Flow problem with CDL 18 X 60

[Yooper Kevin]

Looking for some advice....My flue pan (18 X 42) is dead on level & my finish pan (18 x 18) is 1/8 inch low on the draw off side. The Problem? I have pumped 350 gallons of sap thru the evap and only drawn off once(half gallon). The gradient has not developed and I am now on the verge of making syrup in my flue pan. I am planning on plumbing up the flue pan tomorrow....But, What else could be causing this? The liquid is even caramel colored in the float box. I know from past experience that it should be clear in there. Any advice would be appreciated!!

[regor0]

I have a 2x6 cdl, I have run probably 500 gallons through it this year and only have drawn off once. My sugar content has only been around 1.5 though. Can you see sap trickling into both float boxes? I usually have to put a minimum of 350 gallons thru it before the fist draw off, then it gets more normalized. Make sure you only very small amounts of defoamer in the syrup pan, and only at the draw off outlet. I think you just need to be patient and keep feeding it sap. Good luck.

[Yooper Kevin]

Yeah the sap is coming in like it should(there is only 1 float box with this evap)....but there is no gradient. The stuff in the float box is caramel colored and sweet. The gradient should be obvious I think, last year the float box contained basically only clear sap and then got progressively sweeter. Something is wrong but I can't figure it out. Thanks and good luck this year!

[Biz]

I have a new 18x48" CDL with about the same problem. The syrup in the finishing pan never boils down far enough to finish off, even close. I was watching it, and there is too much mixing between flue pan and finish pan. Syrup is always sloshing back and forth due to the hard boil in the flue pan. I end up drawing off about a gallon every 2 hours but it is very thin and needs a couple hrs of finishing off on the stove. I wonder if it would help to add a divider in the finish pan? That would help isolate half of it from the mixing.

I actually spoke to the CDL rep and he suggested running the level a little lower, at about 1" (I was 1.5) and using a mix of hard/softwood (I use all softwood). It didn't seem to help.

Dave

[Maplebrook]

I've got the same issue with my 18x63 evaporator. I can get up to 3 degrees above at the draw off then the float box starts to get syrup colored.
I can make syrup in the front pan by leaving the inlet from the flue pan plugged. Have to keep a close eye on the level this way and pull the plug to let more sap in as needed.
Usually I draw off at 3 degrees and move to the finishing pan.
Darren

[regor0]

Anybody figured out a solution yet?

[NTBugtraq]

I have the same setup as the OP. I turned sap into carbon in my flue pan last week and nobody could figure out why. The best suggestion was that foam fooled the float into not letting new sap in. Caramel color in the float usually means you haven't put the plugs in judiciously...or that you haven't been able to burn long enough. This season has caused that several times for me. I was told I needed to put some 150 gals through to get a gradient...well, I turned stuff to charcoal after my first draw off, which most people think was too much (I drew off some 5L).

I am very convinced (for no reason other than its my first time using an evap and I'm having so many problems, so it surely can't be my fault!) that this small evap isn't designed to get stuff to syrup. Draw it off at +3 or +4 and finish it inside or, as I do, on a propane finishing tank. Since there is no way to plug between channels in the flue pan, or between channels in the syrup pan, there's just way too much chance for stuff to become equal in two different places...not exactly conducive to establishing or maintaining a gradient.

CDL says run the flue pan at 1", that means turning the bolt on the float to its max...you can't run it less than 1". That means you are 1.5" in the syrup pan...not sure where you got the idea there was only 1/8" difference between the two pans, its 1/2". The outside edge of the flue pan is on an angle...measure at the top of the flue and you'll find its 1/2" difference between flue and syrup pan. 1.5" in the syrup pan is still a lot...so I'm told.

FWIW, I talked to CDL late last week at length about this issue. Quite frankly, I don't think they have any staff using this setup and that its design is based on theory, given how iffy their answers are...welcome to the world of beta testers.

Cheers,
Russ

[Big_Eddy]

Yooper Kevin
How is the boil in the front section of your syrup pan? Is it boiling hard?
How deep are you running the sap in the evaporator?

