CCAT Rocket Stove

An insulated biomass cookstove built into a 16 gallon drum.

CCAT Rocket Stove by Open-Source-Imports
https://thediyjunky.com/@open-source-imports/ccat-rocket-stove
Licence: CC-BY-SA-3.0

Adapted from: https://www.appropedia.org/CCAT_rocket_stove
Original author: Dan Moyer, Tyler Jones, Logan Ward, Erik Rasmussen
Original licence: CC-BY-SA-3.0

• Difficulty: advanced
• Time needed: Several weekends
• Build status: built
• Parts: 7
• Steps: 10

Specifications

Summary

A rocket stove built at the Campus Center for Appropriate Technology. The combustion chamber is insulated ceramic brick inside a 16 gallon drum packed with vermiculite, with a sheet metal shelf, a pot skirt and a chimney.

Parts

Required total: $102.02

Tools

• Hack saw — For cutting and shaping the insulative bricks
• Tin snips
• Drill
• Sawzall — Used to cut the top of the can open for the pot skirt

Build steps

1. Build the combustion chamber

Fig 1: Combustion chamber

The square combustion chamber was constructed out of insulative bricks. Bricks were cut and shaped using a hack saw. Heat resistant putty was used as sealant.

2. Make the metal bracket and case

Fig 2.1: Metal Bracket

A metal bracket supports a sheet metal case that holds the combustion chamber in place. The metal was cut out with tin snips and fastened with screws at the edges.

3. Cut the barrel opening

Fig 1.2: Combustion chamber inside the barrel

Drill and tin snips are used to cut a square out of the barrel corresponding to the dimensions of the metal casing. The casing for the combustion chamber fits into the hole, protruding on both sides.

4. Secure the casing

Fig 1.1: Metal Case

The casing is firmly secured to a metal beam that stretches across the barrel. This beam is secured on both sides with L brackets.

5. Insulate with vermiculite

Fig 2.2: Barrel filled with Vermiculite

Vermiculite is poured into the barrel in order to insulate the combustion chamber. This insulation fills the space between the chamber and the barrel and is filled as high as the top of the chamber.

6. Install the sheet metal shelf

Fig 3: Sheet metal shelf

At the top opening of the combustion chamber we constructed a metal shelf. This shelf is circular and perfectly fits inside of the barrel. It has a square cut in it corresponding to the top opening of the combustion chamber. This allows for gasses to pass through, but seals them off from the bottom half of the barrel. The shelf is secured firmly to the outside of the barrel with L brackets and screws.

7. Build the pot skirt

Fig 4.1: Skirt

In the top half of the barrel, we constructed a skirt. This skirt surrounds the cooking pot, leaving a small gap on the bottom and the sides. The skirt was constructed out of a can. We used tin snips to cut a square opening in the bottom to channel the hot gasses. The top of the can was cut completely open with a Sawzall. The skirt is fastened to the shelf with screws and washers.

8. Seat the pot in the barrel top

Fig 4.2: Skirt inside barrel

The pot is inserted into an opening in the top of the barrel. Here we have cut out a circle with tin snips and then carefully bent the metal down at a right angle using square pliers and a mallet. This way the pot is extra sealed and the opening for it is not jagged or sharp.

9. Fit the chimney

Fig 5.1: Lid

We cut a hole out of the upper side of the barrel and fastened a circular metal chimney over the hole using screws.

10. Use the stove

Fig 6: Stainless steel pot

To use our rocket stove, burn fuel inside the combustion chamber and set the pot inside the skirt.

Keeping it working

References

• Source bill of materials totals $84.02, but its listed line items sum to $102.02: https://www.appropedia.org/CCAT_rocket_stove