Final Commssioning of Digestor

Final Commissioning of Digestor (13 August 2010, 10 am - 6pm, SVF Farm)

Finally got the digestor up without leakage! Methane system Commissioned!!

1. Sealed Balloon Capture with Hose Ring & Silicone Glue
2. Fixed all leakages in this sequence:
   contact glue/silicone/contact glue/silicone + duct tape to provide final mechanical strength
3. Stirrer Sealed (for air tightness)
   
4. Final Loading Capacity = 30L with 12 vol% concentration;
   idea of 30% headspace : 70% waste discarded
5. Gantt chart explained with my 5-stage plan

Stirrer (center 1" pipe) sealed with End-cap


Finally, the completed 2-Stage ATAP Digestor System


What is this 5cm spider doing in my gas pipe? If i had taken a deeper breath to check if the balloon was holding, it would have ended up in my mouth !!!


End of the Day, Meeting with Dr Han (5pm-6pm):

1. With professional design, came out with a improved system
2. To be constructed by Dr Han during Exams period between 29/08/10 - 10/09/10
3. With his advices, we managed to design an:

• Air-tight system
  
• Natural Circulation System for heater
• DIY 2-way check valve to create vacuum in new CH4 capture (improved fuel value)
  
• Digestor Structural stability
• sealant for stirrer vs. static agitation

Lesson Learnt: It's because we spent so much time on DIY-ing the Digestor, we easily understood what Dr Han said in one go.

With every failure you'll learn something new and propel yourself to greater heights.


Mr Kon, we will:

1. Send you the gas detector writeup by monday 16/08/10
2. Draw out a new P&ID and send to Dr Han by Friday 20/08/10
3. Update you our BREAKTHROUGH on Friday 20/08/10
4. Get Archi to auto-cad the system for us

Once exams end, we will conduct the experiments with the 5-stage plan, gas detectors expected to arrive between 08/10/10 - 15/10/10 (optimistic).

Kian How,
Signing off on 13 August 2010, 10.30 pm

Loading & Leak Detection on 10 August 2010

Trial Loading & Leak Detection (10 August 2010, 2pm - 6pm, SVC Farm)

We are sorry Mr Kon, after fixing the leakage on the Anaerobic Stage (top drum), another leakage occurred at the aerobic stage (bottom drum).

Reason: Base was only sealed with silicon, not contact glue.

Rectified issue & redesigned methane capture.


The cow dung:

Mixing the manure precisely at 12 vol% concentration

1. Ratio Method
2. Pail Volume = 18 L
3. 5cm height of cow dung, top up to 25cm of water =20% conc
4. Do it for 2 rounds = 21L for Loading into Anaerobic stage (top blue drum),
   i.e. 70% solid : 30% headspace
   

Unfortunately, after loading, there was a MAJOR LEAK at the base of the bottom drum.
Reason: Did not seal bottom with contact glue; how did this get past us?
See below: No yellow colour means no contact glue



Did a leak test with top drum and no leakage detected:




Contact glue (yellow) + another layer of silicon (white) = double protection; see below
Result = no water leakage
Air-tightness: yet to know until next run


Next Tasks:

1. Seal Stirrer with 1" N-cap for Air-Tightness
2. Buy N-cap and 1"pipe
3. Buy O-ring and burner tip for methane capture
4. Buy small pail and scoop to increase loading rate
5. Buy saw blades to saw (2)
6. Brenda to follow up on gas Detectors
7. Commission and run digestor with methane capture system
   

To be done on 13 August 2010


Kian How
Signing off on 13 August, 2.20 am

Final Sealing & Leak Test on 4 August 2010

Final Sealing & Leak Test (4 August 2010, 11am - 2pm, SVC Farm)

Tasks Completed:

1. Performed Leak test to check for contact glue sealing
2. Sealed Anaeraobic & Aerobic stages together with silicon gel
3. Connected main digestor body to scrubber
4. Searched for duck weeds

Finally, the completed Digestor:


Status of the mini-prototype remains unchanged:



Close-up of the "Supposedly Manifold"


Found out that 1 packet of Duck Weeds costs $2.00. (wetland systems)


Never do this in the middle of the road:

Next Tasks:

• Gas Detectors Write-up
  
• PUB Letter
• Update Archi Students
• Blue Prototype 1st Run on 6 August 2010 (Friday), or thereafter
• Brenda to bring saw blades
  

Kian How
Signing off on 5 August 1.35 am