Horizontal revolving shaft furnace - with radial self unblocking gas injection nozzles

The furnace is fitted in its circumferential wall with supply passages, which are intermittently unblocked by radially applied plungers attached to spring loaded rods, to the outer ends of which are fitted small wheels acting as cam followers in relation to cam projections outside the furnace. The action ensures that the nozzles are kept free, any blocking material being pushed back into the furnace interior. The system is intended for furnaces for the reduction of iron oxides and iron ores.