When helping out Russ, it seems that he has very little heat getting to the front section of the syrup pan. If there is no evaporation there, then there is no "opening" being formed for sap to flow into from behind, and therefore the whole arch gets concentrated instead. In Russ's case - by the time he got to the first draw it was large, and the next draw was right behind it.

If this is the case - you may be able to encourage the intial formation of the gradient by drawing off a couple of gallons from the front section and pouring it back into the flue pan. That will create some flow forward and get more concentrated syrup to the front pan. After the gradient is established, each syrup draw will do the same thing.

Can either of you take some side photos of the arch itself and draw in any differences in the inside shape from the outside? I'm thinking that the flame flow in the arch is such that the heat moves backwards too fast, leaving a "cool spot" under the front pan. A little less boil in the front section is good, but no boil is not. Wood size and cure, firing etc. can all affect flame flow which could be why you're seeing a difference from last year.

[mgale]

move the spacer from the back to the front. this will get more fire under the syrup pan and you should have a good boil to keep the gradient. I had to to this the first year I had mine. put a piece of arch board between the stack and the back of the flue pan to keep it from scorching
good luck this year

[Derf]

I've had the same problem as several of you with my CDL 18X60 not making syrup. When I first got it I let it go for a long time and ran quite a bit of sap through it and didn't get any syrup. I tried a lot of things but to no avail. The last week or so of the '15 season I tried plugging the pipe between the flue and syrup pans so no new liquid could come into the syrup pan until I wanted it to do so. This worked. I'm now able to get the syrup pan to boil properly and concentrate the syrup. I let it boil down until it was almost done, opened the pipe between the flue and syrup pans and then quickly drew off what syrup was ready. I repeated this frequently. I found that I could concentrate syrup in the syrup pan by opening the flow between the flue and syrup pan until they were at the same level and then repeatedly closing and opening the pipe.

I also get boiling in my intake float pan. Not sure what to do about that. Maybe it isn't a problem? Because it gets so hot I really don't need a pre-heater.

I put a variable-speed squirrel-cage blower at the back of the fire box and then put fire brick in the front of the box by the ash door so the air is forced up through the floor grate. I also put split fire bricks on about half of the floor grate towards the back so the air from the blower has to come up through the front of the grate. This forces the fire up onto the syrup pan and I get a REALLY hot spot at the juncture of the back of the syrup pan and front of the flue pan.

[Derf]

Another thing I did with the CDL is use split fire bricks totally and the 1/4" arch paper that Bill Mason has for sale. I was told that I'd burn up the evaporator doing this. I'm in my second year with the evaporator now and, so far, this hasn't happened. In fact, I measured wall temps on the unit while I was boiling hard and they rarely got above 200F. The SS surface is perfect with no discoloration from being too hot. Doing this gives me quite a bit more room in the fire box.
I agree with the reply that stated that CDL probably hasn't used one of these evaporators and doesn't know what to tell us about the unit.

[TedA]

Russ at NTBugtraq and Big Eddy have the best solutions. I have 2x4 drop flue hybrid from Smokey Lake. Works great but very hard to get a gradient and even then it takes a long time. I will go through 250-300 gallons of sap before I have something resembling a gradient. I've learned to keep a good boil in the last pan and draw off when it gets to +3 to +5. I then move it to my finishing pan and 20-30 minutes later, its ready to can. I am convinced that its difficult to get a gradient in these small hobby pans - not enough distance from the inlet (float box) to the draw off point. I asked Jim S at Smokey Lake about this and he offered to add another divider in the flue section. I've not done that and probably won't. Drawing off at +3 and finishing it on a second (flat) pan works fine for me.

[jrgagne99]

I have a home-made 20"x40" hybrid pan and had a similar problem when I first started boiling on it. The front syrup section is 20"x10" with one divider and the back is 20"x30" with 5" drop flues and a divider. A valved jumper-line connects the back section to the front section. The general problem is too much "flue pan" and not enough "syrup pan" I had a similar problem at first, but was able to solve it by adding a blower and loading the good, dry wood very close to the front of the firebox. I often get the door glowing cherry red, esp at night. I need to put a little insulation on the inside of it. I also run the back pan a littler higher than the front pan, which lets me finish batches off the syrup pan a bit more frequently. Next year, I will take some advice from this thread and add some firebrick in the firebox to try to do an even better job of directing the flames up toward the syrup section.

