My last post covered the fabrication of a new WarmHeart designed trough kiln. This was run for the first time on a farm in the South Waikato. Aranui Farm is currently converting from a cow to sheep dairy system. Plans are also underway to incorporate biochar into the farming system at Aranui. HCBA will be used in bedding mixes and animal feed trials are also being planned.

The following photos follow the first firing of the kiln…

The woodpile was a mix of typical unidentified farm biomass… box-thorn, windfall, stumps, some dry, some fresh but all a bit winter damp. The kiln was placed on some old glass insulation and posts to provide separation from the damp, heat sucking ground. Quench water was made available via piping from a trough 100m away. Some uniform sized material was cut, stacked and covered a few days before firing. A ‘rick’ was constructed within the kiln from the similar sized material and then top lit. This is allowed to burn down to form the bed and help get the kiln up to temperature more quickly. A shortage of labor and a tightly bound wood pile limited how much biomass could be processed on the day. Much more could have been done with some better planning but the kiln performed very well, working through some quite damp wood and some large logs (up to 300mm dia).

Some general comments on the kiln: ideal farm-community-cooperative scale… 2-3 able bodies required to operate efficiently depending on biomass access and preparation; insulation of base & sides may increase process heat (the rockwool was only partially successful); success with larger logs requires good management and adequate smaller material to maintain flame cap for extended periods.