 |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Floating-drum plant with filler funnel
Floating-drum
Floating-drum plant without water jacket
Floating-drum
plant with water jacket
Fixed-dome plant without upper opening
Fixed-dome plant with upper opening
Floating-drum plant (quarrystone
masonry)
Floating-drum plant with extremely low VD/VG ratio
Channel-type
digester with folia
The following pages contain constructional drawings for different types of biogas plants.
The form of the plant is determined when the size of the digester and that of the gasholder are known (see calculation on page 26 f.).
The nature of the feed material is another important fundamental planning parameter. The plant shown in Figure 43 is intended particularly for long-fibre feed material. It has a larger outlet diameter to cope with this. The light but hard fibrous constituents accumulate on the surface and form a floating scum. This has to be broken up and if necessary removed. Gas is lost through the inlet funnel. But the floating scum can be raked off without removing the gas bell. Inlet and outlet pipes with a diameter of 100 mm are sufficient for pure manure without litter or for toilet contents. Supernatant scum formation is virtually no problem here.
The plant shown in Figure 51 has an extremely low digester/gasholder volume ratio. The plant is of low construction. The distance from the inlet pipe to the outlet is short. A partition will prevent fresh feed material from discharging again immediately.
In the case of shell structures, the construction dimensions are somewhat difficult to calculate. Consequently, the results of calculation have been simplified, i.e. rendered in tabular form.
The vertical, cylindrical plant (Figure 50) is not optimal, because the digester temperature is lower at the bottom and the water pressure increases with depth. However, this plant may be economic if quarrystone masonry is used instead of brickwork and a shell structure is too complicated.
The cover plate of a floating drum is always thinner than the
metal of the side walls, because the covers rust less than the sides. For the
guide frame, the cheapest solution is the best.
Floating-drum plant with filler
funnel
Fig. 43: Constructional drawing of a
floating-drum plant with filler funnel for long-fibre feed material; external
guide, external gas outlet.
Floating-drum
Fig. 44: Constructional drawing of a
floating-drum plant
Floating-drum plant without water
jacket
Fig. 45: Constructional drawing of a
floating-drum plant with an internal gas outlet and no water jacket
Fig. 46: Calculation of dimensions
Floating-drum plant with
water jacket
Fig. 47: Constructional drawing of a
floating-drum plant with water jacket. Compared to the one is shown in figure
45, this plant is about 40% more expensive but can be expected to last twice as
long and will handle substrate that tends to form substantial amounts of scum.
Detailed building instructions for a system of this kind are available in
several different languages.
Fixed-dome plant without upper
opening
Fig. 48: Constructional drawing of a
fixed-dome plant without upper opening
Fixed-dome plant with upper
opening
Fig. 49: Constructional drawing of a
fixed-dome plant with upper opening
Floating-drum plant (quarrystone
masonry)
Fig 50: Constructional drawing of a
floating-drum plant for quarrystone masonry (vertical plant)
Floating-drum plant with
extremely low VD/VG ratio
Fig. 51: Constructional drawing of a
plant with an extremely low digester/gasholder volume ratio
Channel-type digester with folia
Fig. 52: Constructional drawing of a
channel-type digester with folia (Henning system) The digester walls consists of
netting-wire-reinforced rendering on the surrounding ground. The balloon serving
as gasholder is mounted on a wooden frame. A plywood panel or straw mat on
lathing serves as a sunshade. Weights placed on top make the gas pressure
higher.
 |
 |
