Iterations of the piston pump

Below are three iterations of piston pumps, which we have built and used on our windmill. 

The first is a 1-1/2" PVC cylinder with a 1" PVC piston. On the bottom of the cylinder there is a 1-way valve (that only let's water into the cylinder). On the bottom of the piston, inside the cylinder, there is another 1-way valve that only allows water to enter the piston pipe. As the piston moves up and down, it alternately creates low and high pressure in the cylinder. Under low pressure, water is sucked into the cylinder through the bottom valve. Under high pressure, water is forced up, into the piston pipe. The piston pipe is connected to the water tank (via a flexible hose that accommodates the up and down movement). Performance: low output due to significant leakages between the piston valve and cylinder wall: 400 l/hr in light-moderate winds.

Next we upgraded to a treadle pump. The treadle pump is modified so that the piston can be attached to the pumping rod. Also, we do away the suction pipe typical of treadle pumps by submerging the pump in the water. We run only one cylinder, while the other cylinder is blocked so not to leak pressure during operation. This pump put out more than 10,000 liters per hour, but required strong winds to get started. Ultimately, it put too much stress on the windmill components, and would need a larger windmill to be a viable pump option.

Currently we are running the pump pictures below. This pump has some advantages. It has 4 cylinders, and can be configured to run on any combination of 3, 2, or 1 cylinder. We tested it on 4 cylinders and 2 cylinders. Due to light winds on the day of testing, 2 cylinders showed better results. It pumps in the range of 5,000-7,000 liters per hour in moderate winds.

One advantage of this pump is that the cylinders are 1-1/4" PVC and the piston seals are leather bicycle pump seals. This makes for a rather affordable pump. Each piston is made of a bolt, a nut, two metal washers, and two leather seals, the total cost for which is not more than $0.75.

Good crops at Chifuchambewa

Maize on irrigation at Chifuchambewa in Salima promises more food for the community at a time when scarcity is the norm. The primary harvest was below expectations due to sporadic rains late in the growing season. Irrigation has been limited in the village until recently when AWP began teaching farmers how to pump water from their well springs.

In the distance, deep in the valley, the Lipimbe River flows by, untapped for irrigation. Farmers are looking for ways to use their new pumps to draw water up the hillside.

Nasala Farming Club

Nasala Farming Club impress with good irrigation and nursery management at their training garden, near Likuni, Lilongwe. They can't wait to expand to plant out the onions from the nursery.

Windmill video

Rural Enterprise Forum - a lot of good work being done around Malawi

AWP presenting at the first Rural Enterprise Forum put on by Goods for Good.

Visit from Summit Church

Just going through pictures and found these from a visit by Summit Church at our demo garden in July. We really appreciate all you are doing with Africa Windmill Project. Thank you for coming out and we hope to see you again soon.

Windmill go!

Second generation windmill at Mziza Demo Garden. We installed the windmill last week, letting it run over the weekend to check for any kinks. We hooked on the pumping rod today and a makeshift pump to see if we could get water into the tank. We did get water all the way to the tank, 3m above and 20m laterally from the water source.