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.

20613

[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 20619

[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.

[maple flats]

I would think the vacuum should run the full time the filtering is happening. If it has a little leak in the weld, report it to CDL, if they don't offer a better idea, seal it for now with silicone caulk. Then after the season, arrange to get the weld repaired.

[jdircksen]

3rd batch today and there was some improvement. I put it through 3 pre-filters off the evaporator and finished it inside. Then I used more DE and was able to get 4 quarts through but the 5th quart stayed on top of the clogged filter. I nested a pre-filter inside the ring so I could remove it but I pulled it out when it was submerged and some of the niter went back in.

The actual permeable surface area of this filter is about 5 1/2" diameter, so about 24 sq inches.
For comparison, assuming the 12" CDL vacuum filter has a similar grate, it would have about 57 sq inches.
A 12" x 12" Smoky Lake flat filter would have 144 sq inches.
20693

Next time I'll use even more DE and 2 removable pre-filters.

[BAP]

What are you using for a vacuum source? I assume that you are running it until all the syrup has run through?

[jdircksen]

I am using the same Shop Vac he uses in the video. It's 1.5 gallons and 2.0 hp. I let it run while I see the syrup level going down but after it clogs I'll let it run a little bit and then turn it off. So it probably runs for 30-45 seconds at a time. The shop vac is sucking condensation from within the tank, so I don't want to let it run too long.

[BAP]

You need to keep vacuum going the whole time to make it work well. If you have a wet/dry shop vac, moisture will not hurt it. I am not sure what video you are referring to. I run my shop vacuum until the syrup is all through using 3/4-1 cup filter aid per gallon.

[jdircksen]

Thank you for the feedback. Here is the video. it's a demo of the 9" vacuum filter: https://www.youtube.com/watch?v=91034cvALwo

[buckeye gold]

To quote "Tim The Tool Man" ...."MORE POWER ARRRRRR"

[fishman]

When myprefilter clogged with syrup still inside the ring I just scraped the predicted off to one side with a pancake flipper. Might try just putting the syrup into a prefilter bag on top of the flat filter this year. Make it easy to remove.

[jdircksen]

Still had trouble with my 4th batch. I'll figure it out eventually. I'm curious if I'm the only with the new 9" vacuum filter that is having trouble.

less than 2 quarts went through before it clogged. This was the process I tried:
-near syrup was filtered off the evaporator at 218* through 3 cone prefilters
-boiling water dumped into the filters to wet them and preheat the unit
-syrup was finished on the stovetop
-1/2 cup DE added to roughly 5 quarts of syrup
-hot water drained
-shop vac turned on
-210* syrup poured into the top of the unit with a removable prefilter
-30 seconds later the filter was clogged, so I carefully removed the top prefilter with lots of gunk
-a little more syrup passed through the filter
-used a spatula to gently push the gunk around
-a tiny bit more syrup passed through the filter
-turned shop vac off
-filled a glass bottle (can't fill with the shop vac on because the suction holds the syrup in)

I also have niter?? getting through. I used a brand new synthetic filter and 3+1 used prefilters. Next time I'll use a brand new set of filters. I read that the DE might be stuck in the used filters and that is what I see in the syrup, not niter.

20781

It's really just the top prefilter that holds the niter. When I remove it, the filter underneath looks full of syrup, not niter.

[Chickenman]

You may not be getting a good seal. I know that my home built unit does the same thing UNLESS I have a good seal then the syrup goes through really quick.

[Sugarmaker]

Do you have a gauge for the vacuum pressure? I would think your going to need to fix the leak.
Seems like one pass should get it clear.
Is there a lid on this? Sorry just not familiar with these units yet.
Sugarsand looks dark and thick.
Regards,
Chris

[jdircksen]

You may not be getting a good seal. I know that my home built unit does the same thing UNLESS I have a good seal then the syrup goes through really quick.

The seal on these looks pretty good. It's a thick rubber ring and there are 3 clamps to make the seal. I have a pin hole in one of the welds but for now I put a piece of electrical tape over it.
The other possible culprit might be the Tomlinson spigot valve I have on it. I don't know how much pressure it can handle. Maybe the shop vac is sucking air up through it rather than through the filter. I'll test that.

