The Sunflower system is made up of eight distinct sub-assemblies, as pictured below.
- The boiler is designed from lightweight, corrosion-resistant aluminum. The boiler weight is kept to a minimum to lower the center of gravity of the overall collector dish/boiler assembly. Since the Sunflower pump has a closed steam/water cycle it is important that all internal components be corrosion resistant to avoid build up of wanted precipitates that might clog the system. The solar incidence occurs on the sides and bottom of the boiler. The sides and bottom are painted in a thermal resistant lat black heat paint to help in overall energy absorption. The overall heat balance requires that the top of the boiler be insulated to minimize losses. The isolation tube helps to both protect and insulate the steam tube, and also strengthens the overall assembly.
2. Dish and stand assembly
- The Sunflower uses a low cost, factory-made parabolic dish with a 1.8m diameter, which is supplied in six segments for easy transport. Efficient solar energy capture requires an accurate parabola, so careful assembly of the collector dish is required.
3. Rocker arm
- The rocker arm converts the horiztonal motion of the engine into vertical strokes to lift water. The arm can be adjusted so that the piston stroke length decreases or increases according to well depth. The low-friction brass and polyethylene parts ensure a long working life. As well the low-cost plastic bushings prevent metal to metal contact and eliminate the need for lubricating oil.
4. Flywheel and post
- Both the flywheel and post have been designed to be robust and easy to transport and manufacture. The post allows the entire pump, including the parabolic dish to be assembled in a vertical layout.
5. Stuffing box and condenser
- The Sunflower Pump steam/water cycle is a closed system. Key to the design is the ability to condense the outlet steam and return it to the boiler. This makes it possible for the pump to operate continuously throughout a solar day with minimal user input. Another key element of the design is the stuffing box that makes it possible to pressurize the water delivery system. This allows water to be pumped to overhead storage or to micro-irrigation systems. Integral to the design is a low friction brass sleeve and a low-cost, low friction teflon packing.
6. Engine frame
8. Recirculation pump
- The Sunflower uses a diaphragm style recirculation pump to complete the closed-system steam/water cycle. It is designed with longevity in mind, using rust-resistant materials and has no piston seals or high impact moving parts.