Reccommendations On Automatic Draw-Off Units

[Bruce L]

Hi everyone,I am contemplating going with one of the new high efficiency evaporators for next season,so with a higher evaporation rate I will have to pobably go with an automatic syrup draw-off,Any advice on which type to avoid,or what problems to expect,etc?
Thanks

[Clan Delaney]

Marcland makes auto draw-offs ( [/URL][URL="http://www.marcland-usa.com"]www.marcland-usa.com (http://www.marcland-usa.com%29) ) Can't say good or bad of them - since I've never used them. I'm sure there's plenty here who have, though.

[themapleman54]

D & G has one ,all stainless steel

[maple ridge tappers]

I purchased a Marcland autodraw last year, not knowing what to expect. This set me back about $1000, but it is worth it's weight in gold.
The unit I bought has a smart sensor, that automatically compensates for the barometric pressure, and adjusts the draw-off temperature automatically. This may seem a little confusing, but once you play with it a little, it becomes very simple to operate.

[Sugarmaker]

This will be the third year with the standard Marcland unit and I like it a lot. Allows you to run the rig instead of watching and waiting for syrup to come to temp. It does take some fiddling to get it set and does have to be checked as the weather changes.

Regards,
Chris

[driske]

I'm not much of a record keeper, but we've had our Marcland for something like 15 years. It has been the most reliable piece of gear in the Sugar House. Roughly 50,000 gallons of syrup have passed through that solenoid opening, and it remains a functional entity.

[NH Maplemaker]

I agree! I have a Marcland and love it! Now I can talk and not burn the pans! Not that I ever did. Came close, realllllll close! There were 2 Marclands for sale here in the classified ads. Jim L.

[tapper]

This will be my 3rd season with a Marcland. It is reliable and easy to operate a very good addition and I will never make syrup again without one!

[Haynes Forest Products]

My next big Maple purchase will be a draw off. BUT as usual I will be dumping my syrup bucket when it dumps:mad: Do most people with them just leave the bucket in place and transfer with their filter press to the Bulk drums or to the finisher? I would also want to make use of the burnner shut down if things in the syrup pan get to hot................I could have paid for the thing with my new pans that I set fire to:emb:

[mapleack]

I love our Marcland, it works great. Occasionally I have had a piece of scale come off and plug the valve so it kept dripping. Flipping the valve to open then back to auto would always clear the problem. Haynes, we have to drawoff buckets, just switch them when one gets full.

[Jim Brown]

We too have a Marcland auto and We love it. As Chris said it lets you tend to the other things in the sugar house like firing and talking to the folks that stop in!It will remember to draw off even when you are talking!

Jim

[M & S]

It is wise to put a ball valve before the solenoid valve in case you ever have to remove and clean it while boiling. We have had a marcland for 6 years and the only issue is occasionally it will get restricted with sugar sand.

[farmall h]

What about if you have a beer in your right hand and a smoke in the other...will it still draw-off accurately? Oh, that scenerio would never occur.;)

[Sugarmaker]

Haynes,
We draw into a approx 5 gal stainless milk dumping station. Which is just below the output of the Marcland unit. I built a steel frame from scraps to support the dumping station. To the elbow on the bottom of the dumping station I had a 3/4 inch sst half coupling welded in place. Then threaded in a nipple and a 3/4 inch sst ball valve with a street "ell" turned down. It is high enough that I can draw off several small draws and then run it out into a stainless bucket and transfer to syrup to the strainers.
I believe any of the drawoffs on the market will make you smile if have made syrup for a while.