[74maple farmer]

Need some advice,
I have boiled 3 times now in my 19x48 lapierre mini pro
Each time around 100 gallons . Due to being new to this kind of setup I'm running both flue and syrup pan at about 1-1/2" deep the evaporator seems to be level as good as I could get it (back to front and side to side) the flits are work as they should to maintain the levels, how ever I noticed last night that when I flooded the system in the beginning the sap that flowed to the front channel of the syrup pan is not turning to syrup. There's no gradient forming, and at the end of my boil I noticed that the syrup was gathering in the back float box of the syrup pan I drained from the back and watched a gradient form , but backwards. What am I doing wrong

[sweetvt]

I would first suggest adjusting your front float so that the syrup pan has 1" depth and keep your flue pan at slightly higher. (Just covering the tops of the flues)As others have said, these smaller evaporator are much harder to get finished syrup on, but it can be done. IF you have a ball valve also from the rear to front pan, it also helps if you can close that as you get closer to 215+ temp. I run a drop flue Lapierre 18x66 and I can draw syrup about every 2 hours but only when I plug the back to front pan flow. It takes about a 100 gallons of sweet before any syrup is made. I have a friend who has the 18x60 raised flue Lapierre, and he doesn't have the patience or the stones to run it to syrup in the evaporator, and regularly draws off at 215 or so and finishes on a propane stove.... It never made sense as you have all that fire and heat in the Evaporator, but each person needs to use what works for them. Important thing to know is if you are going to lower your depths the boil will increase and will command much greater attention to sap levels. The other take away I have learned is that the floats can and will stick occasionally which if not watched could lead to burnt pans....

[Bill@mysticmaple]

I have a Smoky Lake 2'x5' hybrid on an oil tank arch, second year in use. My experience is that it takes about 300 to 350 gallons of sap to produce the first gallon of sap and that the more consistent you can keep the process, the better the gradient will be. A consistent fire, whether hot or cool with even, timed loads, is better than allowing the fire to get too hot then too cold. You need to keep as consistent of a boil as possible. Also I do not boil as soon as there is "enough" to start. I will wait and process a large amount sap in one longer day as opposed to several two hour heats. Every time the evaporator cools down, the gradient for the most part is lost.
I do block off the port from the flue to the syrup pan, that helps some but does not totally prevent mixing.


2015 - 35 buckets, flat pans on oil tank arch, 10 g syrup
2016 - 60 taps on gravity, 2x5 Smoky Lake hybrid
2017 - 100 taps on gravity, 20 buckets, home made 100 gph RO

[Maple Bud]

This is the third year that I have been using a LaPierre Minipro. When I used it for the first time, I was having a difficult time establishing a gradient, especially problems with getting a good boil in the front compartment of the syrup pan. The syrup pan wasn't sitting far enough back on the arch. I was able to move both the sap and syrup pans back further on the arch by loosening the bolts at the base of the stack and shifting the plate by about 1/2". It was also suggested that I put my firewood closer to the door (not touching). Both of these changes helped me achieve a better boil in my syrup pan and a better gradient. I am boiling with 2" in the sap pan and 1 1/2 in the syrup pan.1600316004


Need some advice,
I have boiled 3 times now in my 19x48 lapierre mini pro
Each time around 100 gallons . Due to being new to this kind of setup I'm running both flue and syrup pan at about 1-1/2" deep the evaporator seems to be level as good as I could get it (back to front and side to side) the flits are work as they should to maintain the levels, how ever I noticed last night that when I flooded the system in the beginning the sap that flowed to the front channel of the syrup pan is not turning to syrup. There's no gradient forming, and at the end of my boil I noticed that the syrup was gathering in the back float box of the syrup pan I drained from the back and watched a gradient form , but backwards. What am I doing wrong

