Table of content
Most simply an in-ground tube with no sun protection and effluent flow into collection pit. Most of the time called Salchicha or Sausage system but also by its technical term plug-flow system. The materials move from one side of the tube (inlet) to the other side of the tube (outlet)
Materials
PE
PE (poly ethylene) tube digesters are applied in Bolivia (Peru, Ecuador, Colombia and Mexico). The tube PE film is about 300 microns thick. It is bended at the ends and has PVC drainage pipe. PE tubes are very cheap but quite fragile. Also available as LLDPE (linear low density poly ethylene
EPDM
Sausages can be produced using EPDM (ethylene polypropylene diene monomer (M-class).
PVC
Polyvinal chloride is a widely used plastic polymere
Variants
Mexican Salchicha
No info yet
Kenya Flexibiogas
The Kenya based company Flexibiogas offers a system that includes the flexible digester bag as well as a foil greenhouse cover.1
Puxin bags
Digesters solde by the Chinese company Puxin - they are available up to 10qm
Systema Biobolsa
Bag consists of linear low density polyethylene (LLDPE) membrane of 1 to 1.5 mm thickness. Tubes and assemblies: hydraulic and sanitary PVC.2 The system is available up to a size of 40m³.
Solar C³ITIES Salchicha
In 2016 Solar C³ITIES developed a PVC based salchicha style membrane digester.
Links
http://www.sgpindia.org/documents/Biogas_Plants.pdf