Regards,
Chris

[Haynes Forest Products]

Im waiting for a call from Roth Sugar Bush on a Marcland with the alarm and the option to shut down the oil burner if things to hot. Reading other post and seeing others with them. Has anyone had them get stuck open and over fill the tank. Does anyone have the shut down option on theres and does it take a secondary relay???. I was also thinking about using a 3 way ball valve so I can still check with hydro cup..I need to look busy:)

[Grade "A"]

Im waiting for a call from Roth Sugar Bush on a Marcland with the alarm and the option to shut down the oil burner if things to hot. Reading other post and seeing others with them. Has anyone had them get stuck open and over fill the tank. Does anyone have the shut down option on theres and does it take a secondary relay???. I was also thinking about using a 3 way ball valve so I can still check with hydro cup..I need to look busy:)

I made my own but put a gate valve in front the solenoid valve in case it got stuck open. I have had a small peice of niter flake off the pan and it made the valve not seal, but I hit the open button and it flushed out and sealed again.

[Jeff E]

I put solinoids and temp sensors on each side of my rig, one controller unit.
This way my Marcland is ready to go when I switch sides, reversing the flow to help manage niter build up. I can switch sides in about 1 minute on my Leader drop flue.

I am very happy with the Marcland unit.

[Rselleck91]

I just started building my own draw off units same as a marcland but 1/3 of the price and more user friendly. Shoot me a email for inquirers. The Marcland paddle valves are a flakey design using a rubber flapper and a magnet to open and gravity to shut. I run a low profile solenoid valve with a spring return end result no hang ups. I also can inter grade high temp shut downs for oil, stack temp for wood,low sap level, and even put a temp on off for vacuum so it becomes a comand center. My units are custom built for the customer and start at 350$.
I have purchased a Marcland a few years back and have nothing bad to say about the pid controller but the technology is not advanced enough to be worth 1200$ But running auto draw is they way to go even on a small scale. You just can't beat the consistency. Also you can monitor the temp a lot better with a read out to the point where a cold draft comes in and cools the pan half a degree
Ryan
Selleck Automations

[eagle lake sugar]

Today I had a group tour going on and just before the draw, it became question and answer time. I was answering one question after the other and completely forgot about the evaporator! Luckily wifey happened to come in and check it just before the scorching point. Then I got "the look." Next year, I'm getting an auto draw.

[Wanabe1972]

I have a ball valve right off the pan i call the throttle and that feeds to a T. One leg of the T goes to a ball valve for manual draw off ( hydro cup) and the other to the auto valve. I have a union between the T and the auto draw valve so i can pull off quickly and run water through it if it gets sticky. I found with out the throttle valve it draws short bursts of syrup but with the throttle i can draw an 1/8 stream almost nonstop once i get rolling. It is all homemade and also shuts off my blower during draw off and lights a light to let me know its all working.

[rayjavu]

I'd like to know more about your draw-off.

[DrTimPerkins]

A ball-valve between the pan and the autodraw unit is pretty common. The practice mentioned is that you run the evaporator with the ball valve about 3/4 closed most of the time. This will reduce rapid drops in liquid level in the syrup pan and level out the draws considerably by smoothing out the syrup flow from the drawoff valve. It also helps to avoid dropping the liquid level in the pans too much and scorching the rig if you have a huge draw since you can't drop the level below the level of the ball setting. You do need to open it up every now and then (30-60 min) to prevent niter build-up around the valve and if you do need to draw off more syrup than the ball allows at this setting.

It is always good to have some sort of manual open/close either on the autodraw or in addition to it for those occasional moments when you need it.

[rayjavu]

Is it better to use full port ball valves rather than reduced port?

[wiam]

Is it better to use full port ball valves rather than reduced port?

Full port is better. Just in case you need to get syrup out in a hurry. Or when draining pans

[WestfordSugarworks]

I would recommend a modulating auto drawoff. I don't know about what brand to choose but modulating units work better than simple 'open-close' units in my opinion. We have a marcland that just opens and closes and it works fine for us but especially if you are boiling with wood i'd recommend a modulating unit. They help reduce batching when you draw off and you it's more hands-off.

[RIVERWINDS]

I would recommend a modulating auto drawoff. I don't know about what brand to choose but modulating units work better than simple 'open-close' units in my opinion. We have a marcland that just opens and closes and it works fine for us but especially if you are boiling with wood i'd recommend a modulating unit. They help reduce batching when you draw off and you it's more hands-off.


