filters so it can be difficult to get much syrup through before it plugs up. Some producers have found using Filter Aid to be helpful.

[johnallin]

Filtered my first batch of the season today and was reminded of my previous issues. I used a heaping teaspoon of DE in 1.5 gallons of syrup and it clogged after 0.5 gallons. I started looking around and found this:

https://bascommaple.com/collections/...p-filter-press

Use a full cup next time. It won't hurt anything and you'll have better syrup.

[eustis22]

I don't get why MORE DE mitigates clogging? I tried that last year on my press and could never not have the filters clogged. Finally I just went without the DE

[DRoseum]

I believe it's because more DE builds a thicker cake on top, allowing more filtering above the paper in the cake. You can see how much DE it takes to create a 1 -2 inch thick cake around entire filtering surface and use that amount for your batch. That's the concept of a filterpress, a series of 1 inch cakes made in the window plates. You want to try to replicate that because the DE binds to niter and forms the filtering matrix in addition to the papers. The DE does the real filtering work, the papers basically hold the DE.

[eustis22]

My bad..I do not have a filter press, I have the CDL 9" vacuum filter....thats what kept clogging with the DE

[jdircksen]

I don't get why MORE DE mitigates clogging? I tried that last year on my press and could never not have the filters clogged. Finally I just went without the DE

I'm with ya. The magic is confusing. I think having a thicker cake also may require more vacuum. I just have a little shop vac and no vacuum gauge. Part of me wonders if there just isn't enough suction to pul.

This guy has another method. https://www.youtube.com/watch?v=hJFbcJec28w
He makes a slurry with the syrup and DE (didn't look like he used much, maybe 1/4 cup) and made the cake on top before adding syrup. I mixed the DE in with the syrup, which means the cake slowly gets built up, during which time the filter gets clogged.

[DRoseum]

My bad..I do not have a filter press, I have the CDL 9" vacuum filter....thats what kept clogging with the DE

Right, I saw that but was making the analogy of the vacuum unit to a filterpress. The concept is the same. You need sufficient DE to form a cake to do the filtering on top of the papers on you unit. I really like the pre-made slury approach to pre-build a larger cake initially. I would definitely try that.

As for shop vacs....have you considered using a vacuum pump for HVAC instead? Might want to put a moisture trap between the pump and the pot you are pulling a vacuum on.