I have finally finished and tested my Fatboy V2 Gasifier over 50 times and it’s on it’s way to a new home. I thought I would share some pics of the unit as I have refined many areas of the unit since my Fatboy V1.
The inner 75 litre chamber came of a stainless steel pool filter which also included a brass inlet which was modified creating the primary air which can be controlled from outside the unit, this also allows the capture of quench water. The large pin the the centre of the inlet is tried to the grate with string and when the hot char burns the string it drops the pin with a clang indicating the unit has finished and is ready for quenching.
This was the first version, the plans at the top of the page still represent how the unit works. Fatboy V1>>>>
Some quick data.
75 litre chamber produces 30 litres of Biochar.
45 minutes processing time on mixed dry green waste. (25min with larger flue design)
15-20 litre of water for quenching
Can process 35mm dia branches mixed into wood chips.
Easy start, start smoke to clear to 15 seconds. (every time without added liquid fuels)
Tesco flue analyser, 15min after start up from the top of the flue
696 NOx mgm2
305.5c Flue Temp
61 H2 ppm
60 NO ppm
519 CO pmm
This unit runs super hot, the condenser ‘hat’ surface temperature ranges from 550 (green waste) to 900 deg (macadamia nuts shells). When you quench the unit, full coverage of skin with non flammable clothing and good quality welding gloves are required, the image of a metre of flame is what you will commonly have to deal with. Always avoid the quench stream as this contains some carbon monoxide.
Development of the Fatboy continues (see green tank at the bottom of this page), next version will hopefully include a simple thermal oxidiser which should improve emissions. This unit has been developed as a open source style of project please feel free to copy any part of the unit and share your development ideas.
Note: This unit has not produced any Biochar product of Black Earth Products.
All Biochar produced from this unit has been used in my own permaculture food forest and is always layered through my compost bins or blended with composts prior to application.