Page 10 - Biogas Plant Construction

352 Biogas

5.2 Dimensions marking
The marking of dimensions (Fig. 5) for biodigester unit should be performed prior to start of
excavation work. The marking is considered as preparation for excavation and construction
works. An operational area of 3 m width around the digester should be considered, where
the workers will use this area to achieve the construction works around the tank base in
order to prepare the structure of the concrete base, i.e. the bottom of the digester.

Fig. 5. Marking of dimensions for a biodigester

5.3 Excavation works
The depth of digging depends on the specifications of the soil. The inclination of the sides
should be 30 cm for each meter depth for the cohesive soil, 60 cm to one meter for the light
soil, and 90 cm for the sandy soil.

(a, b) BIOGAS PLANT DESIGN
Fig. 6. Excavation works for household units

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