How to build the Digester

The Bio Gas plant can be built by local tradesmen or by newly skilled women for peoples homes as a source of fuel for gas stoves, or other gas fueld appliances. The bio gas plant works by mixin animal waste with water and then transfering this mix to a domed space called a digester. Here the mix breaks down and in the process releases gas. That is captured in the top of the dome and directed into a pipe to where it is needed. This is controlled with a simple valve. The material after is has released gas is then able to be used as a fertiliser which can improve yeilds in personal farms or be sold for profit. What is needed to build the plant is kiln fired bricks, cement, mortar, pvc pipe for the inlet and a metal pipe for the gas outlet.

Dome Digester Reservior

Slurry outlet

Ground Level

A A Top View

Cross-section

Section A-A Deenbandhu plant drawings

1. After digging the hole use a stick to mark out the circle and then pour concrete to make the base of the dome. Lay kiln fired bricks around the edge of the base to form a circle. Then lay bricks on the base in a basket weave pattern.

5. Once the outlet pit has reached 4 rows high you can need to put a supporting beam over the opening to the outlet and brick a row above it. 2. Using the stick as a guide place one end of it in the centre of the base and the other on the edge. Place the brick along the wall with the stick touching the middle.

6. When the dome starts caving in too far that the bricks wont stay in place while they set you need to tie a weight to them to hold them until the whole row is bricked. This image uses spare bricks tied to a string to hold the placed bricks. 3. Keep placing more and more rows of bricks always using the stick as a guide. By following this the wall will start to curve and lean inwards. Once you get 2 rows of bricks in place the inlet pipe into the wall and brick around it.

7. Once the last brick is laid, insert the gas pipe into the top and mortar around it to make it air tight. 4. Keep building the walls higher, remembering to build the outlet pit on the side.

8. Now cement over the entire dome. Then render over the dome. This makes sure no gas gets out.