In the last episode for this season, Shawn Pomrenke shows an animation of his new mega-dredge. I think I saw a problem with the fact that it is a SUCTION dredge and the suction hose goes up over a boom rather high off the water. The problem here is that one atmospheric pressure can only push water 32 feet up a tube that has a perfect vacuum above it. His rig looked like it could have had a high point greater than 32 feet above the surface of the water. Even if it wasn't that high, any substantial height is going to reduce the flow rate. The only way around this is placing the pump at or below the surface of the water and driving the water and material upwards. Anyone know anything else?
That setup will require more careful priming, to initially overcome the height barrier, but once it gets going, the additional height won't matter. Like a siphon, the water falling down after it crosses the high point will drag along the water behind it. They'll probably have an additional pump for the priming.