[jdircksen]

More trial and error today with 2 batches. First off, I don't think the Tomlinson valve is the culprit. When I put a lid over the top, there is quite a bit of suction holding it on. It actually takes a concerted effort to lift it off, my estimate is 5lbs of force. I wish these had a vacuum port, that would answer the big question.

First batch today had zero DE, and it all passed through the filter with no problem whatsoever. It was amazing, just like on TV. But the syrup started off slightly cloudy and now has bigger floating clumps. I probably filtered it at 219* since I didn't stir in DE giving it time to cool.

Second batch was 5 quarts and since I was impressed with the vacuum power of the first batch, I added 1 cup of DE. Huge mistake. The prefilters clog instantly, and layering them only gets a few more ounces through. The syrup is very cloudy. I think the DE is making it through the filters.

The big variable in all my batches is the amount of DE. I am wondering if the stuff I have is too fine of a dust and it clogs the pores in the filters.

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Product description
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Ingredients
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For Pets
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See product label for more information.
Do not inhale. Dust may cause eye and respiratory irritation.

[regor0]

I will guarantee it is the DE that is your problem. Buy DE from a maple supply store that is used for maple filtering. I like to save money and the ease of ordering on amazon is a good option for most things, but ordering DE for you filtering maple is not a good plan.


Sent from my iPhone using Tapatalk

[mainebackswoodssyrup]

Throw that batch away and try again with the correct DE.

[Super Sapper]

I wouldn't throw out what you have done but the DE is the culprit. I would think that the proper DE will filter out the other DE. Your filters may not clean out and you may need to use new ones.

[BAP]

As others have said, your DE is the problem. It is probably ground too fine. You should be able to re-filter the syrup by heating it up and using maple grade DE. If you don’t want to buy a 50 pound bag, find a producer near you who uses it and see if you can buy 5-10 pounds off them. It’s not that expensive, 50 lb bag at Bascoms’s is only $28. You will be amazed at how the vacuum filter works using the correct DE.

[maple flats]

De comes in several particle sizes as well as food grade and non food grade. You must use one made for maple syrup, while it comes in a 40# bag, you should be able to buy a small amount (like 1-2 gal container or so) from a larger producer. If you keep it dry it will keep for years but if you only need 20-30 cups a year you don't want a big bag. You can also try The Maple Guys, they used to sell a small bag.

[fisheatingbagel]

Are you using DE with filter paper or woven synthetic filters? I've tried both with my homemade vacuum filter, and filter paper seems to work better. Filtering with DE using synthetic woven filters seems to clog sooner. I buy large filter papers and cut them to size for mine.

[jdircksen]

Thanks everyone. I am going to refilter this batch. I hope it can be saved because it's my biggest one of the season. Hopefully the maple DE will somehow attach to the stuff I used, because it hasn't separated from the syrup at all.

The stuff I bought was the food grade DE that could be found locally and it was in a manageable quantity. I just bought a 50lb pound bag from a maple dealer, so I'll give it a try. It should last me about 50 years :)

[regor0]

It will filter out just fine. If not just add more maple de, it is hard to have too much as long as you have room for it in the filter.

[maple flats]

To remove the ultra fine DE, you may need to use extra of the maple DE, it will filter out. You might need 2-3 passes, all thru the same set of filters. The DE filter cake builds up and will remove the wrong DE you used. Re-heat to keep it hot, but don't rinse the filter cake, that is the filter.

[jdircksen]

The problem I run into is that the filter cake clogs the filters, so I can't get more syrup through. I'm not the brightest, but I'm having trouble figuring out how to make multiple passes when the filters are clogged.

[johnallin]

The problem I run into is that the filter cake clogs the filters, so I can't get more syrup through. I'm not the brightest, but I'm having trouble figuring out how to make multiple passes when the filters are clogged.

Unlike a filter press - where you can recirculate your syrup back to your mixing tank until the cake is built-up - I don't think there's a way to re-circulate syrup in a vacuum press. You'll probably have to filter and then re-filter a few times to get your syrup clear.

