tri/quad jet building

[yankee joe]

Yes I am back again with more questions. On my quest to build subsurface dredge using one pump. My first task is build and test the power jet. I have built many single port jets from 2 to 4 inch but have never built a multiple port. Are there any of you out there who have built multiples and tried a 2 or 4 degree right or left offset on the tubes to put spinning effect on vortex where the water streams meet. My thought is that this will create a whirlpool behind the vortex and more suction. Give me thoughts. Tell me if I am dreaming.

 

[machineman]

I built a trijet. It worked fine for me. I just divided the area of the single jet and made 3 smaller jets with about the same area. I doubt the vortex action will give more suction, but it may help force the heavies to the outside of the tube faster. Good luck

 

[BillNEWAST]

If you are using an Underwater Dredge of any type, or a surface dredge for that matter, you HAVE to get the Au and other Heavy's on the Bottom of the Water Column as quickly as possible. The closer to the Suction end of the hose this can happen the better. That is why I like to use 20' of hose even it I only need 10'. Plus the extra hose allows the dredge to be positioned further Downstream and doesn't allow the SMOKE to reduce your visibility. This is Especially True if you are in a Pool type area and can't get the flow of current to clear your visibility quick enough.

The best way to get the gold to settle out in the first or second riffle is to have it enter the box from the Bottom of the flow. This is partly why the manufactures changed from the old Bang Box theory to the present flattened and widened jet flare. If you use a single hose Power jet then you need position the flow of water angled slightly up from the horizontal, this will allow less disturbance of the flowing material on the bottom of the hose as it passes jet. The quicker you can get the material to Settle Down once it passes the Jet and enters the Flare the More Fine gold you will recover. Remember that the Gold can Only get caught in the box IF it has an obstruction to settle behind or in front of in the Suction Eddy. If the gold is in the middle third of the Water Column then it will take a LOT longer to settle out and may never make it into the catchments you have in the box.

The old Suction Nozzles were Very Good for catching Fine or Smaller gold because the gold had a chance to settle out while traveling down the hose. This is in essence what is called a Slick-plate in front of the Riffles. Similar to the Flair on the A52 sluice boxes. Watch what the material does while the water eats away at it and how the gold never travels in the upper 2/3s of the water column. I Always slides on the bottom of the box and is caught before or after the First Riffle. only Extremely small dust is caught in the Lower 2/3s of the sluice IF you can get it to settle out of the Water Flow.