Description
Class F23J : REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
Subclass 11/10: Devices for conducting smoke or fumes, e.g. flues (heat insulation therefor E04B 1/94; chimneys E04H 12/28; removing cooking fumes from domestic stoves or ranges F24C 15/2) for tents; for log huts; for other inflammable structures