[Sugarmaker]

Folks,
So what is the expected capacity of one of these CDL vacuum filter systems. I have from 2 to 20 gallons of syrup per day.
What vacuum pump do I need to buy? Why doesn't a vacuum pump come with the machine?
Where does the DE and or sugarsand go to?
Guess I just need to see one work. I kind of understand the concept. Pull liquid hot syrup through a filter using vacuum. Why isnt there a vacuum gage to show your do good or are done for the day? Why do I have so many questions??:)
Where are the CDL folks when you need them?
Regards,
Chris

[jdircksen]

There are videos on YouTube if the new 9” one in action. It has a capacity of 3 gallons. The larger sizes are more expensive and come with a vacuum gauge and a sight glass to see the syrup level. If you are in Western PA, give Fred a call at Richards Maple and be can answer your questions. He’s a big CDL dealer.

[Sugarmaker]

Jdircksen, Folks,
Thanks,
It sounds like Dr. Perkins is using one of these. May be a bigger unit? These must work. Original poster may have several issues that may have contributed to his problems. Sounds like he is doing a good job testing and trials to prove that this works.
Regards,
Chris

[jdircksen]

https://www.cdlusa.com/produits/vacuum-filter-press/

The 12", 15" , and 18" have been around longer. The 9" just came out in the past year and is aimed for hobbyists with fewer features and less cost. I am hoping the DE I used was the problem, but it will be a few more days before I can boil another batch to confirm. It's a really nice unit that will work once I figure out my issues. Quality is good, expect for the weld with the pinhole and now it is developing rust colored deposits on that same weld. I'll deal with those at the end of the season.

[fred]

all thats required is about 17" vac. a simple shop vac works fine, nothing expensive needed. and the shop vac sucks so no need to buy a new one it will never touch or blow into the syrup, just make sure the connections are clean

[maple flats]

Sugarmaker, to answer your question "where do the niter and DE end up'? They are on the filter when finished, looking like a thick filter cake.

[Sugarmaker]

Folks,
So the picture in the first post looks about right? A thick cake of sugarsand. ( I know he is going to get new DE) So is DE recommended to be used in on of these or is it optional? This is kind of what I would suspect too. The DE and or just sugardsand has to be trapped in the filters above the cleaned syrup just like a gravity system. So why would you not make the sailors cap filter system with the extra surface area in the filtering portion of this rather than just flat? Seems that design improvement would be a nice addition to this flat round filter area. Maybe patent protection?? Also why wouldnt the prefilters be able to be removed when they got clogged like a gravity system? Then you couil filter more syrup without taking the seal apart. Or maybe I missed this feature?
Thanks for bring me along and getting me up to date. I see heus is off to get one of these units.
Also folks are using this system set on a burner and bottling from this too?
Sound like a good system upgrade from gravity, if it speeds up the process and results in less syrup waste.
Filtering small batches is always a problem for folks making under 20 gallons per season.
Regards,
Chris

[BAP]

Folks,
So the picture in the first post looks about right? A thick cake of sugarsand. ( I know he is going to get new DE) So is DE recommended to be used in on of these or is it optional? This is kind of what I would suspect too. The DE and or just sugardsand has to be trapped in the filters above the cleaned syrup just like a gravity system. So why would you not make the sailors cap filter system with the extra surface area in the filtering portion of this rather than just flat? Seems that design improvement would be a nice addition to this flat round filter area. Maybe patent protection?? Also why wouldnt the prefilters be able to be removed when they got clogged like a gravity system? Then you couil filter more syrup without taking the seal apart. Or maybe I missed this feature?
Thanks for bring me along and getting me up to date. I see heus is off to get one of these units.
Also folks are using this system set on a burner and bottling from this too?
Sound like a good system upgrade from gravity, if it speeds up the process and results in less syrup waste.
Filtering small batches is always a problem for folks making under 20 gallons per season.

Regards,
Chris
Your filter aid cake will clog before the prefilters clog just like a filter press. Surface area with filter isn’t so much of an issue because the DE is doing the filtering.

[Sugarmaker]

Folks,
Looking forward to the original poster getting quality syrup filtered at some point in the near future. Hoping his change of DE corrects most of the problems.
Regards,
Chris

[johnallin]

I don’t understand how you can build a decent “cake” of DE with only one pass across the paper. A filter press requires a minute or more recirculating until the syrup is clear, then you switch to your bottler. Possibly the paper is doing more work than what it does in a press?

[BAP]

I don’t understand how you can build a decent “cake” of DE with only one pass across the paper. A filter press requires a minute or more recirculating until the syrup is clear, then you switch to your bottler. Possibly the paper is doing more work than what it does in a press?
You are not using paper, you are using the same washable filters that a flat filter uses.