[bagpiper]

I have a Smoky Lake 2x4 drop flue hybrid pan on a home built 275 oil tank arch. I installed a grate and blow air in underneath the grate and up through the fire box. It takes about 100 gals. to sweeten the pan and the sweet is pretty dark even in the flue pan section. After about an hour of boiling, I do get a gradient and can draw off about a quart at a time. I keep a very hot fire going with the fire box about 1/2 full and burn a mix of dry hard and soft wood. I do make sure that I have some fire just inside the door so that the syrup pan is boiling hard. I run the pan shallow at about 1". If I stay on it and keep the sap level low, I average about 20 gals./hr.

[wnybassman]

I would first suggest adjusting your front float so that the syrup pan has 1" depth and keep your flue pan at slightly higher. (Just covering the tops of the flues)As others have said, these smaller evaporator are much harder to get finished syrup on, but it can be done. IF you have a ball valve also from the rear to front pan, it also helps if you can close that as you get closer to 215+ temp. I run a drop flue Lapierre 18x66 and I can draw syrup about every 2 hours but only when I plug the back to front pan flow. It takes about a 100 gallons of sweet before any syrup is made. I have a friend who has the 18x60 raised flue Lapierre, and he doesn't have the patience or the stones to run it to syrup in the evaporator, and regularly draws off at 215 or so and finishes on a propane stove.... It never made sense as you have all that fire and heat in the Evaporator, but each person needs to use what works for them. Important thing to know is if you are going to lower your depths the boil will increase and will command much greater attention to sap levels. The other take away I have learned is that the floats can and will stick occasionally which if not watched could lead to burnt pans....

I have a 18x60 Lapierre also. Can't believe your friend doesn't take it to syrup?? What's the hang-up? I routinely draw-off at 1-3 brix past syrup and thin it down to correct density on propane. That's just the system that works well for me.

[sweetvt]

I here ya, I too make syrup on my Lapierre, but have had a close call or two with plugging it to get it to go the final degree and then it often will over shoot by 2-4 degrees and I have to draw some light after to thin it out. IF you look back though the post there are several people who tend to draw off light (less than 219) and finish off in separate pan.When I bought my evaporator about 10 or so years ago it was right about the time that Lapierre bought out Waterloo- small. I had ordered a raised evaporator direct from Lapierre USA and even but a deposit on it. It got close to sugaring time and no evaporator came. I got nervous and found a drop flue version at Bascoms and grabbed it. IT only has 2 sections in the front and being a drop flue only 1 float. In hindsight I really wish I had searched more for a raised flue which all have 3 Sections in syrup pan and a valve and float now for front pans . Both make good syrup, but even Lapierre realized the drop flue design in the small evaporator was not as good and by the next year I believe they only offered the raised flue versions.

[Dave Puhl]

There are several factors that could be going on ...start with the arch...at the back of the fire box is the wall all the way up to the flue pan..then do you have too much cold air on the bottom of the syrup pan...are you helping to make the gradient when you start up each time..I run an inch deep on the syrup pan..

[wnybassman]

Need some advice,
I have boiled 3 times now in my 19x48 lapierre mini pro
Each time around 100 gallons . Due to being new to this kind of setup I'm running both flue and syrup pan at about 1-1/2" deep the evaporator seems to be level as good as I could get it (back to front and side to side) the flits are work as they should to maintain the levels, how ever I noticed last night that when I flooded the system in the beginning the sap that flowed to the front channel of the syrup pan is not turning to syrup. There's no gradient forming, and at the end of my boil I noticed that the syrup was gathering in the back float box of the syrup pan I drained from the back and watched a gradient form , but backwards. What am I doing wrong

Are you letting the sweet stay in the pans between boils? The bolded text makes me ask that question.

[mellondome]

How does the very front compartment boil? Sounds like it isnt boiling at all. If it isnt, you may need to look at how you manage your firing and the door. It may also help to block off the first 4-6 inches of your grates. I found with a 2x6 that the draft would cheat up the front/door and would not allow the very front if my pans to boil.

