Darrell's smelt makes the foundation of the SSW Lecture happening in October 2014, for a taste of what is to come at the SSW event watch the trailer video on this page.
A clay tower furance is built on a concrete slab base with bricks at the bottom. The clay tower is similar to finds in the local area. The clay furance is heated to finish it, any cracks that form during the process are covered with a fresh clay mixture, the furnace is maintained in this way for the duration of the smelt.
A down pipe is also fitted to the furnace, this pipe is used to observe what is happening within and to provide an airflow. The airflow to the furnace allows the charcoal to burn at a much higher temperature. Traditionally, the airflow would be created with large man operated bellows, today we use an old leaf blower.
To reheat the furance a small wood fire is built inside this is kept burning until the furnace is at a temperature where it can withstand the mass of charcoal to be added. Once hot enough the furnace is packed with charcoal, until it is full. The rate at which the charcoal burns is used to estimate the temperature of the furnace. The charcoal burns off in layers, there is a noticable drop as the furnance consumes charcoal.
When the furnace is burning at the right temperature it is fed a mixture of iron ore and charcoal. In our case the ore used came from an industrial source, this sort of furnace has been used wtih classical types of ore that can be found in the local area.
Charcoal and ore are added to the furance for around 4 hours, the progress of the furnace is observed through the air spout for this whole period.
The research described here is supported by the award made by the RCUK Digital Economy programme to the dot.rural Digital Economy Hub; award reference: EP/G066051/1.