[maple flats]

2 passes or even 3 might be needed, but once a filter cake is established, one pass should do it if using DE intended for maple production.

[johnallin]

2 passes or even 3 might be needed, but once a filter cake is established, one pass should do it if using DE intended for maple production.

That’s my question..how do you establish a filter cake with only one pass?

[Pdiamond]

I have watched the CDL video, the Roth Sugar Bush video and another producers video and there was no DE used in the syrup before it was filtered. They just used the pre-filter and orlon filter.

[BAP]

I have watched the CDL video, the Roth Sugar Bush video and another producers video and there was no DE used in the syrup before it was filtered. They just used the pre-filter and orlon filter.
I have not seen those videos, but I bet they are only showing putting 1 batch of syrup through. The first batch will go through ok without DE, but the nitre slime build up will basically plug up the filter making the next batch hard or even impossible to go through. Same thing will happen to a filter press if you forget to put DE in the syrup. When I started using mine last year for the first time I experimented quite a bit to figure out how best to use it.

[jdircksen]

Folks,
Looking forward to the original poster getting quality syrup filtered at some point in the near future. Hoping his change of DE corrects most of the problems.
Regards,
Chris

Give me a couple more days. We got a good freeze and today it's thawing. I will report back in a couple days after I use maple DE.

[jdircksen]

I have watched the CDL video, the Roth Sugar Bush video and another producers video and there was no DE used in the syrup before it was filtered. They just used the pre-filter and orlon filter.

https://www.youtube.com/watch?v=91034cvALwo
At about 4:35 into this video, he says you can use DE but you do not have to.

[Sugarmaker]

jd,
That sounds about like a gravity filter system, some folks use some DE. I did not use any in my gravity filtering set up. Good luck.
Regards,
Chris

[bryankloos]

Hi Guys,

Just curious if the 9" model comes with filters, and where to buy replacement filters.
I only see ref numbers for the larger units on CDL website and white papers...

Thanks,

Bryan

[jdircksen]

The 9" comes with one finish filter and 4 or 5 pre-filters. I already went through them, so I bought 36"x36" sheets. 9" is great since you'll get 16 circles from each sheet.

[jdircksen]

Ok I finally got to use the filter again. Not much changed :(
I had 1.5 gallons of syrup that I filtered through prefilters and a cone filter when it was around 2.5 gallons yesterday, then went to bed and work. Today I finished boiling it, turned off the burner at 59 brix, added 1/8 cup (that's half of 1/4 cup) of maple DE from the 50lb bag and stirred it up for a minute. Then I let the syrup cool for a few more minutes until it was 210*. While it was cooling I poured boiling water through the filter and let it drain to preheat the unit. Then I turned the shop vac on and began pouring the syrup in slowly. It sucked a quart of syrup in about 30 seconds and then began to clog again. I added more syrup and let it run for a minute but not much more went through. I filled a couple 12oz glass bottles and then decided the dump the clogged syrup back into my pot and replace the pre-filters. The top one was coated in a thin layer of what I assume was DE. I wetted new prefilters and installed them. Then I poured more syrup in, less than a quart until it was clogged. Replaced all the filters again. Got another quart through. In total I rinsed or replaced the filters 5 times to get 1.5 gallons through. Each time the top filter had a light coating, but nothing like in my first picture with the filter cake and tons of niter.

Next batch will be without any DE. And if that doesn't work, I'll keep searching for vacuum leaks. Any ideas for finding it?

[Sugarmaker]

Humm,
I would really like to hear from Dr Perkins or others that are using this system. If it is a vacuum leak problem you need to find that some how. Maybe reverse flow low air pressure with a lid in it??? Just a thought. feel for air escaping at the leak???
Sounds like std cone gravity filters would have done about as as well? in the old days we would filter 10 to 20 gallons a day through cone filters and would have to wash them and the pre filters several times. We also had two sets of filters operational so one could be filtreing and one could be cleaned as needed, we did not use DE.
I filtered 7.5 gallons tonight with about 5 cups of DE in the SIRO, in three batches, total pump time maybe 10 minutes, But we are not comparing apples to apples. Pressure vs Vacuum.
Thought you might see better results with new maple DE???
Maybe BAP has the answers?
Regards,
Chris

[Chickenman]

Is your shop vac set for wet or dry? Try removing the pleated paper filter and see what that does for you. If the paper shop vac filter is still in then it may be getting damp from the steam and not giving you the draw you need at the end of your run.

