turnkey4099
Elite Member
Sand blasting uses Bernoulli effect to suck sand.
The principle BR is using is based on difference in specific gravity of water versus water-air-sand mixture. Since the air-water-sand mixture is lighter than water it is pushed up by water entering from the bottom of the pipe. Because of the velocity of water entering from the bottom is high enough it also sucks in some sand. There is an optimum volume of air to provide maximum flow. Too much or too little will lower the flow.
It's also the principle used in jet pumps. There the water pumped backdown the well is injected into the "up" pipe so that it is pointing up.
Harry K