A Government of India approved Cook Stove Testing Center has confirmed that the Mewar Angithi, a $1 device, really does turn a traditional stove (chula) into one of the best high efficiency cook stoves on the market. The tests conducted at the Maharana Pratap University of Agriculture and Technology by boiling 9.4 liters of water in a traditional stove, with and without the Mewar Angithi, showed that the device reduced wood use by 63% and eliminated 89% of the soot. Here are the details:
Without Mewar Angithi With Mewar Angithi
1) Thermal efficiency% 9.182 24.55
2) Power rating Kw 0.5 1.35
3) CO gm/mjd 13.86 5.97
4) CO:CO2 0.0772 0.0575
5) PM mg/mjd 3051.7 344.31
1kg of fuelwood was used without the Mewar Angithi as per standard testing protocols, with wood moisture content of 0.4.
A traditional stove burns with good thermal efficiency at the start of the cooking session, but the efficiency deteriorates over time as the embers break off the fuelwood and pile up on the surface of the stove, impeding the airflow. Typically, this efficiency ranges from 15% to 5% and the reported thermal efficiency without the Mewar Angithi of 9.182% is in line with the average over this range. With the Mewar Angithi, there is an engineered airflow from below the fuelwood and the efficiency improves even at the start of the cooking session. Since the Mewar Angithi provides the means to separate and drain the ash from the fuel, it maintains this engineered airflow throughout the cooking session, burning up the falling embers cleanly as well. Consequently, the Mewar Angithi facilitates the traditional chula to maintain this improved thermal efficiency throughout the cooking session.
The Mewar Angithi device in the test was constructed using a refined version of the design that we reported earlier. It can be built using just one square foot of a scrap metal sheet and assembled with just 90 degree bends, without any welding. The resulting device would have a simple rectangular cuboidal shape, with dimensions 6"X8"X1.5" and therefore, maintains the surface slope of the traditional stove. The bends occur in a symmetric fashion so that the assembled device is structurally stable even when the heavy fuelwood is placed on it. Figures 1 and 2 show the top and front view of the tested device and Fig 3 shows the bends that need to be made to create the device. The dimensions of the device were chosen to be compatible with the traditional chulas used in the Mewar region of Rajasthan, India. However, the dimensions of the Mewar Angithi can be easily adjusted in different regions of the world to fit the sizes and shapes of the traditional stoves used in those regions.
Thus, the Mewar Angithi is indeed an easily malleable solution for the cook stove deployment problem that has been vexing the world's policymakers to date. It is a simple, yet powerful tool to alleviate the hardships of the 1 billion women who are scrounging for fuelwood daily, while mitigating climate change through substantial reductions in both CO2 and black carbon emissions.
Fig. 1. Top View of the Mewar Angithi
Fig. 2. Front view of the Mewar Angithi
Fig. 3. Bend schematics of the single plate design