[Super Sapper]

Some thoughts, more of the proper DE is better than less. When running a press you need to clean it when it is full of DE and not plugged with niter if you are adding the right amount.

It is possible that the original DE was so fine that it is plugging up the maple DE.

I would use the Maple DE with fresh syrup to see how it performs.

[buckeye gold]

You need smoke to find the vacuum leak. Go around the fitting with some smoke and it'll show ya real quick. I done this to find a leak on an outboard manifold once.

[BAP]

1/8 of a cup of DE is not enough. Put a full cup in and try it, if it works but not as good as you think it should, then try more. 1/8 of a cup is not enough to put a good layer on the filter to keep it from plugging.

[WolfCreekMaple]

I was always told that using a vacuum filter won't allow you to filter MORE but just faster. In terms that your filters are going to get clogged at X gallons and need replacing regardless if your using a vacuum filter vs. gravity filtering. So maybe it's not the idea that you don't have enough DE or the filter but maybe just the fact that you need to change those filters more often and that you aren't going to get any more syrup thru those filters.

[jdircksen]

1/8 of a cup of DE is not enough. Put a full cup in and try it, if it works but not as good as you think it should, then try more. 1/8 of a cup is not enough to put a good layer on the filter to keep it from plugging.

Do you add it to the entire batch before putting syrup into the filter or add it once some syrup is sitting on top of the filter?

[WolfCreekMaple]

Do you add it to the entire batch before putting syrup into the filter or add it once some syrup is sitting on top of the filter?

Mix it in with the hot syrup.

[fred]

jacob everyone in the region is having trouble filtering. some of the 7" presses are only getting 5-10 gallons through before changing out and cleaning. looks like the same issue with you. every year is different

[jdircksen]

Ok here is an update. I made 5 quarts today and actually had what I'd call a success with the filtering process. I think Fred is right - this year is different. Seems like the niter is extra fine.

I made 2 changes on the unit.
1) only use 1 prefilter instead of 3 or 4
2) added the 1/2" ball valve ahead of my Tomlinson valve so I could close it to guaranty no air was getting sucked up the Tomlinson valve

Ended up filtering 3 times, but turned some ugly dark syrup (sap was cloudy after 2 days in the refrigerator) into clear syrup.
1) first pass without any DE. the syrup went through like a dream, but was very cloudy.
2) second pass with 2/3 cup of DE and it ended up clogging after 4 quarts, but was still a little cloudy. the filter had a solid cake on it.
3) replaced the filters this time and only used 1/3 cup of DE. had to run the vacuum for about 5 minutes but it all went through eventually.

seems like my issue is that I was using too many prefilters, but I'll continue to test the other theory that the Tomlinson valve lets air in.

[GeorgianBaySugarCo]

have you used your filter since?

[jdircksen]

Yes, just a few times. The only way I've found to make clear syrup is to filter multiple times.
1) off the evaporator
2) finish it, then add a little DE and send as much through until it clogs
3) dump all the syrup back together, check the density, clean the filters, and send it through again

It ends up wasting some syrup when you clean the filter in between but that is better than having cloudy syrup.

[canaanmaple]

Something to add. I have one, and noticed the later season stuff Ive been bottling with that unit, does have more nitre and getting a few gallons through it (ie: filling up the bottler) without having to change the filter is getting harder.

But, I did just notice something the other day that I would say is a manufacturing flaw. The 3 tabs on the removable ring that you clamp down that holds the syrup, make contact with the flat filters and mesh filter piece BEFORE the entire outside of the ring. Making it impossible for an air-tight connection when clamped down. I plan to grind down the 3 tabs a little so the ring is the first thing to make contact and hopefully make a more air-tight seal. I will report back

[heus]

My 12" cdl filter also has a manufacturing flaw. The draw off actually runs uphill and not parallel with the top/bottom of the tank. Not a huge deal as far as performance, just a noticeable flaw from a supposedly reputable company.Come to think of it, maybe that's an intended design to keep dripping to a minimum when the valve is turned off.:confused:

[BAP]

On my 12” filter, I get crystal clear syrup on one pass, but I put quite a bit of filter aid in. This year I am using probably twice as much as I had to last year. Pre-filter plugging usually comes from not enough filter aid, than too much. I agree that there is some manufacturing oddities, like on mine, the sight gauge is not straight and it has to be tipped up a lot to get all the syrup out.

