Cover Image
close this bookBiogas Plants (GTZ, 1988)
View the document(introduction...)
View the documentAcknowledgements
View the documentPreface
View the document0. Biogas as appropriate technology
View the document1. Benefits and costs of a biogas plant
Open this folder and view contents2. The dgestion process
Open this folder and view contents3. Biogas plants
Open this folder and view contents4. Scaling of biogas plants
Open this folder and view contents5. Design of biogas plants
Open this folder and view contents6. Biogas utilization
View the document7. Planning, design and construction
View the document8. Appendix
View the documentBibliography
View the documentList of figures

8. Appendix

Sl units of calculation. Conversion of imperial measures
Cubic metres and cubic feet; powers of ten
Fundamental geometric formulae
Fundamental static formulae
Water pressure and earth pressure
Change in volume of ideal gases under pressure and temperature
Cross sections of common steels and pipes

SI units of calculation. Conversion of imperial measures


Fig. 53: Units of measurement

Cubic metres and cubic feet; powers of ten


Fig. 54: Cubic metres and cubic feet; powers of ten

Fundamental geometric formulae


Fig. 55: Fundamental geometric formulae

Fundamental static formulae


Fig. 56: Fundamental static formulae Static calculations are not usually necessary for small, simple biogas plants. For larger plants, a rough calculation should be carried out to determine whether the loads and stresses are likely to be high enough for an exact calculation to be necessary. Spherical and conical shells are complicated forms. They are very difficult to estimate by rough calculation. As a rule, only the edges are loaded to the permissible limit.

Water pressure and earth pressure


Fig. 57: Water pressure and earth pressure Water pressure depends directly on height. The amount of water has no effect on the pressure. The earth pressure depends on height, the angle of repose (alfa) and density (ro) of the earth. In the table, (a) is soft loam or clayey sand, (b) is pure sand and (c) is marl or murrum.

Change in volume of ideal gases under pressure and temperature


Fig. 58: Change in volume of ideal gases under pressure and temperature

Cross sections of common steels and pipes


Fig. 59: Cross sections of common steels and pipes