Biogas Installation

Part one Preparation

Step 1

Choosing location

The digester should be constructed near and below the lavatory and hog pen or cowshed, so that the waste can flow into the digester automatically.

Step 2

Preparing construction materials

Cement (grade above 325) 1200kgs; Sand: 3.0m³; Scree : 3.0m³; Brick(60×120×240mm)200 pieces;

Reinforced steel bar(Φ6-8mm)20kg.%%c150MM PVC pipe (L1350MM 1pc, L1250MM 1pc

Step 1 Dig a hole in the ground (diameter 3.0m and depth 3.1m)

Step 3

Cast the basement (thickness 10cm)

Step 4

Assemble the vault mould Install the top and bottom rings

Step 5

Cast the digester stomach

Attention: Make the mould soggy before casting. Cast evenly and symmetrically.

Step 6

Step 7

Assemble the neck outer mould

Attention: The neck outer mould is composed of two parts (upper and lower),The upper and lower must be connected in dislocation.

Step 8

Cast the digester neck

Attention: A hole for the gas pipe pass through, and three cavities used to fix the gas holder must be left in the neck of the digester.

Step 9

Disassemble the mould

Attention: The neck mould is allowed to disassemble, only after at least 24 hours

of the finish of the casting. First disassemble the neck outer mould, and then disassemble the neck inner mould. The vault and stomach mould are to be disassembled, after at least 48 hours of the finish of the casting. First disassemble the vault mould, and then disassemble the stomach mould.

Step 10

Install the inlet and outlet pipes

Attention: The joints between the stomach and the inlet and outlet pipe must be sealed with cement to stop water leaking.

Step 11

Build the inlet and outlet

Attention: The inlet and outlet is build with bricks, and the faces inside the inlet and

outlet must be covered with a layer of cement of 1CM thickness. The inlet is at least 20CM higher than the outlet, so that the waste can automatically flow into the digester through the inlet and flow out from the digester through the outlet by gravity.

Step 12

Paint the digester

Paint the face inside the digester over with liquid cement 1-2 times made sure there is no small hole on the face.

Step 13

Install the gas pipe system and the appliances

Part three checking

Step 1

Water leaking test

After three days of the completion of the digester, fill the digester with water, if the digester is leaking, get the water out from the digester, find out the leaks and seal them with cement.

Step 2

Gas leaking test

Fix the gasholder in the digester neck, the pump air into the gasholder until the

gasholder is full of air. If there is no air bubble from the gasholder, the gasholder is OK. If the gasholder is leaking, find out the leaks and seal them with resin glue inside the gasholder.

Step 3

Gas leaking test

Biogas appliances and fittings