[n8hutch]

Hey Bap I have a friend that has the 12" vacuum filter and he hasn't had great luck with it so far. I gave him a 5 gallon pail full of DE to try, I told him to start with 3 cups to 5 gallons of syrup because that's what I use to start on my filter press. What do you think is a good amount of DE to syrup ratio?

[jdircksen]

Something to add. I have one, and noticed the later season stuff Ive been bottling with that unit, does have more nitre and getting a few gallons through it (ie: filling up the bottler) without having to change the filter is getting harder.

But, I did just notice something the other day that I would say is a manufacturing flaw. The 3 tabs on the removable ring that you clamp down that holds the syrup, make contact with the flat filters and mesh filter piece BEFORE the entire outside of the ring. Making it impossible for an air-tight connection when clamped down. I plan to grind down the 3 tabs a little so the ring is the first thing to make contact and hopefully make a more air-tight seal. I will report back

Have you tried adjusting the tabs? All 3 on mine have bolts that can be lengthened to adjust the tension.

[BAP]

Hey Bap I have a friend that has the 12" vacuum filter and he hasn't had great luck with it so far. I gave him a 5 gallon pail full of DE to try, I told him to start with 3 cups to 5 gallons of syrup because that's what I use to start on my filter press. What do you think is a good amount of DE to syrup ratio?
Nate, that sounds about like what I am using right now given the amount of niter. Tell him that if it helps but still isn’t great try a little more.

[n8hutch]

Thanks Bap, I always figure its easier to use alot of DE and waste some than it is to use too little and fiddle around with syrup that wont go through the filters.

[canaanmaple]

Something to add. I have one, and noticed the later season stuff Ive been bottling with that unit, does have more nitre and getting a few gallons through it (ie: filling up the bottler) without having to change the filter is getting harder.

But, I did just notice something the other day that I would say is a manufacturing flaw. The 3 tabs on the removable ring that you clamp down that holds the syrup, make contact with the flat filters and mesh filter piece BEFORE the entire outside of the ring. Making it impossible for an air-tight connection when clamped down. I plan to grind down the 3 tabs a little so the ring is the first thing to make contact and hopefully make a more air-tight seal. I will report back

grinding the tabs helped a little. I do notice the entire ring itself is not perfectly level/flat. Sitting it on a flat surface you can see light coming through in spots. Probably impossible to fix without a wide belt table sander. That being said, I think there are very many variables to using the cdl vacuum filter efficiently. Air tight connections, size of the vacuum, temp of syrup, and -very importantly- the speed of which you pour the syrup in! I found that to be a huge factor. Also, stacking pre-filters in the ring. I just use the orlon and one prefilter under the ring that gets clamped down. Then I pack 3 more pre-filters in. I can easily get 5 gallons through. The first 2.5 that fills it up, goes right through without changing a filter if you do it fast enough. Then I end up pulling out the pre filters one by one to get the next 2.5 gallons through which isnt a big deal. I do not use DE at all, but I do filter off the evaporator in a cone filter very close to syrup first. Then finish and run it through the vac filter.

very decent unit still. Only problem is that it's too small for me, so I will be selling it and getting the higher capacity one for next season!

[heus]

For those using the 12" vac filter, what are your vacuum readings? My vac gauge reads 6-7 hg using a new 5 or 6 hp shop vac. Jus wondering if these are normal vac levels for this unit.

[BAP]

For those using the 12" vac filter, what are your vacuum readings? My vac gauge reads 6-7 hg using a new 5 or 6 hp shop vac. Jus wondering if these are normal vac levels for this unit.
Heus, I am using a 5hp shop vac Rigid brand and I get 6-7 on the gauge.

