For the very small
maple producer this is a actually a water purification unit that
you could buy online. This is actually a GE Merlin. They did stop making those
few years ago.
There are some used ones around and there are other products on the market
that would be
very similar and what we have with this
is where water is pushed into the unit
where concentrated sap would come off of the unit
and then where purified water would come off the unit.
When you buy a unit like this, it comes
with a carbon filter as the very first thing
and you cannot have a carbon filter anywhere in a sap operation.
The carbon filter will absorb the sugar out of the sap. It will very
quickly become saturated
and then it acts very strangely. So
you need to take that first part off
and that would be empty. There'd be no
filter in there and when you're making
putting sap into the unit that would just simply
fill up with sap and do nothing. The second
part is where there are two reverse osmosis membranes
and they fit right into the cannister and that's what
they look like. Even though it looks like it's in a plastic bag
do not remove that. That is part of the system
and what's going on here is sap is being pushed
into the end of the membrane when it's being pushed into the unit by the pump
and then pure water comes out of the center. Concentrated sap then comes out of the other
side of the membrane
and passes out the other line.
So there's two of these in here
and that type of membrane operates at
what we would call standard pump pressure. We don't need a special pump
with this. We simply will
be operating off of a standard shallow well pump.
So that's what
that's all that's in there and these of course have to be
in tight as the O-rings have to have to seal. So that's
the RO part. That's the reverse osmosis piece of this.
Obviously if I have to
different things coming off my RO I need two different tanks.
I have two tanks sitting here. One that will collect purified water
and the other that will collect slightly concentrated sap.
Now the rating
on a unit like this is that it will give me 30 gallons a purified water per hour
but when I put sap against it rather than just
ordinary water I get on sixth of that productivity.
So this unit will take off somewhere between four and five gallons of purified
water per hour.
That means that many gallons per hour I do not have to boil.
The negative of a unit like this is
since it's only operating at standard pump pressure
it will only bring the sugar content up to between four and a half and five
percent.
That's as high as it can go. That means this will take out half of the water,
it'll save me half my boiling time,
it'll save me half of the energy
but that's the best it can do and for a very small operation
that's wonderful. So this is the RO part of it. Set that in the background
and see what else we need.
This is just a standard shallow well pump
but it has
a couple things that are very important to the
backyard maple producer that you'll want. One of them is
you need a line to go to your sap tank and that line
must have what we call a foot valve.
What that does is it allows this line to fill up with sap
but then it will stay full of sap, so that I don't have to re-prime my pump every time
I change tanks. So the foot
valve with the line goes
right on this part of the pump and it's a little bit cold and stiff in here but I
guess it actually went on.
My sap would be in a container like this.
I would drop that line right to the bottom of the tank
will then suck into here.
The next important thing to have on a pump is a shut-off valve
right on the exit. So the sap is coming in through the pump, it's pressurized.
You have a gauge here that shows what that pressure will be. Typically it will be
somewhere between 50 and 60
PSI and what this valve does
is every time you need to change tanks or
move anything around because on a commercial RO
those changes are all made by valves inside the system but for us, when this tank gets
empty
I have to pull this line out and stick it another tank that I might have
when I do that I have to close this valve
so that it doesn't suck air. If it
sucks air, you lose prime. Priming a pump
if you've never done that it can be a bit of a pain. You have to fill the pump
and the line and then turn it on and then it will function. If there's air
in there, a lot of times
the prime won't take effect and the pump does not work.
So a valve there and a foot valve on the bottom of our line -
critical - have those in place. After the
pump, after the sap enters the pump,
we're then gonna run it through a
small, just a regular water filter.
Usually these would be like a 5 micron style
of filter. You can buy these
at any place that deals with water at all and inside there's this nice little filter
and what that does is it takes any
miscellaneous items out of the sap. Sometimes theres some
insects make it their way in the sap. Sometimes a little dirt does
and this just cleans it out because we do not want that in our RO membranes.
This has a directional flow
and we want to make sure we obey that. So coming out of the pump
we're gonna put it on the entry side of this
filter and like I say it's a little cold here today
and that's not gonna cooperate very well
but from the pump into this filter and then from the filter
into the reverse osmosis unit.
There we have a pressure gauge there. Like I say this pressure gauge and this
pressure gauge should be pretty much the same. If they're not that means the
filter in here is plugged.
You probably have to change that several times during the season but
they're not very expensive.
Now I have a barrel full of sap,
I prime my pump. I push it through the filter
into the reverse osmosis unit and then I have
purified water coming out one line and I have
concentrated sap coming out the other. Now it's not going to be very
concentrated
by just going through this unit once
so what we do is we run this line
right back into
our sap tank.
That way are the sap tank gradually becomes sweeter and sweeter and sweeter
until you are ready to take it off and put it
on the boiler.