Pumps and Solar Steam

Steam Ejector or Injector

A Steam Injector or Ejector has no moving parts and is fairly efficient based on the Venturi Effect. The downside is that the pressure tolerance is very narrow, so a constant supply of steam at a constant pressure is required. This presents some problems for solar energy, which can be fairly variable. There is one elegant potential solution to this problem (I will discuss later, remind me if July comes around and I have still have not replaced this text with a link to the solution, wissenz (at) gmail (dot) com ).

Reciprocating

A ’’’Direct Acting’’’, ’’’Reciprocating’’’, aka. ’’’Positive Plunger Pump’’’ is simply a piston that moves back and forth and pushes water. A one way valve allows water to enter the cylinder when the pump is "push down" and a one way valve allows the water to exit the cylinder when the piston is "pushed" up. A hand pump generally works on this principle. See the wikipedia page on pumps. Such a pump can be powered by steam, the advantage being without rotary motion (just back and forth) the mechanics are simpler than a steam engine powering a crank shaft. Being piston based this kind of pump can work at varying pressures. Disadvantage is that it’s not as efficient as the Steam Injector and still has moving parts.

Steam engine to generator to electric pump

An electric pump has the advantage of being capable of being installed far from the power source, as electricity is easy to move. For instance, deep wells can generally only be powered by Submersible Pumps of which there is no elegant way to power with steam. So for submersible pumps or pumps very far from the solar concentrator, solar-steam-engine-generator-electricity is the only feasible solution.

Pumps Conclusion

In conclusion, all three pumps can be effective in different situations.