[heus]

Thanks BAP

[Conococheague]

I decided to build my own vacuum filter since last season. We made 9 gallons of syrup last season and that has been in gallon glass jars in a refrigerator since March so Mother Nature did a lot of the filtering for us already. Like some have said in other posts, I’m a hobbyist that hates filtering like the plague. It’s my least favorite part of this whole process. Anyway, I learned a lot from this site and, being a mechanical engineer that designs large scientific spectrometers that incorporate radiation, vacuum and cryogenics for a living I get as much satisfaction from designing and making all my own equipment as I do in using it. I do this with a partner that owns/operates a large 1,200 cow dairy and we discussed purchasing the 9” CDL vacuum filter press. My answer to this was “why should we buy something for $600 when I can design and build something for twice that? And, truth be told, I’ve spent much more than $600 on our unit (luckily my wife doesn’t visit this site and the purchases were spread out enough that she hasn’t noticed). Anyway, we tested my unit this last weekend and it worked great. We poured the syrup off of the bottom layer of sludge and heated it to 185°, saving the last of the dirty stuff for the end where we expected to clog the filters. My system incorporates a vacuum reservoir that is separate from the filter unit and connected with a valved line to the bottom vessel of the filter unit. The vacuum inlet to the bottom vessel has a bent tube inside the vessel terminating near the top to avoid sucking too much syrup into the line. The other vessel penetration is a drain valve with an interior bent tube terminating at the bottom of the vessel and another exterior bent tube on the outside that can be rotated to terminate below the bottom of the vessel for near-complete drainage of the filtered syrup and this worked well for bottling. Anyway, the vacuum reservoir is an old deLaval milk bucket (identical to what my grandfather used before building a milking parlor in the 60’s). The top plate has three penetrations: one is for a vacuum gauge, one has an internal tube running to the bottom and the outside is connected to the valved line running to the filter unit. The third connects to my vacuum source. My preferred vacuum source was the Harbor Freight 2-stage 3CFM vacuum pump that others on this site recommended. I also purchased a 6-HP Wet/Dry vac and fittings to use as a Plan B to the HF pump. With the HF pump I can get close to perfect vacuum (29.92” Hg). I only get 6-7” Hg with the Shop Vac and thought I had an issue somewhere but reading this makes me realize that is all that it’s capable of. The top reservoir of the filter unit is a section of polyethylene tube/pipe (~ 9” ID, .5” wall) that squeezes the main filter against the top grid plate of the filter. I put prefilters inside this that have the same diameter as the ID of the poly tube. We fill the top reservoir to a level that we determined by trial/error to match the volume of the lower vessel (a heavy-walled stainless steel stock pot). The vacuum reservoir is evacuated with the valve to the filter unit closed and the valve to the pump open. Then the valve to the pump is closed. Once the syrup is loaded into the syrup reservoir above the filter, the valve between the reservoir and the filter is opened slowly. It’s amazing how fast it sucks the syrup through the filters and into the lower unit. Once it’s through and the filter is hissing, the valve to the vacuum vessel is closed and the vacuum reservoir usually still has 14-15” Hg of vacuum in it. To bottle, we have to break the seal between the grid plate and the bottom vessel. Once we’ve bottled everything in the lower vessel, we start another cycle. We changed filters twice during the 9-gallon session and, as expected, the last stuff filtered would clog the filter before going through but carefully removing the pre filter and hitting it again with vacuum did the trick. The syrup was crystal clear and the bottling was done with barely a drop of wasted syrup. The only change I plan to make is a larger vessel for bottling from as the bottling was the rate-determining step in the process. In the near future, I will post pictures and a video. To the OP – consider the HF vacuum pump if you want more force pushing your syrup through the filter. Just take precautions against sucking syrup into the pump – it will ruin it. I have two safeguards against this. One is the separate vacuum reservoir/ballast and the second is a water separator in the line to the pump (someone on here pointed me to that on Amazon). Another note – I didn’t use any DE and don’t plan to. Sorry for the long post. I’ll start a new thread on my filter with pictures and video when I figure out how to. I no longer dread filtering and bottling and now have a new toy to play with.

Conococheague

[jdircksen]

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?

[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/filtering-canning/products/round-9-vacuum-syrup-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/filtering-canning/products/round-9-vacuum-syrup-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.

[Openwater]

I currently use a shop vac for my vacuum filtering. Could someone post a picture or component list of their Harbor Freight 3.0cfm vacuum pump set-up? I'd like to get higher vacuum under my filters.
Thanks.

