DARC Fall Smelt - Draft Report

A fast overview report - duplicate from 'Hammered Out Bits'

On Saturday November 8, a small band gathered for the normal Fall DARC smelt. This was number four in the main sequence of our Icelandic / Hals series.
Building on the work from the October (Thanksgiving) smelt, this experiment focused primarily on the use of the bellows plate and blow hole combination. Ken Cook served as Smelt Master, with Neil Peterson assisting. (And Darrell constantly sticking his nose in to keep things on track.)
About 3 1/2 hours into the main sequence, the smelter starts to self tap. You can see the arrangment for the air system, handing from supports.

Total Fuel : 48 kg
Total Time : 5 hours (plus 2:40 preheat)
Total Ore : 23 kg (mixed poor Virginia Rock / Hematite grit
Total Bloom : 4.25 kg
Total Yield : 18 %

Average Burn Cycle : 12 minutes per standard 2 kg bucket

The bloom was less consolidated on extration than what is seen from a smelter with an insert tuyere - more of a 'lumpy' texture. It also was positioned a bit futher back from the air inlet than expected, and had a marked crescent shape.

As with the Thanksgiving smelt (which also used the plate / hole) there was a choke point at roughly 2 1/2 hours into the ore charging / about 7 kg. The developing slag bowl threatened to drown the air intake. On this attempt we were better able to control this, and the smelter would settle down once the slag evolved from the early green silica type to the later black iron rich type.

Darrell