[bmbmkr]

I bought an 18x42 drop flue from Bascoms last fall, they also had the 18x18 syrup pan, but instead, I got greedy when I found they had an 18x30, or should I saw 30x18 syrup pan in the clearance aisle. I had to fab some plumbing but I got them hooked together, I have a home made arch, 2 55gal drums welded end to end, barrel stove door kit, angle iron pan rails, skinned with stainless and insulated with blanket and split brick. I have the barrel stove grate standing on top of split brick, on top of mortar sand. Air under fire provided by an old hair dryer from my mothers salon, blows into a joint of 2" gas pipe under the grate. With the 30" pan, I had to add another section of drum and rebuilt the pan rails stack base and the flue shelf. I originally built this arch to hold 5 steam pans.
We got the arch finished on 4 Feb 17, and got the first 50 taps in on Superbowl sunday. Tapped 75 more the next day, and started boiling around 7pm that night. I tested sap that morning at 2%. It took FOREVER to sweeten the pans. Mind you this is my first boil on anything but steam pan batch boiling, I hadn't even used the arch with the steam pans, and this was the first boil, I had leak tested the pans, but no test boil with water. I could not establish a steady boil in the flue pans, it would boil hard at the front of the flue pan, and a bit at the back of the flues, but I could not get it to a rolling boil all along the flues. The sap pan boiled pretty good. One thing that helped was the AUF, and I also put 3 split brick on top of the grate, and left a space between them so that I could adjust the forced draft. I met Mr Kuhn from Sunrise at a maple seminar in Kentucky back in Dec, he told me about one of their hi end rigs that a customer had, and he couldn't hit the advertised boil rate, Mr Kuhns and his son visited their sugar house, and determined the poor performance was due to the firing method, his wood was too long and he wasn't loading consistently. This is my first year, so I DID pay VERY close attention to my sap level, firing sequence, my wood was a little big, but I have very dry white oak, hickory and ash. I was happy to be boiling, but only managed 15gph max, and usually 12gph. My arch is under shed,with the north end blocked off, so not the most efficient set up. My first boil was 16 hours!, and over 220 gals of sap boiled off. My 18x30 with 1 1/2 inches holds 3 1/2 gallons. I did manage a gallon and a half of syrup, which was on the sweet side, - my first time using a hydrometer as well, did not realize there was a difference between hot test and cold test line. I ran it til it was in between. I left sweet in the pans and two days later boiled again, 250 gallons boiled off in 18 hours. The next couple of boils I ran for 5 to 6 hours, and wow, one night I accidentally left the arch door open and boy did I think somethin BAD was happening, it got loud, my flue pan began to roll from front to back- I kept this up and it picked up to 18gph. I guess the little squirrel cage in the hair dryer wasn't pushing enough air. (This is a cabinet like hair dryer that lil ol ladies used to sit under, not the hand held kind). In between my boils, I plugged my flue outlet and drained my syrup pan into a 5 gal stainless milk can and kept in a refrigerator. This helped with the gradient I believe. Wow got a little long winded here, but I'm still excited. This is my first year with an arch and "real" pans. I dumped more sap than I boiled due to the crazy weather. Next year I'll definitely tap earlier,plans are drawn up for a 14x20 timber frame sugar house, and adding RO , AOF and doubling my taps. I have my steam hood started but never got it on this year. And a pre heater for inside the hood. I'm sure these will increase the gph. I think I can get two more years out of this arch and this neat little pan set up.

[EBG18T]

Looking for some advice....My flue pan (18 X 42) is dead on level & my finish pan (18 x 18) is 1/8 inch low on the draw off side. The Problem? I have pumped 350 gallons of sap thru the evap and only drawn off once(half gallon). The gradient has not developed and I am now on the verge of making syrup in my flue pan. I am planning on plumbing up the flue pan tomorrow....But, What else could be causing this? The liquid is even caramel colored in the float box. I know from past experience that it should be clear in there. Any advice would be appreciated!!

Did you guys get your situations with the CDL 18x60 resolved? Mine is coming next week and this thread has me nervous.