[eustis22]

I was just coming here to ask that....I also use a shop vac and it seems it wasn't strong enough to get the syrup through the filter so what kind fo vacuum pump (and what cfm) is optimal?

[Openwater]

Here's my homemade vacuum filter setup I attach a shop-vac to, but would like to try to hook up a Harbor Freight vacuum pump to get more suction and speed up the filtering process.
22827
22828
Why are my pics always sideways?!?!

[BAP]

Biggest problems people have with the vacuum filters is reluctance to use enough Filter Aid in the syrup. Measuring by teaspoons is no where near enough. 2-3 cups per a gallon is a better starting point and then adjusting after you see how it goes. Later season syrup requires more. Be careful about using cheap vacuum pumps because they can give off a very faint oil mist which you don’t want getting in the syrup or on surfaces in your sugar house. I bought one of the first CDL 12” vacuum filters brought into the USA and have used it for several years now. I use a 5.5hp Rigid brand shop vac from HomeDepot. It works good and after the first couple batches filtering each year, I figure out the correct amount of DE to use and adjust as needed. DE is relatively cheap and don’t be afraid to use it.

[eustis22]

I have a 6.5 Craftsman shop-vac and that was not enough to get my syrup thru the filter. I might try the slurry first to see if it makes a difference.

[eustis22]

Arrrghhhhh this fricking thing. TWO (2) cups of DE into 3 quarts of finished, unfiltered and it is STILL not going the the CDL 9" filters. Just sits there. Ima write this thing off as a bad investment.

How do I filter DE OUT of syrup??

[Super Sapper]

Are you using DE from a maple dealer or just some food grade DE? The stuff from a maple dealer will be the right size. Other food grade DE may be too fine and will plug up a press or filter.

[eustis22]

I am using Food Grade DE....I was not aware that was a difference in particulate size. the three different boxes I have do all seem the consistency of talcum powder.

Where would I find this coarser grade DE?

[BAP]

If you didn’t buy your DE from a maple dealer then your filtering problems are most likely caused by using the wrong DE. Food Grade does not mean that it is for filtering maple syrup. The DE needs to be the correct particle size to make it work properly. Buying from Amazon or the pool supply place to save 25 cents doesn’t work.

[Super Sapper]

The good thing is that I think you can salvage your syrup by using DE from a maple dealer. Smoky Lake sells 10 pound bags I believe. Other maple suppliers may as well.

[eustis22]

Thank you...I am getting some Dicalite from a CDL dealer in Wilton, Maine this week and will try the salvaging Sunday evening

[wobbletop]

^^^ Please let us know how it works out. I still have a bunch of syrup in the freezer from last year with food grade DE. :(

[In da bush]

FWIW,
I have a 9” CDL and can usually get almost a gallon through before it just STOPS. Looking at the hose from the shop vac I noticed the end you attach to the vacuum port isn’t airtight,at all. I’m gonna tinker around with trying to get a PVC pipe plumbed into the system for better vacuum performance.

[spike in wi]

We've had our 9" CDL for three years now. First year we thought we made a bad investment also. We now filter hot 200 degree + syrup through with 1 orlon filter and 1 pre filter placed loosely on top of the orlon filter. Pour in about one gallon of syrup and hit the vac for about 30 seconds to a minute. Use a set of tongs to fish out the pre filter and hit the vac again for another 30 to 60 seconds and bottle what you have. Pour out what's left and do it again. Filter aid made all the difference for us. Use at least 1 to 2 cup per gallon of hot syrup. Loose connections will kill the vacuum process!! We get about 6 pints for every filter change. Doesn't seem like much but we filtered 39 gallons through this season. We do have about 20 some orlon filters and pre filters.

[eustis22]

can anyone post a pic of their vacuum connection to their filter? I have an adapter but I dunno if it's tight enough

[Johnmn]

I use a PVC fitting to go from 3/4 npt to 1 1/2 PVC and then a fernco from that to my shop vac. Yes I have to tighten a hose clamp but it's an air tight seal in the end.

[eustis22]

now if somneone can hep me get DE out of doubly-DE'd syrup without the vacuum filter I'd be forever grateful.

[wobbletop]

I guess the different kind of DE didn't help?

Store it and find someone with a filter press to borrow after their season is over? Good luck!

https://i.ibb.co/sg3Rt56/20230401-110331.jpg (https://ibb.co/D1KWLG8)