After experimenting with fluidyne Stirling engines, I wondered if something similar could be made to run on steam.
After many failed attempts and a lot of head scratching this is what I came up with. There’s a 1/4” diameter one and a 1/2” diameter one.
This entire arrangement was filled with water beforehand and bled of any air, so there is absolutely no hot air in this system.
I believe the water at the bottom of the tee is heated to the point in expands to steam, which pushes on the water column above it, sending it out the outlet check valve. Once the steam no longer has the energy to continue pushing the water column, it starts to contract, which closes the outlet check valve. The contractions creates a low pressure area at the tee, which opens the inlet check valve allowing more water into the system.
Here is a drawing of what I’m thinking 2783-A9-CB-4613-4667-9460-EC1-AB029-A500 — ImgBB
I have modified the system to have the pumping unit (the TEE) to be above the water level with the inlet check valve remaining at the base of the tank (like a foot valve) and it does indeed create a suction, so the water level does not have to be above the pumping unit in order for it to work. Unfortunately I don’t have any pictures or videos of when I made this modification.
I would like to see some better flow rates with the 1/2” but unfortunately my little heat gun just doesn’t put out the heat I believe it would take to up that flow rate. My plan is to build or modify some sort of small wood burner with the copper tube inside the chamber so that the water can absorb as much heat as it can, that should increase the flow rate, although I’m sure if it gets too hot it will likely shoot steam out the outlet, but some tweaking can be done to minimize that, such as adjusting the depth of the tube inside the burn chamber.
I’d also like to experiment with putting multiple of these units in parallel to try and make a more even and steady flow rate.
I honestly couldn’t believe it when it worked, make a water pump that runs only on heat and has two moving parts, I know the fluidyne Stirling is the same but I can’t help but wonder if this setup might make for a more powerful pump? Who knows. I have closed the outlet valve and let the pressure build and have reached about 10 psi, but that is also just using my little heat gun, but the fact that it can build any pressure tells me it has some potential and is definitely more powerful that the equivalent fluidyne water pump.
If you look in the picture of the unit, right above the copper tube there are two big 1-1/4 to 1/2 reducers, I actually am trying to use the idea of a “regenerator” that the Stirling engines use, this section I have actually stuffed lightly with stainless steel wool, it should be acting as a heat store. It stores heat when the fluid flows from hot to cold and releases its heat when a fluid flows the other way, from cold to hot. My thoughts being that maybe it would help if the tube didn’t have to try and heat dead cold water every time. I can’t say for sure whether it’s helping or not though.
I definitely think this unit is similar to Thomas savery’s steam pump, although his operated with an external boiler and someone had to be there to open and close the valves. It’s probably a little closer to the pulsometer steam pump, although again this uses no external boiler and only has one pumping chamber instead of two.
Let me know what you think and if you have any ideas that maybe make it work better or possibly more efficient.