827,592. Carbonizing processes. MINISTER OF POWER. Oct. 18, 1956 [July 19, 1955], No. 20868/55. Class 55 (1). Solid fuel is passed through a carbonizing chamber 1 in the form of a thin layer 8a supported on a layer 7a of inert non-fusible and non-agglomerating material carried by the hearth section 2a of a travelling-grate 2. Two hoppers 5, 6 supply respectively the inert material 7, which may be -inch graded coke, porcelain balls or bricks, and the carbonaceous fuel 8. The space 9 beneath hearth section 2a is divided into two compartments 10, 11 formed with ports 10a, 11a in their upper walls.; Part of the gas evolved in carbonization, burns with air injected through inlets 14, the gases at a temperature of about 1000- 1200 C. being drawn, by means not shown, downwardly through layers 8a, 7a and hearth section 2a to pass through ports 10a, compartment 10 and duct 10b into a heat-exchanger 12. After cooling, the gases return through duct 11b, compartment 11, ports 11a, hearth section 2a and layers 7a, 8a, to extract heat from layer 7a and give it to layer 8a and also to cool both layers so that the materials are not spontaneously ignitable when they reach the fuelreceiving hopper 19. Excess gas passes out at 1a In a modification the heat-exchanger 12 is not employed and cold gas is added to the hot gases. In a further form the space 9 is divided into a number of pairs of compartments similar to compartments 10, 11.