Diy dredge nozzle help

[battleox]

So this is the nozzle i built hyrdo dynamics looks like it should work but i ran it today and i had water shooting back out the suction end, not quite sure where i goofed up but that's where the wonderful people on treasure net come in handy thanks for any advise

 

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[Goodyguy]

Simple problem, difficult solution.

Problem: Not enough pressure to create suction.
Solution: The inductor (jet) needs to be restricted to one fourth the size of the supply to create high pressure.
Example: if your supply is 2" then you need to reduce the opening at the entrance to the suction tube to 1/2" if that doesn't work then a more powerful pump is needed.
Also: looks like to me that your nozzle is the same size as your supply. Your supply should be half the size of your nozzle and then the inductor jet reduced accordingly.



Example: If your nozzle is 2" then your supply should be 1" and the jet opening should be restricted to 1/4"




GG~

 

[battleox]

All that gargin got me lost, my supply line needs a reducer before entering my nozzle? Is that correct

 

[Goodyguy]

All that gargin got me lost, my supply line needs a reducer before entering my nozzle? Is that correct

Correct! along with the other mods that I suggested above.
Plus those pvc y's do not work as desired.

Here is a pvc build that would work if the pump is powerful enough. http://indyprospector.com/home_made_dredge.htm


GG~

 

[battleox]

Great thanks

 

[Goodyguy]

It's fun to make one out of pvc as a learning experience but for any serious dredging store bought is best unless you know what you're doing and can weld.

GG~

 

[Bnugget]

Here is one I just made yesterday out of some 2" emt conduit and 1/2" emt for the jet.



Haven't gotten a chance to try it yet but I think it will work. Need to find a place I can legally use it right now.

To get the tight radius on the 1/2" I filled it with sand and bent it around a 4" pipe. Then welded everything together.

 

[nuggy]

Hi there, I have made a few suction venturi nozzles over the years, as I couldn't find or couldn't afford store bought. The last one was four inch and I used a 3/4 inch jet with a flare out to the 1 1/2 inch supply. My pump is a 5 hp Honda driving an Onga pump - a factory built pump/motor unit available here in NZ. The old shop bought venturi had worn totally out and was very hard to get jammed rocks out of. Mostly because my hand wouldn't fit up past the nozzle restriction.
I lined up the new 3/4 inch jet to be slightly pointing downward but up the center of the pipe - so the water jet would hit the bottom of the pipe about 3 or 4 feet up. I used alloy for weight reasons, but also because it was what I had on hand.
I will try to load 2 photos showing what I came up with.

The result was great, power increase was such that the water and gravel came up the hose with such velocity at high rpm, that it shot right over the sluice box and landed back in the creek 2 feet beyond it! I had to slow it right down to be able to wash the gravel. The water was only 2 feet deep where I was working, but the old venturi did not have had that sort of power.
I made a removable restriction nozzle so I could get my hand in to clear blockages, and for easy replacement as it wears out.

 

[nuggy]

A smoother bend would be better, with less blockages resulting, but overall this one is pretty great. Nuggy

 

[Doitlaynstyle]

Here is the build I did and it works great. Good for booming and dredging but when dredging it is more difficult having to deal with 2 hoses...

http://www.treasurenet.com/forums/gold-prospecting/346419-working-new-project.html

 

[battleox]

One thing im having trouble wrapping my mind around is the one hose design, unless ur using a fairly large pump i cant see how it would work also u would need a short suction hose if ur not using a large enough pump. Ive figured out my flaw in my design and working on fixing it but wanted more insight on the single hose design before i modify or redesign my nozzle thanks for the insight

 

[omnicron]

One thing im having trouble wrapping my mind around is the one hose design, unless ur using a fairly large pump i cant see how it would work also u would need a short suction hose if ur not using a large enough pump. Ive figured out my flaw in my design and working on fixing it but wanted more insight on the single hose design before i modify or redesign my nozzle thanks for the insight

Single hose design for a suction nozzle? Or are you talking about just a standard nozzle?
A true suction nozzle will have a water in port, best use for this kind of nozzle is shallow water. This nozzle can be removed from the water and put back in with no problems.



A (single hose) nozzle is used in conjuction with a power jet. While this can be used in shallow water, if it's removed from the water for more then just a fast burp, the hose will lose it's prime, the stream of water from the jet will shoot up the flare and could possibly blow gold right out of the box.


Power jet:

 

[hwayeon511]

Hello !
For some reason my nozzle does not work well.
Any suggestions? recommendations?

 

[russau]

If your NOT using a hi-pressure / Hi volume pump your spitting in the wind! And match the nozzle / venturi to the pumps spec's !! It wont work good enough to suck the material from much of a depth.

 

[Assembler]

View attachment 1943026View attachment 1943026
Hello !
For some reason my nozzle does not work well.
Any suggestions? recommendations?

I know very little. However you may be able to go online and see that the 90 degree angle may not be the best angle. Also the input pipe may need to be changed. Just my 2 cents input here. There are others that know a lot more about this.

 

[Dogbite]

This is my 1 1/4" venturi suction nozzle for my electric micro dredge powered by a 24v 3700gph bilge pump. I figure the pump will produce about 10 - 12 psi.
The 3D printed reduction/injection insert piece has a final reduction of 1/4" from 3/4" supply.

 

[Assembler]

I'm not able to see the video. You may have to change things up some for a better results. You may be closer then you think.

Keep trying.

 

[Dogbite]

Vid of output of nozzle into sluice

 

[Dogbite]

Nozzle in action

 

[Jomsa]

Cool stuff guys. My own dredge nozzle just arrived. Designed it myself and had it manufactured by claim buddy. Cant wait to see it in action. Though that will take time as the ground is still frozen for almost 6 months. Still if you are interested check it out as it is Infinity Jet type, not the basic system.