Piping Systems ................................................................................................................................. 48
PVC piping ................................................................................................................................................... 48
Galvanized steel piping................................................................................................................................. 48
Pipe diameters............................................................................................................................................... 48
Lay-out of the piping system ........................................................................................................................ 49
Water traps.................................................................................................................................................... 49
Valves ........................................................................................................................................................... 50
Pumps for Biogas Plants ................................................................................................................. 51
Types of pumps............................................................................................................................................. 51
Heating.............................................................................................................................................. 53
Internal and external heating systems ........................................................................................................... 53
Agitation ........................................................................................................................................... 55
Mixing methods ............................................................................................................................................ 55
Slurry-Use Equipment .................................................................................................................... 59
Separation of slurry and drying of the moist sludge ..................................................................................... 60
Composting of slurry .................................................................................................................................... 60
Plasters and Coats for Digester and Gas-Holder.......................................................................... 61
Cement plaster with special additives........................................................................................................... 61
Bitumen (several layers) ............................................................................................................................... 61
Bitumen coat with aluminum foil ................................................................................................................. 62
Water-thinnable dispersion paint .................................................................................................................. 62
Single- and dual component synthetic resin paints ....................................................................................... 62
Paraffin ......................................................................................................................................................... 62
Underground Water ........................................................................................................................ 63
Operation and Use ........................................................................................................................... 65
Daily operation ............................................................................................................................................. 65
Weekly / monthly operation ......................................................................................................................... 66
Annual operation .......................................................................................................................................... 66
Security......................................................................................................................................................... 66
Biogas - Sludge Management.......................................................................................................... 68
Sludge storage............................................................................................................................................... 68
Composition of sludge .................................................................................................................................. 68
Fertilizing effect of effluent sludge............................................................................................................... 69
Annual Manure Yield and Nutrient Content of Animal Excrements......................................... 71
Maintainance, Monitoring and Repair .......................................................................................... 72
Daily maintenance work ............................................................................................................................... 72
Weekly/monthly (prophylactic) maintenance work...................................................................................... 73
Annual maintenance work ............................................................................................................................ 73
Monitoring .................................................................................................................................................... 73
Repair ........................................................................................................................................................... 74
Biogas Utilization............................................................................................................................. 76
Gas production.............................................................................................................................................. 76
Conditioning of biogas ................................................................................................................................. 76
Biogas burners .............................................................................................................................................. 77
Efficiency...................................................................................................................................................... 77
Gas demand .................................................................................................................................................. 79
Gas Yields and Methane Contents for Various Substrates.......................................................... 80
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