How does this water pump work and is it suitable for an engine concept?

[twiz_]

I found this water pump (or so I think) that I'm trying to learn more about. I'm not exactly sure how it's intended to work, but I tested it in a way that works: The tube that comes out of the main part at an angle seems to be the input, where air is forced down the tube. Once the air reaches the end of the tube, the air is stopped by a valve that opens to the opposite direction, so the air instead goes down the narrow tube that pushes air downward into the cylindrical mechanism on the bottom of the pump which would be submerged in water. Somehow this forces water up the vertical tube and I think it has something to do with the previously mentioned valve.

The reason I would like to know is that I'm currently developing an engine concept, and this kind of pump would be particularly useful. I need to have a thorough understanding of the principles behind the pump in order to properly build what I need to build, but I'll save that for my own research. Any help is appreciated.

 

[montoyas7940]

Does it provide a smooth continuous flow or pulses? Also, is the air discharged along with the pumped water?