An industrial crop dryer incorporating a fire detection system

An industrial crop dryer 110 incorporates a fire detection system having a heat sensitive cable 180. The dryer comprises a hollow structure (drying column 10) through which a crop passes, in use, and a plurality of rows of ducts (40, 50, Fig.1) arranged across the width of the hollow structure through which heated air is passed to dry the crop. The inlet ducts (40) have an open inlet (42) at one longitudinal end, are closed at the opposite longitudinal end 144 (44), and have an open side (59) along their length acting as the outlet. The hollow structure comprises metal inlet (25) and outlet walls 126 (26), the closed ends 144 (44) of the ducts being formed from or located immediately against the outlet wall. The heat sensitive cable is arranged against the outside of the outlet wall in a series of horizontal rows, at least one row being arranged adjacent the closed ends 144 of the ducts in one of the plurality of rows. The fire detection system monitors for hot spots and fires in crop dryers. The heat sensitive cable may comprise a plurality of discrete lengths of cable connected together by a plurality of junction boxes.