Biodigester Log: Difference between revisions

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=Tue Mar 13, 2018=
=Tue Mar 13, 2018=
Kitchen sink connected to biodigester. Gas outlet closed. Water backing up into the sink.
Marcin connected kitchen sink to the biodigester on the evening of March 12, 2018. The next day Catarina, unaware of how the connections been made, used the kitchen sink. Log of messages:
 
C: I did the dishes, drained the water and all seemed to go well. Then I came to the computer to congratulate you on a good job. But when I next looked at the sink a few minutes later, it was full of dirty water. It seems water is backing up to there. Is this the water that is supposed to remain in the pipes and kept in check by the one-way valve? Or could it be an issue with the level of the sink in relationship to the level of the overflow?
 
I'm trying to trace the source of the issue, but it's puzzling.
 
At first I thought it was the water left at the top of the vertical length of pipe that was backing up into the sink, which is at a lower level. But if that was the case, why wouldn't this have happened before it was hooked up to the digester? It would make much more sense if it had been so. So I can neither understand why it didn't happen before nor why it's happening now. My best guess is that it's either syphoning or there is some pressure from the digester that is sending water back into the sink.
 
The water backing up into the sink continues to rise, much more slowly now. I don't know much about it, but suspect that this means it can't be just gravity. It's probably syphoning. I will allow the sink to keep filling, just to see what's happening, but will bucket it out once it gets close to overfilling. If this is indeed syphoning, the entire contents of the digester will want to flow into the sink, so I'm probably going to spend the day bucketing out water from the sink.
 
More details:
 
- At first the water backflows into the sink quite fast. This must be just gravity: water at the top of the vertical pipe is just flowing down into the sink which is lower. Though I still don't get why this didn't happen before.
- Once the water reaches the bottom of the sink it slows down considerably. I imagine that gravity is giving it the initial push and then the rest is syphoning.
 
Some useful videos:
 
https://www.youtube.com/watch?v=awq-XP5bV18
 
https://www.youtube.com/watch?v=tWlOi9gt8Xo
 
https://www.youtube.com/watch?v=CZmP0vsRBZ8
 
M: I closed off the gas outlet on the biodigester. When you pump water into it, it's like filling an already full balloon—it send the water back. To temporarily address this, you can open the window then open the gas valve, then pump out the water from sink.
 
Catarina did this and no more water backed up into the sink.
 
C: I'm still don't fully understand what happened. I get that the gas valve was closed, so there is was no room to replace gas/air with water. But what about the overflow drain? Shouldn't that have taken care of it? Or was it that the kitchen line was the path of least resistance?
 
M: Apparently the way the 2" overflow pipe works, it was easier for the pressure to release over the thinner 1" pipe, which may have acted as a siphon. The 2" is 18" below water, so overflow is facing 18" of effective head.
 
 
Gas outlet closed. Water backing up into the sink.


=Tue Oct 18, 2016=
=Tue Oct 18, 2016=

Revision as of 16:47, 13 March 2018

See Biodigester for working page.

Tue Mar 13, 2018

Marcin connected kitchen sink to the biodigester on the evening of March 12, 2018. The next day Catarina, unaware of how the connections been made, used the kitchen sink. Log of messages:

C: I did the dishes, drained the water and all seemed to go well. Then I came to the computer to congratulate you on a good job. But when I next looked at the sink a few minutes later, it was full of dirty water. It seems water is backing up to there. Is this the water that is supposed to remain in the pipes and kept in check by the one-way valve? Or could it be an issue with the level of the sink in relationship to the level of the overflow?

I'm trying to trace the source of the issue, but it's puzzling.

At first I thought it was the water left at the top of the vertical length of pipe that was backing up into the sink, which is at a lower level. But if that was the case, why wouldn't this have happened before it was hooked up to the digester? It would make much more sense if it had been so. So I can neither understand why it didn't happen before nor why it's happening now. My best guess is that it's either syphoning or there is some pressure from the digester that is sending water back into the sink.

The water backing up into the sink continues to rise, much more slowly now. I don't know much about it, but suspect that this means it can't be just gravity. It's probably syphoning. I will allow the sink to keep filling, just to see what's happening, but will bucket it out once it gets close to overfilling. If this is indeed syphoning, the entire contents of the digester will want to flow into the sink, so I'm probably going to spend the day bucketing out water from the sink.

More details:

- At first the water backflows into the sink quite fast. This must be just gravity: water at the top of the vertical pipe is just flowing down into the sink which is lower. Though I still don't get why this didn't happen before. - Once the water reaches the bottom of the sink it slows down considerably. I imagine that gravity is giving it the initial push and then the rest is syphoning.

Some useful videos:

https://www.youtube.com/watch?v=awq-XP5bV18

https://www.youtube.com/watch?v=tWlOi9gt8Xo

https://www.youtube.com/watch?v=CZmP0vsRBZ8

M: I closed off the gas outlet on the biodigester. When you pump water into it, it's like filling an already full balloon—it send the water back. To temporarily address this, you can open the window then open the gas valve, then pump out the water from sink.

Catarina did this and no more water backed up into the sink.

C: I'm still don't fully understand what happened. I get that the gas valve was closed, so there is was no room to replace gas/air with water. But what about the overflow drain? Shouldn't that have taken care of it? Or was it that the kitchen line was the path of least resistance?

M: Apparently the way the 2" overflow pipe works, it was easier for the pressure to release over the thinner 1" pipe, which may have acted as a siphon. The 2" is 18" below water, so overflow is facing 18" of effective head.


Gas outlet closed. Water backing up into the sink.

Tue Oct 18, 2016

"Anything but human shit in a 1/4" insinkerator will soon see it burnt out and blades so dulled it's useless- 1 hp on grass and garbage digester appears to work well." Look into a septic shredder pump as it will slurry anything and pump shit from a reservoir up to a digester no sweat - macerator lift pumps.

Sun Oct 16, 2016

  • Sent inquiry to [1] for 3 cu m biogas bag
  • Janice is a good contact, Solar Cities - and 610-745-4403 for Global Vertical Farms - [2]
  • Contacted completebiogas@GMail.com - https://completebiogas.com/workshops.html
  • Contacted Dan on biodigester review on 3 cu m system.