Autodraw off Build

[Dennis H.]

Here is another one of my builds for this up coming season.
I felt that with having an RO I will be drawing off more often so I figured that a autodraw off was in order.

I know that there are very good priced setups out there but I just love building things.

There really is not much to a autodraw off. The build is very close to my vac temp controller, I am just controlling a motorized valve instead of a motor.

The PID controller, Temp probe, switches and indicators I got from Aubers Ins. The Box I got from Lowes. The motorized valve I picked up off of Ebay.
That was the hardest part to find, at least with one that I was happy with.

I am using a tri-clover fitting to mount the valves to the drawoff box. I have one on the other float box on the other side of the syrup pan so that I can quickly flip the pan if and when needed.

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[KV Sappers]

Wow, you've been a busy fellow. Do you hire out. I've upgraded to a Lapierre propane evaporator and I'm hoping to have a sugar shack built by this upcoming season.

[Dennis H.]

Way to go your self kvsappers.

[unc23win]

That is a real nice looking autodraw Dennis nice job!

[Waynehere]

Very nice job Dennis. May I ask what your valve is? I have been looking and am also having trouble finding a good one to try.

[Dennis H.]

The draw off valve was the hardest part to find f the build.
I ended up finding the valve on eBay. It is a 120vac.

There is an interesting story with who sold it to me but it is not for here.

[Waynehere]

Yeah, I think we all have a story or two about eBay purchases.... :(

As for your valve, I can find the 120v in both motorized and solenoid, but having trouble finding ones designed for the higher temps. At least in a decent price range. Most are all Med temp up to 212 degrees.

[bees1st]

Nice ! What do you figure you have in it for materials ?

[Dennis H.]

I have about $460 in the pump build. The gear pump is the largest part of the cost. I found Central Equipment has them at a great price, about $270.

[Machinist67]

Here is the valve I found which is good to 266F. http://www.dudadiesel.com/choose_item.php?id=2WJ20020N

[Waynehere]

Here is the valve I found which is good to 266F. http://www.dudadiesel.com/choose_item.php?id=2WJ20020N

Perfect. I found one of these on eBay for $75 and was about to buy it, so thanks for saving me some cash... :)

[Shiftman]

Thanks Dennis,

Just so I understand, you have a temperature thermometer in the final stage of boiling to indicate your sugar content? Then your controller talks to the valve to draw off syrup?

Have you ever thought about having another valve to dump in emergency water to prevent burning in case your pan runs out of water?
Also, do you feel comfortable enough to leave the arch alone without supervision?

[Dennis H.]

I have the temp probe mounted so that the tip is right beside the dial style thermometer. That way I can compare the two.

As for walking away, this will be the first time with it so I will run the evap like I have done in the past until I see that it is consistently drawing off when it should.

As for adding emergency water, it would not be a hard thing to do. All that would be needed is a small tank to hold the water and a valve. With the pid controller you could use the over temp alarm to activate the valve to open and dump in water or or that matter sap.

[Waynehere]

OK, so I have one built and I know where I want the valve to open, but what is the temp you want it to shut again? I have been looking through these forums and can't find anyone mentioning that?

[regor0]

I have mine close at .5 to 1 degree under syrup. Depending on the barometric pressure of the day. For me it's usually around 218.5. As you valve opens and it starts running syrup out the temp will rise past your open set point a little bit.
Mine ends up being pretty close to the correct brix that way.