Design Requirements
Low cost: $20-$50
- Currently, carbonized cobs are crushed by stepping on them or hitting them with heavy objects like cinder blocks. Inhalation of charcoal dust is reduced by placing carbonized cobs in a rice sack lined with a plastic garbage bag that is lined with another rice sack. The plastic garbage bag develops holes during the crushing process and must be replaced after each batch. If an entrepreneur makes 5 batches of charcoal per day, he will use 25 plastic bags per week or about 1250 bags per year (if he works for 50 weeks per year). If a box of 25 bags cost $2, a year's worth of bags will cost $100. In order to encourage users to buy our device, we are designing a device that is half the cost of the current alternative.
Fast: 6 pounds in 10 min.
- Each batch of carbonized cobs is about 6 pounds, and can be crushed by stepping on it in 10 minutes. Our device
is designed to be just as fast.
Reliable performance
- The device produces particles that are less than 5mm in diameter. It has been found that a mixture of particles ranging from fine powder to 5mm chunks can be formed into a briquette that burns evenly and produces little carbon monoxide.
Safe: minimizes inhalation of charcoal dust
- The device limits the user's exposure to the charcoal dust that is harmful when inhaled. Charcoal dust consists of super fine particles of charcoal that are thrown into the air when the carbonized cobs are being crushed or when the charcoal powder is being transported or agitated. To minimize transfer of the charcoal powder from one receptacle to another, the device deposits charcoal powder directly into the container where it is mixed with a wet binder. After the user deposits carbonized cobs into the device's hopper, the lid prevents the charcoal dust from escaping.
Locally fabricated with available materials
- Both models of the device consist of wooden boards and common steel pipes and rods. Depending on the materials available, the grating cylinder can be made from expanded steel tack welded to a steel pipe, or cement poured into a mold made from a PVC pipe. Both models can be made with hand tools and welding.
Intuitive
- The device is intuitive to use and repair.
Ergonomic
- The device is hand-cranked and can be operated by a single person. The device has the potential to be adapted for pedal-power, but it is not necessary for the speed and torque required.