Here is a brief description of a venturi based siphon assist
that made using materials that I was able to pick up at my local
hardware store. What is it? A venturi based system relies on
the effect of speeding up a fluid reducing the pressure.
Basically pressurized water is sprayed into a tube at a high
velosity. This will cause water and whatever is in the
chamber to be blown out the exhaust tube. This reduces the
pressure in the main chamber and will cause air to be drawn
into it. What can you use it for? This system can be used
to start a siphon, or cause a siphon work work faster when
transfering to a carboy. I have attached this venturi assist
to the water output of my counter flow chiller which allows my
chiller to process the hot wort more quickly, while at the
same time starting the siphon process for me.
Cut one length of 5/8" copper tubing 12 inches long, and
then 4 lengths of 5/8" copper tubing 1 1/2 inches long.
Solder the 12 inch length tube inside the tee on one end of
the straight side. Then solder 2 of the short pieces in the two
remaining parts of the tee.
Cut a 6" length of 3/8" O.D. Tubing and straighten it out if
the tubing came on a roll. Solder that tubing into the small
end of a 1/2" x 1/4" reducer. Using a 1/4" drill bit, drill out
a second reducer so that it can pass completely over the 3/8"
piece of tubing. Place this piece on so that the smallest end
of the reducer is against the one that is soldered (Do not
solder this reducer in place). Finally solder on a copper end
cap on the other end of the 3/8" O.D. tubing.
Connect the female gardenhose adapter to this assembly using
the reducer already soldered onto the 3/8" O.D. tubing. You
will likely need to use one of the 1 1/2" sections of 5/8"
tubing to join these pieces. Solder these connections. Now you
may experiment with creating a spray pattern. Ideally you will
want an agressive stream flow with a fairly spread out pattern.
I used a dremel to cut a cross hatch into the 1/4" end cap.
This seemed to create a fairly spread out pattern. If your
pattern is not to your liking you may try another cut on the
other end cap, just desolder the first and add the new cap to
try again.
The next step is to insert the second assembly into the
first adjusting the position of the 3/8" tubing so that no spray
exits through the side of the tee while allowing a maximum of
air to enter the side. Once you have found the ideal location,
solder the reducer to the tee, then solder the 3/8" tubing
inside the reducer to hold the tubing in the correct position.
Finally attach a 1/2" 90 degree elbow, another reducer, and
a 3" piece of 3/8" tubing so that your venturi assist unit
resembles that in the first picture.
Cut one length of 5/8" copper tubing 4 inches long, and
then 2 lengths of 5/8" copper tubing 1 1/2 inches long.
Solder the 4 inch length tube inside the tee on one end of
the straight side. Then solder 2 of the short pieces in the two
remaining parts of the tee.
Cut a 12" length of 3/8" O.D. Tubing and straighten it out if
the tubing came on a roll. Using a 1/4" drill bit, drill out
the reducer so that the tubing can pass completely through the
reducer. Solder the tubing into the small
end of a 1/2" x 1/4" reducer leaving 2" of tubing sticking
out the small end of the reducer.
Solder a short length of 5/8" copper into the side of the
tee followed by a reducer and then a 2" section of the 3/8"
tubing.
Finally attach the assembly produced in step 3 to the free
end of the tee. You should now have something resembling the
carboy adapter. Apply 1 drop of vegetable oil to the top/inside
of a rubber stopper with a 3/8" hole that is slightly small for
your carboy. Forcefully twist on the rubber stopper over the
5/8" tubing on the end as shown in the first carboy adapter.
Insert the rubber stopper of the carboy adapter into the
neck of your carboy.
Connect the wort line to the top of the
adapter.
Connect the venturi siphon assist to your garden hose and
direct the exhaust tube away from anything that should not
become wet!
Attach 3/8" I.D. tubing from the side of the venturi siphon
assist to the side of the carboy adapter.
When the flow is turned on in the venturi assist equipment,
air will be evacuated from your carboy, which will draw in wort
from your wort line. The amount of suction depends on the effectiveness of your
venturi spray pattern and water velosity exiting the spray nozzle.