I also have seen the modulating draw offs in action and knowing what I know now, I would have paid the couple hundred extra for a modulating unit instead of getting just an open/close valve. I really would like one now that I'm boiling concentrate.

[Tweegs]

OK…that’s it…dog-gonnit!….you guys….

It bugs me, this flippant use of the word “modulated”.
In my world (electronics, with a heavy emphasis on RF), the term “modulation” wouldn’t normally apply to anything syrup related.
Near and dear to my heart, here is the definition of modulation as I understand it:
https://en.wikipedia.org/wiki/Modulation

A brief look at the above page would leave many a folk scratching their heads, much as I’m doing now but from the other side of the fence.

To get to a syrup related form of modulation as it pertains to auto draw offs, we can define modulation in its most simplistic form, which means “change”.

OK, change what??

I’ve been struggling with the answer to that question for a few years now based on what I’ve read here in different threads.

The first auto draw off I built used a PID controller. There were a few issues with this design, most notably was that niter tended to build up and prevent the valve from closing fully.

It struck me then that “modulating” the valve briefly at the end of a draw (rapidly open and close a few times) would help prevent niter build up. Perhaps this is what was meant by a modulated valve? Some responses in other threads seemed to suggest so.

Version two of my auto draw saw the PID controller land in the trash can, replaced with a micro controller. With the flexibility of writing my own software, not only was I able to modulate the valve, but I could calculate the boiling point of water (given the barometric pressure and altitude) and compensate the draw off temperature based on pressure (with a user offset to fine tune the rig).

Other threads seemed to point to this as the definition of “modulated”. (I’d use the term “pressure compensated” rather than “modulated”. Though it’s technically correct, “modulated” is a very loose fit. Cleaver marketing gimmick, perhaps?)

And now, today, I’m reading that “modulated” refers to something that helps prevent “batching”.
I’m once again confused.

Would someone kindly spell out this form of modulation so that I, and other technocrats, can fully understand what is being discussed?

Thank you!

[rayjavu]

Modulating actuators allow a valve to be opened proportionally rather than just on/off.
From the interwebs:

http://www.engineering-dictionary.org/VALVE,_MODULATING
A valve which can be positioned anywhere between fully on and fully off to proportion the rate of flow in response to a modulating controller (see modulating control).

https://assuredautomation.com/modulating-control-valves/
What is Modulating Control?
Many process control valves are quarter-turn on/off valves that rotate 90 degrees from on to off. These are also referred to as stop valves or isolation valves. They are either completely open (90°) or completely closed (0°).
A modulating control valve, however, has the ability to be accurately positioned at any point between 0° and 90° as well. This adds the ability to control the amount of flow in addition to whether there is flow or not.
Quarter-turn valves include ball valves, butterfly valves, and plug valves. All of these can be made into modulating control valves by adding an actuator with modulating capabilities. These actuators can be either electric or pneumatic.
Note: Standard port and full port ball valves do not increase flow evenly in relation to their degree of rotation. There are two methods used to achieve a directly proportional increase of flow with regard to degree of rotation. They are: using a V-port ball, or a trim disc insert.

http://www.ap.emersonprocess.com/en-US/brands/bettis/products/valve_actuators/actuatorbyApps/Pages/modService.aspx
Valve Actuators for Modulating Service
Modulating control valves are used in variable-flow systems in which flow must be adjusted to slow, moderate, or full stream. Due to batch process changes, regulate flow or other control applications, the actuator is adjusted often and its control accuracy of modulating service actuators must remain consistent and not deteriorate.

[DrTimPerkins]

Would someone kindly spell out this form of modulation so that I, and other technocrats, can fully understand what is being discussed?

