Digestate/Sludge Questions

[alucidwake]

Hello

I'm currently researching the technologies of Anaerobic Digestion for a decentralized, personal home use (where land and money is not an issue). I have been able to get virtually all of my questions about the process answered, which has led me to a pretty complete understanding of the technology. I am left with one gap in the process, which is probably the most un-technical of them all! I am currently looking at a single stage anaerobic digestion system. This would produce a digestate that sinks to the bottom of the tank, while the cleansed wastewater floats above it (with gasses as the top layer). My question is, how does one empty the digestate from the bottom of the tank!?

I would initially think that there would be a hose that could be dropped down when the tank needed to be emptied, but this would break the anaerobic seal. Is there a permanent valve at the bottom of the tank that can open to remove the digestate with suction? Or, is it a process that requires the shut-down and stand-by of the anaerboc digester? Is it something completely else?

Any information you could give me would be immensely appreciated. Thanks!