Doug's Homebuilt Brew Page : Venturi Siphon Assist

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Description
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.

Pictures

Materials (venturi syphon assist, and carboy adapter)
Qty Description Amt
2'
5/8" O.D. Hard Copper Pipe
3'
3/8" O.D. Copper Soft Tubing
1
1/2 " x Female Swivel Garden Hose adapter
2
1/2" Copper Tee $ 1.10
5
1/2" x 1/4" Copper Reducer $ 2.95
2
1/4" Copper end caps

Building Notes - Venturi Siphon Assist
  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

Building Notes - Carboy Adapter
  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

Usage Notes
    To start a siphon into your carboy
  1. Insert the rubber stopper of the carboy adapter into the neck of your carboy.
  2. Connect the wort line to the top of the adapter.
  3. Connect the venturi siphon assist to your garden hose and direct the exhaust tube away from anything that should not become wet!
  4. Attach 3/8" I.D. tubing from the side of the venturi siphon assist to the side of the carboy adapter.
  5. 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.

dougbrown@citynet.net