Modulating Draw Off question

[mcraejc]

Hi Everyone

Has anyone upgraded to a modulating auto draw-off valve system (the ones with the belimo valve) from a simpler auto-draw off system? Just curious if people have found a big difference in the systems and if they would recommend upgrading.

I'm thinking I could get more accurate draw-offs with less nitre build up on the pans resulting in less pan changes. But I'm wary of the price tag and worried that it won't really be much better than what I have currently.

For context I'm currently using an older Marcland auto-draw that uses a motorized ball valve. I have a regular ball valve in front of the auto valve that I keep partially closed to prevent draw-offs from lowering pan levels too much. I upgraded to the ball valve from the older plunger style system. My evaporator is a Lapierre storm 2x8 with 2 crossflow syrup pans. I'm boiling concentrate at roughly 8%

Thanks
Jamie

[JoeJ]

I have had a D&G auto draw off with a belimo control for six seasons. One of the best investments yet. I did not have a Marcland draw off valve to start with, but saw other producers use them. As I started to look at auto draw offs to buy, I was at a sugar makers who had a belimo and knew that it was valve to buy. The valve has worked perfectly for six years. Once you get the daily (barometer) temperature setting set correctly, every subsequent draw off comes out right at proper density. The first season I used the draw off valve, I recorded the different barometer readings and the temperature when the syrup came out at proper density. Then I made a chart of the different barometer readings to use as a starting point for the first draw.

My D&G valve has worked very well, but I think that Lapierre has a better set up for the belimo valve. (My opinion)

[ecp]

I doubt it will help much with niter build up. It is better to have a consistent draw the entire time of the boiler for many reasons but in your set up I doubt that will lead to less niter. Don't get me wrong I'd recommend it but if your only hope is it reduces niter you will be let down. On your set up i would recommend H2O's modulating auto draw because they are the only ones using an MFT (multi-function technology) actuator which would allow you to change the stroke of the actuator (you aren't going to need 1.5 inches coming out of a 2x8) also they are the only one's compensation for barometric pressure so as long as you don't lose power, they are much more hands off.

[mainebackswoodssyrup]

ecp has a very good point about H2O's ability to adjust the valve opening for a smaller evaporator. Does anyone know at what size these will actually work well? Like how many GPH of syrup do you need to be drawing off for it to continuously make syrup? I wouldn't expect it to reduce niter, niter is always there. But, it could cut down on foaming in the syrup pan. And in general, anything you can do to keep sap/syrup flow continuous and consistent is an improvement. I've always figured we were too small to consider one of these, but I like the technology.

[ecp]

You can get continuous draw from smaller evaporators like a 2x8 (a pencil stream or smaller usually) depending on pan depth and other things like fuel type/ RO consentration level/ect/ect. The issue with auto draws for smaller evaporators is just size. I've seen 1.5'' auto draws on 4x16 rigs that work fine, but with butterfly valves that's just too much flow for a smaller evap. Smaller evaps should use more like a 3/4'' valve in my opinion. While I am at it butterfly valves are just bad in general because of the paddle in the liquid stream catching debis and clogging up things (ask me how i know).

[Super Sapper]

Unless I am wrong, the modulating ones open and close more or less depending on temperature. The more it goes up the more it opens, and the more it goes down the more it closes. The more basic auto draw just opens and closes fully. Typically on these you would have a second valve to adjust flow.

[mainebackswoodssyrup]

You can get continuous draw from smaller evaporators like a 2x8 (a pencil stream or smaller usually) depending on pan depth and other things like fuel type/ RO consentration level/ect/ect. The issue with auto draws for smaller evaporators is just size. I've seen 1.5'' auto draws on 4x16 rigs that work fine, but with butterfly valves that's just too much flow for a smaller evap. Smaller evaps should use more like a 3/4'' valve in my opinion. While I am at it butterfly valves are just bad in general because of the paddle in the liquid stream catching debis and clogging up things (ask me how i know).

Agreed, we use a smoky lake 1" auto draw and it works fine for our 2x6. It does have a ball valve that I throttle back to get a small dribble at each drawoff- about a 1/2 gallon each time. With that wide open, draws are 1 gallon or a little more which results in the pans getting flooded, longer between draws, etc. That is also boiling raw sap right now. But when the shack is done and the RO is going, I expect to be boiling 8-10% concentrate. There is a Youtube video out there from H2O showing it set up on a 18"x66" evaporator but just to demonstrate how the MFT adjustment works. They aren't actually boiling and drawing to demonstrate. Definitely interested in hearing any real world experience from small sugarmakers who have tried it.
I vote for Jamie (the OP) to try it out and report back so I know if it's worth it!! :lol:

[mainebackswoodssyrup]

Unless I am wrong, the modulating ones open and close more or less depending on temperature. The more it goes up the more it opens, and the more it goes down the more it closes. The more basic auto draw just opens and closes fully. Typically on these you would have a second valve to adjust flow.

You are probably right, looks like the H2O one is just a regular drawoff with the adjustable belimo valve/barometric pressure compensation.

[craigwade2005]

Agreed, we use a smoky lake 1" auto draw and it works fine for our 2x6. It does have a ball valve that I throttle back to get a small dribble at each drawoff- about a 1/2 gallon each time. With that wide open, draws are 1 gallon or a little more which results in the pans getting flooded, longer between draws, etc. That is also boiling raw sap right now. But when the shack is done and the RO is going, I expect to be boiling 8-10% concentrate. There is a Youtube video out there from H2O showing it set up on a 18"x66" evaporator but just to demonstrate how the MFT adjustment works. They aren't actually boiling and drawing to demonstrate. Definitely interested in hearing any real world experience from small sugarmakers who have tried it.
I vote for Jamie (the OP) to try it out and report back so I know if it's worth it!! :lol:

Shane you really need to stop commenting on these posts. If I see any more gadgets / things to build I'm going to have to upgrade the shack to a 200 amp service :lol:

[mainebackswoodssyrup]

Shane you really need to stop commenting on these posts. If I see any more gadgets / things to build I'm going to have to upgrade the shack to a 200 amp service :lol:

Craig- you should thank me. Then you should build a modulating drawoff for small producers. When that's done, make a Turbo 250 or 300 RO to compete with Lapierre's machine. When they're done, give me a call and I will try them out! I ain't very smaht, but I bet there's more money in making and selling equipment than there is in making syrup :D

[ecp]

If I see any more gadgets / things to build I'm going to have to upgrade the shack to a 200 amp service :lol:
Couple things come to mind. Make a Brix reader that can modulate a valve for less than 7K
Make a pneumatic bottler that I don't need to trade in my truck to afford.
PH balancing RO Auto Wash cycle with chem injection.
But it was want the big bucks make a tree tapping robot that can also do leak checking.

Just a tip but don't stop at a 200 amp service because you will be ripping that out in 5 years haha

[craigwade2005]

Craig- you should thank me. Then you should build a modulating drawoff for small producers. When that's done, make a Turbo 250 or 300 RO to compete with Lapierre's machine. When they're done, give me a call and I will try them out! I ain't very smaht, but I bet there's more money in making and selling equipment than there is in making syrup :D

Made the RO this past season. Limited to a smaller 190 pump however as we don't have 220V for the feed pump and bigger electric motor. Still got a low pressure and high temp shutoff built in though.
I currently have an autodraw, His name is Chris and so far it's only cost me a case of PBR.
Also have an automatic fill station, her name is Marissa. She whines a little but it's still quieter than a diaphragm pump.