Here we are developing a new biodigester concept using concrete rings ("Schachtringe") that are readily available througouth Europe.
This is our evolving sketchbook for ideas involving the use of these rings.
1. Horizontal concrete ring digester "The Ring"
The rings under consideration are five rings of 1 meter diameter by 50 cm height sandwhiched between two rings of 1 meter diameter and 20 cm height with end caps. Three of the rings, the two touching the end cap rings and the center ring should have 150 mm holes in them.
The estimated costs so far are:
- 5 x 50 Euro for the 1m diameter x 50 cm = 250 Euro
- 2 x 150 Euro for the end caps = 300 Euro
- Plus 3 x 15 Euro for the 150 mm pipes = 45 Euro
- Plus cement for fixing pipes.
So minimum cost is > 600 Euro.
We are assuming a ballpark of 250 Euro per cubic meter as reasonable based on costs for IBC systems and for materials (not labor or mold) costs for Puxin systems.
This system is approximately 3m3 so as long as we stay under 750 Euro we are using comparable costs but saving intense labor.
For calculation we used http://www.betonwerk-kuehne.de/brunnen-sickerschaechte-preisliste-12-17.pdf
The current design suggests the use of rings with holes in three of the rings.
2. Vertical Ring
The second system is a vertical system made from a poured concrete base slab and then 2 rings of 250 cm diameter x 100 cm tall with a tapered reducer from 250 cm to 100 cm x 60 cm height and then an inverted capped ring of 100 cm diameter with a height of 100 cm to give a cubic meter of gas storage through water displacement. A tube in the center of approximately 50 mm extending down 1 meter into the tank provides the water pressure overspill.
In this system the "basin" or inverted cap fills with water as the tapered part fills with gas.
- The cost for each 250 ring is 384 Euros = 2 x 384 = 768 Euros
- The cost of the reducer is 342 Euros.
- The cost of the 1 meter by 1 meter capped ring is 183 Euros.
The total cost would be 1293 Euro plus the concrete for the slab on the floor for a 5 cubic meter system.
The system bears superficial similarity to the Puxin but it doesn't have a fiberglass gas holder; the gas collects under the cap/swimming pool and the gas comes out the tube in the center which penetrates only to the very top. There is a longer tube going down from the basin (pool) to a meter below where the water line would be pushed to. Disadvantage is you could not easily open this up to do any maintainance. But do you really need to?
These evolving designs are under the Creative Commons License
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.