F
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F27
FURNACES; KILNS; OVENS; RETORTS
F27D
DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
F27D3/00
Charging; Discharging; Manipulation of charge