I'm not sure this is strictly relevant as I'm completely ignorant of the energy efficiency of ram pumps, however I did build and install one of a modified design. It operated with 600 - 700mm of fall in water level (depending on how deep the stream was at the time) and pumped up to a tank over 50m above the pump. It pumped about 200litres a day.(Not much except it's continuous pumping meant it was much more than I needed for household use.) Called a Platypus pump by it's developer, the design differs from the original Montgolfier design and the commonly manufactured types I've seen by using a much larger diameter drive pipe and 'slam' valve, No 'snifter' opening, and a pressure tank modified from a household pressure pump rather than the usual air chamber - the opening is enlarged to allow maximum flow into the pressure tank during the hammer phase and it was stuffed with high density rubber foam to absorb the sudden influx and release it more slowly. The pressure tank was primed by pumping to a pressure about equal to that of the delivery line, The non return valve was also modified with a heavier spring. Without the last 2 items most of the water tended to "bounce" back before the non-return valve closed. Relying as it does on a larger flow through a bigger 'drive' pipe it may not be that much more efficient for the volume flowing through it. Energy wise I suspect (but can't prove) that it's better than the traditional design since the ?snifter' opening has to reduce the peak pressure during the ram phase. It's certainly more effective - operating with a smaller fall and pumping to much higher head. The old style ram pumps wouldn't work at all in my situation. There is also another recent design that I haven't had personal experience with that uses a diaphram connected to a small piston pump. It does use a water hammer in a similar way to provide the pumping energy to the diaphram. It's supposed to be very quiet and efficient (as in height and volume pumped for the amount of drop in water level at river/stream level), but I believe it too uses a larger overall water flow rate than convention types. It's called a Glockerman pump. (no result with web search, sorry ) Ken
- posted
20 years ago