Two kinds of auto-draw valves. Open/close (solenoid) and modulated. Open/close are simpler and cheaper, and just open when it hits the draw off temperature or above, and close when the temperature falls below. Modulated draw-off valves are motor-driven valves that open a variable amount (typically with a butterfly valve) based upon the syrup temperature input and the programming. Typically if the syrup temperature is right at or just slightly above the set temperature, the valve opens just a tiny amount. If the temperature is further above the set temperature it opens more. Thus the opening of the valve is modulated by and proportional to the temperature of the syrup (the input). I believe the use of the term "modulated" is appropriate in that circumstance.

The terms I have more issue with is "sterile" and "gravity vacuum" or just plain "gravity" tubing. All sap in tubing responds to gravity, not just in 3/16" tubing. Also "vacuum transfer." We aren't moving vacuum....we are moving air. But....I just clench my teeth and nod my head. Sometimes it's easier that way.

[RileySugarbush]

Different industries have there own nomenclature. Sometimes it is a legacy from an old technology.

From the world of motion control, a better term for these more sophisticated draw offs might be "proportional control" Where the valve is opened proportionally to the amount of temperature error. For example, 5% open at the set temperature, and another 20% per degree. The inputs then are set point( initial draw temperature) and gain ( % per degree).

For those that are unfamiliar, the PID controller mentioned by Tweegs stands for Proportional, Integral, Derivative control. The basics for servo control like cruise control on your car.

P is like described above,
I is the amount the valve opens if it has been sitting for a long time at a temp above the set temp
D is how you can get the valve to open more if the temp is rising real fast.

[Tweegs]

OK, that makes sense.
And “modulated” would fit.

I use a solenoid. Not sure I’d be comfortable with a butterfly valve. We’ve already scorched the pan a half dozen times or so over 8 years.

I added a little hysteresis in the code (a couple of tenths above and below target draw off temp) to keep the solenoid from chattering uncontrollably.
We start drawing a little thick and end a little thin. It all evens out in the wash.

Those times we overshoot the temp buy a lot (making syrup further back), we’ll fix the density before transferring the syrup to a tote.
Opening a valve wide in response to a temp spike on our rig would have unfortunate consequences, I think. Slow and easy, fix it later, is the way we roll.

I put a manual ball valve between the pan and the solenoid.
That’s to keep from burning my fingers and control the output flow.

“Stuff” happens with electronics.
Should the valve unintentionally go wide open, there’s a small number of us who’d give thought to sticking a finger in the dam, a smaller number would be impulsive enough to act.

You’ll only do that once, briefly, trust me.




I just clench my teeth and nod my head. Sometimes it's easier that way.

No doubt Dr. Tim, no doubt.

In automotive R&D it’s all about the numbers.

Biggest pet peeves:
“It was at -30 and went up to -40”
Or some nimrod will hand me data with unsigned values.

[Tweegs]

Different industries have there own nomenclature. Sometimes it is a legacy from an old technology.

From the world of motion control, a better term for these more sophisticated draw offs might be "proportional control" Where the valve is opened proportionally to the amount of temperature error. For example, 5% open at the set temperature, and another 20% per degree. The inputs then are set point( initial draw temperature) and gain ( % per degree).

For those that are unfamiliar, the PID controller mentioned by Tweegs stands for Proportional, Integral, Derivative control. The basics for servo control like cruise control on your car.

P is like described above,
I is the amount the valve opens if it has been sitting for a long time at a temp above the set temp
D is how you can get the valve to open more if the temp is rising real fast.


Aye,
Many who use the PID controllers for a draw off will turn the P,I and D functions off, leaving basically an ON/OFF thermostatically controlled switch, which is all that’s necessary when using a solenoid.
If using a ball or butterfly valve, enabling the PID functionality would provide this type of modulated valve. Setting up a PID properly has a bit of a learning curve, however.

