The Hoffmann kiln is a series of batch process kilns. Hoffmann kilns are the most common kiln used in production of bricks and some other ceramic products. Patented by German Friedrich Hoffmann for brickmaking in 1858, it was later used for lime-burning, and was known as the Hoffmann continuous kiln.
Lime kiln, Willy Spahn Park in Hannover
Lime kiln and chimney at Llanymynech Heritage Area, Shropshire photo: John M, geograph.org.uk
Cross-section of ring oven, Friedrich Eduard Hoffmann's patent, 1858
Hoffmann ring oven in Mildenberg museum
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay into pottery, tiles and bricks. Various industries use rotary kilns for pyroprocessing and to transform many other materials.
Charcoal kiln in California
Indian brick kiln
Farnham Pottery, Wrecclesham, Surrey with the preserved bottle kiln on the right of photo
A modern tunnel kiln