Page last updated 30/08/2018
Floating steel drum biogas plant (KVIC) design
KVIC developed this design for India. A
standard plant has an internal volume
of 7.1 m
3
and is supposed to generate
100 ft
3
(2.8 m
3
) of biogas per day from
cattle dung.
The floating drum plant uses a brick
cylinder as the main digester, build in a
hole underground. The slurry is fed
through a pipe in one side and
overflows over a gap in the wall at the
top. The biogas is collected in a steeel
drum that floats on the top of the
slurry.
A central guide pipe holds the drum at
the centre, so it can move up and down
as gas is collected and used.
In Nepal, a tapered design was used, to
allow a wider, shallower hole to be used.
Diagram of straight floating drum design
Drawing of floating drum design
Standard KVIC drum plant
Parameter
Value (m)
H
p
1.60
D
p
3.62
H
d
D
d
1.50
1.00
The dimensions for a standard plant are shown in the table:
There are a range of different sizes for floating drum plants, including much larger ones.
More details of biogas plant designs are given in the book.
The equations for the volume of a cylinder can be used to calculate the volumes of both
the digester pit and the drum.