Wash plant
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Justbent
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Ya, when I watched my sluice I could see it needs to be wider. I choked it down and it speeds up. I need to expand it so it slows.You know, I gotta tell you this. My brother in law and I built my sluice based on pictures of a similar design I wanted. It was 3 months longer in the build and a real budget buster, coming in at twice the cost...mostly due to me. $150 was actually $300+. Anyways, yesterday I ran all of my cons from 2013...found a flake or two on top...haven't panned what's left yet...but I'll tell you this...there is NOTHING like a dialed in sluice of your doing. Great job! Oh yeah, I almost forgot...when I posted my results here, I did the same thing you did...watched the video. And guess what? The sluice TELLS you what to do. I thought I would tell it what to do...
SLNugget
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Less angle?
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Justbent
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Then the water is too deep. I think. I loose that wave over the riffle I think spreading it out and keep the volumn is a better option. I think the sluice is too small for the amount of material that you can run thru the hopper. I'm guessing from 12" wide to maybe 24" wide.
Jason in Enid
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Careful, that is a H U G E increase. Look at the available dredges and what volumes they can move. An 1 1/2" dredge has a 10" wide sluice. A 3" uses a 14" and a 4 inch uses a 16". That 4 " is moving about 8 times the water and material as that 1.5" with about a 50% increase in size. I don't think you could move enough water to run a 24" sluice.
Jeff95531
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I would experiment with what you have. PVC is cheap. Try smaller or less holes in the bars, then enlarge them. Or a flow control valve? You may even want to get some pay dirt to dial it in. It worked for me. I wouldn't necessarily start over....yet.
Good luck.
Good luck.
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Justbent
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I'm sure there's a way to calculate this. The pump can deliver 264 gallons per minute. So if I want my water to be about 2" deep, how wide should my sluice be? I can't find those buttons on my calculator so I was guessing. 14" probably be closer to right. Depends on the impeller in there pump. Only 2" more doesn't seem enough just by my eye but hey, I prolly had a few beers by then.
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Justbent
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I don't want to do anything to slow it down. I need to match the sluice with the size of the hopper and the water flow so I get maximum thruput. I want 3 or 4 people to be able to dump there bucket in at the same time, then go back and get another. When they get back, the hoppers ready for another load. The next one is already in the works with some angle changes and the sluice bigger.I would experiment with what you have. PVC is cheap. Try smaller or less holes in the bars, then enlarge them. Or a flow control valve? You may even want to get some pay dirt to dial it in. It worked for me. I wouldn't necessarily start over....yet.
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Jeff95531
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We all learn as we do...can't fault you for that!
Jason in Enid
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It's a calculus function, but I don't know how to figure it myself. You probably should measure the output of your pump and then maybe you could the pick brain of an engineer for the sluice width you need. Or you could just mock-up a couple short plywood sluices find one that works for you.
Jeff95531
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Chris with Fabrication specialist did the calculations for me and my 4' long 15" wide sluice which requires 1.5 to 2" of water. I haven't seen him around for quite a while so I'll post what he gave me. Hope it helps
At 15" wide you're going to need a pump capable of about 2000-2200 gph. A sluice box that wide simply needs more volume of water to flow properly. For plumbing diameter you will need to run 1 1/2" hose from the pump to your hopper and once it's in the hopper you can use 1 1/2" in then T it off with two 3/4" runs going to either side of your hopper, or one long 1 1/2" diameter spray bar along the back, etc. It's really up to you how you want to lay the plumbing out, you just want to ensure you're getting the full 1 1/2" of flow without restriction because as I said you need plenty of volume for your 15" wide box. Drilling holes in your spray bar is actually much easier than most people think. Basically if you have 1 1/2" of water volume coming into your hopper, you want to get that much out (or a little less if you want more pressure). So if you go with one long 1 1/2" spray bar in the back let’s say, you need 1 1/2" worth of holes. So you could do 6- 1/4" holes, 12- 1/8" holes, etc I just evenly space them and make sure each end has holes close to clean material along the edges of your hopper, there no real "system" to drilling holes. You want to be close to your 1 1/2" number or if you have say 15- 1/4" holes all your water will fall out the first few holes and not make it to the end of your spray bar and your pressure will be nonexistent (I hope that makes sense ) Also when building your spray bars it easier if you can remove them to clean them out if you get a clog (either uncap one end or remove the portion of the spray bar for cleaning) you don't have to glue everything, hand pressure will press fit PVC just fine and hold well but you can get it apart in the field if need be.