For those lurking in the wings on this thread, maybe contemplating a DIY draw off, I’ll offer this:
Those $15 PID controllers available on e-bay are cheap Chinese knock-offs.
They use 8 bit A/D’s, op amps as instrumentation amps, the RTD reference is not a precision resistor, no EMI filters, are prone to temperature drift and the instructions are terrible.
That’s techno-jargon for “They’re junk”.
You should plan to spend $50~$100 for a decent product.

[DrTimPerkins]

You can prevent drawing off too much liquid (if your drawoff configuration is suitable) by only cracking open the ball-valve between the evaporator and the drawoff. That way liquid can't drop below the level that the valve is open.


Biggest pet peeves:
“It was at -30 and went up to -40”
Or some nimrod will hand me data with unsigned values.

How about "high" vacuum?

[WestfordSugarworks]

How about "high" vacuum?

What's wrong with saying that?

[Tweegs]

“High” vacuum is an oxymoron.

“Deep” vacuum is a more appropriate description.

[DrTimPerkins]

What's wrong with saying that?

Vacuum is a number that goes negative from air pressure. Saying high means going up, so you're going up in a negative direction, which makes no sense. What we should really say is "very low pressure" or something akin to that.

[Tweegs]

You can prevent drawing off too much liquid (if your drawoff configuration is suitable) by only cracking open the ball-valve between the evaporator and the drawoff. That way liquid can't drop below the level that the valve is open.

In my case, the port is affixed to the bottom, drops to an elbow and swings 90* to outboard.
The result is that the valve is positioned below the bottom of the pan.
(Had some trouble getting a pic both big enough and clear enough to post, else I would have)

There may be a work around, need to think on it a while.

[wmick]

http://www.biomaterial.com.br/vacuo.pdf

[DrTimPerkins]

Yes, I know that the term "high vacuum" is used by convention in some fields (and that the engineering definition for "high vacuum" is around 29.91" Hg, not 24-25" Hg like we think of in maple). That doesn't mean it makes intuitive sense. In maple we talk about vacuum as being something and that we can transfer vacuum, when, in fact, it is the absence of something (air).

[wmick]

Yes, I know that the term "high vacuum" is used by convention in some fields (and that the engineering definition for "high vacuum" is around 29.91" Hg, not 24-25" Hg like we think of in maple). That doesn't mean it makes intuitive sense. In maple we talk about vacuum as being something and that we can transfer vacuum, when, in fact, it is the absence of something (air).

I agree completely... Just enjoying the debate.. :D

[Maple River Sugar]

Revisiting the thread.

I will be purchasing an autodraw off this season and wanted feedback on brands and models. I currently am a one man show and thought this would be a no brainer for me. I have been drawn to the Smoky Lake models: Simplicity and Crescendo only due to price points.

What other brands or models are out there which offer the best value/options for the price.

Thanks in advance.

[minehart gap]

I got a Auber Instrument PID controller (already assembled) and a Echotech stainless steel actuated ball valve. I will use it for the first time this year but have less than $300 in it.

[maple flats]

I have their basic Simplicity auto draw. It works perfectly. I also have a ball valve ahead of the auto draw valve. I regulate the flow with that. Once set it does not need to be adjusted. I wanted the ball valve so when the auto draw opens and closes it does not create surges in the pan. The Crescendo madel would not need the extra valve but to me the extra $300 was not worth it. The ball valve method works perfectly.
I also often boil solo, the auto draw takes that aspect of making syrup and makes it simple. The beauty of an auto draw is (if you set the temp correctly) that you will always draw syrup at the right density.

[mainebackswoodssyrup]

Smoky lake also makes an accessory valve setup to go with their simplicity auto draw to help with the surging. I think it's like $80. Wah re hoping to purchase the simplicity auto draw this year.

[heus]

I have their top of the line Great Lakes Guardian and its has worked well for two seasons. I could have lived with their less expensive versions, though.

[S.S.S]

We ran the smoky lake crescendo for 4 years and is pretty much a flawless unit, but wanted a modulating unit so sold the smoky lake and went with lapierre unit. Ran it one season so far and love it.