Our “Team Performance” conducted a water boiling test on Saturday September 21, 2013. Our goals were to heat 5L water then maintain a steady temperature for 45 minutes. While our test was deviated from the standard WBT, the test was very informative (for me at least). To get started...
1. Put the can inside with the mesh on top of the can. The mesh will hold the wood pellet fuel. Figure 1 shows how the mesh and tin can were set up. Weigh the stove.
2. Prepare three cups of pellets and weigh it. Get a small sample to soak with alcohol. This will help start the fire.
3. Prepare 5L of water. Weigh it.
4. Place the fuel atop the grid. Be sure to spread the alcohol chips around the fuel mix.
5. Light that bad boy. Keep the concentrator lid off until the fire has spread. When the fire is steady, the gasification process has most likely started.
6. Place the concentrator lid on. Put the water on atop the concentrator lid. Start the timer.
7. When the water is boiling, take the water off the stove and record the weight of the stove and water separately.
8. Adjust the primary air control to set the stove to keep the water at the temperature.
9. Wait 45 minutes then record the weight of everything. (For the WBT data excel sheet)
So we had pretty good success starting the fire however we could not reach 100ͦ C and we could not control the fire. The flame seemed out of control as it flared onto the concentrator lid and around the pot. Closing the primary air valve did not affect the flame. I suspect the cause of the excessive flame was fuel in the outside container of the stove that was burning or the amount of fuel that was gasifying was creating too much gas for the fire. Figure 2 shows the flame between the containers. Although the fire seemed wild it kept the water at a steady temperature.
One “mistake” we made was during refueling. We tried to put fresh fuel atop the charcoaling fuel. We had trouble lighting the second batch of fuel while it was on the old fuel. Too much smoke was released. When the relighting attempt failed, we scrapped the fuel and tried again.
Observation: When we dumped the old fuel, was gasifying so we put it in an air tight container and closed it quick. The old fuel creates a lot of gas quickly and the gas can get in your eyes.
Question: We also want to understand why it happens. The hypothesis was that too much wood gas which overwhelms the oxygen stream.
Improvements: We added the can under the mesh because we want to shorten the fuel chamber. Add mesh at the top connecting the inner and outer cylinders to prevent fuel from falling in the gap.
Most interesting: The primary air vent can become useless during the middle of the test. The loss of control was caused by either a fire between the walls of the stove or excessive gasification.
1. Put the can inside with the mesh on top of the can. The mesh will hold the wood pellet fuel. Figure 1 shows how the mesh and tin can were set up. Weigh the stove.
2. Prepare three cups of pellets and weigh it. Get a small sample to soak with alcohol. This will help start the fire.
3. Prepare 5L of water. Weigh it.
4. Place the fuel atop the grid. Be sure to spread the alcohol chips around the fuel mix.
5. Light that bad boy. Keep the concentrator lid off until the fire has spread. When the fire is steady, the gasification process has most likely started.
6. Place the concentrator lid on. Put the water on atop the concentrator lid. Start the timer.
7. When the water is boiling, take the water off the stove and record the weight of the stove and water separately.
8. Adjust the primary air control to set the stove to keep the water at the temperature.
9. Wait 45 minutes then record the weight of everything. (For the WBT data excel sheet)
So we had pretty good success starting the fire however we could not reach 100ͦ C and we could not control the fire. The flame seemed out of control as it flared onto the concentrator lid and around the pot. Closing the primary air valve did not affect the flame. I suspect the cause of the excessive flame was fuel in the outside container of the stove that was burning or the amount of fuel that was gasifying was creating too much gas for the fire. Figure 2 shows the flame between the containers. Although the fire seemed wild it kept the water at a steady temperature.
One “mistake” we made was during refueling. We tried to put fresh fuel atop the charcoaling fuel. We had trouble lighting the second batch of fuel while it was on the old fuel. Too much smoke was released. When the relighting attempt failed, we scrapped the fuel and tried again.
Observation: When we dumped the old fuel, was gasifying so we put it in an air tight container and closed it quick. The old fuel creates a lot of gas quickly and the gas can get in your eyes.
Question: We also want to understand why it happens. The hypothesis was that too much wood gas which overwhelms the oxygen stream.
Improvements: We added the can under the mesh because we want to shorten the fuel chamber. Add mesh at the top connecting the inner and outer cylinders to prevent fuel from falling in the gap.
Most interesting: The primary air vent can become useless during the middle of the test. The loss of control was caused by either a fire between the walls of the stove or excessive gasification.
