"Tangential firing" means a boiler firing design where the burners and air nozzles are mounted in each corner of the furnace chamber where the vertical furnace walls meet. Both the fuel and air are directed from the furnace corners along a line tangential to a circle lying in a horizontal plane of the furnace.
N.H. Admin. Code § Env-A 1302.53
(See Revision Note at chapter heading for Env-A 1300) #9803, eff 10-31-10