Archive for 2024

Testing our 2″ Breurram

Tuesday, May 14th, 2024 No Comments


In the past the Breurram has been built and tested by the WOT. It is a type of hydraulic ram pump, made out of standard components using an airbuble in a piece of flexible tube as expansion ‘tank’.
More about the mechanism behind the Breurram can be found in this youtube video.

Several times the WOT has been asked: What would happen if you scale up the Breurram?
Our earlier demonstration and test set-up uses 1” valves. Following yet another advice request and subsequent visit at the WOT, we decided to test a larger version of our beloved ram pump.
The diameter of the Breurram can, according to the manual, not be larger than it’s supply line.
Because the supply of water from our ferrocement tank/cistern to our testing rig ends in a 2” pipe, a 2” Breurram has been constructed. Only the valves have been purchased, as other materials were present. The cost for these came down to about €95.



Upon first testing it became apparent that the system wouldn’t work reliably without the optional tensioning spring. Next to this problems were found with starting the pump. Therefore a bracket has been placed on the spill valve connected to a bolt sticking out of the pump, allowing the valve to be moved manually at start up. Depending on the setting of the tensioning spring and the pump head the system was able to work without human intervention. The frequency of the pump cycle was far less constant compared to our other, smaller, Breurram. What this is a result of remains a question at this point, but suggested are lower flow speeds and/or quality of components.
Tests are done using a supply head of 184 cm (approximately) and pump heads of 397, 582, 767 and 952 cm. Using a return line and a petrol pump pumping back used water to the supply tank, the supply head was held as constant as possible. So far one test has been completed at a constant setting of the tensioning spring. The yields at different pump heads and several curve fits can be seen in the following figures, as well as some pictures /visualizations of the test/setup.

The plot displays the data points along with an automatic second-order curve fit using the least squares method. It is expected that the flow should approach zero at a pump head approximately ten times the supply head. However, the second-order curve fit does not exhibit this behavior, even when considering the mean and standard deviation. To address this issue, a new curve fit was developed by defining a trial function and making several coefficient guesses

So far, in order to draw more accurate conclusions several more tests will be conducted, of which the results can be expected in the near future. This will also include a (rough) comparison with the yields of our other, smaller, Breurram. You can read more about hydraulic rams here.





Solar shower update

Friday, May 3rd, 2024 1 Comment

Now that the winter has subsided, we decided it was time to turn on our solar shower again. A system that you can read more about here.
The system was turned on during the April working weekend, and two WOTters actually enjoyed a (still very cold) shower, a very welcome surprise after all the mud that was picked up at the other activities 🙃.

At an association night (Wednesday the 10th of April) we noticed two problems with the system.
-The water temperature was rising unexpectedly fast on Saturday and Sunday (for the sun intensity those days) and dropping too fast at nights.
-The pump failed to switch on on Monday and Tuesday. The system thinks it switched on the pump but the return-line temperature was not following the collector temperature. Which also meant the tank-temperature was not increasing on those days.So that Wednesday we checked the water level of the tank and sure enough the tank was almost empty, during dinner we let the tank fill up. And we used the bottom flush of the tank to try to flush some rust out of the system, which might have been blocking the pump.

We were hoping this would work, but during the following days, we noticed that the pump still was not switching on correctly. On some days it was (like Saturday the 12th of April), but on other days it was not. We can however see that the tank now heats up and cools down slower than it did when it was not completely filled.

Here you can find a graph displaying the data that is measured live from the solar shower system. This graph shows the temperatures of various sensors and the time the pump was on for every 10 minutes.
-The pink line shows how long the pump was on, the pump cycles on automatically when the collector temperature is higher than the tank temperature.
-The dark-blue line shows the temperature of the collectors, it quickly rises if the sun is shining.
-The red line shows the temperature of the water flowing out of the collectors and into the tank.
(This means it follows the collector temperature while the pump is on but the temperature quickly drops towards ambient once the pump has shut off)
-The light-blue and yellow line show the actual water temperatures in the isolated storage vat this is the water that is used to heat the shower water through a heat exchanger.

On Monday the 14th of April we flushed more rust out of the pump, this time by actually manually disconnecting the pump and running it with some clean water. This did not seem to work, because on the 18th the pump was jammed. On the 23th a small hole was found in a pipe and had been welded shut, this explains why the tank was as good as empty during the working weekend. The pump was replaced with another one on the 24th and this seemed to have helped, because the pump has been functioning every day up to the day of writing (the 3th of May). Since the 29th of May the days kept getting warmer and on the 1th of May the tank was at a temperature of 45°C and someone had a nice and warm shower 😊.




Working weekend april ’24

Wednesday, April 17th, 2024 1 Comment

It’s finally spring and at the working weekend we were busy like bees. This time the focus was on fixing the windmills on our terrain. The crankshaft of the Oasis needed to be placed back. The mystery of the ripped sails of the Cretan windmill had to be solved and the ripped sail needed to be repaired. The Diever needed a new breaking pin and we also wanted to install an underground power line to the Diever so we can put our praised windmill in the spotlight 🌟. Besides fixing the windmills, the Breurram was going to be tested at the PTB tower to see how much flow it produces on different heights.

We started the working weekend off with some pancakes, but soon after we all started on our projects. The crankshaft of the Oasis was temporarily removed. The Wednesday before the working weekend it was hardened to make it more sturdy, this morning it was placed back. The breaking pin in the Diever was replaced so she could pump again. Meanwhile the dig for the trench towards the Diever started. At the back of the terrain the PTB was cleaned using a pressure washer and prepared for the Breurram test.

The Cretan windmill had a ripped sail that needed to be repaired by gluing pieces of pvc sheets over the tear lines. After a while it was decided that the edge of the wing could be used to cover these tears and still have it look white. Towards the end of Saturday the wing was fixed and put back into the Cretan windmill, which started pumping soon after. The suspected reason why the blade ripped is because the ropes that hold the blades open were too loose.

During the working weekend the Kijito was still waiting on new parts so we could not repair her pump. In the meantime it was suggested that the reason the old pump did not work was because it sucked sand from the bottom of the well. The sand probably made the old pump wear out quicker. Therefore the well was deepened such that when the new pump is installed it will wear out slower.

At the end of the day we finished with a BBQ 😋, celebrating our achievements halfway into the working weekend. And even after this the people who were eager to dig finished the trench and layed the cables towards the new power supply at the Diever. In the afternoon of Sunday the trench with the cables was filled again and the new socket was installed at the Diever.

On Sunday the first test for the 2” Breurram took place. With the water pressure provided by the ferro-cement tank it pumped water up the PTB. The flow of the Breurram at 5 different heights along the PTB was measured by measuring the volume of water displaced up the tower in 15 minutes. The pump itself ran without interruption for more than 1 hour despite a somewhat irregular pulse frequency. The data of this test will be processed and soon you can read the elaborate results in another blogpost, here.

We also appreciate all the smaller maintenance that was done on the terrain, namely that a large portion of the lawn was mown. So the terrain and her windmills can once again be appreciated in their full glory.