At 15" wide you're going to need a pump capable of about 2000-2200 gph. A sluice box that wide simply needs more volume of water to flow properly. For plumbing diameter you will need to run 1 1/2" hose from the pump to your hopper and once it's in the hopper you can use 1 1/2" in then T it off with two 3/4" runs going to either side of your hopper, or one long 1 1/2" diameter spray bar along the back, etc. It's really up to you how you want to lay the plumbing out, you just want to ensure you're getting the full 1 1/2" of flow without restriction because as I said you need plenty of volume for your 15" wide box. Drilling holes in your spray bar is actually much easier than most people think. Basically if you have 1 1/2" of water volume coming into your hopper, you want to get that much out (or a little less if you want more pressure). So if you go with one long 1 1/2" spray bar in the back let’s say, you need 1 1/2" worth of holes. So you could do 6- 1/4" holes, 12- 1/8" holes, etc I just evenly space them and make sure each end has holes close to clean material along the edges of your hopper, there no real "system" to drilling holes. You want to be close to your 1 1/2" number or if you have say 15- 1/4" holes all your water will fall out the first few holes and not make it to the end of your spray bar and your pressure will be nonexistent (I hope that makes sense ) Also when building your spray bars it easier if you can remove them to clean them out if you get a clog (either uncap one end or remove the portion of the spray bar for cleaning) you don't have to glue everything, hand pressure will press fit PVC just fine and hold well but you can get it apart in the field if need be.
Jeff95531
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Just wondering...what pump are you using that can push nearly 16,000 gallons per hour?
SLNugget
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SLNugget
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I did not mean that last post to sound so smart a$$. Sorry. Just trying to indicate IMHO there is nothing wrong with running the pump at something other than WFO. Lots of room for tuning the unit with pump speed, sluice angle and even riffle height/design if using riffles. I have not run a lot of equipment but what I have ran all seems to end up at an angle of about 7 1/2 to 8 1/2 degrees.
Smart A$$....
LOL
I posted this before but it is a VERY good read.
Back pressure / reducing outflow is good for a pump.
Cycle Stop Valves, Inc.
SLNugget
Sr. Member
In my previous life with race cars we always attempted to have the outflow a size smaller than the intake on any pump on the car. It is a huge help to prevent cavitation and maintain constant flow/volume and not introduce bubbles to the fluid. The other critical thing is to use fittings that do not choke the flow. No point in having a 2 inch hose and fittings with only a 1 1/2 inch or smaller bore. Sometimes very difficult to find the "good" fittings though.
Thanks for the link Doc.
Thanks for the link Doc.
AzViper
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Stan this is exactly why I went with 1-1/2" valves as the ID is close to 1-3/8" with the valves I found of which had the largest opening, but I have a tee to spread the water entering the spray bar from both ends to maximize total flow, not to mention I am also feeding the hopper and header box at the top of the sluice. I may find that I need a larger pump than the 133 GPM this pump will deliver. I know I am not getting 133GPM but I can put a flow meter inline and test this. My spray bar has 101 holes of 1/16" opening to maximize the pressure. My concern is the header box on the sluice as this is a wide open 1-1/2" pipe, but this is only in place if I need to add more water in the event the water from the spray bar and hopper do not provide enough water to maintain 1" of water over the Gold Hog Mats.
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