I need information about basic water pumps. I'll have to build a mechanical one for school. Do you have any ideas, information, designs, links? Thanks!
There are a number of different types of pumps (and some overlap between types, too). A suction pump basically sucks water up. This might be a piston pump, or a venturi pump (or some other types). This type of pump raises water up by lowering the air pressure above the water, and letting atmospheric pressure push the water up the tube. Suction pumps can't pull water up more than about 32 feet (because that's how high atmospheric pressure can lift a column of water) but they have the advantage that the pump can be located at the top of where you want the water (rather than down where tie water is). A Lift pump basically uses mechanical force to raise water upwards. This could be a chain of buckets, or an Archimedes screw, or a bubble-lift pump. All these pumps need to have at least part of the pump down at the water level (with the exception of the bubble lift, which is kind of a unique design). The most common water pumps are centrifugal pumps. These use a set of spinning vanes to pressurize the water. Water comes in at the center, and hit spinning vanes; these shove the water outward through centrifugal force, and the outlet pipe is at the outside edge of the circle. One other interesting type of pump is the hammer pump. It's sometimes used in remote farming areas, because you can use the energy of a running stream to pump water high up a cliff. In a hammer pump, you let water flow through a relatively long tube. The tube has a vertical pipe near it's end. You let the water run through, and then suddenly close off the end of the pipe. The momentum of the water (combined with the fact that water isn't very compressible) can force a shot of water very far up the vertical tube. Hope this gives you enough to search for on the web!
A very simple and old design for a water pump is called the ball-chain or bucket-chain pump. A google search should show you what they are. Building one should be fairly straightforward and simple.
