Table 5.11: Quality ratings for various dome-sealing materials (Source: OEKOTOP)
Material
Cold bitumen
Bitumen with alu-foil
Epoxy resin
Paraffin
++ very good
Processin
g
++
+
++
+
+ good
Seal
Durability
o
++
+
o
o satisfactory
o
+
++
o
- problematic
Costs
++
+
-
++
Fig. 5.25: Sealing the masonry with paraffin. 1 Heat wall to 60 - 80
°C with soldering torch, 2 Apply hot (100 °C) paraffin (Source:
OEKOTOP/ BEP Tanzania)
Plastic gasholders
Gasholders made of plastic sheeting serve as integrated gasholders (cf. chapter 5.3.3: earth pits),
as separate balloon/bag-type gasholders and as integrated gas-transport/ storage elements.
For plastic (sheet) gasholders, the structural details are of less immediate interest than the question
of which materials can be used. Table 5.12 (p. 74) surveys the relative suitability of various
commercial grades of plastic sheeting.
Fig. 5.26: Separate, mobile, plastic-sheet gasholder. 1 Cart
for gasholder volumes of 1 m³ and more, 2 Stabilizing
weights and frame, 3 Reinforced plastic gasholder (Source:
Wesenberg 1985)
Separate gasholders
Differentiation is made between:
- low-pressure, wet and dry gasholders (10 - 50 mbar) Basically, these gasholders are identical
to integrated and/or plastic (sheet) gasholders. Separate gasholders cost more and are only
worthwhile in case of substantial distances (at least 50-100 m) or to allow repair of a leaky
fixed-dome plant.
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